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Zhang Y.,Nanjing Southeast University
Magazine of Concrete Research | Year: 2013

Strain hardening cementitious composites (SHCCs) have obvious advantages when used to strengthen reinforced concrete (RC) structures - high tensile and compressive strengths, as well as large tensile strain in uniaxial tensile behaviour. However, when used for flexural strengthening of RC members, the ductility of SHCC is reduced and the cracking behaviour of the SHCC strengthening layer varies with different layer thicknesses. In this paper, a zero-span tensile model using a fictitious material is proposed to assess the cracking behaviour of SHCC used for RC flexural strengthening, considering the localised behaviour of the SHCC on the cracked RC substrate member. In the model, the crack in the RC substrate member is represented by an artificial crack formed by two areas of fictitious material. The proposed model can evaluate the cracking behaviour of SHCC layers of varying thickness used for flexural strengthening of RC members. Source


Yu X.Q.,Nanjing Southeast University | Yu Y.B.,Ningbo University of Technology
Superlattices and Microstructures | Year: 2013

Optical absorptions in semi-parabolic quantum wells are investigated. By using density-matrix approach and iterative procedure, the analytical formula of optical absorption coefficients in this semi-parabolic quantum wells are deduced. The numerical results on typical GaAs/AlGaAs materials are calculated. The relations between the optical absorptions and the quantum confinement from the semi-parabolic quantum wells, the incident optical intensity, and the relaxation rate are investigated. The results indicate that the absorption peaks bule-shift and the values of the peaks increase with the enhancement of the parabolic confining frequency. The values of the absorption peaks increase quickly with the increase of the relaxation time. In addition, the total absorption coefficient decrease with the increase of the incident optical intensity. © 2013 Elsevier Ltd. All rights reserved. Source


Qin Y.L.,Nanjing Southeast University
JACC. Cardiovascular interventions | Year: 2013

This study sought to evaluate the early and long-term effect of thoracic endovascular aortic repair (TEVAR) on type-B acute aortic dissection (AAD). Uncomplicated type-B AAD is generally treated with medical management; complicated dissections require surgery or TEVAR. Studies have demonstrated that long-term outcomes with medical management are suboptimal. Therefore, we sought to determine the long-term effect of TEVAR compared with medical management alone on type-B AAD. From January 2004 to May 2008, 193 consecutive patients in 2 hospitals were treated and retrospectively placed into 1 of 2 groups: 1) the TEVAR group-type-B AAD treated with TEVAR and antihypertensive medications (n = 152); and the 2) medicine group-uncomplicated type-B AAD treated medically alone (n = 41). All TEVAR procedures were performed in the acute phase. There were no significant differences in demographics, comorbidity profiles, or early events between groups. The cumulative freedom from all late adverse events at 1, 3, and 5 years was 97%, 89%, and 67% in the TEVAR group and 97%, 63%, and 34% in the medicine group. Log-rank tests showed that medically treated patients had more late adverse events than TEVAR-treated patients did (p = 0.003). The 5-year cumulative survival rate from all-cause death was not significantly different between the 2 groups. Patients with type-B AAD treated with TEVAR experienced fewer late adverse events than those treated with medical management, but there was no significant difference among the groups in 5-year mortality rates. Further studies of longer-term survival rates are needed to determine whether TEVAR could be an effective treatment for type-B AAD. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved. Source


Lin W.,Nanjing Southeast University
Journal of Combinatorial Optimization | Year: 2016

We initiate the study of relaxed L(2,1)-labelings of graphs. Suppose G is a graph. Let u be a vertex of G. A vertex v is called an i-neighbor of u if dG(u,v)=i. A 1-neighbor of u is simply called a neighbor of u. Let s and t be two nonnegative integers. Suppose f is an assignment of nonnegative integers to the vertices of G. If the following three conditions are satisfied, then f is called an (s,t)-relaxed L(2,1)-labeling of G: (1) for any two adjacent vertices u and v of G,f(u)≠f(v); (2) for any vertex u of G, there are at most s neighbors of u receiving labels from {f(u)-1,f(u)+1}; (3) for any vertex u of G, the number of 2-neighbors of u assigned the label f(u) is at most t. The minimum span of (s,t)-relaxed L(2,1)-labelings of G is called the (s,t)-relaxed L(2,1)-labeling number of G, denoted by λ2,1s,t(G). It is clear that λ2,10,0(G) is the so called L(2,1)-labeling number of G. λ2,11,0(G) is simply written as λ~(G). This paper discusses basic properties of (s,t)-relaxed L(2,1)-labeling numbers of graphs. For any two nonnegative integers s and t, the exact values of (s,t)-relaxed L(2,1)-labeling numbers of paths, cycles and complete graphs are determined. Tight upper and lower bounds for (s,t)-relaxed L(2,1)-labeling numbers of complete multipartite graphs and trees are given. The upper bounds for (s,1)-relaxed L(2,1)-labeling number of general graphs are also investigated. We introduce a new graph parameter called the breaking path covering number of a graph. A breaking path P is a vertex sequence v1,v2,…,vk in which each vi is adjacent to at least one vertex of vi-1 and vi+1 for i=2,3,…,k-1. A breaking path covering of G is a set of disjoint such vertex sequences that cover all vertices of G. The breaking path covering number of G, denoted by bpc(G), is the minimum number of breaking paths in a breaking path covering ofG. In this paper, it is proved that λ~(G)=n+bpc(Gc)-2 if bpc(Gc)≥2 and λ~(G)≤n-1 if and only if bpc(Gc)=1. The breaking path covering number of a graph is proved to be computable in polynomial time. Thus, if a graph G is of diameter two, then λ~(G) can be determined in polynomial time. Several conjectures and problems on relaxed L(2,1)-labelings are also proposed. © 2014, Springer Science+Business Media New York. Source


Wang Z.,Nanjing Southeast University | Wu B.,Ryerson University | Xu D.,Ryerson University | Zargari N.R.,Rockwell Automation
IEEE Transactions on Industrial Electronics | Year: 2012

In this paper, a current-source-converter (CSC)-based high-power high-speed (HPHS) permanent-magnet synchronous motor drive is proposed for high-speed compressor applications. The most important feature of the proposed CSC-fed HPHS drive is that the switching frequency is limited to 420 Hz at 200-Hz fundamental frequency. In the drive system, the whole operation range is divided into three regions, namely, the high-, medium-, and low-speed regions, where different modulation strategies and control schemes are used with the requirement of switching frequency and output filter. In particular, a two-pulse space vector modulation with dynamic capacitor voltage control is proposed for the high-speed region to achieve better dynamic and harmonic performance. Both simulation and experiments verify the proposed control strategy. © 2012 IEEE. Source


Sang X.,Nanjing Agricultural University | Liu X.,Nanjing Southeast University
Soft Computing | Year: 2016

TOPSIS is a popular used model for multiple attribute decision-making problems. Recently, Chen and Lee (Exp Syst Appl 37(4):2790–2798, 2010) extended TOPSIS method to interval type-2 fuzzy sets (IT2 FSs) environment. They first compute the ranking values of the elements in fuzzy-weighted decision matrix, and used the ranking values to compute the crisp relative closeness through traditional TOPSIS computing process. Such ranking computation leads to the information loss of the weighted decision matrix. In this paper, we introduce an analytical solution to IT2 FSs-based TOPSIS model. First, we propose the fractional nonlinear programming (NLP) problems for fuzzy relative closeness. Second, based on Karnik–Mendel (KM) algorithm, the switch points of the NLP models are identified, and the analytical solution to IT2 FSs-based TOPSIS model can be obtained. Compared with Chen and Lee’s method, the proposed method operates the IT2 FSs directly and keeps the IT2 FSs formats in the whole process, and the result of which is precise in analytical form. In addition, some properties of the proposed analytical method are discussed, and the computing process is summarized as well. To illustrate the analytical solution, an example is given and the result is compared with that of Chen and Lee’s method (Exp Syst Appl 37(4):2790–2798, 2010). © 2015, Springer-Verlag Berlin Heidelberg. Source


Yang F.,Nanjing Southeast University | Cheng J.,University of British Columbia
IEEE Communications Letters | Year: 2012

A coherent free-space optical communication system is analyzed for lognormal-Rician turbulence channels using Padé approximants. Highly accurate closed-form BER expressions are developed for binary phase-shift keying with maximum ratio combining and binary differential phase-shift keying with selection combing receptions. Asymptotic error rate analyses for these systems are also presented. © 2012 IEEE. Source


Xu W.,Nanjing Southeast University | Xu W.,Beijing Jiaotong University | Dong X.,University of Victoria
IEEE Transactions on Signal Processing | Year: 2012

This correspondence considers a MIMO relay downlink system using precoding and limited feedback. Since the conventional precoding matrices are directly obtained by treating the quantized channel state information (CSI) feedback as real CSI, we propose an optimized relay precoding strategy by taking both effects of channel quantization error and feedback delay into account. Conditioned on the outdated CSI quantization available at the relay station, the relay precoding is optimized via minimizing an expected mean-square error (MSE) criterion over CSI mismatches. By using Karush-Kuhn-Tucker (KKT) conditions, a closed-form solution to the relay design is achieved with comparable computational complexity relative to the conventional approach. Numerical results verify the effectiveness of the proposed scheme. © 1991-2012 IEEE. Source


Xu Z.,Nanjing Southeast University | Hu H.,PLA University of Science and Technology
International Journal of Information Technology and Decision Making | Year: 2010

The aim of this paper is to investigate the intuitionistic fuzzy multiple attribute decision-making problems where the attribute values are expressed in intuitionistic fuzzy numbers or interval-valued intuitionistic fuzzy numbers. We introduce some notions, such as intuitionistic fuzzy ideal point, interval-valued intuitionistic fuzzy ideal point, the modules of intuitionistic fuzzy numbers, and interval-valued intuitionistic fuzzy numbers. We also introduce the cosine of the included angle between the attribute value vectors of each alternative and the intuitionistic fuzzy ideal point, and the cosine of the included angle between the attribute value vectors of each alternative and the interval-valued intuitionistic fuzzy ideal point. Then we establish two projection models to measure the similarity degrees between each alternative and the intuitionistic fuzzy ideal point, and between each alternative and the interval-valued intuitionistic fuzzy ideal point. Based on the projection models, we can rank the given alternatives and then select the most desirable one. Finally, we illustrate the developed projection models with a numerical example. © 2010 World Scientific Publishing Company. Source


Fang Y.,Nanjing University of Posts and Telecommunications | Li P.,Nanjing Southeast University
Journal of Micromechanics and Microengineering | Year: 2013

Accurate determination of pull-in voltage and pull-in position is crucial in the design of electrostatically actuated microbeam-based devices. In the past, there have been many works on analytical modeling of the static pull-in of microbeams. However, unlike the static pull-in of microbeams where the analytical models have been well established, there are few works on analytical modeling of the dynamic pull-in of microbeam actuated by a step voltage. This paper presents two analytical approximate models for calculating the dynamic pull-in voltage and pull-in position of a cantilever beam and a clamped-clamped beam, respectively. The effects of the fringing field are included in the two models. The two models are derived based on the energy balance method. An N-order algebraic equation for the dynamic pull-in position is derived. An approximate solution of the N-order algebraic equation yields the dynamic pull-in position and voltage. The accuracy of the present models is verified by comparing their results with the experimental results and the published models available in the literature. © 2013 IOP Publishing Ltd. Source


Liu X.,Nanjing Southeast University | Liu X.,Beijing Jiaotong University
Information Sciences | Year: 2012

This paper proposes a general optimization model for determining ordered weighted averaging (OWA) operators and three specific models for generating monotonic and symmetric OWA operators, as well as those with any function shape. In these models, entropy and variance concepts are generalized as general dispersion indices for use in the objective functions, while the ordinary orness level constraints are used in the constraint equations as a special case. We define an orness function for monotonic OWA operators, which measures the closeness of the aggregation value to the maximum value, and a medianness function for symmetric OWA operators, which measures the closeness of the aggregation value to the median value. We also extend the commonly used models for determining OWA operators under given orness values to determine monotonic OWA operators with given orness function values and symmetric OWA operators with given medianness function values. Analytical solutions and properties of these models are discussed. We also provide analytical solutions of the maximum entropy and minimum variance problems with given linear medianness values. By setting different forms of the objective function and constraints, the parameterized OWA operator family elements can achieve various distributions in any desired shape. Two examples are given to show the OWA operator elements distributed in quadratic and Gaussian distribution function shapes. © 2011 Elsevier Inc. All rights reserved. Source


Boeuf J.-P.,CNRS LAPLACE Lab | Yang L.L.,Nanjing Southeast University | Pitchford L.C.,CNRS LAPLACE Lab
Journal of Physics D: Applied Physics | Year: 2013

It has been demonstrated experimentally that a non-equilibrium plasma column can be generated by discharge pulses in a helium jet surrounded by atmospheric-pressure air. The 'plasma jet' can be longer than 10 cm and fast imaging shows that most of the light emitted by the plasma jet is produced in a small 'plasma bullet' that propagates along the helium jet at speeds of several tens of km s-1. With the help of a simple fluid model of the discharge, we show that the plasma jet is very similar to a cathode streamer (ionization wave) guided by the helium jet. We discuss the properties of the helium streamer and of the plasma channel behind the streamer head as a function of parameters such as electrode geometry, voltage pulse waveform and preionization density. The model can reproduce qualitatively and explain most of the features observed experimentally. © 2013 IOP Publishing Ltd. Source


Shi X.,Nanjing Southeast University | Yang W.,Tianhua Architecture Design Company Ltd
Automation in Construction | Year: 2013

Performance-driven architectural design emphasizes on integrated and comprehensive optimization of various quantifiable performances of buildings. As the leading profession of a project team, architects play a vital role in guiding and conducting the performance-driven design. Methodology and techniques start emerging both in literature and practice. However, architects often find them difficult to use for various reasons. Therefore, developing an effective technique to conduct performance-driven design and optimization from the perspective of architects is necessary. This paper starts from discussing the concept of performance-driven architectural design. Existing methodology and techniques are reviewed. The focus is on selecting a basic platform suitable for architects, upon which the technique can be developed. Rhinoceros, an architectural modeling program, is used, along with its graphical algorithm editor Grasshopper, to establish such technique by incorporating three performance simulation programs, namely Ecotect, Radiance, and EnergyPlus. Design cases are presented to demonstrate the technique and its effectiveness. © 2013 Elsevier B.V. All rights reserved. Source


Lin J.,Nanjing University of Posts and Telecommunications | Fei S.,Nanjing Southeast University | Gao Z.,Nanjing University of Posts and Telecommunications
Journal of the Franklin Institute | Year: 2012

This paper is concerned with the problem of state feedback stabilization of a class of discrete-time switched singular systems with time-varying state delay under asynchronous switching. The asynchronous switching considered here means that the switching instants of the candidate controllers lag behind those of the subsystems. The concept of mismatched control rate is introduced. By using the multiple Lyapunov function approach and the average dwell time technique, a sufficient condition for the existence of a class of stabilizing switching laws is first derived to guarantee the closed-loop system to be regular, causal and exponentially stable in the presence of asynchronous switching. The stabilizing switching laws are characterized by a upper bound on the mismatched control rate and a lower bound on the average dwell time. Then, the corresponding solvability condition for a set of mode-dependent state feedback controllers is established by using the linear matrix inequality (LMI) technique. Finally, two numerical examples are provided to illustrate the effectiveness of the proposed method. © 2012 The Franklin Institute. Published by Elsevier Ltd. All rights reserved. Source


Yao X.,Nanjing Southeast University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2015

The Kitaev-Heisenberg model on the honeycomb lattice is investigated in two cases: (I) with the Kitaev interaction between the nearest neighbors, and (II) with the Kitaev interaction between the next nearest neighbors. In the full parameter range, the ground states are searched by Monte Carlo simulation and identified by evaluating the correlation functions. The energies of different phases are calculated and compared with the simulated result to show the phase competition. It is observed from both energy calculation and the density of states that the zigzag order shows a symmetric behavior to the stripy phase in the pure Kitaev-Heisenberg model. By considering more interactions in both cases, the energy of zigzag order can be reduced lower than the energies of other states. Thus the zigzag phase may be stabilized in more parameter region and even extended to the whole parameter range. © 2015 Elsevier B.V.All rights reserved. Source


Mi C.,Nanjing Southeast University | Kouris D.,Texas Christian University
International Journal of Solids and Structures | Year: 2013

Stress concentrations typically occur near discontinuities in structural elements and are often responsible for crack initiation. The aim of this study is to assess the stress concentration effects in the vicinity of a nanovoid located near a free surface. A semi-analytical investigation was carried out using the method of displacement potentials and coherent surface models. We investigated the dependence of stress concentration on a few important parameters like surface properties, external loads, bulk properties, as well as void size and location. Our analysis highlighted a few possible combinations of governing parameters that can reduce, prevent, and even reverse stress concentrations in nanoporous media. © 2013 Elsevier Ltd. All rights reserved. Source


Xu Z.,Nanjing Southeast University | Xu Z.,Chinese University of Hong Kong | Cai X.,Chinese University of Hong Kong
Information Sciences | Year: 2011

In many group decision-making situations, decision makers' preferences for alternatives are expressed in preference relations (including fuzzy preference relations and multiplicative preference relations). An important step in the process of aggregating preference relations, is to determine the importance weight of each preference relation. In this paper, we develop a number of goal programming models and quadratic programming models based on the idea of maximizing group consensus. Our models can be used to derive the importance weights of fuzzy preference relations and multiplicative preference relations. We further develop iterative algorithms for reaching acceptable levels of consensus in group decision making based on fuzzy preference relations or multiplicative preference relations. Finally, we include an illustrative example. © 2010 Published by Elsevier Inc. Source


Xu Y.-J.,Hohai University | Da Q.-L.,Nanjing Southeast University
Expert Systems with Applications | Year: 2010

This paper proposes two methods for multi-attribute decision making problems with linguistic information, in which the preference values take the form of linguistic variables. Based on the ideal that the attribute with a larger deviation value among alternatives should be assigned a large weight, two methods named standard deviation method and mean deviation method are proposed to determine the optimal weighting vector objectively under the assumption that attribute weights are completely unknown. Two numerical examples are examined using the proposed methods to show the advantages from the other methods. It is shown that the proposed methods are straightforward and no loss of information. © 2010 Elsevier Ltd. All rights reserved. Source


Sun L.,Catholic University of America | Sun L.,Nanjing Southeast University | Zhu Y.,Transportation Institute
Construction and Building Materials | Year: 2013

A serial two-stage viscoelastic-viscoplastic constitutive model is developed using internal variables theory and orthogonality principle of thermodynamics for modeling time-dependent behavior of asphalt concrete mixtures. In one stage when the actual stress is lower than the yield stress, the constitutive model only exhibit viscoelastic component, while in another stage when the actual stress exceeds the yield stress, the constitutive model exhibit both viscoelastic and viscoplastic components. Model parameters of viscoelastic component are estimated using data obtained from dynamic modulus test, whereas model parameters of viscoplastic component are consecutively estimated from creep test, assuming a known viscoelastic component. © 2012 Elsevier Ltd. All rights reserved. Source


Jin S.,Nanjing Southeast University | McKay M.R.,Hong Kong University of Science and Technology | Zhong C.,Queens University of Belfast | Wong K.-K.,University College London
IEEE Transactions on Information Theory | Year: 2010

This paper presents an analytical characterization of the ergodic capacity of amplify-and-forward (AF) MIMO dual-hop relay channels, assuming that the channel state information is available at the destination terminal only. In contrast to prior results, our expressions apply for arbitrary numbers of antennas and arbitrary relay configurations. We derive an expression for the exact ergodic capacity, simplified closed-form expressions for the high SNR regime, and tight closed-form upper and lower bounds. These results are made possible by employing recent tools from finite-dimensional random matrix theory, which are used to derive new closed-form expressions for various statistical properties of the equivalent AF MIMO dual-hop relay channel, such as the distribution of an unordered eigenvalue and certain random determinant properties. Based on the analytical capacity expressions, we investigate the impact of the system and channel characteristics, such as the antenna configuration and the relay power gain. We also demonstrate a number of interesting relationships between the dual-hop AF MIMO relay channel and conventional point-to-point MIMO channels in various asymptotic regimes. © 2010 IEEE. Source


Xu J.,Nanjing University of Information Science and Technology | Chen M.,Nanjing University of Information Science and Technology | Fu D.,Nanjing Southeast University
Applied Surface Science | Year: 2011

Bi-doped hollow titania spheres were prepared using carbon spheres as template and Bi-doped titania nanoparticles as building blocks. The Bi-doped titania nanoparticles were synthesized at low temperature. The prepared hollow spheres were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), UV-vis diffuse reflectance spectrum (DRS) and X-ray photoelectron spectroscopy (XPS). The effects of Bi content on the physical structure and photocatalytic activity of doped hollow titania sphere samples were investigated. Results showed that there was an optimal Bi-doped content (4%) for the photocatalytic degradation of methylene blue (MB). © 2011 Elsevier B.V. All rights reserved. Source


Wang H.,Nanjing Southeast University
IEEE Transactions on Biomedical Engineering | Year: 2011

The filtering technique for dimensionality reduction of multichannel electroencephalogram (EEG) recordings, modeled using common spatial patterns and its variants, is commonly used in two-class braincomputer interfaces (BCI). For a multiclass problem, the optimization of certain separability criteria in the output space is not directly related to the classification error of EEG single-trial segments. In this paper, we derive a new discriminant criterion, termed weighted pairwise criterion (WPC), for optimizing multiclass filters by minimizing the upper bound of the Bayesian error that is intentionally formulated for classifying EEG single-trial segments. The WPC approach pays more attention to close class pairs that are more likely to be misclassified than far away class pairs that are already well separated. Moreover, we extend WPC by integrating temporal information of EEG series. Computationally, we employ the rank-one update and power iteration technique to optimize the proposed discriminant criterion. The experiments of multiclass classification on the datasets of BCI competitions demonstrate the efficacy of the proposed method. © 2006 IEEE. Source


Wang Z.,Nanjing Southeast University | Wu B.,Ryerson University | Xu D.,Ryerson University | Zargari N.R.,Rockwell Automation
IEEE Transactions on Power Electronics | Year: 2011

In this paper, a hybrid pulsewidth modulation (PWM) scheme is proposed to suppress the LC resonance for the high-power current-source inverter (CSI) fed drives with low switching frequency. In CSI drive systems, the selective harmonic elimination (SHE) is selected due to the better performance of harmonics, but the LC resonance cannot be effectively damped due to the lack of control flexibility of SHE. In this paper, SHE is only used for the steady-state operation. The modulation scheme is then switched to space vector modulation with dynamic capacitor voltage control when the transient event occurs. The smoothed transitions between different modulation schemes are proposed. The proposed hybrid method effectively solves the resonant issues in CSI drives, while maintaining the power quality. Both simulation and experiments verify the performance of the proposed hybrid PWM scheme. © 2006 IEEE. Source


Li S.,Nanjing Southeast University
Advances in Complex Systems | Year: 2011

This paper develops an analytical model of contagion risk in banking systems with tiered structure. It explores the respective effects of banking network structure and bank activity on contagion risk in banking network evolution. The findings suggest that increasing interbank connections is conducive to handling banking crisis and reducing the effect of contagion risk, but its positive effect is limited; raising bank reserve ratio will enhance the stability of individual banks to a certain extent, but it may immediately lead to liquidity problems for banks that have less excess reserves, causing the occurrence of contagion risk; an excessive drive for risk assets with high return may bring high risk to banks and lead to instability of banking systems; the bank risk preference is crucial to the stability of banking systems, and the radicalness of it may lead to greater systemic instability. © 2011 World Scientific Publishing Company. Source


Wang D.,Nanjing Southeast University
Toxicology Research | Year: 2016

Quantum dots (QDs), semiconductor nanomaterials with tiny light-emitting particles, act as important alternatives to conventional fluorescent dyes for biomedical imaging. With the increased tendency towards QD applications, concerns about the likelihood of adverse health impacts from exposure to QDs have also received attention. The nematode Caenorhabditis elegans is an important non-mammalian alternative model for the toxicological study of environmental toxicants including engineered nanomaterials. In this review, we summarize recent progress on the biological effects, translocation, and metabolism of QDs in the in vivo assay system of C. elegans. Moreover, certain perspectives or suggestions are further raised for the future toxicological study of QDs in nematodes. © The Royal Society of Chemistry 2016. Source


Chen Z.,Nanjing Southeast University
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011

The Dynamic Torque Analysis method (DTA) is applied to large scale power system via uniform linear modeling which can be integrated into system model with various kinds of controllers. Then the calculation process of DTA is proposed, and via some simplifications and assumptions on the channel of damping torque, the reconstruction of output and the extraction of sensitivity, the calculation method is simpler and clearer, which can be more easily extended to the calculation of large scale power system. Finally, the proposed DTA is extended to practical large-scale grid calculation and also applied to the analysis of HVDC and PSS controllers, and the effective results are obtained, which proves the feasibility and accuracy of the DTA algorithm applied extended to large scale power system. Source


Zhang H.,Nanjing Southeast University
Journal of Nanoscience and Nanotechnology | Year: 2012

Biocompatible nanomaterials have emerged as ideal platforms to develop multi-functionalization for achieving a compound effect using one system in which each component has a specially designed function. In this context, this article reviews multifunctional nanomedicine platforms for cancer therapy. The paper describes different types of multifunctional nanomedicine platforms, mainly co-delivery of drugs/genes in a single formulation for synergistic anticancer effect, specific strategies for targeting cancer therapy, smart control released drug delivery systems responding to certain internal or external stimuli, paradigms for theranostics to monitor effects in real time, and combination drug with thermal, sound, and light energies mediating multi-mode cancer treatment. Multifunctional nanomedicine platforms with different designs and therapeutic approaches for cancer and their translation from bench to bedside offer promising opportunities to benefit patients in the future. Copyright © 2012 American Scientific Publishers. All rights reserved. Source


Li Z.Y.,Nanjing Southeast University
Circulation journal : official journal of the Japanese Circulation Society | Year: 2011

Inflammation and biomechanical factors have been associated with the development of vulnerable atherosclerotic plaques. Lipid-lowering therapy has been shown to be effective in stabilizing them by reducing plaque inflammation. Its effect on arterial wall strain, however, remains unknown. The aim of the present study was to investigate the role of high- and low-dose lipid-lowering therapy using an HMG-CoA reductase inhibitor, atorvastatin, on arterial wall strain. Forty patients with carotid stenosis >40% were successfully followed up during the Atorvastatin Therapy: Effects on Reduction Of Macrophage Activity (ATHEROMA; ISRCTN64894118) Trial. All patients had plaque inflammation as shown by intraplaque accumulation of ultrasmall super paramagnetic particles of iron oxide on magnetic resonance imaging at baseline. Structural analysis was performed and change of strain was compared between high- and low-dose statin at 0 and 12 weeks. There was no significant difference in strain between the 2 groups at baseline (P = 0.6). At 12 weeks, the maximum strain was significantly lower in the 80-mg group than in the 10-mg group (0.0850.033 vs. 0.1690.084; P = 0.001). A significant reduction (26%) of maximum strain was observed in the 80-mg group at 12 weeks (0.0180.02; P = 0.01). Aggressive lipid-lowering therapy is associated with a significant reduction in arterial wall strain. The reduction in biomechanical strain may be associated with reductions in plaque inflammatory burden. Source


Wu Q.,Nanjing Southeast University | Wu Q.,Hong Kong Polytechnic University
Expert Systems with Applications | Year: 2011

This paper presents a novel hybrid forecasting model based on support vector machine and particle swarm optimization with Cauchy mutation objective and decision-making variables. On the basis of the slow convergence of particle swarm algorithm (PSO) during parameters selection of support vector machine (SVM), the adaptive mutation operator based on the fitness function value and the iterative variable is also applied to inertia weight. Then, a hybrid PSO with adaptive and Cauchy mutation operator (ACPSO) is proposed. The results of application in regression estimation show the proposed hybrid model (ACPSO-SVM) is feasible and effective, and the comparison between the method proposed in this paper and other ones is also given, which proves this method is better than other methods. © 2011 Published by Elsevier Ltd. Source


Li A.-Q.,Nanjing Southeast University
Gongcheng Lixue/Engineering Mechanics | Year: 2012

As one member of the Chinese and Japanese expert investigatory group, the author had attended the earthquake hazard investigation activities which were organized by China-Japan Technique Committee on Building Structures during June 14th to 18th, 2011. An on-the-spot investigation had been carried out on earthquake calamities brought by the Pacific coast of Tohoku Earthquake on March 11th in Sendai and emphatically the performance of seismic isolation and energy dissipation structures in this magnitude 8.8 earthquake. This paper summarizes seismic isolation and energy dissipation techniques and the basic situation of their application in Japan. The performance of the structures which used these techniques in this earthquake is emphatically introduced. Some conclusions and experience on the application of seismic isolation and energy dissipation structures are also given. Source


Qu X.,Nanjing Southeast University | Wong S.-C.,Hong Kong Polytechnic University | Tse C.K.,Hong Kong Polytechnic University
IEEE Transactions on Power Electronics | Year: 2014

The imbalance in the currents of strings of LEDs will cause fast degradation or even failure in some LEDs. Such current imbalance should be avoided. To balance the common average current, a small duty cycle may necessitate a large LED turn-on current amplitude, which may cause temporal overheat and low luminous efficacy of the LEDs. This paper presents a current balancing method based on pulse-width modulation of a common bus voltage to each LED string to achieve the intended average current. An optimal feedback control scheme is proposed to maximize the duty cycles and minimize the bus voltage. As a result, at least one of the LED strings is operating at unity duty cycle. The analysis, implementation, and verification are detailed in this paper. © 2013 IEEE. Source


Li X.,Nanjing Southeast University | Dezert J.,ONERA | Smarandache F.,University of New Mexico | Huang X.,Huazhong University of Science and Technology
Information Sciences | Year: 2011

This paper presents a new method for reducing the number of sources of evidence to combine in order to reduce the complexity of the fusion processing. Such a complexity reduction is often required in many applications where the real-time constraint and limited computing resources are of prime importance. The basic idea consists in selecting, among all sources available, only a subset of sources of evidence to combine. The selection is based on an evidence supporting measure of similarity (ESMS) criterion which is an efficient generic tool for outlier sources identification and rejection. The ESMS between two sources of evidence can be defined using several measures of distance following different lattice structures. In this paper, we propose such four measures of distance for ESMS and we present in details the principle of Generalized Fusion Machine (GFM). Then we apply it experimentally to the real-time perception of the environment with a mobile robot using sonar sensors. A comparative analysis of results is done and presented in the last part of this paper. © 2010 Elsevier Inc. All rights reserved. Source


Geng X.,Nanjing Southeast University
IEEE Transactions on Knowledge and Data Engineering | Year: 2016

Although multi-label learning can deal with many problems with label ambiguity, it does not fit some real applications well where the overall distribution of the importance of the labels matters. This paper proposes a novel learning paradigm named label distribution learning (LDL) for such kind of applications. The label distribution covers a certain number of labels, representing the degree to which each label describes the instance. LDL is a more general learning framework which includes both single-label and multi-label learning as its special cases. This paper proposes six working LDL algorithms in three ways: problem transformation, algorithm adaptation, and specialized algorithm design. In order to compare the performance of the LDL algorithms, six representative and diverse evaluation measures are selected via a clustering analysis, and the first batch of label distribution datasets are collected and made publicly available. Experimental results on one artificial and 15 real-world datasets show clear advantages of the specialized algorithms, which indicates the importance of special design for the characteristics of the LDL problem. © 1989-2012 IEEE. Source


Li X.,Xiamen University | Cao J.,Nanjing Southeast University
Nonlinearity | Year: 2010

This paper studies the global asymptotic stability of neural networks of neutral type with mixed delays. The mixed delays include constant delay in the leakage term (i.e. 'leakage delay'), time-varying delays and continuously distributed delays. Based on the topological degree theory, Lyapunov method and linear matrix inequality (LMI) approach, some sufficient conditions are derived ensuring the existence, uniqueness and global asymptotic stability of the equilibrium point, which are dependent on both the discrete and distributed time delays. These conditions are expressed in terms of LMI and can be easily checked by the MATLAB LMI toolbox. Even if there is no leakage delay, the obtained results are less restrictive than some recent works. It can be applied to neural networks of neutral type with activation functions without assuming their boundedness, monotonicity or differentiability. Moreover, the differentiability of the time-varying delay in the non-neutral term is removed. Finally, two numerical examples are given to show the effectiveness of the proposed method. © 2010 IOP Publishing Ltd & London Mathematical Society. Source


Wu Q.,Nanjing Southeast University
Expert Systems with Applications | Year: 2010

In view of the bad diagnosing capability of standard support vector classifier machine (SVC) for fault diagnosis pattern series with Gaussian noises, Gaussian function is used as loss function of SVC and a new SVC based on Gaussian loss function technique, by name g-SVC, is proposed. To seek the optimal parameter combination of g-SVC, particle swarm optimization (PSO) is proposed. And then, a intelligent fault diagnosing method based on g-SVC and PSO is put forward. The results of its application to car assembly line diagnosis indicate that the diagnosing method is effective and feasible. © 2010 Elsevier Ltd. Source


Gu W.,Nanjing Southeast University | Zhou T.,University of Texas at Austin | Wilke C.O.,University of Texas at Austin
PLoS Computational Biology | Year: 2010

Recent studies have suggested that the thermodynamic stability of mRNA secondary structure near the start codon can regulate translation efficiency in Escherichia coli, and that translation is more efficient the less stable the secondary structure. We survey the complete genomes of 340 species for signals of reduced mRNA secondary structure near the start codon. Our analysis includes bacteria, archaea, fungi, plants, insects, fishes, birds, and mammals. We find that nearly all species show evidence for reduced mRNA stability near the start codon. The reduction in stability generally increases with increasing genomic GC content. In prokaryotes, the reduction also increases with decreasing optimal growth temperature. Within genomes, there is variation in the stability among genes, and this variation correlates with gene GC content, codon bias, and gene expression level. For birds and mammals, however, we do not find a genome-wide trend of reduced mRNA stability near the start codon. Yet the most GC rich genes in these organisms do show such a signal. We conclude that reduced stability of the mRNA secondary structure near the start codon is a universal feature of all cellular life. We suggest that the origin of this reduction is selection for efficient recognition of the start codon by initiator-tRNA. © 2010 Gu et al. Source


Minzhu Z.,Nanjing Southeast University
Acta Mathematica Scientia | Year: 2010

In this article, we characterize the boundedness from below of multiplication operators between α-Bloch spaces on the unit ball. © 2010. Source


Chen J.,Nanjing Southeast University
Journal of Mathematical Physics | Year: 2010

Each soliton equation in the Korteweg-de Vries (KdV) hierarchy, the 2+1 dimensional breaking soliton equation, and the 2+1 dimensional Caudrey-Dodd-Gibbon-Kotera-Sawada (CDGKS) equation are reduced to two or three Neumann systems on the tangent bundle TSN-1 of the unit sphere SN-1. The Lax-Moser matrix for the Neumann systems of degree N-1 is deduced in view of the Mckean-Trubowitz identity and a bilinear generating function, whose favorite characteristic accounts for the problem of the genus of Riemann surface matching to the number of elliptic variables. From the Lax-Moser matrix, the constrained Hamiltonians in the sense of Dirac-Poisson bracket for all the Neumann systems are written down in a uniform recursively determined by integrals of motion. The involution of integrals of motion and constrained Hamiltonians is completed on TSN-1 by using a Lax equation and their functional independence is displayed over a dense open subset of TSN-1 by a direct calculation, which contribute to the Liouville integrability of a family of Neumann systems in a new systematical way. We also construct the hyperelliptic curve of Riemann surface and the Abel map straightening out the restricted Neumann flows that naturally leads to the Jacobi inversion problem on the Jacobian with the aid of the holomorphic differentials, from which some finite-gap solutions expressed by Riemann theta functions for the 2+1 dimensional breaking soliton equation, the 2+1 dimensional CDGKS equation, the KdV, and the fifth-order KdV equations are presented by means of the Riemann theorem. © 2010 American Institute of Physics. Source


Yu X.,Nanjing Southeast University | Xie X.-J.,Qufu Normal University
IEEE Transactions on Automatic Control | Year: 2010

This paper develops a unifying framework for output feedback regulation of stochastic nonlinear systems with more general stochastic inverse dynamics. The contributions of this work are characterized by the following novel features: 1) Motivated by the concept of integral input-to-state stability (iISS) in deterministic systems and stochastic input-to-state stability (SISS) using Lyapunov function in stochastic systems, a concept of stochastic integral input-to-state stability (SiISS) using Lyapunov function is first introduced, two important properties of SiISS are obtained: (i) SiISS is strictly weaker than SISS using Lyapunov function; (ii) SiISS is stronger than the minimum-phase property. However, only under the minimum-phase assumption, there is no dynamic output feedback control law for global stabilization in probability. 2) Almost sure boundedness, a reasonable and stronger concept than boundedness in probability, is introduced. The purpose of introducing the concept is to prove the boundedness and convergence of some signals in the closed-loop control system. 3) Some important mathematical tools which play an essential role in the boundedness and convergence analysis of the closed-loop system are established. 4) A unifying framework is proposed to design a dynamic output feedback control law, which drives the states to the origin almost surely while maintaining all the closed-loop signals bounded almost surely. © 2010 IEEE. Source


Liu X.,Nanjing Southeast University | Yu S.,Deakin University
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2012

The ordered weighted averaging (OWA) determination method with stress function was proposed by Yager, and it makes the OWA operator elements scatter in the shape of the stress function. In this paper, we extend the OWA determination with the stress function method using an optimization model. The proposed method transforms the OWA optimal solution elements into the interpolation points of the stress function. The proposed method extends the basic form of the stress function method with both scale and vertical shift transformations. We also explore a number of properties of this optimization-based stress function method. The OWA operator optimal solution elements can distribute as the shape of the given stress function in a parameterized way, in which case, the solution always possesses the arithmetic average operator as a special case. © 2011 IEEE. Source


Yang J.,Nanjing Southeast University | Yang J.,University of Western Sydney | Zheng W.X.,University of Western Sydney
IEEE Transactions on Circuits and Systems II: Express Briefs | Year: 2014

A generalized nonlinear model predictive control augmented with a disturbance observer is proposed in this brief to solve the disturbance attenuation problem of nonlinear systems with arbitrary disturbance relative degree. It is shown that the disturbances can be removed from the output channels by the proposed method with appropriately designed disturbance compensation gain. The property of nominal performance recovery is retained with the proposed method. The effectiveness of the proposed method is validated by applying it to a static var compensator system. © 2004-2012 IEEE. Source


Wei J.,Nanjing Southeast University | Wei J.,State University of New York at Buffalo | Liu W.,State University of New York at Buffalo | Yan Z.,State University of New York at Buffalo
Journal of Biological Chemistry | Year: 2010

Accumulating evidence suggests that glycogen synthase kinase 3 (GSK-3) is a multifunctional kinase implicated in neuronal development, mood stabilization, and neurodegeneration. However, the synaptic actions of GSK-3 are largely unknown. In this study, we examined the impact of GSK-3 on AMPA receptor (AMPAR) channels, the major mediator of excitatory transmission, in cortical neurons. Application of GSK-3 inhibitors or knockdown of GSK-3 caused a significant reduction of the amplitude of miniature excitatory postsynaptic current (mEPSC), a readout of the unitary strength of synaptic AMPARs. Treatment with GSK-3 inhibitors also decreased surface and synaptic GluR1 clusters on dendrites and increased internalized GluR1 in cortical cultures. Rab5, the small GTPase controlling the transport from plasma membrane to early endosomes, was activated by GSK-3 inhibitors. Knockdown of Rab5 prevented GSK-3 inhibitors from regulating mEPSC amplitude. Guanyl nucleotide dissociation inhibitor (GDI), which regulates the cycle of Rab5 between membrane and cytosol, formed an increased complex with Rab5 after treatment with GSK-3 inhibitors. Blocking the function of GDI occluded the effect of GSK-3 inhibitors on mEPSC amplitude. In cells transfected with the non-phosphorylatable GDI mutant, GDI(S45A), GSK-3 inhibitors lost the capability to regulate GDI-Rab5 complex, mEPSC amplitude, and AMPAR surface expression. These results suggest that GSK-3, via altering the GDI-Rab5 complex, regulates Rab5-mediated endocytosis of AMPARs. It provides a potential mechanism underlying the role of GSK-3 in synaptic transmission and plasticity. © 2010 by The American Society for Biochemistry and Molecular Biology, Inc. Source


Qu X.,Nanjing Southeast University | Wong S.-C.,Hong Kong Polytechnic University | Tse C.K.,Hong Kong Polytechnic University
IEEE Transactions on Power Electronics | Year: 2011

LEDs are potential successors of incandescent lamps with high luminous efficacy and long lifetime. To improve the overall luminair efficacy and lifetime, the power efficiency and lifetime of LED ballasts become important factors. Efficiency gain in transformerless power converters appears attractive for applications without isolation. Driving solid-state LED bulbs in an existing lighting fixture such as PAR30 style housing from universal mains necessitates a high-voltage step-down ratio in order to produce an output voltage of about 10-20 V, which is very common in LED lighting applications. Traditional nonisolated step-down pulse width modulation buck converters may suffer from poor efficiency due to the long diode freewheeling time at small duty cycles. In this paper, we propose a resonance-assisted buck converter to achieve a high-voltage step-down ratio and high converter efficiency, whilst maintaining durability and compatibility with existing incandescent dimmers. The performance of the proposed LED driver is verified experimentally. © 2006 IEEE. Source


Xu O.,Nanjing Southeast University
Progress in Electromagnetics Research | Year: 2011

The dielectric pyramid loaded and the dielectric cone loaded diagonal horn working at 150 GHz are investigated by using Gaussian beam mode analysis. With extremely low cross-polarized and axially symmetrical field distribution in the horn aperture, the calculated fundamental Gaussian mode coupling achieves about 98%. The far field radiation patterns of the two antennas are analyzed using fundamental Gaussian mode aperture field distribution model whose results agree with high-accuracy CST TM software computations, indicating that the dielectric loaded horns radiate fine Gaussian beams. The dielectric loaded geometry may be used to modify the diagonal horns with distorted beam. Source


He Y.,Open University Milton Keynes | Zhou D.,Nanjing Southeast University
Information Processing and Management | Year: 2011

Sentiment analysis concerns about automatically identifying sentiment or opinion expressed in a given piece of text. Most prior work either use prior lexical knowledge defined as sentiment polarity of words or view the task as a text classification problem and rely on labeled corpora to train a sentiment classifier. While lexicon-based approaches do not adapt well to different domains, corpus-based approaches require expensive manual annotation effort. In this paper, we propose a novel framework where an initial classifier is learned by incorporating prior information extracted from an existing sentiment lexicon with preferences on expectations of sentiment labels of those lexicon words being expressed using generalized expectation criteria. Documents classified with high confidence are then used as pseudo-labeled examples for automatical domain-specific feature acquisition. The word-class distributions of such self-learned features are estimated from the pseudo-labeled examples and are used to train another classifier by constraining the model's predictions on unlabeled instances. Experiments on both the movie-review data and the multi-domain sentiment dataset show that our approach attains comparable or better performance than existing weakly-supervised sentiment classification methods despite using no labeled documents. © 2010 Elsevier Ltd. All rights reserved. Source


Usami T.,Meijo University | Wang C.-L.,Meijo University | Wang C.-L.,Nanjing Southeast University | Funayama J.,Meijo University
Earthquake Engineering and Structural Dynamics | Year: 2012

In order to enhance the durability of high-performance buckling-restrained braces (BRBs) used in bridge engineering, which are expected to withstand severe earthquakes three times without being replaced, aluminum alloys were employed to manufacture BRBs. A series of low-cycle fatigue tests, including 18 specimens, were conducted to address the low-cycle fatigue strength of the aluminum alloy BRB. Test results of all specimens show that stable hysteretic curves were obtained without overall buckling occurrence. Failure mode of the welded aluminum alloy BRB is obviously affected by the ribs' welding under the variable or constant strain amplitude condition. Therefore, another type of aluminum alloy BRB, the bolt-assembled BRB with or without spot-welded stoppers, is proposed and tested. Results showed that the low-cycle fatigue performance of bolt-assembled BRBs with stoppers improved four to five times compared with welded BRBs. However, the stoppers' spot welding has an adverse effect on the failure mode because the crack, which induced the specimen's failure, initiated from the spot weld toes of the stoppers. Both bolt-assembled BRBs with and without stoppers can meet the cumulative inelastic deformation requirement proposed for high-performance BRBs under the constant strain amplitude, not larger than 2%. In addition, under the variable strain amplitude condition, only the bolt-assembled BRB without stoppers has an excellent cumulative inelastic deformation capacity and sustains two cycles of 2.5% strain amplitude. Finally, recommended Manson-Coffin equations and preliminary cumulative damage formulae for welded and bolt-assembled BRBs are given as the references of the strain-based damage evaluation. © 2011 John Wiley & Sons, Ltd. Source


Yang W.-X.,Nanjing Southeast University
Optics Letters | Year: 2015

We investigate the high-order harmonic generation (HHG) in a semiconductor quantum dot (SQD) and metallic nanorod (MNR) complex driven by a moderate intensity (<1012 W/cm2) frequency-chirped Gaussian few-cycle pulse. Our numerical results indicate that the cutoff energy of the HHG can be controlled by optimizing the shape of the MNR and surface-to-surface distance between the SQD and the MNR. We also show that the extreme ultraviolet supercontinuum harmonics (25 eV maximal photon energy) and isolated ultrashort pulses (2.67-4.36 fs FWHM) are achievable. © 2015 Optical Society of America. Source


Zheng J.,Nanjing Southeast University
Oncology Letters | Year: 2012

Metabolic activities in normal cells rely primarily on mitochondrial oxidative phosphorylation (OXPHOS) to generate ATP for energy. Unlike in normal cells, glycolysis is enhanced and OXPHOS capacity is reduced in various cancer cells. It has long been believed that the glycolytic phenotype in cancer is due to a permanent impairment of mitochondrial OXPHOS, as proposed by Otto Warburg. This view is challenged by recent investigations which find that the function of mitochondrial OXPHOS in most cancers is intact. Aerobic glycolysis in many cancers is the combined result of various factors such as oncogenes, tumor suppressors, a hypoxic microenvironment, mtDNA mutations, genetic background and others. Understanding the features and complexity of the cancer energy metabolism will help to develop new approaches in early diagnosis and effectively target therapy of cancer. Source


Liu X.,Nanjing Southeast University | Liu X.,University of Southern California | Mendel J.M.,University of Southern California
IEEE Transactions on Fuzzy Systems | Year: 2011

Based on a new continuous Karnik-Mendel (KM) algorithm expression, this paper proves that the centroid computation of an interval type-2 fuzzy set using KM algorithms is equivalent to the Newton-Raphson method in root-finding, which reveals the mechanisms in KM algorithm computation. The theoretical results of KM algorithms are re-obtained. Different from current KM algorithms, centroid computation methods that use different root-finding routines are provided. Such centroid computation methods can obtain the exact solution and are different from the current approximate methods using sampled data. Further improvements and analysis of the centroid problem using root-finding and integral computation techniques are also possible. © 2006 IEEE. Source


Ye W.,Nanjing Southeast University
Physical Review C - Nuclear Physics | Year: 2010

Using a Langevin model, we explore the role of fissility in probing presaddle nuclear dissipation by calculating the excess of the evaporation residue cross section over its standard statistical-model value as a function of nuclear dissipation strength for nuclei Os190 and Po210, which are taken as two representatives that have the same neutron-to-proton ratio (N/Z) but have a difference in fissility. We find that a large fissility not only amplifies the dissipation effects on the excess of evaporation residues, but also significantly increases the sensitivity of this excess to nuclear dissipation. The results suggest that in experiments, to obtain a more accurate information of nuclear dissipation inside the saddle point by measuring evaporation residue cross sections, it is best to populate among the various compound systems with equal N/Z those with high fissility. © 2010 The American Physical Society. Source


Tian Y.-P.,Nanjing Southeast University
ASCC 2011 - 8th Asian Control Conference - Final Program and Proceedings | Year: 2011

This paper studies the high-order consensus problem for heterogeneous multi-agent systems with unknown communication delays. It is shown that high-order consensus may exist in systems with heterogeneous agents. A necessary and sufficient condition is given for the existence of high-order consensus solution to heterogeneous multi-agent systems. The obtained condition shows that for systems with diverse communication delays, high-order consensus does not require each self-delay of agent is equal to the corresponding communication delay. A matching condition for self-delays and communication delays is derived. Finally, when communication delays are unknown, an adaptive adjustment mechanism is proposed for on-line adjusting self-delays. © 2011 Asian Control Association. Source


Nie X.,Nanjing Southeast University | Huang Z.,Jimei University
Neurocomputing | Year: 2012

In this paper, high-order synaptic connectivity is introduced into competitive neural networks and the multistability and multiperiodicity issues are discussed for high-order competitive neural networks with a general class of activation functions. Based on decomposition of state space, Halanay inequality, Cauchy convergence principle and inequality technique, some sufficient conditions are derived for ascertaining equilibrium points to be located in any designated region and to be locally exponentially stable. As an extension of multistability, some similar results are presented for ensuring multiple periodic solutions when external inputs and time delay are periodic. The obtained results are different from and less restrictive than those given by Nie and Cao (2009 [25]), and the assumption (H1A) by Nie and Cao (2009 [25]) is relaxed. It is shown that high-order synaptic connectivity plays an important role on the number of equilibrium points and their dynamics. As a consequence, our results refute traditional viewpoint: high-order synaptic connectivity has faster convergence rate and greater storage capacity than first-order one. Finally, three examples with their simulations are given to show the effectiveness of the obtained results. © 2011 Elsevier B.V. Source


Liu Y.,Zhejiang Normal University | Zhao S.,Shanghai University of Engineering Science | Lu J.,Nanjing Southeast University | Lu J.,Potsdam Institute for Climate Impact Research
IEEE Transactions on Fuzzy Systems | Year: 2011

In this paper, fuzzy impulsive control is used for stabilization of chaotic systems based on the TakagiSugeno (TS) model. The stability issue of the general nonlinear impulsive control system is first investigated via comparison criterion. Then, a novel impulsive control scheme is presented for chaotic systems based on the TS fuzzy model. Some sufficient conditions are given to stabilize the TS fuzzy model. Our results are proven to be less conservative theoretically and numerically. Moreover, we have also estimated the stable region of the impulsive interval. Finally, the proposed fuzzy impulsive control scheme is successfully applied to stabilize Rsslers system and Chuas circuit. The numerical simulations demonstrate the effectiveness and advantage of our main results. © 2010 IEEE. Source


Zhang H.,Nanjing Southeast University
OncoTargets and Therapy | Year: 2016

Drug delivery system based on nanobiotechnology can improve the pharmacokinetics and therapeutic index of chemotherapeutic agents, which has revolutionized tumor therapy. Onivyde, also known as MM-398 or PEP02, is a nanoliposomal formulation of irinotecan which has demonstrated encouraging anticancer activity across a broad range of malignancies, including pancreatic cancer, esophago-gastric cancer, and colorectal cancer. This up-to-date review not only focuses on the structure, pharmacokinetics, and pharmacogenetics of Onivyde but also summarizes clinical trials and recommends Onivyde for patients with advanced solid tumors. © 2016 Zhang et al. Source


Zeng H.,Nanjing Southeast University | Zeng H.,Hong Kong Baptist University | Cheung Y.-M.,Hong Kong Baptist University
IEEE Transactions on Knowledge and Data Engineering | Year: 2012

The pairwise constraints specifying whether a pair of samples should be grouped together or not have been successfully incorporated into the conventional clustering methods such as k-means and spectral clustering for the performance enhancement. Nevertheless, the issue of pairwise constraints has not been well studied in the recently proposed maximum margin clustering (MMC), which extends the maximum margin framework in supervised learning for clustering and often shows a promising performance. This paper therefore proposes a pairwise constrained MMC algorithm. Based on the maximum margin idea in MMC, we propose a set of effective loss functions for discouraging the violation of given pairwise constraints. For the resulting optimization problem, we show that the original nonconvex problem in our approach can be decomposed into a sequence of convex quadratic program problems via constrained concave-convex procedure (CCCP). Subsequently, we present an efficient subgradient projection optimization method to solve each convex problem in the CCCP sequence. Experiments on a number of real-world data sets show that the proposed constrained MMC algorithm is scalable and outperforms the existing constrained MMC approach as well as the typical semi-supervised clustering counterparts. © 1989-2012 IEEE. Source


Cheng Y.J.,University of Electronic Science and Technology of China | Hong W.,Nanjing Southeast University | Wu K.,University of Montreal | Fan Y.,University of Electronic Science and Technology of China
IEEE Transactions on Antennas and Propagation | Year: 2011

Two types of substrate integrated waveguide (SIW) long slot leaky-wave antennas with controllable sidelobe level are proposed and demonstrated in this paper. The first prototype is able to achieve an excellent sidelobe level of -27.7 dB by properly meandering a long slot etched on the broadside of a straight SIW section from the centerline toward the sidewall then back. But it is known that an asymmetrically curved slot would worsen the cross-polar level. To overcome this drawback, a modified leaky-wave antenna is proposed, which has a straight long slot etched on the broadside of a meandering SIW section. It yields an outstanding sidelobe level of -29.3 dB and also improves the cross-polar level by more than 11 dB at 35 GHz. Experimental results agree well with simulations, thus validating our design. Then, a two-dimensional (2-D) multibeam antenna is developed by combining such 14 leaky-wave antennas with an SIW beamforming network (BFN). It has features of scanning both in elevation orientation by varying frequency and in cross-plane direction by using the BFN. Excited at ports 110 of such a 2-D multibeam antenna at 35 GHz, angular region of 86.6° in azimuth can effectively be covered by 3 dB beam-width of ten pencil beams. Varying frequency from 33 GHz to 37 GHz, the angular region of 37.5° and 38.9° in elevation can be covered by 3 dB beam-width of those continuous scanning beams excited at ports 6 and 8 respectively. © 2006 IEEE. Source


Li L.,Peking University | Li F.,CAS Institute of Electronics | Cui T.J.,Nanjing Southeast University
Optics Express | Year: 2014

This paper investigates the feasibility of the resonant metalens for the imaging beyond the diffraction limit using a single sensor in the farfield. It is shown that the resonant metalens can be related to the superresonance phenomenon. We demonstrate that the super-resonance supports the enhancement of the information capacity of an imaging system, which is responsible for the subwavelength imaging of the probed objects by using a single sensor in combination with a broadband illumination. Such imaging concept has its unique advantage of producing real-time data when an object is illuminated by broadband waves, without the harsh requirements such as near-field scanning, mechanical scanning, or antenna arrays. The proposed method is expected to find its applications in nanolithography, detection, sensing, and subwavelength imaging in the near future. © 2014 Optical Society of America. Source


Zhou Y.J.,Shanghai University | Zhou Y.J.,Nanjing Southeast University | Yang B.J.,Shanghai University
Optics Express | Year: 2014

We propose a broadband slow wave system based on the thin metal-insulator-metal (MIM) graded grating structure composed of two corrugated metal strips with periodic array of grooves on a thin dielectric substrate. The guided spoof surface plasmon polaritons (SSPPs) at different frequencies can be localized at different positions along the ultrathin MIM grating. By introducing specially designed non-corrugated MIM branches with specific lengths at the locations where the EM waves are trapped, the trapped EM waves can be released and propagate along these branches. A 4-way wavelength demultiplexer based on such plasmonic broadband slow wave system is then demonstrated and fabricated. To improve the isolations between different branches at lower frequencies, band-reject filters are inserted at the front of some MIM branches. The measurements and the simulation results have shown very good agreements, which validate the feasibility of the 4-way wavelength demultiplexer. ©2014 Optical Society of America. Source


Peng D.,Nanchang University | Zhang X.,Nanjing Southeast University
Energy | Year: 2011

Solar liquid collector/regenerator combines solar photothermic transformation and liquid regeneration together for solar energy-driven liquid desiccant cooling systems. A group of dimensionless heat and mass transfer equations describing the heat and mass transfer process in the solar C/R(Collector/Regenerator) were obtained by introducing total temperature difference (ΔT0) and dimensionless heat loss coefficient (hz). The increment of solution concentration ΔC was increased 2.9-3.5%/°C and 5.3%/°C for increasing unit inlet temperature of air stream and solution respectively and increased about 6.2%/(g/kg) and 0.9%/(g/kg) for decreasing unit inlet humidity ratio of air and solution concentration. Besides, the increasing number of heat transfer units (NTU), air-to-salt mass flow rate ratio (ASMR) and total temperature difference (ΔT0) can increase the performance of solution regeneration significantly. Compared to parallel flow regeneration, the performance of counterflow regeneration was increased about 10%. © 2011 Elsevier Ltd. Source


Zhang X.,Nanjing Southeast University | Xu Z.,University of Sichuan
International Journal of Intelligent Systems | Year: 2014

Recently, a new model based on Pythagorean fuzzy set (PFS) has been presented to manage the uncertainty in real-world decision-making problems. PFS has much stronger ability than intuitionistic fuzzy set to model such uncertainty. In this paper, we define some novel operational laws of PFSs and discuss their desirable properties. For the multicriteria decision-making problems with PFSs, we propose an extended technique for order preference by similarity to ideal solution method to deal effectively with them. In this approach, we first propose a score function based comparison method to identify the Pythagorean fuzzy positive ideal solution and the Pythagorean fuzzy negative ideal solution. Then,we define a distancemeasure to calculate the distances between each alternative and the Pythagorean fuzzy positive ideal solution as well as the Pythagorean fuzzy negative ideal solution, respectively. Afterward, a revised closeness is introduced to identify the optimal alternative. At length, a practical example is given to illustrate the developed method and to make a comparative analysis. © 2014 Wiley Periodicals, Inc. Source


Zhu B.,Nanjing Southeast University | Xu Z.,University of Sichuan
Fuzzy Sets and Systems | Year: 2014

The existing methods for solving the group decision making (GDM) problems with preference relations generally include four steps: (1) estimation of missing preferences, (2) consistency and consensus reaching, (3) aggregation and (4) exploitation, which make the GDM process complicated. Relatively, very few research results focus on exploring the methods which can simplify this process to improve the efficiency. In this paper, we develop a new fuzzy linear programming method (FLPM) to deal with the GDM problems with additive reciprocal fuzzy preference relations (FPRs). The FLPM can directly produce meaningful results without the four steps. An effect index is developed to measure the decision makers (DMs)' effects in the GDM problems. Based on the FLPM and the effect index, we propose a new method to determine the DMs' weights. A step by step procedure is further proposed to deal with the GDM problems with all the developed methods, and its performance is illustrated by examples. © 2014 Published by Elsevier B.V. Source


Chen X.H.,Nanjing Southeast University | Wang D.W.,RWTH Aachen
Wear | Year: 2011

Studies are conducted to the characterization of the aggregate-surface texture in polishing process by fractal and spectral approaches based on rubber friction theory. The Wehner/Schulze (W/S) polishing machine is adopted to simulate the vehicle tyre polishing action. The commonly used aggregates in wearing courses named basalt, gabbros and greywacke are investigated. The surface profile texture and dynamic friction coefficient were monitored in polishing process. The dynamic friction coefficient was observed to reach a stable equilibrium phase after a sharp decrease at the initial polishing stage and the friction evolution in W/S polishing process can be described with power law. Fractal analysis reveals that the changes of amplitude and curve length of the profiles are the main contribution to the loss of friction. Spectral analysis reveals that the polishing action plays an important role in the changes of micro-texture. It can be concluded that the evolution of friction of the aggregates is primarily governed by micro-texture changes due to differential removal of mineral components. © 2011 Elsevier B.V. Source


Lu Z.,Nanjing Southeast University
Frontiers of Physics | Year: 2016

This article presents a review of our present understanding of the spin structure of the unpolarized hadron. Particular attention is paid to the quark sector at leading twist, namely, the quark Boer–Mulders function, which describes the transverse polarization of the quark inside an unpolarized hadron. After introducing the operator definition of the Boer–Mulders function, a detailed treatment of different non-perturbative calculations of the Boer–Mulders functions is provided. The phenomenology in Drell–Yan processes and semi-inclusive leptoproduction, including the extraction of the quark and antiquark Boer–Mulders functions from experimental data, is presented comprehensively. Finally, prospects for future theoretical studies and experimental measurements are presented in brief. © 2016, The Author(s). Source


Chen S.,Nanjing Southeast University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We demonstrate that there exist globally convergent infinite tanh power series with which the spinless light-bullet solutions in the (3+1)D cubic-quintic complex Ginzburg-Landau equation can be exactly expressed. It is found that as these fixed-point bullet solutions exist, the series coefficients asymptotically approach certain nonzero constants; otherwise they oscillate and eventually decay to nil. In terms of the specific Padé approximants, the analytical solutions obtained for either the conventional bullets or the composite ones are in excellent agreement with numerical simulations. © 2012 American Physical Society. Source


Chen S.,Nanjing Southeast University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

In terms of a tanh-series representation, the stationary dissipative solitons such as arbitrary-amplitude solitons, plain solitons, flattop solitons, and composite solitons in complex Ginzburg-Landau (CGL) systems can be exactly described, as confirmed by extensive simulations. It thus suggests another route to understanding solitons in CGL-like systems that is highly accurate. © 2012 American Physical Society. Source


Yang Y.,Nanjing Audit University | Yang Y.,Nanjing Southeast University | Wang Y.,Soochow University of China
Extremes | Year: 2013

Let the random vector (X,Y) follow a bivariate Sarmanov distribution, where X is real-valued and Y is nonnegative. In this paper we investigate the impact of such a dependence structure between X and Y on the tail behavior of their product Z = XY. When X has a regularly varying tail, we establish an asymptotic formula, which extends Breiman's theorem. Based on the obtained result, we consider a discrete-time insurance risk model with dependent insurance and financial risks, and derive the asymptotic and uniformly asymptotic behavior for the (in)finite-time ruin probabilities. © 2012 Springer Science+Business Media, LLC. Source


Wang J.,Nanjing Southeast University | Fischer S.,Karlsruhe Institute of Technology
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

The valley physics in the two-dimensional graphenelike system has been put forward recently, and one of the key issues is to produce valley currents. We propose in this work to realize the topological valley resonance effect in graphene by using the time-dependent lattice vibration of optical phonon modes, which can pump out a noiseless and quantized valley current flowing into graphene leads. This optimal topological valley pump is protected by a nonzero valley Chern number and is robust against perturbations that could even break the time-reversal symmetry and valley conservation. The electrical measurement of the pumped valley currents is also discussed. © 2014 American Physical Society. Source


Hou J.-M.,Nanjing Southeast University
Physical Review B - Condensed Matter and Materials Physics | Year: 2014

First, we study a square fermionic lattice that supports the existence of massless Dirac fermions, where the Dirac points are protected by a hidden symmetry. We also consider two modified models with a staggered potential and the diagonal hopping terms, respectively. In the modified model with a staggered potential, the Dirac points exist in some range of magnitude of the staggered potential, and move with the variation of the staggered potential. When the magnitude of the staggered potential reaches a critical value, the two Dirac points merge. In the modified model with the diagonal hopping terms, the Dirac points always exist and just move with the variation of amplitude of the diagonal hopping. We develop a mapping method to find hidden symmetries evolving with the parameters. In the two modified models, the Dirac points are protected by this kind of hidden symmetry, and their moving and merging process can be explained by the evolution of the hidden symmetry along with the variation of the corresponding parameter. © 2014 American Physical Society. Source


Xu H.-Y.,Peking Union Medical College | Gu N.,Nanjing Southeast University
Frontiers of Materials Science | Year: 2014

Increasing evidence shows that magnetic fields and magnetic responsive scaffolds can play unique roles in promoting bone repair and regeneration. This article addresses the synergistic effects of magnetic scaffolds in response to external magnetic fields on the bone regeneration in situ. Additionally, the exploration of using magnetic scaffolds as tools in the bone implant fixation, local drug delivery and mimicking microenvironment of stem cell differentiation are introduced. We also discussed possible underlying mechanisms and perspectives of magnetic responsive scaffolds in the bone repair and regeneration. © 2014 Higher Education Press and Springer-Verlag Berlin Heidelberg. Source


Hou J.-M.,Nanjing Southeast University
Physical Review Letters | Year: 2013

We study a two-dimensional fermionic square lattice, which supports the existence of a two-dimensional Weyl semimetal, quantum anomalous Hall effect, and 2π-flux topological semimetal in different parameter ranges. We show that the band degenerate points of the two-dimensional Weyl semimetal and 2π-flux topological semimetal are protected by two distinct novel hidden symmetries, which both correspond to antiunitary composite operations. When these hidden symmetries are broken, a gap opens between the conduction and valence bands, turning the system into a insulator. With appropriate parameters, a quantum anomalous Hall effect emerges. The degenerate point at the boundary between the quantum anomalous Hall insulator and trivial band insulator is also protected by the hidden symmetry. © 2013 American Physical Society. Source


Li C.,University of Wisconsin - Madison | Li C.,Nanjing Southeast University | Sprott J.C.,University of Wisconsin - Madison
Nonlinear Dynamics | Year: 2013

A general approach based on the introduction of a control function for constructing amplitude-controllable chaotic systems with quadratic nonlinearities is discussed in this paper. We consider three control regimes where the control functions are applied to different coefficients of the quadratic terms in a dynamical system. The approach is illustrated using the Lorenz system as a typical example. It is proved that wherever control functions are introduced, the amplitude of the chaotic signals can be controlled without altering the Lyapunov exponent spectrum. © 2013 The Author(s). Source


Wang R.,Nanjing Southeast University | Zhang H.,Ohio State University | Wang J.,Ohio State University
IEEE Transactions on Control Systems Technology | Year: 2014

This paper presents a linear parameter-varying (LPV) control strategy to preserve stability and improve handling of a four-wheel independently actuated electric ground vehicle in spite of in-wheel motors and/or steering system faults. Different types of actuator faults including loss-of-effectiveness fault, additive fault, and the fault makes an actuator's control effect stuck-at-fixed-level, are considered simultaneously. To attenuate the effects of disturbance and address the challenging problem, a novel fault-tolerant (FT) robust linear quadratic regulator (LQR)-based H∞ controller using the LPV method is proposed. With the LQR-based H∞ control, the tradeoff between the tracking performance and the control input energy is achieved, and the effect from the external disturbance to the controlled outputs is minimized. The eigenvalue positions of the system matrix of the closed-loop system are also incorporated to tradeoff between the control inputs and the transient responses. The vehicle states, including vehicle yaw rate, lateral and longitudinal velocities, are simultaneously controlled to track their respective references. Simulations for different fault types and various driving scenarios are carried out with a high-fidelity, CarSim®, full-vehicle model. Simulation results show the effectiveness of the proposed FT control approach. © 2013 IEEE. Source


Li R.,Nanjing Southeast University | Wei H.,Chongqing University
International Journal of Machine Learning and Cybernetics | Year: 2016

This paper is concerned with the sampled-data synchronization issues for delayed memristive neural networks with Markovian jumping and reaction–diffusion terms. In the frame work of inequality techniques and a useful Lyapunov functional, some new testable algebraic criteria are obtained to ensure the stability of the error system, and thus, the master system can synchronize with the slave system. Finally, an illustrative example is exploited to demonstrate the performance and effectiveness of the developed approach. © 2015, Springer-Verlag Berlin Heidelberg. Source


Ding Z.,Newcastle University | Ma Z.,Southwest Jiaotong University | Ma Z.,Nanjing Southeast University | Fan P.,Southwest Jiaotong University
IEEE Transactions on Wireless Communications | Year: 2014

In this paper, we consider a two-way relaying scenario with one pair of source nodes, one relay and one eavesdropper. All nodes are equipped with multiple antennas, and we study the impact of antenna selection on such a secure communication scenario. Three transmission schemes with different tradeoff between secure performance and complexity are investigated respectively. Particularly, when antenna selection is implemented at the relay and no artificial noise is introduced, the condition to realize secure transmissions is established. Then by allowing the sources to inject artificial noise into the system, the secure performance is evaluated by focusing on different eavesdropping strategies. When both the relay and the sources send artificial noise, a low complexity strategy of antenna selection is proposed to efficiently utilize the antennas at the sources and the relay. The developed asymptotic results demonstrate that, by adding more artificial noise and performing joint antenna selection, a better secure performance, such as a larger secrecy rate and a lower outage probability, can be realized at a price of imposing more complexity on the system. Simulation results are also provided to demonstrate the accuracy of the developed analytical results. © 2002-2012 IEEE. Source


Xu Q.,Macau University of Science and Technology | Jia M.,Nanjing Southeast University
IEEE Transactions on Control Systems Technology | Year: 2014

This brief presents a scheme of model reference adaptive control with perturbation estimation (MRACPE) for precise motion control of a piezoelectric actuation micropositioning system. One advantage of the proposed scheme lies in the fact that the size of tracking error can be predesigned, which is desirable in practice. A second-order nominal system is assumed, and the unmodeled dynamics and nonlinearity effect are treated as a lumped perturbation, which is approximated by a perturbation estimation technique. A dead-zone modification of the adaptive rules is introduced to mitigate the parameter drifts and to speed up the parameter convergence. Moreover, the proposed MRACPE scheme employs the desired displacement trajectory rather than the voltage signal as the reference input. The stability of the closed-loop control system is proved through Lyapunov stability analysis. Experimental studies show that the MRACPE is superior to conventional proportional-integral-derivative control in terms of positioning accuracy for both set-point and sinusoidal positioning tasks, which is enabled by a significantly enlarged control bandwidth. © 2013 IEEE. Source


Qin A.K.,Nanjing Southeast University | Clausi D.A.,University of Waterloo
IEEE Transactions on Image Processing | Year: 2010

Multivariate image segmentation is a challenging task, influenced by large intraclass variation that reduces class distinguishability as well as increased feature space sparseness and solution space complexity that impose computational cost and degrade algorithmic robustness. To deal with these problems, a Markov random field (MRF) based multivariate segmentation algorithm called "multivariate iterative region growing using semantics" (MIRGS) is presented. In MIRGS, the impact of intraclass variation and computational cost are reduced using the MRF spatial context model incorporated with adaptive edge penalty and applied to regions. Semantic region growing starting from watershed over-segmentation and performed alternatively with segmentation gradually reduces the solution space size, which improves segmentation effectiveness. As a multivariate iterative algorithm, MIRGS is highly sensitive to initial conditions. To suppress initialization sensitivity, it employs a region-level k-means (RKM) based initialization method, which consistently provides accurate initial conditions at low computational cost. Experiments show the superiority of RKM relative to two commonly used initialization methods. Segmentation tests on a variety of synthetic and natural multivariate images demonstrate that MIRGS consistently outperforms three other published algorithms. © 2006 IEEE. Source


Guo Z.,University of North Carolina at Chapel Hill | Liu Q.,Nanjing Southeast University | Wang J.,Chinese University of Hong Kong
IEEE Transactions on Neural Networks | Year: 2011

In this paper, a one-layer recurrent neural network is presented for solving pseudoconvex optimization problems subject to linear equality constraints. The global convergence of the neural network can be guaranteed even though the objective function is pseudoconvex. The finite-time state convergence to the feasible region defined by the equality constraints is also proved. In addition, global exponential convergence is proved when the objective function is strongly pseudoconvex on the feasible region. Simulation results on illustrative examples and application on chemical process data reconciliation are provided to demonstrate the effectiveness and characteristics of the neural network. © 2011 IEEE. Source


Xu Z.,Nanjing Southeast University | Xu Z.,PLA University of Science and Technology
Applied Soft Computing Journal | Year: 2011

Interval fuzzy preference relations are an extension of fuzzy preference relations, which are usually used by experts to express their uncertain preference information over objects in group decision making. In this paper, we focus our attention on the investigation of consistency of interval fuzzy preference relations. We first establish a quadratic programming model by minimizing all the deviations of individual interval fuzzy preference relations and collective interval fuzzy preference relation, from which an exact solution can be found to derive the importance weights of experts. Then, we give two approaches to constructing additive and multiplicative consistent interval fuzzy preference relations, respectively, and show the relationship between the consistency of individual interval fuzzy preference relations and the consistency of collective interval fuzzy preference relation. At last, a practical application is given to our models and approaches. © 2011 Published by Elsevier B.V. Source


The title compound, {(C7H15N2Cl) 2[Cd3Cl10]·4H2O}n , consists of 1-chloro-methyl-1,4-diazo-nia-bicyclo-[2.2.2]octane di-cations, one-dimensional inorganic chains of {[Cd3Cl10] 4-}∞ anions and uncoordinated water mol-ecules. Each of the two independent CdII ions, one with site symmetry 2/m and the other with site symmetry m, is octa-hedrally coordinated by chloride ions (two with site symmetry m and one with site symmetry 2), giving rise to novel polymeric zigzag chains of corner-sharing Cd-centred octa-hedra parallel to the c axis. The organic cations, bisected by mirror planes that contain the two N atoms, three methyl-ene C atoms and the Cl atom, are ordered. Hydrogen bonds (O-H⋯Cl and O-H⋯O) between the water mol-ecules (both with O atoms in a mirror plane) and the chloride anions of neighbouring chlorido-cadmate chains form a three-dimensional supra-molecular network. © 2010 International Union of Crystallography. Source


Cheng J.,Nanjing Southeast University
International journal of nanomedicine | Year: 2011

To overcome both the dose-limiting side effects of conventional chemotherapeutic agents and the therapeutic failure resulting from multidrug resistance (MDR) and minimize adverse effects of chemotherapy agents, a novel chemotherapy formulation of magnetic nanoparticles co-loaded with daunorubicin and 5-bromotetrandrin (DNR/BrTet-MNPs) was developed, and its effect on MDR leukemic cells was explored. After the DNR and Br were co-loaded onto a pluronic-stabilized and oleic acid-modified magnetic nanosystem, the physical characteristic and drug-loading capacity were evaluated. The cell toxicity of the self-prepared DNR/BrTet-MNPs formulation was then determined by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay; the cellular uptake of drug was demonstrated by fluorescent microscope. Lastly, the transcription of mdr1 and the expression of P-glycoprotein (P-gp) were detected by the reverse transcription reaction and western blotting assay, respectively. The results showed that the self-prepared DNR/BrTet-MNPs formulation possessed a sustained release of drug and displayed a dose-dependent antiproliferative activity on MDR leukemia K562/A02 cells. It also enhanced the accumulation of intracellular DNR in K562/A02 cells and downregulated the transcription of the mdr1 gene and the expression of P-gp. These findings suggest that the remarkable effect of the novel DNR/BrTet-MNPs formulation, acting as a drug depot system for the sustained release of the loaded DNR and BrTet, on multidrug resistance leukemia K562/A02 cells would be a promising strategy for overcoming MDR. Source


Wang Z.Y.,Nanjing Southeast University
International journal of nanomedicine | Year: 2011

To explore the preparation and characterization of a novel nanosized magnetic liposome containing the PEI-As(2)O(3)/Mn(0.5)Zn(0.5)Fe(2)O(4) complex. Mn(0.5)Zn(0.5)Fe(2)O(4) and As(2)O(3)/Mn(0.5)Zn(0.5)Fe(2)O(4) nanoparticles were prepared by chemical coprecipitation and loaded with PEI. The PEI- As(2)O(3)/Mn(0.5)Zn(0.5)Fe(2)O(4) complex was characterized using transmission electron and scanning electron microscopy, X-ray diffraction, energy dispersive spectrometry, and Fourier transform infrared spectroscopy. Cell transfection experiments were performed to evaluate the transfect efficiency. Magnetic nanoliposomes were prepared by rotatory evaporation and their shape, diameter, and thermodynamic characteristics were observed. Mn(0.5)Zn(0.5)Fe(2)O(4) and PEI-As(2)O(3)/Mn(0.5)Zn(0.5)Fe(2)O(4) nanoparticles were spherical, with an average diameter of 20-40 nm. PEI-As(2)O(3)/Mn(0.5)Zn(0.5)Fe(2)O(4) was an appropriate carrier for the delivery of a foreign gene to HepG2 cells. Energy dispersive spectrometry results confirmed the presence of the elements nitrogen and arsenic. Nanoliposomes of approximately 100 nm were observed under a transmission electron microscope. Upon exposure to an alternating magnetic field, they also had good magnetic responsiveness, even though Mn(0.5)Zn(0.5)Fe(2)O(4)was modified by PEI and encased in liposomes. Temperatures increased to 37°C-54°C depending on different concentrations of PEI-As(2)O(3)/Mn(0.5)Zn(0.5)Fe(2)O(4)and remained stable thereafter. Our results suggest that PEI-As(2)O(3)/Mn(0.5)Zn(0.5)Fe(2)O(4) magnetic nanoliposomes are an excellent biomaterial, which has multiple benefits in tumor thermotherapy, gene therapy, and chemotherapy. Source


Yang H.,Nanjing Southeast University | Ye G.,Tsinghua University | Wang X.,Tsinghua University | Keller P.,University Pierre and Marie Curie
Soft Matter | Year: 2011

Over the last few years, following a trend to miniaturization found in many fields of materials science, micron-sized liquid crystalline elastomer (LCE) actuators have been described, with the aim to apply them in such domains like responsive surfaces, microfluidic devices or microsensors. The preparations of the micron-sized LCE actuators involve plenty of cutting-edge, advanced technologies such as soft lithography, microfluidic, microprinting or photomasking. In this highlight, we describe the most striking results obtained in the domain of micron-sized LCE-based responsive systems. © 2011 The Royal Society of Chemistry. Source


Pan Z.,Tongji University | Li B.,Nanyang Technological University | Lu Z.,Nanjing Southeast University
Engineering Structures | Year: 2014

Beam deflections in cases of diagonal and bending cracking of reinforced concrete (RC) beams can be attributed equally to shear and flexural deformations. However, the extent of contribution by shear deformation is hard to quantify and is often underestimated in practical design. To address this, a quantitative analysis of the effect of shear deformation was conducted, considering the effect of tension stiffening after diagonal cracking, and a formula to derive effective shear stiffness is proposed. Five RC beams, comprising of three RC T-section beams with thin web and two RC rectangular beams, were tested to verify the theoretical models with minimum crack angle and total deflection as key points of comparison. The fully cracked responses were analyzed using truss model analogies while exact models applied depended on the crack angle. Results show that shear contribution to the total deflection in the diagonally cracked RC beam is significant. © 2013 Elsevier Ltd. Source


Wang J.,Nanjing Southeast University
International journal of nanomedicine | Year: 2011

A promising approach to optimize the disposition of daunorubicin-loaded magnetic nanoparticles (DNR-MNPs) was developed to minimize serious side effects of systematic chemotherapy for cancer. The physical properties of DNR-MNPs were investigated and their effect on leukemia cells in vitro was evaluated by a standard WST-1 cell proliferation assay. Furthermore, cell apoptosis and intracellular accumulation of DNR were determined by FACSCalibur flow cytometry. Our results showed that the majority of MNPs were spherical and their sizes were from 10 to 20 nm. The average hydrodynamic diameter of DNR-MNPs in water was 94 nm. The in vitro release data showed that the DNR-MNPs have excellent sustained release property. Proliferation of K562 cells was inhibited in a dose-dependent manner by DNR in solution (DNR-Sol) or by DNR-MNPs. The IC(50) for DNR-MNPs was slightly higher than that for DNR-Sol. DNR-MNPs also induced less apoptosis in K562 cells than did DNR-Sol. Detection of fluorescence intensity of intracellular DNR demonstrated that DNR-MNPs could be taken up by K562 cells and persistently released DNR in cells. Our study suggests that optimized DNR-MNPs formulation possesses sustained drug-release and favorable antitumor properties, which may be used as a conventional dosage form for antitumor therapy. Source


An Y.L.,Nanjing Southeast University
International journal of nanomedicine | Year: 2011

Our objective was to prepare a new nano-sized realgar particle and characterize its anti-tumor effect on tumor cells. Nanoparticles were prepared by coprecipitation and were detected by transmission electron microscopy, scanning electron microscopy, energy dispersive spectrometry (EDS), and dynamic light scattering. An anti-proliferative effect of realgar nanoparticles on rat glioma (C6) cells was determined by the MTT assay. Cell cycle and apoptosis rates were observed by flow cytometry. Apoptosis-related gene expression was detected by immunofluorescence staining. Realgar nanoparticles were successfully prepared. The particles were spherical, with an average diameter of approximately 80 nm, and contained arsenic and sulfur elements. Realgar nanoparticles inhibited C6 cell proliferation and induced apoptosis in a dose- and time-dependent manner. Treatment of C6 cells with realgar nanoparticles significantly increased the proportions of cells in S and G2/M phases, decreased the proportion of cells in G0/G1 phase, downregulated Bcl-2 expression, and substantially upregulated Bax expression. Realgar nanoparticles significantly inhibited C6 glioma cell proliferation and promoted cell apoptosis by inducing the upregulation of Bax and downregulation of Bcl-2 expression. Realgar nanoparticles are a promising in vitro anti-cancer strategy and may be applicable for human cancer therapy studies. Source


Gambogic acid (GA), a potent anticancer agent, is limited in clinical administration due to its poor water solubility. The aim of this study was to explore a drug delivery system based on magnetic Fe(3)O(4) nanoparticles (MNP-Fe(3)O(4)) conjugated with GA to increase water solubility of the drug and enhance its chemotherapeutic efficiency for pancreatic cancer. GA was conjugated with the MNP-Fe(3)O(4) colloidal suspension by mechanical absorption polymerization to construct GA-loaded MNP-Fe(3)O(4), which acted as a drug delivery system. Combination therapy with GA and MNP-Fe(3)O(4) induced remarkable improvement in anticancer activity, which was demonstrated by optical microscopic observations, MTT assay, and nuclear DAPI staining. Furthermore, the possible signaling pathway was explored by Western blot. In Capan-1 pancreatic cancer cells, our observations demonstrated that this strategy could enhance potential anticancer efficiency by inducing apoptosis. The mechanisms of the synergistic effect may be due to reducing protein expression of Bcl-2 and enhancing that of Bax, caspase 9, and caspase 3. These findings demonstrate that a combination of GA and MNPs-Fe(3)O(4) represents a promising approach to the treatment of pancreatic cancer. Source


This study aims to evaluate the potential benefit of combination therapy of 2-methoxyestradiol (2ME) and magnetic nanoparticles of Fe(3)O(4) (MNPs-Fe(3)O(4)) on myelodysplastic syndrome (MDS) SKM-1 cells and its underlying mechanisms. The effect of the unique properties of tetraheptylammonium-capped MNPs-Fe(3)O(4) with 2ME on cytotoxicity was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell-cycle distribution and apoptosis were assessed by flow cytometry. The expression of cell-cycle marker protein was measured by Western blotting. Growth inhibition rate of SKM-1 cells treated with the 2ME-loaded MNPs-Fe(3)O(4) was enhanced when compared with 2ME alone. 2ME led to an increase of caspase-3 expression, followed by apoptosis, which was significantly increased when combined with an MNPs-Fe(3)O(4) carrier. Moreover, the copolymer of 2ME with MNPs- Fe(3)O(4) blocked a nearly two-fold increase in SKM-1 cells located in G(2)/M phase than in 2ME alone, which may be associated with an accompanying increase of p21 as well as a decrease in cyclin B1 and cdc2 expression, but there was no obvious difference between the MNPs-Fe(3)O(4) and control group. These findings suggest that the unique properties of MNPs-Fe(3)O(4) as a carrier for 2ME, a new anticancer agent currently in clinical trials, may be a logical strategy to enhance the therapeutic activity of MDS. Source


Wu G.,Nanjing Southeast University | Huang G.,Chinese Academy of Sciences | Ji H.,Chinese Academy of Sciences
Astrophysical Journal | Year: 2010

Anomalous resistivity is a critical parameter for triggering the fast magnetic reconnection and interpreting the eruption of solar flares in the nearly collisionless coronal plasma. However, the mechanism for the production of anomalous resistivity and its evolution are weakly understood. In this paper, the one-dimensional Vlasov equation was numerically solved with the typical solar coronal parameters and realistic mass ratio in the presence of strong inductive electric field, and the relationship between the anomalous resistivity and the reconnecting electric field was inferred for the area near the center of reconnecting current sheets. Our principal findings are summarized as follows. (1) The relationship between the anomalous resistivity and the reconnecting electric field E0 may be represented by ηeff = [10.82-10.99 exp(-0.36 E0)]Ω. m. (2) If E0 is small enough, it may be described by ηeff = [4.02 E0 - 0.18]Ω m, which is basically consistent with the early experimental results on the plasma response to the applied electric field. (3) In comparison with theoretical formulas for the current-driven ion-acoustic and Buneman anomalous resistivities, if E0 is small, the anomalous resistivity may be due to the ion-acoustic instability; if E0 is large, the anomalous resistivity may be due to the Buneman instability. These results are also basically consistent with early experiments. © 2010. The American Astronomical Society. All rights reserved. Printed in the U.S.A. Source


The purpose of this study was to develop intraperitoneal hyperthermic therapy based on magnetic fluid hyperthermia, nanoparticle-wrapped cisplatin chemotherapy, and magnetic particles of albumin. In addition, to combine the multiple-killing effects of hyperthermal targeting therapy, chemotherapy, and radiotherapy, the albumin-nanoparticle surfaces were linked with radionuclide (188)Re-labeled folic acid ligand ((188)Re-folate-CDDP/HSA). Human serum albumin was labeled with (188)Re using the pre-tin method. Reaction time and optimal conditions of labeling were investigated. The particles were intravenously injected into mice, which were sacrificed at different time points. Radioactivity per gram of tissue of percent injected dose (% ID/g) was measured in vital organs. The biodistribution of (188)Re-folate-CDDP/HAS magnetic nanoparticles was assessed. Optimal conditions for (188)Re-labeled folate-conjugated albumin combined with cisplatin magnetic nanoparticles were: 0.1 mL of sodium gluconate solution (0.3 mol/L), 0.1 mL of concentrated hydrochloric acid with dissolved stannous chloride (10 mg/mL), 0.04 mL of acetic acid buffer solution (pH 5, 0.2 mol/L), 30 mg of folate-conjugated albumin combined with cisplatin magnetic nanoparticles, and (188)ReO(4) eluent (0.1 mL). The rate of (188)Re-folate-CDDP-HSA magnetic nanoparticle formation exceeded 90%, and radiochemical purity exceeded 95%. The overall labeling rate was 83% in calf serum at 37°C. The major uptake tissues were the liver, kidney, intestine, and tumor after the (188)Re-folate-CDDP/HSA magnetic nanoparticles were injected into nude mice. Uptake of (188)Re-folate-CDDP/HSA magnetic nanoparticles increased gradually after injection, peaked at 8 hours with a value of 8.83 ± 1.71, and slowly decreased over 24 hours in vivo. These results indicate that (188)Re-folate-CDDP/HSA magnetic nanoparticles can be used in radionuclide-targeted cancer therapy. Surface-modified albumin nanoparticles with folic acid ligand-labeled radionuclide ((188)Re) were successfully prepared, laying the foundation for a triple-killing effect of thermotherapy, chemotherapy, and radiation therapy. Source


Xue H.,Nanjing Southeast University | Chen S.,Nanjing University of Aeronautics and Astronautics | Chen S.,Nanjing University | Yang Q.,Hong Kong University of Science and Technology
IEEE Transactions on Neural Networks | Year: 2011

Support vector machine (SVM), as one of the most popular classifiers, aims to find a hyperplane that can separate two classes of data with maximal margin. SVM classifiers are focused on achieving more separation between classes than exploiting the structures in the training data within classes. However, the structural information, as an implicit prior knowledge, has recently been found to be vital for designing a good classifier in different real-world problems. Accordingly, using as much prior structural information in data as possible to help improve the generalization ability of a classifier has yielded a class of effective structural large margin classifiers, such as the structured large margin machine (SLMM) and the Laplacian support vector machine (LapSVM). In this paper, we unify these classifiers into a common framework from the concept of structural granularity and the formulation for optimization problems. We exploit the quadratic programming (QP) and second-order cone programming (SOCP) methods, and derive a novel large margin classifier, we call the new classifier the structural regularized support vector machine (SRSVM). Unlike both SLMM at the cross of the cluster granularity and SOCP and LapSVM at the cross of the point granularity and QP, SRSVM is located at the cross of the cluster granularity and QP and thus follows the same optimization formulation as LapSVM to overcome large computational complexity and non-sparse solution in SLMM. In addition, it integrates the compactness within classes with the separability between classes simultaneously. Furthermore, it is possible to derive generalization bounds for these algorithms by using eigenvalue analysis of the kernel matrices. Experimental results demonstrate that SRSVM is often superior in classification and generalization performances to the state-of-the-art algorithms in the framework, both with the same and different structural granularities. © 2011 IEEE. Source


Zhu R.-Q.,Nanjing Southeast University
Acta Crystallographica Section E: Structure Reports Online | Year: 2011

In the crystal structure of the title compound, C7H 15ClN22+·2PF6-, the cations and anions are linked by intermolecular N -H⋯F hydrogen bonds. Source


Xu H.,Nanjing Southeast University | Zheng J.,Nankai University
Macromolecular Chemistry and Physics | Year: 2010

A general approach to construct one-dimensional face-to-face alignment of porphyrin/fullerene nanowires has been developed. This system uses extended trans-dihydroxotin(IV) porphyrin and trans-dicarboxylate-substituted [60]fullerenoacetic diacid compounds. The nanowires are arranged in regular one-dimensional linear arrays with lengths in the range 50-300 nm. In the nanowires, each fullerene unit is axially coordinated to the central metal ion of a Sn(IV) porphyrin unit via Sn-carboxylate coordination and forms a face-to-face aligned structure. The synthesis and the hierarchical structure of nanowires have been investigated. They could have potential applications for photoelectronic devices, organic solar cells and so on. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Qian S.Z.,Nanjing Southeast University | Zhou J.,Technical University of Delft | Schlangen E.,Technical University of Delft
Cement and Concrete Composites | Year: 2010

This paper investigates the self-healing behavior of Engineered Cementitious Composites (ECC) with focus on the influence of curing condition and precracking time. Four-point bending tests were used to precrack ECC beams at different age, followed by different curing conditions, including air curing, 3% CO2 concentration curing, cyclic wet/dry (dry under 3% CO 2 concentration) curing and water curing. For all curing conditions, deflection capacity after self-healing can recover or even exceed that from virgin samples with almost all precracking ages. After self-healing, flexural stiffness was also retained significantly compared with that from virgin samples, even though the level of retaining decreases with the increase of precracking time. The flexural strength increases for samples pre-cracked at the age of 14 days and 28 days, presumably due to continuous hydration of cementitious materials afterwards. Furthermore, it is promising to utilize nanoclay as distributed internal water reservoirs to promote self-healing behavior within ECC without relying on external water supply. © 2010 Elsevier Ltd. All rights reserved. Source


Wang J.,Nanjing Southeast University
IEEE Transactions on Signal Processing | Year: 2013

In this paper, we propose a promising discrete game-theoretic framework for distributed energy efficient discrete spectrum sharing strategy selection (i.e., joint discrete power control and multimode precoding strategy selection) with limited feedback for cognitive MIMO interference channels. Given the competitive nature, the secondary users are assumed to be selfish and noncooperative, each of whom attempts to maximize its individual energy efficiency under a minimum data rate constraint and an interference power constraint. A mechanism for shutting down links is proposed to reduce interference and save energy. A payoff function is designed to guarantee the feasibility of the pure strategy Nash equilibrium with no need to know the infeasible strategy profiles (a spectrum sharing strategy profile is said to be feasible if the stated constraints are satisfied; otherwise, the spectrum sharing strategy profile is said to be infeasible, i.e., they may not satisfy the interference power constraint and minimum data rate constraint) in advance. We then investigate the existence and the feasibility of the pure strategy Nash equilibrium, and further devise a pricing-based distributed algorithm for spectrum strategy selection. The proposed algorithm is proved to converge to a feasible pure strategy Nash equilibrium under specific conditions. Moreover, by studying the relationship between our proposed game and the social optimum, we find that the pricing mechanism can result in Pareto improvement and lead to better convergence for the proposed distributed algorithm. Numerical results show that our designed algorithm significantly outperforms the random selection algorithm and the pricing mechanism has a dramatic effect in improving the system performance. © 1991-2012 IEEE. Source


Zhang M.-L.,Nanjing Southeast University | Zhang M.-L.,Nanjing University | Zhang K.,Max Planck Institute for Biological Cybernetics
Proceedings of the ACM SIGKDD International Conference on Knowledge Discovery and Data Mining | Year: 2010

In multi-label learning, each training example is associated with a set of labels and the task is to predict the proper label set for the unseen example. Due to the tremendous (exponential) number of possible label sets, the task of learning from multi-label examples is rather challenging. Therefore, the key to successful multi-label learning is how to effectively exploit correlations between different labels to facilitate the learning process. In this paper, we propose to use a Bayesian network structure to efficiently encode the conditional dependencies of the labels as well as the feature set, with the feature set as the common parent of all labels. To make it practical, we give an approximate yet efficient procedure to find such a network structure. With the help of this network, multi-label learning is decomposed into a series of single-label classification problems, where a classifier is constructed for each label by incorporating its parental labels as additional features. Label sets of unseen examples are predicted recursively according to the label ordering given by the network. Extensive experiments on a broad range of data sets validate the effectiveness of our approach against other well-established methods. © 2010 ACM. Source


Wu W.,Nanjing Southeast University
Journal of Bridge Engineering | Year: 2014

Abstract A new type of bamboo composite I-shaped beam, which consists of bamboo laminate as its upper and down flange plates and bamboo curtain plywood as its web, was introduced in the paper. In this new type of beam, a connection between the flange plates and the web was enabled with a combined action of epoxy resin adhesive and a bolting joint. A model test on the bending mechanical properties (e.g., bending failure mode and bending capacity) and the factors influencing the flexural rigidity of the bamboo composite I-shaped beam was conducted. The preliminary results showed that the bamboo composite I-shaped beam has excellent mechanical properties that could offer high bending capacity and bending rigidity, as well as excellent ductility of the structure. Therefore, the bamboo composite I-shaped beam is potentially interesting for application in small- to medium-span bridges as a new type of structure. Moreover, this experimental research could help with a design method for bamboo composite I-shaped beams in the future. © 2013 American Society of Civil Engineers. Source


Gao D.,Nanjing Institute of Technology | Chen Z.,Nanjing Southeast University | Chen L.,Nanjing Institute of Technology
International Journal of Heat and Mass Transfer | Year: 2014

A thermal lattice Boltzmann model for natural convection in porous media under local thermal non-equilibrium conditions is proposed through an appropriate selection of equilibrium distribution functions and discrete source terms. In this model, two new distribution functions are introduced to simulate the temperature fields of the fluid and solid matrix phases in addition to the density distribution function for the velocity field. The macroscopic energy equations are recovered from the corresponding lattice Boltzmann equations by the Chapman-Enskog procedure. Detailed numerical tests of the proposed model are carried out for three different cases under both steady state and transient conditions. The influence of various parameters such as ratio of solid-to-fluid thermal conductivities, interstitial Nusselt number, Rayleigh number, and Darcy number on the thermal and flow fields is investigated. The present numerical results agree well with the solutions reported in previous studies. Therefore, it is verified that the present model can be served as a feasible and efficient tool for non-equilibrium natural convection problems in porous media. © 2013 Elsevier Ltd. All rights reserved. Source


Yao X.,Nanjing Southeast University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2013

The relaxation of geometrical frustration under different factors is investigated by comparing the density of states and magnetic behavior obtained in Wang-Landau simulation. Starting from the same triangular antiferromagnetic system with high frustration, three typical ways, in which the non-trivial high degeneracy of ground states is lifted by different relaxative factors, are revealed. Correspondingly, the typical magnetic behavior with M0/3 (where M0 is the saturated magnetization) plateau in frustrated triangular system, shows distinct variations in these three cases. © 2012 Elsevier B.V. All rights reserved. Source


Li Z.,Peking University | Wen G.,Nanjing Southeast University | Duan Z.,Peking University | Ren W.,University of California at Riverside
IEEE Transactions on Automatic Control | Year: 2015

This technical note addresses the distributed consensus protocol design problem for multi-agent systems with general linear dynamics and directed communication graphs. Existing works usually design consensus protocols using the smallest real part of the nonzero eigenvalues of the Laplacian matrix associated with the communication graph, which however is global information. In this technical note, based on only the agent dynamics and the relative states of neighboring agents, a distributed adaptive consensus protocol is designed to achieve leader-follower consensus in the presence of a leader with a zero input for any communication graph containing a directed spanning tree with the leader as the root node. The proposed adaptive protocol is independent of any global information of the communication graph and thereby is fully distributed. Extensions to the case with multiple leaders are further studied. © 1963-2012 IEEE. Source


Sun W.,Nanjing Southeast University
Mathematical Problems in Engineering | Year: 2013

This paper investigates the problem of finite-time tracking control for nonholonomic mechanical systems with affine constraints. The control scheme is provided by flexibly incorporating terminal sliding-mode control with the method of relay switching control and related adaptive technique. The proposed relay switching controller ensures that the output tracking error converges to zero in a finite time. As an application, a boat on a running river is given to show the effectiveness of the control scheme. © 2013 Wei Sun. Source


Zhou F.,Nanjing Southeast University | Zhou F.,University of California at Los Angeles | Catton I.,University of California at Los Angeles
Numerical Heat Transfer; Part A: Applications | Year: 2011

A numerical investigation of the thermal and hydraulic performance of 20 different plate-pin fin heat sinks with various shapes of pin cross-sections (square, circular, elliptic, NACA profile, and dropform) and different ratios of pin widths to plate fin spacing (0.3, 0.4, 0.5, and 0.6) was performed. Finite volume method-based CFD software, Ansys CFX, was used as the 3-D Reynolds-averaged Navier-Stokes Solver. A k-ω based shear-stress-transport model was used to predict the turbulent flow and heat transfer through the heat sink channels. The present study provides original information about the performance of this new type of compound heat sink. Copyright © Taylor & Francis Group, LLC. Source


Wu Q.,Nanjing Southeast University
Expert Systems with Applications | Year: 2011

This paper presents a new version of fuzzy support vector machine to diagnose automatic car assembly fault diagnosis, the input and output variables are described as fuzzy numbers and the metric on fuzzy number space is defined. Then by combining the fuzzy theory with v-support vector machine, the fuzzy v-support vector classifier machine (Fv-SVCM) is proposed. A fault diagnosis method based on Fv-SVCM and its relevant parameter-choosing algorithm is put forward. The results of the application in car assembly diagnosis confirm the feasibility and the validity of the diagnosis method. Compared with the fuzzy neural network (FNN) model, Fv-SVCM method requires fewer samples and has better estimating precision. © 2010 Elsevier Ltd. All rights reserved. Source


Yan L.,Nanjing Southeast University | Yang F.,Hohai University
Engineering Analysis with Boundary Elements | Year: 2013

In this paper, an efficient Kansa-type method of fundamental solutions (MFS-K) is extended to the solution of two-dimensional time fractional sub-diffusion equations. To solve initial boundary value problems for these equations, the time dependence is removed by time differencing, which converts the original problems into a sequence of boundary value problems for inhomogeneous Helmholtz-type equations. The solution of this type of elliptic boundary value problems can be approximated by fundamental solutions of the Helmholtz operator with different test frequencies. Numerical results are presented for several examples with regular and irregular geometries. The numerical verification shows that the proposed numerical scheme is accurate and computationally efficient for solving two-dimensional fractional sub-diffusion equations. © 2013 Elsevier Ltd. Source


Yang X.,Chongqing Normal University | Wu Z.,Chongqing Normal University | Cao J.,Nanjing Southeast University
Nonlinear Dynamics | Year: 2013

In this paper, we study the finite-time synchronization problem for linearly coupled complex networks with discontinuous nonidentical nodes. Firstly, new conditions for general discontinuous chaotic systems is proposed, which is easy to be verified. Secondly, a set of new controllers are designed such that the considered model can be finite-timely synchronized onto any target node with discontinuous functions. Based on a finite-time stability theorem for equations with discontinuous right-hand and inequality techniques, several sufficient conditions are obtained to ensure the synchronization goal. Results of this paper are general, and they extend and improve existing results on both continuous and discontinuous complex networks. Finally, numerical example, in which a BA scale-free network with discontinuous Sprott and Chua circuits is finite-timely synchronized onto discontinuous Chen system, is given to show the effectiveness of our new results. © 2013 Springer Science+Business Media Dordrecht. Source


Wan X.,Nanjing University of Posts and Telecommunications | Wu Z.,Nanjing Southeast University
Applied Acoustics | Year: 2013

Sound source localization plays a crucial role in many microphone arrays application, ranging from speech enhancement to human-computer interface in a reverberant noisy environment. The steered response power (SRP) using the phase transform (SRP-PHAT) method is one of the most popular modern localization algorithms. The SRP-based source localizers have been proved robust, however, the methods may fail to locate the sound source in adverse noise and reverberation conditions, especially when the direct paths to the microphones are unavailable. This paper proposes a localization algorithm based on discrimination of cross-correlation functions. The cross-correlation functions are calculated by the generalized cross-correlation phase transform (GCC-PHAT) method. Using cross-correlation functions, sound source location is estimated by one of the two classifiers: Naive-Bayes classifier and Euclidean distance classifier. Simulation results have demonstrated that the proposed algorithms provide higher localization accuracy than the SRP-PHAT algorithm in reverberant noisy environment. © 2012 Elsevier Ltd. All rights reserved. Source


Xie X.-J.,Qufu Normal University | Duan N.,Xuzhou Normal University | Yu X.,Nanjing Southeast University
IEEE Transactions on Automatic Control | Year: 2011

This technical note considers a class of high-order stochastic nonlinear systems with stochastic integral input-to-state stability (SiISS) inverse dynamics, and drift and diffusion terms depending upon the stochastic inverse dynamics and all the states. A new design and analysis approach to the problem of state-feedback global regulation is developed to guarantee that all the signals of the closed-loop system are bounded almost surely and the states can be regulated to zero almost surely. © 2010 IEEE. Source


Jiang W.-Z.,Nanjing Southeast University | Jiang W.-Z.,National Laboratory of Heavy Ion Accelerator
Physical Review C - Nuclear Physics | Year: 2010

Effects of the density dependence of the nuclear symmetry energy on ground-state properties of superheavy nuclei are studied in the relativistic mean-field theory. It is found that the softening of the symmetry energy plays an important role in the empirical shift of spherical orbitals in superheavy nuclei. The calculation based on the relativistic mean-field models NL3 and FSUGold supports the double shell closure in 292120 with the softening of the symmetry energy. In addition, the significant effect of the density dependence of the symmetry energy on the neutron skin thickness in superheavy nuclei is investigated. © 2010 The American Physical Society. Source


Chen S.,Nanjing Southeast University | Soto-Crespo J.M.,CSIC - Institute of Optics | Grelu P.,R.A.U.M.
Optics Express | Year: 2014

We investigate dark rogue wave dynamics in normally dispersive birefringent optical fibers, based on the exact rational solutions of the coupled nonlinear Schrödinger equations. Analytical solutions are derived up to the second order via a nonrecursive Darboux transformation method. Vector dark "three-sister" rogue waves as well as their existence conditions are demonstrated. The robustness against small perturbations is numerically confirmed in spite of the onset of modulational instability, offering the possibility to observe such extreme events in normal optical fibers with random birefringence, or in other Manakov-type vector nonlinear media. © 2014 Optical Society of America Source


Zhang M.-L.,Nanjing Southeast University | Zhou Z.-H.,Nanjing University
IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics | Year: 2011

Co-training is one of the major semi-supervised learning paradigms that iteratively trains two classifiers on two different views, and uses the predictions of either classifier on the unlabeled examples to augment the training set of the other. During the co-training process, especially in initial rounds when the classifiers have only mediocre accuracy, it is quite possible that one classifier will receive labels on unlabeled examples erroneously predicted by the other classifier. Therefore, the performance of co-training style algorithms is usually unstable. In this paper, the problem of how to reliably communicate labeling information between different views is addressed by a novel co-training algorithm named CoTrade. In each labeling round, CoTrade carries out the label communication process in two steps. First, confidence of either classifier's predictions on unlabeled examples is explicitly estimated based on specific data editing techniques. Secondly, a number of predicted labels with higher confidence of either classifier are passed to the other one, where certain constraints are imposed to avoid introducing undesirable classification noise. Experiments on several real-world datasets across three domains show that CoTrade can effectively exploit unlabeled data to achieve better generalization performance. © 2006 IEEE. Source


Chen S.,Nanjing Southeast University | Soto-Crespo J.M.,CSIC - Institute of Optics | Grelu P.,R.A.U.M.
Optics Express | Year: 2015

We investigate the resonant interaction of three optical pulses of different group velocity in quadratic media and report on the novel watch-hand-like super rogue wave patterns. In addition to having a giant wall-like hump, each rogue-wave hand involves a peak amplitude more than five times its background height. We attribute such peculiar structures to the nonlinear superposition of six Peregrine-type solitons. The robustness has been confirmed by numerical simulations. This stability along with the non-overlapping distribution property may facilitate the experimental diagnostics and observation of these super rogue waves. © 2015 Optical Society of America. Source


Liu Q.,Nanjing Southeast University | Guo Z.,University of North Carolina at Chapel Hill | Wang J.,Chinese University of Hong Kong
Neural Networks | Year: 2012

In this paper, a one-layer recurrent neural network is proposed for solving pseudoconvex optimization problems subject to linear equality and bound constraints. Compared with the existing neural networks for optimization (e.g., the projection neural networks), the proposed neural network is capable of solving more general pseudoconvex optimization problems with equality and bound constraints. Moreover, it is capable of solving constrained fractional programming problems as a special case. The convergence of the state variables of the proposed neural network to achieve solution optimality is guaranteed as long as the designed parameters in the model are larger than the derived lower bounds. Numerical examples with simulation results illustrate the effectiveness and characteristics of the proposed neural network. In addition, an application for dynamic portfolio optimization is discussed. © 2011 Elsevier Ltd. Source


Zeng H.,Nanjing Southeast University
Sensors (Basel, Switzerland) | Year: 2013

Ocular contamination of EEG data is an important and very common problem in the diagnosis of neurobiological events. An effective approach is proposed in this paper to remove ocular artifacts from the raw EEG recording. First, it conducts the blind source separation on the raw EEG recording by the stationary subspace analysis, which can concentrate artifacts in fewer components than the representative blind source separation methods. Next, to recover the neural information that has leaked into the artifactual components, the adaptive signal decomposition technique EMD is applied to denoise the components. Finally, the artifact-only components are projected back to be subtracted from EEG signals to get the clean EEG data. The experimental results on both the artificially contaminated EEG data and publicly available real EEG data have demonstrated the effectiveness of the proposed method, in particular for the cases where limited number of electrodes are used for the recording, as well as when the artifact contaminated signal is highly non-stationary and the underlying sources cannot be assumed to be independent or uncorrelated. Source


Liang J.,Nanjing Southeast University | Wang Z.,Brunel University | Liu X.,Brunel University
International Journal of Robust and Nonlinear Control | Year: 2012

In this paper, the distributed state estimation problem is investigated for a class of sensor networks described by uncertain discrete-time dynamical systems with Markovian jumping parameters and distributed time-delays. The sensor network consists of sensor nodes characterized by a directed graph with a nonnegative adjacency matrix that specifies the interconnection topology (or the distribution in the space) of the network. Both the parameters of the target plant and the sensor measurements are subject to the switches from one mode to another at different times according to a Markov chain. The parameter uncertainties are norm-bounded that enter into both the plant system as well as the network outputs. Furthermore, the distributed time-delays are considered, which are also dependent on the Markovian jumping mode. Through the measurements from a small fraction of the sensors, this paper aims to design state estimators that allow the nodes of the sensor network to track the states of the plant in a distributed way. It is verified that such state estimators do exist if a set of matrix inequalities is solvable. A numerical example is provided to demonstrate the effectiveness of the designed distributed state estimators. © 2011 John Wiley & Sons, Ltd. Source


Chen Q.,Nanjing Southeast University | Pugno N.M.,University of Trento
Journal of the Mechanical Behavior of Biomedical Materials | Year: 2013

Natural selection and evolution develop a huge amount of biological materials in different environments (e.g. lotus in water and opuntia in desert). These biological materials possess many inspiring properties, which hint scientists and engineers to find some useful clues to create new materials or update the existing ones. In this review, we highlight some well-studied (e.g. nacre shell) and newly-studied (e.g. turtle shell) natural materials, and summarize their hierarchical structures and mechanisms behind their mechanical properties, from animals to plants. These fascinating mechanisms suggest to researchers to investigate natural materials deeply and broadly, and to design or fabricate new bio-inspired materials to serve our life. © 2012 Elsevier Ltd. Source


Xue P.,Nanjing Southeast University | Sanders B.C.,University of Calgary
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We show that the standard quantum-walk quantum-to-classical transition, characterized by ballistic-to-diffusive spreading of the walker's position, can be controlled by externally modulating the coin state. We illustrate this by showing an oscillation between classical diffusive and quantum ballistic spreading using numerical and asymptotically exact closed-form solutions, and we prove that the walker is in a controllable incoherent mixture of classical and quantum walks with a reversible quantum-to-classical transition. © 2013 American Physical Society. Source


Hu H.,Nanjing Southeast University
Sensors (Basel, Switzerland) | Year: 2014

Sliding tactile perception is a basic function for human beings to determine the mechanical properties of object surfaces and recognize materials. Imitating this process, this paper proposes a novel finger-shaped tactile sensor based on a thin piezoelectric polyvinylidene fluoride (PVDF) film for surface texture measurement. A parallelogram mechanism is designed to ensure that the sensor applies a constant contact force perpendicular to the object surface, and a 2-dimensional movable mechanical structure is utilized to generate the relative motion at a certain speed between the sensor and the object surface. By controlling the 2-dimensional motion of the finger-shaped sensor along the object surface, small height/depth variation of surface texture changes the output charge of PVDF film then surface texture can be measured. In this paper, the finger-shaped tactile sensor is used to evaluate and classify five different kinds of linen. Fast Fourier Transformation (FFT) is utilized to get original attribute data of surface in the frequency domain, and principal component analysis (PCA) is used to compress the attribute data and extract feature information. Finally, low dimensional features are classified by Support Vector Machine (SVM). The experimental results show that this finger-shaped tactile sensor is effective and high accurate for discriminating the five textures. Source


Zhao W.,Nanjing Southeast University
American Journal of Tropical Medicine and Hygiene | Year: 2010

Secondary or reactive hemophagocytic syndrome (HPS) is frequently related to viral infections. However, the novel swine-origin influenza A (H1N1) virus associated HPS has never been reported. On October 10, 2009, a 17-year-old female child with no past medical history, complaining of severe asthenia, pneumonia, myalgia, and high fever, was admitted to our department, and H1N1 DNA was detected. Five days after her hospitalization, all signs and symptoms aggravated into HPS. After treatment for H1N1 influenza, the patient had a recovery and clearance of H1N1 infection 10 days after hospitalization. Three weeks later, the patient was discharged without any complaints, indicating the etiological role of H1N1infection in HPS. Copyright © 2010 by The American Society of Tropical Medicine and Hygiene. Source


Behrman J.R.,University of Pennsylvania | Xiong Y.,Nanjing Southeast University | Zhang J.,Chinese University of Hong Kong
Social Science and Medicine | Year: 2015

Adult health outcomes and health behaviors are often associated with schooling. However, such associations do not necessarily imply that schooling has causal effects on health with the signs or magnitudes found in the cross-sectional associations. Schooling may be proxying for unobserved factors related to genetics and family background that directly affect both health and schooling. Recently several studies have used within-monozygotic (MZ) twins methods to control for unobserved factors shared by identical twins. Within-MZ estimates for developed countries are generally smaller than suggested by cross-sectional associations, consistent with positive correlations between unobserved factors that determine schooling and those that determine health. This study contributes new estimates of cross-sectional associations and within-MZ causal effects using the Chinese Adults Twins Survey, the first study of its type for developing countries. The cross-sectional estimates suggest that schooling is significantly associated with adult health-related behaviors (smoking, drinking, exercising) but not with own or spouse health outcomes (general health, mental health, overweight, chronic diseases). However, within-MZ-twins estimators change the estimates for approximately half of these health indicators, in one case declining in absolute magnitudes and becoming insignificant and in the other cases increasing in absolute magnitudes. Within-MZ estimates indicate significant pro-health effects for at least one of the indicators for own health (better mental health), own health-related behaviors (less smoking) and spouse health (less overweight). © 2014 Elsevier Ltd. Source


Peng D.,Nanchang University | Zhang X.,Nanjing Southeast University
Applied Energy | Year: 2011

Solar collector/regenerator (C/R) using liquid desiccant combines solar photothermic transformation and regeneration of liquid desiccant together, effectively achieving the regeneration for solar energy-driven liquid desiccant cooling systems. In this paper a group of dimensionless heat and mass transfer equations describing the heat and mass transfer process in the solar C/R were obtained by introducing total temperature difference (ΔT0) and dimensionless heat loss coefficient (hz). For the sake of predicting the heat loss of air stream and simplifying calculation, the models of dimensionless air temperature (θa) and equilibrium humidity ratio (YeL) along with the height of solar C/R were put forward. An analytical solution was formed by two differential equations on the dimensionless heat and mass transfer driving potentials and the heat and mass conservation equations. Compared with the numerical simulation results, the analytical results on the outlet parameters of solar C/R have great precision with different Lewis factor Le, total temperature difference ΔT0 and air-to salt mass flow rate ratio ASMR. Simultaneously, the effects of above variables on the regeneration performance were analyzed. Lastly, by comparing with the experimental data, the analytical calculation results can agree well with the experimental results validating the analytical model is an ideal way for predicting the performance of the solar C/R. © 2011 Elsevier Ltd. Source


Xu O.,Nanjing Southeast University
Journal of Electromagnetic Waves and Applications | Year: 2011

The genetic algorithm (GA) is applied to the optimization of a sub-millimeter wave horn-lens collimation equipment operating at 150 GHz, and measurement is carried out to validate the performance of the optimized geometry. The aperture-integration (AI) method is employed to formulate the fitness function of GA in dealing with complex field distribution from an arbitrary radiation source. A diagonal horn and the auxiliary lens are fabricated according to the GA-optimized geometry, and their radiation properties are measured employing a BWO (Backward-wave Oscillator) with a golay cell terahertz detector. The measurement indicates that the gain and near-field beam radius conform to the values predicted by GA. © 2011 VSP. Source


Jianguo C.,Nanjing Southeast University
Journal of Mechanisms and Robotics | Year: 2016

Rolling joints, which are created by attaching two cylindrical surfaces of equal radius using two or more thin tapes or cable, are used for rigid origami considering the panel thickness. First, the concept and two implementation methods of this joint are given. Then planar linkages are chosen to study the mobility and kinematics of foldable plate structures with rolling joints. It can be found that the rolling joints preserve the full-cycle-motion of foldable plate structures. From the closure equations of linkages, the results show that the outputs of linkages with rolling joints are the same as that with traditional revolute joints if the lengths of links are equal. However, the results are different when the lengths of links are unequal. Moreover, the difference between linkages with rolling joints and revolute joints increases with an increase of the size of rolling joints. © 2016 by ASME. Source


Zhu Q.,Ningbo University | Cao J.,Nanjing Southeast University
Neurocomputing | Year: 2011

In this paper, we study a new class of stochastic Cohen-Grossberg neural networks with reaction-diffusion and mixed delays. Without the aid of nonnegative semimartingale convergence theorem, the method of variation parameter and linear matrix inequalities technique, a set of novel sufficient conditions on the exponential stability for the considered system is obtained by utilizing a new Lyapunov-Krasovskii functional, the Poincaré inequality and stochastic analysis theory. The obtained results show that the reaction-diffusion term does contribute to the exponentially stabilization of the considered system. Therefore, our results generalize and improve some earlier publications. Moreover, two numerical examples are given to show the effectiveness of the theoretical results and demonstrate that the stability criteria existed in the earlier literature fail. © 2011 Elsevier B.V. Source


Wang H.,Nanjing Southeast University
Neural Networks | Year: 2012

Subspace learning is a core issue in pattern recognition and machine learning. Linear graph embedding (LGE) is a general framework for subspace learning. In this paper, we propose a structured sparse extension to LGE (SSLGE) by introducing a structured sparsity-inducing norm into LGE. Specifically, SSLGE casts the projection bases learning into a regression-type optimization problem, and then the structured sparsity regularization is applied to the regression coefficients. The regularization selects a subset of features and meanwhile encodes high-order information reflecting a priori structure information of the data. The SSLGE technique provides a unified framework for discovering structured sparse subspace. Computationally, by using a variational equality and the Procrustes transformation, SSLGE is efficiently solved with closed-form updates. Experimental results on face image show the effectiveness of the proposed method. © 2011 Elsevier Ltd. Source


Most computational algorithms mainly focus on detecting highly connected subgraphs in PPI networks as protein complexes but ignore their inherent organization. Furthermore, many of these algorithms are computationally expensive. However, recent analysis indicates that experimentally detected protein complexes generally contain Core/attachment structures. In this paper, a Greedy Search Method based on Core-Attachment structure (GSM-CA) is proposed. The GSM-CA method detects densely connected regions in large protein-protein interaction networks based on the edge weight and two criteria for determining core nodes and attachment nodes. The GSM-CA method improves the prediction accuracy compared to other similar module detection approaches, however it is computationally expensive. Many module detection approaches are based on the traditional hierarchical methods, which is also computationally inefficient because the hierarchical tree structure produced by these approaches cannot provide adequate information to identify whether a network belongs to a module structure or not. In order to speed up the computational process, the Greedy Search Method based on Fast Clustering (GSM-FC) is proposed in this work. The edge weight based GSM-FC method uses a greedy procedure to traverse all edges just once to separate the network into the suitable set of modules. The proposed methods are applied to the protein interaction network of S. cerevisiae. Experimental results indicate that many significant functional modules are detected, most of which match the known complexes. Results also demonstrate that the GSM-FC algorithm is faster and more accurate as compared to other competing algorithms. Based on the new edge weight definition, the proposed algorithm takes advantages of the greedy search procedure to separate the network into the suitable set of modules. Experimental analysis shows that the identified modules are statistically significant. The algorithm can reduce the computational time significantly while keeping high prediction accuracy. Source


Wang L.,Baylor College of Medicine | Wang S.,Nanjing Southeast University | Li W.,Baylor College of Medicine
Bioinformatics | Year: 2012

Motivation: RNA-seq has been extensively used for transcriptome study. Quality control (QC) is critical to ensure that RNA-seq data are of high quality and suitable for subsequent analyses. However, QC is a time-consuming and complex task, due to the massive size and versatile nature of RNA-seq data. Therefore, a convenient and comprehensive QC tool to assess RNA-seq quality is sorely needed.Results: We developed the RSeQC package to comprehensively evaluate different aspects of RNA-seq experiments, such as sequence quality, GC bias, polymerase chain reaction bias, nucleotide composition bias, sequencing depth, strand specificity, coverage uniformity and read distribution over the genome structure. RSeQC takes both SAM and BAM files as input, which can be produced by most RNA-seq mapping tools as well as BED files, which are widely used for gene models. Most modules in RSeQC take advantage of R scripts for visualization, and they are notably efficient in dealing with large BAM/SAM files containing hundreds of millions of alignments. © The Author (2012). Published by Oxford University Press. All rights reserved. Source


Lin J.R.,Nanjing Southeast University
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

In the title salt, C8H9N2+·C7H7O3S -·H2O, the dihedral angle between the cation and anion benzene rings is 50.1 (4)°. In the cation, the Cyanomethyl group is twisted from the plane of the benzene ring [C-C-C-N =-86 (12)°]. In the crystal, the cations, anions and water molecules are linked by N-H⋯O and O-H⋯O hydrogen bonds, forming a chain along the c axis. Source


Wang G.,Nanjing Southeast University
Proceedings - 2011 3rd International Conference on Communications and Mobile Computing, CMC 2011 | Year: 2011

This paper analyzes the form of two data serializing approaches used in web applications, XML and JSON. Considering that though both widely used, highly-efficient data transmission between these two methods is still a problem in application development. The features of these two data objects were analyzed and it was point out that how to translate correctly between these two objects. A recursive algorithm used to translate between these two types of data serializing forms was given based on the multi-tree data structure of XML and JSON objects. The efficiency of this algorithm was proved by translation experiments. When applied in web applications, this paper gives how to add the translation method in system structures of the applications. It gives how this method can improve system structure and the performance of the web applications. © 2011 IEEE. Source


Zhou T.,University of Texas at Austin | Gu W.,Nanjing Southeast University | Wilke C.O.,University of Texas at Austin
Molecular Biology and Evolution | Year: 2010

We present a new computational method to identify positive and purifying selection at synonymous sites in yeast and worm. We define synonymous substitutions that change codons from preferred to unpreferred or vice versa as nonconservative synonymous substitutions and all other substitutions as conservative. Using a maximum-likelihood framework, we then test whether conservative and nonconservative synonymous substitutions occur at equal rates. Our approach replaces the standard rate of synonymous substitutions per synonymous site, dS, with two new rates, the conservative synonymous substitution rate (dSC) and the nonconservative synonymous substitution rate (dSN). Based on the ratio dSN/dSC, we find that 0.05% of all yeast genes and none of worm genes show evidence of positive selection at synonymous sites (dSN/dSC > 1). On the other hand, 9.44% of all yeast genes and 5.12% of all worm genes show evidence of significant purifying selection on synonymous sites (dSN/dSC < 1). We also find that dSN correlates strongly with gene expression level, whereas the correlation between expression level and dSC is very weak. Thus, dSN captures most of the signal of selection for translational accuracy and speed, whereas dSC is not strongly influenced by this selection pressure. We suggest that the ratio dN/dSC may be more appropriate than the ratio dN/dS to identify positive or purifying selection on amino acids. © The Author 2010. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. Source


Chen J.,Nanjing Southeast University
Acta Crystallographica Section E: Structure Reports Online | Year: 2010

The title compound, C23H35BrO3, synthesized by esterification and bromination of isosteviol, comprises a fused four-ring system. Two of the six-membered rings adopt a regular chair conformation, whereas the remaining six-membered ring is an unsymmetrical distorted chair. The stereochemistry at the two six-membered ring junctions is trans, while the five-membered ring adopts an envelope conformation. Source


Wang J.,University of Connecticut | Gao R.X.,University of Connecticut | Yan R.,Nanjing Southeast University
Wind Energy | Year: 2014

Gearbox failure becomes a major concern for reliability of wind turbine because of complex repair procedures, long downtime and high replacement costs. Prior studies showed that the majority of gearbox failures were initiated from bearing failures. Because of the low signal-to-noise ratio (mixture of bearing defect signals and gear meshing signals) and transient nature of bearing signals, it poses significant difficulty for bearing defect diagnosis in wind turbine gearbox at the incipient stage. To address it, this paper presents an effective fault component separation method that integrates ensemble empirical mode decomposition (EEMD; an adaptive signal decomposition method in time-frequency domain) with independent component analysis (ICA; a blind source separation technique), without requiring a priori information on the rotating speeds or bandwidth. The method firstly decomposes one-channel vibration measurements into a series of intrinsic mode functions as pseudo-multi-channel signals, by means of EEMD. ICA is performed on the intrinsic mode functions to separate bearing defect-related signals from gear meshing signals. Envelope spectrum analysis is performed on the bearing defect-related signals to identify bearing structural defects. The effectiveness of the developed method in separating bearing defect-related signals from gear meshing signals for more effective fault diagnosis in bearings is evaluated and confirmed, numerically and experimentally. Copyright © 2013 John Wiley & Sons, Ltd. Source


Liu Y.,Zhejiang Normal University | Lu J.,Nanjing Southeast University | Wu B.,Zhejiang Normal University
ESAIM - Control, Optimisation and Calculus of Variations | Year: 2014

This paper investigates the output controllability problem of temporal Boolean networks with inputs (control nodes) and outputs (controlled nodes). A temporal Boolean network is a logical dynamic system describing cellular networks with time delays. Using semi-tensor product of matrices, the temporal Boolean networks can be converted into discrete time linear dynamic systems. Some necessary and sufficient conditions on the output controllability via two kinds of inputs are obtained by providing corresponding reachable sets. Two examples are given to illustrate the obtained results. © 2014 EDP Sciences, SMAI . Source


Xu L.Q.,National University of Singapore | Neoh K.-G.,National University of Singapore | Kang E.-T.,National University of Singapore | Fu G.D.,Nanjing Southeast University
Journal of Materials Chemistry A | Year: 2013

Mercury pollution is a widespread problem. In this work, a solid-state sensor based on rhodamine derivative-modified cellulose filter papers for detection of Hg2+ ions in aqueous media is demonstrated. A three-step approach, involving the introduction of atom transfer radical polymerization (ATRP) initiating sites, surface-initiated ATRP (SI-ATRP) of pentafluorophenyl methacrylate, and post-functionalization of the reactive surface with amino-containing spirolactam rhodamine derivatives in ester-amine reaction, was developed for the covalent immobilization of mercury-responsive probes on the cellulose filter paper. This solid-state sensor exhibits highly selective recognition of Hg2+ ions in a Tris-HNO3 buffer solution (pH = 7.24) over various environmentally relevant metal ions with remarkably enhanced fluorescent emission intensity and distinct color change from colorless to pink. The response of a rhodamine derivative-modified cellulose filter paper to Hg2+ ions is fast (<2 min). The positive fluorescence response and color change of this functionalized filter paper thus provide a disposable solid-state sensor for fluorescent and "naked-eye" detection of Hg2+ ions. © 2013 The Royal Society of Chemistry. Source


Xue P.,Nanjing Southeast University | Sanders B.C.,University of Calgary
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We consider two independent quantum walks on separate lines augmented by partial or full swapping of coins after each step. For classical random walks, swapping or not swapping coins makes little difference to the random-walk characteristics, but we show that quantum walks with partial swapping of coins have complicated yet elegant interwalker correlations. Specifically we study the joint position distribution of the reduced two-walker state after tracing out the coins and analyze total, classical, and quantum correlations in terms of mutual information, quantum mutual information, and measurement-induced disturbance. Our analysis shows intriguing quantum features without classical analogs. © 2012 American Physical Society. Source


Xue P.,Nanjing Southeast University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

We study the spin-squeezing property of weighted graph states, which can be used to improve the sensitivity in interferometry. Decoherence reduces the spin-squeezing property but the result remains superior over other reference schemes with Greenberger-Horne-Zeilinger (GHZ) type maximally entangled states and product states. We study the time evolution of spin squeezing of weighted graph states coupled to different decoherence channels. Based on the analysis, the spin squeezing of the weighted graph states is robust in the presence of decoherence, and the decoherence limit in the improvement of the interferometric sensitivity is still achievable. © 2012 American Physical Society. Source


Wang S.,Nanjing Southeast University
Applied Categorical Structures | Year: 2013

For a group G, we describe a new construction of a Turaev braided G-category with a particular braided monoidal subcategory and then we study the structure of a Hopf algebra in this subcategory. As an application, we establish a generalized G-Schur-Weyl duality between certain Turaev G-algebra and the symmetric group algebra. © 2011 Springer Science+Business Media B.V. Source


Background: It has been reported that Internet addiction is associated with substance dependence. Eating disorders have high rates of co-morbidity with substance use disorders. The relationship between Internet addiction and eating disorders was reported in a previous study. Aims: To examine the hypothesis that Internet addiction is closely associated with bulimia. The hypothesis that depression mediates the relationship between Internet addiction and bulimia symptoms was also tested. Methods: 2,036 Chinese college students were assessed on Internet addiction, eating behaviors and depression. Binge eating, compensatory behaviors, weight concern, menarche and weight change were also reported. Multiple regression analysis was used to test the mediating effect of depression. Results: Internet addicts showed significantly higher scores on most subscales on EDI-1 than the controls. They reported significantly more binge eating, weight concern and weight change than the controls. Among all of the participants, depression was found to be a partial mediator in the relationship between Internet addiction and bulimia. Conclusion: This survey provides evidence of the co-morbidity of Internet addiction and bulimia. © 2013 Springer International Publishing Switzerland. Source


Pan J.,Nanjing Southeast University | Wu Y.-F.,City University of Hong Kong
Composites Part B: Engineering | Year: 2014

The bonding of FRP plate on the tensile side of concrete members has been accepted as an effective and efficient technology for improving the strength and stiffness of concrete structures. Intermediate crack induced debonding is a common failure mode for FRP strengthened concrete beams. This kind of failure mode can be studied with direct shear test, which involves a FRP plate bonded on a concrete prism with a stretching force acting on one end of the plate. To investigate the failure mechanism of the plate-to-concrete joint, a simplified bond slip model with a linear ascending segment and an exponential softening segment is proposed for the plate-to-concrete interface. With the bond-slip model, the closed-form solutions for the tensile stress in FRP plate, interfacial shear stress and displacement of the FRP plate are derived and verified with experimental results. With the analytical model, a theoretical model is proposed for calculating the effective bond length of a plate-to-concrete joint. Effect of different parameters including stiffness of FRP plate, interfacial fracture energy and interfacial shear strength on the effective bond length are comprehensively studied. Finally, a simple analytical solution of the bond strength for the cases with bond length smaller than the effective bond length is derived and compared with the complicated closed-form solution reported in the literature. © 2014 Elsevier Ltd. All rights reserved. Source


Park B.,KAIST | An Y.-K.,Nanjing Southeast University | Sohn H.,KAIST
Composites Science and Technology | Year: 2014

This study proposes a complete noncontact laser ultrasonic wavefield imaging technique to automatically detect and visualize hidden delamination and debonding in composite structures. First, ultrasonic wavefield is obtained from a target structure by scanning a Nd:YAG pulse laser beam for ultrasonic wave generation and measuring the corresponding ultrasonic responses using a laser Doppler vibrometer. Then, hidden damages are identified and visualized through adoption of a standing wave filter, which can isolate damage-induced standing waves from the obtained wavefield. The proposed technique has following advantages over the existing techniques: (1) it does not require any sensor installation; (2) it is noninvasive, rapidly deployable and applicable to harsh environments; and (3) it can visualize damage with high spatial resolution without any baseline data, which enables automated and intuitive damage diagnosis. The feasibility of the proposed technique is demonstrated by visualizing a debonding in a carbon fiber reinforced plastic aircraft wing and a delamination in a glass fiber reinforced plastic wind turbine blade. Furthermore, the effects of temperature and static loading variations on the proposed technique are also examined. © 2014 Elsevier Ltd. Source


Xu Z.,Nanjing Southeast University | Xu Z.,Nanjing University of Science and Technology
IEEE Transactions on Fuzzy Systems | Year: 2012

We investigate multiattribute decision-making problems, where the attribute values are intuitionistic fuzzy values, and the weight information on attributes cannot be known completely. We first define the concepts of the overall attribute ideal solution and the overall attribute negative ideal solution of alternatives. Based on these two solutions, we define the satisfaction degree of each alternative. After that, we establish a multiobjective optimization model and then transform it into a single-objective optimization model. Furthermore, we establish an interactive method for multiattribute decision making with intuitionistic fuzzy information. A numerical example is also given to illustrate the solution processes of our methods. Finally, the extended results in interval-valued intuitionistic fuzzy situations are also pointed out. © 2012 IEEE. Source


Sun Z.,CAS Fujian Institute of Research on the Structure of Matter | Luo J.,CAS Fujian Institute of Research on the Structure of Matter | Chen T.,CAS Fujian Institute of Research on the Structure of Matter | Li L.,CAS Fujian Institute of Research on the Structure of Matter | And 3 more authors.
Advanced Functional Materials | Year: 2012

Molecular motion associated with rotational and orientational phase transitions is one of the prominent structural strategies for assembling the functional materials such as artificial motors and tunable molecular dielectrics. Here, a new organic chromophore molecule, 4-N,N-dimethylamino-4'- N'-methylstilbazolium trifluoromethanesulfonate (complex 1), which undergoes an exceptional order-disorder phase transition at 322 K, is successfully synthesized. The single crystal X-ray diffraction analysis, thermal analysis, and dielectric measurements are used to characterize its dielectric dynamic behaviors. The results reveal that 1 behaves as a molecular rotator with the obviously distorted bipyramidal geometry of trifluoromethanesulfonate anions. In addition to its disorderings, two very distinct motions of the anionic moieties are confirmed, namely the "earth rotation" of partial units and the "earth revolution" of the whole molecule. Such unique molecular motions are found to be mainly responsible for the order-disorder phase transition together with the abrupt dielectric anomaly and anisotropy. The charge-transfer cationic parts enhance the molecular motions behaving as the stator and give rise to its excellent third-order nonlinearities. The concept may allow for the remote control of molecular events to explore functional materials in organic chromophores. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Xu Z.,Nanjing Southeast University | Xu Z.,PLA University of Science and Technology
Fuzzy Optimization and Decision Making | Year: 2012

Xu and Chen (J Syst Sci Syst Eng 17:432-445,2008) introduced a type of ordered weighted distance measures called ordered weighted distance (OWD) measures whose fundamental aspect is the reordering step, which can be used in many actual fields, including group decision making, medical diagnosis, data mining, and pattern recognition, etc. The OWD measures are very suitable to deal with situations where the input data are expressed in exact numerical values. In this paper, we consider situations with linguistic, interval or fuzzy preference information, and develo p some fuzzy ordered distance measures, such as linguistic ordered weighted distance measure, uncertain ordered weighted distance measure, linguistic hybrid weighted distance measure, and uncertain hybrid weighted distance measure, etc. After that based on hybrid weighted distance measures, we establish a consensus reaching pro cess of group decision making with linguistic, interval, triangular or trapezoidal fuzzy preference information. © Springer Science+Business Media, LLC 2011. Source


Liu L.,Nanjing Southeast University
Zhonghua nei ke za zhi [Chinese journal of internal medicine] | Year: 2012

To investigate the effect of stress dose glucocorticoid on patients with acute respiratory distress syndrome (ARDS) combined with critical illness-related corticosteroid insufficiency (CIRCI). All early ARDS patients combined with CIRCI were screened by an adrenal corticotrophic hormone (ACTH) test and randomly divided into treatment group (hydrocortisone 100 mg intravenous, 3 times/day, consecutively for 7 days, n = 12) and control group (equivalent normal saline, n = 14). General clinical data, changes of arterial blood gas, hemodynamics and respiratory mechanics were observed and recorded at admission and at 7 days after treatment. Ventilator-free and shock-free days, ICU stay within 28 days after admission were recorded and 28-day mortality was used as judge prognosis index. CIRCI rate in 45 early ARDS patients was 57.8% (26 patients), and the shock rate was markedly higher in ARDS patients with CIRCI than patients without CIRCI (46.2% vs 5/19). There were no significant differences in baseline parameters, oxygenation and illness severity between the treatment and control groups, except for markedly lower lactic level in the treatment group [2.7(1.2, 3.9) mmol/L vs 4.6(2.5, 6.3) mmol/L, P < 0.05]. After 7 days of treatment, PaO2/FiO2 markedly increased, while heart rate obviously decreased in the both groups. Compared with the control group, survival time of patients was significantly longer and shock rate of the patients was markedly lower in treatment group within 28 days (5/12 vs 10/14, P < 0.05). The 28-day mortality, which were adjusted by baseline arterial lactic, was lower in the treatment group (2.6/12) than in the control group (5.8/14) while with no significant difference (P > 0.05). There was no significant difference in complication incidence between the two groups. Stress dose glucocorticoid could reduce shock incidence and prolong survival time, and has a tendency of lower 28-day mortality in early ARDS patients combined with CIRCI. Source


Zhou W.,Yunnan University of Finance and Economics | He J.-M.,Nanjing Southeast University
International Journal of Intelligent Systems | Year: 2012

As a useful aggregation technique, the Bonferroni mean (BM) can capture the interrelationship between input arguments and has been a hot research topic recently. Based on the classic BM, many BM operators have been proposed and developed, such as the weighted BM, the generalized BM, the intuitionistic fuzzy BM, and so on. However, these BM operators are all based on the averaging mean, which is one of the basic aggregation approaches and focuses on the group opinion and another basic one is the geometric mean, which gives more importance to the individual opinions. To combine with the geometric mean and the BM, in this paper, we propose the geometric BM, the weighted geometric BM, and the generalized weighted geometric BM. These new geometric BMs can reflect the geometric interrelationship between the individual criterion and other criteria and keep the main advantage of BM. Furthermore, we investigate the geometric BMs under the intuitionistic fuzzy environment, which is more common phenomenon in modern life and develop three intuitionistic fuzzy geometric Bonferroni mean operators, i.e., the intuitionistic fuzzy geometric Bonferroni mean (IFGBM), the intuitionistic fuzzy weighted geometric Bonferroni mean (IFWGBM), and the intuitionistic fuzzy generalized weighted geometric Bonferroni mean (IFGWGBM) and study their desirable properties, such as idempotency, commutativity, monotonicity, and boundedness. Finally, on the basis of the IFWGBM and IFGWGBM operators, we propose an approach to multicriteria decision making under the intuitionistic fuzzy environment, and a practical example is provided to illustrate our results. © 2012 Wiley Periodicals, Inc. Source


Liu Z.-G.,Nanjing Southeast University
Journal of Infrared, Millimeter, and Terahertz Waves | Year: 2010

Fabry-Perot Resonator (FPR) antennas have attracted significant attention in microwave and millimeter waves due to a number of attractive properties, such as low complexity, high directivity and conformal deployment capability. In this paper, a summary of recent publications on FPR antenna is presented focusing on the different capabilities, technologies and architectures that have been proposed. Several structures, analytic models and research developments and a corresponding comparison are also made. It shows that such analytic models as FP cavity model, EBG defect model, transmission line model, leaky wave model and refractive lens model are consistent when applied to analyze this type of resonator antenna. Some interesting topics under recent research are surveyed in detail. At the same time some attractive topics to be further researched are also pointed out. Recent works of the authors are also included in this paper. © 2009 Springer Science+Business Media, LLC. Source


Gao H.,Qingdao University | Deng L.,Nanjing Southeast University
Cell Biochemistry and Biophysics | Year: 2014

Multi-target tyrosine kinase inhibitor Sunitinib has been widely used in cancer treatment, including metastatic renal cell carcinoma. However, most patients who initially benefit from Sunitinib develop resistance with extended usage of Sunitinib, which is referred to as "acquired resistance". The molecular mechanisms contributing to this acquired resistance remain poorly understood. In this present study, we established Sunitinib-resistant cell lines from human renal cell lines (786-O, A498, ACHN and CAKI1) by continuous treatment with Sunitinib to explore the molecular mechanism leading to Sunitinib resistance. We found that PDGFR-β expression in cell seems to be a protective factor against Sunitinib resistance formation. In addition, we found that both SK1 and ERK were activated in Sunitinib-resistance cell lines and SK1 and ERK inhibitors could resensitize Sunitinib-resistant cell lines. In conclusion, our observations suggest that SK1 and ERK activation is a feature of resistant cell lines, which serves as an alternative pathway evading anti-tumor activity of Sunitinib. © 2013 Springer Science+Business Media New York. Source


Li M.,Nanjing Southeast University
International Journal of Computer Mathematics | Year: 2012

This paper proposes a hybrid LQP-based method (LQP, logarithmic-quadratic proximal) to solve a class of structured variational inequalities. In this method, an intermediate point is produced by solving a nonlinear equation system based on the LQP method; a descent direction is constructed using this iterate and the new iterate is obtained by a convex combination of the previous point and the one generated by a projection-type method along this descent direction. Global convergence of the new method is proved under mild assumptions. Preliminary numerical results for traffic equilibrium problems verify the computational preferences of the new method. © 2012 Copyright Taylor and Francis Group, LLC. Source


Wu H.,Nanjing University of Technology | Wang S.,Nanjing Southeast University
Journal of Hazardous Materials | Year: 2012

An experiment was conducted in a batch reactor for a real printing and dyeing wastewater pretreatment using Fenton process in this study. The results showed that original pH, hydrogen peroxide concentration and ferrous sulfate concentration affected ORP value and pretreatment efficacy greatly. Under experimental conditions, the optimal original pH was 6.61, and the optimal hydrogen peroxide and ferrous sulfate concentrations were 1.50 and 0.75gL-1, respectively. The relationship among ORP, original pH, hydrogen peroxide concentration, ferrous sulfate concentration, and color (COD or BOD5/COD) was established, which would be instructive in on-line monitoring and control of Fenton process using ORP. In addition, the effects of wastewater temperature and oxidation time on pretreatment efficacy were also investigated. With an increase of temperature, color and COD removal efficiencies and BOD5/COD ratio increased, and they were in proportion to the exponent of temperature reciprocal. Similarly, color and COD removal efficiencies increased with increasing oxidation time, and both color and COD removal obeyed the first-order kinetics. The BOD5/COD ratio could be expressed by a second-degree polynomial with respect to oxidation time, and the best biodegradability of wastewater was present at the oxidation time of 6.10h. © 2012 Elsevier B.V. Source


Wang W.,Nanjing Southeast University | Liu X.,Beijing Jiaotong University
IEEE Transactions on Fuzzy Systems | Year: 2012

Aggregation of fuzzy information is a new branch of Atanassovs intuitionistic fuzzy set (AIFS) theory, which has attracted significant interest from researchers in recent years. In this paper, we treat the intuitionistic fuzzy aggregation operators with the help of Einstein operations. We first introduce some new operations of AIFSs, such as Einstein sum, Einstein product, and Einstein scalar multiplication. Then, we develop some intuitionistic fuzzy aggregation operators, such as the intuitionistic fuzzy Einstein weighted averaging operator and the intuitionistic fuzzy Einstein ordered weighted averaging operator, which extend the weighted averaging operator and the ordered weighted averaging operator to aggregate Atanassovs intuitionistic fuzzy values, respectively. We further establish various properties of these operators and analyze the relations between these operators and the existing intuitionistic fuzzy aggregation operators. Moreover, we give some numerical examples to illustrate the developed aggregation operators. Finally, we apply the intuitionistic fuzzy Einstein weighted averaging operator to multiple attribute decision making with intuitionistic fuzzy information. © 2012 IEEE. Source


Jia R.,University of Texas at San Antonio | Qian C.,University of Texas at San Antonio | Zhai J.,Nanjing Southeast University
IET Control Theory and Applications | Year: 2012

This study considers the problem of semi-global finite-time stabilisation by output feedback for a class of uncertain non-linear systems with both higher-order and lower-order terms, to which the existing design schemes are inapplicable. Based on the homogeneous domination approach, a scaled homogeneous output feedback controller is constructed to semi-globally stabilise the system in a finite time by choosing an appropriate gain. The proposed approach not only achieves finite-time convergence, but also widens the applicability to broader classes of systems with mixed-order non-linearities and a non-triangular structure. © 2011 The Institution of Engineering and Technology. Source


Qian C.,Nanjing Southeast University
Chaos (Woodbury, N.Y.) | Year: 2011

In this paper, we present an efficient opinion control strategy for complex networks, in particular, for social networks. The proposed adaptive bridge control (ABC) strategy calls for controlling a special kind of nodes named bridge and requires no knowledge of the node degrees or any other global or local knowledge, which are necessary for some other immunization strategies including targeted immunization and acquaintance immunization. We study the efficiency of the proposed ABC strategy on random networks, small-world networks, scale-free networks, and the random networks adjusted by the edge exchanging method. Our results show that the proposed ABC strategy is efficient for all of these four kinds of networks. Through an adjusting clustering coefficient by the edge exchanging method, it is found out that the efficiency of our ABC strategy is closely related with the clustering coefficient. The main contributions of this paper can be listed as follows: (1) A new high-order social network is proposed to describe opinion dynamic. (2) An algorithm, which does not require the knowledge of the nodes' degree and other global/local network structure information, is proposed to control the "bridges" more accurately and further control the opinion dynamics of the social networks. The efficiency of our ABC strategy is illustrated by numerical examples. (3) The numerical results indicate that our ABC strategy is more efficient for networks with higher clustering coefficient. Source


Yao X.,Nanjing Southeast University
Journal of Physical Chemistry A | Year: 2012

It was recently observed by He et al. [ J. Am. Chem. Soc. 2009, 131, 7554 ] that the monoclinic CoV 2O 6 shows an unusual magnetic behavior with a magnetization plateau at the height of 1/3 saturated magnetization, and the critical magnetic field for the second jump in magnetization is about 2 times as large as that for the first one. By using the Wang-Landau simulation, we show that this stepwise magnetic behavior can be well reproduced in a distorted antiferromagnetic triangular model with anisotropic exchange interactions. The 1/3 magnetization plateau here originates from the same ferrimagnetic state as observed in the regular triangular system, but the critical fields show different features due to the frustration relaxed by anisotropy. The relative value of the weakest interaction plays a key role in this stepwise magnetic behavior, and hereby the critical fields of the magnetization plateau can be accurately modulated by tuning exchange interactions, which provides a wide-use principle for the phenomena of 1/3 magnetization plateau observed in experiments. © 2012 American Chemical Society. Source


Chiu L.,Nanjing Southeast University | Xue Q.,City University of Hong Kong
IEEE Transactions on Microwave Theory and Techniques | Year: 2010

This paper presents a new class of wideband 90 ° hybrid coupler with an arbitrary coupling level. The physical size of the proposed coupler is close to that of a conventional two-section branch-line coupler, but it has an additional phase inverter. The impedance bandwidth of the proposed coupler is close to that of a four-section branch-line coupler. The proposed coupler is a backward-wave coupler with a port assignment different from that of a conventional branch-line coupler. The design formulas of the proposed coupler are proved based on its even- and odd-mode half structures. We demonstrated three couplers at the center frequency of 2 GHz with different design parameters. © 2006 IEEE. Source


Yang F.,Lanzhou University | Mei Z.L.,Lanzhou University | Yang X.Y.,Lanzhou University | Jin T.Y.,Lanzhou University | Cui T.J.,Nanjing Southeast University
Advanced Functional Materials | Year: 2013

The theoretical design and the first experimental verification of an exterior dc invisibility cloak that can hide an object from dc detection at a distance are presented. Based on the transformation optics theory, the exterior dc cloak requires negative conductivity material to create folded geometry, which will cancel the real geometry of detected object in distance and make it invisible. Negative conductivities are designed and realized using active devices, together with resistor networks, to generate the equivalent conductivity materials required by the exterior dc cloak. An experimental sample of the dc cloak is fabricated on the printed circuit board and the measured result has excellent agreement with numerical and circuit simulations, showing very good cloaking performance at a distance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Jia B.,Wuhan University | Mei Y.,Nanjing Southeast University | Cheng L.,Wuhan University | Zhou J.,Wuhan University | Zhang L.,Wuhan University
ACS Applied Materials and Interfaces | Year: 2012

Regenerated cellulose (RC) films coated with copper (Cu) nanoparticles were prepared from cellulose-cuprammonium solution through coagulation in aq. NaOH and subsequent reduction in aq. NaBH 4. Structure and morphology of the nanocomposite films were characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). The results established the migration of Cu 2+ from the inner to the surface of the RC films during the coagulation of cellulose-cuprammonium solution and the reduction from Cu 2+ to Cu 0. Cu nanoparticles were found to be firmly embedded on the surface of the RC films. The RC films coated with Cu nanoparticles showed efficient antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). The dramatic reduction of viable bacteria could be observed within 0.5 h of exposure, and all of the bacteria were killed within 1 h. © 2012 American Chemical Society. Source


Zhi Q.,Nanjing Southeast University | Cooperstock J.R.,McGill University
IEEE Transactions on Image Processing | Year: 2012

Mosaicing is largely dependent on the quality of registration among the constituent input images. Parallax and object motion present challenges to image registration, leading to artifacts in the result. To reduce the impact of these artifacts, traditional image mosaicing approaches often impose planar scene constraints or rely on purely rotational camera motion or dense sampling. However, these requirements are often impractical or fail to address the needs of all applications. Instead, taking advantage of depth cues and a smooth transition criterion, we achieve significantly improved mosaicing results for static scenes, coping effectively with nontrivial parallax in the input. We extend this approach to the synthesis of dynamic video mosaics, incorporating foreground/background segmentation and a consistent motion perception criterion. Although further additions are required to cope with unconstrained object motion, our algorithm can synthesize a perceptually convincing output, conveying the same appearance of motion as seen in the input sequences. © 2011 IEEE. Source


Zhao Y.,Peking University | Duan Z.,Peking University | Wen G.,Nanjing Southeast University
International Journal of Robust and Nonlinear Control | Year: 2015

This paper investigates the distributed finite-time tracking problem of networked agents with multiple Euler-Lagrange dynamics. To achieve finite-time tracking, a distributed finite-time protocol is first proposed on the basis of both relative position and relative velocity measurements. By using tools from homogeneous theory, it is theoretically shown that the proposed protocol can guarantee finite-time tracking in the presence of control input constraints. On the basis of the state feedback analysis and with the aid of second-order sliding-mode observer approach, a new class of finite-time tracking protocols based only on the relative position measurements is developed and employed. It is proved that the multiple agents equipped with the designed protocols can track the target location in finite time. Furthermore, a decentralized finite-time protocol based on a distributed estimator is proposed to solve the finite-time tracking problems with a dynamic leader. The effectiveness of the theoretical results is finally illustrated by numerical simulations. Copyright © 2014 John Wiley & Sons, Ltd. Source


Chen A.,Utah State University | Xu X.,Utah State University | Xu X.,Nanjing Southeast University
Expert Systems with Applications | Year: 2012

The transportation network design problem (NDP) with multiple objectives and demand uncertainty was originally formulated as a spectrum of stochastic multi-objective programming models in a bi-level programming framework. Solving these stochastic multi-objective NDP (SMONDP) models directly requires generating a family of optimal solutions known as the Pareto-optimal set. For practical implementation, only a good solution that meets the goals of different stakeholders is required. In view of this, we adopt a goal programming (GP) approach to solve the SMONDP models. The GP approach explicitly considers the user-defined goals and priority structure among the multiple objectives in the NDP decision process. Considering different modeling purposes, we provide three stochastic GP models with different philosophies to model planners' NDP decision under demand uncertainty, i.e.; the expected value GP model, chance-constrained GP model, and dependent-chance GP model. Meanwhile, a unified simulation-based genetic algorithm (SGA) solution procedure is developed to solve all three stochastic GP models. Numerical examples are also presented to illustrate the practicability of the GP approach in solving the SMONDP models as well as the robustness of the SGA solution procedure. © 2011 Elsevier Ltd. All rights reserved. Source


Shi F.,Wenzhou Medical College | Sun S.,Zhejiang University | Xu J.,Nanjing Southeast University
Information Sciences | Year: 2012

KANSEI Engineering (KE) is a method for translating feelings and impressions into product parameters and the objective of KANSEI Engineering is to study the relationship between product forms and KANSEI images. It is most important to extract critical form features of the product relative to specific KANSEI adjectives through a WEB-based KANSEI information system. In this paper, critical form features and KANSEI adjectives were defined as condition attributes and decision attributes respectively, which were formalized as two objects in Decision Table (DT). Then, the Semantic Differential (SD), which measures the connotative meaning of concepts, was applied to evaluate form features of the product through a KANSEI questionnaire system. The evaluation record from an individual's transaction data was reserved if its frequency was higher than the given threshold. Some form features were deleted by using an attribute reduction algorithm based on Rough Sets Theory (RST). Furthermore, the size of the DT was reduced by using a rule-joining operation. A strong association rule set which describes the relationship between the critical form features and the corresponding KANSEI adjectives was subsequently generated. A case study of a mobile phone design was presented to demonstrate the effectiveness of the proposed method by comparing it with other non-linear data mining methods in KANSEI Engineering. © 2012 Elsevier Inc. All rights reserved. Source


A novel accuracy function for interval-valued intuitionistic fuzzy sets is proposed by Jun Ye [Expert Systems with Applications 36 (2009) 6899-6902], and a multicriteria fuzzy decision-making method is established. However, there are several mistakes in the method to compare two interval-valued intuitionistic fuzzy numbers in the above cited reference. In this note we will present a corrected version of some results given therein and prove the proposed accuracy function be equivalent to the existing accuracy functions in the course of comparing any two interval-valued intuitionistic fuzzy numbers. © 2010 Elsevier Ltd. All rights reserved. Source


Yan R.,Nanjing Southeast University | Gao R.X.,University of Connecticut | Chen X.,Xian Jiaotong University
Signal Processing | Year: 2014

Over the last 20 years, particularly in last 10 years, great progress has been made in the theory and applications of wavelets and many publications have been seen in the field of fault diagnosis. This paper attempts to provide a review on recent applications of the wavelets with focus on rotary machine fault diagnosis. After brief introduction of the theoretical background on both classical wavelet transform and second generation wavelet transform, applications of wavelets in rotary machine fault diagnosis are summarized according to the following categories: continuous wavelet transform-based fault diagnosis, discrete wavelet transform-based fault diagnosis, wavelet packet transform-based fault diagnosis, and second generation wavelet transform-based fault diagnosis. In addition, some new research trends, including wavelet finite element method, dual-tree complex wavelet transform, wavelet function selection, new wavelet function design, and multi-wavelets that advance the development of wavelet-based fault diagnosis are also discussed. © 2013 Elsevier B.V. Source


Li Y.,Nanjing Southeast University
International journal of nanomedicine | Year: 2011

This research was conducted to assess the biocompatibility of the core-shell Fe(3)O(4)@ Au composite magnetic nanoparticles (MNPs), which have potential application in tumor hyperthermia. Fe(3)O(4)@Au composite MNPs with core-shell structure were synthesized by reduction of Au(3+) in the presence of Fe(3)O(4)-MNPs prepared by improved co-precipitation. Cytotoxicity assay, hemolysis test, micronucleus (MN) assay, and detection of acute toxicity in mice and beagle dogs were then carried out. The result of cytotoxicity assay showed that the toxicity grade of this material on mouse fibroblast cell line (L-929) was classified as grade 1, which belongs to no cytotoxicity. Hemolysis rates showed 0.278%, 0.232%, and 0.197%, far less than 5%, after treatment with different concentrations of Fe(3)O(4)@Au composite MNPs. In the MN assay, there was no significant difference in MN formation rates between the experimental groups and negative control (P > 0.05), but there was a significant difference between the experimental groups and the positive control (P < 0.05). The median lethal dose of the Fe(3)O(4)@Au composite MNPs after intraperitoneal administration in mice was 8.39 g/kg, and the 95% confidence interval was 6.58-10.72 g/kg, suggesting that these nanoparticles have a wide safety margin. Acute toxicity testing in beagle dogs also showed no significant difference in body weight between the treatment groups at 1, 2, 3, and 4 weeks after liver injection and no behavioral changes. Furthermore, blood parameters, autopsy, and histopathological studies in the experimental group showed no significant difference compared with the control group. The results indicate that Fe(3)O(4)@Au composite MNPs appear to be highly biocompatible and safe nanoparticles that are suitable for further application in tumor hyperthermia. Source


Zhou L.,Nanjing University | Zhou L.,Nanjing Xiaozhuang University | Yu X.,Nanjing Southeast University | Zhu J.,Nanjing University
Nano Letters | Year: 2014

Nanostructure-based photovoltaic devices have exhibited several advantages, such as reduced reflection, extraordinary light trapping, and so forth. In particular, semiconductor nanostructures provide optical modes that have strong dependence on the size and geometry. Metallic nanostructures also attract a lot of attention because of the appealing plasmonic effect on the near-field enhancement. In this study, we propose a novel design, the metal-core/ semiconductor-shell nanocones with the core radius varying in a linearly gradient style. With a thin layer of semiconductor absorber coated on a metallic cone, such a design can lead to significant and broadband absorption enhancement across the entire visible and near-infrared solar spectrum. As an example of demonstration, a layer of 16 nm thick crystalline silicon (c-Si) coated on a silver nanocone can absorb 27% of standard solar radiation across a broad spectral range of 300-1100 nm, which is equivalent to a 700 nm thick flat c-Si film. Therefore, the absorption enhancement factor approaching the Yablonovitch limit is achieved with this design. The significant absorption enhancement can be ascribed to three types of optical modes, that is, Fabry-Perot modes, plasmonic modes, and hybrid modes that combine the features of the previous two. In addition, the unique nanocone geometry enables the linearly gradient radius of the semiconductor shell, which can support multiple optical resonances, critical for the broadband absorption. Our design may find general usage as elements for the low cost, high efficiency solar conversion and water-splitting devices. © 2014 American Chemical Society. Source


Jiang H.X.,Nanjing Southeast University
Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology | Year: 2012

To evaluate the therapeutic efficacy and safety of lamivudine treatment in late pregnancy by analyzing the maternal-fetal outcomes of chronic hepatitis B (CHB) mothers featuring hepatitis B e antigen (HBeAg)-positivity and highly viremic status. A total of 256 pregnant women in the second or third trimester with monoinfected CHB, HBeAg-positivity, and HBV DNA more than 6 log10 copies/mL were divided into two groups: lamivudine (lam) treatment (n=164) or no treatment (controls; n=92). All infants were treated with hepatitis B immune globin (HBIg; 200 IU) within 12 hrs of birth and 15 days later, and were given the recombinant HBV vaccine (20 mug) at 0, 1 and 6 months. All infants were followed-up to at least seven months and hepatitis B surface antigen (HBsAg) and HBV DNA levels were used to determine perinatal transmission (PT) rates. The mothers' data from routine blood analysis, tests of hepatic and renal function, detection of HBV markers and HBV DNA were retrospectively analyzed to determine changes associated with the lam treatment. Correlations of lam treatment with HBV PT rate, alanine aminotransferase (ALT) normalization, adverse reactions, pregnancy complications, congenital deformities, and infants' growth/development were determined by statistical analyses. Prior to delivery, the lam-treated mothers had significantly lower HBV DNA levels (3.72+/-1.78 vs. controls: 7.83+/-0.67 log10 c/ml; t=-22.359, P less than 0.001). The rate of virological response in the lam-treated group was 97.56% (160/164). The lam-treated group had significantly higher ALT normalization rate (90.20% vs. controls: 55.88%; X2=13.349, P less than 0.001) and significantly lower HBeAg titer (957.73+/-458.42 vs. controls: 1296.35+/-383.14 S/CO; t=-5.410, P less than 0.001). At birth, the infants from lam-treated mothers had significantly lower HBsAg-positivity (15.24% (25/164) vs. controls: 30.43% (28/92); X2=8.284, P=0.004). By 7-12 months after birth, none of the infants born to lam-treated mothers tested positive for HBsAg, compared to 8.70% (8/92) of the infants born to mothers in the control group (X2=14.721, P less than 0.001). None of the lam-treated mothers required treatment discontinuation due to adverse events or lam-resistance. No congenital deformities were observed during the study and follow-up periods. There were no differences between the lam-treated and control groups for postpartum hemorrhage, gestational age, infants' height/weight or Apgar scores. In highly viremic HBsAg+ mothers with CHB, lam treatment in the second or third trimester of pregnancy is safe and effective for reducing HBV maternal-neonatal transmission. Source


Zhu D.,Nanjing Southeast University | Zhu D.,Nanjing Hydraulic Research Institute
Coastal Engineering | Year: 2011

The present paper extends the impedance analytical method to the study of the interaction of regular plane waves with a row of rectangular piles. The dissipative energy is estimated from the flow resistance for the row of piles. Formulas of wave reflection and transmission coefficients and the wave force for the row of piles are derived. Predictions obtained using the present model agree with experimental data in the literature. © 2011 Elsevier B.V. Source


Dou J.,Nanjing Southeast University
Cellular and molecular biology (Noisy-le-Grand, France) | Year: 2013

Cancer stem cells (CSCs) are believed to be responsible for drug resistance, metastasis of tumors. To investigate the biological characteristics of CD44+CD133+CSCs with over- expressing microRNA-200c (miR-200c), and to provide evidences for miR-200c as a tumor suppressor to treat melanoma. CD44+CD133+CSCs were isolated from the mouse melanoma B16F10 cell line by using immune magnetic activated cell sorting. The lentivirus miR-200c was transduced into the cells, and the effect of miR-200c overexpression on the biological characteristics of B16F10 CD44+ CD133+CSCs was analyzed by a series assays. The stable overexpression of miR-200c in B16F10 CD44+CD133+CSCs obviously resulted in downregulation of zinc-finger E-box binding homeobox 1 expression, reduction of the cell proliferation, colony forming, cell migratory and invasion ability in vitro as well as tumorigenicity in vivo compared with those of the B16F10 cells and B16F10 non-CD44+ CD133+CSCs. These findings suggest that the miR-200c overexpression as a novel strategy to target therapy of melanoma CSCs. Source


Zhu B.,Nanjing Southeast University | Xu Z.,PLA University of Science and Technology
IEEE Transactions on Fuzzy Systems | Year: 2014

Hesitant fuzzy linguistic term sets (HFLTSs) are used to deal with situations in which the decision makers (DMs) think of several possible linguistic values or richer expressions than a single term for an indicator, alternative, variable, etc. Compared with fuzzy linguistic approaches, they are more convenient and flexible to reflect the DMs' preferences in decision making. For further applications of HFLTSs to decision making, we develop a concept of hesitant fuzzy linguistic preference relations (HFLPRs) as a tool to collect and present the DMs' preferences. Due to the importance of the consistency measures using preference relations in decision making, we develop some consistency measures for HFLPRs to ensure that the DMs are being neither random nor illogical. A consistency index is defined to establish the consistency thresholds of HFLPRs to measure whether an HFLPR is of acceptable consistency. For HFLPRs with unacceptable consistency, we develop two optimization methods to improve the consistency until they are acceptable. Several illustrative examples are given to validate the consistency measures and the optimization methods. © 2013 IEEE. Source


Li Y.,Nanjing Southeast University
International journal of nanomedicine | Year: 2011

Results for implantation efficiency and effective improvement of cardiac function in the field of mesenchymal stem cells (MSCs) are controversial. To attempt to clarify this debate, we utilized magnetic resonance imaging (MRI) and near-infrared optical imaging (OI) to explore the effects of different delivery modes of mesenchymal stem cells on cell retention time and cardiac function after myocardial infarction (MI). Rat MSCs were labeled with superparamagnetic iron oxide nanoparticles and 1, 1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine, 4-chlorobenzenesulfonate salt (DiD) for noninvasive cell tracking in a rat MI model. Rats underwent coronary artery ligation and were randomized into three experimental groups: intravenous (IV), intramyocardial (IM), and a control group. The first two groups referred to the route of delivery of the transplanted dual-labeled MSCs; whereas the control group was given an IV injection of serum-free medium one day post-MI. Cellular engraftment was determined 1 day and 7 days post cell delivery by measuring the iron and optical signals in explanted organs. Prussian blue staining and fluorescent microscopy were performed on histological sections for iron and DiD, respectively. Cardiac function was measured by echocardiography on day 7. The cardiac function of the IM group increased significantly compared to the IV and control groups at day 7. In the IM group, labeled cells were visualized in the infracted heart by serial MRI, and the intensity by OI was significantly higher on day 1. In the IV group, the heart signals were significantly attenuated by dual-modal tracking at two time points, but the lung signals in OI were significantly stronger than the IM group at both time points. IM injection of MSCs increased cell engraftment within infarcted hearts and improved cardiac function after MI. However, IV infusion has a low efficacy due to the cell trapping in the lung. Therefore, direct injection may provide an advantage over IV, with regard to retention of stem cells and protection of cardiac function. Source


Cheng J.,Nanjing Southeast University
International journal of nanomedicine | Year: 2011

To investigate the effect of magnetic nanoparticles (MNPs) of Fe(3)O(4) combined with cyclosporin A (CsA) on acute graft-versus-host disease (aGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in murine models. BALB/c mice preconditioned with total-body irradiation generated aGVHD and then were followed with allo-HSCT from allogeneic C57BL/6. Recipient mice were randomly divided into five groups and then given different supportive care and followed up. The physical signs and median survival time (MST) were recorded, peripheral blood cell counts were assessed, and histological changes of the main tissues were evaluated with hematoxylin-eosin staining. Furthermore, fluorescence polarization immunoassay was used to monitor the concentration of CsA. The irradiated-only mice developed typical aGVHD, and the typical signs of aGVHD in the skin, liver, and intestine were observed by histopathological examination. Both CsA alone and in combination with Fe(3)O(4) MNPs significantly prolonged the MST of recipient mice compared with both the control and the Fe(3)O(4) MNPs groups. Notably, a combination of CsA with Fe(3)O(4) MNPs can elevate the peripheral white blood cells and alleviate the symptoms of GVHD and the pathological damage after allo-HSCT. In addition, the concentration of CsA was higher in plasma, heart, liver, and spleen of recipient mice with supporting care of the combination of CsA with Fe(3)O(4) MNPs than with CsA alone. Taken together, Fe(3)O(4) MNPs may be used as a carrier of immunosuppressive agents to alleviate GVHD after allo-HSCT in murine models. Source


Gao F.,Nanjing Southeast University | Wu Y.,Qufu Normal University
IET Control Theory and Applications | Year: 2014

This study addresses the problem of global stabilisation by state feedback for a class of high-order non-linear systems with more general uncertainties, to which the existing control methods are inapplicable. By introducing sign function and necessarily modifying the method of adding a power integrator, a continuous state feedback controller is successfully constructed to guarantee the global asymptotic stability of the resulting closed-loop system. Two simulation examples are provided to illustrate the effectiveness of the proposed approach. © The Institution of Engineering and Technology 2014. Source


Li P.,Nanjing Southeast University | Fang Y.,Nanjing University of Posts and Telecommunications
Journal of Micromechanics and Microengineering | Year: 2010

Predicting squeeze-film damping in rare air is crucial for the design of high-Q MEMS devices. There have been two approaches to treating the squeeze-film damping in rare air: the approach using the effective viscosity coefficient and the approach using the molecular dynamics method. This paper focuses on the numerical simulation of squeeze-film damping in rare air using the molecular dynamics method. In the past, because of the heavy computational cost of simulation of a large particle system, the molecular dynamics approach was not often used to simulate the gas damping in the MEMS area. Hutcherson and Ye (2004 J. Micromech. Microeng. 14 1726-33) developed a novel molecular dynamics method to simulate the motion of a large number of molecules in the squeeze gas film in the free molecular regime. The method possesses high computational efficiency. However, in their work, the molecules entering into the interaction regime are represented by one computational molecule. Therefore, the method is unsuitable for the torsional plate and flexible microbeam. This paper presents a molecular dynamics approach for calculating the squeeze-film damping of the torsional microplate and flexible microbeam in the free molecular regime. In this approach, several computational molecules are used to represent all of the molecules interacting with the torsional microplate and flexible microbeam. The present paper is an extension of the work done by Hutcherson and Ye (2004 J. Micromech. Microeng. 14 1726-33). The accuracy of the present molecular dynamics approaches is verified by comparing their results with the experimental results available in the literature. © 2010 IOP Publishing Ltd. Source


Yu X.,RMIT University | Yu X.,Nanjing Southeast University | Wang B.,University of Melbourne | Li X.,RMIT University
IEEE Transactions on Industrial Informatics | Year: 2012

Variable Structure Systems (VSSs) have been studied extensively for over 60 years and widely used in practical applications. A particular interest in VSS is the so-called Sliding-Mode Control (SMC), which is simple in control design and robust in parameter variations and disturbances. Modern control systems nowadays are implemented through computers. This presents challenges for SMC based VSS because the digital nature of computer-control weakens the essential assumption of SMC, that is, the switching frequency should be unlimited in order to deliver effective disruptive control actions. Extensive research activities have been since undertaken in computer-controlled VSS over the last thirty years. This survey provides a comprehensive account of the key developments in this field and examines the key technical research challenges for the future developments. © 2011 IEEE. Source


Liu Y.,Nanjing University | Lu Z.,Nanjing Southeast University
Stress and Health | Year: 2012

In a sample of 368 Chinese high school students, the present study examined the different effects of Chinese high school students' academic stress on their depressive symptoms and the moderating effects of gender and students' perceptions of school climate on the relationships between their academic stress and depressive symptoms. Regression mixture model identified two different kinds of subgroups in the effects of students' academic stress on their depressive symptoms. One subgroup contained 90% of the students. In this subgroup, the students' perceptions of academic stress from lack of achievement positively predicted their depressive symptoms. For the other 10% of the students, academic stress did not significantly predict their depressive symptoms. Next, multinomial regression analysis revealed that girls or students who had high levels of achievement orientation were more likely to be in the first subgroup. The findings suggested that gender and students' perceptions of school climate could moderate the relationships between Chinese high school students' academic stress and their depressive symptoms. Copyright © 2011 John Wiley & Sons, Ltd. Source


Hong X.,Nanjing Southeast University
Orthopaedic surgery | Year: 2014

To design a new type of interbody fusion device made of nickel titanium NiTi shape memory alloy and to compare segmental stiffness after various posterior lumbar interbody fusion (PLIF) procedures in vitro and in vivo. Twelve sheep lumbar functional spinal units were randomly allocated to four groups. One acted as controls (N); the other three were treated with autogenous iliac crest bone dowel graft (L), a threaded cylindrical titanium (KC) interbody fusion device (TFC) or a new type of interbody fusion device made of NiTi shape memory alloy (NT) containing autogenous iliac crest graft. In addition, 15 sheep were allocated to three groups; one served as controls and the other two underwent TFC (KC) or NiTi-FC (NT). Nondestructive mechanical tests were performed in pure compression, extension, lateral bending and torsion. The operated spines were photographed regularly to assess changes in interbody height and degree of fusion. The animals were killed at 6 months for histologic testing. Biomechanical tests showed both the strength and axial stiffness of the NT and KC groups were significantly higher than those of the control group and L group (P < 0.05). When the mechanical performance in torque and torsion of each group were compared, the same results could be obtained. The maximal destructive load of the NiTi-TFC was 11 200 N and the safety coefficient was above 1.2. Radiological observations revealed that the bone callus around the interbody fusion device were gradually increased postoperatively (2 months, no obvious; 4 months, poorly define; 6 months, dense). The KC and NT group had lost 16% and 16.5% of their postoperative height but remained well above normal disc height (P < 0.05). Histologic examination showed new trabeculation connected with that of the host. The mechanical characteristics of the NiTi-TFC are excellent and it is safe and reliable. © 2014 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd. Source


Sato T.,Nanjing Southeast University
Journal of Civil Structural Health Monitoring | Year: 2013

In this paper, we apply Monte Carlo filter (MCF) to identify dynamic parameters of structural systems and improve the efficiency of its algorithm. The algorithms using MCF so far have not been practical for applying to structural identification of large-scale systems because computation time increases exponentially as the degrees of freedom of the system increases. To overcome this problem, we developed a method with the ability to reduce the number of particles which express possible structural response state vector. In MCF, there are two steps which are the prediction and filtering processes. The idea is very simple. The prediction process remains intact but the filtering process is conducted at each node of structural system in the proposed method. We named this algorithm as relaxation Monte Carlo filter (RMCF) and demonstrated its efficiency to identify large degree of freedom systems. Moreover, to increase searching field and speed up convergence time of structural parameters, we proposed an algorithm combining the genetic algorithm with RMCF and named GARMCF. © 2013 Springer-Verlag Berlin Heidelberg. Source


Jiang R.,Nanjing Southeast University
International Journal on Smart Sensing and Intelligent Systems | Year: 2013

Cloud Computing, as an emerging, virtual, large-scale distributed computing model, has gained increasing attention these years. Meanwhile it also faces many security challenges, one of which is authentication. Lots of researches have been done in this area. Recently, Choudhury et al proposed a user authentication framework to ensure user legitimacy before entering into the cloud. They claimed their scheme could provide identity management, mutual authentication, session key agreement between the user and the cloud server, and demanded user password change. However, we find the scheme will easily suffer from some attacks such as the masquerading attack, the OOB (out of band) attack, and the password change flaw through our analysis. In this paper, we first point out the security vulnerabilities to the Choudhury et al's scheme, and present the detailed attacks on the scheme. Then, based on some remote user authentication schemes such as Ku-Chen's scheme and Chen's scheme, we apply the two-factor authentication technology to propose our advanced secure user authentication framework which can overcome above security shortages. Without sending one time key through secure OOB channel, our new protocol is able to ensure that only legitimate users can access the cloud service based on smartcard. In addition, our advanced scheme can hold all the merits of the Choudhury et al's scheme. Formal security analysis, which is based on the strand space model and authentication test, proves that our proposed scheme is secure under standard cryptographic. Also, the simulation results illustrate that our advanced scheme is more efficient on the communication performance than other schemes. Source


Liang J.,Nanjing Southeast University | Wang Z.,Brunel University | Liu X.,Brunel University
IEEE Transactions on Neural Networks | Year: 2011

This paper deals with the distributed state estimation problem for a class of sensor networks described by discrete-time stochastic systems with randomly varying nonlinearities and missing measurements. In the sensor network, there is no centralized processor capable of collecting all the measurements from the sensors, and therefore each individual sensor needs to estimate the system state based not only on its own measurement but also on its neighboring sensors' measurements according to certain topology. The stochastic Brownian motions affect both the dynamical plant and the sensor measurement outputs. The randomly varying nonlinearities and missing measurements are introduced to reflect more realistic dynamical behaviors of the sensor networks that are caused by noisy environment as well as by probabilistic communication failures. Through available output measurements from each individual sensor, we aim to design distributed state estimators to approximate the states of the networked dynamic system. Sufficient conditions are presented to guarantee the convergence of the estimation error systems for all admissible stochastic disturbances, randomly varying nonlinearities, and missing measurements. Then, the explicit expressions of individual estimators are derived to facilitate the distributed computing of state estimation from each sensor. Finally, a numerical example is given to verify the theoretical results. © 2010 IEEE. Source


Wu L.,Nanjing Southeast University
Dianbo Kexue Xuebao/Chinese Journal of Radio Science | Year: 2013

The limited spectrum resource has restricted continuing developments of many nations, while the classical channel capacity and spectrum utilization limit based on typical rectangular spectra partition, can not explain the high-efficiency of some sine-like modulations already. Aiming at the sine-like signal characteristic of the ultra narrow band (UNB) modulations, a non-rectangular spectra partition model is proposed which has a monopolized ultra narrow "spectrum tree" plus shared broad "spectrum grasses". Its technique reasonability is demonstrated in aspects of the full use of existing spectrum resources and the rational toleration of dense multi-carrier information transmission scheme. The necessity is pointed out for parallelism derivation of the channel capacity expression and the unit spectrum utilization limit, based on the proposed non-rectangular spectrum partition model. Copyright © 2013 by Editorial Department of Chinese Journal of Radio Science. Source


Rakkiyappan R.,Gandhigram Rural University | Balasubramaniam P.,Gandhigram Rural University | Cao J.,Nanjing Southeast University
Nonlinear Analysis: Real World Applications | Year: 2010

In this paper, by utilizing the Lyapunov-Krasovkii functional and combining with the linear matrix inequality (LMI) approach, we analyze the global exponential stability of neutral-type impulsive neural networks. In addition, an example is provided to illustrate the applicability of the result using LMI control toolbox in MATLAB. © 2008 Elsevier Ltd. All rights reserved. Source


Cao J.,Nanjing Southeast University
Nonlinear Dynamics | Year: 2010

In this paper, the problem of adaptive synchronization is investigated for a class of Cohen-Crossberg neural networks with mixed time delays. Based on a Lyapunov-Krasovskii functional and the invariant principle of function differential equations as well as the adaptive control and linear feedback with update law, a linear matrix inequality approach is developed to derive some novel sufficient conditions achieving synchronization of the two coupled networks with mixed time delays. In particular, the mixed time delays in this paper synchronously consist of constant delays, time-varying delays, and distributed delays, which are more general than those discussed in the previous literature. Therefore, the results obtained in this paper comprise and generalize those given in the previous literature. A numerical example and its simulation are provided to show the effectiveness of the theoretical results. © Springer Science+Business Media B.V. 2010. Source


Yan R.,Nanjing Southeast University | Liu Y.,Anhui University | Gao R.X.,University of Connecticut
Mechanical Systems and Signal Processing | Year: 2012

This paper investigates the usage of permutation entropy for working status characterization of rotary machines. As a statistical measure, the permutation entropy describes complexity of a time series or signal measured on a physical system through phase space reconstruction, and takes into account non-linear behavior of the time series, as often seen in vibration signals of rotary machines. Thus it can be served as a viable tool for detecting dynamic changes of the machine working status. The effect of embedded dimension and time delay on calculation of the permutation entropy value has been studied, and the validity of the permutation entropy for detecting dynamic change of a physical system is studied through a well known non-linear system, the Logistic Map. Comparison with other complexity measures using a numerically formulated signal has also been investigated. Experimental results on bearing vibration analysis have then confirmed that the permutation entropy provides an effective measure for monitoring the working status of rolling bearings. © 2011 Elsevier Ltd. All rights reserved. Source


Li S.,Nanjing Southeast University | Gu H.,Huawei
IEEE Transactions on Industrial Informatics | Year: 2012

In this paper, the speed regulation problem for permanent magnet synchronous motor (PMSM) system under vector control framework is studied. First, a speed regulation scheme based on standard internal model control (IMC) method is designed. For the speed loop, a standard internal model controller is first designed based on a first-order model of PMSM by analyzing the relationship between reference quadrature axis current and speed. For the two current loops, PI algorithms are employed respectively. Second, considering the disadvantages that the standard IMC method is sensitive to control input saturation and may lead to poor speed tracking and load disturbance rejection performances, a modified IMC scheme is developed based on a two-port IMC method, where a feedback control term is added to form a composite control structure. Third, considering the case of large variations of load inertia, two adaptive IMC schemes with two different adaptive laws are proposed. A method based on disturbance observer is adopted to identify the inertia of PMSM and its load. Then a linear adaptive law is developed by analyzing the relationship between the internal model and identified inertia. Considering the control input saturation in practical applications, a fuzzy adaptive law based IMC scheme is developed based on apriori experimental tests and experiences, where a fuzzy inferencer based supervisor is designed to automatically tune the parameter of speed controller according to the identified inertia. The effectiveness of the proposed methods have been verified by Matlab simulation and TMS320F2808 DSP experimental results. © 2012 IEEE. Source


Tan Z.,Lulea University of Technology | Xiao G.,Nanjing Southeast University
Waste Management and Research | Year: 2012

Many of the characteristics of typical medical waste ash can be found by using ash leaching experiments. The present study investigated the characteristics of fly ash derived from incineration of medical waste in China. The particle diameter of the fly ash was in the range 154-900 μm. Elemental analyses of the fly ash indicated that it contained calcium, aluminium, iron, sodium, potassium and magnesium, and that copper, lead, chromium and mercury were the dominant heavy metals it contained. As leaching time was increased the leaching concentrations of the heavy metals increased and the leaching toxicity was augmented. When the pH was neutral, the concentrations of most heavy metals in the leachate were minimum whereas when the pH was alkali or acid, the leaching toxicity was greatly enhanced. High temperature melting was found to be a good method of fixing heavy metals, and the main components of the sinter were Fe 3O 4, SiO 2, CaSO 4 and CaSiO 3, etc. © The Author(s) 2012. Source


Wu Y.,Nanjing Southeast University
Information Processing Letters | Year: 2013

Let γ(G) denote the domination number of a graph G. A Roman dominating function of a graph G is a function f:V(G)→{0,1,2} such that every vertex with 0 has a neighbor with 2. The Roman domination number γR(G) is the minimum of f(V(G))=Σ εV(G) f(v) over all such functions. Let G□H denote the Cartesian product of graphs G and H. We prove that γ(G)γ(H)≤γR(G□H) for all simple graphs G and H, which is an improvement of γ(G)γ(H) ≤2γ(G□H) given by Clark and Suen (2000) [2], since γ(G□H)≤γR(G□H)≤2γ(G□H). © 2012 Elsevier B.V. Source


Wang J.,Nanjing Southeast University
Cellular and molecular biology (Noisy-le-Grand, France) | Year: 2011

The role of Wnt/β-catenin signaling pathway in the etiology and/or progression of ovarian cancer has been well documented. It was demonstrated that ovarian cancer constantly exhibit constitutive activation of canonical Wnt signaling, usually as a result of oncogenic mutations that stabilize and dysregulate the β-catenin protein. In this study, we transfected an expression vector-based small hairpin RNA (shRNA) targeting to β-catenin encoding gene into human A2780 ovarian cancer cells to investigate the effects of β-catenin knockdown on biological characteristics of ovarian cancer cells. The results showed that β-catenin shRNA expression resulted in decreased β-catenin mRNA and protein expression in the transfected A2780 cells, inhibition of cellular proliferation, decreased capability of clonogenicity in the plating and the soft agar, and increased sensitivities to chemotherapy drugs vincristine, paclitaxel and cisplatin compared to untransfected cells. Importantly, we found that shRNA-mediated knockdown of β-catenin strongly decreases tumour growth of human A2780 ovarian cancer cells in xenografts. These results demonstrate that β-catenin might be an effective therapeutic target for human ovarian cancer treatment. Source


Ma H.F.,Nanjing Southeast University
Nature communications | Year: 2010

Since invisibility cloaks were first suggested by transformation optics theory, there has been much work on the theoretical analysis and design of various types and a few experimental verifications at microwave and optical frequencies within two-dimensional limits. Here, we realize the first practical implementation of a fully 3D broadband and low-loss ground-plane cloak at microwave frequencies. The cloak, realized by drilling inhomogeneous holes in multi-layered dielectric plates, can conceal a 3D object located under a curved conducting plane from all viewing angles by imitating the reflection of a flat conducting plane. We also designed and realized, using non-resonant metamaterials, a high-gain lens antenna that can produce narrow-beam plane waves in the near-field region in a broad frequency band. The antenna constitutes the transmitter of the measurement system and is essential for the measurement of cloaking behaviour. Source


Jiang X.,Nanjing Southeast University | Ellis N.,University of British Columbia
Energy and Fuels | Year: 2010

Storage properties and thermal stability of fuels are important background information when dealing with a new potential fuel. Following the first paper on the preparation and characterization of the fuel mixture produced through emulsification of bio-oil and biodiesel, the second part of this investigation reports on the storage and thermal stability of the bio-oil/biodiesel mixture. The physicochemical properties of the samples stored at different temperatures (60 and 80 °C) for up to 180 h are measured. Fuel properties, such as viscosity, water content, acid number, and average molecular weight of the bio-oil/biodiesel mixture, are measured before and after aging. In contrast to the aging properties of bio-oil alone, very little changes in water content and viscosity are shown for the mixtures aged at 80 °C for 180 h. Overall, a slight decrease in acid numbers is observed for the aged mixtures. Chemical changes are characterized using gel permeation chromatography (GPC), showing a slight increase in the molecular weight over time, possibly because of some polymerization and condensation reactions during storage. Further confirmation of the changes is shown through a Fourier transform infrared spectrometer (FTIR), thermal decomposition analysis using a thermogravimetric analyzer (TGA), and proton assignment using proton nuclear magnetic residence (1H NMR) spectroscopy. Finally, the study indicates that the bio-oil/biodiesel mixture is stable within the conditions tested as a fuel. © 2010 American Chemical Society. Source


Liang J.,Nanjing Southeast University | Wang Z.,Brunel University | Liu X.,Brunel University
Information Sciences | Year: 2010

In this paper, the passivity and passification problems are investigated for a class of uncertain stochastic fuzzy systems with time-varying delays. The fuzzy system is based on the Takagi-Sugeno (T-S) model that is often used to represent the complex nonlinear systems in terms of fuzzy sets and fuzzy reasoning. To reflect more realistic dynamical behaviors of the system, both the parameter uncertainties and the stochastic disturbances are considered, where the parameter uncertainties enter into all the system matrices and the stochastic disturbances are given in the form of a Brownian motion. We first propose the definition of robust passivity in the sense of expectation. Then, by utilizing the Lyapunov functional method, the Itô differential rule and the matrix analysis techniques, we establish several sufficient criteria such that, for all admissible parameter uncertainties and stochastic disturbances, the closed-loop stochastic fuzzy time-delay system is robustly passive in the sense of expectation. The derived criteria, which are either delay-independent or delay-dependent, are expressed in terms of linear matrix inequalities (LMIs) that can be easily checked by using the standard numerical software. Illustrative examples are presented to demonstrate the effectiveness and usefulness of the proposed results. © 2010 Elsevier Inc. All rights reserved. Source


Huang D.Y.,Nanjing Southeast University
Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory diseases | Year: 2011

To evaluate the effect of neurally adjusted ventilatory assist (NAVA) on prevention of ventilator-induced diaphragmatic dysfunction (VIDD) in ARDS rabbits. Twenty New Zealand white rabbits were randomly divided into 4 groups: (1) control group (n = 5); (2) Volume control (VC) group (n = 5); (3) Pressure support (PSV) group (n = 5); (4) NAVA group (n = 5). In VC, PSV and NAVA groups, the rabbits were killed and the diaphragm was removed after 4 hours of ventilation. Animals in the control group were not mechanically ventilated, and the diaphragm was also removed immediately after anesthetizing. In all rabbits, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH) of diaphragm were measured. Structure of diaphragm was observed by light microscope, electron microscope, constituent ratio and mean cross-sectional area (CSA) of diaphragm fiber. (1) MDA: Compared with the control [(0.15 ± 0.06) nmol/mg], PSV group [(0.30 ± 0.11) nmol/mg], there was no significant difference in MDA of diaphragm in NAVA group [(0.28 ± 0.19) nmol/mg] (F = 2.730, P > 0.05). MDA in VC group [(0.40 ± 0.16) nmol/mg] was significantly higher than the control group (P < 0.05). (2) SOD: Compared with control [(111 ± 12) U/mg], PSV group [(93 ± 4) U/mg], there was no significant difference in SOD of diaphragm in NAVA group [(94 ± 9) U/mg] (F = 4.422, P > 0.05). SOD in VC group [(80 ± 21) U/mg] was significantly lower than the control group (P < 0.05). (3) GSH: Compared with control [(5.3 ± 1.0) mg/g] and PSV group [(4.5 ± 1.2) mg/g], there was no significant difference in GSH of diaphragm in NAVA group [(5.6 ± 1.0) mg/g] (F = 3.001, P > 0.05). GSH in VC group [(3.3 ± 1.7) mg/g] is significantly lower than control and NAVA groups (P < 0.05). (4) Light microscope: In VC group, many changes were observed in the muscle, such as myelofibrosis, necrosis, and some of muscle fibers became atrophy, but these were no obvious changes of pathological structure in control, PSV or NAVA groups. (5) Electron microscope: In control, PSV and NAVA groups, the ultrastructure of diaphragm was normal. Different from the above 3 groups, some abnormal ultrastructure was observed in VC group, including disrupted myofibrils, swollen mitochondria. (6) CSA of diaphragm fiber: Compared with control and PSV group, there was no significant difference in CSA of diaphragm fiber in NAVA group (P > 0.05); The CSA of type II fibers in VC group was markedly lower than control group (P < 0.05). Compared with volume control ventilation, NAVA may mitigate diaphragmatic oxidative stress, atrophy and injury, and prevent VIDD better than VC. Source


Zhang S.,Nanjing Southeast University
Wireless Personal Communications | Year: 2013

As an innovative communication scheme, ultra narrow band modulation is attracting more and more attention. In order to uncover the essence of the technology, asymmetric binary x shift keying, the general design scheme of UNB, is proposed and studied in this paper as a different modulation scheme from the traditional methods. The general wave function is defined first, and the modulation process is presented, then particular realization of asymmetric BASK, asymmetric BPSK, and asymmetric BFSK were studied. This verified the general characteristics of asymmetric binary x shift keying proposed above as the general modulation format design of UNB technology from the view of modulation essence. On this basis, time domain and frequency characteristics are given by derivation of wave function and PSD equation, and different particular time domain waveforms and PSD are plotted and examined. Next, a general modulation realization is presented, and the modulation and demodulation process are related, which break through the traditional filtering methods. Filter can then be replaced by other signal shaping methods. Finally, demodulation performance formulas of asymmetric binary x shift keying-based ultra narrow band modulation are derived and compared, which can be a base and guide for further modulation study or a trade off for an optimized design of UNB modulation formats. © 2012 Springer Science+Business Media, LLC. Source


Han G.R.,Nanjing Southeast University
Zhonghua gan zang bing za zhi = Zhonghua ganzangbing zazhi = Chinese journal of hepatology | Year: 2012

To evaluate the efficacy and safety of telbivudine use during the second and third trimester of pregnancy for reducing hepatitis B virus (HBV) transmission from highly viremic hepatitis B e antigen-positive (HBeAg+) mothers to their fetuses. Pregnant women, between weeks 20 to 32 of gestation, who were HBeAg+ and had HBV DNA more than 1.0*10(7) copies/mL were enrolled in our study. The women were offered inclusion into one of two treatment arms, based upon their personal preference: telbivudine or no telbivudine. The patients in the telbivudine treatment arm were administered 600 mg/d telbivudine at least until postpartum week 4. All delivered infants in both treatment arms were administered hepatitis B immune globulin (HBIG; 200 IU) within 12 hours of delivery and recombinant HBV vaccine (20 mug) at 0, 1 and 6 months. The HBV perinatal transmission rate was determined by measuring HBsAg and HBV DNA in infants at postpartum week 28. A total of 220 pregnant women were enrolled in our study, 120 chose the telbivudine arm and 100 chose the control arm. All telbivudine treated subjects were registered in the Antiretroviral Pregnancy Registry. Telbivudine treatment was associated with a marked reduction in the mothers' serum HBV DNA, HBeAg and ALT levels before delivery. A striking decline of HBV DNA levels in treated mothers was observed at week 2 of treatment, which was followed by a gradual and steady decrease that continued until delivery. Thirty-seven (31%) of the telbivudine-treated mothers and none (0%) of the untreated controls had polymerase chain reaction-undetectable viremia at delivery. At week 28, 0% of the infants delivered from telbivudine-treated mothers were HBsAg+ or HBV DNA+, as compared to 8% HBsAg+ or HBV DNA+ in the untreated control arm (P = 0.002). No telbivudine discontinuations occurred from adverse events, and no congenital deformities were observed in the infants delivered to telbivudine-treated mothers. Eighty mothers discontinued telbivudine at week 4 postpartum, and there were no cases of severe hepatitis. There were no significant differences between the two treatment arms for postpartum hemorrhage, adverse events during pregnancy, cesarean section, gestational age, or infants' height/weight or Apgar scores. Telbivudine use during the second and third trimester of pregnancy in HBeAg+ highly viremic mothers can safely reduce perinatal HBV transmission rates. Telbivudine was well-tolerated by our patient group. Furthermore, no safety concerns were observed in either the telbivudine-treated mothers or their delivered infants in short term follow-up. Source


Liu X.,Nanjing Southeast University | Liu X.,University of Southern California
International Journal of Approximate Reasoning | Year: 2010

The paper first summarizes the orness measures and their common characteristics of some averaging operators: the quasi-arithmetic mean, the ordered weighted averaging (OWA) operator, the regular increasing monotone (RIM) quantifier and the weighted function average operator, respectively. Then it focuses on the aggregation properties and operator determination methods for two kinds of quasi-arithmetic mean-based compound aggregation operators: the quasi-OWA (ordered weighted averaging) operator and the Bajraktarević mean. The former is the combination of the quasi-arithmetic mean and the OWA operator, while the latter is the combination of the quasi-arithmetic mean and the weighted function average operator. Two quasi-OWA operator forms are given, where the OWA operator is assigned directly or generated from a RIM (regular increasing monotone) quantifier indirectly. The orness indexes to reflect the or-like level of the quasi-OWA operator and Bajraktarević mean are proposed. With generating function techniques, the properties of the quasi-OWA operator and Bajraktarević mean are discussed to show the rationality of these orness definitions. Based on these properties, two families of parameterized quasi-OWA operator and Bajraktarević mean with exponential and power function generators are proposed and compared. It shows that the method of this paper can also be applied to other function-based aggregation operators. © 2009 Elsevier Inc. All rights reserved. Source


Geng Z.,Nanjing Southeast University
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery | Year: 2011

Platelet-rich plasma (PRP) secretes many growth factors, including transforming growth factor beta1 (TGF-beta1), platelet derived growth factor, vascular endothelial growth factor, insulin-like growth factor 1, and so on, which can promote cell proliferation, chemotaxis, and collagen synthesis in wound healing. To investigate the effects of PRP on the tendon healing, and to explore the mechanism of action so as to provide the experimental basis for the tissue engineered tendons. Forty healthy New Zealand white rabbits, weighing 2.5-3.0 kg and male or female, were randomly divided into the experimental group (n = 20) and the control group (n = 20). PRP was prepared from arterial blood of rabbit's ears through twice centrifugation method of Landesberg. The platelet concentrations of whole blood and PRP were determined. The right achilles tendons of the rabbits were transected to make rupture models. In experimental group, the tendon was sutured after PRP (0.5 mL) was immediately applied at repair site. In control group, the tendon was sutured directly after transection. At 1, 2, 4, and 6 weeks after operation, the tendons of 5 rabbits in each group were harvested for morphological, histological, and immunohistochemical observations; the fibroblast counting, the content of collagen fibers, and the expression of TGF-beta1 were detected. The concentration of platelet of PRP was 4.03 times of whole blood. All the animals survived till the end of the experiment, and the incision healed well. No death, infection, and other complications occurred. With time, the tendons almost healed in 2 groups, and the fibrous tissue at anastomosis site was more remarkable in control group than in experimental group. The histological observation showed significant differences in fibroblast counting at 1, 2, and 4 weeks after operation between 2 groups (P < 0.05), while no significant difference at 6 weeks (P > 0.05). The contents of collagen fibers in the parenchyma at repair site in experimental group were significantly higher than those in control group at each time point (P < 0.05). Immunohistochemistry staining showed the expression of TGF-beta1 in experimental group was upregulated at 1 week and 2 weeks and reached the peak at the 2nd week, and subsequently downregulated at 4 and 6 weeks in comparison with the control group, showing significant differences between 2 groups at each time point (P < 0.05). PRP can facilitate rabbit's tendons healing and significantly improve the healing quality, which may be associated with its advancing the peak time of the TGF-beta1 expression in tendon. Source


Xue P.,Nanjing Southeast University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2010

We show that a many-body system of single-electron quantum dots, whose orbital states are dressed by a global magnetic field, can be described by an effective Hamiltonian with an anisotropic XZ spin-spin interaction which is proportional to the Zeeman splitting. We show that these interaction potentials give rise to spin-dependent Hubbard models with tunable nearest neighbor two-body and three-body interactions. The two-body interactions can even be switched off via the external electric field, and hence the three-body interaction plays a dominant role. The derivation of these effective interaction potentials follows from a well-controlled and systematic expansion into many-body interaction terms. Models of this type have appeared in the recent discussion of exotic quantum phases, in particular in the context of topological quantum phases and quantum computing, and we show that quantum dots can be regarded as a realistic experimental route which provides the basic building blocks and techniques toward the study of these phenomena. The main application of this derived model is to develop topological quantum computation. © 2010 The American Physical Society. Source


de Koning A.P.J.,Aurora University | Gu W.,Aurora University | Gu W.,Nanjing Southeast University | Castoe T.A.,Aurora University | And 2 more authors.
PLoS Genetics | Year: 2011

Transposable elements (TEs) are conventionally identified in eukaryotic genomes by alignment to consensus element sequences. Using this approach, about half of the human genome has been previously identified as TEs and low-complexity repeats. We recently developed a highly sensitive alternative de novo strategy, P-clouds, that instead searches for clusters of high-abundance oligonucleotides that are related in sequence space (oligo "clouds"). We show here that P-clouds predicts >840 Mbp of additional repetitive sequences in the human genome, thus suggesting that 66%-69% of the human genome is repetitive or repeat-derived. To investigate this remarkable difference, we conducted detailed analyses of the ability of both P-clouds and a commonly used conventional approach, RepeatMasker (RM), to detect different sized fragments of the highly abundant human Alu and MIR SINEs. RM can have surprisingly low sensitivity for even moderately long fragments, in contrast to P-clouds, which has good sensitivity down to small fragment sizes (~25 bp). Although short fragments have a high intrinsic probability of being false positives, we performed a probabilistic annotation that reflects this fact. We further developed "element-specific" P-clouds (ESPs) to identify novel Alu and MIR SINE elements, and using it we identified ~100 Mb of previously unannotated human elements. ESP estimates of new MIR sequences are in good agreement with RM-based predictions of the amount that RM missed. These results highlight the need for combined, probabilistic genome annotation approaches and suggest that the human genome consists of substantially more repetitive sequence than previously believed. © 2011 de Koning et al. Source


Xue P.,Nanjing Southeast University | Xue P.,University of Calgary
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2010

We develop a scalable architecture for quantum computation using controllable electrons of double-dot molecules coupled to a microwave stripline resonator on a chip. We analyze the performance and stability of all required operations and emphasize that all techniques are feasible with current experimental technologies. © 2010 Elsevier B.V. All rights reserved. Source


Chen M.-Y.,Jiangsu University | Li Y.-R.,Jiangsu University | Zhou J.,Ningbo University | Zhang Y.-K.,Nanjing Southeast University
Journal of Lightwave Technology | Year: 2013

We propose the design of a simple large-mode area microstructured optical fiber with low bending loss and large loss difference between the fundamental mode and the high-order modes. Single-mode operation in the fiber is realized by the introduction of small diameter holes, whereas the bending loss of the fiber is realized by the introduction of three large holes in the two-ring hole microstructured optical fiber. We also introduce low-index rods into the core of the fiber, which can effectively compensate the reduction of mode area induced by bending the fiber. © 1983-2012 IEEE. Source


Yang H.,Ludong University | Zhang Z.,Nanjing Southeast University | Zhang S.,Northeastern University China
International Journal of Robust and Nonlinear Control | Year: 2011

In this paper, the consensus of second-order multi-agent dynamical systems with exogenous disturbances is studied. A pinning control strategy is designed for a part of agents of the multi-agent systems without disturbances, and this pinning control can bring multiple agents' states to reaching an expected consensus track. Under the influence of the disturbances, disturbance observers-based control (DOBC) is developed for disturbances generated by an exogenous system to estimate the disturbances. Asymptotical consensus of the multi-agent systems with disturbances under the composite controller can be achieved for fixed and switching topologies. Finally, by applying an example of multi-agent systems with switching topologies and exogenous disturbances, the consensus of multi-agent systems is reached under the DOBC with the designed parameters. Copyright © 2010 John Wiley & Sons, Ltd. Source


Yao X.,Nanjing Southeast University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2010

The partially disordered antiferromagnetic (PDA) state, as an exotic phase peculiar to the antiferromagnet with Ising spin in triangular lattice, is investigated by using Monte Carlo simulations of Wang-Landau algorithm and Glauber algorithm. It is revealed that PDA state, as the ground state of the triangular antiferromagnetic system, presents the complicated spin configuration due to geometrical frustration. The formation of multi-domain structure within the framework of honeycomb antiferromagnet results in the high degeneracy of PDA state. And this degeneracy of ground state can be lifted by a small magnetic field. Consequently the system shows the ferrimagnetic state, and the magnetization plateau of 1/3 saturate value (Ms) is observed in many experiments. Moreover, due to the multi-domain structure of PDA state and those spins on domain walls, the metastable steps may manifest themselves superposed on the 1 / 3 Ms plateau in some special cases. © 2009 Elsevier B.V. All rights reserved. Source


Xu Z.,Nanjing Southeast University
International Journal of Information Technology and Decision Making | Year: 2011

Multi-stage multi-attribute group decision making (MS-MAGDM) as a familiar decision activity that usually occurs in our daily life, such as multi-stage investment decision making, medical diagnosis, personnel dynamic examination, military system efficiency dynamic evaluation, etc. The aim of this paper is to investigate MS-MAGDM problems in which both the weight information on a collection of predefined attributes and the decision information on a finite set of alternatives with respect to the attributes are collected at different stages. We first propose a Poisson distribution based method to determine the weight vector associated with a time-weighted averaging (TWA) operator. Furthermore, we use a hybrid weighted aggregation (HWA) operator to fuse all individual decision information into group opinions at different stages, and then utilize the TWA operator to aggregate the derived group opinions at different stages into the complex group ones so as to rank the given alternatives. After that, we further investigate MS-MAGDM problems where all decision information at different stages cannot be given in exact numerical values, but value ranges can be obtained. An approach based on the uncertain time-weighted averaging (UTWA) operator and the uncertain hybrid weighted aggregation (UHWA) operator is developed for solving MS-MAGDM problems under interval uncertainty. Finally, a practical example is provided to illustrate the developed approaches. © 2011 World Scientific Publishing Company. Source


Wang Y.T.,Nanjing Southeast University
Orthopaedic surgery | Year: 2013

Pure tibiotalar dislocation without an associated fracture is an extremely rare injury. We present three cases of closed posteromedial tibiotalar dislocation without any associated fractures to the foot, ankle, or leg. All patients were treated conservatively with immediate closed reduction under general or local anaesthesia and immobilised in a short leg cast for six weeks without weight-bearing resulting in a satisfactory outcome at the final follow-up. A review of the literature is also presented in this paper. © 2013 Chinese Orthopaedic Association and Wiley Publishing Asia Pty Ltd. Source


Xia M.,Tsinghua University | Xu Z.,PLA University of Science and Technology | Zhu B.,Nanjing Southeast University
Knowledge-Based Systems | Year: 2013

In this paper, we introduce the Bonferroni geometric mean, which is a generalization of the Bonferroni mean and geometric mean and can reflect the correlations of the aggregated arguments. To describe the uncertainty and fuzziness more objectively, intutionistic fuzzy set could be used for considering the membership, non-membership and uncertainty information. To aggregate the Atanassov's intuitionistic fuzzy information, we further develop the Atanassov's intuitionistic fuzzy geometric Bonferroni mean describing the interrelationship between arguments, and some properties and special cases of them are also discussed. Moreover, considering the importance of each argument, the weighted Atanassov's intuitionistic fuzzy geometric Bonferroni mean is proposed and applied to multi-criteria decision making. An example is given to compare the proposed method with the existing ones. © 2012 Elsevier B.V. All rights reserved. Source


Xu Z.,Nanjing Southeast University | Xu Z.,PLA University of Science and Technology | Zhang X.,PLA University of Science and Technology
Knowledge-Based Systems | Year: 2013

Hesitant fuzzy set (HFS), which allows the membership degree of an element to a set represented by several possible values, is considered as a powerful tool to express uncertain information in the process of multi-attribute decision making (MADM) problems. In this paper, we develop a novel approach based on TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) and the maximizing deviation method for solving MADM problems, in which the evaluation information provided by the decision maker is expressed in hesitant fuzzy elements and the information about attribute weights is incomplete. There are two key issues being addressed in this approach. The first one is to establish an optimization model based on the maximizing deviation method, which can be used to determine the attribute weights. According to the idea of the TOPSIS of Hwang and Yoon [1], the second one is to calculate the relative closeness coefficient of each alternative to the hesitant positive-ideal solution, based on which the considered alternatives are ranked and then the most desirable one is selected. An energy policy selection problem is used to illustrate the detailed implementation process of the proposed approach, and demonstrate its validity and applicability. Finally, the extended results in interval-valued hesitant fuzzy situations are also pointed out. © 2013 Elsevier B.V. All rights reserved. Source


Yu W.,Nanjing Southeast University | Yu W.,RMIT University | Chen G.,City University of Hong Kong | Cao M.,University of Groningen
IEEE Transactions on Automatic Control | Year: 2011

This technical note studies the consensus problem for cooperative agents with nonlinear dynamics in a directed network. Both local and global consensus are defined and investigated. Techniques for studying the synchronization in such complex networks are exploited to establish various sufficient conditions for reaching consensus. The local consensus problem is first studied via a combination of the tools of complex analysis, local consensus manifold approach, and Lyapunov methods. A generalized algebraic connectivity is then proposed to study the global consensus problem in strongly connected networks and also in a broad class of networks containing spanning trees, for which ideas from algebraic graph theory, matrix theory, and Lyapunov methods are utilized. © 2006 IEEE. Source


Zhang X.,Nanjing Southeast University | Xu Z.,University of Sichuan
Applied Soft Computing Journal | Year: 2015

Multi-attribute group decision making (MAGDM) is an important research topic in decision theory. In recent decades, many useful methods have been proposed to solve various MAGDM problems, but very few methods simultaneously take them into account from the perspectives of both the ranking and the magnitude of decision data, especially for the interval-valued intuitionistic fuzzy decision data. The purpose of this paper is to develop a soft computing technique based on maximizing consensus and fuzzy TOPSIS in order to solve interval-valued intuitionistic fuzzy MAGDM problems from such two aspects of decision data. To this end, we first define a consensus index from the perspective of the ranking of decision data, for measuring the degree of consensus between the individual and the group. Then, we establish an optimal model based on maximizing consensus to determine the weights of experts. Following the idea of TOPSIS, we calculate the closeness indices of the alternatives from the perspective of the magnitude of decision data. To identify the optimal alternatives and determine their optimum quantities, we further construct a multi-choice goal programming model based on the derived closeness indices. Finally, an example is given to verify the developed method and to make a comparative analysis. © 2014 Elsevier B.V. All rights reserved. Source


Xu Z.,Nanjing Southeast University | Xu Z.,PLA University of Science and Technology
Knowledge-Based Systems | Year: 2011

Intuitionistic fuzzy numbers (IFNs) are very suitable to be used for depicting uncertain or fuzzy information. Motivated by the idea of power aggregation [R.R. Yager, The power average operator, IEEE Transactions on Systems, Man, and Cybernetics-Part A 31 (2001) 724-731], in this paper, we develop a series of operators for aggregating IFNs, establish various properties of these power aggregation operators, and then apply them to develop some approaches to multiple attribute group decision making with Atanassov's intuitionistic fuzzy information. Moreover, we extend these aggregation operators and decision making approaches to interval-valued Atanassov's intuitionistic fuzzy environments. © 2011 Published by Elsevier B.V. Source


Zhua B.,Nanjing Southeast University
Procedia Computer Science | Year: 2013

Hesitant fuzzy sets (HFSs), as an extension of fuzzy sets, consider the degrees of membership by a set of possible values rather than a single one. For further applications of HFSs to decision making, we develop a concept of hesitant fuzzy preference relations (HFPRs) as a tool to collect and present decision makers' (DMs) preferences. Due to the importance of consistency measure for HFPRs to ensure that DMs are being neither random nor illogical, we develop a regression method to transform HFPRs to fuzzy preference relations (FPRs) with the highest consistency level. Some examples are given for illustration. © 2013 The Authors. Published by Elsevier B.V. Source


Zhang L.,Nanjing Southeast University
Zhonghua jie he he hu xi za zhi = Zhonghua jiehe he huxi zazhi = Chinese journal of tuberculosis and respiratory diseases | Year: 2012

The aim of this study was to evaluate the efficacy and safety of procalcitonin-guided algorithms of antibiotic therapy in lower respiratory tract infections. Using procalcitonin, lower respiratory tract infections, community acquired pneumonia, exacerbations of COPD, exacerbations of chronic obstructive pulmonary diseases, acute bronchitis and asthma as key words, we searched relevant randomized controlled trials (RCT) from Pubmed, EMBASE, Cochrane Library, Chinese Journal Full-text Database, Chinese Biomedical Literature Database, and traced the related references to obtain the information that had not been found. The date of the search was from January of 1990 to December of 2010.We made quality assessment of qualified RCTs assessed by the exclusion and inclusion criteria and used RevMan 4.2.2 provided by the Cochrane Collaboration to perform meta-analysis. Five RCT involving 2322 patients were identified. There were significant differences between procalcitonin-guided treatment and standard treatment in duration of antibiotic treatment in days (WMD = -2.58 d, 95%CI: -3.13 to -2.04, Z = 9.36, P < 0.001), antibiotic prescription rate (OR = 0.23, 95%CI: 0.12 - 0.44, Z = 4.52, P < 0.001), antibiotic costs (WMD = USD-91.72, 95%CI: -109.44 to -74.00, Z = 10.15, P < 0.001) and persistent/relapsed infection rate (OR = 0.70, 95%CI: 0.5 - 0.97, Z = 2.13, P = 0.03). There were no statistical differences in rate of need for intensive care (OR = 0.8, 95%CI: 0.59 - 1.09, Z = 1.41, P = 0.16), in hospital mortality (OR = 1.01, 95%CI: 0.69 - 1.48, Z = 0.07, P = 0.94), length of hospital stay (WMD = -0.27 d, 95%CI: -0.9 - 0.35, Z = 0.86, P = 0.39), and clinical success rate (OR = 1.04, 95%CI: 0.65 - 1.65, Z = 0.16, P = 0.88). The implementation of a procalcitonin-based algorithm may reduce antibiotic exposure in patients with lower respiratory tract infections, but further research is necessary before the wide adoption of this strategy. Source


Lu Z.,Nanjing Southeast University | Lu Z.,Federico Santa Maria Technical University | Schmidt I.,Federico Santa Maria Technical University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2010

We extract the Boer-Mulders functions for the proton by combining the unpolarized pd and pp Drell-Yan data measured by the E866/NuSea Collaboration by the assumption that the cos asymmetry is from the Boer-Mulders functions. Using the extracted Boer-Mulders functions, we present the predictions for the cos asymmetries in future pp experiments at J-PARC and pp̄ experiments at PANDA and PAX. © 2010 The American Physical Society. Source


Zhao X.,Nanjing Southeast University | Evans T.M.,North Carolina State University
Granular Matter | Year: 2011

Discrete element method is used to simulate granular assembly behaviors with different initial conditions under three different loading conditions-plain strain, conventional triaxial compression, and direct shear. Different deformation modes of specimens with different conditions are presented. Some important parameters of the critical state theory are investigated. Uniqueness of the critical state line is checked which shows that there is no a unique critical state line for specimens with different initial void ratios under different loading conditions. Frictional angles and dilation angles of specimens with different conditions at critical state are compared. Void ratios and coordination numbers of specimens at critical state are studied. Anisotropies of the particle orientation and normal contact force at initial state, critical state, as well as the evolutions during shearing are analyzed. The anisotropy is shown to have significant effects on the soil behaviors and is related to the non-uniqueness of the critical state line. The developed numerical models can be used to study the micromechanics and microstructure of the specimen subjected to different loading conditions in the future. © Springer-Verlag 2011. Source


Lu Z.,Nanjing Southeast University | Schmidt I.,Federico Santa Maria Technical University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

We study the polarized Drell-Yan processes from the collision of two spin-1/2 hadrons at order 1/Q based on the framework of transverse-momentum dependent factorization. We give the complete twist-three results of total 16 independent structure functions in terms of twist-two and twist-three transverse-momentum dependent distribution functions. © 2011 American Physical Society. Source


Jiang Y.,Nanjing Southeast University | Jiang Y.,Duke University | Marszalek P.E.,Duke University
EMBO Journal | Year: 2011

In spite of extensive research, the mechanism by which MutS initiates DNA mismatch repair (MMR) remains controversial. We use atomic force microscopy (AFM) to capture how MutS orchestrates the first step of E. coli MMR. AFM images captured two types of MutS/DNA complexes: single-site binding and loop binding. In most of the DNA loops imaged, two closely associated MutS dimers formed a tetrameric complex in which one of the MutS dimers was located at or near the mismatch. Surprisingly, in the presence of ATP, one MutS dimer remained at or near the mismatch site and the other, while maintaining contact with the first dimer, relocated on the DNA by reeling in DNA, thereby producing expanding DNA loops. Our results indicate that MutS tetramers composed of two non-equivalent MutS dimers drive E. coli MMR, and these new observations now reconcile the apparent contradictions of previous 'sliding' and 'bending/looping' models of interaction between mismatch and strand signal. © 2011 European Molecular Biology Organization | All Rights Reserved. Source


Yang F.,Lanzhou University | Mei Z.L.,Lanzhou University | Jin T.Y.,Lanzhou University | Cui T.J.,Nanjing Southeast University
Physical Review Letters | Year: 2012

We present the first experimental demonstration of a dc electric cloak for steady current fields. Using the analogy between electrically conducting materials and resistor networks, a dc invisibility cloak is designed, fabricated, and tested using the circuit theory. We show that the dc cloak can guide electric currents around the cloaked region smoothly and keep perturbations only inside the cloak. Outside the cloak, the current lines return to their original directions as if nothing happens. The measurement data agree exceptionally well with the theoretical prediction and simulation result, with nearly perfect cloaking performance. The proposed method can be directly used to realize other dc electric devices with anisotropic conductivities designed by the transformation optics. Manipulation of steady currents with the control of anisotropic conductivities has a lot of potential applications, such as electric impedance tomography, graphene, natural resource exploration, and military camouflage. © 2012 American Physical Society. Source


Kang W.,Nanjing Southeast University | Ulukus S.,University of Maryland University College
IEEE Transactions on Information Theory | Year: 2011

We study a special class of diamond channels which was introduced by Schein in 2001. In this special class, each diamond channel consists of a transmitter, a noisy relay, a noiseless relay and a receiver. We prove the capacity of this class of diamond channels by providing an achievability scheme and a converse. The capacity we show is strictly smaller than the cut-set bound. We note that there exists a duality between this diamond channel coding problem and the Kaspi-Berger source coding problem. © 2011 IEEE. Source


Zhai J.-Y.,Nanjing Southeast University
IET Control Theory and Applications | Year: 2013

This study discusses the problem of decentralised output-feedback control for a class of stochastic non-linear systems under weaker conditions. Based on the adding one power integrator technique and homogeneous domination approach, a homogeneous observer and controller are constructed for each nominal subsystem without the perturbing non-linearities. Then, a scaling gain is introduced into the homogeneous observers and controllers to render the closed-loop system to be globally asymptotically stable in probability. Two simulation examples are provided to show the effectiveness of the control scheme. © The Institution of Engineering and Technology 2013. Source


Kang W.,University of Maryland University College | Kang W.,Nanjing Southeast University | Ulukus S.,University of Maryland University College
IEEE Transactions on Information Theory | Year: 2011

In the distributed coding of correlated sources, the problem of characterizing the joint probability distribution of a pair of random variables satisfying an n -letter Markov chain arises. The exact solution of this problem is intractable. In this paper, we seek a single-letter necessary condition for this n-letter Markov chain. To this end, we propose a new data processing inequality on a new measure of correlation through a spectral method. Based on this new data processing inequality, we provide a single-letter necessary condition for the required joint probability distribution. We apply our results to two specific examples involving the distributed coding of correlated sources: multiple-access channel with correlated sources and multiterminal rate-distortion region, and propose new necessary conditions for these two problems. © 2006 IEEE. Source


Zhao D.,Nanjing Southeast University | Reynaert P.,Catholic University of Leuven
IEEE Journal of Solid-State Circuits | Year: 2015

This paper describes a direct-conversion E-band transmitter (TX) in 40 nm bulk CMOS. As millimeter-wave (mm-Wave) circuits are vulnerable to process variations including the mismatch between interconnects, this E-band TX design is conducted in a layout floor-plan oriented way. Compact and symmetrical floor-plans of poly-phase filter (PPF) and I/Q modulator are presented in this work to suppress the LO feed-through (LOFT) and I/Q imbalance over both 71-76 and 81-86 GHz bands. In addition, a systematic design methodology is proposed for the mm-Wave PPF to reduce required EM simulations. The calibration methods used in this design are easy to implement for further reducing LOFT and I/Q imbalance with negligible impact on other TX performance metrics. The 0.225 mm2 E-band TX achieves a measured output power of 12 dBm and efficiency of 15% with about 15 GHz bandwidth. It features an uncalibrated I/Q imbalance of less than 30 dB from 62.5 to 85.5 GHz. The calibration circuits further reduce the I/Q imbalance by about 4 dB and ensure the LOFT of less than -30 dBc over more than 30 dB output dynamic range. The presented TX achieves 4.5 Gb/s 64-QAM and 14 Gb/s 16-QAM. © 1966-2012 IEEE. Source


Zhu Q.,Ningbo University | Cao J.,Nanjing Southeast University
Neurocomputing | Year: 2010

In this paper, the global asymptotic stability is investigated for stochastic neural networks of neutral type with both Markovian jump parameters and mixed time delays. The jumping parameters are modeled as a continuous-time, finite-state Markov chain. By employing the Lyapunov-Krasovskii functional and stochastic analysis theory as well as linear matrix inequality technique, some novel sufficient conditions are derived to guarantee the global asymptotic stability of the equilibrium point in the mean square. The proposed model of neutral type is quite general since many factors such as noise perturbations, Markovian jump parameters and mixed time delays are considered in this paper. The activation functions in this paper may be neither monotonically increasing nor continuously differentiable, and they are more general than those usual Lipschitz conditions. The results obtained in this paper comprise and generalize those given in the previous literature. Two numerical examples are provided to show the effectiveness of the theoretical results. © 2010 Elsevier B.V. Source


Qiu J.,Linyi Normal University | Qiu J.,Nanjing Southeast University
Neurocomputing | Year: 2010

In this paper, the global exponential stability and the existence of periodic solution are studied for a class of high-order Hopfield neural networks (HHNNs) with time delays by employing Lyapunov method and linear matrix inequality (LMI) technique. Several simple sufficient conditions are given ensuring global exponential stability and the existence of periodic solution of HHNNs. The obtained results improve some previous works and do not require the symmetry of weight ma