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Chengdu, China

Southwest Jiaotong University is a national key university in Chengdu, Sichuan, affiliated to the Ministry of the Education of China. The university is a member of the 211 Project and the 985 Project. Wikipedia.

Huang Z.W.,Southwest Jiaotong University | Huang Z.W.,University of Birmingham
Intermetallics | Year: 2013

A near lamellar γ-TiAl alloy Ti-44Al-4Nb-4Zr-0.2Si-1B was ingot cast and exposed at 700°C for up to 10,000 h. The combined addition of Nb and Zr rather than Nb alone has a positive effect on stabilization of α2 lamellae. Compared to alloy Ti-44Al-8Nb-1B, less amount of α2 dissolved and less amount of β (B2 + ω) formed in the alloy after the same exposure scheme. However, the exposure-induced embrittlement is still severe in this alloy. The ductility after 10,000-h exposure is only 1/4 of the original value. The exposure-induced embrittlement is attributed to the profound changes in prior β regions: the precipitation of fine D88-ω particles in the B82-ω matrix; the prevalent formation of γ grains inside the prior β regions; and the widespread precipitation of silicide particles at cell interfaces and β grain boundaries. The tensile strengths remain essentially unchanged while fatigue limit increased significantly. The mechanism behind the microstructural changes and mechanical properties is discussed in detail. © 2013 Elsevier Ltd. All rights reserved. Source

Suo W.J.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

To study the effects of deformation on bridges, the finite element analysis method was used. The railway continuous curved rigid frame bridge has been taken into account. Both the deadweight, prestress, and creep of the concrete were used for comparative analysis about the effect on displacement and twisting angel, then some practical application conclusions were obtained. The maximum reaction values were produced in different sections under the extreme cantilever stage and the finished bridge stage. Futhermore, the study of structural spatial behaviors is of great importance. © (2014) Trans Tech Publications, Switzerland. Source

Ye G.,Chongqing University | Yuan H.,Southwest Jiaotong University | Shen L.,Hong Kong Polytechnic University | Wang H.,Chongqing Education College
Resources, Conservation and Recycling | Year: 2012

Construction waste management (CWM) can affect society from an economic perspective, a social perspective and an environmental perspective. It is found from existing literature that scant attention has been paid to take account of the dynamics nature of the CWM system and interactions among major variables in the system when evaluating its environmental performance. Therefore, in order to fill the research gap, we develop a model for evaluating the environmental performance of CWM by using a system dynamics approach; particular focus is given to the dynamic interrelations among major variables in the CWM system and how the dynamics interactions can influence the environmental performance of CWM. The application of the proposed model is demonstrated based on a real case from the construction industry of China. The simulation results not only provide valuable information on how to improve the environmental performance of CWM in the studied project, but also help build confidence in the dynamic model in general so that it can be adopted to simulate, evaluate, and subsequently improve the environmental performance of CWM in construction projects. © 2012 Elsevier B.V. All rights reserved. Source

Wang S.-Y.,Southwest Jiaotong University
Jisuanji Jicheng Zhizao Xitong/Computer Integrated Manufacturing Systems, CIMS | Year: 2010

A dynamic data exchange solution was proposed for the dynamic requirements of collaborative commerce platform for industry chain. Aiming at design and implementation of data exchange Agent model, the PDE-RULES stipulation of data exchange centered on platform of industry chain was proposed. Relevant technologies such as the base of XML-based rule-base conditions and platform data exchange interface based on Web Service were studied. The adapter of platform data exchange interface and the adapter of client were designed and realized. Therefore, the dynamic keyword-driven data exchange as the users'identity and business exchange was accomplished. By application in the collaborative commerce platform of auto industrial chain, results revealed that this method could satisfy dynamic requirements of exchange object and content for platform data. Source

Ma G.T.,TU Darmstadt | Ma G.T.,Southwest Jiaotong University | Rauh H.,TU Darmstadt
Superconductor Science and Technology | Year: 2013

Numerical simulations of thermo-electromagnetic properties of a thin type-II superconductor strip surrounded by open cavity soft-magnetic shields and exposed to an oscillating transverse magnetic field are performed by resorting to the quasistatic approximation of a vector potential approach in conjunction with the classical description of conduction of heat. The underlying definition of the superconducting constituent makes use of an extended 'smoothed' Bean model of the critical state, which includes the field and temperature dependence of the induced supercurrent as well. The delineation of the magnetic shields exploits the reversible-paramagnet approximation in the Langevin form, as appropriate for magnetizations with narrow Z-type loops, and considers induced eddy currents too. The coolant is envisaged as acting like a bath that instantly takes away surplus heat. Based on the Jacobian-free Newton-Krylov approach and the backward Euler scheme, the numerical analysis at hand is tailored to the problem of a high width/thickness aspect ratio of the superconductor strip. Assigning representative materials characteristics and conditions of the applied magnetic field, the main findings for a practically relevant magnet configuration include: (i) an overall rise of the maximum temperature of the superconductor strip tending to saturation in a superconducting thermo-electromagnetic steady state above the operating temperature, magnetic shielding lending increased stability and smoothing the temperature profile along the width of the superconductor strip; (ii) a washing out of the profile of the magnetic induction and a lowering of its strength, a relaxation of the profile of the supercurrent density and an increase of its strength, a tightening of the power loss density and a reduction of its strength, all inside the superconductor strip. The hysteretic ac loss suffered by the superconductor strip is seen to be cut back or, at most, to converge on that of an unshielded strip, thermo-electromagnetic coupling merely playing an insignificant part thereby. © 2013 IOP Publishing Ltd. Source

Ma Z.,Changzhou University | Xia J.,Changzhou University | Bao B.,Changzhou University | Sha J.,Southwest Jiaotong University
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2013

Dual pulse skipping modulation (DPSM), a novel modulation technique for the control of switching power converter was proposed. Unlike pulse skipping modulation (PSM) technique realizing the output voltage regulation by unique control pulse, DPSM technique extends unique control pulse to dual control pulse, and thus overcomes the drawback of relatively large output voltage ripple of switching power converters governed by PSM. Buck converter operating in discontinuous conduction mode (DCM) is taken as an example to explain the operation principle and control laws of DPSM technique. Simulation and experimental results are presented to indicate that DPSM buck converter, with favorable transient performance, has much lower output ripple than PSM buck converter and much wider load adjustable range than pulse train (PT) controlled buck converter. © 2013 Chin. Soc. for Elec. Eng. Source

Yuan H.,Southwest Jiaotong University
Waste Management | Year: 2012

It has been determined by existing literature that a lot of research efforts have been made to the economic performance of construction waste management (CWM), but less attention is paid to investigation of the social performance of CWM. This study therefore attempts to develop a model for quantitatively evaluating the social performance of CWM by using a system dynamics (SD) approach. Firstly, major variables affecting the social performance of CWM are identified and a holistic system for assessing the social performance of CWM is formulated in line with feedback relationships underlying these variables. The developed system is then converted into a SD model through the software iThink. An empirical case study is finally conducted to demonstrate application of the model. Results of model validation indicate that the model is robust and reasonable to reflect the situation of the real system under study. Findings of the case study offer helpful insights into effectively promoting the social performance of CWM of the project investigated. Furthermore, the model exhibits great potential to function as an experimental platform for dynamically evaluating effects of management measures on improving the social performance of CWM of construction projects. © 2012 Elsevier Ltd. Source

Wang Y.,Shanghai JiaoTong University | Wei Y.,Southwest Jiaotong University | Wu C.,Shanghai JiaoTong University
Physica A: Statistical Mechanics and its Applications | Year: 2010

In this paper, we investigate the cross-correlations between Chinese A-share and B-share markets. Qualitatively, we find that the return series of Chinese A-share and B-share markets were overall significantly cross-correlated based on the analysis of a statistic. Quantitatively, employing the detrended cross-correlation analysis, we find that the cross-correlations were strongly multifractal in the short-term and weakly multifractal in the long-term. Moreover, the cross-correlations of small fluctuations were persistent and those of large fluctuations were anti-persistent in the short-term while cross-correlations of all kinds of fluctuations were persistent in the long-term. Using the method of rolling windows, we find that the cross-correlations were weaker and weaker over time, especially after the price-limited reform. We attribute the fact to the improvement of market efficiency. On the volatility series, our results show that the cross-correlations were much stronger than those between return series. Results from rolling windows show that the short-term cross-correlations between volatility series are still high now. We also provide some relevant discussions later. © 2010 Elsevier B.V. All rights reserved. Source

Wang Y.,Shanghai JiaoTong University | Wei Y.,Southwest Jiaotong University | Wu C.,Shanghai JiaoTong University
Physica A: Statistical Mechanics and its Applications | Year: 2010

In this paper, we investigate the long-range auto-correlated behavior of WTI crude oil volatility series employing multifractal detrended fluctuation analysis. Our findings show that the for small time scales, the auto-correlations of volatilities were multifractal while for large time scales, the auto-correlations were nearly monofractal. Based on multiscale analysis, we also investigate the dynamics of auto-correlations for different intervals of time scales and find that several shocks could make significant effects on the auto-correlated behaviors for small time scales. Analyzing the dynamics of multifractality degrees of auto-correlations for small time scales, we find that the stronger auto-correlations were always related to the lower degrees of multifractality. At last, we have discussions on the determination factors of price behavior, the predictive implications of scaling behavior in volatilities for oil markets and the reasons why long-range auto-correlations of volatility were always strong for both small time scales and large time scales. Our results are very important theoretically and practically. © 2010 Elsevier B.V. All rights reserved. Source

Jiang X.,Southwest Jiaotong University | Lyles R.W.,Michigan State University | Guo R.,Tsinghua University
Accident Analysis and Prevention | Year: 2014

Objective The goal is to comprehensively examine the state-of-the-art applications and methodological development of quasi-induced exposure and consequently pinpoint the future research directions in terms of implementation guidelines, limitations, and validity tests. Methods The paper conducts a comprehensive review on approximately 45 published papers relevant to quasi-induced exposure regarding four key topics of interest: applications, responsibility assignment, validation of assumptions, and methodological development. Results Specific findings include that: (1) there is no systematic data screening procedure in place and how the eliminated crash data will impact the responsibility assignment is generally unknown; (2) there is a lack of necessary efforts to assess the validity of assumptions prior to its application and the validation efforts are mostly restricted to the aggregated levels due to the limited availability of exposure truth; and (3) there is a deficiency of quantitative analyses to evaluate the magnitude and directions of bias as a result of injury risks and crash avoidance ability. Conclusions The paper points out the future research directions and insights in terms of the validity tests and implementation guidelines. © 2013 Elsevier Ltd. Source

Jayakar K.,Pennsylvania State University | Liu C.,Southwest Jiaotong University
Telecommunications Policy | Year: 2014

This paper examines the contrast between China's and India's universal service policies as manifestations of the two states' differing self-conceptualizations and legitimation strategies. We examine the timeline of universal service policies in the two countries, differentiating between the territorial, demographic and layered dimensions of universal service. The analysis reveals many similarities between the two countries, as well as some differences primarily related to the mode of funding universal service programs and the lead China has taken in deploying informatization services. We identify some of the proximate causes that resulted in these policy decisions. But in addition, we also examine how universal service policies are related to contrasting models of state legitimation. © 2013 Elsevier Ltd. Source

Webb R.C.,University of Illinois at Urbana - Champaign | Bonifas A.P.,University of Illinois at Urbana - Champaign | Behnaz A.,U.S. National Institutes of Health | Zhang Y.,Tsinghua University | And 15 more authors.
Nature Materials | Year: 2013

Precision thermometry of the skin can, together with other measurements, provide clinically relevant information about cardiovascular health, cognitive state, malignancy and many other important aspects of human physiology. Here, we introduce an ultrathin, compliant skin-like sensor/actuator technology that can pliably laminate onto the epidermis to provide continuous, accurate thermal characterizations that are unavailable with other methods. Examples include non-invasive spatial mapping of skin temperature with millikelvin precision, and simultaneous quantitative assessment of tissue thermal conductivity. Such devices can also be implemented in ways that reveal the time-dynamic influence of blood flow and perfusion on these properties. Experimental and theoretical studies establish the underlying principles of operation, and define engineering guidelines for device design. Evaluation of subtle variations in skin temperature associated with mental activity, physical stimulation and vasoconstriction/dilation along with accurate determination of skin hydration through measurements of thermal conductivity represent some important operational examples. © 2013 Macmillan Publishers Limited. All rights reserved. Source

Pei Y.-L.,Beihang University | He J.,Xian University of Science and Technology | Li J.-F.,Tsinghua University | Fuli,Tsinghua University | And 7 more authors.
NPG Asia Materials | Year: 2013

We report on the high thermoelectric performance of p-type polycrystalline BiCuSeO, a layered oxyselenide composed of alternating conductive (Cu 2Se2)2- and insulating (Bi2O 2)2+ layers. The electrical transport properties of BiCuSeO materials can be significantly improved by substituting Bi3+ with Ca2+ . The resulting materials exhibit a large positive Seebeck coefficient of ∼+330μVK-1 at 300 K, which may be due to the 'natural superlattice' layered structure and the moderate effective mass suggested by both electronic density of states and carrier concentration calculations. After doping with Ca, enhanced electrical conductivity coupled with a moderate Seebeck coefficient leads to a power factor of ∼4.74μWc-1K-2 at 923 K. Moreover, BiCuSeO shows very low thermal conductivity in the temperature range of 300 (∼0.9 Wm -1 K-1 )to923K(∼0.45 Wm-1K-1 ). Such low thermal conductivity values are most likely a result of the weak chemical bonds (Young's modulus, E∼76.5 GPa) and the strong anharmonicity of the bonding arrangement (Gruneisen parameter, γ∼1.5). In addition to increasing the power factor, Ca doping reduces the thermal conductivity of the lattice, as confirmed by both experimental results and Callaway model calculations. The combination of optimized power factor and intrinsically low thermal conductivity results in a high ZT of ∼0.9 at 923K for Bi 0.925Ca0.075CuSeO. © 2013 Nature Publishing Group . Source

Tong S.,Southwest Jiaotong University
World Information on Earthquake Engineering | Year: 2015

Based on instantaneous optimal control, the author derived the approximate discrete instantaneous optimal control algorithm. Using Lyapunov's second method, the author indicated a sufficient condition for the stability of the new algorithm. Selecting the 20-story Benchmark II model as the model for analyzing and the El seismic wave as the load for the model, the author carried out a numerical simulation to illustrate the effectiveness of the new control algorithm. Results of the numerical simulation shows that the controlled system was stable. Comparing with the responses of the model without control, responses of the model under the instantaneous optimal control and approximate discrete instantaneous optimal control were evidently reduced. Responses of the model under instantaneous optimal control and approximate discrete instantaneous optimal control showed no evident difference. © 2015, Science Press. All right reserved. Source

Zhang H.,Southwest Jiaotong University | Lewis F.L.,University of Texas at Arlington
Automatica | Year: 2012

A practical design method is developed for cooperative tracking control of higher-order nonlinear systems with a dynamic leader. The communication network is a weighted directed graph with a fixed topology. Each follower node is modeled by a higher-order integrator incorporating with unknown nonlinear dynamics and an unknown disturbance. The leader node is modeled as a higher-order nonautonomous nonlinear system. It acts as a command generator giving commands only to a small portion of the networked group. A robust adaptive neural network controller is designed for each follower node such that all follower nodes ultimately synchronize to the leader node with bounded residual errors. Moreover, these controllers are distributed in the sense that the controller design for each follower node only requires relative state information between itself and its neighbors. A simulation example demonstrates the effectiveness of the algorithm. © 2012 Elsevier Ltd. All rights reserved. Source

Zhang H.,Southwest Jiaotong University | Chen J.,City University of Hong Kong
International Journal of Robust and Nonlinear Control | Year: 2016

This paper studies bipartite consensus problems for continuous-time multi-agent system over signed directed graphs. We consider general linear agents and design both state feedback and dynamic output feedback control laws for the agents to achieve bipartite consensus. Via establishing an equivalence between bipartite consensus problems and the conventional consensus problems under both state feedback and output feedback control approaches, we make direct application of existing state feedback and output feedback consensus algorithms to solve bipartite consensus problems. Moreover, we propose a systematical approach to design bipartite consensus control laws. © 2016 John Wiley & Sons, Ltd. Source

Chen Z.,Southwest Jiaotong University | Zhu Z.,Nanchang Institute of Technology | Shao Y.,Chongqing University
Engineering Failure Analysis | Year: 2015

Planetary gear transmission has a wide application in different areas due to its advantages such as compactness, large torque-to-weight ratio, reduced noise and vibrations. However, its dynamic responses are much more complex due to the complicated structures and relative motions, which make it difficult in the fault feature extractions at the view point of fault detection. Better understanding on the dynamic features of a planetary gear transmission and the corresponding internal excitation sources will benefit the fault feature extractions. In this paper, an analytical model for mesh stiffness calculation is developed based on the potential energy principle and uniformly curved Timoshenko beam theory, which enables exploring the effects of the tooth root crack fault and the flexible ring gear rim on the dynamic responses. Based on the developed model, the frequency spectrum structures of the planetary gear transmission can be revealed and analyzed theoretically in the presence of tooth crack and flexible ring gear. A case study is performed to demonstrate the effectiveness of the developed model, where the tooth root cracks are seeded in a tooth of the sun, planet, and ring gears. The simulated results indicate that the complicated modulation phenomenon can be observed where the causes of different frequency components can be revealed. This study is expected to be able to give some theoretical guidance on the identification of vibration sources for planetary gear transmissions. © 2015 Elsevier Ltd. Source

Wen G.,Hunan University | Xu H.,Hunan University | Xie J.,Southwest Jiaotong University
Nonlinear Dynamics | Year: 2011

The feedback control problem of designing Hopf-Hopf interaction bifurcations into a dry friction system at a pre-specified parameter point is addressed. A new bifurcation criterion without using eigenvalues is established to preferably determine the control gains. Numerical simulation shows that the torus solution of Hopf-Hopf interaction bifurcation can be created in the friction system at a desired parameter location. © 2010 Springer Science+Business Media B.V. Source

Zhang S.-C.,Southwest Jiaotong University
International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz | Year: 2014

Based on the conservation of particle number, the analytical expressions of the Gaussian-profile density and the self-field of the equilibrium electron beam are deduced in terms of the macroscopic design parameters. Compared to the Gaussian-profile model, both the particle-distribution and the self-field effect of the equilibrium electrons are overestimated by the uniform-profile model. It is demonstrated by the experimental examination that a Gaussian-profile model is much better coincident with the actual fact of the equilibrium electron beam than a uniform-profile model. © 2014 IEEE. Source

Zhang S.-C.,Southwest Jiaotong University
International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz | Year: 2014

Nonlinear simulations show that compared to an axial guide magnetic field, the ion-channel guide field has the advantageous properties in confining the electron motion and stability, resulting in smaller velocity spread and configuration spread of the electrons. The intrinsic factor of this physical phenomenon is that the ion-channel guide field provides the electron motion a smaller Larmor radius and slighter guiding-center excursion from the wiggler axis than an axial magnetic field does. It is also found that over-focusing may occur if the ion-channel guide field is too strong. © 2014 IEEE. Source

Ren F.,Hong Kong University of Science and Technology | Ren F.,University of Illinois at Urbana - Champaign | Lu X.,Southwest Jiaotong University | Leng Y.,Hong Kong University of Science and Technology
Journal of the Mechanical Behavior of Biomedical Materials | Year: 2013

Ab initio quantum mechanical (QM) calculations were employed to study the crystal structure and elastic properties of carbonated apatite (CAp). Two locations for the carbonate ion in the apatite lattice were considered: carbonate substituting for OH- ion (type-A), and for PO4 3- ion (type-B) with possible charge compensation mechanisms. A combined type-AB substitution (two carbonate ions replacing one phosphate group and one hydroxyl group, respectively) was also investigated. The results show that the most energetically stable substitution is type-AB, followed by type-A and then type-B. The most stable configuration of type-A has its carbonate triangular plane almost parallel to c-axis at z=0.46. The lowest energy configuration of type-B is that with a sodium ion substituting for a calcium ion for charge balance and the carbonate lying on the b/c-plane of apatite. Lattice parameter changes after carbonate substitution in hydroxyapatite (HA) agree with reported experimental results qualitatively: for type-A, lattice parameter a increases but c decreases; and for type-B, lattice parameter a decreases but c increases. Using the calculated CAp stable structures, we also calculated the elastic properties of CAp and compared them with those of HA and biological apatites. © 2013 Elsevier Ltd. Source

Yue Y.,Southwest Jiaotong University
Nonlinear Analysis: Real World Applications | Year: 2011

A single-degree-of-freedom symmetric impact oscillator between two rigid stops is considered. The system is strongly nonlinear due to the existence of impacts. The symmetric period n-2 motion of the system is obtained analytically, and the Poincar map is established. The dynamics of the system can be investigated by studying the symmetric fixed point, because symmetric period motion corresponds to a symmetric fixed point of the Poincar map. Because of the symmetry of the Poincar map, a symmetric fixed point of the Poincar map only has pitchfork bifurcation. The stability of the symmetric fixed point is determined by the eigenvalues of the Jacobian matrix of the Poincar map. For an attractor in the Poincar section, all the Lyapunov exponents can be computed via the Jacobian matrix of the Poincar map. Numerical simulations show that the symmetric period motion is stable for larger values of excitation frequency, smaller values of excitation amplitude and smaller values of mass. When the control parameter changes continuously, the symmetric fixed point loses its stability, and generates a pair of antisymmetric period-doubling sequences via pitchfork bifurcation, which subsequently lead to symmetric chaos. The top Lyapunov exponent can be used to distinguish long periodic motion from chaotic motion. © 2010 Published by Elsevier Ltd. All rights reserved. Source

Wei X.,Southwest Jiaotong University
Tiedao Xuebao/Journal of the China Railway Society | Year: 2011

The 3D FEM model of the integral joints of the bottom chord of the inclined main truss of the Zhengzhou Yellow River Highway-railway Bridge was established by using ANSYS. The law of stress distribution of the integral joints subjected to be designed most unfavorable load combination was investigated. Specimen tests of the integral joints with a scale of 1:2 were carried out. Comparing FEM analysis with the specimen tests, the stresses at test points in the FEM model were found to be in good agreement with those of tested specimens. The fine numerical FEM analysis can be used as an effective method to determine local stress distribution of the integral joints and as the basis of structure design. In the loading process where the maximum load reaches 1.4 times of the design load, the linear relationship between measured strains and applied loads indicates that all test points remain in a linear elastic state and stresses of all members are less than the allowable stresses specified in the design code. The bearing capacity of the integral joints is seen to meet the need of design and to leave sufficient room for the structure safety. Source

Lei D.,Wuhan University of Technology | Guo X.,Southwest Jiaotong University
International Journal of Production Research | Year: 2013

We consider lot streaming problem in a job shop with consistent sub-lots and transportation, in which each lot is regarded as an individual job to reduce management complexity. A modified artificial bee colony (MABC) algorithm is proposed to minimise makespan. An effective two-phase decoding procedure is applied, in which a schedule is first built and then transportation tasks are dispatched. A swap and an insertion are used in the employed bee phase and the onlooker bee phase respectively to produce new solutions. No scouts are considered and the worst solution is replaced with the elite solution every certain cycles to enhance the diversity of the swarm. The testing results and the comparisons of MABC with some methods show that MABC performs better than the chosen algorithms on the considered problem. © 2013 Taylor and Francis Group, LLC. Source

Lei D.,Wuhan University of Technology | Guo X.,Southwest Jiaotong University
Computers and Operations Research | Year: 2016

Previous studies of two-sided assembly line balancing problem (TALBP) are mainly about the first type of the problem.TALBP-II which is to minimize cycle time for a given number of stations is seldom investigated. In this study an effective variable neighborhood search (VNS) is proposed to solve TALBP-II. A novel two-string representation is used, which is composed of a precedence- based task string and a side selection string. New solutions are produced by using a side selection operator and two precedence-based operators. A novel comparison principle is applied to guarantee the feasibility of the solutions and approximate the optimal solution. VNS is tested on a number of instances and compared with the existing methods. The computational results show the promising advantage of VNS on the considered TALBP-II. © 2016 Elsevier Ltd. Source

Zhang Z.H.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

Based on the status of tower crane safety monitoring for construction project, the Internet of things technology is applied for tower crane safety monitoring and early warning system, the WSN nodes are designed for displacement, stress and distance monitoring function. Through the wireless transceiver module CC2530, field monitoring data are uploaded timely and accurately to the monitoring center PC, for real-time display and processing. If the monitoring data exceeds the alarm value, the alarm signal will be sent out immediately, to prevent tower crane accidents effectively, and ensure the safe of crane operation. By the network debugging, WSN node performance is reliable, and the measuring data is accurate. It has high performance to price ratio and application value. © (2014) Trans Tech Publications, Switzerland. Source

Xu K.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

According to the investigation and survey of the service condition of the double-block ballastless track in China, the breakage rate in the rich rainfall areas or the poor drainage lots of double-block ballastless track runs much faster than the dry areas. Some typical diseases, such as sleeper loose, contact loss between sleeper and roadbed slab, will lead to water still in the sleeper void. Free water underneath the sleepers would become dynamic water with certain pressure and flow rate under the high speed and high frequency action of train loads. Dynamic water is able to accelerate crack growth rate and scour the bonding interfaces between sleeper and roadbed slab[1,2], affecting the safety,durability and riding quality of track structure. It is meaningful for us to research on sleeper loose of double-block ballastless track under the coupling action of train load and dynamic water and prove the mechanism of sleeper loose in double-block ballastless track under action of dynamic water. Calculating the value of water pressure and velocity of flow and then providing references for study on the hydrodynamic characteristics. © (2014) Trans Tech Publications, Switzerland. Source

Luo S.,Southwest Jiaotong University
Zhongguo Tiedao Kexue/China Railway Science | Year: 2010

Based on the relationship between the inertia force and the hunting frequency & wavelength of the wheelset, the influence of the track gauge on the vehicle yaw stability was studied. The analysis results were validated through the numerical calculations of the eigenvalue for single wheelset running gear and the bogie running gear under different track gauge. Results show that for single wheelset running gear, the wider is the track gauge the higher is the critical stability speed of the vehicle. But for the bogie running gear, the wider is the track gauge the lower is the critical stability speed of the vehicle. The critical stability speed of the single wheelset running gear can be improved after the elastic location being adopted. The optimized suspension design can make the rolling stock achieve high critical stability speed after the elastic location being adopted for the bogie. For the bogie running gear, the impact of the speed on its stability is equivalent with that of the wheel base. Under otherwise fixed conditions, 20% increase of the wheel base can lead to 20% increase of its critical stability speed. The equivalent conicity of the wheel tread and the nominal rolling circle diameter have the same impact with the track gauge on the critical stability speed of the single wheelset or bogie running gear. To increase the conicity or decrease the wheel diameter, both can reduce the stability of the rolling stock. Source

Wang G.,Ningbo University | Chen H.,Southwest Jiaotong University | Li Y.,Ningbo University | Ansari N.,New Jersey Institute of Technology
IEEE Transactions on Wireless Communications | Year: 2014

In this paper, we address the time-of-arrival (TOA) based localization problem in an adverse environment, where line-of-sight (LOS) signal propagation between the source and the sensor is not readily available, in which case we have to resort to non-line-of-sight (NLOS) signals. Two convex relaxation methods, i.e., the semidefinite relaxation (SDR) and the second-order cone relaxation (SOCR) methods, are proposed to mitigate the effect of NLOS errors on the localization performance. We consider two separate cases in which the information of the NLOS status is totally unknown and perfectly known, respectively. The proposed methods can be applied without knowing the distribution of NLOS errors. Moreover, we propose a NLOS error mitigation method that is robust to detection errors, which are generated in the process of detecting NLOS paths. Simulation results show that the proposed convex relaxation methods outperform some existing state-of-the-art methods. © 2002-2012 IEEE. Source

Liao Y.,Southwest Jiaotong University
Tiedao Xuebao/Journal of the China Railway Society | Year: 2010

Mass transit is one of the primary characteristics of intercity trains. In order to derive the headway of intercity trains of the mass transit type which serve two central cities, the process of passenger arrival at train station is regarded as a scholastic process according to the principle of rare events. The interval between passengers arrival complies with exponential distribution. The dual objective and nonlinear optimization model is established after the benefit of the railway enterprise and passengers are considered, the fist goal of which is the minimization of the expectation of the total waiting time of passengers, and the second is the maximization of the expectation of the waiting time of the train. The constraint is the train must achieve requisite seat occupancy rate for satisfying operation costs and save the number of motor train units. The principle and process of the fuzzy multi-objective optimization method is introduced, and matlab 7.0 is applied to solve the model. At last, a numerical example illustrates the model's validity and feasibility. Source

Wang H.,Southwest Jiaotong University | Shan H.,University of Minnesota | Banerjee A.,University of Minnesota
Statistical Analysis and Data Mining | Year: 2011

Cluster ensembles provide a framework for combining multiple base clusterings of a dataset to generate a stable and robust consensus clustering. There are important variants of the basic cluster ensemble problem, notably including cluster ensembles with missing values, row- or column-distributed cluster ensembles. Existing cluster ensemble algorithms are applicable only to a small subset of these variants. In this paper, we propose Bayesian cluster ensemble (BCE), which is a mixed-membership model for learning cluster ensembles, and is applicable to all the primary variants of the problem. We propose a variational approximation based algorithm for learning Bayesian cluster ensembles. BCE is further generalized to deal with the case where the features of original data points are available, referred to as generalized BCE (GBCE). We compare BCE extensively with several other cluster ensemble algorithms, and demonstrate that BCE is not only versatile in terms of its applicability but also outperforms other algorithms in terms of stability and accuracy. Moreover, GBCE can have higher accuracy than BCE, especially with only a small number of available base clusterings. Copyright © 2011 Wiley Periodicals, Inc. Source

Yan F.,Southwest Jiaotong University | Dridi M.,University of Technology of Belfort - Montbeliard | Moudni A.E.,University of Technology of Belfort - Montbeliard
International Journal of Applied Mathematics and Computer Science | Year: 2013

This paper addresses a vehicle sequencing problem for adjacent intersections under the framework of Autonomous Intersection Management (AIM). In the context of AIM, autonomous vehicles are considered to be independent individuals and the traffic control aims at deciding on an efficient vehicle passing sequence. Since there are considerable vehicle passing combinations, how to find an efficient vehicle passing sequence in a short time becomes a big challenge, especially for more than one intersection. In this paper, we present a technique for combining certain vehicles into some basic groups with reference to some properties discussed in our earlier works. A genetic algorithm based on these basic groups is designed to find an optimal or a near-optimal vehicle passing sequence for each intersection. Computational experiments verify that the proposed genetic algorithms can response quickly for several intersections. Simulations with continuous vehicles are carried out with application of the proposed algorithm or existing traffic control methods. The results show that the traffic condition can be significantly improved by our algorithm. Source

Zhou X.J.,Southwest Jiaotong University | Yang C.Y.,The 1st Design Institute of Civil Engineering and Architecture
Applied Mechanics and Materials | Year: 2013

Structural design and construction process for a subway station consists of two tunnels with large transection are discussed according to its function and geological conditions of rock mass in this paper. A composite lining is designed to support surrounding rock, and partial bench cut method, side drift method are utilized to build the special subway transfer station in rock mass. The practice of the designed scenario proves to be a great success and attains the safe construction of the station by tunneling method. © (2013) Trans Tech Publications, Switzerland. Source

Luo M.-X.,Southwest Jiaotong University | Deng Y.,University of Sichuan
Quantum Information Processing | Year: 2013

Immeasurability of a quantum state has important consequence in practical implementation of quantum computers. Our purpose is to analyze the efficiency of the entangled output of Pati-Braunstein deleting machine or Wootters-Zurek quantum copying machine as a quantum channel. Interestingly we find that for special values of the input parameter the state does not violate the Bell's inequality. Moreover, we analyze the performances of the entangled output of Pati-Braunstein deleting after the Wootters-Zurek copying machine. © 2012 Springer Science+Business Media, LLC. Source

Huang M.,Southwest Jiaotong University
ICTE 2011 - Proceedings of the 3rd International Conference on Transportation Engineering | Year: 2011

Transit Metropolis, as a city development strategy, has become the direction of China's central cities. However, lack of implementation, the domestic researches on public transit city are mainly in introduction. By analysis the mechanism of foreign successful cases, based on three strategies, supply, demand and space, this paper establishes a model to build Transit Metropolis, which is applicable to China's central cities. Spatial layout of city along the axis of public transit and development around stations are the cores of space strategy. A city can be divided into three different areas, guide, adaptive and support. Combined with "Smart growth theory" and "TOD" theory, from three levels, macro, meso and micro, this paper gives thorough explanation of the space strategy. In the end, the application to the construction of Public Transit City of Shenzhen demonstrates that the model is scientific and feasible. © 2011 ASCE. Source

Cai J.,Southwest Jiaotong University
ICTE 2011 - Proceedings of the 3rd International Conference on Transportation Engineering | Year: 2011

Running the project of high-speed railway can't do without suppliers, suppliers' excellent degree impact on the business of growing material supply, and affect the entire project's quality, progress and the efficiency. Therefore, for high-speed railway construction project, among a number of uneven level material suppliers, supplier evaluation is of great significance. Through analyzing and designing evaluation index system can ensure that the suppliers can provide the best service, products, and the timely delivery, and strive to obtain the lowest cost and optimal products; out unqualified suppliers; develop potential suppliers, continue to introduce new suppliers; maintain and develop well-developed, long-term and stable supplier partnerships. The graduation thesis summarizes the target analysis which the domestic and foreign suppliers appraise, According to the requirements of high-speed railway construction and the characteristic selection evaluating indicator according to the high-speed railroad, construction evaluating indicator system. The indexes should meet high-speed railway construction quality at the core of the "high standard","high quality","high speed", bulk materials through supervise Party A controlled evaluation of the quality materials to ensure the stability and the stability of material usage. The thesis describe the design process of high-speed railway construction evaluation index supply system, including design principles, methods of selecting indicators and the selection process. Combine improved AHP and a simple model, identifying the weight of every index. According to the design evaluating indicator system in some high-speed railway construction company some road section steel products purchase supplier appraisal. Through the programming, may complete the supplier static state appraisal to the dynamic evaluation transition, not only raise the appraisal efficiency and the rate of accuracy greatly, but also provide convenient evaluation for high-speed railway construction. According to the design of evaluation index system applied in the specific case of steel procurement of supplier evaluation. Through programming, the dynamic evaluation is a favorable means of high-speed railway projection supplier evaluation. The result indicates this method is suitable for the chosen about material supply evaluation for high-speed railway construction. © 2011 ASCE. Source

Li Y.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

During the progress of improvement on scientific technology and national economy level. Chinese financial industry is growing strongly and fast. Facing to large data in network technology and various of uncertain risk factors, firstly the development situation of information technology of commercial bank has been introduced, then the problem in information technology of commercial bank has been analysed. Also we have suggested improvement by using value engineering. Finally finally we have made the conclusion. © (2014) Trans Tech Publications, Switzerland. Source

Xu Y.,Southwest Jiaotong University | Liu J.,University of Ulster | Ruan D.,Belgian Nuclear Research Center | Li X.,Dongbei University of Finance and Economics
Information Sciences | Year: 2011

Key issues for resolution-based automated reasoning in lattice-valued first-order logic LF(X) are investigated with truth-values in a lattice-valued logical algebraic structure-lattice implication algebra (LIA). The determination of resolution at a certain truth-value level (called α-resolution) in LF(X) is proved to be equivalently transformed into the determination of α-resolution in lattice-valued propositional logic LP(X) based on LIA. The determination of α-resolution of any quasi-regular generalized literals and constants under various cases in LP(X) is further analyzed, specified, and subsequently verified. Hence the determination of α-resolution in LF(X) can be accordingly solved to a very broad extent, which not only lays a foundation for the practical implementation of automated reasoning algorithms in LF(X), but also provides a key support for α-resolution-based automated reasoning approaches and algorithms in LIA based linguistic truth-valued logics. © 2010 Published by Elsevier Inc. All rights reserved. Source

Tong X.,Southwest Jiaotong University
Asia-Pacific Power and Energy Engineering Conference, APPEEC | Year: 2010

The wide-area communication network (WAN) has become fundamental support for wide-area control systems in power system. A co-simulation extending for WAN has been studied to provide the communication interfaces to and from OPNET. The co-simulation framework includes the demand side (the control systems based on WAN), co-simulation module (cosim), OPNET and its extended modules. The key technologies are studied, such as the external system module (esys) in OPNET, a virtual UDP application connecting esys to UDP layer, cosim, and the exchange mode between communication demand side and cosim. The implementation of prototype system is given. The simulation testing illustrates the effectiveness of the extending working. It will provide a reference for the simulation in other control systems with WAN in power system. ©2010 IEEE. Source

Li N.,Southwest Jiaotong University | Tang X.,University of Chinese Academy of Sciences
IEEE Transactions on Information Theory | Year: 2011

Three classes of binary sequences of period 4N with optimal autocorrelation value/magnitude have been constructed by Tang and Gong based on interleaving certain kinds of sequences of period N , i.e., the Legendre sequence, twin-prime sequence and generalized GMW sequence. In this paper, by means of sequence polynomials of the underlying sequences, the properties of roots of the corresponding sequence polynomials of the interleaved sequences with period 4N and optimal autocorrelation value/magnitude are discussed in the splitting field of xN-1. As a consequence, both the minimal polynomials and linear complexities of these three classes of sequences are completely determined except for the case of the sequences obtained from the generalized GMW sequences. For the latter, the minimal polynomial and linear complexity can be specially obtained if the sequence is constructed based on m-sequences instead of generalized GMW sequences. © 2011 IEEE. Source

Li A.,University of Melbourne | Chen X.,University of Melbourne | Al Amin A.,University of Melbourne | Ye J.,University of Melbourne | And 2 more authors.
Journal of Lightwave Technology | Year: 2012

Space-division multiplexed (SDM) transmission based on multi-core (MCF) or multi-mode fiber (MMF) emerges as one of the most promising solutions for overcoming the capacity limit of standard single mode fiber (SSMF). This paper places a focus on the MMF transmission for which a data rate of 100-Gb/s and beyond has been recently demonstrated through coherent-optical OFDM (CO-OFDM) and single-carrier (SC) superchannel transmission based on specially-designed few-mode fibers (FMF). However, to unleash the full potential of the high data rate SDM transmission requires brand-new research from device to system level. In this paper, we elucidate the overall system architecture, critical components and sub-system modules for SDM transmission and report the up-to-date demonstration of SDM superchannel transmission. We envisage that the combination of SDM and OFDM modulation could be a potential key route to the future Tb/s and beyond optical transports. © 1983-2012 IEEE. Source

Fu F.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

In the process of urbanization, along with industrial development and population growth, demand of water is rapidly increasing, causing water shortages. Some rivers, lakes, wetlands and other water bodies are invaded, as well as the demise of the transformation has been a serious threat to the survival and development of human society. Therefore, river restoration is one of the hot researches in recent years. In this paper, the author made a preliminary summary on river restoration and repair, technology and related engineering examples in order to promote domestic demand for river restoration longitudinal in-depth study and try to raise the domestic ecological restoration in future research directions: River ecological restoration is a long process. The design process should be integrated into the concept of sustainable development and build a public participation platform integrated with experts, designers, and user. And river restoration technology and related engineering examples literature play the role of reference and guidance on the selection of the river restoration project technical measures. © (2014) Trans Tech Publications, Switzerland. Source

Wang Y.,Shanghai JiaoTong University | Wei Yu.,Southwest Jiaotong University | Wu C.,Shanghai JiaoTong University
Physica A: Statistical Mechanics and its Applications | Year: 2011

In this paper, we study the auto-correlations and cross-correlations of West Texas Intermediate (WTI) crude oil spot and futures return series employing detrended fluctuation analysis (DFA) and detrended cross-correlation analysis (DCCA). Scaling analysis shows that, for time scales smaller than a month, the auto-correlations and cross-correlations are persistent. For time scales larger than a month but smaller than a year, the correlations are anti-persistent, while, for time scales larger than a year, the series are neither auto-correlated nor cross-correlated, indicating the efficient operation of the crude oil markets. Moreover, for small time scales, the degree of short-term cross-correlations is higher than that of auto-correlations. Using the multifractal extension of DFA and DCCA, we find that, for small time scales, the correlations are strongly multifractal, while, for large time scales, the correlations are nearly monofractal. Analyzing the multifractality of shuffled and surrogated series, we find that both long-range correlations and fat-tail distributions make important contributions to the multifractality. Our results have important implications for market efficiency and asset pricing models. © 2010 Elsevier B.V. All rights reserved. Source

Wang Y.,Shanghai JiaoTong University | Wei Yu.,Southwest Jiaotong University | Wu C.,Shanghai JiaoTong University
Physica A: Statistical Mechanics and its Applications | Year: 2011

In this paper, we investigate the efficiency and multifractality of a gold market based on multifractal detrended fluctuation analysis. Our evidence shows that the gold return series are multifractal both for time scales smaller than a month and for time scales larger than a month. For time scales smaller than a month, the main contribution of multifractality is fat-tail distribution. For time scales larger than a month, both long-range correlations and fat-tail distribution play important roles in the contribution of multifractality. Using the method of rolling windows, we find that the gold market became more and more efficient over time, especially after 2001. The abnormal points of scaling exponents can also be related to some occasional events. By defining a new inefficiency measure related to the multifractality, we find that the gold market is more efficient during the upward periods than during the downward periods. © 2010 Elsevier B.V. All rights reserved. Source

Tang X.,Southwest Jiaotong University | Parampalli U.,University of Melbourne
IEEE Transactions on Information Theory | Year: 2010

In this paper, we are concerned with Hadamard matrices with a certain noncyclic property. First we show that when the first column of a Sylvester Hadamard matrix of order 2m, m ≥ 2, a positive integer, is removed, the number of shift distinct row vectors in the matrix is given by 2m-m. Then, for m ≥ 4, we construct an infinite family of Hadamard matrices with a property that when the first column of the Hadamard matrix is removed, all the row vectors of the matrix are shift distinct. These Hadamard matrices are useful in constructing low correlation zone sequences. © 2010 IEEE. Source

Zheng G.Y.,Central South University | Li P.,Southwest Jiaotong University | Zhao C.Y.,Central South University
Applied Clay Science | Year: 2013

Due to the complexity of the non-linear consolidation of soft clay, numerical method is always adopted to its solution. The differential quadrature method (DQ method) equaling to a high precision finite difference method can obtain highly accurate numerical solutions of differential equations using less grid points. This numerical method is always used to solve the complicated nonlinear physical problem governed by partial equations. In this paper, DQ method is implemented to one dimensional non-liner consolidation equation and the boundary conditions. Euler forward scheme is used to solve the discrete equation, and the pore pressure and consolidation curves are prepared. The present numerical results are compared with the analytical solutions. Compared with the other numerical method, the method of solving the non-linear consolidation equation by the DQ method in this paper is very simple and reasonable. The DQ method is successfully implemented to the soft clay consolidation analysis and can assure satisfied numerical results with less grid points. © 2013 Elsevier B.V. Source

Zhang G.,Southwest Jiaotong University | Gheorghe M.,University of Sheffield | Pan L.,Huazhong University of Science and Technology | Perez-Jimenez M.J.,University of Seville
Information Sciences | Year: 2014

Evolutionary membrane computing is an important research direction of membrane computing that aims to explore the complex interactions between membrane computing and evolutionary computation. These disciplines are receiving increasing attention. In this paper, an overview of the evolutionary membrane computing state-of-the-art and new results on two established topics in well defined scopes (membrane-inspired evolutionary algorithms and automated design of membrane computing models) are presented. We survey their theoretical developments and applications, sketch the differences between them, and compare the advantages and limitations. © 2014 Elsevier Inc. All rights reserved. Source

Kang G.,Southwest Jiaotong University
Acta Mechanica Solida Sinica | Year: 2013

The accumulation of inelastic deformation occurring in NiTi shape memory alloy under the stress-controlled cyclic loading condition is named transformation ratcheting, since it is mainly caused by the solid-solid transformation from austenite to martensite phase and vice versa. The transformation ratcheting and its effect on the fatigue life (i.e., transformation-fatigue interaction) are key issues that should be addressed in order to assess the fatigue of NiTi shape memory alloy more accurately. In this paper, the advances in the studies on the transformation ratcheting and ratcheting-fatigue interaction of super-elastic NiTi shape memory alloy in recent years are reviewed: First, experimental observation of the uniaxial transformation ratcheting and ratcheting-fatigue interaction of super-elastic NiTi alloy under the stress-controlled cyclic loading conditions is treated, and the detrimental effect of transformation ratcheting on the fatigue life is addressed; Secondly, two types of cyclic constitutive models (i.e., a macroscopic phenomenological model and a micromechanical one based on crystal plasticity) constructed to describe the transformation ratcheting of super-elastic NiTi alloy are discussed; Furthermore, an energy-based failure model is provided and dealt with by comparing its predicted fatigue lives with experimental ones; Finally, some suggestions about future work are made. © 2013 The Chinese Society of Theoretical and Applied Mechanics. Source

Liu C.,Southwest Jiaotong University | Jayakar K.,Pennsylvania State University
Telecommunications Policy | Year: 2012

This paper is a comparative analysis of the telecommunications policy-making process in China and India. Adopting an institutionalist perspective and multi-streams framework, the paper analyzes the formal structures, rule-making procedures and interest groups involved in telecommunications policy-making in the two countries, in terms of their evolution over the last two decades. Though the two systems began this period with a somewhat similar ministerial-bureaucratic decision-making model, and faced similar problems of assimilating new interest groups and responding to international pressures, the paper finds that the decision systems in the two countries evolved in significantly different directions. Chinas telecommunications decision-making is significantly affected by the macro level political rearrangement and is more likely to be non-incremental. On the other hand, confronted by an increasingly litigious environment and a more fractious interest group culture, India represents a somewhat classical textbook case of incremental policy making. Nevertheless, numerous challenges remain in both countries, including institutional capacity and excessive regulatory deference to political authority. © 2011 Elsevier Ltd All rights reserved. Source

Cai L.,Southwest Jiaotong University
Chinese Control Conference, CCC | Year: 2015

This paper investigates the relationship between overshoot and damping injection for the Port-Hamiltonian (PH) system subject to actuator saturation (AS). According to the decay function, the relationship between overshoot and damping injection for the PH system subject to AS is clear, that is, if the damping injection of control law is larger, the overshoot of PH system subject to AS is smaller. Simulation results are given to show the correctness of presented relationship. © 2015 Technical Committee on Control Theory, Chinese Association of Automation. Source

Wan B.N.,Southwest Jiaotong University
Open Civil Engineering Journal | Year: 2015

The damage caused by earthquake is irresistible for human beings, and the structure with poor robustness is most affected by earthquake. Especially when traffic arteries like bridges and highways are affected, the losses will be unimaginable. To reduce the loss in earthquake, the paper targets the long-span cable-stayed bridge and discusses a method of structural damage control. The energy-dissipation auxiliary pier structure can protect the bridge under strong shock, which has an important realistic significance for reducing losses of the bridge. The model of auxiliary pier is built in the paper. Through the experiment, many aspects including destructive process, hysteretic characteristics, ductility and hysteretic energy, equivalent viscous damping ratio and deforming capacity of energy-dissipation construction are analyzed. Structural damage control can well enhance the safety of bridge. The internal force and displacement of main components can be reduced correspondingly, and thus the safety of long-span cable-stayed bridge is well protected. © Ning Wan; Licensee Bentham Open. Source

Zhang G.-X.,Southwest Jiaotong University
Circuits, Systems, and Signal Processing | Year: 2010

Time-frequency atom decomposition (TFAD) provides a flexible representation for non-stationary signals, but the extremely high computational effort greatly blocks its practical applications. Quantum-inspired evolutionary algorithms (QEA) are efficient optimization methods with strong search capability and rapid convergence. This paper proposes the application of a modified variant of QEA to the TFAD problem. The problem on TFAD with evolutionary algorithms is formulated. By using gray coding, elite groups, and an appropriate termination criterion, the modified QEA is developed to search the suboptimal time-frequency atoms from a very large and redundant time-frequency dictionary. Also, this paper discusses the reduction of the computational time in terms of parameter setting, and presents an application example of radar emitter signals. Extensive experiments show the effectiveness and practicability of the presented algorithm. © Springer Science+Business Media, LLC 2009. Source

Zhang Y.,Xijing University | Zhang Y.,Southwest Jiaotong University
Journal of Modern Transportation | Year: 2012

The aerodynamic drag on a train running in an evacuated tube varies with tube air pressure, train speed and shape, as well as blockage ratio. This paper uses numerical simulations to study the effects of different factors on the aerodynamic drag of a train running at subsonic speed in an evacuated tube. Firstly, we present the assumption of a steady state, two dimensional, incompressible viscous flow with lubricity wall conditions. Subsequently, based on the Navier-Stokes equation and the k-ε turbulent models, we calculate the aerodynamic drag imposed on the column train with a 3-meter diameter running under different pressure and blockage ratio conditions in an evacuated tube transportation (ETT) system. The simulation is performed with FLUENT 6.3 software package. An analyses of the simulation results suggest that the blockage ratio for ETT should be in the range of 0.25-0.7, and the tube internal diameter in the range of 2-4 m, with the feasible vacuum pressure in the range of 1-10000 Pa for the future subsonic ETT trains. © 2012 JMT. All rights reserved. Source

Chen M.-W.,China Railway First Survey and Design Institute Group Co. | Chen M.-W.,Southwest Jiaotong University
Dianli Xitong Baohu yu Kongzhi/Power System Protection and Control | Year: 2011

In order to assure the uninterrupted power supply of high speed railway, the reliability assessment of traction substation is essential at the design stage. A new system reliability analysis method, called the GO methodology, is applied in the reliability assessment of traction substation of high speed railway. Considering the maintainability and shutdown correlation of electrical equipments in substation, the simplified GO diagram is obtained by taking the uninterrupted power supply as its target. Then, the quantitative and qualitative assessment of reliability is realized, the weakness of system is found and the sum of probabilities of minimal cut sets can be calculated as the upper limit of substation failure probability, which can be used for the reliability design of traction power supply system of high speed railway. Source

Cui N.,Southwest Jiaotong University
Journal of Geometry and Physics | Year: 2016

The flag curvature of a Finsler surface is called the Gaussian curvature in Finsler geometry. In this paper, we characterize the surfaces of constant Gaussian curvature (CGC) in the Randers 3-manifold. Then we give a classification of the orientable closed CGC surfaces in two Randers space forms, which are the non-Euclidean Minkowski-Randers 3-space (K = 0) and the Bao-Shen sphere (K = 1). © 2016 Elsevier B.V. Source

Wang C.,Southwest Jiaotong University | Sun D.,National University of Singapore | Toh K.-C.,National University of Singapore
SIAM Journal on Optimization | Year: 2010

We propose a Newton-CG primal proximal point algorithm (PPA) for solving large scale log-determinant optimization problems. Our algorithm employs the essential ideas of PPA, the Newton method, and the preconditioned CG solver. When applying the Newton method to solve the inner subproblem, we find that the log-determinant term plays the role of a smoothing term as in the traditional smoothing Newton technique. Focusing on the problem of maximum likelihood sparse estimation of a Gaussian graphical model, we demonstrate that our algorithm performs favorably compared to existing state-of-the-art algorithms and is much preferred when a high quality solution is required for problems with many equality constraints. © 2010 Society for Industrial and Applied Mathematics. Source

Li Y.-L.,Southwest Jiaotong University | Li Y.-L.,Northeastern University China | Chin K.-S.,City University of Hong Kong | Luo X.-G.,Northeastern University China
Expert Systems with Applications | Year: 2012

Quality function deployment (QFD) has been widely used to translate customer requirements (CRs) into engineering characteristics (ECs) in product planning and improvement. Product planning house of quality (PPHOQ) is of fundamental and strategic importance in the QFD system. Correctly determining the final priority ratings of CRs is essential in the process of constructing PPHOQ, because it will largely affect the target value of ECs for product improvement. This paper present a systematic and operational method based on the integration of a minimal deviation based method (MDBM), balanced scorecard (BSC), analytic hierarchy process (AHP) and scale method to determine the final priority ratings of CRs. To exploit the competition and preference information of product improvement, the MDBM is developed to determine the CPRs of CRs. A concept of the total output of achieving the ITPE of a CR is introduced and analyzed by using the integration of BSC, AHP and scale method in a qualitative and quantitative way, and then the priority rating of achieving the ITPE of this CR is determined. Finally, a case study is provided to illustrate the effectiveness of the proposed method. © 2011 Elsevier Ltd. All rights reserved. Source

Chen H.,Southwest Jiaotong University | Chen X.,University of Sichuan
Nonlinearity | Year: 2016

In this paper, we continue to study the global dynamics of a cubic Liénard system for global parameters in the case of three equilibria to follow (2015 Nonlinearity 28 3535-62), which deals with the case of two equilibria. We first analyse qualitative properties of all equilibria and judge the existences of limit cycles and homoclinic loops and their numbers. Then we obtain the bifurcation diagram and all phase portraits as our main results. Based on these results, in the case of three equilibria a positive answer to conjecture 3.2 of (1998 Nonlinearity 11 1505-19), which is about the existence of some function whose graph is exactly the surface of double limit cycles, is obtained. Moreover, a parameter region for the nonexistence of figure-eight loops is given theoretically to compensate for previous numerical results and is illustrated numerically. © 2016 IOP Publishing Ltd & London Mathematical Society. Source

Cai L.-C.,Southwest Jiaotong University
International Journal of Automation and Computing | Year: 2015

This paper investigates the simultaneous stabilization of Port-Hamiltonian (PH) systems subject to actuation saturation (AS) and input delay. Firstly, two parallel connecting PH systems subject to the AS and input delay are proposed. Secondly, a simultaneous stabilization control law is designed by a difference between the two feedback control laws containing the input delay. Thirdly, computing a Lyapunov-Krasovskii function assures the simultaneous stabilization of the above systems. Finally, simulation is given to show the correctness of the proposed contents. © 2015 Institute of Automation, Chinese Academy of Sciences and Springer-Verlag Berlin Heidelberg Source

Khan M.K.,King Saud University | Zhang J.,Southwest Jiaotong University | Alghathbar K.,King Saud University
Future Generation Computer Systems | Year: 2011

This paper presents a challenge/response-based biometric image scrambling scheme which attempts to overcome the liveness and retransmission issues of biometric image transmission over insecure communication channel. An intelligent biometric sensor is proposed which has computational power to receive challenges from authentication server and generates response against the challenge with encrypted biometric image. The fractional Fourier transform (FRT) has been used for a biometric image encryption process with its scaling factors and random phase masks as the secret keys. The random phase masks of FRT are chaotically generated by piecewise linear chaotic map (PWLCM) to further improve the encryption security. Experimental and simulation results have demonstrated that the proposed system is secure, robust, and deters the risks of attacks for secure biometric image transmission. © 2010 Elsevier B.V. All rights reserved. Source

Lu M.,Southwest Jiaotong University
ICCTP 2010: Integrated Transportation Systems: Green, Intelligent, Reliable - Proceedings of the 10th International Conference of Chinese Transportation Professionals | Year: 2010

The development of inter-city railway in China will greatly facilitate people's travel between cities. Accessibility is a fundamental concept in transportation analysis and planning. Typically, the accessibility of an inter-city railway station means an ease level from an origin to the railway station that can be used to evaluate the service performance of an inter-city railway station. Therefore, the inter-city railway station must have relatively good accessibility in order to reflect the railway's advantage of travel time compared with other traffic modes in terms of four indexes: time, cost, level of comfort and reliability. In this paper, we calculated these four indexes by evaluating the costs of travel time, travel fare and discomfort. This paper mainly discusses the accessibility level depending on groups of people and distances based on each travel mode. © 2010 ASCE. Source

Gong X.,Southwest Jiaotong University | Li X.-X.,University of Sichuan | Feng L.,Sichuan Normal University | Xia R.,Chongqing University of Posts and Telecommunications
International Journal of Machine Learning and Cybernetics | Year: 2012

When applying Chan-Vese (C-V) model to segment a face from an image, the result is always influenced by the initial position, especially in a real scenarios with clutter background. An improved skin tone detection model is proposed based on the Gaussian function, which could generate an accurate initial contour for C-V model. As the single Gaussian model (SGM) only uses the prior information to determine the likelihood of a pixel, it lacks adaptability for an image with lighting and poses variances. A more adaptive SGM (ASGM) is proposed in this paper that, by updating the model parameters according to the input image, could provide a more stable approximation of face region. And then, we apply the estimated initial contour to C-V model for precise face segmentation. Tests conducted on a public face dataset (220 images with pose and illumination changes) have shown that the accuracy of skin region detected by ASGM is at a ratio higher than 99%, which lays a good foundation for further segmentation by the C-V model. Extensive experiments have validated effectiveness and efficiency of our system in face segmentation. © 2011 Springer-Verlag. Source

Li Y.,Southwest Jiaotong University
Wei sheng wu xue bao = Acta microbiologica Sinica | Year: 2010

OBJECTIVE: To construct the in-frame deletion gene mutants in streptococcus equi subsp. zooepidemicusby (S. zooepidemicus) by pJR700 plasmid, a thermosensitive delivery vector system. METHOD: With PCR we amplified a 4017-bp DNA fragment of streptococcal hemoprotein receptor gene from chromatosome DNA. This DNA fragment was subcloned into the pJR700 plasmid to create pXL28. Using pXL28 as the template we got the DNA fragment deleted 1831 bp in streptococcal hemoprotein receptor gene by inverse PCR amplification and ligated the in-frame deletion DNA fragment by T4DNase to create pXL30. Then pXL30 was transformed into S. Zooepidemicus by electroperation. The kanamycin( kan)-resistant clones were selected at 37 degrees C in the presence of kan for three rounds. To induce excision of the plasmid vector sequence, the culture was shifted to 30 degrees C and grown without antibiotics for four rounds. Colonies with kan sensitivity, which indicated that the plasmid had been excised, were selected by plating on THY agar at 37 degrees C. S. Zooepidemicus mutants were identified through PCR with primers homologous to the flanking regions and the streptonigrin sensitive test. RESULT: The in-frame deletion streptococcal hemoprotein receptor mutants were successfully built in S. Zooepidemicus. CONCLUSION:The thermosensitive delivery vector system of pJR700 could be utilized to construct the in-frame deletion gene mutant strains of S. Zooepidemicus. Source

Wang S.-R.,Huaqiao University | Ma Z.-J.,Southwest Jiaotong University
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2011

To optimize emergency logistics system for post-earthquake emergency relief response, a twoechelon Location-Routing Problem (LRP) model was developed to decide emergency facility locationallocation and vehicle routes for relief materials delivery. According to the attributes of the model, a 'triangle' heuristic algorithm based on two-phase decomposition was proposed. The complexity of the algorithm was analyzed, and the heuristic algorithm was compared with an improved genetic algorithm. The computational results of a numerical example show that the model and algorithm can resolve LRP in post-earthquake emergency logistics system, and the advantage of the 'triangle' heuristic algorithm in computational efficiency. Source

Li Z.Y.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

By employing the AHP and Fuzzy Comprehensive Evaluation to analyze and quantify risk factors, this paper introduces an effective and practical method for risk assessment in the bridge construction. It also illustrates the characteristics and necessity of risk assessment in bridge construction. © (2014) Trans Tech Publications, Switzerland. Source

Zheng M.,University of Sichuan | Zhang H.,Southwest Jiaotong University | Xu D.,University of Sichuan
Journal of Physical Chemistry B | Year: 2012

Hyaluronate lyase from Spectrococcus pneumonia can degrade hyaluronic acid, which is one of the major components in the extracellular matrix. The major functions of hyaluronan are to regulate water balance and osmotic pressure and act as an ion-exchange resin. In this work, we focus on the prerequisite issue of the enzymatic reaction, i.e., the initial reactive conformer. Based on the quantum mechanical and molecular mechanical molecular dynamic simulations and free energy profiles, a near attack conformer was obtained for the degradation of hyaluronan catalyzed by the hyaluronate lyase. Along with the substrate binding, the phenylhydroxyl hydrogen atom of Tyr408 will transfer to nearby His399 via a near barrierless transition state, which results in a negatively charged Tyr408 and positively charged His399. The Tyr408, rather than the previously proposed His399, was suggested to act as the general base for the subsequent β-elimination reaction. The His399 was suggested to have the function of neutralizing the C5-carboxyl group. © 2012 American Chemical Society. Source

Wang Q.,Southwest Jiaotong University | Chu B.,Keio University | Wang J.,Tokyo Institute of Technology | Kumakiri Y.,Keio University
International Journal of Production Economics | Year: 2012

Flexible supply contracts with options have been proposed to supply chains with long lead-times, short selling seasons and high demand uncertainties to improve the performance. In this paper, we analyze the risks of introducing options, and find that even if providing a higher expected profit at the beginning of a planning horizon, supply contracts with options may have risks associated with a worse performance later compared with the traditional newsvendor contract model. We derive two important parameters for the buyer to estimate the risks of introducing options. One is a risk indicator that can show whether using options-based contract model has risks or not, and the other is a ratio to measure the probability of such risks. © 2010 Elsevier B.V. All rights reserved. Source

Zhao Y.,Southwest Jiaotong University
International Journal of Fatigue | Year: 2012

An affordable and feasible method with moderate accuracy is developed to realize fatigue reliability assessment and life prediction including super long life regime (SLLR) through series of experimental researches on a railway axle steel and real axles. A competition damage mechanism for fatigue crack initiation and growth in SLLR is revealed to fascinate an understanding on wide fatigue damage behavior and to provide a weigh and balance on material primary quality control and on-line inspection capacity. Affordable material probabilistic strength-life (S-N) curves including SLLR are presented by an extrapolation approach on a concurrent probability rule between the S-N relations in mid-long life regime and the fatigue limits with a specified life definition. And then, structural probabilistic S-N curves are deduced by considering scale-induced effect on the material curves. Random cyclic stress-strain (CSS) relations are depicted for constructing structural random stressing history. Reliability assessment and fatigue life prediction are conducted by an interference model of the applied stress deduced from the random CSS relations and the strength capacity derived from the structural probabilistic S-N curves. Availability and feasibility of the present method are indicated by a successful application on a railway axle steel. © 2010 Published by Elsevier Ltd. All rights reserved. Source

Xiao S.-G.,Southwest Jiaotong University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2010

The distribution mode of landslide thrust on anti-sliding piles directly determines the internal forces and their distribution characteristics over the piles. So it has an important effect on the reasonability of design for the anti-sliding piles. Considering real design conditions for the anti-sliding piles in a practical project, pressure formulae of the landslide thrust are provided approximately by the limit equilibrium analysis on differential horizontal layer of sliding body in soil-like slopes or landslide projects. The formulae indicate that the distribution mode is parabolic along the longitudinal axis of direct anti-sliding segment of the pile with smaller value at its two ends than that at its middle part. The results of laboratory model tests on the limit status of sliding body movement show the approximate theoretical method given is realistic. Source

Liu C.,Southwest Jiaotong University
Telecommunications Policy | Year: 2015

Traditionally, the role of telecommunications carriers is often limited to providing connections in rural informatization programs. This paper illustrates the case of Sichuan's government-carrier cooperative rural informatization model, where the carriers serve as both the information aggregator and distributor. A close historical analysis reveals that this seemingly unprofitable rural informatization service was originally conceived by competing carriers as a marketing strategy to gain a competitive advantage in less lucrative markets. However, when the government decided to promulgate such an informatization program nationwide, the business practice turned into one of the carrier's de facto obligations. Thus, Sichuan's model is a mixture of the passive fulfillment of political duty and the proactive pursuit of business interests. A sustainability failure analytical framework is applied to test the sustainability of Sichuan's model, which is found to be at risk of financial, social and institutional sustainability failures. © 2015 Elsevier Ltd. Source

Lu Y.,Southwest Jiaotong University | Rong Z.,Chinese Research Institute of Highway
Proceedings of the Institution of Civil Engineers: Transport | Year: 2016

The technique of placing hot-mix asphalt (HMA) overlay over a rubblised Portland cement concrete (PCC) pavement is a preferable way of rehabilitating severely deteriorated rigid pavements in south-west China. To investigate fragment size effects of the rubblised PCC on the performance of the HMA overlay, two full-scale experiments were carried out in a controllable environment. Strain development in the HMA was evaluated using data collected by strain sensors embedded at the overlay bottom. It was found that the performance of the overlay under repeated loadings was closely related to the fragment size distribution as well as the initial modulus of the rubblised PCC before the HMA was placed. For overlay paved over rubblised PCC with an insufficient amount of medium-sized fragments, tensile strains at the HMA overlay bottom increased with loading repetitions at a relatively high speed. However, if the fragments of rubblised PCC were graded relatively uniformly, particularly if the gradation matched the requirement for the crushed stone base of the flexible pavement, tensile strains at the HMA overlay bottom developed at a slower pace, indicating an improvement in the deterioration resistance of the overlay system to dynamic loads. © 2016, Thomas Telford Services Ltd. All rights reserved. Source

Huang L.,Ningbo University of Technology | Huang L.,Hong Kong Polytechnic University | Xu Y.-L.,Hong Kong Polytechnic University | Liao H.,Southwest Jiaotong University
Journal of Fluids and Structures | Year: 2014

This paper first presents a numerical simulation of nonlinear aerodynamic forces on a thin flat plate through an integration of the computational fluid dynamics (CFD) method and the forced asymptotic oscillation method. The thin flat plate is forced to have either asymptotic torsional oscillation or asymptotic vertical oscillation of increasing amplitude. A multiple-domain mesh technique together with unstructured dynamic meshes is used in the CFD simulation to accommodate large amplitude oscillations of the plate. The instantaneous frequencies and amplitudes of the aerodynamic forces are then identified from the simulated asymptotic aerodynamic force time histories using the continuous wavelet transform (CWT) in terms of the CWT ridges. Extensive numerical studies are finally performed to examine the feasibility of the proposed approach. The results show that the CFD method used in this study can properly simulate nonlinear aerodynamic forces on the plate. The amplitude of the aerodynamic force depends on the amplitude of the forced oscillation and there are high-order harmonic aerodynamic forces of higher frequency than the forced oscillation frequency, both indicating the nonlinearity of aerodynamic forces. The results also show the flutter derivatives associated with self-excited aerodynamic forces depend on the amplitude of forced oscillation in addition to reduced velocity. © 2013 Elsevier Ltd. Source

Deng Q.F.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

The essence of Bashu traditional garden is a blend of north and south garden art and formed the unique style of landscape layout. Patch - corridor- matrix is applied in this article the traditional spatial pattern index analysis method to Bashu garden Xindu Guihu relative uniformity in the landscape diversity, landscape, landscape dominance index, landscape isolation, etc to study the spatial pattern characteristics and its ecological characteristics and related aspects of the evaluation, to Bashu provide quantitative reference value for the further study of the traditional garden. © (2014) Trans Tech Publications, Switzerland. Source

Zou Y.L.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

Based on a tunnel in western China as a project, with high water pressure, water-rich, karst features and other projects, launched grouting water research, the cement-silicate slurry mixing method for determining the mixing ratio to ensure the effectiveness and construction safety grouting key factors, as well as the specific implementation grouting effect evaluation method has important theoretical and practical value for the design and construction of similar tunnels provide a reference. © (2014) Trans Tech Publications, Switzerland. Source

Yuan H.,Southwest Jiaotong University | Lu W.,University of Hong Kong | Jianli Hao J.,Ryerson University
Renewable and Sustainable Energy Reviews | Year: 2013

Construction waste comprises inert (e.g., sand, bricks, and concrete) and non-inert materials (e.g., bamboo, plastics, glass, wood, and paper). In Hong Kong, the inert portion can be deposited at public filling areas for land reclamation while the non-inert portion is disposed of at landfills. However, construction waste is usually a mixture of both inert and non-inert materials and thus a segregation of the two portions is of paramount importance for effective waste minimization. Previous studies have revealed that construction contractors in Hong Kong were unwilling to carry out on-site construction waste sorting (CWS) even though it has numerous advantages. After a decade, the situation should have changed, particularly given the promulgation of a waste charging scheme in 2006 imposing levies on different methods of construction waste disposal. This study thus aims at ascertaining the state-of-the-art on-site CWS practices in Hong Kong, with a particular interest in its evolution over the past ten years. Data was collected through case studies of six construction sites where a hybrid research method included a literature review, non-participant observations, and interviews. It was found that construction waste management (CWM) regulations have significantly enhanced on-site CWS in Hong Kong. Site space and project stakeholders' attitudes are still regarded as the most critical factors but labor and cost are no longer of major concerns in undertaking on-site CWS. Instead, a market for recyclables and an awareness of the profound environmental benefits are now perceived as being of major importance in these practices. Findings from the study can be used to review the effectiveness of current on-site CWS in Hong Kong, and through benchmarking they can also be used to develop good CWS practices in other economies. © 2012 Elsevier Ltd. Source

Both coverage and morphology of endothelial cells (ECs) on blood contact biomaterials were involved in the antithrombotic and anti-proliferative process. However, most researches have been focused on the ECs amount on the materials surface, but not the morphology. As of now, little is known about the relationship between the ECs morphology and the cytokine secretion, especially those anticoagulant factors on cardiovascular implants. In this study, three sizes of parallel micro-stripes of high molecular weight hyaluronic acid (HMW-HA) were fabricated on the NaOH-treated titanium (TiOH) surface. These micro-patterns of ridges/grooves were used to regulate the distribution, morphology and cytokine secretion of the ECs. The roughness of bare Ti and TiOH was detected by AFM, and the micro-pattern sizes were imaged by SEM. The chemical bonding of HMW-HA to the TiOH surface was demonstrated by FTIR, and the element distribution was examined by EDX. The morphology index of the ECs was analyzed to evaluate the orientation, elongation and spreading of the ECs on the micro-patterned surfaces and the control, while the cell number and cytokine secretion of the ECs were measured by related kits. The characterization of the ECs demonstrated that the bigger L/B index improved NO, PGI2, Fn release and TM, TFPI, E-Selectin expression as well as reducing vWF secretion. The platelet adhesion test and the whole blood clotting time test proved the increasing anticoagulation property of ECs with their elongation increasing. These results suggest that ECs morphology-related function can be regulated by different sizes of micro-patterns. Copyright © 2013. Published by Elsevier B.V. Source

Chen L.,Fuzhou University | Zhang J.,Southwest Jiaotong University | Zhuo W.,Fuzhou University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2013

The basic flowchart and state-of-the-art of the seismic risk assessment for a highway bridge system were firstly summarized. Under the background of the highway transportation network in the Wenchuan region, the seismic activity parameters and fault characteristics were analyzed. Based on the magnitude-frequency relationship, annual average probabilities of occurrence for different magnitude earthquakes were calculated and a set of earthquake scenarios were produced. Reconstruction cost of bridges for different categories and damage ratio to different damage states were determined. Based on the fragility functions for different categorical bridges in the previous studies, the mean value and variance of seismic loss of the highway bridge system for each scenario were estimated. Combined with the annual average probabilities of occurrence to earthquake scenarios, risk curve of system loss was generated. The curve can be used as an evidence for overall planning and retrofit strategy of the transportation system in this region. Source

Yan C.-H.,Sichuan Normal University | Wei L.-F.,Southwest Jiaotong University | Wei L.-F.,Sun Yat Sen University
Optics Express | Year: 2015

An external mirror coupling to a cavity with a two-level atom inside is put forward to control the photon transport along a one-dimensional waveguide. Using a full quantum theory of photon transport in real space, it is shown that the Rabi splittings of the photonic transmission spectra can be controlled by the cavity-mirror couplings; the splittings could still be observed even when the cavity-atom system works in the weak coupling regime, and the transmission probability of the resonant photon can be modulated from 0 to 100%. Additionally, our numerical results show that the appearance of Fano resonance is related to the strengths of the cavity-mirror coupling and the dissipations of the system. An experimental demonstration of the proposal with the current photonic crystal waveguide technique is suggested. © 2015 Optical Society of America. Source

Zhou L.,Transport Bureau | Shen Z.,Southwest Jiaotong University
Journal of Modern Transportation | Year: 2011

This is a review of high-speed train development in the sense of technology advances all over the world. Three generations of high-speed trains are classified according to their technical characteristics and maximum operating speed. Emphasis is given to the newly developed high-speed train in China, CRH380. The theoretical foundations and future development of CRH380 are briefly discussed. © 2011 JMT. All rights reserved. Source

Tang M.,Southwest Jiaotong University
International Journal of Electronics | Year: 2014

In this comment, an explicit form of the characteristic function for the extremal filter derived in a recent paper (Pavlović, V. D. (2013). Explicit form of new class of extremal filter functions with mini-max behaviour of summed sensitivity function. International Journal of Electronics, 100, 582-602) is corrected, and the restriction condition of its approximation expression is excluded. © 2014 © 2014 Taylor & Francis. Source

Zhao W.,Southwest Jiaotong University
Lecture Notes in Electrical Engineering | Year: 2014

The database is the core and foundation of the information management system. And the database design is an important part in the design of information management system. The Web-based laboratory information management system selects Microsoft SQL Server 2000 as the database management system, object-oriented database structure design, from the three aspects of the data dictionary, ER diagram, and data table; the reasonable logic and physical design of the database greatly improves the system development efficiency and quality. © Springer-Verlag Berlin Heidelberg 2014. Source

Tan H.C.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

As the progress of theory and computer technology, nonlinear analysis is widely applied in civil engineering. Strip method, as one of the numerical methods, is used widely especially in the analysis of beams, columns and shell structures. The first half of this paper introduces the theoretical model and the basic assumptions of the strip method; the latter half of this paper compiles the strip method into computer program using FORTRAN language. At last, using beams with rectangular cross-section of reinforced concrete structures as an example, the paper analyze the factors, such as the strength of the steel bars, which have an impact on the bearing capacity of reinforced concrete structures. © (2014) Trans Tech Publications, Switzerland. Source

Zhang S.-C.,Xihua University | Zhang S.-C.,Southwest Jiaotong University
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2013

It is revealed that at anti-resonance in a free-electron laser with a reversed guide magnetic field, the beam self-fields can act to focus the beam transport and prevent the electrons from striking on the waveguide wall before the wiggler exit. It is found that the focusing function results from the modulation of the periodically-varying self-field tangential and normal components on the electron's Larmor rotation. As a potential application, substantial improvement of the wave gain and output power at anti-resonance could be expected, since the beam current loss can be obviated by using this modulation mechanism. © 2012 Elsevier B.V. All rights reserved. Source

Li X.-Y.,Southwest Jiaotong University
Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences | Year: 2013

This paper presents fundamental solutions for an infinite space of one-dimensional hexagonal quasicrystal medium, which contains a penny-shaped or half-infinite plane crack subjected to two identical thermal loadings on the upper and lower crack lips. In view of the symmetry of the problem with respect to the crack plane, the original problem is transformed to a mixed boundary problem for a half-space, which is solved by means of a generalized method of potential theory conjugated with the newly proposed general solutions. When the cracks are under the action of a pair of point temperature loadings, fundamental solutions in terms of elementary functions are derived in an exact and complete way. Important parameters in crack analyses such as stress intensity factors and crack surface displacements are presented as well. The underlying relations between the fundamental solutions for the two cracks involved in this paper are discovered. The temperature fields associated with these two cracks are retrieved in alternative manners. The obtained solutions are of significance to boundary element analysis, and have an important role in clarifying simplified studies and serving as benchmarks for computational fracture mechanics can be expected to play. Copyright © The Royal Society 2013. Source

Dou X.,Southwest Jiaotong University
Energy Policy | Year: 2013

For a developing country such as China, it is important to select a fair pattern that is suitable for China's national conditions for low carbon-economy development, as it has a direct impact on the success (or not) of low carbon-economy development. This research shows that, under the real-life conditions of China's development, different development patterns should be practised depending on specific socioeconomic conditions. Among them, one of the most critical issues is how to make full use of natural forces, and thus the nature-oriented development pattern should be practised in full. At the same time, China should still practise either the single regional differential or the multi-regional linkage development pattern under different conditions and either the imposed or the induced development pattern at the different stages of development. © 2013 Elsevier Ltd. Source

Ma J.,Southwest Jiaotong University | Lo S.M.,City University of Hong Kong | Song W.G.,Hefei University of Technology
Fire Safety Journal | Year: 2012

With the development of modern cities, numerous buildings over 40-storey have been constructed in recent decades. Fire safety issues, especially evacuation, are of the major concerns for building designers, occupants, as well as governments. To ensure the safety of ultra high-rise building evacuation, different performance-based designs have been proposed. In this study, we propose a quantitative and viable elevator aided ultra-high rise building evacuation model which simulates both pedestrian movement and elevator transportation. After validation and calibration, the proposed Ultra high-rise building Evacuation with Elevators (UEE) model is adopted to explore two main evacuation strategies, i.e., phased evacuation and total evacuation with the aid of elevators. In these two strategies, refuge floor plays an important part because it not only provides a place for temporarily stop, but also for the transition from stair evacuation into elevator evacuation. Thus, the effect of refuge floor interval on the high-rise building evacuation process is further investigated. It is found that the interval design of refuge floors has a direct relation with the characteristics of the elevators and building occupants. In the case that a proper ratio of the building occupants is transported to the ground level by fast elevators while others are evacuated by stairs, the evacuation process can reach an optimized state. © 2012 Elsevier Ltd. Source

Li W.-A.,Sun Yat Sen University | Wei L.-F.,Sun Yat Sen University | Wei L.-F.,Southwest Jiaotong University
Optics Express | Year: 2012

By using quantum Zeno dynamics, we propose a controllable approach to deterministically generate tripartite GHZ states for three atoms trapped in spatially separated cavities. The nearest-neighbored cavities are connected via optical fibers and the atoms trapped in two ends are tunably driven. The generation of the GHZ state can be implemented by only one step manipulation, and the EPR entanglement between the atoms in two ends can be further realized deterministically by Von Neumann measurement on the middle atom. Note that the duration of the quantum Zeno dynamics is controllable by switching on/off the applied external classical drivings and the desirable tripartite GHZ state will no longer evolve once it is generated. The robustness of the proposal is numerically demonstrated by considering various decoherence factors, including atomic spontaneous emissions, cavity decays and fiber photon leakages, etc. Our proposal can be directly generalized to generate multipartite entanglement by still driving the atoms in two ends. © 2012 Optical Society of America. Source

Jiang X.,Southwest Jiaotong University | Lyles R.W.,Michigan State University
Accident Analysis and Prevention | Year: 2010

In recent years, the quasi-induced exposure technique has been widely implemented in a variety of traffic safety-related settings. One of the primary concerns associated with the applications of quasi-induced exposure is that the underlying assumptions are not explicitly verified or validated before the exposure measurement is adopted. Of principal interest is the assumption that the non-responsible driver/vehicles in two-vehicle crashes are representative of the general driving population on the road at the time of crash occurrence. The objective here is to provide an alternative to test the not-at-fault assumptions with the use of three-or-more-vehicle crashes, which are readily available in many crash databases. With the use of Michigan and Maine crash data as examples, the examination of the validity is developed at two levels: (1) at all locations where crashes took place; (2) at locations where three-or-more-vehicle crashes are prone to occur. Non-responsible drivers are disaggregated by three basic driver-vehicle characteristics (age, gender, and vehicle type) and compared at these two levels for statistical and operational (practical) differences. Examination of the results demonstrates that all of the examined non-responsible driver distributions are consistently similar from both operational and statistical points of view. Compared to other approaches to validation, such as using "exposure truth" (e.g., actual vehicle miles traveled or a trip diary), the proposed validation is much more simplistic, straightforward, and cost-effective. © 2009 Elsevier Ltd. All rights reserved. Source

Zhao P.,Wuhan University | Wang W.,Southwest Jiaotong University | Sun M.,Wuhan University
Plant Cell, Tissue and Organ Culture | Year: 2011

The plant-specific "no apical meristem" genes are transcription factors that play diverse roles in plant development and stress responses. However, whether the gene family is also involved in somatic embryogenesis remains unknown, and no NAC family genes have been identified from orchid species. Here, we cloned and characterized a new member of NAC family from somatic embryos of Dendrobium candidum. Phylogenetic analysis indicated that DcNAC fell into the NAM subgroup based on similarities in protein sequence. Expression pattern analysis indicated that DcNAC exhibited a specific expression pattern in tissues examined, high levels of DcNAC mRNA was detected in protocorm-like bodies, and predominantly in the shoot apical meristem region as detected by in situ hybrization. Subcellular localization analysis showed that DcNAC protein is restricted in the nucleus through transient expression in Nicotiana benthamiana. Thus, DcNAC is the first NAC family gene isolated from orchid species, and our results provide the foundation for future investigations on the molecular mechanisms of somatic embryogenesis and for genetic improvement of Dendrobium candidum. © 2011 Springer Science+Business Media B.V. Source

Jayasinghe R.C.,Georgia State University | Perera A.G.U.,Georgia State University | Zhu H.,University of Georgia | Zhu H.,Southwest Jiaotong University | Zhao Y.,University of Georgia
Optics Letters | Year: 2012

coating material due to their low n profile. Therefore, it is necessary to better understand the optical properties of these nanorods. TiO2 nanorods grown on glass and Si substrates were characterized in the visible (0.4-0.8 μm) and infrared (2-12 μm) regions to extract their complex n profiles empirically. Application of these nanorods in multilayer AR coatings on infrared detectors is also discussed. Optimization of graded index profile of these AR coatings in the broad infrared region (2-12 μm) even at oblique angles of incidence is discussed. The effective coupling between the incoming light and multiple nanorod layers for reducing the reflection is obtained by optimizing the effect from Fabry-Perot oscillations. An optimized five-layer AR coating on GaN shows the reflectance less than 3.3% for normal incidence and 10.5% at 60° across the whole 2-8 μm spectral range. © 2012 Optical Society of America. Source

Tang X.,Southwest Jiaotong University | Helleseth T.,University of Bergen
IEEE Transactions on Information Theory | Year: 2011

In this paper, a simple but generic method is proposed for transforming any family of quaternary sequences, with low correlation, of any odd period N to another family of quaternary sequences of period 2N with low correlation. As an application of the generic method to sequence Family A, a new optimal quaternary sequence family with length 2(2 n-1), family size 2 n+1 , and maximal nontrivial correlation value 2 n+1/2+2, where n is an odd integer, is obtained. Most notably, unlike all the known optimal quaternary sequence families, the new family has a unique property that the odd integers 1, 3 and the even integers 0, 2 are allocated alternatively in all the sequences. © 2011 IEEE. Source

Zhao J.-W.,Southwest Jiaotong University | Wu S.-S.,Huazhong University of Science and Technology
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2010

The microstructure and mechanical properties of the rheo-diecasting (RDC) A390 alloy under as-cast and T6 heat treatment conditions were investigated. The results indicate that the RDC sample has fine and uniform microstructure throughout the sample under the as-cast condition, and the average size of primary Si spheroids is 20-30 μm. Meanwhile, the intermetallic compounds in RDC sample are reduced. Compared with the alloy produced by conventional liquid die-casting(LDC), RDC samples have improved tensile strength, ductility, hardness and wear resistance. It is also found that heat-treatment of the RDC A390 alloy under T6 condition, can substantially improve mechanical properties, with the tensile elongation more than 100 improvement. © 2010 The Nonferrous Metals Society of China. Source

Duan X.J.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

For artificial irrigation in excess or deficiency, not timely and other shortcomings, the paper expounds the application in agricultural and landscape irrigation system based on the wireless sensor network and single chip computer; at the same time the paper designed system architecture of automatic irrigation system based on wireless sensor network. The hardware of the system adopts CC2430 single chip microcomputer as control core, by the real-time acquisition and processing of data in wireless sensor networks, the control data by wireless way is sent to the irrigation controller. The system can real-time monitor the soil temperature and humidity changes, r realize fine flower required and efficient use of water resources. © (2014) Trans Tech Publications, Switzerland. Source

Lu X.,University of Sichuan | Cui S.,Southwest Jiaotong University
Bioresource Technology | Year: 2010

In this paper, we explored a facile method to prepare stable silver nanoparticles (Ag NPs) using extracted wool keratin as the capping agent. The formation of Ag NPs was investigated by UV-Vis spectroscopy, X-ray photo-electron spectrometer and X-ray diffraction spectrometer. The morphology of the NPs was detected by scanning electron microscopy in vacuum and atomic force microscopy in fluid. The possible interactions between the silver core and the capping agent have been investigated using Fourier transform infrared spectroscopy. The effects of keratin concentration on the incubation of the NPs were studied by UV-Vis spectra. It was found that under alkaline condition the process of incubation was much faster than that under neutral pH condition. The photoluminescence properties of the Ag NPs were also investigated. We believe that this work is helpful for the high-value utilization of wool and other keratin-rich bioresource. © 2010 Elsevier Ltd. All rights reserved. Source

Tang X.,Southwest Jiaotong University | Ding C.,Hong Kong University of Science and Technology
IEEE Transactions on Information Theory | Year: 2010

Sequences with optimal autocorrelation property are needed in certain communication systems and cryptography. In this paper, a construction of balanced quaternary sequences with period N ≡ 2 (mod 4) and optimal autocorrelation value and a construction of almost balanced binary sequences with period N ≡ 0 (mod 4) and optimal autocorrelation value are presented. Both constructions are a generalization of earlier ones. © 2006 IEEE. Source

Ding C.,Hong Kong University of Science and Technology | Tang X.,Southwest Jiaotong University
IEEE Transactions on Information Theory | Year: 2010

Binary sequences with low correlation have applications in communication systems and cryptography. Though binary sequences with optimal autocorrelation were constructed in the literature, no pair of binary sequences with optimal autocorrelation are known to have also best possible cross correlation. In this paper, new bounds on the cross correlation of binary sequences with optimal autocorrelation are derived, and pairs of binary sequences having optimal autocorrelation and meeting some of these bounds are presented. These new bounds are better than the Sarwate bounds on the cross correlation of binary sequences with optimal autocorrelation. © 2006 IEEE. Source

Yang J.,Southwest Jiaotong University
ICLEM 2012: Logistics for Sustained Economic Development - Technology and Management for Efficiency - Proceedings of the 2012 International Conference of Logistics Engineering and Management | Year: 2012

The Internet of Things is one of the new fields of future science and technology development, and it leads the world's third information revolution, affecting our production and life. According to the problems existing in current warehouse management, this paper combines the warehouse management system with the Internet of Things technologies, such as RFID, GPS, and sensor technology, to construct an intelligent logistics warehouse management system based on the Internet of Things. This study focuses on analyzing the overall structure, workflow, and functional module of the system. The system proposed solves problems, such as the low efficiency of the logistics information process and the low level of automation, and achieves the cyberization, intelligentization, and informatization of warehouse management. Further research should be made to improve security and to minimize the cost. © 2012 American Society of Civil Engineers. Source

Dashtban M.,Lakehead University | Maki M.,Lakehead University | Leung K.T.,Lakehead University | Mao C.,Southwest Jiaotong University | Qin W.,Lakehead University
Critical Reviews in Biotechnology | Year: 2010

Cellulose, the major constituent of all plant materials and the most abundant organic molecule on the Earth, is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Enzymatic hydrolysis of cellulose requires mixtures of hydrolytic enzymes including endoglucanases, exoglucanases (cellobiohydrolases), and β-glucosidases acting in a synergistic manner. In biopolymer hydrolysis studies, enzyme assay is an indispensable part. The most commonly used assays for the individual enzymes as well as total cellulase activity measurements, including their advantages and limitations, are summarized in this review article. In addition, some novel approaches recently used for enzyme assays are summarized. © 2010 Informa Healthcare USA, Inc. Source

Jia W.Z.,University of Hong Kong | Jia W.Z.,Southwest Jiaotong University | Wang Z.D.,University of Hong Kong
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2013

We explore theoretically the single-photon transport in a single-mode waveguide that is coupled to a hybrid atom-optomechanical system in a strong optomechanical coupling regime. Using a full quantum real-space approach, transmission and reflection coefficients of the propagating single-photon in the waveguide are obtained. The influences of atom-cavity detuning and the dissipation of atom on the transport are also studied. Intriguingly, the obtained spectral features can reveal the strong light-matter interaction in this hybrid system. © 2013 American Physical Society. Source

Li X.Y.,Southwest Jiaotong University
Mechanics Research Communications | Year: 2011

This paper concerns itself with the fundamental solutions of the thermo-electro-elastic field in an infinite medium, weakened by a half-infinite plane crack with two identical point thermal loads applied on the crack surfaces. The corresponding mixed boundary value problem is solved by virtue of the potential theory method conjugated with the general solutions. The boundary governing equations are solved by using the results available in literature. Exact and complete three-dimensional (3D) fundamental solutions are presented in terms of elementary functions. The singularity at the crack tip is analyzed explicitly. The obtained solutions will be of high significance to the related BEM analysis.© 2011 Elsevier Ltd. All rights reserved. Source

Huang G.,Southwest Jiaotong University
Journal of Engineering Mechanics | Year: 2015

The classic spectral representation method (SRM)-based nonstationary process simulation algorithm is used extensively in the engineering community. However, it is less efficient owing to the unavailability of fast Fourier transform (FFT). In this paper, an efficient, almost accurate, and straightforward algorithm is developed for the simulation of the multivariate nonstationary process. In this method, an evolutionary spectral matrix is decomposed via Cholesky method, and then proper orthogonal decomposition (POD) is used to factorize decomposed spectra as the summation of the products of time and frequency functions. Because original time-dependent decomposed spectra are decoupled via factorization, FFT can be used to significantly expedite the simulation efficiency. This POD-based factorization is totally data-driven and optimal, and fewer items are required in matching decomposed spectra. Therefore, the accuracy and efficiency of the factorization can be guaranteed at the same time. Another attractive feature of this factorization is straightforwardness, because only regular eigenvector decomposition is involved. Numerical examples of nonstationary processes are used to demonstrate the effectiveness and accuracy of the proposed approach. Results show that the factorization and simulation agree with the targets very well. In addition, the speed at which sample functions are generated is significantly improved over classic SRM, in which the full summation of sine/cosine terms is needed. © 2015 American Society of Civil Engineers. Source

Li X.Y.,Southwest Jiaotong University
ZAMM Zeitschrift fur Angewandte Mathematik und Mechanik | Year: 2012

This note revisits the electro-elastic coupling behaviors of a transversely isotropic piezoelectric half-space with a charged surface electrode. A different idea is provided by employing the three-dimensional (3D) general solution of electro-elasticity as well as generalized potential theory method. Compared with the previous studies, the method in this study is very simple and straightforward. The potential theory method is successfully extended to non-axisymmetric case and the electrode can be of any planar configuration. For a charged penny-shaped electrode, exact and complete 3D analysis is conducted. The validity of the present solutions is achieved numerically and analytically via comparing with those in literature. Some phenomena, which have escaped the attention of previous researchers, are observed. The present solutions are of theoretic and practical significance to serve as benchmarks for numerical codes and simplified studies. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Yuan D.,Changzhou University | Wang B.,Changzhou University | Wang L.,Changzhou University | Wang Y.,Changzhou University | Zhou Z.,Southwest Jiaotong University
Composites Part B: Engineering | Year: 2013

Graphene oxide/nylon 11 composites were prepared by in situ melt polycondensation. These composites displayed better mechanical properties including stiffness and toughness than the pure nylon 11 matrix. The enhanced toughness was ascribed to the change of crystal form of nylon 11, namely the triclinic α crystal form to the pseudo-hexagonal δ′ crystal form transition trend with the incorporation of GO. Scanning electron microscopy and transmission electron microscopy images showed that GO bundles and stacks with an average thickness of 20 nm are homogeneously dispersed over the nylon 11 matrix with almost no large agglomerates. © 2013 Elsevier Ltd. All rights reserved. Source

Zhang Z.,Southwest Jiaotong University | Murray C.C.,Auburn University
International Journal of Production Research | Year: 2012

This paper presents a corrected formulation to the mixed integer programming model of the double-row layout problem (DRLP), first proposed by Chung and Tanchoco (2010, The double row layout problem. International Journal of Production Research, 48 (3), 709-727). In the DRLP, machines are placed along two rows of a corridor, where the objective is to minimise the total cost of material handling for products that move between these machines. We highlight the errors in the original formulation, propose corrections to the formulation, and provide an analytical validation of the corrections. © 2012 Copyright Taylor and Francis Group, LLC. Source

Liu Y.-Z.,Sichuan Police College | Qian B.-Y.,Southwest Jiaotong University
Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering | Year: 2011

Aimed for the rational limitation of decision-maker, the multi-objective lattice-order decision-making method was introduced into the scheme selection of rail transit network. The evaluation index system of multi-objective lattice-order decision-making for urban rail transit network was constructed. Each index was turned into dimensionless number according to its type. The relative weights of evaluation indexes were worked out by synthesizing the subjective ones of decision-makers and the objective ones of data discrete degrees. Combining with decision matrix, the comprehensive difference degree of each scheme was calculated in order to achieve the lattice order of alternative schemes, and the decision-making method was applied to evaluate four rail transit network plans of some city. Analysis result shows that the comprehensive difference values of four plans are 0.66, 0.56, 0.24, 0.83 respectively, and the order result is consistent with actual situation, so the method is rational. Source

Li A.,University of Melbourne | Ye J.,Southwest Jiaotong University | Chen X.,University of Melbourne | Shieh W.,University of Melbourne
IEEE Photonics Technology Letters | Year: 2013

Spatial-mode couplers (SMCs) are critical devices for mode-division- multiplexed (MDM) systems. In this letter, we report a low-loss symmetric SMC fabricated with custom-designed two-mode fiber and commercially available standard fused biconical taper station. Sophisticated hydrofluoric etching or pre-pulling on the fiber sample is not needed for fabrication. We characterize the performance of the fabricated SMC, which shows a low loss of 1.1-2 dB and high modal extinction ratio of >20dB for a broad wavelength range from 1539 to 1555 nm. We demonstrate transmission of 69.2-Gb/s LP01/LP1111 dual-mode MDM coherent optical orthogonal-frequency division multiplexing signal over 4.5-km two-mode fiber using the fabricated SMC as mode multiplexer. The signal is successfully received at low (0.1/0.5 dB) optical signal-to-noise ratio penalty, and the estimated channel matrix confirms that there is very low modal crosstalk in both the SMC and the fiber. © 2013 IEEE. Source

Yue Y.,Southwest Jiaotong University
Lixue Xuebao/Chinese Journal of Theoretical and Applied Mechanics | Year: 2016

A three-degree-of-freedom vibro-impact system with symmetry is considered. Due to the symmetry, the Poncaré map P is the second iteration of another virtual implicit map Q. It is shown that the symmetric period n-2 motion of the vibro-impact system corresponds to the symmetric fixed point of the Poncaré map. Then we can investigate bifurcations of the symmetric period n-2 motion by researching into bifurcations of the associated symmetric fixed point. Based on the symmetry of the system, it is shown that the Neimark-Saker-pitchfork bifurcation of the symmetric fixed point of the Poncaré map P corresponds to the Neimark-Saker-flip bifurcation of the map Q. By using the map Q, according to the two-parameter unfolding of the normal form, we reveal the possible local dynamical behaviors of the symmetric fixed point of the Poncaré map P near the Neimark-Saker-pitchfork bifurcation point in detail. Near this codimension two bifurcation point, the dynamic behaviors of the vibro-impact system can be expressed by a single symmetric fixed point, a pair of conjugate fixed points, a pair of conjugate quasi-periodic attractors or a single symmetric quasi-periodic attractor in the projected Poncaré section. The numerical simulation represents various possible cases near the Neimark-Saker-pitchfork bifurcation point. It is shown that the interaction of the Neimark-Saker bifurcation and the pitchfork bifurcation may lead into the creation of some new results. The symmetric fixed point bifurcates into a pair of conjugate unstable fixed points firstly, and the two conjugate fixed points will bifurcate into the same symmetric quasi-periodic attractor finally. © 2016, Editorial Office of Chinese Journal of Theoretical and Applied Mechanics. All right reserved. Source

Peng J.-Y.,Neijiang Normal University | Peng J.-Y.,Sichuan Normal University | Luo M.-X.,Southwest Jiaotong University | Mo Z.-W.,Sichuan Normal University
Quantum Information Processing | Year: 2013

The protocols for joint remote preparation of an arbitrary two-particle pure state from a spatially separated multi-sender to one receiver are presented in this paper. We first consider the situation of two sender and demonstrate a flexible deterministic joint remote state preparation compared with previous probabilistic schemes. And then generalize the protocol to multi-sender and show that by only adding some classical communication the success probability of preparation can be increased to four times. Finally, using a proper positive operator-valued measure instead of usual projective measurement, we present a new scheme via two non-maximally entangled states. It is shown that our schemes are generalizations of the usual standard joint remote state preparation scheme and more suitable for real experiments with requirements of only Pauli operations. © 2013 Springer Science+Business Media New York. Source

Liu S.,City University of Hong Kong | Lo S.,City University of Hong Kong | Ma J.,Southwest Jiaotong University | Wang W.,City University of Hong Kong
IEEE Transactions on Intelligent Transportation Systems | Year: 2014

Guaranteeing a safe, efficient, and comfortable traveling system for pedestrians is one of the most important aspects of an intelligent transportation system. The microscopic simulation of pedestrian flow has attracted increasing research attention in recent years since a reliable simulation model for pedestrian flow may greatly benefit engineers and operators in mass transportation management, as well as designers and planners in urban planning and architecture. This paper introduces CityFlow, an agent-based microscopic pedestrian flow simulation model. The building floor plan in the model is represented by a continuous space constructed in a network approach, and each pedestrian is regarded as a self-adapted agent. Agent movement is implemented in a utility maximization approach by considering various human behaviors. The influences of parameters in the model on the simulation results are investigated. Typical pedestrian flow phenomena, including the unidirectional and bidirectional flow in a corridor as well as the flow through bottlenecks, are simulated. The simulation results are further compared with empirical study results. The comparison reveals that the model can approach the density-speed fundamental diagrams and the empirical flow rates at bottlenecks within acceptable system dimensions. The simulation results of the bidirectional pedestrian flow also show that the model can reproduce the lane-formation phenomenon. © 2000-2011 IEEE. Source

Fang Y.P.,University of Sichuan | Meng K.,Southwest Jiaotong University | Yang X.Q.,Hong Kong Polytechnic University
Operations Research | Year: 2012

In this paper we study piecewise linear multicriteria programs, that is, multicriteria programs with either a continuous or discontinuous piecewise linear objective function and a polyhedron set constraint. We obtain an algebraic representation of a semi-closed polyhedron and apply it to show that the image of a semi-closed polyhedron under a continuous linear function is always one semi-closed polyhedron. We establish that the (weak) Pareto solution/point set of a piecewise linear multicriteria program is the union of finitely many semi-closed polyhedra. We propose an algorithm for finding the Pareto point set of a continuous piecewise linear bi-criteria program and generalize it to the discontinuous case. We apply our algorithm to solve the discontinuous bi-criteria portfolio selection problem with an l ∞ risk measure and transaction costs and show that this algorithm can be improved by using an ideal point strategy. © 2012 INFORMS. Source

Zhao Y.X.,Southwest Jiaotong University
Advanced Materials Research | Year: 2012

Long fatigue crack growth rate (FCGR) model covering the range from threshold to fracture toughness is investigated through a series of experiments on the fatigue crack growth behaviour during nearby the threshold district of stage I, steady growth stage II, and the toughness of railway LZ50 axle steel. It reveals that test data in stage II can be reasonably described by employing a statistical distribution for the FCGR data at a given stress intensity factor range level. While the test data nearby the threshold district can be appropriately characterized using a statistical distribution for the factor range data at a given FCGR level and the case is similarly for the test toughness data. Therefore, the model is constructed using the test data in stage II under a control of the statistical parameters of threshold and toughness data on a principle of concurrent probabilities. Availability is indicated by the modeled result for the present material. © (2012) Trans Tech Publications, Switzerland. Source

Zhao X.,Technical University of Delft | Li Z.,Technical University of Delft | Liu J.,Southwest Jiaotong University
Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit | Year: 2012

A validated three-dimensional (3D) transient finite element model is used to evaluate the wheel-rail impact at singular rail surface defects and the resulted high-frequency dynamic forces at the discrete supports of the rail. A typical ballasted railway track is modeled, in which the supports of the rail are composed of the fastenings, the sleepers, and the ballast. The primary suspension of the vehicle is considered. To include all the important eigen characteristics of the vehicle-track system, the wheel set, the rail, and the sleepers are all meshed using 3D solid elements. The transient wheel-rail rolling contact is solved using a surface-to-surface contact algorithm in the time domain. By simulating the steady-state rolling of a wheel set on a smooth rail, the vertical force distribution at the discrete supports is first compared with Zimmermann solution. Afterward, rail surface defects are applied to calculate the resulted dynamic forces at the wheel-rail interface and at the discrete supports of the rail under different rolling speeds. The obtained dynamic responses confirm the necessity of using such a detailed model for the investigations. © Authors 2011. Source

Jiang Y.,Southwest Jiaotong University
Chinese Journal of Inorganic Chemistry | Year: 2010

Well-crystallized Bi2Te3 hollow spheres and nanosaws were prepared by microwave heating. Both the ionic liquid and the microwave heating play important role in the formation of the above nanostructures. Hollow spheres can not be obtained only by electronic stove heating, while the addition of ionic liquid leads to fast preparation of nanosaws structure under microwave heating conditions. The similar experimental results have been observed in the preparation of Bi2S3, Sb2S 3 and Bi2Se3 nanostructures. Source

Lu S.,Southwest Jiaotong University | Yan H.,Hong Kong Polytechnic University
International Journal of Project Management | Year: 2013

Due to the unique character of construction projects, perceived risk is widely used to quantify risks in the construction industry. This study investigates the two main types of measurement of perceived risk used in construction projects: direct measurement and expected utility-based measurement. Project managers from contract firms in China assess 15 independent risks using three different strategies: direct measurement, risk probability and potential impact. The last two are combined to create the expected utility-based measurement. The results show that the risk ranking order obtained from the direct measurement strategy is significantly different from that obtained from the expected utility-based measurement. Moreover, the former measurement is in general a better predictive indicator of relative managerial input than the latter. Based on these conclusions, some suggestions are presented for better risk management and cooperation in the construction industry. © 2012 Association for Project Management and the International Project Management Association and Elsevier Ltd. Source

Tan J.,Lehigh University | Wang S.,Lehigh University | Yang J.,Lehigh University | Yang J.,Southwest Jiaotong University | Liu Y.,Lehigh University
Computers and Structures | Year: 2013

Prediction of nanoparticle (NP) distribution in a vasculature involves transport phenomena at various scales and is crucial for the evaluation of NP delivery efficiency. A combined particulate and continuum model is developed to model NP transport and delivery processes. In the particulate model ligand-recep-tor binding kinetics is coupled with Brownian dynamics to study NP binding on a microscale. An analytical formula is derived to link molecular level binding parameters to particulate level adhesion and detachment rates. The obtained NP adhesion rates are then coupled with a convection-diffusion- reaction model to study NP transport and delivery at macroscale. The binding results of the continuum model agree well with those from the particulate model. The effects of shear rate, particle size and vascular geometry on NP adhesion are investigated. Attachment rates predicted by the analytical formula also agree reasonably well with the experimental data reported in literature. The developed coupled model that links ligand-receptor binding dynamics to NP adhesion rate along with macroscale transport and delivery processes may serve as a faster evaluation and prediction tool to determine NP distribution in complex vascular networks. © 2012 Elsevier Ltd. All rights reserved. Source

Zhang J.-D.,City University of Hong Kong | Xu J.,Southwest Jiaotong University | Liao S.S.,City University of Hong Kong
IEEE Transactions on Intelligent Transportation Systems | Year: 2013

Because of significant improvements in cost, accuracy, and coverage over dedicated traffic infrastructures, GPS-enabled mobile devices are preferred for continuous collection of traffic data. Estimating traffic states accurately from the obtained GPS data streams has great potential to increase efficiency of the existing traffic systems and to help reduce commuting time and fuel consumption. In this paper, first we propose a novel method to reasonably process GPS data by increasing weights of recent records and high velocity, rather than employing the current two extreme and popular approaches: the naive method aggregating all records with equal weights and the sliding-window (SW) sampling method preserving only the most recent records. Then, in line with the existing works, the proposed weighted approach is explored in two ways: aggregate-based and sampling-based ways. The aggregate-based way is classical but somewhat specific to the particular goal of traffic state estimation, whereas the sampling-based way is somewhat complicated but provides a universal set of samples for performing a variety of analyses. In the sampling-based way, a heuristic method is proposed to accurately estimate traffic states using preserved samples. Both ways are leveraged to evaluate performance of the novel weighed method and the heuristic method for estimating traffic states using samples. Finally, the feasibility and effectiveness of these methods is experimentally validated using a field-experiment data set (Mobile Century) and three simulated data sets. © 2000-2011 IEEE. Source

Tong X.,Southwest Jiaotong University
Dianli Xitong Zidonghua/Automation of Electric Power Systems | Year: 2011

A kind of hierarchical and distributed multi-agent proactive security defense framework based on trusted computing is proposed by combining information security with an analysis of business and algorithm. First, the characteristics of network attack and the causes of security threats are analyzed. Then the structure of the security defense framework is given, including the transport layer, access authority layer, platform authentication layer and advanced trusted behavior analysis layer. Some key techniques and strategies are studied, such as the check of user access authority, digital association, behavior analysis of network and business. The trusted system provides control for the suppression of network attacks and other suspicious events. A preliminary security design is implemented for a kind of wide-area backup protection system. The tests on the processing time for encryption algorithms are performed. © 2011 State Grid Electric Power Research Institute Press. Source

Zhou P.,University of Electronic Science and Technology of China | Wang C.,University of Electronic Science and Technology of China | Ren Y.,Chongqing University | Yang C.,University of Electronic Science and Technology of China | Tian F.,Southwest Jiaotong University
Current Medicinal Chemistry | Year: 2013

The recent focus on protein-protein interaction networks has increasingly been shifted towards the disruption of protein complexes, which either are mediated by the binding of a globular domain in one protein to a short peptide stretch in another, or involve flat, large, and hydrophobic interfaces that classical small-molecule agents are not always ideally suited. Rational design of therapeutic peptides with high affinity targeting such interactions has emerged as a new and promising tool in discovery of potential drug candidates against associated diseases. The design is commonly based on bioinformatics methods or molecular modeling techniques, indirectly exploiting structure-activity relationship at the level of peptide sequence or directly deriving lead entities from protein complex architecture. Here, a newly rising subfield called computational peptidology that focuses on the use of computational and theoretical approaches to treat peptiderelated problems is comprehensively reviewed on the design and discovery of peptide agents targeting protein-protein interactions. We address a systematic discussion on several representative cases in which the computational peptidology is successfully employed to develop peptide therapeutics. Besides, some problems and pitfalls accompanied with the current use of computational methods in peptide modeling and design are also present. © 2013 Bentham Science Publishers. Source

Huang Z.W.,Southwest Jiaotong University | Huang Z.W.,University of Birmingham
Intermetallics | Year: 2013

A γ-TiAl based fully lamellar alloy Ti-44Al-4Nb-4Hf-0.2Si-1B was isothermally forged and exposed at 700 °C for up to 10,000 h. It has been found that the combined addition of Nb and Hf rather than sole Nb has a positive effect on stabilisation of α2 lamellae. Compared to alloy Ti-44Al-8Nb-1B, less amount of α2 dissolved and less amount of β(B2 + ω) formed in alloy 4Nb-4Hf after the same forging and exposure scheme. As a result, the exposure-induced embrittlement is less severe in alloy 4Nb-4Hf. The ductility after 10,000-h exposure is reduced by 1/3, compared to the reduction by 2/3 in alloy 8Nb. The tensile strengths remain essentially unchanged while fatigue limit increased significantly for alloy 4Nb-4Hf. The mechanism behind the reduced α2 dissolution and β formation is discussed in relation to a changed partitioning behaviour and a slower diffusivity due to the combined addition of Nb and Hf. © 2013 Elsevier Ltd. All rights reserved. Source

Li X.-Y.,Southwest Jiaotong University
International Journal of Solids and Structures | Year: 2014

This present work is concerned with planar cracks embedded in an infinite space of one-dimensional hexagonal quasicrystals. The potential theory method together with the general solutions is used to develop the framework of solving the crack problems in question. The mode I problems of three common planar cracks (a penny-shaped crack, an external circular crack and a half-infinite crack) are solved in a systematic manner. The phonon and phason elastic fundamental fields along with some important parameters in crack analysis are explicitly presented in terms of elementary functions. Several examples are given to show the applications of the present fundamental solutions. The validity of the present solutions is discussed both analytically and numerically. The derived analytical solutions of crack will not only play an important role in understanding the phonon-phason coupling behavior in quasicrystals, but also serve as benchmarks for future numerical studies and simplified analyses. © 2013 Elsevier Ltd. All rights reserved. Source

Ma G.-T.,Southwest Jiaotong University
Superconductor Science and Technology | Year: 2014

Numerical simulations of the hysteretic ac loss in a coated superconductor with a more realistic version of the architecture were performed via the finite-element technique in the presence of an oscillating magnetic field. The coated superconductor was electromagnetically modeled by resorting to the quasistatic approximation of a vector potential approach in conjunction with nonlinear descriptions of the superconducting layer and the ferromagnetic substrate therein by a power-law model and the Langevin equation, respectively. A diverse effect of the ferromagnetic substrate on the hysteretic ac loss, depending on the strength of the applied magnetic field, was displayed, and its underlying cause was identified. The dependence of the hysteretic ac loss on the applied frequency is found to be related to a critical amplitude of the applied magnetic field, and the eddy-current loss dissipated in the metal coatings becomes prominent as the frequency increases only at high applied magnetic fields. © 2014 IOP Publishing Ltd. Source

At present, rail transit in China is booming. At the same time, some big cities are undergoing a crucial stage of adjustment of urban spatial structure. Therefore, it is significant to study the relationship between the development of rail transit and the evolution of urban spatial structure. This paper reviews the development of Guangzhou rail transit and the evolution of Guangzhou urban spatial structure, and discusses the relationship between them. The conclusion is that there is interactive relationship between the development of rail transit and the evolution of urban spatial structure, and the construction and planning of rail transit should coordinate with the current condition and future planning of urban spatial structure. During network planning, the focus should not only be placed on the rail transit project itself, but the construction of a scientific and reasonable urban spatial structure, so that rail transit can contribute to sustainable urban development. © (2014) Trans Tech Publications, Switzerland. Source

Chen Z.T.,Southwest Jiaotong University
Progress in Civil, Architectural and Hydraulic Engineering - Selected Papers of the 4th International Conference on Civil, Architectural and Hydraulic Engineering, ICCAHE 2015 | Year: 2016

With the tunnel construction gradually growing deep in direction, problems caused by high geothermal heat damage becomes increasingly prominent. High geothermal occurred mainly in two forms: dry heat and the hot and humid. Under these 2 conditions, the strength of concrete can be affected. Using zeolite powder as admixture is a viable way to improve the mechanical properties. But it remains unknown whether it performs better in hot and humid condition or dry heat. So we set 5 groups of experiments to determine the mechanical properties of zeolite powder concrete. Throughout the date we find that dry heat condition can cause a significant loss of zeolite powder concrete. But in hot and humid conditions, cement and zeolite powder can be fully hydrated, and calcium hydroxide active silica and zeolite powder contained in an alumina produced with cement hydration reaction to form secondary hydration, increasing the content of gelled material, thereby increasing the strength of the concrete. So that similar to the zeolite powder concrete and fly ash concrete, dry heat intensity decreases, and significantly increased strength under hot and humid conditions, it is more suitable for steam curing. © 2016 Taylor & Francis Group, London. Source

Fu F.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

With the continuous progress of urbanization, as well as people increasingly focus on the quality of urban rivers close living environment impact, and the study of river corridor from theory to ecological engineering ecology, landscape ecology theory and expanding. While abroad urban river corridor landscape gradually deepened to include ecological restoration project, the integration landscape design, landscape planning and other regional ecological research focus at different levels. This article looks at foreign urban river landscape ecology studies preliminary analysis, the domestic urban river corridor Landscape study problems related outcomes received inspiration and abroad in order to promote domestic demand for urban river corridor landscape ecology concerns and multi-angle vertical depth research, and also on numerous rivers or river landscape planning and design play Ecological Engineering reference and guidance. © (2014) Trans Tech Publications, Switzerland. Source

Peng B.,Southwest Jiaotong University | Peng B.,Hong Kong Polytechnic University | Zhang L.,Hong Kong Polytechnic University | Zhang D.,Hong Kong Polytechnic University
Pattern Recognition | Year: 2013

Image segmentation is a fundamental problem in computer vision. Despite many years of research, general purpose image segmentation is still a very challenging task because segmentation is inherently ill-posed. Among different segmentation schemes, graph theoretical ones have several good features in practical applications. It explicitly organizes the image elements into mathematically sound structures, and makes the formulation of the problem more flexible and the computation more efficient. In this paper, we conduct a systematic survey of graph theoretical methods for image segmentation, where the problem is modeled in terms of partitioning a graph into several sub-graphs such that each of them represents a meaningful object of interest in the image. These methods are categorized into five classes under a uniform notation: the minimal spanning tree based methods, graph cut based methods with cost functions, graph cut based methods on Markov random field models, the shortest path based methods and the other methods that do not belong to any of these classes. We present motivations and detailed technical descriptions for each category of methods. The quantitative evaluation is carried by using five indices - Probabilistic Rand (PR) index, Normalized Probabilistic Rand (NPR) index, Variation of Information (VI), Global Consistency Error (GCE) and Boundary Displacement Error (BDE) - on some representative automatic and interactive segmentation methods. © 2012 Elsevier Ltd. Source

Zhao X.-F.,Chuzhou University | Jia H.-Y.,Southwest Jiaotong University
Physical Review C - Nuclear Physics | Year: 2012

We attempted to determine the possible models for the neutron star PSR J1614-2230 in the framework of the relativistic mean field theory considering the baryon octet. It was found that the maximum mass of the neutron star will increase as the x ω increases, with the x ρΛ,x ρΣ,x ρΞ, and the x σ being fixed. By successively adopting the approximate methods, we can obtain four of the possible models: (i) x σ=0.33 and x ω=0.6964, (ii) x σ=0.4 and x ω=0.7435, (iii) x σ=0.5 and x ω=0.8106, and (iv) x σ=0.6 and x ω=0.8772. Here, the hyperon coupling constants x ρ are x ρΛ=0, x ρΣ=2, x ρΞ=1, and the nucleon coupling constants are chosen as GL97. Further, the possible value range of x σ and x ω, which corresponds to the mass of the neutron star PSR J1614-2230, is also determined through the four values of hyperon coupling constants determined in this paper. Our results may prove that the hadronic theory model can describe the mass of the neutron star PSR J1614-2230. © 2012 American Physical Society. Source

Ge H.-X.,Ningbo University | Meng X.-P.,Ningbo University | Ma J.,Southwest Jiaotong University | Lo S.-M.,City University of Hong Kong
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2012

In the Letter, a modified car-following model is presented, in which, the effects of vehicles (or non-motor vehicles) on other lanes without isolation belts are taken into account. The stability condition of the model is obtained by using the control theory method. To check the validity of the present theoretical scheme, the numerical simulation is carried out for the new car-following model, and the simulation result is consistent with the theoretical analysis. © 2012 Elsevier B.V. Source

Liang D.,University of Electronic Science and Technology of China | Liu D.,Southwest Jiaotong University
IEEE Transactions on Fuzzy Systems | Year: 2015

Decision-theoretic rough sets (DTRSs) play a crucial role in risk decision-making problems. With respect to the minimum expected risk, DTRSs deduce the rules of three-way decisions. Considering the new expression of evaluation information with hesitant fuzzy sets (HFSs), we introduce HFSs into DTRSs and explore their decision mechanisms. More specifically, we take into account the losses of DTRSs with hesitant fuzzy elements and propose a new model of hesitant fuzzy decision-theoretic rough sets (HFDTRSs). Some properties of the expected losses and their corresponding scores are carefully investigated under the hesitant fuzzy information. Three-way decisions and the associated cost of each object are further derived. With the above analysis, a novel risk decision-making method with the aid of HFDTRSs is developed. Besides the three-way decisions with DTRSs, the method investigates the ranking and resource allocation by utilizing the associated costs of alternatives and multiobjective 0-1 integer programming. Our study also offers a solution in the aspect of determining losses of DTRS and extends the range of applications. © 1993-2012 IEEE. Source

Peng Z.,Dalian Maritime University | Wang D.,Dalian Maritime University | Zhang H.,Southwest Jiaotong University | Sun G.,Dalian Maritime University | Wang H.,Dalian Maritime University
IET Control Theory and Applications | Year: 2013

In this study, a distributed model reference adaptive control architecture is developed to achieve the cooperative tracking of uncertain dynamical multi-agent systems, where the reference model serves as a virtual leader for the group to track. Two adaptive laws, with one adjusting the coupling weights and the other adjusting the neural network weights, are designed based on the relative state information of neighbouring agents. The proposed controller guarantees that the state of each agent synchronizes to that of the reference model over any undirected connected communication graphs, and all signals in the closed-loop network are uniformly ultimately bounded. In contrast to the existing results, the developed controller can be implemented in a fully distributed manner by each agent without using any global information and the accurate model of each agent. An extension to asymptotic stability is further studied. © The Institution of Engineering and Technology 2013. Source

Luo W.,Guangxi University for Nationalities | Luo W.,Southwest Jiaotong University | Fang X.,Guangxi University for Nationalities | Cheng M.,Guangxi University for Nationalities | Zhao Y.,Algorithm
IEEE Transactions on Vehicular Technology | Year: 2013

The capacity of a multiple-input-multiple-output (MIMO) channel with $N$ transmit and receive antennas for high-speed railways (HSRs) is analyzed based on the 3-D modeling of the line of sight (LOS). The MIMO system utilizes a uniform linear antenna array. Instead of increasing the number of antennas or simply changing the parameters of the antenna array, such as separation and geometry, the capacity gain can be obtained by adjusting the weights of multiantenna array groups, because there are few scatterers in strong LOS environments. On the other hand, it is hard to obtain the array gain of MIMO beamforming for HSRs because of drastic changes in the receiving angle when the train travels across E-UTRAN Node B. Without changing the antenna design of Long-Term Evolution systems, this paper proposes a multiple-group multiple-antenna (MGMA) scheme that makes the columns of such a MIMO channel orthogonal by adjusting the weights among MGMA arrays, and the stable capacity gain can be obtained. The value of weights depends on the practical network topologies of the railway wireless communication system. However, the reasonable scope of group number $N$ is less than 6. In selecting $N$, one important consideration is the tradeoff between practical benefit and cost of implementation. © 1967-2012 IEEE. Source

Yuan L.,Academia Sinica, Taiwan | Yuan L.,Southwest Jiaotong University | Chao B.F.,Academia Sinica, Taiwan
Earth and Planetary Science Letters | Year: 2012

We analyze the tidal displacement signals, for the eight major diurnal and semidiurnal tides, from Global Positioning System (GPS) measurements made at the Western United States over the past 16. years with 1075 independent stations. By careful examinations among inland versus coastal GPS data we are able to demonstrate that estimated precisions down to the level of ~0.1. mm (horizontal) and ~0.3. mm (vertical) have been reached for the tidal signals, and that at such precisions coherent spatial patterns are revealed in the residual tidal amplitudes and phases after the removal of a priori modeled effects of body tides and ocean tidal loading (OTL). We demonstrate the facility of modern precise GPS data in not only constraining the ocean tide models but, more significantly, in providing source data in terms of regional, complex Love numbers for geophysical inference of the heterogeneities of elastic and inelastic structures in the solid Earth's deep interior on tidal timescales. © 2012. Source

Chen J.-Q.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

The non-parametric regression prediction model for dissolved gases in power transformer and its application are studied. As the intervals between two analytic experiments of transformer dissolved gas are unfixed, the data sequence sampled with unequal intervals is converted into the data sequences with equal intervals, which is smoothed to form a new sequence. And then use the historical samples data to establish non-parametric regression model for prediction. Compared with the grey model, the non-parametric regression model has better prediction accuracy. The case verifies the correctness and feasibility of the method. © (2014) Trans Tech Publications, Switzerland. Source

Xu L.Y.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

This design adopts the method of horizontal arrangement to set the aerator pipes because it's more effective than an upright way. The pipes are divided into two vertical levels. Firstly there should be an excavation of foundation pit or grooves to put the pipes in two levels. Then the pipes in two levels can be set at vertical directions. After burying the pipe the earth should be backfilled into the grooves. When backfilling the lower level groove, we put some certain microorganism to help cleaning the organic pollution. While working, the pipes above are mainly used to manufacturing gas phase concentration difference, letting the organic volatilize and goes into the atmosphere. The pipes in lower level are mainly used to provide oxygen to microorganisms in the soil, so that they can decompose organic and make them into inorganic which is no harm to the soil and ground water. © (2014) Trans Tech Publications, Switzerland. Source

Zhang J.,Southwest Jiaotong University
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2013

Based on moisture balance of bio-slope-engineering system, the fundamental requirements of water storage capacity of root layer soil in rock slope protection are put forward. By field rainfall tests, the regulations of moisture migration in bio-slope-engineering system for rock slope are studied. Then, the factors governing moisture balance of bio-slope-engineering system are analyzed, such as initial water storage capacity of root layer soil, vegetation interception, slope surface runoff, slope angle, slope surface evapotranspiration, and wilting capacity of root layer soil. It is shown that carrying soil can obtain larger water storage capacity in a relatively short time if its ratio is reasonable and its permeability is good, and adding a good amount of water retention agents and peats into carrying soil can significantly reduce water evapotranspiration; furthermore, water retention agent can reduce wilting capacity of carrying soil, thus more moisture in carrying soil becomes available for plants. It is also shown that vegetation interception cannot be ignored in a good vegetation-covered slope, and slope angle should be appropriately determined to improve the rainfall infiltration. The results may be helpful for moisture balance and bio-slope-engineering system control for rock slope. Source

Ding Q.,Hong Kong Polytechnic University | Chen W.,Hong Kong Polytechnic University | King B.,Hong Kong Polytechnic University | Liu Y.,First Institute of Oceanography | Liu G.,Southwest Jiaotong University
ISPRS Journal of Photogrammetry and Remote Sensing | Year: 2013

Airborne laser scanning LiDAR systems deliver not only geometric (X,. Y,. Z) information of the scanned surfaces but also the returned intensity of the laser pulse. Recent studies have shown the potential of using intensity data for many applications. However, there are limitations in using the raw intensity data because of radiometric system bias, reflectance noise and variations between adjacent strips. To overcome these limitations, a three-step LiDAR intensity correction algorithm is proposed. Following corrections for environmental and surface effects, an overlap-driven least-squares adjustment model that does not rely on the selection of homologous points minimizes intensity differences in the overlap area of strips. Finally, the Phong reflection model, which describes both diffuse and specular reflectance, is used to attenuate the effects of strong reflections that typically occur over wet or water dominated areas. The algorithm was applied to a multi-strip LiDAR dataset that covers wetlands in the estuary of the Yellow River, People's Republic of China. Results demonstrated a significant reduction in radiometric differences in the overlap areas, and strong specular reflections in the nadir regions were reduced. Objects which were obscured by the specular reflection in the original intensity data were clearly identifiable after the adjustment. © 2012 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Source

Wang C.,Shanxi Normal University | Huang T.,Southwest Jiaotong University
International Journal of Robust and Nonlinear Control | Year: 2013

Summary This paper studies the problem of designing the static output feedback controller for the positive linear continuous-time systems. On the basis of a system augmentation approach, a novel characterization on the stable condition of the closed-loop system is firstly established. Then, a necessary and sufficient condition is given to ensure the existence of the desired static output feedback controller, and an iterative linear matrix inequality algorithm is presented to compute the feedback gain matrix. Finally, a numerical example is provided to illustrate the effectiveness of the proposed method. © 2012 John Wiley & Sons, Ltd. Source

Chen H.,Southwest Jiaotong University
International Journal of Bifurcation and Chaos | Year: 2016

Global dynamics of a class of planar Filippov systems with symmetry, which is a discontinuous limit case of a smooth oscillator, is studied. Necessary and sufficient conditions for the existence and the number of limit cycles are given. It is shown that at most two limit cycles or a pair of grazing loops exist. A special method is introduced to study grazing bifurcation. The monotonicity and the C∞ smoothness of the grazing bifurcation curve are proved. All global phase portraits and a complete global bifurcation diagram are described. Finally, some numerical examples are demonstrated. © 2016 World Scientific Publishing Company. Source

Chen X.,Kunming University of Science and Technology | Zhang J.,Southwest Jiaotong University
International Journal of Security and its Applications | Year: 2012

Discriminant locality preserving projection(DLPP) can not obtain optimal discriminant vectors which utmostly optimize the objective of DLPP. This paper proposed a Gabor based optimized discriminant locality preserving projections (ODLPP) algorithm which can directly optimize discriminant locality preserving criterion on high-dimensional Gabor feature space via simultaneous diagonalization, without any dimensionality reduction preprocessing. The proposed method is applied to face and finger vein recognition problems and is compared with some other related Gabor based dimensionality reduction techniques. Experimental results conducted on the VALID face database and a subset of PKU finger vein database indicates the effectiveness of the proposed algorithm. Source

Li Y.,Southwest Jiaotong University
Asian Journal of Chemistry | Year: 2014

In order to find mixed strains which are highly effective in decomposing straw cellulose to decompose straws so as to utilize resources optimally, this research starts from separating strains and takes the soil chronically covered by straws and other plants as the sample. Through repeatable enrichment cultivation, separation and purification, fourteen natural strain stubs which can grow on solid cultivation medium with carboxymethyl cellulose medium-Na (CMC-Na) as the only carbon source are gradually obtained. Then, through the degradation test of filter paper and the identification of congo red cellulose, ten fungi with strong adaptability and excellent effect of decomposing cellulose are screened, from which four combination ways are formed. A combination of mixed strains with the best effect to decompose cellulose is finally gained by comparing the CMC, FPA enzyme activity and the syngenesis property of the four combinations. Through identification, the two strains are, respectively Mucor sp. and Aspergillus sp. Source

Zhou T.,Southwest Jiaotong University
Science China: Physics, Mechanics and Astronomy | Year: 2016

We consider the quantum measurements on a finite quantum system in coherence-vector representation. In this representation, all the density operators of an N-level (N ⩾ 2) quantum system constitute a convex set M(N) embedded in an (N2 − 1)-dimensional Euclidean space (Formula Presented.), and we find that an orthogonal measurement is an (N − 1)-dimensional projector operator on (Formula Presented.). The states unchanged by an orthogonal measurement form an (N − 1)-dimensional simplex, and in the case when N is prime or power of prime, the space of the density operator is a direct sum of (N + 1) such simplices. The mathematical description of quantum measurement is plain in this representation, and this may have further applications in quantum information processing. © 2016, Science China Press and Springer-Verlag Berlin Heidelberg. Source

Hong S.-M.,Southwest Jiaotong University
Gaoya Wuli Xuebao/Chinese Journal of High Pressure Physics | Year: 2013

For investigating kinetic behavior of pressure induced phase transitions, it is the most expected to combine high time-resolved diagnostic probes with the precise compression techniques. In fact, an indirect way in large volume press is compare characterization results of recovered samples with their experienced conditions including pressure, temperature and time. As a typical example, relationship between p-T conditions and time for diamond nucleation in C-H-O system is discussed by previous experimental data, demonstrated that extending loading time under HP/HT is propitious to form high pressure stable phase. In contrast, some meta-stable phases, such as bulk amorphous sulfur, metallic glasses and amorphous polymers etc., were obtained by rapid compression process. The results indicated that many substances can show the kinetic features of phase transition in the scale of compression rate from 1 GPa to 1 TPa/s. The kinetic phase diagrams with three dimensions (pressure, temperature and time) could be established through both of the static or rapid compression experiments. Source

Lei D.,Wuhan University of Technology | Guo X.,Southwest Jiaotong University
International Journal of Production Research | Year: 2014

Dual-resource constrained flexible job shop scheduling problem (FJSP) is considered and an effective variable neighbourhood search (VNS) is presented, in which the solution to the problem is indicated as a quadruple string of the ordered operations and their resources. Two neighbourhood search procedures are sequentially executed to produce new solutions for two sub-problems of the problem, respectively. The search of VNS is restarted from a slightly perturbed version of the current solution of VNS when the determined number of iterations is reached. VNS is tested on some instances and compared with methods from literature. Computational results show the significant advantage of VNS on the problem. © 2013 © 2013 Taylor & Francis. Source

Zhou Z.,Southwest Jiaotong University | Ding C.,Hong Kong University of Science and Technology
Finite Fields and their Applications | Year: 2014

Cyclic codes are a subclass of linear codes and have applications in consumer electronics, data storage systems, and communication systems as they have efficient encoding and decoding algorithms. In this paper, a class of three-weight cyclic codes over Fp whose duals have two zeros is presented, where p is an odd prime. The weight distribution of this class of cyclic codes is settled. Some of the cyclic codes are optimal. The duals of a subclass of the cyclic codes are also studied and proved to be optimal. © 2013 Elsevier Inc. Source

Xie S.,Southwest Jiaotong University
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2010

The rank regression is proposed for harmonic impedance analysis and harmonic assessment. Based on the equivalent circuit of system and customer, the analytical expressions of system harmonic impedance, background harmonic and harmonic at PCC(Point of Common Coupling) are obtained. With the harmonic voltage and current measured at PCC, the least-square estimation of system harmonic impedance and background harmonic are calculated as the regression coefficients of regression equation. The rank regression based estimation function is deduced from the scoring function of residual rank. The steepest descent method is applied to calculate its minimum, and the rank-regression-based estimation and the harmonic emission level are thus calculated. With the proposed method, the impact of abnormal sample data on the regression coefficients is avoided and the normal distribution of errors is not required. Its effectiveness and correctness are verified by the simulative results. Source

Geng W.,Southwest Jiaotong University | Qiu M.,IBM | Zhao X.,Tsinghua University
International Journal of Production Economics | Year: 2010

We consider a single-distributor multi-retailer inventory system in six operating scenarios for a finite horizon. Five scenarios are in decentralized control and the other one is in centralized control. Approximate dynamic programming (ADP) procedures are developed to obtain system performances for scenarios in decentralized control, and a stochastic dynamic programming approach is applied to the scenario in centralized control. The efficiency and effectiveness of ADP procedures are demonstrated by numerical results. Taking the system performance in centralized control as a benchmark, system performances in decentralized control are investigated and compared for different operating scenarios. The results provide useful insights in system planning and operations. © 2010 Elsevier B.V.All rights reserved. Source

Shanglian P.,Southwest Jiaotong University
Proceedings - The 2015 10th International Conference on Intelligent Systems and Knowledge Engineering, ISKE 2015 | Year: 2015

Event detection over RFID event streams is one of the most important applications of RFID based monitoring systems. Event detection over data stream extracts meaningful complex patterns from high volume, fast speed and real time raw event streams. This research aims to detect RFID event patterns by introducing context information to reduce event instances effectively. Context of an RFID application is modeled and merged into event query optimization framework. Context information is further applied into evaluation of pattern detection. Experimental results show that context information can optimize complex event detection process both on CPU time and memory consumption. © 2015 IEEE. Source

Li S.,Sichuan University | Liang Z.,Sichuan University | Xu L.,Southwest Jiaotong University | Zou F.,Sichuan University
Molecular and Cellular Biochemistry | Year: 2012

MiRNAs are a new class of small RNA molecules that regulate gene expression at the post-transcriptional and translational levels. MiRNAs have been implicated in the control of many vital biological processes including development, cell proliferation, differentiation, and apoptosis. A growing number of studies have shown that miRNAs also play an important role in carcinogenesis and other diseases. Among the miRNAs identified, miRNA-21 is dramatically up-regulated in cancer cells of various origins. It regulates a wide range of genes and pathways involved in cancer initiation, transformation, invasion, and metastasis. MiRNA-21 also acts as a pro-survival factor in cardiovascular diseases. Aberrant expression in these diseases makes miRNA-21 a potential marker for disease diagnosis and prognosis. This review highlights the complex roles that miRNA-21 plays in cancer and cardiovascular diseases and its potential clinical applications. © 2011 Springer Science+Business Media, LLC. Source

In this note, a study on the equivalence of two stability criteria for continuous-time switched linear systems with dwell time constraint is presented. It is demonstrated that, for any dwell time satisfying the conditions in stability criterion proposed in Geromel and Colaneri (2006), the conditions in stability criterion of Allerhand and Shaked (2011) also hold as long as the number of decision variables and related LMIs is sufficiently large, which implies the two stability criteria are intrinsically equivalent. The equivalence is obtained by showing that two criteria can be derived from each other with a sufficiently large number of decision variables and LMIs. A numerical example is proposed to illustrate the theoretical results, and an extension to uncertain case is briefly presented. © 2015 Elsevier Ltd. Source

Zhang H.,Southwest Jiaotong University | Chen J.,City University of Hong Kong
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2014

This paper studies bipartite consensus problems for multi-agent system over signed directed graphs. We consider general linear agents and design a dynamic output feedback control law for the agents to achieve bipartite consensus. Our results show that structural balance property of the graph and an appropriate consensus error information are two crucial factors of bipartite consensus. © IFAC. Source

Li Q.,Southwest Jiaotong University
Journal of Modern Transportation | Year: 2016

To avoid stray current and maintain the benefit of no phase-split in the DC traction power supply system, an AC traction power supply system was proposed for the urban public transport such as metro and light rail transit. The proposed system consists of a main substation (MSS) and cable traction network (CTN). The MSS includes a single-phase main traction transformer and a negative-sequence compensation device, while the CTN includes double-core cables, traction transformers, overhead catenary system, rails, etc. Several key techniques for the proposed system were put forward and discussed, which can be summarized as (1) the power supply principle, equivalent circuit and transmission ability of the CTN, the cable-catenary matching technique, and the selection of catenary voltage level; (2) the segmentation technology and status identification method for traction power supply network, distributed and centralized protection schemes, etc.; (3) a power supply scheme for single-line MSS and a power supply scheme of MSS shared by two or more lines. The proposed industrial frequency single-phase AC traction power supply system shows an excellent technical performance, good economy, and high reliability, hence provides a new alternative for metro and urban rail transit power supply systems. © 2016, The Author(s). Source

Bao B.C.,Jiangsu Teachers University of Technology | Liu Z.,Nanjing University of Science and Technology | Xu J.P.,Southwest Jiaotong University
Electronics Letters | Year: 2010

By replacing Chua's diode in the canonical Chua's oscillator with a smooth flux-controlled memristor, a memristor based oscillator is presented. The memristor oscillator generates a steady periodic orbit and has a transition from transient chaotic to steady periodic behaviour. The complicated dynamical behaviour is extremely dependent on the initial condition of the memristor. © 2010 The Institution of Engineering and Technology. Source

Li Y.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

In recent years, along with the amount of our country's vehicle increasing year by year, the downtown areas or CBDs in many S/M Cities have appeared parking problems. To provide some effective decision-making reference for traffic management, this article tries to help S/M City find a method to solve its urban parking problem by studying persons' parking choice behavior. We have made the parking behavior surveys about 3 ground parking lots and 2 underground parking lots in Dazhou city, a S/M City in the east of Sicuan Province, and analyzed surveys data to regard the Saturation of Berth as a leading indicator, the distance to destination and the parking fee as two main factors that affect parking choice behavior. On basis of research we established the Binary Logit (BL) models to quantitatively depict the parking behavior. And according to the coefficients in model and the symbols of t value view, under the premise that the confidence level of t is 95%, the BL model owned a high precision. Finally, based on the qualitative analysis of parking fee, the article got a preliminary threshold of parking fee: The basic fee is 7 yuan/h, and when the parking fee exceeds the value, it has significant effect on adjusting the ground and underground parking lot choice behavior in Dazhou urban area. © ASCE. Source

Shi J.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

Split delivery vehicle routing problem (SDVRP) is a variation of vehicle routing problem, where some customers may be served by more than one vehicle. This paper is a survey on the models and solution approaches for SDVRP. Some models is reviewed. Heuristic and exact solution approaches for the SDVRP are presented. Finally, future work about SDVRP are given. © ASCE. Source

Cheng Z.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

It is an important item to assess the effects of west transportation improvement on economic growth in China's Ethnic Area. Our findings show that local economy growth doesn't benefit from transportation improvement in Guizhou ethnic area. That is to say, the effects of transportation improvement are fully spilled. Although the transportation costs of households and firms are reduced by transportation improvement, the flow of production factors (population mobility & movement of goods) are one-way from ethnic area to developed region. On this condition, transportation improvement has negative spatial spillover effects to the economic development in ethnic area. © ASCE. Source

Ruan X.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

TOD refers to transit-oriented development. This paper analyses the development scale of foreign high-speed railway stations and the surrounding areas by referencing the successful experience of TOD mode in foreign cities and combining the related information of land development and city development. It comes out that the development scale is different from various kinds of high-speed railway stations and the surrounding areas, and summarizes the differences as well. In the meanwhile, this paper puts forward the calculation basis of the development scale of high-speed railway stations based on TOD mode through analysis, as well as the basic ideas and method of determining the upper and lower bounds. © ASCE. Source

Zhang Y.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

This paper analyzes the interaction process of the running trains associated with the minimal headway for high-speed railway in a more reasonable and sophisticated way after systemically investigating previous researches. A set of new formulas are proposed to improve the calculation accuracy of minimal headway. In the case study section, the proposed methods are tested to calculate the minimal headway of the running trains of different speeds range from 250 km/h to 350 km/h with the calculation step of 10 km/h. The case study results show that with the increase of the maximal allowed speed, the headway between two trains running in one section, the headway between two arrival trains and the minimal headway of the high-speed railway increase, while the headway between two departing trains is a constant. The main conclusions can be drew from the case study results: (1) Headway between two arrival trains is always the bottle neck to narrow down minimal headway of high-speed railway no matter how the maximal allowed speed of the train changes from 250 km/h to 350 km/h. (2) The minimal headway of high-speed railway is always greater than 180 s with the maximal allowed speed of the train ranges from 250 km/h to 350 km/h, which means that some improvement measures should be taken to accomplish the goal of reducing minimal headway to 3 min. (3) The improvement of braking performance of the train can reduce the minimal headway of high-speed railway. © ASCE. Source

Sun J.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

Through detailed analysis of train operation control procedure of urban rail transit, in view of the present condition of Fuzzy Neural Network (FNN) in train operation control, a new model of train operation adjustment on the FNN is developed, five levels fuzzy neural network were built and its input and output were designed, the weighing and parameters were revised in order to get different membership function, then corresponding fuzzy rule and could execute fusion decision could be got in the new method. Furthermore, the simulation perception processing of train operation adjustment was completed using Matlab, the mean square error between actual output and experiments output was got the simulation results show that the validity of train operation control procedure of urban rail transit based on FNN. © ASCE. Source

Cheng T.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

Containerization and multimodal transport are the development direction of railway cold-chain transportation. The increasing market demand also put new requirements on railway cold-chain transportation. The fact that China is a country covering vast territory with backward cold-chain transport equipment restricts the range of railway refrigerated freight transport. Therefore railway cold-chain transportation lost its comparative advantage that combined large freight volume and long transport distance. For solving this problem, railway transportation department uses 45ft integrated diesel-electric refrigerated container as cold-chain carrier, at the same time, adopts stop and refueling strategies in transit to extent continuous refrigerating time. Due to China's railway cold-chain transportation is still in early stages, the location of gas stations along the route is uncertain and the refueling plan is lack of scientificity, the efficiency of railway refrigerated container transportation can be improved obviously. For extending the depth of railway cold-chain transportation and promoting the development of containerization and multimodal transport, this paper considers the features of railway cold-chain transportation in China and the method of using 45ft integrated diesel-electric refrigerated container. By setting the minimum cost as the objective function and involve other constraint condition in railway cold-chain transportation, this paper gives a optimization plan of refrigerated container refueling strategies in transit based on dynamic programming. Based on the research results on optimization plan, railway transportation department can reduce the time of refueling-stop and number of gas station which are unnecessary to reduce the cost of railway container freight station building, improve the efficiency and quality of railway cold-chain transportation. © ASCE. Source

Xu X.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

In order to fully realize the potential of Urban Rail Transit (URT) system in maintaining the viability of major cities, one of the key elements-the competency of staff operating the URT system-must be managed effectively. As driverless URT systems have the ability to achieve higher efficiency while still maintaining the required safety standard, more driverless URT systems are being built and operated. When an URT becomes driverless, the operating concept of the URT will become significantly different from that of an URT with drivers as well. This has resulted in new challenges to the management of staff competency for a driverless URT system. This paper started off with discussions of the Competency Curve and then used the driverless Singapore North East Line (NEL) as a study case to examine the two main challenges faced when managing staff competency in a driverless URT context: the manual driving of a driverless train, and the driverless train control in the Operating Control Center (OCC). Strategies towards the handling of the above-mentioned new challenges were proposed based on the experiences gained on the ground. © ASCE. Source

Li M.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

The application conditions of the safety limit of height of gravity center of loaded wagon in "The railway freight loads and firms regulation" are not described in detail. In this paper, we established the particular three-dimension dynamic model for the container flat car and the container to simulate the dynamic behavior of freight wagon through the curve under cross-wind. We analyzed safety of loaded wagon under different height of gravity center and obtained the safety limit of height of gravity center of loaded wagon under cross-wind. From the analysis of calculation results, we can know that the height of gravity center can reach 2.2 m or higher when the wind speed is lower than 9 grade; when the wind speed is 9 grade, loaded wagon should run with speed limit while the height of gravity center is over 2.2 m; when the wind speed is 10 grade, loaded wagon should run with speed limit while the height of gravity center is over 1.9 m; when the wind grade is 11 or above, loaded wagon should run with speed limit or stop running. © ASCE. Source

Feng R.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

Under the background of development of international trade in Sichuan province, Sichuan province is actively developing international logistics to raise trade. International logistics demand, presents obvious growth in recent years. In this thesis, from both the macro (economic, policy, industrial, etc.) and micro (logistics, transportation operations, etc.) levels, using the method of gray correlation analyze the influencing factors of international logistics demand. Then, calculate the correlation between influencing factors and international logistics demand. Secondly, according to current situation of international logistics development of Sichuan province, analyze the trends and causes of international logistics demand change of Sichuan province and on the brief analysis of the future development trend of international logistics in Sichuan province. © ASCE. Source

Tang D.,Southwest Jiaotong University
IOP Conference Series: Materials Science and Engineering | Year: 2015

A thermal-mechanical coupling model was developed based on thermal-elastic- plastic theory according the special process of plasma spraying Hydroxyapatite (HA) coating upon Ti-6Al-4V substrate. On the one hand, the classical Fourier transient heat conduction equation was modified by introducing the effect item of deformation on temperature, on the other hand, the Johnson-Cook model, suitable for high temperature and high strain rate conditions, was used as constitutive equation after considering temperature softening effect, strain hardening effect and strain rate reinforcement effect. Based on the above coupling model, the residual stress field within the HA coating was simulated by using finite element method (FEM). Meanwhile, the substrate preheating temperature and coating thickness on the influence of residual stress components were calculated, respectively. The failure modes of coating were also preliminary analyzed. In addition, in order to verify the reliability of calculation, the material removal measurement technique was applied to determine the residual stress of HA coating near the interface. Some important conclusions are obtained. Source

Chu K.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

The financing of land plays an important role in the process of the construction of rail transit. Risk assessment of financing is a systematic project, which needs scientific and rational design. This article divides 5 risk sources of financing by land in metro construction and operation, every risk source is divided into several risk factors. Afterwards, the article assesses the financing risk by using bi-level fuzzy comprehensive evaluation model. Finally, this paper analyses the merits and demerits of this method in actual application. © ASCE. Source

Qin W.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

On the basis of extensive research and interviews with experts, we propose a quality evaluation indicator system for rail freight service, which consider both factors of rail transport enterprise and customer satisfaction. We recommend the application of these indicators to assess the quality of rail freight services in order to improve the market competitiveness of railway enterprise. © ASCE. Source

Sun J.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

Through detailed analysis of control problem of urban rail transit intelligent transportation system, a distributed hierarchical control method was proposed by blending the factitious division of hierarchical system and the natural division of distributed control system. This method is based on the hierarchical control theory of large scale system, and includes three levels: the organization level, the coordination level, and the execution level. The objectives are decreasing the total delay time and increasing the absorption to passengers of the successive trains, a method for train operation adjustment based on Multi-Agent is developed, and the control strategy based on rules is proposed. The distributed hierarchical control method deals with the train planning, the coordination of trains, and the action control of trains in different layers. The simulation results show the effectiveness of the model and the revised algorithm based on Multi-Agent comparing with the traditional control theory. © ASCE. Source

Xu D.,Southwest Jiaotong University
ICTE 2015 - Proceedings of the 5th International Conference on Transportation Engineering | Year: 2015

Current evaluation research of bus signal priority strategy adopting means of traffic simulation, lack of evaluation combined with the actual traffic flow data collected for analysis, based on the common bus priority strategies at home and abroad, on the basis of the current main bus signal priority strategy, including active and passive preference strategy has carried on the analysis and research; Based on HCM method, considering the influence of proportion of buses for intersection saturation flow rate, build the city road bus priority strategy performance evaluation method, On the basis of the traffic data, the urban road bus signal priority control strategies focus on a single point of intersection and compares the implementation of performance evaluation. © ASCE. Source

Wen C.,Southwest Jiaotong University
2010 The 2nd International Conference on Computer and Automation Engineering, ICCAE 2010 | Year: 2010

Information entropy is a manifestation for the usefulness of information. The information entropy theory was used in the process of analyzing each object of the train operation adjustment decision table, and the function of each condition attribute for reducing decision-making uncertainty was studied. Then, the importance ranking of the train operation attributes were determined. A measure for train operation conflict degree is proposed on the bases of studying the train operation condition attributes' weight by information entropy. Meanwhile, the optimization sub-objectives' weight coefficient of train operation adjustment are determined. A single-object optimal model that is accordance with the decision-making procedure of the dispatchers is established. In this model, the sub-objectives of improving trains' punctuality rate and average travel speed, reducing total delay time are considered simultaneously. It has good adaptability and can provide reference to the dispatchers during train operation adjustment. ©2010 IEEE. Source

Luo M.,Southwest Jiaotong University | Luo M.,Chinese Academy of Sciences | Wang X.,Dublin City University
Science China: Physics, Mechanics and Astronomy | Year: 2014

Quantum circuit model has been widely explored for various quantum applications such as Shors algorithm and Grovers searching algorithm. Most of previous algorithms are based on the qubit systems. Herein a proposal for a universal circuit is given based on the qudit system, which is larger and can store more information. In order to prove its universality for quantum applications, an explicit set of one-qudit and two-qudit gates is provided for the universal qudit computation. The one-qudit gates are general rotation for each two-dimensional subspace while the two-qudit gates are their controlled extensions. In comparison to previous quantum qudit logical gates, each primitive qudit gate is only dependent on two free parameters and may be easily implemented. In experimental implementation, multilevel ions with the linear ion trap model are used to build the qudit systems and use the coupling of neighbored levels for qudit gates. The controlled qudit gates may be realized with the interactions of internal and external coordinates of the ion. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg. Source

Han N.,Southwest Jiaotong University
Asian Journal of Chemistry | Year: 2014

In this study, the enthalpy of dissolution of 4'-demethylepipodophyllotoxin (DMEP) in dimethyl sulfoxide (DMSO) was measured by using a RD496-2000 Calvet Microcalorimeter at 309.65 K under atmospheric pressure. The differential enthalpy (ΔdifHm) and molar enthalpy (ΔsolHm) about 4'-demethylepipodophyllotoxin dissolution in dimethyl sulfoxide were determined and the relationship between heat and the amount of solute was established as well. Based on these experimental data and calculated results, the kinetic equation, half-life, ΔsolHm, ΔsolGmand ΔsolSmof the dissolution process were obtained. This study can provide a simple method to determine the half-life of a drug, as well as offer a theoretical reference for the clinical application of 4'-demethylepipodophyllotoxin. © 2014, Chemical Publishing Co. All rights reserved. Source

Li L.,Southwest Jiaotong University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2010

Porous surfaces have an important effect on bioactivity of titanium implants. In this study, two micro/nanostructural titanium surfaces were prepared by chemical and electrochemical method. The two samples had different diameters of nanotubes. Tests of biomineralization and codeposition in simulated body fluid and bovine serum albumin (BSA) were carried out in order to evaluate the bioactivity of micro/nanostructural titanium surfaces. The information of the surfaces was detected using scanning electron microscope and X-ray diffractometer. The results showed that the bioactivity of micro/nanostructural titanium increased with the diameter of nanotubes. Furthermore, the existence of BSA can accelerate biomineralization and decrease the crystallinity of hydroxyapatite coating. Source

Lv W.,Hefei University of Technology | Song W.-G.,Hefei University of Technology | Ma J.,Southwest Jiaotong University | Fang Z.-M.,CAS Shanghai Advanced Research Institute
IEEE Transactions on Intelligent Transportation Systems | Year: 2013

Modeling and simulation of pedestrian movement is a feasible and effective way to evaluate evacuation facilities and risk. Inspired by the visual field and movement characteristic of pedestrians, we developed a 2-D continuous model that integrates a self-slowing, local direction-changing mechanism, and visual hindrance information. The model allows for the movement in continuous space and time, only controlled by simple kinematic equations and visual hindrance distribution. In order to get the parameters of the kinematic equations, we conducted controlled experiments, collected empirical data, and obtained velocity-changing and direction-changing relations. We then validate the model by simulating three experimental scenarios, i.e., passage, bottleneck, and classroom evacuation. It is found that some typical phenomena such as the stop-and-go waves in the passage and lane formation in the bottleneck can be reproduced. The obtained fundamental diagram and specific flow agree with classic conclusions and experimental measures very well. It is hoped that the idea of this study may be helpful in promoting the modeling and simulation study of pedestrian flow. © 2000-2011 IEEE. Source

Lei D.,Wuhan University of Technology | Guo X.,Southwest Jiaotong University
International Journal of Production Economics | Year: 2015

In this study, scheduling problem in dual-resource constrained (DRC) job shop with interval processing time and heterogeneous resources is investigated. A lexicographical method is applied to minimize interval carbon footprint and makespan. A dynamical neighborhood search (DNS) is proposed, which is composed of two phases. Two-string representation is used and its chromosome consists of the operation-based string and the resource string. Several initial solutions are produced and improved in the first phase and only one solution is applied in the second phase. Four neighborhood structures and their dynamical transition mechanism are utilized to produce new solutions. DNS is tested on a number of instances and compared with other algorithms. Computational experiments show DNS can provide the promising results for the problem. © 2014 Elsevier B.V. All rights reserved. Source

Lu W.,University of Hong Kong | Yuan H.,University of Hong Kong | Yuan H.,Southwest Jiaotong University
Renewable and Sustainable Energy Reviews | Year: 2013

The construction industry around the globe has been increasingly advocated to utilize prefabrication to minimize waste, thereby alleviating associated negative impacts on environment and the society. Previous studies have reported on waste reduction potential from adopting prefabrication in various economies including Hong Kong. A significant shortcoming of these studies; however, is the neglect of the upstream processes of prefabrication including the manufacturing and transportation of components, which causes construction waste as well. To date it is still unclear how this portion of construction waste is generated and quantified. The issues are even more complicated in Hong Kong where components are manufactured in the offshore Pearl River Delta Region (PRDR) of mainland China and transported across the border to construction sites in Hong Kong. Against the theoretical backdrop of whole life cycle thinking, the aim of this study is to empirically investigate the manufacture and cross-border transportation processes, thereby to assess the waste reduction potentials of using prefabrication in construction. It does so by conducting three in-depth case studies with selected PRDR prefabrication factories. A hybrid of research methods are employed in the study. It is found that the waste generation rate in the upstream processes of offshore prefabrication is around 2% or lower by weight. This proves the orthodox that prefabrication in a factory environment is more conducive to waste reduction than the traditional cast in-situ construction manner. However, transporting the components adds cost and simultaneously increases the risk of waste generation. This study provides insights into understanding construction waste reduction through offshore prefabrication from a holistic view. © 2013 Elsevier Ltd. Source

Lin H.,Chinese University of Hong Kong | Chen M.,Chinese University of Hong Kong | Lu G.,Nanjing Normal University | Zhu Q.,Southwest Jiaotong University | And 5 more authors.
Earth-Science Reviews | Year: 2013

Virtual Geographic Environments (VGEs) are proposed as a new generation of geographic analysis tool to contribute to human understanding of the geographic world and assist in solving geographic problems at a deeper level. The development of VGEs is focused on meeting the three scientific requirements of Geographic Information Science (GIScience) - multi-dimensional visualization, dynamic phenomenon simulation, and public participation. To provide a clearer image that improves user understanding of VGEs and to contribute to future scientific development, this article reviews several aspects of VGEs. First, the evolutionary process from maps to previous GISystems and then to VGEs is illustrated, with a particular focus on the reasons VGEs were created. Then, extended from the conceptual framework and the components of a complete VGE, three use cases are identified that together encompass the current state of VGEs at different application levels: 1) a tool for geo-object-based multi-dimensional spatial analysis and multi-channel interaction, 2) a platform for geo-process-based simulation of dynamic geographic phenomena, and 3) a workspace for multi-participant-based collaborative geographic experiments. Based on the above analysis, the differences between VGEs and other similar platforms are discussed to draw their clear boundaries. Finally, a short summary of the limitations of current VGEs is given, and future directions are proposed to facilitate ongoing progress toward forming a comprehensive version of VGEs. © 2013 Elsevier B.V. Source

Zheng F.,Technical University of Delft | Zheng F.,Southwest Jiaotong University | Van Zuylen H.,Technical University of Delft
Transportation Research Part C: Emerging Technologies | Year: 2013

In the urban signalized network, travel time estimation is a challenging subject especially because urban travel times are intrinsically uncertain due to the fluctuations in traffic demand and supply, traffic signals, stochastic arrivals at the intersections, etc. In this paper, probe vehicles are used as traffic sensors to collect traffic data (speeds, positions and time stamps) in an urban road network. However, due to the low polling frequencies (e.g. 1. min or 5. min), travel times recorded by probe vehicles provide only partial link or route travel times. This paper focuses on the estimation of complete link travel times. Based on the information collected by probe vehicles, a three-layer neural network model is proposed to estimate complete link travel time for individual probe vehicle traversing the link. This model is discussed and compared with an analytical estimation model which was developed by Hellinga et al. (2008). The performance of these two models are evaluated with data derived from VISSIM simulation model. Results suggest that the Artificial Neural Network model outperforms the analytical model. © 2012 Elsevier Ltd. Source

Zhu Q.,Southwest Jiaotong University
Journal of molecular modeling | Year: 2014

NAC (NAM/ATAF/CUC) transcription factors regulate the expression of the target genes by formation of NAC-DNA complex, which are involved in development, stress responses and nutrient distribution in many metaphyta plants. AtNAC1, a NAC transcription factor from Arabidopsis thaliana, plays an important role in auxin signaling and root development. In order to understand the structure and DNA binding model of AtNAC1, the 3D structure model of AtNAC1 was constructed and docked with its target DNA. The structure of AtNAC1 monomer contained four α-helices and eight β-sheets. Two homo monomers of AtNAC1 formed a homo-dimer. The N-terminal sheet S1, Arg24 and Glu31 played an important role in forming AtNAC1 homo-dimer. AtNAC1 dimer interacted with DNA via its core β-sheet (S5) which contained WKATGKD motif inserting into the major groove of DNA and formed a tight AtNAC1-DNA complex. The DNA sites for AtNAC1 binding were 5'-CTGACGTA-3' and 5'-GATGACGC-3'. Lys102, Ala103, Thr104, Gly105, Lys106, and Asp107 interacting with sugars/bases of DNA were probably responsible for specific recognition of DNA sites. Meanwhile, Arg91, Lys135, and Lys171 binding with phosphate groups of DNA backbone might be the key residues for affinity with DNA. The study provided the in silico framework to understand the interactions of AtNAC1 with DNA at the molecular level. Source

Li Y.-J.,University of Electronic Science and Technology of China | Zhu H.-Q.,Southwest Jiaotong University
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2014

Based on the online and offline subscription ratios of investors in IPOs of Chinese A-share stock markets, this paper explores the information contents of subscription ratios and their forecasting ability for stock performance after IPO. The results show that the online subscription ratio of individual investors and the offline subscription ratio of institutional investors are significantly negatively related the first day return, turnover ratio and 3-month-held return. The first day return and 3-month-held return are more sensitive to offline subscription ratio of institutional investors than online subscription ratio of individual investors. The first day turnover ratio, however, are more sensitive to online subscription ratio of individual investors. Contrary to the returns of main board (ME) stocks, the first day return and 3-month-held return of stocks listed on small and medium-size enterprise board (SME) or growth enterprise (GE) board could be forecasted much better by the online and offline subscription ratios of investors. Our results are beneficial to IPOs pricing and investors' investment decision in secondary markets. Source

Yan L.-S.,Southwest Jiaotong University | Liu X.,Alcatel - Lucent | Shieh W.,University of Melbourne
IEEE Photonics Journal | Year: 2011

Progress in high-capacity optical communication systems in 2010 is reviewed, with spectral efficiency (SE) as the main figure of merit. Advanced modulation formats, such as quadrature amplitude modulation (QAM) and orthogonal frequency-division multiplexing (OFDM), together with polarization-division multiplexing (PDM) and digital coherent detection, are playing key roles in approaching the Shannon limit of SE for optical fiber communication. Photonics is now entering into a new era of high SE on par with electronics (wireless), yet with orders of magnitude higher overall system capacity. © 2011 IEEE. Source

Zhou X.J.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

On the basis of ground geology and hydrogeology of an urban river, a municipal tunnel in which public pipes and cables are placed is designed to cross the river by means of open cut method. The main structure of the municipal tunnel and its waterproof measures are both summarized in this paper. Reinforced concrete frame structure with one story and three box-shaped sections is used in the design of the municipal tunnel. Both self-waterproof structure and waterproof sheet are applied to prevent ground water from permeating into the subaqueous tunnel. The installation of public cables and pipes are still elucidated in the paper. The typical structure of the municipal tunnel can be a guiding reference for the design of other subaqueous tunnel to cross urban rivers under analogous conditions. © (2014) Trans Tech Publications, Switzerland. Source

Zhao Y.M.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

The continuous beam bridge is a kind of bridge type used widely on the project. With the design theory and construction technology, prestressed concrete continuous beam bridge shown strong vitality. This design is a high-speed rail (40+56+40) m prestressed concrete continuous beam bridge design, whose width is 12.2m and its maximum Design speed is 300km/h. The form of the railway is double line which is 4.8m far away, and the cross-sectional slope is 2%.ZK load was applied on the bridge. A three-span P.C continuous Beam structure with variable cross-section is used in this bridge. The girder body adopts single cell and single box, the height of beam takes quadratic parabola relation, which is 5m high at the middle fulcrum, while at the side fulcrum and the mid-span is 2.5m. The design uses Midas/Civil to establish the finite element model that is reasonable and simple, analyzing the structure behavior of the girder body under loading, especially the internal forces of bridge structure under dead load, live load and additional force. © (2014) Trans Tech Publications, Switzerland. Source

Fan W.-B.,Southwest Jiaotong University
Jiaotong Yunshu Xitong Gongcheng Yu Xinxi/Journal of Transportation Systems Engineering and Information Technology | Year: 2013

The reliability of the park-and-ride (P&R) system is one of the important elements that influence its attractiveness to the users. To measure the magnitude of metro-based P&R reliability, this paper proposes two concepts: transfer reliability and mode reliability. The uncertainty is considered in these concepts, which are caused by random travel times on roadways, random parking searching times within parking facilities, as well as random waiting times on metro stations. The stochastic user equilibrium analysis is adopted to simulate auto-travelers' behaviors (e.g., model choice, route choice, and parking choice) under the principle of travel costs minimization. The formulated model is resolved by the Monte Carlo method and the method of successive average. A numerical example is designed to demonstrate the significant effect of reliability/uncertainty on P&R mode share. In addition, P&R reliability analysis is conducted with respect to factors such as the metro train dispatching frequency, parking capacity and the level of total demand. Source

Li X.,Southwest Jiaotong University
Proceedings - 2016 8th International Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2016 | Year: 2016

This paper concentrates on the problem of urban construction waste recycling network optimization, and the main innovation of this paper is to introduce mixed integer programming in this problem. Firstly, the system layout of the construction waste recycling industry is proposed. Moreover, to construct an urban construction waste recycling network, we should formulate the rules of resource optimization and combination, determine the relationship between enterprises, and realize reasonable division of labor and coordination in advance. Secondly, an urban construction waste recycling network optimization algorithm is developed using the mixed integer programming, and three components are contained in our objective function. Finally, to make performance evaluation, we choose Chengdu city in Sichuan province to construct the dataset, and experimental results demonstrate that the proposed can effectively optimize the urban construction waste recycling network. © 2016 IEEE. Source

Zhao W.-L.,City University of Hong Kong | Wu X.,City University of Hong Kong | Wu X.,Southwest Jiaotong University | Ngo C.-W.,City University of Hong Kong
IEEE Transactions on Multimedia | Year: 2010

With the proliferation of Web 2.0 applications, user-supplied social tags are commonly available in social media as a means to bridge the semantic gap. On the other hand, the explosive expansion of social web makes an overwhelming number of web videos available, among which there exists a large number of near-duplicate videos. In this paper, we investigate techniques which allow effective annotation of web videos from a data-driven perspective. A novel classifier-free video annotation framework is proposed by first retrieving visual duplicates and then suggesting representative tags. The significance of this paper lies in the addressing of two timely issues for annotating query videos. First, we provide a novel solution for fast near-duplicate video retrieval. Second, based on the outcome of near-duplicate search, we explore the potential that the data-driven annotation could be successful when huge volume of tagged web videos is freely accessible online. Experiments on cross sources (annotating Google videos and Yahoo! videos using YouTube videos) and cross time periods (annotating YouTube videos using historical data) show the effectiveness and efficiency of the proposed classifier-free approach for web video tag annotation. © 2006 IEEE. Source

Zhou X.J.,Southwest Jiaotong University
Advanced Materials Research | Year: 2014

This paper mainly summarizes the structural design of mountain tunnels used to lay natural gas pipes in the 3rd pipeline project of natural gas transmission from west to east China according to the main requirement of laying gas pipes in mountain tunnels supported with concrete lining in light of geological conditions of surrounding rock, the designed parameters for tunnel lining are presented and meanwhile, the installation of gas pipe is also illustrated in the paper. The type of laying gas pipe and designing of tunnel support in mountainous regions proposed in this paper can provide practicable guidance to the design and construction of oil and gas pipe tunnels under similar circumstances. © (2014) Trans Tech Publications, Switzerland. Source

Zhao Y.X.,Southwest Jiaotong University | Zhang B.,China Academy of Railway Sciences
Advanced Materials Research | Year: 2012

Causes are investigated on the earlier failures of the bearings for China railway freight cars with radial bogie. Through observing failure objects, checking manufacturing quality, and calculating rolling contact fatigue (RCF) stresses, it reveals that poor manufacturing quality of bearing outer ring plays a key role to the earlier failures and, in addition, mismatch design of RCF stresses between the outer ring and the inner ring acts as an aid actor. Checks verify that surface and core of the outer ring have lower hardness values than requirements; seldom micro-structures, i.e. black-white bands with thickness of around 0.6 to 1.3 mm, appear in the carburized layer of the bearing outer ring; the white part is needle like martensites with higher hardness values, while the black part is pearlites with lower hardness values; and more contingently, crack like manufacturing flaws may appear in the carburized layer with equiaxed grains of ferrites having lower hardness values are around the flaws. RCF values of the outer ring are much larger than that of the inner ring. But the equivalent RCF stress on the present car with radial bogie is lower than that on other cars. This indicates that main cases of the present earlier failures are due the bearings themselves other than the cars. © (2012) Trans Tech Publications, Switzerland. Source

Liu H.,Dongguan University of Technology | Li N.,Southwest Jiaotong University | Zhao Q.,Northeastern University China
Applied Optics | Year: 2015

Optical chaos generated by chaotic lasers has been widely used in several important applications, such as chaosbased communications and high-speed random-number generators. However, these applications are susceptible to degradation by the presence of time-delay (TD) signature identified from the chaotic output. Here we propose to achieve the concealment of TD signature, along with the enhancement of chaos bandwidth, in three-cascaded vertical-cavity surface-emitting lasers (VCSELs). The cascaded system is composed of an external-cavity master VCSEL, a solitary intermediate VCSEL, and a solitary slave VCSEL. Through mapping the evolutions of TD signature and chaos bandwidth in the parameter space of the injection strength and frequency detuning, photonic generation of polarization-resolved wideband chaos with TD concealment is numerically demonstrated for wide regions of the injection parameters. © 2015 Optical Society of America. Source

Feng L.,Agency for Science, Technology and Research Singapore | Monterola C.P.,Agency for Science, Technology and Research Singapore | Hu Y.,Southwest Jiaotong University | Hu Y.,Sun Yat Sen University
New Journal of Physics | Year: 2015

Interdependent networks in areas ranging from infrastructure to economics are ubiquitous in our society, and the study of their cascading behaviors using percolation theory has attracted much attention in recent years. To analyze the percolation phenomena of these systems, different mathematical frameworks have been proposed, including generating functions and eigenvalues, and others. These different frameworks approach phase transition behaviors from different angles and have been very successful in shaping the different quantities of interest, including critical threshold, size of the giant component, order of phase transition, and the dynamics of cascading. These methods also vary in their mathematical complexity in dealing with interdependent networks that have additional complexity in terms of the correlation among different layers of networks or links. In this work, we review a particular approach of simple, self-consistent probability equations, and we illustrate that this approach can greatly simplify the mathematical analysis for systems ranging from single-layer network to various different interdependent networks. We give an overview of the detailed framework to study the nature of the critical phase transition, the value of the critical threshold, and the size of the giant component for these different systems. © 2015 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft. Source

Lu S.,Southwest Jiaotong University | Hao G.,City University of Hong Kong
International Journal of Project Management | Year: 2013

Trust and power are considered to be two necessary mechanisms for promoting cooperation among construction partners. In this paper, trust is regarded as a mediator between power and cooperative performance. A model of the relationship between trust and power is developed and tested using the results of an empirical study based on a sample of Chinese contractors. The results show that an owner's expert power can influence a contractor's cognition- and affect-based trust in the owner and that coercive power has little direct impact on the formation of trust. However, coercive power is found to moderate the relationship between expert power and cognition-based trust, in that the relationship is more positive when the level of coercive power is lower. Moreover, affect-based trust has a significantly greater positive influence on cooperative performance than cognition-based trust. These findings are interpreted in light of Chinese culture, and provide some suggestions for how owners can exercise power to foster cooperation with their contractors. © 2012 Published by Elsevier Ltd. APM and IPMA. Source

Ma G.,Southwest Jiaotong University
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2013

The principal basis of the Jacobian-free Newton-Krylov (JFNK) algorithm was firstly introduced in conjunction with its iterative scheme using the split preconditioning technique, and then the partial differential equation with magnetic vector potential as the state variable for governing the electromagnetic properties of a 2-D superconductor (SC) subjected to time-varying/nonuniform magnetic fields was established, and the related nonlinear systems of finite element equations plus the adopted strategy for numerical iteration were released. Taking the ac loss problems of a high-aspect-ratio SC strip in a time-varying field and the maglev problems of a bulk high temperature superconductor (HTS) above a magnetic track as the studied cases, the computational performance of the preconditioned JFNK algorithm was tested on the basis of the validated program. It was found by this investigation that the preconditioned JFNK algorithm has the ability to rapidly solve the large nonlinear electromagnetic problems of SC, and is thus an advanced approach for developing the program to solve the electromagnetic problems of SC. © 2013 Chinese Society for Electrical Engineering. Source

Ingason H.,SP Technical Research Institute of Sweden | Ying Zhen Li,Southwest Jiaotong University
Journal of Fire Protection Engineering | Year: 2011

Experimental results are presented from a series of tests in a model scale tunnel (1 : 23). This study focuses on single and two-point extraction ventilation systems to complement a previous study with the same apparatus using longitudinal ventilation only. The point extraction ventilation system in this test series was operated under different fire loads and flow conditions of either forced longitudinal ventilation or natural ventilation. Wood crib piles were used to simulate the fire source, which was designed to correspond to a 'heavy goods vehicle' fire load at full scale. The parameters varied were the number of wood cribs, the longitudinal ventilation velocity, and the arrangement of the extraction vent openings and their exhaust capacity. Measurement data were obtained for maximum heat release rates, fire growth rates, maximum excess temperatures beneath the ceiling, and heat fluxes. Fire spread between wood cribs with a separation distance corresponding to 15 m at full scale was also investigated. These data are reproduced well by empirical correlations that were established as part of the study. It is concluded that fire and smoke flows upstream and downstream of the fire source can be fully controlled if the ventilation velocities upstream and downstream are above about 2.9 and 3.8 m/s, respectively, at full scale for a single-point extraction ventilation system and greater than about 2.9 m/s on both sides at full scale for a two-point system. © The Author(s) 2011. Source

Luo M.-X.,Southwest Jiaotong University | Luo M.-X.,Beijing University of Posts and Telecommunications | Ma S.-Y.,Henan University | Chen X.-B.,Beijing University of Posts and Telecommunications | Wang X.,Dublin City University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

Quantum state joining has been recently experimentally demonstrated [C. Vitelli, Nat. Photon. 7, 521 (2013)1749-488510.1038/nphoton.2013.107] which can transfer two input photonic qubits into a photonic ququart. Here, we revisit these processes from a hybrid point of view. By exploring the giant optical circular birefringence induced by quantum-dot spins in one-sided optical microcavities, we introduce some deterministic joining schemes including two quantum-dot spin joining, hybrid photon and quantum-dot spin joining, and two-photon joining. The input quantum information is represented by one photon with polarization and spatial mode degrees of freedom (DOFs). These schemes are also adapted to the inverse processes called quantum state splitting because all the joining procedures are unitary and do not require projection and feed-forward steps. The fused photon is convenient for realizing elementary logic gates such as the controlled-not (cnot) gate, swap gate, and Toffoli gate. These hybrid fusion and splitting schemes provide flexible synthesis of the quantum-dot spin and photon in quantum applications. The transmission superiority of photons and storage superiority of the quantum-dot spin may be combined for quantum network communication or quantum computations. © 2015 American Physical Society. Source

Xiao J.,Nanjing University of Technology | Hsein Juang C.,Clemson University | Wei K.,Southwest Jiaotong University | Xu S.,Nanjing University of Technology
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2014

The authors investigated the effects of principal stress rotation (PSR) on the traffic load-induced settlement of subways in soft subsoil. Here, a series of hollow cylinder tests on normally consolidated, medium-plasticity soft clay with and without principal stress rotation were performed along with finite-element modeling and simulation. The results show significant increases in both excess pore-water pressure and cumulative deformation of the normally consolidated soft clay when PSR is present and simulated, and the effects become more pronounced as the maximum effective principal stress ratio or load frequency increases. Under the actual traffic load-induced stress in subsoil below the subway tunnel, the presence of PSR increases the cumulative deformation of soft clay by 9-23% compared with that without PSR. As an approximation, the cumulative deformation of soft clay with the effect of PSR can be estimated by multiplying the deformation derived from the repeated triaxial testing without PSR with the ratio of axial strain between the two tests. © 2013 American Society of Civil Engineers. Source

Sun X.,Southwest Jiaotong University | Hartzell S.,U.S. Geological Survey
Geophysical Research Letters | Year: 2014

The slip model for the 2011 Mw 5.6 Prague, Oklahoma, earthquake is inferred using a linear least squares methodology. Waveforms of six aftershocks recorded at 21 regional stations are used as empirical Green's functions (EGFs). The solution indicates two large slip patches: one located around the hypocenter with a depth range of 3-5.5km; the other located to the southwest of the epicenter with a depth range from 7.5 to 9.5 km. The total moment of the solution is estimated at 3.37 × 1024 dyne cm (Mw 5.65). The peak slip and average stress drop for the source at the hypocenter are 70 cm and 90 bars, respectively, approximately one half the values for the Mw 5.8 2011 Mineral, Virginia, earthquake. The stress drop averaged over all areas of slip is 16 bars. The relatively low peak slip and stress drop may indicate an induced component in the origin of the Prague earthquake from deep fluid injection. © 2014. American Geophysical Union. All Rights Reserved. Source

Xiang W.,Southwest Jiaotong University | Xiao J.,Southwest University of Science and Technology
International Journal of Robust and Nonlinear Control | Year: 2012

In this paper, we investigate the stability analysis problem of switched impulsive nonlinear systems and several stabilization problems of switched discrete-time linear systems are studied. First, sufficient conditions ensuring globally uniformly asymptotically stability of switched nonlinear impulsive system under arbitrary and DDT (dynamical dwell time which defines the length of the time interval between two successive switchings) switching are derived, respectively. In the DDT switching case, we first consider the switched system composed by stable subsystems, then we extend the results to the case where not all subsystems are stable. The stabilizations of switched discrete-time linear system under arbitrary switching, DDT switching and asynchronous switching are investigated respectively. Based on the stability analysis results, the control synthesis consists of controller design for each subsystem and state impulsive jumping generators design at switching instant. With the aid of the state impulsive jumping generators at switching instant, the 'energy' produced by switching can be minimized, which leads to less conservative results. Several numerical examples are given to illustrate the proposed results within this paper. Copyright © 2011 John Wiley & Sons, Ltd. Copyright © 2011 John Wiley & Sons, Ltd. Source

Hou B.P.,Sichuan Normal University | Wei L.F.,Southwest Jiaotong University | Wang S.J.,University of Sichuan
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

We present the normal-mode splitting and optomechanically induced transparency or absorption phenomena in the strongly tunnel-coupled optomechanical cavities. In the probe output spectrum, there appear central transparency windows or absorption peaks around which two broad sidebands are symmetrically located. It has been confirmed by the quantitative findings that two broad sidebands, which include the distorted absorption peaks, indicate the normal-mode splitting of the two hybridized cavities, and central transparency windows or absorption peaks character the interference induced by the optomechanical interactions. Additionally, the switching from absorption to amplification can be realized by only adjusting the tunnel interaction. These spectrum properties can be used for the coherent control of light pulses via microfabricated optomechanical arrays. © 2015 American Physical Society. ©2015 American Physical Society. Source

Wei G.,Chongqing University of Arts and Sciences | Zhang N.,Southwest Jiaotong University
Journal of Intelligent and Fuzzy Systems | Year: 2014

Hesitancy is the most common problem in decision making, for which hesitant fuzzy set can be considered as a suitable means allowing several possible degrees for an element to a set. And, the VIKOR method is an effective tool to determine a compromise solution by providing a maximum 'group utility' for the 'majority' and a minimum 'individual regret' for the 'opponent' in decision making, particularly in a situation where the decision maker is not able or does not know to express his/her preference. In many practical situations, the inter-dependent or interactive characteristics among criteria and preference of decision makers should be taken into account, we generally utilize the Choquet integral to depict the correlations and interactions in the decision process. When the Choquet integral is used to solve the correlative decision making problems, we ignore the importance of the ordered position of the element. In fact, each element has the same probability to be drawn and all permutations have the same probability. In this paper, we introduce the Shapley value to solve correlative problem, which is used to be interpreted as a kind of average value of the contribution of an element alone in all coalitions with the same position probability. Firstly, we present some concepts of hesitant fuzzy set and define the Shapley value-based Lp-metric (SLp,μ- metric). With the SLp,μ-metric, an extended VIKOR method is developed to deal with the correlative multiple criteria decision making (MCDM) problem under hesitant fuzzy environment. To comparative analysis, we also apply the TOPSIS method to solve the problem based on the Shapley value. Finally, a comparative analysis of the two methods is illustrated with a numerical example. © 2014 - IOS Press and the authors. All rights reserved. Source

Buhagiar J.,University of Birmingham | Qian L.,Southwest Jiaotong University | Dong H.,University of Birmingham
Surface and Coatings Technology | Year: 2010

Based on the success of the feasibility study reported, the surface properties of low-temperature plasma carburised P558 Ni-free medical grade (ASTM F2581) austenitic stainless steel have been fully evaluated in terms of electrochemical corrosion, dry- and corrosion-wear and fretting-wear in Ringer's solution. Anodic polarization tests demonstrated that the precipitate-free S-phase generated by low-temperature plasma carburising at 500 °C for 15 h can retain the good corrosion resistance of the untreated ASTM F2581 Ni-Free material in Ringer's solution. The wear resistance of the Ni-free austenitic stainless steel can be improved by 700% and 140% when reciprocating against a WC ball in air (dry-wear) and in Ringer's solution (corrosion-wear) respectively. In addition, the low-temperature plasma carburising treatment can considerably reduce the friction coefficient and improve the fretting-wear resistance of the Ni-free austenitic stainless steel in Ringer's solution. © 2010 Elsevier B.V. Source

Lu L.,Southwest Jiaotong University
2015 IEEE 12th International Conference on Electronic Measurement and Instruments, ICEMI 2015 | Year: 2016

This paper wasfocused on the ride-comfort. There are different effects in differentoperating conditions on the high-speed train. Based on the practical testing of the high-speed train, the changes of vibration on the high-speed train were researched in this paperin the conditions of operating on the railway or in the tunnel. With the frequency-domain analysis and time-domain analysis, the distribution of the vibration main frequency was given in the paper. According to UIC513R standard ⟪Guidelines for evaluating passenger comfort in relation to vibration in railway vehicles⟫, the ride-comfort value of different operating conditions was calculated and the ride-comfort grade wasevaluated. © 2015 IEEE. Source

Liang D.,University of Electronic Science and Technology of China | Liu D.,Southwest Jiaotong University
Information Sciences | Year: 2014

Decision-theoretic rough sets (DTRS) are a representative rough set model. The loss function is a pivotal ingredient of DTRS, which is associated with the decision maker's evaluation. Considering the value of loss function with the imprecise evaluation, interval-valued DTRS (IVDTRS) and its mechanism in this paper are explored. First, we construct a basic model of IVDTRS. The comparison between DTRS and IVDTRS is discussed. In the frame of IVDTRS, we then focus on deriving three-way decisions with the aid of two conventional methods, i.e., a certain ranking method and a degree of possibility ranking method, respectively. The certain ranking method converts an interval value into single and derives decision rules under a certain risk attitude of decision maker; the degree of possibility ranking method assumes the flexibility of interval and utilizes the preference between interval values. All the combinations and their prerequisites are summarized, in which we obtain two types of decision rules. Based on the above analysis, we further propose an optimization method for three-way decisions with IVDTRS, which is designed to minimize the overall uncertainty based on the Shannon entropy. We also compare these methods based on standard data sets. Finally, the criteria for choosing a suitable method to three-way decisions with IVDTRS are generated. These results can support decision making in the uncertain environment. © 2013 Elsevier Inc. All rights reserved. Source

Wang F.,University of Sichuan | Wang M.,Southwest Jiaotong University | Wang Q.,University of Sichuan
Tunnelling and Underground Space Technology | Year: 2012

A computational study was carried out to investigate the effects of deflected angles of jet fans, equipped with silencers, on the tunnel ventilation system. An optimal deflected angle for the normal ventilation in a curved tunnel was proposed. As the fans deflect an angle (β) of 3° towards the convex wall, maximum pressure-rise coefficient and lowest wall shear stress on the ceilings were obtained. An offset of jets on the cross-section was observed for various deflected angles (β) initially. For β= 3°, a relatively gradual velocity profile was obtained as compared to the other values of β which yielded steep velocity profiles downstream. The static pressure increased gradually and overlapped with each other for various values of β initially. The divergence in the longitudinal pressure curves was found when the jets arrived at the curved walls. A relatively shorter distance was required for the pressure-rise to complete at β= 3°. © 2012 Elsevier Ltd. Source

Ma G.-T.,Southwest Jiaotong University
IEEE Transactions on Applied Superconductivity | Year: 2013

A robust and fast numerical course for investigating the magnetic levitation (maglev) performance of high-temperature superconductors (HTSs) is proposed and implemented via finite-element methods (FEMs) in this paper. This numerical course uses the magnetic vector potential as the state variable to establish the partial differential equations (PDEs) for governing the electromagnetic properties of 2-D simplified HTSs, a smoothed Bean-Kim's model of a critical state to describe the nonlinear constitutive law of HTSs, and the advanced algorithm of Jacobian-free Newton-Krylov (JFNK) to handle the nonlinear system of the FEM equation. After being tested, this homemade FEM model was applied to investigate the influence of various FEM parameters, e.g., the dimension of the computational domain, the prescribed tolerance for convergence, the coarseness of the mesh, and the time step, upon the precision of levitation/guidance force on an HTS bulk while moving in a nonuniform field generated by a permanent-magnet track. The most important findings through these studies are that the coarse choice of tolerance can cause the nonphysical phenomena such as the crossings in the force loops, and the numerical results are very robust against the dimension of the computational domain, the coarseness of the mesh, and the time step. Based on these findings, it was found that the time consumed for performing a typical cycle of levitation force calculation is merely a few seconds, making the application of this FEM model for optimizing the HTS maglev system very attractive. © 2002-2011 IEEE. Source

Zhang H.,Southwest Jiaotong University | Chen J.,City University of Hong Kong
Proceedings of the American Control Conference | Year: 2014

Collective behaviors of multi-agent systems over signed graphs find applications in a variety of scenarios including social networks, predator-prey dynamics, which however have not been adequately addressed as their counterparts with nonnegative graphs. This paper studies bipartite consensus problem of general linear multi-agent systems over signed digraphs. First, we show that for general linear agents, bipartite consensus over signed graphs and ordinary consensus over nonnegative graphs are equivalent. This indicates that prevailing consensus controllers for nonnegative graphs can be adopted to solve bipartite consensus problems. Based on this observation, an existing Riccati equation based cooperative tracking controller is extended to solve the bipartite consensus problem for general linear systems. © 2014 American Automatic Control Council. Source

Cui H.,Southwest Jiaotong University
International Journal of Energy Economics and Policy | Year: 2016

Economic growth needs to consume large amounts of fossil energy, which will result in greenhouse gas emissions and global climate warming. Therefore, how to save energy and protect environment has become a worldwide problem. This paper establishes an econometric model including labor, fixed capital stock, energy inputs and other explanatory variables based on the Cobb-Douglas production function to empirically analyze the relation between China’s economic growth and energy consumption. Meanwhile, this paper illustrates the relation of China’s carbon dioxide emissions to export trade, too. The study results show that China still promotes economic growth at the costs of high energy consumption and heavily environment pollution. Therefore, how to achieve the transition of a high carbon economy to a low carbon economy will be a fundamental problem that has to solve in China’s future development. To this end, China should participate in international environmental cooperation, promote energy saving and environment conservation. © 2016, Econjournals. All rights reserved. Source

Li X.,Southwest Jiaotong University | Chen W.,Zhejiang University | Wang H.,University of Poitiers | Wang G.,University of Poitiers
Engineering Fracture Mechanics | Year: 2012

The plastic zone in the vicinity of a penny-shaped Dugdale crack embedded in an inhomogeneous infinite medium is estimated, for the first time. By virtue of the Dugdale's hypothesis along with the method of potential theory, the equation governing the size of plastic zone is derived in terms of Hypergeometric functions. The normal stress outside the plastic zone is expressed by special functions. The validity of the present solutions is examined both analytically and numerically. Systematical calculations are made to investigate the influence of some physical parameters on the size of plastic zone and the distribution of the normal stress. © 2012 Elsevier Ltd. Source

Chen L.,Beijing University of Posts and Telecommunications | Chen W.,BUPT | Wang B.,BUPT | Zhang X.,BUPT | And 2 more authors.
IEEE Communications Magazine | Year: 2011

System-level simulation has been widely used to evaluate the comprehensive performance of different mobile cellular systems. System-level simulation methodologies for different systems have been discussed by different organizations and institutions. However, the framework for a unified simulation methodology and platform has not been established. In this article, we propose a general unified simulation methodology for different cellular systems. Both the design of the simulation structure and the establishment of the simulation platform are studied. Meanwhile, the unified modeling and the realization of various modules related to the system-level simulation are presented. The proposed unified simulation methodology and the general simulation platform can be used to evaluate the performance of multiple mobile communication systems fairly. Finally, the overall performance of LTE and Mobile WiMAX systems is evaluated through the proposed framework. The key simulation results for both Full Buffer and VoIP traffics are presented and discussed. It is shown that the LTE system exhibits better performance than Mobile WiMAX. © 2010 IEEE. Source

Xia C.-C.,Tongji University | Tang Z.-C.,Tongji University | Xiao W.-M.,Tongji University | Xiao W.-M.,Southwest Jiaotong University | Song Y.-L.,Tongji University
Rock Mechanics and Rock Engineering | Year: 2014

The prime objective of this work is to improve our understanding of the shear behavior of rock joints. Attempts are made to relate the peak shear strength of rock joints with its three-dimensional surface morphology parameters. Three groups of tensile joint replicas with different surface morphology are tested with direct shear tests under constant normal load (CNL) conditions. Firstly, the three-dimensional surface characterization of these joints is evaluated by an improved roughness parameter before being tested. Then, a new empirical criterion is proposed for these joints expressed by three-dimensional quantified surface roughness parameters without any averaging variables in such a way that a rational dilatancy angle function is used instead of {\text{JRC}} \cdot \log-{10} \left({{{\text{JCS}} \mathord{\left/ {\vphantom {{\text{JCS}} {\sigma-{\text{n}} }}} \right. \kern-\nulldelimiterspace} {\sigma-{\text{n}} }}} \right) by satisfying the new peak dilatancy angle boundary conditions under zero and critical-state normal stress (not physical infinite normal stress). The proposed criterion has the capability of estimating the peak shear strength at the laboratory scale and the required roughness parameters can be easily measured. Finally, a comparison among the proposed criterion, Grasselli's criterion, and Barton's criterion are made from the perspective of both the rationality of the formula and the prediction accuracy for the three groups of joints. The limitations of Grasselli's criterion are analyzed in detail. Another 37 experimental data points of fresh rock joints by Grasselli are used to further verify the proposed criterion. Although both the proposed criterion and Grasselli's criterion have almost equal accuracy of predicting the peak shear strength of rock joints, the proposed criterion is easier and more intuitive from an engineering point of view because of its Mohr-Coulomb type of formulation. © 2013 Springer-Verlag Wien. Source

Wu Q.,Central Queensland University | Cole C.,Central Queensland University | Luo S.,Southwest Jiaotong University | Spiryagin M.,Central Queensland University
Vehicle System Dynamics | Year: 2014

Longer and heavier trains mean larger in-train forces and more complicated force patterns. Practical experience indicates that the development of fatigue failure of coupling systems in long heavy trains may differ from conventional understanding. The friction-type draft gears are the most widely used draft gears. The ever developing heavy haul transport environment requires further or new understanding of friction draft gear behaviour and its implications for train dynamics as well as fatigue damage of rolling stock. However, modelling of friction draft gears is a highly nonlinear question. Especially the poor predictability, repeatability and the discontinuity of friction make this task more challenging. This article reviews current techniques in dynamics modelling of friction draft gears to provide a starting point that can be used to improve existing or develop new models to achieve more accurate force amplitude and pattern predictions. © 2014 Taylor and Francis. Source

Feng L.,University of Science and Technology Beijing | Fan P.,Southwest Jiaotong University | Zhou X.,University of Science and Technology Beijing
Wireless Personal Communications | Year: 2013

A set of binary codes is called a Z-complementary code set if the sum of the autocorrelation functions of the codes involved is zero in the zero correlation zone (ZCZ) except at zero shift. Comparing to the traditional complementary code sets, the Z-complementary code sets not only have more freedom on the code length, but also have much more mates. In this paper, lower bounds on periodic/aperiodic correlation of Z-complementary binary code sets with respect to the number of mates, family size, sequence length, the length of ZCZ, maximum periodic/aperiodic autocorrelation sidelobe inside the ZCZ and maximum periodic/aperiodic crosscorrelation value inside the ZCZ, are derived. The proposed lower bounds provide theoretical criteria for designing, optimizing and choosing Z-complementary code set in applications. © 2013 Springer Science+Business Media New York. Source

Zhang X.,Southwest Jiaotong University | Aifantis K.,University of Arizona
Reviews on Advanced Materials Science | Year: 2015

Gradient plasticity frameworks arise from the consideration of the gradient of the plastic strain as an independent variable. In doing so a new material parameter, the internal length (or gradient coefficient) is introduced, which governs the gradient effects. Despite the efficiency of these theories, there does not exist a unified interpretation of the internal length, and its relationship with the material microstructure has not been clearly understood. The present article provides a review on the various interpretations that recent studies have provided for the internal length that go beyond fitting it to experimental data. © 2015 Advanced Centr Co. Ltd. Source

Zhao Q.,CAS National Center for Nanoscience and Technology | Wang S.,Southwest Jiaotong University | Xie Y.,CAS National Center for Nanoscience and Technology | Zheng W.,CAS National Center for Nanoscience and Technology | And 4 more authors.
Advanced Healthcare Materials | Year: 2012

This report demonstrates an in vitro method for screening wound dressing candidates that can minimize the use of animals for developing better methods for wound care. The development of materials and formulations for wound dressings, an important application of biomaterials, is laboriously and ethically challenging because of the use of a large number of animals. A method for rapid and effective screening of wound dressings in vitro , therefore, is in great need. A cell-on-a-chip model was used to simulate the cutaneous wound in vitro and screen the performances of several electrospun fibrous wound dressings in enhancing wound healing. For comparison, the performances of wound dressings were also evaluated in a rat model. It was found that the results acquired by microchip model corroborates well with animal experiments. It is the first time, as far as we know, that a good correlation between in vitro and in vivo results is reported for fibrous wound dressings. The cell-on-a-chip wound model we developed here may change the way that scientists screen candidates for wound dressings. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Fan L.,Shantou University | Lei X.,Southwest Jiaotong University
IEEE Communications Letters | Year: 2011

An exact closed-form bit-error-rate (BER) expression is derived for the scheduled cognitive user (CU) in the uplink cellular networks with opportunistic scheduling considered by Li. Simulation results corroborate the theoretical analysis. © 2011 IEEE. Source

Chen J.,Sun Yat Sen University | Wei L.F.,Sun Yat Sen University | Wei L.F.,Southwest Jiaotong University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015

Fast Rabi π-pulse technique has been widely applied to various coherent quantum manipulations, although it requires precise designs of the pulse areas. Relaxing the precise pulse designs, various rapid adiabatic passage (RAP) approaches have been alternatively utilized to implement various population passages deterministically. However, the usual RAP protocol could not be implemented desirably fast, as the relevant adiabatic condition should be robustly satisfied during the passage. Here, we propose a modified shortcut to adiabaticity (STA) technique to accelerate significantly the desired deterministic quantum state population passages. This transitionless technique is beyond the usual rotating wave approximation (RWA) performed in the recent STA protocols, and thus can be applied to deliver various fast quantum evolutions wherein the relevant counter-rotating effects cannot be neglected. The proposal is demonstrated specifically with the driven two- and three-level systems. Numerical results show that with the present STA technique beyond the RWA the usual Stark-chirped RAPs and stimulated Raman adiabatic passages could be significantly speeded up; the deterministic population passages could be implemented as fast as the widely used fast Rabi π pulses, but are insensitive to the applied pulse areas. © 2015 American Physical Society. Source

Li Z.,Hong Kong Polytechnic University | Li Z.,Southwest Jiaotong University | Zhou Q.,Hong Kong Polytechnic University
International Journal of Geographical Information Science | Year: 2012

Spatial data can be represented at different scales, and this leads to the issue of multi-scale spatial representation. Multi-scale spatial representation has been widely applied to online mapping products (e.g., Google Maps and Yahoo Maps). However, in most current products, multi-scale representation can only be achieved through a series of maps at fixed scales, resulting in a discontinuity (i.e., with jumps) in the transformation between scales and a mismatch between the available scales and users' desired scales. Therefore, it is very desirable to achieve smoothly continuous multi-scale spatial representations. This article describes an integrated approach to build a hierarchical structure of a road network for continuous multi-scale representation purposes, especially continuous selective omission of roads in a network. In this hierarchical structure, the linear and areal hierarchies are constructed, respectively, using two existing approaches for the linear and areal patterns in a road network. Continuous multi-scale representation of a road network can be achieved by searching in these hierarchies. This approach is validated by applying it to two study areas, and the results are evaluated by both quantitative analysis with two measures (i.e., similarity and average connectivity) and visual inspection. Experimental results show that this integrated approach performs better than existing approaches, especially in terms of preservation of connectivity and patterns of a road network. With this approach, efficient and continuous multi-scale selective omission of road networks becomes feasible. © 2012 Copyright Taylor and Francis Group, LLC. Source

Chen X.Z.,Southwest Jiaotong University
Applied Mechanics and Materials | Year: 2014

The Extra-dosed cable-stayed bridge is considered as a new popular type of bridge structure in recent 20 years, whose mechanical properties and economic span both lie between continuous beam (or rigid frame) bridges and cable-stayed bridges.This design is a double-cable-plane (85+150+85)m prestressed concrete Extra-dosed cable-stayed bridge, whose maximum Design speed is 100km/h and its width is 25.50m. The form of the highway is sextuple line which is 10.75m far away,and the cross-sectional slope is 2%.The girder body adopts three cell and single box,the height of beam takes quadratic parabola relation, which is 5m high at the middle support, while at the side support and the midspan is 3m.Vehicle standard load was applied on the bridge.The design uses Midas/Civil to establish the finite element model that is reasonable and simple, analyzing the structure behavior of the girder body under loading, especially the internal forces of bridge structure under dead load, live load and additional force. © (2014) Trans Tech Publications, Switzerland. Source

Ouattara M.,Georgia State University | Bentley Cunha E.,Georgia State University | Li X.,Southwest Jiaotong University | Huang Y.-S.,Georgia State University | And 2 more authors.
Molecular Microbiology | Year: 2010

A growing body of evidence suggests that surface or secreted proteins with NEAr Transporter (NEAT) domains play a central role in haem acquisition and trafficking across the cell envelope of Gram-positive bacteria. Group A streptococcus (GAS), a β-haemolytic human pathogen, expresses a NEAT protein, Shr, which binds several haemoproteins and extracellular matrix (ECM) components. Shr is a complex, membrane-anchored protein, with a unique N-terminal domain (NTD) and two NEAT domains separated by a central leucine-rich repeat region. In this study we have carried out an analysis of the functional domains in Shr. We show that Shr obtains haem in solution and furthermore reduces the haem iron; this is the first report of haem reduction by a NEAT protein. More specifically, we demonstrate that both of the constituent NEAT domains of Shr are responsible for binding haem, although they are missing a critical tyrosine residue found in the ligand-binding pocket of other haem-binding NEAT domains. Further investigations show that a previously undescribed region within the Shr NTD interacts with methaemoglobin. Shr NEAT domains, however, do not contribute significantly to the binding of methaemoglobin but mediate binding to the ECM components fibronectin and laminin. A protein fragment containing the NTD plus the first NEAT domain was found to be sufficient to sequester haem directly from methaemoglobin. Correlating these in vitro findings to in vivo biological function, mutants analysis establishes the role of Shr in GAS growth with methaemoglobin as a sole source of iron, and indicates that at least one NEAT domain is necessary for the utilization of methaemoglobin. We suggest that Shr is the prototype of a new group of NEAT composite proteins involved in haem uptake found in pyogenic streptococci and Clostridium novyi. © 2010 Blackwell Publishing Ltd. Source

Nonlinear model and simulation technique of the interaction and energy transfer between a fast wave and a large-orbit relativistic electron beam in a coaxial electrostatic wiggler are presented. Unlike the situations in a magnetostatic-wiggler free-electron laser (MWFEL) and in an electron cyclotron maser (ECM), the electrostatic potential of the electrons plays an important role and participates in the energy exchange between the wave and the electron beam. Compared to MWFEL and ECM, the coaxial electrostatic-wiggler configuration has a distinguishing peculiarity that besides the electron-beam's kinetic energy, its electrostatic potential energy can be effectively transferred to the fast wave. Simulation shows that wave could be amplified with ultrahigh gain by extracting both the kinetic energy and electrostatic potential energy of the electron beam. © 2010 American Institute of Physics. Source

Chen J.-Q.,Southwest Jiaotong University
Gaoya Dianqi/High Voltage Apparatus | Year: 2013

A transformer fault diagnosis method based on RIMER (belief rule-base inference methodology using the evidential reasoning approach) expert system and data of dissolved gasses analysis (DGA) is proposed to deal with the complex nonlinear relation in transformer fault diagnosis. Considering the probability uncertainty and fuzzy uncertainty of the transformer fault characters, a new DGA fault diagnosis model is established based on the evidence consequence and the parameters of belief rule base from both IEC three-ratio method and training of fault samples of dissolved gasses. The RIMER-DGA transformer fault diagnosis model solves the problem of fault code missing in IEC three-ratio method, thus improves the fault diagnosis accuracy and obtains better description of mixed-type fault. Simulation shows that the proposed method is simple and feasible. Source

Chen X.,University of Massachusetts Amherst | Chen X.,Southwest Jiaotong University | Kalish J.,University of Massachusetts Amherst