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Qinhuangdao, China

Yanshan University is a university in Qinhuangdao, Hebei, China under the provincial government. It has student population of 38,000 and a staff population of 3000 .The origin of Yanshan University can be traced back to the Harbin Institute of Technology founded in 1920. In 1958, the Department of Heavy Machinery of HIT and its related specialties moved to the strategic industrial town of Fulaerji, Qiqihar in Northeast China's Heilongjiang Province and was renamed the School of Heavy Machinery of HIT. In 1960, the school became independent as the Northeast Heavy Machinery Institute, and in 1978, it was accredited as one of the eighty-eight national key institutions of higher learning. Starting in 1985, it began to relocate southward to the historic seaside city of Qinhuangdao in Hebei Province and completed the migration in 1997 when it was accredited by the former State Education Commission to adopt the present name of Yanshan University .The YSU campus covers an area of 5,000 mu with a total construction area of nearly one million square meters. At present, the university has a faculty and staff of 3000, including 2,000 teachers, of which 326 are professors and 422 are associate professors. The university has a student population of 38,000.YSU has five postdoctoral research stations, six disciplines of 35 subdisciplines conferring doctoral degrees, 13 disciplines of 80 subdisciplines conferring master degrees, 16 masters of engineering programs, one Master of Public Administration program, one Master of Business Administration program, as well as 60 undergraduate programs. With such a wide range of programs, YSU has become a multiversity with emphasis laid on engineering studies and importance attached to liberal arts, science, economics, management, law and education.YSU consists of twenty-one colleges and schools. YSU runs five national key disciplines, four key disciplines of national defense, thirteen key provincial disciplines, one key national laboratory, thirteen key provincial laboratories and engineering centers.YSU is known for its world-renowned achievements in the development of whole-set heavy machinery and equipment, the theory and technology of parallel robots, the technology of fluid transmission and electro-hydraulic servo-systems, the technology and equipment of precision plasticity figuration, technology of thermal treatment of big forging, the technology of mega amorphous bodies, metastable materials and technology, the theory and technology of industrial automation, etc.YSU has won seventeen national scientific and technological awards in a row since 1996, including three first-class China State Science and Technology Progress Awards, ten second-class Awards, two third-class Awards, one State Technology Invention Award, and one second-class National Natural science Award. The university has undertaken more than 300 national research projects, including those funded by the 973 Programs, the 863 Programs, as well as the National Natural science Foundation and the National Social science Foundation. In 1999, YSU established its high-tech park in the Qinhuangdao Economic and Technological Development Zone. The park was officially established by the Chinese Ministry of Science and Technology and Ministry of Education as a national university science park in September 2003, thus becoming one of the 34 national university science parks of its kind.The university also attaches great importance to international academic exchange and collaboration, and has conducted joint study and research programs with institutions from the United Kingdom, the United States, Canada, Norway, Germany, France, Italy, Ireland, Japan, Korea, etc.Qinhuangdao City in which YSU is located is a coastal resort city just 260 km northeast of Beijing. As one of the Class A tourist destinations in China, Qinhuangdao attracts visitors from China and abroad with the beginning of the Great Wall , the First Pass Under Heaven on the Great Wall, the summer resort Beidaihe Beach, the sandy Golden Beach at the Nandaihe area, the safari zoo, and other scenic spots which are all within easy access. Wikipedia.


Dou Y.-K.,Beijing Institute of Technology | Li J.-B.,Beijing Institute of Technology | Fang X.-Y.,Yanshan University | Jin H.-B.,Beijing Institute of Technology | Cao M.-S.,Beijing Institute of Technology
Applied Physics Letters | Year: 2014

The dielectric properties and microwave attenuation performance of N-doped SiC have been evaluated in 8.2-12.4GHz in the temperature range of 293-673K. The N doping dramatically improves the microwave absorption capability of SiC. The minimum reflection loss of N-doped SiC is enhanced to nearly -30dB with the effective absorption bandwidth [RL(dB) ≤ -10 dB] up to 3GHz at 673K. The excellent high-temperature dielectric properties are attributed to multi-relaxations, originated from the polarization relaxations of dipoles induced by the N doping and vacancy defects. © 2014 AIP Publishing LLC. Source


Han H.-L.,CAS Changchun Institute of Applied Chemistry | Liu Y.,CAS Changchun Institute of Applied Chemistry | Liu Y.,Yanshan University | Liu J.-Y.,CAS Changchun Institute of Applied Chemistry | And 2 more authors.
Dalton Transactions | Year: 2013

A series of novel binuclear phenoxyimino organoaluminum complexes of the type [(RNCH)C6H3OAlMe2]2 [R = C 6H5 (2a), 2,6-iPr2C 6H3 (2b), 2,6-Ph2C6H3 (2c), adamantyl (2d), tBu (2e)] have been prepared in high yields, and these complexes were identified by 1H, 13C NMR and elemental analysis. Structural analysis for 2a-e revealed that these complexes have a distorted tetrahedral geometry around Al and both the Al-O and the Al-N bond distances were considerably influenced by substituents in the imino groups. The complexes were tested as catalyst precursors for ring-opening polymerisation (ROP) of ε-caprolactone (CL) in the presence of BnOH, and their catalytic activities were strongly affected by the catalyst structures and polymerisation conditions. An efficient living ROP has been achieved using the 2b/BnOH system. © 2013 The Royal Society of Chemistry. Source


Li J.,CAS Institute of Physics | Wang D.-S.,Beijing Information Science and Technology University | Wu Z.-Y.,CAS Institute of Physics | Wu Z.-Y.,Yanshan University | And 2 more authors.
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2012

A three-dimensional study of the ring vortex solitons is conducted for both attractive and repulsive Bose-Einstein condensates subject to harmonic potential confinement. A family of stationary ring vortex solitons, which is defined by the radial excitation number and the winding number of the intrinsic vorticity, are obtained numerically for a given atomic interaction strength. We find that stabilities of the ground and radially excited states of the ring vortex soliton are dependent on the winding number differently. The ground state of the ring vortex soliton with the large winding number is unstable dynamically against random perturbation. The radially excited state of the ring vortex soliton with large winding number corresponds to the increased collapse threshold and therefore can be made stable for sufficiently small atomic interaction strengths. The ground and radially excited states also demonstrate different dynamic evolutions under large atomic interaction strengths. The former exhibits simultaneous symmetric splitting in the transverse plane, while the latter displays periodic expand-merge cycles in the longitudinal direction. © 2012 American Physical Society. Source


Gao F.,Yanshan University
Journal of Applied Physics | Year: 2012

Anisotropy is prominent in the hardness test of single crystals. However, the anisotropic nature is not demonstrated quantitatively in previous hardness model. In this work, it is found that the electron transition energy per unit volume in the glide region and the orientation of glide region play critical roles in determining hardness value and hardness anisotropy for a single crystal material. We express the mathematical definition of hardness anisotropy through simple algebraic relations. The calculated Knoop hardnesses of the single crystals are in good agreement with observations. This theory, extended to polycrystalline materials by including hall-petch effect and quantum size effect, predicts that the polycrystalline diamond with low angle grain boundaries can be harder than single-crystal bulk diamond. Combining first-principles technique and the formula of hardness anisotropy the hardness of monoclinic M-carbon, orthorhombic W-carbon, Z-carbon, and T-carbon are predicted. © 2012 American Institute of Physics. Source


Hao A.,Northeastern University China | Zhu Y.,Yanshan University
Journal of Applied Physics | Year: 2012

We investigate the phase transition, elastic constants, and phonon dispersion curves of beryllium at high pressure using density functional theory. By comparing the Gibbs free energy, in the quasiharmonic approximation, of hexagonal-closed-packed (hcp, α) with those of body-centered-cubic (bcc, β), we find that α phase is stable up to 320 GPa, and then transforms to β phase. We further investigate high-pressure elastic behavior of α-Be by computing the second-order elastic constants and their variation with pressure. Using Born conditions of mechanical stability at high pressure, we confirm that α-Be structure is an unstable phase at 320 GPa. The phonon dispersion curves of α-Be under high pressure up to 320 GPa do not show any imaginary frequencies. Contrarily to α phase, β-Be phonon dispersion curves show anomalous features at zero pressure. The imaginary frequencies become real ones as pressure increases up to 320 GPa, indicating that β-Be becomes one mechanical stability structure at this pressure. © 2012 American Institute of Physics. Source


Zhu J.-Z.,Yanshan University | Li W.-L.,CAS Changchun Institute of Optics and Fine Mechanics and Physics
Faguang Xuebao/Chinese Journal of Luminescence | Year: 2012

High efficiency white organic light-emitting diodes (WOLEDs) with high color rendering index (CRI) was fabricated. The white light was composed by the blue emission of 9, 10-di(2-naphthyl) anthracene and the enhanced green and red emissions of tris-(8-hydroxyquinolinato) aluminum and 4-(dicyanomethylene)-2-t-butyl-6- (1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran, respectively. The WOLED shows the Commission Internationale de l'Eclairage-1931 coordinates vary from (0.3432, 0.3397) to (0.3243, 0.3218), the correlated color temperature varies from 5035 K to 5915 K and all the CRIs exceed 90 when the driving voltage changes from 8 V to 12 V. A maximum brightness of 27853 cd/m 2 at 14 V and a peak current efficiency of 9.58 cd/A at 7.5 V are attained, respectively. The electroluminescent (EL) spectrum is tuned by changing the thickness of the green and red emission layers. The efficiency enhancement is realised by sensitising the green and red light emissions. The maximum efficiency is increased by 73.6% compared to the control device. Source


Wu Y.,Hebei University of Technology | Wang L.,Hebei University of Technology | Ren J.,Yanshan University | Ding W.,University of Massachusetts Boston | And 2 more authors.
Applied Intelligence | Year: 2014

Mining frequent patterns with periodic wildcard gaps is a critical data mining problem to deal with complex real-world problems. This problem can be described as follows: given a subject sequence, a pre-specified threshold, and a variable gap-length with wildcards between each two consecutive letters. The task is to gain all frequent patterns with periodic wildcard gaps. State-of-the-art mining algorithms which use matrices or other linear data structures to solve the problem not only consume a large amount of memory but also run slowly. In this study, we use an Incomplete Nettree structure (the last layer of a Nettree which is an extension of a tree) of a sub-pattern P to efficiently create Incomplete Nettrees of all its super-patterns with prefix pattern P and compute the numbers of their supports in a one-way scan. We propose two new algorithms, MAPB (Mining sequentiAl Pattern using incomplete Nettree with Breadth first search) and MAPD (Mining sequentiAl Pattern using incomplete Nettree with Depth first search), to solve the problem effectively with low memory requirements. Furthermore, we design a heuristic algorithm MAPBOK (MAPB for tOp-K) based on MAPB to deal with the Top-K frequent patterns for each length. Experimental results on real-world biological data demonstrate the superiority of the proposed algorithms in running time and space consumption and also show that the pattern matching approach can be employed to mine special frequent patterns effectively. © 2014 Springer Science+Business Media New York. Source


Hu Y.,Yanshan University
Guti Lixue Xuebao/Acta Mechanica Solida Sinica | Year: 2013

The dynamics theoretical model of axially moving current-conducting thin plate in magnetic field was investigated and the basic magneto-elastic coupled vibration equations and corresponding relational expressions were derived in this paper. The kinetic energy, strain energy and virtual work done by external force of the thin plate were obtained when geometric nonlinearity was taken into account. The nonlinear magneto-elastic coupled vibration equations of an axially moving thin plate in magnetic field were deduced by using Hamilton principle, and boundary conditions of force and displacement were also obtained. Based on the Maxwell equations, the corresponding electromagnetic constitutive relations and boundary conditions, the electrodynamics equations and electromagnetic forces expressions of axially moving current-conducting thin plate in general magnetic field were constructed. In particular, the expressions of vibration equations, electrodynamics equations and electromagnetic forces were simplified in terms of longitudinal, transverse magnetic field and strip thin plate. The results are expected to be a theoretical reference for further analysis of this case. Source


Jin F.,Yanshan University
Analytical and Bioanalytical Chemistry | Year: 2011

A rapid, sensitive, and selective liquid chromatography-tandem mass spectrometry method for the detection of tandospirone in human plasma is described. It was employed in a pharmacokinetic study. The analyte and internal standard diphenhydramine were extracted from plasma using liquid-liquid extraction, then separated on a Zorbax XDB C18 column using a mobile phase of methanol-water-formic acid (80:20:0.5, v/v/v). The detection was performed with a tandem mass spectrometer equipped with an electrospray ionization source. Linearity was established in the concentration range of 10.0-5,000 pg/ml. The lower limit of quantification was 10.0 pg/ml. The intraday and interday relative standard deviation across three validation runs over the entire concentration range was less than 13%. Accuracy determined at three concentrations (25.0, 200, and 4,000 pg/ml for tandospirone) ranged from 94.4 to 102.1%. Each plasma sample was chromatographed within 3.4 min. The method proved to be highly selective and suitable for bioequivalence evaluation of different formulations containing tandospirone and clinical pharmacokinetic investigation of tandospirone. © 2011 Springer-Verlag. Source


Song J.-S.,Duke University | Song J.-S.,Shanghai JiaoTong University | Zhang H.,Academia Sinica, China | Zhang H.,National University of Singapore | And 2 more authors.
Operations Research | Year: 2010

We study a single-item (r, q) inventory system, where r is the reorder point and q is the order quantity. The demand is a compound-Poisson process. We investigate the behavior of the optimal policy parameters and the long-run average cost of the system in response to stochastically shorter or less-variable lead times. We show that although some of the properties of the base-stock system can be extended to this more general model, some cannot. The same findings also apply when the comparison is conducted on the lead-time demand distributions. © 2010 INFORMS. Source


Du G.-J.,Yanshan University | Wang J.,Dalian Jiaotong University
Cailiao Kexue yu Gongyi/Material Science and Technology | Year: 2011

Forming mechanism of the residual stress field in the case of carburize quencher is detail expounded. Based on the parameters thermal conductivity coefficient, specific heat, convection coefficient, facies change temperature, specific enthalpy and thermal expansion coefficient etal. which are obtain by experiment, the numerical simulation about the course of carburize with multi time-varying parameters by the finite element software ANSYS, obtain the correspond to data of forming the stress field in the course of carburize and the residual stress field after carburize. The effects of carburize depth on residual stress field are discussed, so providing reliable theory gist for effective controlling the formation of residual stress field. Source


Zhao X.,Yanshan University
Journal of hazardous materials | Year: 2011

The melamine-diethylenetriaminepentaacetic acid/polyvinylidene fluoride (MA-DTPA/PVDF) chelating membrane bearing polyaminecarboxylate groups was prepared for the removal of Ni(II) from wastewater effluents. The membrane was characterized by SEM, (13)C NMR and FTIR techniques. Quantitative adsorption experiments were performed in view of pH, contact time, temperature, the presence of Ca(II) and lactic acid as the controlling parameters. Adsorption kinetics and equilibrium were examined regarding the single Ni(II) system, binary Ni(II) and Ca(II) system and nickel-lactic acid complexes system. The desorption efficiency was also evaluated, and the adsorption mechanism was suggested based on experimental data. The results show that the sorption kinetics fit well to Lagergren second-order equation and the isotherms can be well described by Langmuir model. At 298 K, the second-order rate constant is calculated to be 4.171, 11.39, 6.203 cm(2)/(mg min) and the equilibrium uptake is 0.0264, 0.0211 and 0.0216 mg/cm(2) in the aforementioned three systems. The distribution coefficient of Ni(II) slowly decreases from 4.27 to 2.72, and the separation factor (f(Ni(II)/Ca(II))) increases from 3.10 to 8.46 when the initial Ca(II) concentration varies from 20 to 200mg/L. This reveals the chelating membrane shows more affinity for Ni(II) than Ca(II) ions. In the studied range of lactic acid concentration, Ni(II) uptake decreases with the maximum ratio of 10%. Chemical bonding (chelation) dominates in the adsorption process, and the negative ΔG° and ΔH° indicate the spontaneous and exothermic nature of adsorption. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved. Source


Wang C.F.,Yanshan University
Advanced Materials Research | Year: 2014

Automatic recognition of the line in the image is an important work in the field of machine vision and image processing. Focusing on the problem of the computational cost and large invalid sampling in the line extraction algorithm using standard Hough transform(HT). An improved HT algorithm is proposed to solve these problems. The parameters of the improved algorithm can be reduced to one and the accumulator is operated by setting the tolerance. Then the existence of linear is determined by seting the threshold. The experimental results show that the algorithm not only can effectively solve the problem of local maxima and improves the algorithm speed and reduces the storage space, but also the accuracy of line extraction is improved. © (2014) Trans Tech Publications, Switzerland. Source


Nie G.,Shijiazhuang University | Liu J.,Shijiazhuang University | Fang X.,Shijiazhuang University | An Z.,Yanshan University
Acta Mechanica | Year: 2012

This work considers the propagation of shear horizontal (SH) waves in a bilayer system consisting of a piezoelectric (PE) layer and a piezomagnetic (PM) substrate. The interface between the PE layer and the PM substrate is imperfectly bonded. The surfaces of the bilayer system are free of traction, electrically shorted or open and magnetically open or shorted. The exact dispersion equations are derived. The numerical examples are given to illustrate the effects of the electromagnetic boundary conditions, the imperfect interface, the different PE layers and the thickness ratio on the dispersion behaviors. It is found that (a) the electrical boundary conditions dominate the propagation characteristics of SH waves; (b) the imperfect bonding lowers the phase velocities; (c) the thickness ratio and the properties of PE layers have a significant effect on the dispersion behaviors. The obtained results provide a predictable and theoretical basis for applications of PE-PM composites to acoustic wave devices. © Springer-Verlag 2012. Source


Cheng S.,Harbin Institute of Technology | Wang C.,Harbin Institute of Technology | Ma M.,Yanshan University | Shan D.,Harbin Institute of Technology | Guo B.,Harbin Institute of Technology
Thermochimica Acta | Year: 2014

The thermodynamics and kinetics of Zr41.2Ti 13.8Cu12.5Ni10Be22.5 amorphous alloy under non-isothermal condition were evaluated using differential scanning calorimetry (DSC). The first and third exothermic events at the heating rates of 5 K/min and 10 K/min split into two peaks. The local Avrami exponents at various heating rates calculated by the Kolmogorov-Johnson-Mehl-Avrami equations showed different trends. The grain growth was controlled by atom diffusion at all heating rates. But their growth dimensionality reduced from 2 to 1 as heating rates increase at the beginning of crystallization process. The result exhibited that the heating rate had a great influence on growth mechanism, the crystallization peaks of Zr41.2Ti13.8Cu 12.5Ni10Be22.5 amorphous alloy separated into two single-step processes for the change of growth dimensionality. Two fragility indexes evaluated by Angell and DA equations were 44 and 42.5, respectively, implying that the as-cast Zr41.2Ti13.8Cu 12.5Ni10Be22.5 amorphous alloy should be considered as "intermediate glasses". © 2014 Elsevier B.V. Source


Zhang Z.,Dalian University of Technology | Zhang Z.,Tsinghua University | Zhang Z.,Yanshan University | Wang B.,Dalian University of Technology | Zhang X.,Dalian University of Technology
Scripta Materialia | Year: 2014

By varying the twin thickness from 4 to 23 nm, a maximum of hardness is achieved by molecular dynamics simulations at a twin thickness of 16 nm. When the twin thickness is >16 nm, the hardness is consistent with the Hall-Petch effect, whereas the hardness of a twin ≤16 nm thick is in a good agreement with the reverse Hall-Petch effect. This is attributed to a transformation of the synergistic effect between both twin boundaries from monotonically increasing to decreasing with increasing twin thickness. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Source


Bian Z.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

The diabetes-induced cognitive impairment complications have serious effects on the patients' lives, and there is an enormous and financial burden on patients, their families and society as a whole. This review investigates the current research status of diabetes-induced cognitive impairment from different view points including molecular, models, clinics and electrophysiology. The relationship between diabetes and cognitive function and developments of research are hereby summarized. And finally, future issues of diabetes-induced cognitive impairments are pointed out, and the effective rehabilitation methods should be considered. Source


Wang Y.,Yanshan University | Li B.,North China Institute of Aerospace Engineering
Journal of Optical Communications and Networking | Year: 2010

An optical code-labeled router that performs packet forwarding through optical code label swapping (OCLS) based on code division multiplexing technology is proposed. It can enhance the processing speed of packets that can adapt to the growth of data and the aggregation of data service. The throughput of the router increases obviously since the optical code division multiplexing (OCDM) paths on the same wavelength can be processed in parallel. Moreover, it is attractive for its traffic control, bandwidth efficiency, protocol transparency, channel granularity, and so on. © 2010 Optical Society of America. Source


Wang Y.-l.,Yanshan University
Journal of Convergence Information Technology | Year: 2012

The empirical analysis on the relationship among money supply, economic growth, and inflation in china from 1998 to 2007 with co-integration and Granger Causality test approaches shows: there is no cointegration relationship among money supply, inflation, and economic growth, but there is cointegration relationship between money supply and inflation while there is no co-integration relationship between money supply and economic growth. There is contradiction between the goal of economic growth and of price stability in China. We may be able to implement a loose monetary policy in the short run, but we should seek a new source to stimulate economic growth other than monetary policy in the long run. Source


Wang K.,Yanshan University
Journal of Convergence Information Technology | Year: 2012

According to high development of embedded devices technology, especially mobile phones, tablets, car electronics equipment and hybrid equipment, embedded browser technology is becoming more and more important, the demand of embedded devices is also becoming higher and higher. It's a trend that more and more embedded devices will connect to internet and can access rich internet content. The conventional embedded browser can't show web pages dynamically and fully support JavaScript, which blocked applications interact with users. Therefore, this paper research on embedded JavaScript interpreter to provide a rich content internet for embedded devices. Designed the data type interpreter, regular expression module, error handing, provides the interpretive execution working process and designed the resource management mechanism to save CPU and memory resources. Finally, this paper designed a set of experiment to validate the performance of embedded JavaScript interpreter; the result shows it can execute JavaScript codes effectively with low error rate. Source


Wang K.,Yanshan University
Journal of Convergence Information Technology | Year: 2012

The paper introduces the familiar XY dimension order routing algorithm, odd-even turn model and the combination of both of them with DyAD algorithm, brings forward an improved algorithm that is based on the DyAD. The algorithm aims at the phenomena that when the DyAD meets the congestion, the delay increases seriously as a result that choose the non shortest way. Make a waiting period of time, and then detect the direction of the shortest way of XY and judge if it could transfer the dates in the period of the time. Using the limited waiting instead of choosing the longer path can attain to reduce the delay. The simulations results show that the algorithm can get the least delay and jitter, and provide a better service quality. Source


Wang C.,Yanshan University
ICIC Express Letters | Year: 2012

This paper focuses on the asynchronous H ∞ control problem for a class of switched linear systems. Based on multiple Lyapunov function and average dwell time approach, appropriate switched controllers and switching rules are designed to guarantee the studied switched systems to be globally exponentially stabilizable with H ∞ disturbance attenuation even if there are unstabilizable subsystems and delay time of controllers. Finally, two numerical examples are given to show the feasibility and effectiveness of the obtained results. © 2012 ISSN. Source


Li H.,Yanshan University
Journal of Internet Technology | Year: 2016

A new biological method is proposed for the recognition of human actions based on geometric parameter features and the Radial Basis Function (RBF) neural network. First, the shape feature of the binary image sequences of a human body is calculated. Next, the geometric parameter features of the shape are computed based on the binary image sequences by using a vector which consists of the region and the shape feature. An improved RBF neural network classifier is then employed to identify the human action through posture recognition. To increase the learning efficiency of the neural network, improvements to the RBF learning algorithm are suggested to train the neural network. Experimental results indicate that the proposed scheme can effectively classify human actions and achieve a superior recognition rate. Source


Zhang P.,Dalian University of Technology | Zhao J.,Dalian University of Technology | Wen B.,Yanshan University
Journal of Nuclear Materials | Year: 2012

First-principles calculations were performed to illustrate the trapping mechanism of multiple hydrogen atoms in a monovacancy of vanadium solid in terms of the stability of hydrogen-vacancy (mH-VA) complexes and H-H interactions. The preferential site for single H is not vacancy center but close to octahedral interstitial site with solution energy of -0.67 eV. Lower electron density in the presence of vacancy explains why H impurities can be easily trapped at vacancy. Among the possible mH-VA complexes, the 2H-VA conjuration is the most stable complex energetically. According to computed trapping energies, up to six H atoms can be trapped in one monovacancy inside vanadium solid. We also found that H 2 molecule is extremely difficult to survive in a small vacancy complex. The present results provide an elementary picture of the H trapping mechanism as well as H bubble formation in vanadium solid. © 2012 Elsevier B.V. All rights reserved. Source


Zhang P.,Dalian University of Technology | Zhao J.,Dalian University of Technology | Qin Y.,Dalian University of Technology | Wen B.,Dalian University of Technology | Wen B.,Yanshan University
Journal of Nuclear Materials | Year: 2011

The stability and migration behavior of helium and self defects in vanadium and V-4Cr-4Ti alloy are studied by first-principles calculations. The tetrahedral site is found as the most stable configuration for interstitial He, followed by the octahedral and substitutional sites. Among the self defects, the monovacancy has lower formation energy (1.71 eV for V and 2.14 eV for V-4Cr-4Ti alloy) than the self interstitial ones. The migration energies for He hopping between the tetrahedral sites are 0.06 and 0.09 eV for vanadium and V-4Cr-4Ti alloy, respectively. Our calculations reveal strong repulsion between two interstitial He atoms and strong attraction between He and vacancy, suggesting that vacancy acts as a trapping site for He impurity and a seed for further bubble formation. © 2011 Elsevier B.V. All rights reserved. Source


Cui M.,Yanshan University
Proceedings - 2012 International Conference on Control Engineering and Communication Technology, ICCECT 2012 | Year: 2012

To achieve the goal that in 2020 the carbon dioxide emissions per unit of GDP in China dropped to 40% ~ 45% of that in 2005, it is necessary to make full use of the clean and renewable energy, develop distributed generation technology and realize low carbon dispatch. According to the characteristics of wind turbine and photovoltaic, a novel model of low carbon dispatch of distribution network containing Microgrid was presented which considering different greenhouse gas emission level and generation cost of various distributed generation. At last, using chaotic ant swarm algorithm, the simulation results show the correctness and validity of the model considering different price of CO2 emission. © 2012 IEEE. Source


Gao Y.Y.,Yanshan University
Advanced Materials Research | Year: 2014

For extracting relatively stable and invariable feature from non-stationary EEG in mult-class pattern, many scholars study a feature extraction method, which is called as modified multi-classcommon spatial pattern. It adopts one-to-one strategy to expand common spatial pattern to multi-class classification. While for the solution of airspace filter, Kullback-Leibler distance defines pattern of discrimination of minimize difference within class and maximize difference between classes. And it establishes a function to measure difference within the class. The experiment verifies that the algorithm can obtain feature information with recognition capability which implys in the non-stationary EEG and acquires preferable classification result. © (2014) Trans Tech Publications, Switzerland. Source


Yan C.,Hebei University of Science and Technology | Li Y.,Yanshan University | Zhang J.,Hebei University of Science and Technology
International Journal of Modelling, Identification and Control | Year: 2014

This study develops a generalised procedure in adaptive neural network enhanced controller design for strict feedback non-linear time delay systems. Under the framework, recurrent neural network is tailored to accommodate the on-line identification, by which the weights of the neural network are iteratively and adaptively updated through the system state. Based on the neural network online approximation model, the state feedback adaptive controller is obtained by constructing a Lyapunov-Krasovskii function, which the integral type efficiently overcomes the controller singularity problem. To guarantee the correctness, rigorousness, and generality of the developed results, Lyapunov stability theory is used to prove the closed-loop control systems semiglobally, uniformly, and ultimately bounded stable. Two bench mark tests are simulated to demonstrate the effectiveness and efficiency of the procedure and furthermore these could be the showcases for potential users to apply to their demanded tasks. Copyright © 2014 Inderscience Enterprises Ltd. Source


Wang C.,Yanshan University
International Journal of Innovative Computing, Information and Control | Year: 2014

This paper is devoted to adaptive tracking control for a class of uncertain MIMO switched nonlinear systems. A novel systematic recursive algorithm is proposed to design adaptive update laws and an adaptive controller by multiple Lyapunov functions method combining with backstepping recursive technique. And then, by means of stability theory about the switched systems and the average dwell time conception, two kinds of switching signals are constructed to ensure that all the signals in the closed-loop systems are bounded and the outputs of the switched systems converge to a small neighborhood of the desired trajectories. The effectiveness is investigated by a simulation example. © 2014 ICIC International. Source


Yu C.,Yanshan University
ICIC Express Letters | Year: 2011

Combined with FMM and BEM, a boundary FM-BEM is proposed for 3-D potential problems. Its implementation mechanism is analyzed and the division principle of computational regions is presented. Then, a high efficient and feasible algorithm is designed. Finally, the newly proposed method is successfully applied to the simulation of a heat conduction problem. Numerical experimentation shows the new method has signi cant superiorities over the conventional BEM especially when it is used to solve large-scale potential problems. © 2011 ISSN 1881-803X. Source


Hua C.-C.,Carleton University | Hua C.-C.,Yanshan University | Liu X.P.,Carleton University
IEEE Transactions on Robotics | Year: 2010

This paper addresses the stability-analysis problem for teleoperation systems with time delays. Compared with previous work, communication delays are assumed to be both time-varying and asymmetric, which is the case for network-based teleoperation systems. The stability analysis is performed for two classes of controllers: delayed position-error feedback and delayed torque feedback. By choosing LyapunovKrasovskii functional, we show that the masterslave teleoperation system is stable under specific linear-matrix- inequality (LMI) conditions. With the given controller-design parameters, the proposed stability criteria can be used to compute the allowable maximal transmission delay. Finally, both simulations and experiments are performed to show the effectiveness of the proposed method. © 2010 IEEE. Source


Li D.,Yanshan University | Li X.,Beijing Normal University | Hagihira S.,Osaka University | Sleigh J.W.,Waikato Hospital
British Journal of Anaesthesia | Year: 2013

BackgroundFourier bicoherence has previously been applied to investigate phase coupling in the EEG in anaesthesia. However, there are significant theoretical limitations regarding its sensitivity in detecting transient episodes of inter-frequency coupling. Therefore, we used a recently developed wavelet bicoherence method to investigate the cross-frequency coupling in the EEG of patients under isoflurane anaesthesia; examining the relationship between the patterns of wavelet bicoherence and the isoflurane concentrations.MethodsWe analysed a set of previously published EEG data, obtained from 29 patients who underwent elective abdominal surgery under isoflurane anaesthesia. Artifact-free, 1 min EEG segments at different isoflurane concentrations were extracted from each subject and the wavelet bicoherence calculated for all pairs of frequencies from 0.5 to 20 Hz.ResultsIsoflurane caused two peaks in the α (6-13 Hz) and slow δ (<1 Hz) regions of the bicoherence matrix diagonal. Higher concentrations of isoflurane shifted the α peak to lower frequencies [11.3 (0.9) Hz at 0.3% to 7.1 (1.2) Hz at 1.5%], as has been previously observed in the power spectra. Outside the diagonal, we also found a significant α peak that was phase-coupled to the slow δ waves; higher concentrations of isoflurane shifted this peak to lower frequencies [10.8 (1.2) to 7.7 (0.7) Hz].ConclusionsIsoflurane caused cross-frequency coupling between α and slow δ waves. Increasing isoflurane concentration slowed the α frequencies where the coupling had occurred. This phenomenon of α-δ coupling suggests that slow cortical oscillations organize the higher α band activity, which is consistent with other studies in natural sleep. © The Author [2012]. Source


Zeng T.,Yanshan University
Applied Mechanics and Materials | Year: 2014

Unlike other networks based on wireless sensor networks, such as the characteristics of Ad hoc network design algorithm to reduce the energy consumption of wireless sensor networks. The main study of wireless sensor networks in a variety of energy-saving protocols and algorithms, analyze the impact of these agreements on energy saving in different environments, MAC protocol for wireless sensor network design energy efficient use of its improvement, based on the maximum advantage disjoint approximate area set covering algorithm. Energy efficient or superior energy savings in the paper can prolong survival time of the network to provide scientific reference. © (2014) Trans Tech Publications, Switzerland. Source


Liu Y.,CAS Changchun Institute of Applied Chemistry | Liu Y.,Yanshan University | Dong W.-S.,CAS Changchun Institute of Applied Chemistry | Liu J.-Y.,CAS Changchun Institute of Applied Chemistry | Li Y.-S.,CAS Changchun Institute of Applied Chemistry
Dalton Transactions | Year: 2014

A series of novel aluminium complexes containing cyclic β-ketiminato ligands of type Me2Al{O-[(ArNCHC4H4(C 6H4))]} (3a, Ar = 2,6-iPr2C 6H3; 3b, Ar = C6H5; 3c, Ar = C 6F5) have been prepared in high yields. These complexes were identified by 1H, 13C NMR spectroscopy and elemental analysis. X-ray structural analyses for 3a-c revealed that these complexes have a distorted tetrahedral geometry around Al, and both bond distances and bond angles were considerably influenced by the ligand structure. These complexes were tested as catalyst precursors for ring-opening polymerisation of ε-caprolactone (ε-CL) and l-lactide (l-LA) in the presence of 2-propanol as an initiator. Complex 3a could polymerize ε-CL in a controlled manner with high efficiency. Based on the living characteristics, the preparation of well-defined block copolymers PCL-b-PLLA via sequential addition of monomers was performed by 3a. Note that complex 3c exhibited rather high catalytic activity for the ROP of l-LA with narrow molecular weight distribution. The monomer conversion reached completion only in 4 h when the l-LA/Al molar ratio was 100 at 80 °C. PLLA-b-PCL copolymers were thus easily produced by 3c. © 2014 The Royal Society of Chemistry. Source


Zhang P.,Dalian University of Technology | Zhao J.,Dalian University of Technology | Wen B.,Dalian University of Technology | Wen B.,Yanshan University
Journal of Nuclear Materials | Year: 2012

We report the energetics and diffusion behavior of H, He, O, and C impurities in beryllium as fusion materials from first-principles calculations. Among the six interstitial sites in Be, the basal tetrahedral one is most stable for H, He, O, while C prefers to occupy an octahedral site. Solution of O impurity in Be is an exothermic process with solution energy of -2.37 eV, whereas solution of H, C and He is an endothermic process (solution energy: 1.55 eV, 2.46 eV, and 5.70 eV, respectively). Overall speaking, these impurities prefer to diffuse along longer paths. The H and O impurities share the same out-of-plane diffusion path via basal tetrahedral sites, while the He and C impurities in Be mainly diffuse via basal tetrahedral and octahedral sites along the (0 0 1) plane. Diffusion of He in Be is easiest with a lowest barrier of 0.14 eV; whereas H diffusion in Be is also rather fast with migration energies of 0.4 eV. On the contrary, diffusion of C and O impurities is more difficult because of strong bonding with lattice atoms and high energy barriers of 0.42 and 1.63 eV, respectively. Our theoretical results provide the fundamental parameters for understanding the impurity aggregation and bubble formation in early stage of irradiation damage. © 2012 Elsevier B.V. All rights reserved. Source


Tang Y.,Yanshan University
International Journal of Circuits, Systems and Signal Processing | Year: 2012

Wiener model consists of a linear dynamic block followed by a static nonlinear function. This paper presents a novel method for parameter identification of Wiener model using differential evolution algorithm. The linear dynamic block is represented by autoregressive moving average (ARMA) model and the structure of static nonlinear function is assumed to be known in advance. The parameter estimation of Wiener model is converted to a parameter optimization problem. Differential evolution (DE) algorithm is used to search the optimal parameters by minimizing the error between the output of the actual model and that of the identified model. For the convenience of determining the search range of parameters to be estimated, the zeros and poles of linear dynamic block are identified. A new solution representation scheme is proposed for DE algorithm such that it can deal with the case that the linear dynamic block has complex number zeros and poles. The effectiveness of the proposed method is verified through two numerical examples. Source


Li H.,Yanshan University
Applied Mechanics and Materials | Year: 2013

This paper reports the investigation results of the possibilities for using pure and mixed refrigerants as working fluids to replace R22 for the DX-SAHP systems. Firstly, pure refrigerants are compared in terms of COP, discharge temperature and mass flow rate. Comparison results show that R290 is the most promising alternative to R22. Secondly, two kinds of mixed refrigerants are investigated as well. It indicated that the mixed refrigerant R290/R22 with more R290 performs better than the others in terms of COP. Meanwhile, the mixed refrigerants produce relatively low discharge temperatures and proper mass flow rates can be created due to appropriate mixture in suitable mass proportion. Further investigation indicates that R290 and R290/R22 show better system performance with relatively high superheating temperatures. © (2013) Trans Tech Publications, Switzerland. Source


Hua C.-C.,Yanshan University | Ding S.X.,University of Duisburg - Essen
IEEE Transactions on Automatic Control | Year: 2011

The model following control problem is addressed for a class of nonlinearly interconnected systems with time delays. The subsystems are with multiple dead-zone actuators and mismatched time-varying disturbances. To deal with the multiple unknown dead-zone inputs, we decompose the system properly based on the input matrix. By using the adaptive method to compensate the unknown parameters, we design a new and simple memoryless controller. The stability of the resultant closed-loop error system is proved by employing a new Lyapunov Krasovskii functional. The designed controller is tolerant to any dead-zone inputs and general time delays. Finally, the simulations are performed and the results show the potential of the proposed method. © 2006 IEEE. Source


Bian Y.-H.,Yanshan University
International Applied Mechanics | Year: 2015

Two-dimensional magnetoelastic problems of a thin current-carrying plate under the interaction of an unsteady electromagnetic field and a mechanical field are studied. The nonlinear magnetoelastic kinetic equations, geometric equations, physical equations, electrodynamics equations, and expressions for the Lorentz force of a thin current-carrying plate under the action of a coupled field are given. The normal Cauchy form nonlinear differential equations, which include ten basic unknown functions in all, are obtained by the variable replacement method. Using the difference and quasi-linearization methods, the nonlinear magnetoelastic equations are reduced to a sequence of quasilinear differential equations, which can be solved by the discrete-orthogonalization method. Numerical solutions for the magnetoelastic stresses and strains in a thin current-carrying elastic plate are obtained by considering a specific example. The results that the stresses and strains in the thin current-carrying elastic plate change with variation of the electromagnetic parameters are discussed. The results show that the stress–strain state in thin plates can be controlled by changing the electromagnetic parameters. This provides a method of theoretical analysis and numerical calculation for changing the service conditions and intensity research of thin plates of engineering structures in the electromagnetic field © 2015 Springer Science+Business Media New York Source


Lu Z.,Yanshan University | Lu C.,State Grid Corporation of China
Dianwang Jishu/Power System Technology | Year: 2013

Along with the demand on CO2 emission reduction becoming more and more explicit, various emission reduction technologies are matured and perfected more and more. It is an important subject to be worth researching to make power generation enterprises ensuring their benefits with the demand on emission reduction being considered through the selection and coordination of different emission reduction technologies. For this purpose, according to the theory of value engineering, a concept of low-carbon benefit, i.e., the quantity of carbon emission reduction under specific investment for a certain emission reduction project during its life cycle, is proposed to make different technologies or assessment methods comparable, and three indices, namely technical feasibility, economic rationality and social friendliness, are established to perform the assessment; then taking the maximization of low-carbon benefit as the objective, a model to coordinate the investment for carbon capture system and wind power system is built; and then an investment planning scheme that confirms to both economic development trend and demand on carbon emission reduction is given; finally, from the perspective of the three indices the assessment is performed to offer guiding opinion for the development of emission reduction projects in future. Source


Zhang K.,Yanshan University
Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering | Year: 2011

The structural free-volume of the bulk amorphous Zr41Ti14Cu12.5 Ni10Be22.5 alloy and the undercooled liquid range were investigated by X-ray diffraction (XRD) and positron annihilation techniques (PAT). The results show that the positron annihilation lifetime in the as-prepared Zr41Ti14Cu12.5 Ni10Be22.5 is about 176 ps, indicating that the structural free-volume with a size larger than that of one lattice vacancy of pure Fe is available in the alloy. The positron annihilation lifetime decreases with increasing annealing time when the alloy is annealed at 400°C in the undercooled liquid region, which reaches a value of 167 ps with annealing time of 300 min. The structure of the bulk amorphous Zr41Ti14Cu12.5 Ni10Be22.5 alloy becomes more compact when annealed in the undercooled liquid region. Source


Zhang X.,Yanshan University | Dong X.,Chengdu Electric Power Bureau
Dianwang Jishu/Power System Technology | Year: 2013

There are two objective functions in the proposed multi-objective economic dispatching model for low-carbon power system containing wind farms: generation cost and carbon emission. Considering economy of power system the carbon emission should be reduced; considering the risk brought by wind farms, the risk cost should be added in the generation cost; to achieve the energy-saving and carbon emission reduction, the output of wind farms should be increased while the economy of power system is ensured. The proposed multi-objective economic dispatching model for low-carbon power system containing wind farms is solved by improved multi-objective particle swarm optimization algorithm. Simulation results of IEEE 13-machine system show that the proposed multi-objective economic dispatching model is correct and effective. Source


A thermo-kinetic model for the transient thermal stress field of the wall-shaped part produced using laser direct powder deposition process is developed. In case of numerical modeling, the capabilities of ANSYS parametric design language and the the 'birth and death' element technique were employed. The distribution of the thermal stress of the wall-shaped part at different time was calculated by the model. Results show that during process, the X-direction thermal stress within top layer of the wall-shape part and that within the interior deposited layers of the wall-shape part was tensile stress and compressive stress, respectively. The deformation of the wall-shaped part and base plate was also calculated. © (2013) Trans Tech Publications, Switzerland. Source


Li X.-J.,Yanshan University
Environment, Energy and Sustainable Development - Proceedings of the 2013 International Conference on Frontier of Energy and Environment Engineering, ICFEEE 2013 | Year: 2014

On the base of the magneto-elastic random vibrations dynamic equations of a randomcurrent- carrying beam in a magnetic field. As the first mode shape of a simply-supported beam occupies the most amount of the vibration energy, and the thesis analysis the random displacement response of the beam on the assumption that the coupled part of Lorentz force is a kind of damp of the beam and the other Lorentz force is random distributing load. The magneto-elastic random vibration of the simplysupported beam is simplified of the random vibration of the simply-supported beam which the SDOF theory may be used to analyse its dynamic response. Based on this, the power spectral density function of the random displacement response and the peak power spectral density of the maximum displacement and the maximum stress are deduced. This technique helps to provide guidelines for further researchs on beams of the magneto-elastic random vibration theory. © 2014 Taylor & Francis Group, London. Source


Wang P.,Yanshan University
Jinshu Rechuli/Heat Treatment of Metals | Year: 2014

The plastic deformation of Cu-11.68Al alloy before and after 4 GPa pressure treatment were measured by nanoindention method, optical microscope and transmission electron microscope were employed to analyze the microstructure of the alloy, and the effect of 4 GPa pressure treatment on plastic deformation of Cu-11.68Al alloy was studied. The results show that 4GPa pressure treatment can refine the microstructure of Cu-11.68Al alloy and increase internal dislocation density, and reduce plastic deformation of Cu-11.68Al alloy effectively, the plastic deformation of the alloy after 4 GPa pressure treatment at 2000 μN pressure for 30 s is 98.22 nm, which is reduced by 22.13% than that of the untreated alloy. Source


Wang M.T.,Yanshan University
Applied Mechanics and Materials | Year: 2013

To reduce the algorithm complexity and improve performance, comparison table is created, and then encrypted by a randomized ten-bit serial number. Serial number forms the first key named key1, and the encrypted comparison table forms the second key named key2. Watermarking image is transformed into a binary bit stream. By using tuple's primary key, key1 and key2, each tuple's unique Id is computed. According to the watermarking length, all tuples are divided into different groups. Using tuple Id, by searching the encrypted comparison table, each tuple group can embed one bit information of watermarking. Robustness and security of this algorithm are tested by experiment. © (2013) Trans Tech Publications, Switzerland. Source


Dou C.-X.,Yanshan University | Liu B.,Hunan University of Technology | Liu B.,Australian National University
IEEE Transactions on Smart Grid | Year: 2013

This paper studies the smart control issue for an autonomous microgrid in order to maintain the secure voltages as well as maximize economic and environmental benefits. A control scheme called as multi-agent based hierarchical hybrid control is proposed versus the hierarchical control requirements and hybrid dynamic behaviors of the microgrid. The control scheme is composed of an upper level energy management agent, several middle level coordinated control agents and many lower level unit control agents. The goals of smart control are achieved by designed control strategies. The simulations are given to demonstrate the effectiveness of proposed smart control for an autonomous microgrid. © 2010-2012 IEEE. Source


Kang Y.-Q.,Beijing Institute of Technology | Cao M.-S.,Beijing Institute of Technology | Yuan J.,Center University for Nationality | Zhang L.,Beijing Institute of Technology | And 2 more authors.
Journal of Alloys and Compounds | Year: 2010

Basalt fiber/nickel core-shell heterostructures with different thicknesses of nickel shells are fabricated successfully. The electromagnetic parameters of basalt fiber/nickel-paraffin composites ranging from 8.2 to 12.4 GHz (X band) are measured for investigating the microwave absorption properties. The electromagnetic parameters of basalt fiber/nickel are several times higher than those of naked basalt fibers due to the formation of the core-shell interface. The measured results indicate that effective electromagnetic match is realized in the whole X band. The values of complex permittivity and permeability of basalt fiber/nickel increase monotonically with the increasing thicknesses of the nickel shells. It is interesting that the reflection loss of basalt fiber/nickel do not show the monotonic character with the increasing thicknesses of the nickel shells. The basalt fiber/nickel with the nickel shell thickness about 300 nm shows the strongest reflection loss. The value of reflection loss is more than 15 dB in the whole X band and reaches 40 dB at 8.9 GHz, while the naked basalt fibers hardly exhibit any microwave absorption. The excellent microwave absorption properties of the basalt fiber/nickel core-shell heterostructures are attributed to the good electromagnetic match between the dielectric loss and magnetic loss. © 2010 Elsevier B.V. All rights reserved. Source


Gas chromatography resonance-enhanced multiphoton ionization time-of-flight mass spectrometry (GC/REMPI-TOFMS) using a nanosecond laser has been applied to analyze the 16 polycyclic aromatic hydrocarbons (PAHs). The excited-state lifetime, absorption characters, energy of electronic states of the 16 PAHs were investigated to optimize the ionization yield. The results suggested that REMPI is superior to elctron impact ionization method for soft ionization, and suppresses the background signal caused by the aliphatic hydrocarbons. Thus, GC/REMPI-TOFMS is a more reliable method for the determination of PAHs present in the environment. © (2014) Trans Tech Publications, Switzerland. Source


Capaccioli S.,CNR Institute for Chemical and Physical Processes | Paluch M.,University of Silesia | Prevosto D.,CNR Institute for Chemical and Physical Processes | Wang L.-M.,Yanshan University | Ngai K.L.,CNR Institute for Chemical and Physical Processes
Journal of Physical Chemistry Letters | Year: 2012

Most glass-forming systems are composed of basic units interacting with each other with a nontrivial anharmonic potential. Naturally, relaxation and diffusion in glass formers is a many-body problem. Results from recent experimental studies are presented to show the effects of many-body relaxation and diffusion manifested on the dynamic properties of glass formers. Considering that the effects are general and critical, the problem of glass transition will not be solved until the many-body nature of the relaxation process has been incorporated fundamentally into any theory. © 2012 American Chemical Society. Source


Gao F.,Yanshan University
Inorganic Chemistry | Year: 2010

Size dependence effects in semiconductor clusters have been a subject of extensive studies for the last two decades. However, it is still difficult to employ the existing theoretical models to give reliable results of energies for clusters in the whole nanometer region. Here we offer a new theoretical method for the quantum size effects based on the idea that the energy gap shift of the cluster arises from the sum of the surface effect shift and quantum effect shift parts. We express the effects through algebraic relations rather than through variational solutions of the wave equation, without the use of any special adjustable parameter. Results reveal for the first time that the shape of the energy gap shift curve is dominated by the surface energy shift. Our method can also predict quantitatively the size dependence of dielectric constant. The new theoretical findings in the ultrasmall (<1 nm) anatase TiO2and the silicon clusters cannot be explained using previous theories. © 2010 American Chemical Society. Source


Li X.J.,Yanshan University
Applied Mechanics and Materials | Year: 2014

The random vibration of simply-supported beam is simplified of the random vibration of the SDOF theory, the paper analyse its random response. We get the displacement power spectral density function, the velocity power spectral density and the acceleration power spectral density function of the maximum displacement point. The same example is calculated by ANSYS, it also get the same results.It proved that using the finite element analysis software ANSYS to anlaysis the random vibration of the simply-supported beam has advantages of fast speed, high precision, easy steps, the small error and so on. © (2014) Trans Tech Publications, Switzerland. Source


Yun X.Q.,Yanshan University
Applied Mechanics and Materials | Year: 2014

This paper deals with a stochastic model in which claim number follows compound Poisson-Geometric process. By the total expectation formula, renewal equation satisfied by ruin probability has been given, and then, the explicit ruin probability formula is gotten in case of exponential claim amounts. © (2014) Trans Tech Publications, Switzerland. Source


Dong J.,Yanshan University | Shao L.,Dalian University of Technology
Yanshilixue Yu Gongcheng Xuebao/Chinese Journal of Rock Mechanics and Engineering | Year: 2010

In the unsaturated compacted soil triaxial tests under controlled suction conditions, the digital image measurement technique is used, with which the strength and deformation behaviours of unsaturated compacted soil can be studied by considering the influence of end effect. The comparison of test results of the overall specimen and 1/3 zone in the middle of specimen under controlled suction reflects that end effect has a little influence on 1/3 zone in the middle of specimen; the test result of this part can better stand for the actual deformation properties of unsaturated soil; and it provides credible test data for the study of unsaturated soil stress-strain relationship. The end effect has great influence on parameters of shear strength formula, when using the double-stress state variable method to analyze the shear strength. The elastoplastic model of Alonso for unsaturated soil is adopted to further analyze the influence of end effect on numerical calculation. Source


Guoxin H.,Shanghai JiaoTong University | Xu Z.,Shanghai JiaoTong University | Xu Z.,Yanshan University
Fullerenes Nanotubes and Carbon Nanostructures | Year: 2015

Monodisperse iron oxide nanoparticle-reduced graphene oxide composites were prepared by self-assembly in aqueous phase. Pre-synthesized iron oxide nanoparticles were transferred to aqueous phase and then mixed with graphene oxide dispersion. The iron oxide nanoparticles, with a diameter of around 10 nm, were self-assembled on the reduced graphene oxide sheets through electrostatic attraction during the reduction of graphene oxide. The magnetization curves indicated that all samples exhibited ferromagnetic behavior at room temperature with small coercivity. The values of specific saturated magnetization of composites with different densities of iron oxide nanoparticles are 38.3, 19.5, and 7.7 emu/g. Permittivity and permeability of composites exhibit obvious fluctuations, which are ascribed to the multiple magnetic resonances. The multiple resonances involve exchange resonances (the consequence of small size effect, surface effect, and spin wave excitations) and natural resonance. © 2015 Taylor and Francis Group, LLC. Source


Feng H.-B.,Yanshan University
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2013

The workspace of the 4-HSPS/PRPUR macro/micro actuated parallel mechanism applied to a scanning electron microscope is analyzed. The 4-HSPS/PRPUR macro/micro actuated parallel mechanism is composed of a base and a moving platform connected by four HSPS branches and a middle PRPUR branch. It has three translational degrees of freedom and two rotational degrees of freedom about the X axis and Y axis. Because the macro actuation and micro actuation are integrated together in this mechanism, this paper analyzes the constant orientation workspace and the dexterous workspace of this mechanism. The analysis shows that this mechanism can move flexibly in large workspace and the link length of the middle branch has considerable influence on the shapes of the workspaces. On the analysis of the constant orientation and dexterous workspaces of this mechanism, it demonstrates that the mechanism is suitable for the work condition of smaller platform mount space, large workspace and higher positioning accuracy. This study provides a theoretical basis for the application of the 4-HSPS/PRPUR parallel mechanism. Source


Sun F.-Z.,Yanshan University
Lecture Notes in Electrical Engineering | Year: 2014

Internet of Things has been developing rapidly in the recent years. In view of problems that the current sensing data have a wide variety of formats, this paper studies IOT based on SOA, and proposes a data exchange middleware which can be divided into two parts: data collection module and data exchange module. Data acquisitionmodule is responsible for sampling sensing data from sensing equipment, and filtering data according to the user request; data interchange module provides a unified service call and data exchange interface based on SOAP technology. © Springer-Verlag Berlin Heidelberg 2014. Source


Liu X.,Beijing University of Posts and Telecommunications | Liu X.,Yanshan University | Qiao Y.,Beijing University of Posts and Telecommunications | Ji Y.,Beijing University of Posts and Telecommunications
Optics Communications | Year: 2010

In this paper, optical phase conjugation (OPC) located in the transmitter based on four wave mixing (FWM) in a semiconductor optical amplifier (SOA) is first simulated in 40 Gb/s CO-OFDM systems, and the fiber nonlinearity impairment of the transmission link is precompensated before OPC by transmission through a fiber with large nonlinearity coefficient. Simulation results show that the nonlinear threshold (NLT) can be increased by about >3 dB and maximum Q factor can be increased by about 2 dB for the single-channel system. For 50-GHz-Spacing WDM systems, the maximum Q and NLT are increased by about 1 dB, even in the presence of cross phase modulation (XPM) from neighbouring WDM channels. It is found that this OPC subsystem located in the transmitter, not necessary to be inserted into the middle of link, can mitigate the fiber nonlinearity impairment for both single-channel and WDM systems. Crown Copyright © 2010 Published by Elsevier B.V. All rights reserved. Source


Under the action of buckling and whirling, the compressed rotary drill string immersed in drilling fluid is readily to fatigue failure, which may result in well deviation. This topic has been studied more thoroughly, but many problems remain yet to be resolved. For example, what is the reason that as the deviation angle of a well increases, the whirling phenomenon decreases until disappears, whether the buckled drill string must touch wellbore walls or not, whether there exists sliding between the drill string surface and wellbore walls or not, if so, what factors affect the sliding, how the stability of drill string couples with rotary speed, and how the eccentricity of drill string varies with rotary speed. In order to search for research methods to solve these problems, research advances have been introduced in sinusoidal buckle and helical buckle of the rotary drill string, the maximum whirling angular velocity of rotary drill string, interaction between rotary drill string and drilling fluid, and collision between rotary drill string and wellbore walls. Problems remaining in these research methods were investigated and it was pointed out that the combination of drilling fluid power lubrication with drill-string dynamics is an inevitable way in drill-string whirling research. Source


Xu Z.,Yanshan University | Wen W.,University of Kentucky | Zhai T.,University of Kentucky
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2012

The stress field around a pore was analyzed as a function of the pore position in depth in the surface of a linear elastic solid using finite element modeling. It was found that the pore depth dominated the stress field around the pore on the surface and that the maximum stress was increased sharply when the pore intercepted with the surface at its top. Given the applied nominal stress, the magnitude of the maximum main stress only depended on the relative depth of the pore, while the pore size affected the stress distribution in the surface. An elastic-plastic model was also used to account for the yielding effect in the region where stress was over the yield strength. The results still indicated a significant maximum stress concentration when the pore was just buried underneath the surface, but with a lowered value than that of the linear elastic model. These results were consistent with the experimental observations that fatigue cracks were preferably initiated from pores and particles, which were just intercepted at their top with the sample surface or just buried beneath the surface. © The Minerals, Metals & Materials Society and ASM International 2011. Source


Guo X.,Yanshan University | Guerrero J.M.,University of Aalborg
IEEE Transactions on Smart Grid | Year: 2016

Current regulation is crucial for operating singlephase grid-connected inverters. The challenge of the current controller is how to fast and precisely track the current with zero steady-state error. This paper proposes a novel feedback mechanism for the conventional proportional integral controller. It allows the steady-state error suppression with no need of additional complex control algorithms such as the synchronous reference frame transformation. Five alternative implementation methods are comparatively evaluated from the viewpoint of the steady-state and dynamic responses. Further, the theoretical analysis done indicates that the widely used P+Resonant control is just a special case of the proposed control solution. The time-domain simulation in MATLAB/Simulink and experimental results from a TMS320F2812 DSP-based laboratory prototypes are in good agreement, which verify the effectiveness of the proposed generalized method. © 2015 IEEE. Source


Zhang K.-C.,Bohai University | Li Y.-F.,Inner Mongolia University of Science and Technology | Liu Y.,Yanshan University | Zhu Y.,Nanjing University of Aeronautics and Astronautics
Journal of Alloys and Compounds | Year: 2015

Recently, p-type conduction of InN doped by alkaline earth was reported in experiments. However, the magnetic property of the doped systems has not been studied. We systematically investigate the magnetic property of alkaline-earth doped InN by density-functional theory. Our results reveal that the ground state of the doped system transits from nonmagnetic state to spin-polarized state, and the holes introduced into the valence band become more localized as the defect ranges from Be to Ba. As a result, strong half-metallic ferromagnetism emerges for Sr- or Ba-doped InN. Our calculations reveal that the formation energy of defect is much lower for nitrogen-rich condition, under which the doped system can be favorably synthesized. © 2014 Elsevier B.V. All rights reserved. Source


Li Y.L.,Yanshan University
Environment, Energy and Applied Technology - Proceedings of the 2014 3rd International Conference on Frontier of Energy and Environment Engineering, ICFEEE 2014 | Year: 2015

The emerging green accounting strengthen the environment protection consciousness of enterprise, but in calculation system also exists difficulty in one way of another, especially those measure of indirect benefits and costs caused by environmental upgrade or degradation exists certain difficulties, because it involves environment level. This text put forward a new measurement method—fuzzy identification and fuzzy clustering method against the part of environmental costs and benefits, it means measuring the factors of costs and benefits on the basis of distinguishing environmental upgrade or degradation. © 2015 Taylor & Francis Group, London. Source


Jin H.,Yanshan University
Lecture Notes in Electrical Engineering | Year: 2013

According to the real time rapidity characteristic of generalized predictive control, dual drive control synchronous subsystem based on generalized predictive is designed. Based on coordinated control principle, a fuzzy controller is added between the channels of two drive subsystems. Aiming to minimize the cor-responding state difference of two subsystems, control scheme with synchronous error non-equal common feedback fuzzy correction is adopted, which keep the output of two synchronous subsystems consistent, improve the response speed of synchronous error to system, and reduce the synchronous error of two drive sub-systems effectively. The simulation results show that synchronous control strategy presented in this paper improve the response speed of synchronous error to system, reduce the synchronous error of two motors effectively, and provide advantageous guarantee for the high precision of large rotary dual drive synchronous systems. © 2013 Springer-Verlag. Source


TA15 titanium alloy thick-wall parts have been deposited by Laser rapid forming (LRF) process. In this paper, a new overlap method between two adjacent laser tracks has been used to deposit the thick-wall titanium part. Results showed that the LRFed thick-wall titanium part was good in shape by using the new overlap method. The microstructure of the LRFed titanium alloy primarily consists of columnar prior-beta grain, which is perpendicular to the substrate resulting from directionally solidification. It also could be observed that the size of alpha phase increased with increasing laser power and decreasing scanning velocity. Tensile properties of LRFed titanium was slightly lower than that of the wrought annealed TA15 titanium alloy, after the heat-treatment of 940°C/1h/AC, the heat-treated titanium alloy showed good tensile properties which were equivalent to that of the wrought annealed TA15 titanium alloy. © (2013) Trans Tech Publications, Switzerland. Source


Hua C.,Yanshan University | Liu X.P.,Carleton University
IEEE Transactions on Instrumentation and Measurement | Year: 2011

This paper addresses the controller design problem for teleoperation over networks such as the Internet. The forward and backward network transmission time delays are assumed to be asymmetric and time varying, which is the case for computer network communications. We propose a novel masterslave controller, which renders the entire system stable with relatively good steady- and transient-state performances. The relations among the parameters of the controller and the allowable maximum time delays are built in the form of linear matrix inequality. The designed controller is extended to the case that the velocity information is not available. A high-gain observer is designed to estimate the velocities of the master and slave joints online, and the controller is constructed on the basis of the estimated velocities. The stability of the closed-loop system is proved. Both simulations and experiments are performed to verify the correctness and effectiveness of the proposed method. © 2010 IEEE. Source


Wang L.-M.,Yanshan University | Mauro J.C.,Corning Inc.
Journal of Chemical Physics | Year: 2011

The kinetic fragility of a liquid is correlated to the magnitude of enthalpy hysteresis in various glass-forming materials during thermal cycling across the glass transition. While the lower bound of liquid fragility is well known, there has been little research into the possibility of an inherent upper limit to fragility. In this paper, we present a theoretical argument for the existence of a maximum fragility and show that the correlation between fragility and enthalpy hysteresis allows for an empirical evaluation of the upper limit of fragility. This upper limit occurs as the enthalpy hysteresis involved in thermal cycling about the glass transition approaches zero, leading to m max≈175. This result agrees remarkably well with our previous estimate. The dynamics of maximum fragility liquids are discussed, and a critical temperature of ∼1.5 Tg (where Tg is the glass transition temperature) is revealed where a transition from nonexponential to exponential structural relaxation occurs. © 2011 American Institute of Physics. Source


Chen Y.-J.,Yanshan University
Jisuan Lixue Xuebao/Chinese Journal of Computational Mechanics | Year: 2013

Considering the influence of lateral shear deformation towards the stability of the sandwich plate, the lateral shear governing equation, fundamental solution, boundary condition as well as the static force condition of buckling instability of the rectangular sandwich plate are presented in this paper. The power of reciprocal method is applied to solve the rectangular sandwich board buckling instability problems. Source


Capaccioli S.,CNR Institute for Chemical and Physical Processes | Capaccioli S.,University of Pisa | Ngai K.L.,CNR Institute for Chemical and Physical Processes | Ngai K.L.,Yanshan University
Journal of Chemical Physics | Year: 2011

We consider experimental data on the dynamics of water (1) in glass-forming aqueous mixtures with glass transition temperature Tg approaching the putative Tg 136 K of water from above and below, (2) in confined spaces of nanometer in size, and (3) in the bulk at temperatures above the homogeneous nucleation temperature. Altogether, the considered relaxation times from the data range nearly over 15 decades from 10-12 to 10 3 s. Assisted by the various features in the isothermal spectra and theoretical interpretation, these considerations enable us to conclude that relaxation of un-crystallized water is highly non-cooperative. The exponent K of its Kohlrausch stretched exponential correlation function is not far from having the value of one, and hence the deviation from exponential time decay is slight. Albeit the temperature dependence of its -relaxation time being non-Arrhenius, the corresponding Tg-scaled temperature dependence has small steepness index m, likely less than 44 at Tg, and hence water is not fragile as a glassformer. The separation in time scale of the - and the -relaxations is small at Tg, becomes smaller at higher temperatures, and they merge together shortly above Tg. From all these properties and by inference, water is highly non-cooperative as a glass-former, it has short cooperative length-scale, and possibly smaller configurational entropy and change of heat capacity at Tg compared with other organic glass-formers. This conclusion is perhaps unsurprising because water is the smallest molecule. Our deductions from the data rule out that the Tg of water is higher than 160 K, and suggest that it is close to the traditional value of 136K. © 2011 American Institute of Physics. Source


Gao A.-H.,Yanshan University
Proceedings of the 5th International Asia Conference on Industrial Engineering and Management Innovation, IEMI 2014 | Year: 2014

This paper applies the method of game logic, to private enterprise's competition strategy for the analysis of several points, the object of competition and cooperation, first of all players that private enterprises; followed by the use of optimal strategy of private enterprises by the game logic virtual model and dynamic game process, enterprise advantage; and from the perspective of game theory how to enhance the credibility of enterprises, using matrix method is necessary to the national macroeconomic regulation and control of the private enterprises are discussed. © Atlantis Press and the authors 2015. Source


Wang J.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2011

The magnetoencephalography (MEG) can be used as a control signal for brain computer interface (BCI). The BCI also includes the pattern information of the direction of hand movement. In the MEG signal classification, the feature extraction based on signal processing and linear classification is usually used. But the recognition rate has been difficult to improve. In the present paper, a principal component analysis (PCA) and linear discriminant analysis (LDA) method has been proposed for the feature extraction, and the non-linear nearest neighbor classification is introduced for the classifier. The confusion matrix is analyzed based on the results. The experimental results show that the PCA + LDA method is effective in the analysis of multi-channel MEG signals, improves the recognition rate to the extent of the average recognition rate 55.7%, which is better than the recognition rate 46.9% in the BCI competition IV. Source


The global exponential stability issues are considered for almost periodic solution of the neural networks with mixed time-varying delays and discontinuous neuron activations. Some sufficient conditions for the existence, uniqueness, and global exponential stability of almost periodic solution are achieved in terms of certain linear matrix inequalities (LMIs), by applying differential inclusions theory, matrix inequality analysis technique, and generalized Lyapunov functional approach. In addition, the existence and asymptotically almost periodic behavior of the solution of the neural networks are also investigated under the framework of the solution in the sense of Filippov. Two simulation examples are given to illustrate the validity of the theoretical results. © 2013 Yingwei Li. Source


Yang Z.,Jiangsu Xuzhou Construction Machinery Research Institute | Shi D.,East China University of Technology | Wen B.,Yanshan University | Melnik R.,Wilfrid Laurier University
Journal of Alloys and Compounds | Year: 2012

Structural, elastic and electronic properties, as well as heats of formation, of seven Ca-Zn intermetallic compounds have been studied by using first principles methods. It was found that with increasing Zn concentration, the bulk moduli and shear moduli of Ca-Zn intermetallic compounds increase monotonically. Our results also indicate that Ca 3Zn, Ca 5Zn 3, and CaZn are ductile, while CaZn 2, CaZn 5, CaZn 11, and CaZn 13 are brittle. Furthermore, calculations of the electronic properties and heats of formation indicate that seven Ca-Zn intermetallic compounds, considered in this work, are all conductors and thermodynamically stable. © 2012 Elsevier B.V. Source


Yang H.,Beijing Institute of Technology | Yang H.,Yanshan University | Xia Y.,Beijing Institute of Technology
Automatica | Year: 2012

A strictly positive real control problem for delta operator systems in a low frequency range is presented by using the generalized Kalman- Yakubovič-Popov lemma. The objective of the strictly positive real control problem is to design a controller such that the transfer function is strictly positive real and the resulting closed-loop system is stable. Sufficient conditions for the low frequency strictly positive real controller of the closed-loop delta operator systems are presented in terms of solutions to a set of linear matrix inequalities. A numerical example is given to illustrate the effectiveness and potential for the developed techniques. © 2012 Elsevier Ltd. All rights reserved. Source


Gao Y.,Yanshan University
Proceedings of the Institution of Civil Engineers: Transport | Year: 2016

Top-down cracking is a type of cracking that significantly impacts traffic safety and comfort and reduces a pavement’s service life. Here, a cement concrete pavement containing a top-down crack is investigated under traffic load using a theoretical analysis method. In order to simplify the problem, the cement concrete pavement is modelled as an elastic plate on a Winkler foundation. Fourier transform methods and a dislocation density function are used to determine the stress intensity factors of a crack tip. A parametric study is conducted to isolate the effects of crack length, pavement stiffness and distance between the crack and the edge of a vehicle wheel. The results of the study show that crack length and load position significantly affect the stress intensity factors. However, stress intensity factors are less affected by the elastic modulus of the pavement material. © 2016, Thomas Telford Services Ltd. All rights reserved. Source


Zhou R.-F.,Yanshan University
19th International Conference on Industrial Engineering and Engineering Management: Management System Innovation | Year: 2013

The purpose of this paper is to study the concrete way for small to medium enterprises (SMEs) to reengineer its business process in the E-commerce environment. Following the organization structure design principle, the concrete countermeasures of reengineering business process are proposed from the following aspects. From the aspect of organization structure, re-integrate the existing department, outstanding information department function; from the aspect of decision making mechanism, empower to workers sufficiently; from the aspect of organization run, establish the trust mechanism, information share mechanism, principal-agent mechanism and benefit share mechanism. Finally, the validity of proposed reengineering project has been verified through an actual example. © 2013 Springer-Verlag Berlin Heidelberg. Source


Wang C.,Yanshan University
2013 25th Chinese Control and Decision Conference, CCDC 2013 | Year: 2013

This paper focuses on adaptive stabilization problems for a class of switched nonlinear systems in lower triangular structure with uncertain parameter vector. A systematic recursive algorithm for designing an adaptive stabilizing controller is proposed by extending the backstepping method for no-switched nonlinear systems to the switched ones. The constructed controller guarantees the resultant closed-loop switched system to be globally stable in sense of Lyapunov at the equilibrium under the designed switching law and adaptive law. Finally, the simulation of an example is given to show the effectiveness of the proposed recursive approach. © 2013 IEEE. Source


As masterpieces in Chinese classical literature, the Four Great Chinese Classical Novels with their multilingual translations have exerted a profound influence in literature and translation studies both home and abroad. Building a Chinese-French bilingual parallel corpus of the Four Great Chinese Classical Novels is believed to facilitate large-scale investigations into the original Chinese text and their French translations in terms of stylistics, diction, culture and translation techniques. In this paper, we introduced the French translations of the four novels and illustrated the process of building the parallel corpus in detail. When the parallel corpus is completed, statistical analysis can thereby be carried out by employing different corpus tools. In order to enhance the availability and convenience of the parallel corpus, a web-based query platform is designed to provide world-wide search through the Internet for interested researchers and language learners. © (2014) Trans Tech Publications, Switzerland. Source


Liu C.S.,Yanshan University
Physica C: Superconductivity and its Applications | Year: 2016

Motivated by the experimental measurement of the two-magnon Raman scattering in iron Pnictides and Chalcogenides superconductors (Okazaki et al., 2011; Sugai et al., 2012), the underlying spin excitations of the (π, 0) collinear and the (π/2, π/2) diagonal double stripe antiferromagnetic superstructures are investigated in detail with the spin density wave approximation. By calculating the Fleury-London (FL) Raman cross-section of various quantum spin models proposed for this new class of superconductors, it is found that the unfrustrated quantum spin models are well consistent with the Raman data. Our calculation results also show that the broad peak around 2500 cm-1 of iron Pnictides in Bg channel come from the quasiparticle excitations of two optical magnons, whereas, in Ag channel the Raman response is from two optical magnons and two acoustic magnons with almost the same weights. In addition, our calculation results reveal that the broad peak around 2300 cm-1 of the iron Chalcogenides in Bg channel is caused by one acoustic magnon and one optical magnon, which is simultaneously excited by the Raman scattering. While in Ag channel, Raman scattering will mainly excite two optical magnons. © 2015 Elsevier B.V. Source


Liu Y.,CAS Shanghai Advanced Research Institute | Li Y.,Yanshan University | Li X.-M.,CAS Shanghai Advanced Research Institute | He T.,CAS Shanghai Advanced Research Institute
Langmuir | Year: 2013

Silanization of magnetic ironoxide nanoparticles with (3-aminopropyl) triethoxylsilane (APTES) is reported. The kinetics of silanization toward saturation was investigated using different solvents including water, water/ethanol (1/1), and toluene/methanol (1/1) at different reaction temperature with different APTES loading. The nanoparticles were characterized by Fourier transform infrared spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and thermal gravimetric analysis (TGA). Grafting density data based on TGA were used for the kinetic modeling. It is shown that initial silanization takes place very fast but the progress toward saturation is very slow, and the mechanism may involve adsorption, chemical sorption, and chemical diffusion processes. The highest equilibrium grafting density of 301 mg/g was yielded when using toluene/methanol mixture as the solvent at a reaction temperature of 70 C. © 2013 American Chemical Society. Source


Liu X.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

Facial paralysis is a frequently-occurring disease, which causes the loss of the voluntary muscles on one side of the face due to the damages the facial nerve and results in an inability to close the eye and leads to dropping of the angle of the mouth. There have been few objective methods to quantitatively diagnose it and assess this disease for clinically treating the patients so far. The skin temperature distribution of a healthy human body exhibits a contralateral symmetry. Facial paralysis usually causes an alteration of the temperature distribution of body with the disease. This paper presents the use of the histogram distance of bilateral local binary pattern (LBP) in the facial infrared thermography to measure the asymmetry degree of facial temperature distribution for objective assessing the severity of facial paralysis. Using this new method, we performed a controlled trial to assess the facial nerve function of the healthy subjects and the patients with Bell's palsy respectively. The results showed that the mean sensitivity and specificity of this method are 0.86 and 0.89 respectively. The correlation coefficient between the asymmetry degree of facial temperature distribution and the severity of facial paralysis is an average of 0.657. Therefore, the histogram distance of local binary pattern in the facial infrared thermography is an efficient clinical indicator with respect to the diagnosis and assessment of facial paralysis. Source


Li Q.,Zhejiang Sci-Tech University | Chen Q.,Zhejiang Sci-Tech University | Wu C.,Zhejiang Sci-Tech University | Huang Z.,Yanshan University
Mechanism and Machine Theory | Year: 2013

A 3-[P][S] parallel mechanism consists of three limbs and each limb can generate a planar-spherical ([P][S]) kinematic bond. Typically, the 3-[P][S] parallel mechanism family includes four types of architectures, namely, 3-RPS, 3-PRS, 3-RRS and 3-PPS, where R denotes a revolute pair, P a prismatic pair, and S a spherical joint. The 3-[P][S] parallel mechanism has received extensive attention due to its practical potential. But little is known about the geometrical distribution of the axes of the two rotational DOF (degrees of freedom) of the 3-[P][S] parallel mechanism. Consequently, although the kinematic derivations of the 3-[P][S] parallel mechanism are correct, the interpretation of the actual instantaneous rotation is not clear. This fact may hinder its application. This paper concentrates on the identification of the rotational axes of the 3-[P][S] parallel mechanism with different limb arrangements. First, the geometrical condition for the axis of a feasible rotation of a rigid body constrained by a force is discussed using screw theory. Then, the 3-[P][S] PMs are classified into four categories and seven subcategories based on the geometrical condition of their LPs (limb planes) and spherical joint centers, The instantaneous and finite rotational axes of the seven subcategories of 3-[P][S] parallel mechanism are identified using reciprocal screw theory. The results apply to all 3-[P][S] PMs. © 2013 Elsevier Ltd. All rights reserved. Source


Ken K.,Yanshan University
[Nippon kōshū eisei zasshi] Japanese journal of public health | Year: 2010

Objective In the People's Republic of China (China), caregivers carry a large burden because of the rapid aging of the population, the one-child policy and the uncertainty of the social security system. The situation is further complicated by the fact of 56 ethnic groups in the country. Few studies on caregiver burden in different ethnic groups have been reported, although different customs, cultures and methods of caring for the elderly do certainly exist. The aim of the present study was to compare the caregiver burden for the elderly among Han Chinese and the Korean Minority living in a community and to examine the factors affecting this burden. An investigation was conducted using a questionnaire for 76 pairs of elderly people and their caregivers in Yanji City, China (Korean Minority pairs 52, Han pairs 24). The questionnaires for the elderly included their characteristics, economic conditions, ADL, behavioral disturbances associated with dementia, etc. For the caregivers, their characteristics, the state of their health, daily length of care time, social support, intent to continue home care, and Zarit Caregiver Burden Interview (ZBI) score were investigated. The rate (70.8%) of caregivers with a "high caregiver burden," i.e., those with a median ZBI total score of 33 or more, and the personal strain scores of the Han Chinese were significantly higher than in the Korean Minority. As for who was a suitable caregiver, a high percentage of Han caregivers answered the "children" of the elderly, while Korean Minority caregivers answered the "spouses". When the caregiver was a child of the elderly receiving care, the Hans' ZBI score was higher than that for the Korean Minority. Factors most affecting caregiver burden in the Korean Minority were behavioral disturbances associated with dementia of the elderly, ADL, and degree of life independence of the elderly, along with disorders, sex and health state of the caregivers, relations, length of daily care time, number of vice-caregivers, and social support. Factors affecting caregiver burden in the Han group were the presence of private rooms for the elderly, their life satisfaction and family economic conditions. About 80% of caregivers of both groups had the intention to continue home care, and about 50% of the elderly of both groups answered that entering an institution was not acceptable. Factors affecting caregiver burden differ between these two ethnic groups, although in both cases about 80% of caregivers intend to continue home care. Therefore, it is necessary to support the elderly and caregivers in ways that suit their ethnic characteristics. Source


Xu X.,Beijing University of Technology | Su J.,Beijing University of Technology | Su J.,Yanshan University | Chen W.,Beijing University of Technology | Wang C.,Beijing University of Technology
Journal of Biomolecular Structure and Dynamics | Year: 2011

The thermo-stability and unfolding behaviors of a small hyperthermophilic protein Sso7d as well as its single-point mutation F31A are studied by molecular dynamics simulation at temperatures of 300 K, 371 K and 500 K. Simulations at 300 K show that the F31A mutant displays a much larger flexibility than the wild type, which implies that the mutation obviously decreases the protein's stability. In the simulations at 371 K, although larger fluctuations were observed, both of these two maintain their stable conformations. High temperature simulations at 500 K suggest that the unfolding of these two proteins evolves along different pathways. For the wild-type protein, the C-terminal alpha-helix is melted at the early unfolding stage, whereas it is destroyed much later in the unfolding process of the F31A mutant. The results also show that the mutant unfolds much faster than its parent protein. The deeply buried aromatic cluster in the F31A mutant dissociates quickly relative to the wild-type protein at high temperature. Besides, it is found that the triple-stranded antiparallel β-sheet in the wild-type protein plays an important role in maintaining the stability of the entire structure. ©Adenine Press (2011). Source


Wang X.,Yanshan University
Journal of Materials Science | Year: 2012

Titania (TiO 2) nanowires with diameters of 20, 50, and 80 nm were successfully synthesized via the template-assistant method. The TiO 2 nanowires embedded in anodic aluminum oxide template have extremely high crystallization and anatase-to-rutile phase transition temperatures than that of the free-state TiO 2 powders, and the thermal stability of embedded TiO 2 nanowires depends on the diameter of the templates. The growth and nucleation activation energy of rutile in 20 nm nanowires are determined to be E g = 2.8 ± 0.2 eV and E n = 2.7 ± 0.2 eV, respectively, much higher than that of the free-state TiO 2 powders with E g = 1.6 ± 0.2 eV and E n = 1.9 ± 0.2 eV. The pressure induced by the difference of thermal expansion coefficient between the TiO 2 and aluminum oxide acts as an effective barrier that prevents phase transition, resulting in the enhancement of the TiO 2 structural stability. © 2011 Springer Science+Business Media, LLC. Source


Liu H.,University of Chinese Academy of Sciences | Yang H.,University of Chinese Academy of Sciences | Hao X.,CAS Changchun Institute of Applied Chemistry | Xu H.,CAS Changchun Institute of Applied Chemistry | And 4 more authors.
Small | Year: 2013

A class of core-shell nanoparticles possessing a layer of biocompatible shell and hydrophobic core with embedded oxygen-sensitive platinum-porphyrin (PtTFPP) dyes is developed via a radical-initiated microemulsion co-polymerization strategy. The influences of host matrices and the PtTFPP incorporation manner on the photophysical properties and the oxygen-sensing performance of the nanoparticles are investigated. Self-loading capability with cells and intracellular-oxygen-sensing ability of the as-prepared nanoparticle probes in the range 0%-20% oxygen concentration are confirmed. Polymeric nanoparticles with optimized formats are characterized by their relatively small diameter (<50 nm), core-shell structures with biocompatible shells, covalent-attachment-imparted leak-free construction, improved lifetime dynamic range (up to 44 μs), excellent storage stability and photostability, and facile cell uptake. The nanoparticles' small sensor diameter and core-shell structure with biocompatible shell make them suitable for intracellular detection applications. For intracellular detection applications, the leak-free feature of the as-prepared nanoparticle sensor effectively minimizes potential chemical interferences and cytotoxicity. As a salient feature, improved lifetime dynamic range of the sensor is expected to enable precise oxygen detection and control in specific practical applications in stem-cell biology and medical research. Such a feature-packed nanoparticle oxygen sensor may find applications in precise oxygen-level mapping of living cells and tissue. Core-shell-type oxygen nanosensors with optimized formats are developed. They are characterized by their relatively small diameter (<50 nm), biocompatible and protective shells, covalent-attachment-imparted leak-free construction, improved lifetime dynamic range (up to 44 μs), and excellent storage stability and photostability. Their facile cell uptake and ability to sense intracellular oxygen are confirmed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source


Zhou X.-F.,Nankai University | Zhou X.-F.,State University of New York at Stony Brook | Dong X.,Nankai University | Dong X.,State University of New York at Stony Brook | And 6 more authors.
Physical Review Letters | Year: 2014

It has been widely accepted that planar boron structures, composed of triangular and hexagonal motifs are the most stable two-dimensional (2D) phases and likely precursors for boron nanostructures. Here we predict, based on an ab initio evolutionary structure search, a novel 2D boron structure with nonzero thickness, which is considerably, by 50 meV/atom, lower in energy than the recently proposed α-sheet structure and its analogues. In particular, this phase is identified for the first time to have a distorted Dirac cone, after graphene and silicene the third elemental material with massless Dirac fermions. The buckling and coupling between the two sublattices not only enhance the energetic stability, but also are the key factors for the emergence of the distorted Dirac cone. © 2014 American Physical Society. Source


Liu B.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

Non-contact measurement is an effective method of long time measurement of human electrocardiograph (ECG) signal. Because the relative position between measuring electrode and human body is not fixed, this method could result in constant changes of ECG signal collection. It often appears ECG signal distorting and weakened in filtering. This paper, using the principal component analysis (PCA) basic theory, proposes a fast adaptive PCA denoising algorithm which can automatically adjust the parameters according to the changes of ECG signal. The experiment proved that PCA denoising could be barely impacted by signal changes and can disposably remove interference signal on the premise of keeping the main features of ECG signal and can prevent ECG signal from being weakened in filtering at the same time. Source


Wang J.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

Using human electroencephalogram (EEG) to control external devices in order to achieve a variety of functions has been focus of the field of brain-computer interface (BCI) research. P300 is experiments which stimulate the eye to produce EEG by using letters flashing, and then identify the corresponding letters. In this paper, some improvements based on the P300 experiments were made??. Firstly, the matrix of flashing letters were modified into words which represent a certain sense. Secondly, the BCI2000 procedures were added with the corresponding source code. Thirdly, the smart car systems were designed using the radiofrequency signal. Finally it was realized that the evoked potentials were used to control the state of the smart car. Source


Fan F.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

On the basis of the theory of formal concept analysis (FCA), a new method for generation of an attribute hierarchical graph is proposed in this paper. This method can solve the problems of how to mine and express classification knowledge and rules in compatibility of prescription. In this paper, we view prescriptions as objects that possess certain attributes of the named drugs. First, the formal context is established based on theory. Then optimization of the original formal context and extracts the connotation and extension of the concept are followed, constructing attribute hierarchical graph. Finally, useful knowledge from the hierarchical diagram of attributes based on the way of knowledge representation is mined. The result showed that the method for discovering Traditional Chinese Prescription (TCP) diagnostic knowledge is feasible and effectual for small samples. The research of large samples is 13th open question of FCA. It is an international subject to be studied urgently. Source


In this paper, an ultra compact cascaded microring filter consisting of two master rings with radius of 2.5 μm and two slave rings with radius of 1 μm is presented and studied theoretically. The filter with a very large free spectral range (FSR) of 206 nm, a deep extinction ratio of 23 dB, a high quality factor of 2.76×105, and greatly suppressed spurious modes of less than 0.1 dB is achieved. The spectral responses of the filter are simulated by transfer matrix method, and the results show that this filter has a great potential of sensor application. © 2014 Tianjin University of Technology and Springer-Verlag Berlin Heidelberg. Source


Bian Y.H.,Yanshan University
Applied Mechanics and Materials | Year: 2013

In this paper, the nonlinear magnetoelastic kinetic equations and the electrodynamics equations of a thin current-carrying plate under the action of a coupled field are given. Using the difference and quasi-linearization methods, the nonlinear magnetoelastic equations are reduced to a sequence of quasilinear differential equations, which can be solved by the discrete-orthogonalization method. The stresses and deformations in a thin current-carrying plate under the interaction of an electromagnetic field and mechanical load are calculated, and the magnetoelastic effect on the plate by the side electric current and magnetic induction intensity is studied. Numerical results show that the states of the strains and stresses in thin plates can be controlled by changing the electromagnetic parameters. © (2013) Trans Tech Publications, Switzerland. Source


Wang W.,Yanshan University
ICIME 2010 - 2010 2nd IEEE International Conference on Information Management and Engineering | Year: 2010

Time constraints play a very important role in realtime systems, in this paper local time constraints are converted to global time constraints according to token's movement from one place to another in the workflow Petri net. Firstly, temporal reasoning method of three basic workflow patterns based on Petri net is presented, so that the global time constraint formula for each pattern is obtained. Finally, an application example for information system of administration and service for Tangshan urban-rural integration model is introduced. The example shows that global time constraints can effectively solve the problem of the workflow exceptions. © 2010 IEEE. Source


Yu H.-S.,Yanshan University
Guocheng Gongcheng Xuebao/The Chinese Journal of Process Engineering | Year: 2013

n-butyl acetate was synthesized with n-butanol and glacial acetic acid as raw materials in a slurry bubble column reactor by modified D001 cationic exchange resin catalyst. The technological advances of column reactor and characteristics of the catalyst were examined, and the effects of catalyst type, content, and used life time on the synthesis investigated. The results showed that under the optimized conditions of molar ratio of n-butanol to acetic acid 1.2:1, amount of catalyst 40% to that of the acetic acid, reaction temperature 110°C, and reaction time 75 min, the yield and purity of n-butyl acetate were 98% and 99.5%, respectively. By washing, activation and regeneration, the catalyst could be reused 6 times. Source


Yu Y.-M.,CAS Institute of Physics | Voigt A.,CAS Institute of Physics | Guo X.,TU Dresden | Liu Y.,Yanshan University
Applied Physics Letters | Year: 2011

Through phase-field simulations, we investigate simultaneous step meandering and bunching instabilities with the presence of Ehrlich-Schwoebel barrier and elastic interaction. The meandering instability induced by the Ehrlich-Schwoebel barrier is found to be dependent on the elastic interaction at low adatom deposition rate. The ordered step meandering-bunching structure is designed by using the predefined magnitude distribution of the force monopoles on vicinal surfaces based on interplay between the Ehrlich-Schwoebel barrier and the elastic interaction. © 2011 American Institute of Physics. Source


Xie Y.C.,Northeastern University China | Li Y.M.,Yanshan University
Advanced Materials Research | Year: 2014

To find a cheap and effective hydrogen evolution reaction catalyst, a series of Ni-doped MoS2 microspheres consisting of MoS2 nanosheets have been prepared via hydrothermal synthesis and characterized by scanning electron microscopy (SEM), and X-ray powder diffraction (XRD). Their performance as electrochemical hydrogen evolution reaction (HER) catalyst was studied. It is found that the Ni-doped MoS2 exhibited superior electrocatalytic activity in the HER to undoped MoS2 catalysts. The overpotential of Ni-doped MoS2 has decreased compared with that of undoped sample, indicating an improved activity in HER. Furthermore, the cathodic current for the Ni-doped MoS2 catalyst is about 9 times as much as that for undoped MoS2. Based on our findings, the resulting Ni-doped MoS2 might be promising inexpensive alternative to platinum catalysts in hydrogen production. © (2014) Trans Tech Publications, Switzerland. Source


Jiao X.,Yanshan University | Zhang J.,Dalian Nationalities University | Shen T.,Sophia University
IEEE Transactions on Industrial Electronics | Year: 2014

In order to achieve higher precise positioning of the throttle plate, an adaptive servo control strategy is presented for the electronic throttle control system. Compared with the existing results on the electronic throttle control schemes, in this paper, the throttle valve reference tracking controller comprises a proportional-integral-derivative-type feedback controller with adaptive gain parameters, an adaptive feedforward compensator, and adaptive nonlinearity compensators for friction, limp-home (LH), and backlash. The closed-loop controller is realized by only utilizing the information of the throttle valve position measured by a cheap potentiometer of low resolution. The theoretical proof and analysis show that the designed throttle control system can ensure fast and accurate reference tracking of the valve plate angle in the case of the uncertain parameters related to production deviations, variations of external conditions and aging, and the effects of transmission friction, return-spring LH, and gear backlash nonlinearity with uncertain parameters. Moreover, the capability of the adaptive controller to preserve the transient performance and accuracy is evaluated in both simulation and experiment. © 1982-2012 IEEE. Source


Zhao J.,Yanshan University
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2012

To enhance the visual effect of the traditional spot noise method, a much more intuitionistic method was proposed to use near-regular texture and triangular-patch texture mapping to animate the 3D flow visualization for curved surfaces. First of all, the triangular-patch model was constructed. On the basis of the triangular unit, the flow filed of the Gravity Center of a triangle was adopted as the field of the triangular-patch. Then the triangular-patch made a texture mapping with the directional information of the near regular texture. At the same time, the max sample set and the best sample set were introduced to alleviate the time loss of the texture re-mapping on the movement of the flow field. At last, the flow synthesis method with the additional vector point was illustrated. The experimental results show that this algorithm can achieve better effect than the traditional ones. Source


Sun S.-T.,Yanshan University
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2012

A more available way of remote information model simulation and description was proposed and a novel method based on service on demand mode was proposed, and the semantic relationship description of information processing procedure gave the basic knowledge of resource selection and matching based on application demands. A hierarchical mapping and description method of remote information model was provided to realize the transformation from abstract model to concrete service chain, and a case study shows the work procedure of this method. Source


Jin H.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

This paper introduces the characteristics of the Hilbert-Huang transform (HHT), and studies the classification of movement imagery EEG based on the HHT method and BP neural network. After preprocessed, the movement imagery EEG data were descomposed with empirical mode decomposition (EMD) into a series of intrinsic mode functions (IMFs). Then the low frequency IMFs were removed, and the rest of IMFs were conducted by Hilbert transform to get Hilbert marginal spectrum. The marginal spectrum subtracted values between the channal C3 and channal C4 were selected as the original features which were then decreased the dimension by the principal components analysis so as to be jointed with EEG complexity to construct the feature vector. The BP neural network was utilized to classify the EEG pattern of left and right hand motor imagery. The brain computer interface (BCI) competition II data set III was selected to carry out the discrimination, and the classification accuracy rate is up to 87.14%, which is a comparably good result and proves HHT to be a feasible and effective method on EEG analysis. Source


Ji S.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

A modified "cross-modal delayed response" paradigm was used to investigate whether the visual mismatch negativity can be elicited by cartoon facial expressions, and to define the mechanism underlying automatic processing of facial expressions. Subjects taking part in the tests were instructed to discriminate the type of the tones they heard as quickly and accurately as possible, and to act merely when they heard the response imperative signal. Neutral, happy and angry faces were presented during intervals between a tone and a response imperative signal. Visual mismatch negativity (VMMN) was obtained by subtracting the event - related potential (ERP) elicited by neutral faces from that elicited by happy faces or angry faces. The angry-related VMMN was more negative than happy-related VMMN, and both were more negative in the left than in the right cerebral hemisphere. The results indicated that VMMN can be elicited by the cartoon facial expressions, and the facial expressions can be processed automatically. Source


Yan-liang W.,Yanshan University
Research Journal of Applied Sciences, Engineering and Technology | Year: 2013

The aim of this study is to improve and increase the logistics system effectiveness and to solve the problem of optimal movement of different flows. Logistics transport carrying the world on material resources transfer exchange important mission and economic development and our lives are closely linked, logistics chain logistics transport occupies an important position and in the e logistics chain in port logistics has play a decisive role. For many coastal countries port logistics is the economic lifeline of the country, on China's economic development role as important, port logistics transport bear the material exchange with the external communication of important role, so the Chinese port logistics transportation research, clear port logistics transportation, current situation, find the existing problems in the light of the problem, to find a suitable method for solving has great realistic meaning. To promote logistics development, improve the logistics supply chain system has play an important role in this filed. Source


Lv X.-J.,CAS Technical Institute of Physics and Chemistry | She G.-W.,CAS Technical Institute of Physics and Chemistry | Zhou S.-X.,CAS Technical Institute of Physics and Chemistry | Li Y.-M.,Yanshan University
RSC Advances | Year: 2013

Ni-promoted MoS2 microspheres consisting of nanosheets have been prepared via a facile one-pot hydrothermal synthesis for the first time. The electrochemical hydrogen evolution reaction (HER) results demonstrated that the Ni-promoted MoS2 catalysts showed superior catalytic activity in the HER compared to pure MoS2 catalysts. This journal is © The Royal Society of Chemistry 2013. Source


Piao Z.,Yanshan University | Piao Z.,Academy of Armored force Engineering | Xu B.,Academy of Armored force Engineering | Wang H.,Academy of Armored force Engineering | Pu C.,Academy of Armored force Engineering
Tribology International | Year: 2010

The aim of this paper was to address the influence of undercoating on the rolling contact fatigue (RCF) performance of coatings. The Fe-based alloy and Ni/Al alloy were deposited on substrates as surface coating and undercoating by plasma spraying. The failure modes were investigated for two kinds of coatings. RCF performances were compared using Weibull distribution plot. The results showed undercoating played an important role on increasing RCF life of coating for the higher bond strength, and decreasing the scatter of RCF life data. The deposited undercoating could influence the failure mode of coating and prevent the occurrence of catastrophic delamination. © 2009 Elsevier Ltd. All rights reserved. Source


Liu X.,Beijing University of Posts and Telecommunications | Liu X.,Yanshan University | Qiao Y.,Beijing University of Posts and Telecommunications | Ji Y.,Beijing University of Posts and Telecommunications
Chinese Optics Letters | Year: 2011

We study an electronic compensator (EC) as a receiver for a 100-Gb/s polarization division multiplexing coherent optical orthogonal frequency division multiplexing (PDM-CO-OFDM) system without optical dispersion compensation. EC, including electrical dispersion compensation (EDC), least squares channel estimation and compensation (LSCEC), and phase compensation (PC), is used to compensate for chromatic dispersion (CD), phase noise, polarization mode dispersion (PMD), and channel impairments, respectively. Simulations show that EC is highly effective in compensating for those impairments and that the performance is close to the theoretical limitation of optical signal-to-noise rate (OSNR), CD, and PMD. Its robustness against those transmission impairments and fiber nonlinearity are also systematically studied. © 2011 Chinese Optics Letters. Source


Guo X.,Yanshan University | Xu D.,Ryerson University | Wu B.,Ryerson University
IEEE Transactions on Industrial Electronics | Year: 2015

Common-mode voltage (CMV) is one of the most important issues for the power electronics inverters. An interesting space vector modulation of the three-leg current-source inverter has been reported for the CMV reduction recently. However, it has the disadvantages of the bipolar current pulses and modulation index range limitation. In order to solve these problems, a four-leg current-source inverter with a new space vector modulation is proposed in this paper. With the proposed method, the system CMV can be significantly reduced without bipolar current pulses and modulation index range limitation. Finally, the experimental tests are carried out on a four-leg current-source inverter, and the experimental results verify the effectiveness of the proposed method. © 1982-2012 IEEE. Source


Li J.-H.,Shanxi University | Liu W.-Q.,Shanxi University | Tian N.-S.,Yanshan University
Performance Evaluation | Year: 2010

This paper analyzes a discrete-time batch arrival queue with working vacations. In a GeoXG1 system, the server works at a lower speed during the vacation period which becomes a lower speed operation period. This model is more appropriate for the communication systems with the transmit units arrived in batches. We formulate the system as an embedded Markov chain at the departure epoch and by the M/G/1-type matrix analytic approach, we derive the probability generating function (PGF) of the stationary queue length. Then, we obtain the distribution for the number of the customers at the busy period initiation epoch, and use the stochastic decomposition technique to present another equivalent PGF of the queue length. We also develop a variety of stationary performance measures for this system. Some special models and numerical results are presented. Finally, a real-world example in an Ethernet Passive Optical Network (EPON) is provided. © 2010 Elsevier B.V. Source


Yang Y.,Nanjing University of Posts and Telecommunications | Yue D.,Nanjing University of Posts and Telecommunications | Dou C.,Yanshan University
Information Sciences | Year: 2016

In this paper, we consider a leader-follower output consensus problem for a class of uncertain heterogeneous non-affine pure-feedback multi-agent systems (MASs) in the presence of time-delay items and input saturation restrictions under switching directed topologies. A distributed adaptive control scheme is constructed by combining Lyapunov-Krasovskii functionals, backstepping methods, neural networks (NNs), auxiliary systems, graph theory, the mean value theorem and the implicit function theory along with the dynamic surface control (DSC) technique. The key advantages of the designed control approach are that there is no requirement of precise knowledge about uncertain dynamics and time-delay items of individual agents and the computational burden can drastically be reduced by employing the DSC technique. Also, norms of unknown weight of neural networks are estimated online instead of weight vectors themselves. In theory, it can be proven that the output signals of follower agents can synchronize with the leader's and all signals in the closed-loop system are cooperatively semiglobally uniformly ultimately bounded (CSUUB) by suitable choice of design parameters. Two simulation examples are presented to demonstrate the effectiveness of the proposed strategy. © 2016 Elsevier Inc. All rights reserved. Source


Jin S.,Yanshan University | Yue W.,Konan University
Journal of Global Optimization | Year: 2013

For reducing the energy consumption of the Mobile Station in mobile Broadband Wireless Access networks, IEEE 802.16 offers three kinds of sleep mode operations called power saving classes type I, type II and type III. In order to investigate mathematically the inherent relationships between the performance measures and the system parameters, we propose in this paper a novel method for modeling the sleep mode with the power saving class type II in IEEE 802.16 and analyzing the performance of this sleep mode. Considering the attractive feature that some data frames can be transmitted during the listening state, we present a queueing model with two kinds of busy mechanisms to capture the working principle of the sleep mode operations with the power saving class type II. With the first and higher derivatives of the probability generating functions, we can give the averages and the standard deviations for the system performance using the diffusion approximation for the operating process of the system. We also propose methods for measuring the system performance in terms of the switching ratio, the energy saving ratio, and the average response time of data frames, as well as giving the expressions for these performance measures. Numerical results are provided with analysis and simulation to show the average performance measures, standard deviations and the cost function with different system loads. Moreover, we construct a cost function with the aim of determining the optimal time length of the sleep window to minimize the cost function. © 2012 Springer Science+Business Media, LLC. Source


Sun S.,Yanshan University
International Geoscience and Remote Sensing Symposium (IGARSS) | Year: 2012

This paper has study the description and simulation computation methods of remote sensing information model, and try to propose a more available way to solve this problem. This paper presents our research works on the description and simulation methods of remote sensing information model: the service on demand method provides a basic methodology of model analysis, the semantic relationship description of information processing procedure gives the basic knowledge of resource selection and matching based on user's demand, and the hierarchical mapping method of remote sensing information model shows the transformation from abstract model to concrete service chain, which can help to design the executable workflow of model simulation and computation. © 2012 IEEE. Source


Wang Y.,University of Science and Technology Beijing | Lin C.,Tsinghua University | Li Q.-L.,Yanshan University
Performance Evaluation | Year: 2010

Email is a crucial part of our daily life, but email systems are facing increasing security threats such as attacks and spam. Because of this, new mechanisms are being provided to defend against the attacks and to reduce the amount of spam in email systems. Up to now, few available works have been reported on the performance evaluation of email systems under attack, which has become necessary for enhancing email security. In this paper, we propose a novel method to study the impact of three types of attacks on email systems. We construct a multiple queueing model to characterize three types of attacks integrally, and study the performance metrics of system security such as system availability, average queue length and information leakage probability. Numerical examples indicate that the approach of this paper is effective and efficient for dealing with the security analysis of email systems under attack. We believe that this work will open a new avenue for the performance evaluation of computer networks under email attack and other forms of attacks. © 2010 Elsevier B.V. All rights reserved. Source


Tang X.,Yanshan University
Journal of Computational Information Systems | Year: 2015

Finding all the common elements from several sorted lists is a central operation in information retrieval engines, search engines, and databases. We propose a novel set intersection algorithm, namely SEJoin, to efficiently find such common elements. SEJoin can dynamically adjust the join strategy according to the distribution of the underlying data. Rich experimental results verify the benefits of our SEJoin algorithm, where the overall performance can be improved by more than one order of magnitude in many cases. ©, 2015, Journal of Computational Information Systems. All right reserved. Source


Wang J.,Yanshan University
Applied Mechanics and Materials | Year: 2012

CAPP (computer aided process planning) is a key technology for integration of CAD and CAM. Process planning relies on manufacturing knowledge and CAPP is characterized with multi-knowledge resources, multi-task, multi-level and multi-constrain so process planning is hard to automate. This paper introduces the artificial neural network for unstructured manufacturing knowledge modeling, knowledge is represented as neural network weight value matrix, and then form ANN database to support intelligent CAPP. Example about cutting force modification is presented to test the feasibility of this approach. As Intelligent CAPP is knowledge based and structure of CAPP varies with types of knowledge representation, this paper presents the system structure of intelligent CAPP system. This system employs the black-board inference, unified manufacturing resource and part model, multi-knowledge database to realize the process planning automatically. Source


Li Z.,Yanshan University
Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | Year: 2015

Horizontal well can be considered as a special case of directional wells, but the target window of a horizontal well is not included in the target area of the directional well. In fact, the target window of the horizontal well is in conflict with the target area of the directional well using the current well-design method. The basis for the unitization of the target area and the target widow is the redefinition of the relationship between the directional-horizontal well borehole axis and the target plane, namely the target plane should always be vertical to the borehole axis, and the target area in the target plane should vary with the increase of the inclination angle, gradually changing from a circular shape for a vertical well to a rectangle or oval shape for a horizontal well. In this paper, mathematical models of the target area with oval and rounded rectangle shapes were established respectively, and calculation software was formulated for mapping the safe boundary of the elliptic cone and rounded corner pyramid in the target area. The results show that the target plane should be perpendicular to the borehole axis, and the transition of the vertical well target area to the horizontal well target window along with the inclination angle is one of the effective methods to resolve the conflict. © 2015, University of Petroleum, China. All right reserved. Source


Guo X.,Yanshan University
Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical Engineering | Year: 2015

Proportional complex integral control is one of the control solutions for PV grid-connected inverters. From the conventional point of view, it can only be implemented in three-phase orthogonal frame (e.g. stationary α β frame), but not in abc frame or single-phase system. In order to solve the problem, a generalized proportional complex integral control scheme is proposed in this paper. It can be realized not only in three-phase abc frame without any transformation matrix, but also in single-phase system with no need of delay to reconstruct the virtual frame. Theoretical analysis and simulation are carried out. The digital-controlled hardware platform based on TMS320F2812 DSP is built for experimental tests. Results verify the feasibility and effectiveness of the propose method. © 2015 Chin. Soc. for Elec. Eng. Source


Guo X.-Q.,Yanshan University
Measurement: Journal of the International Measurement Confederation | Year: 2011

Measurement of dc injection is crucial for the transformerless PV systems. IEEE Std.929-2000 specifies that the PV systems shall not inject the dc current greater than 0.5% of the full rated output current. Dc injection measurement is not only useful for evaluating whether a transformerless PV system meets IEEE standards, but also for the effective dc suppression with injecting an equal but opposite dc component via a proper control scheme. In practice, however, it is difficult to extract the very low-level (0.5% I rated) dc currents in the presence of high levels of ac currents in transformerless PV systems. In order to overcome the limitation, this paper presents a real-time dc injection measurement technique. Some major issues such as the basic operating principle, frequency excursion effect mitigation and discrete-domain implementation of the proposed method are discussed. Theoretical analysis and performance evaluation results verify the effectiveness of the proposed dc injection measurement technique. © 2011 Elsevier Ltd. All rights reserved. Source


Li X.,Yanshan University | Zhong F.,Agricultural University of Hebei
Inflammation | Year: 2014

Exposure to nickel (Ni2+) can trigger allergic reactions in susceptible individuals, which is widely accepted as the major cause of allergic contact hypersensitivity (CHS) worldwide. Although Ni2+-induced proinflammatory responses clearly play a pivotal role in CHS, the underlying molecular mechanism has not been fully defined. Here we report that Ni 2+ activates the NLRP3-ASC-caspase-1 immune signaling pathway in antigen-presenting cells, leading to the proteolytic processing and secretion of a proinflammatory cytokine, interleukin-1β (IL-1β). The activation of this signaling axis is independent of phagolysosome-cathepsin B pathway. Instead, Ni2+ induces mitochondrial reactive oxygen species accumulation and cation fluxes, both of which are required for activating the NLRP3-ASC-caspase-1 pathway. Together, these results identified a novel innate immune signaling pathway (NLRP3-ASC-caspase-1-IL-1β) activated by Ni 2+ and provided a mechanistic basis for optimizing the therapeutic intervention against Ni2+-induced allergy in patients. © 2013 Springer Science+Business Media New York. Source


Dou C.-X.,Yanshan University | Liu B.,University of Sydney | Liu B.,Hunan University of Technology
International Journal of Electrical Power and Energy Systems | Year: 2014

Due to an increased penetration of distributed energy resources, as well as more uncertain operating environment, etc., present distribution power system is facing many challenges. For improving the performance regarding dynamic stability, self-healing, security, as well as economical and environmental benefit, this paper proposes a hierarchical management and control strategy for the high-penetrated distribution grid based on multi-agent systems structure via intelligent switching of operating mode. Corresponding to the complex hybrid behaviors, the hierarchical control scheme is designed as a three-level decentralized coordinated hybrid control. The simulation studies certify that the hierarchical hybrid control is effective and feasible to deal with comprehensive problems of high-penetrated distribution grids. © 2013 Elsevier Ltd. All rights reserved. Source


Jing X.-L.,Yanshan University
Shiyou Diqiu Wuli Kantan/Oil Geophysical Prospecting | Year: 2010

Regarding the data picking-up difficulty when using seismic reflection travel-time tomography in velocity modeling for complex media, the theoretical analysis of the cause for the difficulty is conducted in this paper. The author believes that the introduction of the reflection horizon in modeling description caused the difficulty. In order to overcome the difficulty the new modeling description method and inversion object function were applied in this paper, seismic wave propagation direction and travel time were taken as the input for the inversion, the picked-up seismic wave propagation direction was used to constrain the ray path, so the uniqueness of the ray path was assured, at last it was not needed to define the seismic reflection horizon for the model. In order to validate the effectiveness of the new method, test calculation was carried out with Marmousi model, the test results show that the new method can in a certain extent overcome the difficulty which is often encountered in velocity modeling in complex media. Source


Wang J.,Yanshan University | Wang W.,University of Science and Technology Beijing
Zhongguo Jixie Gongcheng/China Mechanical Engineering | Year: 2010

For the no-wait flow shop scheduling problem with a delivery time window to minimize the punishment of the E/T, a constraint satisfaction model was established, and a algorithm was proposed based on constraint propagation and neighborhood search. Firstly, an initial scheduling was generated using heuristic method embedded constraint propagation. Secondly, a swap search based on neighborhood structure was designed for iterate operation, in order to avoid falling into local optimum, a disturbance strategy based on dynamic swap was used. The simulation results show the effectiveness of the algorithm. Source


Hua C.-C.,Yanshan University | Liu X.P.,CarletonUniversity
IEEE/ASME Transactions on Mechatronics | Year: 2013

The control design problem is investigated for network-based teleoperation systems under the condition of asymmetric and time-varying delays. The classic teleoperation model is considered forwhich the position of the master is transmitted to the slave site as the control command and the slave torque is directly transmitted to the master in order for the user to have a feeling of the remote interaction. The slave controller is constructed based on the master-slave position error plus a new nonlinear damping function, while the master controller is composed of the transmitted slave torque and the introduced nonlinear damping function. By employing a new Lyapunov Krasovskii functional, we prove the exponential input-to-state stability of the closed-loop system. The relationship is built among the control design parameters and the maximum allowable time delays, which is in the form of linear matrix inequality. Both the simulations and experiments are performed to show the effectiveness of the proposed method. Comparedwith existing approaches, transmission delays considered are both time varying and asymmetric, and the passivity conditions on the remote environment and the human operator are removed. In addition, the method is very simple. © 2012 IEEE. Source


Liu J.,Yanshan University
Journal of Computers (Finland) | Year: 2013

In this paper we described the process of generating a high-dimensional hyperchaos in signal communication and computer chaotic encryption. We found out four new high-dimensional complex hyperchaotic systems and three regular ways to generate highdimensional hyperchaotic systems. Then we revealed the relationship between the low-dimensional chaos and highdimensional hyperchaos and studied the features of phase space maps and Lyapunov exponents maps of highdimensional complex hyperchaotic system. The results of theoretical analysis and experiment show that the new highdimensional complex hyperchaotic system have strong chaotic features. © 2013 ACADEMY PUBLISHER. Source


Xu S.,Northeast Petroleum University | Li F.,Yanshan University
Advanced Materials Research | Year: 2013

On the base of summarizing and contrasting the objectives of sequencing problem in mixed model assembly lines (MMAL), and in consideration of the influence sequence-dependent setup times, a objective is proposed to minimize the total unfinished works and idle times over all jobs and stations, And the corresponding model is presented. To solve this model, a modified genetic algorithm is proposed to determine suitable sequences. Comparing with the Lingo 9 software, the proposed GA turns out to have a good ability to solve the sequencing problems.© (2013) Trans Tech Publications, Switzerland. Source


Si Y.,Yanshan University
ICIC Express Letters | Year: 2014

An E-commerce protocol formal analysis method based on Colored Petri Net is proposed which improves the timeliness disadvantage in the existing CPN methods. The method can analyze three important security properties of E-commerce protocols: accountability, fairness and timeliness. In order to analyze timeliness, status color set is established which represents whether an entity successfully receives messages or not, timeliness color set is established which represents the entity's self-defined time factor, and full consideration of timeliness effects on fairness is given in order to analyze more accurately. After giving the method, KZG protocol is taken as an example, the corresponding hierarchical CPN model is established and simulated by CPN Tools, and the analysis of protocol's property using state space and query function shows that the proposed method is correct and effective. © 2014 ISSN 1881-803X. Source


The study of innovation performance helps to complete the measure of development ability of venture enterprise for college students. The study builds models of Stochastic Frontier Analysis on innovation performance of college students' venture enterprise by setting up Variable quantity and putting forward a hypothesis. This paper sampled 20 historical data about college students' venture enterprise, employed statistic software to measure and analyzes and brought forward some strategies in developing innovation performance in the process of starting new work for college students. Conclusion is reached that the innovation performance of new venture enterprises generally promotes with the development of enterprises and that the innovation performance of different professions is influenced by such factors as scale, field and economy. Media enterprises, concerned about by college students, have better innovation performances but have bigger risk, machinery industry has worse innovation performance but more stable condition, light industry is between them. © 2012 ACADEMY PUBLISHER. Source


Li X.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2012

Chromatography of fingerprint as an important tool has been used in identification and quality control of herbal medicines, and it is gaining more and more attention. Among the various methods, chromatography gradually becomes the mainstream for its characteristics. This paper describes the techniques of chromatography of fingerprint including pretreatments for sample data set, the establishment of chromatographic fingerprint and fingerprint visualization. It emphasizes several analysis methods and their scope of application. Visualization technology combined with fingerprint makes analysis more intuitive. Finally, existing key problems and future works were also discussed. Source


Hou Y.,Yanshan University
Digital Scholarship in the Humanities | Year: 2015

This study is designed to analyze the use of nominalization in English translations of Chinese literary prose based on eight English translations of Chinese novels. It follows 'Lees, R. (1963). The Grammar of English Nominalizations. The Hague: Mouton' in defining English nominalization as a nominalized transform of a finite verbal form and 'Mathesius, V. (1975). Selected Writings in English and General Linguistics. The Hague: Mouton' theory of 'complex condensation of the sentence'. It describes English nominalization from the formal-syntactic level as adverbial, in the positions of subject and object, condensing a finite clausal structure. In the qualitative analysis, various effects of the use of nominalization are described based on three English versions of the Chinese classic novel Hong Lou Meng. In the quantitative analysis, three general patterns of the use of nominalization are found in the eight English translations of Chinese novels: it is predominantly used as adverbial (as opposed to in the positions of object and subject), in the form of gerundive nominalization (as opposed to derived and zero-derived nominalizations), and in the narrative (as opposed to dialogues). In comparison with nominalization used in some English novels, it is found that nominalization is significantly more used in the English translations of Chinese novels at large. © The Author 2013. Published by Oxford University Press on behalf of EADH. Source


Yang X.,Taiyuan University of Science and Technology | Xiao H.,Yanshan University | Chen Z.,Chongqing University
Yingyong Lixue Xuebao/Chinese Journal of Applied Mechanics | Year: 2014

Due to the strong non-linearity of roll bearing contact problem, the Boundary Element Method (BEM) is used to study the roll bearing contact problem. Bearing boundary elements are used to simulated the bearing contact elements, and the Hertz contact theory is used to revise the contact widths of rollers with inner race and outer race in the bearing BEM. According to the assemble and fit characteristics of mill conical roller bearings, both loose fits are adopted to the inner race with the roll and the outer race with the block, the program of bearing BEM for the four-bodies elastic contact with friction is compiled, with which a mill four-row conical roller bearing is simulated. According to the results, the small ends of the conical rollers bear the larger pressure and the pressure on the ends is lager by far than the pressure on the middle. The direction of axial pressure on the rollers is consistent with the conicity of the rollers and the maximum pressure occurs in the mill roll side on the first-row rollers. The distribution law of the contact widths of the rollers is consistent with the radial load on the rollers and the radial pressure distribution on non-bearing contact area corresponds to the location of the rollers bearing load. The numerical example illustrates the viability and accuracy of the algorithm . Source


Cui F.,Yanshan University
Gaojishu Tongxin/Chinese High Technology Letters | Year: 2015

Considering that color face images contain much more identification information than gray face images, the chroma Mahalanobis distance map was introduced into color face recognition, and a color face recognition algorithm based on the adaptive fusion of chroma and luminosity features was proposed. The algorithm separates the chroma and luminosity information of color face images based on the YDbDr color space to construct Mahalanobis distance maps based on chroma information, and extracts the luminosity information based gray maps from orignal color facial images by separation; constructs the recognition features of color face images through the adaptive fusion of chroma and luminosity features; constructs and fuses the optimum feature discrimintion vectors of chroma and luminosity maps in the real domain and the complex domain respectively by using the feature representation method based on the energy of wavelet packet sub-nodes to achieve the optimal chroma feature-luminosity feature complementation; and uses the classifier based on the variance similarity degree to obtain the face recognition results. The experimental results show that the proposed algorithm has the higher recognition rate and the better robustness. ©, 2015, Inst. of Scientific and Technical Information of China. All right reserved. Source


Li Z.,Yanshan University | Li X.,Beijing Normal University
PLoS ONE | Year: 2013

Estimating the causal interaction between neurons is very important for better understanding the functional connectivity in neuronal networks. We propose a method called normalized permutation transfer entropy (NPTE) to evaluate the temporal causal interaction between spike trains, which quantifies the fraction of ordinal information in a neuron that has presented in another one. The performance of this method is evaluated with the spike trains generated by an Izhikevich's neuronal model. Results show that the NPTE method can effectively estimate the causal interaction between two neurons without influence of data length. Considering both the precision of time delay estimated and the robustness of information flow estimated against neuronal firing rate, the NPTE method is superior to other information theoretic method including normalized transfer entropy, symbolic transfer entropy and permutation conditional mutual information. To test the performance of NPTE on analyzing simulated biophysically realistic synapses, an Izhikevich's cortical network that based on the neuronal model is employed. It is found that the NPTE method is able to characterize mutual interactions and identify spurious causality in a network of three neurons exactly. We conclude that the proposed method can obtain more reliable comparison of interactions between different pairs of neurons and is a promising tool to uncover more details on the neural coding. © 2013 Li, Li. Source


Wang Z.-B.,Yanshan University | Wang Z.-G.,North China Electrical Power University
International Journal of Theoretical Physics | Year: 2016

In this article, we calculate the contributions of the condensates up to dimension-6, including the one-loop corrections to the quark condensates, in the operator product expansion in a consistent way, and study the masses and decay constants of the heavy pseudoscalar mesons with the thermal QCD sum rules. We reproduce the experimental values of the masses of the D, Ds, B and Bs and obtain the decay constants at zero temperature. Then we study the thermal behaviors of the masses and decay constants, which are useful in explaining the heavy-ion collision experiments. © 2016, Springer Science+Business Media New York. Source


Liu J.,Yanshan University
International Journal on Smart Sensing and Intelligent Systems | Year: 2013

In this paper, a new type of steel-concrete composite member, concrete-filled core steel tube with outer angle steel plank reinforced concrete stub column, is proposed and a series of nonlinear 3- D(three-dimensional) full-range numerical calculations under axial compression are carried out, some important factors are analyzed, such as the strength of the concrete, the steel tube and the angle steel, the volume ratio of the steel tube and the angle steel to the overall column, position coefficient(the ratio of the diameter of the core steel tube to the overall width of the column section). RBFNNs(Radial Basis Function Neural Networks) are employed for calculated the loading capacity of the concrete-filled core steel tube with outer angle steel plank reinforecd concret stub columns under axial compression, and the prediction results based on RBFNNS are compared with theoretical formula calculation results. The maximum and minimum error ratio of prediction is 12.32% and 4.17%, respectively. Source


Cheng Y.,Yanshan University
Information Technology Journal | Year: 2011

An evaluation indicator system for enterprise scientific information services can be use to guide the development directions of enterprise information services and to provide theoretical support for the government and industrial management. This evaluation indicator system is constructed according the present status of Chinese enterprise information services, by integrating scientific and practicality, integrating quantity, according to the comparability principle, by using hierarchical analysis method and considering the four aspect of information awareness and mechanism, financial investment and service facilities, in formation resource development and device effects. © 2011 Asian Network for Scientific Information. Source


This paper studied the relationship between the management characteristics and the earnings forecast disclosure willingness within Chinese listed companies. Management characteristics were being defined and summarized as four aspects: structure characteristics, incentive characteristics, background characteristics and external governance mechanism. The Logistic regression model was applied to carry out an empirical analysis on the effect of specific variables of management characteristics on the earnings forecast disclosure willingness. The results show that the board size, managers' changes, asset-liability ratio and managers' stockholdings are the major factors. The board size relates with the earnings forecast disclosure willingness significant negative; manager's changes, assetliability ratio and managers' stockholdings relate with the earnings forecast disclosure willingness significant positive. Other variables of management characteristics have no significant influence. © 2012 ACADEMY PUBLISHER. Source


Zhang F.X.,Yanshan University | Zhang F.X.,University of Michigan | Lang M.,University of Tennessee at Knoxville | Ewing R.C.,Stanford University
Applied Physics Letters | Year: 2015

Gd2Zr2O7 pyrochlore with different degrees of cation disorder were synthesized by isothermal annealing at various temperatures (1100-1550°C), and the related changes in the structure were investigated by ambient and high pressure x-ray diffraction (XRD) measurements. Unit cell parameters increase almost linearly with increasing treatment temperature. The degree of cation order in pyrochlore also increases with the increase of temperature, but saturates at ∼60%. The compressibility of the pyrochlore structures decreases when the degree of cation order increases. High pressure XRD measurements also indicate that the phase stability of Gd2Zr2O7 is not very sensitive to the degree of atomic disorder in the pyrochlore structure. © 2015 AIP Publishing LLC. Source


Hui Z.,Yanshan University
Journal of Computers | Year: 2012

The mathematical model of an two-phases-service M/M/1/N queuing system with the server breakdown and multiple vacations was realized and established in the Graduate Employment Services system. Secondly, equations of steady-state probability were derived by applying the Markov process theory. Then, we obtained matrix form solution of steady-state probability by using blocked matrix method. Finally, some performance measures of the system such as the expected number of users in the system and the queue were also presented. © 2012 ACADEMY PUBLISHER. Source


Liu D.,Yanshan University
Applied Surface Science | Year: 2016

Recently, it has been reported that the reaction selectivity of catalytic hydrogenation of acetylene to ethylene can be significantly enhanced via the approach of Pd mono-atomic catalysis [Pei et al. ACS Catal. 5 (2015) 3717-3725]. To explain the catalytic mechanism of this binary alloy catalyst, C2H2 hydrogenation reactions on Pd doping Ag nanoclusters are studied using density functional theory simulations. The simulation results indicate that H2 and C2H2 can simultaneously bind with a single Pd doping atom no matter it is on vertex and edge sites of Ag clusters. The following H2 dissociation and C2H2 hydrogenation are not difficult since the corresponding reaction barrier values are no more than 0.58 eV. The generated C2H4 molecule can not be further hydrogenated since it locates on the top of Pd doping atom, which is the only adsorption site for H2. On two Pd doping atoms at contiguous sites of Ag clusters, C2H4 hydrogenation reactions can be carried out since there are enough sites for co-adsorption of H2 and C2H4. © 2016 Elsevier B.V. All rights reserved. Source


Chen Y.-J.,Harbin Engineering University | Zhang F.,Harbin Engineering University | Zhao G.-G.,Heilongjiang Institute of Science and Technology | Fang X.-Y.,Yanshan University | And 5 more authors.
Journal of Physical Chemistry C | Year: 2010

Fe3O4/ZnO core/shell nanorods are successfully fabricated by combing an inorganic-phase reaction with a hydrogen annealing process. The transmission electron microscopy analysis indicates that the diameter and the length of the core/shell nanorods are 25-80 and 0.35-1.2 μm, respectively. Electromagnetic properties of the core/shell nanorod-wax composites are investigated. The permittivity of the composites shows four dielectric resonant peaks in 2-18 GHz, which can be explained by the transmission line theory. The resonant behavior mainly results from interface polarization induced by the special core/shell structures, dipole polarization of both Fe3O4 and ZnO, and electron transfer between Fe2+ and Fe3+ ions in Fe3O4. The maximum reflection loss is about -30 dB at 10.4 GHz for the composites with a thickness of 1.5 mm, and the absorption bandwidth with the reflection loss below -20 dB is up to 11 GHz for an absorber with the thickness in 2-4 mm. Thus, our results demonstrate that the Fe3O4/ZnO core/shell nanorods are attractive candidates for a new kind of the electromagnetic wave absorptive materials. © 2010 American Chemical Society. Source


Chen Z.,Chongqing University | Xiao H.,Yanshan University
Computational Mechanics | Year: 2012

Fast multipole boundary element methods (FMBEMs) are developed based on the couple of fast multipole algorithm and generalized minimal residual algorithm. The FMBEMs improve the efficiency of conventional BEMs, accelerate the computing, enlarge the solving scale, and it is applied in various engineering fields. The paper tried to do a brief reviewfor the FMBEMs, and focus on the description of basic principles and applications in rolling engineering. The basic principles and main frameworks of two typical methods of FMBEMs (sphere harmonic function multipole BEM and Taylor series multipole BEM) are briefly described, and then the key numerical iterative and preconditioning techniques suitable for the FMBEMs are introduced. The typical numerical examples are presented, including the elasticity problems, the elastic contact problems and the elastoplasticity problems, etc. The validity and effectiveness of FMBEMs are effectively illustrated by engineering analysis examples. The numerical results suggest that the FMBEMs are suitable for the analysis and solution of large scale rolling engineering problems. The implementation process of numerical analysis can provide useful reference for the applications in other engineering fields. Source


Li Z.,Yanshan University
Shiyou Xuebao/Acta Petrolei Sinica | Year: 2016

Tubular strings are considered as the backbone and central nervous system for oil drilling and production operations in oil and gas wells. Tubular mechanics in oil and gas wells is the most important basic and applied science in petroleum and natural gas engineering. In this study, the monographs on tubular mechanics, the scholars engaged in this field and relevant research methods were introduced and some basic concepts were clarified firstly. Then, this study focuses on the research advances and debates on the fundamental principles and basic equations of tubular mechanics, the motion states, stability and steady state tension-torque of tubular strings, the 3D mechanical analysis of bottom hole assembly, the dynamic analyses of drill strings, the mechanical analyses, casing strings, testing strings and fracturing water injection/steam injection tubular strings, the diagnosis, parameter optimization and energy saving of rod pumping system, the vibration of gas production tubular strings, the impact vibration of strings, the mechanical analyses of swelling screen pipe/casing and riser strings, the propagation of vibration wave signals in strings, as well as string wear, corrosion and erosion, and the residual strength and fatigue strength forecast of strings. Finally, the key directions for future research are prospected. © 2016, Science Press. All right reserved. Source


Li Z.,Yanshan University
Open Petroleum Engineering Journal | Year: 2013

Pipes are under the trial of internal and external pressure of fluid in oil well drilling and production. Changes of internal and external pressure of fluid may affect equivalent axis force using for stability analysis of pipes in some cases. Errors in traditional mechanical model and fictitious force are discussed. Mechanical model representing true tubular conditions is established. Internal and external pressure of fluid and its changes have no effects on the stability of hanging pipes. Changes in internal and external pressure of fluid show effects on equivalent axis force and stability of pipes fixed at two ends. Equations for calculating equivalent axis force are established depending on constant axis strain. For pipes fixed at two ends, equivalent axis force decreases when internal pressure increases, equivalent axis force increases when external pressure increases; increase of internal pressure and decrease of external pressure may make equivalent axis force negative, even less than critical buckling force. © Zifeng Li. Source


Li J.,Yanshan University | Li J.,Shanghai JiaoTong University | Li Z.,Shanghai JiaoTong University | Chen J.,Shanghai JiaoTong University
Applied Intelligence | Year: 2011

This paper introduces the path planning of a 1 cm3 mobile microrobot that is designed for microassembly in a microfactory. Since the conventional path planning method can not achieve high microassembly positioning accuracy, a supervised learning assisted reinforcement learning (SL-RL) method has been developed. In this mixed learning method, the reinforcement learning (RL) is used to search a movement path in the normal learning area. But when the microrobot moves into the buffer area, the supervised learning (SL) is employed to prevent it from moving out of the boundary. The SL-RL uses a gradient descent algorithm based on uniform grid tile coding under SARSA(?) to handle the large learning state space. In addition to the uniform grid tile model, two irregular tile models called an uneven grid tile model and a cobweb tile model are designed to partition the microrobot state space. The main conclusions demonstrated by simulations are as follows: First, the SL-RL method achieves higher positioning accuracy than the conventional path planning method; second, the SL-RL method achieves higher positioning accuracy and learning efficiency than the single RL method; and third, the irregular tile models show higher learning efficiency than the uniform tile model. The cobweb tile model performs especially well. © Springer Science+Business Media, LLC 2009. Source


Wang S.R.,Yanshan University | Jia H.H.,Chengde Petroleum College
Applied Mechanics and Materials | Year: 2012

Under low stress conditions, when the load exerting on the mined-out areas roof is less than the rock long-term strength, the rock roof will generate some creep deformation. In order to prevent the roof of the mined-out areas suddenly collapse, and to ensure the operator and construction equipment above the mined-out areas safety, it is an important security technical problem to reveal the creep characteristics of the shallow mined-out areas roof. Taking the mined-out areas of Antaibao Surface Mine as background, considering the rheological properties of rock roof, and assuming the roof was a rectangular thick plate, the creep characteristics of mined-out areas roof were analysed by applying the thick plate theory and Kelvin creep model. The regression equation of the roof deflection increment over time was given, and the creep characteristics of the shallow mined-out areas roof were revealed also. The above results can provide a theoretical basis to ensure the surface mine safety construction, which has some reference to similar engineering. © (2012) Trans Tech Publications. Source


Zhang P.,Dalian University of Technology | Zhao J.,Dalian University of Technology | Qin Y.,Dalian University of Technology | Wen B.,Dalian University of Technology | Wen B.,Yanshan University
Journal of Nuclear Materials | Year: 2011

We report the energetics, stability, and diffusion behavior of helium (He), vacancies (V), and helium-vacancy complex clusters HenVm (n, m = 0-4) in vanadium solid from first-principles calculations. For He, vacancy site is more energetically favorable than tetrahedral interstitial by ∼0.74 eV, while hydrogen always prefers to stay in tetrahedral sites in vanadium. He exhibits a low migration energy (0.06 eV) and can be easily trapped in vacancy. A nearly linear relationship between formation energy and the number of He or vacancy is obtained for He or vacancy clusters, and the weak binding energies of He clusters indicate that He clusters themselves are unstable. The binding energies and dissociation energies of He and vacancy to helium-vacancy complex clusters are computed and compared well with the experimental observation from helium desorption spectra. The cluster stability depends on He content. Finally, He diffusion coefficients are predicted to be (1.07-1.27) × 10-8 m2 s-1 at typical temperatures of 600-800 K. We thus propose that He aggregation via vacancy trapping should be the main mechanism for He bubble formation. © 2011 Elsevier B.V. All rights reserved. Source


Li Y.,Tsinghua University | Li Y.,Yanshan University | Fu L.,Tsinghua University | Zhang S.,Tsinghua University | And 2 more authors.
Energy Conversion and Management | Year: 2011

A new type of district heating (DH) method based on Co-ah cycle was designed to improve both the capacity of heating system and the energy efficiency of Cogeneration plant. In the DH system substations, the temperature of return water of the primary heat network is reduced to about 25 °C through the absorption heat-exchange units. In the thermal station of the Cogeneration plant, the return water of the primary heat network is heated orderly by the exhaust steam in the condenser, the absorption heat pumps and the peak load heater. Compared with the traditional DH methods, this system runs with a greater circuit temperature drop so that the delivery capacity of the heat network increases dramatically. The heating capacity and the energy efficiency of the Cogeneration plant is significantly increased by the exhausted heat recovery from the condensers. A remarkable economic advantage can be achieved in this technology. At present, an application demonstration project had been built up in Chifeng city of Inner Mongolia Autonomous Region in north China. © 2010 Elsevier Ltd. All rights reserved. Source


Bian L.,Yanshan University | Bian L.,Dalhousie University | Taheri F.,Dalhousie University
Materials and Design | Year: 2011

In the present paper, the crack initiation and propagation in rectangular magnesium alloy plates containing an inclined through crack are investigated experimentally and theoretically. Based on the complex stress state at the crack tip, a maximum ratio criterion is developed to determine the crack propagation for a given inclination angle by means of an opening mode theory. It is assumed that the crack begins to propagate when the maximum value of ratio approaches its critical value, and the direction of crack propagation coincides with the direction of maximum ratio defined. The experiments for checking the theoretical predictions from the proposed criterion have been conducted. The material properties and fracture characteristics are evaluated during the tests. The results obtained are compared with those obtained using the commonly employed fracture criteria and the experimental data. © 2010 Elsevier Ltd. Source


Zhao W.,Henan Polytechnic University | Huang D.,Henan Polytechnic University | Hu Z.Q.,Yanshan University
Key Engineering Materials | Year: 2011

Analysis of BTA deep hole drilling bar on Liquid-Solid Coupled Vibration model, there are vortex and unstability on bending deformation of the rotating boring drilling bar induced by cutting fluid force. At first, the rotating fluid force inside the boring bar was expressed linear physical form, and it's stiffness and damping coefficients were derived by the unsteady reynolds dynamic equation of the fluid. Then establish conditions including eddy and mechanical mechanism of the boring bar by cutting fluid force. The results of analysis show that the solution on coupled vibration model are more accurate than the other vibration model. Coriolis effect is the main reason for eddy or unstability of the deep hole boring bar induced by cutting fluid internal the drilling bar's wall. Some rules are also derived with which cutting parameters can be selected reasonably, which is coincide with the parameters used in heavy machine building industry. Source


Zhang P.,Dalian University of Technology | Zhao J.,Dalian University of Technology | Wen B.,Dalian University of Technology | Wen B.,Yanshan University
Journal of Physics Condensed Matter | Year: 2012

The microscopic mechanism for H and He trapping by vacancy defects and bubble formation in a Be host lattice is investigated using first-principles calculations. A single He atom prefers to occupy a vacancy centre while H does not. He can segregate towards the vacancy from the interstitial site much more easily than H. Both H and He exhibit lower diffusion barriers from a remote interstitial to a vacancy with regard to their diffusion barriers inside a perfect Be solid. Up to five H or 12 He atoms can be accommodated into the monovacancy space, and the BeHe interaction is much weaker than BeH. The physical origin for aggregation of multiple H or He atoms in a vacancy is further discussed. The strong tendency of H and He trapping at vacancies provides an explanation for why H and He bubbles were experimentally observed at vacancy defects in materials. We therefore argue that vacancies provide a primary nucleation site for bubbles of H and He gases inside Be materials. © 2012 IOP Publishing Ltd. Source


Wang G.W.,Beijing Institute of Technology | Xu T.Z.,Beijing Institute of Technology | Feng T.,Yanshan University
PLoS ONE | Year: 2014

In this paper, using the Lie group analysis method, we study the invariance properties of the time fractional fifth-order KdV equation. A systematic research to derive Lie point symmetries to time fractional fifth-order KdV equation is performed. In the sense of point symmetry, all of the vector fields and the symmetry reductions of the fractional fifth-order KdV equation are obtained. At last, by virtue of the sub-equation method, some exact solutions to the fractional fifth-order KdV equation are provided. © 2014 Wang et al. Source


Guo X.,Yanshan University | Cavalcanti M.C.,Federal University of Pernambuco | Farias A.M.,Federal University of Pernambuco | Guerrero J.M.,University of Aalborg
IEEE Transactions on Power Electronics | Year: 2013

Modulation strategy is one of the most important issues for three-level neutral-point-clamped inverters in three-phase transformerless photovoltaic systems. A challenge for modulation is how to keep the common-mode voltages constant to reduce the leakage currents. Asingle-carrier modulation strategy is proposed. It has a very simple structure, and the common-mode voltages can be kept constant with no need of complex space-vector modulation or multicarrier pulsewidth modulation. Experimental results verify the theoretical analysis and the effectiveness of the presented method. © 2013 IEEE. Source


Yang Y.,Yanshan University
Proceedings - 2014 IEEE Workshop on Advanced Research and Technology in Industry Applications, WARTIA 2014 | Year: 2014

At present, countries around the world attach great importance to college students' employment. The employment of university graduates has also been a focus of social attention. Playing the advantages of university students hunting for a job on the Internet, on constructing and developing online self-employment service and employment information service and improving the employment information degree are the trend of the reform of college employment. The employment mode has changed from distribution to the mode of 'independent career, two-way choice'. With the change of the college employment modes, employment informatization is put to the agenda. © 2014 IEEE. Source


Ying J.,Yanshan University
Electronic Journal of Geotechnical Engineering | Year: 2012

The finite element-element free Galerkin coupling method (FEM-EFGM) is used to analyze soil-pile interaction under seismic liquefaction. This method establishes governing equations between finite elements and gridding nodes by contact elements. It can avoid computation break caused by element distortion when using finite element method, then the whole liquefaction process will be simulated. Varieties of excess pore water pressure in liquefying soil and deformations of the pile are computed under different kinds of soils and earthquake accelerations. The specific numerical results and analysis conclusions would be helpful in aseismic engineering. © 2012 ejge. Source


Voss L.J.,Waikato District Health Board | Baas C.H.,Linkoping University | Hansson L.,Linkoping University | Li D.,Yanshan University | Sleigh J.W.,University of Auckland
Brain Research | Year: 2013

How general anaesthetic drugs cause unconsciousness is a topic of ongoing clinical and scientific interest. It is becoming increasingly apparent that they disrupt cortical information processing, but the effects appear to depend on the spatial scale under investigation. In this study we investigated whether the intravenous anaesthetic etomidate synchronises neuronal activity on a sub-millimetre scale in mouse neocortical slices. In slices generating no-magnesium seizure-like event (SLE) field activity, we analysed the morphology of field potential activity recorded with 50 μm extracellular electrodes. The analysis was based on the understanding that the amplitude and sheerness of field potential oscillations correlates with the synchrony of the underlying neural activity. When recorded from the region of the slice initiating SLE activity, etomidate consistently increased both population event amplitude (median(range) 85(24-350) to 101(30-427) μV) and slope 16.6(1.5-106.2) to 20.2(1.7-111.1) μV/ms (p=0.016 and p=0.0013, respectively). The results are consistent with an increase in neuronal synchrony within the receptive field of the recording electrode, estimated to be a circle diameter of 300 μm. In conclusion, the neocortical slice preparation supports in vivo data showing that general anaesthetics increase neuronal synchrony on a local scale and provides an ideal model for investigating underlying mechanisms. © 2013 Elsevier B.V. All rights reserved. Source


Li C.H.,Beijing University of Technology | Cao L.B.,Beijing University of Technology | Su J.G.,Beijing University of Technology | Su J.G.,Yanshan University | And 2 more authors.
Proteins: Structure, Function and Bioinformatics | Year: 2012

Understanding the key factors that influence the preferences of residue-nucleotide interactions in specific protein-RNA interactions has remained a research focus. We propose an effective approach to derive residue-nucleotide propensity potentials through considering both the types of residues and nucleotides, and secondary structure information of proteins and RNAs from the currently largest nonredundant and nonribosomal protein-RNA interaction database. To test the validity of the potentials, we used them to select near-native structures from protein-RNA docking poses. The results show that considering secondary structure information, especially for RNAs, greatly improves the predictive power of pair potentials. The success rate is raised from 50.7 to 65.5% for the top 2000 structures, and the number of cases in which a near-native structure is ranked in top 50 is increased from 7 to 13 out of 17 cases. Furthermore, the exclusion of ribosomes from the database contributes 8.3% to the success rate. In addition, some very interesting findings follow: (i) the protein secondary structure element π-helix is strongly associated with RNA-binding sites; (ii) the nucleotide uracil occurs frequently in the most preferred pairs in which the unpaired and non-Watson-Crick paired uracils are predominant, which is probably significant in evolution. The new residue-nucleotide potentials can be helpful for the progress of protein-RNA docking methods, and for understanding the mechanisms of protein-RNA interactions. © 2011 Wiley Periodicals, Inc. Source


Li A.,Kyushu University | Li A.,Yanshan University | Uchimura T.,Kyushu University | Watanabe-Ezoe Y.,Kyushu University | Imasaka T.,Kyushu University
Analytical Chemistry | Year: 2011

Dioxins in a soil sample were measured using gas chromatography/resonance- enhanced multiphoton ionization/time-of-flight mass spectrometry coupled with different types of laser sources. The fourth-harmonic emission (266 nm) of a nanosecond Nd:YAG laser (1 ns) provided low ionization efficiency, especially for highly chlorinated dioxins/dibenzofurans (CDDs/CDFs). The ionization efficiency was improved using the fourth-harmonic emission (266 nm) of a picosecond Nd:YAG laser (4 ps), due to shorter singlet excited-state lifetimes. It was, however, difficult to efficiently ionize hepta-CDD and octa-CDD/CDF, because of their shorter lifetimes, which were induced by stronger spin-orbit coupling that led to efficient relaxation of the excited molecule to triplet levels. The ionization efficiency was substantially improved using the fifth-harmonic emission (213 nm) of the picosecond Nd:YAG laser (4 ps), in which the analyte molecule that was relaxed to triplet levels was efficiently ionized using a photon with sufficient energy for ionization, although the pulse energy obtained at 213 nm was only one-third of the pulse energy obtained at 266 nm. The limits of detection achieved for 17 toxic polychlorinated dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs) were 0.41-45 pg. The analytical instrument developed in the present study performed sufficiently well for the practical trace analysis of dioxins in soil samples. © 2010 American Chemical Society. Source


Jin H.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2011

This article introduces some commonly used methods of ozone concentration detection, including chemical method, UV absorption method, and electrochemical method etc., introduces the latest four ozone concentration sensors, and summarizes the advantages and disadvantages of each method. In addition, the article emphatically introduces the ozone's applications and development in the medical aspects. Prospects for the use of ozone concentration detection, ozone treatment and ozone therapy instrument are also demonstrated in it. The literature collected and reviewed on ozone concentration detection and ozone therapy includes 37 papers in English, and 50 papers in Chinese, but only 30 articles among them are included in this review (19 in Chinese and 11 in English), according to the principle of eliminating the old information and repetitive contents. The present paper selects only those on ozone, ozone concentration, ozone therapy and ozone therapy instrument. Source


Zhao D.,Yanshan University | Zhao D.,Dalian University of Technology | Li H.,Dalian University of Technology
Smart Materials and Structures | Year: 2010

The seismic response reduction of the semi-active fuzzy control system including a new type of piezoelectric variable-friction damper and fuzzy controller was investigated on the shaking table under various earthquake records for a building model. The performance of the piezoelectric actuator under different preloads was tested in advance to identify its force generation. The feature test of the damper under either constant or linear increased voltage was carried out to study its motion characteristics. Based on the experimental tests of the damper, a semi-active fuzzy control algorithm was presented for the real-time manipulation of the damper according to the structural response. The seismic performance of the building structural model was tested for the uncontrolled, passive-controlled and semi-active controlled cases. The semi-active control effectiveness of the damper was compared with other cases. Experimental results have indicated that the proposed semi-active control system based on the fuzzy controller and piezoelectric variable-friction damper can be more efficient in reducing the inter-storey drifts and accelerations of the building under various earthquake excitations. © 2010 IOP Publishing Ltd. Source


Dou C.-X.,Yanshan University | Liu B.,Australian National University | Liu B.,Hunan University of Technology
International Journal of Electrical Power and Energy Systems | Year: 2012

For the purpose of improving comprehensive performance including stability, security and economic benefit of power system, in this study a two-level hierarchical hybrid control is proposed in a real-time manner. First, a novel hybrid model is founded to clearly explain the hybrid dynamical behaviors of the power systems. On the basis of the model, a hybrid control scheme is designed in an interaction manner between the discrete control strategies at the upper level and the continuous dynamical controls at the lower level. The upper level discrete control strategies are responsible for converting operating modes to guarantee the security during significant disturbances and the economic benefit of overall system. After locating operating modes, the lower level local continuous controllers are responsible for regulating dynamic behavior of each controlled unit to obtain the satisfactory stability performance. The effectiveness of the proposed hybrid control is demonstrated through simulation examples. © 2012 Elsevier Ltd. All rights reserved. Source


Chen G.,Academy of Military Medical Science | You G.,Academy of Military Medical Science | Wang Y.,Academy of Military Medical Science | Lu M.,Academy of Military Medical Science | And 4 more authors.
Critical Care | Year: 2013

Introduction: This study compared the effects of hydroxyethyl starch 130/0.4, hydroxyethyl starch 200/0.5, and succinylated gelatin on oxidative stress and the inflammatory response in a rodent hemorrhagic shock model.Methods: Sodium pentobarbital-anesthetized adult male Wistar rats (200 g to 220 g) were subjected to a severe volume-controlled hemorrhage using arterial blood withdrawal (30 mL/kg to 33 mL/kg) and resuscitated with a colloid solution at the same volume as blood withdrawal (hydroxyethyl starch 130/0.4, hydroxyethyl starch 200/0.5, or succinylated gelatin). Arterial blood gas parameters were monitored. Malondialdehyde (MDA) content and myeloperoxidase (MPO) activity in the liver, lungs, intestine, and brain were measured two hours after resuscitation. The levels of tumor necrosis factor-alpha (TNF-α) and interleukin-6 in the intestine were also measured.Results: Infusions of hydroxyethyl starch 130/0.4, but not hydroxyethyl starch 200/0.5 or succinylated gelatin, significantly reduced MDA levels and MPO activity in the liver, intestine, lungs and brain, and it also inhibited the production of TNF-α in the intestine two hours after resuscitation. However, no significant difference between hydroxyethyl starch 200/0.5 and succinylated gelatin was observed.Conclusions: Hydroxyethyl starch 130/0.4, but not hydroxyethyl starch 200/0.5 or succinylated gelatin, treatment after hemorrhagic shock ameliorated oxidative stress and the inflammatory response in this rat model. No significant differences were observed after hydroxyethyl starch 200/0.5 or succinylated gelatin administration at doses of approximately 33 mL/kg. © 2013 Chen et al.; licensee BioMed Central Ltd. Source


Fang S.,CAS Beijing Institute of Geographic Sciences and Nature Resources Research | Fang S.,Chinese Academy of Sciences | Xu L.,CAS Institute of Computing Technology | Xu L.,Old Dominion University | And 6 more authors.
IEEE Transactions on Industrial Informatics | Year: 2014

Water scarcity and floods are the major challenges for human society both present and future. Effective and scientific management of water resources requires a good understanding of water cycles, and a systematic integration of observations can lead to better prediction results. This paper presents an integrated approach to water resource management based on geoinformatics including technologies such as Remote Sensing (RS), Geographical Information Systems (GIS), Global Positioning Systems (GPS), Enterprise Information Systems (EIS), and cloud services. The paper introduces a prototype IIS called Water Resource Management Enterprise Information System (WRMEIS) that integrates functions such as data acquisition, data management and sharing, modeling, and knowledge management. A system called SFFEIS (Snowmelt Flood Forecasting Enterprise Information System) based on the WRMEIS structure has been implemented. It includes operational database, Extraction-Transformation-Loading (ETL), information warehouse, temporal and spatial analysis, simulation/prediction models, knowledge management, and other functions. In this study, a prototype water resource management IIS is developed which integrates geoinformatics, EIS, and cloud service. It also proposes a novel approach to information management that allows any participant play the role as a sensor as well as a contributor to the information warehouse. Both users and public play the role for providing data and knowledge. This study highlights the crucial importance of a systematic approach toward IISs for effective resource and environment management. © 2005-2012 IEEE. Source


Zhao M.,Yanshan University
Control Engineering and Information Systems - Proceedings of the International Conference on Control Engineering and Information System, ICCEIS 2014 | Year: 2015

With the development of the wireless sensor network, the position information of sensor node plays a crucial role, and the sensor node localization has become a crucial research topic. By researching on the distributed weighted multidimensional scaling algorithm in WSN, especially the dwMDS algorithm, the SDdwMDS algorithm is proposed in this paper by applying the adaptive neighbor selection mechanism and approved Gauss kernel weighted mechanism, and introducing the steepest descent method to optimize the local cost function. Through experimental analysis, the SDdwMDS algorithm is more precise and more suitable than the dwMDS algorithm for the sensor node localization in sparse and irregular topology structure network. © 2015 Taylor & Francis Group, London. Source


Yang H.,Yanshan University | Xia Y.,Beijing Institute of Technology | Shi P.,University of Adelaide | Shi P.,Victoria University of Melbourne | Liu B.,Beijing Institute of Technology
International Journal of Adaptive Control and Signal Processing | Year: 2013

SUMMARY In this paper, the problem of guaranteed cost control for networked control systems is addressed by using delta operator Kalman filter approach. To cope with network-induced delays and packet dropout, we take into account the quality-of-service of networks. The networked control system is described as a kind of delayed Markovian jump delta operator systems. Sufficient conditions for the solvability of underlying problem are derived in terms of linear matrix inequalities. A numerical example is given to illustrate the effectiveness of the developed techniques. Copyright © 2012 John Wiley & Sons, Ltd. Copyright © 2012 John Wiley & Sons, Ltd. Source


Chen D.,Hubei University | Liu Z.,Yanshan University | Wang L.,Hubei University | Dou M.,Hubei University | And 2 more authors.
Mobile Networks and Applications | Year: 2013

The wireless sensor network (WSN) technology has applied in monitoring natural disasters for more than one decade. Disasters can be closely monitored by augmenting a variety of sensors, and WSN has merits in (1) low cost, (2) quick response, and (3) salability and flexibility. Natural disaster monitoring with WSN is a well-known data intensive application for the high bandwidth requirements and stringent delay constraints. It manifests a typical paradigm of data-intensive application upon low-cost scalable system. In this study, we first assessed representative works in this area by classifying those in the domains of application of WSNs for disasters and optimization technologies significantly distinguishing these from general-purpose WSNs. We then described the design of an early warning system for geohazards in reservoir region, which relies on the WSN technology inspired by the existing work with focuses on issues of (1) supporting reliable data transmission, (2) handling huge data of heterogeneous sources and types, and (3) minimizing energy consumption. This study proposes a dynamic routing protocol, a method for network recovery, and a method for managing mobile nodes to enable real-time and reliable data transmission. The system incorporates data fusion and reconstruction approaches to bring together all data into a single view of the geohazard under monitoring. A distributed algorithm for joint optimal control of power and rate has been developed, which can improve utility of network (> 95 %) and to minimize the energy consumption (reduction by > 20 % in comparison with LEACH). Experimental results indicate the potentials of the proposed approaches in terms of adapting to the needs of early warning on geohazards. © 2013 Springer Science+Business Media New York. Source


Zhao Q.,Yanshan University | Zhang J.,Dezhou Power Supply Company
Dianli Zidonghua Shebei/Electric Power Automation Equipment | Year: 2013

A passive lossless snubber based on magnetic coupling is proposed, which restrains the reverse recovery current and reduces the overlapping area of voltage and current during the turning-on period of switch. Therefore, the efficiency of PFC(Power Factor Correction) is enhanced and the EMI(ElectroMagnetic Interference) reduced. The energy is absorbed and transferred through the resonance of snubber inductor and capacitor. The coupled winding makes the energy of snubber inductor easy to be reset and no additional voltage stress is introduced by the snubber to the switch. The operating principle of snubber and the parameters design of key passive components are presented in detail. The experimental waveforms and efficiency comparison tests of 500 W prototype show the high efficiency of the proposed snubber. Source


Dou C.X.,Yanshan University | Liu B.,Australian National University | Liu B.,Hunan University of Technology
International Journal of Electrical Power and Energy Systems | Year: 2012

With the rapid increase in the rate of distributed generation (DG) penetration depth, the issues of improving micro-grid transient become more significant. This paper investigates a two-level hierarchical hybrid control consists of continuous local controller for each DG unit at the first level coordinated by discrete supervisory control strategies at the secondary level for transients performance enhancement of micro-grid with various DG units following pre-planned or accidental events. The discrete supervisory control strategies are established based on information fusion technique by using wide-area measurements (WAMs) in order to switch each DG subsystem into apposite operational mode following large disturbances. The continuous local controller for each DG unit is designed based on multiple Lyapunov stability theory integrating linear matrix inequality (LMI) techniques in order to regulate the set point of each DG subsystem to reach the best performance and acceptable operation indexes. The effectiveness of the proposed hybrid control is demonstrated through simulation examples. © 2012 Elsevier Ltd. All rights reserved. Source


Liu L.-Z.,Yanshan University
Advances in Information Sciences and Service Sciences | Year: 2012

In this paper, base on the data of Qinhuangdao port and Qinhuangdao GDP from 1995 to 2010, we analysis dynamic correlations between port logistics and regional economic development by vector auto-regressive (VAR) model. The results show that, Qinhuangdao port logistics and regional economic development consists of a mutual have long-term effect of dynamic linear system, but is different, that is, Goods growth is to promote the increase of the GDP throughput Granger causes, but the influence of the reverse is not significant. This shows that the port logistics development of Qinhuangdao city can improve economic growth. Source


Yan-Liang W.,Yanshan University
Advances in Information Sciences and Service Sciences | Year: 2012

Peer-to-Peer (P2P) networks define a series of rules and applications, where peers are absolutely equal. Peers can both supply server to others and consume server from others. But the efficient data retrieval in a peer-to-peer system is a challenge problem, such as freenet, which aims to provide freedom of speech through a peer-to-peer network with strong protection of anonymity. Therefore, this paper designed an enhanced cache replacement method to improve the network. After simulations, it shows this method can increase the availability and decrease the average number of hops per request. Finally, this paper test the performance of Freenet with enhance cache replacement method in stimulate network environment. The results give a reference for research on P2P networks. Source


Xu J.,Hunan University | Zhuang X.,Hunan University | Guo P.,Hunan University | Zhang Q.,Hunan University | And 10 more authors.
Nano Letters | Year: 2012

Compact wavelength-sensitive optical components are desirable for optical information processing and communication in photonic integrated system. In this work, optical waveguiding along single composition-graded CdS xSe 1-x nanowires were systematically investigated. Under a focused laser excitation, the excited light can be guided passively along the bandgap-increased direction of the nanowire, keeping the photonic energy of the guided light almost unchanged during the whole propagation. In comparison, the excited light is guided actively through incessantly repeated band-to-band reabsorption and re-emitting processes along the bandgap-decreased direction, resulting in a gradual wavelength conversion during propagation. On the basis of this wavelength-converted waveguiding, a concept of nanoscale wavelength splitter is demonstrated by assembling a graded nanowire with several composition-uniform nanowires into branched nanowire structure. Our study indicates that composition-graded semiconductor nanowires would open new exciting opportunities in developing new wavelength-sensitive optical components for integrated nanophotonic devices. © 2012 American Chemical Society. Source


Jin S.,Yanshan University | Yue W.,Konan University
Computer Networks | Year: 2011

In this paper, we present an effective method to analyze the performance of the power saving class type III initiated by the base station with unsolicited MOB-SLP-RSP or DL sleep control extended subheader in a self-similar traffic. We build a batch arrival queueing model, in which the batch size is described by a random variable following a Pareto(c, α) distribution in order to capture the self-similar property in multimedia WiMAX based on the IEEE 802.16. By using the discrete-time embedded Markov chain, we can examine and analyze the power saving class type III systems for the following items: the probability generating functions of the number of data frames and batches when the busy period begins, the queueing length, the waiting time and finally the busy cycle. With the first and higher derivatives of the probability generating functions, we can give the averages and the standard deviations for the system performance using the diffusion approximation for the operation process of the system. Next, we give the formulas for the system performance such as the energy saving ratio, the switching ratio, the system utility and the response time of data frames. Moreover, we construct a cost function with the aim of determining the optimal sleep window length that minimizes the cost function. Numerical results are provided with analysis and simulation to show the average performance measures, standard deviations and a cost function with different degrees of self-similarity and different sleep window lengths. © 2011 Elsevier B.V. All rights reserved. Source


Sun F.-Z.,Yanshan University
Applied Mechanics and Materials | Year: 2013

Internet of Things has received more and more attention, due to a wide range of potential applications. In this paper, we propose a secure data aggregation framework for the Internet of Things. It is based on fully homomorphic encryption. Moreover, this is a form of encryption where any specific algebraic operation performed on the raw sensor data is equivalent to the same algebraic operation performed on the cryptographic sensor data. © (2013) Trans Tech Publications, Switzerland. Source


Liu X.,Tianjin Polytechnic University | Xu L.Z.,Yanshan University
Applied Mechanics and Materials | Year: 2013

Dual-stator toroidal motor is a new type of motor. The basic structure and principle of the motor were introduced. The state equations of toroidal motor were presented, the response considering speed fluctuations of the motor was given as well. The objection function was given, and the optimal servo of the motor was designed. The control strategy was used to remove the speed fluctuations and realize desired speed tracking. The state feedback control scheme was obtained and the control signals were also presented. Small speed track errors were achieved and the speed fluctuations of the motor system were eliminated. The results justify the validity of the servo, and offer meaningful instruction for further research and practical application of the novel motor. © (2013) Trans Tech Publications, Switzerland. Source


Xin G.,Dalian University of Technology | Pan H.,Dalian University of Technology | Chen D.,Dalian University of Technology | Zhang Z.,Dalian Jiaotong University | Wen B.,Yanshan University
Journal of Physics and Chemistry of Solids | Year: 2013

N-doped TiO2 was synthesized by calcining a mixture of titanic acid and graphitic carbon nitride (g-C3N4) at temperatures above 500 °C. The final samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), and UV-vis diffuse reflectance spectra. The photocatalytic activity of N-doped TiO2 was studied by assessing the degradation of methylene blue in an aqueous solution, under visible light and UV light irradiation. It was found that the N-doped TiO2 displayed higher photocatalytic activity than pure TiO2, under both visible and UV light. © 2012 Elsevier Ltd. All rights reserved. Source


Guo X.,Yanshan University | Xu D.,Ryerson University | Wu B.,Ryerson University
IEEE Transactions on Power Electronics | Year: 2016

Common-mode voltage (CMV) problem is one of the most important issues for back-to-back current-source converters. In this paper, the theoretical analysis is presented to clarify that the system CMV mainly depends on the CMV difference between a rectifier and an inverter. And then, a new CMV mitigation technique is proposed. Different from the existing methods, the proposed method coordinates the active and zero vectors of both rectifier and inverter in the back-to-back current converter, instead of eliminating zero vectors or optimal selection of a zero vector. In this way, the CMV difference between a rectifier and an inverter is minimized. Consequently, the system CMV can be significantly mitigated. Finally, the experimental tests are carried out on a 10-kVA back-to-back current-source converter, and experimental results verify the effectiveness of the proposed method. © 2015 IEEE. Source


Yu J.,Yanshan University
WIT Transactions on Engineering Sciences | Year: 2014

In the age of low-carbon economy, the tourism industry needs to change its traditional development patterns and low-carbon tourism begins to serve as an inevitable trend for the development of tourism in the future. First, the paper analyzes the main factors and structure modules of the development of lowcarbon tourism; then an operation system and an operation matrix for low-carbon tourism are established to discuss its mechanism; finally, the paper proposes some development strategies for the low-carbon tourism. © 2014 WIT Press. Source


Graft copolymers were usually introduced to improve the compatibility and mechanical properties of polymer blends. In this paper, the effect of cationic vinyl monomer grafted polypropylene (FPP) with different grafting yields (GY) on mechanical properties of polypropylene (PP)/poly(vinyl chloride) (PVC) blends had been investigated. The results indicated that FPP could enhance compatibility of PP/PVC blend remarkably. The tensile strength and the impact strength of PP/PVC blends with a concentration of FPP (GY= 16.78%) at 4 phr increased up to 18.10% and 74.67%, respectively. The viscosity of PP/PVC/FPP blends had been also investigated, and the results showed PP/PVC/FPP (80/20/4) blend was higher than that of other PP/PVC/FPP when FPP (GY=16.78%) was added. The SEM micrographs suggested that the compatibility of the PP/PVC blend was optimum when FPP (GY= 16.78%) was added. © 2016 The Polymer Society of Korea. All rights reserved. Source


Wang M.T.,Yanshan University
Applied Mechanics and Materials | Year: 2014

With the development of computer science and multimedia technology, network act as an important role in adult education. The traditional adult education mode are not suitable the modern teaching mode's need. To construct an adult education self-help study platform is urgent needed. This paper analyses the defects of the traditional adult education mode, rises a new education mode based on the internet, and realizes the framework design of the self-help study platform based on Internet. © (2014) Trans Tech Publications, Switzerland. Source


Wang Z.-Q.,Yanshan University | Zhao J.-C.,Shanghai JiaoTong University
Journal of Structural Engineering (United States) | Year: 2014

A first-order torsion formulation for closed thin-walled (CTW) beam subjected to restrained torsion is developed to consider the warping deformation and restrained shear stresses on cross section and their effect on the behavior of thin-walled (TW) beam. The total torque on closed cross section in the current formulation consists of four component torques. The expressions of various torques and corresponding shear stresses are given. To account for the distribution of true restrained shear stress due to restrained shear rotation in TW cross section, torsion shear coefficient is proposed for CTW beam. Like the transverse shear coefficient in Timoshenko beam theory, the torsion shear coefficient lies at the heart of the first-order torsion theory. The new governing equations of restrained torsion of CTW beam are obtained, which have obvious physical meaning and is easy to be used in engineering and can also be used to solve the torsion problem of open thin-walled beam. The initial parameter method is developed so as to obtain the analytical solution effectively. To demonstrate the accuracy and applicability of the present theory, numerical and closed-form results are compared with those of some other available method. The effects of restrained shear stress on the behavior of open and CTW beams are investigated and verified. © 2014 American Society of Civil Engineers. Source


Wen D.,Yanshan University
Science China Technological Sciences | Year: 2011

A theory for multi-pump and multi-motor hydraulic systems is presented in this paper based on the analysis of the advantages and disadvantages of the popular hydraulic transmission and the double-stator motor (pump). By taking the single-acting fixed displacement multi-pump and multi-motor driving system as an example, the output speeds in a variety of connections of this novel hydraulic transmission are analyzed theoretically. This research work lays a theoretical foundation for the study of the multi-pump and multi-motor driving system and for the design of the system principle diagram. © 2011 Science China Press and Springer-Verlag Berlin Heidelberg. Source


Zhang J.,Yanshan University
Advanced Materials Research | Year: 2013

The method of numerical simulation and experiment were adopted to research the molten steel flow with electromagnetic stirring(EMS). Woods metal was used to simulate molten steel flow by changing electromagnetic parameters in laboratory.The results of numerical simulation was verified. The results showed that the velocity of round mold is larger than rectangle in same EMS conditions. In order to play a fully stirring,the EMS current and frequencies shouldn't too high in round mold, but the current is as big as possible in rectangle mold. © (2013) Trans Tech Publications, Switzerland. Source


Li A.,Kyushu University | Li A.,Yanshan University | Imasaka T.,Kyushu University | Uchimura T.,Kyushu University | Uchimura T.,University of Fukui
Analytica Chimica Acta | Year: 2011

Gas chromatography/multiphoton ionization/time-of-flight mass spectrometry (GC/MPI/TOFMS) was utilized for analysis of a standard mixture sample containing 49 pesticides and 4 real samples using the third-harmonic emission (267. nm) of a femtosecond Ti:sapphire laser (100. fs) as the ionization source. A sample of a standard mixture of n-alkane was also measured for calibration of the retention time indices of the pesticides. Two photons are required for the excitation of n-alkane due to an absorption band located in the far ultraviolet region (140. nm). The n-alkane molecule in the excited state was subsequently ionized either directly or by absorbing another photon because of a high ionization potential. Due to a large excess of energy, the molecular ion was decomposed and formed many fragment ions. Compared to n-alkanes, most of the pesticides were softly ionized by the femtosecond laser; one photon was used for excitation and another was used for the subsequent ionization. The pesticides with no conjugated double bond had a lower ionization efficiency. The present analytical instrument was applied to several samples prepared from a variety of vegetables and a single fruit after pretreatment with solid-phase extraction. Three pesticides were found in these samples, although some of them were not detected by conventional GC/EI/MS-MS due to insufficient sensitivity and selectivity. © 2011 Elsevier B.V. Source


Ren W.,Yanshan University
IEEE Transportation Electrification Conference and Expo, ITEC Asia-Pacific 2014 - Conference Proceedings | Year: 2014

An battery management system based on MSP430 and BQ76PL536A is developed in this paper. It has several significant function in this design, which using ampere-hour integration method with temperature and current correction as a simple and effective algorithm for SOC, using the full charge-discharge and the circles for SOH, using SD card for using information recording for trace. It using CAN bus communication between MSP430 and controller, using USB communication between MSP430 and computer. It has voltage and temperature monitoring, battery equalization, charge and discharge protection,etc. © 2014 IEEE. Source


Li Z.,Yanshan University
International Journal of Rock Mechanics and Mining Sciences | Year: 2014

The research history of cavitation jets is reviewed, and a mechanism that explains cavitation, methods to measure when cavitation occurs and factors that affect cavitation are introduced. The rationality of the cavitation number, which is often used to predict cavitation, is discussed. The results show that cavitation cannot be predicted using the cavitation number. The problems with the Rayleigh equation in calculating the impulse pressure under an annihilation of a cavity for explaining that a cavitation jet having more power to break rocks than that of a common jet are analyzed. A new explanation is suggested: the rock surface pressure pulses due to density changes in the cavitation jet, which makes the cavitation jet more effective. Because the static pressure at the bottom of the well is extremely high and cavitation only occurs at the vapor pressure, the pressure in the nozzle must decrease from the static pressure to the vapor pressure. Reducing the pressure in the nozzle from the static pressure to the vapor pressure is extremely difficult, and thus, much work is still required before cavitation jet drilling can be used in a practical application. © 2014 Elsevier Ltd. Source


Zhao Y.-Y.,Yanshan University
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014

In this paper, the 120fs pulse transmission experiment was carried out using disordered birefringent microstructure fibers with cladding ventages. Thought this experiment, properties of the two waves under the effect of femtosecond laser pulses with different parameters were studied. The results show that the central wavelength of anti-stokes waves and stokes waves produced under the two orthogonal polarization states shift by 63nm and 160nm, respectively. The strength and central position of the two waves in birefringent fibers can be controlled by adjusting the phase match condition and the polarization direction of incident pulses. © 2014 SPIE. Source


Sun H.,Tsinghua University | Yu Y.,Yanshan University | Yu Y.,Northeast Petroleum University | Luo J.,Tsinghua University | And 2 more authors.
CrystEngComm | Year: 2012

ZnO 3D hierarchical structures assembled by different low-dimensional building blocks (nanosheet, nanoneedle) have been successfully synthesized at room temperature without the addition of organic agents. The morphology of the hierarchical structures can be well controlled by simply changing the concentration of the reactant. On the basis of the experimental results, a possible mechanism for the formation of the ZnO 3D hierarchical structures is proposed. The room temperature photoluminescence spectra of the ZnO 3D hierarchical structures show that the relative intensity of UV emission increases from nanosheets to the thin needle flowers and can be tuned by controlling the morphology. Importantly, the thin needle flowers sample exhibits an enhanced photocatalytic performance as compared with the other ZnO nanostructures due to structural features and good optical quality. This journal is © The Royal Society of Chemistry. Source


Zhang M.L.,Yanshan University
Applied Mechanics and Materials | Year: 2014

The formation of the network organization is an important stage in the development of industrial clusters. Application of system dynamics analysis and combined with the successful typical case, taking Shannon Airport Free Zone for an example, analyzed its hetero-organization characteristics and mechanism. © (2014) Trans Tech Publications, Switzerland. Source


Yang X.J.,Yanshan University
Engineering Management and Industrial Engineering - Proceedings of the 2014 International Conference on Engineering Management and Industrial Engineering, EMIE 2014 | Year: 2015

Engineering fluid mechanics is an important fundamental course for petroleum engineering majors. After analyzing the basis and background of reforms in education, this paper elaborates the need for reforms of the course from three perspectives—the theoretical teaching, practical teaching, and the assessment. Based on the specific situation of the major of petroleum, the paper proposes suggestions on the teaching of the course in order to achieve better teaching results. © 2015 Taylor & Francis Group, London. Source


Zhao G.,Yanshan University | Wang J.,Shanghai JiaoTong University
IET Control Theory and Applications | Year: 2015

This study considers the use of reset control to achieve non-overshoot step response for minimum-phase linear single-input single-output systems. Novel reset controllers with state-dependent reset conditions are proposed to asymptotically track a constant step reference with zero overshoot, and rise time can be arbitrarily tuned with mild assumption. Moreover, the existence of such non-overshoot reset controllers is also presented. The proposed design method can also be used for a class of input-output linearisable non-linear systems and set point regulation. Simulation examples support authors' results. © The Institution of Engineering and Technology 2015. Source


Liu Z.,Yanshan University
Science China: Physics, Mechanics and Astronomy | Year: 2013

The exchange bias (EB) has been investigated in magnetic materials with the ferromagnetic (FM)/antiferromagnetic (AFM) contacting interfaces for more than half a century. To date, the significant progress has been made in the layered magnetic FM/AFM thin film systems. EB mechanisms have shown substantive research advances. Here some of the new advances are introduced and discussed with the emphasis on the influence of AFM layer, the interlayer EB coupling across nonmagnetic spacer, and the interlayer coupling across AFM layer, as well as EB related to multiferrioc materials and electrical control. © 2012 Science China Press and Springer-Verlag Berlin Heidelberg. Source


Tian N.-S.,Yanshan University
International Journal of Information and Management Sciences | Year: 2010

This paper studies a fluid model driven by an M/M/l/N queue with single exponential vacation. With the standard spectral method, the exact expression of the steady-state distribution of the buffer content is acquired. Then the performance measure- mean buffer content is obtained. Finally, using the numerical example, we present the parameter effect on the stationary distribution of the buffer content. Source


Li H.,Tsinghua University | Yang H.,Yanshan University | Sun F.,Tsinghua University | Xia Y.,Beijing Institute of Technology
Automatica | Year: 2013

This paper presents a new stabilization method for networked control systems (NCSs). An improved stability criterion dependent on both time delay bound and packet loss bound is derived and the corresponding stabilizing controller design technique is also provided. The merit of the proposed method lies in its much less conservatism, which is achieved by explicitly considering NCSs physical properties and by guaranteeing the deceasement of Lyapunov functional at each control signal updating step rather than at each sampling step, which is largely ignored in the existing literature. Illustrative examples are provided to show the advantage and effectiveness of the developed results. © 2013 Elsevier Ltd. All rights reserved. Source


Chen X.,Shandong University of Science and Technology | Feng W.,Shandong University of Science and Technology | Zhao Y.,Yanshan University
Nongye Jixie Xuebao/Transactions of the Chinese Society for Agricultural Machinery | Year: 2013

A 4-UPS-UPU spatial 5-DOF parallel robot mechanism was introduced. A dynamics model of 4-UPS-UPU was presented. The kinematics of the UPS and UPU chain of leg was analyzed and the velocity mapping relationships between the parts and the driving axis were established. The exterior force load and the equivalent driving force were educed. The dynamics model of 4-UPS-UPU parallel robot mechanism was educed by the virtual work principle approach, which was the foundation of the dynamic analysis. Combined with engineering application examples, numerical verification and virtual simulation verification of the results of driving force and constraining torque was carried out. Source


Yang H.,Beijing Institute of Technology | Yang H.,Yanshan University | Xia Y.,Beijing Institute of Technology | Shi P.,Beijing Institute of Technology | And 2 more authors.
IEEE Transactions on Automatic Control | Year: 2012

This note generalizes the stability analysis for a high frequency networked control system. The high-frequency networked control system is described by a delta operator system with a high frequency constraint. Stability conditions are given for the high frequency delta operator system. Furthermore, by developing the generalized Kalman-Yakubovic-Popov lemma, improved stability conditions are also presented in terms of linear matrix inequalities. Some experiment results are presented to illustrate the effectiveness of the developed techniques. © 2012 IEEE. Source


Jiang W.G.,Yanshan University | Yan L.J.,Xuzhou Construction Machinery Group
Conference Program for the 3rd International Conference on Heterogeneous Materials Mechanics, ICHMM 2011 | Year: 2011

Finite element modeling of repetitive unit cell (RUC) with imposed periodic boundary conditions (PBCs) is a widely used approach for not only determining effective macroscopic material properties but also studying the damaging mechanism of composite materials. In this paper, a stress loading RUC model with PBCs was developed. The procedures for obtaining the effective homogeneous material properties are presented in detail. Thus the proposed model can be easily reconstructed by interested readers. Source


Hui Z.,Yanshan University
BioTechnology: An Indian Journal | Year: 2014

This paper aimed at the university admission ratio changes, and chose per capita GDP, per capita education index, per capita national investment in education, school and teacher number five factors as explanatory variables, using the software of SAS obtained the fitting equation that the heteroscedasticity, autocorrelation, multicollinearity proved that can be used. Aiming the significant of influence of various factors, the paper used the visual analysis method in orthogonal experimental design to determine the optimal combination of factor levels, and used the analysis of variance to discuss significant of factors, and lastly determined the combination of factors sustain the biggest university entrance proportion, and then analyze the combination of the largest influence on China's college enrollment ratio, and to promote the management of students. © 2014 Trade Science Inc. - INDIA. Source


Xu X.H.L.,Yanshan University
Journal of Computational and Nonlinear Dynamics | Year: 2010

In this paper, the electromechanical coupled nonlinear equations for the electromechanical integrated toroidal drive are proposed. Using the equations, the free vibration and forced response under internal resonance are investigated. The effects of the drive parameters on the resonance are investigated. Three different resonance types exist for the different drive parameters. They are the normal resonance, internal resonance, and jump vibration between the normal and internal resonances. Compared with the normal resonance without internal resonance, the internal resonance has a large amplitude and the energy exchange occurs between the vibrations of the different components. The resonance types of the drive system are dependent on the electromechanical parameters of the drive system. In the design stage, one can select properly the electromechanical parameters of the drive system to remove the internal resonance and the jump vibration. © 2010 by ASME. Source


Xue Y.,North University of China | Li H.,Yanshan University
Journal of Computational Information Systems | Year: 2012

The problem of model predictive fault-tolerant controller design for networked control systems with both packet dropout and transmission delay is studied in this paper. A buffer is designed to store the predicted control sequence in the actuator node, using the predicted control input to compensate the time delay and packet dropout. A new model is constructed. Later, a controller is designed with the Mean-square asymptotic stability for the closed-loop networked control systems. Finally, simulations are performed to show the effectiveness of the proposed method. © 2012 Binary Information Press. Source


Sun S.,Yanshan University
Journal of Computational Information Systems | Year: 2012

Graph mining is an important way to implement Social Network Analysis (SNA). Based on the research of current frequent subgraph discovery methods and algorithms, this paper tries to study the relationship topology detection of social network from the characters analysis of basic topology subgraph. The detection of basic topology substructures can discover potential relationship among persons, instead of only detecting frequent or dense subgraph. This paper presents the initiative idea and method of subgraph topology detection, and shows the preliminary comparative experiment of subgraph detection based on the social network data of following relationship in twitter. © 2012 Binary Information Press. Source


Wang J.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2013

Discriminative common vector (DCV) is an effective method that was proposed for the small sample size problems of face recognition. There is the same problem in brain-computer interface (BCI). Using directly the linear discriminative analysis (LDA) could result in errors because of the singularity of the within-class matrix of data. In our studies, we used the DCV method from the common vector theory in the within-class scatter matrix of data of all classes, and then applied eigenvalue decomposition to the common vectors to obtain the final projected vectors. Then we used kernel discriminative common vector (KDCV) with different kernel. Three data sets that include BCI Competition I data set, Competition II data set IV, and a data set collected by ourselves were used in the experiments. The experiment results of 93%, 77% and 97% showed that this feature extraction method could be used well in the classification of imagine data in BCI. Source


Luo X.,Nankai University | Liu L.-M.,Beijing Computational Science Research Center | Hu Z.,Nankai University | Wang W.-H.,Nankai University | And 7 more authors.
Journal of Physical Chemistry Letters | Year: 2012

A novel carbon allotrope consisting of parallel zigzag and armchair chains alternatively each other (10 atoms/cell, named pza-C10) was discovered. The calculated band gap of pza-C10 is 0.31 (0.71) eV with PBE (HSE06), and thus the new member of carbon family is a semiconductor. The pza-C10 sheet not only is thermodynamically more stable than the other known semiconducting carbon sheets, but also it can perfectly graft with graphene. The unprecedented properties of pza-C10 provide a new approach of modulating intrinsic band gap through forming graphene-based monolayer carbon superlattices (GSLs). The band gaps of GSLs with zigzag type of interface oscillate between semiconducting and semimetallic (mostly at the Dirac point) states as the number of zigzag chains increases, showing quantum size effect. The 2D superlattice achieved in GSLs opens a new strategy to design the crystal structures and modulate the electronic properties of 2D materials, nanoribbons, and nanotubes. © 2012 American Chemical Society. Source


Chen Z.X.,Kyushu University | Qian L.H.,Yanshan University | Zhu S.J.,Fukuoka Institute of Technology
Engineering Fracture Mechanics | Year: 2010

Ceramic thermal barrier coatings (TBCs) are increasingly applied to enhance the performance of advanced gas turbine engines. However, the delamination cracks initiated in these coatings limit their applications. In this research, a sandwiched four-point bend specimen is used to evaluate the crack growth resistance in plasma-sprayed TBCs. Well controlled, stable and measurable crack extension is obtained. A rising crack growth resistance curve is found. The steady state strain energy release rate is obtained to be about 170J/m2. The delamination crack evolution behavior is in situ observed and simulated by the finite element analysis based on a crack bridging model. © 2010 Elsevier Ltd. Source


Li H.,Intelligent Systems Technology, Inc. | Yang H.,Yanshan University | Sun F.,Intelligent Systems Technology, Inc. | Xia Y.,Beijing Institute of Technology
IEEE Transactions on Industrial Electronics | Year: 2014

This paper addresses the output feedback stabilization problem for a class of networked control systems (NCSs) under a multiple-packet transmission policy. To compensate the time delays and packet losses, a sliding-mode predictive controller is constructed by taking full advantage of network transmission capacity. A Kalman predictor is used to estimate the current and predict the future plant states, while sliding-mode control (SMC) is employed to compute the control sequences. The estimated state errors are transformed into a system disturbance, and the stability of the closed-loop NCSs is guaranteed by constructing the robust stabilizing SMC controller. Simulation and experimental results are given to demonstrate the effectiveness of the proposed approach. © 1982-2012 IEEE. Source


Zhao Y.,Yanshan University
Sheng wu yi xue gong cheng xue za zhi = Journal of biomedical engineering = Shengwu yixue gongchengxue zazhi | Year: 2012

Epilepsy is a common chronic neurological disease, which is caused by excessive brain neuron discharge. The epileptic seizure has the characteristic of abruptness and reiteration. Prediction of seizures has great significance for patients to take timely and effective clinical measures. The symbolic dynamics method was introduced to analyze absence epilepsy EEG. The key parameters affecting the symbolic statistical quantities were discussed. The symbolic entropy and time irreversebility were calculated in different epilepsy stages. It was found that the symbolic entropy and the time irreversebility were rather big in interictal stage. The two parameters declined significantly during the transformation process from interictal stage to ictal stage and maintained lower value during ictal stage. The results showed that the symbolic dynamics method could reflect the changes of epilepsy EEG. The symbolic entropy and time irreversebility are sensitive features indicating different stages of seizures and have potential important clinical applications. Source


Jiang W.-G.,Yanshan University
Journal of Composite Materials | Year: 2013

A domain superposition technique for the nonlinear modeling of composite materials has been developed in this paper. Instead of explicitly modeling the conjugate matrix domain and reinforcement domain with proper matching mesh interfaces between them in the manner of a traditional finite element analysis, a domain superposition technique model uses the global domain geometry superimposed with the reinforcement phase material domain geometries. The major purpose of doing so is to avoid the difficulty of directly constructing the matrix phase material geometries, which are usually hard to build due to the presence of likely geometric degeneracies in most composite materials internal architectures. The finite element meshes for domain superposition technique analyses are much simpler to establish than those used for traditional finite element analyses. Numerical examples are given to show the validity of the proposed modeling procedures. © The Author(s) 2012 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav. Source


Li Z.-F.,Yanshan University
Zhongguo Shiyou Daxue Xuebao (Ziran Kexue Ban)/Journal of China University of Petroleum (Edition of Natural Science) | Year: 2011

Pipes are under actions of internal and external pressure of fluid in oil well drilling and production, so the stability of the pipes is affected by the pressures. The traditional mechanical model and fictitious force were discussed. A mechanical model representing true tubular conditions was established. Equations of calculating equivalent axis force used for stability analysis of pipes were established based on constant axis strain. The results show that the internal and external pressure of fluid and their change have no effect on stability of hanging pipes, and have effect on equivalent axis force and stability of pipes fixed at two ends. For pipes fixed at two ends, equivalent axis force decreases with internal pressure increasing and increases with external pressure increasing. The increase of internal pressure or decrease of external pressure may make equivalent axis force negative, even less than critical buckling force. Source


Li Q.-L.,Yanshan University | Lui J.C.S.,Chinese University of Hong Kong
Discrete Event Dynamic Systems | Year: 2014

Supermarket models are a class of parallel queueing networks with an adaptive control scheme that play a key role in the study of resource management of, such as, computer networks, manufacturing systems and transportation networks. When the arrival processes are non-Poisson and the service times are non-exponential, analysis of such a supermarket model is always limited, interesting, and challenging.This paper describes a supermarket model with non-Poisson inputs: Markovian Arrival Processes (MAPs) and with non-exponential service times: Phase-type (PH) distributions, and provides a generalized matrix-analytic method which is first combined with the operator semigroup and the mean-field limit. When discussing such a more general supermarket model, this paper makes some new results and advances as follows: (1) Providing a detailed probability analysis for setting up an infinite-dimensional system of differential vector equations satisfied by the expected fraction vector, where the invariance of environment factors is given as an important result. (2) Introducing the phase-type structure to the operator semigroup and to the mean-field limit, and a Lipschitz condition can be established by means of a unified matrix-differential algorithm. (3) The matrix-analytic method is used to compute the fixed point which leads to performance computation of this system. Finally, we use some numerical examples to illustrate how the performance measures of this supermarket model depend on the non-Poisson inputs and on the non-exponential service times. Thus the results of this paper give new highlight on understanding influence of non-Poisson inputs and of non-exponential service times on performance measures of more general supermarket models. © 2014 Springer Science+Business Media New York. Source


Li Y.,University of California at Davis | Lin Y.J.,University of California at Davis | Lin Y.J.,Yanshan University | Xiong Y.H.,University of California at Davis | And 2 more authors.
Scripta Materialia | Year: 2011

Extended twins, up to 100 nm in length and occupying the length of an entire grain, are observed in an Al-4%Mg alloys/B4C nanocomposite material processed via high-temperature, high-strain-rate forging. High-resolution electron microscopy, used to identify the extended twins and to formulate the mechanism for their formation, indicates that they are created by the emission of 1/6h1 1 2i twinning partial dislocations. The macroscopic origin is attributed to the local high stress field present during the forging process. © 2010 Acta Materialia Inc. Source


Zhou X.-F.,Nankai University | Qian G.-R.,Nanjing University | Dong X.,Nankai University | Zhang L.,Nankai University | And 3 more authors.
Physical Review B - Condensed Matter and Materials Physics | Year: 2010

A body-centered tetragonal carbon (bct-carbon) allotrope has been predicted to be a transparent carbon polymorph obtained under pressure. The structural transition pathways from graphite to diamond, M-carbon, and bct-carbon are simulated and the lowest activation barrier is found for the graphite-bct transition. Furthermore, bct-carbon has a higher shear strength than diamond due to its perpendicular graphenelike structure. Our results provide a possible explanation for the formation of a transparent carbon allotrope via the cold compression of graphite. We also verify that this allotrope is hard enough to crack diamond. © 2010 The American Physical Society. Source


Yu J.,Yanshan University
WIT Transactions on Information and Communication Technologies | Year: 2014

The development of modern information technology has produced major impacts on the tourism industry and the emergence of E-business has brought profound change in the tourism value chain. Based on the theory of value chain, the paper first elaborated the impact of traditional tourism value chain and E-business on the tourism value chain and then a tourism value chain model under the E-business environment was established accordingly. Finally, some proposals for the optimization of tourism value chain were presented. © 2014 WIT Press. Source


Zhao M.,Yanshan University
WIT Transactions on Information and Communication Technologies | Year: 2014

With the development of wireless sensor technology, congestion control in wireless sensor network has become the focus of increasing concern. In view of the wireless sensor network clustering structure, this paper has proposed a wireless sensor network congestion control algorithm VCH by setting virtual cluster head nodes, based on using different adjustment strategies to the cluster structure, to realize the congestion control in wireless sensor network. Through the experiment analysis, compared with STCP and COMUT algorithm, VCH algorithm has better performances in network throughput, packet transmission delay, and packet loss rate. © 2014 WIT Press. Source


Wan S.,Huangshan University | Ma Z.,Huangshan University | Xue Y.,Huangshan University | Ma M.,Huangshan University | And 3 more authors.
Industrial and Engineering Chemistry Research | Year: 2014

In the present study, the sorption ability of three metal ions, lead, cadmium, copper, from aqueous solution by tea waste was investigated. Sorption of the evaluated toxic metals by tea waste was pH-dependent, and kinetic data for three metal ions not only indicated a quick sorption process but also were excellently represented by the pseudo-second-order model with all correlation coefficients R2 > 0.97. In addition, the sorption processes of three metal ions by tea waste in different temperatures could be described satisfactorily by both Langmuir and Freundlich isotherms. According to calculated results by the Langmuir equation, the maximum removal capacities of Pb(II), Cd(II), and Cu(II) were 33.49, 16.87, and 21.02 mg/g, respectively. Fourier transform infrared (FT-IR) analysis of the tea waste samples laden with different metals indicated that multiple functional groups were involved in the sorption of metal ions, and the carboxyl group (Cî - O) and bonded-OH group were primary binding sites in lead and cadmium removal, while the -CN stretching and the carboxyl group were primary binding sites in copper removal. All the results reported strongly implied the potential of tea waste as an economic and excellent bioadsorbent for removal of metal ions from contaminated waters. © 2014 American Chemical Society. Source


Liu L.-Z.,Yanshan University
International Journal of Digital Content Technology and its Applications | Year: 2012

Cities which are near the sea have become the most important zone in the world economic cycle. Within these cities-by-sea, it is the post that is most directly related to the world logistics system. Asked by the development of logistic economy, modern ports are net only the hubs of sea-land transportation, but also the distribution center of international goods storage and distribution. In this article, we analyzes the logistic requirement of Qinhuangdao, and we also forecasts every logistic needs of Qinhuangdao port with BP nets and conclude that the logistic service of port is logged with the requirement. Source


Wang D.-C.,Yanshan University
Journal of Iron and Steel Research International | Year: 2012

The shortcomings of an exit stress variation formula which has been well accepted are analyzed; it is found that the exit stress variation formula violates the premise of the law of volume constancy. The shortcomings of an entry stress variation formula are analyzed too, and the basic assumption of the formula is uniform exit velocity. However, for a rigid-plastic material uniform exit velocity implies that the lateral distribution of elongation is uniform, so the exit stress must be uniform and any type of flatness defect is impossible, which is contrary to the practice. In fact, entry and exit velocity variation influence entry and exit stress variation, and entry and exit stress variation influence entry and exit velocity variation too, so a precise explicit stress variation formula cannot be got easily. Considering the relationship between stress variation and velocity variation, an iteration method is presented to calculate entry and exit stress variation of cold rolling strip. To avoid divergent phenomenon of the iteration course, a relaxation factor method is adopted. The calculation results are compared with the entry and exit stress variation formula commonly used by many researchers. The difference is remarkable, while the result calculated agree more well with measured result if the exit elastic recovery zone is considered. Specially, the incoming flatness' propagate efficiency calculated gives a more realistic result. © 2012 Central Iron and Steel Research Institute. Source


Zhang X.,Yanshan University
Materials China | Year: 2015

Nanocomposite exchange coupled magnets are most likely next-generation magnets because of their potentially high energy products. Microstructural control is the key to achieve high energy products. This paper reviews our studies on microstructural control of nanocomposite magnets. The study of the kinetics of phase transition in amorphous Nd-Fe-B demonstrates that the mechanism underlying the coarse grain size (20~100 nm) of α-Fe phase in nanocomposite magnets is a high nucleation activation energy (En) and a low growth activation energy (Eg), that is, the difficult nucleation and easy growth processes of the α-Fe phase, Eg/En < 1. The growth process of soft and hard phases is dependent on atomic diffusion mediated by vacancy-type thermal defects, in which the growth of α-Fe grains in size is dominantly controlled by the diffusion of Fe atoms mediated by thermal vacancies. Room-temperature severe plastic deformation (SPD) affects the grain size (10~20 nm) and volume fraction of soft phase significantly and inhibits the formation of metastable intermediate phases in the alloy. Temperature gradient, high pressure and hot deformation at high stress can induce the easy-axis alignment of Nd2Fe14B hard-phase grains, obtaining anisotropic α-Fe/Nd2Fe14B nanocomposite magnets. The exchange-coupling strength between soft and hard phase grains and the coercivity of magnets can be enhanced through the modification of interfacial structure and chemistry. © 2015, The Editorial Board of Materials China. All right reserved. Source


Zhang X.M.,CAS Institute of Physics | Zhang X.M.,Hebei University of Technology | Wang W.H.,CAS Institute of Physics | Liu E.K.,CAS Institute of Physics | And 3 more authors.
Applied Physics Letters | Year: 2011

The electronic structures of tetragonally distorted half-Heusler compound LaPtBi in the C1b structure are investigated in the framework of density functional theory using the full potential linearized augmented plane with local spin density approximation method. The calculation results show that both the band structures and the Fermi level can be tuned by using either compressive or tensile in-plane strain. A large bulk band gap of 0.3 eV can be induced through the application of a compressive in-pane strain in LaPtBi with the assumption of a relaxed volume of the unit cell. Our results could serve as a guidance to realize topological insulators in half-Heusler compounds by strain engineering. © 2011 American Institute of Physics. Source


Gao F.,Yanshan University
Applied Physics Letters | Year: 2011

A quantum confinement model for nanocrystals developed is extended to study for the optical gap shifts in core/shell quantum dots and nanowires. The chemical bond properties and gap shifts in the InP/ZnS, CdSe/CdS, CdSe/ZnS, and CdTe/ZnS core/shell quantum dots are calculated in detail. The calculated band gaps are in excellent agreement with experimental values. The effects of structural taping and twinning on quantum confinement of InP and Si nanowires are elucidated. It is found theoretically that a competition between the positive Kubo energy-gap shift and the negative surface energy shift plays the crucial role in the optical gaps of these nanosystems. © 2011 American Institute of Physics. Source


Zhu J.,Guangxi Normal University | Li Z.,Yanshan University | Qin L.,Guangxi Normal University
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2015

The effects of surface plasmon polariton (SPP) propagation on the physical properties of cavities in the MIM) structure was studies. Theory methods were drawed using waveguide mode, resonance, reflection coefficient, and phase. The effects of relevant parameters were discussed, including length and thickness, on cavities in SPP propagation. Moreover, the electromotive force (EMF) of Metal-Insulator- Metal (MIM) waveguide and the effect of structure by varying cavity length and reflection coefficient were simulated, etc. Results show that EMF, which is in the SPP propagation, becomes relatively larger than 1 V, and the energy field can be amplified. Moreover, the effective power increases with increased cavity length, and the cavity length has a similar effect on SPP propagation in different cavity thicknesses, with the propagation coefficient reaching a maximum value in the near field. In general, analysis and discussion of this text are significant in studies on nonlinear THz spectroscopy, nanophotoelectric detection, generation of SPP mode, and strong local field. ©, 2015, Chinese Society of Astronautics. All right reserved. Source


Cui F.,Yanshan University
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2015

The color provides much more information than the gray. Considering that the color facial image contains much more identification information than the gray facial image, the chroma Mahalanobis distance map was introduced into color face recognition. Based on the YCbCr color space, the information of chroma and brightness for one color facial image can be separated. Then Mahalanobis distance maps based on chroma information were constructed, at the same time, gray maps based on brightness information can be extracted by orignal color facial images. An algorithm for color face recognition using adaptive feature fusion based on chroma Mahalanobis distance map and gray map was presented. Based on energy values of wavelet packet sub-nodes, normalized feature vectors of chroma Mahalanobis distance maps and gray maps were constructed, respectively. Then identification feature vectors were constructed using several feature fusion methods, and fusion parameters were selected adaptively according to fusion effects. So feature complementation of chroma and brightness was achieved. Results of face recognition were obtained by the classifier based on the variance similarity degree. Experiments show that the algorithm has the characteristics of high recognition rate and good robustness. ©, 2015, Chinese Society of Astronautics. All right reserved. Source


Zhang Z.,Dalian University of Technology | Zhang Z.,Yanshan University | Zhang X.,Dalian University of Technology | Guo X.,Dalian University of Technology | And 2 more authors.
Scripta Materialia | Year: 2013

Deformations of cadmium telluride (CdTe) under nanoindentation were simulated by molecular dynamics. CdTe slides along the {1 1 1} planes under nanoindentation through edge dislocations. During loading, the sliding of CdTe was limited at twin boundaries, inducing the pile-up phenomenon. When dislocations transferred across the twin boundary, a sessile dislocation and steps formed. The coherence effect of both twin boundaries locked the dislocations at the twin boundary effectively, indicating a better hardening effect. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. Source