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A family of explicit algorithms for general pseudodynamic testing

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Earthquake Engineering and Engineering Vibration 2011年第1期10卷 51-64页

作者： Shuenn-Yih chang Chi-wei Hsu Department of Civil Engineering Taipei University of Technology (NTUT) NTUT Box 2653

A new family of explicit pseudodynamic algorithms is proposed for general pseudodynamic testing. One particular subfamily seems very promising for use in general pseudodynamic testing since the stability problem for a structure does not need to be considered. This is because this subfamily is unconditionally stable for any instantaneous stiffness softening system, linear elastic system and instantaneous stiffness hardening system that might occur in the pseudodynamic testing of a real structure. In addition, it also offers good accuracy when compared to a general second-order accurate method for both linear elastic and nonlinear systems.

关键词： pseudodynamic test explicit method unconditional stability dominant mode structural dynamics instantaneous degree of nonlinearity

Response of harmonically and stochastically excited strongly nonlinear oscillators with delayed feedback bang-bang control

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第1期10卷 54-61页

作者： chang-shui FENG wei-qiu ZHU Institute of Mechatronic Engineering Hangzhou Dianzi University Hangzhou 310018 China State Key Laboratory of Fluid Power Transmission and Control Department of Mechanics Zhejiang University Hangzhou 310027 China

We studied the response of harmonically and stochastically excited strongly nonlinear oscillators with delayed feedback bang-bang control using the stochastic averaging method. First, the time-delayed feedback bang-bang control force is expressed approximately in terms of the system state variables without time delay. Then the averaged It6 stochastic differential equations for the system are derived using the stochastic averaging method. Finally, the response of the system is obtained by solving the Fokker-Plank-Kolmogorov （FPK） equation associated with the averaged lt6 equations. A Duffing oscillator with time-delayed feedback bang-bang control under combined harmonic and white noise excitations is taken as an example to illus- trate the proposed method. The analytical results are confirmed by digital simulation. We found that the time delay in feedback bang-bang control will deteriorate the control effectiveness and cause bifurcation of stochastic jump of Duffing oscillator.

关键词： Nonlinear system Delayed feedback bang-bang control Combined harmonic and white noise excitation Stochastic averaging Stationary response Stochastic jump

An improved PSO algorithm for solving nonlinear programing problems with constrained conditions

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International Journal of Modeling, Simulation, and Scientific Computing 2021年第1期12卷 142-156页

作者： wei-Der chang Department of Computer and Communication Shu-Te University Kaohsiung 824Taiwan

Engineering optimization problems can be always classified into two main categories including the linear programming(LP)and nonlinear programming(NLP)*** programming problem further involves the unconstrained conditions and constrained conditions for design variables of the optimized *** paper will focus on the issue about the design problem of NLP with the constrained *** employed method for such NLP problems is a variant of particle swarm optimization(PSO),named improved particle swarm optimization(IPSO).The developed IPSO is to modify the velocity updating formula of the algorithm to enhance the search ability for given optimization *** this work,many different kinds of physical engineering optimization problems are examined and solved via the proposed IPSO *** results compared with various optimization methods reported in the literature will show the effectiveness and feasibility for solving NLP problems with the constrained conditions.

关键词： Engineering optimization nonlinear programming constrained conditions improved particle swarm optimization(IPSO)

A gauge theory for two-band model of Chern insulators and induced topological defects

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Communications in Theoretical Physics 2022年第1期74卷 124-133页

作者： Zhi-Wen chang wei-chang Hao Xin Liu Institute of Theoretical Physics Faculty of SciencesBeijing University of TechnologyBeijing 100124China School of Physics Beihang UniversityBeijing 100191China

In this paper a gauge theory is proposed for the two-band model of Chern *** on the so-calle't Hooft monopole model,a U(1)Maxwell electromagnetic sub-field is constructed from an SU(2)gauge field,from which arise two types of topological defects,monopoles and e2 *** focus on the topological number in the Hall conductance σ_(xy)=e^(2)/hC,where C is the Chern *** is discovered that in the monopole case C is indeterminate,while in the meron case C takes different values,due to a varying on-site energy *** a typical example,we apply this method to the square lattice and compute the winding numbers(topological charges)of the defects;the C-evaluations we obtain reproduce the results of the usual ***,based on the gauge theory we propose a new model to obtain the high Chern numbers|C|=2,4.

关键词： Chern insulator Chern number monopole meron

Comparison of capability of time integration methods in capturing dynamic loading

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Earthquake Engineering and Engineering Vibration 2010年第3期9卷 409-423页

作者： Shuenn-Yih chang Chi-wei Hsu Department of Civil Engineering Taipei University of Technology

Numerical properties of the time integration method proposed by the first author of this paper in 2007 are the same as those of the constant average acceleration method （AAM） for linear elastic systems, except that the capability to capture dynamic loading was not explored. It was found that there were different quadrature equations to predict the next step displacement increment. A modified quadrature equation of this method was derived so that the equation to determine the next step displacement was numerically equivalent to the equation used in the constant AAM. It was verified that the original form of this method, in general, had a better capability to capture dynamic loadings than the constant AAM. This excellent property, in addition to computational efficiency, will help to make this method competitive with general secondorder accurate integration methods.

关键词： equations of motion quadrature equation constant average acceleration method integration methods

Special Relationship among Decision Making Units based on Partially Ordered Set and New Evaluation and Projection Methods

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Journal of Systems Science and Systems Engineering 2022年第2期31卷 226-246页

作者： Muren chang Liu wei Cui Jinquan Dong School of Statistics Jilin University of Finance and EconomicsChangchun130117China bSchool of Management Science and Information Enginering Jilin University of Finance and EconomicsChangchun130117China cSchool of Economic and Management Inner Mongolia University of TechnologyHohhot010051China

This paper provides data envelopment analysis methods based on partially ordered set *** methods reveal the special relationships between two decision making units from the perspective of mathematical theory and offer the classification,projection and improvement methods of decision making *** is proved that an efficient decision making unit must be a maximal element of the related poset,and the maximal element may not be *** this,we introduce the concepts of minimum envelope and efficiency envelope which further reveal the special relationship among efficient and inefficient decision making *** with the previous methods,this method not only reveals theoretically the complex relationship among decision making units and the causes of the ineffectiveness,but also gives a new importance and competitiveness measurement method to each decision making ***,related algorithm and examples are given for the application of these methods to complex decision making problems.

关键词： Data envelopment analysis partially ordered set returns to scale projection maximal element

Flexible Nanocomposite Conductors for Electromagnetic Interference Shielding

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Nano-Micro Letters 2023年第10期15卷 210-259页

作者： Ze Nan wei wei Zhenhua Lin Jingjing chang Yue Hao State Key Discipline Laboratory of Wide Band Gap Semiconductor Technology School of MicroelectronicsXidian University2 South Taibai RoadXi’an 710071People’s Republic of China Advanced Interdisciplinary Research Center for Flexible Electronics Xidian University2 South Taibai RoadXi’an 710071People’s Republic of China

With the extensive use of electronic communication technology in integrated circuit systems and wearable devices, electromagnetic interference(EMI) has increased dramatically. The shortcomings of conventional rigid EMI shielding materials include high brittleness, poor comfort, and unsuitability for conforming and deformable applications. Hitherto, flexible(particularly elastic) nanocomposites have attracted enormous interest due to their excellent deformability. However, the current flexible shielding nanocomposites present low mechanical stability and resilience, relatively poor EMI shielding performance, and limited multifunctionality. Herein, the advances in low-dimensional EMI shielding nanomaterials-based elastomers are outlined and a selection of the most remarkable examples is discussed. And the corresponding modification strategies and deformability performance are summarized. Finally, expectations for this quickly increasing sector are discussed, as well as future challenges.

关键词： Electromagnetic interference shielding Intrinsically stretchable nanocomposites Compressible monolith Low-dimensional materials Flexible devices

Composition and distribution of NSO compounds in two different shales at the early maturity stage characterized by negative ion electrospray ionization coupled with Fourier transform ion cyclotron resonance mass spectrometry

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Petroleum Science 2018年第2期15卷 289-296页

作者： chang-wei Ke Yao-Hui Xu Xiang-Chun chang wei-Bin Liu Key Laboratory of Exploration Technologies for Oil and Gas Resources (Yangtze University) Ministry of Education College of Resources and Environment Yangtze University College of Earth Science and Engineering Shandong University of Science and Technology Oil and Gas Survey China Geological Survey

Gas chromatography/mass spectrometry （GC/MS） can only analyze volatile molecular compounds, and it has limitations when applied to determine the complex components of crude oils and hydrocarbon source rocks. Based on Fourier transform ion cyclotron resonance mass spectrometry （FT-ICR-MS） and GC/MS analyses, the molecular compositions of NSO compounds in extracts from the Permian Dalong Formation, Sichuan Basin and the Permian Lucaogou Formation, Junggar Basin in China were compared. Analyses of types of heteroatoms present （S~, $2, $3, OS, OS2, 02S, NS, and NOS compounds） suggest that marine shales from the Dalong Formation are mainly composed of carboxylic acids （02 com- pounds） with a high abundance of fatty acids, indicating a marine phytoplankton organic source. However, lacustrine shales from the Lucaogou Formation are dominated by pyrrolic compounds （N1 compounds） with abundant dibenzocar- bazole. It suggests that the organic source materials may be derived from lower aquatic organisms and lacustrine algae. Overall, FT-ICR-MS has potential for applications in analyses and determination of depositional environments and organic sources in petroleum geology.

关键词： Fourier transform ion cyclotron resonance mass spectrometry Dalong Formation Lucaogou Formation NSO compounds Sedimentary environment

To Be,Or Not To Be:The Calculated Politics of Acupuncture in JAMA

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Chinese Journal of Integrative Medicine 2017年第11期23卷 803-808页

作者： GONG chang-zhen LIU wei American Academy of Acupuncture and Oriental Medicine RosevilleMN(55113)United States

Ten acupuncture-related articles were published in The Journal of the American Medical Association（JAMA） between 1998 and 2017. Five studies showed positive results in terms of the effectiveness of acupuncture/Chinese medicine（CM）; five studies showed negative results. This article summarizes the acupuncturerelated clinical trials published over the last 20 years in JAMA, and addresses what seems to be a fundamental ambivalence in Western medical journals regarding the scientific validity of acupuncture/CM. As yet there has been no consensus on the role of acupuncture in healthcare in Western countries. This is hardly surprising, considering the conflicting evidence found in published studies. Skepticism regarding acupuncture/CM is largely grounded in the fact that an accurate model for assessing the true clinical effects of acupuncture has yet to be created. This article discusses some of the pitfalls which result from applying Western-based scientific principles to CM, and suggests that in many cases, ＂negative＂ studies have been misinterpreted. The clinical experience of acupuncture practitioners is often in direct conflict with many of the negative conclusions published in journals. We are in need of an accurate model for sham and placebo treatments, and must analyze all published studies for design flaws and faulty conclusions.

关键词： Chinese medicine acupuncture Western medical journals study design