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CONVERGENCE RATES TO TRAVELLING WAVES FOR A RELAXATION MODEL WITH LARGE INITIAL DISTURBANCE 被引量:2
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作者 张辉 赵引川 《Acta Mathematica Scientia》 SCIE CSCD 2004年第2期213-227,共15页
This paper is concerned with the convergence rates to travelling waves for a relaxation model with general flux functions. Compared with former results in this direction, the main novelty in this paper lies in the fac... This paper is concerned with the convergence rates to travelling waves for a relaxation model with general flux functions. Compared with former results in this direction, the main novelty in this paper lies in the fact that the initial disturbance can be chosen large in suitable norm. Our analysis is based on the L^1-stability results obtained by C. Mascia and R. Natalini in [12]. 展开更多
关键词 Convergence rate RELAXATION travelling waves large initial disturbance
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Nonlinear Propagation of Positron-Acoustic Periodic Travelling Waves in a Magnetoplasma with Superthermal Electrons and Positrons
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作者 E.F.EL-Shamy 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第6期70-74,共5页
The nonlinear propagation of positron acoustic periodic (PAP) travelling waves in a magnetoplasma composed of dynamic cold positrons, superthermal kappa distributed hot positrons and electrons, and stationary positi... The nonlinear propagation of positron acoustic periodic (PAP) travelling waves in a magnetoplasma composed of dynamic cold positrons, superthermal kappa distributed hot positrons and electrons, and stationary positive ions is examined. The reductive perturbation technique is employed to derive a nonlinear Zakharov Kuznetsov equation that governs the essential features of nonlinear PAP travelling waves. Moreover, the bifurcation theory is used to investigate the propagation of nonlinear PAP periodic travelling wave solutions. It is found that kappa distributed hot positrons and electrons provide only the possibility of existence of nonlinear compressive PAP travelling waves. It is observed that the superthermality of hot positrons, the concentrations of superthermal electrons and positrons, the positron cyclotron frequency, the direction cosines of wave vector k along the z-axis, and the concentration of ions play pivotal roles in the nonlinear propagation of PAP travelling waves. Tile present investigation may be used to understand the formation of PAP structures in the space and laboratory plasmas with superthermal hot positrons and electrons. 展开更多
关键词 Nonlinear Propagation of Positron-Acoustic Periodic travelling waves in a Magnetoplasma with Superthermal Electrons and Positrons
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Travelling Waves in a Compressible Mooney-Rivlin Rod 被引量:1
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作者 YUFeng LUOJing-guo 《Journal of Shanghai University(English Edition)》 CAS 2001年第4期282-286,共5页
This article deals with waves in a circular cylindrical rod composed of a compressible Mooney Rivlin material. All kinds of travelling waves and the conditions for their existence are studied by using the method of ... This article deals with waves in a circular cylindrical rod composed of a compressible Mooney Rivlin material. All kinds of travelling waves and the conditions for their existence are studied by using the method of nonlinear dynamics. 展开更多
关键词 travelling wave hemoclinic orbit heterclinic orbit
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THE SMOOTH AND NONSMOOTH TRAVELLING WAVESOLUTIONS IN A NONLINEAR WAVE EQUATION
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作者 LI Shu-min(李庶民) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2001年第11期1333-1343,共11页
The travelling wave solutions (TWS) in a class of P. D. E. is studied. The travelling wave equation of this P. D. E. is a planar cubic polynomial system in three-parameter space. The study for M became the topological... The travelling wave solutions (TWS) in a class of P. D. E. is studied. The travelling wave equation of this P. D. E. is a planar cubic polynomial system in three-parameter space. The study for M became the topological classifications of bifurcations of phase portraits defined by the planar system. B using the theory of planar dynamical systems to do qualitative analysis, all topological classifications of the cubic polynomial system can be obtained. Returning the results of the phase plane analysis to TWS, u(xi), and considering discontinuity of the right side of the equation of TWS when xi = x - ct is varied along a phase orbit and passing through a singular curve, all conditions of existence of smooth and nonsmooth travelling waves are given. 展开更多
关键词 nonlinear wave equation solitary travelling wave periodic travelling wave dissmoothness of wave
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Ocean internal waves interpreted as oscillation travelling waves in consideration of ocean dissipation
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作者 姜祝辉 黄思训 +1 位作者 游小宝 肖义国 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第5期52-59,共8页
Most studies of the synthetic aperture radar remote sensing of ocean internal waves are based on the solitary wave solutions of the Korteweg-de Vries (KdV) equation, and the dissipative term in the KdV equation is n... Most studies of the synthetic aperture radar remote sensing of ocean internal waves are based on the solitary wave solutions of the Korteweg-de Vries (KdV) equation, and the dissipative term in the KdV equation is not taken into account. However, the dissipative term is very important, both in the synthetic aperture radar images and in ocean models. In this paper, the traveling-wave structure to characterize the ocean internal wave phenomenon is modeled, the results of numerical experiments are advanced, and a theoretical hypothesis of the traveling wave to retrieve the ocean internal wave parameters in the synthetic aperture radar images is introduced. 展开更多
关键词 synthetic aperture radar ocean internal waves oscillation travelling wave Korteweg-de Vriesequation
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Application of Fault Location Mode Based on Travelling Waves for Neutral Non-effective Grounding Systems
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作者 Tao Ji Qian-qian Yuan +2 位作者 Chang-ming Li Ying Sun (Scientific Research Office Weifang University Weifang,China College of Information and Electrical EngineeringShandong University of Science and Technology Qingdao,China) 《Journal of Measurement Science and Instrumentation》 CAS 2010年第S1期133-138,共6页
Fault location for distribution feeders short circuit especially single-phase grounding fault is an important task in distribution system with non-effectively grounded neutral.Fault location mode for distribution feed... Fault location for distribution feeders short circuit especially single-phase grounding fault is an important task in distribution system with non-effectively grounded neutral.Fault location mode for distribution feeders using fault generated current and voltage transient traveling waves was investigated.The characteristics of transient traveling waves resulted from each short circuit fault and their transmission disciplinarian in distribution feeders are analyzed.This paper proposed that double end travelling waves theory which measures arriving time of fault initiated surge at both ends of the monitored line is fit for distribution feeders but single end traveling waves theory not.According to different distribution feeders,on the basis of analyzing original traveling waves reflection rule in line terminal, Current-voltage mode,voltage-voltage mode and current-current mode for fault location based on traveling waves are proposed and aerial mode component of original traveling waves is used to realize fault location.Experimental test verify the feasibility and correctness of the proposed method. 展开更多
关键词 distribution feeders neutral non-effective grounding traveling waves fault locationmode
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Existence of Travelling Waves with Strong Generic Kernel in a Vector-Disease Model
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作者 邵明哲 彭亚红 《Journal of Donghua University(English Edition)》 EI CAS 2011年第3期281-284,共4页
In this paper, traveling wave solutions for a vector-disease model incorporating time delay and diffusion have been studied. The existence of traveling wave solutions for the sufficiently small delays has been proved.... In this paper, traveling wave solutions for a vector-disease model incorporating time delay and diffusion have been studied. The existence of traveling wave solutions for the sufficiently small delays has been proved. In order to solve these problems, we are able to deal with travelling wave solutions using dynamical systems techniques, invariant manifold theory, together with linear chain techniques and the geometric singular perturbation theory. For the strong generic delay kernel, traveling wave solutions exist while the delay is sufficiently small, using the methods above. 展开更多
关键词 travelling wave solution vector-disease model non-local interaction
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Coexisting fast–slow dendritic traveling waves in a 3D-array electric field coupled neuronal network
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作者 魏熙乐 任泽宇 +2 位作者 卢梅丽 樊亚琴 常思远 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期614-626,共13页
Coexistence of fast and slow traveling waves without synaptic transmission has been found in hhhippocampal tissues,which is closely related to both normal brain activity and abnormal neural activity such as epileptic ... Coexistence of fast and slow traveling waves without synaptic transmission has been found in hhhippocampal tissues,which is closely related to both normal brain activity and abnormal neural activity such as epileptic discharge. However, the propagation mechanism behind this coexistence phenomenon remains unclear. In this paper, a three-dimensional electric field coupled hippocampal neural network is established to investigate generation of coexisting spontaneous fast and slow traveling waves. This model captures two types of dendritic traveling waves propagating in both transverse and longitude directions: the N-methyl-D-aspartate(NMDA)-dependent wave with a speed of about 0.1 m/s and the Ca-dependent wave with a speed of about 0.009 m/s. These traveling waves are synaptic-independent and could be conducted only by the electric fields generated by neighboring neurons, which are basically consistent with the in vitro data measured experiments. It is also found that the slow Ca wave could trigger generation of fast NMDA waves in the propagation path of slow waves whereas fast NMDA waves cannot affect the propagation of slow Ca waves. These results suggest that dendritic Ca waves could acted as the source of the coexistence fast and slow waves. Furthermore, we also confirm the impact of cellular spacing heterogeneity on the onset of coexisting fast and slow waves. The local region with decreasing distances among neighbor neurons is more liable to promote the onset of spontaneous slow waves which, as sources, excite propagation of fast waves. These modeling studies provide possible biophysical mechanisms underlying the neural dynamics of spontaneous traveling waves in brain tissues. 展开更多
关键词 hippocampal network EPILEPTIFORM dendritic oscillation traveling wave electric field coupling
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ON MONOTONE TRAVELING WAVES FOR NICHOLSON'S BLOWFLIES EQUATION WITH DEGENERATE p-LAPLACIAN DIFFUSION
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作者 Rui HUANG Yong WANG Zhuo YIN 《Acta Mathematica Scientia》 SCIE CSCD 2024年第4期1550-1571,共22页
We study the existence and stability of monotone traveling wave solutions of Nicholson's blowflies equation with degenerate p-Laplacian diffusion.We prove the existence and nonexistence of non-decreasing smooth tr... We study the existence and stability of monotone traveling wave solutions of Nicholson's blowflies equation with degenerate p-Laplacian diffusion.We prove the existence and nonexistence of non-decreasing smooth traveling wave solutions by phase plane analysis methods.Moreover,we show the existence and regularity of an original solution via a compactness analysis.Finally,we prove the stability and exponential convergence rate of traveling waves by an approximated weighted energy method. 展开更多
关键词 degenerate diffusion P-LAPLACIAN traveling waves stability
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Propagation and Pinning of Travelling Wave for Nagumo Type Equation
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作者 Sharon-Yasotha Veerayah-Mcgregor Valipuram Manoranjan 《Journal of Applied Mathematics and Physics》 2024年第3期861-869,共9页
In this paper, we study the propagation and its failure to propagate (pinning) of a travelling wave in a Nagumo type equation, an equation that describes impulse propagation in nerve axons that also models population ... In this paper, we study the propagation and its failure to propagate (pinning) of a travelling wave in a Nagumo type equation, an equation that describes impulse propagation in nerve axons that also models population growth with Allee effect. An analytical solution is derived for the traveling wave and the work is extended to a discrete formulation with a piecewise linear reaction function. We propose an operator splitting numerical scheme to solve the equation and demonstrate that the wave either propagates or gets pinned based on how the spatial mesh is chosen. 展开更多
关键词 Operator Splitting travelling Wave Piecewise Reaction Nagumo Equation PINNING Finite Differences
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Finite Travelling Waves for a Semilinear Degenerate Reaction-Diffusion System 被引量:8
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作者 Shu WANG Cheng Fu WANG Dang LUO Department of Mathematics, Henan University, Kaifeng 475001, P. R. China Institute of Mathematics, Academy of Mathematics and System Sciences Chinese Academy of Sciences, Beijing 100080, P. R. China Department of Mathematics, Suzhou University, Suzhou 215006, P. R. China Department of Basic Science, North China Institute of Water Conservancy and Hydroelectric Power, Zhengzhou 450045, P. R. China 《Acta Mathematica Sinica,English Series》 SCIE CSCD 2001年第4期603-612,共10页
In this paper, the existence and nonexistence of finite travelling waves (FTWs) for a semilinear degenerate reaction-diffusion system (u<sub>i</sub><sup>αi</sup>t=u<sub>ixx</sub>... In this paper, the existence and nonexistence of finite travelling waves (FTWs) for a semilinear degenerate reaction-diffusion system (u<sub>i</sub><sup>αi</sup>t=u<sub>ixx</sub>-multiply from j=1 to N u<sub>j</sub><sup>mij</sup>, x∈R, t】0,i=1,. . . ,N (Ⅰ) is studied. where 0【a<sub>i</sub>【1. mij≥0 and sum from j=1 to N mij】0, i, j=1, . . . ,N .Necessary and sufficient conditions on existence and large time behaviours of FTWs of (Ⅰ) are obtained by using the matrix theory. Schauder’s fixed point theorem, and upper and lower solutious method. 展开更多
关键词 Finite traveling waves Degenerate reaction-diffusion system Global solution Blow up
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Enhancing the resolution of sparse rock property measurements using machine learning and random field theory 被引量:1
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作者 Jiawei Xie Jinsong Huang +3 位作者 Fuxiang Zhang Jixiang He Kaifeng Kang Yunqiang Sun 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第10期3924-3936,共13页
The travel time of rock compressional waves is an essential parameter used for estimating important rock properties,such as porosity,permeability,and lithology.Current methods,like wireline logging tests,provide broad... The travel time of rock compressional waves is an essential parameter used for estimating important rock properties,such as porosity,permeability,and lithology.Current methods,like wireline logging tests,provide broad measurements but lack finer resolution.Laboratory-based rock core measurements offer higher resolution but are resource-intensive.Conventionally,wireline logging and rock core measurements have been used independently.This study introduces a novel approach that integrates both data sources.The method leverages the detailed features from limited core data to enhance the resolution of wireline logging data.By combining machine learning with random field theory,the method allows for probabilistic predictions in regions with sparse data sampling.In this framework,12 parameters from wireline tests are used to predict trends in rock core data.The residuals are modeled using random field theory.The outcomes are high-resolution predictions that combine both the predicted trend and the probabilistic realizations of the residual.By utilizing unconditional and conditional random field theories,this method enables unconditional and conditional simulations of the underlying high-resolution rock compressional wave travel time profile and provides uncertainty estimates.This integrated approach optimizes the use of existing core and logging data.Its applicability is confirmed in an oil project in West China. 展开更多
关键词 Wireline logs Core characterization Compressional wave travel time Machine learning Random field theory
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Travelling Wave Solutions to Stretched Beam's Equation: Phase Portraits Survey 被引量:1
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作者 Gambo Betchewe Kuetche Kamgang Victor +1 位作者 Bouetou Bouetou Thomas Timoleon Crepin Kofane 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第4期605-608,共4页
In this paper, following the phase portraits analysis, we investigate the integrability of a system which physically describes the transverse oscillation of an elastic beam under end-thrust. As a result, we find that ... In this paper, following the phase portraits analysis, we investigate the integrability of a system which physically describes the transverse oscillation of an elastic beam under end-thrust. As a result, we find that this system actually comprises two families of travelling waves: the sub- and super-sonic periodic waves of positive- and negative- definite velocities, respectively, and the localized sub-sonic loop-shaped waves of positive-definite velocity. Expressing the energy-like of this system while depicting its phase portrait dynamics, we show that these multivaiued localized travelling waves appear as the boundary solutions to which the periodic travelling waves tend asymptotically 展开更多
关键词 phase portraits elastic beam travelling waves
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Higher-dimensional Chen-Lee-Liu equation and asymmetric peakon soliton
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作者 韩巧红 贾曼 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期224-229,共6页
Integrable systems play a crucial role in physics and mathematics.In particular,the traditional(1+1)-dimensional and(2+1)-dimensional integrable systems have received significant attention due to the rarity of integra... Integrable systems play a crucial role in physics and mathematics.In particular,the traditional(1+1)-dimensional and(2+1)-dimensional integrable systems have received significant attention due to the rarity of integrable systems in higher dimensions.Recent studies have shown that abundant higher-dimensional integrable systems can be constructed from(1+1)-dimensional integrable systems by using a deformation algorithm.Here we establish a new(2+1)-dimensional Chen-Lee-Liu(C-L-L)equation using the deformation algorithm from the(1+1)-dimensional C-L-L equation.The new system is integrable with its Lax pair obtained by applying the deformation algorithm to that of the(1+1)-dimension.It is challenging to obtain the exact solutions for the new integrable system because the new system combines both the original C-L-L equation and its reciprocal transformation.The traveling wave solutions are derived in implicit function expression,and some asymmetry peakon solutions are found. 展开更多
关键词 higher dimensional Chen-Lee-Liu equation Lax integrable system deformation algorithm implicit traveling wave solutions
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Harmonic balance simulation of the influence of component uniformity and reliability on the performance of a Josephson traveling wave parametric amplifier
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作者 郑煜臻 熊康林 +1 位作者 冯加贵 杨辉 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期339-343,共5页
A Josephson traveling wave parametric amplifier(JTWPA),which is a quantum-limited amplifier with high gain and large bandwidth,is the core device of large-scale measurement and control systems for quantum computing.A ... A Josephson traveling wave parametric amplifier(JTWPA),which is a quantum-limited amplifier with high gain and large bandwidth,is the core device of large-scale measurement and control systems for quantum computing.A typical JTWPA consists of thousands of Josephson junctions connected in series to form a transmission line and hundreds of shunt LC resonators periodically loaded along the line for phase matching.Because the variation of these capacitors and inductors can be detrimental to their high-frequency characteristics,the fabrication of a JTWPA typically necessitates precise processing equipment.To guide the fabrication process and further improve the design for manufacturability,it is necessary to understand how each electronic component affects the amplifier.In this paper,we use the harmonic balance method to conduct a comprehensive study on the impact of nonuniformity and fabrication yield of the electronic components on the performance of a JTWPA.The results provide insightful and scientific guidance for device design and fabrication processes. 展开更多
关键词 Josephson traveling wave parametric amplifier(JTWPA) harmonic balance method YIELDS UNIFORMITY
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Measurement of very low-molecular weight metabolites by traveling wave ion mobility and its use in human urine samples
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作者 Alongkorn Kurilung Suphitcha Limjiasahapong +9 位作者 Khwanta Kaewnarin Pattipong Wisanpitayakorn Narumol Jariyasopit Kwanjeera Wanichthanarak Sitanan Sartyoungkul Stephen Choong Chee Wong Nuankanya Sathirapongsasuti Chagriya Kitiyakara Yongyut Sirivatanauksorn Sakda Khoomrung 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2024年第5期733-743,共11页
The collision cross-sections(CCS)measurement using ion mobility spectrometry(IMS)in combination with mass spectrometry(MS)offers a great opportunity to increase confidence in metabolite identification.However,owing to... The collision cross-sections(CCS)measurement using ion mobility spectrometry(IMS)in combination with mass spectrometry(MS)offers a great opportunity to increase confidence in metabolite identification.However,owing to the lack of sensitivity and resolution,IMS has an analytical challenge in studying the CCS values of very low-molecular-weight metabolites(VLMs250 Da).Here,we describe an analytical method using ultrahigh-performance liquid chromatography(UPLC)coupled to a traveling wave ion mobility-quadrupole-time-of-flight mass spectrometer optimized for the measurement of VLMs in human urine samples.The experimental CCS values,along with mass spectral properties,were reported for the 174 metabolites.The experimental data included the mass-to-charge ratio(m/z),retention time(RT),tandem MS(MS/MS)spectra,and CCS values.Among the studied metabolites,263 traveling wave ion mobility spectrometry(TWIMS)-derived CCS values(TWCCSN2)were reported for the first time,and more than 70%of these were CCS values of VLMs.The TWCCSN2 values were highly repeatable,with inter-day variations of<1%relative standard deviation(RSD).The developed method revealed excellent TWCCSN2 accuracy with a CCS difference(DCCS)within±2%of the reported drift tube IMS(DTIMS)and TWIMS CCS values.The complexity of the urine matrix did not affect the precision of the method,as evidenced by DCCS within±1.92%.According to the Metabolomics Standards Initiative,55 urinary metabolites were identified with a confidence level of 1.Among these 55 metabolites,53(96%)were VLMs.The larger number of confirmed compounds found in this study was a result of the addition of TWCCSN2 values,which clearly increased metabolite identification confidence. 展开更多
关键词 Very low-molecular-weight metabolites Traveling wave ion mobility Collision cross-section Human urine
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THE EQUIVALENT CIRCUIT AND CONTROL SYSTEM OF TRAVELLING WAVE TYPE ULTRASONIC MOTOR
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作者 夏长亮 史婷娜 +1 位作者 薛向党 刘承榆 《Transactions of Tianjin University》 EI CAS 1997年第2期23-27,共5页
The ultrasonic motor is a sort of new type of micromotor with special structure. By use of piezoelectric converse effect of ceramics, the electrical energy is transformed into mechanical energy. Its operating principl... The ultrasonic motor is a sort of new type of micromotor with special structure. By use of piezoelectric converse effect of ceramics, the electrical energy is transformed into mechanical energy. Its operating principle is quite different from that of the traditional motors. In this paper the equivalent circuits of the ring stator and even the whole motor are proposed after studying the equivalent circuit of piezoelectric vibrator. Then the paper makes detailed analyses of each part of the control system, which has been simplified by the equivalent circuit. The theory in this paper has been proved through experiments. 展开更多
关键词 travelling wave type ultrasonic motor equivalent circuit control system
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Multi-Branch Fault Line Location Method Based on Time Difference Matrix Fitting
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作者 Hua Leng Silin He +3 位作者 Jian Qiu Feng Liu Xinfei Huang Jiran Zhu 《Energy Engineering》 EI 2024年第1期77-94,共18页
The distribution network exhibits complex structural characteristics,which makes fault localization a challenging task.Especially when a branch of the multi-branch distribution network fails,the traditional multi-bran... The distribution network exhibits complex structural characteristics,which makes fault localization a challenging task.Especially when a branch of the multi-branch distribution network fails,the traditional multi-branch fault location algorithm makes it difficult to meet the demands of high-precision fault localization in the multi-branch distribution network system.In this paper,the multi-branch mainline is decomposed into single branch lines,transforming the complex multi-branch fault location problem into a double-ended fault location problem.Based on the different transmission characteristics of the fault-traveling wave in fault lines and non-fault lines,the endpoint reference time difference matrix S and the fault time difference matrix G were established.The time variation rule of the fault-traveling wave arriving at each endpoint before and after a fault was comprehensively utilized.To realize the fault segment location,the least square method was introduced.It was used to find the first-order fitting relation that satisfies the matching relationship between the corresponding row vector and the first-order function in the two matrices,to realize the fault segment location.Then,the time difference matrix is used to determine the traveling wave velocity,which,combined with the double-ended traveling wave location,enables accurate fault location. 展开更多
关键词 Multi-branch lines distribution network fault location double-ended traveling wave positioning least square method
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Simulation and Traffic Safety Assessment of Heavy-Haul Railway Train-Bridge Coupling System under Earthquake Action
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作者 Liangwei Jiang Wei Zhang +3 位作者 Hongyin Yang Xiucheng Zhang Jinghan Wu Zhangjun Liu 《Structural Durability & Health Monitoring》 EI 2024年第6期835-851,共17页
Aiming at the problem that it is difficult to obtain the explicit expression of the structural matrix in the traditional train-bridge coupling vibration analysis,a combined simulation system of train-bridge coupling s... Aiming at the problem that it is difficult to obtain the explicit expression of the structural matrix in the traditional train-bridge coupling vibration analysis,a combined simulation system of train-bridge coupling system(TBCS)under earthquake(MAETB)is developed based on the cooperative work of MATLAB and ANSYS.The simulation system is used to analyze the dynamic parameters of the TBCS of a prestressed concrete continuous rigid frame bridge benchmark model of a heavy-haul railway.The influence of different driving speeds,seismic wave intensities,and traveling wave effects on the dynamic response of the TBCS under the actions of the earthquakes is discussed.The results show that the bridge displacement increase in magnitude in the lateral direction is more significant than in the vertical direction under the action of an earthquake.The traveling wave effect can significantly reduce the lateral response of the bridge,but it will significantly increase the train derailment coefficient.When the earthquake intensity exceeds 0.2 g,the partial derailment coefficient of the train has exceeded the limit value of the specification. 展开更多
关键词 Train-bridge coupling vibration analysis dynamic response earthquake action traveling wave effect
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Speed Control of Travelling Wave Type Ultrasonic Motors Using Artificial Neural Network
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作者 杨忠 金龙 《Journal of Southeast University(English Edition)》 EI CAS 1999年第2期63-68,共6页
Ultrasonic motor (USM) is a newly developed motor, and it has some excellent performances and useful features, therefore, it has been expected to be of practical use. However, the driving principle of USM is different... Ultrasonic motor (USM) is a newly developed motor, and it has some excellent performances and useful features, therefore, it has been expected to be of practical use. However, the driving principle of USM is different from that of other electromagnetic type motors, and the mathematical model is complex to apply to motor control. Furthermore, the speed characteristics of the motor have heavy nonlinearity and vary with driving conditions. Hence, the precise speed control of USM is generally difficult. This paper proposes a new speed control scheme for USM using an artificial neural network. An accurate tracking response can be obtained by random initialization of the weights of the network owing to the powerful on line learning capability. Two prototype ultrasonic motors of travelling wave type were fabricated, both having 100 mm outer diameters of stator and piezoelectric ceramic. The usefulness and validity of the proposed control scheme are examined in experiments. 展开更多
关键词 artificial neural networks ultrasonic motors travelling wave type speed control
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