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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 842-852页

作者： Qing Yang Gang Chen Ting Wang State Key Laboratory of Power Transmission Equipment and System Security and New Technology and the School of AutomationChongqing UniversityChongqing 400044China IEEE

By virtue of alternating direction method of multipliers(ADMM), Newton-Raphson method, ratio consensus approach and running sum method, two distributed iterative strategies are presented in this paper to address the economic dispatch problem(EDP) in power systems. Different from most of the existing distributed ED approaches which neglect the effects of packet drops or/and time delays, this paper takes into account both packet drops and time delays which frequently occur in communication networks. Moreover, directed and possibly unbalanced graphs are considered in our algorithms, over which many distributed approaches fail to converge. Furthermore, the proposed schemes can address the EDP with local constraints of generators and nonquadratic convex cost functions, not just quadratic ones required in some existing ED approaches. Both theoretical analyses and simulation studies are provided to demonstrate the effectiveness of the proposed schemes.

关键词： Alternating direction method of multipliers(ADMM) average consensus directed graph(digraph) distributed algorithm economic dispatch packet drops time delays

Evaluation of packet loss impairment on streaming video

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第z1期7卷 131-136页

作者： RUI Hua-xia LI Chong-rong QIU Sheng-ke Network Research Center Tsinghua University Beijing 100084 China Network Research Center Tsinghua University Beijing 100084 China Network Research Center Tsinghua University Beijing 100084 China

Video compression technologies are essential in video streaming application because they could save a great amount of network resources. However compressed videos are also extremely sensitive to packet loss which is inevitable in today's best effort IP network. Therefore we think accurate evaluation of packet loss impairment on compressed video is very important. In this work, we develop an analytic model to describe these impairments without the reference of the original video (NR) and propose an impairment metric based on the model, which takes into account both impairment length and impairment strength. To evaluate an impaired frame or video, we design a detection and evaluation algorithm (DE algorithm) to compute the above metric value. The DE algorithm has low computational complexity and is currently being implemented in the real-time monitoring module of our HDTV over IP system. The impairment metric and DE algorithm could also be used in adaptive system or be used to compare diffeient error concealment strategies.

关键词： packet loss, Video streaming, MPEG-2 video, Video quality, No-Reference

Quantum dynamics of dissociative adsorption of H_2 and D_2:The time-dependent wave packet method

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Science China Chemistry 1998年第4期41卷 403-409页

作者：关大任华东明张庆刚丁世良 1. Institute of Theoretical Chemistry Shandong University 250100 Ji’nan China 2. Institute of Atomic and Molecular Physics Shandong Normal University 250014 Ji’nan China

A time dependent quantum wave packet method was used to study the dynamics of dissociative adsorption of H 2 and D 2 on a flat and static surface. The molecule surface interaction is described using a modified London Eyring Polanyi Sato (LEPS) type potential for the H 2/Ni(100) system. The three dimensional (3 D) dissociation probabilities were calculated for different initial rovibrational states as a function of initial incident energies. Our results show that the dissociation of the diatomic rotational states whose quantum numbers satisfy j+m =odd is forbidden at low energies for the homonuclear H 2 and D 2 due to the selection rule. The effect of the rotational orientation of diatoms on adsorption predicts that the in plane rotation (m=j) is more favorable for dissociation than the out of plane rotation (m=0) . Enhanced dissociation for vibrationally excited molecules and the significant enhancement of the dissociation probability of H 2 when compared to D 2 were explained reasonably in terms of quantum mechanical zero point energies, the tunneling effect and the reflection from an activation barrier.

关键词： time dependent wave packet method dissociative adsorption quantum dynamics optical potential.

Wave packet solutions in a bounded equatorial ocean and its interannual and decadal variabilities

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Acta Oceanologica Sinica 2019年第3期38卷 45-59页

作者： Dongling Zhang Juan Zhu Xu Lu Ming Zhang Institute of Atmospheric Physics Chinese Academy of Sciences Special Office of Marine Environment National Marine Environment Forecasting Center Ministry of Natural Resources Atmospheric Circulation and Short-term Climate Prediction Laboratory of Meteorology and Marine Institute National University of Defense Technology 32021 Troop People's Liberation Army

Linearized shallow water perturbation equations with approximation in an equatorial β plane are used to obtain the analytical solution of wave packet anomalies in the upper bounded equatorial ocean. The main results are as follows. The wave packet is a superposition of eastward travelling Kelvin waves and westward travelling Rossby waves with the slowest speed, and satisfies the boundary conditions of eastern and western coasts, *** decay coefficient of this solution to the north and south sides of the equator is inversely proportional only to the phase velocity of Kelvin waves in the upper water. The oscillation frequency of the wave packet, which is also the natural frequency of the ocean, is proportional to its mode number and the phase velocity of Kelvin waves and is inversely proportional to the length of the equatorial ocean in the east-west direction. The flow anomalies of the wave packet of Mode 1 most of the time appear as zonal flows with the same direction. They reach the maximum at the center of the equatorial ocean and decay rapidly away from the equator, manifested as equatorially trapped waves. The flow anomalies of the wave packet of Mode 2 appear as the zonal flows with the same direction most of the time in half of the ocean, and are always 0 at the center of the entire ocean which indicates stagnation, while decaying away from the equator with the same speed as that of Mode 1. The spatial structure and oscillation period of the wave packet solution of Mode 1 and Mode 2 are consistent with the changing periods of the surface spatial field and time coefficient of the first and second modes of complex empirical orthogonal function(EOF)analysis of flow anomalies in the actual equatorial ocean. This indicates that the solution does exist in the real ocean, and that El Ni?o-Southern Oscillation(ENSO) and Indian Ocean dipole(IOD) are both related to Mode *** considering the Indonesian throughflow, we can obtain the length of bounded equa

关键词： bounded equatorial ocean wave packet solutions decadal variability Kelvin wave Rossby wave

Environmental variability study on the measured responses of Runyang Cablestayed Bridge using wavelet packet analysis

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Science China(Technological Sciences) 2008年第5期51卷 517-528页

作者： DING YouLiang LI AiQun LIU Tao College of Civil Engineering Southeast UniversityNanjing 210096China

The structural damage alarming method based on wavelet packet energy spectrum (WPES) for long-span cable-stayed bridges is presented through combination of ambient vibration test and wavelet packet analysis. The environmental variability in the measured WPES and damage alarming indices ERVD of the Runyang Cable-stayed Bridge are discussed in detail using the wavelet packet analysis of the measured acceleration responses of the bridge under daily environmental conditions. The analysis results reveal that the actual environmental conditions including traffic loadings, environmental temperature and typhoon loadings have remarkable correlations with the measured WPES. The changes of environmental temperature have a long-term trend influence on the WPES, while the influences of traffic and typhoon loadings on the measured WPES of the bridge present instantaneous changes because of the nonstationary properties of the loadings. The analysis results of the measured responses further reveal that the damage alarming indices ERVD can sensitively reflect the influences of environmental temperature and typhoon loadings on the dynamic properties of Runyang Cable-stayed Bridge. Therefore, the proposed structural damage alarming indices ERVD under ambient vibrations are suitable for real-time damage alarming for long-span cable-stayed bridges.

关键词： cable-stayed bridge wavelet packet analysis wavelet packet energy spectrum ambient vibration structural damage alarming

Measurement of the fluidized velocity in gas-solid fluidized beds based on AE signal analysis by wavelet packet transform

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Science China Chemistry 2007年第2期50卷 284-289页

作者： WANG JingDai YANG YongRong GE PengFei SHU WeiJie HOU LinXi Department of Chemical and Biochemical Engineering State Key Laboratory of Chemical EngineeringPolymer Reaction Engi-neering DivisionZhejiang UniversityHangzhou 310027China College of Chemical Engineering and Materials Science Ningbo UniversityNingbo 315211China

An energy distribution theory was presented based on regular evolvement of energy fraction of acous-tic signals with fluidization velocity. Wavelet packet analysis was used in processing the acoustic sig-nals originated from particle impact on the wall of a fluidized bed. A new criterion of judging incipient fluidization(Umf) velocity and minimum turbulent velocity(Umt) was proposed according to the energy distribution theory. Experiments were performed with five groups of high density polyethylene(PE) particles and one bimodal PE to acquire incipient fluidization velocity and minimum turbulent velocity by using the criterion. The feasibility of this method in obtaining characteristic fluidization parameters was further verified by comparing it to results from the pressure drop method and the empirical value from industry.

关键词： fluidized bed minimum fluidization velocity minimum turbulent velocity acoustic emission wavelet packet transform

Research on seasonal correlation of wavelet packet energy spectrum and temperature of Runyang Suspension Bridge

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Science China(Technological Sciences) 2009年第6期52卷 1776-1785页

作者： YouLiang Ding AiQun Li Jun Sun Yang Deng School of Civil Engineering Southeast University Nanjing 210096 China

In order to establish an environmental-condition-normalized structural damage alarming method, the seasonal correlation analysis of wavelet packet energy spectrum (WPES) and temperature of Runyang Suspension Bridge is performed by means of the 236-day health monitoring data. The analysis results reveal that the measured WPES has remarkable seasonal correlation with the environmental temperature. The seasonal change of environmental temperature accounts for the variation of the damage alarming parameter I p of the dominant frequency bands with an averaged variance of 200%. The statistical modeling technique using a 6th-order polynomial is adopted to formulate the correlation between the WPES and temperature, on the basis of which the abnormal changes of measured damage alarming parameter I p are detected using the mean value control chart. It is found that the proposed method can effectively eliminate temperature complications from the time series of WPES and exhibit good capability for detecting the damage-induced 10% variances of the damage alarming parameter I p . And the proposed WPES-based method is superior the modal frequency and hence is more suitable for online real-time damage alarming for long-span bridges.

关键词： structural damage alarming wavelet packet energy spectrum wavelet packet analysis temperature seasonal correlation suspension bridge

Wave-packet method for instability of three-dimensionalboundary layer of swept wing

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Chinese Science Bulletin 1998年第6期43卷 461-464页

作者： ZHAO Gengfu Department of Physics, Tianjin University, Tianjin 300072, China Department of Physics Tianjin University Tianjin China

A wave-packet method is proposed to study evolution the behavior of disturbances in 3-D boundary layer on a swept plate. It is proved that the constant-phase lines are equivalent to the streaks observed in flow-visual... 详细信息

关键词： swept plate wave packet structure of streaks.

Time-dependent wave packet approach to the pulse delay effect upon RbI photoelectron spectrum

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Science China Chemistry 2006年第3期49卷 214-218页

作者： LIU Chunhua MENG Qingtian ZHANG Qinggang College of Physics and Electronics Shandong Normal University Jinan 250014 China College of Physics and Electronics Shandong Normal University Jinan 250014 China College of Physics and Electronics Shandong Normal University Jinan 250014 China

The time-resolved photoelectron spectrum (TRPES) of Rbl molecule is simulatedusing the time-dependent wave-packet method. Both the normal three-photon ionization process andauto-ionization process are involved in the simulation. The calculated results show that the changeof delay time will influence the shape of the photoelectron spectrum (PES), and the influence issubstantially due to the existence of the crossing between excited states and the strong laser fieldwhich will change the position of relevant curves.

关键词： time-dependent wave packet method, multiphoton ionization (MPI), time-resolved photoelectron spectrum (TRPES), auto-ionization.

Three-dimensional quantum dynamics study of vibrational predissociation of HeI_2 van der Waals molecule for low vibrational excitation using the time-dependent wave packet method

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Science China Chemistry 1997年第4期40卷 442-448页

作者：关大任赵显邓从豪 John Z.H.Zhang Institute of Theoretical Chemistry Shandong UniversityJinan 250100China Department of Chemistry New York UniversityNew YorkNY 10003USA

Three-dimensional quantum mechanical calculations for vibrational predissociation of HeI2(B) van der Waals molecules are presented using the time-dependent wave packet technique within the golden rule approxima *** total and partial decay widths,lifetimes,rates and their dependence on initial vibrational states were obtained for HeI2 at low initial vibrational excited *** calculations show that the calculated tota decay widths,lifetimes and rates agree well with those extrapolated from experimental data available The predicted total decay widths as a function of initial vibrational states exhibit highly nonlinear *** very short propagation time (*** 1 ps) required in the golden rule wave packet calculation is determined by the duration time of the final state inter-action between the fragments on the vibrationally deexcited adiabatic potential *** final state interaction between the fragments is shown to play an important role in determining the final rotational distribution This interpreta tion clearly explains the dynamical effect that the final rotational distribution shifts to the lower rotational energy levels as the initial vibrational quantum number v increases.

关键词： time-dependent golden rule wave packet approach vibrational predissociation HeI2 van der Waats molecule decay widths final rotational distribution