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2019中国智能自动化大会(CIAC 2019)

作者： Ying Zhou Jing-song Yang Tong Wang Hong Wang Hebei University of Technology The 53rd Research Institute of CETGC 93756 Troops

The traditional system identification method based on least square method has the disadvantages of heavy computation and slow operation speed in a particular *** this paper,the off-line identification based on the equation error autoregressive model is studied by using the relaxation algorithm which is proved the unbiasedness and ***,on the basis of off-line identification parameters,the system is identified online by recursive relaxation algorithm that calculated by relaxation *** simulation results show that the recursive relaxation algorithm has good computational speed and identification accuracy in the multi-input-multi-output linear system.

关键词： relaxation algorithm Online identification Linear system Multiple input multiple output

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relaxation algorithms to find Nash equilibria with economic applications

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ENVIRONMENTAL MODELING & ASSESSMENT 2000年第1期5卷 63-73页

作者： Krawczyk, JB Uryasev, S Victoria Univ Wellington Commerce & Adm Fac Wellington New Zealand Univ Florida Dept Ind & Syst Engn Gainesville FL 32611 USA

Recent theoretical studies have shown that a relaxation algorithm can be used to find noncooperative equilibria of synchronous infinite games with nonlinear payoff functions and coupled constraints. In this study, we introduce an improvement to the algorithm, such as the steepest-descent step-size control, for which the convergence of the algorithm is proved. The algorithm is then tested on several economic applications. In particular, a River Basin Pollution problem is considered where coupled environmental constraints are crucial for the relevant model definition. Numerical runs demonstrate fast convergence of the algorithm for a wide range of parameters.

关键词： computational economics Nash equilibrium coupled constraints relaxation algorithm

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Vision-based correspondence using relaxation algorithms for particle tracking velocimetry

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MEASUREMENT SCIENCE AND TECHNOLOGY 2021年第2期32卷

作者： Benkovic, Theo Krawczynski, Jean-Francois Druault, Philippe Sorbonne Univ Inst Jean Le Rond dAlembert CNRS F-75005 Paris France

A new particle tracking algorithm is derived based on consolidated methods, with the aim of overcoming the current limits encountered with high particle density flows. The proposed method consists of an integration of the relaxation algorithm based on matching probabilities into vision-based features association concepts. Hybridization with PIV pre-analysis is suggested to help with the estimation of parameters. A dual calculation strategy is also developed in order to reduce the amount of spurious vectors. Simulation tests using synthetically generated images are carried out to evaluate the sensitivity of the proposed method to the particle image density, the background noise and the nature of the flow. Three flow configurations with a growing degree of complexity are successively considered: a 2D flow over a moving wall, a steady 2D Lamb-Oseen vortex ring, and a 3D unsteady homogeneous isotropic turbulence. The ability of the new tracking algorithm to provide better matching performances with high reliability than conventional techniques, out of a dense particle image field, is demonstrated.

关键词： PTV particle tracking relaxation algorithm vision-based technique high particle density

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A NOVEL SLIGHTLY COMPRESSIBLE MODEL FOR LOW MACH NUMBER PERFECT GAS FLOW CALCULATION

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Acta Mechanica Sinica 2002年第3期18卷 193-208页

作者：邓小刚庄逢甘 China Aerodynamics Research and Development Center P.O.Box 211 Mianyang Sichuan China 621000 Chinese Aerodynamic Society P.O.Box 849 Beijing China 100830

By analyzing the characteristics of low Mach number perfect gas flows, a novel Slightly Compressible Model (SCM) for low Mach number perect gas flows is derived. In view of numerical calculations, this model is proved very efficient, for it is kept within thep-v frame but does not have to satisfy the time consuming divergence-free condition in order to get the incompressible Navier-Stokes equation solution. Writing the equations in the form of conservation laws, we have derived the characteristic systems which are necessary for numerical calculations. A cell-centered finite-volume method with flux difference upwind-biased schemes is used for the equation solutions and a new Exact Newton relaxation (ENR) implicit method is developed. Various computed results are presented to validate the present model. Laminar flow solutions over a circular cylinder with wake developing and vortex shedding are presented. Results for inviscid flow over a sphere are compared in excellent agreement with the exact analytic incompressible solution. Three-dimensional viscous flow solutions over sphere and prolate spheroid are also calculated and compared well with experiments and other incompressible solutions. Finally, good convergent performances are shown for sphere viscous flows.

关键词： slightly compressible flow numerical simulations low Mach number flow calculations Newton iteration relaxation algorithm

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DETECTING MYOCARDIAL BOUNDARIES OF LEFT-VENTRICLE FROM A SINGLE FRAME 2DE IMAGE

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PATTERN RECOGNITION 1990年第7期23卷 799-806页

作者： CHOU, WS WU, CM CHEN, YC HSIEH, KS NATL TSING HUA UNIV INST ELECT ENGN HSINCHU 30043 TAIWAN VET GEN HOSP SHIH PAI DEPT PEDIAT CARDIOL SECT TAIPEI 112 TAIWAN

A new method for detecting myocardial boundaries of the left ventricle from a short-axis viewed, two-dimensional echocardiographic (2DE) image is presented. The method extracts the outer boundary based on an ideal echo-intensity image model and relaxation algorithm, while the endocardial border is detected by the principle employed by Klingler et al. with some modifications. The only a priori information needed in this method is to assign the approximated contraction center of the left ventricle. Neither the searching limits used in the radial search method nor information about rough positions of myocardial borders used in a plan-based detection scheme is required. Practical examples are given and illustrated. Methods for the generalization of the proposed method are discussed.

关键词： Two-dimensional echocardiography relaxation algorithm Binary morphology Border detection Model-based detection system

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Quantification and segmentation of brain tissues from MR images: A probabilistic neural network approach

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IEEE TRANSACTIONS ON IMAGE PROCESSING 1998年第8期7卷 1165-1181页

作者： Wang, Y Adali, T Kung, SY Szabo, Z Catholic Univ Amer Dept Elect Engn & Comp Sci Washington DC 20064 USA Georgetown Univ Sch Med Dept Radiol Washington DC 20007 USA Univ Maryland Baltimore Cty Dept Comp Sci & Elect Engn Baltimore MD 21250 USA Princeton Univ Dept Elect Engn Princeton NJ 08544 USA Johns Hopkins Med Inst Dept Radiol Baltimore MD 21205 USA

This paper presents a probabilistic neural network based technique for unsupervised quantification and segmentation of brain tissues from magnetic resonance images. Ht is shown that this problem can be solved by distribution learning and relaxation labeling, resulting in an efficient method that may be particularly useful in quantifying and segmenting abnormal brain tissues where the number of tissue types is unknown and the distributions of tissue types heavily overlap. The new technique uses suitable statistical models for both the pixel and context images and formulates the problem in terms of model-histogram fitting and global consistency labeling. The quantification is achieved by probabilistic self-organizing mixtures and the segmentation by a probabilistic constraint relaxation network. The experimental results show the efficient and robust performance of the new algorithm and that it outperforms the conventional classification based approaches.

关键词： finite mixture models image segmentation information theoretic criteria model estimation probabilistic neural networks relaxation algorithm

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The greedy strategy for optimizing the Perron eigenvalue

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MATHEMATICAL PROGRAMMING 2022年第1期193卷 1-31页

作者： Cvetkovic, Aleksandar Protasov, Vladimir Yu GSSI Laquila Italy DISIM Univ Aquila Laquila Italy Moscow MV Lomonosov State Univ Moscow Russia

We address the problems of minimizing and of maximizing the spectral radius over a compact family of non-negative matrices. Those problems being hard in general can be efficiently solved for some special families. We consider the so-called product families, where each matrix is composed of rows chosen independently from given sets. A recently introduced greedy method works very fast. However, it is applicable mostly for strictly positive matrices. For sparse matrices, it often diverges and gives a wrong answer. We present the "selective greedy method" that works equally well for all non-negative product families, including sparse ones. For this method, we prove a quadratic rate of convergence and demonstrate its efficiency in numerical examples. The numerical examples are realised for two cases: finite uncertainty sets and polyhedral uncertainty sets given by systems of linear inequalities. In dimensions up to 2000, the matrices with minimal/maximal spectral radii in product families are found within a few iterations. Applications to dynamical systems and to the graph theory are considered.

关键词： Iterative optimization method Non-negative matrix Spectral radius relaxation algorithm Cycling Spectrum of a graph Quadratic convergence Dynamical system Stability

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Joint road toll pricing and capacity development in discrete transport network design problem

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TRANSPORTATION 2017年第4期44卷 731-752页

作者： Xu, Meng Wang, Guangmin Grant-Muller, Susan Gao, Ziyou Beijing Jiaotong Univ State Key Lab Rail Traff Control & Safety 3 Shangyuan Residence Beijing 100044 Peoples R China China Univ Geosci Sch Econ & Management Wuhan 430074 Peoples R China Univ Leeds Inst Transport Studies 34-40 Univ Rd Leeds LS2 9JT W Yorkshire England Beijing Jiaotong Univ Sch Traff & Transportat 3 Shangyuan Residence Beijing 100044 Peoples R China

The paper demonstrates a method to determine road network improvements that also involve the use of a road toll charge, taking the perspective of the government or authority. A general discrete network design problem with a road toll pricing scheme, to minimize the total travel time under a budget constraint, is proposed. This approach is taken in order to determine the appropriate level of road toll pricing whilst simultaneously addressing the need for capacity. The proposed approach is formulated as a bi-level programming problem. The optimal road capacity improvement and toll level scheme is investigated with respect to the available budget levels and toll revenues.

关键词： Toll pricing Road development Discrete network design problem (DNDP) Bilevel programming relaxation algorithm

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Estimation of an N-L-N Hammerstein-Wiener model

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AUTOMATICA 2002年第9期38卷 1607-1614页

作者： Zhu, YC Eindhoven Univ Technol Fac Elect Engn Sect CS NL-5600 MB Eindhoven Netherlands

Estimation of a single-input single-output block-oriented model is studied. The model consists of a linear block embedded between two static nonlinear gains. Hence, it is called N-L-N Hammerstein-Wiener model. First, the model structure is motivated and the disturbance model is discussed. The paper then concentrates on parameter estimation. A relaxation iteration scheme is proposed by making use of a model structure in which the error is bilinear-in-parameters. This leads to a simple algorithm which minimizes the original loss function. The convergence and consistency of the algorithm are studied. In order to reduce the variance error, the obtained linear model is further reduced using frequency weighted model reduction. Simulation study will be used to illustrate the method. (C) 2002 Elsevier Science Ltd. All rights reserved.

关键词： identification nonlinear process block-oriented model parameter estimation relaxation algorithm

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Joint link-based credit charging and road capacity improvement in continuous network design problem

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TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE 2014年 67卷 1-14页

作者： Wang, Guangmin Gao, Ziyou Xu, Meng Sun, Huijun China Univ Geosci Sch Econ & Management Wuhan 430074 Peoples R China Beijing Jiaotong Univ Sch Traff & Transportat Beijing 100044 Peoples R China

In this paper, we will discuss the urban road network improvement problem from both supply and demand sides, and propose a bilevel programming model considering joint optimal link-based tradable credit charging scheme and road capacity improvement. The upper level decision-maker tries to minimize the total system travel time under a budget constraint by optimizing both link-based credit charging and road capacity improvement, whilst at the lower level considering the users' route choice behavior through the generalized travel time including the travel time and the converted time from the value of credit charging for using the link. Therefore, this proposed model integrates the improvement of the urban road network according to improving the road capacity with the given budget constraint and decreasing the travel demand with the tradable credit scheme. After presenting a relaxation algorithm, the numerical experiments on the nine node network are illustrated. Analysis shows that the proposed model is efficient in mitigating traffic congestion according to the less total system travel time than the other ways compared in this paper. The tradable credit scheme offers the better combination of cost-effectiveness, administrative flexibility and distributional fairness comparing with congestion pricing. Moreover, this tradable credit scheme is revenue neutral. (C) 2014 Elsevier Ltd. All rights reserved.

关键词： Continuous network design problem (CNDP) Bilevel programming problem relaxation algorithm Tradable credit scheme

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