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MARKOV - A COMPUTER-PROGRAM FOR MULTISTATE MARKOV-MODELS WITH COVARIABLES

COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 1995年第2期47卷 147-156页

作者： MARSHALL, G GUO, WS JONES, RH UNIV COLORADO HLTH SCI CTRSCH MEDDEPT PREVENT MED & BIOMETRDENVERCO 80262

This paper discusses a computer program, called MARKOV, designed to fit a multi-state Markov model with covariables, with a particular emphasis on the analysis of survival data. The Markov model consists of k - 1 transient disease states and one absorbing state. The exact transition times are not observed, except in situations such as death. Baseline transition intensities and regression coefficients are estimated via the method of maximum likelihood using a quasi-newton optimization algorithm. The program's output includes the parameter estimates, the standard error of the estimates, the matrix of the correlation of the estimates and minus two times the log-likelihood function, evaluated at the initial values and at the maximum likelihood estimates. Optionally, survival curves can be generated from each transient state, for one or more combination of covariable values and simple tests about the parameters. The program is illustrated by using a four-state model to determine factors influencing diabetic retinopathy in young subjects with insulin-dependent diabetes mellitus.

关键词： MULTISTATE MODELS MARKOV PROCESSES SURVIVAL ANALYSIS quasi-newton algorithm TIME-DEPENDENT COVARIABLES DIABETIC RETINOPATHY

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Dynamic optimization of constrained semi-batch processes using Pontryagin's minimum principle An effective quasi-newton approach

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COMPUTERS & CHEMICAL ENGINEERING 2017年 99卷 135-144页

作者： Aydin, Erdal Bonvin, Dominique Sundmacher, Kai Max Planck Inst Dynam Complex Tech Syst Sandtorstr 1 D-39106 Magdeburg Germany Ecole Polytech Fed Lausanne Lab Automat CH-1015 Lausanne Switzerland Otto von Guericke Univ Univ Pl 2 D-39106 Magdeburg Germany

This work considers the numerical optimization of constrained batch and semi-batch processes, for which direct as well as indirect methods exist. Direct methods are often the methods of choice, but they exhibit certain limitations related to the compromise between feasibility and computational burden. Indirect methods, such as Pontryagin's Minimum Principle (PMP), reformulate the optimization problem. The main solution technique is the shooting method, which however often leads to convergence problems and instabilities caused by the integration of the co-state equations forward in time. This study presents an alternative indirect solution technique. Instead of integrating the states and co-states simultaneously forward in time, the proposed algorithm parameterizes the inputs, and integrates the state equations forward in time and the co-state equations backward in time, thereby leading to a gradient-based optimization approach. Constraints are handled by indirect adjoining to the Hamiltonian function, which allows meeting the active constraints explicitly at every iteration step. The performance of the solution strategy is compared to direct methods through three different case studies. The results show that the proposed PMP-based quasi-newton strategy is effective in dealing with complicated constraints and is quite competitive computationally. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Constrained dynamic optimization Pontryagin's minimum principle Indirect optimization methods quasi-newton algorithm Semi-batch processes

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Image-based robot motion simulation

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OPTICS COMMUNICATIONS 2002年第4-6期205卷 257-263页

作者： Zhao, QJ Sun, ZQ Tsinghua Univ Dept Comp Sci & Tecnol Beijing 100084 Peoples R China

This paper describes an image-based robot animation technique. The technique utilizes eigen space method to generate compact representations of images from a set of reference images. A wavelet neural network is used to learn the relationship between robot joints and image representations. The learning algorithm is quasi-newton algorithm with Levenberg-Marquardt modifications. The trajectory in the joint space is first planned to generate a joint sequence. A corresponding sequence of representations can be obtained through the trained wavelet neural network and the image sequence can be synthesized using the result of eigen space method. No a priori models of robot and camera or any calibrations are needed. The virtual motion of the robot UP6 is demonstrated. (C) 2002 Elsevier Science B.V. All rights reserved.

关键词： robot motion simulation eigen space method wavelet neural network quasi-newton algorithm

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New approach for the nonlinear programming with transient stability constraints arising from power systems

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COMPUTATIONAL OPTIMIZATION AND APPLICATIONS 2010年第3期45卷 495-520页

作者： Tong, Xiaojiao Wu, Soon-Yi Zhou, Renjun Natl Cheng Kung Univ Inst Appl Math Tainan 70101 Taiwan Changsha Univ Sci & Technol Coll Math & Comp Sci Changsha Hunan Peoples R China Natl Ctr Theoret Sci Tainan Taiwan Changsha Univ Sci & Technol Coll Elect & Informat Changsha 410076 Hunan Peoples R China

This paper presents a new approach for solving a class of complicated nonlinear programming problems arises from optimal power flow with transient stability constraints (denoted by OTS) in power systems. By using a functional transformation technology proposed in Chen et al. (IEEE Trans. Circuits Syst. I Fundam. Theory Appl. 48:327-339, [2001]), the OTS problem is transformed to a semi-infinite programming (SIP). Then based on the KKT (Karush-Kuhn-Tucker) system of the reformulated SIP problem and the finite approximation technology, an iterative method is presented, which develops Wu-Li-Qi-Zhou' (Optim. Methods Softw. 20:629-643, [2005]) method. In order to save the computing cost, some typical computing technologies, such as active set strategy, quasi-newton method for the subproblems coming from the finite approximation model, are addressed. The global convergence of the proposed algorithm is established. Numerical examples from power systems are tested. The computing results show the efficiency of the new approach.

关键词： Optimal power flow (OPF) Transient stability constraint (TSC) Semi-infinite programming (SIP) quasi-newton algorithm

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A semi-infinite programming algorithm for solving optimal power flow with transient stability constraints

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JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2008年第2期217卷 432-447页

作者： Tong, Xiaojiao Ling, Chen Qi, Liqun Hong Kong Polytech Univ Dept Appl Math Kowloon Hong Kong Peoples R China Zhejiang Univ Finance & Econ Sch Math & Stat Hangzhou Zhejiang Peoples R China Changsha Univ Sci & Technol Inst Math Changsha Hunan Peoples R China

This paper proposes a new algorithm for solving a type of complicated optimal power flow (OPF) problems in power systems, i.e., OPF problems with transient stability constraints (OTS). The OTS is converted into a semi-infinite programming (SIP) via some suitable function analysis. Then based on the KKT system of the reformulated SIP, a smoothing quasi-newton algorithm is presented in which the numerical integration is used. The convergence of the algorithm is established. An OTS problem in power system is tested, which shows that the proposed algorithm is promising. (C) 2007 Elsevier B.V. All rights reserved.

关键词： optimal power flow transient stability constraint semi-infinite programming quasi-newton algorithm

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Symbolization assisted SVM classifier for noisy data

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PATTERN RECOGNITION LETTERS 2004年第4期25卷 495-504页

作者： Kumar, R Kulkarni, A Jayaraman, VK Kulkarni, BD Natl Chem Lab Div Chem Engn Pune 411008 Maharashtra India

The paper reports on the robust pattern classification of experimental data using a combined approach of symbolization followed by support vector machine (SVM) classification. Symbolization of data removes unwanted features such as noise whereas SVM provides the classification. The SVM parameters are tuned on-line using a genetic-quasi-newton algorithm. Benchmark examples illustrate the proposed approach. (C) 2004 Elsevier B.V. All rights reserved.

关键词： symbolization SVM classification genetic algorithm quasi-newton algorithm

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Damage Evolution and Post-peak Gas Permeability of Raw Coal Under Loading and Unloading Conditions

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TRANSPORT IN POROUS MEDIA 2017年第3期117卷 465-480页

作者： Zhang, Xian-meng Zhang, Dong-ming Leo, Chin Jian Yin, Guang-zhi Feng, Dan Liyanapathirana, D. S. Chongqing Univ State Key Lab Coal Mine Disaster Dynam & Control Chongqing 400044 Peoples R China Chongqing Univ Coll Resources & Environm Sci Chongqing 400044 Peoples R China Western Sydney Univ Sch Comp Engn & Math Locked Bag 1797 Penrith NSW 2751 Australia

Coalbed methane, a naturally occurring gas in coal, is regarded as a relatively clean-burning and eco-friendly resource. During mining, coalbed methane may be leaked to the environment, leading to potential coal mine catastrophes such as coal and gas outbursts, and gas explosions. In the interest of mine stability, and to enhance resource recovery and utilisation, it is fundamentally important to understand the permeability characteristics of coal, in particular its post-peak permeability behaviour. In this paper, an in-house developed tri-axial apparatus with the ability to investigate coupled thermal-hydrological-mechanical behaviour under servo-controlled seepage has been used to carry out a series of gas permeation experiments in coal samples. The coal samples were subjected to tri-axial tests, including the simulation of coal extraction by unloading the confining pressure applied on the test specimens. The deformation and permeability characteristics of raw coal during these tests were recorded. The volume changes of the coal samples during the tests were observed to occur in three stages: Stage 1: contraction, Stage 2: little or no volume change, and Stage 3: dilation. Corresponding to the volume changes, the gas seepage can also be divided into three stages: seepage decrease, steady seepage, and accelerated seepage. Based on the observed behaviour of coal samples during the tri-axial permeation tests, an analytical model to simulate damage evolution and its effect on the permeability of coal containing gas is proposed in this paper. It may be used to study the evolution of permeability with stress changes, and to provide insights into coal and gas outbursts in practice.

关键词： Coal containing gas Permeability Damage evolution Volumetric strain quasi-newton algorithm

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Minimization of Weighted Pole and Zero Sensitivity for State-Space Digital Filters

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2016年第1期63卷 103-113页

作者： Hinamoto, Takao Doi, Akimitsu Lu, Wu-Sheng Hiroshima Univ Higashihiroshima 7398527 Japan Hiroshima Inst Technol Fac Engn Hiroshima 7315193 Japan Univ Victoria Dept Elect & Comp Engn Victoria BC V8W 3P6 Canada

This paper presents a systematic study of pole and zero sensitivity minimization for state-space digital filters in several different yet related settings. First, a new weighted measure for pole and zero sensitivity for state-space digital filters is proposed and the problem of minimizing this measure is investigated. To this end, two efficient iterative techniques for minimizing this measure are developed by employing a quasi-newton algorithm and relying on a recursive matrix equation, respectively. Furthermore, minimization of the proposed sensitivity measure subject to l(2)-scaling constraints is examined by extending the two aforementioned solution methods-one converts the constrained optimization problem at hand into an unconstrained problem and solves it using a quasi-newton algorithm, while the other relaxes the constraints into a single constraint on matrix trace and solves the relaxed problem with an effective matrix iteration scheme. In addition, a simple yet novel method for the minimization of a zero sensitivity measure subject to minimal pole sensitivity is explored by pursuing an optimal coordinate transformation matrix. Simulation studies are presented to demonstrate the validity and effectiveness of the proposed techniques.

关键词： IIR digital filter Lagrange function l(2)-scaling overflow oscillation pole and zero sensitivity quasi-newton algorithm sensitivity minimization state-space model

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Evaluation of optimization techniques for parameter estimation: Application to ethanol fermentation considering the effect of temperature

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PROCESS BIOCHEMISTRY 2006年第7期41卷 1682-1687页

作者： Rivera, Elmer Ccopa Costa, Aline C. Atala, Daniel I. P. Maugeri, Francisco Maciel, Maria R. Wolf Maciel Filho, Rubens Univ Estadual Campinas Lab Optimizat Design & Adv Control Sch Chem Engn BR-13081970 Campinas SP Brazil Univ Estadual Campinas Dept Food Engn Sch Food Engn BR-13081970 Campinas SP Brazil

Optimization techniques are evaluated to estimate the kinetic model parameters of batch fermentation process for ethanol production using Saccharomyces cerevisiae. Batch experimental observations at five temperatures (28, 31, 34, 37 and 40 degrees C) are used to formulate the parameter estimation problem. The potential of quasi-newton (QN) and Real-Coded Genetic algorithm (RGA) to solve the estimation problem is considered to find out the optimal solution. Subsequently, the optimized parameters (mu(max) X-max, P-max, Y-x and Y-px) were characterized by correlation functions assuming temperature dependence. The kinetic models optimized by QN and RGA describe satisfactorily the batch fermentation process as demonstrated by the experimental results. (c) 2006 Elsevier Ltd. All rights reserved.

关键词： ethanol fermentation batch fermentation parameter estimation temperature effect genetic algorithm quasi-newton algorithm

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Improved semidefinite bounding procedure for solving Max-Cut problems to optimality

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MATHEMATICAL PROGRAMMING 2014年第1-2期143卷 61-86页

作者： Krislock, Nathan Malick, Jerome Roupin, Frederic INRIA Grenoble Rhone Alpes Grenoble France Univ British Columbia Dept Comp Sci Vancouver BC V6T 1W5 Canada No Illinois Univ Dept Math Sci De Kalb IL 60115 USA CNRS Lab J Kunztmann Grenoble France Univ Paris 13 Sorbonne Paris Cite CNRS LIPNUMR 7030 F-93430 Villetaneuse France

We present an improved algorithm for finding exact solutions to Max-Cut and the related binary quadratic programming problem, both classic problems of combinatorial optimization. The algorithm uses a branch-(and-cut-)and-bound paradigm, using standard valid inequalities and nonstandard semidefinite bounds. More specifically, we add a quadratic regularization term to the strengthened semidefinite relaxation in order to use a quasi-newton method to compute the bounds. The ratio of the tightness of the bounds to the time required to compute them depends on two real parameters;we show how adjusting these parameters and the set of strengthening inequalities gives us a very efficient bounding procedure. Embedding our bounding procedure in a generic branch-and-bound platform, we get a competitive algorithm: extensive experiments show that our algorithm dominates the best existing method.

关键词： Combinatorial optimization Semidefinite programming quasi-newton algorithm Triangle inequalities

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