检索结果-内蒙古大学图书馆

AN INVARIANT MEASURE APPROACH TO THE CONVERGENCE OF STOCHASTIC APPROXIMATIONS WITH STATE DEPENDENT NOISE

SIAM JOURNAL ON CONTROL AND OPTIMIZATION 1984年第1期22卷 13-27页

作者： KUSHNER, HJ SHWARTZ, A BROWN UNIV DEPT APPL MATHPROVIDENCERI 02912

A new method is presented for quickly getting the ODE (ordinary differential equation) associated with the asymptotic properties of the stochastic approximation $X_{n + 1} = X_n + a_n f(X_n ,\zeta _n )$ (or the projected algorithm for the constrained problem). Either $a_n \to 0$, or $a_n $ can be constant, in which case the analysis is on the sequence obtained when $a \to 0$. The method requires that $\{ X_n ,\zeta _{n - 1} \} $ be Markov with a “Feller” transition function, but little else. The simplest result requires that if $X_n \equiv x$, the corresponding noise process $\{ \zeta _n (x),n \geqq 0\} $ have a unique invariant measure; but the “nonunique” case can also be treated. No mixing condition is required, nor the construction of averaged test functions, and $f(\cdot ,\cdot )$ need not be continuous. A detailed analysis of the way that $\{ \zeta _n \} $ varies with $\{ X_n \} $ is not required. For the class of sequences treated, the conditions seem easier to verify than for other methods. There are extensions to the non-Markov case. Two examples illustrate the power and ease of use of the approach. Aside from the advantages of the method in treating standard problems, it seems to be particularly useful for handling the type of iterative algorithms which arise in adaptive communication theory, where the dynamics are often discontinuous and the “noise” is often state-dependent due to the effects of feedback. If the noise $\{ \zeta _n \} $ is not “state-dependent,” then the Markov assumption can be dropped, and the method is even easier to use.

关键词： stochastic approximation recursive algorithms adaptive control

来源：评论

学校读者我要写书评

暂无评论

EFFICIENT FORMULATION OF COMPUTER algorithms TO PLAN MACHINING PROCESSES

引用

JOURNAL OF MANUFACTURING SYSTEMS 1983年第1期2卷 31-38页

作者： LEWIS, WC BARTLETT, E FINFTER, II BARASH, MM Rensselaer Polytechnic Institute Troy New York USA Troy New York USA Armament Development Authority Haifa Israel Purdue University West Lafayette Indiana USA

A tool oriented approach to automating the planning of machining processes is presented. The approach is intended to permit efficient formulation and implementation of process planning capabilities, and to keep constant the effort required to add new capabilities to a program. Process planning is modeled as a collection of functions and a recursive algorithm. Because the process planning procedures do not interact and are treated identically by the recursive procedure, a program can grow in size without growing in complexity. Software was developed in order to test the concepts. Feasible process plans were generated, and time to execute was short. Efforts to add a new process planning capability was independent of the number of capabilities previously provided. This approach can efficiently produce general and flexible process planning programs.

关键词： Process Planning Algorithm Computerized Process Planning Automatic Tool Identification Structured Programming recursive algorithms

来源：评论

学校读者我要写书评

暂无评论

EXPERIMENTS IN TEXT RECOGNITION WITH BINARY N-GRAM AND VITERBI algorithms

引用

IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE 1982年第5期4卷 520-530页

作者： HULL, JJ SRIHARI, SN Department of Computer Science State University of New York at Buffalo Amherst NY 14226

The binary n-gram and Viterbi algorithms have been suggested as alternative approaches to contextual postprocessing for text produced by a noisy channel such as an optical character recognizer. This correspondence describes the underlying theory of each approach in unified terminology, and presents new implementation algorithms for each approach. In particular, a storage efficient data structure is proposed for the binary n-gram algorithm and a recursive formulation is given for the Viterbi algorithm. Results of extensive experiments with each algorithm are described.","doi":"10.1109/TPAMI.1982.4767297","publicationTitle":"IEEE Transactions on Pattern Analysis and Machine Intelligence","startPage":"520","endPage":"530","rightsLink":"http://***/AppDispatchServlet?publisherName=ieee&publication=0162-8828&title=Experiments+in+Text+Recognition+with+Binary+n-Gram+and+Viterbi+algorithms&isbn=&publicationDate=Sept.+1982&author=Jonathan+J.+Hull&ContentID=10.1109/TPAMI.1982.4767297&orderBeanReset=true&startPage=520&endPage=530&volumeNum=PAMI-4&issueNum=5","displayPublicationTitle":"IEEE Transactions on Pattern Analysis and Machine Intelligence","pdfPath":"/iel5/34/4767284/***","keywords":[{"type":"IEEE Keywords","kwd":["Text recognition","Viterbi algorithm","Optical character recognition software","Character recognition","Feature extraction","Text processing","Error correction","Context modeling","Optical noise","Data structures"]},{"type":"Author Keywords ","kwd":["text processing","Contextual pattern recognition","data structures","recursive algorithms","storage complexity"]}],"allowComments":false,"pubLink":"/xpl/***?punumber=34","issueLink":"/xpl/***?isnumber=4767284","standardTitle":"Experiments in Text Recognition with Binary n-Gram and Viterbi algorithms

关键词： Text recognition Viterbi algorithm Optical character recognition software Character recognition Feature extraction Text processing Error correction Context modeling Optical noise Data structures Author Keywords text processing Contextual pattern recognition data structures recursive algorithms storage complexity

来源：评论

学校读者我要写书评

暂无评论

Identification by the Stochastic Variant of the Steepest Descent Method

引用

IFAC Proceedings Volumes 1982年第4期15卷 1247-1251页

作者： F.Ζ. Unton Systems Research Institute Polish Academy of Sciences ul. Newelska 6 01-447 Warsaw Poland

The main problem considered is on-line identification by the stochastic approximation methods. Some modifications of the algorithms are introduced. The modified methods increases the efficiency of the algorithms with respect to number of observations of the system. Convergence with probability one to the true parameters is also obtained. Efficiency of the algorithms is tested on two fourth-order discrete-time systems.

关键词： Identification parameter estimation linear systems recursive algorithms

来源：评论

学校读者我要写书评

暂无评论

ANALYSIS OF A GENERAL recursive PREDICTION ERROR IDENTIFICATION ALGORITHM

引用

AUTOMATICA 1981年第1期17卷 89-99页

作者： LJUNG, L Department of Electrical Engineering Linköping University Linköping Sweden

A general class of algorithms for recursive identification of (stochastic) dynamical systems is studied. In this class, the discrepancy between the measured output and the output, predicted from previous data according to a candidate model (‘the prediction error’) is minimized over the model set using a stochastic approximation approach. It is proved that this class of methods has the same convergence properties as its off-line counterparts under mild and general assumptions. These assumptions do not, for example, include stationary conditions or conditions that the true system can be exactly represented within the model set. The considered class of methods contains as special cases several well-known algorithms. Other common recursive identification methods, like the extended least squares method and the extended Kalman filter can be interpreted as approximate prediction error methods with simplified gradient calculations. Therefore, the approach taken here, may also serve as a basis for unified description of many recursive identification methods.

关键词： convergence analysis Identification recursive algorithms

来源：评论

学校读者我要写书评

暂无评论

STOCHASTIC FRAMEWORK FOR recursive COMPUTATION OF SPLINE FUNCTIONS .2. SMOOTHING SPLINES

引用

JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS 1980年第2期30卷 255-268页

作者： WEINERT, HL BYRD, RH SIDHU, GS JOHNS HOPKINS UNIV DEPT MATH SCIBALTIMOREMD 21218 UNIV NACL AUTONOMA MEXICO INST INVEST MATEMAT APLICADES & SISTEMASMEXICO CITY 20MEXICO

Many of the optimal curve-fitting problems arising in approximation theory have the same structure as certain estimation problems involving random processes. We develop this structural correspondence for the problem of smoothing inaccurate data with splines and show that the smoothing spline is a sample function of a certain linear least-squares estimate. Estimation techniques are then used to derive a recursive algorithm for spline smoothing.

关键词： least-squares estimation recursive algorithms reproducing kernels Splien smoothing

来源：评论

学校读者我要写书评

暂无评论

The Global Error Approach to the Convergence and Accuracy of Complex recursive Identification algorithms

引用

IFAC Proceedings Volumes 1979年第8期12卷 1195-1202页

作者： Antoni Niederliński Instytut Automatyki Politechnika Slaska 44-100 Gliwice Poland

The global error is the identification error expressed expiIcItly as a function of all unknown system parameters, model parameters and external system inputs. It is used to transform the difficult problem of mean-square convergence and accuracy testing for recursive identification algorithms into a relatively simple problem of determining the properties of the solution for a polynomial equation. The method is introduced for the simple problem of closed-loop identification of time-discrete systems. Its full power is demonstrated for the case of the self-tuning regulator and self-tuning predictor.

关键词： Identification parameter estimation recursive algorithms accuracy of identification adaptive control prediction discrete-time systems

来源：评论

学校读者我要写书评

暂无评论

SELF-TUNING CONTROL

引用

PROCEEDINGS OF THE INSTITUTION OF ELECTRICAL ENGINEERS-LONDON 1979年第6期126卷 633-640页

作者： CLARKE, DW GAWTHROP, PJ Department of Engineering Science University of Oxford Oxford UK

Self tuning is an important new branch of control which is attracting increasing theoretical and practical interest. The objective of self tuning is to control systems with unknown constant or slowly varying parameters, so theoretical interest is concerned with the stability, performance and convergence of the recursive algorithms involved, while practical interest derives from its potential as a simple controller commissioning tool, both as a method for controlling time-varying or nonlinear plant over a range of operating points, and for dealing with batch problems where the plant or materials vary over successive batches. This paper summarises and expands previous work on the design of self-tuning controllers. It discusses the closed-loop properties of various classes of self tuner, convergence concepts and results, and some of the technical problems involved with implementing self tuners on small computers or microprocessors.

关键词： controller commissioning tool controllers microprocessor implemented systems Nonlinear control systems Control system analysis and synthesis methods performance recursive algorithms convergence computerised control control system synthesis self tuning control Controllers Control engineering computing nonlinear control systems

来源：评论

学校读者我要写书评

暂无评论

HIERARCHIES OF recursive COMPUTATIONS

引用

INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS 1979年第4期7卷 271-286页

作者： STIMSON, MJ SAVITCH, WJ UNIV CALIF SAN DIEGO DEPT APPL PHYS & INFORMAT SCIPROGRAM COMP SCILA JOLLACA 92093

A recursive version of the Turing machine model is used to analyze the time and storage complexity of recursive algorithms. Hierarchy theorems are proven for time and for width of recursion (the amount of storage used at a level). A particular language is shown to be the “hardest” language to recognize without recursion. Previous results relating recursive and non-recursive time bounded computations are sharpened.

关键词： Turing machine Tape complexity Time complexity recursive algorithms Nondeterministic algorithm Hierarchy 5.25 5.26 5.23

来源：评论

学校读者我要写书评

暂无评论

THEORETICAL-ANALYSIS OF recursive IDENTIFICATION METHODS

引用

AUTOMATICA 1978年第3期14卷 231-244页

作者： SODERSTROM, T LJUNG, L GUSTAVSSON, I LINKOPING UNIV DEPT ELECT ENGN S-58183 LINKOPING SWEDEN LUND INST TECHNOL DEPT AUTOMAT CONTROL S-22007 LUND 7 SWEDEN

In this paper five different recursive identification methods will be analyzed and compared, namely recursive versions of the least squares method, the instrumental variable method, the generalized least squares method, the extended least squares method and the maximum likelihood method. They are shown to be similar in structure and need of computer storage and time. Making use of recently developed theory for asymptotic analysis of recursive stochastic algorithms, these methods are examined from a theoretical viewpoint. Possible convergence points and their global and local convergence properties are studied. The theoretical analysis is illustrated and supplemented by simulations.

关键词： accuracy of identification convergence analysis Identification parameter estimation recursive algorithms

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：