the purpose of this study is to develop a diagnosis and simulation tool for a circulatory system model. We use Coleman's (1979) dynamic model Human, which consists of 25 modules including equations of about 1000 l...
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the purpose of this study is to develop a diagnosis and simulation tool for a circulatory system model. We use Coleman's (1979) dynamic model Human, which consists of 25 modules including equations of about 1000 lines, over 200 variables, and over 100 static parameters. We propose a qualitative method for understanding causal propagation of variables in the model structure. the proposed method: generates cause and effect relations between variables; visualizes a hierarchical directed graph of variables; and enables to trace the hierarchy of the circulatory model.
An adaptive fuzzy sliding-mode control (AFSMC) design method is proposed to control an induction servomotor system. the proposed AFSMC system comprises a fuzzy controller and a compensation controller. the fuzzy contr...
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ISBN:
(纸本)0780370783
An adaptive fuzzy sliding-mode control (AFSMC) design method is proposed to control an induction servomotor system. the proposed AFSMC system comprises a fuzzy controller and a compensation controller. the fuzzy controller is used to mimic an ideal computational controller. the compensation controller is designed to compensate for the difference between the ideal computational controller and the fuzzy controller. All parameters in the proposed AFSMC system are tuned in the Lyapunov sense; thus the stability of the system can be guaranteed. Simulation and experimental results verify that the proposed design method can achieve satisfactory control performance with regard to parameter variations and external disturbance.
In modular and hierarchical evolutionary design of Takagi-Sugeno (T-S) fuzzy systems, an important issue involves the determination of an effective procedure to optimize rule consequent parameters. All the aspects ass...
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In modular and hierarchical evolutionary design of Takagi-Sugeno (T-S) fuzzy systems, an important issue involves the determination of an effective procedure to optimize rule consequent parameters. All the aspects associated withthe antecedent part of each fuzzy rule are evolved through generations, and given a specification of the antecedent part of the rules that compose a candidate fuzzy system, the best set of consequent parameters should be determined. this paper investigates the use of global and local least squares optimization procedures to perform this task. Function approximation problems are solved to test the performance of the evolutionary process in comparison with alternative solutions.
this paper describes a model of metabolic networks that uses fuzzy cognitive maps. Nodes of the map represent specific biochemicals such as proteins, RNA, and small molecules, or stimuli, such as light, heat, or nutri...
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this paper describes a model of metabolic networks that uses fuzzy cognitive maps. Nodes of the map represent specific biochemicals such as proteins, RNA, and small molecules, or stimuli, such as light, heat, or nutrients. Edges of the map capture regulatory and metabolic relationships found in biological systems. these relationships are established by a domain expert, the biological literature, and extracted from RNA microarray data. this work is part of the development of a software tool, FCModeler, which models and visualizes metabolic networks. A model of the metabolism of the plant hormone gibberellin in Arabidopsis is used to show the capabilities of the fuzzy model.
Modern train traffic systems have to fulfill high requirements on service reliability and availability. this becomes especially important with competitive transport markets. Train operators can only meet withthese re...
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Modern train traffic systems have to fulfill high requirements on service reliability and availability. this becomes especially important with competitive transport markets. Train operators can only meet withthese requirements by quickly developing an efficient action in case of traffic disturbances. this paper describes a dispatching support system which employs fuzzy expert knowledge. the approach is based on a fuzzy Petri net notion that combines the graphical power of Petri nets and the capabilities of fuzzy sets to model rule-based expert knowledge in a decision support system. An assistant system for train traffic control is presented, and the advantages of this fuzzy Petri net notion are shown in the context of a complex railway on-line control problem.
A strategy for dynamic system failure detection and diagnosis is proposed, based on sliding mode observers, employed for residual generation with discrimination among the error subspaces, and a fuzzy neural network us...
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A strategy for dynamic system failure detection and diagnosis is proposed, based on sliding mode observers, employed for residual generation with discrimination among the error subspaces, and a fuzzy neural network used for pattern classification. A control reconfiguration scheme is proposed, employing boththe fault diagnosis information and the robust observer generated data. the resulting structure has been evaluated in a simulated D.C. electric drive.
Incomplete, ambiguous, or rapidly changing requirements can have a profound impact on the quality and cost of software development. In an effort to provide a more rigorous approach to flight-critical system developmen...
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Incomplete, ambiguous, or rapidly changing requirements can have a profound impact on the quality and cost of software development. In an effort to provide a more rigorous approach to flight-critical system development, Rockwell Collins used a formal specification modeling approach to develop the mode control logic of a Flight Guidance system (FGS) for a General Aviation class aircraft Rockwell Collins later used an early version of Test Automation Framework (TAF) approach for model-based analysis and test automation to analyze the requirement model and generate tests for a new implementation of the FGS systemthe TAF approach integrates various government and commercially available model development and test generation tools to support defect prevention and automated testing of systems and software. this paper describes the TAF model-based verification approach. It summarizes the new model and implementation errors that have been discovered. It briefly describes how the TAF approach can be used to locate requirement defects early in the development process, reduce manual test development effort, and reduce rework. It describes how the use of model-based development and test automation can be effectively used in the development and verification of systems that must meet the highest standards of safety, reliability, and quality.
this paper considers the problem of detecting local linear substructures of a system in a high-dimensional data space by applying a fuzzy clustering technique. We propose a linear fuzzy clustering method using eigenva...
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this paper considers the problem of detecting local linear substructures of a system in a high-dimensional data space by applying a fuzzy clustering technique. We propose a linear fuzzy clustering method using eigenvalues of the fuzzy scatter matrix in the objective function for optimizing the dimensional coefficients. the optimal solutions for the objective function and some illustrative examples are shown in this paper.
Describes an automatically online tuned fuzzy navigation system for an autonomous robot using a modular structure to generate the angular speed as a function of the sensor data. the goal is to obtain a reactive behavi...
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Describes an automatically online tuned fuzzy navigation system for an autonomous robot using a modular structure to generate the angular speed as a function of the sensor data. the goal is to obtain a reactive behavior, such as wall-following, withthe adaptivity necessary for coping with large modifications in the physical characteristics of the robot. For this behavior, the building of the navigation controller is done entirely online by the optimization of a zero-order Takagi-Sugeno fuzzy inference system (FIS) by a backpropagation-like algorithm. It is used to minimize a cost function that is made up of a quadratic error term and a weight decay term that prevents excessive growth of the parameters of the consequent part. the procedure is performed entirely online, but in two steps. the first one is done on a miniature robot or on a dedicated simulator. then the obtained controller is transferred to the real robot and a further optimization step is performed. At the end of the procedure, it is possible to extract knowledge by interpreting the result parameters in a symbolic form. One can notice that the two tables deduced for the miniature robot and for the real robot are very close with respect to their linguistic concepts. Moreover, these two automatically extracted rule tables are quite close to those written empirically, but we can observe that some human expertise rules work wrongly because the expert doesn't expect a particular situation. In fact, the main advantage of this procedure is the optimization of the controller with respect to the actual characteristics of the robot. that means that, for example, the rough manual tuning of the global gain acting on the width of the universe of discourse is replaced by a fine local automatic tuning, and this improves the performance very significantly. this method is simple, economical and safe, since it is done on a miniature robot. It leads to a very quick and efficient optimization technique.
the paper presents the development of an expert system modeled by using connectionist and fuzzy paradigms for fault detection in the Itaipu Hydroelectric company. For this purpose, a rule based knowledge system alread...
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the paper presents the development of an expert system modeled by using connectionist and fuzzy paradigms for fault detection in the Itaipu Hydroelectric company. For this purpose, a rule based knowledge system already in use by Itaipu operation has been taken as reference. the main aim was the development of the NEUFI Production system (NEUro-Fuzzy for Itaipu), whose knowledge base contains rules modeled by the neuro-fuzzy architecture. To make the implementation of the NEUFI Production system easier, a simulator, entitled Neuro-Fuzzy Simulator, was also developed, which allows training and writing of neuro-fuzzy networks.
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