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074 Acoustical surveillance of industrial plants: An approach using neural networks
1070
Abstracts
scnted structure eliminated the need for integer adjustments. search space was reduced by the use of precalculation, allowing the rapid calculation of feasible solutions. The neural-net structure was reliable in simulated operation and its performance was superior to structures which have been previously presented.
~l~•
073 Immune Networks Using Genetic Algorithms for Adaptive
Production Scheduling T. Fukuda, K. Morl, M. Tsuklyama, pp 353.356
An immune system has powerful abilities such as memory, endre~:a3gnitionand learning, in order to respond to invading antigens, the concepts are ~ to be appficable to many industrial applications, together with neural networks. This paper proposes an algorithm imitating the immune system to solve the optimization problem, partly by using a genetic algorithm. The proposed algorithm is shown to be capable of searching for a glolad solution, but not local solutions, through an illustrative example of a resource-atlocation problem.
074 Acoustical Surveillance of Industrial Plants: An Approach Using Neural Networks P. l)egoul, A. Lemer, pp 357-360 The exploitation of industrial processes makes more and more frequent use of un-line surveillance techniques in order to detect any malfunction early, and to give a diagnosis. A general surveillance approach which can be used for acoustical or vibratory signatures is proposed. This approach is decomposed into a preprocessing stage and a decision stage, and makes use of advanced signal-processing techniques, neural networks, and knowledge-based system. As an illustration, the acoustic surveillance of transient noises in an industrial process is presented.
075 Robot Vision System by Neural Network. Active Vision and Self.Learning Y. Mori, H. Kobayashi, K. Uchida, pp 361-364 This paper describes a robot vision system which finds a target object and focuses on it from a specified distance. A neural network is used as a decision maker which determines how to move the robot to reach the target object, on the basis of the image acquit~ by the camera. The camera is attached to the end of the robot ann; therefore, the relative positions of the target object and the end effector are considered. In the experiments, the task of the robot vision system is to capture the target objects at the center of the image. The validity of the proposed architecture is demonstrated.
076 Modeling and Analysis of Transfer Lines Using TimedEvent-Graphs J.E.R. Cury, C. Commault, pp 365-370 This paper deals with the problem of the modeling and analysis of transfer lines. A timed-event-graph model is obtained for transfer lines where machines are assmned to have a known cyclic behavior. On the basis of this model, analytical results concerning the performance of the system are derived for an isolated machine and for two machine lines separated by an intermediate buffer. These results relate line para~aeters and performance indices.
077 Multiple-Weighted Marked Graphs D.T. Chao, M. Zhou, D.T. Wang, pp 371-374 Theory regarding marked graphs is not applicable when concurrent systems must be constructed as a Pctri net in which each place has exactly one input and output transition and multiple arcs exist between a place and a transition. Many parallel programs and manufacturing systems capable of bulk production can be modeled as multiple-weighted marked graphs OVMGs). Motivated by the practical need to analyze their performance, this paper presents the conditions under which a WMGcan be evaluated. An application to a parallel computer system is also given.
078 Maximally Permissive Policies for Controlled Time Marked Graphs Y. Brave, B.H. Krogh, pp 375-378 This paper presents the formulation of the forbidden state problem for controlled time marked graphs, a class of timed Petn nets in which exogenous control inputs can force enabled transitions to fire at specified sampling times. An algorithm for computing a maximally permissive control policy is presented, based on the structural properties of the Petri-net model of the discrete-state transition logic. Properties of controlled time marked graphs and the application of the maximally permissive control algorithm are demonstrated for an example of the supervisory coordination of automated guided vehicles. 079 Petri Net Supervisors for Generalized Mutual Exclusion Constraints A. Giua, F. DiCesare, M. Silva, pp 379-382 The paper discusses the problem of enforcing generalized mutual exclusion constraints on place/transition nets with uncontrollable transitions. For a dass of Petri nets, marked graphs with control safe places, two Petri-net structures capable of enforcing these constraints are presented. The first is a monitor-based solution, the second a supervisory-based solution. Both structures are fully compiled, i.e., they are given as simpleplace/transition nets with no associated predicates, thus permtttmg the construction and analysis of a closed-loop-model of the controlled system.
080 Dispatching-Driven Deadlock Avoidance Controller Synthesis for Flexible Manufacturing Systems Fu-Shlung Hsleh, Shi-Chung Chang, pp 383-386 A new method for synthesizing deadlock avoidance controllers for the job- and machine-dispatching policies for a flexible manufacturing system into deadlock-free control actions is based on an umimed Petri-net formalism. It consists of a bottom-up approach for synthesizing a controlled production Petri-net model, a necessary and sufficient liveness condition, a sufficient procedure to test whether the liveness condition is retained after control action execution, and an algorithm that combines the test rocedure with the given dispatching policy. Such controllers eel> the FMS capable of repeating any of its operations, i.e.. live, and achieve high resource utilization under any given dispatching policy.
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081 A Class of Petri Nets for Modeling and Control of Flexible Manufacturing and Assembly Systems with Shared Resources Mu Der Jeng, F. DICesare, pp 387-390 A case study of a theory on the modular synthesis of Petri nets for the modeling and control of shared-resource systems ispresented. A class of live and bounded nets can be generated by the theory. The applicability of the theory is demonstrated using a fairly general flexible manufacturing and assembly system. 082 Parallel Simulation of Air Pollution Transport for Urban Decision Making A. Sydow, M. Schmidt, S. Unger, T. Lux, P. Mieth, R.-P. Schiifer, pp 391.394 The concept of an air pollution simulation environment to predict and manage smog situations is presented, consisting of data bases, a mesoseale meteorological model, an air chemistry model, and decision-suppor~ tools including result visualization. Simulation runs and scenario analyses of such numerically complex models take hours of computing time, even on today's supercomputers. A strategy for model decomposition and imp.lementation on massively parallel computers is therefore described. Simulation results are shown for an ozone smog situation in Berlin. 083 The Stochastic Control Problem of Investment Rate in a Production/Storage System: Main Results J.B. Ribelro do Val, J.L.F. Salles, pp 395-398 One of the simplest problems of optimal control of the investment rote in a production/storage system is presented here. Optimal solutions are fully characterized by means of the theory of continuous time control of piecewise deterministic processes. An efficient algorithm is proposed for which a recursive procedure
Abstracts
scnted structure eliminated the need for integer adjustments. search space was reduced by the use of precalculation, allowing the rapid calculation of feasible solutions. The neural-net structure was reliable in simulated operation and its performance was superior to structures which have been previously presented.
~l~•
073 Immune Networks Using Genetic Algorithms for Adaptive
Production Scheduling T. Fukuda, K. Morl, M. Tsuklyama, pp 353.356
An immune system has powerful abilities such as memory, endre~:a3gnitionand learning, in order to respond to invading antigens, the concepts are ~ to be appficable to many industrial applications, together with neural networks. This paper proposes an algorithm imitating the immune system to solve the optimization problem, partly by using a genetic algorithm. The proposed algorithm is shown to be capable of searching for a glolad solution, but not local solutions, through an illustrative example of a resource-atlocation problem.
074 Acoustical Surveillance of Industrial Plants: An Approach Using Neural Networks P. l)egoul, A. Lemer, pp 357-360 The exploitation of industrial processes makes more and more frequent use of un-line surveillance techniques in order to detect any malfunction early, and to give a diagnosis. A general surveillance approach which can be used for acoustical or vibratory signatures is proposed. This approach is decomposed into a preprocessing stage and a decision stage, and makes use of advanced signal-processing techniques, neural networks, and knowledge-based system. As an illustration, the acoustic surveillance of transient noises in an industrial process is presented.
075 Robot Vision System by Neural Network. Active Vision and Self.Learning Y. Mori, H. Kobayashi, K. Uchida, pp 361-364 This paper describes a robot vision system which finds a target object and focuses on it from a specified distance. A neural network is used as a decision maker which determines how to move the robot to reach the target object, on the basis of the image acquit~ by the camera. The camera is attached to the end of the robot ann; therefore, the relative positions of the target object and the end effector are considered. In the experiments, the task of the robot vision system is to capture the target objects at the center of the image. The validity of the proposed architecture is demonstrated.
076 Modeling and Analysis of Transfer Lines Using TimedEvent-Graphs J.E.R. Cury, C. Commault, pp 365-370 This paper deals with the problem of the modeling and analysis of transfer lines. A timed-event-graph model is obtained for transfer lines where machines are assmned to have a known cyclic behavior. On the basis of this model, analytical results concerning the performance of the system are derived for an isolated machine and for two machine lines separated by an intermediate buffer. These results relate line para~aeters and performance indices.
077 Multiple-Weighted Marked Graphs D.T. Chao, M. Zhou, D.T. Wang, pp 371-374 Theory regarding marked graphs is not applicable when concurrent systems must be constructed as a Pctri net in which each place has exactly one input and output transition and multiple arcs exist between a place and a transition. Many parallel programs and manufacturing systems capable of bulk production can be modeled as multiple-weighted marked graphs OVMGs). Motivated by the practical need to analyze their performance, this paper presents the conditions under which a WMGcan be evaluated. An application to a parallel computer system is also given.
078 Maximally Permissive Policies for Controlled Time Marked Graphs Y. Brave, B.H. Krogh, pp 375-378 This paper presents the formulation of the forbidden state problem for controlled time marked graphs, a class of timed Petn nets in which exogenous control inputs can force enabled transitions to fire at specified sampling times. An algorithm for computing a maximally permissive control policy is presented, based on the structural properties of the Petri-net model of the discrete-state transition logic. Properties of controlled time marked graphs and the application of the maximally permissive control algorithm are demonstrated for an example of the supervisory coordination of automated guided vehicles. 079 Petri Net Supervisors for Generalized Mutual Exclusion Constraints A. Giua, F. DiCesare, M. Silva, pp 379-382 The paper discusses the problem of enforcing generalized mutual exclusion constraints on place/transition nets with uncontrollable transitions. For a dass of Petri nets, marked graphs with control safe places, two Petri-net structures capable of enforcing these constraints are presented. The first is a monitor-based solution, the second a supervisory-based solution. Both structures are fully compiled, i.e., they are given as simpleplace/transition nets with no associated predicates, thus permtttmg the construction and analysis of a closed-loop-model of the controlled system.
080 Dispatching-Driven Deadlock Avoidance Controller Synthesis for Flexible Manufacturing Systems Fu-Shlung Hsleh, Shi-Chung Chang, pp 383-386 A new method for synthesizing deadlock avoidance controllers for the job- and machine-dispatching policies for a flexible manufacturing system into deadlock-free control actions is based on an umimed Petri-net formalism. It consists of a bottom-up approach for synthesizing a controlled production Petri-net model, a necessary and sufficient liveness condition, a sufficient procedure to test whether the liveness condition is retained after control action execution, and an algorithm that combines the test rocedure with the given dispatching policy. Such controllers eel> the FMS capable of repeating any of its operations, i.e.. live, and achieve high resource utilization under any given dispatching policy.
~
081 A Class of Petri Nets for Modeling and Control of Flexible Manufacturing and Assembly Systems with Shared Resources Mu Der Jeng, F. DICesare, pp 387-390 A case study of a theory on the modular synthesis of Petri nets for the modeling and control of shared-resource systems ispresented. A class of live and bounded nets can be generated by the theory. The applicability of the theory is demonstrated using a fairly general flexible manufacturing and assembly system. 082 Parallel Simulation of Air Pollution Transport for Urban Decision Making A. Sydow, M. Schmidt, S. Unger, T. Lux, P. Mieth, R.-P. Schiifer, pp 391.394 The concept of an air pollution simulation environment to predict and manage smog situations is presented, consisting of data bases, a mesoseale meteorological model, an air chemistry model, and decision-suppor~ tools including result visualization. Simulation runs and scenario analyses of such numerically complex models take hours of computing time, even on today's supercomputers. A strategy for model decomposition and imp.lementation on massively parallel computers is therefore described. Simulation results are shown for an ozone smog situation in Berlin. 083 The Stochastic Control Problem of Investment Rate in a Production/Storage System: Main Results J.B. Ribelro do Val, J.L.F. Salles, pp 395-398 One of the simplest problems of optimal control of the investment rote in a production/storage system is presented here. Optimal solutions are fully characterized by means of the theory of continuous time control of piecewise deterministic processes. An efficient algorithm is proposed for which a recursive procedure