{"title":"Strategic refinements in abstraction based supervisory control of hybrid systems","authors":"T. Moor, J. Davoren, J. Raisch","doi":"10.1109/WODES.2002.1167707","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167707","url":null,"abstract":"A common approach to hybrid control problems is to alternate refinement of a plant abstraction with trial controller synthesis performed on the current abstraction. These steps are repeated until a solution to the control problem can be found, or computational resources are exhausted. In this paper we use a temporal decomposition of the control problem in order to gain relevant diagnostic information for those steps when synthesis fails. We use this information to focus the abstraction refinement on those features of the plant that are most crucial for the synthesis task at hand. This work is an advance over earlier abstraction based synthesis procedures which use an unfocused and global refinement on the plant model.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"711 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115560775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A discrete-event systems approach to communication induced checkpointing","authors":"S. L. Ricker","doi":"10.1109/WODES.2002.1167671","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167671","url":null,"abstract":"A particular communication protocol for distributed computations is examined in the context of supervisory control. A critical part of these protocols allows for the formation of special system states the system reliably returns to in the event of deadlock or failure. The proposed discrete-event system makes use of Z-path theory from distributed computing literature to provide decentralized controllers with information to identify these special states.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128385692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Self learning call admission control for multimedia wireless DS-CDMA systems","authors":"F. Vázquez-Abad, V. Krishnamurthy","doi":"10.1109/WODES.2002.1167717","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167717","url":null,"abstract":"The call admission problem for wireless CDMA systems is formulated as a semi-Markov decision process with constraints on the blocking probabilities and SIR (signal to interference ratio). We show that the optimal call admission policy can be computed via a stochastic gradient algorithm. Similar to neuro-dynamic programming algorithms, the algorithms proposed are s simulation based and do not require explicit knowledge of the underlying parameters such as transition probabilities (or equivalently invariant distributions). However, unlike Q-learning or temporal difference methods, the algorithms proposed here can straightforwardly handle constraints.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"407 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127600472","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Supervisory eventuality synthesis","authors":"H. Xia, A. Trontis, Y. Pang, M. Spathopoulos","doi":"10.1109/WODES.2002.1167706","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167706","url":null,"abstract":"This paper presents a study on the eventuality synthesis problem for hybrid automata. Given a hybrid automaton and a target set of states, we seek to compute a feedback controller as well as the maximal set of initial states from which all the trajectories of the closed system eventually reach the target set. Considering control action on the discrete event level only and applying reachability analysis, we derive a feedback eventuality controller Since, generally, there does not exist a least restrictive eventuality controller we propose a second controller and derive the necessary condition under which it becomes the least restrictive eventuality controller Finally, we investigate the relationship between eventuality and safety synthesis for hybrid automata and reach the conclusion that there is no duality in the extraction of the control law.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"198 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132374297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Variability expansion for performance characteristics of (max,plus)-linear systems","authors":"B. Heidergott","doi":"10.1109/WODES.2002.1167695","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167695","url":null,"abstract":"We propose a new approach to performance evaluation of transient performance characteristics of stochastic (max,+)-linear systems. Our motivating example is the transient waiting time in the G/G/1 queue. Numerical results are given to illustrate the performance of our method.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131476875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Distributed diagnosis for qualitative systems","authors":"R. Su, W. Wonham, J. Kurien, X. Koutsoukos","doi":"10.1109/WODES.2002.1167684","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167684","url":null,"abstract":"In this paper we propose a novel automaton-based architecture to build a diagnoser, based on which an efficient distributed diagnostic method consisting of local computation and communication is presented. The method proposed here is highly scalable and robust to partial failures of the overall diagnoser.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128094691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A formal mapping of static information models into dynamic models for process planning and control purposes","authors":"P. Falkman, J. Nielsen, B. Lennartson","doi":"10.1109/WODES.2002.1167667","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167667","url":null,"abstract":"A formal mapping between static information models and dynamic models is presented. The static information models are given according to an international standard for product, process and resource information exchange. The dynamic models are described as discrete event systems. The product, process and resource information is automatically converted into product routes and used for simulation, controller synthesis and verification. The focus in this paper is on resource booking problems. A high level language, which combines Petri nets and process algebra, is presented and used for specification of desired routes. A main implication of this methodology is to enable the reuse of process information when creating dynamic models for process control. This method also enables simulation and verification to be conducted early in the development.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134570185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Deadlock-free distributed control for repetitive flows","authors":"Z. Banaszak, M. Polák","doi":"10.1109/WODES.2002.1167699","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167699","url":null,"abstract":"This paper addresses resource allocation issues that are at the heart of a methodology proposed for the design of distributed control of a class of repetitive processes. In particular, conditions, sufficient for deadlock-free and starvation-free execution of a system of closed, sequential,. repetitive processes are considered. The relationship between system resource capacities and an initial state as well as priority rules allocation is investigated. Finally, following developed conditions sufficient for design and allocation of priority rules a distributed buffer control policy that restricts a process entering a buffer in a specific sequence is proposed.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127721890","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An application of IPA approach on the optimization of a mining port stockyard system","authors":"M. A. Ayu, M. Cardew-Hall","doi":"10.1109/WODES.2002.1167698","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167698","url":null,"abstract":"In this research a stockyard system of a mining operation was analyzed using backward analysis. The system was decomposed into two sub-systems : sub-system 1 modelled the outflow from the stockyard and sub-system 2 the inflow. The Perturbation Analysis Robbins Monro Single Run (PARMSR) algorithm was applied in the optimization of sub-system 1 and rules devised to determining optimal operating condition in sub-system 2. The results show that PARMSR algorithm applying IPA can be used to estimate the optimal cost function in subsystem 1 with a high level of confidence. Using the result from sub-system 1, sub-system 2 was analyzed based on rules devised to obtain an overall optimal result of the stockyard system. The overall results can be used to build an optimal operating management strategy of a stockyard system of a mining operation at certain set of stockyard capacity.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116729033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On minimal representations of Petri net languages","authors":"R. Sreenivas","doi":"10.1109/WODES.2002.1167694","DOIUrl":"https://doi.org/10.1109/WODES.2002.1167694","url":null,"abstract":"Given a metric over the class of labeled Petri nets, we consider the existence of a procedure that takes as input a description of an arbitrary, labeled Petri net, and returns a description of a (possibly different) labeled Petri net with the smallest metric that generates the same language as the input. We refer to such procedures as minimization procedures. In this paper we investigate the existence of minimization procedures for a variety of metrics.","PeriodicalId":435263,"journal":{"name":"Sixth International Workshop on Discrete Event Systems, 2002. Proceedings.","volume":"209 1-2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115562071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}