{"title":"Decentralized prognosis of failures in discrete event systems","authors":"R. Kumar, S. Takai","doi":"10.1109/WODES.2008.4605975","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605975","url":null,"abstract":"We study the prognosis of failures, i.e., their prediction prior to their occurrence, in discrete event systems in a decentralized setting where multiple prognosers use their local observations to issue local prognosis decisions. We define the notion of correctness of a decentralized set of prognosers in terms of ldquono missed detectionsrdquo (each failure is prognosed prior to its occurrence) and ldquono false alarmsrdquo (an incorrect prognostic decision is never issued), and introduce the notion of coprognosability as an existence condition. When specialized to the centralized case (i.e., the case of a single prognoser), this condition turns out to be weaker than the one introduced in (S. Gene and Sl Lafortune, 2006) since a uniform bound on the number of steps within which a failure will occur is not required. For comparison we also introduce the stronger notion of ldquouniformly bounded coprognosabilityrdquo and identify the subclass of decentralized prognosers for which it serves as an existence condition. We show that the two notions coincide when the underlying system and its nonfailure specification possess finite-state representations, and present a verification algorithm. We also introduce the notion of reaction bound for coprognosis as the earliest time beyond a prognostic decision when a failure can occur, and present an algorithm for computing it. An algorithm is also presented for an online prognosis of failures. We show that the notions of coprognosability and its uniformly bounded version are in general incomparable with the notion of codiagnosability (that guarantees a uniformly bounded delay detection of a failure by a local diagnoser). When the system cannot execute an unbounded sequence of unobservable events, uniformly bounded coprognosability implies codiagnosability, whereas coprognosability and codiagnosability remain incomparable.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127471156","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 time diagnosis of discrete event systems","authors":"A. Mahajan, D. Teneketzis","doi":"10.1109/WODES.2008.4605976","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605976","url":null,"abstract":"A formulation and solution methodology for on-time fault diagnosis in discrete event systems is presented. This formulation and solution methodology captures the timeliness aspect of fault diagnosis and is therefore different from all other approaches to fault diagnosis in discrete event systems which are asymptotic in nature. A monitor observes a projection of the events that occur in the system. After each observation it can either raise an alarm and shut down the system or allow the system to continue. If the system is stopped when no fault had occurred, a false alarm penalty is incurred; on the other hand if a fault had occurred, a delayed detection penalty is incurred. Both these penalties are trace dependent. The on-time diagnosis problem is formulated as a minimax optimization problem where the objective is to choose a monitoring rule which minimizes the worst case cost along all traces of the language describing the discrete event system. An optimal diagnosis rule is determined using a dynamic programming algorithm. An example is presented which illustrates our methodology and high lights the difference between our formulation of on-time diagnosis with existing results on asymptotic diagnosis of discrete event systems.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"2013 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128086708","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":"Perturbation analysis of Markov chains","authors":"B. Heidergott","doi":"10.1109/WODES.2008.4605929","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605929","url":null,"abstract":"We present a new approach to perturbation analysis of Markov chains. Our analysis is based on bounding the distance of stationary distributions in a suitable functional space.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"222 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131688661","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}
Edwin K. P. Chong, Christopher M Kreucher, Alfred O. Hero
{"title":"Monte-Carlo-based partially observable Markov decision process approximations for adaptive sensing","authors":"Edwin K. P. Chong, Christopher M Kreucher, Alfred O. Hero","doi":"10.1109/WODES.2008.4605941","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605941","url":null,"abstract":"Adaptive sensing involves actively managing sensor resources to achieve a sensing task, such as object detection, classification, and tracking, and represents a promising direction for new applications of discrete event system methods. We describe an approach to adaptive sensing based on approximately solving a partially observable Markov decision process (POMDP) formulation of the problem. Such approximations are necessary because of the very large state space involved in practical adaptive sensing problems, precluding exact computation of optimal solutions. We review the theory of POMDPs and show how the theory applies to adaptive sensing problems. We then describe Monte-Carlo-based approximation methods, with an example to illustrate their application in adaptive sensing. The example also demonstrates the gains that are possible from nonmyopic methods relative to myopic methods.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115017016","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":"Communication of distributed discrete-event supervisors on a switched network","authors":"K. Schmidt, E. G. Schmidt","doi":"10.1109/WODES.2008.4605982","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605982","url":null,"abstract":"In order to tackle the controller synthesis problem for large-scale discrete-event systems, recent approaches suggest the design of interacting modular or decentralized supervisors. In these works, information exchange between the supervisors is either required implicitly by the synchronization of shared events or explicitly by the communication of events or symbols. However, it is not discussed how the communication can be realized if the supervisors are implemented in distributed controller devices that are connected by a communication network. In this paper, we study the synchronization of shared events among distributed supervisors on a switched network. In particular, we develop a communication model that accounts for possible transmission delays, and enables the correct operation of the communicating supervisors.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"7 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114007829","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}
S. Tadepalli, Naren Ramakrishnan, B. Mishra, L. T. Watson, R. Helm
{"title":"Deriving Kripke structures from time series segmentation results","authors":"S. Tadepalli, Naren Ramakrishnan, B. Mishra, L. T. Watson, R. Helm","doi":"10.1109/WODES.2008.4605980","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605980","url":null,"abstract":"Kripke structures are important modeling formalisms to understand the behavior of reactive systems. We present an approach to automatically infer Kripke structures from time series datasets. Our algorithm bridges the continuous world of time profiles and the discrete symbols of Kripke structures by incorporating a segmentation algorithm as an intermediate step. This approach identifies, in an unsupervised manner, the states of the Kripke structure, the transition relation, and the properties (propositions) that hold true in each state. We demonstrate experimental results of our approach to understanding the interplay between key biological processes.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116113026","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":"Building effective formal models to prove time properties of networked automation systems","authors":"S. Ruel, O. D. Smet, Jean-Marc Faure","doi":"10.1109/WODES.2008.4605968","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605968","url":null,"abstract":"This paper proposes a method to build formal models of networked automation systems, in the form of sets of communicating timed automata, which are reduced enough to avoid (or limit) combinatory explosion, but accurate enough to provide meaningful proof results, when they are checked. This method starts from a detailed initial model, which includes all behaviours of all components of the system, and comprises two steps. First, given a property to prove, the structure of the model is simplified so as to keep only the components models which impact directly this proof. Then the formal models of the remaining components are modified to take the previous simplification into account; the resulting models are worst-case models which guarantee trustworthy results. Experiments show the effectiveness of this modeling.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123412173","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":"Optimal timing control of interconnected, switched systems with applications to robotic marionettes","authors":"P. Martin, M. Egerstedt","doi":"10.1109/WODES.2008.4605938","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605938","url":null,"abstract":"We present an optimal timing control formulation of the problem of controlling autonomous puppets. In particular, by appropriately timing the different movements, entire plays can be performed. Such plays are produced by concatenating sequences of motion primitives and a compiler optimizes these sequences, using recent results in optimal switch-time control. Experimental results illustrate the operation of the proposed method.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"177 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121017630","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":"State feedback stabilization of single-input min-max-plus systems","authors":"Yuegang Tao, Guoping Liu, Dehui Sun","doi":"10.1109/WODES.2008.4605950","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605950","url":null,"abstract":"Min-max-plus systems are discrete-event systems in which the operations minimum, maximum and addition appear simultaneously. This paper describes a general model of single-input min-max-plus systems and proposes the concept of the state feedback stabilization for these systems. It is derived that the reachable single-input min-max-plus systems can be stabilized using the max-plus linear state feedback. The method based on max-plus algebra is constructive in nature and yields a direct design to achieve the feedback stabilization.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117093398","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":"STSLib and its application to two benchmarks","authors":"Chuan Ma, W. Wonham","doi":"10.1109/WODES.2008.4605932","DOIUrl":"https://doi.org/10.1109/WODES.2008.4605932","url":null,"abstract":"State tree structures (STS) are an adaptation of statecharts to supervisory control theory. STSLib is a C++ library that we have developed to support the symbolic analysis and synthesis of STS. This paper presents a short introduction to the library, and then applies the library to two benchmarks: (1) cat and mouse tower (CMT), (2) dining philosophers (DP). We demonstrate that STSLib can design optimal nonblocking supervisors for systems of state size up to 10626, and the resulting controllers are tractable and readily comprehensible.","PeriodicalId":105225,"journal":{"name":"2008 9th International Workshop on Discrete Event Systems","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127606493","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}