G. Friedrich and W. Nejdl, "Choosing observations and actions in model-based diagnosis/repair systems," in Proc. 3rd Int. Conf. Principles Knowledge Representation Reasoning (KR-92), 1992, pp. 489--498.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... for our problem of real time search, as used for instance in the GPT planner, and of the general purpose POMDP heuristics given in [6, 3] Supply restoration is also typical of problems of interests in other areas such as model based diagnosis, repair, reconfiguration, and execution, see e.g. [8, 15, 18]. The approaches in this area are often rely on a two level architecture featuring a diagnostic reasoner and a quasi classical planner. If systems based on these approaches have so far been the most e#ective in dealing with similar application contexts, they still have some limits when confronted ....

....generates a sequence of actions for the most probable state hypothesis, starts its execution, and revises this plan whenever the history of actions observations shows that another hypothesis is more probable. Diagnosis and supply restoration in power transmission systems has been studied e.g. in [8]. A crucial di#erence with our proposed testbed is that observations and actions are assumed to be reliable, which is reasonable when considering transmission systems. Sensor and actuator uncertainty make power distribution systems much more challenging. The model based reactive planner Burton ....

G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proc. KR, pages 489--498, 1992.

....Heckerman et al. HBR94] have examined the problem of interactively generating repair plans under uncertainty using Bayes nets, a single fault assumption and a myopic lookahead heuristic. Actions are limited to simple observations and component replacement. In contrast Friedrich et al. e.g. [FN92]) developed a set of greedy algorithms to choose between performing simple observations and repair actions, assuming a most likely diagnosis. They do not limit their system to repair alone but rather generalize their goal to some notion of purpose; purpose does not include specification of ....

G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosis /repair systems. In Proc. of KR 92, pages 489--498, 1992.

....repair actions. If this is often the case for static devices such as digital circuits, it is not always sufficient when dealing with complex processes, for which actions are decided 12 according to the identified sequence of events, rather than according to the components and their state. [12, 20] propose the use of planning techniques to interleave repair actions and observation actions during the diagnosis process. Our proposal, viewing diagnoses as sequences of events, seems to be adequate to get a unified framework in which controlled events, such as repair or observation actions, and ....

G. Friedrich and W. Nejdl. Choosing observations and actions in modelbased diagnosis-repair systems. In Proc. KR-92, pages 489--498, 1992.

....problem, and describes the pragmatic approach we have retained so far. 1 INTRODUCTION The integration of model based diagnosis and repair has mainly been studied in the context of applications for which it is suboptimal to completely identify the state of the system prior to repairing it [ Friedrich and Nejdl, 1992; Sun and Weld, 1992 ] The motivations are generally the following: observations are expensive and time consuming, and prohibitive breakdown costs force us to take some repair actions urgently. For some application domains, integrating diagnosis and repair is even more crucial because it is ....

....missing information, erroneous information, and stochastic actions which are more elaborate than simple replacement of components. Furthermore, different candidate diagnoses require subsequently different repair plans. We found that existing work on integrating model based diagnosis and repair [ Friedrich and Nejdl, 1992; Sun and Weld, 1992 ] as well as work on planning in partially observable stochastic domains [ Cassandra et al. 1994; Draper et al. 1994 ] are unable to solve the problems raised by this application because the formalisms and methods used are not powerful enough or computationally too ....

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G. Friedrich and W. Nejdl. Choosing observations and actions in modelbased diagnosis-repair systems. In Proc. DX-92, pages 76--85, 1992.

....Heckerman et al. HBR94] have examined the problem of interactively generating repair plans under uncertainty using Bayes nets, a single fault assumption and a myopic lookahead heuristic. Actions are limited to simple observations and component replacement. In contrast Friedrich et al. e.g. [FN92]) developed a set of greedy algorithms to choose between performing simple observations and repair actions, assuming a most likely diagnosis. They do not limit their system to repair alone but rather generalize their goal to some notion of purpose; purpose does not include speci cation of ....

G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosis /repair systems. In Proc. of KR 92, pages 489-498, 1992.

....activities. The decision results from a look ahead search based on the plans returned by the planner and on a utility function taking into account breakdown, observations, and repair costs. Upon executing an action and obtaining new observations, the diagnostic reasoner updates the candidate set. (Friedrich and Nejdl 1992; Sun and Weld 1992) are representative of this approach and generalize (de Kleer and Williams 1987) dedicated to the choice of the best next measurement. An important limit of these works is their dependence on the assumption that every relevant observation can be made reliably when needed, and ....

....the assessment of the benefits of these algorithms. Power systems Other works of interest here are those concerned with similar applications in power systems. Power systems being economically important, many such applications exist (see e.g. ISAP 1996) We only mention a few of them here. (Friedrich and Nejdl 1992; Beschta et al. 1993) study diagnosis and supply restoration in power transmission systems. A crucial difference with our proposed testbed is that observations and actions are assumed to be reliable. This may be reasonable when considering transmission systems, but far too restrictive for power ....

G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proc. DX-92, pages 76--85, 1992.

....repair actions. If it is often the case for static devices such as digital circuits, it is not always sufficient when dealing with complex processes, for which actions are decided according to the identified sequence of events, rather than according to the components and their state. [11, 25] proposes the use of planning techniques to interleave repair actions and observation actions during the diagnosis process. Our proposal, viewing diagnosis as a sequence of events, seems to be quite adequate to get an unified framework in which controlled events, such as repair or observation ....

....It might be interesting to further refine these preference criteria, starting from preferences among states and events, as it is done in the decision theoretic planning framework. In the diagnosis framework, decision theory has already been successfully applied to the generation of repair plans [11, 25]. ffl As previously said, it might be worth looking at more expressive representations, e.g. representations involving numeric time, parallel events, partially ordered sets of events, and abstraction. ffl An adequate algorithm for computing event based diagnoses has still to be provided, and we ....

G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosisrepair systems. In Proc. KR-92, pages 489--498, 1992.

....repair actions. If it is often the case for static devices such as digital circuits, it is not always sufficient when dealing with complex processes, for which actions are decided according to the identified sequence of events, rather than according to the components and their state. [7, 14] propose the use of planning techniques to interleave repair actions and observation actions during the diagnosis process. Our proposal, viewing diagnoses as sequences of events, seems to be adequate to get an unified framework in which controlled events, such as repair or observation actions, and ....

G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proc. KR-92, pages 489--498, 1992.

....context, a unique diagnosis isn t always an end in itself. The generation and discrimination of candidate diagnoses may only be performed to the extent that they enable an action to be selected. Recently, some researchers have cast diagnostic problem solving in a more purposive role (e.g. 2] [3], 10] 16] making diagnosis a secondary side effect of reasoning to select a unique repair. Much of the work to date on diagnosis, testing and repair has been devoted to reasoning about circuits or related electro mechanical systems, where testing is nonintrusive and repair involves the simple ....

....identifying the extent of malfunction, and in prescribing suitable repair. In these real world domains, diagnostic problem solving must involve reasoning about action and change. There have been some attempts at incorporating rudimentary actions into programs which reason to repair (e.g. 2] [3], 13] 16] Friedrich et al. 2] 3] have provided a procedure to choose between performing simple observations and repair actions, assuming a most likely diagnosis. Sun and Weld [16] present a diagnostic reasoner which calls a decision theoretic planner subroutine to plan repair actions. Their ....

[Article contains additional citation context not shown here]

G. Friedrich and W. Nejdl (1992). Choosingobservations and actions in model-based diagnosis/repair systems. In B. Nebel et al. (ed.), Proceedings of the Third International Conference on Principles of Knowledge Representation and Reasoning, 489--498. Morgan Kaufmann.

....Kleer and Williams, 1987) Reiter, 1987) Testing could subsequently be performed to acquire sufficient discriminatory observations in order to identify a unique diagnosis. Recently, some researchers have cast diagnostic problem solving in a more purposive role (e.g. Provan and Poole, 1991) (Friedrich and Nejdl, 1992), Friedrich et al. 1992) Sun and Weld, 1993) making diagnosis a secondary side effect of reasoning to repair a system. In this setting, diagnosis and testing are only performed to the extent that they enable the problem solver to select an appropriate repair. Much of the work to date on ....

....(Reiter, 1987) Testing could subsequently be performed to acquire sufficient discriminatory observations in order to identify a unique diagnosis. Recently, some researchers have cast diagnostic problem solving in a more purposive role (e.g. Provan and Poole, 1991) Friedrich and Nejdl, 1992) (Friedrich et al. 1992), Sun and Weld, 1993) making diagnosis a secondary side effect of reasoning to repair a system. In this setting, diagnosis and testing are only performed to the extent that they enable the problem solver to select an appropriate repair. Much of the work to date on diagnosis, testing and repair ....

G. Friedrich and W. Nejdl (1992). Choosing observations and actions in model-based diagnosis/repair systems. In B. Nebel, C. Rich and W. Swartout (ed.), Proceedings of the Third International Conference on Principles of Knowledge Representation and Reasoning (KR'92), 489-- 498. Morgan Kaufmann Publishers..

....does not fulfill all requirements but the most important to be applicable in an industrial context. For example metaknowledge, e.g. relations between models, cannot be described. However, repair costs for components can be stated allowing to trade of between adding observations and doing repair (Friedrich Nejdl 1992). Not all of these requirements are equally important. Having a language that is independent of the diagnosis engine and allowing to describe models declaratively is important in the case where the model should be used by different companies or where knowledge transfer is a requirement, e.g. ....

Friedrich, G., and Nejdl, W. 1992. Choosing observations and actions in model-based diagnosis-repair systems. In Proceedings of the International Conference on Principles of Knowledge Representation and Reasoning, 489-- 498. Cambridge, MA: Morgan Kaufmann.

....will imply (as in a logical proof) a restoration of the diagnosed system to a proper working condition. Presented not as a theory of diagnosis but as a theory of repair planning, their work applies a possible models planning approach (Winslett, 161] to a diagnostic domain. Friedrich and Nejdl [52] describe a set of algorithms for diagnosis and repair plans. Sun and Weld use uwl, a strips like language, in an approach which integrates gde style diagnosis and strips style planning. The link between diagnosis and repair planning in real applications is also emphasized by Pepper and Kahn ....

Friedrich, G., and Nejdl W., Choosing Observations and Actions in Model-Based Diagnosis/Repair Systems. Proc. 3rd International Workshop on Principles of Diagnosis. Seattle WA, 1992, pp. 76-85. Also appears in Proc. Third International Conference on Principles of Knowledge Representation and Reasoning, Boston MA, 1992, pp. 489-498.

....observe, use replacement, and use other testcase (with test cases automatically chosen from a library) It is interesting to note that the relative costs for these actions can be (depending on program size and complexity) significantly different from the usual relationships in the hardware domain. [Friedrich and Nejdl, 1992; Williams and Nayak, 1997] provide a basic framework for integrating planning in model based diagnosis and can be adapted to be used in the software domain. ....

Gerhard Friedrich and Wolfgang Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proc. KR Conf., pages 489-- 498, Cambridge, MA, October 1992. Morgan Kaufmann.

.... Group of the Institut fur Informationssysteme located at the TU Wien has done research in many subfields of AI, including Model based Reasoning (MBR) Within MBR algorithms for consistency based diagnosis [7, 3] abductive diagnosis [4] and the integration of repair into the diagnosis process [5, 6, 8] has been explored. In the last years research has focused on applying model based diagnosis to software debugging [1] This line of research was initiated by the DDV project funded by Siemens Austria. Section 2 gives an overview of the project and future research activities. Another direction of ....

Gerhard Friedrich and Wolfgang Nejdl, Choosing observations and actions in model-based diagnosis-repair systems', in Proceedings of the International Conference on Principles of Knowledge Representation and Reasoning, pp. 489--498, Cambridge, MA, (October 1992). Morgan Kaufmann Publishers, Inc.

....intermingled with the diagnosis process. Reconfiguration might be an interesting extension for irs; we plan to investigate (Crow and Rushby 1991) more carefully. Planning to minimize breakdown costs is another ability that complements irs s strengths; it would be straightforward to incorporate (Friedrich et al. 1992) s time dependent cost function into our system, but their greedy algorithms are unlikely to extend gracefully to handle the statedependent probe costs addressed by irs. Our research is also similar to work on test generation programs which may also be thought of as a kind of planner that needs ....

G. Friedrich, , and W. Nejdl. Choosing Observations and Actions in Model Based Diagnosis / Repair Systems. In Proceedings of KR-92, October 1992.

....preference levels enables modeling of a variety of problems including default reasoning, belief revision and model based reasoning. It has been implemented as a Prolog interpreter and tested on a spate of examples, namely the representation of diagnosis strategies in model based reasoning systems ([19, 26, 43, 23]) In [18] we compare REVISE with a number of diagnostic and knowledge update systems, including [14] and [74] Compared to other approaches, which are based on specific systems and specific extensions of these systems such as [23] REVISE has big advantages in declarativity, and is built upon on ....

Gerhard Friedrich and Wolfgang Nejdl. Choosing observations and actions in model-based diagnosisrepair systems. In In Proc. KR'92, pages 489--498. Morgan Kaufmann, 1992.

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G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proceedings of the International Conference on Principles of Knowledge Representation and Reasoning, Cambridge, MA, Oct. 1992.

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G. Friedrich and W. Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. Technical report, Technical University of Vienna, Dec. 1991.

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Gerhard Friedrich and Wolfgang Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proceedings of the International Conference on Principles of Knowledge Representation and Reasoning, pages 489--498, Cambridge, MA, October 1992. Morgan Kaufmann Publishers, Inc.

....on an extended logic programming framework. It is powerful enough to express a wide variety of problems including various nonmonotonic reasoning and belief revision strategies and more application oriented knowledge such as diagnostic strategies in modelbased reasoning systems ( de Kleer, 1991, Friedrich and Nejdl, 1992, Lackinger and Nejdl, 1993, Dressler and Bottcher, 1992] We start, in Section 2, by reviewing the well founded semantics with explicit negation and two valued contradiction removal [Pereira et al. 1993b] which supplies the basic semantics for REVISE. We then introduce in Section 3 the ....

Gerhard Friedrich and Wolfgang Nejdl. Choosing observations and actions in modelbased diagnosis-repair systems. In In Proc. KR'92, pages 489--498, Cambridge, MA, October 1992. Morgan Kaufmann Publishers, Inc.

No context found.

G. Friedrich and W. Nejdl, "Choosing observations and actions in model-based diagnosis/repair systems," in Proc. 3rd Int. Conf. Principles Knowledge Representation Reasoning (KR-92), 1992, pp. 489--498.

No context found.

G. Friedrich and W. Nejdl, "Choosing observations and actions in model-based diagnosis/repair systems," in Proc. 3rd Int. Conf. Principles Knowledge Representation Reasoning (KR-92), 1992, pp. 489--498.

No context found.

Gerhard Friedrich and Wolfgang Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proceedings of the International Conference on Principles of Knowledge Representation and Reasoning, pages 489--498, Cambridge, MA, October 1992. Morgan Kaufmann Publishers, Inc.

No context found.

Friedrich, G., and Nejdl W., Choosing Observations and Actions in Model-Based Diagnosis /Repair Systems. Proc. 3rd Int'l Conf. on Principles of Knowledge Representation and Reasoning, pp. 489-498, Cambridge MA, 1992.

No context found.

Gerhard Friedrich and Wolfgang Nejdl. Choosing observations and actions in model-based diagnosis-repair systems. In Proceedings of the International Conference on Principles of Knowledge Representation and Reasoning, pages 489--498, Cambridge, MA, October 1992. Morgan Kaufmann Publishers, Inc.

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