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- Berndtsson, Mikael
(author)
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Active Capability Support for Cooperation Strategies in Cooperative Information Systems
- 1998
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Doctoral thesis (other academic/artistic)abstract
- One important feature for the current and next generation of information systemsis the ability to be able tocooperate. Information systems that are able to cooperateare referred to as cooperative information systems. The problem of moving the stateof the art from information systems designed asislands of automationto cooperativeinformation systems has primarly been addressed by the distributed artificial intelli-gence community and the database community. For example, the distributed artificialintelligence community has investigated cooperation strategies such as task sharingand result sharing, whereas the database community has developed techniques forinteroperability over heterogenous databases. One characteristic of cooperative infor-mation systems is that no individual solution can satisfactorily support all requiredcharacteristics of cooperative information systems. This thesis takes the position thata synthesis of results from the distributedartificial intelligence community and thedatabase community is a promising direction for developing cooperative informationsystems.In this thesis, active capability (as defined within active databases) is considered asan important core technology for cooperative information systems. Active capabilityis supported by event condition action (ECA) rules with the following semantics:when an event E occurs, evaluate condition C, and if the condition is satisfied, thenexecute action A. The applicability of using ECA rules has primarly been exploredwithin database systems and has recently initiated ECA related research within otherresearch communities such as real-time and workflow.This thesis focuses on what is required in an interface between information sys-tems when using an active capability approach to supporting the major cooperationstrategies as formulated in distributed artificial intelligence. The significance of the2work reported in this thesis concerns two major issues. First, advanced types ofcooperation strategies such as task sharing and result sharing can now span the do-mains of database and distributed artificial intelligence architectures. Second, as thiswork synthesizes and extends results from two different research communities, it pro-vides a good foundation for using active capability as one of the core technologies forcooperative information systems.
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| 4. |
- Berndtsson, Mikael, et al.
(author)
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Coordination Among Agents Using Reactive Rules
- 1996
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Reports (other academic/artistic)abstract
- Coordination and collaboration are naturally used by groups for carrying out activities and solving problems that require cooperation. However, getting a set of computer agents to do that same has been a problem -- primarily addressed by the AI community and recently by the database community as workflow and process management problems (e.g. in business processes, electronic commerce, logistics).Not surprisingly, the problem has been addressed at different levels of abstraction by the two communities. Coordination protocols (both static and dynamic) as well as task and result sharing have been investigated by the AI community; system level support as well as specification and execution of relaxed notions of transaction (sometimes termed an activity) have been addressed by the database community. It is evident that combining the two will provide an effective unified solution for a class of problems that require cooperation. This paper classifies problems addressed in the AI and database literature according to degree of coordination and collaboration. It reports on work done by the authors in utilising the reactive paradigm to synthesize, from the yechniques in these areas, a common framework for the support of multi-agent problem solving, workflow, and process management. In addition to resolving the terminology used by different groups, task sharing is used to demonstrate the approach described. It is accomplished by creating either static or dynamic plans that are coordinated by ECA rules -- both pre-defined and dynamically created. The paper details the applicability of ECA rules in this domain, their adequacy, and a prototype implementation.
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| 5. |
- Berndtsson, Mikael, et al.
(author)
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Extending Active Capability Mechanisms for Context Based Subscriptions
- 1998
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Reports (other academic/artistic)abstract
- Interest has increased recently in synthesizing solutions to CIS problems by using results from the database and distributed AI communities. Such synthesis is not without its difficulties; results do not always transfer seamlessly to a new, complex domain. In this paper we highlight the difficulties encountered in our attempts to use event detection and subscription mechanisms (proposed in current active databases) for the problem of efficient result sharing in CIS. A solution to such problems is described, in the form of a refined, context based subscription mechanism.
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| 6. |
- Berndtsson, Mikael, et al.
(author)
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Extending database support for coordination among agents
- 1997
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In: International Journal of Cooperative Information Systems (IJCIS). - 0218-8430. ; 6:3-4, s. 315-339
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Journal article (peer-reviewed)abstract
- Coordination and collaboration are naturally used by groups for carrying out activities and solving problems that require cooperation. However, getting a set of computer agents to do the same has been a problem - primarily addressed by the AI community and recently by the database community as workflow and process management problems (for example, in business processes, electronic commerce, logistics). Not surprisingly, the problem has been addressed at different levels of abstraction by the two communities. Coordination protocols as well as task and result sharing have been investigated by the AI community; specification of alternative transaction models to meet the requirements of non-traditional applications, and their execution have been addressed by the database community. It is evident that there is a need for bringing the two approaches together to develop systems that support cooperative problem solving. This paper - argues for the use of active databases in general and active capability in particular as an enabling technology for cooperative problem solving and cooperative information systems - details a novel approach for supporting task sharing, a key aspect of CPS, using active capability - elaborates on a methodology for mapping task shared protocols expressed in high level speech acts to Event Condition-Action (ECA) rules.
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| 7. |
- Berndtsson, Mikael, et al.
(author)
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Logical Events and ECA Rules
- 1995
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Reports (other academic/artistic)abstract
- This paper presents an approach to support event-condition-action rules and logical events in an object-oriented environment. Previous approaches in active object-oriented databases support either traditional event-condition-action rules or logical events. We see the need to integrate these two concepts in order to efficiently support specialization of events.
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| 8. |
- Berndtsson, Mikael, et al.
(author)
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On Developing Reactive Object-Oriented Databases
- 1992
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In: IEEE Data Engineering Bulletin. ; 15:1-4, s. 31-34
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Journal article (peer-reviewed)abstract
- This paper outlines the ongoing work in Reactive Object-oriented Database Systems between the Departments of Computer Science in the University of Exeter(UK) and the University of Skovde(Sweden). The group is currently designing a monitoring system based on a reactive object oriented database with the objective of supporting efficient interaction between the active DBMS and applications (including intelligent systems). Initial work has centered on a prototype reactive object-oriented system built on top of ONTOS, a commercial OODBMS which has C++ as its base language. The prototype is referred to as ACOOD (ACtive Object Oriented Database system). We briefly discuss this prototype, showing how reactive behaviour has been incorporated into a full OODBMS albeit with some restrictions. We also outline our plans for its future extensions, and how these are motivated.
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| 9. |
- Berndtsson, Mikael, et al.
(author)
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Result Sharing Among Agents Using Reactive Rules
- 1997
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In: Cooperative Information Agents. - Berlin, Heidelberg : Springer Berlin Heidelberg. - 3540625917 - 9783540625919 ; , s. 126-137
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Conference paper (peer-reviewed)abstract
- This paper critically analyse the use of active databases as an enabling technology for result sharing as defined in the DAI literature. In particular, we demostrate how ECA (Event-Condition-Action) rules can be used for supporting result shared cooperation. Further, we demonstrate how composite events as defined within active databases can help a problem solving agent to precisely specify when to take responsive action to multiple result notifications.
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| 10. |
- Berndtsson, Mikael, et al.
(author)
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Systematic Treatment of Events and Rules
- 1995
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Reports (other academic/artistic)abstract
- Current prototype Active Object-Oriented database systems introduce powerful event and rule specification languages. We contend that this is not in general done in a uniform and integral manner. We present a modified design for an ACtive Object-Oriented DBMS (ACOOD) currently under development at the University of Skovde. The design emphasises the key concepts being investigated, namely Events and Rules as 1st Class (ER1C). It is important because it addresses the key issue of inheritance, something not prominent in current prototype systems with a fully developed event specification system. Key features in the design are that it has a unifying concept of primitive event and of behaviour, and achieves uniformity and power with respect to inheritance. It further relates this to event specification languages for composite events, guaranteeing orthogonality of features. The paper emphasises modeling concepts, and the design is therefore of relevance to all active, object-oriented database systems. It seeks to explore the wider implications and underpinnings of current active O-O suggestions rather than enriching event and/or rule specification languages.
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