• Title/Summary/Keyword: default reasoning

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A Nonmonotonic Inheritance Reasoner with Probabilistic Default Rules (확률적 디폴트 규칙들을 이용한 비단조 상속추론 시스템)

  • Lee, Chang-Hwan
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.2
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    • pp.357-366
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    • 1999
  • Inheritance reasoning has been widely used in the area of common sense reasoning in artificial intelligence. Although many inheritance reasoners have been proposed in artificial intelligence literature, most previous reasoning systems are lack of clear semantics, thus sometimes provide anomalous conclusions. In this paper, we describe a set-oriented inheritance reasoner and propose a method of resolving conflicts with clear semantics of defeasible rules. The semantics of default rule is provided by statistical analysis of $\chi$ method, and likelihood of rule is computed based on the evidence in the past. Two basic rules, specificity and generality, are defined to resolve conflicts effectively in the process of reasoning. We show that the mutual tradeoff between specificity and generality 추 prevent many anomalous results from occurring in traditional inheritance reasoners. An algorithm is provided. and some typical examples are given to show how the specificity/generality rules resolve conflicts effectively in inheritance reasoning.

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Applying CBR for Default Risk Forecasting (채무불이행위험의 예측을 위한 CBR응용)

  • Kim Jin-Baek
    • Management & Information Systems Review
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    • v.3
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    • pp.179-199
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    • 1999
  • Case-Based Reasoning(CBR) offers a new approach for developing knowledge based systems. In case-based approach the problem solving experience of the domain expert is encoded in the form of cases. CBR has successfully been applied to many kinds of problems such as design, planning, diagnosis and forecasting. In this paper, CBR was applied for forecasting default risk. The applied result was successful in spite of the small casebase. Generally, CBR requires large casebase. So, if the number of data was large, the result was better. But in this paper, what financial variable was more forecastable was not tested. Next, this should be tested.

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Integration of Ontology Open-World and Rule Closed-World Reasoning (온톨로지 Open World 추론과 규칙 Closed World 추론의 통합)

  • Choi, Jung-Hwa;Park, Young-Tack
    • Journal of KIISE:Software and Applications
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    • v.37 no.4
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    • pp.282-296
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    • 2010
  • OWL is an ontology language for the Semantic Web, and suited to modelling the knowledge of a specific domain in the real-world. Ontology also can infer new implicit knowledge from the explicit knowledge. However, the modeled knowledge cannot be complete as the whole of the common-sense of the human cannot be represented totally. Ontology do not concern handling nonmonotonic reasoning to detect incomplete modeling such as the integrity constraints and exceptions. A default rule can handle the exception about a specific class in ontology. Integrity constraint can be clear that restrictions on class define which and how many relationships the instances of that class must hold. In this paper, we propose a practical reasoning system for open and closed-world reasoning that supports a novel hybrid integration of ontology based on open world assumption (OWA) and non-monotonic rule based on closed-world assumption (CWA). The system utilizes a method to solve the problem which occurs when dealing with the incomplete knowledge under the OWA. The method uses the answer set programming (ASP) to find a solution. ASP is a logic-program, which can be seen as the computational embodiment of non-monotonic reasoning, and enables a query based on CWA to knowledge base (KB) of description logic. Our system not only finds practical cases from examples by the Protege, which require non-monotonic reasoning, but also estimates novel reasoning results for the cases based on KB which realizes a transparent integration of rules and ontologies supported by some well-known projects.

A STUDY ON NON-MONOTONIC REASONING SYSTEM (비단조 논리를 이용한 추론 범위 확장에 관한 연구)

  • Lee, Kang-Heuy;Cha, Kuk-Chan;Choi, Jong-Soo
    • Proceedings of the KIEE Conference
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    • 1987.07b
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    • pp.1038-1041
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    • 1987
  • Non-monotonic logic is one in which the introduction of new axioms can eliminate old theorems. Such logic is very important in modeling the beliefs of the systems which, in the presence of complete information, must make and subsequently revise assumptions in light of new observations. In the present paper, we suggest that the formal systems, such as Reiter's default logic could be the useful implement for the specification and description of non-monotonic systems. WE develop a theory of inheritance network in order to illustrate the benefits of this theory.

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Term Rewriting Semantics of Lazy Functional Programming Languages (지연 함수형 프로그래밍 언어의 항 개서 의미)

  • Byun, Sug-Woo
    • Journal of KIISE:Computer Systems and Theory
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    • v.35 no.3
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    • pp.141-149
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    • 2008
  • Most functional programming languages allows programmers to write ambiguous rules, under the strategy that pattern-matching will be performed in a direction of 'from top to bottom' way. While providing programmers with convenience and intuitive understanding of defining default rules, such ambiguous rules may make the semantics of functional languages unclear. More specifically, it may fail to apply the equational reasoning, one of most significant advantage of functional programming, and may cause to obscure finding a formal way of translating functional languages into the ${\lambda}$-calculus; as a result, we only get an ad hoc translation. In this paper, we associate with separability of term rewriting systems, holding purely-declarative property, pattern-matching semantics of lazy functional languages. Separability can serve a formalism for translating lazy functional languages into the ${\lambda}$-calculus.

Critical Reconstruction of The Korean Science Culture (한국 과학문화의 비판적 재구성)

  • Lee Cho-Sik
    • Journal of Science and Technology Studies
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    • v.1 no.1 s.1
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    • pp.5-27
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    • 2001
  • This paper makes a preparatory attempt to reconstruct 'the Korean Science Culture' toward which I think the Koreans should direct and orient themselves rather than describe the history of the science culture in Korea. This task requires us to define 'science culture.' So I propose, based on the definitions of science culture so far made, to consider the model of 'Humanized Science Culture' as a regulating ideal of the Korean Science Culture. To support the model, analyzing the concept of 'science literacy' of the 2061 Project, I posit the model of KDSC (Korean Designer of Science Culture) as the Koreans who will actually come to design the Korean Science Culture. KDSC refers to 'a reasonable man' who will represent a desirable Korean, rather than to a natural Korean. Then I spell out the conditions of becoming a KDSC and scrutinize the philosophical backbones of those conditions. Finally, I make a few suggestions for developing a program of designing and implementing the Korean Science Culture from the viewpoint of a model of KDSC.

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