• 제목/요약/키워드: Production Rules

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A Study on Dynamic Inference for a Knowlege-Based System iwht Fuzzy Production Rules

  • Song, Soo-Sup
    • 한국국방경영분석학회지
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    • 제26권2호
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    • pp.55-74
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    • 2000
  • A knowledge-based with production rules is a representation of static knowledge of an expert. On the other hand, a real system such as the stock market is dynamic in nature. Therefore we need a method to reflect the dynamic nature of a system when we make inferences with a knowledge-based system. This paper suggests a strategy of dynamic inference that can be used to take into account the dynamic behavior of decision-making with the knowledge-based system consisted of fuzzy production rules. A degree of match(DM) between actual input information and a condition of a rule is represented by a value [0,1]. Weights of relative importance of attributes in a rule are obtained by the AHP(Analytic Hierarchy Process) method. Then these weights are applied as exponents for the DM, and the DMs in a rule are combined, with the Min operator, into a single DM for the rule. In this way, the importance of attributes of a rule, which can be changed from time to time, can be reflected in an inference with fuzzy production systems.

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퍼지규칙으로 구성된 지식기반시스템에서 동적 추론전략 (A Strategy of Dynamic Inference for a Knowledge-Based System with Fuzzy Production Rules)

  • 송수섭
    • 한국경영과학회지
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    • 제25권4호
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    • pp.81-95
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    • 2000
  • A knowledge-based system with fuzzy production rules is a representation of static knowledge of an expert. On the other hand, a real system such as the stock market is dynamic in nature. Therefore we need a strategy to reflect the dynamic nature of real system when we make inferences with a knowledge-based system. This paper proposes a strategy of dynamic inferencing for a knowledge-based system with fuzzy production rules. The strategy suggested in this paper applies weights of attributes of conditions of a rule in the knowledge-base. A degree of match(DM) between actual input information and a condition of a rule is represented by a value [0,1]. Weights of relative importance of attributes in a rule are obtained by AHP(Analytic Hierarcy Process) method. Then these weights are applied as exponents for the DM, and the DMs in a rule are combined, with MIN operator, into a single DM for the rule. In this way, overall DM for a rule changes depending on the importance of attributes of the rule. As a result, the dynamic nature of a real system can be incorporated in an inference with fuzzy production rules.

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퍼지 페트리네트를 이용한 구간값 퍼지 집합 후진추론 (Interval-Valued Fuzzy Set Backward Reasoning Using Fuzzy Petri Nets)

  • 조상엽;김기석
    • 한국멀티미디어학회논문지
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    • 제7권4호
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    • pp.559-566
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    • 2004
  • 일반적으로 퍼지 생성규칙의 확신도와 규칙에 나타나는 퍼지 명제의 확신도는 0과 1사이의 실수로 표현한다. 만일 퍼지 생성규칙의 확신도와 퍼지 명제의 확신도를 구간값 퍼지 집합으로 표현한다면, 규칙기반시스템이 더 유연한 방법으로 퍼지 추론을 하는 것이 가능하게 된다. 본 논문에서는 퍼지 페트리네트와 이 네트에 기반을 둔 규칙 기반시스템을 위한 구간값 퍼지 집합 후진추론 알고리즘을 제안한다. 규칙 기반시스템에 있는 퍼지 생성규칙은 퍼지 페트리네트로 모형화된다. 여기에서 퍼지 생성규칙에 나타나는 퍼지 명제의 확신도와 규칙의 확신도는 구간값 퍼지 집합으로 표현한다. 여기에서 제안한 알고리즘은 목표노드에서 시작노드까지 후진추론 통로를 찾아낸 후 목표노드의 확신도를 계산한다. 구간값 퍼지 집합 후진추론 알고리즘은 규칙 기반 시스템이 더 유연하고 사람들이 하는 것과 같은 퍼지 후진추론을 가능하게 한다.

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퍼지 페트리네트를 이용한 구간간 퍼지집합 추론 (Interval-valued Fuzzy Set Reasoning Using Fuzzy Petri Nets)

  • 조경달;조상엽
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제31권5호
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    • pp.625-631
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    • 2004
  • 일반적으로 퍼지 생성규칙의 확신도와 규칙에 나타나는 퍼지 명제의 확신도는 0과 1사이의 실수로 표현한다. 만일 퍼지 생성규칙의 확신도와 퍼지 명제의 확신도를 구간 값 퍼지 집합으로 표현한다면, 규칙기반시스템이 더 유연한 방법으로 퍼지 추론을 하는 것이 가능하게 된다[15]. 본 논문에서는 퍼지 페트리네트와 이 네트에 기반을 둔 규칙기반시스템을 위한 구간 값 퍼지 집합 추론 알고리즘을 제안한다. 규칙기반시스템에 있는 퍼지 생성규칙은 퍼지 페트리네트로 모형화 된다. 여기에서 퍼지 생성규칙에 나타나는 퍼지 명제의 확신도와 규칙의 확신도는 구간 값 퍼지 집합으로 표현한다. 제안한 구간 값 퍼지집합 추론알고리즘은 규칙기반시스템에서 더 유연한 퍼지추론을 하는 것을 가능하게 한다.

중첩생산을 고려한 개별생산방식의 일정계획에 관한 연구 (A Study on Job Shop Scheduling with Overlapping Production)

  • 김봉선;이춘선
    • 산업경영시스템학회지
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    • 제16권28호
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    • pp.165-171
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    • 1993
  • The algorithm of Giffler and Thompson is modified for solving job shop scheduling problems related to the overlapping production The start-lag and stop-lag are also applied New priority rules for the overlapping production are proposed and the efficiency of them is compared with that of the classical priority rules.

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Application of Expert System for Non-Axisymmetric Deep Drawing Products

  • Park, Diong-Hwan;Kang, Sung-Soo
    • International Journal of Precision Engineering and Manufacturing
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    • 제2권1호
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    • pp.26-32
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    • 2001
  • An ecpert system for rotationally symmetric deep drawing products has been developed. The application for non-axisymmetric components, however, has not been reported yet. This study construsctus and expert system for non-axisymmetric motor frame which shape is classified into ellipse in deep draqing process and investigates process sequence design with elliptical shape. The developed system consists of four modules. The first is recognition of calculate surface area for non-axisymmetric products. The third is blank design module the creates an oval-shaped blank with the same surface area. The fourth is a processplanning module based on production rules that play the best important roles in an expert system for manufacturing .The production rules are generated and upgraded by interviewing field engineers. Especially, drawing coefficient, punch and die radii for elliptical shape products are considered as main design parameters. The constructed system for elliptical deep drawing product would be very useful to reduce lead time and improve accuracy for products.

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Fuzzy Petri Nets를 이용한 퍼지 추론 시스템의 모델링 및 추론기관의 구현 (A Model with an Inference Engine for a Fuzzy Production System Using Fuzzy Petri Nets)

  • 전명근
    • 전자공학회논문지B
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    • 제29B권7호
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    • pp.30-41
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    • 1992
  • As a general model of rule-based systems, we propose a model for a fuzzy production system having chaining rules and an inference engine associated with the model. The concept of so-called 'fuzzy petri nets' is used to model the fuzzy production system and the inference engine is designed to be capable of handling inexact knowledge. The fuzzy logic is adopted to represent vagueness in the rules and the certainty factor is used to express uncertainty of each rules given by a human expert. Parallel, inference schemes are devised by transforming Fuzzy Petri nets to matrix formula. Futher, the inference engine mechanism under the Mamdani's implication method can be desceribed by a simple algebraic formula, which makes real time inference possible.

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Evolvable Neural Networks Based on Developmental Models for Mobile Robot Navigation

  • Lee, Dong-Wook;Seo, Sang-Wook;Sim, Kwee-Bo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제7권3호
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    • pp.176-181
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    • 2007
  • This paper presents evolvable neural networks based on a developmental model for navigation control of autonomous mobile robots in dynamic operating environments. Bio-inspired mechanisms have been applied to autonomous design of artificial neural networks for solving practical problems. The proposed neural network architecture is grown from an initial developmental model by a set of production rules of the L-system that are represented by the DNA coding. The L-system is based on parallel rewriting mechanism motivated by the growth models of plants. DNA coding gives an effective method of expressing general production rules. Experiments show that the evolvable neural network designed by the production rules of the L-system develops into a controller for mobile robot navigation to avoid collisions with the obstacles.

유연생산시스템에 있어서의 투입우선규칙에 관한 연구 (A Study on Dispatching Rules in a Flexible Manufacturing System)

  • 이근형;황승국;이강우
    • 산업경영시스템학회지
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    • 제22권52호
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    • pp.191-201
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    • 1999
  • There have been a huge volume of researches concerning dispatching rules in job shop environments. Strangely, studies all but one pay no attention to multiple identical jobs due to the existence of production orders each of which calls for a fixed quantity, called an order size, of a specific part. Jobs arrive in the form of production orders in most, if not all, job shop type flexible manufacturing systems. This paper presents simple processing-time-based dispatching rules, and shows experimentally based on simulation that the rules with order-size considerations perform consistently well for tardiness and utilization measures. Several alternative strategies for rule specifications are examined.

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반도체 생산 라인에서의 이탈 처리 추적 전문가 시스템의 지식베이스 구축 (Construction of Knowledge Base for Fault Tracking Expert System in Semiconductor Production Line)

  • 김형종;조대호;이칠기;김훈모;노용한
    • 제어로봇시스템학회논문지
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    • 제5권1호
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    • pp.54-61
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    • 1999
  • Objective of the research is to put the vast and complex fault tracking knowledge of human experts in semiconductor production line into the knowledge base of computer system. We mined the fault tracking knowledge of domain experts(engineers of production line) for the construction of knowledge base of the expert system. Object oriented fact models which increase the extensibility and reusability have been built. The rules are designed to perform the fault diagnosis of the items in production device. We have exploited the evidence accumulation method to assign check priority in rules. The major contribution is in the overall design and implementation of the nile base and related facts of the expert system in object oriented paradigm for the application of the system in fault diagnosis in semiconductor production line.

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