• Title/Summary/Keyword: Heuristic Knowledge

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A Study on the Fault Diagnosis Expert System for 765kV Substations (765kV 변전소의 고장진단 전문가 시스템에 관한 연구)

  • Lee, Heung-Jae;Kang, Hyun-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.7
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    • pp.1276-1280
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    • 2009
  • This paper presents a fault diagnosis expert system for 765kV substation. The proposed system includes the topology processor and intelligent alarm processing subsystems. This expert system estimates the fault section through the inference process using heuristic knowledge and the output of topology processor and intelligent alarm processing system. The rule-base of this expert system is composed of basic rules suggested by Korea Electric Power Corporation and heuristic rules. This expert system is developed using PROLOG language. Also, user friendly Graphic User Interface is developed using visual basic programming in the windows XP environment. The proposed expert system showed a promising performance through the several case studies.

A Study on the Application of Fuzzy Neural Network for Troubleshooting of Injection Molding Problems (사출성형 문제해결을 위한 퍼지 신경망 적용에 관한 연구)

  • 강성남;허용정;조현찬
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.11
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    • pp.83-88
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    • 2002
  • In order to predict the moldability of a injection molded part, a simulation of filling is needed. Short shot is one of the most frequent troubles encountered during injection molding process. The adjustment of process conditions is the most economic way to troubleshoot the problematic short shot in cost and time since the mold doesn't need to be modified at all. But it is difficult to adjust the process conditions appropriately in no times since it requires an empirical knowledge of injection molding. In this paper, the intelligent CAE system synergistically combines fuzzy-neural network (FNN) for heuristic knowledge with CAE programs for analytical knowledge. To evaluate the intelligent algorithms, a cellular phone flip has been chosen as a finite element model and filling analyses have been performed with a commercial CAE software. As the results, the intelligent CAE system drastically reduces the troubleshooting time of short shot in comparison with the experts' conventional methodology which is similar to the golden section search algorithm.

A Study on Comprehensive Domain Ontology Methodology (도메인 온톨로지 구축에 관한 연구)

  • Liu, Haitao;Shin, Ju-Hyun;Kim, Pan-Koo
    • Proceedings of the Korea Information Processing Society Conference
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    • 2005.05a
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    • pp.651-654
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    • 2005
  • Ontology developing process has aroused a lot of controversy among knowledge engineers and knowledge users. The recent surges on ontology building methodologies and practical ontology applications have explored a broad spectrum of knowledge management challenges. On the one hand, the abundant methodology theories provide us with a set of useful heuristic rules, from which we get the overview of ontology building process. But on the other hand, every research groups would like to justify their theories by listing their specific characteristics and unique method when approaching the right way. However, there is still no one “correct” way or methodology for developing ontologies. In this case, the methods used to evaluate only a subset of specific domain do not make any sense to the commonsense users. As a result, a comprehensive understanding of domain ontology is urgent and necessary.

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A Knowledge-based Design System for Injection Molding

  • Huh, Yong-Jeong
    • Journal of the Microelectronics and Packaging Society
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    • v.8 no.3
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    • pp.11-17
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    • 2001
  • The design and manufacture of injection molded polymeric parts with desired properties is a costly process dominated by empiricism, including the repeated modification of actual tooling. This paper presents an expert design evaluation system which can predict the mechanical performance of a molded product and diagnose the design before the actual mold is machined. The knowledge-based system synergistically combines a rule-based expert system with CAE programs. Heuristic knowledge of injection molding is formalized as rules of an expert consultation system. The expert system interprets the analytical results of the process simulation, predicts the performance, evaluates the design and generates recommendations for optimal design alternatives.

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A Study Fuzzy model for Risk Analysis of Uncertainly FTA(Fault Tree Analysis) (FTA(Fault Tree Analysis)에서 불확실한 위험분석을 위한 퍼지모형 연구)

  • 임총규;박주식;강경식
    • Journal of the Korea Safety Management & Science
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    • v.4 no.1
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    • pp.37-47
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    • 2002
  • Risk analysis is a formal deductive procedure for determining combinations of component failures and human errors that could result in the occurrence of specified undesired events at the system level. This method can be used to analyze the vast majority of industrial system reliability problems. This study deals with the application of knowledge-engineering and a methodology for the assessment & measurement of reliability, availability, maintainability, and safety of industrial systems using FTA(fault tree analysis), A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach (insufficient Information concerning the relative frequencies of hazard events). To improve the quality of results, the membership functions must be approximated based on heuristic considerations, The purpose of this study is to describe the knowledge engineering approach, directed to integrate the various sources of knowledge involved in a FTA.

A SHdy on the Development of an Expert System for Chemical Plant Diagnosis Fault -An Object Description System based on Functional Structure- (화학 플랜트의 고장원 탐색 전문가 시스템에 관한 연구 -기능구조에 의한 대상의 지식표현 방법-)

  • 황규석
    • Journal of the Korean Society of Safety
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    • v.7 no.2
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    • pp.14-23
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    • 1992
  • A methodology for developing an object description system based on functional-structure of chemical plant is proposed. A knowledge base for chemical plant fault diagnosis is also organized in a generic fashion using the heuristic knowledge of human operators. A plant can be seen as a hierarchical set of subsystems. Each subsystem is called a SCOPE. The state of the plant and the behavior of each subsystem is managed by the SCOPES. A computer-based system based on thls methodology and knowledge base has been developed and applied to the subprocess of ethylene plant to evaluate the effectiveness of the methodology.

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A Study on Fault Diagnostic Model for Behaviour Appearance of Components (부품의 가동형태에 따른 고장진단 모델 연구)

  • 박주식;하정호;강경식
    • Journal of the Korea Safety Management & Science
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    • v.4 no.4
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    • pp.97-108
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    • 2002
  • This study deals with the application of knowledge-based engineering and a methodology for the assessment & measurement of reliability, availability, maintainability, and safety of industrial systems using fault-tree representation. A fuzzy methodology for fault-tree evaluation seems to be an alternative solution to overcome the drawbacks of the conventional approach. To improve the quality of results, the membership functions must be approximated based on heuristic considerations. Conventionally, it is not always easy to obtain a system reliability for components with different individual failure probability density functions(p.d.f.), We utilize fuzzy set theory to solve the adequacy of the conventional probability in accounting and processing of built-in uncertainties in the probabilistic data. The purpose of this study is to propose the framework of knowledge-based engineering through integrating the various sources of knowledge involved in a FTA.

A Knowledge-Based Mastitis Diagnostic System for Dairy Participants in USA (지식베이스에 의한 젖소 유방염 진단체계 개발)

  • 김태운;이재득
    • Journal of Intelligence and Information Systems
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    • v.3 no.2
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    • pp.93-104
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    • 1997
  • The major economic health problem of dairy cattle is mastitis which can affect 10 to 50% of cow-quarters. This health problem is difficult for many dairy farmers and health advisors to understand, diagnose and control. Without special laboratory testing, most mastitis is overlooked. Estimates of annual mastitis cast per cow vary from $50 to $200. For the nearly 9 million cows in the United States, annual loss to the dairy industry amounts to over one billion. A knowledge-based decision aid has been developed to evaluate mastitis data retrieved electronically from two of nine U. S. regional dairy records processing centers. Heuristic rules to diagnose herd mastitis problems were collected and incorporated into the system from various domain experts. This system information. It allows users to select mastitis control schemes with various degrees of aggressiveness and teaches commonly accepted mastitis control practices.

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Knowledge-based Decision Support System for Process Planning in the Electric Motor Manufacturing (전동기 제조업의 지식기반 공정계획 지원시스템에 관한 연구)

  • Song, Jung-Su;Kim, Jae-Gyun;Lee, Jae-Man
    • IE interfaces
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    • v.11 no.2
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    • pp.159-176
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    • 1998
  • In the motor manufacturing system with the properties of short delivery and order based production, the process plan is performed individually for each order by the expert of process plan after the completion of the detail design process to satisfy the specification to be required by customer. Also it is hard to establish the standard process plan in reality because part routings and operation times are varied for each order. Hence, the production planner has the problem that is hard to establish the production schedule releasing the job to the factory because there occurs the big difference between the real time to be completed the process plan and the time to be required by the production planner. In this paper, we study the decision supporting system for the process plan based on knowledge base concept. First, we represent the knowledge of process planner as a database model through the modified POI-Feature graph. Then we design and implement the decision supporting system imbedded in the heuristic algorithm in the client/server environment using the ORACLE relational database management system.

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Effect of Potential Model Pruning on Official-Sized Board in Monte-Carlo GO

  • Oshima-So, Makoto
    • International Journal of Computer Science & Network Security
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    • v.21 no.6
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    • pp.54-60
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    • 2021
  • Monte-Carlo GO is a computer GO program that is sufficiently competent without using knowledge expressions of IGO. Although it is computationally intensive, the computational complexity can be reduced by properly pruning the IGO game tree. Here, I achieve this by using a potential model based on the knowledge expressions of IGO. The potential model treats GO stones as potentials. A specific potential distribution on the GO board results from a unique arrangement of stones on the board. Pruning using the potential model categorizes legal moves into effective and ineffective moves in accordance with the potential threshold. Here, certain pruning strategies based on potentials and potential gradients are experimentally evaluated. For different-sized boards, including an official-sized board, the effects of pruning strategies are evaluated in terms of their robustness. I successfully demonstrate pruning using a potential model to reduce the computational complexity of GO as well as the robustness of this effect across different-sized boards.