• 전산구조공학
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• 제4권3호
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• pp.107-115
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• 1991

지진예측을 위한 확률론적퍼지모형을 제안하였다. 제안된 모형은 지진발생에 대하여 무작위성(randomness)과 퍼지니스(fuzziness)를 같이 사용하여, 기존의 확률론에 근거한 지진예측방법을 개선할 수 있도록 하였다. 이 연구의 결과는 (a) 주어진 초과확률에 대한 지반가속도 또는 주어진 지반가속도에 대한 초과확률의 멤버쉽함수와 (b) 멤버쉽함수를 대표할 수 있는 특성값(characteristic value)이다. 확률론적 퍼지모형을 미국 Utah주의 Wasatch Front Range의 자료에 적용하여 서로 다른 연간 초과확률, 최대지반가속도에 대하여 지진도를 작성하였다.

• Journal of Yeungnam Medical Science
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• 제21권1호
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• pp.1-11
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• 2004

Total knee arthroplasty has become a common procedure for treatment of severe osteoarthritis, rheumatoid arthritis and post-traumatic arthritis. In the past, failure of total knee arthroplasty was commonly attributable to aseptic loosening, often associated with component malalignment, soft tissue imbalance. With improved surgical instrumentation and soft tissue balancing techiniques, failure secondary to mechanical loosening has been minimal. But surgeons are still dissatisfied with implant malalignment. Correct tibiofemoral alignment seems to be particularly important since it is generally agreed that axial deviation and imprecise implantation may lead to loosening of the implant component. Navigation systems and robotic techniques could potentially solve problems of imprecision in traditional total knee arthroplasty. It is expected that the success rate and longevity of total knee arthroplasty will be improved during the twenty first century.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (1)
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• pp.474-476
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• 2000

소프트웨어 프로젝트의 비용의 대부분이 구현(implementation) 단계나 테스트 단계에서의 에러 수정에 소모되고 있으며, 이러한 에러들의 대부분은 프로젝트 개발 초기 단계에서의 부정확(imprecision)에 기안한 것이다. 정형 명세 기법은 명세 단계에서 기인하는 에러들을 줄이기 위해 Z나 VDM과 같은 정형 표기법에 의해 쓰여진다. 그러나, Z 표기법의 병행성 표현 능력의 부족으로 병행성을 요구하는 시스템의 명세에서 사용할 수 없거나, Process Algebra의 CSP(Communicating Sequence Processes)등과 같은 다른 정형 언어와 함께 명세해야 하는 단점이 있다. 본 연구에서는 Z와 같은 범용 목적의 명세 언어가 병행성(concurrency)을 표현할 수 있도록 하기 위해서, 병행 프로세서(concurrent process) 개념을 도입하며, 이를 나타내는 표기를 정의하고 사용한다. 또한, 병행성의 제어를 위해서 프로시듀어 기술부(procedure description)의 도입 및 관련 스키마(schema)들을 정의한다.

• Communications for Statistical Applications and Methods
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• 제7권1호
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• pp.65-86
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• 2000

The estimates from an EM when it is applied to a large causal model of 10 or more categorical variables are often subject to the initial values for the estimates. This phenomenon becomes more serious as the model structure becomes more serious as the model structure becomes more complicated involving more variables. In this regard Wu(1983) recommends among others that EMs are implemented several times with different sets of initial values to obtain more appropriate estimates. in this paper a new approach for initial values is proposed. The main idea is that we use initials that are calibrated to data. A simulation result strongly indicates that the calibrated initials give rise to the estimates that are far closer to the true values than the initials that are not calibrated.

• 한국산업융합학회 논문집
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• 제18권1호
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• pp.30-36
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• 2015

This paper presents the theoretical development of a complete navigation problem of a nonholonomic mobile robot by using ultrasonic sensors. To solve this problem, a new method to computer a fuzzy perception of the environment is presented, dealing with the uncertainties and imprecision from the sensory system and taking into account nonholonomic constranits of the robot. Fuzzy perception, fuzzy controller are applied, both in the design of each reactive behavior and solving the problem of behavior combination, to implement a fuzzy behavior-based control architecture. The performance of the proposed obstacle avoidance robot controller in order to determine the exact dynamic system modeling system that uncertainty is difficult for nomadic controlled robot direction angle by ultrasonic sensors throughout controlled performance tests. In additionally, this study is an in different ways than the self-driving simulator in the development of ultrasonci sensors and unmanned remote control techniques used by the self-driving robot controlled driving through an unmanned remote controlled unmanned realize the performance of factory antomation.

• Journal of Construction Engineering and Project Management
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• 제5권2호
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• pp.35-43
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• 2015

Project Management Consultant (PMC) plays a vital role in the overall performance of any project. Selecting right PMC for right project is the most crucial challenge for any construction owner. Thus, PMC selection is one of the main decisions made by owners at the early phase of construction project. It is not easy for the project owner to select a competent PMC due to the fuzziness, imprecision, vagueness, incomplete and qualitative criteria of the decision. This paper presents a model for selecting PMC contractor using the Fuzzy Analytical Hierarchy Process (FAHP). And a fuzzy number based framework is proposed to be a viable method for PMC contractor selection. A case study to illustrate the application of the model is also presented in this paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 D
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• pp.864-866
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• 1997

This paper presents fault recognition and interpretation in power transformers using dissolved gas analysis embedded Kohonen feature mapping. The imprecision of gas ratio analysis in dissolved gas analysis are managed by mapping in accordance with learning of Kohonen neural network. To verify the effectiveness of the proposed system, it has been tested by the historical gas records to power transformers of Korea Electric Power Corporation. More appropriate fault types can support the maintenance personnels to increase the disgnostic performance for fault of power transformers.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1996년도 추계학술대회 학술발표 논문집
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• pp.137-140
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• 1996

In order to solve the specific problems in system, the implementing of knowledge base suitable to the system architecture has to be expressed and leads to the resoning of the new facts. Not only the simple knowledge based on the bivalent logic but also the representation and acqusition of knowledge related to vague and imprecise linguistic variable is necessary to the knowledge in the real world,i.e the knowledge of which facts and rules are composed. In this point of view, this survey implements the inference and retrieval of the fuzzy linguistic variables so that it can process the ambiguous information which appears the imprecision of the linguistic boundary.

• 산업경영시스템학회지
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• 제13권21호
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• pp.29-41
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• 1990

An assessment of risk in industrial and urban environments is essential in the prevention of accident and in the analysis of situations which are hazardous to public health and safety. The risk imposed by a particular hazard increases with the likelihood of occurence of the event, the exposure and the possible consequence of that event. In a traditional approach, the calculation of a quantitative value of risk is usually based on an assignment of numerical values of each of the risk factors. Then the product of the values of likelihood, exposure and consequences called risk score is derived. However vagueness and imprecision in mathematical quantification of risk are equated with fuzziness rather than randomness. In this paper, a fuzzy set theoretic approach to risk analysis is proposed as an alternative to the techniques currently used in the area of systems safety. Then the concept of risk evaluation using linguistic representation of the likelihood, exposure and consequences is introduced. A risk assessment model using approximate reasoning technique based on fuzzy logic is presented to drive fuzzy values of risk and numerical example for risk analysis is also presented to illustrate the results.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.133-140
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• 1998

Material nonlinear analyses of RC(Reinforced Concrete) beams considering the tension stiffening effect and plastic hinge length have been conducted. Instead of taking the sophisticated layer approach which has some limitations in application to the large structures with many degrees of freedom. the moment-curvature relationships of RC sections previously constructed through the section analysis have been used. To reduce the numerical instability in nonlinear analysis and to remove the imprecision in calculation of ultimate resisting capacity, according to the used finite element mesh size, the tension stiffening effect and plastic hinge length have been taken into consideration. Finally, correlation studies between analytical and experimental results have been conducted with the objective to establish the validity of the proposed algorithms.