• Title/Summary/Keyword: fuzzy process

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A Research on Inference Method in Fuzzy Production System (퍼지 프러덕션시스템의 추론방법에 관한 연구)

  • 송수섭
    • Journal of Intelligence and Information Systems
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    • v.2 no.2
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    • pp.1-15
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    • 1996
  • 전문가의 지식을 지식베이스화하여 의사결정지원시스템으로 사용하려는 노력이 증대하고 있다. 특히 투자의사결정과 같은 원인결과의 관계를 명확히 규정할 수 없는 복작한 영역에서 전문가의 지식베이스는 비전문가의 의사결정에 중요한 조언을 제공할 수 있다. 불확실한 지식을 지식베이스화하는 한 방법으로 퍼지프러덕션시스템이 널리 사용되고 있다. 주식시장과 같은 동태적인 시스템에서 어떤 정보의 중요성은 상황에 따라 변화하는데 이를 정태적인 프로덕션시스템의 규칙으로 지식베이스화하는 것은 불가능하다. 그러나 추론을 수행하는 과정에서 수행당시 각 정보의 중요도에 부응하는 가중치를 부여하여 평가함으로써 정태적인 지식베이스에 동태적인 실제시스템의 특성을 반영할 수 있다. 이는 가중치가 높은 정보에 해당하는 조건명제의 충족정도가 해당규칙의 전체평가결과에 더욱 중요하게 반영되게 하여 좀더 현실성 있는 추론 결과를 얻게 한다. AHP(Analytic Hierachy Process) 방법에 의하여 얻어진 정보의 상대적 중요도에 따른 가중치 (w)를 해당 정보와 조건명제의 합치정도(Degree of Match : DM)에 (DM)w 의 형식으로 적용함으로써 퍼지프러덕션시스템에서 정보의 중요도를 반영하여 프러덕션규칙을 평가하는 방법을 제시한다.

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A Study on the Feature Region Segmentation for the Analysis of Eye-fundus Images (안저영상(眼低映像) 해석(解析)을 위한 특징영성(特徵領域)의 분할(分割)에 관한 연구(硏究))

  • Kang, Jeon-Kwun;Kim, Seung-Bum;Ku, Ja-Yl;Han, Young-Hwan;Hong, Hong-Seung
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.11
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    • pp.27-30
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    • 1993
  • Information about retinal blood vessels can be used in grading disease severity or as part of the process of automated diagnosis of diseases with ocular menifestations. In this paper, we address the problem of detecting retinal blood vessels and optic disk (papilla) in Eye-fundus images. We introduce an algorithm for feature extraction based on Fuzzy festering(FCM). The results ore compared to those obtained with other methods. The automatic detection of retinal blood vessels and optic disk in the Eye-fundus images could help physicians in diagnosing ocular diseases.

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Comparison of Classification rate of PD Sources (부분방전원 분류기법의 패턴분류율 비교)

  • Park, Seong-Hee;Lim, Kee-Joe;Kang, Seong-Hwa
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.566-567
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    • 2005
  • Until now variable pattern classification methods have been introduced. So, variable methods in PD source classification were applied. NN(neural network) the most used scheme as a PD(partial discharge) source classification. But in recent year another method were developed. These methods is present superior to NN in the field of image and signal process function of classification. In this paper, it is show classification result in PD source using three methods; that is, BP(back-propagation), ANFIS(adaptive neuro-fuzzy inference system), PCA-LDA(principle component analysis-linear discriminant analysis).

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Speed Control for Low Speed Diesel Engine by Hybrid F-NFC (Hybrid F-NFC에 의한 저속 디젤 기관의 속도 제어)

  • Choi, G.H.;Yang, J.H.
    • Journal of Power System Engineering
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    • v.10 no.4
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    • pp.159-164
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    • 2006
  • In recent, the marine engine of a large size is being realized a lower speed, longer stroke and a small number of cylinders for the energy saving. Consequently the variation of rotational torque became larger than former days because of the longer delay-time in fuel oil injection process and an increased output per cylinder. It was necessary that algorithms have enough robustness to suppress the variation of the delay-time and the parameter perturbation. This paper shows the structure of hybrid F-NFC against the delay-time and the perturbation of engine parameter as modeling uncertainties, and the design of the robust speed controller by hybrid F-NFC for the engine. And, The Parameter values of linear equation are determined by RC-GA for F-NFS. The hybrid F-NFC is combined the F-NFC and PID controller for filling up each.

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Non-destructive evaluation and pattern recognition for SCRC columns using the AE technique

  • Du, Fangzhu;Li, Dongsheng
    • Structural Monitoring and Maintenance
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    • v.6 no.3
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    • pp.173-190
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    • 2019
  • Steel-confined reinforced concrete (SCRC) columns feature highly complex and invisible mechanisms that make damage evaluation and pattern recognition difficult. In the present article, the prevailing acoustic emission (AE) technique was applied to monitor and evaluate the damage process of steel-confined RC columns in a quasi-static test. AE energy-based indicators, such as index of damage and relax ratio, were proposed to trace the damage progress and quantitatively evaluate the damage state. The fuzzy C-means algorithm successfully discriminated the AE data of different patterns, validity analysis guaranteed cluster accuracy, and principal component analysis simplified the datasets. A detailed statistical investigation on typical AE features was conducted to relate the clustered AE signals to micro mechanisms and the observed damage patterns, and differences between steel-confined and unconfined RC columns were compared and illustrated.

INVESTMENT EVALUATION OF TRANSPORTATION INFRASTRUTURE PROJECTS USING BINOMIAL REAL OPTION MODEL

  • Qiyu Qian;Xueqing Wang;Charles Y.J. Cheah
    • International conference on construction engineering and project management
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    • 2007.03a
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    • pp.563-572
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    • 2007
  • Transportation infrastructure is critical to economic growth of a country such as China. Careful evaluation of investments in traffic infrastructure projects is therefore pertinent. As traditional evaluation methods do not consider the uncertainty of future cash flows and mobility during project execution, the real option approach is gradually gaining recognition in the context of valuing construction and infrastructure projects. However, many of the cases only evaluate individual options separately although multiple options often exist in a typical large infrastructure project. Using a highway project in China as a case study, this paper first evaluates a deferment option and a growth option embedded in the project. Subsequently, the values are combined using the fuzzy analytical hierarchy process. It is found that the combined value is less than the sum of the two option values. This finding is consistent with the theoretical observations given in past real option literature despite the use of a different approach.

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Architecture of knowledge-Base and Management System for Grining Operations (연삭가공용 데이타베이스 설게와 활용(기존지식베이스에 관하여))

  • Kim, G.H.;Inasaki, I.;Lee, J.K.
    • Journal of the Korean Society for Precision Engineering
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    • v.11 no.1
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    • pp.211-218
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    • 1994
  • Grinding is considered as a very effective machining technology to attain high production rates and a good surface quality of hard and brittle components. However, the grinding operations till needs the skill and the experience of an operator because of a lack of scientific knowledge and engineering principles. This is the reason why grinding operations are not completley intergrated in CIMS(Computer Intergrated Manufacturing System. Recent develop- ment focus on expert system which deals with domain specific knowledge in order to solve this problem. Firstly, in this study, a basic strategy to develop the grinding knowledge-base for grinding is discussed. Next, the architecture of knowledge-base and management of the grinding knowledge-base(GKB) is described.

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Observation of the Rebound Shock Waves and the EUV Brightening of a Light Bridge Jet

  • Yang, Heesu
    • The Bulletin of The Korean Astronomical Society
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    • v.45 no.1
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    • pp.44.1-44.1
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    • 2020
  • Hα jets of cool chromospheric plasma are protruding into the solar corona 10-100 Mm above the photosphere. The driving mechanisms of Hα jets have been widely studied for decades. However, the detailed process is still elusive. We observed shock signatures moving along a dark jet using 1.6 meter Goode Solar Telescope at Big Bear Solar Observatory. The first shock front of the jet shows sharp --- when it moves upward, while fuzzy and granulated when it moves downward. The jet itself extends upward when the second shock front of the jet reaches the top of the jet. We find abrupt EUV brightenings when the second shock front collides with the edge of the jet. The third front and the fouth front quasi-periodically. These phenomena might be the signs of the rebound shock waves triggered by p-mode wave leakages at the bottom of the jets. Our observation suggests that the jet can be triggered by the rebound shock waves generated by the p-mode waves leaked at the bottom of the jets.

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Non-destructive assessment of carbonation in concrete using the ultrasonic test: Influenced parameters

  • Javad Royaei;Fatemeh Nouban;Kabir Sadeghi
    • Structural Engineering and Mechanics
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    • v.89 no.3
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    • pp.301-308
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    • 2024
  • Concrete carbonation is a continuous and slow process from the outside to the inside, in which its penetration slows down with the increased depth of carbonation. In this paper, the results of the evaluation of the measurement of concrete carbonation depth using a non-destructive ultrasonic testing method are presented. According to the results, the relative nonlinear parameter caused more sensitivity in carbonation changes compared to Rayleigh's fuzzy velocity. Thus, the acoustic nonlinear parameter is expected to be applied as a quantitative index to recognize carbonation effects. In this research, combo diagrams were developed based on the results of ultrasonic testing and the experiment to determine carbonation depth using a phenolphthalein solution, which could be considered as instructions in the projects involving non-destructive ultrasonic test methods. The minimum and maximum accuracy of this method were 89% and 97%, respectively, which is a reasonable range for operational projects. From the analysis performed, some useful expressions are found by applying the regression analysis for the nonlinearity index and the carbonation penetration depth values as a guideline.

Applications of Fuzzy Theory on The Location Decision of Logistics Facilities (퍼지이론을 이용한 물류단지 입지 및 규모결정에 관한 연구)

  • 이승재;정창무;이헌주
    • Journal of Korean Society of Transportation
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    • v.18 no.1
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    • pp.75-85
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    • 2000
  • In existing models in optimization, the crisp data improve has been used in the objective or constraints to derive the optimal solution, Besides, the subjective environments are eliminated because the complex and uncertain circumstances were regarded as Probable ambiguity, In other words those optimal solutions in the existing models could be the complete satisfactory solutions to the objective functions in the Process of application for industrial engineering methods to minimize risks of decision-making. As a result of those, decision-makers in location Problems couldn't face appropriately with the variation of demand as well as other variables and couldn't Provide the chance of wide selection because of the insufficient information. So under the circumstance. it has been to develop the model for the location and size decision problems of logistics facility in the use of the fuzzy theory in the intention of making the most reasonable decision in the Point of subjective view under ambiguous circumstances, in the foundation of the existing decision-making problems which must satisfy the constraints to optimize the objective function in strictly given conditions in this study. Introducing the Process used in this study after the establishment of a general mixed integer Programming(MIP) model based upon the result of existing studies to decide the location and size simultaneously, a fuzzy mixed integer Programming(FMIP) model has been developed in the use of fuzzy theory. And the general linear Programming software, LINDO 6.01 has been used to simulate, to evaluate the developed model with the examples and to judge of the appropriateness and adaptability of the model(FMIP) in the real world.

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