• Title/Summary/Keyword: fuzzy set model

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Development of Diagnosis of Trouble Model for Effective Operation of Air-compressor (효율적인 공기압축기 운영을 위한 이상진단모델 연구)

  • Im, Sang Don;Jung, Young Deuk;Kim, Jong Rae
    • Journal of the Korea Safety Management & Science
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    • v.16 no.3
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    • pp.239-248
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    • 2014
  • Most systems used in industrial sites, actually have non-linearity and uncertainty. Therefore there are a lot of difficulties in evaluating conditions of these systems. Generally, the quantitative analysis and expression are found hard because the general public cannot easily make an accurate interpretation on the systems. Thus development of a system that utilizes an expertise from skilled analysts is required. In this research, a real-time sensor signal conditioning system and Fuzzy-expert system have been separately set up into an inference algorithm. So that it ensures a fast, accurate, objective and quantitative operational condition value provided to the manager. Therefore, FE_AFCDM is suggested in this literature, as an effective system for diagnosing the problems related to the air compressor. It can quantify the uncertain and absurd condition to operate the air compressor facilities safely and financially.

A Study on the Evaluation of Competitiveness for Container Terminal Operators (컨테이너터미널 운영사의 기업경쟁력 평가에 관한 연구)

  • Ko, Hyun-Jeung;Kil, Kwang-Soo
    • Journal of Navigation and Port Research
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    • v.35 no.8
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    • pp.667-675
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    • 2011
  • As the annual growth rate of port handling container volume in Korea has faced slowdown, this paper attempts to find strategies for the domestic container terminal operators in order to enhance competitiveness. For this, the model of using AHP and the fuzzy set theory is used for evaluating competitiveness between domestic and global container terminal operators. The evaluation model hierarchy is developed based on SERM(subject-environment-resource-mechanism) theory of business strategy. The results show domestic operators are ranked lower than global player so that they particularly pay attention to the areas of scale of economy, business diversification, and globalization strategy.

Development and application of urban flood alert criteria considering damage records and runoff characteristics (피해이력 및 유역특성을 고려한 도시침수 위험기준 설정 및 적용)

  • Cho, Jeawoong;Bae, Changyeon;Kang, Hoseon
    • Journal of Korea Water Resources Association
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    • v.51 no.1
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    • pp.1-10
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    • 2018
  • Recently, localized heavy rainfall has led to increasing flood damage in urban areas such as Gangnam, Seoul ('12), Busan ('13), Ulsan ('16) Incheon and Busan ('17) etc. Urban flooding occurs relatively rapidly compared to flood damage in river basin, and property damage including damage to houses, cars and shopping centers is more serious than facility damage to structures such as levees and small bridges. In Korea, heavy rain warnings are currently announced using the criteria set by KMA (Korea Meteorological Administration). However, these criteria do not reflect regional characteristics and are not suitable to urban flood. So in this study, estimated the flooding limit rainfall amount based on the damage records for Seoul and Ulsan. And for regions that can not estimate the flooding limit rainfall since there is no damage records, we estimated the flooding limit rainfall using a Neuro-Fuzzy model with runoff characteristics. Based on the estimated flooding limit rainfall, the urban flood warning criteria was set. and applied to the actual flood event. As a result of comparing the estimated flooding limit rainfall with the actual flooding limit rainfall, the error of 1.8~20.4% occurred. And evacuation time was analyzed from a minimum of 28 minutes to a maximum of 70 minutes. Therefore, it can be used as a warning criteria in the urban flood.

Development of Fuzzy Travel Time Estimator for Interrupted Traffic Flow (단속류 퍼지 통행시간 추정기의 개발)

  • 오기도;김영찬
    • Journal of Korean Society of Transportation
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    • v.18 no.5
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    • pp.57-67
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    • 2000
  • Two fuzzy travel time estimators for interrupted traffic flow were developed based on field survey data and simulation data 7hat is collected from DETSIM, which is microscopic traffic simulation model that car-following theory is applied. One is FETTOS(Fuzzy Estimator of Travel Time using Occupancy and Spot speed) and the other is FETTOS(Fuzzy Estimator of Travel Speed using Volume and Occupancy). Fuzzy logic controller was applied to the estimators to deal with non-linear relationship between traffic variables and travel time. According to results of simulation and field survey. estimation of travel time can be modeled by using percent occupancy better than any other traffic variables. Detector location from storyline and signal timing Plan of intersection are affected to estimate travel time. With a few findings, the estimator was constructed and its performance was tested for observed travel time data and simulated data. FETTOS which needs signal timing plan and detector location estimates travel time with accurate better than FETSVO does. However. FETSVO has excellent transferability because the estimator needs set of input data only; volume and time mean speed.

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Evaluation of Edge Detector′s Smoothness using Fuzzy Ambiguity (퍼지 애매성을 이용한 에지검출기의 평활화 정도평가)

  • Kim, Tae-Yong;Han, Joon-Hee
    • Journal of KIISE:Software and Applications
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    • v.28 no.9
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    • pp.649-661
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    • 2001
  • While the conventional edge detection can be considered as the problem of determining the existence of edges at certain locations, the fuzzy edge modeling can be considered as the problem of determining the membership values of edges. Thus, if the location of an edge is unclear, or if the intensity function is different from the ideal edge model, the degree of edgeness at the location is represented as a fuzzy membership value. Using the concept of fuzzy edgeness, an automatic smoothing parameter evaluation and selection method for a conventional edge detector is proposed. This evaluation method uses the fuzzy edge modeling, and can analyze the effect of smoothing parameter to determine an optimal parameter for a given image. By using the selected parameter we can detect least ambiguous edges of a detection method for an image. The effectiveness of the parameter evaluation method is analyzed and demonstrated using a set of synthetic and real images.

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Optimal design of the PID Controller using a predictive control method

  • Kim, Sang-Joo;Lee, Jang-Myung
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.1
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    • pp.69-75
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    • 2005
  • This paper is concerned with the design of a predictive PID controller, which has similar features to the model-based predictive controller. A PID type control structure is defined which includes prediction of the outputs and the recalculation of new set points using the future set point data. The optimal values of the PID gains are pre-calculated using the values of gains calculated from an unconstrained generalized predictive control algorithm. Simulation studies demonstrate the performance of the proposed controller and the results are compared with generalized predictive controller and the results are compared with generalized predictive control solutions.

Phonetics and Language as a formal System

  • Port, Robert F.;Leary, Adam P.
    • Lingua Humanitatis
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    • v.5
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    • pp.221-264
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    • 2003
  • This paper takes issue with the idea of language as a 'serial-time structure' as opposed to the 'real-time event' of speech, an idea entrenched in Chomskyan model of linguistic theory. The discussion centers around the leitmotif question: Is language constructed entirely from a finite set of apriori discrete symbol types, as the 'competence vs performance' dichotomy implies\ulcorner A set of linguistic patterns examined in this study, largely with regard to phonological considerations, points to the evidence to the contrary. That is, while the patterns may be said to be linguistically distinct, they are not discretely, different, i.e. not different enough to be reliably differentiated. It is demonstrated that much of current research in phonology, including the most recent Optimality Theory, is misdirected in that it falsely presupposes a discrete universal phonetic inventory. The main thrust of the present study is that there is no sharp boundary between 'competence' defined as the formal, symbolic, discrete time domain of language and human cognition on the one hand and 'performance' as the continuous, fuzzy, real-time domain of human physiology on the other.

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Biosign Recognition based on the Soft Computing Techniques with application to a Rehab -type Robot

  • Lee, Ju-Jang
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.29.2-29
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    • 2001
  • For the design of human-centered systems in which a human and machine such as a robot form a human-in system, human-friendly interaction/interface is essential. Human-friendly interaction is possible when the system is capable of recognizing human biosigns such as5 EMG Signal, hand gesture and facial expressions so the some humanintention and/or emotion can be inferred and is used as a proper feedback signal. In the talk, we report our experiences of applying the Soft computing techniques including Fuzzy, ANN, GA and rho rough set theory for efficiently recognizing various biosigns and for effective inference. More specifically, we first observe characteristics of various forms of biosigns and propose a new way of extracting feature set for such signals. Then we show a standardized procedure of getting an inferred intention or emotion from the signals. Finally, we present examples of application for our model of rehabilitation robot named.

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A Material Handling Performance Evaluation Model for Cellular Manufacturing System of Based on Multi-Attributes Analysis Method (다 속성분석방법을 이용한 제조물류시스템의 성능산정모델)

  • 황홍석
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2000.10a
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    • pp.167-170
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    • 2000
  • This paper is concerned with development of a performance evaluation model for material handling system in cellular manufacturing system based on multi-attributes analysis method. We used the AHP(analytic hierarchy process) and fuzzy set ranking methodologies to overcome the special decision problems; those of multi -objective, multi-criterion, and multi-attributes. We proposed a 3-step approaches and we developed a systemic and practical computer program to solve the problems in the proposed methods. Computational experiments are then performed to cellular manufacturing system and show the effectiveness of the proposed model.

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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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    • v.7 no.3
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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.