• Title/Summary/Keyword: Linguistic variables

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The Condition and Safety Assessment using Fuzzy Fault Tree Analysis for Bridge System (퍼지결함수분석을 이용한 교량시스템의 상태 및 안전성 평가)

  • 이중빈;나기현;손용우;박주원
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.10a
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    • pp.79-86
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    • 1999
  • This paper aims to propose a method that helps maintenance engineers to evaluate the damage states of bridge systems by using a Fuzzy Fault Tree Analysis(FFTA). It may be stated that Fuzzy Fault Tree Analysis may be may useful for the systematic md rational condition and safety assessment for real bridge systems problems because the approach is able to effectively deal with all the related bridge system damages in terms of the linguistic variables that incorporate systematically experts experiences and subjective judgement.

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Self-Tuning Method for Fuzzy Controller (퍼지제어기의 자기동조 방법에 관한 연구)

  • Choi, Han-Soo;Kim, Sung-Joong
    • Proceedings of the KIEE Conference
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    • 1993.07a
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    • pp.218-220
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    • 1993
  • This paper deals with a self-tuning fuzzy controller. The fuzzy controller is constructed with linguistic rules which consist of the fuzzy variables and fuzzy sets. Each of fuzzy sets is characterized by a membership function. The tuning fussy controller has paramemters to effect control output. In this paper we propose tuning method for the scaling factor. Computer simulations carried out on a second-order process will show how the present tuning approach improves the transient and steady-state characteristics of the overall system.

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Application of the Fuzzy Set Theory to Uncertain Parameters in a Countermeasure Model (비상대응모델의 불확실한 변수에 대한 퍼지이론의 적용)

  • Han, Moon-Hee;Kim, Byung-Woo
    • Journal of Radiation Protection and Research
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    • v.19 no.2
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    • pp.109-120
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    • 1994
  • A method for estimating the effectiveness of each protective action against a nuclear accident has been proposed using the fuzzy set theory. In most of the existing countermeasure models in actions under radiological emergencies, the large variety of possible features is simplified by a number of rough assumptions. During this simplification procedure, a lot of information is lost which results in much uncertainty concerning the output of the countermeasure model. Furthermore, different assumptions should be used for different sites to consider the site specific conditions. Tn this study, the diversity of each variable related to protective action has been modelled by the linguistic variable. The effectiveness of sheltering and evacuation has been estimated using the proposed method. The potential advantage of the proposed method is in reducing the loss of information by incorporating the opinions of experts and by introducing the linguistic variables which represent the site specific conditions.

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Implementation of Real-Time Fuzzy Controller for SCARA Type Dual-Arm Robot (스카라형 이중 아암 로봇의 실시간 퍼지제어기 실현)

  • Kim Hong-Rae;Han Sung-Hyun
    • Journal of Institute of Control, Robotics and Systems
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    • v.10 no.12
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    • pp.1223-1232
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    • 2004
  • We present a new technique to the design and real-time implementation of fuzzy control system basedon digital signal processors in order to improve the precision and robustness for system of industrial robot in this paper. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The TMS320C80 is used in implementing real time fuzzy control to provide an enhanced motion control for robot manipulators. In this paper, a Self-Organizing Fuzzy Controller for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variables of the controller. In the synthesis of a Fuzzy Logic Controller, one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult Self-Organizing Fuzzy Controller is proposed for a hierarchical control structure consisting of basic and high levels that modify control rules. The proposed Self-Organizing Fuzzy Controller scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Performance of the SOFC is illustrated by simulation and experimental results for a Dual-Arm robot with eight joints.

Utilizing Prosodic Information on the Sentence Comprehension in Children with High Functioning Autism

  • Chung, Chan-Hee;Lee, Hee-Ran;Kim, Jin-Dong
    • Biomedical Science Letters
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    • v.23 no.4
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    • pp.362-371
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    • 2017
  • The purpose of this study is to investigate difficulties in using prosodic information to identify the meaning of ambiguous sentences in children with high functioning autism (HFA). Fifteen high functioning autistic children and fifteen children who matched their chronological age (CA) participated in this study. We compared the performance of the two groups by conducting syntactically and affectively ambiguous sentence comprehension (SASC and AASC) tasks. The results of this study show that in both tasks, the difference between the two groups was statistically significant at each condition and the performance of high functioning autistic children was significantly lower. In a correlation analysis of major variables, children who matched CA showed a correlation between prosody-only (PO) and AASC, while children with HFA showed a correlation between PO and MO (morpheme-only). Children with HFA used grammatical morpheme information to understand general sentences. We found that the ability to use prosodic information in children with HFA is significantly lower than that of normally developed children. Considering the relevance of prosody to linguistic, non-linguistic and emotional aspects of communication, improving prosodic perception is thought to be a way to mediate deficits in the comprehension of ambiguous sentences in children with HFA.

A Decision Support System for the Selection of a Rapid Prototyping Process (쾌속조형공정 선정을 위한 지원 시스템)

  • 변홍석;이관행
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.5-8
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    • 2003
  • This paper presents a methodology to be able to select an appropriate RP system that suits the end use of a part. Evaluation factors used in process selection include major attributes such as accuracy, roughness, strength, elongation, part cost and build time that greatly affect the performance of RP systems. Crisp values such as accuracy and surface roughness are obtained with a new test part developed. The test part is designed with conjoint analysis to reflect users' preference. The part cost and build time that have approximate ranges due to cost and many variable parameters are presented by linguistic values that can be described with triangular fuzzy numbers. Based on the evaluation values obtained, an appropriate RP process for a specific part application is selected by using the modified TOPSIS(Technique of Order Preference by Similarity to Ideal Solution) method. It uses crisp data as well as linguistic variables, and each weight on the alternatives is assigned by using pair-wise comparison matrix. The ranking order helps the decision making of the selection of RP systems.

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FMECA using Fault Tree Analysis (FTA) and Fuzzy Logic (결함수분석법과 퍼지논리를 이용한 FMECA 평가)

  • Kim, Dong-Jin;Shin, Jun-Seok;Kim, Hyung-Jun;Kim, Jin-O;Kim, Hyung-Chul
    • Proceedings of the KSR Conference
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    • 2007.11a
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    • pp.1529-1532
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    • 2007
  • Failure Mode, Effects, and Criticality Analysis (FMECA) is an extension of FMEA which includes a criticality analysis. The criticality analysis is used to chart the probability of failure modes against the severity of their consequences. The result highlights failure modes with relatively high probability and severity of consequences, allowing remedial effort to be directed where it will produce the greatest value. However, there are several limitations. Measuring severity of failure consequences is subjective and linguistic. Since The result of FMECA only gives qualitative and quantitative informations, it should be re-analysed to prioritize critical units. Fuzzy set theory has been introduced by Lotfi A. Zadeh (1965). It has extended the classical set theory dramatically. Based on fuzzy set theory, fuzzy logic has been developed employing human reasoning process. IF-THEN fuzzy rule based assessment approach can model the expert's decision logic appropriately. Fault tree analysis (FTA) is one of most common fault modeling techniques. It is widely used in many fields practically. In this paper, a simple fault tree analysis is proposed to measure the severity of components. Fuzzy rule based assessment method interprets linguistic variables for determination of critical unit priorities. An rail-way transforming system is analysed to describe the proposed method.

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Real-Time Fuzzy Control for Dual-Arm with 8 Joints Robot Using the DSPs(TMS320C80) (DSPs(TMS320C80)을 이용한 8축 듀얼 아암 로봇의 실시간 퍼지제어)

  • 한성현;김종수
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.13 no.1
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    • pp.35-47
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    • 2004
  • In this paper presents a new approach to the design and real-time implementation of fuzzy control system based-on digital signal processors(DSP:IMS320C80) in order to improve the precision and robustness for system of industrial robot(Dual-Arm with 8 joint Robot). The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The IMS320C80 is used in implementing real time fuzzy control to provide an enhanced motion control for robot manipulators. In this paper, a Self-Organizing Fuzzy Controller(SOFC) for the industrial robot manipulator with a actuator located at the base is studied. A fuzzy logic composed of linguistic conditional statements is employed by defining the relations of input-output variables of the controller. In the synthesis of a FLC(Fuzzy Logic Controller), one of the most difficult problems is the determination of linguistic control rules from the human operators. To overcome this difficult SOFC is proposed for a hierarchical control structure consisting of basic and high levels that modify control rules. The proposed SOFC scheme is simple in structure, Int in computation, and suitable for implementation of real-time control. Performance of the SOFC is illustrated by simulation and experimental results for a Dual-Arm robot with eight joints.

On the Design of Simple-structured Adaptive Fuzzy Logic Controllers

  • Park, Byung-Jae;Kwak, Seong-Woo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.3 no.1
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    • pp.93-99
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    • 2003
  • One of the methods to simplify the design process for a fuzzy logic controller (FLC) is to reduce the number of variables representing the rule antecedent. This in turn decreases the number of control rules, membership functions, and scaling factors. For this purpose, we designed a single-input FLC that uses a sole fuzzy input variable. However, it is still deficient in the capability of adapting some varying operating conditions although it provides a simple method for the design of FLC's. We here design two simple-structured adaptive fuzzy logic controllers (SAFLC's) using the concept of the single-input FLC. Linguistic fuzzy control rules are directly incorporated into the controller by a fuzzy basis function. Thus some parameters of the membership functions characterizing the linguistic terms of the fuzzy control rules can be adjusted by an adaptive law. In our controllers, center values of fuzzy sets are directly adjusted by an adaptive law. Two SAFLC's are designed. One of them uses a Hurwitz error dynamics and the other a switching function of the sliding mode control (SMC). We also prove that 1) their closed-loop systems are globally stable in the sense that all signals involved are bounded and 2) their tracking errors converge to zero asymptotically. We perform computer simulations using a nonlinear plant.

Pragmatic Strategies of Self (Other) Presentation in Literary Texts: A Computational Approach

  • Khafaga, Ayman Farid
    • International Journal of Computer Science & Network Security
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    • v.22 no.2
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    • pp.223-231
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    • 2022
  • The application of computer software into the linguistic analysis of texts proves useful to arrive at concise and authentic results from large data texts. Based on this assumption, this paper employs a Computer-Aided Text Analysis (CATA) and a Critical Discourse Analysis (CDA) to explore the manipulative strategies of positive/negative presentation in Orwell's Animal Farm. More specifically, the paper attempts to explore the extent to which CATA software represented by the three variables of Frequency Distribution Analysis (FDA), Content Analysis (CA), and Key Word in Context (KWIC) incorporate with CDA decipher the manipulative purposes beyond positive presentation of selfness and negative presentation of otherness in the selected corpus. The analysis covers some CDA strategies, including justification, false statistics, and competency, for positive self-presentation; and accusation, criticism, and the use of ambiguous words for negative other-presentation. With the application of CATA, some words will be analyzed by showing their frequency distribution analysis as well as their contextual environment in the selected text to expose the extent to which they are employed as strategies of positive/negative presentation in the text under investigation. Findings show that CATA software contributes significantly to the linguistic analysis of large data texts. The paper recommends the use and application of the different CATA software in the stylistic and corpus linguistics studies.