• Title/Summary/Keyword: fuzzy logic inference system

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Fault Diagnosis in Gas Turbine Engine Using Fuzzy Inference Logic (퍼지 로직 시스템을 이용한 항공기 가스터빈 엔진 오류 검출에 대한 연구)

  • Mo, Eun-Jong;Jie, Min-Seok;Kim, Chin-Su;Lee, Kang-Woong
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.1
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    • pp.49-53
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    • 2008
  • A fuzzy inference logic system is proposed for gas turbine engine fault isolation. The gas path measurements used for fault isolation are exhaust gas temperature, low and high rotor speed, and fuel flow. The fuzzy inference logic uses rules developed from a model of performance influence coefficients to isolate engine faults while accounting for uncertainty in gas path measurements. Inputs to the fuzzy inference logic system are measurement deviations of gas path parameters which are transferred directly from the ECM(Engine Control Monitoring) program and outputs are engine module faults. The proposed fuzzy inference logic system is tested using simulated data developed from the ECM trend plot reports and the results show that the proposed fuzzy inference logic system isolates module faults with high accuracy rate in the environment of high level of uncertainty.

Parallel Fuzzy Inference Method for Large Volumes of Satellite Images

  • Lee, Sang-Gu
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.1 no.1
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    • pp.119-124
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    • 2001
  • In this pattern recognition on the large volumes of remote sensing satellite images, the inference time is much increased. In the case of the remote sensing data [5] having 4 wavebands, the 778 training patterns are learned. Each land cover pattern is classified by using 159, 900 patterns including the trained patterns. For the fuzzy classification, the 778 fuzzy rules are generated. Each fuzzy rule has 4 fuzzy variables in the condition part. Therefore, high performance parallel fuzzy inference system is needed. In this paper, we propose a novel parallel fuzzy inference system on T3E parallel computer. In this, fuzzy rules are distributed and executed simultaneously. The ONE_To_ALL algorithm is used to broadcast the fuzzy input to the all nodes. The results of the MIN/MAX operations are transferred to the output processor by the ALL_TO_ONE algorithm. By parallel processing of the fuzzy rules, the parallel fuzzy inference algorithm extracts match parallelism and achieves a good speed factor. This system can be used in a large expert system that ha many inference variables in the condition and the consequent part.

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A Construction of Fuzzy Inference Network based on Neural Logic Network and its Search Strategy

  • Lee, Mal-rey
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2000.11a
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    • pp.375-389
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    • 2000
  • Fuzzy logic ignores some information in the reasoning process. Neural networks are powerful tools for the pattern processing, but, not appropriate for the logical reasoning. To model human knowledge, besides pattern processing capability, the logical reasoning capability is equally important. Another new neural network called neural logic network is able to do the logical reasoning. Because the fuzzy inference is a fuzzy logical reasoning, we construct fuzzy inference network based on the neural logic network, extending the existing rule- inference. network. And the traditional propagation rule is modified. For the search strategies to find out the belief value of a conclusion in the fuzzy inference network, we conduct a simulation to evaluate the search costs for searching sequentially and searching by means of search priorities.

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A Development of Fuzzy-Logic Application for Improving Safety Diagnosis Rating Method of Agricultural Fill Dam (농업용 필댐의 안전진단등급 평가법 개선을 위한 퍼지논리 적용법 개발)

  • Yun, Sung-wook;Yu, Chan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.4
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    • pp.33-43
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    • 2023
  • In this study, it was developed and verified an application method of fuzzy-logic theory to the rating process of agricultural fill dam safety. A fuzzy-logic is very famous logical system when some decision making is made on the status of a lack of information. Three proxies were selected and configured membership functions (MFs) and these MFs were activated in the process of fuzzification procedures. Fuzzified vlaues were passed through the rule-based inference system, then fire strength could classified among cases of the rule-based inference system. To obtain final results, Mandani-type was adapted in the defuzzification process. As the results, it was shown the developed system can give a correct results that was compared with Matlab - fuzzy inference function. More ever it could perform the detailed analysis and improvement on the infrastructure safety rating process using classical diagnosis method.

Evaluation of arousal level by EDA and fuzzy inference (피부전기 활동과 fuzzy추론에 의한 각성도의 평가)

  • Kim, Yeon-Ho;Ko, Han-Woo;Yoo, Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1856-1859
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    • 1997
  • This paper describes the arousal measurement and the control system using fuzzy logic to prevent drowsy driving. Sugeno's method was used for fuzzy inference in this study. Membership function and rule base were determined form the modfied arousal level criteria. The output of fuzzy inference tracked well the change of subject's arousal level. When IRI(Inter-SIR interval) was under the 60sec, maximum output of three step warning method was medium sound, but that of fuzzy logic system was changed from medium to big. Furthermore, the output of the fuzzy inference was highly correlated with $N_{z}$(r=0.99). Therefore, the fuzzy inference method for evaluation and the control of arousal will be more effective at real driving sityation than three step warning method.ning method.

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Multiple Instance Mamdani Fuzzy Inference

  • Khalifa, Amine B.;Frigui, Hichem
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.15 no.4
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    • pp.217-231
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    • 2015
  • A novel fuzzy learning framework that employs fuzzy inference to solve the problem of Multiple Instance Learning (MIL) is presented. The framework introduces a new class of fuzzy inference systems called Multiple Instance Mamdani Fuzzy Inference Systems (MI-Mamdani). In multiple instance problems, the training data is ambiguously labeled. Instances are grouped into bags, labels of bags are known but not those of individual instances. MIL deals with learning a classifier at the bag level. Over the years, many solutions to this problem have been proposed. However, no MIL formulation employing fuzzy inference exists in the literature. Fuzzy logic is powerful at modeling knowledge uncertainty and measurements imprecision. It is one of the best frameworks to model vagueness. However, in addition to uncertainty and imprecision, there is a third vagueness concept that fuzzy logic does not address quiet well, yet. This vagueness concept is due to the ambiguity that arises when the data have multiple forms of expression, this is the case for multiple instance problems. In this paper, we introduce multiple instance fuzzy logic that enables fuzzy reasoning with bags of instances. Accordingly, a MI-Mamdani that extends the standard Mamdani inference system to compute with multiple instances is introduced. The proposed framework is tested and validated using a synthetic dataset suitable for MIL problems. Additionally, we apply the proposed multiple instance inference to fuse the output of multiple discrimination algorithms for the purpose of landmine detection using Ground Penetrating Radar.

A Study of Construct Fuzzy Inference Network using Neural Logic Network

  • Lee, Jae-Deuk;Jeong, Hye-Jin;Kim, Hee-Suk;Lee, Malrey
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.1
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    • pp.7-12
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    • 2005
  • This paper deals with the fuzzy modeling for the complex and uncertain nonlinear systems, in which conventional and mathematical models may fail to give satisfactory results. Finally, we provide numerical examples to evaluate the feasibility and generality of the proposed method in this paper. The expert system which introduces fuzzy logic in order to process uncertainties is called fuzzy expert system. The fuzzy expert system, however, has a potential problem which may lead to inappropriate results due to the ignorance of some information by applying fuzzy logic in reasoning process in addition to the knowledge acquisition problem. In order to overcome these problems, We construct fuzzy inference network by extending the concept of reasoning network in this paper. In the fuzzy inference network, the propositions which form fuzzy rules are represented by nodes. And these nodes have the truth values representing the belief values of each proposition. The logical operators between propositions of rules are represented by links. And the traditional propagation rule is modified.

Distinction of Hot-Cold Using Fuzzy Inference (퍼지 추론에 의한 한열 판별)

  • Jang, Yun Ji;Kim, Young Eun;Kim, Chul;Song, Mi Young;Rhee, Eun Joo
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.19 no.3
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    • pp.141-149
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    • 2015
  • Objectives Recently the fuzzy logic is widely used in the decision making, identification, pattern recognition, optimization in various fields. In this study, we propose the fuzzy logic as the objective method of distinguishing hot and cold, the basis of diagnosis in Korean medicine. Methods We developed fuzzy inference system to distinguish whether the subjects had hot or cold. The cold and hot questionnaire of Korean traditional university textbook, the pulse rate and the DITI value of face used in the system. These three kinds of information were defined as 'fuzzy sets,' and 54 fuzzy rules were established on the basis of clinical practitioners' knowledge. The fuzzy inference was performed by using the Mamdani's method. To evaluate the usefulness of the fuzzy inference system, 200 cases of data measured in the Woosuk university hospital of oriental medicine were used to compare the determining hot, normal, cold results obtained from the experts and from the proposed system. Results As a result, 100 cases of "cold", 54 cases of "normal", and 34 cases of "hot" were matched between the experts and the proposed system. This fuzzy system showed the conformity degree of 94%(${\kappa}=0.853$). Conclusions In this study, we could express the process of distinguishing hot-cold using the fuzzy logic for objectification and quantification of hot-cold identification. This is the first study that introduce a fuzzy logic for distinguish pattern identification. The degree of the heat characteristic of the patients inferred by this system could provide a more objective basis for diagnosing the hot-cold of patients.

Fuzzy Control of DC Servo System and Implemented Logic Circuits of Fuzzy Inference Engine Using Decomposition of $\alpha$-level Fuzzy Set (직류 서보계의 퍼지제어와 $\alpha$-레벨 퍼지집합 분해에 의한 퍼지추론 연산회로 구현)

  • 홍정표;홍순일;이요섭
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.5
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    • pp.793-800
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    • 2004
  • The purpose of this study is to develope a servo system with faster and more accurate response. This paper describes a method of approximate reasoning for fuzzy control of servo system based on the decomposition of $\alpha$-level fuzzy sets. We propose that fuzzy logic algorithm is a body from fuzzy inference to defuzzificaion cases where the output variable u directly is generated PWM The effectiveness for robust and faster response of the fuzzy control scheme are verified for a variable parameter by comparison with a PID control and fuzzy control A position control of DC servo system with a fuzzy logic controller is demonstrated successfully.

A Cooperative Spectrum Sensing Scheme Using Fuzzy Logic for Cognitive Radio Networks

  • Thuc, Kieu-Xuan;Koo, In-Soo
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.4 no.3
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    • pp.289-304
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    • 2010
  • This paper proposes a novel scheme for cooperative spectrum sensing on distributed cognitive radio networks. A fuzzy logic rule - based inference system is proposed to estimate the presence possibility of the licensed user's signal based on the observed energy at each cognitive radio terminal. The estimated results are aggregated to make the final sensing decision at the fusion center. Simulation results show that significant improvement of the spectrum sensing accuracy is achieved by our schemes.