• Title/Summary/Keyword: Fuzzy Application

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COINCIDENCE THEOREMS VIA CONTRACTIVE MAPPINGS IN ORDERED NON-ARCHIMEDEAN FUZZY METRIC SPACES

  • Prasad, Gopi;Tomar, Anita;Dimri, Ramesh Chandra;Bartwal, Ayush
    • The Pure and Applied Mathematics
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    • v.27 no.4
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    • pp.187-205
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    • 2020
  • In this article, we prove coincidence point theorems for comparable 𝜓-contractive mappings in ordered non-Archimedean fuzzy metric spaces utilizing the recently established concept of 𝓣-comparability and relatively weaker order theoretic variants. With a view to show the usefulness and applicability of this work, we solve the system of ordered Fredholm integral equations as an application. In the process, this presentation generalize and improve some prominent recent results obtained in Mihet [Fuzzy Sets Syst., 159 (6), 739-744, (2008)], Altun and Mihet [ Fixed Point Theory Appl. 2010, 782680, (2010)], Alam and Imdad [Fixed Point Theory, 18(2), 415-432, (2017)] and several others in the settings of partially ordered non-Archimedean fuzzy metric spaces.

Semi-active fuzzy based control system for vibration reduction of a SDOF structure under seismic excitation

  • Braz-Cesar, Manuel T.;Barros, Rui C.
    • Smart Structures and Systems
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    • v.21 no.4
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    • pp.389-395
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    • 2018
  • This paper presents the application of a semi-active fuzzy based control system for seismic response reduction of a single degree-of-freedom (SDOF) framed structure using a Magnetorheological (MR) damper. Semi-active vibration control with MR dampers has been shown to be a viable approach to protect building structures from earthquake excitation. Moreover, intelligent damping systems based on soft-computing techniques such as fuzzy logic models have the inherent robustness to deal with typical uncertainties and non-linearities present in civil engineering structures. Thus, the proposed semi-active control system uses fuzzy logic based models to simulate the behavior of MR damper and also to develop the control algorithm that computes the required control signal to command the actuator. The results of the numerical simulations show the effectiveness of the suggested semi-active control system in reducing the response of the SDOF structure.

Extraction of Facial Region Using Fuzzy Color Filter (퍼지 색상 필터를 이용한 얼굴 영역 추출)

  • Kim, M.H.;Park, J.B.;Jung, K.H.;Joo, Y.H.;Lee, J.;Cho, Y.J.
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.147-149
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    • 2004
  • There are no authentic solutions in a face region extraction problem though it is an important part of pattern recognition and has diverse application fields. It is not easy to develop the facial region extraction algorithm because the facial image is very sensitive according to age, sex, and illumination. In this paper, to solve these difficulties, a fuzzy color filer based on the facial region extraction algorithm is proposed. The fuzzy color filter makes the robust facial region extraction enable by modeling the skin color. Especially, it is robust in facial region extraction with various illuminations. In addition, to identify the fuzzy color filter, a linear matrix inequality(LMI) optimization method is used. Finally, the simulation result is given to confirm the superiority of the proposed algorithm.

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Shortest Path Problem in a Type-2 Fuzzy Weighted Graph (타입 2-퍼지 가중치 그래프에서 최단경로 문제)

  • 이승수;이광형
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.6
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    • pp.528-531
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    • 2001
  • Finding a shortest path on a graph is a fundamental problem in the area of graph theory. In an application where we cannot exactly determine the weights of edges fuzzy weights can be used instead of crisp weights. and Type-2 fuzzy weight will be more suitable of this uncertainty varies under some conditions. In this paper, shortest path problem in type-1 fuzzy weighted graphs is extended for type 2 fuzzy weighted graphes. A solution is also given based on possibility theory and extension principle.

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A Causal Knowledge-Driven Inference Engine for Expert System

  • Lee, Kun-Chang;Kim, Hyun-Soo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.8 no.6
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    • pp.70-77
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    • 1998
  • Although many methods of knowledge acquisition has been developed in the exper systems field, such a need form causal knowledge acquisition hs not been stressed relatively. In this respect, this paper is aimed at suggesting a causal knowledge acquisition process, and then investigate the causal knowledge-based inference process. A vehicle for causal knowledge acquisition is FCM (Fuzzy Cognitive Map), a fuzzy signed digraph with causal relationships between concept variables found in a specific application domain. Although FCM has a plenty of generic properties for causal knowledge acquisition, it needs some theoretical improvement for acquiring a more refined causal knowledge. In this sense, we refine fuzzy implications of FCM by proposing fuzzy causal relationship and fuzzy partially causal relationship. To test the validity of our proposed approach, we prototyped a causal knowledge-driven inference engine named CAKES and then experimented with some illustrative examples.

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Design of Fuzzy PI Controller for Variable Speed Drive of Switched Reluctance Motor (SRM의 가변속 구동을 위한 퍼지 PI 제어기 설계)

  • Yoon, Yong-Ho;Park, Jun-Suk;Song, Sang-Hoon;Won, Chung-Yuen;Kim, Jae-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.10
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    • pp.1529-1535
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    • 2012
  • This paper presents the application algorithm for speed control of Switched Reluctance Motor. The conventional PI controller has been widely used in industrial applications. But it is very difficult to find the optimal PI control gain. Fuzzy control does not need any model of plant. It is based on plant operator experience and heuristics. The proposed fuzzy logic modifier increases the control performance of conventional PI controller. Simulation and experimental results show that the proposed fuzzy control method was superior to the conventional PI controller in the respect of system performance. The experiments are performed to verify the capability of proposed control method on 6/4 salient type SRM.

The Valuation of RFID Using Fuzzy Real Option (퍼지실물옵션을 이용한 RFID 투자가치평가)

  • Lee, Young-Chan;Lee, Seung-Seok
    • Knowledge Management Research
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    • v.9 no.4
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    • pp.113-125
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    • 2008
  • Net present value (NPV) and return on investment (ROI) are commonly used to evaluate investment in new technologies. Sometimes, however, measuring the value of investment in new IT becomes very difficult due to its wide scope of application coupled with embedded options in its adoption. Therefore, comprehensive but easily understandable methodologies are needed to solve the complicated problems resulting from the complexity of new technologies. This paper employs a real option analysis to evaluate RFID adoption in the supply chain. Real options analysis should be a better way to evaluate a disruptive technology like RFID. However, the pure (probabilistic) real option rule characterizes the present value of expected cash flows and the expected costs by a single number, which is not realistic in many cases. To solve the problem, this paper considers the real option rule in a more realistic setting, namely, when the present values of expected cash flows and expected costs are estimated by trapezoidal fuzzy numbers.

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A Study on the Boiler System Control of Fossil-Power Plant Using a Self-organizing Fuzzy Logic Control (자동 학습 퍼지 제어기를 이용한 발전용 보일러 시스템 제어에 관한 연구)

  • Mun, Un-Cheol
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.11
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    • pp.514-519
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    • 2001
  • This Paper presents an application of a on-line self-organizing fuzzy logic controller to a boiler system of fossil-power plant. A boiler-turbine system is described as a MIMO nonlinear system in this paper. Then, three single loop fuzzy logic controllers are designed independently. The control rules and the membership functions of proposed fuzzy logic control system are generated automatically without using plant model. The simulation shows successful results for wide range operation of boiler system of fossil-power plant.

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Fuzzy Theory and Reservoir Operation Guidelines for Agricultural Purposes (퍼지이론과 관개용 저수지의 조작)

  • 정하우;이남호
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.33 no.4
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    • pp.45-51
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    • 1991
  • The objective of this paper is to show how the fuzzy sets theory can be applied to the reservoir operation guidelines for agricultural purposes. The concepts of the theory has been resented as a new tool for the decision problems which contains fuzziness and it's application can be found in operations research, expert systems, robotics, fuzzy computers, and pattern recognition. The fuzzy control system for the reservoir operation composed of a set of reservoir operation rules and a fuzzy inference engine was built. Water demand for paddy fields, water availability, and inflow to a reservoir were selected as main factors which determine the magnitude of reservoir release. The behavior of the control system was evaluated for different level of water demand and the results seemed to be reasonable.

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The Design of Optimized Type-2 Fuzzy Neural Networks and Its Application (최적 Type-2 퍼지신경회로망 설계와 응용)

  • Kim, Gil-Sung;Ahn, Ihn-Seok;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.8
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    • pp.1615-1623
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    • 2009
  • In order to develop reliable on-site partial discharge (PD) pattern recognition algorithm, we introduce Type-2 Fuzzy Neural Networks (T2FNNs) optimized by means of Particle Swarm Optimization(PSO). T2FNNs exploit Type-2 fuzzy sets which have a characteristic of robustness in the diverse area of intelligence systems. Considering the on-site situation where it is not easy to obtain voltage phases to be used for PRPDA (Phase Resolved Partial Discharge Analysis), the PD data sets measured in the laboratory were artificially changed into data sets with shifted voltage phases and added noise in order to test the proposed algorithm. Also, the results obtained by the proposed algorithm were compared with that of conventional Neural Networks(NNs) as well as the existing Radial Basis Function Neural Networks (RBFNNs). The T2FNNs proposed in this study were appeared to have better performance when compared to conventional NNs and RBFNNs.