• Title/Summary/Keyword: fuzzy-set theory

Search Result 378, Processing Time 0.024 seconds

Fuzzy Deterministic Relations (퍼지 디터미니스틱 관계)

  • Sung, Yeoul Ouk;Lee, Hyun Kyu;Yang, Eunmok
    • Journal of Digital Convergence
    • /
    • v.19 no.10
    • /
    • pp.377-382
    • /
    • 2021
  • A fuzzy relation between X and Y as fuzzy subset of X × Y was proposed by Zadeh. Subsequently, several researchers have applied the notion of fuzzy subsets to various branches of mathematics and computer sciences. Murali an Nemitz have studied fuzzy relations connected with fuzzy equivalence relations and fuzzy functions. Ounalli and Jaoua defined a fuzzy difunctional relation on a set. difunctional relations are versatile mathematical tool, which can be used in software design and in database theory. Their work have revealed the usefulness of difunctional relations in program specification and in defining program correctness. The main goal of this paper is to define a fuzzy deterministic relation on a set, characterize the fuzzy deterministic relation as its level subsets and investigate some properties in connection with fuzzy deterministic relation. In particular we prove that a fuzzy relation R is fuzzy deterministic iff R is a fuzzy function.

A Study on the Transmission System Expansion Planning using Fuzzy Integer Programming (Fuzzy 정수계획법을 이용한 송전망의 확충계획에 관한 연구)

  • Kim, Hong-Sik;Moon, Seung-Pil;Lee, Young-Jin;Choi, Hyong-Lim;Choi, Jae-Seok
    • Proceedings of the KIEE Conference
    • /
    • 2001.11b
    • /
    • pp.350-353
    • /
    • 2001
  • This study proposes a new method for the transmission system expansion planning using the fuzzy integer programming. It presents stepwise cost characteristics analysis which is a practical condition of an actual systems. A branch and bound method which includes the network flow method and the maximum flow-minimum cut set theorem has been used in order to proceed the stepwise cost characteristics analysis. Uncertainties of the permission of the construction cost and not strict reserve rate and load forecasting of expansion planning have been included and also processed using fuzzy set theory in this study. In order to proceed the latter analysis, the solving procedure is illustrated in detail by branch and bound method which includes the network flow method and maximum flow-minimum cut set theorem. Finally, case studies on 21-bus test system show that the algorithm proposed is efficiently applicable to the practical expansion planning of transmission systems in future.

  • PDF

Agent Based Information Security Framework for Hybrid Cloud Computing

  • Tariq, Muhammad Imran
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.13 no.1
    • /
    • pp.406-434
    • /
    • 2019
  • In general, an information security approach estimates the risk, where the risk is to occur due to an unusual event, and the associated consequences for cloud organization. Information Security and Risk Management (ISRA) practices vary among cloud organizations and disciplines. There are several approaches to compare existing risk management methods for cloud organizations but their scope is limited considering stereo type criteria, rather than developing an agent based task that considers all aspects of the associated risk. It is the lack of considering all existing renowned risk management frameworks, their proper comparison, and agent techniques that motivates this research. This paper proposes Agent Based Information Security Framework for Hybrid Cloud Computing as an all-inclusive method including cloud related methods to review and compare existing different renowned methods for cloud computing risk issues and by adding new tasks from surveyed methods. The concepts of software agent and intelligent agent have been introduced that fetch/collect accurate information used in framework and to develop a decision system that facilitates the organization to take decision against threat agent on the basis of information provided by the security agents. The scope of this research primarily considers risk assessment methods that focus on assets, potential threats, vulnerabilities and their associated measures to calculate consequences. After in-depth comparison of renowned ISRA methods with ABISF, we have found that ISO/IEC 27005:2011 is the most appropriate approach among existing ISRA methods. The proposed framework was implemented using fuzzy inference system based upon fuzzy set theory, and MATLAB(R) fuzzy logic rules were used to test the framework. The fuzzy results confirm that proposed framework could be used for information security in cloud computing environment.

Development of Fuzzy Inference Mechanism for Intelligent Data and Information Processing (지능적 정보처리를 위한 퍼지추론기관의 구축)

  • 송영배
    • Spatial Information Research
    • /
    • v.7 no.2
    • /
    • pp.191-207
    • /
    • 1999
  • Data and information necessary for solving the spatial decision making problems are imperfect or inaccurate and most are described by natural language. In order to process these arts of information by the computer, the obscure linguistic value need to be described quantitatively to let and computer understand natural language used by humans. For this , the fuzzy set theory and the fuzzy logic are used representative methodology. So this paper describes the construction of the language model by the natural language that user easily can understand and the logical concepts and construction process for building the fuzzy inference mechanism. It makes possible to solve the space related decision making problems intellectually through structuring and inference used by the computer, in case of the evaluation concern or decision making problems are described inaccurate, based on the inaccurate or indistinct data and information.

  • PDF

A Study on Mating Chamferless Parts by Integrating Fuzzy Set Tyeory and Neural Network (퍼지 및 신경회로망을 이용한 면취가 없는 부품의 자동결합작업에 관한 연구)

  • 박용길;조형석
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.18 no.1
    • /
    • pp.1-11
    • /
    • 1994
  • This paper presents an intelligent robotic control method for chamferless parts mating by integrating fuzzy control and neural network. The successful assembly task requires an extremely high position accuracy and a good knowledge of mating parts. However, conventional assembly method alone makes it difficult to achieve satisfactory assembly performance because of the complexity and the uncertainties of the process and its environments such as not only the limitation of the devices performing the assembly but also imperfect knowledge of the parts being assembled. To cope with these problems, an intelligent robotic assembly method is proposed, which is composed of fuzzy controller and learning mechanism based upon neural net. In this method, fuzzy controller copes with the complexity and the uncertainties of the assembly process, while neural network enhances the assembly scheme so as to learn fuzzy rules from experience and adapt to changes in environment of uncertainty and imprecision. The performance of the proposed assembly scheme is evaluted through a series of experiments using SCARA robot. The results show that the proposed control method can be effectively applied to chamferless precision parts mating.

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
    • /
    • v.19 no.2
    • /
    • pp.109-120
    • /
    • 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.

  • PDF

Service Development using Fuzzy QFD in the banking industry

  • Yu, Eun Jin;Kwak, Choonjong
    • Journal of Korean Society for Quality Management
    • /
    • v.43 no.1
    • /
    • pp.103-124
    • /
    • 2015
  • Purpose: This paper proposes a structured approach based on Quality Function Deployment (QFD) for service development in the banking industry. Methods: SERVQUAL is modified and adopted as a tool to understand customer requirements for the QFD. Fuzzy theory is used to resolve the subjectivity and ambiguity of customer requirements and satisfaction. This research also uses the importance- satisfaction model to construct an additional House of Quality (HOQ). A pair of houses of quality provides a confluence of results to avoid a risk of depending solely on the results of a single HOQ. Results: A case study is introduced with three domestic banks. Conclusion: The proposed approach effectively addresses a service development problem.

Fatigue Life Prediction using Fuzzy Reliability theory (퍼지신뢰성이론에 의한 피로수명 예측)

  • 심확섭;이치우;장건의
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 1995.10a
    • /
    • pp.672-675
    • /
    • 1995
  • Because of a sudden growth of the research of fatigue failure, recent machines or structures have been designed by damage tolerance design in many fields. Consequently, it is the most primary factor to clarity the specific character of fatique failure in the design of machines or structures considering reliability. A statistical analysis is required to analyze the outcome of an experiment or a life estimate by reason of that fatigue failure contains lots of random elements. Reliability analysis which has tukenn the place of the existing analyses in the consideration of the uncertainty of a material, is a very efficient way. Even reliability analysis, however, is not a perfect way to analyses the uncertainties of all the materials. This thesis would refer to a newly conceived data analysis that the coefficient of a system could cause the ambiguity of the relationship of an input and output.

  • PDF

Development of MAP Network Performance Manger Using Artificial Intelligence Techniques (인공지능에 의한 MAP 네트워크의 성능관리기 개발)

  • Son, Joon-Woo;Lee, Suk
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.14 no.4
    • /
    • pp.46-55
    • /
    • 1997
  • This paper presents the development of intelligent performance management of computer communication networks for larger-scale integrated systems and the demonstration of its efficacy using computer simula- tion. The innermost core of the performance management is based on fuzzy set theory. This fuzzy perfor- mance manager has learning ability by using principles of neuro-fuzzy model, neuralnetwork, genetic algo- rithm(GA). Two types of performance managers are described in this paper. One is the Neuro-Fuzzy Per- formance Manager(NFPM) of which learning ability is based on the conventional gradient method, and the other is GA-based Neuro-Fuzzy Performance Manager(GNFPM)with its learning ability based on a genetic algorithm. These performance managers have been evaluated via discrete event simulation of a computer network.

  • PDF

Fuzzy logic control of a planar parallel manipulator using multi learning algorithm (다중 학습 알고리듬을 이용한 평면형 병렬 매니퓰레이터의 Fuzzy 논리 제어)

  • Song, Nak-Yun;Cho, Whang
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.5 no.8
    • /
    • pp.914-922
    • /
    • 1999
  • A study on the improvement of tracking performance of a 3 DOF planar parallel manipulator is performed. A class of adaptive tracking control sheme is designed using self tuning adaptive fuzzy logic control theory. This control sheme is composed of three classical PD controller and a multi learning type self tuning adaptive fuzzy logic controller set. PD controller is tuned roughly by manual setting a priori and fuzzy logic controller is tuned precisely by the gradient descent method for a global solution during run-time, so the proposed control scheme is tuned more rapidly and precisely than the single learning type self tuning adaptive fuzzy logic control sheme for a local solution. The control performance of the proposed algorithm is verified through experiments.

  • PDF