• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.193-196
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• 2002

This paper proposes the control problem of an inverted pendulum system based on Sugeno-Type of fuzzy logic. The universal approximating capability, learning ability, adaptation capability and disturbance rejection are collected in one control strategy. The proposed scheme does not require an accurate dynamic model and the joint acceleration measurement, yet it guarantees asymptotic trajectory tracking. Experimental results perform with an inverted pendulum to show the effectiveness of the approach.

• 한국지능시스템학회논문지
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• 제10권6호
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• pp.584-590
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• 2000

Urban traffic situations are extremely complex and highly interactive. The multi-agent systems approach can provide a new desirable solution. Currently, a traffic simulator is needed to understand and explore the difficulties in an agent-oriented traffic control. This paper presents an agent-oriented fuzzy logic controller for multiple crossroads simulation. A fuzzy logic control simulation with variables of arrival, queue, and traffic volume could alleviate traffic congestion. We developed an agent-oriented simulator suitable for traffic junctions with η$\times$η intersections in Visual C++. The proposed method adaptively controls the cycle of traffic signals even though the traffic volume varies. The effectiveness of this method was shown through simulation of multiple intersections.

• 산업경영시스템학회지
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• 제37권4호
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• pp.1-11
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• 2014

This paper addresses the emotion computing model for software affective agents. In this paper, emotion is represented in valence-arousal-dominance dimensions instead of discrete categorical representation approach. Firstly, a novel emotion model architecture for affective agents is proposed based on Scherer's componential theories of human emotion, which is one of the well-known emotion models in psychological area. Then a fuzzy logic is applied to determine emotional statuses in the emotion model architecture, i.e., the first valence and arousal, the second valence and arousal, and dominance. The proposed methods are implemented and tested by applying them in a virtual training system for children's neurobehavioral disorders.

• 전자공학회논문지B
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• 제28B권11호
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• pp.934-940
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• 1991

The multi-layer neural network that has broadly been utilized in designing the controller of robot manipulator possesses the desirable characteristics of learning capacity, by which the uncertain variation of the dynamic parameters of robot can be handled adaptively, and parallel distributed processing that makes it possible to control on real-time. However the error back propagation algorithm that has been utilized popularly in the learning of the multi-layer neural network has the problem of its slow convergencs speed. In this paper, an approach to improve the convergence speed is proposed using fuzzy logic that can effectively handle the uncertain and fuzzy informations by linguistic level. The effectiveness of the proposed algorithm is demonstrated by computer simulation of PUMA 560 robot manipulator.

• 한국지능시스템학회논문지
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• 제26권5호
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• pp.402-408
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• 2016

본 논문에서는 퍼지 슬라이딩 평면의 개념을 터미널 슬라이딩 평면의 기울기를 선정하는데 적용한 일차원 퍼지규칙 슬라이딩 평면을 이용한 터미널 슬라이딩 제어기를 제안하였다. 터미널 슬라이딩 모드 제어기의 개념을 확장하여 연속인 도달법칙을 가지는 터미널 슬라이딩 모드 제어 입력을 제안하였다. 컴퓨터 모의실험에서 제안한 제어기는 터미널 슬라이딩 모드 제어기 보다 빠른 수렴 특성과 채터링이 발생하지 않는 특성을 보여주었으며 일차원 퍼지 규칙을 사용하여 계산량이 작다는 장점을 가지고 있다.

• 디지털융복합연구
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• 제11권2호
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• pp.221-228
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• 2013

시나리오 기반 학습과 관련하여 학습 관련 효과에 관한 많은 연구들이 집중되고 있다. 그렇지만, 이와 관련하여 바람직한 효과 측정 방법이 제시되지 못하고 있다. 본 연구는 시나리오 학습과 관련하여 보다 바람직한 학습 효과 측정을 위해 하나의 퍼지 논리 기반 프레임워크를 제안하는데 있다. 이러한 프레임워크의 사용은 학습 효과의 측정에 있어서 언어적인 불확실성 문제를 해결할 수 있다. 본 연구에서는 시나리오 기반 학습의 효과 측정을 위해 정확성, 이해성, 완비성의 3가지 불확실성 측도를 사용한다. 이러한 측도의 사용은 시나리오 맥락 측면에서 완전성뿐만 아니라 사용자 선택에 따른 효과 차이를 최소화시킬 수 있는 강점을 가진다. 다른 무엇보다도 시나리오 기반의 학습에 퍼지 논리의 적용은 실제 학습 상황에서 학습 목표 도달을 위한 학습 경로 진행 상황을 쉽게 관측할 수 있다.

• 한국정보통신학회논문지
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• 제15권9호
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• pp.1925-1931
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• 2011

본 논문에서는 Canny 에지 검출 알고리즘의 핵심이라 할 수 있는 언어적인 애매한 개념인 "좋은 검출"과 "좋은 지역화" 문제를 퍼지 추론 방식을 통해 처리하는 접근방식을 제안하고, 그레이 스케일 이미지에 관해 퍼지 규칙 기반의 Canny 에지 검출기를 설계한다. 설계의 핵심은 화소들의 그레이 레벨들을 몇 가지의 언어적인 변수들로 분할한 다음에 퍼지 추론 규칙에 따라 편미분 계수들을 근사시키는데 있다. 이러한 접근방식은 기울기 및 기울기 변화에 따른 퍼지 제어 기법과 유사한 측면을 가진다. 이러한 작업을 바탕으로 퍼지 규칙 기반 Canny 에지 검출기를 구현하고, 결과들을 기존 방법과 비교한다. 특히, 제안된 접근 방식은 좁은 동적 범위의 그레이 레벨 이미지의 에지 검출 및 선명화에 있어서 장점을 가진다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.541-551
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• 2020

Based on the trend, there have been numerous researches analysing the ship collision risk. However, in this scope, the navigational conditions and external environment are ignored or incompletely considered in training or/and real situation. It has been identified as a significant limitation in the navigational collision risk assessment. Therefore, a novel algorithm of the ship navigational collision risk solving system has been proposed based on basic collision risk and vulnerabilities of marine accidents. The vulnerability can increase the possibility of marine collision accidents. The factors of vulnerabilities including bad weather, tidal currents, accidents prone area, traffic congestion, operator fatigue and fishing boat operating area are involved in the fuzzy reasoning engines to evaluate the navigational conditions and environment. Fuzzy logic is employed to reason basic collision risk using Distance to Closest Point of Approach (DCPA) and Time of Closest Point of Approach (TCPA) and the degree of vulnerability in the specific coastal waterways. Analytical Hierarchy Process (AHP) method is used to obtain the integration of vulnerabilities. In this paper, vulnerability factors have been proposed to improve the collision risk assessment especially for non-SOLAS ships such as coastal operating ships and fishing vessels in practice. Simulation is implemented to validate the practicability of the designed navigational collision risk solving system.

• 한국산업융합학회 논문집
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• 제21권2호
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• pp.95-101
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• 2018

This paper presents a collision free mobile robot navigation based on the fuzzy inference fusion model in unkonown environments using multi-ultrasonic sensor. Six ultrasonic sensors are used for the collision avoidance approach where CCD camera sensors is used for the trajectory following approach. The fuzzy system is composed of three inputs which are the six distance sensors and the camera, two outputs which are the left and right velocities of the mobile robot's wheels, and three cost functions for the robot's movement, direction, obstacle avoidance, and rotation. For the evaluation of the proposed algorithm, we performed real experiments with mobile robot with ultrasonic sensors. The results show that the proposed algorithm is apt to identify obstacles in unknown environments to guide the robot to the goal location safely.

• 산업경영시스템학회지
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• 제13권21호
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• pp.29-41
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• 1990

An assessment of risk in industrial and urban environments is essential in the prevention of accident and in the analysis of situations which are hazardous to public health and safety. The risk imposed by a particular hazard increases with the likelihood of occurence of the event, the exposure and the possible consequence of that event. In a traditional approach, the calculation of a quantitative value of risk is usually based on an assignment of numerical values of each of the risk factors. Then the product of the values of likelihood, exposure and consequences called risk score is derived. However vagueness and imprecision in mathematical quantification of risk are equated with fuzziness rather than randomness. In this paper, a fuzzy set theoretic approach to risk analysis is proposed as an alternative to the techniques currently used in the area of systems safety. Then the concept of risk evaluation using linguistic representation of the likelihood, exposure and consequences is introduced. A risk assessment model using approximate reasoning technique based on fuzzy logic is presented to drive fuzzy values of risk and numerical example for risk analysis is also presented to illustrate the results.