• 제목/요약/키워드: Fuzzy control

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퍼지 클러스터링을 이용한 이동 차량 추적 (Moving Vehicle Tracking using Fuzzy Clustering)

  • 양상규;이정재;소영성
    • 한국지능시스템학회논문지
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    • 제6권4호
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    • pp.92-101
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    • 1996
  • 차량의 증가와 도로 신장율의 저조로 교통체증은 날로 심해지고 있다. 이문제를 풀기 위한 한 방법은 교통류에 관한 실시간 정보를 얻어 교통신호를 동적으로 제어하는 것이다. 현재까지 교통류 정보를 얻기 위해 가장 많이 쓰인 것은 루프코일 인데 이것은 통과 차량의 평균속도를 측정하기 위해 필요한 차량 추적을 할 수 없는 단점이 있다. 따라서 이 문제를 해결하기 위해 영상 검지기가 출현하게 되었고 농담영상 혹은 칼라 영상열을 가정하고 있다. 본 논문에서는 칼라영상의 형태로 주어진 영상열에서 퍼지 클러스터리에 기반을 둔 이동 차량 추적 방법을 제안한다.

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A system model for reliability assessment of smart structural systems

  • Hassan, Maguid H.M.
    • Structural Engineering and Mechanics
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    • 제23권5호
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    • pp.455-468
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    • 2006
  • Smart structural systems are defined as ones that demonstrate the ability to modify their characteristics and/or properties in order to respond favorably to unexpected severe loading conditions. The performance of such a task requires a set of additional components to be integrated within such systems. These components belong to three major categories, sensors, processors and actuators. It is wellknown that all structural systems entail some level of uncertainty, because of their extremely complex nature, lack of complete information, simplifications and modeling. Similarly, sensors, processors and actuators are expected to reflect a similar uncertain behavior. As it is imperative to be able to evaluate the impact of such components on the behavior of the system, it is as important to ensure, or at least evaluate, the reliability of such components. In this paper, a system model for reliability assessment of smart structural systems is outlined. The presented model is considered a necessary first step in the development of a reliability assessment algorithm for smart structural systems. The system model outlines the basic components of the system, in addition to, performance functions and inter-relations among individual components. A fault tree model is developed in order to aggregate the individual underlying component reliabilities into an overall system reliability measure. Identification of appropriate limit states for all underlying components are beyond the scope of this paper. However, it is the objective of this paper to set up the necessary framework for identifying such limit states. A sample model for a three-story single bay smart rigid frame, is developed in order to demonstrate the proposed framework.

이동체 추적을 이용한 대역폭 예약 기법 (Bandwidth Reservation scheme Using Mobile Tracking)

  • 정혜명
    • 한국통신학회논문지
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    • 제25권10A호
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    • pp.1512-1520
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    • 2000
  • 무선 통신망은 음성위주의 아날로그 방식에서 출발하여, 다양한 서버스 능력을 갖는 디지럴 방식으로 진화되고 있으며 궁극적으로는 멀티미디어 서비스가 가능한 IMT -2000으로 발전할 것이다. 무선망에서 멀티미디어 서비스를 제공하기 위해서는 한정된 무선 대역폭을 트래픽 특성에 따라 동적으로 활용할 수 있는 방안이 요구된다. 본 논문에서는 IMT - 2000 환경에서 이동체의 이동 방향을 추정하여 이를 근거로 대역폭을 예약하고, 멀티미디어 트래픽을 전송하는 대역 할당 및 호 수락 제어 기법을 제안한다. 이 기법은 수신 신호 세기(RSS: Received Si맹a1 Strength) 이외에 이동체와 기지국간이 거리, 이동체의 이동방향, 이동체의 이전위치와 같은 부정확한 다수의 파라미터를 동시에 고려하는 퍼지 다기준(multi-criteria) 의사 결정 방법을 이용하여 이동체의 위치를 추정한다. 시뮬레이션에 의해 성능을 분석하였다.

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Intelligent Coordination Method of Multiple Distributed Resources for Harmonic Current Compensation in a Microgrid

  • Kang, Hyun-Koo;Yoo, Choel-Hee;Chung, Il-Yop;Won, Dong-Jun;Moon, Seung-Il
    • Journal of Electrical Engineering and Technology
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    • 제7권6호
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    • pp.834-844
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    • 2012
  • Nonlinear electronic loads draw harmonic currents from the power grids that can cause energy loss, miss-operation of power equipment, and other serious problems in the power grids. This paper proposes a harmonic compensation method using multiple distributed resources (DRs) such as small distributed generators (DGs) and battery energy storage systems (BESSs) that are integrated to the power grids through power inverters. For harmonic compensation, DRs should inject additional apparent power to the grids so that certain DRs, especially operated in proximity to their rated power, may possibly reach their maximum current limits. Therefore, intelligent coordination methods of multiple DRs are required for efficient harmonic current compensation considering the power margins of DRs, energy cost, and the battery state-of-charge. The proposed method is based on fuzzy multi-objective optimization so that DRs can cooperate with other DRs to eliminate harmonic currents with optimizing mutually conflicting multi-objectives.

윤곽선 추적 알고리즘과 개선된 ART1을 이용한 영문 명함 인식에 관한 연구 (A Study on the Recognition of an English Calling Card by using Contour Tracking Algorithm and Enhanced ART1)

  • 김광백;김철기;김정원
    • 지능정보연구
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    • 제8권2호
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    • pp.105-115
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    • 2002
  • 본 논문에서는 4 방향 윤곽선 추적 알고리즘(contour tracking algorithm)과 개선된 ART1을 이용한 영문 명함인식 방법을 제안한다. 영문 명함 영상에서 문자열 추출은 영상을 3배로 축소하여 수평 스미어링 기법(smearing method)과 4방향 윤곽선 추적 방법을 적용하여 문자열 후보 영역을 추출하고 수평 및 수직의 비율과 면적을 이용하여 문자열 영역과 비문자열 영역을 구분하였다. 추출된 문자열 영역에서 개별 문자 추출은 수평 스미링 기법과 윤곽선 추적 알고리즘을 이용하여 추출하였고 개별 문자들의 인식은 ART1 알고리즘을 개선하여 인식에 적용하였다. 본 논문에서 제안한 ARTI 알고리즘은 퍼지 합 접속 연산자를 이용하여 유사도를 동적으로 조정함으로써 기존의 ART1을 개선하였다. 추출 및 인식 실험 결과, 제안된 추출 및 인식 방법이 영문 명함 인식에서 효율적인 것을 확인하였다.

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다중센서를 사용한 챔퍼가 없는 부품의 능동적인 삽입작업 (Active Peg-in-hole of Chamferless Parts Using Multi-sensors)

  • 전훈종;김갑일;김대원;손유석
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1993년도 하계학술대회 논문집 A
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    • pp.410-413
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    • 1993
  • Chamferless peg-in-hole process of the cylindrical type parts using force/torque sensor and vision sensor is analyzed and simulated in this paper. Peg-in-hole process is classified to the normal mode (only position error) and tilted mode(position and orientation error). The tilted mode is sub-classified to the small and the big tilted mode according to the relative orientation error. Since the big tilted node happened very rare, most papers dealt with only the normal or the small tilted mode. But the most errors of the peg-in-hole process happened in the big tilted mode. This problem is analyzed and simulated in this paper using the force/torque sensor and vision senor. In the normal mode, fuzzy logic is introduced to combine the data of the force/torque sensor and vision sensor. Also the whole processing algorithms and simulations are presented.

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태양광 발전 시스템의 전역 최대 발전전력 추종을 위한 인공지능 기반 기법 비교 연구 (Comparative Study of Artificial-Intelligence-based Methods to Track the Global Maximum Power Point of a Photovoltaic Generation System)

  • 이채은;장요한;정승훈;배성우
    • 전력전자학회논문지
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    • 제27권4호
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    • pp.297-304
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    • 2022
  • This study compares the performance of artificial intelligence (AI)-based maximum power point tracking (MPPT) methods under partial shading conditions in a photovoltaic generation system. Although many studies on AI-based MPPT have been conducted, few studies comparing the tracking performance of various AI-based global MPPT methods seem to exist in the literature. Therefore, this study compares four representative AI-based global MPPT methods including fuzzy logic control (FLC), particle swarm optimization (PSO), grey wolf optimization (GWO), and genetic algorithm (GA). Each method is theoretically analyzed in detail and compared through simulation studies with MATLAB/Simulink under the same conditions. Based on the results of performance comparison, PSO, GWO, and GA successfully tracked the global maximum power point. In particular, the tracking speed of GA was the fastest among the investigated methods under the given conditions.

A Metaheuristic Approach Towards Enhancement of Network Lifetime in Wireless Sensor Networks

  • J. Samuel Manoharan
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제17권4호
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    • pp.1276-1295
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    • 2023
  • Sensor networks are now an essential aspect of wireless communication, especially with the introduction of new gadgets and protocols. Their ability to be deployed anywhere, especially where human presence is undesirable, makes them perfect choices for remote observation and control. Despite their vast range of applications from home to hostile territory monitoring, limited battery power remains a limiting factor in their efficacy. To analyze and transmit data, it requires intelligent use of available battery power. Several studies have established effective routing algorithms based on clustering. However, choosing optimal cluster heads and similarity measures for clustering significantly increases computing time and cost. This work proposes and implements a simple two-phase technique of route creation and maintenance to ensure route reliability by employing nature-inspired ant colony optimization followed by the fuzzy decision engine (FDE). Benchmark methods such as PSO, ACO and GWO are compared with the proposed HRCM's performance. The objective has been focused towards establishing the superiority of proposed work amongst existing optimization methods in a standalone configuration. An average of 15% improvement in energy consumption followed by 12% improvement in latency reduction is observed in proposed hybrid model over standalone optimization methods.

Novel ANFIS based SMC with Fractional Order PID Controller for Non Linear Interacting Coupled Spherical Tank System for Level Process

  • Jegatheesh A;Agees Kumar C
    • International Journal of Computer Science & Network Security
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    • 제24권2호
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    • pp.169-177
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    • 2024
  • Interacting Spherical tank has maximum storage capacity is broadly utilized in industries because of its high storage capacity. This two tank level system has the nonlinear characteristics due to its varying surface area of cross section of tank. The challenging tasks in industries is to manage the flow rate of liquid. This proposed work plays a major role in controlling the liquid level in avoidance of time delay and error. Several researchers studied and investigated about reducing the nonlinearity problem and their approaches do not provide better result. Different types of controllers with various techniques are implemented by the proposed system. Intelligent Adaptive Neuro Fuzzy Inference System (ANFIS) based Sliding Mode Controller (SMC) with Fractional order PID controller is a novel technique which is developed for a liquid level control in a interacting spherical tank system to avoid the external disturbances perform better result in terms of rise time, settling time and overshoot reduction. The performance of the proposed system is obtained by analyzing the simulation result obtained from the controller. The simulation results are obtained with the help of FOMCON toolbox with MATLAB 2018. Finally, the performance of the conventional controller (FOPID, PID-SMC) and proposed ANFIS based SMC-FOPID controllers are compared and analyzed the performance indices.

Support Vector Machine Based Arrhythmia Classification Using Reduced Features

  • Song, Mi-Hye;Lee, Jeon;Cho, Sung-Pil;Lee, Kyoung-Joung;Yoo, Sun-Kook
    • International Journal of Control, Automation, and Systems
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    • 제3권4호
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    • pp.571-579
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    • 2005
  • In this paper, we proposed an algorithm for arrhythmia classification, which is associated with the reduction of feature dimensions by linear discriminant analysis (LDA) and a support vector machine (SVM) based classifier. Seventeen original input features were extracted from preprocessed signals by wavelet transform, and attempts were then made to reduce these to 4 features, the linear combination of original features, by LDA. The performance of the SVM classifier with reduced features by LDA showed higher than with that by principal component analysis (PCA) and even with original features. For a cross-validation procedure, this SVM classifier was compared with Multilayer Perceptrons (MLP) and Fuzzy Inference System (FIS) classifiers. When all classifiers used the same reduced features, the overall performance of the SVM classifier was comprehensively superior to all others. Especially, the accuracy of discrimination of normal sinus rhythm (NSR), arterial premature contraction (APC), supraventricular tachycardia (SVT), premature ventricular contraction (PVC), ventricular tachycardia (VT) and ventricular fibrillation (VF) were $99.307\%,\;99.274\%,\;99.854\%,\;98.344\%,\;99.441\%\;and\;99.883\%$, respectively. And, even with smaller learning data, the SVM classifier offered better performance than the MLP classifier.