• 한국항행학회논문지
• /
• 제14권4호
• /
• pp.495-503
• /
• 2010

클러스터링은 모바일 노드들에 대한 정보를 효율적으로 제공해 주며, 라우팅, 대역폭 할당과 같은 처리성능을 향상시키는 중요한 메카니즘이다. 본 논문에서 우리는 이동성(mobility)으로 인한 동적 속성, 평면구조 구조상에서 발생하는 노드 분산 등과 같은 문제를 효과적으로 해결하고 라우팅 성능을 향상시키기 위한 퍼지 적합도 기반의 클러스터링 기법을 제안한다. 제안된 기법은 FSV(Fuzzy_State_Viewing) 구조를 이용하여 퍼지 적합도${\alpha}$를 수행한다. 퍼지 적합도${\alpha}$는 FSV 구조에서 클러스터링을 수행하기 위한 클러스터헤드 CH(ClusterHead)를 선정하는 역할을 수행한다. 본 논문에서는 이와 같이 제안된 클러스터링 기법을 통해서 기존의 1-홉 클러스터 및 2-hop 클러스터에서 발생되는 문제를 해결하도록 하였다. 제안된 기법의 성능을 알아보기 위하여 우리는 NS-2 시뮬레이터를 이용하여 시뮬레이션을 수행하였다. 우리는 시뮬레이션 평가를 위해 기존의 Lowest-ID, MOBIC, SCA 기법 그리고 제안된 기법과의 성능을 비교하였다. 시뮬레이션 결과 제안된 기법의 성능이 Lowest-ID, MOBIC, SCA 기법에 비해서 우수함을 알 수 있다.

• Journal of Electrical Engineering and Technology
• /
• 제8권5호
• /
• pp.1163-1168
• /
• 2013

In this paper, Adaptive Neuro-Fuzzy Inference System (ANFIS) is applied for modeling and simulation of DC characteristic of cylindrical Silicon Nanowire Transistor (SNWT). Device Geometry parameters, terminal voltages, temperature and output current were selected as the main factors of modeling. The results obtained are compared with numerical method and a good match has been observed between them, which represent accuracy of model. Finally, we imported the ANFIS model as a voltage controlled current source in a circuit simulator like HSPICE and simulated a SNWT inverter and common-source amplifier by this model.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 A
• /
• pp.223-225
• /
• 2002

In this paper, we designed fuzzy legit controller(FLC) for HVDC current control using genetic algorithm. The proposed method was applied to HVDC power system simulator in Korea Electrotechnology Research Institute(KERI). We are adjusted input/output gain of FLC by real-time using genetic algorithm. Experimental results show that FLC has the better control performance than PI controller in terms of settling time, rising time.

• 전자공학회논문지B
• /
• 제31B권6호
• /
• pp.53-62
• /
• 1994

In this paper, a fuzzy logic-based idle speed controller is designed for automotive engine with a purpose of high efficiency and low pollution. When the idle speed is low engine operation is not smooth, otherwise fuel consumption is incresed. Therefore the idle speed must be maintained as low as possible within the scope that ensures smooth operation of engine. By simulation, we show that the idle speed controller has generated a proper control signal as engine condition or enviornment varies, and also operated well for unexpected cases. Also, an engine simulator, which is used as a basic tool for controller design, is developed and utilized for reduction of development time and cost.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
• /
• pp.1374-1377
• /
• 1993

In this paper, a predictive fuzzy control algorithm to supervise the elevator system with plural elevator cars is developed and its performance is evaluated. Elevator group controller must decide which of the cars is suitable for responding the registered hall call and allocate it to the selected car controller. In most cases, the purpose of group control is to minimize waiting time of passengers and occurrence of long wait as much as possible. The proposed algorithm ensures the efficient operations of the group cars and provides the improved level of service, coping with multiple control objects and uncertainty of system state. The feasibility of the proposed control algorithm is evaluated by graphic simulator on computer.

• 대한전기학회논문지:전력기술부문A
• /
• 제52권1호
• /
• pp.36-43
• /
• 2003

This paper presents an optimal tuning method for Fuzzy Logic Controller (FLC) of current controller for HVDC using Genetic Algorithm(GA). GA is probabilistic search method based on genetics and evolution theory. The scaling factors of FLC are tuned by using real-time GA. The proposed tuning method is applied to the scaled-down HVDC simulator at Korea Electrotechnology Research Institute(KERI). Experimental result shows that disturbances are well-damped and the dynamic performances of FLC have the better responses than those of PI controller for small and large disturbances such as ULTC tap change, reference DC current change and DC ground fault.

• 한국항해학회지
• /
• 제23권2호
• /
• pp.1-9
• /
• 1999

A trailer truck is a major equipment for transporting containers, and its driving is difficult due to two degrees of freedom which exist in the joint part between truck and trailer. Especially Backing a trailer truck to a parking home is a difficult exercise for all but the most skilled truck drivers. Normal driving instincts lead to erroneous movements. When watching a truck driver backing toward a parking home, one often observes the driver backing, going forward, backing again, going forward, etc., and finally backing to the desired position along the parking home. This paper discusses the design of the controller to control the steering of a trailer truck while only backing up to a parking home from an initial position. In this paper, we propose a backing up control system for a container trailer truck using fuzzy theory where the primitive fuzzy control rules are macroscopically designed using an expert's knowledge, and the control rules are regulated by LIBL(Linguistic Instruction Based Learning) to enable to back up successfully the trailer tuck to a parking home from arbitrary initial position. The validity of the proposed parking control system is shown by applying it to some initial positions on the simulator for container trailer truck.

• KIEE International Transactions on Power Engineering
• /
• 제3A권4호
• /
• pp.181-190
• /
• 2003

This paper presents the design of a fuzzy power system stabilizer (FPSS) using an adaptive evolutionary algorithm (AEA). AEA consists of genetic algorithm (GA) for a global search capability and evolution strategy (ES) for a local search in an adaptive manner when the present generation evolves into the next generation. AEA is used to optimize the membership functions and scaling factors of the FPSS. To evaluate the usefulness of the FPSS, we applied it to a single-machine infinite bus system (SIBS) and a power system simulator at the Korea Electrotechnology Research Institute. The FPSS displays better control performance than the conventional power system stabilizer (CPSS) for a three-phase fault in heavy load, which is used when tuning FPSS. To show the robustness of the FPSS, it is applied with disturbances such as change of mechanical torque and three-phase fault in nominal and heavy load, etc. The FPSS also demonstrates better robustness than the CPSS. Experimental results indicate that the FPSS has good system damping under various disturbances such as one-line to ground faults, line parameter changes, transformer tap changes, etc.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
• /
• pp.633-636
• /
• 1991

This paper describes the auto depth control system for underwater vehicle that can be used for both near surface and deeply submerged depthkeeping operations. This controller uses the fuzzy control algorithm and is implemented on the 16 bit microprocessor 8086 and coprocessor 8087. For verifying this system design, the digital simulator using PC-386 based T800 transputer is proto-totyped and the real time simulations show us satisfactory results.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2014년도 전력전자학술대회 논문집
• /
• pp.449-450
• /
• 2014

풍력 발전 시스템은 풍력 터빈이 바람에 의해 회전함으로써 발전이 된다. 실험실에서 풍력 발전 시스템을 연구하기 위해서는 바람이 하는 역할을 별도의 모터를 사용하여 회전시켜 주어야 하는데 본 논문에서는 유도전동기의 직접 토크 제어를 이용하여 풍속 데이터를 가지고 상응하는 토크의 지령치로 환산하여 풍력 에너지를 모델링 하였다. 이렇게 발전된 에너지를 최대의 효율로 전달하기 위해서는 MPPT기능이 수행되어야 하며 별도의 센서가 필요없는 Fuzzy MPPT를 수행하였다.