• 조명전기설비학회논문지
• /
• 제18권1호
• /
• pp.146-153
• /
• 2004

본 연구에서는 Fuzzy Goal Programming을 이용하여 배전계통에서 분산형 전원의 설치 및 운영에 대한 새로운 방안을 제시하였다. 분산형전원의 설치 및 운영을 위하여 최적화 알고리즘의 탐색공간의 크기를 줄이면서 계통상황 변동에 적합하게 정식화하였다. 특히, 목적함수인 계통 유효전력손실과 제약조건인 분산형전원의 수 또는 총용량 및 모선전압에 대하여 각각의 부정확한 성질을 평가하기 위하여 퍼지 Goal Programing으로 모델링 하였으며, 유전알고리즘을 사용하여 최적해를 탐색하였다.

• 에너지공학
• /
• 제22권2호
• /
• pp.205-210
• /
• 2013

Cycle-to-cycle variation has long been recognized as limiting the range of operating conditions of spark ignition engines, in particular, under lean and highly diluted operation conditions. At a part load, some of the cycles tend to knock, while others may have incomplete combustion by the time the exhaust valve opens. An experimental study has been performed in order to evaluate the relative contribution of several relevant parameters on the cyclic variability in spark ignition engines. In general, the stability of engine operation is improved with fuel injector according to the optimal injection timing, but the stability of engine operation at idle is not improved compared with a practical gasoline engine. In this study, we investigated the relationship of the effect of operating conditions for the stability at low speed and load.

• International Journal of Automotive Technology
• /
• 제5권3호
• /
• pp.201-208
• /
• 2004

Response characteristics of the CVT system for a parallel hybrid electric vehicle (HEV) are investigated. From the experiment, CVT ratio control algorithm for the optimal engine operation is obtained. To investigate the effect of the CVT system dynamic characteristics on the HEV performance, a hardware in the loop simulation (HILS) is performed. In the HILS, hardwares of the CVT belt-pulley and hydraulic control valves are used. It is found that the engine performance by the open loop CVT ratio control shows some deviation from the OOL in spite of the RCVs open loop control ability. To improve the engine performance, a closed loop control of the CVT ratio is proposed with variable control gains depending on the shift direction and the CVT speed ratio range by considering the nonlinear characteristics of the RCV and CVT belt-pulley dynamics. The HILS results show that the engine performance is improved by the closed loop control showing the operation trajectory close to the OOL.

• 산업공학
• /
• 제14권4호
• /
• pp.385-393
• /
• 2001

In this paper, a scheme of scheduling a bottleneck operation is presented for production planning of make-to-order. We focus on the problem of capacity-dependent processing time in which processing time of the bottleneck operation is not fixed, but varies with job sequence or equipment capacity. For this, a genetic algorithm is applied for job sequencing with an objective function of mean square of weighted deviation. An experimental study is implemented in power transformer plant and results are compared with those of the EDD rule. It shows that the genetic algorithm is relatively good for most cases.

• Journal of Biosystems Engineering
• /
• 제25권1호
• /
• pp.55-62
• /
• 2000

Autonomous farm operation needs to be developed for safety, labor shortage problem, health etc. In this research, an autonomous tractor for tillage was investigated using machine vision and a fuzzy logic controller(FLC). Tractor heading and offset were determined by image processing and a geomagnetic sensor. The FLC took the tractor heading and offset as inputs and generated the steering angle for tractor guidance as output. A color CCD camera was used fro the image processing . The heading and offset were obtained using Hough transform of the G-value color images. 15 fuzzy rules were used for inferencing the tractor steering angle. The tractor was tested in the file and it was proved that the tillage operation could be done autonomously within 20 cm deviation with the machine vision and the FLC.

• 한국산업융합학회 논문집
• /
• 제2권2호
• /
• pp.147-153
• /
• 1999

An in-process extraction method of the ground surface roughness is a bottle-neck and essential field in conventional machining process. We define the D.A.R.F(Dimensionless Average Roughness Factor) that has a roughness characteristic of ground surface. D.A.R.F include the absolute average and the standard deviation values which are the analytic parameters of the AE(Acoustic Emission) signal generated during the grinding operation. The theoretical equation between the surface roughness and the D.A.R.F has been derived from the linear regressive analysis and verified its availability through the experimentation on the surface grinding machine.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
• /
• 제7권1호
• /
• pp.33-44
• /
• 2001

This study is about the Spatial Composition and Area Calculation in Plastic Surgical Clinics. 1. The space of the plastic surgical clinics are divided into 4 sections; exam, exam support, the staffs, and waiting and reception area. 2. The average G/N ratio of width was 1.46. The Plastic surgical clinics which had great deviation in the ratio showed these characteristics; first, when they were planned at first, the operation rooms were not assigned enough space; second. space for supporting exam and the activities of staffs was given too little consideration in their first drafts. 3. The average size of operation rooms was $21.76m^2$. The most desirable size was found to be $26.4m^2$ when we put the number of staffs, the movement area of stretcher, and the movement lines of operation room into consideration.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1991년도 하계학술대회 논문집
• /
• pp.375-378
• /
• 1991

This paper presents a design method of synchronous generator excitation controller using self-tuning PID algorithm. Controller parameter is determined by using adaptive control theory in order to maintain optimal operation of generator under the various operating conditions. To determine the optimal parameter of controller. minimum variance algorithm using the recursive leastsquare(RLS) indentification method is adopted and the difference between the speed deviation with weighted factor and voltage deviation is used as the input signal of adaptive controller, which provides good damping and conversion characteristics. The results tested on a single machine infinite bus system verify that the proposed controller has better dynamic performances than conventional controller.

• 대한전기학회논문지:전력기술부문A
• /
• 제49권10호
• /
• pp.486-493
• /
• 2000

This paper presents an application to a multimachine power system of power system stabilizer using revised pole shift adaptive algorithm. Controller parameters are determined by using adaptive control theory in order to maintain optimal operation of generator under the various operating conditions. To determine the optimal parameters of controller and overcome the problem of pole placement algorithm, this paper presents pole shift algorithm revised pole shift factor. Also, the difference between the speed deviation with weighted factor and voltage deviation is used as the input signal of adaptive controller, which provides good damping characteristics. The results tested on a multimachine power system verify that the proposed controller has better dynamic and transient performance than conventional controller.

• Elastomers and Composites
• /
• 제51권4호
• /
• pp.280-285
• /
• 2016

The purpose of this study is to get optimum design and operation conditions of the heating rubber roller for laminating process. The cause of performance degradation of heating rubber roller is delamination of rubber on metal tube, rubber aging due to high temperature. We measured the material properties of thermal expansion, thermal conductivity, specific heat and density and analyzed thermal distributions of rubber layer using finite element method. As a result of heat/flow analysis, the density distribution of heating coil must shorten the stabilization time by reducing the temperature deviation on the length direction at the temperature rising section after increasing the density of the area contacting with the laminate film at the center part which is an opposite of the current composition while enabling to maintain the temperature of heater to be consistent while maintaining the temperature deviation to be low when heat loss is created. Finally, we determined optimum heating method of heating rubber roller.