• 유체기계공업학회:학술대회논문집
• /
• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
• /
• pp.437-442
• /
• 2004

The optimization of a blade sweep for a transonic axial compressor rotor (NASA rotor 37) has been performed using a response surface method and a Reynolds-averaged Wavier-Stokes (RANS) flow simulation. Two shape variables of the rotor blade, which are used to define a blade sweep, are introduced to increase an adiabatic efficiency. Data points for response evaluations have been selected by D-optimal design, and linear programming method has been used for an optimization on a response surface. The result shows that the adiabatic efficiency is increased to about 1 percent compared to that of the reference shape of the rotor blade. Relatively high increasement of the adiabatic efficiency is obtained between 20 and 60 percent span. In the present study, backward swept blade is more effective to increase the adiabatic efficiency In the axial compressor rotor.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제5권4호
• /
• pp.360-366
• /
• 2005

In the past, when there were few vehicles on the road, the T.O.D.(Time of Day) traffic signal worked very well. The T.O.D. signal operates on a preset signal cycling which cycles on the basis of the average number of average passenger cars in the memory device of an electric signal unit. Now days, with increasing many vehicles on restricted roads, the conventional traffic light creates startup-delay time and end-lag-time. The conventional traffic light loses the function of optimal cycle. And so, $30-45\%$ of conventional traffic cycle is not matched to the present traffic cycle. In this paper we proposes electro sensitive traffic light using fuzzy look up table method which will reduce the average vehicle waiting time and improve average vehicle speed. Computer simulation results prove that reducing the average vehicle waiting time which proposed considering passing vehicle length for optimal traffic cycle is better than fixed signal method which doesn't consider vehicle length.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
• /
• pp.398-401
• /
• 2000

This paper describes the design of optimal location and capacity of DC substation for Mass Transit System. Three factors are considered for the design i.e. substation arrangements, line configuration and substation power capacity. In this study, we considered all of them for capacity calculation of power supply system for MTS. At first, DC-fed-traction system is introduced on an outline, a characteristics of train and fed network, and design method of substation arrangements. Optimal design procedures are described, and program for capacity calculation of the system is presented. In addition, the computer simulated results are compared with the conventional simple calculation method.

• 대한기계학회논문집A
• /
• 제35권9호
• /
• pp.1007-1013
• /
• 2011

상용차용 다층관 벨로우즈는 우수한 유연성과 내구성이 요구되므로 단층으로 제조되는 승용차용 벨로우즈와는 다르게 다층의 형태로 제작된다. 단층 벨로우즈의 유한요소해석과 최적화에 대한 연구는 활발히 진행되고 있으나, 층과 층사이에 갭이 존재하는 다층형 벨로우즈의 유한요소해석과 최적화 연구는 미진하다. 따라서 본 연구에서는 해석의 신뢰성 향상을 위해 다층형 벨로우즈에 적합한 유한요소 모델을 제시하였으며, 다층관 벨로우즈의 형상 최적화를 위해 실험계획법과 D-Optimal 방법에 기반을 둔 순차적 실험계획에 의한 크리깅 메타모델을 적용하였다.

• 한국생산제조학회지
• /
• 제8권3호
• /
• pp.52-58
• /
• 1999

In this study, the growth-strain method was used for shape optimization. The adequate value of growth ratio in the method was used the value obtained by volume control. And the linear PID control theory was applied to control internal stresses by stresses required by a designer. The effect of the values of $K_{P}$, $K_{I}$, and $K_{D}$ was investigated and the adequate values of $K_{P}$, $K_{I}$, and $K_{D}$ were determined empirically. Finally, a shape optimal design system was built up by the improved the growth-strain method with a commercial software I-DEAS. The effectiveness and practicality of the developed shape optimal design system was verified by some examples.les.les.les.

• 대한전자공학회논문지
• /
• 제27권7호
• /
• pp.1025-1032
• /
• 1990

We proposed a neural network energy function for the optimal graph partitioning and its optimization method using Boltzmann Machine. We composed a Boltzmann Machine with the proposed neural network energy function, and the simulation results show that we can obtain an optimal solution with the energy function parameters of A=50, B=5, c=14 and D=10, at the Boltzmann Machine parameters of To=80 and \ulcorner0.07 for a 6-node 3-partition problem. As a result, the proposed energy function and optimization parameters are proved to be feasible for the optimal graph partitioning.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제5B권3호
• /
• pp.262-266
• /
• 2005

In this paper, in order to enhance thrust of slotless type Permanent Magnet Linear Synchronous Motor, an optimal design is achieved by combining a genetic algorithm with 3D space harmonic method. In the case of multi-objective functions, the ratio of thrust/weight and thrust/volume are increased by $\7.56[%]l\;and\;7.98\[%]$, respectively. Thus, miniaturization and lightweight were realized at the same time.

• 한국정밀공학회지
• /
• 제32권9호
• /
• pp.815-824
• /
• 2015

In this study, we conducted the approximate multi-objective optimization of gap sizes of pressurized-water reactor (PWR) annular fuels. To determine the contacting tendency of the inner-outer gaps between the annular fuel pellets and cladding, thermoelastic-plastic-creep (TEPC)analysis of PWR annular fuels was performed, using in-house FE code. For the efficient heat transfer at certain levels of stress, we investigated the tensile, compressive hoop stress and temperature, and optimized the gap sizes using the non-dominant sorting genetic algorithm (NSGA-II). For this, response surface models of objective and constraint functions were generated, using central composite (CCD) and D-optimal design. The accuracy of approximate models was evaluated through $R^2$ value. The obtained optimal solutions by NSGA-II were verified through the TEPC analysis, and we compared the obtained optimum solutions and generated errors from the CCD and D-optimal design. We observed that optimum solutions differ, according to design of experiments (DOE) method.

• Communications for Statistical Applications and Methods
• /
• 제6권1호
• /
• pp.53-68
• /
• 1999

To improve the slow convergence property of the steepest ascent type algorithm for continuous D-optimal design problems. we develop a new algorithm. We apply the nonlinear system of equations as the necessary condition of optimality and develop the two-point algorithm that solves the problem of clustering. Because of the nature of the steepest coordinate ascent algorithm avoiding the problem of clustering itself helps the improvement of convergence speed. The numerical examples show the performances of the new method is better than those of various steepest ascent algorithms.

• International Journal of Aeronautical and Space Sciences
• /
• 제5권2호
• /
• pp.71-76
• /
• 2004

This paper describes the antenna analysis of the multi-beam for communicationsatellite. The design core parameters of the antenna system are optimal antennadiameter, feed horn type and hom size, F/D, and the coordinate of offset horns. Thepaper deals with the method to determine design core parameters of optimal antennadiameter, feed horn type and horn size. F/D, and the coordinate of offset horns, andthe performances of design result.