• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.2
• /
• pp.172-176
• /
• 2015

In this research, a tool was developed to automate one-dimensional finite element analysis (1D FEA) for design of a machine tool spindle. Based on object-oriented programing, this tool employs the objects of a CAD system to construct a geometric model and then to convert it into the FE model of 1D beams at the workbenches of the CAD system with minimum data to define the spindle such as bearing positions and cross-sections of the shaft. Graphic user interfaces were developed for users to interact with the tool. This tool is helpful in identifying a near optimal design of the spindle with the automation of the FEA process with numerous design changes in minimum time and efforts. It is also expected to allow even design engineers to perform the FEA in search of an optimal design of the machine tool spindle.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.2
• /
• pp.211-216
• /
• 2015

Recently, because of the growth in the leisure industry and interest in health, the demand for bicycles has increased. In this research, considering the vertical load on a bike frame under static state conditions, the deflection and mass of the bike frame were minimized by satisfying the service condition and performing optimization. The thickness of the bicycle-frame tube was set to a design variable, and its sensitivity was confirmed by an analysis of means (ANOM). To optimize the solution, a response-surface-method (RSM) model was constructed using D-Optimal and central composite design(CCD). The optimization was performed using a non-dominant sorting genetic algorithm (NSGA-II), and the optimal solution was verified by finite-element analysis.

• Proceedings of the KIEE Conference
• /
• 1990.07a
• /
• pp.55-59
• /
• 1990

This study presents new algorithm for generating octree by volume intersection with pseudo-octrees which are constructed for each orthogonal face views in order to represent 3D objects exactly. In this algorithm, optimal quadtree is constructed for depth images in which distance information is represented in gray level, and then pseudo-octrees are constructed by using optimal quadtree in each orthogonal face view. It is shown that 3D object with concave parts can be reconstructed exactly by our suggested algorithm, and that memory space and tree construction time are also reduced compared with other algorithms.

• The Transactions of the Korean Institute of Electrical Engineers D
• /
• v.50 no.11
• /
• pp.514-521
• /
• 2001

This paper uses the distributed heating thin metal moving at constant velocity which are modeled as distributed parameter systems, and applies the Paley order of Walsh functions to high order partial differential equations and matrix partial differential equations. This thesis presents a new algorithm which usefully exercises the optimal control in the distributed parameter systems. In this paper, the excellent consequences are found without using the existing decentralized control or hierarchical control method.

• 유체기계공업학회:학술대회논문집
• /
• 2004.12a
• /
• 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.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.18 no.2
• /
• pp.186-191
• /
• 2006

In this study, five experiments were carried out, with an orifice located downstream of a fan in case I where upstream duct length is 6 D, and that in the downstream is 4 D and different downstream distance to the fan in the rest, so as to determine the optimal location of the orifice and reduce the duct length of airflow measurement device. The resulting flow rate-pressure drop correlations were found to satisfy the limitation of SMACNA standard, which specified an error of $\pm7.5\%$ based on the real flow rate. Also, the best one of five. cases was achieved with the orifice located midway of the orifice duct four times its diameter long.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.5 no.4
• /
• 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.

• Proceedings of the KIEE Conference
• /
• 2000.07b
• /
• pp.1405-1407
• /
• 2000

This paper is on optimal design for DC substation capacity 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 discussed substation power capacity only. At first, DC-fed-traction system is introduced on an outline, a characteristics of train and fed network. Optimal design procedures is described, and modelling for DC-fed-traction system are presented. The circuit-solution method is presented by matrix formula. In order to simulate DC substation power capacity more closely to actual situations, we proposed the program.

• Proceedings of the KIEE Conference
• /
• 2000.11b
• /
• 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.

• Journal of Korean Institute of Industrial Engineers
• /
• v.39 no.6
• /
• pp.461-472
• /
• 2013

In this paper, we deal with a simulation-based reliability and maintainability design problem of a warship and want to determine the optimal values of MTBF and MTTR of all units and ALDT of the warship. The system availability and life cycle cost are used as optimization criteria and estimated by simulation. A hybrid genetic algorithm with a heuristic method is proposed to find near-optimal solutions and numerical examples are also studied to investigate the effect of model parameters to the optimal solutions and compare with a general genetic algorithm.