• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.927_929
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• 2009

This paper reports the case that unitizes heat analysis simulation in housing design of DC-DC converter. Icepak4.3 is used for heat analysis simulation program. 1.5kW prototype is produced with base of finally selected structure through simulation and is compared heating characteristic. Propriety of development application is confirmed through the result, shortening case of development cost and period is introduced.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.325-327
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• 1998

Disk type single-phase switched reluctance motor which has an advantage of simple robust construction, simple control circuity, and low manufacturing cost has a specific property of axial flux machine and radial flux machine simultaneously. So, this DSPSRM has a complicated magnetic circuit and it is difficult to analyze characteristics of DSPSRM for design. In this paper, we used to analyze the effects of radial flux and axial flux simultaneously by 3D-finite element method. From the results of 3-D FEM, we obtained the approximated torque characteristics of DSPSRM. It's analysis results can be used in optimal design of DSPSRM considering the saturation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.7
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• pp.1475-1482
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• 2009

In this paper, a computer simulation is developed for isotachophoretic protein separation in a serpentine micro channel for optimal lab on a chip design using 2D Finite Element Method. This 2D ITP model is composed of 5 components such as hydrochloric acid as Leader, caproic acid as terminator, acetic acid and benzoic acid as two proteins, and histindine as background electrolyte. The computer model is based on mass conservation equation for 5 components, charge conservation equation for electric potential, and electro neutrality condition for pH calculation. For the validation of the 2D spatial ITP model, the results are compared with the Simul5 developed by Bohuslav Gas Group. The simulation results are in a good agreement in a ID planar channel. This proves the precision of our model. The 2Dproteinseparation is conducted in a 2D curved channel for Lab on a chip design and dispersions of proteins are revealed during the electrophoretic process in a curved shape.

• Journal of IKEEE
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• v.26 no.3
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• pp.445-455
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• 2022

This paper presents the optimal design of flyback transformer with the flat copper winding method of injection type suitable for the small-size and winding method of automatic type used in 90W DC to DC converter for LED-TV. This paper also proposes the flyback transformer with the flat copper winding method of injection type capable of the winding method of automatic type and the reduction of transformer size and enhanced uniformity in electrical characteristics compared to the conventional mass-production flyback transformer with the winding method of manual type. In particular, the flat copper winding transformer of injection type proposed in this paper is constructed in a vertical winding method of its transformer to realize the winding method of automatic type. The primary and secondary windings of flyback transformer with the flat copper winding method of injection type used the conventional winding, triple insulated winding and the flat copper winding method of injection type, respectively. The optimal design of flyback transformer with the flat copper winding transformer of injection type proposed in this paper suitable for small-size and winding method of automatic type was carried out based on the simulation results using Maxwell 2D and 3D tool.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.3
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• pp.285-295
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• 2016

A contact strip shape of a high speed train pantograph system was optimized with CFD to increase the aerodynamic performance and stability of contact force, and the results were validated by a wind tunnel test. For design of the optimal contact strip shape, a Kriging model and genetic algorithm were used to ensure the global search of the optimal point and reduce the computational cost. To enhance the performance and robustness of the contact strip for high speed pantograph, the drag coefficient and the fluctuation of the lift coefficient along the angle of attack were selected as design objectives. Aerodynamic forces were measured by a load cell and HWA (Hot Wire Anemometer) was used to measure the Strouhal number of wake flow. PIV (Particle Image Velocimetry) was adopted to visualize the flow fields. The optimized contact strip shape was shown a lower drag with smaller fluctuation of vertical lift force than the general shaped contact strip. And the acoustic noise source strength of the optimized contact strip was also reduced. Finally, the reduction amount of drag and noise was assessed when the optimized contact strip was applied to three dimensional pantograph system.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.5
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• pp.105-112
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• 2017

In this study, plastics were deformed after molding due to the characteristics of the material. The Taguchi experimental design method was utilized to find the molding conditions that minimized deformation of the plastic bezel to be assembled in an automotive steering wheel. The injection molding conditions applied to the experimental design method are the melt temperature, cavity plate coolant temperature, core plate coolant temperature, and cooling time. Each condition was divided into five levels, and a total of 25 experiments were planned. However, instead of performing 25 actual molding experiments, the injection molding analysis was performed using the Moldflow program, and the deformation values for each molding analysis were obtained. The optimal molding conditions were obtained from these deformation values. The actual injection molding experiment using optimal molding conditions was compared with the deformation amount of the current molded product. The deformation was measured using a precise 3D scanner. The deformation amount of the molded product under optimal molding conditions was 16.1% lower than the deformation amount of the current molded product.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.4
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• pp.31-38
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• 2021

In this paper, we proposed an optimal design for determining the shape of a lifting lug freely by applying a multivariate function to the D-type lug, which is commonly used in shipyards. We derived the optimal aspect ratio of the lug through structural analysis and analyzed the safety and behavior of the lug aspect ratio. As a result, two types of final candidates, both lighter than the existing lug weight, were suitable for the ratio. They were found to have the greatest force at an angle of 45 degrees when a load of 100 tons was imposed. When the horizontal and vertical feature ratio of the lug was 1:3, it showed excellent results in terms of safety rates while maintaining weight reduction and functional aspects.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.1
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• pp.59-65
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• 2019

In this study, optimal design of direct-drive VCMs (Voice Coil Motor) for a missile fin actuator is carried out. The torque performance and the characteristics of the VCM are predicted by commercial electromagnetic analysis software, ANSYS Maxwell. The optimal design is obtained at the minimum and maximum actuating angles where the aerodynamic load acting on the fin is the largest in the operating range. The critical variables of the actuator is designed and the RSM (Response Surface Method) is used for the optimization. The response surface model consists of second-order functions and its experimental points are selected by a central composite design. This design is widely used for fitting a second-order response surface. The adjustment regression coefficients is computed for adequacy checking of the response surface model. Finally, the torque values obtained by the RSM and the ANSYS Maxwell are shown in good agreement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.946-949
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• 2006

This study is a trial to make a design chart of sound insulation for multiple panel. Dilatational frequency, ${\Large f}_d$ becomes a key factor for optimal design since it acts like a turning point in sound insulation performance of such panels. Hence, in tuning the ${\Large f}_d$ optimally, elastic modulus of core material and thickness of the skin panel is designated to parameters. Based on these parameter, a design chart of sound insulation for multiple panel is made. Its applicability is proved by the case study of High noise reduction panel.

• The KSFM Journal of Fluid Machinery
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• v.14 no.5
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• pp.55-62
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• 2011

Shape optimization of a Printed circuit heat exchanger (PCHE) has been performed by using three-dimensional Reynolds-Averaged Navier-Stokes (3-D RANS) analysis and surrogate modeling techniques. The objective function is defined as a linear combination of effectiveness of the PCHE term and pressure drop in the cold channels of the PCHE. The cold channel angle and the ellipse aspect ratio of the cold channel are used as design variables for the optimization. Design points are selected through Latin-hypercube sampling. The optimal point is determined through surrogate-based optimization method which uses 3-D RANS analyses at design points. The results of three types of surrogate model are compared each other. The results of the optimizations indicate improved performance in friction loss but low performance in effectiveness than the reference shape.