• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.2
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• pp.103-110
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• 2020

Riveting is mainly used to assemble the aircraft fuselage. An average of 2~3 workers is needed to assemble an aircraft fuselage consisting of various size frames by riveting. In this study, a riveting process that enables one-person operation using an automated C-frame riveting machine was proposed for improving the efficiency of productivity. The proposed process was verified stability through structural analysis. In the range that can maintain structural stability, panel thickness of the riveting machine and shape were modified to optimizing the shape for reducing the weight of the riveting process. The structural analysis was performed by software ANSYS workbench 19.2. The optimized riveting machine was reduced by 257kg compared to the existing model.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.4
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• pp.29-35
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• 2007

The main objective of this paper is to propose the optimal design method of forging process using genetic algorithm. Design optimization of forging process was doing about one stage and multi stage. The objective function is considered the filling of die. The chosen design variables are die geometry in multi stage and initial billet shape in one stage. We performed FE analysis to simulated forging process. The optimized preform and initial billet shape was obtained by genetic algorithm and FE analysis. To show the efficiency of GA method in forging problem are solved and compared with published results.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.6
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• pp.97-104
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• 2006

The geometric configuration in the weight reduction designis very required to be started from the conceptual design with low cost, high performance and quality. In this point, a structural-topological shape concerned with conceptual design of structure is important. The method used in this paper combines three optimization techniques, where the shape and physical dimensions of the structure and material distribution are hierachically optimized, with the maximum rigidity of structure and lightweight. As the results, the technology of weight reduction design is considered in designs of aluminum control arm and inner panel of door.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.58-66
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• 2011

In this paper, the starting torque and efficiency characteristics of the induction motor (IM) for the electric vehicle (EV) are improved by changing the slot shapes of squirrel cage. The initial model of the induction motor is designed by the loading distribution method (LDM), and then the rotor with squirrel cage of NEMA class A is selected to optimize the slot shape by response surface method(RSM). The design variables of rotor slot shape are obtained by the RSM. Starting torque and efficiency were calculated by the equivalent circuit method. As a result, starting torque and efficiency of the optimized model shows good performance through whole-speed range.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.877-879
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• 1995

In this study, we developed the efficient brushless DC motor for a compressor of air conditioner. The characteristics of motor are under the control of the material of some parts and the shape of magnet. Especially we compared the interior shape to the surface shape of the magnet. And we optimized the parameters like the temperature and the materials of magnet and core by tool for more efficient motor.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.6
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• pp.24-33
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• 2009

The present study deals with the optimization of the leading edge shape around a wing-body junction to minimize the strength of the horseshoe vortex, which is one of the main factor generating the secondary flow losses. For this purpose, approximate optimization method is used for the optimization. The study is performed by using $FLUENT^{TM}$ and $iSIGHT^{TM}$. The total pressure coefficient for the optimized model was decreased about 9.79% compared with the baseline model.

• International Journal of Fluid Machinery and Systems
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• v.9 no.4
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• pp.313-324
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• 2016

Surrogate model based shape optimization methodology to enhance performance of a centrifugal pump has been implemented in this work. Design variables, such as blade number and blade angles defining the pump impeller blade shape were selected and a three-level full factorial design approach was used for efficiency enhancement. A three-dimensional simulation using Reynolds-averaged Navier Stokes (RANS) equations for the performance analysis was carried out after designing the geometries of the impellers at the design points. Standard $k-{\varepsilon}$ turbulence model was used for steady incompressible flow simulations. The optimized impeller incurred lower losses by shifting the trailing edge towards the impeller pressure side. It is observed that the surrogates are problem dependent and most accurate surrogate does not deliver the best design always.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.55-61
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• 2014

This paper presents a method to reduce the stray loss of core Tie-Plate of distribution power transformer. The method combines a 3-dimensional FEM with PSO(Particle Swarm Optimization) algorithm to determine the shape of the Tie-Plate that minimizes eddy current and flux-leakage losses. To verify the method a 24MVA distribution(cast-resin) transformer was simulated using one objective function and two design variables with some constraints. The final optimized Tie-Plate has nine($3{\times}3$) slots of 10mm width, 15mm thickness and 25mm distance. After four iterations, the Tie-Plate loss was reduced to about 21 % of the original.

• Transactions of Materials Processing
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• v.21 no.1
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• pp.42-48
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• 2012

Hydroforming has attracted the attention of manufacturing industries for vehicles and transportation systems. A wide range of products such as subframes, camshafts, radiator frames, axles and crankshafts are made by the hydroforming process. Hydroformed parts often need to be structurally joined to other components during assembly. Therefore it is useful if the hydroformed automotive parts can be attached with a localized flange. In this study, a hydroforming process to produce a rectangular shape flange is proposed. FE analysis to form the flanged rectangular shape was performed by Dynaform 5.5. The hydroforming characteristics at various die aspect ratios and feeding conditions were analyzed and optimal process conditions which can avoid defects are suggested. For validation purposes, hydroforming experiments to form the flange were conducted with the optimized conditions. The results show that the flanged parts can be successfully formed with a hydroforming process without additional processing steps.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.600-604
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• 2013

A CTBA(Coupled Torsion Beam Axle) is a general type for rear suspension of small/compact sedans. It connects left and right knuckles using torsion beam axle and trails rear wheels. Therefore, a CTBA performs a main role of ride & handing. But, a CTBA suspension has main bending mode around 120Hz and causes road booming noise in the interior of a car. Therefore, the mode control of a CTBA is very important for reducing road noise. In this paper, we optimized the shape of a CTBA to reduce road noise considering R&H performance, simultaneously. The vibration mechanism of CTBA was investigated using ODS(Operational Deflection Shape) and mode shape.