• 한국자동차공학회논문집
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• 제12권5호
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• pp.25-31
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• 2004

In order to prepare for the large power diesel vehicle, the current trend of advanced nations is to shift from the aluminum alloy piston to the steel piston. In this research, a steel forging piston which replaces the aluminum alloy piston is developed to improve the power performance of the diesel engine. The three dimensional flow and combustion analysis of the target engine is conducted. Using the result of the analysis, the piston is optimized, and a prototype of the articulated steel forging piston is built. The reliability of the piston has been evaluated through durability test using a Hydropuls Test Machine for 300,000 km.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.15-20
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• 2001

In this study, several basic data for road design and GIS data were used for selecting the optimized road alignment database system. The cut and fill volumes were compared with existing manual road design method through the analysis and data application in this database system. We solved and estimated objective, economic, environmental and technical problems caused in road construction comparing existing manual method with the road alignment which was selected in GIS automatically. Also, we performed three dimensional simulation with the existing road design program and simulation of virtual reality through Virtual GIS. This study showed the method in selecting the optimized road alignment through the analysis and comparison of the selected road alignment. The goal of this study is comparison and analysis of definite cut and fill volume and environmental problem after the road construction through analyzing and comparing the social, economic, technical and environmental aspect in the road alignments with various statistic data.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.763-764
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• 2006

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

• International Journal of Advanced Culture Technology
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• 제9권4호
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• pp.385-391
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• 2021

3D modeling of the human body is an integral part of computer graphics. Among them, several studies have been conducted on hair modeling, but there are generally few studies that effectively implement hair and face modeling simultaneously. This study has the originality of providing users with customized face modeling and hair modeling that is different from previous studies. For realistic hair styling, We design and realize hair segmentation using FCN, and we select the most appropriate model through comparing PSPNet, DeepLab V3+, and MobileNet. In this study, we use the open dataset named Figaro1k. Through the analysis of iteration and epoch parameters, we reach the optimized values of them. In addition, we experiment external parameters about the location of the camera, the color of the lighting, and the presence or absence of accessories. And the environmental analysis factors of the avatar maker were set and solutions to problems derived during the analysis process were presented.

• 한국유체기계학회 논문집
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• 제19권1호
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• pp.18-23
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• 2016

A HVAC(Heating Ventilation and Air Conditioning) is adapted to increase the comfort of the cabin environment for train. The train HVAC duct system has very long duct and many outlets due to the shape of a train set. the duct cross section shape is limited by a roof structure and equipments. Therefore, the pressure distribution and flow uniformity is an important performance indicator for the duct system. In this study, the existing blow down type HVAC duct system for a train was supplemented to improve the flow uniformity by applying a design method combining design of experiment (DOE) with numerical analysis. The design variables and the test sets were selected and the performance for each test set was evaluated using CFD(Computational Fluid Dynamics). The influence of each design variable on the system performance was analysed based on the results of the performance evaluation on the test sets. Furthermore, the optimized model, whose the flow uniformity was improved was produced using the direct optimization(gradient-based method). Finally, the performance of the optimized model was evaluated using numerical analysis, and it was confirmed that its flow uniformity has indeed improved.

• 한국멀티미디어학회논문지
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• 제20권8호
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• pp.1406-1420
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• 2017

Artificial neural networks (ANNs) play an important role in the fields of function approximation, prediction, and classification. ANN performance is critically dependent on the input parameters, including the number of neurons in each layer, and the optimal values of weights and biases assigned to each neuron. In this study, we apply the particle swarm optimization method, a popular optimization algorithm for determining the optimal values of weights and biases for every neuron in different layers of the ANN. Several regression models, including general linear regression, Fourier regression, smoothing spline, and polynomial regression, are conducted to evaluate the proposed method's prediction power compared to multiple linear regression (MLR) methods. In addition, residual analysis is conducted to evaluate the optimized ANN accuracy for both training and test datasets. The experimental results demonstrate that the proposed method can effectively determine optimal values for neuron weights and biases, and high accuracy results are obtained for prediction applications. Evaluations of the proposed method reveal that it can be used for prediction and estimation purposes, with a high accuracy ratio, and the designed model provides a reliable technique for optimization. The simulation results show that the optimized ANN exhibits superior performance to MLR for prediction purposes.

• Tribology and Lubricants
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• 제23권3호
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• pp.103-108
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• 2007

In this paper, the optimized design and strength analysis have been presented based on the finite element and Taguchi's experimental methods. The stress, strain and displacement characteristics of OPC drum tubes are affected by rolling contact pressures between an OPC drum tube and a paper, design parameters of an aluminum tube and material properties. The OPC drum tubes with nine different geometrical models are analyzed for design parameters that are related to the outer diameter, the thickness, and the length of an aluminum tube for a toner cartridge. The optimized design parameters for an aluminum tube may be selected as the outer diameter of 28 mm, the thickness of 0.8 mm, and the length of 220 mm. But the currently used aluminum tube for a laser printer is fairly optimized based on the Taguchi's design analysis. The calculated FEM results showed that the affection ratio of the design parameter t, which may control the strength of an aluminum tube, is the most influential parameter among the length and an outer diameter of a tube.

• Advances in Computational Design
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• 제3권1호
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• pp.71-86
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• 2018

Thin-walled cross-sections can be optimized to enhance their resistance and progress their behaviour, leading to more competent and inexpensive structural system. The aim of this study is to afford a methodology that would facilitate progress of optimized cold formed steel (CFS) column section with maximum ultimate strength for practical applications. The proposed sections are designed to comply with the geometrical standards of pre-qualified column standards for CFS structures as well as with the number of industrialized and practical constraints. The stiffening evaluation process of CFS lipped channel columns, a five different cross section are considered. The experimental strength and behaviour of the proposed sections are verified by using the finite element analysis (FEA). A series comprehensive parametric study is carried out covering a wide range of section slenderness and overall slenderness ratio of the CFS column with and without intermediate web stiffeners. The ultimate strength of the sections is determined based on the Direct Strength Specification and other design equation available from the literature for CFS structures. A modified design method is proposed for the DSM specification. The results indicate that the CFS column with complex edge and intermediate web stiffeners provides an ultimate strength which is up to 78% higher than standard optimized shapes with the same amount of cross sectional area.

• Spatial Information Research
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• 제10권2호
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• pp.275-287
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• 2002

HEC-HMS와 HEC-GeoHMS를 이용하여 황룡강유역의 유출분석을 수행하였다. 황룡강유역을 HEC-GeoHMS와 GIS를 이용하여 3개의 소유역으로 분할하고 입력자료를 구축하였다. HEC-HMS의 SCS 유출곡선지수 손실계산모형, Snyder 단위유량도 직접유출모형, 지수함수 감수 기저유출모형, Muskingum 추적모형을 사용하여 선택된 홍수사상에 대한 유출량을 모의하였고 매개변수의 최적화를 실시하였다. 최적화된 매개변수를 사용하여 계산한 첨두유량을 관측치와 비교한 결과 매우 양호한 결과를 얻을 수 있었다. 최적화된 매개변수값은 향후 황룡강유역의 유출량을 계산할 때 사용될 수 있을 것이다.

• 대한기계학회논문집A
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• 제28권3호
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• pp.267-273
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• 2004

The purpose of this paper is to develop a systematic design method for the suspension system hard points and compliance elements, which have great influence on the handling stability of a vehicle. In this paper, a method to optimize J-turn responses is presented based on the principles of design of experiments, multi-body dynamic analysis and optimum design technique. The design variables associated with the J-turn maneuver are selected through the experimental design sensitivity analysis using the perturbation method. An objective function is defined as an approximate function for the J-turn characteristics using the TSA(Taylor series approximation). The values of the design variables, which make the optimized J-turn characteristics, are obtained using the conjugate gradient method. The result of the J-turn simulation shows that the optimized vehicle has more improved handling stability than the optimized vehicle.