• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.94-99
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• 2014

Recently, trends in new transportation system development have been primarily focused on sustainable and ecofriendly mobility solutions. The personal rapid transit (PRT) system has been considered a promising candidate in this category; its competitiveness is being improved through convergence with cutting-edge electric vehicle (EV) technologies. However, battery-powered vehicles pose difficult technical challenges in attempts to achieve reliable and efficient operation. In this study, a design approach for a solar-power assisted PRT system is presented with small-scale demonstrations aimed at circumventing challenges facing its adoption, as well as helping speed the transition to electric-powered ground transportation. From the results, it is expected that flexible photovoltaic (PV) cells will be able to supply 11% of the power required by the service equipment installed in a prototype vehicle. In particular, flexible photovoltaic (PV) cells are advantageous in terms of cost, weight, and design considerations. Most importantly, the cells' flexibility and attach-ability are expected to give them great potential for extended application in various areas.

• Journal of Technology Innovation
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• v.27 no.2
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• pp.37-71
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• 2019

How has the passenger car's architecture evolved? In the meantime, the discussions on the car architecture have been mixed, i.e., integral, modular, and the coexistence of two types. Therefore, in this study, we aim to develop two indices can measure the degree of modularization of passenger car and its all modules using global trade data. By applying the indices to the framework of architecture positioning that reflects the hierarchical structure of a product, we examined that the degree of modularization of the passenger car architecture has been enhanced. Meanwhile, the degree of modularization differs across the modules that make up the car. Specifically, we observed the higher degree of modularization in front-end, cockpit and seat modules. Whereas, we found that body module had a relatively low degree of modularization. In particular, we observed that the platform of passenger car has notably modularized due to carmakers' efforts to achieve model diversification and reduction of cost and period in new product development at the same time. Interestingly, we showed that three modules, i.e., engine, chassis (relatively less modularized), and transmission (relatively highly modularized), had a different level of modularization, even if they commonly make up the platform. We contribute to the suggestion for analytical approaches that examine the degree of modularization and its progress longitudinally. In addition, we propose the necessity of decomposition of a system into elements in a study of product architecture, considering the possibly distinctive progress of modularization across the elements.

• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.179-184
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• 2018

The driving methods of car are front wheel drive, rear wheel drive and four wheel drive. At driving methods, constant velocity joint is the most important part at carrying out two functions for converting to the direction which the driver wants and transferring the power to wheels. At driving on the road, the impact can be applied to the parts transmitting power according to the state of road surface. In this study, each models of three constant velocity joints whose shaft length are different respectively were modelled with CATIA and the structural and fatigue analyses were carried out by using ANSYS. This study result is thought to be the useful material at designing the constant velocity joint with the durability against impact. And it is possible to be grafted onto the convergence technique at the design of constant velocity joint and show the esthetic sense.

• Applied Chemistry for Engineering
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• v.18 no.5
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• pp.407-414
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• 2007

Using the MPI (Moldflow Plastics Insight) software from Moldflow Co., the optimum conditions for producing the upper part of the automobile air cleaner were obtained for 20% talc filled polypropylene (PP). The analysis was carried out to solve the cracking problem between upper and lower parts and the improved process was proposed using the flow balance. The comparative results between the conventional process, CASE-1, with one-pin gate and the new process (CASE-2) comprising two-pin gate system are the followings. In the case of CASE-2, the shorter filling time and reduced cycle time induced an improved production and processibility. In addition, the orientation and volumetric shrinkage are similar to those observed in the lower part, but the assembly, deformation, and physical characteristics are enhanced. The problem induced by the CASE-1 did not originate from the residual stress, but from the difference in the size of the upper part air cleaner after shrinkage. Thus, the orientation problem was expected to improve by optimizing the gate structure.

• Journal of Biomedical Engineering Research
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• v.44 no.2
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• pp.157-165
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• 2023

The purpose of this study was to evaluate the importance of developing slim seats with ergonomic design to improve seat comfort and expand the interior space. Two seats were used for the experiment: a sample seat designed based on hip shape and spinal alignment and a normal seat with a flat design without curves. Subjects sat in both the sample seat and a normal seat applied to the vehicle simulator and the experiment was conducted. The next part of the experiment was conducted in two different postures: a driving posture and a relaxed posture. The subjects filled out a comfort questionnaire immediately after sitting and after 30 minutes. The results showed that the comfort in the sample seat was found to be more comfortable than the normal seat. However, no significant difference was noted for the relaxation posture. Pressure distribution was also recorded immediately after sitting and after 30 minutes. In the case of pressure distribution, it was confirmed that the pressure in the sample seat was more evenly distributed in both the driving and relaxed postures than in the normal seat. The results showed that the ergonomically designed sample seat greatly improved seating comfort and pressure distribution compared to the normal seat, which is a general vehicle seat design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.2
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• pp.161-168
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• 2013

Nowadays, one of the most interested area of automobile industry is the production of vehicle which has collision safety and ability to produce less amount of $CO_2$. The achievement of such a dual performance is done by choosing the materials like dual phase steel, ferrite bainite steel, etc. These steels have been used in automotive chassis and body parts, and also used to be formed by hole flanging to meet the goal of strength and design requirement. The formability of sheet material was experimented by hole expansion test and the judgement relies on human eye and his experience. This manual judgement involves many errors and large deviation. This paper develops the automatic crack recognition system which finds a crack based on CCD image to complement the problem of the current method depending on human's sense.

• Journal of the Korea Convergence Society
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• v.6 no.1
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• pp.57-63
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• 2015

In this study, the lower arm is connected and fixed at the model of the automotive stabilizer link as the moment is applied. There are models of 1, 2 and 3 as a length control type, a general type and a single body type respectively. These models are investigated by performing the convergence technique through the design and the strength analysis with CATIA and ANSYS. As the maximum equivalent stress of model 3 has the least, model 3 can endure the highest load among three models. As the fatigue analysis, model 3 has the minimum blocks as the frequency of stress state, model 3 becomes also safest among three models. As models of 1, 2 are in the order of the next safety, the number of blocks becomes larger as the frequency of stress state and the instability becomes higher. And it is possible to be grafted onto the convergence technique at design and show the esthetic sense.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.283-290
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• 2007

Recently, plastic products in air-intake parts of automotive engines have become very popular due to advantages that include reduced weight, constricted cost, and lower intake air temperature. However, flow-induced noise in air-intake parts becomes a more serious problem for plastic intake-manifolds than for conventional aluminum-made manifolds. This is due to the fact that plastic manifolds transmit more noise owing to their lower material density. Internal aerodynamic noise from an Idle Speed control Actuator (ISA) is qualitatively analyzed by using a scaling law, which is expressed with some flow parameters such as pressure drop, maximum flow velocity, and turbulence kinetic energy. First, basic flow characteristics through ISA passage are identified with the flow predictions obtained by applying Computational Fluid Dynamics techniques. Then, the effects on ISA passage noise of each design factors including the duct turning shape and vane geometries are assessed. Based on these results, the preliminary low noise design for the ISA passage are proposed. The current method for the prediction of internal aerodynamic noise consists of the steady CFD and the scaling laws for the noise prediction. This combination is most cost-effective, compared with other methods, and therefore is believed to be suited for the preliminary design tool in the industrial field.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2012.03a
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• pp.19-19
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• 2012

최근 산업환경 변화에 순응하는 환경 친화적 소재를 사용하여 자동차, 선박, 철도 등 수송용 인테리어 내장재를 구성하는 기술로서, 난연성 및 기계적 물성 유지 기술, 그리고 실내 쾌적감을 부여하기 위한 감성기술 및 심미적 요소를 부여하는 디자인 기술이 가미된 복합 기능화 기술개발이 구되고 있다. 기존의 자동차용 시트 제품은 대부분 PU Foam을 시트원단에 불꽃으로 Lamination 하는 방식으로 제조되었으며, 이러한 제조 방식은 많은 공정을 거치게 되고 PU Foam을 제조하는 공정 및 불꽃으로 Lamination 하는 공정에서 많은 환경유해가스가 발생하는 등 환경적으로도 많은 문제점을 감수하면서 생산하는 방식이다. 또한 각종 원단의 표피재로 많이 사용되고 있는 PU와 PVC의 경우 제조과정에서 용제와 가소제 사용 등으로 인해 환경적으로 많은 문제점이 있으며, 이를 대체하기 위한 노력이 많은 부분에서 이루어지고 있지만, 마땅히 대체할 소재를 찾지 못하고 있는 실정이다. 본 연구에서 제안하는 실리콘수지는 기존의 PU와 PVC를 대체할 수 있는 소재로서 각광받고 있으며, 응용기술 개발을 통해 충분히 적용이 가능한 소재라고 판단된다. 본 연구에서 개발하고자 하는 기술은 난연성을 가진 실리콘 내장 표피재에 불꽃으로 Lamination하는 공정을 배제한 친환경 PUD Foam을 바로 Back Coating함으로써 일체형 고 기능 친환경 제품을 개발함으로써 친환경 복합화 기술 및 SEAT 원단과 표피재의 일체형 모듈화 공법개발을 이루고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.3
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• pp.967-976
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• 2012

This study presents a model to minimize vibration and noise of powertrain mount on a compact car which has the application of Stop & Go performance, in order to reduce CO2 and achieve better fuel-efficiency in accordance with the environmental regulations in automotive industries. In the first step, we analyze the powertrain mount system of the automobile "A" and present variables about rubber stiffness applied on powertrain mount using the Taguchi method. In the next step, we verify the optimization of vibration and noise which meet Stop & Go performance using the AHP(Analytic Hierarchy Process) method on the proto products for each variable. Using this validation system on the initial stage of the powertrain mount design, it is expected that we can grasp vibration and noise problems caused by engine movements and control them effectively without engineering know-how about powertrain mount rubber stiffness.