• 한국ITS학회 논문지
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• 제10권5호
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• pp.113-123
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• 2011

최근 온난화 문제가 대두됨에 따라 세계 각국에서 $CO_2$ 배출감소를 위한 여러 가지 규제를 설정하고 있다. 특히 수송부분에서의 $CO_2$ 배출량 감소는 매우 영향력이 크므로 자동차 산업에서도 전기자동차를 비롯한 그린자동차 개발에 대한 관심이 높아지고 있다. 이에 따라 전기자동차 시대 도래 대비를 위하여 전기자동차 보급에 따른 인프라 구축 전략안 및 전력량 수요 예측이 필요하지만, 이의 기반이 되는 전기자동차 수요예측 방법은 소개되어 있지 않고 있다. 따라서 본 연구에서는 선택기반 다세대 확산모형을 이용하여 전기자동차의 수요를 예측하는 방법론을 제시하였다. 전기자동차와 비슷한 성격을 가지는 하이브리드 자동차의 과거 데이터를 이용하여 Bass 모형의 혁신계수와 모방계수를 추정하고 SP(Stated Preference)조사를 통하여 잠재적인 총수요를 추정함으로써 전기자동차의 수요를 년도별로 예측하였다. 또한, 전기자동차가 발전하는 속성 진화에 따른 다세대 확산과정을 모형에 반영하여 보다 정확한 수요예측이 가능하도록 하였다. 본 연구의 수요예측 방법론을 통하여 향후 전기자동차의 시장 점유율을 예측함으로써 전기자동차 보급과 밀접한 관련이 있는 전력수급 및 충전인프라 구축 연구에 활용 될 수 있도록 한다.

• 대한기계학회논문집B
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• 제33권4호
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• pp.255-263
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• 2009

The most concerning issue of these days is the energy crisis caused by increasing threat of dependence on imported oil and volatile market trend. Under these circumstances, the PHEV(plug-in hybrid electric vehicle) is drawing attention for the next generation's car which could give a chance to decrease the dependence on imported oil and reduce the environmental impact of vehicle. The fueling cost of PHEV, one of the core factor of decision about buying car, should be calculated in the circumstances of Korea to make sure that PHEV has competitive power in real market. The fuel cost saving of PHEV versus CV(conventional vehicle) is simulated and discussed in the condition of increasing gasoline cost, electricity rate, and city-gas rate. In conclusion, the PHEV60-FS shows the best economic feasibility when gasoline price goes up. The PHEV20 has the most stable economic feasibility as electricity rate increases. The fuel cell cogeneration system for RPG could be an alternative for charger of PHEV in the near future.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.238-240
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• 2005

This paper presents harmonic evaluation of an IAT(Intra Airport Transit) system in Incheon International Airport. It will be used electric vehicles with 80 kW per car that are produced Mitsubishi Heavy Industries Ltd, and one car is constructed with SIV(Static Inverter), VVVF controller and two induction motor. The operated vehicles in the IAT system are rapidly changing DC load and at a feeding substation, 3-phase electric power is transferred to DC 750 V by rectifier. Since, vehicles are also changing continuously, the voltages for the load fluctuate in the IAT system, and moreover, the fluctuating voltages generate high-order har -monies. This means that there is the difficulty in maintaining power quality in KEPCO systems' side. Therefore, the power quality of the IAT system in Incheon International Airport is evaluated using PSCAD/EMTDC simulator in the paper The THD(Total Harmonic Distortion) of voltages and TDD(Total Demand Distortion) of currents, indices are calculated for the IAT system using the results of PSCAD/EMTDC dynamic simulation.

• 산업기술연구
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• 제24권A호
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• pp.37-46
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• 2004

A performance analysis for newly being considered electric rail car office has been made in this study. The major purpose is to examine a proposed design in terms of its capacity and the proposed number of travels (82-84) per day. For this study we first examined the overall system configuration with detailed operational processes of cleaning and inspection. We then developed a simulation model using ARENA and designed input data from 12 selected factors and their interaction effects. A simulation run for each treatment combination of $L_{16}(2^{15})$ orthogonal array was run and 20 batch means were obtained. Through careful analyses of the results obtained, we drew a diversity of suggestions including the best factor level combination. Our confirmation experiments at the optimal level combination further validate the possibility of 82 runs and the consistency in the results.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.788-793
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• 2005

This paper presents harmonic evaluation of an IAT(Intra Airport Transit) system in Incheon International Airport. It will be used electric vehicles with 80 kW per car that are produced Mitsubishi Heavy Industries Ltd, and one car is constructed with SIV(Static Inverter), VVVF(Variable Voltage and Variable Frequency) and two induction motor. The operated vehicles in the IAT system are rapidly changing DC load, and at a feeding substation, 3-phase electric power is transferred to DC 750 V by rectifier. Since, vehicles are also changing continuously, the voltages for the DC load fluctuate in the IAT system, and moreover, the fluctuating voltages generate high-order harmonics. This means that there is the difficulty in maintaining power quality in KEPCO systems' side. Therefore, the power quality of the IAT system in Incheon International Airport is evaluated using PSCAD/EMTDC simulator in the paper. The THD(Total Harmonic Distortion) of voltages and TDD(Total Demand Distortion) of currents, indices are calculated for the IAT system using the results of PSCAD/EMTDC dynamic simulation.

• 한국자동차공학회논문집
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• 제21권1호
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• pp.36-42
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• 2013

Recently, the automobile of the future will be able to substitute an electric vehicle for an internal combustion engine, so the following research is actively in the process of advancing. A traction motor is one of the core parts which compose the electric vehicle. Especially, it is difficult to connect cooling water piping to an in-wheel motor because the in-wheel motor is located within the wheel structure. This structure has disadvantage for closed type and air cooling, so the cooling design of motor housing and internal in-wheel motor is important. In this study, thermo-flow analysis of the in-wheel motor for vehicles was performed in consideration of ram air effect. In order to improve cooling efficiency of the motor, we variously changed geometries of housing and internal shape. As a result, we found that the cooling efficiency was most excellent, in case the cooling groove direction was same with air flow direction and arranged densely. Furthermore, we investigated the cooling performance enhancement with respect to variable geometries of internal in-wheel motor.

• 한국자동차공학회논문집
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• 제21권5호
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• pp.145-150
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• 2013

Recently, many vehicles have applied electric parts for saving fuel consumption and reducing levels of environmental pollution. ISG (integrated starter & generator) is one of main electric parts and can improve fuel efficiency by using idle stop & go function and regenerative braking system. However, if ISG driving inverter works under the continuously high load condition, it will make the performance and durability of the inverter decreased with rising temperature. In this study, we carried out the analysis on the fluid flow and thermal characteristics of the inverter. As a result, we found the MOSFET of the air cooled inverter was increased up to $116^{\circ}C$ over the limit temperature. On the other hand, the liquid cooled type inverter's MOSFET was decreased by about $17^{\circ}C$ compared to that of the air cooled inverter. Therefore, we verified the feasibility of the liquid cooled type using the present cooling structure.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1160-1165
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• 2008

The development of a new railway vehicle is under progress through the Next Generation High-Speed Rail Development Project in Korea. Its aim is to develope fundamental technology of the vehicle that can run over 400km/h. The new distributed traction bogie system, 'HEMU'(High-speed Electric Multiple Unit), will be used and is different from previously developed high speed railway vehicles. Previous vehicles adopted push-pull type system, which means one traction-car drives rest of the vehicle. Due to the difference, investigation on dynamic behavior and its safety evaluation are necessary, as a part of verification of the design specification. In this paper, current progresses of researches are presented. And the High-Speed Railway vehicle system is evaluated for a dynamic characteristic simulation. Proper models including air-suspension system, wheel-rail, bogie and car-body will be developed according to the vehicle simulation scenario. International safety standard will be applied for final verification of the system. This research can propose a better solution when test running shows a problem in the parts and elements. Finally, the vehicle that has excellent performance will be developed, promoting academic achievement and technical development.

• 대한인간공학회지
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• 제33권6호
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• pp.543-551
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• 2014

Objective: The purpose of this study is to identify visual perception of and satisfaction with the orange peel effect of surface. The orange peel effect is a type of finish on painted or coated surface. Background: Gloss paint sprayed on a smooth surface (such as car body, smart phone, and electric home appliances, etc.) should also dry into a smooth surface. Then, a surface resembling the texture of an orange peel can be caused by some factors. The orange peel effect can degrade user's satisfaction with a product. Method: Visual perception and emotional satisfaction were subjectively evaluated using Likert scale. The significance of orange peel effect on visual perception and satisfaction were then analyzed by the analysis of variance. The correlation between visual perception and satisfaction was also analyzed. Results: Surface roughness significantly influenced visual perception and emotional satisfaction. The level of visual perception increased and emotional satisfaction decreased with the increase of orange peel effect. Emotional satisfaction decreased with the increase of visual perception level. Conclusion: It was identified that orange peel phenomenon on surface was a very important factor for emotional satisfaction. The orange peel effect on the surface of a product should be minimized to improve the emotional satisfaction of the product. Application: The result of this study can be applied to the texture design of the body of a car, smart phones, and electric home appliances, etc.

• 무역학회지
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• 제47권6호
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• pp.71-96
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• 2022

This research will study the conversion intention of the users in China from fuel vehicle to new energy vehicles through the empirical methods. To this end, a questionnaire survey was conducted with car users as the object, combined with the theory of user migration and the PPM model to analyze the impact of fuel vehicle users' conversion intention to new-energy vehicles factor. The results showed that purchase experience contains the moderating effect, in which perceived risk and switching costs had a greater impact on the groups without purchase experience, whereas social identity, perceived value, personal attitude, and willingness to switch had a greater impact on groups with the purchase experience. Among all five factors, perceived risk had no discernible impact on the switching intention, but social identity, perceived value, attitude toward switching, and switching costs all had discernible impact on the switching intention. This study expects to come out with sustainable advises for the future growth of new energy vehicles from the study of car users' switching intention and the collective difference test of purchasing experience.