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        검색결과 32

        21.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In South Korea, Jeju Island has a role as a test bed for electric vehicles (EVs). All conventional cars on the island are supposed to be replaced with EVs by 2030. Accordingly, how to effectively set up EV charging stations (EVCSs) that can charge EVs is an urgent research issue. In this paper, we present a case study on planning the locations of EVCS for Jeju Island, South Korea. The objective is to determine where EVCSs to be installed so as to balance the load of EVCSs while satisfying demands. For a public service with EVCSs by some government or non-profit organization, load balancing between EVCS locations may be one of major measures to evaluate or publicize the associated service network. Nevertheless, this measure has not been receiving much attention in the related literature. Thus, we consider the measure as a constraint and an objective in a mixed integer programming model. The model also considers the maximum allowed distance that drivers would detour to recharge their EV instead of using the shortest path to their destination. To solve the problem effectively, we develop a heuristic algorithm. With the proposed heuristic algorithm, a variety of numerical analysis is conducted to identify effects of the maximum allowed detour distance and the tightness of budget for installing EVCSs. From the analysis, we discuss the effects and draw practical implications.
        4,500원
        22.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper describes result of a study on safety against a fire of charging cable for mobile phone for vehicle. Combustion on the USB cable in the car was happened while driving. Gas coming from the burning USB cable could be a reason which can make a secondary car accident since the driver also can be embarrassed while driving. In order to prevent a secondary car accident connected on the road, to research a reason why USB cable can emit gas and be burned in charging. We did simulation test with abnormal fault condition for the electronic component on the board in the USB cable. So we get the result from abnormal fault condition simulation test, for instance, shorted test for output terminal of 8 pin switch, shorted test for chip resistor after thermal aging in the condition 25 ℃ , 93 % RH during 48 hours. To analysis the result of all test, Combustion on the USB cable was not the 8 pin but other electrical component such as a chip resistor. Therefore we guess that the reason for USB cable combustion in charging in a car was not 8 pin and a LED but another defective component.
        4,000원
        23.
        2015.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 2012~2013년 국내 전기차 시장에서 크게 논란이 되었던 콤보 전기 자동차 충전 표준과 국내 스마트그리드 표준 간 충돌 사례를 이해관계자 이론을 활용하여 분 석하였다. 사례 연구를 위해 문헌 조사 및 복수의 전문가 인터뷰를 실시하였다. 전기 자동차 는 충전을 위해 전력망과 연결될 때 데이터 교환을 한다. 따라서 통신 표준 문제가 대두된다. BMW는 글로벌 전기 자동차 시장에서 업계를 대표하는 사실상 표준의 지위를 얻어 가고 있 던 콤보 충전 기술을 채택하여 국내 전기차 시장에 진입하였는데, 그 과정에서 국내 스마트 그리드 전력망의 원격검칭용 통신 기술과 상호 주파수 간섭을 일으키는 문제가 발생하였다. 이 문제를 둘러싸고 이해관계자들의 대립이 계속되면서 국내 전기 자동차 충전 기술 관련 표 준(국가표준 및 단체표준)화를 위한 의사결정들이 지연되었고, 이 논란은 2014년 1월 콤보 기술이 한국자동차공학회의 단체표준(KSAE SAE 1772-2040, 2014.1)으로 인정되면서 일단 락되었다. 이 사건은 전기 자동차 표준 그 자체만이 아니라, 융합산업 시대에 있어서 타 산업 표준과의 충돌 및 조정의 필요성을 부각시키는 의미있는 사례이다. 본 연구는 전기 자동차 충전 표준과 스마트그리드 표준이라는 이종 산업 간의 표준 충돌의 복잡한 역학 관계를 이해 관계자 이론을 적용하여 분석하였다. 본 연구는 표준화 과정을 둘러싼 경험적 및 이론적 연 구가 충분하지 않다는 점에서, 이해관계자 이론을 활용한 사례 축적과 방법론 정립에 기여하 고, 또한 표준화 과정에 참가하는 이해관계자들이 이 과정에 영향을 미치기 위한 행위 양식 정립과 전략 수립에 유용한 시사점을 제공한다.
        7,700원
        24.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The diesel engine uses the intercooler for cooling of charging air by the turbo-charger. But the cooling efficiency of the intercooler which is influenced by the vehicle speed is decreased in low vehicle speed. If the vortex tubes are substituted for the intercooler due to their many intrinsic benefits in many industrial fields as parts for refrigerating machines, the cooling efficiency could be advanced in the low speed range. In this study, a counter-flow type of vortex tube is employed to investigate the temperature separation characteristics with various geometric configurations for optimization of charging air cooling. A parametric study was conducted to evaluate the performance of the vortex tube with various geometric structures and operating inlet pressures. The results show that variation of the cold exit orifice hole diameter significantly influences the energy separation between two exits.
        4,000원
        25.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hybrid car can improve fuel efficiency using a power of motor that is generated during constant-speed or deceleration driving. The motor is located between engine and transmission. But, when voltage of main battery is low, fuel efficiency is low because the voltage can't run the motor. In this situation, this study observed fuel efficiency when using solar cell for assistance power. In order to verify a fuel consumption of hybrid car equipped solar cell for assistance power, the car was tested downtown driving. As hybrid car was equipped solar cell for assistance, fuel consumption was reduced 8.35 % at running air conditioner. And, at air conditioner doesn't work, fuel consumption was reduced 6.88 %. This point of view, CO2 is expected to reduce in similar proportion.
        4,000원
        26.
        2011.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        전기자동차의 상용화시대에 대비한 전기자동차 충전네트워크가 시급해지고 있다. 해외에서는 주차장에 PV시스템을 설치하여 얻어진 전력으로 전기자동차 충전을 할 수 있는 전기자동차 충전소가 설치되어지고 있다. 또한 우리나라에서도 충전인프라 구축방안 및 전기자동차 충전시설 지원기준 등을 설정하여 제시하고 있지만 해외처럼 PV시스템을 이용한 전기자동차 충전소의 사례가 국내에는 없으며, 일반전력을 이용한 전기자동차 충전소만 제시하고 있다. 따라서 본 논문에서는 국내의 전기자동차 충전네트워크 구축에 대비하여 국내 외 태양광 주차장과 해외 PV시스템 전기자동차 충전소의 사례를 조사하여 구조시스템, 구조 재료 등을 분석하여 비교 분석한 결과, 해외 PV시스템 전기자동차 충전소의 경우 캔틸레버 구조와 소규모 타입이 많이 설치되었다.
        4,000원
        27.
        2010.11 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        High strength sheet steels for automobile are seriously compromised by hydrogen embrittlement. This issue has been continuously studied, but the field of interest, which lies between microstructural characteristics and hydrogen behavior with hydrogen charging, has not yet been thoroughly investigated. This study was done to investigate the behavior of hydrogen according to the hydrogen volume fraction on 590MPa grade DP steels, which are developed under hydrogen charging conditions as high strength sheet steels for automobiles. The penetration depths and the mechanical properties, according to charging conditions, were investigated through the distribution of micro-hardness and the microstructural observation of the subsurface zone. It was found that the amount of hydrogen trapping in 590MPa DP steels was related to the austenite volume fraction. It was confirmed that the distribution of micro-hardnesses according to the depth of the subsurface zone under the free surface showed the relationship of the depth of the hydrogen saturation between the charging conditions.
        4,000원
        28.
        2009.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        HFC-134a is currently used as a refrigerant in automotive air conditioning system replacing the ozone depleting CFC-12 refrigerant. This paper was experimentally studied on the performance characteristics of an automotive air conditioning system with variations of charging refrigerant and compressor speed. An air conditioning system was composed of laminated type evaporator, parallel flow type condenser, vane rotary type compressor, externally equalized thermostatic expansion valve and receiver drier with specifications of Hyundai Sonata Ⅱ vehicle. And the automatic measuring system of air conditioner used KTE-1000BA developed by a KT ENG Co., Ltd.. of Korea. The optimum conditions which were tested as available parameters for better performance are indicated charging refrigerant 800 g and compressor speed 1700 rpm.
        4,000원
        29.
        2008.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 에어컨의 적정냉매충전량 진단을 위한 자료를 제공하기 위하여 수행하였다. 공기 온도 33∼35℃, 습도 55∼57%RH로 조절되는 실내에서 SONATA III(Hyundai motor Co., Korea)자동차의 에어컨시스템을 대상으로 냉매충전 및 성능시험장치를 구성하고 냉매충전량 변화에 따른 냉매라인의 측정량으로 각 지점 온도와 고압 및 저압을 측정하고 분석하였다. 냉매라인의 측정온도는 압축기, 응축기, 리시버드라이어 및 증발기의 입구와 출구 파이프표면온도와 응축기와 증발기벤트 입구와 출구의 송풍공기온도이다. 이들 각 온도와 압력은 정도의 차이는 있으나 모두 냉매충전량(Wr)에 따른 영향을 받으며, 이들을 측정하여 냉매충전 정도를 진단할 수 있는 것으로 나타났다. 엔진회전속도 2,000 rpm과 1,500 rpm에 따른 각 측정량의 변화양상은 차이가 나타나지 않아 에너지사용량이 낮은 1500 rpm이 시험 회전수로 적당할 것으로 판단된다. 냉매충전량에 가장 큰 영향을 입는 측정량은 증발기벤트 입출구온도차(Td)이며, 그 다음이 냉매라인 고압측의 압력(P1)으로 나타났다. 1,500 rpm에서 Wr이 350 g까지 증가함에 따라 Td는 급격히 증가하다가 350g에서 700g까지는 12.8℃에서 16.7℃로 완만하게 증가하였고, 700g을 초과하면서 완만하게 감소하였다. P1은 Wr이 400 g까지 증가함에 따라 급격히 증가하다가 400 g에서 700 g까지는 14.3 kgf/cm2에서 16.0 kgf/cm2으로 완만하게 증가하였고 700 g을 초과하면 급격하게 상승하였다. 에어컨사용설명서에 제시된 냉매충전량이 720 g인 것을 고려하면 1,500 rpm에서 적정냉매충전량 진단은 5%오차범위에서 증발기벤트 입출구 공기온도차가 15℃, 고압측압력 15 kgf/cm2일 때로 추정된다. 에어컨상태가 정상인 진단은 Td가 12℃이상과 P1이 14 kgf/cm²에서 16 kgf/cm² 사이일 때로 판단된다.
        4,000원
        30.
        2006.03 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Numerical analysis was conducted to characterize the particle charging quantities in the charging cell of a 2-stage parallel-plate electrostatic precipitator with respect to particle size. The numerical method took into consideration of particle charging rate equations and particle equations of motion, allowing the locally varying non-uniform electric field and ion number concentration along the particle trajectory. The charging rate model developed by Lawless (1996) was used in the present study. According to the present study, the numerical results showed good agreement with the available experimental data.
        4,000원
        31.
        2015.03 KCI 등재 서비스 종료(열람 제한)
        As environmental concerns including climate change drive the strong regulations for car exhaust emissions, electric vehicles attract the public eye. The purpose of this study is to identify rural areas vulnerable for charging infrastructures based on the spatial distributions of the current gas stations and provide the target dissemination rates for promoting electric cars. In addition, we develop various scenarios for finding optimal way to expand the charging infrastructures through the administrative districts data including 11,677 gas stations, the number of whole national gas stations. Gas stations for charging infrastructures are randomly selected using the Monte Carlo Simulation (MCS) method. Evaluation criteria for vulnerability assessment include five considering the characteristic of rural areas. The optimal penetration rate is determined to 21% in rural areas considering dissemination efficiency. To reduce the vulnerability, the charging systems should be strategically installed in rural areas considering geographical characteristics and regional EV demands.
        32.
        2014.12 KCI 등재 서비스 종료(열람 제한)
        Car exhaust emissions are recognized as one of the key sources for climate change and electric vehicles have no emissions from tailpipe. However, the limited charging infrastructures could restrict the propagation of electric vehicles. The purpose of this study is to find the vulnerable districts limited to the charging station services after meeting the goal of Ministry of Knowledge Economy(12%). We assumed that the charging service can be provided by current gas stations. The range of the vulnerable grades was determined by the accessibility to current gas stations and the vulnerable regions were classified considering the optimal number of charging stations estimated by the efficiency function. We used 4,827 sub-municipal divisions and 11,677 gas station locations for this analysis. The results show that most of mountain areas are vulnerable and the fringe areas of large cities generally get a good grade for the charging infrastructure. The gangwon-do, jeollanam-do, gyeongsangbuk-do, and chungcheongnam-do include more than 40% vulnerable districts.
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