• 방송공학회논문지
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• 제21권4호
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• pp.609-620
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• 2016

최근 발생빈도가 높은 차량 간 충돌사고를 미연에 방지하고 운전자의 편의를 증진하기 위한 전방 충돌 경고 시스템에 관한 연구가 활발히 진행되고 있다. 충돌 회피를 위한 차량 시스템에 자동으로 차량을 검출하는 기술은 필수적 요소이다. 기존의 학습 기반 차량 검출 방법들은 일반적으로 차량의 후면 전체를 학습하며, 외형이 다른 승용차와 트럭, SUV의 경우 클래스를 분류하여 학습해야 한다는 단점이 있다. 본 논문에서는 이러한 단점을 해결하기 위해 차종에 관계없이 후미등 하단 부의 외형은 유사하다는 점에 착안하여 하단부에 한해 Haar-like feature를 학습함으로써 전방 차량을 검출하는 방법을 제안하였다. 또한 검증단계로서 후미등 검출을 통해 실제 차량과 차량이 아닌 것들을 분류하고 후미등 검출이 어려운 작은 크기의 후보 영역은 HOG(Histogram Of Gradient) 특징과 SVM(Support Vector Machine) 분류기를 통해 검증하여 오검출률을 낮추었다. 도로 주변에 건물이 많은 복잡한 영상에서도 차종에 관계없이 95%에 해당하는 정확도를 보여 전방 차량 검출 성능이 개선된 것을 확인하였다.

• 자원ㆍ환경경제연구
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• 제33권1호
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• pp.33-57
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• 2024

본 연구는 전기 소형화물차에 대한 구매보조금이 환경편익의 측면과 총보유비용 동등성 측면에서 볼 때 적정한 수준인지에 대하여 분석하였다. 환경편익에 대해서는 발전믹스에 따라 발생하는 환경오염물질 배출량을 고려하였으며, 기온분포에 따른 전기차의 효율변화도 반영하였다. 소형화물차의 경우, 경유차 대신 전기차를 운행함에 따른 환경편익은 차량의 총운행기간에 걸쳐 217~530만 원 수준으로 추정되었다. 또한, 현행 구매보조금 제도하에서 경유차 대비 전기차의 총보유비용은 사업용은 약 360만 원, 비사업용은 약 660만 원 낮은 것으로 추산되었다. 즉, 환경편익의 관점에서든 총보유비용의 관점에서든 보다 효율적으로 재정을 활용하고자 한다면 같은 예산이라도 전기 소형화물차에 대한 구매보조금 단가를 낮추는 것이 합리적이다. 그 대신 남은 예산은 화물차 전용 충전기의 확보와 같이 충전인프라를 고도화하는 데에 좀 더 집중한다면 잠재적인 구매자들의 금전적인 부담뿐만 아니라 충전 관련 불편함까지 줄여 전기 소형화물차 보급에 더 비용효과적일 것으로 판단된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.14-21
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• 2011

Reliability means that a product maintains its initial quality and performance at certain period of time(time, distance, cycle etc) under given condition without failure. Given conditions include both environmental condition and operating condition. Environmental condition means common natural environment such as temperature, humidity, vibration, and working condition means artificial environment such as voltage, current load, install place, hours of use, which occurs during using the product. In the field of railway vehicles, although components of railway vehicles with reliability are the trend of mandatory as persisting period of railway vehicles is extended, using components of railway vehicles is insufficient for the practical reliability assessment. but the meaning of the first railway operating agnecy to acquire the parts in the field, the data suggest the reliability of products if you can and can show the reliability of modular units and modular units can provide the reliability of if you can present reliability of the entire system is thought to be here. In this study, lifespan of micro-switch for master controller is analyzed and prediction is performed based on its field data considering the special circumstances of railway vehicles operating agency, such as a large number of trains operates on the same line.

• 동력기계공학회지
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• 제2권2호
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• pp.47-54
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• 1998

Underwater robotic vehicles(URVs) have been an important tool for various underwater tasks such as pipe-lining, data collection, hydrography mapping, construction, maintenance and repairing of undersea equipment, etc because they have greater speed, endurance, depth capability, and safety than human divers. As the use of such vehicles increases, the vehicle control system is one of the most critical subsystems to increase autonomy of the vehicle. The vehicle dynamics are nonlinear and their hydrodynamic coefficients are often difficult to estimate accurately. It is desirable to have an intelligent vehicle control system because the fixed-parameter linear controller such as PID may not be able to handle these changes promptly and result in poor performance. In this paper we described and analyzed a new type of fuzzy model-based controller which is designed for underwater robotic vehicles and based on Takagi-Sugeno-Kang(TSK) fuzzy model. The proposed fuzzy controller: 1) is a nonlinear controller, but a linear state feedback controller in the consequent of each local fuzzy control rule; 2) can guarantee the stability of the closed-loop fuzzy system; 3) is relatively easy to implement. Its good performance as well as its robustness to parameter changes will be shown and compared with those of the PID controller by simulation.

• 시스템엔지니어링학술지
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• 제7권1호
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• pp.57-69
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• 2011

Reliability means that a product maintains its initial quality and performance at certain period of time(time, distance, cycle etc) under given condition without failure. Given conditions include both environmental condition and operating condition. Environmental condition means common natural environment such as temperature, humidity, vibration, and working condition means artificial environment such as voltage, current load, install place, hours of use, which occurs during using the product. In the field of railway vehicles, although components of railway vehicles with reliability are the trend of mandatory as persisting period of railway vehicles is extended, using components of railway vehicles is insufficient for the practical reliability assessment. but the meaning of the first railway operating agency to acquire the parts in the field, the data suggest the reliability of products if you can and can show the reliability of modular units and modular units can provide the reliability of if you can present reliability of the entire system is thought to be here In this study, lifespan of micro-switch for master controller is analyzed and prediction is performed based on its field data considering the special circumstances of railway vehicles operating agency, such as a large number of trains operates on the same line.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.244-251
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• 2013

This paper presents a study the change of the load profile on the power system by the charging impact of electric vehicles (EVs) in 2020. The impact of charging EVs on the load demand is determined not only by the number of EVs in usage pattern, but also by the number of EVs being charged at once. The charging load is determined on an hourly basis using the number of the EVs based on different scenarios considering battery size, model, the use of vehicles, charging at home or work, and the method of charging, which is either fast or slow. Focusing on the impact of future load profile in Korea with EVs reaching up 10 and 20 percentage, increased power demand by EVs charging is analyzed. Also, this paper analyzes the impact of a time-of-use (TOU) tariff system on the charging of EVs in Korea. The results demonstrate how the penetration of EVs increases the load profile and decreases charging demand by TOU tariff system on the future power system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.264-266
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• 1997

Fuel cell systems offer high energy efficiencies for transportation application. In addition, they can use alcohols and alternative fuels as the fuel, while producing little or no noxious emissions. Fuel cell-powered vehicles should be competitive in performance characteristics and in capital and maintenance costs with internal combustion engine vehicles. The objective of the present study is to design a fuel cell-powered passenger car to analyze technical feasibility.

• 한국생산제조학회지
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• 제22권4호
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• pp.693-699
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• 2013

Environmental issues are attracting increasing interest worldwide, and accordingly, environmental regulations for vehicles are being made more stringent. As a result, the car industry is conducting studies focusing on fuel efficiency and lightweight vehicles. To manufacture lightweight vehicles, existing steel parts are replaced by composite materials and lightweight metals. In this study, the fatigue life of a new material for manufacturing lightweight car door hinges was predicted using a finite-element analysis program. The existing steel material was replaced by carbon-fiber-reinforced plastic (CFRP) and aluminum alloy 6061, and the test results were analyzed. The maximum stress decreased by approximately three times, whereas the fatigue life and safety factor increased. When only CFRP was used, its allowable stress, safety factor, and fatigue life were excellent, but the sagging of the product exceeded the allowable value, which posed a limitation in use. Therefore, it seems desirable to use an appropriate combination of steel, AA6061, and CFRP for this product.

• 한국정보시스템학회지:정보시스템연구
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• 제30권4호
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• pp.95-118
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• 2021

Purpose This study verified the moderating effect of consumer knowledge in relation to the factors affecting the acceptance intention of autonomous vehicles by adding trust to the United Theory of Acceptance and Use of Technology model for the commercialization of autonomous vehicles. Design/methodology/approach For this purpose, this study conducted a survey on general consumers who are interested in automobiles. A total of 250 questionnaires were distributed and collected, and 242 questionnaires were used for analysis. To test the hypotheses, multiple regression analysis and multiple group analysis were performed. Findings Performance expectations, effort expectations, social influence, and trust were found to have a positive effect on the acceptance intention of autonomous vehicles. In addition, consumer knowledge between performance expectation and acceptance intention and between effort expectation and acceptance intention was confirmed as a variable that can moderate the relationship.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.413-416
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• 2003

This paper proposes an adaptive background image generation method based on the frame difference for traffic monitoring. The performance of the conventional method is limited when there are more vehicles due to traffic Jam. To improve on this, we use frame differencing to separate vehicles from background in frame differencing, we adopt selective approach by using part of the image not considered as vehicle fer extraction of background. The proposed method generates background more efficiently than conventional methods even in the presence of heavy traffic.