• 대한기계학회논문집A
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• 제33권8호
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• pp.773-778
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• 2009

Chevron rubber springs are used in primary suspensions for rail vehicle. Chevron rubber spring have function which reduce vibration and noise, support load carried in operation of rail vehicle. Prediction and evaluation of characteristics are very important in design procedure to assure the safety and reliability of the rubber spring. The computer simulation using the nonlinear finite element analysis program executed to predict and evaluate the load capacity and stiffness for the chevron spring. The non-linear properties of rubber which are described as strain energy functions are important parameters. These are determined by material tests which are uniaxial tension, equi-biaxial tension and shear test. The appropriate shape and material properties are proposed to adjust the required characteristics of rubber springs in the three modes of flexibility.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2008년도 추계학술대회 논문집
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• pp.47-50
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• 2008

The sub-zero cold is a major environmental consideration for the operational readiness of FCEVs because fuel cells produce water and utilize wet air with varying water content to generate electricity. Typical fuel cells thus have a fatal flaw in freezing conditions at startup. This drawback becomes more serious with the outsourced fuel cell that is entirely water-based for its internal humidification. In this background, the HMC's self-designed fuel cell was developed as an alternative and was employed in the Tucson-based FCEV in 2006 demonstrating its good cold-startup characteristics. The cold-startup capacity of the vehicle was validated through tests in the cold chamber and on the road, resulting in 50% stack power achieved in 250 seconds at $-15^{\circ}C$.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 춘계학술대회 논문집
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• pp.186-192
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• 2001

A chevron rubber spring is used in primary suspension system for rail vehicle. The chevron spring has function which support the load carried and reduce vibration and noise in operation of rail vehicle. The computer simulation using the non-linear finite element analysis program MARC executed to predict and evaluate the load capacity and stiffness for tile chevron spring. The appropriate shape and material properties are proposed to adjust the required characteristics of chevron spring in the three modes of flexibility. Also, several samples of chevron spring are manufactured and experimented. It is shown that the predicted values agree well tile results obtained from experiments.

• Safety and Health at Work
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• 제1권2호
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• pp.107-111
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• 2010

This paper provided a brief summary of the current strategic goals, activities, and impacts of the NIOSH (National Institute for Occupational Safety and Health) occupational injury research program. Three primary drivers (injury database, stakeholder input, and staff capacity) were used to define NIOSH research focuses to maximize relevance and impact of the NIOSH injury-prevention-research program. Injury data, strategic goals, program activities, and research impacts were presented with a focus on prevention of four leading causes of workplace injury and death in the US: motor vehicle incidents, falls, workplace violence, and machine and industrial vehicle incidents. This paper showcased selected priority goals, activities, and impacts of the NIOSH injury prevention program. The NIOSH contribution to the overall decrease in fatalities and injuries is reinforced by decreases in specific goal areas. There were also many intermediate outcomes that are on a direct path to preventing injuries, such as new safety regulations and standards, safer technology and products, and improved worker safety training. The outcomes serve as an excellent foundation to stimulate further research and worldwide partnership to address global workplace injury problems.

• 전기학회논문지
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• 제64권12호
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• pp.1810-1817
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• 2015

The railway vehicle has an auxiliary power unit for supplying power to the associated electronic control devices and passenger service unit. Typically, input voltage from the catenary for rolling stock is highly fluctuating according to the substation capacity, vehicle propulsion and regeneration. Especially, the frost and freezing on contact wire in winter can cause a blackout inside vehicle, and also brings about electronic components damaging and the system down. To prevent this problem, a large filter and capacitor is used. But this is not a perfect solution, because it is increasing weight of the unit. In this paper, a new algorithm is proposed to suppress the disturbance without adding devices. Simulation and experimental results show that the proposed algorithm has performance to suppress the disturbance at the sudden input voltage variations.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.157-161
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• 2008

The main purpose of this study is to analysis of urban MAGLEV vehicle for the Incheon International Airport Maglev railway, in the process of construction at the moment, in Korea. For analysis of urban MAGLEV, we have measurement power a special quality of MAGLEV operating the center science museum in Deajeon. 1) The power property related to urban MAGLEV vehicle demand on the Incheon International Airport Maglev railway track and substation capacity compared to the result given. 2) The optimum design of substation is determined based on the analysis. 3) The equipments of substation are determined based on the analysis. The result of measurement performance, therefore, enables us to reflect the good property, to the power supply design. The result of research performance, therefore, enables us to reflect the Power Supply System design for the stabilized and economized MAGLEV operation.

• 자동차안전학회지
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• 제15권4호
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• pp.65-70
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• 2023

In the paper, we propose a design method and process of a hybrid V2X communication module that combines WAVE communication, LTE-V2X communication, and legacy LTE communication in evaluating vehicle V2X electromagnetic compatibility. C-ITS is suitable for safety service applications due to its low latency, and legacy LTE is suitable for applications such as traffic information and infotainment due to its high latency and high capacity. In order to evaluate the V2X communication system, the evaluation equipment must have communication performance of the same level or higher. The main design contents presented in this paper will be applied to the implementation of a hybrid V2X communication module for electromagnetic compatibility evaluation.

• Advances in aircraft and spacecraft science
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• 제10권5호
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• pp.393-418
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• 2023

Drones are increasingly used in logistics delivery due to their low cost, high-speed and straight-line flight. Considering the small cargo capacity, limited endurance and other factors, this paper optimized the pickup and delivery vehicle routing problem with time windows in the mode of "truck+drone". A mixed integer programming model with the objective of minimizing transportation cost was proposed and an improved adaptive large neighborhood search algorithm is designed to solve the problem. In this algorithm, the performance of the algorithm is improved by designing various efficient destroy operators and repair operators based on the characteristics of the model and introducing a simulated annealing strategy to avoid falling into local optimum solutions. The effectiveness of the model and the algorithm is verified through the numerical experiments, and the impact of the "truck+drone" on the route cost is analyzed, the result of this study provides a decision basis for the route planning of "truck+drone" mode delivery.

• 한국지반환경공학회 논문집
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• 제15권2호
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• pp.67-74
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• 2014

최근 산업의 발달로 증가하는 도로와 이를 이용하는 차량의 증가로 인한 교통사고가 지속적으로 증가하고 있다. 교통사고는 운전자과실, 차량결함, 주행도로상태, 자연환경 등의 다양한 불안정 인자들로 인하여 발생한다. 방호울타리의 한 종류인 가드레일은 교통사고 및 이탈을 방지하여 탑승자의 상해와 차량의 파손을 최소로 줄여 차량을 정상주행 시키는 것을 목적으로 한다. 가드레일은 8 tonf 차량이 $15^{\circ}$로 80 km/h의 속도로 가드레일에 충돌하는 시험으로 가드레일의 안정성을 평가하며, 지반은 상대적으로 지지력이 큰 무한평지에서 평가된다. 하지만 국내의 경우 성토사면에 설치된 가드레일은 보호길어깨에 설치되며, 이로 인해 가드레일의 지지력 저하 및 성능저하로 가드레일의 안정성에 문제가 발생할 가능성이 있다. 이러한 가드레일에 대한 기존 연구는 무한평지에 설치된 가드레일 및 차량의 안정성에 대한 연구가 수행되었다. 하지만 차량 충돌 시 가드레일이 설치된 성토사면의 거동에 대한 연구는 미비한 실정이다. 이에 본 연구에서는 차량 충돌 시 성토사면의 거동을 확인하기 위해 유한요소프로그램인 LS-DYNA를 이용하여 성토사면에 설치된 가드레일의 지주 매입깊이를 변화시켜 수치해석을 수행하였다. 그리고 수치해석은 NCAN(National Crash Analysis Center)에서 제공하는 8 tonf 트럭을 이용하여 성토사면에서 가드레일 지주의 매입깊이를 변화시키면서 충돌 해석을 수행하였다. 그 결과, 가드레일 지주의 매입깊이가 증가함에 따라 성토사면의 변위와 응력이 증가하는 것으로 나타났으며, 450 mm 깊이에서 지반지지력이 저하되는 것으로 나타났다.

• 대한토목학회논문집
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• 제34권1호
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• pp.243-250
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• 2014

기존의 신호교차로에 비해 상대적으로 효율적이고 안전한 것으로 평가되고 있는 회전교차로(roundabout)가 최근 전국적으로 설치 운영 중에 있으며 이에 따라 회전교차로의 효율성과 안전성을 개선하기 위한 다양한 연구가 수행 중에 있다. 본 연구에서는 현재까지 시도된 적이 없는 회전교차로와 커넥티드 차량(connected vehicle) 기법의 접목을 통해 Smart Roundabout이라는 새로운 개념의 첨단교통정보시스템을 개발하고 미시적 시뮬레이션을 이용하여 평가하고자 한다. Smart Roundabout은 교차로를 회전하는 차량에 장착된 단말기(on-board equipment, OBE)를 통해 차량들의 주행정보(위치, 속도, 차두시간 등)를 커넥티드 차량(connected vehicle) 기법을 통해 전달받고 회전교차로에 접근하는 차량 내부의 단말기를 통해 교차로 진입에 대한 상환판단을 도와 안전성을 확보함과 동시에 보다 짧은 차두시간(critical headway)을 구현하여 회전교차로의 용량을 증대시킬 수 있을 것으로 기대된다.