• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2002년도 추계학술대회 논문집(I)
• /
• pp.721-726
• /
• 2002

The topic on today is dynamic response analysis of curved bridge-AGT(Automated Guide-way Transit) vehicle interaction system. Rubber wheel type AGT vehicle is adopted in this study, and the vehicle is idealized as three dimensional eleven DOF model. Three types of composited steel box girder bridges are modelized with F.E. method. And three types of artificially generated surface roughnesses are adopted for analysis. The dynamic equations of curved bridge, AGT vehicle and surface roughness are derived by using Lagrange's equation of motion. And the equations are solved by Newmark-${\beta}$ method. As a result, The dynamic increasement factor is inverse proportional to radius curvature.

• 한국안전학회지
• /
• 제33권5호
• /
• pp.120-126
• /
• 2018

The traffic accident types are largely classified into vehicle to vehicle accident, vehicle-to-person accident and single-vehicle. Especially, the single-vehicle accident types are severe when the vehicle crashed into road facilities such as bridge, piers, utility poles. The severity of single-vehicle accidents are ten times higher than that of all other accidents types. It is needed to consider to reduce accident severity. This study was conducted to develop crash worthy safety design facility to ensure the vehicle occupant safety. The simulation and the crash tests were conducted for assessment of the safety performance to check the criteria of CC2(Crash Cushion 2) level. THIV(Theoretical Head Impact Velocity) and PHD(Post-impact Head Deceleration) were used to assess occupant impact severity for crashes. The non-redirection collision test conditions for 900 kg and 1,300 kg-head on crash tests, 900 kg-1/4 offset crash tests, 1,300 kg-head on crash test with $15^{\circ}$angle were conducted. The simulation and experiment test result showed that THIV values were below 44 km/h criterion, PHD values were below the 20G. The development non-redirective crash cushion is expected to be used for the fixed object such as bridge piers for assuring occupant safety.

• 대한교통학회지
• /
• 제27권4호
• /
• pp.55-61
• /
• 2009

차종분류는 교통의 흐름 및 안전에 미치는 영향을 분석하고 도로의 포장 및 시설의 설계를 위하여 이루어진다. 국내에서는 국토해양부의 12종 분류에 따라 고속국도, 일반국도, 지방도의 차종분류 자료가 제공되고 있다. 기계식 차종분류를 위한 AVC(Automatic Vehicle Classification) 장비는 차량길이, 축거, 내민 거리(overhang) 등의 측정값과 미리 입력된 모든 차량 모델의 제원값을 비교하여 차종을 판단한다. 하지만, 기존의 방법은 센서의 관리상태에 분류 정확도가 크게 영향받게 된다. 본 연구에서는 실제 조사지점에서 발생하는 장비 오차와 차량 제원정보에 민감하지 않은 차종분류 알고리즘을 개발하였다. 알고리즘을 단순화하기 위하여 차량길이와 축거 중심으로 추세선을 이용하여 차종을 분류하므로 센서의 정확도 변화의 영향을 감소시켰다. 개발된 알고리즘의 평가를 위하여 일반국도에 설치된 AVC 장비에서 축수, 차량길이, 축거, 내민거리를 추출하여 비디오 판독 결과와 비교하였다. 실험 결과는 전체 차량에 대하여 88.2%의 정확도를 얻었다. 본 연구에서 개발된 차종분류 알고리즘은 센서의 감도 변화 등 현장 환경의 변화에 덜 영향을 받도록 설계되어 차종분류를 위한 기계식 장비의 안정적 정확도 유지에 활용될 수 있을 것으로 기대된다.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2011년도 제37회 추계학술대회논문집
• /
• pp.904-907
• /
• 2011

Various types of gases and propellants are used in launch vehicle. In order to fulfill the mission of the launch vehicle, the components and systems used in launch vehicle should ensure flawless operation in these environments. The pneumatic test is the test performed using compressed gas to prove requirements of the components and systems. This paper describes the requirements of the gas quality for pneumatic test, leak test method, and pneumatic test of the launch vehicle.

• 한국대기환경학회지
• /
• 제9권1호
• /
• pp.69-77
• /
• 1993

Exhaust emissions are calculated as a product of the emission factor and the vehicle kilometer traveled(VKT). The emission factor is a function of several parameters such as vehicle model year, vehicle mileage, traffic conditions, etc. The representative driving cycles classified as ten different types of an average vehicle speed were selected by analyzing passenger car driving patterns in Seoul. 51 vehicles were sampled and analyzed by types of vehicles, fuels used, model years and vehicle mileages also, exhaust emissions of them were measured by chassis dynamometer. Regression equations between average vehicle speeds and exhaust emissions are made for the estimation of emission factors at different vehicle speeds. Annual emission rates of air pollutants from motor vehicles in Korea were 1116$\times10^3 ton, 149\times10^3 ton, 413\times10^3 ton and 67\times10^3$ ton for CO, HC, NOx and particulats, respetively in 1990. It was found that 56% of CO and 49% of HC were originated from passenger cars and taxis, in addition, 87% of NOx and 100% of particulates were from buses and trucks using diesel fuels.

• 자동차안전학회지
• /
• 제15권1호
• /
• pp.35-44
• /
• 2023

The purpose of this study is to predict how the actual accident changes by reconstructing the accident with an Autonomous Emergency Braking system (AEB) based on the actual accident of the LTAP-OD (Left Turn Crossing Path - Opponent Direction) intersection. A virtual AEB sensor was developed, and 150 head-on collision accident reports were secured to the insurance company to reconstruct the accident. As a result of the accident type analysis, a total of 13 types of head-on collision accidents were derived, and it is the LTAP-OD intersection accident with the highest frequency. In the LTAP-OD intersection accident, the simulation was conducted by applying the virtual AEB of each vehicle, the accident rate decreased by 90% or more when the AEB of the left-turn vehicle was applied, and the accident rate decreased by 50%. In addition, the most frequent collision types in LTAP-OD accidents were the front bumper on the driver's side of a vehicle going straight and the front bumper on the passenger's side of a vehicle turning left.

• 한국정보시스템학회지:정보시스템연구
• /
• 제32권3호
• /
• pp.225-251
• /
• 2023

Purpose The purpose of this study is to examine the future direction of in-vehicle app development and service, the relationship between potential customers' intention to use and the factors that affect it was explored. It was also checked whether the two types of app development platform and the experience of the existing smartphone app platform had a moderating effect on these relationships. Design/methodology/approach Data was gathered through surveys, collecting responses from 904 potential consumers of vehicle app services in Korea. Structural equation modeling was utilized to analyze the data. Findings According to the empirical analysis result, it was found that potential customers considered enjoyment as the most important benefit factor in in-vehicle app service, and the most important external factor affecting enjoyment was functional compatibility with smartphone. The type of vehicle app development platform did not have a meaningful moderating effect on the factor relationship, whereas the smartphone app platform experience showed a meaningful moderating effect on the relationship between factors. It was analyzed that the risk of app performance, personal information privacy, and driving safety data did not have a negative effect on the intention to use the vehicle app service.

• 한국도로학회논문집
• /
• 제18권5호
• /
• pp.105-115
• /
• 2016

PURPOSES : This study was initiated to analyze the characteristics of bus traffic accidents, by bus types, using the decision tree in order to establish customized safety alternatives by bus types, including the intra-city bus, rural area bus, and inter-city bus. METHODS : In this study, the major elements involved in bus traffic accidents were identified using decision trees and CHAID algorithm. The decision tree was used to identify the characteristics of major elements influencing bus traffic accidents. In addition, the CHAID algorithm was applied to branch the decision trees. RESULTS : The number of casualties and severe injuries are high in bus accidents involving pedestrians, bicycles, motorcycles, etc. In the case of light injury caused by bus accidents, different results are found. In the case of intra-city bus accidents, the probability of light injury is of 77.2% when boarding a non-owned car and breaching of duty to drive safely are involved. In the case of rural area bus accidents, the elements showing the highest probability of light injury are boarding an owned car, vehicle-to-vehicle accidents, and breaching of duty to drive safely. In the case of intra-city bus accidents, boarding owned car, streets, and vehicle-to-vehicle accidents work as the critical elements. CONCLUSIONS : In this study, the bus accident data were categorized by bus types, and then the influential elements were identified using decision trees. As a result, the characteristics of bus accidents were found to be different depending on bus types. The findings in this study are expected to be utilized in establishing effective alternatives to reduce bus accidents.

• 스마트미디어저널
• /
• 제10권1호
• /
• pp.70-78
• /
• 2021

청각정보는 시각에 비해 방향에 제한을 받지 않으므로 자동차 내에서 긴급한 알림이나 경고의 목적으로 활용된다. 그러나 청각장애 운전자는 청각정보를 인지할 수 없으므로 이를 대체하기 위해 다양한 시각화 방법이 시도되고 있다. 청각정보를 시각화할 때는 시각에 집중되는 인지과부하를 방지하기 위해 중요한 정보만을 선별해서 제공하여야 하며, 이를 위해서는 자동차 내 청각정보의 유형 분석이 우선되어야 한다. 본 연구에서는 청각장애 운전자의 운전상황 관찰을 통해 자동차 내에서 경험하는 청각정보를 수집하였다. 수집된 33가지의 청각정보는 전문가 그룹에 의한 개방적 카드소팅을 통해 12개의 그룹으로 분류되었으며, 그룹 간 상대적 중요도 비교를 통해 4개의 계층으로 분석하였다. 제시된 자동차 내 청각정보 유형은 청각정보를 시각 또는 촉각으로 변환하여 표시할 때 중요한 정보를 선별하기 위한 가이드 라인으로서 활용이 가능하다. 본 연구는 청각장애 운전자를 대상으로 일상에서의 실제 운전상황 관찰에 의한 사용자 경험 분석이 이루어졌다는 데 의의가 있다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2008년도 춘계학술대회 논문집
• /
• pp.115-115
• /
• 2008