• 자동차안전학회지
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• 제11권4호
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• pp.39-49
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• 2019

Autonomous vehicle is a car which drives itself without any human interaction. SAE provides technical definitions for autonomous and international standards for test evaluation. Accordingly, automobile industry is actively researching development and evaluation of various ADAS (Advanced Driver Assistance Systems), : representative technology of autonomous technology. Recently, ADAS is in the commercialization level such as ACC, LKAS, AEB, and HDA etc. And it also has issues about safety evaluation. The purpose of HDA in ADAS is reduced the driving load on highway. It has a function which can maintain lane keeping and control distance from forward vehicle. This function is evaluated to be useful for accident prevention. Therefore, this paper proposes the safety evaluation scenario of HDA, considering the domestic highway design criteria and the situation that may arise on the actual highway. We compared and analyzed the data acquired through simulation and actual vehicle test. And verified the reliability of the proposed safety evaluation scenario. The verified result is expected safety evaluation of HDA is possible even under the bad condition, which cannot be tested.

• 품질경영학회지
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• 제45권4호
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• pp.981-994
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• 2017

Purpose: In this study, the reliability growth management procedures for armed vehicle is suggested and an illustrative case study of launcher system is given. Methods: Crow-AMSAA model is adopted to manage reliability growth of armed vehicle using failure data acquired from development test phase to field operation phase. Between the development test phase and the production phase, the suggested reliability growth procedures for armed vehicle entails accelerated life test of the selected module whose design is changed to improve its reliability for assuring the target system reliability. And it can be verified through estimating the system reliability based on the failure data of field operation phase. Results: It is shown that the proposed reliability growth management procedures are effective for armed vehicle based on the case study of launcher system. After estimating the reliability of launcher system at every development test, some items are selected to change their designs for improving reliability. Accelerated life test is performed to prove the reliability improvement and finally it is verified through the field operation. Conclusion: The reliability growth management procedures for armed vehicle is suggested and the case study of launcher system shows it can be effective for managing the reliability growth of the armed vehicle.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.308-313
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• 2005

An urban railway vehicle has a characteristics such as that a lot of passenger use it and the major of passenger is standee. The ride comfort of standee is greatly influenced by the lateral dynamic characteristics of vehicle. So the lateral vibration is important factor for the improvement of ride comfort. In this study, vibration test of railway vehicle is carried out under the same condition of field driving to find out the major factor of vibration. By considering the test results under the various driving condition, the vibrational characteristics of vehicle is verified.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1998년도 추계학술대회 학술발표 논문집
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• pp.274-281
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• 1998

This paper describes a visual control of autonomous vehicle using neural network. Visual control for road-following of autonomous vehicle is based on road image from camera. Road points on image are inputs of controller and vehicle speed and steering angle are outputs of controller using neural network. Simulation study confirmed the visual control of road-following using neural network. For experimental test, autonomous electric vehicle is designed and driving test is realized

• 대한인간공학회지
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• 제32권3호
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• pp.217-227
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• 2013

Objective: The purpose of this study was to analyze 'response time', 'peak response time' and 'overshoot value' for each muscle by applying the EMG signal to the vehicle response in ISO 7401 and to quantify the response of the driver according to vehicle characteristics by comparing vehicle characteristics and muscle responses of the driver. Background: The Open-loop test defined in international standards ISO 7401 is the only method for evaluating the performance of the vehicle. However, this test was focused only on mechanical responses, not driver's ones. Method: One skilled male driver(22 yrs. experience) was participated in this experiment to measure muscle activities of the driver in transient state. Then the seven muscle signals were applied to calculate 'response time', 'peak response time', and 'overshoot value'. Results: In the analyses of the EMG data, the effects of vehicle type and muscle were statistically significant on the 'response time' and 'peak response time'. Also, the effects of vehicle type, muscle, and lateral acceleration level were statistically significant on the 'overshoot value' in this study. According to the analyses of the vehicle motion data, vehicle motion variable(LatAcc, Roll, YawVel) was statistically significant on the 'response time' and vehicle type, vehicle motion variable, and lateral acceleration level were statistically significant on the 'peak response time', respectively. Conclusion: In the analyses of the 'response time' and 'overshoot value', the data of muscle activities(EMGs) was better index that could evaluate the vehicle characteristic and performance than the data of vehicle motion. In case of peak response time, both EMG and vehicle motion data were good index. Application: The EMGs data from a driver might be applicable as index for evaluation of various vehicle performances based on this study.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.1006-1010
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• 2017

본 논문은 발사체의 지상대기 및 운용 중 격실 내부의 열제어 및 화재/폭발 방지를 위해서 적용되는 열제어/화재안전계에 대한 설계 및 시험에 대해서 기술한다. 고려된 시스템은 한국형발사체 개발의 일환으로 진행되고 있는 시험발사체의 열제어/화재안전 시스템으로 이 시스템은 나로호의 경험을 토대로 고압 시스템을 적용한다. 고압 및 저압 시스템의 선정은 발사대의 가스공급 설비 및 발사체의 특성을 고려해서 선정하며 이에 따라 시스템의 구성도 달라진다. 결과적으로 개발된 시스템은 시험을 통해서 초기의 설계 조건을 만족하는 결과를 얻을 수 있음이 확인되었으며, 이러한 시스템은 한국형발사체의 개발에 그대로 확장되어 적용될 예정이다.

• 한국자동차공학회논문집
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• 제24권6호
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• pp.635-641
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• 2016

Regenerative braking performance of an electrically powered vehicle is closely related to driving distance per battery charge. An electric vehicle uses appropriate amounts of mechanical braking force and electromagnetic regenerative braking force to recover energy and increase driving efficiency. In particular, when it drives on a downhill road, energy recovery rate is maximized through regenerative braking during coasting based on the mass inertia of the vehicle. Since an electric two-wheeled vehicle covered in this paper is lighter than an electric four-wheeled vehicle, the improvement of its driving distance per battery charge through regenerative braking is different from an electric four-wheeled vehicle. This study compared the driving characteristics of an electric two-wheeled vehicle based on regenerative braking. Two driving test modes were simulated with a chassis dynamometer system. By analyzing the measurement of a chassis dynamometer, the driving characteristics of a two-wheel electric vehicle, such as driving efficiency, were analyzed. In addition, test results were reviewed to draw the limitations of conventional test methods for regenerative braking performance of an electric two-wheel vehicle.

• International Journal of Automotive Technology
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• 제6권4호
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• pp.351-357
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• 2005

Development of a real-time simulation model for high-speed and multibody tracked vehicles is difficult because they involve hundreds of highly nonlinear equations. In the development of a reliable tracked vehicle model for real-time simulation, it is helpful to use an off-line tracked vehicle model developed by considering all the degrees of freedom of each element. This paper presents a step-by-step procedure for the development of a real-time simulation model based on the off-line tracked vehicle model. The road input data, Profile IV, is used for the real time simulation and simulation results are compared with vehicle test results obtained in the military test field. It is noted that the simulation results are quite close to the test results.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.207-210
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• 2014

This paper is concerned with the prediction of lift-off acoustic loads for a launch vehicle. Intense acoustic load is generated when a launch vehicle is lifted off, and it can induce vibrations of a launch vehicle which cause damage or malfunction of a launch vehicle and a satellite. Lift-off acoustic loads of NARO are predicted by the modified Eldred's second method and the result is compared with the measured data in flight test. The prediction shows similar peak and shape of spectrum to the test data, but some discrepancy can be observed due to the predicted margin. In order to reduce such discrepancy, the sound pressure levels with four source distribution assumptions are calculated. Also, the surface diffraction effects are considered in the predict ion of lift-off acoustic loads, and the predicted result is more similar to the test data.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 추계학술대회 논문집
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• pp.364-369
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• 2012

The vehicle sound classified into driving sound due to power-train, operating sound due to electric motor like sunroof, door lock and electronic sound. These vehicle sound has various features depend on the characteristic of sound that user required. And it based on cultural and regional difference of user. In this study, the user required vehicle sound characteristics for luxury sedan was investigated in overall viewpoint. And virtual target sound was developed through the result of user preference investigation. Next, Jury test was carried out in Germany, USA and Korea for evaluating the target sound. And the regional and individual difference of preference was analyzed through the result of jury test. This result of research will be contributed to design of vehicle sound quality and target sound setting.