• 한국도로학회논문집
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• 제12권4호
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• pp.47-51
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• 2010

도로를 주행하는 차량들을 구분하는 차종자료는 도로 및 포장의 설계와 관리 등 여러 분야에서 기초자료로 활용되고 있다. 본 연구에서는 차종구분에 차량높이라는 분류기준을 적용하기 위해 주행하는 차량의 높이를 계측할 수 있는 방법을 고안하고 현장에 장비를 설치한 후 실험을 통해서 차량길이와 차량최고높이 자료를 획득하였다. 차량높이 측정과 동시에 동영상을 촬영하여 국토해양부 12종 차종분류에 의거하여 차종분류 기준값을 작성하였다. 영상을 통해 작성된 차종자료 기준값과 측정된 차량길이와 차량높이를 토대로 판별함수를 이용한 차종분류값을 서로 비교한 결과 88.6%의 차종정확도를 확인하였다. 이를 통해 차량높이라는 분류기준을 적용하여 차종분류에 활용할 수 있는 방안을 제시하였다.

• 한국자동차공학회논문집
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• 제18권5호
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• pp.91-99
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• 2010

The center of gravity on vehicle is a fundamentally important point for assessing and measuring the characteristics of vehicle dynamics. Especially, the center of gravity height on vehicles is the closest factor with respect to rollover accidents in a social issue nowadays. In this paper, the center of gravity height in conjunction with vehicle parameters of vehicle weight, driving axle and roof height after measured by vehicle weight and loading location by means of VCGM developed by KATRI with good performance that the accuracy was less than 0.6% and repeatability 0.3% for vehicles being used in the whole world was observed. As a result of study, the location of center of gravity height on vehicle was able to be estimated with only roof height on vehicle.

• 한국자동차공학회논문집
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• 제10권6호
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• pp.178-186
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• 2002

3-D numerical studies are performed to investigate the effect of the trunk height and approaching air velocities on the pressure distribution of notchback road vehicle. For this purpose, the models of test vehicle with four different trunk heights are introduced and PHOENICS, a commercial CFD code, is used to simulate the flow phenomena and to estimate the values of pressure coefficients along the surface of vehicle. The standard k-$\xi$ model is adopted for the simulation of turbulence. The numerical results say that the height variation of trunk makes almost no influence on the distribution of the value of pressure coefficient along upper surface but makes very strong effects on the rear surface. That is, the value of pressure coefficient becomes smaller as the height is increased along the rear surface and the bottom surface. Approaching air velocity make no differences on pressure coefficients. Through the analysis of pressure coefficient on the vehicle surfaces one tried to assess aerodynamic drag and lift of vehicle. The pressure distribution on the rear surface affected more on drag and lift than pressure distribution on the front surface of the vehicle does. The increase of trunk height makes positive effects on the lift decrease but negative effects on drag reduction.

• 소음진동
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• 제5권2호
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• pp.197-206
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• 1995

Microphone array is designed to measure the equivalent source height of vehicle noise. The equivalent source position is defined for an arbirary distribution of acoustic sources above a perfectly reflecting plane and a microphone array for its measurement is developed. The normalized errors of the measured equivalent source heights are defined including the effects of background noise, the geometric near field, and source size. Normalized errors of the measured source heights obtained by a nemerical simulation for each parameter lead to optimization of the microphone spacing and to the design of an array which gives the equivalent source height as a function of frequency. The performance of the designed array is verified using the stationary loudspeaker experiments.

• 대한기계학회논문집B
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• 제33권12호
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• pp.961-967
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• 2009

A 3-dimensional numerical investigation of a WIG effect vehicle with DUP (direct underside pressurization) is performed to predict aerodynamic characteristics and the static height stability. DUP can considerably reduce take-off speed and minimize the hump drag while the vehicle accelerates on the water to take off. The DUP of the model vehicle, Aircat, consists of a propeller in the middle of the fuselage and an air chamber under the fuselage. The air accelerated by the propeller comes into the camber through the channel in the middle of fuselage and augments lift by changing its dynamic pressure to static pressure dramatically. However, the air accelerated by a propeller produces excessive drag and reduces static height stability.

• Journal of Multimedia Information System
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• 제6권3호
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• pp.119-124
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• 2019

In this paper, a method of detecting vehicle plates through depth pictures is proposed. A vehicle plate can be recognized by detecting the plane areas. First, plane factors of each square block are calculated. After that, the same plane areas are grouped by comparing the neighboring blocks to whether they are similar planes. Width and height for the detected plane area are obtained. If the height and width are matched to an actual vehicle plate, the area is recognized as a vehicle plate. Simulations results show that the recognition rates for the proposed method are about 87.8%.

• 산업기술연구
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• 제22권B호
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• pp.27-34
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• 2002

3-D numerical studies are performed to investigate the effect of the air dam height and approaching air velocities on the pressure distribution of notchback road vehicle. For this purpose, the models of test vehicle with four different air dam heights are introduced and PHOENICS, a commercial CFD code, is used to simulate the flow phenomena and to estimate the values of pressure coefficients along the surface of vehicle. The standard $k-{\varepsilon}$ model is adopted for the simulation of turbulence. The numerical results show that the height variation of air dam makes almost no influence on the distribution of the value of pressure coefficient along upper and rear surface but makes strong effects on the bottom surface. That is, the value of pressure coefficient becomes smaller as the height is increased along the bottom surface. Approaching air velocity makes no differences on pressure coefficients. Through the analysis of pressure coefficient on the vehicle surface, one tries to assess aerodynamic drag and lift of vehicle. The pressure distribution on the bottom surface affects more on lift than the pressure distribution on the upper surface of the vehicle does. The increase of air dam height makes positive effects on the lift decrease but no effects on drag reduction.

• 한국산학기술학회논문지
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• 제14권2호
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• pp.561-566
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• 2013

본 연구는 유압식 자동차고 조절장치 개발 및 상기장치를 일반 상용차에 적용시키기 위한 것이다. 운전자의 승차감에 영향을 줄 진동특성을 주행시험을 통하여 파악하고자 하였다. 유압식 자동차고 조절장치는 현재 승용차에 가장 많이 사용되고 있는 맥퍼슨 형식의 형태로 설계되었다. 맥퍼슨 형식의 순정현가장치, 튜닝현가장치, 유압식 자동차고 조절장치를 장착한 차량으로 시험을 수행하였다. 자동차에 전달되는 진동특성은 랜덤형태이므로 PSD(Power Spectrum Density)값을 비교하였다.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.133-139
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• 2009

When two cars impact each other, it is usually known smaller vehicle's passenger likely to be more seriously injured than bigger one's. Generally it is known that SUVs and Light Truck Vehicles (LTVs) are bigger and heavier than passenger vehicles and their drive height such as bumper rail and side member, and front end stiffness are higher than those of passenger vehicles. Because of these characteristics the occupants of passenger vehicle struck by SUVs or LTVs are more likely to experience severe injury or fatal injury. To evaluate SUV and LTV's aggressivity to passenger vehicle, SUV to passenger vehicle and LTV to passenger vehicle head-on crash test have been carried out. And finally the way how to reduce incompatibility between SUV and LTV and passenger vehicles is suggested.

• 한국ITS학회 논문지
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• 제10권5호
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• pp.47-52
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• 2011

본 연구는 차량 제원이 유사한 2축 차량의 차종분류에 있어서 정확도를 높이고자 차량 외형의 높이 프로파일을 이용한 차종분류 방안을 제시했다. 차종별 교통량 자료 생성은 도로를 주행하는 차량을 대상으로 AVC장비에서 계측되는 차량 제원들인 축수, 축간거리, 차량길이, 오버행 등을 활용하여 12종 분류 체계에 의해서 분류되고 있다. 그러나 차량 축이 2개인 2축 차량(1~4종 차량)의 경우 승용차(1종)의 다양화, 대형화로 인하여 화물수송용 차량(3종, 4종)의 제원과 유사해짐에 따라 기존 차량분류인자(축수, 축간거리, 차량길이 등)에 의한 차종분류 시 분류 오류가 발생할 수 있다. 이에 본 연구는 이러한 분류상의 한계를 극복하고자 차량 외관의 높이 프로파일 값을 통하여 주행차량의 형태를 파악하고 이를 이용한 차종분류 방법을 제시하였다. 그리고 현장실험을 통하여 제안된 방법의 정확도를 검증하였다.