• Journal of Korean Society of Transportation
• /
• v.19 no.6
• /
• pp.119-129
• /
• 2001

본 연구는 국내의 화물차(이하 트럭) 특성, 도로 조건과 주행 저항이 고려된 트럭 성능 곡선 산출식의 매개변수를 추정하기 위하여 수행되었다. 이를 위해 국내 대표트럭을 선정하고 경사지 진입속도를 산출하였다. 국내 대표트럭의 선정은 자동차 등록현황 자료를 토대로 하여 트럭 중량/마력비에 대한 누적 분포를 작성하고 이 중에서 주요 차종(적재 중량 11톤 이상)의 총중량은 과적 검문소 자료로 보정하여 이루어졌다. 경사지 진입속도는 도별 평지부 직선 구간을 한 곳씩 선정하여 4차로도로와 2차로도로에서 수집되는 자료를 분석하여 산출하였다. 트럭 성능 곡선 산출식을 정립하기 위해 오르막 한계속도$(V_x)$ 산출식을 정리한 뒤 총중량(W), 엔진성능(P), 경사도(G)는 독려 변수로 k, $f_{rc}$, $f_{rv}$, $\Phi$는 매개변수로 설정하였다. 현장조사를 통해서 오르막 한계속도에 도달한 트럭의 총중량과 엔진성능, 속도, 경사도 등의 자료를 수집하여 매개변수 산출에 이용하였다. 마지막으로 추정된 매개변수를 이용하여 트럭 성능 곡선을 도출하였다.

• Journal of Korean Society of Transportation
• /
• v.25 no.5
• /
• pp.79-90
• /
• 2007

In determining vertical grades in highway alignment design, engineers usually consider heavy vehicle performances on the upgrade. Heavy vehicles usually experience speed reduction on the upgrade and with recent years weight/horsepower improvements for heavy vehicles the speed reduction shows some change. However, in spite of the weight to horsepower improvements for the design vehicles from 300lb/HP to 200lb/HP in the AASHTO, there was no change in the maximum vertical grades. Therefore, a review of the maximum vertical grade reflecting existing heavy vehicle performances is required. In particular, in South Korea where highways pass through lots of mountaineous terrain, the maximum vertical grades must be reviewed throughly. In this study the amount of heavy vehicle performances during past decades were investigated and their expected impacts on highway vertical alignment designs were subsequently analyzed. A worldwide terrain analysis and international design standards were compared to set South Korean vertical grade standards. Traffic flow simulation Vissim was utilized to simulate vehicular flows on the upgrade and new truck performance curves on the grades were developed. Based on the new curve, it was decided that $1{\sim}2%$ increase of the maximum vertical grades could be allowed.

• Journal of Korean Society of Transportation
• /
• v.24 no.5 s.91
• /
• pp.35-44
• /
• 2006

Acceleration and deceleration curves have been used for design purposes worldwide. The curve in design level has been regarded as an single deterministic curve to be used for design of climb lanes. It should be noted that the curve was originally made using ideal driving truck and that the curve is applied during design based on the assumption of no difference between ideal and real driving conditions. However. observations show that aged vehicles and lazy behavioring drivers nay make lower performance of vehicles than the ideal performance. The present paper provides the results of truck speeds at climbing lanes then probabilistic variation of acceleration and deceleration corves. For these purposes. a study about identification of vehicle makers, and weights for trucks at freeway toll gates and then observation of vehicle-following speed were performed. The 85%ile results obtained were compared with the deterministic performance curves of 180, 200, and 220 Ib/hp. It was identified that the performance of 85%ile results obtained from vehicle-following-speed observations were lower than one from deterministic performance curves. From these results, it may be concluded that at the beginning Point of climbing lanes additional $16.19{\sim}67.94m$ is necessary and that at the end point of climbing lanes $53.12{\sim}103.24m$ of extension is necessary.

• Geophysics and Geophysical Exploration
• /
• v.23 no.4
• /
• pp.230-242
• /
• 2020

We performed a magnetotelluric (MT) survey to delineate the geological structures below the depth of 20 km in the Gyeongju area where an earthquake with a magnitude of 5.8 occurred in September 2016. The measured MT data were severely distorted by electrical noise caused by subways, power lines, factories, houses, and farmlands, and by vehicle noise from passing trains and large trucks. Using machine-learning methods, we classified the MT time series data obtained near the railway and highway into two groups according to the inclusion of traffic noise. We applied three schemes, stochastic gradient descent, support vector machine, and random forest, to the time series data for the highspeed train noise. We formulated three datasets, Hx, Hy, and Hx & Hy, for the time series data of the large truck noise and applied the random forest method to each dataset. To evaluate the effect of removing the traffic noise, we compared the time series data, amplitude spectra, and apparent resistivity curves before and after removing the traffic noise from the time series data. We also examined the frequency range affected by traffic noise and whether artifact noise occurred during the traffic noise removal process as a result of the residual difference.