• 대한교통학회지
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• 제12권1호
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• pp.55-73
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• 1994

The objective of this research is to evaluate the pedestrian signal time involving green and flashing green times. The minimum pedestrian green indication should give time for pedestrian to start crossing safely, and the flashing green indication should give time to complete the crossing. An average pedestrian crossing speed of 1.1(m/s) was estimated by analyzing the field data which was slower than the 1.2(m/s) currently used. Furthermore, the study proposed that design speed for the flashing green time should be slow speed for considerations pedestrian safety, not the average speed. The 0.78-1.01(m/s) of pedestrian speed was estimated at the elementary school areas that indicated 0.2(m/s) slower than the other areas. The pedestrian starting time (perception/reaction time) and time headway from front to back of herd was estimated to determine minimum pedestrian green time. the pedestrian starting time was estimated to determine minimum pedestrian green time. The pedestrian starting time was ranged 2.52-4.29 seconds. The time interval between the pedestrian rows was found to be 1.25-1.86 seconds, which declines as the pedestrian rows increases, The equation to calculate the pedestrian signal, which declines as the pedestrian rows increases. The equation to calculate the pedestrian signal time is proposed using the pedestrian starting time, the time interval between the pedestrian rows, and pedestrian crossing speed given area types (commercial, business, mixed, and elementary school areas), number of both-directional pedestrians for a cycle, crosswalk length and width.

• 한국자동차공학회논문집
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• 제19권5호
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• pp.82-91
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• 2011

In this paper, a planar model for mechanics of a vehicle/pedestrian collision incorporating road gradient is derived to evaluate the pre-collision speed of vehicle. It takes into account a few physical variables and parameters of popular wrap and forward projection collisions, which include horizontal distance traveled between primary and secondary impacts with the vehicle, launch angle, center-of-gravity height at launch, distance from launch to rest, pedestrian-ground drag factor, the pre-collision vehicle speed and road gradient. The model including road gradient is derived analytically for reconstruction of pedestrian collision accidents, and evaluates the vehicle speed from the pedestrian throw distance. The model coefficients have physical interpretations and are determined through direct calculation. This work shows that the road gradient has a significant effect on the evaluation of the vehicle speed and must be considered in accident cases with inclined road. In additions, foreign/domestic empirical cases and multibody dynamic simulation results are used to construct a least-squares fitted model that has the same structure of the analytical one that provides an estimate of the vehicle speed based on the pedestrian throw distance and the band within which the vehicle speed would be expected to be in 95% of cases.

• 한국기계가공학회지
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• 제6권3호
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• pp.71-76
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• 2007

The fatalities of pedestrian account for about 40.0% of all fatalities in Korea 2005. Vehicle-Pedestrian accident generates trajectory of pedestrian. In pedestrian involved accident, the most important data to inspect accident is throw distance of pedestrian. The throw distance of pedestrian can be influenced by many variables. The variables that influence trajectory of pedestrian can be classified into vehicular factors, pedestrian factors, and road factors. Vehicular factors are the frontal shape of vehicle, impact speed of vehicle, the offset of impact point. Many studies have been done about the relation between impact speed and throw distance of pedestrian. But the influence of the offset of impact point was neglected. The influence of the offset of impact point was analyzed by Working Model, and the trajectory of pedestrian, dynamic characteristics of multi-body were analyzed by PC-CRASH, a kinetic analysis program for a traffic accident. Based on the results, the increase of offset reduced the throw distance of pedestrian. However box type vehicle just like bus, the offset of impact point did not influence the throw distance of pedestrian considerably.

• 한국ITS학회 논문지
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• 제15권5호
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• pp.54-61
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• 2016

본 연구는 차량-보행자 사고시 보행자의 신장에 따라 보행자의 두부가 승용차의 전면유리에 닿을 수 있는 최저 속도를 제시하기 위하여 수행되었다. 마디모(MADYMO) 프로그램을 사용하여, NF쏘나타 차량에 대하여 보행자의 신장을 160cm, 170cm 180cm로 구분하여 평가하였다. 평가 결과, 승용차의 최저 속도값은 보행자의 신장이 160cm인 경우 약 49km/h, 170cm일 때 약 41km/h, 그리고 180cm일 때 약 29km/h로 나타났다. 이러한 값은 승용차 대 보행자 교통사고에서 승용차의 전면유리에 보행자 두부의 충돌흔적이 있을 시 속도추정의 중요 자료로 활용할 수 있을 것으로 기대된다.

• 한국기계가공학회지
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• 제6권3호
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• pp.105-111
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• 2007

The type of pedestrian accident can be characterized by vehicular frontal shape and the height of pedestrian. The trajectory of pedestrian after collision by passenger car is different from that by bus due to vehicular frontal shape. The frontal shape of SUV vehicles is dissimilar to passenger car and bus. So, the trajectory and throw distance of pedestrian by SUV vehicles is not the same of passenger car and bus. In this paper, a series of pedestrian kinetic simulation were conducted to inspect the difference in throw distance between SUV vehicle and passenger car and bus by PC-CRASH that is the program for kinetic analysis of articulated body. From the results, if the height of pedestrian is taller than 1.70m, there is no difference in throw distance between SUV vehicle and passenger car, but if the height of pedestrian is about 1.55m throw distance of SUV vehicle is about 4m longer than that of passenger car at each impact speed. The throw distance of pedestrian by Bus is shorter than that of passenger car and SUV at each impact speed.

• 국제초고층학회논문집
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• 제11권4호
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• pp.301-314
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• 2022

Various studies have been conducted on pedestrian-level wind environments around buildings. With regard to the speed-up mechanism of pedestrian-level winds, there are references to downwash effect due to the vertical pressure gradient of boundary layer flow and venturi effect due to flow blocking by the building. Two factors contribute to increase or decrease of downwash effect: change in twodimensional / three-dimensional air flow pattern (Type 1) and change in downwash wind speed due to building size that does not accompany change in airflow pattern (Type 2). Previous studies have shown that downwash effect has a greater influence in increasing or decreasing the area of strong wind than venturi effect. However, these considerations are derived from the horizontal mean wind speed distribution at pedestrian level and are not the result of three-dimensional flow field around the building. Therefore, in this study, Computational Fluid Dynamics using Large Eddy Simulation were performed to verify the downwash phenomena that contributes to increase in wind speed at pedestrian level.

• 대한교통학회지
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• 제24권5호
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• pp.57-66
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• 2006

본 연구에서는 보행신호시간에 대한 국내 외 사례 분석 광범위한 보행자특성조사, 보행신호시간 운영방법에 대한 설문조사 등을 통해 보행자수요, 보행자특성 및 주변지역 특성 등을 고려한 보행신호시간 산정식을 제안하였으며, 실제 현장 자료를 이용하여 현재의 보행신호시간과 본 연구의 제안식에 의해 산출된 보행신호시간을 비교, 분석하였다. 보행자특성조사는 횡단보행속도와 인지반응시간에 대해 실시하였다. 서울시 총 16개 지역을 선정하여 토지이용, 도로 폭, 연령, 개인/그룹, 성별에 따라 자료를 수집하였다. 분석결과 서울시 보행자의 평균 횡단보행속도는 1.30m/s, 15th percentile속도는 1.11m/s로 나타났다. 인지반응시간은 평균 2.24초로 조사되었다. 횡단보행속도는 토지이용. 도로 폭, 연령, 개인/그룹, 성별에 따라 차이가 있었고, 인지반응시간은 도로 폭, 연령, 개인/그룹에 따라 차이가 있었다. 또한 각 분석결과에 대한 통계 점정을 실시하여 본 연구에서 조사된 자료의 신뢰성을 확보하였다 따라서 이 자료들은 추후 관련 연구에 기본 자료로 활용이 가능할 것이다. 보행자특성 현장조사 및 보행자 설문조사 분석결과를 종합해 보면 현재의 보행신호시간과 그 운영방법은 개선이 시급한 것으로 분석됨에 따라 본 연구에서는 보행자의 수요, 보행자특성 및 횡단보도 기하구조 등을 고려한 합리적인 보행신호시간을 산출할 수 있는 산정식을 개발하였다

• 동력기계공학회지
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• 제13권2호
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• pp.56-62
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• 2009

The fatalities of pedestrian account for about 40.0% of all fatalities in Korea 2005. Vehicle-Pedestrian accident generates trajectory of pedestrian. In pedestrian involved accident, the most important data to inspect accident is throw distance of pedestrian. The throw distance of pedestrian can be influenced by many variables. But existing studies have been done for simple factors. The variables that influence trajectory of pedestrian can be classified into vehicular factors, pedestrian factors, and road factors. The trajectory of pedestrian, dynamic characteristics of multi-body were analyzed by PC-CRASH, a kinetic analysis program for a traffic accident. PC-CRASH enables an analyst to investigate the effect of many variables. The influence of the offset of impact point was analyzed by Working Model. Based on the results, the variables that influence trajectory of pedestrian were vehicular frontal shape, vehicular impact speed, the offset of impact point, the height of pedestrian, friction coefficients of pedestrian. However the weight of pedestrian did not affect trajectory of pedestrian considerably.

• Journal of Multimedia Information System
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• 제6권1호
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• pp.1-6
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• 2019

In the field of industrial applications, the real-time performance of the target detection problem is very important. The most serious time consumption in the pedestrian detection process is the extraction phase of the candidate window. To accelerate the speed, in this paper, a fast extraction of pedestrian candidate window based on the BING (Binarized Normed Gradients) algorithm replaces the traditional sliding window scanning. The BING features are extracted with the positive and negative samples and input into the two-stage SVM (Support Vector Machine) classifier for training. The obtained BING template may include a pedestrian candidate window. The trained template is loaded during detection, and the extracted candidate windows are input into the classifier. The experimental results show that the proposed method can extract fewer candidate window and has a higher recall rate with more rapid speed than the traditional sliding window detection method, so the method improves the detection speed while maintaining the detection accuracy. In addition, the real-time requirement is satisfied.

• 한국안전학회지
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• 제23권4호
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• pp.90-98
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• 2008

Presently, pedestrian's signal time models in korea are not considering Vulnerable-Pedestrian. So, the safety of Vulnerable-Pedestrian is being threatener and the number of accidents is increasing. Besides, the existing operational system for pedestrians can't offer the cross signal time in road corresponded the changing environment when the school zone is revitalized and the Silver zone is introduced for Vulnerable-Pedestrian. Conclusively, Vulnerable-Pedestrian's signal time models which are able to consider classified Vulnerable-Pedestrian speed, Vulnerable-Pedestrian perception-reaction time, Vulnerable-Pedestrian Spare(congestion-delay) time are suggested by the result of experiment in virtual crosswalk. the application of suggested models in this study to the site. It is possible to use as a basic stuff on study of pedestrian's signal time and expected to contribute the safety and mobility in future.