Parking lots are environments in which various types of vehicles such as passenger cars, trucks, and personal mobility (PM) devices coexist. Despite numerous studies analyzing parking lot crash characteristics, PM devices have received limited attention. Analyzing parking lot crash characteristics involving PMs is essential, given that the market penetration rate of PM is increasing. This study quantitatively analyzed the severity characteristics of vehicle-to-PM crashes in parking lots by aggregating the number of crashes and identified factors influencing crash severity through the development of an ordered probit model. According to the quantitative analysis results, PM users experienced a higher crash severity owing to insufficient personal protective equipment. Additionally, crashes involving parked or illegally parked PMs tended to have a lower severity than those involving PMs being ridden. The developed crash severity model identified several key factors, including crashes related to illegally parked vehicles, crashes in which a vehicle was at fault for a collision with a parked PM, cases in which the vehicle type of the at-fault driver was a passenger car, and cases in which the at-fault driver was a female. A higher probability of property damage crashes, rather than injury or fatal crashes, was observed in cases involving parked or illegally parked PMs owing to lower relative speeds. Passenger cars generally have shorter braking distances than trucks or buses, allowing quicker responses to sudden situations. A female at-fault driver may experience longer perception–reaction times, potentially increasing the probability of injury or fatal crashes. The findings of this study can provide foundational data for revising ordinances or laws to enhance parking lot safety or preliminary data for developing parking lot management systems. Furthermore, the identified crash severity factors can be prioritized to develop effective measures for crash prevention and severity reduction in parking lots.
Current portable reference equipment used to evaluate the performance of vehicle detectors can collect traffic volume and speed only for the outermost lanes in each direction. Passing vehicles on the other lanes are manually counted by reviewing the recorded videos. Consequently, only traffic volume—without vehicle speed—is used as a reference value. This method is time-consuming for comparing the performance data from the equipment with the reference data and can compromise the performance evaluation. This study aims to enhance the efficiency of vehicle detection system (VDS) performance evaluations by developing multilane portable reference equipment that can accurately collect traffic information for lanes beyond the outermost lane or for more than two lanes. This study introduced the core technologies of multilane portable reference equipment and compared and analyzed the measurement accuracy of the developed equipment against data from fixed reference equipment operated by the Intelligent Transportation System (ITS) Certification and Performance Evaluation Center, following ITS performance evaluation criteria. The data from the fixed reference equipment were considered the true values, providing a basis for evaluating the accuracy of the measurements by the developed equipment. First, the accuracy of the vehicle length was determined by driving four test vehicles, each measuring 7,085 mm in length, 24–29 times in each lane. The accuracy was calculated by comparing the vehicle length data obtained from the fixed reference equipment with the actual vehicle length. A confidence interval was established for this accuracy. To assess the accuracy of the speed and occupancy time in relation to the accuracy of the analyzed vehicle length, we evaluated the error range of the vehicle length according to variations in speed and occupancy time. This analysis was based on the following relationship equation: “vehicle length = speed × occupied time – sensor spacing.” The analysis used data from approximately 16,000 vehicles, including the speed, occupancy time, and vehicle length, collected between 8:00 am and 12:00 pm on August 8, 2024. The principle behind measuring traffic volume and vehicle speed using multilane portable reference equipment involves detecting a vehicle by analyzing the time difference between the driver and passenger tires. The vehicle speed was calculated using the installation angle of the tire detection sensor and trigonometric functions. An analysis of the measurement accuracy revealed that the traffic volume accuracy of the outermost lane (the fourth lane) was 100% during both day and night. The speed accuracy was 98.8% during the day and 97.7% at night, representing the highest performance in these metrics. Additionally, the traffic volume accuracy for the innermost lane (the first lane), as measured by the detection sensor from the third lane, was more than 99.3% at all times, with a speed accuracy exceeding 96% during the day and night, that also demonstrated excellent results. The analysis results indicated that the multilane portable reference equipment developed in this study was suitable for evaluating the VDS performance. This equipment allowed the collection of traffic volume and speed data from all lanes, rather than only the outermost lanes. This capability enabled consistent analysis for each lane and enhanced efficiency by reducing the analysis time. Additionally, this is expected to improve the reliability of the performance evaluations.
국내 도심지에 적용하고 있는 중앙버스정류장의 포장은 주로 아스팔트 포장으로 시공되어 있으나 중차량인 버스의 하 중으로 인해 포장 파손 사례가 증가하여 시민들의 안전에 악영향을 미치고 있으며 유지보수 비용이 매년 증가하고 있다. 서울시에서는 이러한 문제를 해결하기 위해 국내 최초로 중앙버스정류장 신설 구간에 현장타설 방식으로 연속철근 콘크 리트 포장(CRCP)을 시공하였다. 본 연구에서는 이러한 구간의 연속철근 콘크리트 포장에 대한 이동차량 하중에 의한 동 적 거동 특성을 분석하고자 포장 슬래브에 콘크리트 변형률계를 설치하고 덤프트럭을 통과시키며 동적 하중 재하 실험 을 수행하였다. 실험에서는 이동차량의 속도를 다양하게 변화시켜 차량 속도에 따른 포장 슬래브의 동적 거동을 비교 분 석하였으며 이동차량이 CRCP의 여러 위치에서 정지하도록 하여 정지 위치에 따른 거동도 분석하였다. 실험 결과, 차량 이 CRCP를 통행할 경우 차량 속도 및 정지 위치에 따른 포장 슬래브의 동적 변형률은 매우 유사한 것으로 분석되었다.
도서관은 문화 공간으로서 누구나 이용할 수 있고 다양한 분야의 지식과 정보를 제공하여 삶의 질을 높이는 중요한 사회기반 시설 중 하나이다. 현재 한국의 도서관 수는 수요에 비해 공급이 부족한 상황이며, 이를 해결하기 위해 일부 지자체는 차량을 수단으로 이동형 도서 서비스를 제공하는 분관 형태의 이동 도서관을 운영하고 있다. 주로 도서관을 이용하기 어려운 사람들을 대상으로 순회하며 도서관 서비스를 제공하지만, 비효율적인 운행 노선과 균일하지 않은 서비스로 실질적인 효과를 발휘하지 못하고 있다. 따라서 본 연구에서는 성남시 새마을 이동 도서관을 대상으로 순회 경로 현황을 파악하고, 최소 이동 거리로 개선된 이동 도서관 노선을 제시하고자 한다. 더욱 효율적인 운영을 위해 서비스 권역을 나누고, 시간 제약을 결합한 차량경로설정 문제를 사용하여 도서 서비스의 이용 격차를 줄인 새로운 운행 노선을 구축하였다. 본 연구는 이동 도서관의 효과적인 노선 운영에 대한 기초적인 자료로 활용될 수 있다는 점에서 의의가 있다. 향후 이동 도서관 뿐만 아니라 이동형 공공 서비스를 위한 유용하고 현실적인 가이드라인으로 활용될 수 있을 것이다.
The purpose of this study is to analyze the adequacy of production capacity of the assembly process system of mobile bath vehicle’s top box panel and process design through a simulation analysis. Towards this end, the layout of the facility designed with pre-verification job using a simulation modeling and an experiment, and facility, logistics process, and personnel input method were made into a simulation model, and the design system’s adequacy was evaluated through an experiment. To produce 120 mobile bath vehicles annually, it was analyzed that 14 general workers and seven skilled workers were adequate through the experiment. It was also identified that three painting process lines carried out through outsourcing were adequate. Production lead time was 201.7 hours on average and it was 230 hours maximum. To meet customer delivery service level of 95% within the deadline when establishing a customer order and vehicle delivery plan, it was analyzed that more than 215 hours of lead time is needed minimum. If the process cycle time is reduced to 85% upon system stabilization and skillfulness improvement, it was analyzed that annual output of 147 vehicles can be achieved without additional production line expansion.
A retractable bollard system has been used for the traffic control and protection of important facilities such as electric power plants, airports and government buildings etc. The power source of the driving unit of the conventional protective bollard system is on hydraulic or pneumatic system which has several disadvantages compared to an electric driven unit.
In this research, an electric driven unit for an automatic retractable bollard is designed and developed to replace the conventional hydraulic and pneumatic driven type. For the reliability test of the developed electric driven unit, a field test has been successfully done.
A case study was conducted to develop a defensive retractive bollard which the target performance is 9sec. and 7sec. on its raising and descending operation speed respectively with 750mm in stroke. The required time limit was fully satisfied as the time measured from the experiment were 7.5sec and 5.5sec for each operation. The developed unit also passed 364,000 cycles of operation without any serious malfunctions at the load test proving its reliability.
The design theory and process of an electric driven unit of the automatic retractable bollard presented in this article is believed to be very useful contribution and design tool in advancing the physical security industry.
PURPOSES: This paper develops a new stochastic approach to analyze the pavement-vehicle interaction model with a certain roughness and elasticity for the pavement foundation, thereby accommodating the deflection of the pavement, and to identify the road subsidence zone represented with a sudden changes in the elasticity of the foundation.
METHODS: In the proposed model, a quarter-car model was combined with a filtered white noise model of road roughness and a two-layer foundation (Euler-Bernoulli beam for the top surface and Winkler foundation to represent the sub-structure soil). An augmented state-space model for the subsystems was formulated. Then, because the input is White noise and the system is represented as a single system, the Lyapunov equation governing the covariance of the system’s response was solved to obtain a structurally weak zone index (WZI).
RESULTS: The results showed that the WZI from the pavement-vehicle interaction model is sensitive enough to identify road subsidence. In particular, the WZI rapidly changed with a small change in foundation elasticity, indicating that the model has the potential to detect road subsidence in the early stage.
CONCLUSIONS: Beacause of the simplicity of the calculation, the proposed approach has potential applications in managing road conditions while a vehicle travels along the road and detecting road subsidence using a device with an on-board computational capability, such as a smart phone.
가축질병 바이러스는 매우 빠르게 전파되는 특징을 가지고 있으며 질병에 걸린 동물의 분비물에 접촉하거 나, 사람이나 차량에 의한 바이러스의 이동, 또는 공기를 통하여 전파가 이루어진다. 본 연구에서는 가축 및 분뇨 운반차량이 질병을 전파시키는 요인이 될 수 있다고 판단하고 전염병 발생 시 질병의 이동 경로를 파악 하고 효율적인 방역범위를 설정하는데 기초자료로 활용 하고자 한다. 축산차량의 이동경로를 분석하기 위해 ArcGIS(Ver. 10.3, ESRI, USA)의 Spatial Statistics tool에서 Measuring geographic distribution방법을 활용하여 Directional distribution을 추출하였다. 결과 값으로 위도(Latitude), 경도(Longitude), Rotation, XstdDist, YstdDist을 얻었다. 그 결과 특정한 목적을 가지고 출발지가 일정 지역에 귀속되어 있는 가축 및 분뇨 차량의 경우 출발지점, 도착지점, 목적지가 크게 바뀌지 않을 경우, 이용하는 도로는 한정되어 있었다. 30대의 차량 중 대다수의 차량이 일정한 패턴을 가지고 평상 시 이용하는 경로만 이용하여 분뇨를 운반하는 것을 확인 할 수 있었다. 본 연구를 통해 전염병 발생 시 질병의 이동 경로를 파악하고 효율적인 방역범위를 설정하여 투입 인원과 장비를 줄이면서 현재보다 효율적인 방역 범위를 설정이 가능할 것으로 판단되었다.
본 연구에서는 가축전염병의 전국적 확산에 직접적으로 관련이 있는 축산차량 이동 상황을 파악하고자 국가동물방역통합시스템(KAHIS)에서 보유하고 있는 축산차량 이동 데이터를 이용하여 현재 운영 중인 도축장의 서비스 범위를 분석하였다. 축산차량 이동 데이터는 2014년 기준으로 1년에 3,200만 건 이상 생성되는 빅데이터(big data)이다. 분석결과 개별 도축장의 서비스 범위는 각 도축장의 거래처와 주변 소비시장의 입지 등에 따라 전국적인 범위로 형성되어 있음을 확인할 수 있었다. 이러한 결과는 가축 질병이 발생하는 순간 이미 질병의 전파 범위가 전국단위가 될 수 있음을 의미한다. 본 연구 결과는 전염성이 높은 가축질병이 발생할 경우 차단방역의 범위를 설정하는 정보로 활용될 수 있으며, 가축 질병 가상방역훈련(CPX)을 위한 기초자료로도 활용될 수 있다. 분석 도구로는 데이터분석으로 특화된 R과 공간분석 도구인 GIS를 활용하였다.
ABSTRACT PURPOSES: It is desirable for buses to be parallel to the face of the bus shelter at a bus stop. In this way, passengers can safely use the buses without moving into the vehicle area. The study was a review of the current bus bay geometric guidelines, to determine whether they lead buses to stop parallel to the face of the bus shelter by analyzing vehicle trajectory.
METHODS : A commercial software program for vehicle trajectory analysis was used under our assumptions about bus dimensions and geometric values. The final position of the bus was analyzed for multiple trajectory simulations, reflecting various geometric alternatives.
RESULTS: Within the scope of the study, we concluded that the current design guidelines need to be revised by the design values suggested by the study.
CONCLUSIONS : The results of the study suggested alternative design values for bus bay geometry, based on the assumption that buses should be parallel to the face of the bus shelter in order to prevent passengers from moving into the vehicle area.
A sweep-based heuristic using common area is developed for multi-vehicle VRPs under time various and unsymmetric forward and backward vehicle moving speed. One depot and 2 delivery vehicle are assumed in this research to make the problem solving strategy simple. A common area is held to make adjustment of possible unbalance of between two vehicle delivery completion times. The 4 time zone heuristic is used to solve for efficient delivery route for each vehicle. The current size of common area needs to be studied for better results, but the suggested problem solving procedures can be expanded for any number of vehicles.
PURPOSES : The lack of details of design guideline for zig-zag shaped section approaching central bus stop leads an traffic accident proneness. So, this study analysed the geometric elements of central bus stop area in terms of vehicle dynamics and suggested design alternatives.
METHODS: The study analysed a dynamic behaviour of bus moving in and out of zig-zag shaped section using Auto-Turn under scenarios. Based upon dynamic analysis, the study found out the width of overtaking lane is the most influential factor for a safe moving at zig-zag alignment.
RESULTS : The width of overtaking lane at design speed of 40, 50, and 60 km/h respectively was suggested given taper ratio of 1 to 10 required for Bus Rapid Transit (BRT), and the lane width is not wider than 4.0m which possibly makes two vehicles using the same lane. Also, the width of overtaking lane which mitigates the taper ratio was suggested with the same restriction about the maximum lane width.
CONCLUSIONS: The results of the study can be used to prepare a design guideline on zig-zag shaped alignment of central bus exclusive lanes. The more stable moving is expected by applying the design alternatives suggested, therefore the lower rate of traffic crashes at the vicinity of central bus stops.
An efficient vehicle routing heuristic for different vehicle moving times for forward and backward between two points is studied in this research. Symmetric distance or moving times are assumed to move back and forth between two points in general, but it is not true in reality. Also, various moving speeds along time zones are considered such as the moving time differences between rush hours or not busy daytimes. To solve this type of extremely complicated combinatorial optimization problems, delivery zones are specified and delivery orders are determined for promising results on the first stage. Then delivery orders in each zone are determined to be connected with other zones for a tentative complete delivery route. Improvement steps are followed to get an effective delivery route for unsymmetric-time-varing vehicle moving speed problems. Performance evaluations are done to show the effectiveness of the suggested heuristic using computer programs specially designed and developed using C++.
미국선녀벌레[Metcalfa pruinosa (Say, 1830)]는 2009년 우리나라에서 처음으로 발견된 선녀벌레과(Flatidae) 외래해충이다. 이 해충은 원산지인 북미지역에서는 피해가 미미하였으나 1979년 이탈리아를 시작으로 2000년대 중반까지 유럽지역에서 꾸준히 분포가 확대되면서 농작물 및 산림해충으로서 널리 알려지게 되었다. 과수, 채소 등 농작물 피해는 약(성)충의 흡즙과 분비물(밀납)에 의한 직접적인 피해 이외에도 잎, 줄기에 서식하는 약충 집단의 감로 분비에 따른 그을음에 의한 피해가 매우 위협적이다.
다른 많은 외래해충과 마찬가지로 이 해충의 분포확대는 알이나 약, 성충이 부착된 식물의 국가간 수출입 또는 자국내 이동에 따른 것으로 추정되고 있으나, 다른 한편으로 일부 유럽국가(예를 들면, 스위스)에서는 승용차, 버스, 트럭 등 교통수단에 의해 확산되는 것으로 추정하고 있다. 본 연구는 최초 발견 이듬해인 2010년부터 2011년까지 미국선녀벌레의 확산상황을 파악하고 경기, 충북 등 중부지방을 중심으로 주요 발생지점을 집중적으로 조사한 결과로부터 우리나라에서도 이 해충의 분포확산 경로의 하나로서 성충이 고속도로(특히 중부고속도로, 영동고속도로)나 국도 등을 왕래하는 차량에 부착하여 이동했을 가능성이 매우 높다는 점을 제시하고자 한다.