http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Park, Dongjoo,You, Soyoung,Rho, Jeonghyun,Cho, Hanseon,Lee, Kangdae Canadian Science Publishing 2009 Canadian journal of civil engineering. Revue canad Vol.36 No.4
<P> With recent increases in the deployment of intelligent transportation system (ITS) technologies, traffic management centers have the ability to obtain and archive large amounts of data regarding the traffic system. These data can then be employed in estimations of current conditions and the prediction of future conditions on the roadway network. In this paper, we propose a general solution methodology for the identification of the optimal aggregation interval sizes of loop detector data for four scenarios (i) link travel-time estimation, (ii) corridor / route travel-time estimation, (iii) link travel-time forecasting, and (iv) corridor / route travel-time forecasting. This study applied cross validated mean square error (CVMSE) model for the link and route travel-time estimations, and a forecasting mean square error (FMSE) model for the link and corridor / route travel-time forecasting. These models were applied to loop detector data obtained from the Kyeongbu expressway in Korea. It was found that the optimal aggregation sizes for the travel-time estimation and forecasting were 3 to 5 min and 10 to 20 min, respectively. </P>
Multiple Path Based Vehicle Routing in Dynamic and Stochastic Transportation Networks
Dongjoo Park 대한교통학회 2000 대한교통학회 학술대회지 Vol.37 No.-
In route guidance systems fastest-path routing has typically been adopted because of its simplicity. However, empirical studies on route choice behavior have shown that drivers use numerous criteria in choosing a route. The objective of this study is to develop computationally efficient algorithms for identifying a manageable subset of the nondominated (i.e. Pareto optimal) paths for real-time vehicle routing which reflect the drivers' preferences and route choice behaviors. We propose two pruning algorithms that reduce the search area based on a context-dependent linear utility function and thus reduce the computation time. The basic notion of the proposed approach is that i) enumerating all nondominated paths is computationally too expensive, ii) obtaining a stable mathematical representation of the drivers' utility function is theoretically difficult and impractical, and iii) obtaining optimal path given a nonlinear utility function is a NP-hard problem. Consequently, a heuristic two-stage strategy which identifies multiple routes and then select the near-optimal path may be effective and practical. As the first stage, we utilize the relaxation based pruning technique based on an entropy model to recognize and discard most of the nondominated paths that do not reflect the drivers' preference and/or the context-dependency ofthe preference. In addition, to make sure that paths identified are dissimilar in terms of links used, the number of shared links between routes is limited. We test the proposed algorithms in a large real-life traffic network and show that the algorithms reduce CPU time significantly compared with conventional multi-criteria shortest path algorithms while the attributes of the routes identified reflect drivers' preferences and generic route choice behaviors well.
박형준(PARK, Hyeongjun),박동주(PARK, Dongjoo),신성일(Sin, Seong-Il),이창훈(Lee, Chang-Hun),남대식(Nam, Dae-Sik) 대한교통학회 2013 대한교통학회 학술대회지 Vol.69 No.-
도심형 택배물류는 전자상거래의 발달로 택배 물동량 및 화물차 통행량의 증가에 따른 교통정체 가중, 대기오염 증가 등 도시운 영의 비효율과 사회적비용의 증가를 초래한다. 서울시의 경우, 건축물의 대형화 및 복합화에 따라 개별적인 배송시스템을 활용하는 택배물류가 많은 사회적인 문제를 야기하고 있다. 한편, 택배물류공동화는 자사물류처리에 따른 물류비용의 한계, 도심권 교통문제 및 환경오염 등의 문제점을 완화시킴으로써 물류비용의 절감 및 사회적 비용을 감소할 수 있다. 본 연구는 서울시 아파트단지를 대상으로 택배물류공동화 도입으로 인한 효과를 추정하고 시사점을 도출하고자 한다.