• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.177-178
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• 2009

본 연구는 반입 작업에서 수출 컨테이너의 작업순서 및 장치위치를 결정하는 문제를 다루었다. 수직 배치형 컨테이너 터미널에서 적하작업시간의 단축을 위해서는 가능한 해측에 컨테이너를 장치하는 것이 유리하지만 반입 외부 트럭의 빠른 회전시간의 측면에서는 육측이 선호된다. 이때 수출 컨테이너의 장치위치는 본선작업 우선순위에 따라 가중치가 다르고 이에 소요되는 장치소요시간에 따라 외부트럭들의 대기시간도 달라진다. 따라서 본 연구는 외부 트럭들의 예정 도착시간과 최대대기시간 그리고 적하작업의 선호 장치위치를 동시에 고려한 혼합정수모델을 개발하고 이를 활용한 적용 예를 제시하였다.

• Journal of Navigation and Port Research
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• v.35 no.8
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• pp.657-665
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• 2011

This study deals with an integrated problem for deciding sequencing and storage location of export containers together at its receiving operation in the container terminal with a perpendicular layout. The preferred storage location of an export container varies with the priority of the corresponding loading operation and the waiting time of an external truck depends on its storage time. This paper proposes the mixed integer programming model considering the expected arrival time and expected finish time of an external truck and the preferred storage location for its loading operation. And we suggest the heuristic algorithm based on a simulated annealing algorithm for real world adaption. We compare the heuristic algorithm with the optimum model in terms of the computation times and total cost and the performance of the heuristic algorithm is analyzed through a numerical experiment.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.890-900
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• 1999

In homogeneous multiprocessor systems, the task allocation algorithm which equally assigns tasks to processors if possible is generally used. But this algorithm is not suitable to accomplish to accomplish effective task allocation in heterogeneous multiprocessor systems. JSQ (Join the Shortest Queue) algorithm is often used in heterogeneous multiprocessor systems. Unfortunately, JSQ algorithm is not efficient when the differences of capabilities of processors are far large. To solve this problem, we suggest a heuristic task allocation algorithm that makes use of dynamic information such as task arrival time, task service time, and number of finished tasks. The results of simulation show that the proposed heuristic allocation algorithm improves the system performance.

• Journal of Korean Society of Transportation
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• v.21 no.5
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• pp.19-29
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• 2003

The purpose of this study is to analyse the effect of the parking information on the waiting time using the simulation method. Stated Preference survey has been implemented to construct the parking lot choice model. A queue simulation is carried out to investigate the effect of various parking information on the waiting time. The results show that providing parking information is likely to increase the utilization of parking place and to decease the waiting time of individual vehicle. Furthermore, as the parking demand increases, the detailed and quantitative parking information such as "5 minutes delay" is more effective than qualitative parking information such as "available".

• Journal of Korean Society of Transportation
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• v.24 no.6 s.92
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• pp.89-102
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• 2006

The purpose of this paper is to develop a dynamic OD estimating model to overcome the limitation of depicting teal situations in dynamic simulation models based on static OD trip. To estimate dynamic OD matrix we used the hybrid discrete choice model(called the 'Demand Simulation Model'), which combines travel departure time with travel mode and travel path. Using this Demand Simulation Model, we deduced that the traveler chooses the departure time and mode simultaneously, and then choose his/her travel path over the given situation In this paper. we developed a hybrid simulation model by joining a demand simulation model and the supply simulation model (called LiCROSIM-P) which was Previously developed. We simulated the hybrid simulation model for dependent/independent networks which have two origins and one destination. The simulation results showed that AGtt(Average gap expected travel time and simulated travel time) did not converge, but average schedule delay gap converged to a stable state in transportation network consisted of multiple origins and destinations, multiple paths, freeways and some intersections controlled by signal. We present that the hybrid simulation model can estimate dynamic OD and analyze the effectiveness by changing the attributes or the traveler and networks. Thus, the hybrid simulation model can analyze the effectiveness that reflects changing departure times, travel modes and travel paths by demand management Policy, changing network facilities, traffic information supplies. and so on.

• Journal of Korean Society of Transportation
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• v.26 no.6
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• pp.61-70
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• 2008

The study proposed a new type of bus information, Real-time Bus Crowdedness (RBC) information, to meet various demands of users and improve the convenience level of using public transportation, while existing bus information provided by bus information systems(BIS) were limited to bus operating information such as predicted bus arrival time. To analyze the impacts of providing the proposed RBC information, stated preference(SP) survey was performed and a methodology of disaggregate analysis (e.g., binary logit) was applied to develop passenger choice models. Additionally, passenger choice models incorporating the heterogeneity of different user groups(i.e., by age or trip purposes) were developed to evaluate the different responses on RBC information. The results showed that providing RBC information was significantly related to users' bus choices and the responses of user groups were significantly different, especially the age group of more then 60 was most affected by the RBC information on their bus choices. Also trip purposes were significantly related to users' bus choices, for instance the impacts of providing RBC information was bigger for non-business trips(leisure/meet friend/personal business, shopping, hospital) compared to business trip.