• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.2
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• pp.120-125
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• 2002

In this paper, we propose a new ordering model for the mixed parts transportation problem with multi-items based on the depot system. Order scale are used as decision parameters instead of order point for ordering multi-items. Finally we test the model with simple example and show computational result that verifies the effectiveness of the model.

• Journal of Korean Institute of Industrial Engineers
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• v.11 no.2
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• pp.155-163
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• 1985

This paper presents a heuristic algorithm for a multidepot aircraft scheduling and crew scheduling with deal-head flights. This algorithm is extended from a Greedy heuristic algorithm for a multi-depot multi-salesman traveling salesman problem. We first transform a given flight schedule into a multi-depot multi-traveling salesman problem, considering aircraft flight policies and crew management constraints. Then we solve this problem by applying a modified Greedy heuristic algorithm.

• Journal of Digital Convergence
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• v.17 no.2
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• pp.135-144
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• 2019

The importance of logistics of warehouse stores has increased as their prices are cheaper and more convenient than those of large supermarkets. However, few studies on integrated depot location selection of warehouse stores have been conducted. In this regard, this study aims to derive factors for integrated depot location selection and calculate weights and select the location priority of target candidates by introducing an analytic hierarchy process (AHP). The analysis results exhibited that the most important selection factor was the cost reduction in transportation and delivery (0.198) followed by distance reduction in transportation and delivery (0.168), and time reduction in transportation. This study quantified the reduction in cost and increase in efficiency if depots were integrated and operated thereby presenting more realistic foundational data to hands-on workers. For the future study, the analysis model will be needed to be advanced through additional investigation on the factors in the analysis.

• Industrial Engineering and Management Systems
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• v.13 no.2
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• pp.163-171
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• 2014

Under amazing increase in markets and certain demand on qualified service in the delivery system, global logistic optimization is becoming a keen interest to provide an essential infrastructure coping with modern competitive prospects. As a key technology for such deployment, we have been engaged in the practical studies on vehicle routing problem (VRP) in terms of Weber model, and developed a hybrid approach of meta-heuristic methods and the graph algorithm of minimum cost flow problem. This paper extends such idea to multi-depot VRP so that we can give a more general framework available for various real world applications including those in green or low carbon logistics. We show the developed procedure can handle various types of problem, i.e., delivery, direct pickup, and drop by pickup problems in a common framework. Numerical experiments have been carried out to validate the effectiveness of the proposed method. Moreover, to enhance usability of the method, Google Maps API is applied to retrieve real distance data and visualize the numerical result on the map.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.42
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• pp.21-30
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• 1997

This research fundamentally deals with an analysis of service level for a multi-level inventory distribution system which is consisted of a central distribution center and several branches being supplied stocks from the distribution center, Under continuous review policy, the distribution center places an order for planned order quantity to an outside supplier, and the order quantity is received after a certain lead time. Also, each branch places an order for particular quantity to its distribution center, and receives the order quantity after a lead time. In most practical distribution environment, demands and lead times are generally not fixed or constant, but variable. And these variabilities make the analysis more complicated. Thus, the main objective of this research is to suggest a method to compute the service level at each depot, that is, the distribution center and each branch with variable demands and variable lead times. Further, the model will give an idea to keep the proper level of safety stocks that can attain effective or expected service level for each depot.

• Journal of the Korea Safety Management & Science
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• v.3 no.3
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• pp.65-75
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• 2001

This research fundamentally deals with an analysis of service level for a multi-level inventory distribution system which is consisted of a central distribution center and several branches being supplied stocks from the distribution center, Under continuous review policy, the distribution center places an order for planned order quantity to an outside supplier, and the order quantity is received after a certain lead time. Also, each branch places an order for particular quantity to its distribution center, and receives the order quantity after a lead time. In most practical distribution environment, demands and lead times are generally not fixed or constant, but variable. And these variabilities make the analysis more complicated. Thus, the main objective of this research is to suggest a method to compute the service level at each depot, that is, the distribution center and each branch with variable demands and variable lead times. Further, the model will give an idea to keep the proper level of safety stocks that can attain effective or expected service level for each depot.

• Journal of Intelligence and Information Systems
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• v.13 no.1
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• pp.49-58
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• 2007

MDPDPTW (Multi-Depot Pickup and Delivery Problem with Time Windows) is a typical model among the optimization models based on the pickup and delivery flow in supply chains. It is based on multi-vehicles in multi-depots and does not consider moving vehicles near pickup and delivery locations. In ubiquitous environments, it is possible to obtain information on moving vehicles and their baggage. Providing the proper context from the perspective of moving vehicles and their baggage allows for more effective vehicle routings. This study proposes Integer Programming-based MDPDPTW including the information on moving vehicles and their baggage in a ubiquitous environment: u-MDPDPTW, and shows the viability and effectiveness of u-MDPDPTW through comparative experiments of MDPDPTW and u-MDPDPTW.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.167-178
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• 2019

In this paper, we study the multi-objectives vehicle and drone routing problem with time windows, MOVDRPTW for short, which is defined in an urban delivery network. We consider the dual modal delivery system consisting of drones and vehicles. Drones are used as a complement to the vehicle and operate in a point to point manner between the depot and the customer. Customers make various requests. They prefer to receive delivery services within the predetermined time range and some customers require fast delivery. The purpose of this paper is to investigate the effectiveness of the delivery strategy of using drones and vehicles together with a multi-objective measures. As experiment datasets, we use the instances generated based on actual courier delivery data. We propose a hybrid multi-objective evolutionary algorithm for solving MOVDRPTW. Our results confirm that the vehicle-drone mixed strategy has 30% cost advantage over vehicle only strategy.

• Proceedings of the KAIS Fall Conference
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• 2002.05a
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• pp.87-89
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• 2002

본 연구는 전자상거래의 발전으로 인해 더욱 그 중요성이 부각되고 있는 중간창고(대포)에서의 반주시스템에 대한 새로운 개념을 도입한 모델을 제안하고 있다. 제안 모델은 종래의 발주점방식과 비교되는 발주범위에 의한 발주방식이며, 발주시 수송조건을 고려하고 있다. 본 논문에서는 모델의 정식화가 해법을 제안하고 있으며 수치 예를 통하여 그 유용성을 보여주고 있다.

• Journal of the Korean housing association
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• v.24 no.6
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• pp.81-92
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• 2013

Recently, the interest in the mixed-use development of various urban planning facilities has been increased, but the interest in the Mixed-use development of bus depots that is closely related to our daily life is insufficient circumstance so far. Accordingly, this study aims to realize the necessity for the mixed-use development of bus depots as methods to improve the living environment and use efficiently the land, and to suggest reasonable development directions by analyzing their physical character after classifying bus depots according to their position in the residential area. As the results of study, bus depots have different properties according to their position in residential area and have the problem of space shortage. Also, many things such as location of entrances, the finish method of edge of bus depot's area are affected by the surrounding environment. So development plan to consider the each condition is required.