• Journal of Korea Society of Industrial Information Systems
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• v.19 no.4
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• pp.87-104
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• 2014

This paper proposes regionally centralized multistage reverse logistics (cmRL) networks and regionally decentralized multistage reverse logistics (dmRL) networks. cmRL considers whole area of RL network, while dmRL regionally distributed area of RL network. Each type is formulated by the mixed integer programming (MIP) models, which are realized in genetic algorithm (GA) approach. Two types of numerical experiments using RL network are presented and various measures of performance are used for comparing the efficiency of the cmRL and the dmRL. Finally, it is proved that the performance of the cmRL is superior to that of the dmRL.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.6
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• pp.587-598
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• 2013

In Korea military (KM), various military supplies are distributed to individual military units via three different multi-tier supply networks owned and operated by army, navy, and air force, respectively. Under the current supply networks, the chances for the occurrence of delayed supply, undersupply, and oversupply increase, and supply redundancy also can become a problem. Thus, KM is now trying to improve its current multi-tier supply networks by constructing logistics consolidation centers. Private companies operate logistics consolidation centers to effectively manage various types of inventories before delivering them to final customers. In this paper, we newly propose a mathematical model for building the optimized military supply network considering adopting the military logistics consolidation centers. Based on the real situation of KM, the proposed model was validated in terms of its feasibility, and it seems that the outcome (the location of the military logistics consolidation centers) of the proposed model can be one of the good alternatives for KM.

• IE interfaces
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• v.25 no.4
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• pp.458-471
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• 2012

In this study, we investigate the cooperative relationships between researchers who have co-authorship in the logistics-related journals in Korea by using social network analysis (SNA). We analyzed the co-authorship data of 781 articles published from 2005 to 2011 in four journals of 'Logistics Study', 'Journal of Korean Society of SCM', 'Korea Logistics Review' and 'Journal of Shipping and Logistics.' We examined the trend of cooperative research in the field of logistics with basic data of the co-authorship network. Then, we analyzed structural properties of the network and the sub-networks of research groups having co-authorship. We could verify the authors who play important roles within the network by using SNA indicators. In addition, we constructed the keyword networks based on the keyword data of all articles by research groups in order to understand the research topics of each group, and thereby we could draw several implications on the cooperative researches in the field of logistics.

• Korea Trade Review
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• v.46 no.5
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• pp.31-47
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• 2021

Recently, third-party logistics and second-party logistics are well known as a form of logistics service. However, there are several opinions about the effectiveness of second-party logistics and third-party logistics. In this study, the efficiency of second-party logistics companies and third-party logistics companies, which are the main providers of logistics services, was compared and the sales impact on the logistics market was measured. Efficiency was measured using DEA's CCR and BCC models. Debt and equity were used as input variables, and sales, operating profit, and net income were used as output variables. As a result of measuring the efficiency of logistics companies, the efficiency of third-party logistics companies was higher than that of second-party logistics companies in 2019 and 2020, and it had a positive effect on the rate of change in sales.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.565-565
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• 2004

Due to limitation of resources and increasing concerns about environment, reverse logistics has received growing attention in recent years. In this paper, we propose three types of reverse logistics networks based on reuse of returnable containers, materials recycling process and remanufacturing for parts reuse. First, the sender in the re-usable item network supplies containers for the recipient and orders either new containers from external supplier or returnable containers cleaned from the container depot. Second, the recycling center in the proposed recycling network collects either end of life products from customer or faulty goods from manufacturer, collected products are dismantled into materials and materials go into recycling process. Finally, the manufacturer in the proposed remanufacturing network has two alternatives for supplying parts: either ordering the required parts to external supplier or overhauling disassembled parts and bringing them back 'as new' conditions. In this product recovery environment, we build optimal order quantity models to minimize the total logistics costs related to reverse logistics network. The validity of the proposed model is investigated through comprehensive computational experiments.

• Journal of Korea Port Economic Association
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• v.21 no.3
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• pp.191-217
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• 2005

Ninety percent of an average Chinese manufacturer's time spent is on logistics. Therefore, logistics presents the greatest challenge for multinational companies conducting businesses in China. Although more than 18,000 registered logistics companies exist in China, 85 percent of their revenues are generated from basic trucking and storage services. These facts indicate that China will need increasing presence of high-quality foreign 3PL providers, who are able to provide sophisticated IT systems, industry/operational expertise, standardized operating processes, and international networks, compared to their Chinese counterparts. However, they are facing complicated array of laws and regulations as well as difficulty of finding qualified people to fulfill these needs. There are a number of foreign 3PL providers engaged in China's logistics sector to reap a huge opportunity. Nevertheless, many 3PL foreign providers are still cautious about making large investments. Thus they arelooking for alliances that can provide complementarities instead. Another salient feature of strategy is to take over the transportation assets and warehousing of major Chinese manufacturers and distributors.

• Journal of Korea Port Economic Association
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• v.28 no.2
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• pp.113-128
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• 2012

By strengthening the market control and expanding the networks, providers of global logistics are expanding their service scope. Warehouses connects networks to between internal and external warehouses worldwide by using employees. The paper focuses on analyzing the efficiency of the top forty Global Logistics Providers. Therefore, the study classifies the factors which specify the efficiency of a total logistics industry and verified its firmness. Furthermore, the most recent published reports by Logistics Quarterly and Armstrong Association in 2012 was used in order to guarantee credibility of the study. For scope period for analysis, this study utilizes three years of materials, from 2007 to 2010. By applying the DEA Window model and Malmquist, the trend in efficiency and stableness was analyzed. Consequently, the main purpose of the paper is evaluating the efficiency. Also, analyzing its determinants and illustrating a long-term relationship between the annual turnover and the number of Industry Focus/Key Customers was used as output measures. In addition, the number of warehouses worldwide and employees worldwide, of Logistics Providers were used as input measures.

• Journal of Navigation and Port Research
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• v.36 no.4
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• pp.305-311
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• 2012

The market competition of express package deliveries in Korea is severe because a large number of companies have entered into the market. This study thus suggests an approach to the reconfiguration of express service networks with respect to the strategy partnership of closing/keeping service centers among companies involved and the adjustments of their cutoff times. For this we propose an integer programming model and a genetic algorithm based solution procedure for allowing companies involved to maximize their incremental profit. An illustrative numerical example is presented to demonstrate the practicality and efficiency of the proposed model.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.06a
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• pp.149-150
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• 2009

The problem of vehicle routing problem(VRP) with pair operations of pick up and delivery are well-known in real applications in logistics networks, as in planning the routes for automatic guided vehicles(AGVs) in an automatic container terminal(ACT), warehouses or in some just-in-time services. This paper will present a formulation to modeling the problem mathematically which can be used to generate optimal routes of carried vehicles in the field to reduce the incurred cost of moving goods. This selected model could be used in (semi-)automatic short-term planning systems for vehicle fleet working in ACT, or in modern warehouses which the long list of requests is parted and sorted in preprocessing orders systems.

• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.181-191
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• 2024

Ports play a crucial role in the complex global supply chain. While many researchers have used social network analysis (SNA) to study active networks, there is a lack of SNA cohesion analysis specifically related to logistics and trade. Therefore, this study aims to identify time-series structural changes in all domestic import and export logistics networks, including regions, ports, and airports, by utilizing techniques such as k-core and community analysis. To carry out this analysis, we rely on data from the Korea Customs Service's Import and Export Logistics Statistical Yearbook spanning from 2004 to 2022. The findings from the k-core and community analysis indicate that the cohesion of the domestic import and export logistics network has continuously strengthened over time. Moreover, it reveals that regions, ports, and airports are becoming more cohesive and homogeneous, with Busan Port emerging as the central hub of a large community. These insights are expected to enhance our understanding of global logistics dynamics and contribute to the development of policies and sustainable import and export logistics processes.