• Industrial Engineering and Management Systems
• /
• v.13 no.4
• /
• pp.383-397
• /
• 2014

Reverse logistics network design issues have been popularly discussed in recent years. However, few papers in the past literature have been dedicated to incentive effect on return quantity of used products. The purpose of this study is to formulate a dynamic nonlinear programming model of reverse logistics network design with the aim of managing the used products allocation by coordinating the collection centers and recovery facilities to warrant economic efficiency. In the optimization model, a fuzzy approach is applied to interpret the relationship between the rate of return and the suggested incentives. Due to funding constraints in setting up the collection centers, this work considers these centers as multi-capacity levels, which can be opened or closed at different periods. In view of the fact that the problem is known as NP-hard, we propose a heuristic method based on tabu search procedure to solve the presented model. Finally, several dominance properties of optimal solutions are demonstrated in comparison with the results of a state-of-the-art commercial solver.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.8 no.4
• /
• pp.193-203
• /
• 2012

This study analyzed regular transportation costs between port warehouses and processing plants and between processing plants and central distribution centers and further transportation costs relations according to empty transfer rates in each circulation by examining the distribution routes of imported grain including wheat, barley, corn, and soybean, namely port warehouses, processing plants, and central distribution centers. Based on the results, the study compared and reviewed the logistics transportation costs. The analysis results of the alternative model show that logistics operational costs could be considerably cut down by introducing a flexible vehicle transportation operational method, which is to change the vehicle loading parts for proper substitute transportation after unloading and transport them to other locations such as central distribution centers instead of returning empty, as an alternative to high operational costs deriving from empty vehicle operation in each circulation after unloading items in case of transportation of imported grain and processed items. The results allow for a more realistic approach to general problems with large-scale distribution network operation and provide a theoretical foundation to serve as a guide to establish policies for corporate operation of imported grain logistics systems.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.19 no.37
• /
• pp.263-269
• /
• 1996

The cost and customer service level of a logistics system depend primarily on the system design of the physical supply system and physical distribution system. The study presents the mathematical model and a huristic solution method of a combined location - vehicle routing problem(LVRP). In LVRP the objective is to determine the number and location of the distribution centers, the allocation of customers to distribution centers, and the vehicle delivery routes, so as to minimize the logistics total cost and satisfy the customer.

• Korea Trade Review
• /
• v.46 no.2
• /
• pp.55-74
• /
• 2021

Despite the growing importance of the logistics industry, it has been socially recognized as a 3D job and is perceived as a field of lower professional identity since the workers themselves think that they are engaged in a less important job. According to the related researches, it shows that professional identity affects the quality of service to customers, and applying it to the workers who are engaged in the logistics industry should be a meaningful subject of research. Therefore, this study intends to look into the impact of professional identity by managers in logistics centers on their service orientation and job engagement. To this end, this study surveyed managers in logistics centers across the country and conducted exploratory factor analysis, confirmatory factor analysis, and path analysis through structural equation models. The results of this study are summarized as follows. First, among the sub-factors of professional identity, recognition of professionalism did not have a significant effect on service orientation and job engagement, while acquisition recognition and range cognition had significant effects on it. Second, service orientation had a significant effect on job engagement. It believes that this study suggested implications for educational institutions and logistics companies that develop human resources of logistics in the aspect of that it presented the importance of developing human resources of logistics as well as the directivity to where the working environment such as the autonomy in their works and the extension of their authority should take their way.

• Industrial Engineering and Management Systems
• /
• v.13 no.4
• /
• pp.398-407
• /
• 2014

Shortages and delays in a humanitarian logistics system can contribute to the pain and suffering of survivors or other affected people. Humanitarian logistics budgets should be sufficient to prevent such shortages or delays. Unlike commercial supply chain systems, the budgets for relief supply chain systems should be able to satisfy demand. This study describes a comprehensive model in an effort to satisfy the total relief demand by minimizing logistics operations costs. We herein propose a strategic model which determines the locations of distribution centers and the total inventory to be stocked for each distribution center where a flood or other catastrophe may occur. The proposed model is formulated and solved as a mixed-integer programming problem that integrates facility location and inventory decisions by considering capacity constraints and time restrictions in order to minimize the total cost of relief operations. The proposed model is then applied to a real flood case involving 47 disaster areas and 13 distribution centers in Thailand. Finally, we discuss the sensitivity analysis of the model and the managerial implications of this research.

• Korea Real Estate Review
• /
• v.27 no.1
• /
• pp.45-57
• /
• 2017

In this study, the factors influencing logistics warehouse price were analyzed using Hedonic price model. All the actual transaction cases of the logistics centers in Gyeonggi province for 10 years from 2006 to 2015 were investigated. In this hedonic model, statistically significant variables includes building, economic, investment and time characteristics. The analysis permits a better insight of price determinants of warehouse price. First, the purchase price of large size logistics centers is relatively high. Second, the indirect investment shows higher price due to active investment tendency. Third, Foreign investors with various know-how on investment are leading the selling price.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.10
• /
• pp.6799-6806
• /
• 2015

Electric energy consumption is always followed by the introduction of diversity scale-up and state-of-the-art equipments in logistic centers. In order to analyze the status and the characteristic of the electric energy consumption quantitatively, and also to evaluate the efficiency of the electric energy, this research aims to develop an estimation model of standard electric energy consumption for logistic centers. The proposed model applies the thermodynamics theory so as to effectively reflect the peculiarity that the temperature in the logistic center influences the electric energy consumption. And the model consists of the energy consumed by the refrigerator, which can be subdivided into the heat conducted through the wall, the heat convected by the open doors and the heat lost into the goods, and the electric consumption of the machinery equipments. The model also includes a variety of explanatory variables to support an operator of logistics centers in evaluating the efficiency of energy consumption and establishing improvement strategies for energy efficiency. Application of the model developed in this study is discussed with observed data on energy consumption of a logistics center.

• Journal of Distribution Research
• /
• v.7 no.1
• /
• pp.1-20
• /
• 2002

Many of logistics-related research in automobile industry has focused on inbound logistics and procurement. Research into outbound logistics is relatively few. As a starting research into outbound logistics in automobile industry, this paper examined its logistics network problems with three aspects - location strategy, inventory strategy and transportation strategy. We proposed alternatives of logistics network design resolution, and presented three practical scenarios based on those alternatives. Based on interview, on-site visit and internal data collection processes, we identified major domestic outbound logistics problems such as redundant logistics bases, inefficient delivery policy, insufficient inventory capacity, inventory stock quality deterioration, inefficient transportation system, and etc. In order to cope with those problems, we proposed such strategic alternatives as introduction of hub-and-spoke system, integration of logistics bases, introduction of (automatic) parking building, diversification of transportation mode, and etc. At the same time, we constructed three practically executable scenarios based on those ideas. The first is "Center Hub" scenario, the second is "Metropolitan Hub" scenario. The third and last scenario is "Regional Consolidation of Warehouses (distribution centers)".

• Industrial Engineering and Management Systems
• /
• v.13 no.3
• /
• pp.297-303
• /
• 2014

Stock pre-positioning is one of the most important decisions for preparing the stage of emergency logistics planning. In this paper, a mixed integer model for stock pre-positioning is derived to support an emergency disaster relief response against the event of earthquake. A maximum response time limit, budget availability, multiple item types, and capacity restrictions are considered. In the model, the decision of the distribution centers to cover a disaster area and the amount of supplies to be stocked in each distribution center are simultaneously determined to maximize the total expected relief demand of the disaster areas covered by the existing distribution centers. The proposed model is applied to a real case with 33 disaster areas and 16 distribution centers in Indonesia. Several sensitivity analyses are conducted to estimate the fluctuation on the emergency stock pre-positioning planning by changing the maximum response time and budgets.

• IE interfaces
• /
• v.11 no.1
• /
• pp.23-32
• /
• 1998

This paper presents a model for assessing the efficiency of logistics activities in distribution centers. The DEA approach is adopted to compare the relative efficiency of distribution centers, where considered as input and output factors are warehouse floor area, field storage area, average inventory level, overhead costs, number of workers, number of orders, and total value of goods handled. The artificial neural network approach is also adopted to overcome the limitation of DEA. The 12 distribution centers of Korea Telecom are studied for the validation of the model, which results in 84.9% of learning accuracy. This model can be used to identify the inefficient factors in a distribution center and to reveal changes in the degree of efficiency over time.