• Journal of Korean Society of Industrial and Systems Engineering
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• v.30 no.3
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• pp.12-19
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• 2007

This paper is to determine the transportation size and the location of distribution centers to minimize logistics cost in a distribution system where products are transported from the distribution centers to the retailers. Logistics cost consists of the fixed cost of distribution centers, the transportation cost from the distribution centers to the retailers and the inventory holding cost in the retailers. The logistics cost is affected by the transportation size and the location of distribution centers. The transportation size affects transportation cost and inventory holding cost. The location of distribution centers affects the transportation cost. A mathematical model is formulated and the algorithm is developed. A numerical example is shown to explain the problem.

• Journal of Distribution Science
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• v.18 no.11
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• pp.5-13
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• 2020

Purpose: This research investigates the cost behavior of the distribution industry. Specifically, we investigate if the ratio of the increase in costs with an increase in sales is consistent with the ratio of the decrease in costs when sales decrease. Traditionally, cost is assumed to be symmetrical. In the case of the distribution industry, it was expected that the downward rigidity of the cost would be shown because it would be very difficult to decide to adjust resources when sales temporarily decrease. Therefore, studies have looked at Korean capital markets based on manufacturing and steel industries. However, no research has been done on the distribution industry. Research design, data, and methodology: To verify the hypothesis of this study, the asymmetry of cost was measured by Anderson et al. (2003). The sample used 28,695 firm-year data from 2002 to 2019 for the KOSPI and KOSDAQ stock markets. Results: The empirical analysis results are as follows. First, asymmetry of cost was observed in the case of the distribution industry. We confirm cost rigidity when sales decreased. Conclusions. This is the first study to look at cost behavior in the distribution industry, and the downward rigidity of cost in the distribution industry is observed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.31 no.2
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• pp.19-27
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• 2008

This paper addresses determining the location of the distribution centers in a discrete dynamic distribution system. In discrete and finite time horizon, the demands of retailers are dynamic for the periods. Some locations among the retailers can be chosen for the role of the distribution centers at the beginning of each period. The distribution centers have to be located at the location of minimizing logistics cost. Logistics cost factors are the operation cost and the fixed cost of distribution center, and the transportation cost. The distribution centers of minimizing sum of operation cost, fixed cost and transportation cost are determined among retailers in each period for the planning period. A mathematical model was formulated and a dynamic programming based algorithm was developed. A numerical example was shown to explain our problem.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.5
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• pp.232-237
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• 2002

It is increased for methodology to evaluate distribution power system interruption cost in power supply zones under competitive electricity market. This paper presents algorithms to evaluate system interruption cost in distribution power supply zones taking into consideration failure rate of distribution facilities and composite customer interruption cost. In this paper, it is introduced for weighting factor for each customer failure duration and failure rate of distribution facilities to evaluate reasonable system interruption cost in distribution power supply area. Also, this Paper estimates evaluation results of system interruption cost using a sample model system. Finally, evaluation results of system interruption cost based on failure rate of distribution facilities and composite customer interruption cost are shown in detail.

• Journal of Distribution Science
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• v.21 no.4
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• pp.21-33
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• 2023

Purpose: To study, analyze, and investigate how to improve the service quality distribution and perceived value of passenger loyalty in low-cost airlines in Thailand. Research Design, data, and methodology: The data was collected from low-cost airline passengers who had used low-cost airlines within Thailand more than twice in the last 12 months. In total, 632 questionnaires were received, representing 97.32%, and in-depth interviews were done using the semi-structured technique. The key informants were either executives or representatives from 4 low-cost airlines operating in Thailand. We utilized structural modeling techniques to examine the data relevant to the investigation. Results: The results show that low-cost airline passengers in Thailand have strong opinions about the perceived value of the passenger loyalty of low-cost airlines within this sector of the Thai air travel industry. The variables were sorted in order of importance and included passenger loyalty, satisfaction, trust, perceived value, and service quality distribution. The relationship between the service quality distribution variables and the significance in relation to passenger loyalty according to low-cost airlines in Thailand showed that service quality distribution had a positive effect on perceived value and that passenger satisfaction has a direct positive effect on passenger loyalty. Conclusions: The 8 QPSTL strategy is successful in terms of service quality distribution and passenger satisfaction, therefore it is an important aspect of low-cost airlines in Thailand.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.33
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• pp.161-171
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• 1995

When physical distribution cost can be correctly measured, its management can also be efficient. Thus the primary objective of the study is to develop systems for measuring correctly physical distribution cost. The systems have two aspects : the One is the consumption of the resourses(materials, labor service, the other services), the other is the creation of physical distribution services(transportation, storage, cargo, packing, distribution conversion, management). By measuring the cost through the systems, the commoditization of the physical distribution services is possible and measurement of the cost and revenue can also be reasonable ,which makes its management efficient.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.9
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• pp.481-486
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• 2004

In operation of distribution system, $DG_s$ Distributed Generations) are installed as an alternative of extension and establishment of substations and transmission and distribution lines according to increasing power demand. In operation planning of $DG_s$, determining optimal capacity and allocation gets economical pro(it and improves power reliability. This paper proposes determining a optimal number, size and allocation of $DG_s$ needed to minimize operation cost of distribution system. Capacity of $DG_s$ (or economical operation of distribution system estimated by the load growth and line capacity during operation planning duration, DG allocations are determined to minimize total cost with power buying cost. operation cost of DG, loss cost and outage cost using GA(Genetic Algorithm).

• Industrial Engineering and Management Systems
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• v.3 no.2
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• pp.134-139
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• 2004

During the last three decades, a few attentions have been paid for investigating the cost distribution for the optimal maintenance problems. In this article, we derive the moment of the discounted cost distribution over an infinite time horizon for the basic age replacement problem. With first two moments of the discounted cost distribution, we approximate the underlying distribution function by three theoretical distributions. Through a Monte Carlo simulation, we conclude that the log-normal distribution is the best fitted one to approximate the discounted cost distribution.

• KIEE International Transactions on Power Engineering
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• v.5A no.1
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• pp.9-15
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• 2005

In the operation of distribution systems, DGs (Distributed Generations) are installed as an alternative to extension and the establishment of substations, transmission and distribution lines according to the increasing power demand. In the operation planning of DGs, determining optimal capacity and allocation achieves economical profitability and improves the reliability of power distribution systems. This paper proposes a determining method for the optimal number, size and allocation of DGs in order to minimize the operation costs of distribution systems. Capacity and allocation of DGs for economical operation planning duration are determined to minimize total cost composed with power buying cost, operation cost of DGs, loss cost and outage cost using the GA (Genetic Algorithm).

• Journal of Korean Society of Industrial and Systems Engineering
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• v.27 no.2
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• pp.102-113
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• 2004

This paper addresses the transportation planning that is based on genetic algorithm for determining transportation time and transportation amount of minimizing cost of distribution system. The vehicle routing of minimizing the transportation distance of vehicle is determined. A distribution system is consisted of a distribution center and many retailers. The model is assumed that the time horizon is discrete and finite, and the demand of retailers is dynamic and deterministic. Products are transported from distribution center to retailers according to transportation planning. Cost factors are the transportation cost and the inventory cost, which transportation cost is proportional to transportation distance of vehicle when products are transported from distribution center to retailers, and inventory cost is proportional to inventory amounts of retailers. Transportation time to retailers is represented as a genetic string. The encoding of the solutions into binary strings is presented, as well as the genetic operators used by the algorithm. A mathematical model is developed. Genetic algorithm procedure is suggested, and a illustrative example is shown to explain the procedure.