• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.632-637
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• 2014

In this paper the concept of the performance-based logistics (PBL) support for weapon systems is discussed and an enhancement is studied such that prior to the Operational phase, the development of the PBL can begin from the Engineering & Manufacturing Development (EMD) phase together with multiple performance indices considered. The genetic algorithm should be considered for the complex system to solve the maintenance policy optimization. In particular, the requirement of repair level analysis model is developed based on reflecting the PBL concept. To decide the maintenance policy prior to Operational phase in accordance with customer requirements, the PIDO(Process Integration and Design Optimization) technique useful in choosing the performance indices and changing the constraints was used. The genetic algorithm of PIDO tool, like PIAnO and ModelCenter, was verified that it could be applied to optimize the maintenance policy.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.116-122
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• 2015

Motivated by continuous increase in flight demand, awareness of the importance in developing ways to increase aircraft operational efficiency on the airport movement area has been raised. This paper proposes a new routing algorithm for providing the shortest path in a right time, enhancing the aircraft movement efficiency. Many researches on developing algorithms have been performed, for example, Dijkstra algorithm and $A^*$ algorithm. The Dijkstra algorithm provide optimal solution but could possibly provide it with a cost of relatively longer computation time. On the other hand, $A^*$ algorithm does not guarantee the optimality of a solution. In this paper, we suggest a Hybrid $A^*$ algorithm, incorporating both algorithms to eliminate the weaknesses. Rigorous test shows the proposed Hybrid $A^*$ algorithm may achieve shorter computing time and optimality in searching the shortest path.

• Journal of Korea Port Economic Association
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• v.23 no.2
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• pp.41-61
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• 2007

After the joining in the WTO of China, the container throughputs have begun to increase notably and Continuous developments of China ports are influencing operation and policy of Korea ports. At this point Pyeongtaek Dangjin port which has potency as China trading port confronts with turning point of port development as new port. To this, correct need grasping of North China shippers is important strategic element of PyeongTaek Dangjin Port activation. In this study, there is purpose to present Pyeongtaek Port's activation strategy by grasping customer needs executing questionnaire to China local company about Pyeongtaek Dangjin Port. As a research result, Pyeongtaek Dangjin Port possesses high geographical strength but has problems like development delay, tribe of various route, absence of marketing strategy. To solve this problem, this paper proposes expansion of port and logistics physical distribution equipment, improvement of services, foundation of joint logistics center, establishment of marketing organization etc. Namely, it may overcome only new port's limitation though develop to port of cargo creation style that is not simple cargo dependence style port.

• Journal of Korea Port Economic Association
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• v.25 no.3
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• pp.1-20
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• 2009

A survey to pallet users was conducted in an aspect of the efficiency and benefit. The questionnaire identified the preference about the main variables such as price, size, conformity, material, which are the criteria of the users' choice. staffs in the capital region was selected as respondents and Cluster Analysis and Simulations was carried out with Conjoint Analysis. The result shows that the variables of material and conformity between facilities and products were more important than the variable of size. The respondents prefer the pallets with a various range of products because warehouses should keep a range of products under various condition of temperature. In accordance, the companies that provide a pallet pool service should set up individual marketing strategy by a type of customers so as to maximize the competitiveness in domestic or international markets. Furthermore, supplying standardized pallets should be consistent with the standardization not for individual logistics units, but for whole logistic systems. To achieve this, it requires the compatibility amongst a range of logistics activity participants by their characteristics.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.195-200
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• 2021

Seafarers play an important role in shipping and logistics. However, seafarers are relatively vulnerable to mental illness because they have to board ships for a considerable period of time and work in isolation. In particular, in the pandemic situation caused by COVID-19, the crew change is delayed due to the closure of many ports around the world, increasing the mental burden on seafarers. The mental health management of the crew is important because these mental problems can lead to major accidents of lives and ships. This paper identified the necessity of mental health management of seafarers through a survey and identified problems with the currently operated mental health management program and curriculum. Especially, this study proposed VR-based programs to help crews receive mentally counseling treatment in a timely manner and to reduce the mental burden on them by preventing sensitive personal information exposure. Through this, it is expected to contribute to the stable development of the logistics industry by establishing a safe seafarers working environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.287-290
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• 2014

The Large-scale Agricultural & Livestock Products consists largely of distribution at The nation's of school and military foods. but false information on the Agricultural & Livestock Products in a safe food supply has become a social issue. The food suppliers deliver food resource in a school-large food establishments such as Change to domestic high-quality Livestock products from low-quality foreign Livestock products, Change to eco-friendly agricultural produce from normal agricultural produce, Change to fresh vegetables from contaminated vegetables. In this paper, e-Discovery system applies to the methods and security of incorrect logistics information and evidential data about illegal products of agriculture & livestock, it is necessary as studies about compensation and liability.

• Journal of the Korea Society for Simulation
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• v.28 no.1
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• pp.81-91
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• 2019

The ROK military uses Performance Based Logistics(PBL) as one of the ways to utilize civilian resources and advanced techniques. However, the Korean PBL is mainly focused on purchasing and repairing parts, which is not contributing to the improvement of the availability of overall system. The objective of this study is to suggest the methodology to evaluate the PBL metrics using the simulation and meta model. A meta model is a regression model to analyze the effect of the PBL through simulating various scenarios with performance metrics. As a result, if the PBL is limited to the part level, the performance has little influence on the availability of overall system. In addition, analysis using the meta model shows that it cannot achieve the performance targets when the same metrics are applied to various items without considering the characteristics of the applied items. Therefore, in order to improve availability, PBL coverage should be extended to a system level that includes key components that have a large impact on availability. If multiple items are included in the PBL coverage, the metrics should be applied differently, taking into account the characteristics of each item.

• Journal of Digital Convergence
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• v.17 no.4
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• pp.65-73
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• 2019

This study performed Panel Regression Analysis (PRA) with the debt ratio as a dependent variable and the ROE (return on equity), sales volume, current ratio, total capital, and Shanghai Containerized Freight Index (SCFI) as an independent variable. According to the GLS analysis, the current ratio to liabilities ratio was negative, and for sales, the ratio of liabilities was positive. Capital totals also had a negative impact on the debt ratio. However, ROE, unlike the hypothesis, had negative effects on the liability ratio, and the SCFI index was not significant. As implications of this research, the company confirmed that its sales increased as the debt ratio of global shipping companies rose, achieving economies of scale. However, it was confirmed that the actual size of the economy through the injection of other capital would help increase sales but not affect net profit. Shipping companies should expand their business power and secure large container vessels to secure credibility of shippers. In the future research, an analysis considering exchange rate, global economic growth rate, and manufacturing production index is needed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.1-14
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• 2021

It is highly challenging to measure the efficiency of electric vehicle charging stations (EVCSs) because factors affecting operational characteristics of EVCSs are time-varying in practice. For the efficiency measurement, environmental factors around the EVCSs can be considered because such factors affect charging behaviors of electric vehicle drivers, resulting in variations of accessibility and attractiveness for the EVCSs. Considering dynamics of the factors, this paper examines the technical efficiency of 622 electric vehicle charging stations in Seoul using data envelopment analysis (DEA). The DEA is formulated as a multi-period output-oriented constant return to scale model. Five inputs including floating population, number of nearby EVCSs, average distance of nearby EVCSs, traffic volume and traffic congestion are considered and the charging frequency of EVCSs is used as the output. The result of efficiency measurement shows that not many EVCSs has most of charging demand at certain periods of time, while the others are facing with anemic charging demand. Tobit regression analyses show that the traffic congestion negatively affects the efficiency of EVCSs, while the traffic volume and the number of nearby EVCSs are positive factors improving the efficiency around EVCSs. We draw some notable characteristics of efficient EVCSs by comparing means of the inputs related to the groups classified by K-means clustering algorithm. This analysis presents that efficient EVCSs can be generally characterized with the high number of nearby EVCSs and low level of the traffic congestion.

• The Journal of Society for e-Business Studies
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• v.26 no.1
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• pp.67-78
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• 2021

The number of domestic e-commerce transactions has been breaking its own record by an annual average growth rate of over 20% based on volume for the past 5 years. Due to the rapid increase in e-commerce market, retail companies that have difficulty meeting consumers in person are in fierce competition to take the lead in the last mile service, which is the only point of contact with customers. Especially in the delivery area, where competition is most intense, the role of the fulfillment center is very important for service differentiation. It must be capable of fast product preparation ordered by consumers in accordance with the delivery service level. This study focuses on the order picking system for rapid order processing in the fulfillment center as an alternative for companies to gain competitive advantage in the e-commerce market. A mixed integer programming model was developed and implemented to optimize the stock replenishment in order picking facilities. The effectiveness was scientifically and objectively verified by simulation using the actual operation process and data.