• Journal of Ocean Engineering and Technology
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• v.27 no.1
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• pp.51-58
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• 2013

Recently, there has been an increase in the demand for natural gas as a source of clean energy, which has increased the demand for LNG carriers. However, LNG carriers require a capital investment to obtain equipment for the regasification process, which prevents fires and explosions. Thus, on account of NIMBY, a CNG carrier is suggested that eliminates the need for regasification equipment. Meanwhile, carbon dioxide emissions are more and more regulated by international conventions such as the Kyoto Protocol. Because of this, $CO_2$ carriers have also received international attention as a methodology to transport and store $CO_2$ cargoes. Several vessels or tanks to transport and store $CO_2$ gas have been studied in various countries. This paper proposes a conceptual design for a 20ft container shaped tank to effectively transport small cargoes of $CO_2$ and CNG. The proposed pressure vessel or tank will be carried by a conventional containership or special cargo ship. The influences of the design parameters for proposed pressure vessel or tank. Including the materials, scantlings, and shape of the pressure vessel, are studied theoretically and computationally.

• Journal of the Korean Institute of Navigation
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• v.22 no.4
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• pp.1-14
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• 1998

There are three basic modes of operation of ships: liner, tramp and industrial operations. Industrial operations, where the owner of the cargo, i.e. the industrial carrier controls the ships, abound in the shipment of bulk commodities, such as oil, chemicals and ores. Industrial carriers strive to minimize the shipping cost of their cargoes. This paper is concerned with the operational optimization problem of a fleet owned by major international oil company. The major oil company is a holding corporation for a group of oil producing, transporting, refining, and marketing companies located in various countries throughout the world. The operational optimization problem of the fleet is divided into two-phases. The front end corresponds to the optimization of transporting crude oil, product mix, and the distribution of product oil to meet market demand. The back end tackles the operational optimization problem of the fleet to meet the transportation demand derived from the front end. A case study is carried out with the H major oil company problem composed by reflecting the practices of an international major oil company. The results are summarized and examined in the point of optimization for the total operation of the H major oil company and the operational optimization problem of the fleet. The paper concludes with the remark that the results of the study might be useful and applicable in practices of these related decision problems.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.185-186
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• 2009

According to increase of container transportation, demands of empty container handling has been increasing, so research of empty container has been studied steadily. However, the handling of containers and empty containers is not handled simultaneously. Moreover, as Korean ICD(Inland Container Depot) and ODCY(Off-Dock Container Yard), the inland depot in many environments, relocation research due to demand of empty container has not been studied sufficiently. This paper formulates and analyzes logical mathematical relocation model according to demands of empty container which are required in container terminal, ICD, and ODCY as cargo depots. This paper also aims to help reduce cost by improving q current empty container relocation as same as the past procedure.

• Journal of Navigation and Port Research
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• v.35 no.2
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• pp.159-165
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• 2011

The aim of paper is to calculate the optimized size of Mobile Harbor(MH) which would be operated in South Korea coast area. MH is the combined entity which has the function of both ship and container port. In estimating the optimized size, the total cost concept is applied to the different size of MH. Trade-off factors for calculating total cost are MH cost and the over-capacity lost cost. The factors for MH cost estimation are the cargo demand, distance from origin to destination, voyage route and MH's fixed and variable cost in both sailing and port. The other cost is the over-capacity lost cost which is occurred from dead space in case of oversize compared with a voyage demand. The alternatives for the least cost are 250TEU, 500TEU, 750TEU and 1,000TEU sized vessel. The result of research is that 250TEU sized vessel is optimized in a South Korea costal service. If the coastal area be separated in terms of voyage distance or the specific area in considering trade, the optimized size is changed depending upon distance.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.148-160
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• 2023

The air transport industry is experiencing unprecedented fluctuations in aviation demand through the Covid-19 pandemic, and is more focused than ever on maintaining and generating business profitability. During the pandemic, demand for air cargo has soared, and the conversion business from passenger aircrafts to freighters(P2F) is drawing attention as a new business in the aviation maintenance industry. This study derives important factors to be considered in order to successfully carry out the P2F project through a wide range of cases and related literature, and analyzes the relative importance of each factor using the analytic hierarchy process. Through a survey of 33 aviation maintenance experts with more than 20 years of field experience, the importance of main factors and their sub factors was determined and implications were drawn. As a primary result, in order to succeed in the P2F project, the main factors were identified in the order of skill, finance, and location. The most important sub factors for each main factors were identified in order of securing airframe modification skill, securing infrastructure construction cost, and creating P2F business complex and district. The quantified success factors suggested the critical direction for the successful development of Korea's P2F business, and presented viable and specific business strategies and implementation plans for each factors.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.11a
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• pp.120-121
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• 2023

Recently, there has been a continuous imbalance between the demand and supply in the shipping industry. Consequently, shipping companies are implementing blank sailing to adjust the supply of vessels and achieve a balance between demand and supply. Blank sailing can create negative ripple effects by delaying cargo transportation, so this study uses Poisson regression analysis,

• Transactions of The Korea Fluid Power Systems Society
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• v.3 no.3
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• pp.20-24
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• 2006

Air balancer is a conveyance cargo-handling machine, used in assembly and process lines of car and machining industries. This can lift up an object, the weight of which is from 5 to 200 kg, and moves it to a position. As industrial technologies evolve, it is required to move an object and fit it into a specified position with greater accuracy, rather than performing simple tasks such as lifting objects up and down as conventional ones do. There is also a demand to handle an object with one hand, rather than with two hands,. Through designs of manifold unit for an air balancer function, pilot regulator unit to keep pressure constant, hand unit for an accurate load perception function, and air balancer circuit, this study enables everybody to work it with ease and convenience. Experiments and comparisons were conducted for the performance evaluation of the circuit.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.263-268
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• 2011

There are many exclusive freight cars in railway freight transportation system. Gondola is one kind of freight cars. Gondolas have a role to carry bulk-type cargo such as coals and ores. A few problems are occurring due to exclusive freight cars. Operation company has redundant freight cars because exclusive freight cars can carry limited items. And purchasing cost of freight cars is higher and higher because of irregular bid. Operation efficiency of gondola is very low because return time of gondola is much longer than that of container car. In this study, we analysed the introduction effect of hopper-type container for through transit. First, we identified the characteristics of spatial distribution on freight stations. And we provided the effect of hopper-type container in terms of operation efficiency, cost reduction, new demand excavation and image enhancement of eco-friendly railroad.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2635-2643
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• 2011

Current freight electric locomotives (132 ton) of the eco-friendly and can carry large cargo logistics as a means of generation has increased the demand at home and abroad. Especially, Freight electric locomotives to increase the traction, it is easy to mass and rapid transport. In addition, Freight electric locomotives is no exhaust and low noise compared to diesel -electric locomotives and it can be eco-friendly transportation. CO_CO BOGIE of Freight electric locomotives has no the center pivot and Traction_Rod and Spring of CO_CO BOGIE is mounted on the body. These freight electric locomotives to be satisfied with the safety regulations. Carbody development satisfied Implementation of optimum body and collision is the focus. Accordingly, the different approach in the upper and lower carbody structure and interior and equipment placement is needed. On this paper, the contents give explanation of cases on carbody design composed of freight electric locomotives now developed and process of improvement by structure analysis and collision analysis.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2007.11a
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• pp.7-11
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• 2007

This paper considers a shipment planning of products from manufacturers to a third-party warehouse for demands with production time windows where a demand must be replenished in its time window. The underling lot-sizing model also assumes cargo delivery cost in each inbound replenishment to the warehouse. For this model, an optimal O($nT^4$) is presented where n is the number of demands and T is the length of the planning horizon.