• Korean Journal of Microbiology
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• v.48 no.2
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• pp.57-65
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• 2012

Phosphorous is an essential element for the synthesis of various biomolecules including phospholipids, carbohydrates and nucleic acids. Bacterial cells can uptake it as forms of phosphate and phosphate-containing nutrients from extracellular environments, and reserve extra phosphate to polyphosphate inside the cell. Among five phosphate transport systems, Pst plays central roles in phosphate transport, and its expression is coordinated by the regulation of PhoB-PhoR two component signal transduction system in response to extracellular levels of phosphate. Genomic studies on the response regulator PhoB reveal many genes independent of phosphate metabolism. Based on recent findings on phenotypes of bacteria lacking proper function of each phosphate transport system, this review discusses roles of phosphate transporters in maintaining optimum intracellular phosphate levels, and presents diverse phenotypes of phosphate transporters related with other environmental signals as well as phosphate, then finally points out functional redundancy among phosphate transport systems or their regulators, which emphasize importance of phosphate homeostasis in governing metabolism, adaptation, and virulence of bacteria.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.4 no.1
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• pp.51-58
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• 2006

Since 2002, more than 400 PWR spent nuclear fuel assemblies have been transported and stored on-site using transport casks in order to secure the storage capacity of PWR spent nuclear fuel of Kori nuclear power plant. The complete on-site transport system, which includes KN-12 transport casks, the related equipment and transport vehicles, had been developed and provided. KN-12 transport casks were designed, fabricated and licensed in accordance with Korean and IAEA's transport regulations, and the related equipment was also provided in accordance with the related regulations. The on-site transport and storage operation using two KN-12 casks and the related equipment has been conducted, and the strict Quality Control and Radiation Safety Management through the whole process has been carried out so as to achieve the required safety and reliability of the on-site transport of spent nuclear fuel.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.5-8
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• 2011

기존의 물류 관리 시스템에서는 고객의 예상하지 못한 물류 수송 요청이 접수되면, 현재 진행하고 있는 물류 수송 상황에 대해 게시판에 메모를 하거나 관리자의 기억에 의존하여 계획을 수립하여 진행하고 있으며, 상황이 종료된 후에 수송 차량의 기사가 진행 상황을 회사에 보고하고 있다. 본 논문에서는 이러한 문제를 해결하기 위해 GPS 기능이 내장되어 있는 스마트 폰을 이용하여 차량과 화물의 부가적인 정보(위치, 물류의 상태 등)를 실시간 관리할 수 있도록 하고, 물류 수송 상에서 발생되는 데이터를 실시간으로 모니터링이 가능하도록 하였다. 그리고 관리자와 수송 기사간의 신속한 정보 전달을 통해 수송 계획을 최적화시켜 배송시 발생하는 비용 및 시간 문제에 대한 신속한 해결을 통해서 문제를 최소화할 수 있도록 하였다. 본 논문에서 제안한 시스템을 사용하게 되면 인적 물적 자원을 체계적으로 관리하여 적재적소에 분배함으로써, 이들의 활용성을 높일 수 있고 업무 효율을 극대화할 수 있다.

• Information Systems Review
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• v.10 no.1
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• pp.115-133
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• 2008

The third-party logistics industry mainly delivers goods from a place to an arrival place on behalf of the freight owner. To handle the work, they need a transportation route including transportation equipment between the starting place and the arrival place, schedule information for departure/arrival and transportation cost. Actually, automatic searching for an optimal transportation route, which considers arrival and departure points for intermodal transportation, is not a simple problem. To search efficiently transportation route, the collection of schedule information for intermodal transportation and transportation route generation have become critical and vital issues for logistics companies. Usually, they manually make a plan for a transportation route by their experience. Because of this, they are limited in their ability if there is too much cargo volume and a great many transactions. Furthermore, their dependence on the conventional way in doing business causes an inefficient selection of transporters or transportation routes. Also, it fails to provide diverse alternatives for transportation routes to the customers, and as a result, increases logistics costs. In an effort to solve these problems, this study aims to develop a route planning system based on agent, which can collect scattered schedule information on the Web. The route planning system also has an algorithm for transportation route generation in intermodal transportation.

• Journal of Korean Society of Transportation
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• v.32 no.3
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• pp.227-238
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• 2014

There is no question that railroad investment is crucial for better transport systems and the Korean government has continued to invest in railroad facilities. Nevertheless, the modal share of railroad, in particular, for freight has decreased. This is because rail freight transport can hardly meet customer needs such as just-in-time(JIT), a door-to-door service, compared to road transport, to be specific, trucking which can directly carry the freights to the final destinations. This has made the value of the railroad infrastructure less, which has been operated for the past 114 years. This study proposes a new freight movement concept called Piggy Back System. This system can carry freight trucks on the trains and deliver the freights to the final destinations. It can make a door-to-door deliver system possible for railroad transportation, which is the key factor for modal shift from road to railroad. For implementing this, this study proposes three important things: the cost-efficient reforming way of railroad yard that has been used for the past 114 years, the diagram plan of train services, and some technical reviews like clearance limits. This is the first study with practical proposals and solutions on this topic in Korea. The suggestions of this study cut down distribution costs by more than seven trillion won.

• Journal of the Korean Society for Railway
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• v.17 no.5
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• pp.373-380
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• 2014

With a view to the commercialization of the Korean automatic variable-gauge bogie in the Eurasia railway system, the aim of this research was to perform an economic analysis concerning the possible introduction and operation of this bogie at the present time. For this purpose, we compared the possible types of freight connection service for container transportation, transshipment and the gauge-adjustable system, estimating the total life-cycle cost (LCC) incurred by each system, depending on type and quantity, over the whole process of acquisition, operation, maintenance and disposal. Based on this, we presented a case-by case analysis. Furthermore, in estimating economic feasibility, we analyzed the cost-benefit ratio taking into account not only the objective LCC, but also the reduced time required for the gauge-change and customer convenience. After estimating the LCC and analyzing the cost-benefit ratio of the respective systems, we demonstrated the economic superiority of view of the gauge adjustable system.

• Journal of the Korean Society for Railway
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• v.6 no.3
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• pp.7-14
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• 2003

21세기의 사회적 환경변화는 크게 개도국의 인구증가, 선진국 인구감소, 인구의 노령화(2025년 전세계 인구의 20%가 65세 이상)와 연관된 인구통계의 변화와 경제발전으로 인한 세계화, 도시화(현재 전세계 인구의 45%가 도시지역에 생활하고 있으나, 2025년에는 60%로 증가) 등의 문제가 나타날 것으로 예측되며, 이로 인해 유동인구 및 물동량의 증가로 수송시스템에 대한 수요가 급격하게 증가할 것으로 예상된다. 특히 철도는 안전성, 정시성, 환경친화성, 대량수송성, 경제성 등에 장점을 바탕으로 국가교통의 핵심수단으로 확대되고 있다. 그러나, 미래사회는 각종 재해, 테러 등 다양한 위험원의 증가에 노출되면서, 안전에 대한 사회적 요구도 또한 증대될 것이다. (중략)

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1998.10a
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• pp.9-16
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• 1998

• Bulletin of the Society of Naval Architects of Korea
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• v.38 no.2
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• pp.62-66
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• 2001

• Journal of the Korean Professional Engineers Association
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• v.31 no.6
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• pp.40-43
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• 1998