• Journal of KIISE
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• v.41 no.12
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• pp.1075-1080
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• 2014

One of the important roles used to ensure victory in a war is to maximize the overall military forces and to make sure that the capability of the military forces can be sustained as much as possible. Although several researchers have proposed various possible methodologies for logistics support, no research trials have been undertaken to investigate logistics support that considers all relevant elements of such. Unlike previous in trials that consider and analyze the system fault ratio as the main methodology, we propose an approach that simultaneously decides and recommends logistic priority by reflecting and combining item costs, transportation, fault-ratio, and system complexity. Also, we designed an algorithm that can recommend optimized logistics support priority using stationary distribution.

• Journal of the Korean Institute of Gas
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• v.4 no.2 s.10
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• pp.7-14
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• 2000

LNG (Liquified Natural Gas) carried by LNG ship is unloaded into the LNG storage tanks at the very low temperature (a little lower than the boiling point of LNG). Because LNG is unloaded through the pipeline, two phase flow appears in the pipeline. In this study, we have studied the pressure-drop mechanisms of the two-phase flow in the pipeline, and the calculation method of BOG (Boil-off Gas) amount based on the heat transfer mechanism through the insulation and the surface of the pipeline. We have developed a computer program for thermal-hydraulic analysis on the LNG pipeline system. We have also developed the optimal design program to find the optimal thickness of insulation and the pipeline size. The program searches the optimal design with the minimum capital cost of pipelines and insulation on the operating conditions of maximum allowance pressure-drop and BOG amount, etc.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.174.2-174.2
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• 2011

최근 유가상승과 석유, 천연가스의 가채 매장량의 한계등과 함께 온실가스에 의한 지구온난화 방지를 위하여 미국, 유럽국가 및 캐나다 등에서는 바이오매스를 이용한 에너지 회수 기술개발에 많은 관심과 연구를 수행하고 있다. 바이오 매스는 에너지 밀도 대비 존재하는 지역이 광범위하여 발생, 수집, 수송에 따른 비용이 많이 소요되는 특성이 있어 산지에서 직접처리하거나 수집하여 대규모처리등과 같이 여러 가지 현장상황에 따라 적정한 플랜트 운용의 유연성을 갖추고 있어야 한다. 일반적으로 바이오매스로부터 중소형으로 분산형 발전이나 수소제조를 위해서는 직접 연소법 보다는 가스화 방식을 이용하고 있는데, 연소에 의해 열을 생산하여 전기를 생산하는 방식은 스팀터빈을 이용하는 것이며, 스팀터빈은 소형 운용이 어렵기 때문이다. 본 연구에서는 폐목재로부터 합성가스제조를 위하여 5톤/일 규모 가스화기를 제작하였으며, 타르 및 수트와 같은 미반응 물질을 제거할 수 있는 집진, 세정장치를 설계 및 제작하였다. 또한 합성가스에 함유된 현열로부터 열회수를 위하여 열교환기를 설치하였으며, 정제된 합성가스를 이용하는 가스엔진을 통하여 열병합 발전시스템 연계운전을 수행하였다. 운전 실험을 폐목재 가스화 3톤/일 규모로 수행하였으며, 평균 1,500kcal/$Nm^3$의 발열량을 갖는 합성가스를 생성시킬 수 있었다. 사이클론, 스크러버 및 기수분리 장치를 이용하여 정제된 합성가스는 합성가스 엔진을 통하여 72kW 이상의 전력생산이 가능하였다. 열교환기를 통하여 평균 15,000kcal/h의 배열 회수가 가능하였으며, 바이오매스 가스화 합성가스를 이용한 열병합 발전이 가능함을 입증하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.5
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• pp.413-421
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• 2015

Since the first Cubesat was launched in 2003, there have been more than 230 Cubesats launched so far. Due to their small size and lightweight, Cubesats were launched by utilizing the empty space of regular launch vehicle. However, this launch method has a weakness that has been easily affecting by the schedule of major payloads. As a new solution to this problem, it has been proposed that a robot arm installed on ISS would be used to launch Cubesats. The orbits of Cubesat deployed from the ISS in various angles and directions are analyzed in this paper. We also analyze the possibility of collision between the Cubesat and ISS within the operational orbit of the CubeSat and eventually calculate the optimal angle of a robot arm, which maximizes the lifetime of Cubesat and minimizes the risk of collision between the Cubesat and ISS.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.11
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• pp.6932-6942
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• 2014

The expressway is a key area of road networks for national industry, economics and social development. In addition, the number of lines are increasing continuously. Recently, road management policy have shown a paradigm shift to safe road, low-carbon and green etc. Nevertheless, the road condition has deteriorated dramatically by fatigue cracking, thermal cracking and weather impact. On the other hand, the budgets for highway maintenance have shrunk dramatically. In this study, an effective pavement management and maintenance process was developed to extend the pavement serviceability and pavement life to overcome the rack of budgets.

• Journal of Environmental Policy
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• v.14 no.1
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• pp.33-52
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• 2015

The purpose of this paper is to analyze the sector-specific greenhouse gas reduction implementation strategies priority using the multi-criteria analysis methods (AHP and Feedback ANP). Our analysis demonstrates that the highest priority among the evaluation criteria is given to the feasibility compared to the efficiency and the effectiveness in most of the sectors. In the public and the building sectors, it has been found that the governmental driving force is absolutely crucial in technological dissemination and diffusion. The results and the main findings are as follows. Firstly, the priority of the policy evaluation criteria has been changed by analysis methods. Secondly, the total weight and the priority of each sector's alternatives also have been changed. Finally, the priority of the alternatives for criteria has been changed by the analysis methods.

• Journal of the Korean Institute of Gas
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• v.13 no.3
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• pp.15-21
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• 2009

Gas hydrate is an ice-like crystalline compound that forms at low temperature and high pressure conditions. It consists of gas molecules surrounded by cages of water molecules. Although hydrate formation was initially found to pose serious flow-assurance problems in the gas pipelines or facilities, gas hydrates have much potential for application in a wide variety of areas, such as natural gas storage and transportation. Its very high gas-to-solid ratio and remarkably stable characteristics makes it an attractive candidate for such use. However, it needs to be researched further since it has a slow and complex formation process and a high production cost. In this study, formation experiments have been carried out to investigate the effects of pressure, temperature, water-to-storage volume ratio, SDS concentration, heat transfer and stirring. The results are presented to clarify the relationship between the formation process and each factor, which consequently will help find the most efficient production method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.3
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• pp.1225-1234
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• 2013

According to the importance of greenhouse gas emissions, it grows day by day, the goverment is promoting to prepare the specific policy implementation to enhance building energy-saving design standars as the development agenda. In this study, the statistical analysis was performed by Descriptive statistics, Regression analysis, and Hypothesis testing to collect to generate and storage energy usage data in real time to settle parameter setting to affect energy consumption under energy-guzzling apartment not single building. This study is expected to be utilized as the basis for the optimum energy-saving design of the future of the building or facility energy costs rise and the demand for energy-efficient and stable management.

• Journal of Navigation and Port Research
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• v.32 no.3
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• pp.179-184
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• 2008

The aim of this paper is to establish the evaluation system of port logistics of Incheon using the QFD(Quality Function Deployment) model. The research methodology is consisted of four phases. The first step is to investigate the important factors consisting the port logistics of Incheon and then calculate the weighting of factors by Analytic Hierarchy Process (AHP). The second step is to draw out the degree of inter-relation among factors by Fuzzy Subordination Relations (FSR). At the third step, the established system through the QFD method using results of the first and second steps will be used to evaluate and diagnosis the level of port logistics of Incheon. Finally, the sensitivity analysis will be performed and the degree of improving port logistics will be presented according to the rising the relevant factors.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.907-910
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• 2007

Recently, a container shipping volume has increased dramatically and continued on a trend of rapid growth, and so the number of container handled at the port increase. therefore, it's increasing about concern of harbor automatism to save distribution costs in harbor. harbor automatism classifies into four large automatism's, gate automatism by using RFID that trailer come with burdening the container to be loaded on ships go though with RFID and Quay-Side container crane automatism that treats cargos loading on ships and automatism of CG that loads containers from yard, and automatism of container transporters that carries containers in between gates. To increase the using efficiency of harbor, detecting exact location of yard crane is very important matter. In this paper, it intends to discuss about yard crane automatism applied UWB Ranging system and bring up the development direction.