• 한국산업융합학회 논문집
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• 제8권4호
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• pp.197-204
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• 2005

It is well known that pipelines have the highest capacity and are the safest and least environmentally disruptive form of transporting oil and gas. However, pipeline damages caused by both internal and external corrosion is a major concern threatening the reliability of oil and gas transportation and the soundness of pipeline structure. In this study, we estimated the expected allowable damage defect by comparing the ASTM B31G code which has been developed as the evaluation method of reliability and incident prevention of damaged pipelines based on the amount of loss due to corrosion and the yield strength of materials to a modified theory considering diverse detailed corrosional forms. Furthermore, we suggested the method that estimates the expected life span of used pipelines by utilizing the reliability method based on major variables such as, the depth and length of damage and corrosional rate affecting the life expectancy of pipelines.

• 융복합기술연구소 논문집
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• 제3권1호
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• pp.9-14
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• 2013

Recently, the development of renewable energy sources in Mongolia has been needed due to climate change and air pollution in Ulaanbaatar as rapid economic growth. Biodiesel can be considered as an alternative fuel for petroleum based diesel in order to decrease air pollution in Ulaanbaatar because of its no emission of particle materials from internal combustion engine in automobile. Rapeseed oil having low cloud point and pour point was suggested as a promising raw material for biodiesel production in Mongolia. Considering high population density and severe air pollution by particle materials and SOx in Ulaanbaatar, prior supplying site of biodiesel in Mongolia was the capital region including Ulaanbaatar. In the production of biodiesel in Mongolia, adsorption process was a effective alternative to washing process for the removal of residual alkali catalyst and reactants due to long winter time in Mongolia. For the stable supply of biodiesel, subsidy and no tax policy is needed in the early stage of biodiesel supply in Mongolia.

• 한국항해항만학회지
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• 제32권9호
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• pp.711-716
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• 2008

Marine accidents related to the tug-barges are frequent recently, such as oil spill caused by collision between oil tankers and tug-barges. There are many causes of these accidents, but poor working condition of operators takes up a considerable part of most causes. That is, the danger of accidents caused by fatigue accumulation exists in tug-barges of less than 200 gross tonnage engaged on near-coastal voyages or short shipping, because of the long-distance navigational watch by only one master. This paper aims to deduce problems of human element part out of the plan of sqfe navigation, and to propose legal amendments for preventing marine accidents by tug-barges.

• 전기학회논문지P
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• 제65권1호
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• pp.41-46
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• 2016

It has been proven that the dissolved gas analysis (DGA) is the most effective and convenient method to diagnose the transformers. The DGA is a simple, inexpensive, and non intrusive technique. Among the various diagnosis methods, IEC 60599 has been widely used in transformer in service. But this method cannot offer accurate diagnosis for all the faults. This paper proposes a fault diagnosis method of oil-filled power transformers using IEC code based neuro-fuzzy model. The proposed method proceeds two steps. First, IEC 60599 method is applied to diagnosis. If IEC code can't determine the fault type, neuro-fuzzy model is applied to effectively classify the fault type. To demonstrate the validity of the proposed method, experiment is performed and its results are illustrated.

• 한국안전학회지
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• 제21권2호
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• pp.1-6
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• 2006

It is well known that pipelines have the highest capacity and are the safest and least environmentally disruptive form of transporting oil and gas. However, pipeline damage caused by both internal and external corrosion is a major concern threatening the reliability of oil and gas transportation and the soundness of the pipeline structure. In this study, we estimate the allowable damage by comparing the ASTM B31G code to a modified theory considering diverse detailed corrosive forms. The ASTM B31 G code has been developed as the evaluation method for reliability and incident prevention of damaged pipelines based on the amount of loss due to corrosion and the yield strength of materials. Furthermore, we suggest a method for estimating the expected life span of used pipelines by utilizing the reliability method based on major variables such as the depth and length of damage and the corrosion rate affecting the life expectancy of the pipelines.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.216-221
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• 2004

Linepipe steels with a low carbon acicular ferrite microstructure have been recently developed to accommodate the current transportation condition of the gas and oil industry, and they are finally applied to West- East pipeline project in China. By adopting acicular microstructure, both better formability and better toughness could be obtained due to low yield ratio and fine grained microstructure. Mechanical properties of pipe are not greatly different from those of base plates or hot coils with a microstructure of acicular ferrite. Merits of introducing higher strength steels are well known, i.e., reducing the gauge of pipe and the material cost, increasing the welding speed and decreasing construction cost because of reducing the construction period. Threfore, gas and oil industry has required higher strength steel than APIX70 grade steel. Under this background, API-X80 steel has been developed and shall be applied to the several projects. In this paper, developing stage of API-X80 steel is also presented and discussed.

• Corrosion Science and Technology
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• 제7권4호
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• pp.193-196
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• 2008

This article briefly tests and analyzes the sulfur content and the distribution of active sulfur in the crude oil of Kurkow Kazakhstan and Siberian Russian, and discusses the relationship between active sulfur content and total sulfur content, active sulfur and corrosion. At the same time, it measures the open circuit potential of X70 steel and X60 steel witch have been immerged in the above two kind of crude oil for a period of time, discusses the sulfur corrosion to metal.

• International Journal of Naval Architecture and Ocean Engineering
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• 제5권1호
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• pp.21-32
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• 2013

Marine transportation industry is undergoing a number of problems. Some of these problems are associated with conventional marine fuel-oils. Many researchers have showed that fuel-oil is considered as the main component that causes both environmental and economic problems, especially with the continuous rising of fuel cost. This paper investigates the capability of using natural gas and hydrogen as alternative fuel instead of diesel oil for marine gas turbine, the effect of the alternative fuel on gas turbine thermodynamic performance and the employed mathematical model. The results showed that since the natural gas is categorized as hydrocarbon fuel, the thermodynamic performance of the gas turbine cycle using the natural gas was found to be close to the diesel case performance. The gas turbine thermal efficiency was found to be 1% less in the case of hydrogen compared to the original case of diesel.

• 대한교통학회지
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• 제27권2호
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• pp.199-206
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• 2009

교통시설 투자평가에 대한 경제성 분석과 관련하여 일반적인 예비타당성조사 지침 및 투자평가지침에서 적용하는 차량운행 비용 절감편익 중 유류비 산정 자료는 차량운행시 유류소모량과 주행속도와의 관계만을 고려하여 분석하고 있다. 신호로 인한 정지지체가 발생하지 않는 연속류의 경우 주행속도와 통행시간의 변화로 인한 절감편익에 대한 고려가 가능하나, 실제 신호교차로상에 신호제어로 인해 정지가 발생하는 단속류에 대해서는 정지지체시간감소 및 정지율 개선에 대한 고려가 없어 개선 효과분석의 현실반영이 어렵다. 따라서 기존 연구에 정지지체시간감소에 따른 절감편익을 보완하여 차량운행비산정 모형 관계식을 개발함으로써 신호교차로 특성을 반영한 편익을 분석 할 수 있는 기틀을 만드는 데 본 연구의 목적을 두었다. 공회전시 유류소모량 적용으로 정지지체시간를 고려한 차량운행비용을 재정립하였고, 서산시 가로축 2개에 대한 교통신호체계 최적화사업에 적용하여 기존 모형 적용시와 개발모형 적용시 경제적 편익에 대하여 분석하였다. 도로의 혼잡지역 증가로 교통체계관리의 중요성이 부각되는 가운데 신호연동체계 개선 및 혼잡개선 사업등의 효과분석에 있어 신호교차로 특성을 고려한 경제성 분석의 모형제시를 통해 지체도 개선을 반영한 좀 더 현실적 경제성분석에 도움을 줄 수 있을 것으로 기대한다.

• The Journal of Asian Finance, Economics and Business
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• 제2권3호
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• pp.41-46
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• 2015

Energy saving in the transport sector in the framework of the annual growth of energy consumption, the degree of negative impact on the environment and the amount of harmful emissions are becoming increasingly important. The article considers the world tendencies of energy consumption in transportation sector and emphasizes its dependency from oil. Also article describes the dynamics of energy use and CO₂ emissions from transport of city Almaty. In conclusion authors identify a number of problems in the transport sector, which hinder the implementation of energy efficiency measures and measures to reduce CO₂ emissions.