• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.305-310
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• 2003

This study is intended to outline the lessons that can be learned from European experience of the opportunities and challenges involved in operating train ferries to carry freight. The study considers the various train ferry routes that have operated over recent years in Europe, examines their characteristics, and then proceeds to evaluate the economic viability of train ferries in general. On the basis of this analysis, we have attempted to outline the conditions that appear to be required under which Train Ferries may be competitive. This study shows that long crossing train ferries in Europe have survived where the adjacent railway systems handle a significant volume of domestic traffic and do themselves playa serious role in the transport industry. There is no reason to suppose railway wagons cannot be carried economically over long distances. Experience in Western Europe is that they are best operated as mixed road trailer and rail wagon services. Only the lower deck need carry railway wagons, which greatly simplifies loading and the physical construction of the ship. Existing road based ro-ro ferries can be adapted to become rail ferries. It is, however, essential that there is commercial clarity as to the responsibility for ensuring the overall service is viable. To that end, the ferry company is responsible for marketing the service and managing relationships between the two railway authorities.

• Journal of Mechanical Science and Technology
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• 제18권12호
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• pp.2310-2318
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• 2004

The effects of change in injection pressure on spray structure in high temperature and pressure field have been investigated. The analysis of liquid and vapor phases of injected fuel is important for emissions control of diesel engines. Therefore, this work examines the evaporating spray structure using a constant volume vessel. The injection pressure is selected as the experimental parameter, is changed from 400 bar to 800 bar by using a common rail injection system. Also, we conducted simulation study by modified KIVA-II code. The results of simulation study are compared with experimental results. The images of liquid and vapor phase for free spray were simultaneously taken by exciplex fluorescence method. As experimental results, the vapor concentration of injected fuel is leaner due to the increase of atomization in the case of the high injection pressure than in that of the low injection pressure. The calculated results obtained by modified KIVA-II code show good agreements with experimental results.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.2455-2462
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• 2008

Global warming has become one of the most important social responsibilities. After Kyoto protocol for greenhouse gas reduction by climatic change convention came into effect, developed countries are presenting various policies to reduce greenhouse gas that is produced in transport field. One of those policies is modal shift that change from road freight to sea, inland waterway and railway transportation that is eco-friendly. Because increase of road freight brings about road congestion and accident, logistics cost, air pollution and green house gases. Railways are superior to all other modes of transport in mass transportability, high speed, timeliness, safety and environmental-friendliness, but the railway industry has been pushed behind in competition. In developed country's government actively promoted relevant legislation, policies, and countermeasures known as modal shift policies to shift freight transport from road to large volume mode such as railway and ship. In this paper, we discuss the current situation in modal shift, compare it with cases in other countries EU and Japan, identify problems in Korea, and propose the following ways to enhance competitiveness of rail freight.

• 한국자동차공학회논문집
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• 제12권6호
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• pp.16-22
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• 2004

Dimethyl Ether (DME) has been considered as one of the most attractive alternative fuels for a compression ignition engine. The major advantage of DME-fuelled engine is a great potential for soot-free combustion without sacrificing an inherent high thermal efficiency of diesel engine, despite a necessity for modification of the conventional fuel injection system. An experimental study on DME and conventional diesel sprays was conducted by employing a common-rail type fuel injection system with a 5-holes sac type nozzle, including a constant volume vessel pressurized with nitrogen gas. The injection rates of DME and diesel fuel were recorded with the Bosch type injection rate meter. The injection delay of DME was shorter than that of diesel fuel. The measured injection rates of DME and diesel fuel were correlated with spray penetrations. The prediction method of spray penetration was established using the injection rates, which was verified with the Dent's penetration model and found to agree well for DME case.

• 한국항만경제학회지
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• 제23권1호
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• pp.61-73
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• 2007

한중, 한일, 중일간의 FTA에 대한 관심과 노력은 보다 효율적이고 합리적인 운송서비스의 개설을 요구하고 있다. 따라서 이러한 추세에 부응하며 운송 서비스의 고효율화를 위해 제시하고자 하는 방안이 열차페리이다. 특히 서해안지역항만과 중국의 주요항만을 연계하고 아울러 한일간의 열차페리 운영을 통해 한중일간의 통합물류체계의 구축이 가능하다. 본 연구는 동 서비스에 대한 기초 연구로써 그 의미를 지니고 있으나 지속적이고 구체적인 후속연구가 필요하다. 특히 한중일 간의 열차페리는 TAR의 노선 연계의 방안으로 TKR이 북측노선을 우회하여 나머지 아시안 및 유럽항만들과 연계가 가능하며 중국과 일본, 한국의 국내 물류비용에 관한 경쟁력의 제고도 가능할 것이다. 특히 한중일은 열차노선의 궤도가 동일하며 FTA 추진이나 2, 3차 산업제품중심의 교역구조로의 전환에 따른 운임 부담력이 높은 화물의 교역량의 증대 등으로 실현 가능성이 더욱 증대되고 있다. 특히 기존의 해상 운송 중심의 복합운송을 철도와 해상운송이 연계된 효율적인 복합운송체계의 구축을 통해 한반도의 동북아 물류중심국가 발전에 공헌 할 수 있는 방안으로 활용해야 할 것이다.

• 대한교통학회지
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• 제23권2호
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• pp.25-36
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• 2005

본 연구에서는 도시철도의 중장거리 통행 특성에 따른 통행거리에 대한 분포수요이 불규칙성을 반영하고 통행거리와 분포수요간의 다양한 함수관계를 고려하기 위해서 도시철도 분포수요 예측모형에 대한 퍼지제어를 이용한 접근방밥을 제시하고자 하였다. 모형구축 및 검정을 위한 자료로는 대구시 지하철 1호선의 실제 통행량 자료와 통행거리 자료를 활용하였으며, 통행량 자료는 역무자동화 기기에서 하루동안 수집된 각 역별 발생량 및 집중량과 역간 분포량을 집계한 것이고 통행거리 자료는 대구시 지하철 1호선의 영업연장을 활용하여 추바역과 도착역간의 거리를 산정하여 집계한 것이다. 모형의 적합성 검토에서는 도시철도 역세권을 기반으로 한 동일한 자료를 이용하여 모형을 구축한 퍼지제어모형과 중력모형을 비교 ${\cdot}$ 검토하였다. 그 결과 증력모형에서는 통행거리 변수가 모형에 좋지 못한 영향을 미치는 반면, 각 변수간의 다양한 함수관계를 표현할 수 있는 퍼지제어모형에서는 통행거리가 상당히 유용한 자료로 활용되었을 뿐만 아니라 중력모형보다 높은 예측정도를 나타내는 것으로 분석되었다. 따라서 향후 도시철도만의 발생 ${\cdot}$집중량을 토대로 도시철도 분포수요 예측시에는 퍼지제어를 이용할 경우 양호한 예측결과가 기대되어지며, 본 여구에서 미진하였던 초적의 소속함수 정의 와 퍼지규칙 설정문제는 신경망 이론과 조합하면 더욱 진보한 예측의 정도 향상과 모혀안 절대비교가 가능할 것으로 판단된다.

• 대한방사선치료학회지
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• 제26권1호
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• pp.51-57
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• 2014

목 적 : 췌장암의 경우 십이지장에 부여되는 선량 분포가 중요하게 다뤄진다. 십이지장의 경우는 호흡에 따라 변화가 발생된다. 이에 본 논문에서는 본원에 설치된 CT-on rail System을 이용하여 환자의 Kilovoltage Cone-Beam CT 촬영하여 십이지장의 위치 변화를 파악하고 체적 당 부여받는 선량의 변화를 파악하고자 한다. 대상 및 방법 : 3 명의 환자를 대상으로 CT-on rail System을 이용하여 KVCBCT를 획득하고 SYNGO Software를 이용하여 최초의 치료계획 영상과 비교 십이지장의 위치 변화를 파악하였다. 획득한 영상을 치료계획장치인 Pinnacle로 전송하여 변화된 위치에서 치료 용적에 포함되는 십이지장의 체적 변화를 파악하고 같은 선량에서 발생되는 체적의 변화를 분석하였다. 결 과 : 위치 변화 분석에서 좌우(Left-Right Direction) 방향에서 1.2cm, 1.0cm 머리 다리(Craniocaudal Direction) 방향에서는 0cm, 0.8cm 전후(Anterior-Posterior Direction) 방향에서는 0.1cm, 1.0cm의 변화를 나타내었다. 체적의 변화는 환자 1의 경우는 최초 치료계획에 비해 체적이 최대 약 460%, 최소 120% 증가하였고 환자 2는 최대 490%, 최소 160% 증가하였다. 반면 환자 3은 최대 150% 증가하였으나 최소 값에서는 약 30% 감소함을 나타내었다. 호흡의 변화에 따라 가장 많은 변화를 나타낸 환자 1의 경우는 최초의 치료계획과 비교하였을 시 초기 선량에서는 변화가 크게 나타나지 않았지만 선량이 증가함에 따라서 $V_{10}$에서는 118%, $V_{20}$ 117%, $V_{30}$ 400%, $V_{40}$ 480%의 체적 변화가 발생됨을 알 수 있었다. 결 론 : 현재 3D-CRT를 이용한 방사선 치료 시 4D-CT를 이용한 모의치료를 통해 환자의 호흡에 따른 십이지장의 위치 변화에 대해 파악하고 정확한 치료계획용적의 설정을 통해 호흡에 따른 십이지장의 체적 변화를 예측하고 이에 맞는 적합한 치료 계획을 세워 십이지장에 부여될 수 있는 선량을 최소화 시켜야 할 필요성이 있다고 사료된다.

• 한국분무공학회지
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• 제13권4호
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• pp.206-211
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• 2008

In this research, combustion and spray characteristics were investigated experimentally in a constant volume chamber by applying bio-diesel fuel to a common-rail system in which precise control is available for utilizing environmentally friendly properties of bio-diesel fuel. The experiment was conducted at fuel temperatures $20^{\circ}C$ and $-20^{\circ}C$ to investigate combustion characteristics of bio-diesel fuel provoking problems in fluidity specially in a low temperature. For the visualization, the experiment was carried out under various conditions of ambient pressure, injection pressure and fuel temperature. The test was made by three different types of diesel fuels, conventional diesel, BD20 and BD100. In summary, this research aims to investigate combustion characteristics in the application of bio-diesel fuels and compare the results with performance of conventional diesel fuel. This experimental data may provide fundamentals of spray and combustion of bio-diesel fuels at a low temperature and contribute to the development of bio-diesel engines in future.

• 한국분무공학회지
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• 제17권2호
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• pp.71-76
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• 2012

The aim of this work was to investigate the combustion and nanoparticle emission characteristics of premixed charge compression ignition (PCCI) combustion at various test conditions using a single cylinder common-rail diesel engine. In order to create the homogeneity of fuel-air mixture, the premixed fuel (gasoline) was injected into premixing chamber during the intake process and then the diesel fuel was directly injected into the combustion chamber as an ignition source for the gasoline premixture. From these results, it revealed that the ignition delays and combustion durations were gradually prolonged and the peak combustion pressure were increased because diesel fuel was injected early injection timing with the increase of premixed ratio. In addition, as the increase of premixed ratio, total particle number is generally decreased and particle volume also indicated low levels at the direct injection timing from BTDC $20^{\circ}$ to TDC. At further advanced injection timing, total particle number and volume were generally increased

• 한국분무공학회지
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• 제20권4호
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• pp.217-222
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• 2015

In this study, Injection rate tests of a Diesel common-rail injector have been performed with injection volume measurement type injection rate test system EMI21 for construction of injector model can be used in an engine calibration mean valued model. The measuring principle of the test system is based on measurement of dispalcement of a movable measurement piston by the volume of fluid released by the injector. From these injection rate test results, the characteristics on shape of instantaneous injection rate and injection fuel amount have been investigated and injection fuel amount calculation equation based on test results has been newly constructed. This equation is very simple and calculation error is less than 5% with test results for wide range injection pressure (200~1800 bar) and injection duration ($200{\sim}1800{\mu}s$) conditions. So, it is anticipated that newly constructed simple injection fuel amount model in this study can be efficiently used on engine calibration and control model.