• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.638-644
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• 2008

Mungyeng line(Jupyung${\sim}$Mungyeng) was closed due to a rapid decrease in demand in 1995. However, as the rail transportation demand is expected to increase with the plan to develop a tourist resort and a traffic network in Mungyeng area, it is required to forecast future demand to meet the change of transportation environment in this region. This study predicts the rail transportation demand and analyzes financial benefit in operator's side in case of reopening this line, based on nation-wide traffic volume data from Korean Transportation Database(KTDB). The results of this research can be applied to not only establishing a train operation plan also improving customer service. Moreover, Korail will have an opportunity to develop new business by linking train service to tourist attractions around the Mungyeng area.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1254-1268
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• 2009

정부고속철도 건설계획이 1998년 IMF로 인하여 서울 시흥구간 및 대구$\sim$부산간은 기존 경부선을 이용하여 우선 개통하고, 2단계로 대구$\sim$부산구간을 신설 개통하는 것으로 변경됨에 따라 서울도심 입출구부인 서울$\sim$시흥구간은 고속열차, 일반열차 및 화물열차의 운용운행으로 일반열차 운행횟수 축소로 인한 서비스 저하, 고속철도 서비스 추가 어려움 등으로 동 구간의 신설확장에 대한 지속적인 필요성이 제기 되어 왔으며, 호남고속철도 또한 수서 출발을 위한 강남권 고속철도 건설계획이 경제성 등의 이유로 오송에서 분기하는 것으로 변경됨에 따라 강남권 및 경기남부지역 주민들의 고속철도 서비스혜택의 기회가 박탈되는 결과률 초래하였다. 경부고속철도 개통이후 국가교통체계가 고속철도 중심으로 변화하고 있고, 경부고속철도 2단계 개통, 경전선 및 전라선 복선전칠 완공, 2014년 호남고속철도 개통시 고속열차 추가수요가 발생하나, 서울$\sim$시흥구간의 선로용량 부족으로 고속열차 광명역 출발, 일반열차 운행횟수 축소 등의 파행적인 열차운영이 불가피하므로 이와 같은 문제점을 근본적으로 해소하기 위한 강북구간 (광명$\sim$화전) 의 선로확장과 더불어 강남구간 (수서$\sim$평택)의 고속철도 신설을 추진하여야 한다. 이에 따라 본 고찰에서는 수도권 고속철도 선로확충을 위한 효율적인 열차운영방안, 시설계획 등 고려 하여야 할 사항에 대하여 검토하고자 한다.

• Journal of Mechanical Science and Technology
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• 제19권5호
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• pp.1194-1205
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• 2005

The common-rail injection systems, as a new diesel injection system for passenger car, have more degrees of freedom in controlling both the injection timing and injection rate with the high pressure. In this study, a piezo-driven injector was applied to a high pressure common-rail type fuel injection system for the control capability of the high pressure injector's needle and firstly examined the piezo-electric characteristics of a piezo-driven injector. Also in order to analyze the effect of injector's needle response driven by different driving method on the injection, we investigated the diesel spray characteristics in a constant volume chamber pressurized by nitrogen gas for two injectors, a solenoid-driven injector and a piezo-driven injector, both equipped with the same injection nozzle with sac type and 5-injection hole. The experimental method for spray visualization was based on back-light photography technique by utilizing a high speed framing camera. The macroscopic spray propagation was geometrically measured and characterized in term of the spray tip penetration, spray cone angle and spray tip speed. For the evaluation of the needle response of the above two injectors, we indirectly estimated the needle's behavior with an accelerometer and injection rate measurement employing Bosch's method was conducted. The experimental results show that the spray tip penetrations of piezo­driven injector were longer, on the whole, than that of the solenoid-driven injector. Besides we found that the piezo-driven injector have a higher injection flow rate by a fast needle response and it was possible to control the injection rate slope in piezo-driven injector by altering the induced current.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.225-233
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• 2006

한중일 각국은 동북아지역이 세계경제의 핵심으로 위상을 확보하고자 노력하고 있다. 특히 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 열차훼리이다. 특히 서해안지역항만과 중국의 주요항만을 연계하고 아울러 한일간의 열차훼리 운영을 통해 한중일간의 통하물류체계의 구축이 가능하다. 본 연구는 동 서비스에 대한 초보적인 연구로써 그 의미를 지니고 있으나 지속적이고 구체적인 후속연구가 필요하다. 특히 한중일 간의 열차훼리는 TAR의 노선 연게의 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 있으며 특히 기존의 해상 운송 중심의 복합운송을 철도와 해상운송이 연계한 효율적인 복합운송체계의 구축을 통한 한반도의 동북아물류중심항만으로의 발전에 일조를 할 수 있는 방안으로도 활용해야 할 것이다.

• The Journal of Asian Finance, Economics and Business
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• 제8권5호
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• pp.345-354
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• 2021

With the evolution of containerization and globalization of supply chains, aspects of port functions have made the transition from the sea to the inland region that forms the dry port. To explore the relationship between dry ports and regional economic development, this study uses a gravity model and forecast model to analyze 1,040 observations in 104 cities (22 dry port cities) along the Yangtze River Economic Belt (YREB) from 2008 to 2017. The model includes economic variables, logistics variables, foreign relations variables, and human capital variables. It was found that the dry port is positively correlated with trade volume. Compared with a city without a dry port, the trade volume of a city with a dry port will increase 0.099 times. It can be concluded that a dry port is crucial for the economic development of the YREB. It was also found that per capita GDP as an economic variable, road area and rail number as logistics variables, and foreign relation variables are positively correlated with trade volume, while the human capital variable has no significant effect on trade volume. In addition, governmental policy implications are addressed from the aspects of dry port and industry cluster caused by foreign investment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.621-626
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• 2005

A major part of permanent way maintenance effort is justified by inadequacies in the track substructure and in particular in drainage conditions, which need to be put right across the entire network. In most cases nowadays, improvements of the substructure can be carried out on rail to a high standard of quality. However, this entails substantial movements of material for the removal of spoil and provision of new material. In the future, recycling of old material on site, and use of geosynthetics, will be necessary to help considerably reduce this volume.

• 한국항만경제학회지
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• 제33권3호
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• pp.17-34
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• 2017

본 연구는 물류 네트워크상 중요한 입지 여건을 갖추고 있는 국제산업물류도시와 부산 신항에 신규 자동화물운송시스템 도입에 따른 화물 물동량 및 편익을 분석하기 위해 수행되었다. 이를 위해 본 연구는 대상지역의 장래 화물 물동량 및 전환물동량을 예측하였으며, 그에 따른 사회적 편익을 분석하기 위해 4개의 시나리오 설정하였다. 화물물동량 예측은 사업체 원단위법과 종사자수 원단위법을 적용하였으며, 편익은 기존 도로를 이용하는 화물자동차가 인터모달 자동화물운송시스템으로 전환되는 물동량을 기반으로 산정하였다. 본 연구에서의 편익항목은 직접편익(통행시간 절감, 차량운행비용 절감, 교통사고 절감, 환경비용 절감)이외에 해외 관련 연구를 기반으로 화물통행시간가치 편익, 혼잡비용 절감 편익, 도로유지관리 절감편익을 추가적으로 고려하였다. 분석 결과, 종사자수 원단위를 적용하고, 부산시 강서구의 업종별 종사자수 비율을 적용한 방법론의 화물물동량 및 편익이 가장 큰 것으로 예측되었다. 본 연구는 패러다임 변화에 따른 새로운 자동운송시스템 도입을 기반으로 물동량의 추정과 사업 편익 추정을 하였다는 점에서 학술적 의미가 있을 것으로 기대된다.

• 한국분무공학회지
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• 제13권2호
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• pp.65-72
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• 2008

It is recognized that alternative fuel such as dimethyl ether (DME) has better combustion polluting characteristics than diesel fuel, even though the cetane number of DME is almost the same as that of diesel. Characteristics of DME spray were observed experimentally under various ambient conditions using a constant volume chamber and a common-rail injection system. N-dodecane and LPG fuel sprays were also observed under same conditions of DME spray. Using spray images from backlight scattering and Mie scattering, characteristics of fuel sprays such as penetration and spray volume were visualized and quantitatively measured. The measurements showed that the penetration of early period decreased remarkably, because evaporation of alternative fuels became prosperous by the influence of flash boiling phenomenon under the condition of the low temperature and pressure compared with n-dodecane. The penetration of DME and LPG spray received the influence of temperature more largely in comparison with low density, because the specific surface area increased by atomizing in high density.

• 한국분무공학회지
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• 제14권2호
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• pp.84-89
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• 2009

In this research, combustion and spray characteristics were investigated experimentally in a constant volume chamber by applying different composition rates of octane number in diesel fuel to a common-rail system. For the visualization, the experiment was carried out under different injection pressures and different cetane number. The test was done by three different types of diesel fuels, the different composition rates of cetane number in diesel fuel and HBD. In summary, this research aims to investigate the combustion characteristics in the application of fuels and compare the results with performance of conventional diesel fuel. This experimental data may provide with fundamentals of the development of diesel engines in future.

• Journal of Electrical Engineering and Technology
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• 제9권6호
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• pp.2154-2161
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• 2014

Growth analysis and selection of sea cucumbers (Stichopus japonicas) is typically performed through length or weight measurements. However, because sea cucumbers continuously change shape depending on the external environment, weight measurement has been the preferred approach. Weight measurements require extensive time and labor, moreover it is often difficult to accurately weigh sea cucumbers because of their wet surface. The present study measured sea cucumber features, including the body length, width, and thickness, by using a vision system and regression analysis to generate $R^2$ values that were used to develop a weight estimation algorithm. The $R^2$ value between the actual volume and weight of the sea cucumbers was 0.999, which was relatively high. Evaluation of the performance of this algorithm using cross-validation showed that the root mean square error and worst-case prediction error were 1.434 g and ${\pm}5.879g$, respectively. In addition, the present study confirmed that the proposed weight estimation algorithm and single slide rail device for weight measurement can measure weights at approximately 4,500 sea cucumbers per hour.