• International Journal of Railway
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• 제6권2호
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• pp.33-44
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• 2013

In recent years, energy consumption in the transportation sector by expanding motorization continues to increase in almost every country in the world. Moreover, the growth rate of the transportation energy consumption is significantly higher than those of the civilian and industrial sectors. Therefore, every country strives to reduce its dependence on private transport, which is the main contributor to the transportation energy consumption. In many countries, concepts such as Transit Oriented Development (TOD) or New Urbanism, which controls road traffic by increasing the proportion of the public transportation significantly, have been implemented to encourage a modal shift to public transport. However, the level of change required for eliminating environmental problems is a challenging task. Minimizing transportation energy consumption by controlling the increase of the traffic demand and maintaining the level of urban mobility simultaneously is a pressing dilemma for each city. Grasping the impact of the diversity of the urban transport and infrastructure is very important to improve transportation energy efficiency. However, the potential for reducing urban transportation energy consumption has often been ineffectively demonstrated by the diversity of cities. Therefore, the accuracy of evaluating the current efficiency rate of the urban energy consumption is necessary. Nevertheless, quantitative analyses related to the efficiency of transportation energy consumption are scarce, and the research on the current condition of consumption efficiency based on international quantitative analysis is almost nonexistent. On the basis of this background problem definitions, this research first built a database of the transportation energy consumption of private modes in 119 cities, with an attempt to reflect individual travel behaviors calculated by Person Trip data. Subsequently, Data Envelopment Analysis (DEA) was used as an assessment method to evaluate the efficiency of transportation energy consumption by considering the diversity of the urban traffic features in the world cities. Finally, we clarified the current condition of consumption efficiency by attempting to propose a target values for improving transportation energy consumption.

• Journal of Korean Society of Transportation
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• 제28권5호
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• pp.31-41
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• 2010

The objective of this paper is to evaluate production efficiency of the commercial road freight transportation industry using quarterly actual data by individual truck drivers from January 2005 to September 2009. In addition, this study analyzes various impact factors that influence production efficiency, including regulatory factors (e.g., entrust management system and multi-level transactions). For this purpose, this study uses data envelopment analysis and a truncated Tobit model. As a result, production efficiency of the general freight sector is higher than those of the other two sectors. Also, production efficiency in the steel goods sector ranks the highest; meanwhile, production efficiency in the oil goods sector ranks the lowest. In particular, production efficiency indicators of the commercial road freight transportation industry fluctuate with time by a small margin, and have an upward tendency on the whole. Finally, some policy implications are given to promote production efficiency of the commercial road freight transportation industry.

• Journal of the Korean Society of Safety
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• 제32권5호
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• pp.141-148
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• 2017

Over the past 30 years, the business effects of the improvement project at black spot have been decreasing since 2010, with a reduction in the amount of government spending, coupled with proposing a uniform improvement plan. In order to promote more efficient improvement projects, it is necessary to evaluate the efficiency of local governments and improve the business methods of local governments with low efficiency. However, more sophisticated efficiency analysis methods are needed. Because in previous studies have been limited to the analysis of effects before and after the project through the simple before-after analysis. For this purpose, this study analyzed the efficiency of improvement project at black spot by local governments in Gyeonggi-do using DEA to compare and analyze efficiency in various fields. As a result, Goyang, Seongnam, Paju, Hanam and Yangju showed high efficiency local governments. For local governmetns with low efficiency, the improvement projets to improve efficiency were divided into civil engineering work, structure work, pavement work, additional work and transportation work, and the appropriate construction ratios of each local government were analyzed and presented.

• Proceedings of the KSR Conference
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1544-1549
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• 2011

Transportation Efficiency Act of 2009 System National Integrated Transportation System Efficiency Act and the revised Road Traffic in the center of the Intelligent Transportation Systems rail, sea and air transport sector is expanding in various areas to promote business and Industry is planning to. Accordingly, the introduction of Intelligent Transportation Systems Outlook and Direction of the railway sector and to provide a comprehensive introduction of Intelligent Transportation Systems rail sector has raised the need. In this paper, the introduction of Intelligent Transportation Systems rail sector strategy is presented as follows. First, the rail users a convenient rail-centric information system used. Second, the reliability and value-added operating system built for the creation of high-tech rail. Third, crime and accidents are implemented in a safe railway. The results of this paper, the railway sector through the national Intelligent Transportation Systems to develop and introduce strategies to provide operational direction is expected to be present.

• Journal of the Korea Safety Management & Science
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• 제9권6호
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• pp.137-146
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• 2007

The objective of this paper is to study the establishing system of truck collaboration and to reduce traffic cost for participating transportation enterprises. The system of truck collaboration can enhance the transport efficiency and to reduce traffic cost without new investment for trucks and equipments. The type of truck collaboration should be enumerated (1) the system of head and branch base (2) the system of central terminal (3) the system of separating collection and delivery for cargo (4) the system of cooperating cargo order and truck allocation. The efficiency of truck collaboration is possible to be realized for transportation enterprises, receiver and sender of cargo.

• International Journal of Railway
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• 제5권4호
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• pp.167-174
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• 2012

As wireless power transfer (WPT) technologies emerge in a wide range of applications including public transportation, many expect that applying the technology to the current railway systems will bring positive effects to current railway systems. In this paper, we introduce design methodology of a WPT system for railway application. Fundamental principles of magnetic fields and a WPT circuit are first analyzed, and advantages and efficiency of a possible train system are discussed. It then examines other significant factors such as performance requirements and EMC criteria to design a wireless train system.

• The Journal of Economics, Marketing and Management
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• 제11권2호
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• pp.13-22
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• 2023

Purpose: The purpose of this study is to examine the policy implications of establishing a compact city in Seoul, analyzing whether it is an appropriate and efficient eco-friendly housing supply alternative. Research design, data, and methodology: The analysis criteria include efficiency, safety, and comfort, with efficiency encompassing economic, energy, and public transport links' efficiency. Safety and comfort are aspects of eco-friendliness, housing safety, and improvement in living environments. Results: In terms of economic efficiency, compact cities are a less expensive option than purchasing land for housing construction. To increase energy efficiency, we plan to adopt eco-friendly energy sources. Transportation efficiency is high in locations near public transport stations. To enhance safety and comfort, we intend to create large-scale parks and forests in Seoul. To ensure residential safety, measures will be taken to reduce road vibration, vehicle noise, and scattering dust. Conclusions: Selecting an appropriate location that provides convenient public transportation is essential for creating a compact city for housing in a large city. Combining a compact and smart city is necessary, and implementing smart technologies is needed to prevent dust, noise, and vibrations, which are undesirable in a residential environment.

• The Transactions of The Korean Institute of Electrical Engineers
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• 제64권11호
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• pp.1651-1657
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• 2015

In MHz operating wireless power transfer systems, skin- and proximity-effect losses in the transmitter and the receiver coils dominate the coil-to-coil efficiency of the system. A Litz-wire was regarded as a common solution for minimizing such Ohmic losses in high frequencies. In this paper, equivalent series resistances of 12 different cables including Litz-wire and copper tubing have been calculated and measured for a 6.78 MHz, 100W, 30 cm wireless power transfer system. It has been shown that the copper tubing has lower resistances compared to the Litz-wire in that frequency and a wireless power transfer system with the copper tubing was able to achieve much higher efficiency than a system using the Litz-wire. Calculations of the resistances and efficiencies were accomplished with analytical equations and those calculations were evaluated by experimental results.

• Proceedings of the KSR Conference
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.657-665
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• 2008

The main transportation mode of long distance inter-city passenger trips is high-speed rail and the modal share of transportation has been changed profoundly since the KTX service has been started in the Kyung-Bu railroad transportation corridor in the day of 1 April, 2004. After an opening of KTX service in the second stage Kyung-Bu and Ho-Nam railroad transportation corridors, a capacity of incumbent railroads will be increased and operational environments of freight train will be improved. The purpose of this paper is to examine the impact of KTX service operation on the national logistics thoroughly. This paper establishes a deceptive scheme in the national railroad logistic transportation and a route operational strategy between the main origins and destinations efficiently considering the changes of the current freight transportation system in the future. We expect to achieve efficiency of logistic transportation in this paper through alternative routes for example Ho-Nam, Chang-Hang, Seo-Hae line.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제27권4호
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• pp.209-216
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• 2014

The screen printed technique is one of the electrode forming technologies for crystalline silicon solar cell. It has the advantage that can raise the production efficiency due to simple process. The electrode technology is the core process because the electrode feature is given a substantial factor (for solar cell efficiency). In this paper, we tried to change conditions such as squeegee angle $55{\sim}75^{\circ}$, snap off 0.5~1.75 mm, printing pressure 0.6~0.3 MPa and 1.6~2.0 mm finger spacing. As a result, the screen printing process showed an improved performance with an increased height higher finger height. Optimization of fabrication process has achieved 17.48% efficiency at screen mesh of 1.6 mm finger spacing.