• Proceedings of the KSR Conference
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• 2002.05a
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• pp.498-502
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• 2002

Section insulators are indispensible devices for the electric railways, which divide electrical connections between the trolley lines without losing mechanical connections, and this means that they should have both good electrical insulation performance and mechanical performance for pantograph interaction. This paper reviews some technical aspects of the several type section insulators and makes analysis of difficulties during operation. The closed type section insulators are proposed for newly electrified railways, because they have good mechanical and electrical performances for high speed trains up to 200[km/H]. Technical specifications of closed-type section insulators based on survey of the advanced technologies are provided, and also the neutral section configuration method which might be the best solution for newly electrified railways in Korea of 200km/H speed.

• The Korean Journal of Food & Health Convergence
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• v.6 no.6
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• pp.17-23
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• 2020

The main task of agro-industrial production is to provide the population with food products for the production of which energy is expended in the form of electricity, technical means, fuels and lubricants, mineral fertilizers, etc. Accordingly, we have developed a concept and general methodological principles for the analysis of ecological and biotechnical systems in animal husbandry, it makes it possible to simulate the influence of various factors on the energy and ecological efficiency of systems, to compare and search for energy-saving modes and technologies. General methodological principles have been developed for the analysis of energy efficiency and environmental safety of agricultural ecological and biotechnical systems, which are based on the definition of the bioenergy efficiency coefficient, the quantitative expression of which is the ratio of energy accumulated in products to the total energy consumption for its production. This makes it possible to model with sufficient accuracy the influence of various factors on the energy and environmental efficiency of the system, to compare and search for energy-saving modes and technologies in order to find and select the most energy efficient ones to increase the energy efficiency of the complex.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.767-775
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• 2005

Power Supply System for electric railways is diversified with technical development and is required high technologies. especially, recently there is required many research and development for earthing to ensure safety of people and protection of installations. Generally, leakage resistance is high between rail and ground at tunnel section of subway. because of short circuit of feeding line, earthing interference by transient overvoltage between signals and communication system, and insulation failure, it can damage to human and equipments To minimize these obstacles, earthing equipment is installed at underground section of railway, but it brings about problems in accordance with operate each earthing system to be not enough required protection provisions for electrified railways. This paper proposes effective earthing method to be concerned about installation cost and maintenance. The validity of the proposed earth method is verified by simulation results at underground section of railways.

• The Korean Journal of Food & Health Convergence
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• v.5 no.6
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• pp.17-21
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• 2019

This article addresses issues related to environmental pollution.Particular attention is paid to the prevention of environmental pollution by livestock waste, which prompted the creation of closed ecological and biotechnical systems as environmentally closed production structures that can fit into the equilibrium system of the environment with minimal damage to it. An energy-saving and environmental protection technology for the processing and disposal of livestock waste with a maximum coefficient of energy transfer to livestock products has been developed, which consists in a combined treatment of waste in three stages, by transferring waste from one technological module to another, which makes it possible to completely utilize mineral substances in waste. The focus is on vermicultivation, microalgae cultivation and anaerobic fermentation in a bioenergy plant. To increase the productivity of growing microalgae, the authors proposed a deep type cultivator with submerged movable light sources.The technological parameters of the bioenergy installation for waste treatment are determined. An energy-saving and environmental-friendly technology has been developed for processing The main contribution of the study is the development of energy-saving and environmental technology for the processing and disposal of livestock waste with a maximum coefficient of energy transfer to livestock products.

• Journal of ILASS-Korea
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• v.28 no.4
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• pp.176-183
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• 2023

Many countries are striving to reduce carbon emissions with the goal of net zero by 2050. Accordingly, vehicles are rapidly being electrified to reduce greenhouse gases in the transportation sector. However, many organizations predict that internal combustion engines of LDV (light-duty vehicle) will exist even in 2050, and it is difficult to electrify aircraft and large ships in a short time. Therefore, synthetic fuel (i.e., e-Fuel) that can reduce carbon emissions and replace existing fossil fuels is in the spotlight. The e-Fuel refers to a fuel synthesized by using carbon obtained through various carbon capture technologies and green hydrogen produced by eco-friendly renewable energy. The purpose of this study is to compare and analyze the injection and spray characteristics of the simulated e-Gasoline. We mixed the hydrocarbon fuel components according to the composition ratio of the synthetic fuel produced based on the FT(Fischer-Tropsch) process. As a result of injection rate measurement, simulated e-Gasoline showed no significant difference in injection delay and injection period compared to standard gasoline. However, due to the low vapor pressure of the simulated e-Gasoline, the spray tip penetration (STP) was lower, and the size of spray droplets was larger than that of traditional gasoline.

• Applied Chemistry for Engineering
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• v.34 no.4
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• pp.331-346
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• 2023

Recently, green processes that can be directly used in an energy-efficient and electrified society to achieve carbon neutrality are attracting attention. Existing heat and pressure-based desalination technologies that consume tremendous amounts of energy are no exception, and the growth of next-generation electrochemical-based desalination technologies is remarkable. One of the most representative electrochemical desalination technologies is electrochemical ion separation (EIONS) technology, which includes capacitive desalination (CDI) and battery desalination (BD) technology. In the research field of EIONS, various system applications have been developed to improve system performance, such as capacity and cyclability. However, it is very difficult to understand the meaning and novelty of these applications immediately because there are only a few papers that summarize the research background for domestic readers. Therefore, in this review paper, we aim to describe the technological advances and individual characteristics of each system in clear and specific detail about the latest EIONS research. The driving principle, research background, and strengths and weaknesses of each EIONS system are explained in order. In addition, this paper concluded by suggesting the future development and research direction of EIONS. Researchers who are just beginning out in EIONS research can also benefit from this study because it will help them understand the research trend.

• Journal of Korean Society of Transportation
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• v.23 no.5 s.83
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• pp.15-25
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• 2005

Using a stochastic cost frontier approach(SCFA), this paper annually estimates the efficiency and productivity with same data in the papers which analyze the efficiency and productivity using data envelopment analysis(DEA) to compare the results and suggest the political findings of raising the efficiency and productivity for three publicly-owned rail transit properties. the Seoul Subway Corporation (SSC), the Seoul Metropolitan Electrified Railways Sector of Korea National Railroad (SMESRS) and the Busan Urban Transit Authority (BUTA). The results show that the results of SCFA are higher than DEA for efficiency and lower for productivity in that DEA regards the stochastic error and measurement error as the inefficiency contrary to SFCA. But the political findings from these results appears to be similar as follows. First, the productivity of the three properties should be first improved by using existing technologies efficiently and then by introducing new ones. Second, the three properties should improve the technical efficiency through reducing input quantities to raise their efficiency. Finally, all the three components of the productivity such as productive efficiency change, technical change, and scale change should be considered to evaluate their productivity more correctly.

• Journal of Korean Society of Transportation
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• v.22 no.6
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• pp.35-47
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• 2004

Using data envelopment analysis, this paper annually estimates Malmquist total factor productivity indices and decomposes them into productive efficiency change, technical change, and scale change components for three publicly-owned rail transit properties: the Seoul Subway Corporation(SSC), the Seoul Metropolitan Electrified Railways Sector of Korea National Railroad (SMESRS) and the Busan Urban Transit Authority (BUTA). The paper then conceptualizes that the property produces a single output(car-kilometers) using four inputs(labor, electricity, car and maintenance, and track) and uses unbalanced panel data consisted of annual observations on SSC, SMESRS and BUTA. The results show that the average annual growth rate of productivity of the three properties is 6.6 percent, which is 0.5 percent less than the average annual increasing rate of their labor price. They also show that the greatest part of the growth in productivity is explained by technical change and to a lesser degree by scale change and changes in productive efficiency though each of the three components contributes more than 20 percent to the growth in productivity, These results suggest that the three properties should base the increasing rate of their wages on the growth rate of their productivity and utilize existing technologies more efficiently prior to introducing new ones to raise their productivity, and that all the three components should be considered to evaluate their productivity more correctly.