• 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.

• STI Policy Review
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• 제4권1호
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• pp.135-161
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• 2013

This paper examines Japan's Science and Technology (S&T) Basic Plans in accordance with its S&T Basic Law. The Basic Plans promote two major innovation (Green Innovation and Life Innovation) towards the creation of new markets and jobs, specifically under the Fourth S&T Basic Plan enacted on August 2011. Successful smart community demonstration projects at four urban localities were launched under plans to promote Green Innovation research and development of renewable energy technologies. However, the expectation that renewable energy such as solar or wind power can replace nuclear power is not backed by sufficient evidence. Furthermore, the electricity produced by these sources is expensive and unstable owing to its reliance on weather conditions. The Fukushima nuclear power plant accident on March 2011 has also seriously affected Japan's future energy plans. According to a government estimate, electricity charges would double if nuclear power generation were abandoned, imposing a heavy burden on the Japanese economy. Japan is in need of energy policies designed on the basis of more far-sighted initiatives.

• 한국수소및신에너지학회논문집
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• 제20권6호
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• pp.534-539
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• 2009

One of the most efficient techniques improving the heat transfer performance of a diesel electric generation is a corrosion control in jacket cooling water system. The environmental parameters most affecting corrosion are dissolved salt concentration, temperature, and pH of cooling water. No corrosion occurs in carbon steel probe at pH 11 in normal operating condition of diesel electric generation cooling water. pH control agent in this study is trisodium phosphate. pH control appears to be the most convenient way to enhance the thermal performance of a diesel electric generation.

• Journal of Electrical Engineering and Technology
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• 제7권1호
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• pp.23-33
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• 2012

The current paper deals with a new live-line insulator inspection tool system that will be used by the Korea Electric Power Corporation for its 154 kV power transmission lines in 2011. Unlike the existing contact type tools, the developed inspection tool automates parts of the insulator inspection process using a sensor and an actuator. The tool sustains its weight independently, not by a lineman. In addition, the inspection tool measures the insulation resistance of an insulator together with its distribution voltage, thus providing more information for analysis and diagnosis. Such characteristics improve the system's operation efficiency, measurement reliability, and usability. We confirmed its effectiveness through live-line field tests with actual power transmission lines.

• Animal cells and systems
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• 제2권2호
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• pp.217-222
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• 1998

Green peach aphid, Myzus persicae(Sulzer) (Homoptera: Aphididae), interacts with many predatory insects in potato fields during the summer. The concept of the predator complex associated with green peach aphids was applied to explain the interactions between the aphid and its predators. The predator power of the predator complex was determined by two factors: the number of predators and the relative feeding capacity. The dynamics of the green peach aphid population was expressed by the number of individuals while the predator power was used to characterize the predator complex. Cumulative degree-days for green peach aphids were used as a time scale to analyze phonology and dynamics patterns of the aphid and its predator complex. The patterns of population changes in aphids were similar during the period of study(1993-1995) although the highest density of aphids fluctuated significantly from year to year. However, the predator power appeared more stable than the green peach aphid population over the three year period. The results indicated that the predator complex plays an important role to suppress the aphid populations during the latter part of the season and that the applications of control measures for green peach aphids in between the initiation and the peak timing of aphid populations are critical to minimize the damage on potatoes.

• 한국산업융합학회 논문집
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• 제27권2_1호
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• pp.269-276
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• 2024

Many countries across the world are making efforts beyond reducing CO₂ levels and declaring 'net zero,' which aims to cut greenhouse gas emissions to zero by not emitting any carbon or capturing carbon, by 2050. Hydrogen is considered a key energy source to achieve carbon neutrality goals. Korean companies are also interested in building overseas green ammonia production plants and importing hydrogen into Korea in the form of ammonia. Green hydrogen production uses renewable energy sources such as solar and wind power, but the variability of power production poses challenges in plant design. Therefore, optimization of the configuration of a green ammonia production plant using renewable energy is expected to contribute as basic information for securing the economic feasibility of green ammonia production.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.866-867
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• 2011

As part of the green growth, The Green Car has attracted wide attention. Types of the Green Car are Electric Vehicle, Plug-in Hybrid Electric Vehicle, Hybrid Electric Vehicle, Fuel Cell Vehicle and Clean Diesel Vehicle. Of these, The electric vehicle is equipped with the BDU(Battery Disconnecting Unit). BDU is supplying stable battery power and blocking it to protect electrical system of the electric vehicle. The BDU consists of electric components such as current sensor, fuse and pre-charge resistor. These must pass Voltage withstand test, Salt mist test, Thermal shock test, Vibration test and Short-circuit test commonly to verify reliability of the electric components. In addition, The current sensor should be verified whether normal operation. The breaking capacity of fuse should be verified. The durability of pre-charge resistor should be verified by supplying battery power and blocking it repeatedly. The reliability of BDU as well as the electric vehicle is secured by verifying the reliability of electric components. In addition, It will contribute to the acceleration and promotion of Green Car Technology.

• KIEAE Journal
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• 제17권1호
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• pp.77-82
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• 2017

In power supply systems for urban areas, issues such as a progressive tax have escalated recently. In this regard, photovoltaic power generation, which is appraised as an alternative power generation system, is drawing attention increasingly for its high stability and applicability to existing infrastructure. This study assessed the realistic feasibility of photovoltaic power generation and also analyzed the economic benefits expected when it is linked with green roof, which is likely to promote ecological functions in urban areas, based on the Seoul solar map, RPS, and actual monitoring data. The economics analysis of 30kW photovoltaic power generation applied with the monthly average horizontal solar radiation of six grades in the Seoul solar map showed that positive NPV was up to grade 4, while grade 5 or poorer showed negative NPV and indicated that it is difficult to assure appropriate feasibility. Compared with non-afforestation, when green roof was applied, monthly average power improvement efficiency was 7.2% at highest and 3.7% at lowest based on yearly actual monitoring data. The annual average was 5.3%, and the efficiency was high relatively in summer, including September and November. As for the economic benefits expected when 30kw photovoltaic power generation is combined with green roof based on the average horizontal solar radiation of grade 1 in the Seoul solar map, SP has improved 0.2 years to 7.4 years, and EP has improved 0.5 years to 8.3 years.

• 한국산업융합학회 논문집
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• 제26권6_3호
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• pp.1259-1267
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• 2023

In recent years, as the demand for distributed power has increased, the need for microgrids connected to grid power and renewable power generation sources has emerged. In the case of DC microgrids, reactive power does not occur, and power conversion losses are reduced compared to AC when connecting to the load and power grid[2]. With the revitalization of the DC distribution network industry, various studies and demonstrations of DC microgrids have been carried out. In the case of the recent unit distribution, its stability and effectiveness have been verified through empirical and research analysis. However, there is a lack of empirical tests to prevent chain accidents for the protection of the power grid circuits and the misoperation of the distributed power system caused by individual accidents when connecting various distributed power sources and power grids. In this paper, the operation plan of a stable multi-circuit DC distribution connection for the demonstration site was verified through the protection cooperation and operation algorithm for the stable linkage management of the DC distribution network composed of such a multi-circuit.

• 한국전자통신학회논문지
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• 제8권2호
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• pp.249-253
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• 2013

본 논문에서는 그린 IT 분야에 대한 특허 정보를 이용하여 분야별 기술 경쟁력 분석과 분야에 적용되는 기술의 다양성 및 분야간 유사도를 분석하였다. 이를 위해 그린 IT를 전기 전자기들의 에너지소모량의 절감 및 IT기술을 기반으로 전력 소비를 줄이는 친환경적인 기술을 개발하는 분야로 범위를 한정하여, 절전기기 및 시스템, 조명제어시스템, 스마트 전력관리시스템, 클라우드 컴퓨팅, 그린하우스/에코시스템으로 한정하여 특허 분석을 수행하였다. 그 결과 절전기기 및 시스템 분야의 기술개발이 가장 활발히 이루어지고 있는 것으로 나타났다. 기술분야 간 기술적 유사도의 경우, 절전기기 제어 및 시스템분야와 클라우드 컴퓨팅 분야와 기술적으로 유사한 것으로 나타났으며, 조명제어시스템과 그린하우스/에코시스템 및 스마트 전력 관리 시스템이 기술적으로 유사한 것으로 분석되었다.