• 한국농촌건축학회논문집
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• 제5권1호
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• pp.1-11
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• 2003

The purpose of this study is to investigate and analyze the present state of elementary school libraries in Daejeon Metropolitan City. For this 50 schools are surveyed by questionnaires on two groups of teachers, those that take charge of school library and those who do not. As a results of this research following issues are emerged. First, the present state of surveyed school libraries is below standard with regard to the amount of books and size and it is required to improve these poor conditions. Second, the space programs are not sufficient to conduct enlarging scope of school libraries, which is conspicuous in spaces for affording librarians, supporting various activities and serving user's convenience. Third, in spite of poor conditions in school library facilities, respondents' satisfaction rate is not so low and there's no obvious demand for diversity of spaces.

• 경영과정보연구
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• 제1권
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• pp.75-112
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• 1997

This Report aims at Development of field approached MIS curriculumn appropriate to specialty of junior college, based on the thoughts that it is necessary to set the skill and the conception rightly through the knowledge and the theory about the whole field of management, to provide a continous and consistant education, to produce MIS graduates required at enterprises. For that, considering function and roll of the junior college, curriculumns which have been opened and managed as a major study, the level of knowledge which is required to the men who is in charge of practical information business at demand site, subjects which is desirable to be a major study, the knowledge which is required to the MIS graduates in present and future, a condition of deucation investment.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.99.1-99.1
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• 2016

The materials for an electronic packaging provide diverse important functions including electrical contact to transfer signals from devices, isolation to protect from the environment and a path for heat conduction away from the devices. The packaging materials composed of metals, ceramics, polymers or combinations are crucial to the device operating properly and reliably. The demand of effective charge and heat transfer continuous to be challenge for the high-speed and high-power devices. Nanomaterials including graphene, carbon nanotube and boron nitride, have been designed for the purpose of exploiting the high thermal, electrical and mechanical properties by combining in the matrix of metal or polymer. In addition, considering the inherent electrical and surface properties of graphene, it is expected that graphene would be a good candidate for the surface layer of a template in the electroforming process. In this talk, I will present recent our on-going works in nanomaterials for microelectronic packaging: 1) porous graphene/Cu for heat dissipations, 2) carbon-metal composites for interconnects and 3) nanomaterials-epoxy composites as a thermal interface materials for electronic packaging.

• 한국항공운항학회지
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• 제25권4호
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• pp.178-186
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• 2017

Air travel has become an essential part of the global society and its sustainable development is expected. Airlines profit structure and network operation will be influenced by internalization of external costs like emission charge. This additional cost of the airlines will be directly pose air ticket fare increase and demand of air passenger will be decreased. EU-ETS is a part of environmental binding to airlines fly to EU territory airports. This study analyzes the impact of emission charges by application of EU-ETS on airlines network change. For long-term forecast, a reliable estimation of the future price of carbon dioxide (CO2) will be used.

• 전기학회논문지
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• 제59권1호
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• pp.65-69
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• 2010

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. And, social demand on fuel economy and reducing pollution needs equipment of new function such as energy storage system with good power performance, high cyclability and good energy efficiency. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the fundamental characteristics of supercapacitor unit and charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle.

• 전력전자학회논문지
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• 제23권4호
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• pp.265-272
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• 2018

This paper proposes a new control method for the supercapacitor (SC) to compensate the pulsed load and to enhance the power quality of the DC microgrid. By coordinating the operating frequency, the SC is controlled to handle the surge current, while the low-frequency current component is dealt with by the remaining sources in the system. The operation mode of the SC unit is automatically changed based on the state of charge and DC bus voltage level. Meanwhile, the mismatch in the power demand is covered by the SC unit by regulating the DC bus voltage level. The effectiveness of the proposed method is verified experimentally by the prototype with two distributed generators and one SC unit.

• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.1983-1988
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• 2015

This paper proposes the enhanced application of superconducting magnetic energy storage (SMES) for the effective compensation of power fluctuations based on the interleaving technique. With increases in demand for renewable energy based photovoltaic (PV) generation system, the output power fluctuations from PV generation system due to sudden changes in environmental conditions can cause serious problems such as grid voltage and frequency variations. To solve this problem, the SMES system is applied with its superior characteristics with respect to high power density, fast response for charge and discharge operations, system efficiency, etc. In particular, the compensation capability is effectively improved by the proposed interleaving technique based on its parallel structure. The dynamic performance of the system designed using the proposed method is evaluated with several case studies through time-domain simulations.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.277-284
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• 2003

To meet demand for large-scale new personnel caused by active railway investment projects such as high-speed line construction, electrification and double-tracking of the existing lines, we KNR need to establish a subsidiary firm for each field instead of personnel augmentation. The establishment of subsidiaries is expected to solve the problem of the current outsourcing services, reduce costs and in the long term, improve the efficiency of railway business. In addition, we also suggest, as a pilot project, setting up Korean Freight Inspection Company in charge of conducting light and heavy maintenance for freight cars.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.250-253
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• 1989

As the necessity of increasing the midnight base load is extensively increased, electric power companies have to increase the demand of midnight electrical power by lowering the electrical charge rate at midnight. One of the most widely used midnight equipments is the heat Storage type's electrical boiler. A Single chip microprocessor controller for the heat-storage type's electrical boiler is developed. This controller call reduce the undesirable peak load at the begining of midnight (i.e.11 P.M.) time band by using backward load control method. Futhermore, this controller enables reservation of heat storge and the effective heating control the field test has been done by use the boiler for 66$m^2$ with the heater of 21KW quality.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.341-342
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• 2015

Attention has been focused on how to charge an electric vehicle in accordance with the increase of interest in the electric vehicle in recent years. The charging of an electric vehicle with a solar power is way to increase the stability of the grid and to supplement the grid power demand. In this paper, the EMTP / ATPDraw presents a method of charging an electric vehicle in connection to the grid and the solar power system, and analyze the trends in supply power from the solar power system according to changes in temperature and irradiation.