• 신재생에너지
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• 제8권3호
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• pp.38-46
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• 2012

Enhanced Geothermal System (EGS) among geothermal system types enables to produce sustainable energy even in non-volcanic region while conventional geothermal energy has been restricted to obtain only from hot and permeable formation such as in volcanic regions. Successful EGS project in terms of economy, however, can be expected only when the project is managed effectively considering most of influencing factors (e.g., tangible and intangible resources, cost, time, risks, etc.). In particular, well construction is of the utmost importance in geothermal project as it dominantly influences on time and cost in the whole project. Therefore, when it comes to viable geothermal project without abundant experience, managing drilling economically and efficiently is inevitable. In this study, a project management system for well construction in geothermal project based on project control system including work breakdown structure and cost account was developed to predict and assess the performance of drilling and to visualize the progress.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1993년도 춘계학술대회 논문집
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• pp.44-48
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• 1993

Recently, superconducting cable has attracted a great deal of interest from the viewpoint of energy saving, one of the most important and difficult problems to be solved to assure the high reliability, safety and economy of cable is breakdown is cryogenic temperature. In this paper, we will report on the characteristics and mechanisms of the breakdown and creeping discharge in cryogenic liquids, dual role of those as the cooling and insulating material, and composited system of cryogenic liquid - gas taking into consideration for application.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1440-1442
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• 1996

The laser annealing effects on the TEOS (Tetra-Ethyl-Ortho-Silicate) oxide of MOS (Al/TEOS/n+ Silicon) structures was investigated with different initial oxide conditions, such as breakdown field. The breakdown field increased up to the 170 $mJ/cm^2$ with increasing laser energy density and decreased at 220 $mJ/cm^2$. It is considered that the increase of breakdown field is originated from the restore of strains which exist mainly at the metal/oxide interface.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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• pp.335-338
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• 2008

With the improvement of industrial society, the high quality electrical energy, simplification of operation and maintenance, ensuring reliability are being required Also we request urgently change a $SF_6$ for an environment friendly gas insulation material. In this paper the experiments of breakdown characteristics by pressure and gap change of Imitation-Air in model GIS(Gas Insulated Switchgear) were described. Also assess of breakdown characteristics about Imitation-Air and $SF_6$. It is considered in this paper that the results are fundamental data for electric insulation design of Distribution Power Facilities which will be studied and developed in the future.

• 대한전기학회논문지
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• 제37권12호
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• pp.872-878
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• 1988

During the past few years, a great deal of attention has been directed to the application of superconductivity to the electrical systems such as superconducting power transmission lines, superconducting magnet energy storage and so on. Yet in order to develop the practical model of these electrical equiqments utilizing suprconductivety and other phenomena at cryogenic temperautre, it is necessary to know the dielectric behaviour of insulating materials at cryogenic temperature in view of reliability, safety and economy of these machines. Investigation of dielectric properties of cryogenic liquids is very important due to the dual role of those as the dielectric and cooling medium. In this study, we investigated results measured over several kinds of dielectric characteristics of liquid nitrogen taking into consideration for application of high Tc superconductor. Dependence of breakdown voltage of gap width, polarity and pressure is reported in this paper and time delay characteristics of breakdown is also the subject of this discussion.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.239-239
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• 2013

The peak klystron power for the PAL (Pohang Accelerator Laboratory) XFEL (X-ray Free Electron Laser) is up to 80 MW which is higher than that of PLS-II LINAC. To prevent the RF breakdown such a high power operation, some of RF components need to be redesigned to reduce the surface electric field gradient to be less than the breakdown gradient at the vacuum-metal surface. For instances, the redesign of the Stanford Linear Accelerator Energy Doubler (SLED) system, the directional coupler and 3dB power splitter using the finite-difference time-domain (FDTD) simulation will be presented.

• 한국식품과학회지
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• 제33권2호
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• pp.195-199
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• 2001

Amylograph를 이용하여 방사선 조사된 검은후추가루의 amylograph characteristics의 변화를 검사하고, 변화된 amylograph characteristics에 의해서 검은후추가루의 검지가 가능한지를 알아보기 위하여 본 실험은 수행되었다. Initial pasting temperatures, maximum viscosity temperatures는 조사선량의 증가에 따른 유의적인 변화가 관찰되지 않았다. Maximum viscosity(P), $93^{\circ}C$ viscosity, $93^{\circ}C$에서 15분 후의 viscosity(H), $45^{\circ}C$ viscosity(C), $45^{\circ}C$에서 30분 후의 viscosity, $45^{\circ}C$에서 60분 후의 viscosity는 조사선량이 증가할수록 감소하는 경향을 보여주었으며, p<0.05의 수준에서 통계적인 유의성이 관찰되었다. 그러나 breakdown(P-H), setback(C-P), 그리고 consistency(C-H)는 조사선량의 증가에 따른 명확한 차이가 관찰되지 않았다. breakdown(P-H)이 0.75, setback(C-P)이 0.88, consistency(C-H)가 0.31의 $R^2$ 값을 보인 것을 제외하고는 모든 amylograph characteristics 의 $R^2$ 값은 0.97 이상의 높은 상관성을 보여 주었다. 따라서 amylograph characteristics에 의해서 검은후추가루의 방사선 조사여부 확인이 가능하였다.

• 한국태양에너지학회 논문집
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• 제24권4호
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• pp.55-63
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• 2004

The purpose of this study is to development of life cycle cost analysis methodology of HVAC system for decision maker. The results of this study are as follows; maintenance/management, equipment construction, planning/design, and demolition/sell phases (1) To develop the cost breakdown structure for LCC in HVAC system, this study apply the method of additional pertinent level, title, CBS number, block number and variable index. (2) LCC analysis order of HVAC system compose four phase. (3) Life cycle costing influence diagram can bring us to make the most efficient decision through a visual graphical diagram that is shown relationship among variables and that decision maker traces easily from life cycle cost analysis situation.

• 한국전기전자재료학회논문지
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• 제28권4호
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• pp.222-228
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• 2015

Power MOSFETs (metal oxide semiconductor field effect transistor) operate as energy control semiconductor switches. In order to reduce energy loss of the device, it is essential to increase its conductance. However, a trade-off relationship between the breakdown voltage and conductance of the device have been the critical difficulty to improve. In this paper, theoretical analysis of electrical benefits on single floating island power MOSFET is proposed. By the method, the optimization point has set defining the doping limit under single floating island structure. The numerical multiple 2.22 was obtained which indicates the doping limit of the original device, improving its ON state voltage drop by 45%.

• ETRI Journal
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• 제27권4호
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• pp.449-452
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• 2005

The electrical characteristics of solid state devices such as the bipolar junction transistor (BJT), metal-oxide semiconductor field-effect transistor (MOSFET), and other active devices are altered by impinging photon radiation and temperature in the space environment. In this paper, the threshold voltage, the breakdown voltage, and the on-resistance for two kinds of MOSFETs (200 V and 100 V of $V_{DSS}$) are tested for ${\gamma}-irradiation$ and compared with the electrical specifications under the pre- and post-irradiation low dose rates of 4.97 and 9.55 rad/s as well as at a maximum total dose of 30 krad. In our experiment, the ${\gamma}-radiation$ facility using a low dose, available at Korea Atomic Energy Research Institute (KAERI), has been applied on two commercially available International Rectifier (IR) products, IRFP250 and IRF540.