• 전기학회논문지
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• 제58권2호
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• pp.239-241
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• 2009

In this paper, an estimation methodology for stand-by energy savings of electric appliances is proposed and some case studies are carried out for televisions. The methodology is based on learning curves and diffusion models, which are able to explain the market characteristics such as market prices and the diffusion speed. Some models were developed to estimate power and energy savings for high-efficient appliances and these model have been used broadly. These models are also applied to this study and modified to estimate stand-by energy savings.

• Nuclear Engineering and Technology
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• 제26권2호
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• pp.285-293
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• 1994

압축 벤토나이트에서 핵종이동은 확산에 의해 지배된다. 국산 벤토나이트에 대한 음이온핵종의 확산 특성 규명을 위해서 요오드이온을 대상으로 관통확산실험을 수행하였다. 대상매질은 동해안 지역의 벤토나이트를 사용하였으며, 실험용액은 합성 모의지하수에 I-125를 첨가하여 사용하였다. 압축 벤토나이트의 충전밀도는 1.2, 1.4, 1.7Mg/㎥등 세가지로 하였다. 요오드이온의 겉보기확산계수와 유효확산계수는 충전밀도가 증가함에 따라 감소하였고, 이들 확산계수의 값은 각자 3.80-7.12$\times$$10^{-11}$ $m^2$/s와 1.25-7.97$\times$$10^{-12}$ $m^2$/s의 범위에 있었다. 실험결과, 겉보기확산계수는 벤토나이트의 공극구조에 의존하였으며, 유효확산계수는 공극구조는 물론 핵종확산이동에 이용된 유효공극율에 의해 좌우되었다. 본 연구에서 얻어진 결과는 처분장안전성평가의 기초자료로 활용될 것이다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.592-599
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• 2005

Renewable energy technology development has been carrying out in 11 different areas so far. Many technologies are being applied to the required areas according to its own characteristics. Before launching the development, these technologies have been evaluated by their commercial effect and contribution to energy supply. In this paper, the impact factors enhancing the distribution of renewable energy were developed to select appropriate diffusion regulations for each technology area. In addition, AHP methodology was introduced to investigate priorities of the regulations along with weights of impact factors.

• 한국컴퓨터정보학회논문지
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• 제16권2호
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• pp.165-172
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• 2011

무선 센서 네트워크는 제한된 에너지를 갖는 배터리에 의해 가동되며 한번 배치되면 사용자가 접근할 수 없고 배터리 교환이 불가능하다. 따라서 네트워크의 수명을 늘리기 위하여 네트워크 디자인 시에 에너지 효율성이 매우 중요하게 고려되어야 한다. 디렉티드 디퓨젼은 데이터 중심 라우팅 알고리즘으로 널리 알려진 기법이다. 본 논문에서는 디렉티드 디퓨젼의 효율을 향상시키기 위하여 클러스터링 기법을 활용한다. 먼저 클러스터를 구성한 후 클러스터 헤드 노드를 선출하고 클러스터 헤드 노드끼리 디렉티드 디퓨젼에서 제안한 것처럼 라우팅을 실시하는 C-디렉티드 디퓨젼 기법을 제안한다. 제안 알고리즘은 그 적용이 간단하고 성능면에서 디렉티드 디퓨젼 보다 우수한 것으로 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.234-234
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• 2010

Most high efficiency silicon solar cells use a passivated selective emitter. It have been an important research subject for crystalline silicon solar cells for decades. It is being used in production for high efficiency solar cells. Most of the selective emitter process require expensive extra masking, etching steps, and a double diffusion process making selective emitters not cost effective. In this paper, we study method for single diffusion step selective emitter process as an alternative to not cost effective double diffusion process. Cost effective selective emitter that the efficiency should be increased significantly (mare than 0.2%) and that the process should simple, robust and cheap.

• Journal of the Korean Wood Science and Technology
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• 제19권4호
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• pp.27-33
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• 1991

Three kinds of specimens(radiata pine sapwood, radiata pine heartwood and whemlock heartwood) were dried at four temperature levels (30, 40, 50 and $60^{\circ}C$) in an emvironmental chamber. Unsteady-state diffusion coefficients were calculated from obtained drying fates by using infinite slab equation for first half of sorption and interval diffusion equation for second half of sorption. Activation energies for moisture diffusion in wood were calculated from the diffusion coefficients obtained at four temperatures. In most cases diffusion coefficients for radial movement were higher than those for tangential movement. Activation energy differences between sapwood and heartwood weren't significant for radial movement, but were significant for tangential movement. Most activation energies calculated from drying rates were lower than heat of water condensation(about 11,000cal/mole). Specially the avenge activation energy for sapwood tangential movement was only 5,000cal/mole.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.280-280
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• 2012

We examined ammonia diffusion on the surface of amorphous ice film through the measurement of decreasing residual quantity of $NH_3$ molecules compared to $H_2O$. The populations of $NH_3$ molecules on the surface of amorphous ice were monitored by using the techniques of temperature programmed reactive ion scattering (TPRIS) method. The ratio of intensity between ammonia and water was examined as a function of time at controlled temperature. When ammonia molecules were externally added onto an ice film at a temperature of 80 K, ammonia coverage with regard to ice was 0.12-0.16 ML. The intensity of ammonia molecules on the surface of ice decreased as time increased and the extent of decreased intensity of ammonia increased as controlled temperature increased. Moreover, energy barrier was estimated to be $51kJmol^{-1}$ on amorphous ice film. The results of the experiment indicate that ammonia molecules have a property of vertical diffusion into amorphous ice and the energy barrier of ammonia diffusion into bulk of ice is higher than that of hydrogen bonding.

• 신재생에너지
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• 제1권2호
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• pp.79-90
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• 2005

New & renewable energy technology development has been carrying out in 11 different areas so far. Many technologies are being applied to the required areas according to its own characteristics. Before launching the development, these technologies have been evaluated by their commercial effect and contribution to energy supply. In this paper, the impact factors enhancing the distribution of renewable energy were developed to select appropriate diffusion regulations for each technology area. In addition, AHP methodology was introduced to investigate priorities of the regulations along with weights of impact factors.

• 방사성폐기물학회지
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• 제3권2호
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• pp.85-93
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• 2005

Isotopes of alkali and alkaline earth metals (AM and AEM) are the main contributors to the heat load and the radiotoxicity of spent fuel (SF) . These components are separated from the SF and dissolved in a molten LiCl in an electrolytic reduction process. A mass transfer model is developed to describe the diffusion behavior of Cs, Sr, and Ba in the SF into the molten salt. The model is an analytical solution of Fick's second law of diffusion for a cylinder which is the shape of a cathode in the electrolytic reduction process. And the model is also applied to depict the concentration profile of the oxygen ion which is produced by the electrolysis of Li$_{2}$O. The regressed diffusion coefficients of the model correlating the experimentally measured data are evaluated to be greater in the order of Ba, Cs, and Sr for the metal ions and the diffusion of the oxygen ion is slower than the metal ions which implies that different mechanisms govern the diffusion of the metal ions and the oxygen ions in a molten LiCl.

• 대한산업공학회지
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• 제40권3호
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• pp.333-341
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• 2014

The purpose of this study is to forecast the penetration rate of renewable energy and a reasonable scale for the R&D investment plan in Korea based on the relationship between the diffusion and R&D investments drawn by analogy from empirical cases of advanced countries. Among numerous candidate developed countries, the German market was chosen based on the similarity of the diffusion patterns to those of the Korean plan. We then figured out how the investment triggers the growth of technology from the selected benchmark, and applied the technology S-curve relation formula to derive the desirable investment plan for Korea. The present paper is a pioneering attempt to forecast the diffusion process of renewable energy technology in Korea using the comparative analogy from cases of advanced countries.