• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.363-363
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• 2013

태양광 발전산업에서 현재 주류인 결정 실리콘 태양전지의 변환효율은 꾸준히 향상되고 있으나, 태양전지의 가격이 매년 서서히 하강되고 있는 실정에서 결정질 실리콘 가격의 상승 등으로 부가가치 창출에 어려움이 있으며, 생산 원가를 낮출 수 있는 태양전지 제조기술로는 2 세대 태양전지로 불리는 박막형이 현재의 대안이며, 특히 에너지 변환 효율과 생산 원가에서 장점이 있는 것이 CIGS 박막 태양전지로 판단된다. 화합물반도체 베이스인 CIGS 박막태양전지는 연구실에서는 세계적으로 20.3% 높은 효율을 보고하고 있으며, 모듈급에서도 13% 효율로 생산이 시작되고 있다. 국내에서도 연구실 규모 뿐만 아니라 대면적(모듈급) CIGS 박막태양전지 증착용 장비, 제조공정 등의 기술개발이 진행되고 있다. CIGSe2를 광흡수층으로 하는 CIGSe2 박막 태양전지의 구조는 여러 층의 단위박막(하부전극, 광흡수층, 버퍼층, 상부투명전극)을 순차적으로 형성시켜 만든다. 이중에 소다라임유리를 기판으로 하는 하부전극은 Mo 재료를 스퍼터링 방법으로 증착하여 주로 사용한다. 하부전극은 우수한 전기적 특성이 요구되며, 주상조직으로 성장하여야 하며, 고온 안정성 확보를 위하여 기판과의 밀착성이 좋아야하고 또한 레이저 패턴시 기판에서 잘 떨어져야 하는 특성을 동시에 가져야 한다. 본 연구에서는 대면적 CIGSe2 박막태양전지에서 요구되는 하부전극 Mo 박막의 제작과 그 특성에 대해 평가하고, 최종적으로 대면적 CIGSe2 박막태양전지 공정에 적용 그 결과를 논하고자 한다.

• Environmental and Resource Economics Review
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• v.15 no.2
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• pp.297-318
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• 2006

Imported natural gas has been consumed by urban gas use and generation sector in Korea. The share of generating sector in total demand for natural gas is only 33% at 2000. This paper examines the potential of natural gas use in generation sector in the future. We build some hypothetical but realistic scenarios reflecting rapidly changing economic environment. We used standard programs for plant mix decision under those scenarios. We found that it is very likely to have high gas demand in the future, if we remove the cross-subsidizing price structure.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.125-131
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• 2007

Electric motor efficient improvement from home appliance field is important to the effect reducing the energy consumption. But the electric motor design/analysis technology is still insufficient. Specially the electric motor design/analysis technology of satisfying characteristic of both the induction motor and the synchronous motor such as Line start permanent motor. Therefore the electric motor design/analysis technology is urgently demanded reliability. This paper proposes the sing1e-phase line-start permanent magnet motor to develop the motor it with be able to alternate the sing-phase induction motor it is a refrigerator compressor motor. The sing-phase induction motor is analyzed in the steady state. And we have a certification test to compare our single-phase line-start permanent magnet motor with the sing-phase induction motor. In order to improve the performance, the stator of the single-phase line-start permanent magnet motor is same as the stator of the sing-phase induction motor and changes the rotor form and has the permanent magnet. It used the Finite Element Method(FEM) which is widely used with electronic-magnetic field numerical analysis method.

• Journal of the Korean Society of Safety
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• v.25 no.3
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• pp.53-60
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• 2010

LPG(Liquefied Petroleum Gas) vehicles in metropolitan area are being applied to improve air quality and have been proven effective for the reduction of air pollutant. In addition, LPG demand is growing rapidly as an environmentally friendly energy source and its gas station is also increasing every year. Consequently, this study tries to find out the influence of flame caused by the VCE(Vapor Cloud Explosion) in filling station on the adjacent combustibles and people by simulating relevant quantity of TNT. In addition, the damage estimation was conducted by using API regulations. If the scale of the radiation heat is known by calculating the distance of flame influence from the explosion site, the damage from the site can be easily estimated. And the accident damage was estimated by applying the influence on the adjacent structures and people into the PROBIT model. According to the probit analyze, the spot which is 30m away from the flame has 100% of the damage probability by the first-degree burn, 99.2% of the damage probability by the second-degree burn and 93.4% of the death probability by the fire.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.81-81
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• 2001

최근 적절한 사양관리를 위해서 유중 요소태질소 수준(MUN)과 유단백을 이용하여 사료 내 에너지와 단백질의 균형을 평가하는 지표로 활용하고 있으며 요소태질소 수준이 정상보다 크게 높거나 낮았을 때 번식능력이 저하되기 때문에 번식효율의 지표로서 활용되고 있다. 따라서 본 연구에서는 우유내 요소태질소 수준이 번식장애에 미치는 영향을 조사하여 요소태질소 수준을 번식장애의 진단지표로 활용하고자 실시하였다. 본 실험에 공시된 우유시료는 경기도 안성시와 이천시에 소재한 낙농목장에서 사육중인 조사두수를 대상으로 개체당 약 30~50$m\ell$의 우유를 채유하고 냉장보관하여 실험실로 운반하였다. 우유의 분석은 유성분분석기(Fosscomb : 4000, Fossmatic 5000, Denmark)를 이용하여 우유의 일반성분인 유지방, 유당, 유단백, 무지고형분, 총고형분, 빙점, 유중요소태질소, 구연산과 체세포를 동시에 분석하였다. 번식장애우의 진단은 낙농가가 번식장애우로 분류한 개체를 대상으로 직장검사 및 초음파 진단기를 이용하여 진단하였다. MUN준에 따른 공태일수의 조사 결과 MUN수준이 7이하 군의 공태일수가 88.98$\pm$120.68로 7-16의 92.20$\pm$105.39와 16이상의 94.42$\pm$87.51보다 다소 낮은 결과를 나타냈다. 또한 번식장애우의 발생빈도와 유성분 분석결과를 살펴보면 낙농가가 번식장애우로 분류한 68두를 진단한 결과 발정발견을 하지 못하여 번식장애우로 분류된 두수가 30두(44.1%)와 비정상두수 38두(55.9%)로 나타났으며 비정상 두수 중 난포난종이 19두(27.9%)로 영구항체6두(8.8%), 자궁내막염(10.3%), 자궁축농증 6두(8.8%)보다 많은 것으로 나타났다. 번식장애우의 유성분 분석결과 자궁축농증이 있는 개체의 유단백 평균이 3.43$\pm$0.35로 다른군에 비해 높았으며 영구항체가 있는 개체군의 MUN수준이 7.73$\pm$8.58로 다른군의 10.84$\pm$4.92, 10.89$\pm$7.38와 10.61$\pm$5.52에 비해 낮게 나타났다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.9
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• pp.38-45
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• 2003

This research is concerned with the dynamic modeling of the multi-purpose satellite with deployable solar arrays equipped with strain energy hinges(SEH). To this end, we proposed the use of the equivalent torsional spring for the SEH and derived the equations of motion assuming that the satellite and solar arrays are being rigid. We also considered the effect of the support string for the ground experiment model, which has been observed as a critical factor affecting the deployment in the ground experiments. From the numerical simulation results, it is found that solar arrays are deployed in a similar pattern but the hub motions are different because of the support strings. It was concluded that the non-gravity deployment of the solar arrays can be approximately simulated by the ground experimental facility. The effects of the support string are also investigated by varying the length of the string. It was found that the current length of the string is adequate for the ground experiment. Ground experimental results will follow.

• Journal of Advanced Navigation Technology
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• v.20 no.5
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• pp.401-407
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• 2016

This paper introduces 3-dimensional path planning and guidance including power model for high altitude long endurance (HALE) UAV using solar energy. Dubins curve used in this paper has advantage of being directly available to apply path planning. However, most of the path planning problems using Dubins curve are defined in a two-dimensional plan. So, we used 3-dimensional Dubins path generation algorithm which was studied by Randal W. Beard. The aircraft model which used in this paper does not have an aileron. So we designed lateral controller by using a rudder. And then, we were conducted path tracking simulations by using a nonlinear path tracking algorithm. We generate examples according to altitude conditions. From the path tracking simulation results, we confirm that the path tracking is well on the flight path. Finally, we were modeling the power system of HALE UAVs and conducting path tracking simulation during 48hours. Modeling the amount of power generated by the solar cell through the calculation of the solar energy yield. And, we show the 48hours path tracking simulation results.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.559-565
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• 2000

This studies were to investigate the effects of low power Helium-Neon Infra-Red (He-Ne IR) laser on the healing of the peripheral neuropathy in diabetic rats. The twenty one Spraque-Dewley adult male rats were assigned to the 3 groups: the control group (7), the diabetic group (7) and the laser group (7). The diabetic group was induced with a single intravenous injection of 50mg/kg body weight streptozotocin dissolved to 0.01mol/L citrate buffer, pH 4.5. The experimental laser group was irradiated low power He-Ne IR laser for 5 minutes every day during 21 days to the diabetic group. The results were as follows: For on and two weeks with laser treatment, there were significantly increased the terminal latencies of the laser treatment group than those of diabetic group, but that was significantly decreased to be similar to the control group on the laser treatment group for three weeks. The change of the amplitude on the laser treatment groups for three weeks was significantly increased to be similar to normal group than that of the diabetic group. As the result, we thank that there were activately effected of lower power He-Ne IR laser on the heeling of the peripheral neurophathy in diabetic rats.

• Journal of Nutrition and Health
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• v.44 no.2
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• pp.119-130
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• 2011

Metabolic syndrome (MetS), which is heavily dependent on dietary and lifestyle practices, is prevalent in Korean adults. Because dietary practices are unique for each race, nationality, and culture, it is important to identify Korean adult dietary practices that are associated with MetS. Macronutrient intake patterns were analyzed and compared across health status using the 2007-2008 Korean National Health and Nutrition Examination Survey data (8,143 adults who had dietary data and biomarkers related to MetS). Although intake levels were different by age, gender, and health status, carbohydrate intake was high and fat intake was low among Korean adults. The carbohydrate energy ratio was higher and the fat energy ratio was lower for subjects > 60 years old who were diagnosed with diabetes, hypertension, or MetS than those in other age groups. The main source of fat from food differed depending on the group. These results demonstrated that macronutrient intake patterns were different between age, gender, and health status subgroups. Hence, it is recommended that nutritional policy and practices aimed at controlling MetS should be based on the dietary characteristics of the target group.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.18-26
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• 2010

Outdoor lighting has become a necessary essential part of society for safety and comfortable space. However, inappropriate outdoor lighting leads to energy waste and poor landscape. Outdoor lighting is a very important social element, which enables us to conduct various activities at night in a safe, efficient and comfort way. River Thames in UK, Venice in Italy and Sydney in Australia is a good example of the coastal area. This paper aims to evaluate the light pollution of outdoor lighting in coastal area in Busan city. The Radiant Imaging ProMetric-1400 was used to measure the luminance of Gwangalli Beach, Marine City and Haeundae Beach. Compare to the CIE recommendation level the luminance of the all outdoor lighting were about 2~20 times higher. Outdoor lighting of the building facade luminance level and color should be particularly limited.