• New & Renewable Energy
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• v.5 no.3
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• pp.22-25
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• 2009

For increasing the output voltage, six SMD(surface mount device) type AlGaAs/GaAs solar cells were connected in series. The electrical properties of the array were measured and compared with one sun (100 mW/$cm^2$) and indoor light (480 lux) conditions. Under one sun condition, output power was 21.57 mW and it was $14.67\;{\mu}W$ under indoor light condition. Under the indoor light condition, the intensity of the light is very low compared to one sun condition. Thus the Voc(open circuit voltage) and Isc (short circuit current) of the sample under indoor light condition decreased very much compared to that of under the one sun condition. This kind of solar cell power supply can be used as a power source for ubiquitous sensor network (USN).

• Journal of Environmental Health Sciences
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• v.25 no.3
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• pp.7-12
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• 1999

Bioremediation is the technology to harness nature's biodegradative capabilities to remove or detoxify pollutions that threaten public health as environmental contaminants. Composting may become one of major bioremediation technologies for treating soils contaminated with petroleum if the fate of contaminants during composting is better understood Most composting research of petroleum was primarily focused on removing contaminant by optimizing composting conditions. Accordingly, laboratory feasibility studies may be useful to establish a realistic basis in co-composting complex substrate such as petroleum hydrocarbons. The purpose of this study was to assess the optimal conditions of kerosene biodegradation following supplementation with nutrient amendments under simulated composting conditions. Although it increased the growth of bacterial consortium, addition of co-substrates 0.5%(w/v) such as acetic acid, citric acid, glucose, and malic acid was not beneficial. Combination of nitrogen and phosphorous source enhanced kerosene biodegradation and reduced VOC evolution. These results showed that kerosene was able to utilize in bioremediation technology.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.335-338
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• 2012

Recently, the energy has been used much more than ever, but there has been many problems including atmospheric pollution. So we need alternative energy resources, which are solar heat, solar light, wind power, small water power, etc. The field, which is most popular these days, is the energy source by solar light which transform electric energy using the solar cell and it is available with many researches. In this paper, we manufactured the solar power generation system over 90W using solar module which was 9.90V for Voc, 0.93 A for Isc, 8.64 V for Vmp, 0.75 A for Imp, 6.5 W for power. System was controlled by step motor with worm gear to operate optimum condition between $0^{\circ}{\sim}70^{\circ}$ angle. This system was very effective in tracking space use because it need less space than general solar module.

• KSBB Journal
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• v.17 no.3
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• pp.307-310
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• 2002

In order to obtain high density seed cells for biofiltration, we studied batch and fed-batch culture of P. putida. Studies were carried out to find optimum fermentation conditions such as pH, concentration of glucose and agitation speed. Specific growth rate of P. putida was dependent on agitation speed and a high rpm of 300 was necessary to carry out the efficient aerobic growth of P. putida. Specific growth rate was highest at pH 7. Feeding glucose and yeast extract continuously at the initial growth phase was the most effective way to get high cell density of P. putida.

• Proceedings of the KAIS Fall Conference
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• 2012.05b
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• pp.677-679
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• 2012

다공질 폴리프로필렌 시트는 압전센서 및 VOC 발생이 적은 자동차 내장소재로 주목을 받고 있으며, 특히 경량화를 위한 다공질 폴리프로필렌 시트의 가공기술이 중요하다. 이 연구에서는 기존의 가교형 폴리프로필렌 시트를 활용하여 압출과 사출이 아닌 압연공정과 열처리 발포공정을 접목하였다. 발포를 위한 마스터배치와 폴리프로필렌의 혼합으로 제조된 두께 1mm의 폴리프로필렌시트를 $200^{\circ}C$온도에서 온간압연공정에 의해 0.1-0.2mm 두께로 제조하고, 이를 $200^{\circ}C$에서 5분동안 발포함으로써 기공률 65%의 시트를 제조함으로써 저가의 압전센서 소재로 활용 가능성을 확인하였다.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.2
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• pp.203-210
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• 2012

The purpose of this study is to evaluate the diesel retrofit program which have been proceeded for the last 7 years in Gyeonggi-do. Diesel retrofit programs in Gyeonggi-do consist of the attachment of DPF (Diesel Particulate Filter), p-DPF (partial-DPF) and DOC (Diesel Oxidation Catalyst), switching to LPG engine, scraping an old cars. Emission reduction by diesel retrofit program was estimated $N_2O$ 8,313.4 ton/year, PM10 3,626.4 ton/year, VOC 8,078.5 ton/year in 2010. The benefit-cost analysis shows that the 964 billion wons of benefits are greater than the 853 billion wons of total costs. Diesel retrofit programs could be one of the most effective measures to improve PM10 concentration in metropolitan area. But retrofit programs also need to be properly maintained by each vehicle.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1989.06a
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• pp.59-61
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• 1989

The cell parameters of the sintered CdS/CdTe solar cells in which te CuCl$_2$was added in the carbon paste after the sintering of the CdS/CdTe composites an were annealed at 35$0^{\circ}C$ for 10 min in nitrogen are investigated. Voc and FF do not change significantly as the CuCl$_2$increasing up to 500 ppm, Jsc increases with futher increase in copper. The hole concentration, determined by C-V measurement, increases to $1.5\times$10$^{16}$ ㎤ as the copper increased to 25 ppm and then stays at about the same value with further increase in copper.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.210-210
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• 2000

In this paper, we have investigated the properties of multi-layer perceptron (MLP) for odour patterns classification and concentration estimation simultaneously. When the MLP may be has a fast convergence speed with small error and excellent mapping ability for classification, it can be possible to use for classification and concentration prediction of volatile chemicals simultaneously. However, the conventional MLP, which is back-Propagation of error based on the steepest descent method, was difficult to use for odour classification and concentration estimation simultaneously, because it is slow to converge and may fall into the local minimum. We adapted the Levenberg-Marquardt(LM) algorithm [4,5] having advantages both the steepest descent method and Gauss-Newton method instead of the conventional steepest descent method for the simultaneous classification and concentration estimation of odours. And, We designed the artificial odour sensing system(Electronic Nose) and applied LM-BP algorithm for classification and concentration prediction of VOC gases.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.595-595
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• 2012

현재 대부분의 태양전지는 약 90% 이상이 si을 기판으로 제작되고 있다. Solar cell의 효율을 감소시키는 원인은 여러 가지가 있다. bulk life time 감소, 수분침투, 우박, 바람에 의한 영향들이 태양전지 효율을 감소시킨다. 모듈에 눈이 쌓이거나 바람이 불어 외부적 힘이 가해져 micro crack 가게 된다면 전체 모듈은 과부하와 발열 현상이 일어나고 interconnection 감소로 인하여 효율도 떨어지게 된다. 본 연구에서는 평균적인 효율이 17.5%, 크기가 6인치 단결정 태양전지에 일정 간격으로 힘을 가하여 파라미터 변화를 측정하였다. 두께가 $250{\mu}m$인 cell에 0.8lb에 힘을 가했을 때 cell이 파괴 되는 것을 알 수 있었다. 힘을 가해줄 수록 Voc와 Isc가 감소하는 경향성을 보였고 결국에 효율도 감소하였다. 또한 ANSYS 시뮬레이션을 사용하여 셀에 힘이 가해졌을 때 어떤 변화가 생기는 지 확인하였다. 시뮬레이션을 통하여 셀에 힘이 가해졌을 때 힘의 분포도, bowing 현상을 3D 그래프로 나타내었다. 힘이 세기가 강해질수록 bowing 현상은 심해졌고 힘의 분포도도 달라졌다.

• Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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• 2001.06a
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• pp.11-13
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• 2001

본 연구진은 비교적 청정한 공기질을 유지하는 것으로 알려진 강화도 하리지역을 중심으로 2001년 3월 봄철의 일주일 (3/20∼3/27) 기간동안 미량기체의 교환량을 측정하기 위한 공동연구사업을 수행하였다. 본 연구에서는 수은, VOC, 메탄, 비메탄계 탄화수소를 위시한 가스상 성분은 물론 입자상성분을 대표할 수 있는 PM 10의 농도를 지면상부 1m와 5m 고도에서 관측하였다.(중략)