• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.43-48
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• 1998

Prior to launch, simulated radiances of the Ocean Scanning Multispectral Imager (OSMI) will be very useful to guess the real imagery of OSMI and to check the data processing system for OSMI. The data processing system for OSMI which is one sensor of Korea Mult i - Purpose Satellite (KOMPSAT) scheduled for launch in 1999 is being developed based on the SeaWiFS Data Analysis System (SeaDAS). Such a simulation should include the spectral bands, orbital and scanning characteristics of the OSMI and KOMPSAT spacecraft. The simulation is also very helpful for finding and preparing for problem areas before launch. This paper describes a method to create simulated radiances of the OSMI over the oceans. Our method for constructing a simulated OSMI imagery is to propagate a KOMPSAT orbit over a field of Coastal Zone Color Scanner (CZCS) pigment values and to use the values and atmospheric components to calculate total radiances. A modified Brouwer - Lyddane model with drag was used for the realistic orbit prediction, the CZCS pigment data were used to compute water - leaving radiances, and a variety of radiative transfer models were used to calculate atmospheric contributions to total radiances detected by OSMI. Imagery of the simulated OSMI total radiances for 6 nominal bands was obtained. As expected, water - leaving radiances were only a small fraction of total radiances and sun glint contaminations were observed near the solar declination. Therefore, atmospheric correction is very important in the calculation of pigment concentration from total radiances. Because the imagery near the sun's glitter pattern is virtually useless and must be discarded, more advanced mission planning will be required.

• 원예과학기술지
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• 제32권3호
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• pp.340-345
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• 2014

Since the moisture content (MC) of growing medium closely related with the crop transpiration, the MC should be included to the environmental factors to be considered for irrigation control in soilless culture. The objective of this study was to analyze the transpiration of paprika plants using daily mean solar radiation (RAD) and vapor pressure deficit (VPD) as well as the growth of the plants at different MCs of rockwool growing media. The starting points of irrigation were controlled by a moisture sensor with minimum set points of 40%, 50%, and 60% of MCs. The canopy transpirations were measured for 80 to 120 days after transplanting and analyzed. The transpirations were well regressed with a combination of both RAD and VPD rather than daily mean RAD only under the controlled MCs. The transpiration at 60% MC was higher than those at 50% and 40% MCs. Leaf area, leaf fresh and dry weights at 60% MC were higher than those at 50% and 40% MCs while the number of leaves had no significant difference among the MCs. There were no significant differences in number of fruits and fruit size among all the MCs, while fruit weight was significantly lower at 40% MC than other treatments. Fresh and dry fruit yields were the highest at 60% MC. Therefore it was concluded that the transpiration was affected by the MC of rockwool growing medium and the minimum set point of 50-60% MC of rockwool growing medium gave better effects on the growth of the paprika plants.

• 한국통신학회논문지
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• 제10권1호
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• pp.1-10
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• 1985

태양은 그 원천에서부터 무제한의 에너지를 가지고 있을 뿐만 아니라, 짧은 파장으로 아무런 제약도 받지 않는다는 잇점을 가지고 있다. 이러한 잇점으로 우리는 광범위한 태양 에너지의 응용을 기대할 수 있었다. 본 연구은 태양 에너지를 올바르게 추적하여 그 효과를 나타내여 보려고 시도해 보았다. 이 실험은 感光器의 각도를 변화시켜 빛을 추적하여 보았는데 이것은 2개의 포토 트랜지스터에 의해서 얻어진 빛을 증폭시켜 TTL게이트를 통해 일정 레벨 이상만 감지된 빛을 INTEL 8080CPU의 入力데이터로 이용하였다. 또한 이 장치는 8080CPU의 제어 펄스를 모우터 구동회로에 전송하고 感光器는 이것을 기본 데이터로 대치하도록 하였다. DC 보우터는 업/다운 카운터가 필요없는 잇점을 가지고 있으며 스테핑모우터와는 회로 구성면에서 차이가 있다. 이 실험장치는 感光器, A/D콘버어터, 입력 인터페이스, INTEL 8080CPU, 출력 인터페이스, 모우터 구동회로로 구성되어 있다. 이 실험으로 수광 오차각이 1.2밖에 되지 않았지만 올바르게 빛을 수광할 수 있었다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.213-216
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• 2011

The feasibility study must be conducted for construction of complex for generation of electric power such as items to get permission and grid connection etc. including wind resource to construct a complex for wind power generation. Since wind power can be used by converting only around 20~40% of energy coming in that kinetic energy of wind passes through blades and driving device into electric energy, when constructing a complex, the survey of wind resource takes up the most important part. Data logger used to measure this wind energy are expressed by calculating generally electromotive that is created from a sensor, variable-type, pulse-type signal to be proper for the actual value, and most data loggers have a type without considering geographical features. Besides, in the case of Met mast that is installed to survey the wind resource, since it is installed lower than the hub height of a wind power generator due to permission matters and the economic factors, the height of wind speed by utilizing Deacon equation is compensated to revise this. In this study, a device measuring wind speed was made by using algorithm that is possible to compensate the height of wind speed according to regional features and by applying Deacon equation, and the function of data storage through SD card or RS232 communication was added as well. Besides it's possible to check data more easily with a type of graph by using LCD touch screen for the convenience of users.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2004년도 한국우주과학회보 제13권2호
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• pp.372-375
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• 2004

The UV radiometer payload was launched successfully from the west coastal area of Korea Peninsula aboard KSR-III on 28, Nov 2002. KSR-III was the Korean third generation sounding rocket and was developed as intermediate step to larger space launch vehicle with liquid propulsion engine system. UV radiometer onboard KSR-III consists of UV and visible band optical phototubes to measure the direct solar attenuation during rocket ascending phase. For UV detection, 4 channel of sensors were installed in electronics payload section and each channel has 255, 290, 310nm center wavelengths, respectively. 450nm channel was used as reference for correction of the rocket attitude during the flight. Transmission characteristics of all channels were calibrated precisely prior to the flight test at the Optical Lab. in KARI (Korea Aerospace Research Institute). During a total of 231s flight time, the onboard data telemetered to the ground station in real time. The ozone column density was calculated by this telemetry raw data. From the calculated column density, the vertical ozone profile over Korea Peninsula was obtained with sensor calibration data. Our results had reasonable agreements compared with various observations such as ground Umkhr measurement at Yonsei site, ozonesonde at Pohang site, and satellite measurements of HALOE and POAM. The sensitivity analysis of retrieval algorithm for parameters was performed and it was provided that significant error sources of the retrieval algorithm.

• 중소기업융합학회논문지
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• 제1권1호
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• pp.39-44
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• 2011

인류가 석탄, 석유, 천연가스 화석 연료 등 연로들에 대한 무절제한 사용으로 하여 전 세계적으로 심각한 환경오염과 화석 연료의 자원 고갈문제에 직면하게 되었다. 따라서 이러한 환경오염 문제를 줄이고 또한 고갈돼가고 있는 화석 연료를 대체할 태양 에너지, 풍력, 수력, 바이오매스, 지열 등과 같은 신재생에너지 자원의 개발이 필요하게 되었다. 최근 센서 네트워크 기술의 발달로 인하여 신재생 에너지 데이터는 각종 센서들로부터 원격으로 수집이 된다. 그러나 이러한 데이터는 센서 네트워크로부터 실시간으로 연속적으로 무한히 수집되는 센서 스트림 데이터이기 때문에 주기적으로 갱신되는 데이터 수집 방법으로는 최신의 데이터를 유지하기 어려우며, 부정확한 분석 결과를 도출할 수 있다. 따라서 본 논문에서는 무선 센서 네트워크 내에서 데이터 스트림을 효율적으로 수집하고 센서의 전송 횟수를 감소하기 위한 칼만 필터링 기법에 기반 한 필터링 기법을 제안하였다.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.259-264
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• 2009

Most of the fossil power plants firing lower grade coals are challenged with maintaining good combustion conditions while maximizing generation and minimizing emissions. In many cases significant derate, availability losses and increase in unburned carbon levels can be attributed to poor combustion conditions as a result of poorly controlled local fuel and air distribution within the boiler furnace. The poor combustion conditions are directly related to the gas flow deviation in upper furnace and convection tube-bank but a less reported issue related to in large-scale oppose wall fired boilers. In order to develop a on-line combustion monitoring system and suggest an alternative heat flux estimation method at tube bank, which is very useful information for boiler design tool and blower optimizing system, field test was conducted at operating power boiler. During the field test the exhaust gases' temperature and tube metal temperature were monitored by using a spatially distributed sensors grid which located in the boiler's high temperature vestibule region. At these locations. the flue gas flow is still significantly stratified, and air in-leakage is minimal which enables tracing of poor combustion zones to specific burners and over-fire air ports. Test results showed that the flue gas monitoring method is more proper than metal temperature distribution monitoring for real time combustion monitoring because tube metal temp. distribution monitoring method is related to so many variables such as flue gas, internal flow unbalance, spray etc., Heat flux estimation at the tube bank with flue gas temp. and metal temp. data can be alternative method when tube drilling type sensor can't able to use.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권5호
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• pp.237-241
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• 2004

Amorphous silicon (a-Si) films are used in a broad range of solar cell, flat panel display, and sensor. Because of the greater ease of deposition and lower processing temperature, thin films are widely used for thin film transistors (TFTs). However, they have lower stability under the exposure of visible light and because of their low field effect mobility ($\mu$$_{FE}$ ) , less than 1 c $m^2$/Vs, they require a driving IC in the external circuits. On the other hand, polycrystalline silicon (poly-Si) thin films have superiority in $\mu$$_{FE}$ and optical stability in comparison to a-Si film. Many researches have been done to obtain high performance poly-Si because conventional methods such as excimer laser annealing, solid phase crystallization and metal induced crystallization have several difficulties to crystallize. In this paper, a new crystallization process using a molybdenum substrate has been proposed. As we use a flexible substrate, high temperature treatment and roll-to-roll process are possible. We have used a high temperature process above 75$0^{\circ}C$ to obtain poly-Si films on molybdenum substrates by a rapid thermal annealing (RTA) of the amorphous silicon (a-Si) layers. The properties of high temperature crystallized poly-Si studied, and poly-Si has been used for the fabrication of TFT. By this method, we are able to achieve high crystal volume fraction as well as high field effect mobility.

• 센서학회지
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• 제6권5호
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• pp.414-422
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• 1997

CSVT(close spaced vapor transport)법으로 CdS/CdTe 이종접합 태양전지의 창재에 적합한 낮은 비저항과 적절한 광투과도를 갖는 CdS막을 증착하였다. 기판온도, 분위기압, 소스온도 등의 증착조건에 따른 CdS막의 전기적 및 광학적 특성을 조사하였다. 최적 증착조건은 기판온도 $300^{\circ}C$, 분위기압 100mTorr 및 소스온도 $730^{\circ}C$였으며, 이 때 증착된 CdS 막의 비저항은 $7.21{\times}10^{3}{\Omega}cm$있으며 광투과도는 63%이상이었다. 일반적인 고진공증착법으로 제조된 CdS막에 비해서 결정성이 크게 향상되었고 비저항은 약 3승정도 감소하였으며 광투과도는 비슷하여 창재로서 우수한 특성을 나타내었다.

• 한국군사과학기술학회지
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• 제16권4호
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• pp.545-552
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• 2013

This paper is a part of developing a computer code that can be used to generate IR images of a naval ship by considering the emitted and reflected infrared signals. The spectral radiance received by an IR sensor is consisted of the self-emitted component from the ship surface, the reflected component of the solar/sky irradiance at the ship surface, the emitted radiance from the ship surface and the exhaust plume gas, and the scattered radiance by the atmosphere. The plume gas radiance occupies a large part of the emitted radiance from a naval ship in operation. Therefore plume gas radiance must be taken into account when calculating the radiance from a naval ship for reliable IR images. In this paper, IR images of a naval ship with the exhaust gas effect in various environmental conditions are generated by using an exhaust gas prediction model called the JPL model. The contrast radiance (CR) values of the IR images are calculated to analyze the effect of the exhaust gas radiance quantitatively. The results obtained by quantitative analysis show that the IR signatures with the exhaust plume gas are 2.26 times larger than those neglecting the plume gas effect. The effect of the exhaust plume gas is shown to be more eminent in winter than in summer in the daytime.