• 동굴
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• 제88호
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• pp.26-30
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• 2008

The black pollution that was able to include green pollution to appear for the intensity of light by an illumination institution is what after all I cannot ignore, and it may be said that chase thing damage by the isolation action that is white pollution done a long story in this outside a certain range by air quality change, dried present situation is really the environmental disruption by development and a damage phenomenon. If I am replaced in winker and I install a sensor light in the outlet by addition and use the electricity illumination that I installed for a tourist in the cave, it is expected that I can be available all the time that it is possible for electricity reduction more than the present and watches tourist passage plan private business Electric illumination in the cave for the environmental save in the cave because it is possible for more electricity reduction to be particularly off-season than on-season.

• 한국조경학회지
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• 제40권5호
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• pp.1-7
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• 2012

실내 광환경은 자연 상태와 달라 실내 조경 식물의 생장 및 생리활성에 영향을 줄 것으로 생각된다.본 연구는 광질(光質)이 월계수의 생장 및 생리활성에 미치는 영향을 평가하기 위해 실시하였다. 월계수 묘목은 4개의 다른 광원 처리구(control, +UV, -FR, +UV-FR 처리구)에서 180일 동안 생육시켰다. 자외선 추가 처리구(+UV)에서 생육한 월계수는 건중량 및 잎 면적이 감소되었지만, 잎 두께 및 잎내 자외선 흡수 물질의 함유량은 증가했다. 반면, 원적외선 차단 처리구(-FR)에서 생육한 월계수는 큰 변화를 나타내지 않았다. 하지만, 자외선 추가 및 원적외선 차단 처리구(+UV-FR)에서 생육한 월계수는 신장생장 및 광합성 속도가 유의적으로 저하했다(P<0.05).이상의 결과, 광질이 실내 조경 식물인 월계수의 생장 및 생리활성에 큰 영향을 주는 것으로 밝혀졌다. 실내 조경 식물인 월계수를 관리할 때 광질을 이용한 관리의 기초 자료로 활용될 수 있을 것이다.

• 한국항공운항학회지
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• 제22권2호
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• pp.27-33
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• 2014

There are several methods to improve the flight efficiency of HALE(High Altitude Long Endurance) UAV(Unmaned Aerial Vehicle). Airframe structural point of view, weight reduction of the airframe structure is the most important method to improve the flight efficiency. In order to reduce the weight of airframe structures, new concepts which are different from traditional airframe structure design such as the mylar wing skin should be introduced. The spar is the most important component in a mylar skin wing structure, so the spar weight reduction is the key point for reduction of the wing structural weight. In this study, design trade-off study for the front spar of the HALE UAV wing is conducted in order to reduce the weight. Design and analysis procedure of high aspect ratio wing spar are introduced. Several front spar structures are designed and trade-off study regarding the weight and strength for the each spar are performed. Spar design configurations are verified by the static strength test. Finally, optimal front spar design is decided and applied to the HALE UAV wing design.

• 한국의상디자인학회지
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• 제2권1호
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• pp.113-121
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• 2000

The effect of Sunlight exposure on reducing the microorganism counts in the bedding materials was experimented by using 3 kinds of microorganisms(S. aureus, K. pnenmoniae and E. coli) and 3 kinds of fabrics (cotton, silk and polyester). Counts of the microorganism were examined before and after sunlight exposure. The sunlights were controlled U.V and Daylight D50 using MacBeth artificial light source. The specimens were exposed for 5 min, 10 min and 30 minutes under the $20^{\circ}C$ and 60% R.H, distance is 50cm from the light source. Results were as follows, 1. The reduction rate of the 3kinds of microorganisms was remarkably great under the U.V exposure. The U.V. exposure was very effective way to sterlize the bedding materials in the house care. 2. S. aureus was the most susceptible to U.V. exposure and the sunlight exposure. E. coli was the most resistant to the U.V and the sunlight exposure. 3. The reduction rate of the 3 kinds of fabrics was not significantly different. The polyester is more resistant than the silk and the cotton. Those were shown good reduction rate if all kinds of microorganism under the U.V and daylight.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권3호
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• pp.1136-1151
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• 2018

This paper proposes a new hybrid scheme to decrease the high peak to average power ratio (PAPR) of optical orthogonal frequency division multiplexing (OFDM) signals in visible light communication (VLC) systems. The PAPR causes nonlinear signal distortions and high power requirements for the VLC transmitter (light emitting diode, LED). The proposed method is applicable for both direct current-biased optical OFDM (DCO-OFDM) and asymmetrically clipped optical OFDM (ACO-OFDM). In the proposed scheme, the PTS method is firstly modified to fit both optical OFDM approaches transmission and then combined with signal clipping method for further PAPR reduction and bit error rate (BER) improvement of the VLC system. The performance of hybrid scheme has been evaluated and compared with the original OFDM based VLC system, conventional PTS and clipping methods. The results show that the hybrid scheme outperforms other methods in terms of both the PAPR reduction and BER performance.

• 대한공간정보학회지
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• 제24권2호
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• pp.37-46
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• 2016

The difference between definition time of GPS (Global Positioning System) position data and actual display time of car positions on a map could reduce the accuracy of car positions displayed in PND (Portable Navigation Device)-type CNS (Car Navigation System). Due to the time difference, the position of the car displayed on the map is not its current position, so an improved method to fix these problems is required. It is expected that a method that uses predicted future positionsto compensate for the delay caused by processing and display of the received GPS signals could mitigate these problems. Therefore, in this study an analysis was conducted to correct late processing problems of map positions by mapmatching using a Kalman filter with only GPS position data and a RRF (Road Reduction Filter) technique in a light-weight CNS. The effects on routing services are examined by analyzing differences that are decomposed into along and across the road elements relative to the direction of advancing car. The results indicate that it is possible to improve the positional accuracy in the along-the-road direction of a light-weight CNS device that uses only GPS position data, by applying a Kalman filter and RRF.

• Journal of Photoscience
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• 제3권1호
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• pp.15-21
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• 1996

To investigate the chilling sensitivity related injuries in the photosynthetic apparatus of cucumber leaves, the light-chilling induced alterations of chlorophyll fluorescence transients in cucumber leaves were compared with those in pea leaves. As an early effect of light-chilling, an increase in Fp/Fm$^*$ was observed in both pea and cucumber leaves, which was saturated by about 6 h chilling. However, the saturated value of Fp/Fm was almost 1.0 in cucumber, in contrast to about 0.8 in pea. During the recovery period after 24 h chilling, the light-chilling induced changes in pea seemed to be reversed, but those in cucumber leaves were thought to be irreversible, because Fo was increased significantly. Light-chilling caused significant decreases in qQ and qE in cucumber leaves, but qR was increased until 6 h, and decreased thereafter. In both pea and cucumber leaves, Fm was increased by 2 h dark treatment. The Fm from the predarkened pea leaf discs was higher than the value from the preilluminated ones during the whole period of light-chilling (500 $\mu$mol m$^{-2}$s$^{-1}$ PAR). However, the predarkened cucumber leaf discs showed a reduction in Fm and an increase in Fo during the 2 h chilling in the light. These results indicate that the causes of chilling sensitivities in photosynthetic apparatus of cucumber leaves are possibly related with the damage in PSI reaction center and the ability of acidification of lumen by PSII.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 춘계학술발표대회
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• pp.189-192
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• 2000

광합성 홍색세균의 light harvesting complex II (LHC II)발현 유전자가 제거된 돌연변이종을 halogen 램프 하에서 거리에 따라 광도를 달리하며 배양하여 wild type과 생산성을 비교한 결과 낮은 광도(34 ${\mu}E/m^2/s$)에서는 wild type가 높은 광도 (376, 118 ${\mu}E/m^2/s$)에서는 mutant가 높은 세포농도를 나타내었다. 특히 118 ${\mu}E/m^2/s$에서 LHC $II^-$ mutant가 56% 높은 세포생산량을 보였다. 이는 세포내 pigment양의 감소로 mutual shading effect가 감소하였기 때문으로 판단되었다.

• 천문학논총
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• 제32권1호
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• pp.321-326
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• 2017

We analyzed spectral data of the astrophysical diffuse emission obtained with the low-resolution spectroscopy mode on the AKARI InfraRed Camera (IRC) in the $1.8-5.3{\mu}m$ wavelength region. Advanced reduction methods specialized for slit spectroscopy of diffuse sky spectra have been developed, and a catalog of 278 spectra of the diffuse sky covering a wide range of Galactic and ecliptic latitudes was constructed. Using this catalog, two other major foreground components, the zodiacal light (ZL) and the diffuse Galactic light (DGL), were separated and subtracted by taking correlations with ZL brightness estimated by the DIRBE ZL model and with the $100{\mu}m$ dust thermal emission, respectively. The isotropic emission was interpreted as the extragalactic background light (EBL), which shows significant excess over the integrated light of galaxies at <$4{\mu}m$.

• Nuclear Engineering and Technology
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• 제42권2호
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• pp.175-182
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• 2010

As part of a fundamental study on the volume reduction of contaminated concrete wastes, the separation characteristics of the aggregates and the distribution of the radioactivity in the aggregates were investigated. Radioisotope $^{60}Co$ was artificially used as a model contaminant for non-radioactive crushed concrete waste. Volume reduction for radioactively contaminated dismantled concrete wastes was carried out using activated heavy weight concrete taken from the Korea Research Reactor 2 (KRR-2) and light weight concrete from the Uranium Conversion Plant (UCP). The results showed that most of the $^{60}Co$ nuclide was easily separated from the contaminated dismantled concrete waste and was concentrated mainly in the porous fine cement paste. The heating temperature was found to be one of the effective parameters in the removal of the radionuclide from concrete waste. The volume reduction rate achieved was above 80% for the KRR-2 concrete wastes and above 75% for the UCP concrete wastes by thermal and mechanical treatment.