• 한국동물학회:학술대회논문집
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• 한국동물학회 1998년도 공동 춘계학술대회
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• pp.42.1-42
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• 1998

No Abstract, See Full Text

• 한국동물학회:학술대회논문집
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• 한국동물학회 1995년도 한국생물과학협회 학술발표대회
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• pp.330.1-330
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• 1995

No Abstract, See Full Text

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.58.1-58.1
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• 2007

See Full Text

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2007년도 제48회 학술심포지움 및 추계국제학술대회
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• pp.82.2-82.2
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• 2007

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• 한국동물학회:학술대회논문집
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• 한국동물학회 1999년도 한국생물과학협회 학술발표대회
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• pp.195.2-195
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• 1999

No Abstract, See Full Text

• 한국산림과학회지
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• 제96권4호
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• pp.462-469
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• 2007

본 연구는 인위적인 피음처리 수준을 4단계(상대 투광율; 100%, 54~65%, 26~37%, 8~13%)로 조절한 생육환경 하에서 생장시킨 튜울립나무, 거제수나무, 까치박달나무를 대상으로 광합성과 생장 특성을 조사 비교하였다. 튜울립나무와 거제수나무의 광합성률은 전광 처리구에서 13.59, $16.29{\mu}mol\;CO_2{\cdot}m^{-2}{\cdot}s^{-1}$로서 가장 높게 나타났으며 피음처리 수준이 높아질수록 낮은 광합성 능력, 생장 및 물질생산량을 보였다. 까치박달나무는 보통피음 처리구(26~37%)에서 광합성률이 $9.47{\mu}mol\;CO_2{\cdot}m^{-2}{\cdot}s^{-1}$으로 가장 높았으며, 생장과 물질생산량도 가장 많았다.

• 한국농림기상학회지
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• 제8권2호
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• pp.54-60
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• 2006

내음성이 강한 죽절초 유묘를 대상으로 죽절초의 생육환경 변화에 따른 반응을 보기 위하여 서로 다른 광조건의 비음처리 I, II, III 그리고 자연조건(full sunlight)을 구분하여 각 처리구별 죽절초의 생리적 반응을 비교하였다. 생리적 반응의 비교를 위한 측정요소로 엽록소 함량, 광합성율, 기공전도도, 엽육 세포내 $CO_2$농도를 조사하였다. 비음처리구간간의 차이는 크게 나타나지 않았으나, 자연조건과 비음 처리구와의 차이는 크게 나타났다. 자연조건(full sunlight)일 때, 죽절초는 비음 처리구에 비하여 낮은 엽록소 함량과 광합성율, 기공전도도를 나타냈으며, 엽육 세포내 $CO_2$농도와 수분이용효율이 높게 나타났다. 이것은 죽절초의 광합성기구에 광저해 현상이 일어나 광반응 기구에 피해를 준것으로 보여지며, 적은 양의 빛을 효율적으로 이용하기 위해 순화된 죽절초는 높은 광조건하에서 잘 적응하지 못하고, 높은 광이 스트레스로 작용함을 알 수 있다.

• Journal of Communications and Networks
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• 제14권4호
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• pp.352-363
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• 2012

In this paper, we study the role of cooperative relays to provide and improve secure communication rates through decodeand-forward (DF) strategies in a full-duplex multiple relay network with an eavesdropper. We consider the DF scheme as a basis for cooperation and propose several strategies that implement different versions of this scheme suited for cooperation with multiple relays. Our goal is to give an efficient cooperation paradigm based on the DF scheme to provide and improve secrecy in a multiple relay network. We first study the DF strategy for secrecy in a single relay network. We propose a suboptimal DF with zero forcing (DF/ZF) strategy for which we obtain the optimal power control policy. Next, we consider the multiple relay problem. We propose three different strategies based on DF/ZF and obtain their achievable secrecy rates. The first strategy is a single hop strategy whereas the other two strategies are multiple hop strategies. In the first strategy, we show that it is possible to eliminate all the relays' signals from the eavesdropper's observation (full ZF), however, the achievable secrecy rate is limited by the worst source-relay channel. Our second strategy overcomes the drawback of the first strategy, however, with the disadvantage of enabling partial ZF only. Our third strategy provides a reasonable compromise between the first two strategies. That is, in this strategy, full ZF is possible and the rate achieved does not suffer from the drawback of the first strategy. We conclude our study by a set of numerical results to illustrate the performance of each of the proposed strategies in terms of the achievable rates in different practical scenarios.

• Journal of Ecology and Environment
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• 제37권2호
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• pp.91-97
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• 2014

Little is known about how the increased porosity of a deciduous windbreak, which results from loss of leaves, influences wind speed reduction. We hypothesized that, with loss of foliage, the wind speed reduction effectiveness of a deciduous windbreak decreases on near leeward side but not on further leeward side and that wind speed recovers faster in the full foliage season than in other seasons. During summer, autumn, and winter (full, medium, and non-foliage season, respectively), we observed wind speed and direction around a deciduous windbreak in a traditional Korean village on windward and near and further leeward sides (at -8H, 2H, and 6H; H = 20 m, a windbreak height). We used a linear mixed effects model to determine that the relative wind speed reduction at 2H significantly decreased from 83% to 48% ($F_{2,111.97}=73.6$, P < 0.0001) with the loss of foliage. However, the relative wind speed reduction at 6H significantly increased from 26% to 43% ($F_{2,98.54}=18.5$, P < 0.0001). Consequently, wind speed recovery rate between 2H and 6H in summer was two times higher than in autumn and ten times higher than in winter ($F_{2,102.93}=223.1$, P < 0.0001). These results indicate that deciduous windbreaks with full foliage seem to induce large turbulence and increase wind speed recovery rate on leeward side. Our study suggests that further research is needed to find the optimal foliage density of a deciduous windbreak for maximizing windbreak effectiveness regardless of seasonal foliage changes.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2000년도 유체기계 연구개발 발표회 논문집
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• pp.259-264
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• 2000

The functions of the plug valve are the control of flow rate as well closing and opening pipe lines. Analyses on the flow characteristics in plug valve port are required to improve the performance and safety at severe operating conditions such as high-pressure and high-temperature. In this study, numerical analyses are carried out with varying the opening rate (fraction of the full open to close) of the valve and the shapes of valve Uk: straight, convex, concave and mixed shapes. The parameters influencing the flow characteristics in the valve are the discharge coefficient( $C_v$) and the resistance coefficient( K). Therefore, the distributions of static pressure, velocity vector and stream lines are investigated, and $C_v$ and K are calculated in each opening rate and shape. In case of full open, the static pressure passed through the valve port has almost been recovered. However, in case of other opening rates, the pressure does not permanently regained due to pressure drop leading to loss. This phenomenon in each shape of the valve shows the different behaviors. Calculation results show that the mixed shape has the best flow attribute.