• The Korean Journal of Ecology
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• 제20권3호
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• pp.175-179
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• 1997

To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

• 한국지능시스템학회논문지
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• 제17권1호
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• pp.32-38
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• 2007

무선 Ad-Hoc 망은 기존의 인프라 스트럭쳐의 지원 없이 이동 단말들 간의 통신만으로 동작하는 네트워크로 기존 유선망과는 다른 형태의 통신 프로토콜이 요구된다. 이중 많은 통신 프로토콜에서 Flooding 알고리즘이 일반적으로 사용되고 있다. 그러나 이러한 Flooding 알고리즘은 패킷 전송 노트의 수에 따른 에너지 소비등과 같은 문제점을 갖는다. 이에 본 연구에서는 기존 Flooding 알고리즘을 개선할 수 있는 새로운 형태의 알고리즘을 제안하고 컴퓨터 시뮬레이션을 이용하여 제안된 알고리즘이 기존 Flooding 알고리즘에 비해 성능을 크게 향상시킴을 보인다.

• Journal of Crop Science and Biotechnology
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• 제10권2호
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• pp.79-85
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• 2007

Rice bran application just after transplanting has been increasingly practiced as an herbicide-substitute for organic rice production in Korea. However, this practice is frequently reported to be unsatisfactory in weed suppression. An experiment with five treatments that combines flooding depth, rice bran application dose, and herbicide treatment was done in the paddy field to evaluate whether rice bran application under deep flooding can lead to a successful weed control in compensation for the single practice of rice bran application. Rice bran was broadcasted on the flood water surface just after deep flooding of 8 to 10cm that was started at seven days after transplanting. In the shallow flooding plot without herbicide six weed species were recorded: Monochoria vaginalis, Echinochloa crus-galli, Ludvigia prostrate, Cyperus amuricus, Aneima keisak, and Bidens tripartite. Among the first four dominant weed species, deep flooding significantly suppressed the occurrence of Echinochloa crus-galli and Cyperus amuricus while did not suppress the occurrence of Monochoria vaginalis and Ludwigia prostrate. On the contrary, rice bran application under deep flooding suppressed significantly Monochoria vaginalis and Ludwigia prostrate while didn't exert an additional suppression of Echinochloa crus-galli and Cyperus amuricus compared to deep flooding alone. Rice bran application and deep flooding suppressed complimentarily all the six weed species to a satisfactory extent except for Monochoria vaginalis of which suppression efficacy was 31.9%. Deep flooding reduced the panicle number substantially by inhibiting the tiller production, increased the spikelet number per panicle slightly, and leaded to a lower rice grain yield compared to shallow flooding with herbicide. Rice bran application under deep flooding mitigated the panicle reduction due to deep flooding, increased the spikelets per panicle significantly, and thus produced even higher grain yield in the rice bran application of 2000kg $ha^{-1}$ as compared to the shallow flooding treatment with herbicide. In conclusion, this practice applying rice bran under deep flooding would be promising to be incorporated as an integral practice for an organic rice farming system.

• Nuclear Engineering and Technology
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• 제39권3호
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• pp.215-220
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• 2007

The existing flooding Probabilistic Safety Analysis(PSA) was updated to reflect the Korean plant specific operating experience data into the flooding frequency to improve the PSA quality. Both the Nuclear Power Experience(NPE) database and the Korea Nuclear Pipe Failure Database(NuPIPE) databases were used in this study, and from these databases, only the Pressurized Water Reactor(PWR) data were used for the flooding frequencies of the flooding areas in the primary auxiliary building. With these databases and a Bayesian method, the flooding frequencies for the flooding areas were estimated. Subsequently, the Core Damage Frequency(CDF) for the flooding PSA of the Ulchin(UCN) unit 3 and 4 plants based on the Korean Standard Nuclear Power Plant(KSNP) internal full-power PSA model was recalculated. The evaluation results showed that sixteen flooding events are potentially significant according to the screening criterion, while there were two flooding events exceeding the screening criterion of the existing UCN 3 and 4 flooding PSA. The result was compared with two kinds of cases: (1) the flooding frequency and CDF from the method of the existing flooding PSA with the PWR and Boiled Water Reactor(BWR) data of the NPE database and the Maximum Likelihood Estimate(MLE) method and (2) the flooding frequency and CDF with the NPE database(PWR and BWR data), NuPIPE database, and a Bayesian method. From the comparison, a difference in CDF results was revealed more clearly between the CDF from this study and case (2) than between case (1) and case (2). That is, the number of flooding events exceeding the screen criterion further increased when only the PWR data were used for the primary auxiliary building than when the Korean specific data were used.

• 한국환경복원기술학회지
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• 제18권2호
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• pp.45-52
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• 2015

Cool-season turfgrass is a rapidly increasing of usage for the revegetation of waterside slopes in dams, lakes and rivers. The purpose of this research is to identify the flooding tolerance of cool-season turfgrass with respect to the flooding periods of 0(control), 2, 4 and 6 days, respectively. The surface coverage ratio, turfgrass injury and soil moisture content were measured to assess the flooding tolerance of cool-season turfgrass. The increase in the flooding periods with 4 and 6 days resulted in the lower surface coverage ratio for cool-season turfgrass while no significant difference was found in the 2 days flooding when compared to 0 day (the control plot) flooding plot. In case of the turfgrass injury and the soil moisture content, however, the higher values were found with the increase of flooding periods in 2, 4 to 6 days. We observed that the higher the turfgrass injury and soil moisture content increased, the lower the surface covrage ratio decreased. In these regards, we also observed that the tolerance of cool season turfgrass were high in the 2 days flooding condition, medium in the 4 days flooding condition and low in the 6 days flooding condition. The flooding tolerance of cool-season turfgrass was gradually weakened in over 2 days flooding periods due to $O_2$ deficiency in the anaerobic soil condition. Therefore, we could suggest cool-season turfgrass within 2 days flooding periods for the revegetation of waterside slopes in dams, lakes and rivers.

• 컴퓨터교육학회논문지
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• 제14권6호
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• pp.65-73
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• 2011

최근 사이버공격을 보면 전세계 해킹공격 트랜드로 APT 공격이 지속 발생하고 있다. 특히, HTTP Get Flooding 공격은 사이버공격기법 중 가장 효과적인 공격 중 하나이다. 기존의 HTTP Get Flooding 공격 기술에 대해 알아보고 ATP 공격 특성을 결합한 새로운 공격 기술을 제안한다. 본 논문은 HTTP Get Flooding 기술을 이용하여 효과적인 APT 공격 도구 제작 관한 내용이다. 이 공격도구를 통해 지속적인 DDoS 공격에 대한 적극적 방어 대책이 필요하다.

• 한국작물학회지
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• 제46권3호
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• pp.215-220
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• 2001

본 연구는 혀의 분얼최성기의 관수스트레스 시 탁도(청수, 반탁수, 탁수) 및 관수시간에 따라 반응하는 단백질, 지방산 조성 및 지질과산화(malodialdehyde)를 정량하여 관수에 따른 생육장해 및 그 작용기작을 구명하여, 관수에 따른 생화학적 대사의 기초자료를 제공하고자 실시되었다. 관수스트레스에 의해 가용성단백질은 약 20%가 감소하였다. 특히 탁도가 높고 관수시간이 경과할수록 급격히 감소하였으며, 관수 36시간부터 감소량이 크게 나타났다. 단백질 전기영 동패턴은 관수스트레스에 따라 생성이나 소멸한 펩타이드는 없었으나 약 53Kd부위의 폴리펩타이드는 관수초기부터 함량이 증가하였고, 약 28Kd는 48시간, 54시간에서만 함량이 증가하였다. 관수스트레스에 의한 지질의 과산화정도는 약 150%가 증가하였고, 탁도처리에서 청수와 반탁수간의 차이는 작은 경향이었지만, 관수 60시간에서 약 160-180%가 증가하였다. 그러나 탁수에서는 관수초기부터 malondialdehyde함량이 높았고, 36시간이후부터는 약 190-200%로 급격히 증가하였다. Catalase는 탁도가 높고 처리시간이 경과할수록 활성은 급격히 증가하였다. 관수 48시간을 기준으로 catalase 활성변화가 크게 나타났다. 지방산조성의 변화는 포화지방산의 조성비율은 증가하고 불포화지방산은 감소하였다. 특히 불포화지방산 중 monounsaturated은 증가하였고 polyunsaturated의 상대적인 조성비율은 감소하였다. Double bond index는 탁도가 높을수록 관수기간이 경과할수록 감소폭은 커서 불포화정도가 떨어짐을 나타냈다.

• 한국작물학회지
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• 제46권3호
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• pp.209-214
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• 2001

본 실험은 청수, 반탁수, 탁수에 따른 탁도처리와 관수시간에 따른 광합성, 엽록소형광, 증산량 및 회복능을 분석하여 관수스트레스에 대한 벼의 생리반응을 구명하고자 실시한 결과는 다음과 같다. 1. 광합성은 탁도가 높고, 관수 시간이 경과할수록 감소하였다. 특히 관수 36시간 전까지는 약 25%, 42시간이후에는 약 50%가 감소하였다. 증산량은 탁도 및 관수시간이 증가함에 따라 증가하였으며, 청수에서는 약 30%, 반탁수에서는 약 25%, 탁수에서는 약 20%가 증가하였다. Fv/Fm은 탁도 및 관수시간 증가에 따라 감소하였으며, 청수에서는 48시간이후에, 반탁수 및 탁수에서는 36시간이후 약 20%가 감소하였다. 전질소함량은 관수스트레스에 의해 감소하였고, 탁수처리 36시간이후부터 감소량이 켰다. 2. 관수스트레스에 따른 회복력을 나타내는 건물중은 탁도 리별 차이는 작았으나, 관수시간이 경과할수록 크게 감소하였다. 피해정도는 24시간안에는 약 25%, 42시간이후에는 각 처리구 모두에서 약 50%의 생장감소가 일어났다. 관수 48시간의 반탁수 및 탁수는 고사하였다. 광합성은 탁도에 따라서는 청수에서 약 15%, 반탁수, 탁수에서는 10%가 감소하였고, 특히 42시간이후에는 30-50% 감소하였다. 증산량은 탁도 및 관수시간에 처리간의 차이 없이 약 20%증가하였다. 3. 관수 24시간처리에서 관수처리 시 및 퇴수 후 회복기간에도 광합성과 증산량의 일시적인 감소가 일어났다

• 한국작물학회지
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• 제52권3호
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• pp.320-324
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• 2007

본 실험은 내습성 품종과 감수성 품종을 5엽기에 9일간 침수 처리한 후 잎과 배축을 대상으로 횡단면을 해부학적 특성을 광학현미경으로 관찰하여 그 결과 다음과 같다. 1. 엽록소함량, 광합성, 책상조직 수, 엽두께 및 잎 건물중은 습해에 의해 급격히 감소되었으며 풍산나물콩보다 소백나물콩의 감소가 더 많았다. 2. 잎 조직의 책상조직의 치밀함은 습해에 의해 급격히 감소되었고 품종간 차이도 관찰되었으며, 풍산나물콩은 주맥의 통도조직 중 목부의 발달을 볼 수 있었다. 3. 배축의 통기조직 형성은 소백나물콩은 보이지 않았으나 풍산나물콩은 피층에 파생통기조직이 형성되는 것을 볼 수 있었다.

• 한국환경복원기술학회지
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• 제4권2호
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• pp.45-51
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• 2001

This study was carried out to select the useful plants for the revegetation of flooded slopes in dams, lakes and streams. In this study, four woody plants were investigated for their survival and growth in nursery with various flooding conditions. The results are as follows: Salix gracilistyla showed a very high survival rate and grew continuously under the complete flooding condition. Especially, it grew better under partly flooding condition than non-flooding condition. Amorpha fruticosa showed growth disorder when the flooding period was over 30 days, but the part of stem which was flooded in water adapted itself by branching the adventitious roots. Wisteria floribunda showed respectively high flooding tolerance until 30 days. Lespedeza bicolor were very weak in excessive moisture and flooding conditions. This study confirmed Salix gracilistyla, Amorpha fruticosa and Wisteria floribunda are efficient woody plants for covering the flooded slopes of dam and various impoundment sites.