• 정보처리학회논문지C
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• 제10C권6호
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• pp.683-694
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• 2003

인터넷 사용이 급속도로 증가함에 따라 XML/HTML 문서와 같이 트리 구조로 표현되는 데이터의 변화 탐지가 중요한 연구 분야로 등장하고 있다. 본 논문에서는 효율적인 변화 탐지를 위한 데이터 구조로 X-tree와 이에 기초한 휴리스틱 변화 탐지 알고리즘 X-tree Diff 를 제안한다. X-tree Diff 는 X-tree 의 변화 내용에 대한 최소 비용 편집 스크립트를 찾는 알고리즘과는 달리 휴리스틱 트리 대응 알고리즘을 통해 병화 내용을 확인하는 알고리즘으로, X-tree 에 속한 모든 노드에 대해 각각의 노드를 루트로 하는 서브트리의 구조와 서브트리속에 속한 노드들의 데이터들을 128비트 해시값으로 표현한 값인 트리 MD를 각 노드에 저장하고, 이를 변화 탐지 과정에서 활용하여 신-구 버전의 X-tree들에 속한 서브트리들의 비교을 효율적으로 처리한다. X-tree Diff 는 4단계로 구성되며 1)신-구버넌의 X-tree노드들에 대해, 우선 1:1 대응이 가능한 모든 동등한 서브트리 쌍을 찾고, 2) 이들 서브트리 쌍의 루트로부터 신-구 버전의 X-tree의 루트까지의 경로 상에 존재하는 노드들에 대한 대응관계를 결정한다. 3) 그 후 신-구 버전의 X-tree의 루트들로부터 깊이 우선 탐색으로 노드를 방문하며 대응이 결정되지 않은 노드들에 대한 대응여부를 결정해 나간다. 4) 마지막까지 대응여부가 결정되지 않은 도드들은 삭제나 삽입된 것으로 간주한다. X-tree Diff XML 문서들에 대한 버저닝(Versioning) 을 목적으로 설계된 BUILD Diff 알고리즘과 달리 XML/HTML 에 공통적으로 사용할 수 있을 뿐 아니라, 알고리즘이 명확하고 간결하여 다양한 형태의 확장이 가능하다. 알고리즘의 성능도 개선되어 신-구 X-tree의 노드의 수를 n이라 할 때, O(n)의 시간 복잡도를 갖는다. 제안된 알고리즘은 현재 보안 관련 상용 시스템인 WIDS(Web-Document Instrusion Detection System) 에서 사용되고 있으며, 본 논문에서는 WIDS를 이용하여 20여개 신문-방송 사이트에서 변화가 탐지된 11,000 개 페이지에 대한 성능평가를 보이고 있다.

• 한국응용곤충학회지
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• 제15권1호
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• pp.17-21
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• 1976

식물 virus병 매개체로서 그 중요성이 대두되고 있는 Xiphinema 속선충(Dorylaimida: Longidoridae)을 분류한 결과 우리나라에서는 X. radicicola, X. bakeri, X. pini와 X. americanum의 4종이 밟혀졌으며, 이중에서 X. radicicola, X. bakeri 및 X. pini의 3종은 우리나라 말기fhr종들이 있다. X. radicicola는 수원, 평택의진위, 경북의 대구 및 의성등지의 사과과수원과 제주도 한라산의 느릅나무와 보리수나무에서 채집되었으며 X. bakeri는 수원잠업시험장의 뽕나무밭에서 그리고 X.pini는 계룡산의 동학사부근에 있는 때총나무와 단풍나무의 뿌리부근토양에서 발견되었다. 4종의 Xiphinema속선충중에서 X. americanum은 유일한 우리나라 기록종으로서 편의상 여기서는 X. americanum과 X. mediterraneum에 유사한 개체군을 모두 포함시켰다.

• Journal of Forest and Environmental Science
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• 제36권1호
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• pp.17-24
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• 2020

This study aimed to figure out and compare the increment of biomass by thinning intensity focused on the plantation of the two major coniferous species (Larix kaempferi and Pinus koraiensis) of South Korea. The inventory interval was three years under the effects of three types of thinning treatments; control (no thinning), light (20% thinning) and heavy (40% thinning). The results showed standing biomass increment of both species decreased as thinning intensity increased (heavylight>control). Meanwhile, the lowest of on-site biomass changes occurred in the control plot, and the greatest was in the heavy thinning plot because thinning was involved with leaving the felling residual biomass (leaves, branches and roots) on the site. According to the results from this short-term study, unthinned stands is preferable for maximizing standing biomass as well as carbon sequestration. However long-term investigation should be considered in order to see more clear results.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2000년도 추계학술대회
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• pp.182-195
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• 2000

Indigenous bacteria from poplar roots (Populus mnadensis var. eugenei, 'Imperial Carolina') and Southern Californian shrub rhizospheres as well as two tree-colonizing Rhizobium strains (ATCC 10320 and 35645) were genetically engineered to express constitutively and stably toluene o-monooxygenase (TOM) from Burkholderia cepacia G4 by integrating the torn locus into the chromosome. The poplar and Rhizobium recombinants degraded trichloroethylene (TCE) at 0.8-2.1 nmol/min.mg protein (initial TCE concentration, 10u M) and competitive against the unengineered hosts in wheat and barley rhizospheres for one month (colonization at 1-23 $\times$ 10$^{5}$ CFU/cm root). In addition, six of these recombinants colonized poplar roots stably and competitively with populations as high as 79 $\pm$ 12% of all rhizosphere bacteria after 28 days (0.2-31 $\times$ 10$^{5}$ CFU/cm root). Furthermore, five of the most-competitive poplar recombinants (e.g., Pb3-1 and Pb5-1 which were identified as Pseudomonas PsK) retained the ability to express TOM for 29 days as 100 $\pm$ 0% of the recombinants detected in the poplar rhizosphere had constitutive expression of TOM.

• Journal of Ecology and Environment
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• 제31권3호
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• pp.167-176
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• 2008

Atmospheric N deposition has far-reaching impacts on forest ecosystems, including on-site impacts such as soil acidification, fertilization, and nutrient imbalances, and off-site environmental impacts such as nitrate leaching and nitrous oxide emission. Although chronic N deposition has been believed to lead to forest N saturation, recent evidence suggests that N retention capacity, particularly in the forest floor, can be surprisingly high even under high N deposition. This review aims to provide an overview of N retention processes in the forest floor and the implications of changing C-N interactions for C sequestration. The fate of available N in forest soils has been explained by the competitive balance between tree roots, soil heterotrophs, and nitrifiers. However, high rates of N retention have been observed in numerous N addition experiments without noticeable increases in tree growth and soil respiration. Alternative hypotheses have been proposed to explain the gap between the input and loss of N in N-enriched, C-limited systems, including abiotic immobilization and mycorrhizal assimilation, both of which do not require additional C sources to incorporate N in soil N pools. Different fates of N in the forest floor have different implications for C sequestration. N-induced tree growth can enhance C accumulation in tree biomass as observed across temperate regions. C loss from forests can amount to or outweigh C gain in N-saturated, declining forests, while another type of 'C-N decoupling' can have positive or neutral effects on soil C sequestration through hampered organic matter decomposition or abiotic N immobilization, respectively.

• Journal of Plant Biology
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• 제3권1호
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• pp.32-38
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• 1960

Since the peculiar virus disease of chinese date tree (Zizyphus jujuba Mill. var. inermis Rehd.) has been noted in South Korea around 1950, 70% to 80% of the economically important trees have been either completely destroyed or infected with the virus, severe damage has been noted, particularly, across the area ranged from middle east to the middle part of Korea, including Seoul area. Yoon-Koock-Byung in 1958 first reported the disease and descirbed it might be caused by a kinds of yellows. But he did not conform in his paper that the disease is pecisely caused by yellows virus. The authors, hereby intend to identify the true cause of the desease of the chinese data tree by studying the external symptoms of the disease and the internal morphological characteristics of the diseaset plant which shows various abnormalities in contrast to the healthy checks. In view of fact that leaves of the infected plants become yellowish in color similar to the peach yellows, aster yellows, it is likely to be identifiable as the common yellows. Furthermore, the abnormal characteristics observed by the authors are as follow: The floral organs such as petals, sepals, stamens, and pistil turn into vegetative leaves, the leaves on heavily infected plant appear as small sized one and also showing as a common witch's broom like symptom. There are also an occuring of numerous advantitious shoots developed from both of stems and roots. The amount of photosynthetic starch grains increases in parenchymatous cells, necrosis takes place in mesophyll, Particularly, Palisade Parenchyma in the leaves of infected plants are distinguished in contrast to the healthy checks. From the symptoms and the present experimetns described above, the authors are believed that the disease of chinese data tree is not caused by the yellows. It appears the disease is rather similar to the symptoms of sandal spike virus which was noted in India early in this centry. But the host plant of standal disease, Santalum albun L. and the insect vector, Jassus indicus Wal., have never been reported in Korean flora and the founa. The termperature and the otehr environmental factors is quite different Korea and India. Thus the authors believe that the peculiar disease must be an endemic new virus origin in Korea and must be called as "shoot cluster disease of chinese date tree."

• The Korean Journal of Ecology
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• 제15권1호
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• pp.19-33
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• 1992

The density, litterfall, phytomass, and primary productivity for 7 years in quercus mongolian forest locasted at mt. nambyengsan, pyeongchang-gun, gangwon provance in central part of korean peninsula were estimated quantitatively. at the first year in 1984, a stand had 1, 450 trees/ha in tree density, which was 0.67 of skewness and 0.54 of kurtosis in frequency distribution, however, at the 7th year in 1990, the stand had 1, 133 trees/ha in the density with 22%(or 316 tree/ha)in mortality, which was 1.16 of skewness and 1.89 of kurtosis in the frequency. annual mean litterfall was 5 ton DM/ha, which was composed of 68% of leaves, 17% of branches, 3% of bud scales, 9% of arcons and cups, 0.7% of flowers and others. the phytomass of tree layer for 7 years was gradually increased from 149.7 ton DM/ha at the first year to 188.5 ton DM/ha at the 7th year.annual net productivity for the tree layer studied ranged from 8.76 ton DM/ha.yr-1 to 11.62 ton DM/ha. yr-1 with heavy fluctuation year by year. average annual productivity of the stand of trunk, branches, leaves and roots for 7 years were 4.42, 0.67, 3.85 and 1.29 ton DM/ha.yr-1, respectively. turnover rate of the stand was 6.9% at the first year and 5.6% at the 7th year. such fluctuation of the productivity was caused by the chang of density, mortality, mortality and turnover rate.

• 문화기술의 융합
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• 제7권1호
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• pp.49-57
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• 2021

본 연구는 자연환경 속에서 스스로 성장하는 나무의 시스템을 통하여, 건축물에 있어서도 스스로 에너지를 생산할 수 있는 방법을 모색하고자 한 것으로, 나무의 구조, 순환 및 환경반응 시스템으로 구분하여 실 사례와 문헌중심으로 살펴본 것이다. 1) 나무의 구조는 지상계와 뿌리조직으로 나뉘며, 가압된 세포막들로 강성을 유지한다. 지상계인 줄기와 크라운에 의한 풍력의 저항은 건축물의 내진구조원리에, 측면 뿌리의 판형 버트레스는 수평트러스 및 현수교에 적용될 수 있다. 또한 다세포의 블록들은 공기막 구조의 원리에 해당된다. 2) 나무의 순환시스템에 있어서, 나뭇잎의 미세한 기공을 통한 증산작용은 많은 양의 열 방출로 효과적인 냉각 수단이 될 수 있어, 건축물의 냉방에 직접 도입할 수 있다. 또한 증산 작용은 물의 양수와 급수, 태양 그늘을 이용한 창문의 자동 개폐 등에도 적용될 수 있다. 3) 나무의 잎과 꽃에서 읽어낼 수 있는 환경변화에 따른 반응 시스템은 새로운 감지기술과 재료의 사용을 통하여 건축물의 지붕 및 외피디자인에 적용될 수 있다.

• 한국산림과학회지
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• 제89권2호
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• pp.216-222
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• 2000

가시오갈피나무의 약효성분에 대한 기초자료를 제공하고자 자생지 및 재배지간, 산지별, 직경별, 부위별 eleutheroside E 및 chlorogenic acid는 함량을 HPLC로 분석하였다. Eleutheroside E 및 chlorogenic acid의 함량을 분석한 결과 자생지와 재배지간에 함량차이가 나타났다. 뿌리의 chlorogenic acid 함량은 덕유산(0.863%), 대암산(0.667%) 및 치악산(0.630%)의 재배지에서 채취한 시료에서 가장 높았고, eleutheroside E의 함량은 오대산(0.086%) 및 응봉산(0.074%) 자생지에서 채취한 시료에서 가장 높았다. 줄기에서의 두 성분 함량은 모두 재배종 보다 자생종에서 높았으며, chlorogenic acid 함량은 오대산(0.882%)과 연엽산(0.664%), eleutheroside E 성분은 계방산(0.141%) 및 가마봉(0.125%) 산지에서 가장 높았다. 잎에서 eleutheroside E 맞 chlorogenic acid 함량은 산지간에 차이를 보였으며, 뿌리나 줄기의 함량에 비하여 낮았다. 뿌리와 줄기의 직경에 따른 eleutheroside E함량은 직경 크기가 클수록 함량이 높았다.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제3권3호
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• pp.189-196
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• 1999

The community structure, phytomass, and primary productivity in Thuja orientalis stands on a limestone area located in Maepo-up, Chungbuk province in Korea were estimated quantitatively. Seven species including a small proportion of Quercus dentata were identified in the tree layer, 26 species including Ulmus macrocarpa in the shrub layer, and 79 species including Carex lnceolata in the herb layer of the Thuja stands. The vertical distribution of the fine root phytomass exhibited a power functional decrease relative to the soil depth. The seasonal changes in the fine root phytomass at a soil depth of 5 cm were closely related to the pecipitation in the study area. The productivity of the stand of stems, branches, leaves, and roots were 10.72, 0.82, 0.45 and 6.46 ton DM. $ha^{-1}$ .$yr^{-1}$, respectively. The Thuja stand had a high foliage(25%) and low rate of production per unit of foliage. The annual turnover rate of the fine roots int he Thuja stand was 6.71 $yr^{-1}$. The net primary production of the overstory including the understory was estimated at 19.48 ton DM.$ha^{-1}$.$yr^{-1}$ including an underground section of 6.46 ton DM.$ha^{-1}$.$yr^{-1}$(33%). The allocation ratio of net production to root was lower in the limestone Thuja communities than at the nearby non-limestone ones, whereas the production efficiency to leaf weight was higher in the limestone communities. These results would seem to indicate that the limited production capacity is due to the calcium toxicity and low availability of iron and phosphorus in a limestone soil with a high pH, calcium, and bicarbonate content with a strategy for survival in a hostile habitat.