• 한국제4기학회지
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• 제17권2호
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• pp.163-163
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• 2003

The study area, Kwangneung Experiment Forest (KEF) is located on the west-central portion of Korean peninsula and belongs to a cool-temperate broadleaved forest zone. At the old-growth deciduous forest near Soribong-peak (533.1m) in KEF, we have established a permanent plot and a flux tower, and the site was registered as a KLTER site and also a KoFlux site. In this study, we aimed to present basic ecological characteristics and synthetic data of carbon budgets and flows, and some monitoring data which are essential for providing important parameters and validation data for the forest dynamics models or biogeochemical dynamics models to predict or interpolate spatially the changes in forest ecosystem structure and function. We made a stemmap of trees in 1 ha plot and analyzed forest stand structure and physical and chemical soil characteristics, and estimated carbon budgets by forest components (tree biomass, soils, litter and so on). Dominant tree species were Quercus serrata and Carpinus laxiflora, and accompanied by Q. aliena, Carpinus cordata, and so on. As a result of a field survey of the plot, density of the trees larger than 2cm in DBH was 1,473 trees per ha, total biomass 261.2 tons/ha, and basal area 28.0 m2/ha. Parent rock type is granite gneiss. Soil type is brown forest soil (alfisols in USDA system), and the depth is from 38 to 66cm. Soil texture is loam or sandy loam, and its pH was from 4.2 to 5.0 in the surface layer, and from 4.8 to 5.2 in the subsurface layer. Seasonal changes in LAI were measured by hemispherical photography at the l.2m height, and the maximum was 3.65. And the spatial distributions of volumetric soil moisture contents and LAIs of the plot were measured. Litterfall was collected in circular littertraps (collecting area： 0.25m2) and mass loss rates and nutrient release patterns in decomposing litter were estimated using the litterbag technique employing 30cm30cm nylon bags with l.5mm mesh size. Total annual litterfall was 5,627 kg/ha/year and leaf litter accounted for 61% of the litterfall. The leaf litter quantity was highest in Quercus serrata, followed by Carpinus laxiflora and C. cordata, etc. Mass loss from decomposing leaf litter was more rapid in C. laxiflora and C. cordata than in Q. serrata litter. About 77% of C. laxiflora and 84% of C. cordata litter disappeared, while about 48% in Q. serrata litter lost over two years. The carbon pool in living tree biomass including below ground biomass was 136 tons C/ha, and 5.6 tons C/ha is stored in the litter layer, and about 92.0 tons C/ha in the soil to the 30cm in depth. Totally more than about 233.6 tons C/ha was stored in DK site. And then we have drawn a schematic diagram of carbon budgets and flows in each compartment of the KEF site.

• 한국산림과학회지
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• 제110권4호
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• pp.496-503
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• 2021

소나무는 우리나라 자생수종 중 모든 지역에서 가장 넓은 분포를 보이고 있다. 소나무림의 입지환경 및 임분구조 특성을 구명하기 위해 제7차 국가산림자원조사(2016년~2020년)를 수행하며 얻은 자료를 활용하여 흉고단면적 기준으로 소나무가 50% 이상인 조사구를 대상으로 분석하였다. 총 15,139개 표본점 중 소나무림으로 분류된 원형조사구(400 m²) 수는 3,665개소이다. 소나무림은 해발 600 m 이하의 낮은 지역의 산림에서 가장 많이 나타났다(평균 출현율 25%). 해발 800 m 이상에서는 주로 남사면과 서사면에 분포했고(57%), 해발고가 낮은 지역에서는 모든 사면에 분포하는 경향을 보였다. 소나무림의 토성은 대부분 사양토(33%), 양토(29%), 미사질양토(24%)였고, 양분 수준은 다소 척박했다. 소나무와 함께 중요도가 높게 나타난 수종은 신갈나무, 굴참나무, 졸참나무, 잔털벚나무, 밤나무 등의 순이었다. 소나무, 곰솔, 리기다소나무 등은 소나무림에서 대경급으로 많이 분포하고 있었다. 신갈나무, 굴참나무, 졸참나무, 떡갈나무, 물푸레나무 등은 중경급의 주요 수종이며, 노간주나무와 때죽나무는 소경급으로 많이 분포하고 있었다. 소나무림에서 하층을 주로 점유하는 수종은 진달래, 졸참나무, 생강나무, 쇠물푸레나무, 개옻나무, 철쭉 등의 순으로 나타났다.

• 한국산림과학회지
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• 제94권6호
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• pp.410-419
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• 2005

상록활엽수림의 지속적 보전을 도모하기 위하여 전남 진도의 여귀산에서 상록활엽수림을 대상으로 식생조사를 실시하였다. 주요 상록수종에 대하여 흉고직경분포와 개체군분포상황을 파악하였으며, 수종의 중요치를 사용하여 cluster 분석에 의하여 군집을 분류하였다. 군집별로 종다양도, 균재도, 종상관 등을 산출하였으며, CCA분석에 의하여 군집과 토양환경인자간의 연관관계를 파악하였다. Cluster 분석에 의하면 여귀산의 상록활엽수림은 동백나무군집군과 붉가시나무군집군으로 분류되었다. 이는 다시 동백나무-상록활엽수군집, 동백나무-참식나무군집, 동백나무-낙엽활엽수군집, 붉가시나무-동백나무군집, 붉가시나무군집의 5개 군집으로 세분되었다. 상록활엽수 수종 중에서는 동백나무, 붉가시나무, 참식나무, 후박나무, 붓순나무, 광나무 등이 우점종으로 나타났고, 낙엽활엽수 수종 중에서는 때죽나무, 비목나무, 산딸나무, 산벚나무, 자귀나무, 상수리나무 등이 생육하고 있었다. 각 군집의 종다양도는 붉가시나무-동백나무군집이 종다양도가 0.8231로 가장 높게 나타났으며 붉가시나무군집(0.8135), 동백나무-낙엽활엽수군집(0.7931), 동백나무-상록활엽수군집(0.7674), 동백나무-참식나무군집(0.6164) 순이었다. 여귀산의 주요 상록수종은 2 cm~10 cm의 직경급이 전체의 약 80%를 차지하는 것으로 나타났으며 DBH 5 cm 이하의 동백나무가 전 지역에 걸쳐 괴상으로 분포하고 DBH가 증가함에 따라 임의분포하는 경향을 보였다. 한편 DBH 15 cm 이상에서는 붉가시나무가 참식나무, 후박나무 등에 비해 집중되는 경향을 보였다. 동백나무와 붉가시나무, 붓순나무, 산딸나무 사이에는 유의적인 부의 상관관계를 보였지만, 참식나무와는 유의적인 정의 상관관계를 나타냈다. 붉가시나무는 참식나무, 후박나무와는 유의적인 부의 상관관계를 나타냈고, 붓순나무와는 유의적인 정의 상관관계를 나타냈으며 참식나무는 산딸나무와 부의 상관관계를 보였다. 조사지의 토양 pH는 4.04~5.16이었고, 유기물함량은 3.15~9.21%, 유효인산함량은16.1~37.1 ppm, 양이온치환용량은 7.6~11.5 me/100 g이었다. CCA분석에 의하여 5개 군집 및 주요 수종의 분포를 살펴본 결과 토양유기물함량과 양이온치환용량이 높고 토양 산도가 낮아질수록 동백나무가 우점종으로 생육하면서 점차 참식나무, 붉가시나무의 혼효군집으로 발달하는 경향을 나타내었다.

• 한국환경과학회지
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• 제17권1호
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• pp.1-6
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• 2008

The characters of Castanea crenata community which is associated with human activities recently extended around the field of Saengbiryang-myeon at Sanseong-gun in Gyeongsangnam-do. The C. crenata community and its outskirts were investigated for several ecological parameters and the results can be summarized as fellows. C. crenata is prevailing in the plantation area, whereas Pinus densiflora and Quercus mongolica are prevailing in its outskirts. The mean species diversity of plantation was lower than that of natural forests. In stratification of investigated areas, overstory tree layer was dominant in the zone of plantation and dominant layers in the natural forest were understory tree layer, shrub, and herb. Plant biomass and net production which estimated from degree of green naturality were much higher in natural forests than those of the plantation community. Least significant differences (LSD) post hoc analysis revealed that P. densiflora and Q. mongolica community had significantly greater than densities than C. crenata community.

• 대한수학회보
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• 제52권3호
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• pp.955-962
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• 2015

It has been established that the role played by complete graphs in graph theory is similar to the role Dowling group geometries and Projective geometries play in matroid theory. In this paper, we introduce a notion of H-tree, a class of representable matroids which play a similar role to trees in graph theory. Then we give some properties of H-trees such that when q = 0, then the results reduce to the known properties of trees in graph theory. Finally we give explicit expressions of the characteristic polynomials of H-trees, H-cycles, H-fans and H-wheels.

• Journal of Plant Biology
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• 제20권4호
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• pp.141-149
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• 1977

In this sampling obtained 7,108 measurements for all trees larger than 2.5cm (1.0 inch) dbh from seven stands in Kwhangnung. In terms of similarity indices seven stands are classified into three kind of forest coniferous, mixed, and broadleaved froest communiteis. For ten major tree species in a three forest communities the size distributions are studied. Two forms of size distributions were observed: (1) linear relationships of log numbers of stem vs. size indicating stablesize distributions; (2) convex to bell shaped size distributions reflecting declining populaitons with a low natality rate. Survivorship analyses showed that successional trends seem to be: Pinus densilfloralongrightarrowQuercus aliena and Q. serratalongrightarrowCarpinus laxifloralongrightarrowC. erosalongrightarrowAcer pseudo-sieboldianum var. Koreanum. These results agree with the results from ordination method. An alternate pathways that Pinus koraiensis seems to be replaced by C. laxiflora were observed. It seems that successional trend is not unidireciton, but rather multi-directional.

• KIEE International Transactions on Electrophysics and Applications
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• 제11C권2호
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• pp.12-17
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• 2001

In this work, the correlation between the PD Patterns and the electrical tree propagation has been investigated by use of the specimen removed from the insulation of the real 154 kV XLPE underground power cables. As a result, it could be deduced that the PD pattern regarding electrical trees depends on their type which could be classified into three different distinct groups such as branch-bush mixed. Considering the results of our investigation, if the partial discharge magnitude is only considered for the diagnosis of the cable system, it is possible to draw a wrong decision. Therefore, it is possible to propose that the time characteristics of PD pattern should be taken into account for the diagnosis of the cable system in addition to the conventional $\Phi$-q-n characteristics.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 가을 학술발표논문집 Vol.33 No.2 (A)
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• pp.63-66
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• 2006

본 논문에서는 SNP데이터를 이용하여 간경화에 대한 감수성을 예측하기 위해 의사결정 트리를 이용하였다. 데이터는 간경화 환자와 정상환자 총 116명의 데이터를 사용하였으며, Feature 값으로는 간질환과 밀접한 연관성을 갖는 28개의 SNP데이터를 사용하였다. 실험방법은 각각의 SNP에 대하여 의사결정트리로 분류율을 측정한 후 가장 높은 분류율을 가지는 SNP부터 조합해 나가는 방식으로 C4.5 의사결정트리를 이용 leave-one-out cross validation으로 간경화와 정상을 구분하는 정확도를 측정하였다. 실험결과 간 질환 관련 SNP중 IL1RN-S130S, IRNGR2-Q64R, IL-10(-592), IL1B_S35S 4개의 SNP조합에서 65.52%의 정확도를 얻을 수 있었다.

• International Journal of Internet, Broadcasting and Communication
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• 제12권3호
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• pp.46-55
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• 2020

Ad Hoc network is a special wireless network, mainly because the nodes are no control center, the topology is flexible, and the networking could be established quickly, which results the transmission stability is lower than other types of networks. In order to guarantee the transmission of data packets in the network effectively, an improved Queue Ad Hoc On-demand Distance Vector Routing protocol (Q-AODV) for node detection by using blockchain technology is proposed. In the route search process. Firstly, according to the node's daily communication record the cluster is formed by the source node using the smart contract and gradually extends to the path detection. Then the best optional path nodes are chained in the form of Merkle tree. Finally, the best path is chosen on the blockchain. Simulation experiments show that the stability of Q-AODV protocol is higher than the AODV protocol or the Dynamic Source Routing (DSR) protocol.

• The Korean Journal of Ecology
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• 제17권2호
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• pp.113-119
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• 1994

Vertical and horizontal distribution and seasonal changes of fine roots as well as inorganic nitrogen content in soil were determined in Quercus mongolica and Quercus acutissima stands in Mt. Taemosan, Seoul. The vertical distribution of fine rooth phytomass showed a power-functional decrease as descending soil depth. Fine root phytomass was 170 g $DM/m^2$(46%) and 225 g $DM/m^2$(47%) in top soil of 5 cm depth, and 370 g $DM/m^2$ and 480 g $DM/m^2$ from soil surface to 50 cm depth in Q. mongolica and Q. acutissima stands, respectively. Fine roots in relation to the distance from the nearest tree were evenly distributed horizontally in both stands. Fine roots phytomass in top soil of 5 cm depth reached a peak in June, and thereafter decreased gradually in both stands. Patterns of seasonal changes in fine root phytomass were closely related to inorganic nitrogen and moisture content.