• Animal Systematics, Evolution and Diversity
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• no.nspc2
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• pp.243-250
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• 1988

The wing morphometric characters of P.elaeagni complex feeding on the genus Elaeagnus plants was analysed by the multivariate methods using clustering of generalized distance and discriminant analysis. On the clustering of the species, the effect of sexual differences, seasonal variation and geographic population sensitively appeared . However, four species of this group was precicely divided by the discriminant analysis.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.135-140
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• 2007

이탈 고객 예측은 데이터 마이닝에서 다루는 주요한 문제 중에 하나이다. 이탈 고객 예측은 일종의 분류(classification) 문제로 의사결정나무추론, 로지스틱 회귀분석, 인공신경망 등의 기법이 많이 활용되어왔다. 일반적으로 이탈 고객 예측을 위한 모델은 고객의 인구통계학적 정보와 계약이나 거래 정보를 입력변수로 하여 이탈 여부를 목표변수로 보는 형태로 분류 모델을 생성하게 된다. 본 연구에서는 고객과의 지속적인 접촉으로 발생되는 추가적인 사건 정보를 활용하여 연관성 규칙을 생성하고 이 결과를 기존의 방식으로 생성된 분류 모델과 결합하는 이탈 고객 예측 방법을 제시한다. 제시한 방법의 유용성을 확인하기 위해서 특정 국내 신용카드사의 실제 데이터를 활용하여 실험을 수행하였다. 실험 결과 제시된 방법이 기존의 전통적인 분류 모델에 비해서 향상된 성능을 보이는 것을 확인할 수 있었다. 제시된 예측 방법의 장점은 기존의 이탈 예측을 위한 입력 변수들 이외에 고객과 회사간의 접촉을 통해서 생성된 동적 정보들을 통합적으로 활용하여 예측 정확도를 높이고 실시간으로 이탈 확률을 갱신할 수 있다는 점이다.

• Communications for Statistical Applications and Methods
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• v.16 no.6
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• pp.959-969
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• 2009

Decision tree is a typical tool for data classification. This tool is implemented in DAVIS (Huh and Song, 2002). All the visualization tools and statistical clustering tools implemented in DAVIS can communicate with the decision tree. This paper presents methods to apply data visualization techniques to the decision tree using a real data set.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.46-46
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• 2018

본 연구는 봉화군 청옥산 산림유전자원보호구역에 분포하는 관속식물을 파악하고자 수행하였다. 청옥산 보호구역은 산림청에서 '희귀식물자생지' 유형으로 지정하여 관리하고 있으며, 면적은 약 2,051ha에 달하며 주로 신갈나무군락과 소나무군락이 우점하고있다. 현지조사는 2017년 3월부터 10월까지 계절별로 수행하였다. 조사결과, 보호구역내 관속식물은 86과 258속 390종 4아종 54변종 6품종으로 총 454분류군의 분포가 확인되었다. 이 중 한국특산식물은 가야물봉선, 처녀치마, 할미밀망, 키버들 등 11분류군이며, 산림청 지정 희귀식물은 취약종(VU)에 주목, 백작약, 꼬리진달래 3분류군, 약관심종(LC)에 등칡, 도깨비부채, 정향나무, 말나리, 나도개감채 등 14분류군이다. 식물구계학적 특정식물로는 IV등급인 회리바람꽃, 가지괭이눈, 산겨릅나무, 귀박쥐나물 등 10분류군, III등급인 애기감둥사초, 중나리, 토현삼, 선갈퀴, 금강제비꽃, 노랑갈퀴, 분비나무 등 23분류군, II등급 32분류군, I등급 30분류군이 확인되었다. 외래식물은 오리새, 털별꽃아재비, 왕포아풀, 주걱개망초, 지느러미엉겅퀴, 족제비싸리 등 18분류군이 임도 주변에서 확인되었다. 조사된 관속식물을 용도별로 구분하면 식용식물 181분류군, 섬유용식물 6분류군, 약용식물 143분류군, 관상용식물 52분류군, 사료용식물 172분류군, 염료용식물 9분류군, 목재용식물 22분류군으로 분석되었다.

• Journal of Korean Society of Forest Science
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• v.104 no.3
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• pp.368-374
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• 2015

On the basis of vegetation data by point quarter sampling method, the natural forest of Jirisan(Mt.) was classified into eight forest types by cluster analysis. They were Quercus mogolica forest type, Fraxinus mandshurica - Betula costata forest type, Mixed mesophytic forest type, Abies koreana forest type, Carpinus laxiflora forest type, Quercus serrata forest type, Pinus densiflora forest type, and Quercus variabilis forest type. Then, succession index was estimated for each forest type so as to evaluate succession process comparatively among forest types. The results showed that Carpinus laxiflora forest type had highest succession index of 219.7, followed by Mixed mesophytic forest type with little difference of the index of 218.3. Pinus densiflora forest type had lowest index. Succession indices were hardly correlated with species diversity indices of forest types. We presumed that the higher value of succession index a forest type had, the closer toward the climax forest. However, the estimated index was not supposed to be absolute level of successional stage, but it could play a role of comparative assessment in the position of the seral stage among forest types.

• The Korean Journal of Applied Statistics
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• v.18 no.2
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• pp.343-354
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• 2005

The goal of this paper is to compare classification performances and to find a better classifier based on the characteristics of data. The compared methods are CART with two ensemble algorithms, bagging or boosting and SVM. In the empirical study of twenty-eight data sets, we found that SVM has smaller error rate than the other methods in most of data sets. When comparing bagging, boosting and SVM based on the characteristics of data, SVM algorithm is suitable to the data with small numbers of observation and no missing values. On the other hand, boosting algorithm is suitable to the data with number of observation and bagging algorithm is suitable to the data with missing values.

• Journal of Korean Society of Forest Science
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• v.105 no.2
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• pp.157-166
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• 2016

This study was carried out to classify the current forest cover types and to propose the successional trends in the natural forest of Mt. Deogyu. The vegetation data were collected by the point-centered quarter method. The forest cover types were classified by various multivariate statistical analysis methods such as cluster analysis, indicator species analysis and multiple discriminant analysis. This forests were classified into five forest types by the species composition of upper layer and topographic positions: Quercus mongolica forest in the ridge, Fraxinus mandushurica-F. rhynchophylla-Cornus controversa forest and F. mandushurica forest in the valley, the Q. serrata - Pinus densiflora - Q. mongolica forest and P. densiflora forest in the low-slope. As a result of the forest successional trends depending on ecological and environmental characteristics in each forest type, the current forest types were expected that the forest succession would be proceeded toward Q. mongolica forest, F. mandshurica forest, mixed mesophytic forest, and oak-Carpinus laxiflora forest.

• Journal of Korean Society of Forest Science
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• v.108 no.2
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• pp.147-167
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• 2019

This study was conducted to analyze forest vegetation structure in the Marugeum (Ridge) area of Gitdaebaegibong to Jukryeong, Baekdudaegan. Data were collected in 298 quadrates through a Braun-Blanquet vegetation survey from April, 2018 to October, 2018. Forest vegetation was classified into 13 vegetation units. A Quercus mongolica community was divided into Morus bombycis, Filipendula glaberrima, Fraxinus sieboldiana, Prunus maackii unit and Q. mongolica typical unit. The M. bombycis unit was further classified into a Deutzia glabrata group and M. bombycis typical group. The F. glaberrima unit was subdivided into a Veratrum oxysepalum group, Arundinella hirta group, and F. glaberrima typical group. The F. sieboldiana unit was divided into a Pinus densiflora group, Larix kaempferi group, and F. sieboliana typical group. The relationship between vegetation units and environmental factors was studied through coincidence analysis and CCA. The F. glaberrima unit (VU 6~8) was distributed by elevation above 1,200 m and other vegetation units were distributed below 1,200 m. Results of the CCA analysis showed that the F. glaberrima unit distribution is positively correlated with elevation. As a result of species diversity, the F. glaberrima unit was higher than other vegetation units. A similarity index analysis revealed that the F. sieboldiana unit (VU 9~11) was relatively homogeneous, and the M. bombycis unit (VU 1~5) and A. girta group (VU 7) were relatively heterogeneous. A detrended correspondence analysis determined that the distance between the statistical axes of the M. bombycis and F. glaberrima units was the greatest, which is consistent with the analysis of the similarity index. As a result of interspecific correlation of major woody plants, hydrophilic species were positively correlated, and a negative correlation was found between Q. mongolica and intolerant species such as P. densiflora and L. kaempferi.

• Korean Journal of Environmental Biology
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• v.20 no.3
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• pp.216-223
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• 2002

This study was carried out to classify forest vegetation community of Dodeokbong and Baekwunbong in Gyeryongsan. Employing the releve method of Dierssen, 89 plots were sampled. Forest community was classified into Quercus mongolica community, Quercus serrata community, Quercus variabitis community, Pinus densiflora community, Carpinus laxiflora community, and Pinus rigida-Pinus thunbergii community. Quereus mongolica community was found in high altitude and steep area, Quercus serrata community in relatively low altitude and steep slope area, and Quercus variabilis in southern arid and low area compared with Quercus mongolica community. Pinus densiflora community is present in relatively high altitude and narrow arid ridge area. And, Carpinus laxiflora community is mainly distributed in southern valley area. Pinus rigida-Pinus thunbergii community is planted community.

• Journal of Korean Society of Forest Science
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• v.78 no.3
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• pp.255-262
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• 1989

Vegetation data of the mixed mesophytic forest in Mt. Chombong area were analyzed by the methods of classification and ordination. 'Weighted group average linkage cluster analysis' recognized five distinctive vegetation groups, based on the abundance data of 83 woody plant species in 70 sampling units. The species diversity was also examined for each group. The importance values of 42 tree species in the groups were subjected to principal component analysis (PCA). The PCA ordinated five vegetation groups on the first two axes, so as to compare similarity among them in terms of species composition. Acer palmatum, Fraxinus rhynchophylla, Quercus mongolica, and Acer mono had greatest influence on the determination of group scores with high eigenvectors (component loadings) in the first axis. Distribution of these four dominant species appeared to be important in determining community association in this diversified forest.