• Title, Summary, Keyword: 2단계 군집분석

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Environmental factors affecting neustonic zooplankton in the southwestern area of Korea in summer (여름 남해 서부 해역에 출현하는 수표성 동물플랑크톤에 미치는 환경요인)

  • Choi, Jang Han;Kim, Dae-Jin;Soh, Ho Young
    • Korean Journal of Environmental Biology
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    • v.38 no.3
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    • pp.461-475
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    • 2020
  • This study was conducted in the southwestern area of Korea using a neuston net in September (14 stations) 2017 to understand the environmental factors affecting neustonic zooplankton. Temperature, salinity, chlorophyll a concentration, suspended solids, and microplastics were included as environmental factors. Based on the density of the copepods, the study area was divided into three regions: the Seomjin River water influence area, the frontal mixing area, and the warm water affected area (Jeju warm current and Tsushima warm current). In the latter two areas, the major species were Pontella chierchiae, Canthocalanus pauper, and Oncaea spp. Also, neustonic zooplankton showed a significant relationship between the density of phytoplankton and microplastics in the frontal mixing area, and temperature and suspended solids in the warm water affected area, respectively (p<0.05). This indicates that microplastics can affect the offshore zooplankton community.

Two-Phase Clustering Method Considering Mobile App Trends (모바일 앱 트렌드를 고려한 2단계 군집화 방법)

  • Heo, Jeong-Man;Park, So-Young
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.4
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    • pp.17-23
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    • 2015
  • In this paper, we propose a mobile app clustering method using word clusters. Considering the quick change of mobile app trends, the proposed method divides the mobile apps into some semantically similar mobile apps by applying a clustering algorithm to the mobile app set, rather than the predefined category system. In order to alleviate the data sparseness problem in the short mobile app description texts, the proposed method additionally utilizes the unigram, the bigram, the trigram, the cluster of each word. For the purpose of accurately clustering mobile apps, the proposed method manages to avoid exceedingly small or large mobile app clusters by using the word clusters. Experimental results show that the proposed method improves 22.18% from 57.48% to 79.66% on overall accuracy by using the word clusters.

Vegetation Structure and Management Planning of Mountain Type Urban Green Space in Inchon, Korea : a case study of Kangwhado area (인천광역시 산지형 도시녹지의 식생구조 및 관리계획: 강화도지역을 중심으로)

  • Cho, Woo
    • Korean Journal of Environment and Ecology
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    • v.12 no.2
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    • pp.119-130
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    • 1998
  • The purposes of this study were to investigate vegetation structure and to present management plan of mountain type green space in Kangwhado, Inchon. The actual vegetation in survey sites(11,331ha) was divided into 19 community types. It was consisted of secondary forest(92.32%) which was Quercus acutissima, Pinus densiflora-Q. acutissima, and Q. mongolica community so on. Artificial planting forest area, such as Robinia pseudoacacia and Pinus rigida forest and others, was 5.40%(612ha) and it was less than cases in other cities in the Metropolitan area. According to the classification by TWINSPAN, 57 survey plots were divided into seven community types; P rigida(community A), Q. acutissima(community B) P. densiflora-Q. acutissima(community C), Q. acutissima-P. densiflora (community D), P. densiflora-Carpinus laxiflora-Q. serrata-Q. acutissima(community E), Q. serrata-Q. mongolica(community F), and Zelkova serrata-Acer mono(community G). From this result, ecological succession trend of vegetation in this area seems to be change from P. densiflora forest through Q. acutissima forest to Q. mongolica, Q. serrata, and C. laxiflora forest. It was similar to the ordinary successional trend of temperate deciduous forest in middle area, Korea. In addition, this study area was showed acid soil(pH 4.17). Therefore, there is a need for managing the soil environment for effective vegetation management.

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Vegetation Structural Restoration Model for Naturalness of Robinia pseudo-acacia Forest in the Case of Korean National Capital Region (수도권 지역 아까시나무림의 식생구조의 자연성 복원 모델)

  • 강현경;방광장
    • Korean Journal of Environment and Ecology
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    • v.15 no.2
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    • pp.159-172
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    • 2001
  • 본 연구는 수도권 지역의 아까시나무림을 중심으로 식물군집의 식생구조적 특성을 분석함으로써 향후, 도시녹지의 자연성 복원을 위한 기초 자료로 제시하고자 하였다. 조사지역은 서울도심지역으로 중구 남산과 서대문구 안산, 서울외곽지역으로 은평구 봉산과 부천시, 성주산, 비도시지역으로 경기도 천마산을 선정하였다. 주요 연구분야는 생태적 특성과 복원모델로 구분하였가. 생태적 특성평가는 천이단계, 자연성 및 다층적 식생구조와 종다양성을 실시하였으며, 복원모델은 적정수종, 개체수, 흉고단면적, 수목간 최단거리를 선정하였다. 조사결과, 복원모델은 비도시지역 중 자연성이 높으며 다층구조를 이루고 있는 자생식물군집을 선정하였으며 적정식물은 교목성장 3종, 아교목성정 7종, 관목성장 16종, 주연부 수종 4종 초본식물 27종이 적절한 것으로 판단되었다. 향후, 아끼시나무림읜 자연성 복원을 위해서 자연림인 참나무류로의 천이를 유도할 수 있도록 자생종 중심의 생태적 복원방안의 모색이 이루어져할 것이다.

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A study on Analysis of Human Sensibility Word in Water Bodies (수공간의 감성 어휘 분석에 관한 연구)

  • Kim, Jong-Pyo;Kim, Yong-Soo;Lim, Won-Hyeon
    • Science of Emotion and Sensibility
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    • v.10 no.2
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    • pp.209-220
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    • 2007
  • The purpose of this study is to investigate the words that represent the human sensibility for the water space. The selection of certain words for human sensibility valuation is very important things because of make standard for human sensibility valuation in water bodies. At the first step of the research, 129 words were collected from the subjects by imagination in group of specialist, studies on water space, studies on landscape valuation and studies on human sensibility valuation in out door environmental. At the second step, the suitability test was done and 39 words collected over an average 3.5 point. This words test was 5 point measure to similarity water bodies. At the third step, the factor analysis, cluster analysis, Multi Dimensional Scaling was performed on data, and 9 words were selected from the analysis. Finally, selected comfortable words for human sensibility valuation in water space is hands-on experience, natural, sensibility, harmony, clear, good-feeling, dynamic, free-heart, romantic. The significance of the present study is that it contributes the progress of uncovering the axis of the human sensibility by carefully selecting the words that represent the human sensibility.

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Correlation Analysis between Climatic Factors and Radial Growth and Growth Prediction for Pinus densiflora and Larix kaempferi in South Korea (소나무와 일본잎갈나무의 연륜생장과 기후 요소와의 상관관계 분석 및 생장예측)

  • Chung, Junmo;Kim, Hyunseop;Kim, Meesook;Chun, Yongwoo
    • Journal of Korean Society of Forest Science
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    • v.106 no.1
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    • pp.77-86
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    • 2017
  • This study was conducted to analyze the relationship among climatic factors and radial growth of Pinus densiflora and Larix kaempferi in South Korea. To determine the climate-growth relationship, cluster analysis was applied to group surveyed regions by the climatical similarity, and a dendroclimatological model was developed to predict radial growth for each climate group under the RCP 4.5 and RCP 8.5 scenarios for greenhouse gases. The cluster analysis showed four climatic clusters (Cluster 1~4) from 10 regions for P. densiflora and L. kaempferi. The dendroclimatological model was developed through climatic variables and standardized residual chronology for each climatic cluster of P. densiflora and L. kaempferi. Four climatic variables were used in the models for P. densiflora ($R^2$ values between 0.38 to 0.58). Two to five climatic variables were used in the models for L. kaempferi ($R^2$ values between 0.31 to 0.43). The growth simulations with two RCP climate-change scenarios(RCP 4.5 and RCP 8.5) were used for growth prediction. The radial growth of the Cluster 4 of P. densiflora, the mountainous region at high elevation, tend to increase, while those of cluster 2 and 3 of P. densiflora, the region of the hightest average temperature, tends to decrease. The radial growth of the Cluster 1 of L. kaempferi the region of the lowest minimum temperature, while that of Cluster 2, the region of the highest average temperature, tends to decrease. The radial growth of Cluster 3 of L. kaempferi, the region in the east coast and Cluster 4, the region at high elevation, tends to hold steady. The results of this study are expected to provide valuable information necessary for predicting changes in radial growth of Pinus densiflora and Larix kaempferi caused by climate change.

Segmentation Method of Overlapped nuclei in FISH Image (FISH 세포영상에서의 군집세포 분할 기법)

  • Jeong, Mi-Ra;Ko, Byoung-Chul;Nam, Jae-Yeal
    • The KIPS Transactions:PartB
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    • v.16B no.2
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    • pp.131-140
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    • 2009
  • This paper presents a new algorithm to the segmentation of the FISH images. First, for segmentation of the cell nuclei from background, a threshold is estimated by using the gaussian mixture model and maximizing the likelihood function of gray value of cell images. After nuclei segmentation, overlapped nuclei and isolated nuclei need to be classified for exact nuclei analysis. For nuclei classification, this paper extracted the morphological features of the nuclei such as compactness, smoothness and moments from training data. Three probability density functions are generated from these features and they are applied to the proposed Bayesian networks as evidences. After nuclei classification, segmenting of overlapped nuclei into isolated nuclei is necessary. This paper first performs intensity gradient transform and watershed algorithm to segment overlapped nuclei. Then proposed stepwise merging strategy is applied to merge several fragments in major nucleus. The experimental results using FISH images show that our system can indeed improve segmentation performance compared to previous researches, since we performed nuclei classification before separating overlapped nuclei.

Segmentation of Cooperatives' Mutuality Bank for Effective Risk Management using Factor Analysis and Cluster Analysis

  • Cho, Yong-Jun;Ko, Seoung-Gon
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.3
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    • pp.831-844
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    • 2008
  • Since cooperatives consist of many distinct members in the management environment and characteristics, it is necessary to make similar cooperatives into a few groups for the effective risk management of cooperatives' mutuality bank. This paper is a priori research for suggesting a guidance for effective risk management of cooperatives with different management strategy. For such purpose, we propose a way to group the members of cooperative's mutuality bank. The 30 continuous variables which is relative to cooperatives' management status are considered and six factors are extracted from those variables through factor analysis with empirical consideration to avoid wrong grouping and to enhance the practical interpretation. Based on extracted six factors and additional 3 categorical variables, six representative groups are derived by the two step clustering analysis. These findings are useful to execute a discriminatory risk management and other management strategy for a mutuality bank and others.

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Structure of Forest Communities in Chiak Mountain National Park - Case Study of Guryong Temple - Birobong Area - (치악산 국립공원의 삼림군집 구조 -구룡사-비로봉지역을 중심으로-)

  • 박인협;이경재;조재창
    • Korean Journal of Environment and Ecology
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    • v.2 no.1
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    • pp.1-8
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    • 1988
  • To investigate the forest structure of Guryongsa-Birobong area in Mt. Chiak, four districts were selected and forty-five plots were set up at the districts. The leading dominant species of District I, the valley forest in which users' density was very high. was Pinus densiflora. That of District II, the valley forest in which users' density was high. and Districs III, the valley forest in which entering was restricted recently. was Comus controversa. That of District III, the ridge forest in which users' density high, was Quercus mongolica. Species diversities of District I, II, III, and IV were 1.3252, 1.3736, 14421, and 1.2546, respectively. DCA ordination were showed that successional trends of tree species seem to be from Pinus densiflora through Quercus spp. to Carpinus laxtflora in ridge and midslope forest and from Pinus densiflora through Quercus spp. to Comtus controversa and Carpinus cordata.

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Spatial and Seasonal Patterns of Polychaete Community During the Reclamation and Dredging Activities for the Construction of the Pohang Steel Mill Company in Kwangyang Bay, Korea (광양제철소 건설을 위한 매립과 준설공사 기간중 저서 다모류 군집의 공간 및 계절 변화)

  • JUNG Rae-Hong;HONG Jae-Sang;LEE Jae-Hac
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.5
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    • pp.730-743
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    • 1997
  • Community structure and distribution patterns of benthic polychaetes were studied in Aug. 1983 and Feb. 1984 in Kwangyang Bay, Korea. During the study period, the large-scale reclamation and dredging operations were taking place. Polychaetes were composed of 76 species with a mean density of $342\;ind.{\cdot}m^{-2}$ during the summer 1983 and 77 species with a mean density of $437\;ind.{\cdot}m^{-2}$ during the winter 1984. Community structure indices were applied to the seasonal data. The stations influenced by the Seomjin river are characterized by a low species number and low diversity, while the stations located in channel regions represent high species richness and highdiversity. The inner bay stations showed the intermediate level in terms of species richness and diversity. On the basis of taxa composition and abundance in summer, the cluster analysis indicated that the study area was divided into live regions. The main factors that govern the polychaete distributions appeared to be the fresh water run-off and bottom sediment composition. However, a slight difference was observed in winter community, and changes in composition of the dominant species were found from Lagis bocki and Chone teres to Glycinde gurjanovae and Heteromastus filiformis. As a result, the broad scale reclamation and dredging activities may have played a role in changes of the polychaete community structure and the dominant species composition in Kwangyang Bay.

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