• Title/Summary/Keyword: ClusterAnalysis

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A PRELIMINARY STUDY OF RELATIONSHIP AMONG TEMPERAMENTAL CHARACTERISTICS, FAMILY ENVIRONMENT AND DEVELOPMENTAL HISTORY (기질과 가정환경 및 발달사이의 관계에 관한 예비연구)

  • Hong, Sung-Do
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.8 no.1
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    • pp.50-56
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    • 1997
  • The objective of this study was to compare the family environment and developmental history of three groups of children classified by their temperament. The parents of 484 Korean children aged between 3 and 7 years completed the Korean version of Parental Temperamental Questionnaire developed by Thomas and Chess and Developmental Questionnaire created by Division of Child and Adolescent Psychiatry, Samsung Medical Center. After clustering these children into 5 temperamental groups according to the method proposed by Fullard et al, 98 Easy, 36 Difficult, and 21 Slow-To-Warm-Up children were included in the analysis. Statistically meaningful differences observed among three groups were as follow:1) Marital conflict of parents was more frequent in Difficult and Slow-To-Warm-Up children than in Easy children. 2) Parentchild conflict was more frequent in Difficult children than in Easy children. 3) Conflict among siblings was more frequent in Difficult children than in Easy children. 4) Average monthly income of family was less in Difficult children than in Easy children. 5) Toilet training was achieved later in Difficult children than in Easy children. 6) Motor development was slower, between 2 and 5 years old, in Slow-To-Warm-Up children than in Easy children. 7) Fear of stranger started earlier in Slow-To-Warm-Up children than in easy children. 8) Physical health was poorer in Difficult and Slow-To-Warm-Up children than in easy children. The findings indicate that Difficult child or Slow-To-Warm-Up child group have unfavorable family environment, different developmental milestone and poorer physical health in comparison with Easy child group.

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Water Quality and Epilithic Diatom Community in the Lower Stream near the South Harbor System of Korean Peninsula (한반도 서남부 하천 하구역의 수질 및 부착돌말 군집 특성)

  • Kim, Ha-Kyung;Lee, Min-Hyuk;Kim, Yong-Jae;Won, Du-Hee;Hwang, Soon-Jin;Hwang, Su-Ok;Kim, Sang-Hoon;Kim, Baik-Ho
    • Korean Journal of Ecology and Environment
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    • v.46 no.4
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    • pp.551-560
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    • 2013
  • Environmental factors and epilithic diatom communities in the lower streams near the harbor region of South Korean peninsula were examined during no monsoon period in May 2013. The sampling of water and epilithic diatoms was conducted at both streams, 19 regulated streams (RS) that there are one or several dams constructed in the river system, and 19 un-regulated streams (US) that there are no dams within the river. A cluster analysis based on the number of species and abundance of epilithic diatoms through the stations, divided into three groups such as groups I (mainly US), II (mixed with US and RS) and III (mainly RS), respectively. Group I showed that water quality is good and high diversity of diatom, while Group II and III was water quality is relatively poor, but not differed in biomass of diatom from Group I. In addition, Group II that had high conductivity, nitrogen and phosphorus, was the lowest in diatom diversity among them. Dominant species were Nitzschia palea (17%) and Navicula seminuloides (11%) in Group I, Nitzschia inconspicua (19%) and Navicula perminuta (9%) in Group II, and Nitzschia inconspicua (15%) and Nitzschia palea (14%) in Group III, respectively. These taxa were widely distributed in brackish water, and not closely related with specific water quality, like eutrophic water. However, the groups II and III belonged to RS, had not only little biomass, but bad water quality such as high concentrations of nutrient and chlorophyll-a. Therefore, to determine the effect of dam construction on the lower water ecosystem, the planktonic algae, which can occur algal bloom in the estuary, also was considered to be a parallel investigation.

A Ecological Study of Phytoplankton Community in the Geum River Estuary (금강 하구 기수역 식물플랑크톤 군집의 생태학적 연구)

  • Shin, Yoon Keun
    • Korean Journal of Ecology and Environment
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    • v.46 no.4
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    • pp.524-540
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    • 2013
  • After the construction of the Geum River estuary dam, we investigated the ecological property of phytoplankton community with physicochemical property in 9 stations of Geum River estuary 4 times seasonally in 2010 about the environmental changes through the change of phytoplankton. Physicochemical property seems to show eutrophication which developed from the tendency of accruing of the nutrients (those involved in intermittency of freshwater which flows from the dike and the surrounding cities), caused by the changing of tidal flow, the decreasing of the inflow of seawater after the construction of the Geum River estuary dam (dike). A total of 233 species of species composition of phytoplankton emerged, showing a highly increased result compared to that of the former research. The reason for the increase in number is considered as a phenomenon resulting from the mix of blackish and freshwater marine species in the flow of intermittency of freshwater discharge. Also, the standing crops of phytoplankton considerably increased compared to when the dike had not yet been built. Highly affected by the discharge of occasional freshwater, the diatoms of blackish water zone dominated in spring and winter, while freshwater species appeared to dominate in summer and autumn. The species diversity showed over 2.0 except in winter season. After a cluster analysis, the result showed that the Geum River estuary was influenced by runoff from cities like Gunsan, the sewage which flows from Gyeongpo River, and the intermittency of freshwater discharge from the Geum River estuary dam.

Community Structure and Health Assessment of Macrobenthic Assemblages at Spring and Summer in Geoje-Hansan Bay, Southern Coast of Korea (거제한산만에 서식하는 대형저서동물의 춘계와 하계의 군집구조 및 건강도 평가)

  • Jung, Rae Hong;Seo, In-Soo;Choi, Byoung-Mi;Choi, Minkyu;Yoon, Sang-Pil;Park, Sang Rul;Na, Jong Hun;Yun, Jae Seong
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.22 no.1
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    • pp.27-41
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    • 2016
  • This study was performed to investigate the community structure and health assessment of macrobenthic assemblages in Geoje-Hansan Bay, Southern Coast of Korea. Macrobenthos were collected by van Veen grab sampler at May (spring) and August (summer) 2013. The total species number and mean density were 300 species $7.6m^{-2}$ and $1,994ind.\;m^{-2}$, respectively. The major dominant species were the polychaetes Lumbrineris longifolia ($299{\pm}164ind.\;m^{-2}$), Aphelochaeta monilaris ($100{\pm}57ind.\;m^{-2}$), the bivalve Musculista senhousia ($91{\pm}96ind.\;m^{-2}$) and the polychaete Praxillella affinis ($80{\pm}66ind.\;m^{-2}$). From the community statistics [cluster analysis and nonmetric multidimentional scaling (NMDS) ordination], the macrobenthic community was distinguished into two groups of inner bay (farming ground of near Sandal Island) and channel station(from Hansan Island to Chubong Island) group. In this study, the ecological status was assessed by four biotic indices Shannon's H', the ATZI Marine Biotic Index (AMBI), multivariate-AMBI (M-AMBI) and the Environment Conservation Index (ECI). The ecological status of the macrobenthic community in Geoje-Hansan Bay were poorer in the inner bay station than in the channel station. The results of the present study showed that three biotic indices (Shannon's H', M-AMBI and ECI) were valid as an index for evaluating the ecological status than the AMBI.

The Variation of Natural Populations of Pinus densiflora S. et Z. in Kangwondo - The Morphological Characteristics of Needle and Cone - (강원도 지역 소나무 천연집단의 변이에 관한 연구 - 침엽과 구과의 형태적 특성을 중심으로 -)

  • Yi, Jae-Seon;Song, Jeong-Ho;Han, Sang-Sup;Park, Wan-Geun
    • Journal of Forest and Environmental Science
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    • v.15 no.1
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    • pp.107-116
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    • 1999
  • For the study on the variation of Pinus densiflora S. et Z. natural populations. 13 stands were selected in Kangwondo region in 1994. They were located in Hyoja-Dong, Chunchon-Si [plot 1]; Sinnam-Myun, lnje-Gun [plot 2]; Buk-Myun, lnje-Gun [plot 3]; Seo-Myun, Yangyang-Gun [plot 4 and 5]; Sonyang-Myun, Yangyang-Gun [plot 6]; Toseong-Myun, Goseong-Gun [plot 7]; Synrim-Myun, Wonju-Si [plot 8]; Dunnae-Myun, Hoengsong-Gun [plot 9]; Jinbu-Myun, Pyungchang-Gun [plot 10]; Sogumgang, Kangneung-Si [plot 11]; Seo-Myun, Ulchin-Gun [plot 12]; and Mitan- Myun, Pyungchang-Gun [plot 13]. The morphological characteristics of needles and cones were investigated for twenty individual trees from each population. The results are summarized as follows: 1. Among needle characteristics, length, the number of serration. and the number of stoma row were significantly different among populations and between individuals within a population. They were 69.3~91.9mm, 25.1~28.7 per 0.5cm, and 4.1~6.2 rows for abaxial side and 2.9~4.6 rows for adaxial side, respectively. 2. Among cone characters surveyed. length and diameter were significantly different among populations and between individuals within a population. They were 31.1~43.7mm and 20.0~24.1mm, respectively. 3. A highly positive correlation was observed between the number of stoma row of abaxial side and that of adaxial side. and between length and diameter of cone. But the number of serration was negatively correlated with all traits. 4. The distance from seashore was positively correlated with needle length and the number of serration, but negatively correlated with the number of stoma row and cone length. However, the altitude was positively correlated with the number of serration, but negatively correlated with the number of stoma row and cone length. 5. Cluster analysis using average linkage method for needle and cone characteristics showed two groups to Euclidean distance 1.0. They were group I consisting of plots 1, 8, 12, and 13 and group II of plots 2, 3, 4, 5, 6, 7, 9, 10, and 11. However, group II was divided again to Euclidean distance 0.8, that is a group including plots 2, 3, 9, and 11 and the other group comprising plots 4, 5, 6, 7, and 10.

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Evaluation of Germplasm and Development of SSR Markers for Marker-assisted Backcross in Tomato (분자마커 이용 여교잡 육종을 위한 토마토 유전자원 평가 및 SSR 마커 개발)

  • Hwang, Ji-Hyun;Kim, Hyuk-Jun;Chae, Young;Choi, Hak-Soon;Kim, Myung-Kwon;Park, Young-Hoon
    • Horticultural Science & Technology
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    • v.30 no.5
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    • pp.557-567
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    • 2012
  • This study was conducted to achieve basal information for the development of tomato cultivars with disease resistances through marker-assisted backcross (MAB). Ten inbred lines with TYLCV, late blight, bacterial wilt, or powdery mildew resistance and four adapted inbred lines with superior horticultural traits were collected, which can be useful as the donor parents and recurrent parents in MAB, respectively. Inbred lines collected were evaluated by molecular markers and bioassay for confirming their disease resistances. To develop DNA markers for selecting recurrent parent genome (background selection) in MAB, a total of 108 simple sequence repeat (SSR) primer sets (nine per chromosome at average) were selected from the tomato reference genetic maps posted on SOL Genomics Network. Genetic similarity and relationships among the inbred lines were assessed using a total of 303 polymorphic SSR markers. Similarity coefficient ranged from 0.33 to 0.80; the highest similarity coefficient (0.80) was found between bacterial wilt-resistant donor lines '10BA333' and '10BA424', and the lowest (0.33) between a late blight resistant-wild species L3708 (S. pimpinelliforium L.) and '10BA424'. UPGMA analysis grouped the inbred lines into three clusters based on the similarity coefficient 0.58. Most of the donor lines of the same resistance were closely related, indicating the possibility that these lines were developed using a common resistance source. Parent combinations (donor parent ${\times}$ recurrent parent) showing appropriate levels of genetic distance and SSR marker polymorphism for MAB were selected based on the dendrogram. These combinations included 'TYR1' ${\times}$ 'RPL1' for TYLCV, '10BA333' or '10BA424' ${\times}$ 'RPL2' for bacterial wilt, and 'KNU12' ${\times}$ 'AV107-4' or 'RPL2' for powdery mildew. For late blight, the wild species resistant line 'L3708' was distantly related to all recurrent parental lines, and a suitable parent combination for MAB was 'L3708' ${\times}$ 'AV107-4', which showed a similarity coefficient of 0.41 and 45 polymorphic SSR markers.

Quality Characteristics of Doenjang by Aging Period (전통 된장의 숙성 기간에 따른 감각·화학적 품질특성)

  • Ku, Kyung-Hyung;Park, Kyungmin;Kim, Hyun Jung;Kim, Yoonsook;Koo, Minseon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.5
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    • pp.720-728
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    • 2014
  • In order to characterize the quality of Doenjang, fermented Korean soybean paste, subjected to long-term aging, this study performed physico-chemical analyses and sensory evaluation according to aging period (from 1 to 9 years). Regarding the proximate composition of Doenjang according to aging period, moisture, crude protein, crude lipid, crude ash, and salt contents showed little differences among Doenjang samples. Amino-type nitrogen content was 1,046.7 mg% in the 1 year-aged sample, 990.9~996.9 mg% in the 2~5 year-aged samples, and 1,214.1~1,304.8 mg% in the samples fermented more than 5 years. ${\Delta}$E value, reflecting total color differences between the samples, increased according to aging period. Ratios of linoleic and linolenic acids, which are essential fatty acids in soybeans, constituted 55% of total fatty acids, which was the most abundant among all fatty acids. The major free sugar in Doenjang was fructose at a content of 1.6~2.2% in 1~9 year-aged Doenjang. Glycoside form of isoflavones in Meju constituted 77.1%, and the aglycon form constituted 22.9%. However, the glycoside type of isoflavones in soybeans was converted to aglycon type in Doenjang through fermentation and aging. In the sensory evaluation of Doenjang samples, brown color, salt smell, soy sauce flavor, and viscosity all increased according to aging period, whereas sweet flavor, roast smell, beany flavor, salty taste, and acrid taste showed no significant differences. In cluster analysis of the sensory attributes of Doenjang according to aging period, 1 year-aged Doenjang was significantly different between 2 year- and 3~5 year-aged Doenjang.

Benthic Marine Algae in the East Coast of Korea : Flora, Distribution and Community Structure (한국 동해 연안역의 저서 해조류 : 해조상, 분포 및 군집구조)

  • NAM Ki Wan;KIM Young Sik;KIM Young Hwan;SOHN Chul Hyun
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.5
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    • pp.727-743
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    • 1996
  • To know the floristic composition, vortical distribution and community structure of marine benthic algae inhabiting in the intertidal and subtidal zones of Yongil Bay, east coast of Korea, the study has performed using the quadrat method along a transect line from July, 1995 to June, 1996. In this area, a total of 144 species including 2 new red algae to Korea was found: 5 blue-green, 18 green, 20 brown and 101 red algae. The representative species throughout the year were Ulva pertusa, Gelidium amansii and Symphyocladia latiuscula. Dominant species were Sargassum thunbergii in spring, U. pertusa in summer and autumn. In winter, Chondrus ocellatus and Monostroma grevillei occurred dominantly. The standing crop exhibited mean value as $185.8g/m^2$ dry weight. Maximum value was recorded in spring $(267.3g/m^2)$ and minimum was observed in winter $(93.7g/m^2)$. Shannon's species diversity (H') and evenness (J') as maximum value were recorded in spring, whereas minimum values were shown in winter. Vertical distribution, rerognized by cluster analysis based on relative coverage of the species, could be divided into two or three algal groups except spring. In general, green algae (M. grevillei, Capsosiphon fulvescens, U. pefusa, Enteromorpha compressa) and brown algae (Sargassum fulvellum, S. thunbergii) were represented in the upper and middle zone and red algae (G. amansii, C. ocellatus, S. latiuscula, Crateloupia okamurae, Pachymeniopsis eilliptica) in the lower zone. The algal community varied according to season and environmental conditions. Particularly, seasonal variation of vortical distribution seemed to be affected primarily by water temperature. Also seasonal tidal level and tolerance of algal species to desiccation appeared to be associated with it in this area.

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Evaluation of Spatial and Temporal Variations of Water Quality in Lake Shihwa and Outer Sea by Using Water Quality Index in Korea: A Case Study of Influence of Tidal Power Plant Operation (수질평가지수를 이용한 시화호 내측 및 외측 해역의 시·공간적 수질 변화 평가: 조력발전소 가동에 따른 영향 연구)

  • Ra, Kongtae;Kim, Joung-Keun;Kim, Eun-Soo;Kim, Kyung-Tae;Lee, Jung-Moo;Kim, Sung-Keun;Kim, Eu-Yeol;Lee, Seung-Yong;Park, Eun-Ju
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.16 no.2
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    • pp.102-114
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    • 2013
  • The basin of Lake Shihwa is one of highly industrialized region of Korea and a current environmental issue of study area is the operation of tidal power plant (TPP) to improve water quality. The application of water quality index (WQI) which integrates five physiochemical parameters (transparency, DO, DIN, DIP and chlorophyll-a) of water quality in Lake Shihwa and outer sea during 2011~2012 were performed not only to evaluate the spatial and temporal distribution of the water quality but also to assess the effect of water quality improvement by the operation of tidal power plant. The higher WQI values were observed in monitored sites near the industrial complexes in Lake Shihwa and the outfall of wastewater treatment plants (WWTPs) in outer sea. This indicates that the quality of seawater is influenced by diffuse non-point sources from industrial, municipal and agricultural areas in Lake Shihwa and by point sources from the effluence of municipal and industrial wastewater throughout WWTPs in outer sea. Mean WQI value decreased from 53.0 in 2011 to 42.8 in 2012 of Lake Shihwa. Water quality has improved significantly after TPP operation because enhancement of seawater exchange between Lake Shihwa and outer sea leads to improve a hypoxic condition which is primarily a problem in Lake Shihwa. Mean WQI of outer sea showed similar values between 2011 and 2012. However, the results of hierarchical cluster analysis and the deterioration of water quality in summer season indicate that the operation of tidal power plant was not improved the water quality in the upper most area of Lake Shihwa. To successfully improve overall water quality of Lake Shihwa, it is urgently necessary to manage and reduce of non-point pollution sources of the basin of Lake Shihwa.

Community Structure of Macrobenthic Invertebrates during Spring and Autumn around Ui Island, Sinan-gun, Jeollanam-do (우이도 주변해역 조하대에서 춘계와 추계에 서식하는 대형무척추동물의 군집구조)

  • Seo, In-Soo;Choi, Byoung-Mi;Yun, Jae-Seong;Kim, Dae-Ik;Lee, Jong-Uk;Hwang, Choul-Hee;Kang, Yang-Soon;Kang, Young-Shil;Son, Min-Ho
    • Korean Journal of Environmental Biology
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    • v.28 no.3
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    • pp.133-142
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    • 2010
  • This study was performed to investigate the community structure of the macrobenthic invertebrates around Ui Island, Sinan-gun, Jeollanam-do, Korea. Benthic invertebrates were collected during May and September 2008 at seven stations. A total of 63 macrobenthic species was collected. The overall average macrobenthos density and biomass were 268 inds. $m^{-2}$ and 11.54 gWWt $m^{-2}$, respectively. Based on abundance data, there were 5 dominant species accounting for approximately 72.00% of total individuals. The polychaetes Notomastus latericeus, Scolelepis sagittaria, Amaeana occidentalis, Glycera chirori and the amphipoda Mandibulophoxus mai were found in high densities. The conventional multi-variate statistics (cluster analysis and non-metric multidimensional scaling) applied to assess spatial variation in macrobenthic assemblages. As a result, three communities could be distinguished: a sand dominated, a mixed sediment and a third community in the mud dominated station. The community in the sand dominated station was characterized by high abundance of the polychaetes S. sagittaria and the amphipods M. mai, Monoculodes sp. and Grandifoxus malipoensis. However, the most common species within the mixed sediment station were the polychaetes N. latericeus, A. occidentalis and amphipoda Urothoe sp.. Finally the mud dominated station was numerically dominated by the polychaetes Scolelepis sp., Heteromastus filiformis and Sigambra tentaculata. In conclusion, the sediment composition may be important factors controlling of the macrobenthic community structure in the study area.