• Title/Summary/Keyword: cluster analyses

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Colonization and community changes in benthic macroinvertebrates in Cheonggye Stream, a restored downtown stream in Seoul, Korea

  • Shin, Il-Kwon;Yi, Hoon-Bok;Bae, Yeon-Jae
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.175-191
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    • 2011
  • Colonization patterns and community changes in benthic macroinvertebrates in the Cheonggye Stream, a functionally restored stream in downtown Seoul, Korea, were studied from November 2005 to November 2007. Benthic macroinvertebrates were quantitatively sampled 15 times from five sites in the stream section. Taxa richness (59 species in total) increased gradually over the first year, whereas the density revealed seasonal differences with significantly lower values in the winter season and after flood events. The benthic macroinvertebrate fauna may have drifted from the upstream reaches during floods and from the Han River, arrived aerially, or hitchhiked on artificially planted aquatic plants. Oligochaeta, Chironommidae, Psychodidae, and Hydropsychidae were identified as major community structure contributors in the stream. Swimmers and clingers colonized relatively earlier in the upper and middle reaches, whereas burrowers dominated particularly in the lower reaches. Collector-gatherers colonized at a relatively early period throughout the stream reaches, and collector-filterers, such as the net-spinning caddisfly (Cheumatopyche brevilineata), predominated in the upper and middle reaches after a 1-year time period. Cluster analyses and multi-response permutation procedures demonstrated that the Cheonggye Stream shares more similarities with the Jungnang Stream than with the Gapyeong Stream. Detrended correspondence analysis and nonmetric multidimensional scaling demonstrated that physical environmental factors (depth, current velocity, dissolved oxygen, and pH) as well as nutrients (total nitrogen and total phosphorous), water temperature, and conductivity could affect the distribution of benthic macroinvertebrates in the study streams.

Sportswear Evaluative Criteria Segments: Benefits Sought, Attitudes toward Imported and Domestic Brands, and Sportswear Image Preferences (스포츠웨어 선택기준 집단의 추구혜택, 국내 및 해외 브랜드에 대한 태도, 스포츠웨어 선호이미지)

  • Hwang, Jin-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.12
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    • pp.1742-1753
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    • 2007
  • The purposes of this study were to segment consumer groups by evaluative criteria and to find the differences among the groups in regard to sportswear benefits sought, domestic and imported brand attitudes, and sportswear image preferences. The subjects used for the study were 773 male and female consumers who were residents in Seoul. The data were analyzed by factor analysis, cluster analysis, t-test, and chi-square test. The results showed that there were two sportswear segments : brand/design-oriented group and function-oriented group. Statistical analyses showed that the two sportswear segments were different in regard to sportswear benefits sought, domestic and imported brands attitudes, sportswear image preferences, and demographics. Brand/design-oriented group sought the benefits of sex appeal/impression improvement, individuality, and conspicuousness, had a more favorable attitude toward imported brands, and preferred a prestigious image. They were relatively younger and had a higher income. In the meanwhile, function oriented group sought a comfort benefit from sportswear, had a more favorable attitude toward domestic brands, and preferred simple and active images. There were more high school graduates and home makers in function-oriented group. The implications of the study were discussed.

Phylogenetic relationships of Arthrospira strains inferred from 16S rRNA gene and cpcBA-IGS sequences

  • Choi, Gang-Guk;Ahn, Chi-Yong;Oh, Hee-Mock
    • ALGAE
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    • v.27 no.2
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    • pp.75-82
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    • 2012
  • $Arthrospira$ $platensis$ and $Arthrospira$ $maxima$ are species of cyanobacteria used in health foods, animal feed, food additives, and fine chemicals. This study conducted a comparison of the 16S rRNA gene and $cpcBA$-intergenic spacer ($cpcBA$-IGS) sequences in $Arthrospira$ strains from culture collections around the world. A cluster analysis divided the 10 $Arthrospira$ strains into two main genotypic clusters, designated I and II, where Group I contained $A.$ $platensis$ SAG 86.79, UTEX 2340, $A.$ $maxima$ KCTC AG30054, and SAG 49.88, while Group II contained $A.$ $platensis$ PCC 9108, NIES 39, NIES 46, and SAG 257.80. However, although $A.$ $platensis$ PCC 9223 belonged to Group II-2 based on its $cpcBA$-IGS sequence, this strain also belonged to Group I based on its 16S rRNA gene sequence. Phylogenetic analyses based on the 16S rRNA gene and $cpcBA$-IGS sequences showed no division between $A.$ $platensis$ and $A.$ $maxima$, plus the 16S rRNA gene and $cpcBA$-IGS sequence clusters did not indicate any well-defined geographical distribution, instead overlapping in a rather interesting way. Therefore, the current study supports some previous conclusions based on 16S rRNA gene and $cpcBA$-IGS sequences, which found that $Arthrospira$ taxa are monophyletic. However, when compared with 16S rRNA sequences, $cpcBA$-IGS sequences may be better suited to resolve close relationships and intraspecies variability.

Genetic Characterization of Clinical Acanthamoeba Isolates from Japan using Nuclear and Mitochondrial Small Subunit Ribosomal RNA

  • Rahman, Md Moshiur;Yagita, Kengi;Kobayashi, Akira;Oikawa, Yosaburo;Hussein, Amjad I.A.;Matsumura, Takahiro;Tokoro, Masaharu
    • Parasites, Hosts and Diseases
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    • v.51 no.4
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    • pp.401-412
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    • 2013
  • Because of an increased number of Acanthamoeba keratitis (AK) along with associated disease burdens, medical professionals have become more aware of this pathogen in recent years. In this study, by analyzing both the nuclear 18S small subunit ribosomal RNA (18S rRNA) and mitochondrial 16S rRNA gene loci, 27 clinical Acanthamoeba strains that caused AK in Japan were classified into 3 genotypes, T3 (3 strains), T4 (23 strains), and T5 (one strain). Most haplotypes were identical to the reference haplotypes reported from all over the world, and thus no specificity of the haplotype distribution in Japan was found. The T4 sub-genotype analysis using the 16S rRNA gene locus also revealed a clear subconformation within the T4 cluster, and lead to the recognition of a new sub-genotype T4i, in addition to the previously reported sub-genotypes T4a-T4h. Furthermore, 9 out of 23 strains in the T4 genotype were identified to a specific haplotype (AF479533), which seems to be a causal haplotype of AK. While heterozygous nuclear haplotypes were observed from 2 strains, the mitochondrial haplotypes were homozygous as T4 genotype in the both strains, and suggested a possibility of nuclear hybridization (mating reproduction) between different strains in Acanthamoeba. The nuclear 18S rRNA gene and mitochondrial 16S rRNA gene loci of Acanthamoeba spp. possess different unique characteristics usable for the genotyping analyses, and those specific features could contribute to the establishment of molecular taxonomy for the species complex of Acanthamoeba.

Effects of Long-Term Fertilization on Microbial Diversity in Upland Soils Estimated by Biolog Ecoplate and DGGE

  • An, Nan-Hee;Lee, Sang-Min;Cho, Jung-Rai;Lee, Byung-Mo;Shin, Jae-Hun;Ok, Jung-Hun;Kim, Seok-Cheol
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.6
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    • pp.451-456
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    • 2014
  • Organic amendment practices can influence diversity and activities of soil microorganisms. There is a need to investigate this impact compared with other types of materials. This study was carried out to evaluate the long term effects of chemical and organic fertilizer on soil microbial community in upland field. During the last 11 years green manure, rice straw compost, rapeseed cake, pig mature compost, NPK, and NPK + pig mature compost were treated in upland soil. Organic fertilizer treatment found with high bacterial colony forming units (CFUs) as compared to chemical and without fertilizer treatment. There was no significant difference in the actinomycetes and fungal population. The average well color development (AWCD) value was the highest in green manure and, the lowest in without fertilizer treatment. Analyses based on the denaturing gradient gel electrophoresis (DGGE) profile showed that rice straw compost and pig mature compost had a similar banding pattern while rapeseed cake, NPK, NPK + pig mature compost and without fertilizer treatment were clustered in another cluster and clearly distinguished from green manure treatment. Bacterial diversity can be highly increased by the application of organic fertilizer while chemical fertilizer had less impact. It can be concluded that green manure had a beneficial impact on soil microbial flora, while, the use of chemical fertilizer could affect the soil bacterial communities adversely.

Independent Component Analysis for Clustering Analysis Components by Using Kurtosis (첨도에 의한 분석성분의 군집성을 고려한 독립성분분석)

  • Cho, Yong-Hyun
    • The KIPS Transactions:PartB
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    • v.11B no.4
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    • pp.429-436
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    • 2004
  • This paper proposes an independent component analyses(ICAs) of the fixed-point (FP) algorithm based on Newton and secant method by adding the kurtosis, respectively. The kurtosis is applied to cluster the analyzed components, and the FP algorithm is applied to get the fast analysis and superior performance irrelevant to learning parameters. The proposed ICAs have been applied to the problems for separating the 6-mixed signals of 500 samples and 10-mixed images of $512\times512$ pixels, respectively. The experimental results show that the proposed ICAs have always a fixed analysis sequence. The results can be solved the limit of conventional ICA without a kurtosis which has a variable sequence depending on the running of algorithm. Especially. the proposed ICA can be used for classifying and identifying the signals or the images. The results also show that the secant method has better the separation speed and performance than Newton method. And, the secant method gives relatively larger improvement degree as the problem size increases.

Fashion Leadership, Underwear Purchase Behaviors and Attitude of Females in Their 20s-30s (20~30대 여성의 유행선도력에 따른 속옷 구매행동 및 태도에 관한 연구)

  • Kim, Jung-Woo;Jin, Sun-Young
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.8
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    • pp.1319-1330
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    • 2010
  • This study examines the underwear purchase behaviors of female consumers based on fashion leadership. Data research was conducted on 348 females in their 20s and 30s located in the city of Seoul & the surrounding Gyeonggi provincial area. The SPSS 17.0 software program was used to conduct data analyses such as descriptive statistics, frequency analysis, factor analysis, cluster analysis, ANOVA, and Scheffe's test as a post-hoc analysis. The results of this study are as follow. 1. Fashion leadership was identified with four factors; fashion opinion leadership, fashion innovation, confidence of fashion, and potential fashion leadership. Customers were segmented into the following three subdivisions: fashion leaders, fashion followers, and fashion laggards. 2. The factors derived from the factor analysis of underwear purchase motive included pursuit of fashion, economic, and fashion coordination. Fashion leaders highly regarded the pursuit of fashion & fashion coordination, but fashion laggards regarded economics highly. 3. The factors derived from the factor analysis of selection criteria included design attributes, brand attributes, functionality of clothes, and practicality. Fashion leaders regarded the attributes of design and brands highly; fashion followers regarded design attributes highly. 4. The factors derived from the factor analysis of underwear attitude included fashion/shopping orientation, fashion coordination orientation, and wear sensation/modesty orientation. Fashion leaders regarded fashion, shopping, design, and fashion coordination orientation highly relative to fashion followers and fashion laggards. 5. Fashion leadership showed significant differences in purchase motives, selection criteria, and underwear attitude.

Isolation and Charaterization of the Fibrinolytic Enzyme Producing Bacterium isolated from Naturally Fermented Chungkookjang (청국장에서 분리한 혈전용해효소 생산세균의 분리 및 동정)

  • Sohn Byung-Hee;Oh Kye-Heon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.3
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    • pp.476-482
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    • 2006
  • The aim of this work was to perform the screening and identification of the bacterium, MK-15 having the activity of fibrinolytic enzyme for the commercial use. Initially, strain MK-15 was enriched and isolated from naturally fermented soybean. Morphological and various physiological characteristics of the strain MK-15 was examined. The activity of fibrinolytic enzyme derived from supernatants of test culture MK-15 was performed by fibrin plate method for solid fibrinolytic activity. As the result, the fibrinolytic activity of MK-15 grown on the soybean media was about 2.7 times greater than that of plasmin used as stardard. 16S rRNA analyses revealed that strain MK-15 was 99.9% similar to Bacillus subtilis species cluster, and the bacterium was designated as Bacillus sp. MK-15. Strain MK-15 was registered in GenBank as [DQ163021].

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Study on Risk Reduction Behavior According to Participation Motivation of Mountain Climbing Activity and Level of Risk Perception (등산 활동 참여동기와 위험지각 수준에 따른 위험감소행동 연구)

  • Bang, Gi Seong;Yoo, Shin Jung
    • Fashion & Textile Research Journal
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    • v.15 no.4
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    • pp.523-532
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    • 2013
  • This study investigates risk reduction behavior with risk perception in outdoor wear purchase situations. Data were collected via a questionnaire from 400 consumers between the ages of 20 to 50 residing in Seoul and Kyonggi-do. Data analysis were conducted with SPSS 20 program on the reliability test, factor analysis, cluster analysis, t-test, ANOVA, and Duncan's multiple range test. Factor analyses were employed for the participation motivation of mountain climbing activities, risk reduction behavior and risk perception. Five factors were for the participation motivation of mountain climbing activities (health and fitness, external ostentation, achievement and excitement, improvement of climbing skills, and society). Five factors were for risk perception (fashionability loss and social risk, time and convenience loss, economic risk, performance risk, and psychological risk). Five factors were for the risk reduction behavior (interpersonal information sources use, marketer-dominated information sources use, professional information sources use, pre-purchase deliberation/observation/experience, and brand dependence). Three clusters were identified based on the motivation of outdoor activities (the affiliation/display, the health/internal informativeness and low motivation). The participation motivation for mountain climbing activities were varied. Manufacturers should increase efforts to develop products with good qualities at a reasonable cost as well as establish new marketing strategies since the risk of product performance and economic efficiency in the purchase of outdoor wear was a significant consumer perception.

Content Analysis of Webzine for Gist-based Health Message Design (핵심정보 중심 건강 메시지 디자인을 위한 웹진 내용분석)

  • Cho, Young Hoan;Choi, Hyoseon;You, Myoung Soon
    • The Journal of the Korea Contents Association
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    • v.14 no.2
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    • pp.192-204
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    • 2014
  • Gist-based message design is essential in the Internet in which a lot of health messages are created and shared constantly. This study intended to identify the characteristics of health messages in a webzine and explore a way to design gist-based health messages. A total of 72 webzine articles published in Korean Ministry of Food and Drug Safety were selected, and text and visual messages of the articles were analyzed in terms of content types, the frequency and position of gists, and intuitive expression. The articles were also categorized regarding the characteristics of health messages through cluster analyses. This study found that most texts of the health articles consisted of facts and methods, while most visual messages represented concepts. In addition, both text and visual messages had limitations in presenting a gist effectively. It was also necessary to explore an effective way to improve an intuitive understanding of jargon and quantitative information in health messages. Based on these findings, this study provided suggestions for the design of gist-based health messages in the Internet.