• Title/Summary/Keyword: ClusterAnalysis

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Short-term changes of community structure of microbenthic invertebrates in the coastal waters Jeju Island, Korea from 2013 to 2015 (제주연안 저서무척추동물 군집구조의 단기변화 (2013-2015))

  • Ko, Jun-Cheol;Kim, Bo-Yeon;Sonh, Myoung-Ho;Jo, Woon-Chan;Lee, Kwan-Cheol
    • The Korean Journal of Malacology
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    • v.32 no.4
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    • pp.297-328
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    • 2016
  • This study was performed to know and compare the community structures of macrobenthic invertebrates of five fishing grounds in the coastal waters of Jeju Island from 2013 to 2015. A total of 629 species was identified. Molluscans comprised 282 species (44.8%), Arthropods 88 (14.0%), Poriferans 61 (9.7%), Bryozoans 52 (8.3%) and the others including Cnidarians 51 (8.1%). Density and biomass were estimated to be $71,007ind./m^2$ and $599,208.0gwwt/m^2$, respectively. Gastropods was the most dominant taxon in terms of abundance ($24,625ind./m^2$ ) and number of species as well, and Gastropods was predominant in biomass ($190,789.0gwwt/m^2$). The dominant species were Omphalius pfeifferi, Astralium haematragum, Musculus viridulus, Halosydna brevisetosa, Phascolosoma scolops, Herdmania monus in 5-20 m. Based on the cluster analysis, the study area could be divided into five station groups. The biodiversity, evenness and richness index appeared as follows: H' = 4.28-4.64, E' = 0.74-0.79, R = 33.17-35.45. The dominance index were highest in Sagye and lowest in Sinhung.

A Comparative Study of Insect Community at Streamside zones at the Daejeon and Yudeung Streams (대전천과 유등천의 하천변 곤충군집 비교 연구)

  • Lim, Heon-Myoung;Cho, Youngho;Park, Young-Jun;Han, Yong-Gu;Nam, Sang-Ho
    • Korean Journal of Environment and Ecology
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    • v.27 no.1
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    • pp.30-51
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    • 2013
  • This study was conducted to identify the impact of river improvement efforts by studying terrestrial insects inhabiting at streamside locations at the Daejeon and Yudeung streams. Seven surveys were conducted from April to October on 2008 and the results were analyzed. Totally 428 species of 110 families belonging to 11 orders of insects were investigated during the course of the present study. The insects identified at the Daejeon stream belonged to 335 species, 99 families and 11 orders, while those at the Yudeung stream were of 350 species, with 98 families and 11 orders. At the Daejeon stream, D-1 and D-2 points were the sites where the most species(178 species) were identified, while at the Yudeung stream, the Y-1 point was the site where the most species(179 species) emerged. In a cluster analysis based on a similarity index, Group A(without river improvement works) and Group B(downtown passing area with river improvement works) were created. Within Group A, survey points were classified as the Daejeon stream group(the A-1 Group) and the Yudeung stream group(the A-2 Group). It was found that the emergence patterns of insects were related to regional characteristics of the streams.

Nonnegative Matrix Factorization Based Direction-of-Arrival Estimation of Multiple Sound Sources Using Dual Microphone Array (이중 마이크로폰을 이용한 비음수 행렬분해 기반 다중음원 도래각 예측)

  • Jeon, Kwang Myung;Kim, Hong Kook;Yu, Seung Woo
    • Journal of the Institute of Electronics and Information Engineers
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    • v.54 no.2
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    • pp.123-129
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    • 2017
  • This paper proposes a new nonnegative matrix factorization (NMF) based direction-of-arrival (DOA) estimation method for multiple sound sources using a dual microphone array. First of all, sound signals coming from the dual microphone array are segmented into consecutive analysis frames, and a steered-response power phase transform (SRP-PHAT) beamformer is applied to each frame so that stereo signals of each frame are represented in a time-direction domain. The time-direction outputs of SRP-PHAT are stored for a pre-defined number of frames, which is referred to as a time-direction block. Next, In order to estimate DOAs robust to noise, each time-direction block is normalized along the time by using a block subtraction technique. After that, an unsupervised NMF method is applied to the normalized time-direction block in order to cluster the directions of each sound source in a multiple sound source environments. In particular, the activation and basis matrices are used to estimate the number of sound sources and their DOAs, respectively. The DOA estimation performance of the proposed method is evaluated by measuring a mean absolute error (MAE) and the standard deviation of errors between the oracle and estimated DOAs under a three source condition, where the sources are located in [$-35{\circ}$, 5m], [$12{\circ}$, 4m], and [$38{\circ}$, 4.m] from the dual microphone array. It is shown from the experiment that the proposed method could relatively reduce MAE by 56.83%, compared to a conventional SRP-PHAT based DOA estimation method.

Health Behaviors among Adolescents in the Rural Area in Korea (농촌지역 청소년의 건강행태)

  • Park, Soon-Woo
    • Journal of agricultural medicine and community health
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    • v.34 no.2
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    • pp.202-213
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    • 2009
  • Objectives: The aim of this study was to compare health related behaviors among adolescents in the rural area with those in the urban area in Korea. Methods: The data source was the Korea Youth Risk Behavior Web-based Survey in 2005. With two stage cluster sampling, a total of 58,224 sample was selected from 799 middle and high schools nationwide. The area was classified into county area, small to medium city, and large city, and then the county area was considered as a rural area. Data was analyzed with STATA 9.0 using the method of complex survey data analysis considering sampling weight, strata, and primary sampling unit. Results: The prevalence of health related behaviors among adolescents in the rural area was higher than the city area as following health behaviors: smoking behaviors of smoking experience, smoking experience before entrance to middle school; drinking behaviors of frequent drinking, high risk behaviors with drinking; dietary behaviors of omitting of lunch or dinner, less intake of fruits or milk, more intake of cooky; oral hygiene of less tooth brushing, less preventive oral care, more oral symptoms and less dentist visit; safety behaviors of less wearing of safety belt or protective device; general hygiene of less hand washing before meal or after visiting rest room. Conclusions: The health behaviors among adolescents in the rural area were generally poorer than the city area. The results showed national health program for adolescents should be conducted primarily for those in rural areas. Further study is needed to explore the factors related with the discrepancy of health behaviors between the rural and urban area.

Utilization Behaviour and Influencing Factors of Complementary and Alternative Medicine Therapies Among the Elderly (일부 노인의 보완대체요법 이용행태와 영향요인)

  • Moon, Gi-Won;Kim, Jun-Ho;Kim, Chun-Bae
    • Journal of agricultural medicine and community health
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    • v.38 no.1
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    • pp.25-38
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    • 2013
  • Objectives: The aim of this study is to analyze the utilization behaviour and influencing factors of complementary and alternative medicine (CAM) therapies among elderly people with chronic diseases. Methods: The study population was selected among 9 welfare facilities for the aged in 2 cities among Daegu Metropolitan City & Gyeongsangnam Province by two-stage cluster sampling. 250 senior citizens participated in a face-to-face interview using a structured questionnaire. Logistic regression analysis was performed to examine the association between the utilization of CAM therapies and various characteristics of the elderly. All statistics were analyzed using the PASW (ver 18.0). Results: Among 233 elderly peoples, 70.4% (164 persons) had used various kinds of CAM therapies (including nutritional methods, pharmacologic and biologic treatments, etc.) more than once during the last year. 48.8% (64 persons) ~ 60.7% (88 persons) of the elderly used CAM therapies without health and medical experts' counsel. The elderly with perceptions of CAM therapy used it 2 times more than those without knowledge of CAM therapies. The number of chronic diseases was more likely to increase the usage of nutritional methods (OR=2.92, 95% CI: 1.07-7.97), manipulative and body-based practices (OR=5.85, 95% CI: 1.97-17.34), pharmacologic and biologic treatments (OR=2.92, 95% CI: 1.49-8.17). Elderly with diabetes used nutritional methods 3.76 (95% CI: 1.49-9.47) more than elderly without diabetes. Conclusions: CAM therapies use in the aged with chronic diseases appears common. The findings suggest that the clinical efficacy and safety of CAM therapies on medical management of chronic disease may be investigated and that patient-physician communication need to be strengthened.

A Rolling Sampling Design for the Korea National Health and Nutrition Examination Survey (제4기 국민건강.영양조사를 위한 순환표본 설계연구)

  • Lee, Kay-O;Park, Jin-Woo
    • Survey Research
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    • v.8 no.2
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    • pp.67-89
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    • 2007
  • The Korea National Health and Nutrition Examination Survey(KNHANES) consists of Health Interview Survey, Health Behaviour Survey, Nutrition Survey, and Health Examination, and is designed to produce a broad range of descriptive health and nutritional statistics for sex and age subdomains of the population. These data can be used to measure and monitor the health and nutritional status of the population of Korea. The survey has been conducted three times from 1998. The Korea Centers for Disease Control and Prevention(KCDC) is preparing for the 4th survey which is to be conducted from 2007 through 2009. This study is to design a sample for the 4th survey. The main new feature of the sampling design is using a rolling sampling design method. Since KCDC has imposed some operational requirements, e,g., the needs of producing the annual national statistics and of year-round data collection by some regular staffs, a rolling sampling design method is introduced. This is the first time in history of applying a rolling sampling design for a national-wide large scale survey in Korea. Bringing in the rolling sampling, measurement variation due to different data collectors may be minimized.

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RAPD Analysis and Antimicrobial Susceptibility of Streptococcus equi subsp. zooepidemicus Isolated from Thoroughbred Horses (더러브렛 말에서 분리한 Streptococcus equi subsp. zooepidemicus의 RAPD 분석 및 약제 감수성)

  • Choi, Seong-Kyoon;Park, Yong-Soo;Cho, Kwang-Hyun;Cho, Gil-Jae
    • Journal of Life Science
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    • v.20 no.5
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    • pp.649-654
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    • 2010
  • A total of 68 samples were collected including vaginal mucosa (n=66) from Jangsu stud farm, an equine aborted fetus (n=1), and uterine contents (n=1) from Jeju island. Seventeen Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) strains isolated from horses in Korea were identified as S. zooepidemicus by biochemical tests and sodA.seeI specific multiplex PCR. All isolated strains were divided into 4 clusters: group 1 (No. 2, 3, 5, 6, 7, 11, 12, 13, 14, 15), group 2 (No. 4, 9), group 3 (No. 10, 16, 17), and group 4 (No. 1, 8) by RAPD typing. In group 3, No. 10 isolate that was isolated from vaginal mucosa was indistinguishable from No. 16 and 17 isolates, which were isolated from the equine uterine contents and the equine aborted fetus, respectively. The results of this study suggest that a limited epidemiological relationship exists between the strains from Jangsu (No. 10) and Jeju (No. 16 and No. 17). All isolates showed a high susceptibility to ampicillin, cefoxitin, ceftiofur, cephalothin, florofenicol, gentamicin, nalidixic acid, oxacillin, penicillin, tiamulin, tylosin and vancomycin in antimicrobial susceptibility tests. These results may provide the basic information needed to establish strategies for the treatment and prevention of reproductive diseases in mares in Korea.

The Effects of Climatic Factors on the Tree Ring Growth of Pinus densiflora (기후인자가 Pinus densiflora의 연륜 생장에 미치는 영향)

  • Lee, Sang-Tae;Park, Mun-Seop;Jun, Hyang-Mi;Park, Jin-Young;Cho, Hyun-Seo
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.10 no.4
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    • pp.177-186
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    • 2008
  • This study was carried out to analyze the relationship between major climatic factors (temperature and precipitation) and tree ring growth of Pinus densiflora in 28 cities and counties in Korea. To examine tree ring growth of Pinus densiflora and the response of the climatic factors to climate change, the regional climatic data (for how many years??) from weather stations were categorized by five groups using cluster analysis for major climatic factors. In terms of relationship between monthly average temperature and tree ring growth of Pinus densiflora, negative correlations were observed for the temperatures in March of the present year in Baekdudaegan region and those in February and March in Gyeongbuk and East coast region. In addition, the temperature in October of the previous year was also negatively correlated with tree ring growth. Precipitation was positively correlated with the April and June temperatures of the present year in Baekdudaegan region and Gyeongbuk, respectively. Precipitation effect on the tree ring growth with current year June in Honam and Gyeongnam inland region and June, September in East coast region.

Construction of Parent attachment Scale for Children (초등학생용 부모애착척도의 구성)

  • Lee, Hyun-Sook;Hong, Sang-Hwang
    • The Korean Journal of Elementary Counseling
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    • v.9 no.2
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    • pp.143-162
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    • 2010
  • The purpose of this study is to construct Parent Attachment Scale for Children. Adapting the item consisting method used in Experiences in Close Relationships-Revised(ECR-R), Parent Attachment Scale for Children was constructed to measure child's attachment style with their parent, reliably and validly. Also, reliability and item trait informations based on item response theory were reviewed. First preliminary items were derived from the original items of ECR-R and existing Attachment Inventories. These items were modified and complemented to be easier and keep the original meaning of each item. Second preliminary items were administrated to 4~6th grades students(N=576). Finally, Parent Attachment Scale for Children were consisted with 30 items based on two-parameter graded response model. Internal consistency ranges of the scales of Parent Attachment Scale for Children are as follows : Avoidance scale is .94~.96; Anxiety scale is .85~.88. Test-retest reliability ranges are as follows; Avoidance scale is .71~.80; Anxiety scale is .53~.68. Item discrimination and item information value were within an appropriated range. Hierarchical cluster analysis with Ward's Method revealed four types of attachment style : Secure, Dismissing, Preoccupied, Fearful. Other implications and limitations of this study were discussed.

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Cloning and Nucleotide Sequence Analysis of xylC Gene Encoding 5C-2HMS Dehydrogenase from Pseudomonas sp. S-47. (Pseudomonas sp. S-47로부터 5-Chloro-2-Hydroxymuconic Semialdehyde Dehydrogenase를 암호화하는 xylG 유전자의 클로닝 및 염기서열 분석)

  • Park, Song-Yi;Lee, Dong-Hoon;Kim, Young-Soo;Lee, Kyung;Kim, Chi-Kyung
    • Microbiology and Biotechnology Letters
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    • v.30 no.1
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    • pp.8-14
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    • 2002
  • Pseudomonas sp. S-47 is capable of degrading 4-chlorobenzoate to produce 5-chloro-2-hydroxymuconic semialdehyde (5C-2HMS) by the enzymes encoding by xylXYZLTE cluster. In this study, the resulting 5C-2HMS was confirmed to be transformed to 5-chloro-2-hydroxymuconic acid (5C-2HMA) by 5C-2HMS dehydrogenase. The xylG gene encoding 5C-2HMS dehydrogenase was cloned from the chromosomal DNA of strain S-47. The nucleotide sequence of xylG showed to be composed of 1,600 base pairs with ATG initiation and TGA termination codons. A deduced amino acid sequence of the 5C-2HMS dehydrogenase (XylG) exhibited 98%, 93%, and 89% identity with those of the dehydrogenases from P. putida mt-2, P. putida G7, and Pseudomonas sp. CF600, respectively.