• Title/Summary/Keyword: cluster method

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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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3D Shape Reconstruction using the Focus Estimator Value from Multi-Focus Cell Images (다초점 세포 영상으로부터 추정된 초점 값을 이용한 3차원 형태 복원)

  • Choi, Yea-Jun;Lee, Dong-Woo;Kim, Myoung-Hee;Choi, Soo-Mi
    • Journal of the Korea Computer Graphics Society
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    • v.23 no.4
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    • pp.31-40
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    • 2017
  • As 3D cell culture has recently become possible, it has been able to observe a 3D shape of cell and volume. Generally, 3D information of a cell should be observed with a special microscope such as a confocal microscope or an electron microscope. However, a confocal microscope is more expensive than a conventional microscope and takes longer time to capture images. Therefore, there is a need for a method that can reconstruct the 3D shape of cells using a common microscope. In this paper, we propose a method of reconstructing 3D cells using the focus estimator value from multi-focal fluorescence images of cells. Initially, 3D cultured cells are captured with an optical microscope by changing the focus. Then the approximate position of the cells is assigned as ROI (Region Of Interest) using the circular Hough transform in the images. The MSBF (Modified Sliding Band Filter) is applied to the obtained ROI to extract the outlines of the cell clusters, and the focus estimator values are computed based on the extracted outlines. Using the computed focus estimator values and the numerical aperture (NA) of the microscope, we extract the outline of the cell cluster considering the depth and reconstruct the cells into 3D based on the extracted outline. The reconstruction results are examined by comparing with the combined in-focus portions of the cell images.

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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A Study of Post-processing Methods of Clustering Algorithm and Classification of the Segmented Regions (클러스터링 알고리즘의 후처리 방안과 분할된 영역들의 분류에 대한 연구)

  • Oh, Jun-Taek;Kim, Bo-Ram;Kim, Wook-Hyun
    • The KIPS Transactions:PartB
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    • v.16B no.1
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    • pp.7-16
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    • 2009
  • Some clustering algorithms have a problem that an image is over-segmented since both the spatial information between the segmented regions is not considered and the number of the clusters is defined in advance. Therefore, they are difficult to be applied to the applicable fields. This paper proposes the new post-processing methods, a reclassification of the inhomogeneous clusters and a region merging using Baysian algorithm, that improve the segmentation results of the clustering algorithms. The inhomogeneous cluster is firstly selected based on variance and between-class distance and it is then reclassified into the other clusters in the reclassification step. This reclassification is repeated until the optimal number determined by the minimum average within-class distance. And the similar regions are merged using Baysian algorithm based on Kullbeck-Leibler distance between the adjacent regions. So we can effectively solve the over-segmentation problem and the result can be applied to the applicable fields. Finally, we design a classification system for the segmented regions to validate the proposed method. The segmented regions are classified by SVM(Support Vector Machine) using the principal colors and the texture information of the segmented regions. In experiment, the proposed method showed the validity for various real-images and was effectively applied to the designed classification system.

Use of Microsatellite Markers Derived from Genomic and Expressed Sequence Tag (EST) Data to Identify Commercial Watermelon Cultivars (수박 시판 품종의 식별을 위한 Genomic과 Expressed Sequence Tag (EST)에서 유래된 Microsatellite Marker의 이용)

  • Kwon, Yong-Sham;Hong, Jee-Hwa;Kim, Du-Hyun;Kim, Do-Hoon
    • Horticultural Science & Technology
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    • v.33 no.5
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    • pp.737-750
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    • 2015
  • This study was carried out to construct a DNA profile database for 102 watermelon cultivars through the comparison of polymorphism level and genetic relatedness using genomic microsatellite (gMS) and expressed sequence tag (EST)-microsatellite (eMS) markers. Sixteen gMS and 10 eMS primers showed hyper-variability and were able to represent the genetic variation within 102 watermelon cultivars. With gMS markers, an average of 3.63 alleles per marker were detected with a polymorphism information content (PIC) value of 0.479, whereas with eMS markers, the average number of alleles per marker was 2.50 and the PIC value was 0.425, indicating that eMS detects a lower polymorphism level compared to gMS. Cluster analysis and Jaccard's genetic distance coefficients using the unweighted pair group method with arithmetic average (UPGMA) based on the gMS, eMS, and combined data sets showed that 102 commercial watermelon cultivars could be categorized into 6 to 8 major groups corresponding to phenotypic traits. Moreover, this method was sufficient to identify 78 out of 102 cultivars. Correlation analysis with Mantel tests for those clusters using 3 data sets showed high correlation ($r{\geq}0.80$). Therefore, the microsatellite markers used in this study may serve as a useful tool for germplasm evaluation, genetic purity assessment, and fingerprinting of watermelon cultivars.

A study for High Efficiency Dewatering of Sludge Contained Fine Particles (미세입자(微細粒子)를 함유(含有)한 슬러지의 고효율(高效率) 탈수(脫水) 연구)

  • Lee, Jung-Eun;Lee, Jae-Keun
    • Resources Recycling
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    • v.15 no.4 s.72
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    • pp.36-43
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    • 2006
  • There was some difficulty dewatering properties due to small porosity diameter of cake, when pigment sludge contained fine particle was formed by cake under the dewatering. It was difficult to dewater the sludge with fine particles with the conventional mechanical dewatering method. This study was to improve the dewatering rate as discharging the water from porosity of cake easily, supplying the low heat to the cake layer. Thermal dewatering equipment of piston type to keep up constant temperature on the cake was set up and relative experiment was conducted for sludge of 200 g with fine pigment particle. As test results. filtration of 176.8 g, cake weight of 19.4 g, cake thickness of 4.2 mm was measured, and it was analyzed that the water content of cake was 47 wt% and dewatering velocity, which moaned the residual d교 sloid amount per dewatering area, was $2.1DS\;m^{2}{\cdot}cycle$. This results showed that filtration increased, cake weight and thickness decreased and dewatering velocity increased against mechanical dewatering method. And water content of cake decreased about 30%, so the result which dewatering rate improved was drew generally. The reason is that the inner vapor pressure working at the cake porosity increased as applying the low heat to the cake layer, which lead to discharge the water from porosity easily. Therefore, this study was estimated by the useful technology for sludge reduction.

Pre-arrangement Based Task Scheduling Scheme for Reducing MapReduce Job Processing Time (MapReduce 작업처리시간 단축을 위한 선 정렬 기반 태스크 스케줄링 기법)

  • Park, Jung Hyo;Kim, Jun Sang;Kim, Chang Hyeon;Lee, Won Joo;Jeon, Chang Ho
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.11
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    • pp.23-30
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    • 2013
  • In this paper, we propose pre-arrangement based task scheduling scheme to reduce MapReduce job processing time. If a task and data to be processed do not locate in same node, the data should be transmitted to node where the task is allocated on. In that case, a job processing time increases owing to data transmission time. To avoid that case, we schedule tasks into two steps. In the first step, tasks are sorted in the order of high data locality. In the second step, tasks are exchanged to improve their data localities based on a location information of data. In performance evaluation, we compare the proposed method based Hadoop with a default Hadoop on a small Hadoop cluster in term of the job processing time and the number of tasks sorted to node without data to be processed by them. The result shows that the proposed method lowers job processing time by around 18%. Also, we confirm that the number of tasks allocated to node without data to be processed by them decreases by around 25%.

Genetic Variation of Pinus densiflora Populations in South Korea Based on ESTP Markers (ESTP 표지를 이용한 국내 소나무 집단의 유전변이)

  • Ahn, Ji Young;Hong, Kyung Nak;Lee, Jei Wan;Hong, Yong Pyo;Kang, Hoduck
    • Korean Journal of Plant Resources
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    • v.28 no.2
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    • pp.279-289
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    • 2015
  • Genetic diversity and genetic differentiation of thirteen Pinus densiflora populations in South Korea were estimated using nine ESTP (Expressed Sequence Tag Polymorphism) markers. The numbers of allele and the effective allele were 2.2 and 1.8, respectively. The percentage of polymorphic loci (P) was 98.8%. The observed and the expected heterozygosity were 0.391 and 0.402, respectively, and the eleven populations except for Ahngang and Gangneung population were under Hardy-Weinberg equilibrium state. The level of genetic differentiation (Wright’s FST = 0.057) was higher than those of isozyme or nSSR markers. We could not find out any relationship between the genetic distance and geographic distribution among populations from cluster analysis. Also, the genetic differentiation between populations was not correlated with the geographic distance (r = 0.017 and P = 0.344 from Mantel test). From the result of FST-outlier analysis to identify a locus under selection, six loci were detected at confidence interval of 99% by the frequentist’s method. However, only three loci (sams2+AluⅠ, sams2+RsaⅠ, PtNCS_p14A9+HaeⅢ) were presumed as outliers by Bayesian method. The sams2+AluⅠ and sams2+RsaⅠlocus were originated from the sams2 gene and seemed to be the loci under balancing selection.

Point Cloud Video Codec using 3D DCT based Motion Estimation and Motion Compensation (3D DCT를 활용한 포인트 클라우드의 움직임 예측 및 보상 기법)

  • Lee, Minseok;Kim, Boyeun;Yoon, Sangeun;Hwang, Yonghae;Kim, Junsik;Kim, Kyuheon
    • Journal of Broadcast Engineering
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    • v.26 no.6
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    • pp.680-691
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    • 2021
  • Due to the recent developments of attaining 3D contents by using devices such as 3D scanners, the diversity of the contents being used in AR(Augmented Reality)/VR(Virutal Reality) fields is significantly increasing. There are several ways to represent 3D data, and using point clouds is one of them. A point cloud is a cluster of points, having the advantage of being able to attain actual 3D data with high precision. However, in order to express 3D contents, much more data is required compared to that of 2D images. The size of data needed to represent dynamic 3D point cloud objects that consists of multiple frames is especially big, and that is why an efficient compression technology for this kind of data must be developed. In this paper, a motion estimation and compensation method for dynamic point cloud objects using 3D DCT is proposed. This will lead to switching the 3D video frames into I frames and P frames, which ensures higher compression ratio. Then, we confirm the compression efficiency of the proposed technology by comparing it with the anchor technology, an Intra-frame based compression method, and 2D-DCT based V-PCC.

A Study on Content Characteristics, Consumer Behavior and Economic Value According to the Degree of Consideration of Graphic Content (그래픽 콘텐츠 고려 정도에 따른 콘텐츠 특성, 소비자 행동, 경제적 가치에 관한 연구)

  • Lee, Sangho;Cho, Kwangmoon
    • Journal of Internet of Things and Convergence
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    • v.7 no.4
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    • pp.85-94
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    • 2021
  • This study verified what differences in screen golf content characteristics, intention to reuse, customer satisfaction and economic value experienced by consumers according to the image feeling, expression method, and image color provided by screen golf graphic content. In addition, the purpose of this study was to analyze what kind of influence the content characteristics of screen golf have on the economic value and what kind of influence the intention to reuse and customer satisfaction have in this process. From September 1, 2021 to September 30, 2021, a survey of 225 copies of consumers using the screen golf course was conducted. For data processing, frequency analysis, factor analysis, reliability analysis, cluster analysis, chi-square analysis and 3-step mediated regression analysis were performed. The research results are as follows. First, the preferred image feeling showed a high level of clean and sophisticated feeling and the preferred expression method showed a high realistic image. In addition, the preferred image color showed a high level of green color. Second, there were differences in competitiveness, ease of use, sense of solidarity and realism according to the degree of consideration of graphic content and differences in consumer's intention to reuse, customer satisfaction, and economic value. Third, in the relationship between screen golf content characteristics and economic value, customer satisfaction and re-use intention had a mediating effect. Through this study, by providing basic data to derive the graphic design model of screen golf, the operating entity suggested a way to improve economic benefits and tried to contribute to the growth of the screen golf industry.