• Title/Summary/Keyword: cluster method

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Association between energy intake and skeletal muscle mass according to dietary patterns derived by cluster analysis: data from the 2008 ~ 2010 Korea National Health and Nutrition Examination Survey (군집분석으로 도출한 식사패턴별 에너지 섭취량과 골격근육량의 연관성 분석 : 2008 ~ 2010년 국민건강영양조사 자료를 활용하여)

  • Jang, Bo Young;Bu, So Young
    • Journal of Nutrition and Health
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    • v.52 no.6
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    • pp.581-592
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    • 2019
  • Purpose: This study investigated major dietary patterns among healthy Korean adults using cluster analysis and analyzed the relationship between energy intake and skeletal muscle mass. Methods: This study was conducted using the data from the 2008 ~ 2010 Korea National Health and Nutrition Survey. The data of 7,922 subjects aged 30 years and over, without any missing values, were included in the final analysis. K-means cluster analyses were conducted to identify the dietary patterns of the study subjects, which were based on the energy intake from 21 food groups using a 24-h recall method. The changes in energy intake with each dietary pattern, according to quartiles of skeletal muscle mass, were investigated. Results: Three dietary patterns were identified for both men and women: 'Flour, Animal fat', 'White rice' and 'Healthy mixed diet'. The association between energy intake and skeletal muscle mass for both men and women was significant only in the 'White rice' dietary pattern. In the 'White rice' pattern, the energy intake increased up to > 300 kcal from the lowest to the highest quartile of skeletal muscle mass after adjustment for covariates. Within the 'White rice' pattern, skeletal muscle mass was linearly associated with energy intake in all the age groups in men. Conclusion: Energy intake was significantly associated with changes in skeletal muscle mass only in the 'White rice' pattern. Furthermore, the degree of association between the change in skeletal muscle mass and energy intake differed according to gender. These results indicate that the association between skeletal muscle mass and energy intake may be specific to Korean people who are accustomed to a traditional Korean diet.

External morphology and vegetation of Megaleranthis saniculifolia populations in four different habitats (모데미풀의 자생지별 외부형태 및 식생)

  • 유기억;이우철;오영주
    • Korean Journal of Plant Resources
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    • v.12 no.4
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    • pp.312-323
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    • 1999
  • External morphology, principal component analysis, cluster analysis, and vegetation were investigated to understand the taxonomic relationships and native environmental characters of Megaleranthis saniculifolia populations in four different habitats. Morphological characters such as calyx length and width, calyx index, presence or absence of serrate in calyx lobe, length of peduncle, branch of peduncle and fruit characters were useful for the identification of four different habitats. But, characters of plant height, bract and seed in four habitats were similar. The results obtained based on the principal component(PC) analysis of treated 96 OTU were divided into two groups by PC 1, 2, 3, and the sums of contributions for the total variance were 66.79%(PC1 31.3%, PC2 20.7%, PC3 15.8%, respectively), and only Mt. Taeki population was distinctly different from populations of other three habitats. In cluster analysis based on average linkage cluster analysis and Ward's method, there were similarities in the composition of clustered taxa, and each populations were not identified. Importance value by relative coverage and frequency appeared in M. saniculifolia(50.81%), Aruncus dioicus(12.64%), Corydalus turtschanovii(11.62%), Veratrum oxysepalum(11.45%), Anemone koraiensis(8.96%), Meehania urticifolia(8.76%), Filipendula palmata(7.06%), Aconitum pseudo-laeve(5.66%), Pseudostellaria palibiniana(5.45%) and Smilacina japonica(5.25%), respectively. These species were considered to be highly similar with M. saniculifolia. The highest importance value in all investigated sites was M. saniculifolia, but specific composition of high level different from each habitat. Average diversity of species was 1.40, and the highest in Mt. Kwangdeok(1.31), lowest in Mt. Jumbong(1.17). Average soil pH was 5.25 and similar in each habitat. Although the lowest content of K ion, but the highest the EC, water capacity, organic compound, Ca content were found in soil of Mt. Sobaek. Soils in Mt. Kwangdeok had the lowest content of EC, organic compound, Ca. Soils of Mt. Jumbong showed the highest of Mg content, but the lowest of water capacity, $P_2O_5$, and K contents.

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Efficacy of Listeria Innocua Reduction on Enoki Mushrooms by Utilization of an Air Sterilization Device (공기 살균 장치 적용 팽이버섯 재배사의 Listeria Innocua 저감 효과)

  • Lee, Hyun-Dong;Yu, Byeong-Kee;Seo, Da-Som;Kim, Se-Ri;Lee, Chan-Jung;Kwak, Kang-Su
    • Journal of Mushroom
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    • v.19 no.3
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    • pp.210-215
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    • 2021
  • For sterilization of microorganisms of the Listeria genus contaminating enoki mushroom, pilot mushroom grower equipped with air sterilization devices were developed. Sterilization experiments were performed using physical and chemical treatments. Internal temperature and humidity were controlled, maintaining 6.62℃±0.30 in the upper shelves, 6.46℃±0.24 in the middle shelves, and 6.48℃±0.25 in the lower shelves. Humidities were 79.97%±4.42, 79.43%±4.06, and 79.94±4.30%, respectively, with a temperature setting of 6.5℃, and a relative humidity of 75%. A suitable enoki mushroom cultivation stage for air sterilizer application was during the growth stage, with temperature in the 6.5~8.5℃ range, and humidity of 70~80%. At these same internal conditions, the ozone concentration in the mushroom cultivator was found to be 160 ppb during ion-cluster generator operation. After physical sterilization, the Listeria innocua survival rate was 0.1 to 0.9% using ion cluster sterilization, and 9.3 to 10.6% using UV air sterilization. The Listeria innocua survival rates on different materials were 9.3~10.6% on the metal specimen, and 9.9~16.2% on the plastic wrapper. The survival rate was particularly high on the rough side of the plastic wrapper. Ion cluster air sterilization is a labor-saving and effective method for suppressing the occurrence of Listeria bacteria on mushroom growers walls and shelves. For the plastic wrapper, chemical sterilization is more effective than physical sterilization.

The Characteristics of Korean Family Law - A Comparison with EU-Countries in Regard to Regime Classification - (한국 가족법의 특수성 - EU 국가와의 비교를 통한 유형 구분 -)

  • Chung, Yun Tag
    • Korean Journal of Social Welfare Studies
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    • v.41 no.4
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    • pp.161-187
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    • 2010
  • This study begins with two research interests. Firstly, there seems to be a break of research in the field of family policy in Korea which exists especially in regard to family law. Family law was originally the core of state interventions in family life, but has been neglected because of the lack of literature with comparative research methods. This shortcoming needs to be addressed. Secondly, through inquiry into the definition of family or family policy with the lens of the law, the definition of family or family policy can be correctly extended. With these two interests combined, this research tries to derive an analytical tool - maintenance community - of the law and compare some important points of the family law of Korea with those of 16 EU-countries in terms of regime classification. The method used is, firstly, to describe the subjects of family law with a focus on partnering and parenting without subjective interpretation, and secondly, to classify the countries' family-law regimes with the criteria of privacy and autonomy using cluster analysis. The results show that the countries can be classified into three clusters: Nordic (Norway and Sweden), West-Northern (Denmark, France, England, Finland, and Belgium) and Middle South (Italy, Spain, Austria, Portugal, Netherlands, Greece, Ireland, Germany, and Korea). This result can be compared to a precedent research result which showed that 21 OECD countries can be classified in three clusters according to family policy. The number of the clusters is the same as this study, but some countries belong to other clusters; for example Denmark and Finland belong to the Nordic cluster according to family policy, while they belong to the West-Northern according to family law, and Austria, Germany, and Ireland belong to the Middle-South cluster according to family law, while they belong to the Continental according to family policy. From this result we can interpret Korean family law to be in the middle range according to both criteria of privacy and autonomy like other South-European countries including some Continental countries. We can make some theoretical suggestions. The fact that both family law and family policy regimes in countries can be classified into three clusters can be interpreted to mean that there exists parallelism between family law and family policy in a broad sense. But from the fact that some countries belong to different clusters according to family law and family policy, we can say that the family policy in a country is not always consistent with family law.

Improvement of the PFCM(Possibilistic Fuzzy C-Means) Clustering Method (PFCM 클러스터링 기법의 개선)

  • Heo, Gyeong-Yong;Choe, Se-Woon;Woo, Young-Woon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.1
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    • pp.177-185
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    • 2009
  • Cluster analysis or clustering is a kind of unsupervised learning method in which a set of data points is divided into a given number of homogeneous groups. Fuzzy clustering method, one of the most popular clustering method, allows a point to belong to all the clusters with different degrees, so produces more intuitive and natural clusters than hard clustering method does. Even more some of fuzzy clustering variants have noise-immunity. In this paper, we improved the Possibilistic Fuzzy C-Means (PFCM), which generates a membership matrix as well as a typicality matrix, using Gath-Geva (GG) method. The proposed method has a focus on the boundaries of clusters, which is different from most of the other methods having a focus on the centers of clusters. The generated membership values are suitable for the classification-type applications. As the typicality values generated from the algorithm have a similar distribution with the values of density function of Gaussian distribution, it is useful for Gaussian-type density estimation. Even more GG method can handle the clusters having different numbers of data points, which the other well-known method by Gustafson and Kessel can not. All of these points are obvious in the experimental results.

Mass Spectrometry-based Comparative Analysis of Membrane Protein: High-speed Centrifuge Method Versus Reagent-based Method (질량분석기를 활용한 막 단백질 비교분석: High-speed Centrifuge법과 Reagent-based법)

  • Lee, Jiyeong;Seok, Ae Eun;Park, Arum;Mun, Sora;Kang, Hee-Gyoo
    • Korean Journal of Clinical Laboratory Science
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    • v.51 no.1
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    • pp.78-85
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    • 2019
  • Membrane proteins are involved in many common diseases, including heart disease and cancer. In various disease states, such as cancer, abnormal signaling pathways that are related to the membrane proteins cause the cells to divide out of control and the expression of membrane proteins can be altered. Membrane proteins have the hydrophobic environment of a lipid bilayer, which makes an analysis of the membrane proteins notoriously difficult. Therefore, this study evaluated the efficacy of two different methods for optimal membrane protein extraction. High-speed centrifuge and reagent-based method with a -/+ filter aided sample preparation (FASP) were compared. As a result, the high-speed centrifuge method is quite effective in analyzing the mitochondrial inner membranes, while the reagent-based method is useful for endoplasmic reticulum membrane analysis. In addition, the function of the membrane proteins extracted from the two methods were analyzed using GeneGo software. GO processes showed that the endoplasmic reticulum-related responses had higher significance in the reagent-based method. An analysis of the process networks showed that one cluster in the high-speed centrifuge method and four clusters in the reagent-based method were visualized. In conclusion, the two methods are useful for the analysis of different subcellular membrane proteins, and are expected to assist in selecting the membrane protein extraction method by considering the target subcellular membrane proteins for study.

Rapid Typing of Clinical Strains of Mycobacterium tuberculosis by IS6110-based Outward PCR

  • Kim, Yeun;Lee, Uen-Ho;Park, Young-Kil;Bai, Gill-Han;Cho, Sang-Nae;Lee, Hye-Young
    • Biomedical Science Letters
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    • v.10 no.2
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    • pp.163-169
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    • 2004
  • Worldwide, tuberculosis remains one of the leading infectious diseases, accounting for nearly 3 million deaths and more than 8 million new cases annually. DNA typing of Mycobacterium tuberculosis is important for the control of tuberculosis, since it can be used to track transmission route of tuberculosis, source of internal laboratory contaminations, and to answer questions on the nature of tuberculosis infections such as reactivation or exogenous reinfection of disease. At present, IS6110-based RFLP is the choice of method for typing large numbers of clinical isolates of M. tuberculosis, since it has the highest resolution power. However, RFLP requires long time, high cost and qualified experts, so only reference level laboratories can use the RFLP technique. In order to have an optional molecular typing method suitable for the clinical settings, this study evaluated the use of one of PCR-based typing methods, IS6110-based outward PCR for typing clinical isolates of M. tuberculosis. In brief, the results from this study showed that IS6110-based RFLP is useful to discriminate diverse clinical isolates of M. tuberculosis as well as to identify clinical isolates that belong to the same family or cluster groups that have been previously classified by RFLP analysis. In addition, the banding profiles resulted from IS6110-based outward PCR seemed to represent genomic characteristics of M. tuberculosis, since strains belong to the K-family generated unique band that is not present in any other strains but present only in the genome of K-family strains. The IS6110-based outward PCR was also shown to be useful with DNAs isolated directly from liquid cultures indicating this method can be suitable for typing M. tuberculosis in clinical settings.

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Automated Cell Counting Method for HeLa Cells Image based on Cell Membrane Extraction and Back-tracking Algorithm (세포막 추출과 역추적 알고리즘 기반의 HeLa 세포 이미지 자동 셀 카운팅 기법)

  • Kyoung, Minyoung;Park, Jeong-Hoh;Kim, Myoung gu;Shin, Sang-Mo;Yi, Hyunbean
    • Journal of KIISE
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    • v.42 no.10
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    • pp.1239-1246
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    • 2015
  • Cell counting is extensively used to analyze cell growth in biomedical research, and as a result automated cell counting methods have been developed to provide a more convenient and means to analyze cell growth. However, there are still many challenges to improving the accuracy of the cell counting for cells that proliferate abnormally, divide rapidly, and cluster easily, such as cancer cells. In this paper, we present an automated cell counting method for HeLa cells, which are used as reference for cancer research. We recognize and classify the morphological conditions of the cells by using a cell segmentation algorithm based on cell membrane extraction, and we then apply a cell back-tracking algorithm to improve the cell counting accuracy in cell clusters that have indistinct cell boundary lines. The experimental results indicate that our proposed segmentation method can identify each of the cells more accurately when compared to existing methods and, consequently, can improve the cell counting accuracy.

Estimation of Drought Rainfall by Regional Frequency Analysis using L and LH-Moments(I) - On the Method of L-Moments - (L 및 LH-모멘트법과 지역빈도분석에 의한 가뭄우량의 추정(I) - L-모멘트법을 중심으로 -)

  • 이순혁;윤성수;맹승진;류경식;주호길
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.45 no.5
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    • pp.97-109
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    • 2003
  • This study is mainly conducted to derive the design drought rainfall by the consecutive duration using probability weighted moments with rainfall in the regional drought frequency analysis. It is anticipated to suggest optimal design drought rainfall of hydraulic structures for the water requirement and drought frequency of occurrence for the safety of water utilization through this study. Preferentially, this study was conducted to derive the optimal regionalization of the precipitation data that can be classified by the climatologically and geographically homogeneous regions all over the regions except Cheju and Ulreung islands in Korea. Five homogeneous regions in view of topographical and climatological aspects were accomplished by K-means clustering method. Using the L-moment ratio diagram and Kolmogorov-Smirnov test, generalized extreme value distribution was confirmed as the best fitting one among applied distributions. At-site and regional parameters of the generalized extreme value distribution were estimated by the method of L-moments. Design drought rainfalls using L-moments following the consecutive duration were derived by the at-site and regional analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE), relative bias (RBIAS) and relative reduction (RR) in RRMSE for the design drought rainfall derived by at-site and regional analysis in the observed an simulated data were computed and compared. In has shown that the regional frequency analysis procedure can substantially more reduce the RRMSE. RBIAS and RR in RRMSE than those of at-site analysis in the prediction of design drought rainfall. Consequently, optimal design drought rainfalls following the regions and consecutive durations were derived by the regional frequency analysis.

Underdetermined Blind Source Separation from Time-delayed Mixtures Based on Prior Information Exploitation

  • Zhang, Liangjun;Yang, Jie;Guo, Zhiqiang;Zhou, Yanwei
    • Journal of Electrical Engineering and Technology
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    • v.10 no.5
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    • pp.2179-2188
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    • 2015
  • Recently, many researches have been done to solve the challenging problem of Blind Source Separation (BSS) problems in the underdetermined cases, and the “Two-step” method is widely used, which estimates the mixing matrix first and then extracts the sources. To estimate the mixing matrix, conventional algorithms such as Single-Source-Points (SSPs) detection only exploits the sparsity of original signals. This paper proposes a new underdetermined mixing matrix estimation method for time-delayed mixtures based on the receiver prior exploitation. The prior information is extracted from the specific structure of the complex-valued mixing matrix, which is used to derive a special criterion to determine the SSPs. Moreover, after selecting the SSPs, Agglomerative Hierarchical Clustering (AHC) is used to automaticly cluster, suppress, and estimate all the elements of mixing matrix. Finally, a convex-model based subspace method is applied for signal separation. Simulation results show that the proposed algorithm can estimate the mixing matrix and extract the original source signals with higher accuracy especially in low SNR environments, and does not need the number of sources before hand, which is more reliable in the real non-cooperative environment.