• East Asian Journal of Business Economics (EAJBE)
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• v.7 no.2
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• pp.21-30
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• 2019

Purpose - In this work, we categorize the 21 shopping items which foreign tourists purchase in South Korea and monitor the level of dissimilarity (or similarity) between each item by utilizing distance matrix, and both hierarchical and k-means cluster analyses, respectively, based on several purpose of visit attributes in 2017. In addition, multidimensional scaling (MDS) method is applied for mining visual appearance of proximities among shopping items based on purpose of visit attributes. Research design and methodology - This study is carried out in 2017 by Ministry of Culture, Sports and Tourism and conduct a face-to-face survey of foreign tourists from 20 countries who purchase shopping items in South Korea. CLUSTER, PROXIMITIES and ALSCAL modules in IBM SPSS 23.0 are used to perform this work. Results - We ascertain that 21 shopping items can be classified into five similar groups which have homogeneous traits by going through two-step cluster analysis. We can position homogeneous places of cluster and shopping items joining each cluster. Conclusions - We can relatively assess patterns and characteristics of each shopping item, come by useful information in activating shopping tour based on the actual state of recognition of foreign tourists and practically apply to each tourism industry on underlying results.

• Journal of the Korean Chemical Society
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• v.48 no.4
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• pp.436-438
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• 2004

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.567-573
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• 2011

We investigated the phylogenetic diversity of ammoniaoxidizing bacteria (AOB) in Yellow Sea continental shelf sediment by the cloning and sequencing of PCR-amplified amoA and 16S rRNA genes. Phylogenetic analysis of the amoA-related clones revealed that the diversity of AOB was extremely low at the study site. The majority (92.7%) of amoA clones obtained belonged to a single cluster, environmental amoA cluster-3, the taxonomic position of which was previously unknown. Phylogenetic analysis on AOB-specific 16S rRNA gene sequences also demonstrated a very low diversity. All of the cloned 16S rRNA gene sequences comprised a single phylotype that belonged to the members of uncultured Nitrosospira cluster-1, suggesting that AOB belonging to the uncultured Nitrosospira cluster-1 could carry amoA sequences of environmental amoA cluster-3.

• Communications for Statistical Applications and Methods
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• v.23 no.1
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• pp.47-55
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• 2016

Stratified cluster sampling has been widely used for effective parameter estimations due to reductions in time and cost. The probability proportional to size (PPS) sampling method is used when the number of cluster element are significantly different. However, simple random sampling (SRS) is commonly used for simplicity if the number of cluster elements are almost the same. Also it is known that the ratio estimator produces a good performance when the total number of population elements is known. However, the two stage cluster estimator should be used if the total number of elements in population is neither known nor accurate. In this study we suggest a composite estimator by combining the ratio estimator and the two stage cluster estimator to obtain a better estimate under a certain population circumstance. Simulation studies are conducted to compare the superiority of the suggested estimator with two other estimators.

• Journal of Korean Society for Atmospheric Environment
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• v.30 no.5
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• pp.504-509
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• 2014

Twenty-five stations of the urban monitoring network in Seoul were assessed with a focus on surveillance function of the exceedances of 8-hour ozone and 24-hour $PM_{10}$ standards. The two standards were selected because their attainment rates were particularly low. Two hierarchical cluster analyses were performed to group stations with similar atmospheric environments-one using daily highest 8-hour [$O_3+NO_2$], 8-hour $O_3$ concentrations plus corresponding 8-hour $NO_2$ concentrations considering the interconversion of $O_3$ and $NO_2$, and the other using 24-hour $PM_{10}$ concentrations. An index to measure higher concentration and exceedances of the standards was introduced. Within a cluster, sufficiently high score was assigned to the trends station or the station with higher index. Scores for $O_3+NO_2$ and $PM_{10}$ of a given station were added and ranked in the descending order to determine the relative importance.

• International Journal of Computer Science & Network Security
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• v.22 no.10
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• pp.107-112
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• 2022

Nowadays clusters are recognized as an important instrument for promoting industrial development, innovation, competitiveness and growth. An educational cluster is a set of interrelated vocational educational institutions of various levels that are united by industry with each other and are connected by partnership with industry enterprises. This article attempts to develop and describe cluster model of university students' multilingual training. The purpose of this study is to describe multilingual training of university students and their polycultural competencies formation and to define the process of multilingual training in form of a cluster. The authors consider clusters as an integral part of the educational campus within the concept framework of Shadrinsk State Pedagogical University. To determine the essence of the concept of a cluster model of university students' multilingual training, theoretical, empirical, observational, and diagnostic methods were implemented, such as a review of scientific literature, a compilation of best practices, observation, statistical methods, etc. The authors analyzed the programs of partner universities and organized international webinars and internships for bachelors and masters abroad and developed online courses "Foreign language for undergraduate students and masters". Experimental data obtained during the implementation of cluster training show the effectiveness of the formation of students' polycultural competencies.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10a
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• pp.490-493
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• 2006

본 논문은 Linux Cluster의 MPICH에서 MPI_Allgather Algorithm의 성능을 개선하고 실험을 통해 최대 30%의 성능향상을 증명하였다. MPICH의 기존 버전이 메시지의 크기와 실행 프로세스 수에 따라 Recursive Doubling, Bruck Algorithm, Ring Algorithm을 차등 적용했던 것을, 앞의 Algorithm을 개선하여 Double Bruck Algorithm, Double Ring Algorithm을 제안, 구현하였다.

• Korean Journal of Social Welfare
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• v.62 no.1
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• pp.133-153
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• 2010

The purpose of this study was to observe the difference and patterns of relationship between parents-in-law and foreign daughters-in-law based on the perceived agreement of quality of relationship and communication. A total of 138 dyad relationships between parents-in-law and foreign daughters-in-law from Seoul, Kyunggi-Do, and Cholla-Do were analyzed. The study results showed that parents-in-law and foreign daughters-in-law perceived their relationship as an average and above and parents-in-law perceived their relationship more positively than daughters-in-law. A total of 4 clusters were categorized by cluster analysis based on the agreement of perceived relationship and communication: parents-in-law perceived their relationship positively but daughters-in-law were not(cluster 1), daughters-in-law perceived their relationship positively but parents-in-law were not(cluster 2), both parents-in-law and daughters-in-law perceived their relationship positively(cluster 3), both parents-in-law and daughters-in-law perceived their relationship negatively(cluster 4). In order to observe the characteristics of relationship patterns, ANOVA were performed. Cultural competency of parents-in-law appeared to relate to their relationship with daughters-in-law. Acculturative stress of daughters-in-law who have good relationship with their parents-in-law was low and marital satisfaction of them was high. In addition, life satisfaction of parents-in-law who have good relationship with their daughters-in-law was high. Implication of this study was discussed.

• Proceedings of the KSPS conference
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• 2007.05a
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• pp.109-113
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• 2007

Second language learners' variable degree of production difficulty according to the cluster type has previously been accounted for in terms of sonority distance between adjacent segments. As an alternative to this previous model, I propose a Phonetically Based Consonant Cluster Acquisition Model (PCCAM) in which consonant cluster markedness is defined based on the articulatory and perceptual factors associated with each consonant sequence. The validity of PCCAM has been tested through Korean speakers' production of English consonant clusters.

• Journal of Microbiology
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• v.41 no.3
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• pp.232-238
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• 2003

Previous phylogenetic studies on human immunodeficiency virus type 1 (HIV-1) isolated from Korean patients suggest that the major subtype of Korean isolate is subtype B. In this subtype, some of the Korean isolates seem to be clustered exclusively of foreign isolates. Presence of this so-called “Korean clade” among Korean isolates is unique but needs verification since the number of Korean isolates used in previous studies was limited. This study aimed to identify the presence of the “Korean clade” by molecular phylogenetic analysis using all the Korean nef gene sequences registered in the NCBI GenBank (N=243) together with 32 reference strains and 77 foreign isolates. Extensive analysis of the nef gene nucleotide sequences by neighbor-joining method revealed the following. Most (83.1 ％) of the Korean isolates belonged to subtype B, and 81.2％ of subtype B were clustered together and excluded foreign isolates (bootstrap value=91.9％ ). Within Korean subtype B cluster, no characteristic subcluster formation was evident since the bootstrap values for the subcluster were very low. Due to limited information, the phylogenetic analysis failed to identify the epidemiological linkage among specific groups such as homosexuals and hemophiliacs within the Korean subtype B cluster. Detailed analysis and epidemiological information are needed to clarify the origin and significance of the Korean subtype B cluster.