• The Korean Journal of Applied Statistics
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• v.17 no.3
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• pp.535-545
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• 2004

The clustering method suggested in this paper produces clusters based on the 'rules of variables' by merging the 'training' and the identically structured reference data and then by filtering it to obtain the clusters of the 'training data' through the use of the 'tree classification model'. The reference dataset is generated by spatially contrasting it to the 'training data' through the 'reverse arcing' algorithm to effectively identify the clusters. The strength of this method is that it can be applied even to the mixture of continuous and discrete types of 'training data' and the performance of this algorithm is illustrated by applying it to the simulated data as well as to the actual data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.3
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• pp.649-655
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• 2013

Recently, researches are studied in developing efficient techniques for accessing, querying, and managing XML documents which are frequently used in the Internet. In this paper, we propose a new method to cluster XML documents efficiently. An element and an inclusion relationship of a XML document corresponds to a node and a level of the corresponding tree, respectively. Therefore, when two XML documents are similar then their nodes' names and levels of the corresponding trees are also similar. In this paper, we cluster XML documents by using nodes' names and levels of the corresponding tree as a feature of a document. The experiment shows that our proposed method has a good performance.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.9
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• pp.1145-1157
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• 1999

본 논문에서는 RFC 2022에서 제안한 MARS 모델을 기반으로 하여 단일 대규모 클러스터를 가지는 ATM 망에서 다중의 멀티캐스팅 서버(MCS)를 이용한 멀티캐스팅 방안을 제안하고 그 성능을 평가하였다. 클러스터 내의 한 ATM 호스트가 특정 IP 멀티캐스트 그룹에 가입할 경우 ATM 호스트의 위치와 이미 존재하는 멀티캐스팅 서버들 사이의 전송 지연을 고려하여 가능한 한 종단간 전송 지연을 최소화하는 멀티캐스팅 서버를 선택하는 방안을 기술하였다. 이 방안은 최단거리 경로 알고리즘(shortest path algorithm)에 기반하여 최적의 MCS를 선정하고 송수신자 사이의 최소 지연을 가지는 멀티캐스트 트리를 구성한다. 다양한 망 위상에서 MCS의 분포 패턴을 다르게 할 경우에도 이 방안은 멀티캐스트 트리의 평균 전달 지연을 줄이는 것을 시뮬레이션을 통하여 확인하였다.Abstract In this paper, we proposed a scheme to support multiple MCSs over a single and large cluster in ATM networks, evaluated its performance by simulation. When an ATM host requests joining into a specific multicast group, the MARS designate a proper MCS among the multiple MCSs for the group member to minimize the average path delay between the sender and the group members. This scheme constructs a multicast tree through 2-phase partial multicast tree construction based upon the shortest path algorithm.We reduced the average path delay in multicast tree using our scheme under various cluster topologies and MCS distribution scenarios.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.383-386
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• 2006

In this study, we propose a new fast algorithm for calculating short range forces in molecular dynamics, This algorithm uses a new hierarchical tree data structure which has a high adaptiveness to the particle distribution. It can divide a parent cell into k daughter cells and the tree structure is independent of the coordinate system and particle distribution. We investigated the characteristics and the performance of the tree structure according to k. For parallel computation, we used orthogonal recursive bisection method for domain decomposition to distribute particles to each processor, and the numerical experiments were performed on a 32-node Linux cluster. We compared the performance of the oct-tree and developed new algorithm according to the particle distributions, problem sizes and the number of processors. The comparison was performed sing tree-independent method and the results are independent of computing platform, parallelization, or programming language. It was found that the new algorithm can reduce computing cost for a large problem which has a short search range compared to the computational domain. But there are only small differences in wall-clock time because the proposed algorithm requires much time to construct tree structure than the oct-tree and he performance gain is small compared to the time for single time step calculation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.219-221
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• 2022

Seoul Metropolitan City, the world's top 10 cities and Metro City, has traditional urban manufacturing industries such as printing, sewing, and mechanical metals. These manufacturing industries have developed in the form of mutual assistance by forming small business clusters according to detailed industries and processes. Due to the nature of the cluster, logistics between companies for each process in the cluster are being carried out quickly, but it is difficult for relatively small small business owners to prepare order processing services for consumers of finished products. Therefore, it is urgent to introduce an integrated order fulfillment service platform for collective business owners for smooth order and delivery processing. In this paper, we collect and analyze the existing Fulfillment Service data of small business owners in the printing industry among traditional urban industries, and design an artificial intelligence Fulfillment Service Platform system applying CRNN, k-NN, and ID3 Decision Tree algorithm. Through this study, it is expected to greatly contribute to the increase in sales and capacity of small business owners by enabling the use of individual orders and customized delivery services that can be used by any small business owner in the cluster.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.12
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• pp.3815-3835
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• 2022

Density-based outlier detection is one of the hot issues in data mining. A point is determined as outlier on basis of the density of points near them. The existing density-based detection algorithms have high time complexity, in order to reduce the time complexity, a new outlier detection algorithm DODMD (Density-based Outlier Detection in Multidimensional Datasets) is proposed. Firstly, on the basis of ZH-tree, the concept of micro-cluster is introduced. Each leaf node is regarded as a micro-cluster, and the micro-cluster is calculated to achieve the purpose of batch filtering. In order to obtain n sets of approximate outliers quickly, a greedy method is used to calculate the boundary of LOF and mark the minimum value as LOF_min. Secondly, the outliers can filtered out by LOF_min, the real outliers are calculated, and then the result set is updated to make the boundary closer. Finally, the accuracy and efficiency of DODMD algorithm are verified on real dataset and synthetic dataset respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.3
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• pp.37-48
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• 1986

The purpose of this study was to analyze 'the natural groupings' of subjects in order to classify highly similar somatotype for clothing construction. The sample for the study was drawn randomly out of senior high school boys in Seoul urban area. The sample size was 425 boys between age 16 and 18. Cluster analysis was more concerned with finding the hierarchical structure of subjects by three dimensional distance of stature. bust girth and sleeve length. The groups forming a partition can be subdivided into 5 and 6 sets by the hierarchical tree of the given subjects. Ward's Minimum Variance Method was applied after extraction of distance matrix by the Standardized Euclidean Distance. All of the above data was analyzed by the computer installed at Korea Advanced Institute of Science and Technology. The major findings, take for instance, of 16 age group can be summarized as follows. The results of cluster analysis of this study: 1. Cluster 1 (32 persons means $18.29\%$ of the total) is characterized with smaller bust girth than that of cluster 5, but stature and sleeve length of the cluster 1 are the largest group. 2. Cluster 2 (18 Persons means $10.29\%$ of the total) is characterized with the group of the smallest stature and sleeve length, but bust girth larger than that of cluster 3. 3. Cluster 3(35persons means $20\%$ of the total) is classified with the smallest group of all the stature, bust girth and sleeve length. 4. Cluster 4(60 persons means $34.29\%$ of the total) is grouped with the same value of sleeve length with the mean value of 16 age group, but the stature and bust girth is smaller than the mean value of this age group. 5. Cluster 5(30 persons means $17.14\%$ of the total) is characterized with smaller stature than that of cluster 1, and with larger bust girth than that of cluster 1, but with the same value of the sleeve length with the mean value of the 16 age group.

• Korean Journal of Environment and Ecology
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• v.18 no.2
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• pp.124-130
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• 2004

The valley forests at Songgyesa-Motbong-Wolhatan Area in Deogyusan National Park were studied to investigate forest structure in relation to aspect and altitude of the slope. Density, mean DBH, mean height and basal area of the tree and subtree layers in the north-facing slope were greater than those in the south-facing slope. The impotance percentage of Fraxinus mandshurica and Carpinus cordata increased with increasing elevation while those of Quercus serrata and Quercus aliena decreased. Species diversity of the north-facing slope was 1.362 and that of the south-facing slope was 1.242. There was a tendency that number of species and species diversity decreased with increasing elevation. The result of cluster analysis for the tree and sub-tree layer indicated that the studied forests were classified into broad-leaved tree species community at the low and middle elevation belts of the south-facing slope and the north-facing slope, Fraxinus mandshurica-Quercus mongolica community at the high elevation belts of the south-facing slope and the north-facing slope and Quercus mongolica community at the top area. There were significantly positive correlations in the importance percentages among Quercus serrata, Betuzo davurica and Tilia amurensis. Carpinus laxiflora was significantly correlated with Cornus controversa, Tilia amurensis and Lindera obtusiloba. There was significantly negative correlation between Fraxinus mandshurica and Pinus densiflora.

• Korean Journal of Environment and Ecology
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• v.16 no.4
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• pp.457-464
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• 2003

A valley forest in Sangbuun area at Jirisan National Park was studied to investigate forest structure in relation to altitude and part of the slope. Forty-eight quadrats were set up in the valley forest along altitude of 726m to 1,090m and part of the slope, and vegetation analysis for the woody species in the tree and subtree layers were carried out. With increasing elevation belt, mean DBH, height and basal area of the trees in the tree layer increased while their density decreased. This trends may be caused by the disturbance which was relatively severe in the low elevation area. As elevation increased, the importance percentages of Fraxinus rhynchophylla, Quercus variabilis and Quercus mongolica increased while those of Styyax japonicus, Carpinus laxiflora and Pinus densiflora decreased. The importance percentages of Quercus variabilis and Pinus densiflora increased as going from lower part to upper part of the slope. However, the opposite trend was found for the importance percentages of Acer mono and Corlus heterophylla var. thunbergii. Number of species and species diversity decreased as increasing elevation and going from lower part to upper part of the slope. According to importance percentage and cluster analysis, the valley forest was classified into three forest communities of Quercus serrata-broad-leaved tree species community in lower part of the slope at low elevation belt, middle elevation belt and middle and upper parts of the slope at high elevation belt, Pinus dnsiflora-Quercus serrata community in middle and upper parts at low elevation belt, and Quercus mongolica-broad-leaved tree species community in lower part of the slope at high elevation belt and top area.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.3
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• pp.562-569
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• 2019

Raman spectroscopy has been receiving increased attention as a standoff explosive detection technique. In addition, there is a growing need for a fast search method that can identify raman spectrum for measured chemical substances compared to known raman spectra in large database. By far the most simple and widely used method is to calculate and compare the Euclidean distance between the given spectrum and the spectra in a database. But it is non-trivial problem because of the inherent high dimensionality of the data. One of the most serious problems is the high computational complexity of searching for the closet spectra. To overcome this problem, we presented the MPS Sort with Sorted Variance+PDS method for the fast algorithm to search for the closet spectra in the last paper. the proposed algorithm uses two significant features of a vector, mean values and variance, to reject many unlikely spectra and save a great deal of computation time. In this paper, we present two new methods for the fast algorithm to search for the closet spectra. the PCA+PDS algorithm reduces the amount of computation by reducing the dimension of the data through PCA transformation with the same result as the distance calculation using the whole data. the Hierarchical Cluster Tree algorithm makes a binary hierarchical tree using PCA transformed spectra data. then it start searching from the clusters closest to the input spectrum and do not calculate many spectra that can not be candidates, which save a great deal of computation time. As the Experiment results, PCA+PDS shows about 60.06% performance improvement for the MPS Sort with Sorted Variance+PDS. also, Hierarchical Tree shows about 17.74% performance improvement for the PCA+PDS. The results obtained confirm the effectiveness of the proposed algorithm.