• 제목/요약/키워드: Cluster Reduction

검색결과 217건 처리시간 0.024초

CCD Photometry of the Globular Cluster M30

  • Yim, Hong-Seo;Chun, Mun-Suk
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 1992년도 한국우주과학회보 제2권1호
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    • pp.14.2-14
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    • 1993
  • We present UBV CCD Photometry of the very metal-poor globular duster M3O,covering a region of r f 100 arcsec from the duster center. The data was obtained from the 40 inch telescope at Mt Soomlo Siding Spring Observator in August 1992. We used DAOPHOT CCD reudction package for data reduction to obtain Color-Magnitude Diagram(CMD). We have determined some fludamental parameters of the globular Ouster such as metal abundance, helium abundance and distance from the CMD. finally, we have attempted to determine the age of M3O using the revised Yale isochrones.

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합성곱 오토인코더 기반의 응집형 계층적 군집 분석 (Agglomerative Hierarchical Clustering Analysis with Deep Convolutional Autoencoders)

  • 박노진;고한석
    • 한국멀티미디어학회논문지
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    • 제23권1호
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    • pp.1-7
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    • 2020
  • Clustering methods essentially take a two-step approach; extracting feature vectors for dimensionality reduction and then employing clustering algorithm on the extracted feature vectors. However, for clustering images, the traditional clustering methods such as stacked auto-encoder based k-means are not effective since they tend to ignore the local information. In this paper, we propose a method first to effectively reduce data dimensionality using convolutional auto-encoder to capture and reflect the local information and then to accurately cluster similar data samples by using a hierarchical clustering approach. The experimental results confirm that the clustering results are improved by using the proposed model in terms of clustering accuracy and normalized mutual information.

Efficient Multistage Approach for Unsupervised Image Classification

  • Lee Sanghoon
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.428-431
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    • 2004
  • A multi-stage hierarchical clustering technique, which is an unsupervised technique, has been proposed in this paper for classifying the hyperspectral data .. The multistage algorithm consists of two stages. The 'local' segmentor of the first stage performs region-growing segmentation by employing the hierarchical clustering procedure with the restriction that pixels in a cluster must be spatially contiguous. The 'global' segmentor of the second stage, which has not spatial constraints for merging, clusters the segments resulting from the previous stage, using a context-free similarity measure. This study applied the multistage hierarchical clustering method to the data generated by band reduction, band selection and data compression. The classification results were compared with them using full bands.

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A Bayesian Model-based Clustering with Dissimilarities

  • Oh, Man-Suk;Raftery, Adrian
    • 한국통계학회:학술대회논문집
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    • 한국통계학회 2003년도 추계 학술발표회 논문집
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    • pp.9-14
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    • 2003
  • A Bayesian model-based clustering method is proposed for clustering objects on the basis of dissimilarites. This combines two basic ideas. The first is that tile objects have latent positions in a Euclidean space, and that the observed dissimilarities are measurements of the Euclidean distances with error. The second idea is that the latent positions are generated from a mixture of multivariate normal distributions, each one corresponding to a cluster. We estimate the resulting model in a Bayesian way using Markov chain Monte Carlo. The method carries out multidimensional scaling and model-based clustering simultaneously, and yields good object configurations and good clustering results with reasonable measures of clustering uncertainties. In the examples we studied, the clustering results based on low-dimensional configurations were almost as good as those based on high-dimensional ones. Thus tile method can be used as a tool for dimension reduction when clustering high-dimensional objects, which may be useful especially for visual inspection of clusters. We also propose a Bayesian criterion for choosing the dimension of the object configuration and the number of clusters simultaneously. This is easy to compute and works reasonably well in simulations and real examples.

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The Function of eryBVII Gene is to Epimerize TDP-6-Deoxy-L-threo-D-glycero-4-hexulose in the Biosynthesis of Erythromycin A

  • Kim, Won-Young;Kim, Choon-Keun;Han, Ok-Soo
    • BMB Reports
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    • 제32권1호
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    • pp.72-75
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    • 1999
  • In an effort to understand the function of the eryBVII gene in the erythromycin biosynthetic gene cluster, we overexpressed the eryBVII gene in E. coli and TDP-6-deoxy-L-threo-D-glycero-4-hexulose was used as a substrate of the overexpressed EryBVII enzyme. The enzymatic reaction product was chemically modified by reduction and peracetylation. Structural analysis of the derivatized enzymatic products by GC-Mass Spectrophotometry indicated that TDP-6-deoxy-L-threo-D-glycero-4-hexulose could be converted into its epimer by EryBVII enzyme. Based on this result, TDP-6-deoxy-L-threo-D-glycero-4-hexulose was indeed the substrate of EryBVII enzyme and the function of the eryBVII gene was confirmed.

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해양프로그램 실태조사를 통한 운영 개선방안 및 정책 제안 연구 (A Study on Policy Proposal of Marine Environment Education Program through Research on the Actual Condition)

  • 신상현;배준성
    • 수산해양교육연구
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    • 제29권1호
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    • pp.169-179
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    • 2017
  • The purpose of this research is to identify the overall operation status of the marine program, which operates in the Department attempted, in various qualities and operational programs consisting of lecturers derives the problem, and to the policy proposal accordingly. In order to complete the purpose, to analyzed based on the status of marine programs of the Marine Training Center Chungcheong Cluster of three Education Offices from 2014 until the first half of 2016. In addition to direct visit the scene to confirm the status of the data collected through field surveys and interviews were officials confirm the validity of the data, and also to obtain additional study. In conclusion, First, Establish measures for the reduction of blind spots urgent law. Second, Appliances installed for program development and Instructors training.

홀로그래픽 정보 저장 장치에서 클러스터링을 이용한 에러 감소 기법 제안 및 비교 (Design and Comparison of Error Reduction Methods Using Clustering in Holographic Data Storage System)

  • 김상훈;김장현;양현석;박영필
    • 정보저장시스템학회:학술대회논문집
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    • 정보저장시스템학회 2005년도 추계학술대회 논문집
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    • pp.83-87
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    • 2005
  • Data storage related with writing and retrieving requires high storage capacity, fast transfer rate and less access time in. Today any data storage system can not satisfy these conditions, but holographic data storage system can perform faster data transfer rate because it is a page oriented memory system using volume hologram in writing and retrieving data. System architecture without mechanical actuating pare is possible, so fast data transfer rate and high storage capacity about 1Tb/cm3 can be realized. In this paper, to correct errors of binary data stored in holographic digital data storage system, find cluster centers using clustering algorithm and reduce intensities of pixels around centers. We archive the procedure by two algorithms of C-mean and subtractive clustering, and compare the results of the two algorithms. By using proper clustering algorithm, the intensity profile of data page will be uniform and the better data storage system can be realized.

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Empirical Analysis on Change of Korean Male Pro- Basketball Players Draft System

  • Choi, Kyoung-Ho
    • Journal of the Korean Data and Information Science Society
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    • 제19권4호
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    • pp.1081-1089
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    • 2008
  • Beginning in the 2007-2008 season, the men's pro-basketball league changed a foreigner selection method by introducing a draft system which leads to a tryout from the free agency system. Also in the same season, the woman's pro-basketball league changed its system from one that permitted foreign players to one that doesn't allow foreign player participation. The reason for this change is thought to be financial problems. However this institutional change brings about the reduction in the quality of basketball and it will affect spectators in a negative way. The empirical study attempted to analyze the effects which follows an institutional change in Korean men's pro-basketball. The research showed that the men's pro-basketball league wasn't affected at all due to foreigner selection method by a draft system that led to a tryout from the free agency system.

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PB/MC-CDMA 기반 two-hop 중계 망에서의 자원 할당 방식 (Resource Allocation in Two Hop Relay Network based on PB/MC-CDMA System)

  • 얀순;이계산
    • 한국위성정보통신학회논문지
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    • 제5권1호
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    • pp.94-99
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    • 2010
  • In this paper, we discuss a proposed two hop relay network with PB/MC-CDMA(partial block MC-CDMA) technique. The main advantages of PB/MC-CDMA system are the increased cell capacity and the high quality of performances. In the system, we employ relay scheme to focus on the coverage reduction and hotspot problem, hotspot is a location where a cluster of users are blocked or dropped for the reason of insufficient frequency resources. Frequency resource allocation scheme is put forward in a three cells system according to each problem. The simulation result shows the performance of the two hop transmission is better than the direct transmission and the proposed network can support much more users to relief hotspot effect compared to the conventional one.

계층적 WSN에서 에너지 사용 감소를 위한 릴레이 클러스터 헤더 선출 기법 (A Relay Cluster Header Selection Scheme for Reduction of Energy Usage on Hierarchical WSN)

  • 박시용;조현숙
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2009년도 춘계학술발표대회
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    • pp.1094-1097
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    • 2009
  • 본 논문에서는 클러스터 기반의 계층적 무선 센서 네트워크에서 에너지 사용을 줄이기 위해서 클러스터 헤더를 선출할 때 에너지 소모량을 고려하여 선출하는 기법을 제안한다. 제안하는 기법은 무선센서 네트워크의 크기나 위치 정보와 같은 전체적인 정보 없이 분산 환경을 기반으로 하고 있으며, 이전 클러스터 헤더가 에너지 잔류량과 현재 라운드에서의 에너지 소비량을 예측하여 다음 라운드의 클러스터 헤더를 선출한다. 실험결과 제안한 기법은 비교기법인 LEACH에 비하여 에너지 소모를 향상시켰고, 라운드마다 고른 에너지 소비량을 보였다.