• 제목/요약/키워드: cluster value

검색결과 851건 처리시간 0.033초

Performance Evaluation of AMC in Clustered OFDM System

  • Cho, Ju-Phil
    • 한국멀티미디어학회논문지
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    • 제8권12호
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    • pp.1623-1630
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    • 2005
  • Adaptive modulation and coding (AMC), which has a number of variation levels in accordance with the fading channel variation, is a promising technique for communication systems. In this paper, we present an AMC method using the cluster in OFDM system for bandwidth efficiency and performance improvement. The AMC schemes applied into each cluster or some clusters are determined by the minimum or the average SNR value among all the sub carriers within the corresponding cluster. It is important to find the optimal information on cluster because AMC performance can be varied according to the number and position of cluster. It is shown by computer simulation that the AMC method outperforms the fixed modulation in terms of bandwidth efficiency and its performance can be determined by the position and number of clusters.

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Probing Tidal Field Strength of Virgo Cluster Galaxies

  • 윤혜인;정애리
    • 천문학회보
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    • 제36권2호
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    • pp.74.2-74.2
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    • 2011
  • We probe the tidal perturbation parameter f of Virgo cluster galaxies. The goal is to measure the strength of tidal fields around individual galaxies to get better understanding gravitational processes that can affect galaxy evolution in the cluster environment. The f-value is defined as a logarithmic ratio between the net internal gravitational force within a galaxy and the external tidal force exerted by a neighboring galaxy. Hence, it provides one way to quantify the tidal field strength of galaxies, in particular, due to galaxy neighbors. In this study, we determine f-values of the VIVA galaxies, samples of the VLA Imaging study of Virgo galaxies in Atomic gas, using the Extended Virgo Cluster Catalog (EVCC) which is the most complete Virgo cluster catalog to date. With diagnostics based on the HI gas and R-band morphologies, we discuss the impact of the tidal fields on the evolution of the VIVA sample. Also, we compare the tidal field strength to the intra cluster medium (ICM) pressure for each sample galaxy to pin down environmental processes at work.

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사상체질과 의복가치관의 연구 (A Study on the Relationship between Sasang Constitution and Clothing Value)

  • 정옥임
    • 복식
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    • 제27권
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    • pp.87-101
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    • 1996
  • The purpose of this study is to grasp the re-lationship between Sasang constitution of the disposition side and clothing value in grown-up women in order to apply Sasang consti-tution theory to the marketing strategy in clothing industry. The study is based on a questionnaie about Sasang constitution and clothing value. The questionnarie was answered by 519 women. The data ere collected from September 12 to September 30, 1994 and analyzed by cluster analysis correlation analysis ANOVA and fac-tor analysis using SAS. The Findings of this study are as follows: 1. The women were classfied in to 3 clusters by cluster analysis :Sp-Yaung-In type (30.8%) Tae-Em-In type (40.7%) So-em-in(28.5%). 2. Correlations between SO-Yaug In type and each of clothing values showed all signifi-cant and specially social value showed high corelation(0.57163) 3. In Tae-Em-In type all correlations showed significant and esocial value showed the highest correlation of all correlations. 4. In So-Em-In type there was no corre-lation inpolitical value and the order of cloth-ing values showing high correlation was theor-etical social economic and religious value. 5. The aesthetic valu among and consti-tution types showed the lowest correlation of all correlation. By means of the about study results we may know that all women belong to three types think social value of the more important value than any other in clothing value. This is because grown-up women in korea prefer yet clothing of the harmonic and similar type to this of individual type.

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국내 신선물류클러스터의 구축방안 - 인천송도경제자유구역을 대상으로 (Proposal of the fresh logistics cluster for Songdo FEZ)

  • 손병석;전일수;송인석
    • 한국항만경제학회지
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    • 제23권1호
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    • pp.41-59
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    • 2007
  • 본 연구의 목적은 매년 증가하고 있는 수입 식품의 안전한 관리를 위한 방안으로서 식품의 수입, 보관, 배송의 전 과정을 통합적으로 관리할 수 있는 신선물류클러스터 구축 방안을 제시하고자 한다. 이를 위해 신선물류클러스터를 인천송도경제자유구역에 구축함으로써 기대되는 경제적 효과를 분석하고 향후 신선물류클러스터 구축을 위한 관련 주체의 역할과 함께 정책적인 지원방안을 모색하였다. 본 연구에서는 신선물류시스템을 정의하고 분석하여 보다 구체적인 신선물류클러스터의 구축방안을 제시하였으며, 또한 신선물류클러스터 구축의 경제적 효과를 부가가치와 물류비 절감효과로 분석하였다. 이와 같은 신선물류클러스터를 인천송도경제자유구역에 구축하기 위한 방안으로 국내 관련 법률을 검토하고 일관성 있는 정책 방향을 제시하였다. 그러나 본 논문은 신선물류라는 조금은 생소한 분야의 연구로서 선행연구의 검토, 관련데이터 수집 등에 있어 다소 부족한 부분이 있다. 하지만 향후 본 연구를 토대로 다양한 신선물류와 신선물류클러스터에 대한 연구가 수행되기를 희망한다.

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외부 군집 연관 기준 정보를 이용한 군집수 최적화 (A Study on Optimizing the Number of Clusters using External Cluster Relationship Criterion)

  • 이현진;지태창
    • 디지털콘텐츠학회 논문지
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    • 제12권3호
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    • pp.339-345
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    • 2011
  • 군집화는 주어진 데이터를 분할하여 데이터 속에 숨겨져 있는 의미를 자동으로 발견하는 방법이다. k-means는 간단하고 빠른 군집화 알고리즘 중의 하나이다. 군집의 수 k는 군집화를 수행하는데 매우 중요한 요소이며, k의 값에 의해 군집화 결과가 달라진다. 본 논문에서는 반복적인 k-means 수행과 군집의 품질을 평가하는 외부 군집 연관 기준 정보를 결합하여 최적의 군집수를 결정하는 방법을 제안한다. 실험 결과 기존의 방법들에 비하여 제안하는 방법이 군집수의 정확성 측면에서 우수한 성능을 보였다.

순위-기반 클러스터링 이용한 PSO (Rank-based PSO Using Clustering)

  • 강신호;임동현;안창욱
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2009년도 추계학술발표대회
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    • pp.295-296
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    • 2009
  • 본 논문은 기존 PSO의 문제점으로 지적되는 Local minimum에의 고착을 해결하여 평균적인 성능을 향상시킬 수 있는 방법을 제안한다. 이를 위해 기존에는 하나의 Best Value만을 향해서 이동하는 것에서 벗어나, 각 Particle들을 Cluster로 나누고 각각의 Best Value를 중심으로 이동하며, 각 Cluster Leader들은 다른 Cluster Leader와 통신하며 순위에 따라 이동한다. 제안 방법으로 수렴속도와 Local minimum 회피에 대해 실험을 통해 비교 분석한다. 실험 결과로부터 제안 방법이 Local minimum 회피에서 성능 향상이 있음을 고찰하였다.

군집분석을 이용한 국지해일모델 지역확장 (Regional Extension of the Neural Network Model for Storm Surge Prediction Using Cluster Analysis)

  • 이다운;서장원;윤용훈
    • 대기
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    • 제16권4호
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    • pp.259-267
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    • 2006
  • In the present study, the neural network (NN) model with cluster analysis method was developed to predict storm surge in the whole Korean coastal regions with special focuses on the regional extension. The model used in this study is NN model for each cluster (CL-NN) with the cluster analysis. In order to find the optimal clustering of the stations, agglomerative method among hierarchical clustering methods was used. Various stations were clustered each other according to the centroid-linkage criterion and the cluster analysis should stop when the distances between merged groups exceed any criterion. Finally the CL-NN can be constructed for predicting storm surge in the cluster regions. To validate model results, predicted sea level value from CL-NN model was compared with that of conventional harmonic analysis (HA) and of the NN model in each region. The forecast values from NN and CL-NN models show more accuracy with observed data than that of HA. Especially the statistics analysis such as RMSE and correlation coefficient shows little differences between CL-NN and NN model results. These results show that cluster analysis and CL-NN model can be applied in the regional storm surge prediction and developed forecast system.

글리치를 고려한 매핑가능 클러스터 생성 방법을 이용한 저전력 알고리즘 (The Low Power Algorithm using a Feasible Clustert Generation Method considered Glitch)

  • 김재진
    • 디지털산업정보학회논문지
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    • 제12권2호
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    • pp.7-14
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    • 2016
  • In this paper presents a low power algorithm using a feasible cluster generation method considered glitch. The proposed algorithm is a method for reducing power consumption of a given circuit. The algorithm consists of a feasible cluster generation process and glitches removal process. So that glitches are not generated for the node to which the switching operation occurs most frequently in order to reduce the power consumption is a method for generating a feasible cluster. A feasible cluster generation process consisted of a node value set, dividing the node, the node aligned with the feasible cluster generation. A feasible cluster generation procedure is produced from the highest number of nodes in the output. When exceeding the number of OR-terms of the inputs of the selected node CLB prevents the signal path is varied by the evenly divided. If there are nodes with the same number of outputs selected by the first highest number of nodes in the input produces a feasible cluster. Glitch removal process removes glitches through the path balancing in the same manner as [5]. Experimental results were compared with the proposed algorithm [5]. Number of blocks has been increased by 5%, the power consumption was reduced by 3%.

Effect of Component Factors of Innovation Clusters on the Corporate Business Activity: The Moderating Effect of Financial Support

  • Im, Jongbin;Chung, Sunyang
    • World Technopolis Review
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    • 제4권3호
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    • pp.144-156
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    • 2015
  • Globalization and knowledge-based economy have increased the importance of local areas as the units of global competition. Therefore, the meaning of localities has been emphasized as the core value of economic activities. In this context, innovation cluster has been recognised and emphasized as effective policy measure for innovation. Therefore, most countries have been trying to develop innovation clusters with their expectation for a rapid growth of economy. Nevertheless, there have been minimal empirical researches on innovation cluster. Therefore, for suggesting implications that activation factors of innovation cluster are to have an effect on tenant's business activities, this study conducted a literature review for the theories of regional innovation system(RIS) and innovation cluster. As a result, the activation factors of innovation cluster were classified into institutional, physicals, and social factor. The case of Gyeonggi province's innovation cluster policy was examined for an empirical analysis. Data were analyzed using ordered logistic regression. The results were as follows:First, Institutional and Infra factors had a positive influence on firms' business activities in every empirical test, so they were the most important activation factors of innovation cluster. Second, regarding the interactive effects of financial support, the interactive effects between financial support and Infra factor had a positive influence on the firms' business activities, according to the result of the empirical test.

관광행동에 따른 여행상품속성 선택의 차이에 관한 연구 : 해외여행객을 중심으로 (Research on the Difference on Selection of Travel Product Attributes by Tourism Action: Focus on Outbound Tourist)

  • 이채은;이진영
    • 한국콘텐츠학회논문지
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    • 제9권10호
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    • pp.398-406
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    • 2009
  • 본 연구의 목적은 관광행동에 따른 여행상품속성의 차이를 살펴봄으로써 여행업계가 더 주력해야 할 여행상품을 판매하기 위한 마케팅 전략을 제시하는 것에 도움을 주고자 하는 것이다. 본 연구를 위해 군집분석과 ANOVA분석이 이용되었는데, 군집분석 결과 4개의 군집으로 나타났다. '합리적 관광형', '약한 과시적 관광형', '가치적 관광형'과 '과시적 가치적 관광형'으로 분류되었다. ANOVA분석 결과 여행서비스와 오락을 제외한 교통 숙박시설, 관광매력물, 쇼핑, 식사에서는 관광행동에 있어 군집들이 차이를 보이는 것으로 나타났다.