• Title/Summary/Keyword: 그래프 밀도

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A Bottom-up Algorithm to Find the Densest Subgraphs Based on MapReduce (맵리듀스 기반 상향식 최대 밀도 부분그래프 탐색 알고리즘)

  • Lee, Woonghee;Kim, Younghoon
    • Journal of KIISE
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    • v.44 no.1
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    • pp.78-83
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    • 2017
  • Finding the densest subgraphs from social networks, such that people in the subgraph are in a particular community or have common interests, has been a recurring problem in numerous studies undertaken. However, these algorithms focused only on finding the single densest subgraph. We suggest a heuristic algorithm of the bottom-up type, which finds the densest subgraph by increasing its size from a given starting node, with the repeated addition of adjacent nodes with the maximum degree. Furthermore, since this approach matches well with parallel processing, we further implement a parallel algorithm on the MapReduce framework. In experiments using various graph data, we confirmed that the proposed algorithm finds the densest subgraphs in fewer steps, as compared to other related studies. It also scales efficiently for many given starting nodes.

Modeling Scheme for Calculating Encounter Probability Versus Minefleld Density (지뢰지대 밀도별 접촉확률 산정 모델링 방안)

  • Baek, Doo-Hyeon;Lee, Sang-Heon
    • Journal of the military operations research society of Korea
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    • v.35 no.2
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    • pp.77-86
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    • 2009
  • The encounter probability graph is measured by the chance(in percent) that a vehicle, blindly moving through a minefield, will detonate a mine. The encounter probability graph versus minefield density is presented in ROK and US Army field manual but this graph is baseless because these data had not been presented as those of live mobility or wargame. In this paper, we verified this graph building procedure model as using computer program. The result values of program are almost like those of graph. Therefore this model for our to suggest have validation, verification that a modeling demand and we convince that this model will be useful for calculating encounter probability of multiple vehicles.

Selecting the Number and Location of Knots for Presenting Densities

  • An, Jeong-Yong;Mun, Gil-Seong;Han, Gyeong-Su
    • Proceedings of the Korean Statistical Society Conference
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    • 2003.10a
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    • pp.31-34
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    • 2003
  • 본 연구에서는 연속형 확률밀도함수의 그래프를 표현하기 위한 하나의 방법으로 보간점을 이용하는 문제에 대해 살펴보고자 한다. 이를 위해 최적화 기법을 이용하여 보간점의 수와 위치를 선택하는 알고리즘을 제안하고, 제안한 방법을 이용하여 확률밀도함수의 그래프를 구현한다.

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Physicochemical Properties of Korean Raw Noodle Flours (우리나라 생면용 밀가루의 성질)

  • Shin, Soong-Nyong;Kim, Sung-Kon
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.418-424
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    • 2005
  • The physicochemical properties of raw noodle flours (n = 11) commercially produced from Australian Standard White (ASW) (Group 1, n = 8) and blonds (Group 2, n = 3) of ASW and Australian hard, western white or hard red winter were investigated. Protein and ash contents were lower in Group 1. The tristimulus color values, mean particle size, flour swelling volume (FSV) and rheological parameters of farinograph and extensigraph were not different between two flour groups. Peak viscosity measured with Rapid Visco Analyzer was higher in Group 1. The protein content was positively correlated with mean particle size, dough stability and dough extensibility, and negatively correlated with FSV and peak viscosity. The FSV wag positively correlated with the peak viscosity. The rheological parameters of dough did not show any correlations with FSV and peak viscosity.

An Algorithm for Construction of Distribution Breadth-First Search Tree Using New Threshold Values (새로운 임계값을 이용한 분산 너비우선탐색 트리(Distributed Breadth-First Search Tree)의 구성 에 관한 알고리즘)

  • 송인섭;신재호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.5
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    • pp.468-574
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    • 1991
  • In construction of breadth-frist tree, the communication complexity can be reduced by efficent synchronization schemes based on several threshold values, We determine several new threshold values by considering the graph density represented as lognm, where n and m are the number of nodes and links., repectively. When thesethreshold values are used in the synchroization method for constructing distrbuted bradth-first search tree, we can obtain a more efficient algorithm in sparse graphs, and also, this algorithm has vthe same performance for communication complexity in dense graphs.

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Social Network Analysis using Common Neighborhood Subgraph Density (공통 이웃 그래프 밀도를 사용한 소셜 네트워크 분석)

  • Kang, Yoon-Seop;Choi, Seung-Jin
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.4
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    • pp.432-436
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    • 2010
  • Finding communities from network data including social networks can be done by clustering the nodes of the network as densely interconnected groups, where keeping interconnection between groups sparse. To exploit a clustering algorithm for community detection task, we need a well-defined similarity measure between network nodes. In this paper, we propose a new similarity measure named "Common Neighborhood Sub-graph density" and combine the similarity with affinity propagation, which is a recently devised clustering algorithm.

Particle Size Distribution and Rheological Properties of Australian Noodle Flours (호주산 제면용 밀가루의 리올로지 성질과 입도분포)

  • Yoon, Yeon-Hee;Kim, Sung-Kon
    • Applied Biological Chemistry
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    • v.41 no.5
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    • pp.367-371
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    • 1998
  • The characteristics of four samples of noodle flours milled from Australian Standard White(ASW) wheat were compared with one sample of noodle flour prepared from a blend of hard red winter(HRW) and western white(WW) American wheats. The ASW flours had lower content of protein and ash. Farinograms revealed that the absorption of the ASW flours was slightly higher than that of the HRW-WW flour. The mixing time, however, showed no difference between ASW flours and HRW-WW flour. The stability and the mechanical tolerance index were different among ASW flours, which were lower than HRW-WW flour. The ratios of resistance to extention determined by extensigraph for ASW flours were higher except one flour than HRW-WW flour. The flours showed characteristic mean particle sizes, which may reflect the differences in hardness of wheat used in the flour production. Farinograph indices showed no correlations with protein content and extensigraph indices. The amylograph peak viscosity was inversely correlated with the protein content (p<0.05).

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Science Gifted Students' Interpretation and Understanding of Concept about T-S Diagram (과학영재학생의 수온-염분도에 대한 해석과 개념 이해)

  • Yu, Eun-Jeong;Jeong, Deuk Sil
    • Journal of the Korean earth science society
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    • v.40 no.6
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    • pp.639-653
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    • 2019
  • The purpose of this study is to investigate the science gifted students' level of interpreting the oceanic graph and of understanding the oceanic physical concept through analyzing the Temperature-Salinity (T-S) diagram and inferring the SOFAR (SOund Fixing And Ranging) channel. A total of 106 gifted students in the 3rd year of a science gifted high school, using T-S diagrams published in one of the journals of Oceanology, developed descriptive questions asking the depth of the SOFAR channel to conduct the quantitative and qualitative analysis of graph interpretation ability. As a result, there was a big difference in the level of graphs interpretation and concepts understanding for each science gifted students such as interpreting, modeling, and converting, and exposed their alternative concepts about water temperature, salinity, and density. The results of this study will be used to understand the levels of science gifted students' graph interpretation in oceanology, and to provide the basic data for improving the teaching and learning methods of oceanology and also provide basic data for teaching material development related to graph analysis.

A study on log-density with log-odds graph for variable selection in logistic regression (로지스틱회귀모형의 변수선택에서 로그-오즈 그래프를 통한 로그-밀도비 연구)

  • Kahng, Myung-Wook;Shin, Eun-Young
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.1
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    • pp.99-111
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    • 2012
  • The log-density ratio of the conditional densities of the predictors given the response variable provides useful information for variable selection in the logistic regression model. In this paper, we consider the predictors that are needed and how they should be included in the model. If the conditional distributions are skewed, the distributions can be considered as gamma distributions. Under this assumption, linear and log terms are generally included in the model. The log-odds graph is a very useful graphical tool in this study. A graphical study is presented which shows that if the conditional distributions of x|y for the two groups overlap significantly, we need both the linear and quadratic terms. On the contrary, if they are well separated, only the linear or log term is needed in the model.

Fast Random Walk with Restart over a Signed Graph (부호 그래프에서의 빠른 랜덤워크 기법)

  • Myung, Jaeseok;Shim, Junho;Suh, Bomil
    • The Journal of Society for e-Business Studies
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    • v.20 no.2
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    • pp.155-166
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    • 2015
  • RWR (Random Walk with Restart) is frequently used by many graph-based ranking algorithms, but it does not consider a signed graph where edges may have negative weight values. In this paper, we apply the Balance Theory by F. Heider to RWR over a signed graph and propose a novel RWR, Balanced Random Walk (BRW). We apply the proposed technique into the domain of recommendation system, and show by experiments its effectiveness to filter out the items that users may dislike. In order to provide the reasonable performance of BRW in the domain, we modify the existing Top-k algorithm, BCA, and propose a new algorithm, Bicolor-BCA. The proposed algorithm yet requires employing a threshold. In the experiment, we show how threshold values affect both precision and performance of the algorithm.