• Title/Summary/Keyword: Graph theory

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CAS IMPLEMENTATION OF RECURSIVE STRUCTURE IN A SPANNING TREE

  • Song, Kee-Hong
    • East Asian mathematical journal
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    • v.21 no.2
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    • pp.249-260
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    • 2005
  • Experimentation using computer plays an important part in education and research in graph theory. The purpose of this paper is to develop the CAS techniques for the hands-on approach in graph theory specifically on the topic of constructing the spanning tree. This paper discusses the advantages of CAS as the software system for doing graph theory and introduces the software solutions integrating multimedia user interface developed by the author, which extend the functionality of the existing CAS-based graph theory software package.

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Time-Series Causality Analysis using VAR and Graph Theory: The Case of U.S. Soybean Markets (VAR와 그래프이론을 이용한 시계열의 인과성 분석 -미국 대두 가격 사례분석-)

  • Park, Hojeong;Yun, Won-Cheol
    • Environmental and Resource Economics Review
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    • v.12 no.4
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    • pp.687-708
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    • 2003
  • The purpose of this paper is to introduce time-series causality analysis by combining time-series technique with graph theory. Vector autoregressive (VAR) models can provide reasonable interpretation only when the contemporaneous variables stand in a well-defined causal order. We show that how graph theory can be applied to search for the causal structure In VAR analysis. Using Maryland crop cash prices and CBOT futures price data, we estimate a VAR model with directed acyclic graph analysis. This expands our understanding the degree of interconnectivity between the employed time-series variables.

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H-TREES, RESTRICTIONS OF DOWLING GROUP GEOMETRIES

  • Mphako-Banda, Eunice
    • Bulletin of the Korean Mathematical Society
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    • v.52 no.3
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    • pp.955-962
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    • 2015
  • It has been established that the role played by complete graphs in graph theory is similar to the role Dowling group geometries and Projective geometries play in matroid theory. In this paper, we introduce a notion of H-tree, a class of representable matroids which play a similar role to trees in graph theory. Then we give some properties of H-trees such that when q = 0, then the results reduce to the known properties of trees in graph theory. Finally we give explicit expressions of the characteristic polynomials of H-trees, H-cycles, H-fans and H-wheels.

A Historical Background of Graph Theory and the Computer Representation (그래프 이론의 역사적 배경과 그 컴퓨터 표현)

  • Kim Hwa-jun;Han Su-young
    • Journal for History of Mathematics
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    • v.18 no.1
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    • pp.103-110
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    • 2005
  • This paper is aimed at studying a historical background of graph theory and we deal with the computer representation of graph through a simple example. Graph is represented by adjacency matrix, edge table, adjacency lists and we study the matrix representation by Euler circuit. The effect of the matrix representation by Euler circuit economize the storage capacity of computer. The economy of a storage capacity has meaning on a mobile system.

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Optimal Layout for Irrigation Pipeline Networks using Graph Theory (Graph 이론을 이용한 농업용 관수로망의 최적배치)

  • Im, Sang-Jun;Park, Seung-Woo;Cho, Jae-Pil
    • Journal of Korean Society of Rural Planning
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    • v.6 no.2
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    • pp.12-19
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    • 2000
  • Irrigation pipeline networks consist mainly of buried pipes and are therefore relatively free from topographic constraints. Installation of irrigation pipeline systems is increasing since the systems have several advantages compared to open channel systems. To achieve economic design of pipeline networks, the layout should meet several conditions such as shortest path, maximum flow, and least cost. Graph theory is mathematical tool which enable to find out optimum layout for complicated network systems. In this study, applicability of graph theory to figure out optimum layout of irrigation pipeline networks was evaluated.

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Mobile robot indoor map making using fuzzy numbers and graph theory

  • Kim, Wan-Joo;Ko, Joong-Hyup;Chung, Myung-Jin
    • 제어로봇시스템학회:학술대회논문집
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    • pp.491-495
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    • 1993
  • In this paper, we present a methodology to model an indoor environment of a mobile robot using fuzzy numbers and to make a global map of the robot environment using graph theory. We describe any geometric primitive of robot environment as a parameter vector in parameter space and represent the ill-known values of the prameterized geometric primitive by means of fuzzy numbers restricted to appropriate membership functions. Also we describe the spatial relations between geometric prinitives using graph theory for local maps. For making the global map of the mobile robot environment, the correspondence problem between local maps is solved using a fuzzy similarity measure and a Bipartite graph matching technique.

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Recent developments of constructing adjacency matrix in network analysis

  • Hong, Younghee;Kim, Choongrak
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.5
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    • pp.1107-1116
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    • 2014
  • In this paper, we review recent developments in network analysis using the graph theory, and introduce ongoing research area with relevant theoretical results. In specific, we introduce basic notations in graph, and conditional and marginal approach in constructing the adjacency matrix. Also, we introduce the Marcenko-Pastur law, the Tracy-Widom law, the white Wishart distribution, and the spiked distribution. Finally, we mention the relationship between degrees and eigenvalues for the detection of hubs in a network.

Database Segment Distributing Algorithm using Graph Theory (그래프이론에 의한 데이터베이스 세그먼트 분산 알고리즘)

  • Kim, Joong Soo
    • Journal of Korea Multimedia Society
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    • v.22 no.2
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    • pp.225-230
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    • 2019
  • There are several methods which efficiencies of database are uprise. One of the well-known methods is that segments of database satisfying a query was rapidly accessed and processed. So if it is possible to search completely parallel multiple database segment types which satisfy a query, the response time of the query will be reduced. The matter of obtaining CPS(Completely Parallel Searchable) distribution without redundancy can be viewed as graph theoretic problem, and the operation of ring sum on the graph is used for CPS. In this paper, the parallel algorithm is proposed.

Fuzzy ideal graphs of a semigroup

  • Rao, Marapureddy Murali Krishna
    • Annals of Fuzzy Mathematics and Informatics
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    • v.16 no.3
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    • pp.363-371
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    • 2018
  • The main objective of this paper is to connect fuzzy theory, graph theory and fuzzy graph theory with algebraic structure. We introduce the notion of fuzzy graph of semigroup, the notion of fuzzy ideal graph of semigroup as a generalization of fuzzy ideal of semigroup, intuitionistic fuzzy ideal of semigroup, fuzzy graph and graph, the notion of isomorphism of fuzzy graphs of semigroups and regular fuzzy graph of semigroup and we study some of their properties.