• Title/Summary/Keyword: Vertex Ordering

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Reordering Algorithm for Hypergraph Partitioning (하이퍼그래크 분할을 위한 재서열화 알고리즘)

  • Kim, Sang-Jin;Yun, Tae-Jin;Lee, Chang-Hui;An, Gwang-Seon
    • Journal of KIISE:Computer Systems and Theory
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    • v.26 no.12
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    • pp.1548-1555
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    • 1999
  • 본 논문에서는 하이퍼그래프의 {{{{k분 분할을 위한 서열화(vertex ordering) 알고리즘의 효율을 개선하기 위한 후처리 알고리즘인 재서열법을 소개한다. 제안된 알고리즘은 {{{{k분 분할을 위한 다양한 알고리즘에 쉽게 적용될 수 있다. 보통 초기 분할은 서열화를 기반으로 하는 알고리즘에 의해 형성된다. 그 후 제안된 알고리즘은 클러스터와 정점을 재배열하여 분할하는 과정을 반복함으로써 분할의 효율을 향상시켜간다. 이 방법을 여러 가지 그래프에 적용하여 향상된 결과를 얻었다.Abstract This paper addresses the post-processing algorithm for {{{{k-way hypergraph partitioning by using a cluster and vertex reordering method. The proposed algorithm applies to several {{{{k-way partitioning algorithm. Generally, the initial partition generating method is based on a vertex ordering algorithm. Our reordering algorithm construct an enhanced partitioning by iteratively partition the reodered clusters and vertices. Experimental results on several graphs demonstrate that reodering provides substantial enhancement.

Clusters Re-placement for Circuit Partitioning (클러스터 재배치를 이용한 회로분할)

  • Kim, Sang-Jin;Yun, Tae-Jin;Lee, Chang-Hee;Ahn, Gwang-Seon
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.6
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    • pp.1-8
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    • 1999
  • In circuit partitioning problem, work on vertex ordering have used to get good results for k-way partitioning. Body of work constructs a partitioning by first consturcting a vertex ordering, then splitting it. We present a re-placement algorithm for enhanced results by replacing and splitting the cllusters repeatedly. Experimental results on several circuits show that our approach achieves enhancement.

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Inverse of Frobenius Graphs and Flexibility

  • Aljouiee, Abdulla
    • Kyungpook Mathematical Journal
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    • v.45 no.4
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    • pp.561-570
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    • 2005
  • Weak Crossed Product Algebras correspond to certain graphs called lower subtractive graphs. The properties of such algebras can be obtained by studying this kind of graphs ([4], [5]). In [1], the author showed that a weak crossed product is Frobenius and its restricted subalgebra is symmetric if and only if its associated graph has a unique maximal vertex. A special construction of these graphs came naturally and was known as standard lower subtractive graph. It was a deep question that when such a special graph possesses unique maximal vertex? This work is to answer the question partially and to give a particular characterization for such graphs at which the corresponding algebras are isomorphic. A graph that follows the mentioned characterization is called flexible. Flexibility is to some extend a generalization of the so-called Coxeter groups and its weak Bruhat ordering.

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Color Data Compression for Three-dimensional Mesh Models Using Connectivity and Geometry Information (연결성 정보와 기하학 정보를 이용한 삼차원 메쉬 모델의 색상 정보 압축 방법)

  • Yoon, Young-Suk;Kim, Sung-Yeol;Ho, Yo-Sung
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.745-746
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    • 2006
  • In this paper, we propose a new predictive coding scheme for color data of three-dimensional (3-D) mesh models. We exploit connectivity and geometry information to improve coding efficiency. After ordering all vertices in a 3-D mesh model with a vertex traversal technique, we employ a geometry predictor to compress the color data. The predicted color can be acquired by a weighted sum of reconstructed colors for adjacent vertices using both angles and distances between the current vertex and adjacent vertices.

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On Diameter, Cyclomatic Number and Inverse Degree of Chemical Graphs

  • Sharafdini, Reza;Ghalavand, Ali;Ashrafi, Ali Reza
    • Kyungpook Mathematical Journal
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    • v.60 no.3
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    • pp.467-475
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    • 2020
  • Let G be a chemical graph with vertex set {v1, v1, …, vn} and degree sequence d(G) = (degG(v1), degG(v2), …, degG(vn)). The inverse degree, R(G) of G is defined as $R(G)={\sum{_{i=1}^{n}}}\;{\frac{1}{deg_G(v_i)}}$. The cyclomatic number of G is defined as γ = m - n + k, where m, n and k are the number of edges, vertices and components of G, respectively. In this paper, some upper bounds on the diameter of a chemical graph in terms of its inverse degree are given. We also obtain an ordering of connected chemical graphs with respect to the inverse degree.

Finite element modeling of multiplyconnected three-dimensional areas

  • Polatov, Askhad M.;Ikramov, Akhmat M.;Razmukhamedov, Daniyarbek D.
    • Advances in Computational Design
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    • v.5 no.3
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    • pp.277-289
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    • 2020
  • This article describes the technology for constructing of a multiply-connected three-dimensional area's finite element representation. Representation of finite-element configuration of an area is described by a discrete set that consist of the number of nodes and elements of the finite-element grid, that are orderly set of nodes' coordinates and numbers of finite elements. Corresponding theorems are given, to prove the correctness of the solution method. The adequacy of multiply-connected area topology's finite element model is shown. The merging of subareas is based on the criterion of boundary nodes' coincidence by establishing a simple hierarchy of volumes, surfaces, lines and points. Renumbering nodes is carried out by the frontal method, where nodes located on the outer edges of the structure are used as the initial front.

Hypergraph Partitioning By Using Reodered Simulated-anealing (정련법을 이용한 하이퍼그래프 분할)

  • Kim, Sang Jin;Ryoo, Myung Chun;Jung, Young Seok
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.9 no.4
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    • pp.11-19
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    • 2013
  • In this paper we present a reodered simulated-anealing algorithm which is capable of applying odering based k-way partitioned clusters. This method is used for improvement of the objectives of partitioning which are k-way partitioned by using odering algorithm. It changes the positions of the clusters and the vertices in each clusters. Reodered vertices are splitted by using DP-RP method and this process has an opportunity to improve the objective functions. This algorithm has advantages to improve the quality of the solutions for various purposes. Experimental results on several graphs demonstrate that proposed algorithm provides substantial enhancement.

A Minimum Cut Algorithm Using Maximum Adjacency Merging Method of Undirected Graph (무방향 그래프의 최대인접병합 방법을 적용한 최소절단 알고리즘)

  • Choi, Myeong-Bok;Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.1
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    • pp.143-152
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    • 2013
  • Given weighted graph G=(V,E), n=|V|, m=|E|, the minimum cut problem is classified with source s and sink t or without s and t. Given undirected weighted graph without s and t, Stoer-Wagner algorithm is most popular. This algorithm fixes arbitrary vertex, and arranges maximum adjacency (MA)-ordering. In the last, the sum of weights of the incident edges for last ordered vertex is computed by cut value, and the last 2 vertices are merged. Therefore, this algorithm runs $\frac{n(n-1)}{2}$ times. Given graph with s and t, Ford-Fulkerson algorithm determines the bottleneck edges in the arbitrary augmenting path from s to t. If the augmenting path is no more exist, we determine the minimum cut value by combine the all of the bottleneck edges. This paper suggests minimum cut algorithm for undirected weighted graph with s and t. This algorithm suggests MA-merging and computes cut value simultaneously. This algorithm runs n-1 times and successfully divides V into disjoint S and V sets on the basis of minimum cut, but the Stoer-Wagner is fails sometimes. The proposed algorithm runs more than Ford-Fulkerson algorithm, but finds the minimum cut value within n-1 processing times.