• Title/Summary/Keyword: Kruskal

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An Efficient Implementation of Kruskal's and Reverse-Delete Minimum Spanning Tree Algorithm (Kruskal과 역-삭제 최소신장트리 알고리즘의 효율적 구현 방법)

  • Choi, Myeong-Bok;Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.2
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    • pp.103-114
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    • 2013
  • This paper suggests a method to reduce the number of performances of Kruskal and Reverse-delete algorithms. Present Kruskal and Reverse-delete algorithms verify whether the cycle occurs within the edges of the graph. For this reason, they have problems of unnecessarily performing extra algorithms from the edges, even though they've already obtained the minimum spanning tree. This paper, first of all, suggests the 1st method which reduces the no. of performances by introducing stop point criteria of algorithm, but at the same time, performs algorithms from all the edges, just like how Kruskal and Reverse-delete algorithms. Next, it suggests the 2nd method which finds the minimum spanning tree from the remaining edges after getting rid of all the unnecessary edges which are considered not to affect the minimum spanning tree. These suggested methods have an effect of terminating algorithm at least 1.4 times and at most 3.86times than Kruskal and Reverse-delete algorithms, when applied to the real graphs. We have found that the 2nd method of the Reverse-delete algorithm has the fastest speed in terminating an algorithm, among 4 algorithms which are results of the 2 suggested methods being applied to 2 algorithms.

A Study on Distribution System Reconfiguration using GA and Kruskal Algorithm (유전 알고리즘과 Kruskal 알고리즘을 이용한 배전계통 재구성에 관한 연구)

  • An, Jin-O;Kim, Se-Ho
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.49 no.3
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    • pp.118-123
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    • 2000
  • This paper presents an efficient algorithm for loss reduction and load balancing by sectionalizing switch operation in large scale distribution system of radial type. We use Genetic algorithm and Kruskal algorithm to solve distribution system reconfiguration. Genetic algorithm is used to minimize objective function including loss and load balancing items. Kruskal algorithm is used to satisfy the radial condition of distribution system. The experimental results show that the proposed method has the ability to search a good solution regardless of initial configuration and size of system.

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Smooth Tests for Seasonality (평활 계절성 검정)

  • Lee, Geung-Hee
    • The Korean Journal of Applied Statistics
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    • v.24 no.1
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    • pp.45-59
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    • 2011
  • When using X-12-ARIMA for seasonal adjustment, we usually check whether the series has stable seasonality or not via D8 F-tests, Kruskal-Wallis test, and the spectral diagnostics. In this paper, we develop several smooth tests for seasonality based on a Fourier series to improve the spectral diagnostics of X-12-ARIMA. A simulation study is conducted to compare five smooth tests for seasonality and X-12-ARIMA's D8 F-test an Kruskal-Wallis test. The simulation study shows that smooth tests for seasonality performed well compared with D8 F-tests and a Kruskal-Wallis test.

Hybrid Minimum Spanning Tree Algorithm (하이브리드 최소신장트리 알고리즘)

  • Lee, Sang-Un
    • The KIPS Transactions:PartA
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    • v.17A no.3
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    • pp.159-166
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    • 2010
  • In this paper, to obtain the Minimum Spanning Tree (MST) from the graph with several nodes having the same weight, I applied both Bor$\dot{u}$vka and Kruskal MST algorithms. The result came out to such a way that Kruskal MST algorithm succeeded to obtain MST, but not did the Prim MST algorithm. It is also found that an algorithm that chooses Inter-MSF MWE in the $2^{nd}$ stage of Bor$\dot{u}$vka is quite complicating. The $1^{st}$ stage of Bor$\dot{u}$vka has an advantage of obtaining Minimum Spanning Forest (MSF) with the least number of the edges, and on the other hand, Kruskal MST algorithm has an advantage of always obtaining MST though it deals with all the edges. Therefore, this paper suggests an Hybrid MST algorithm which consists of the merits of both Bor$\dot{u}$vka's $1^{st}$ stage and Kruskal MST algorithm. When applied additionally to 6 graphs, Hybrid MST algorithm has a same effect as that of Kruskal MST algorithm. Also, comparing the algorithm performance speed and capacity, Hybrid MST algorithm has shown the greatest performance Therefore, the suggested algorithm can be used as the generalized MST algorithm.

KRUSKAL-WALLIS ONE-WAY ANALYSIS OF VARIANCE BASED ON LINEAR PLACEMENTS

  • Hong, Yicheng;Lee, Sungchul
    • Bulletin of the Korean Mathematical Society
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    • v.51 no.3
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    • pp.701-716
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    • 2014
  • The limiting distribution for the linear placement statistics under the null hypotheses has been provided by Orban and Wolfe [9] and Kim [5] when one of the sample sizes goes to infinity, and by Kim, Lee and Wang [6] when the sample sizes of each group go to infinity simultaneously. In this paper we establish the generalized Kruskal-Wallis one-way analysis of variance for the linear placement statistics.

A Note on Kruskal's Theorem

  • Lee, Gyesik;Na, Hyeon-Suk
    • Korean Journal of Logic
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    • v.15 no.3
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    • pp.307-322
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    • 2012
  • It is demonstrated that there is a simple, canonical way to show the independency of the Friedman-style miniaturization of Kruskal's theorem with respect to $(\prod_{2}^{1}-BI)_0$. This is done by a non-trivial combination of some well-known, non-trivial previous works concerning directly or indirectly the (proof-theoretic) strength of Kruskal's theorem.

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Watershed Delineation Algorithm Using Kruskal's Algorithm and Triangulated Irregular Network (크루스칼 알고리즘과 불규칙 삼각망을 이용한 유역 추출 알고리즘)

  • Park Mee-Jeong;Heo Hyun;Kim Tae-Gon;Suh Kyo;Lee Jeong-Jae
    • Journal of The Korean Society of Agricultural Engineers
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    • v.48 no.4
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    • pp.3-12
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    • 2006
  • Watershed is the land area that contributes runoff to an outlet point. To delineate an watershed, watershed delineation using GIS that contains grid data structure is the most general method. Some researchers have studied to implement algorithms that revise the TIN topography since it is difficult to delineate watershed boundary more accurately. In this study kruskal's greedy algorithm and triangulated irregular network (TIN) were used to delineate a watershed. This method does not require a conversion from to DEM in grid and automatically obtain(generates) the oulet points. Delineation algorithm was tested in Geosan-gun, Chung-cheongbuk-do and get small watershed areas. Finally, kruskal's algorithm could operate more precisely with revision algorithm.

Proposal of Minimum Spanning Tree Algorithm using 2-Edges Connected Grap (2-간선 연결 그래프를 사용한 최소신장트리 알고리즘 제안)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.4
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    • pp.233-241
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    • 2014
  • This paper suggests a fast minimum spanning tree algorithm which simplify the original graph to 2-edge connected graph, and using the cycling property. Borůvka algorithm firstly gets the partial spanning tree using cycle property for one-edge connected graph that selects the only one minimum weighted edge (e) per vertex (v). Additionally, that selects minimum weighted edge between partial spanning trees using cut property. Kruskal algorithm uses cut property for ascending ordered of all edges. Reverse-delete algorithm uses cycle property for descending ordered of all edges. Borůvka and Kruskal algorithms always perform |e| times for all edges. The proposed algorithm obtains 2-edge connected graph that selects 2 minimum weighted edges for each vertex firstly. Secondly, we use cycle property for 2-edges connected graph, and stop the algorithm until |e|=|v|-1 For actual 10 benchmark data, The proposed algorithm can be get the minimum spanning trees. Also, this algorithm reduces 60% of the trial number than Borůvka, Kruskal and Reverse-delete algorithms.

Generalized Borůvka's Minimum Spanning Tree Algorithm (일반화된 Borůvka 최소신장트리 알고리즘)

  • Choi, Myeong-Bok;Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.6
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    • pp.165-173
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    • 2012
  • Given a connected, weighted, and undirected graph, the Minimum Spanning Tree (MST) should have minimum sum of weights, connected all vertices, and without any cycle taking place. Borůvka Algorithm is firstly suggested as an algorithm to evaluate the MST, but it is not widely used rather than Prim and Kruskal algorithms. Borůvka algorithm selects the Minimum Weight Edge (MWE) from each vertex with distinct weights in $1^{st}$ stage, and selects the MWE from each MSF (Minimum Spanning Forest) in $2^{nd}$ stage. But the cycle check and the number of MSF in $1^{st}$ stage and $2^{nd}$ stage are difficult to implication by computer program even if it is easy to verify visually. This paper suggests the generalized Borůvka Algorithm, This algorithm selects all of the same MWEs for each vertex, then checks the cycle and constructs MSF for ascending sorted MWEs. Kruskal method bring into this process. if the number of MSF greats then 1, this algorithm selects MWE from ascending sorted inter-MSF edges. The generalized Borůvka algorithm is verified its application by being applied to the 7 graphs with the many minimum weights or distinct weight edges for any vertex. As a result, the generalized Borůvka algorithm is less required for cycle verification then the Kruskal algorithm. Therefore, the generalized Borůvka algorithm is more fast to obtain MST then Kruskal algorithm.

Effects of Habitat Environment on Bird Community in Forest (산림지역에서 서식지 환경이 조류군집에 미치는 영향)

  • Kim, Jung-Soo;Shin, Ju-Ryul;Lee, Hwa-Su;Koo, Tae-Hoe
    • Journal of Environmental Policy
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    • v.7 no.3
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    • pp.141-160
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    • 2008
  • The effects of disturbance on bird community were studied in Ssanggok Valley and Beopju Temple area, Songni Mt. National Park in $2006{\sim}2008$. We divided three sites by habitat condition such as traffic road(strong disturbance), trail(medium) and control(weak) site. During breeding and non-breeding seasons(n=12), number of species, number of individuals, species diversity and density did not differ among three sites, but in breeding season(n=9), number of species(Kruskal Wallis, $x^2$=10.32, p=0.006), number of individuals(Kruskal Wallis, $x^2$=7.118, p=0.028) and species diversity of birds(Kruskal Wallis, $x^2$=9.847, p=0.007) were significantly higher in trail site with medium disturbance than in other sites. In breeding season, nesting and foraging guild rate were not different among three sites. In guild analysis, hole was the highest nesting guild and canopy was the highest foraging guild in three sites.

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