• Title/Summary/Keyword: 최소신장 트리

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Minimum Spanning Tree Algorithm for Deletion of Maximum Weight Edge within a Cycle (한 사이클 내에서 최대 가중치 간선을 제거하기 위한 최소 신장트리 알고리즘)

  • Choi, Myeong-Bok;Han, Tae-Yong;Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.2
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    • pp.35-42
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    • 2014
  • This paper suggests a method that obtains the minimum spanning tree (MST) far more easily and rapidly than the present ones. The suggested algorithm, firstly, simplifies a graph by means of reducing the number of edges of the graph. To achieve this, it applies a method of eliminating the maximum weight edge if the valency of vertices of the graph is equal to or more than 3. As a result of this step, we can obtain the reduced edge population. Next, it applies a method in which the maximum weight edge is eliminated within the cycle. On applying the suggested population minimizing and maximum weight edge deletion algorithms to 9 various graphs, as many as the number of cycles of the graph is executed and MST is easily obtained. It turns out to lessen 66% of the number of cycles and obtain the MST in at least 2 and at most 8 cycles by only deleting the maximum weight edges.

A Polynomial Time Approximation Scheme for Enormous Euclidean Minimum Spanning Tree Problem (대형 유클리드 최소신장트리 문제해결을 위한 다항시간 근사 법)

  • Kim, In-Bum
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.48 no.5
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    • pp.64-73
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    • 2011
  • The problem of Euclidean minimum spanning tree (EMST) is to connect given nodes in a plane with minimum cost. There are many algorithms for the polynomial time problem as EMST. However, for numerous nodes, the algorithms consume an enormous amount of time to find an optimal solution. In this paper, an approximation scheme using a polynomial time approximation scheme (PTAS) algorithm with dividing and parallel processing for the problem is suggested. This scheme enables to construct a large, approximate EMST within a short duration. Although initially devised for the non-polynomial problem, we employ naive PTAS to construct a vast EMST with dynamic programming. In an experiment, the approximate EMST constructed by the proposed scheme with 15,000 input terminal nodes and 16 partition cells shows 89% and 99% saving in execution time for the serial processing and parallel processing methods, respectively. Therefore, our scheme can be applied to obtain an approximate EMST quickly for numerous input terminal nodes.

Problem Solving Path Algorithm in Distance Education Environment

  • Min, Youn-A
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.6
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    • pp.55-61
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    • 2021
  • As the demand for distance education increases, it is necessary to present a problem solving path through a learning tracking algorithm in order to support the efficient learning of learners. In this paper, we proposed a problem solving path of various difficulty levels in various subjects by supplementing the existing learning tracking algorithm. Through the data set obtained through the path for solving the learner's problem, the path through the prim's minimum Spanning tree was secured, and the optimal problem solving path through the recursive neural network was suggested through the path data set. As a result of the performance evaluation of the contents proposed in this paper, it was confirmed that more than 52% of the test subjects included the problem solving path suggested in the problem solving process, and the problem solving time was also improved by more than 45%.

Water Region Segmentation Method using Graph Algorithm (그래프 알고리즘을 이용한 강물 영역 분할 방법)

  • Park, Sang-Hyun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.4
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    • pp.787-794
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    • 2018
  • The various natural disasters such as floods and localized heavy rains are increasing due to the global warming. If a natural disaster can be detected and analyzed in advance and more effectively, it can prevent enormous damage of natural disasters. Recent development in visual sensor technologies has encouraged various studies on monitoring environments including rivers. In this paper, we propose a method to detect water regions from river images which can be exploited for river surveillance systems using video sensor networks. In the proposed method, we first segment a river image finely using the minimum spanning tree algorithm. Then, the seed regions for the river region and the background region are set by using the preliminary information, and each seed region is expanded by merging similar regions to segment the water region from the image. Experimental results show that the proposed method separates the water region from a river image easier and accurately.

A Tree-based Greedy Algorithm for Minimum Power Broadcast in Wireless Networks (무선 네트워크에서 최소 전력 브로드캐스트를 위한 트리 기반 탐욕 알고리즘)

  • Lee, Dong-ho;Jang, Kil-woong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.21 no.5
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    • pp.921-928
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    • 2017
  • Unlike wired networks, broadcasting in wireless networks can transmit data to several nodes at a time in a single transmission. The omnidirectional broadcasting of node in wireless networks simultaneously reaches all neighboring nodes. In this paper, we propose a greedy algorithm to solve the minimum power broadcasting problem that minimizes the total transmission power when broadcasting in wireless networks. The proposed algorithm uses a neighborhood list which is a set of nodes that can transmit messages within the maximum transmission range of each node, and among the transmitting nodes that have received the data, the node having the largest number of the neighboring nodes firstly transmits the data to neighboring node. The performance of the proposed algorithm was evaluated by computer simulation, and was compared with existing algorithms in terms of total transmission power and broadcasting frequency for broadcasting to all nodes. Experiment results show that the proposed algorithm outperforms the conventional algorithms.

A Pareto Ant Colony Optimization Algorithm for Application-Specific Routing in Wireless Sensor & Actor Networks (무선 센서 & 액터 네트워크에서 주문형 라우팅을 위한 파레토 개미 집단 최적화 알고리즘)

  • Kang, Seung-Ho;Choi, Myeong-Soo;Jung, Min-A;Lee, Seong-Ro
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.4B
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    • pp.346-353
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    • 2011
  • Routing schemes that service applications with various delay times, maintaining the long network life time are required in wireless sensor & actor networks. However, it is known that network lifetime and hop count of trees used in routing methods have the tradeoff between them. In this paper, we propose a Pareto Ant Colony Optimization algorithm to find the Pareto tree set such that it optimizes these both tradeoff objectives. As it enables applications which have different delay times to select appropriate routing trees, not only satisfies the requirements of various multiple applications but also guarantees long network lifetime. We show that the Pareto tree set found by proposed algorithm consists of trees that are closer to the Pareto optimal points in terms of hop count and network lifetime than minimum spanning tree which is a representative routing tree.

Efficient Multicast Tree Algorithm for Acceptable Delay and Minimum Delay Variation (지연시간 한계의 만족과 효율적인 최소 지연변이 멀티캐스트 트리 생성 알고리즘)

  • Kim Moon-Seong;Choo Hyun-Seung;Lee Young-Ro
    • The KIPS Transactions:PartC
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    • v.12C no.1 s.97
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    • pp.105-110
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    • 2005
  • With the proliferation of multimedia group applications, the construction of multicast trees satisfying QoS requirements is becoming a problem of prime importance. In this paper, we study the delay- and delay variation-bounded multicast tree (DVBMT) problem which is NP-complete. The problem is to construct a spanning tree for destination node, which has the minimized multicast delay variation, and the delay on the path from the source to each destination is bounded. A solution to this problem is required to provide decent real-time communication services such as on-line games, shopping, and teleconferencing. Performance comparison shows that the proposed scheme outperforms DDVCA which is known to be effective so far in any network topology. The enhancement is up to about $3.6{\%}{\~}11.1{\%}$ in terms of normalized surcharge for DUVCA. The time complexity of our algorithm is $O(mn^2)$.

Cluster-based Distributed Topology Control for Wireless Sensor Networks (무선 센서네트워크에서 클러스터 기반의 분산형 토폴로지 제어)

  • Kong, Young-Bae;Shim, Il-Joo;Chang, Kyung-Bae;Park, Gwi-Tae
    • Proceedings of the KIEE Conference
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    • 2006.07d
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    • pp.2144-2145
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    • 2006
  • 무선 센서네트워크는 환경 모니터링과 같은 다양한 어플리케이션을 갖고 있는 향상된 기술이다. 이를 구성하는 각각의 노드들은 특정지역에 분산되어 네트워크를 구성해서 해당 지역의 이벤트나 정보를 주기적으로 사용자에게 전달한다. 이때 토폴로지 제어는 네트워크의 수명과 통신에 중요한 영향을 미치는 요인이다. 본 논문에서는 무선 센서 네트워크에서 클러스터 기반의 분산형 토폴로지 제어기법을 제안한다. 이 기법은 먼저 네트워크를 클러스터 기반의 계층적인 구조로 구성한 후, 각각의 클러스터 내에서 최소 신장트리 (Minimum Spanning Tree)를 이용하여 토폴로지 제어를 수행한다. 이를 통해 무선센서 네트워크는 에너지 효율적이며 분산된 토폴로지 제어를 수행할 수 있고, 결과적으로 네트워크의 수명을 연장할 수 있다.

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Cluster-based keyword Ranking Technique (클러스터 기반 키워드 랭킹 기법)

  • Yoo, Han-mook;Kim, Han-joon
    • Annual Conference of KIPS
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    • 2016.10a
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    • pp.529-532
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    • 2016
  • 본 논문은 기존의 TextRank 알고리즘에 상호정보량 척도를 결합하여 군집 기반에서 키워드 추출하는 ClusterTextRank 기법을 제안한다. 제안 기법은 k-means 군집화 알고리즘을 이용하여 문서들을 여러 군집으로 나누고, 각 군집에 포함된 단어들을 최소신장트리 그래프로 표현한 후 이에 근거한 군집 정보량을 고려하여 키워드를 추출한다. 제안 기법의 성능을 평가하기 위해 여행 관련 블로그 데이터를 이용하였으며, 제안 기법이 기존 TextRank 알고리즘보다 키워드 추출의 정확도가 약 13% 가량 개선됨을 보인다.

Load Balancing Technique to Release Multiple Overloading of Distribution Feeders using Minimum Spanning Tree (최소신장트리를 이용한 배전선로 다중 과부하 해소 방법)

  • Oh, Seong-Hyeon;Lee, Han-Seong;Kim, Young-Kook;Lim, Seong-Il
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.2
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    • pp.33-39
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    • 2015
  • Power supplying capacity of the distribution feeder should be maintained within thermal capacity of the wire. This paper presents the minimum spanning tree based load balancing technique to release multiple overloading of distribution feeders. In order to minimize number of involved backup feeders, Dijkstra and Prim algorithm are adopted to construct minimum spanning tree. Simulation testing result based on part of KEPCO's commercial distribution systems shows effectiveness of proposed scheme.