• Title/Summary/Keyword: Edges Population

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Fast Determination of Minimum Spanning Tree Based on Down-sizing Technique of Edges Population (간선 모집단 규모축소 기법을 적용한 빠른 최소신장트리 결정)

  • Lee, Sang-Un;Choi, Myeong-Bok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.1
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    • pp.51-59
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    • 2014
  • This paper suggests a method of lessening number of a graph's edges population in order to rapidly obtain the minimum spanning tree. The present minimum spanning tree algorithm works on all the edges of the graph. However, the suggested algorithm reduces the edges population size by means of applying a method of deleting maximum weight edges in advance from vertices with more than 2 valencies. Next, it applies a stopping criterion which ideally terminates Borůvka, Prim, Kruskal and Reverse-Delete algorithms for reduced edges population. On applying the suggested algorithm to 9 graphs, it was able to minimize averagely 83% of the edges that do not become MST. In addition, comparing to the original graph, edges are turned out to be lessened 38% by Borůvka, 37% by Prim, 39% by Kruskal and 73% by Reverse-Delete algorithm, and thereby the minimum spanning tree is obtained promptly.

Minimum Spanning Tree with Select-and-Delete Algorithm (선택-삭제 최소신장트리 알고리즘)

  • Choi, Myeong-Bok;Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.4
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    • pp.107-116
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    • 2013
  • This algorithm suggests a method in which a minimum spanning tree can be obtained fast by reducing the number of an algorithm execution. The suggested algorithm performs a select-and-delete process. In the select process, firstly, it performs Borůvka's first stage for all the vertices of a graph. Then it re-performs Borůvka's first stage for specific vertices and reduces the population of the edges. In the delete process, it deletes the maximum weight edge if any cycle occurs between the 3 edges of the edges with the reduced population. After, among the remaining edges, applying the valency concept, it gets rid of maximum weight edges. Finally, it eliminates the maximum weight edges if a cycle happens among the vertices with a big valency. The select-and-delete algorithm was applied to 9 various graphs and was evaluated its applicability. The suggested select process is believed to be the vest way to choose the edges, since it showed that it chose less number of big edges from 6 graphs, and only from 3 graphs, comparing to the number of edges that is to be performed when using MST algorithm. When applied the delete process to Kruskal algorithm, the number of performances by Kruskal was less in 6 graphs, but 1 more in each 3 graph. Also, when using the suggested delete process, 1 graph performed only the 1st stage, 5 graphs till 2nd stage, and the remaining till 3rd stage. Finally, the select-and-delete algorithm showed its least number of performances among the MST algorithms.

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.

Policy and Management of Exotic Sika Deer: A Case Study on the Effects of Cervus nippon yesonensis in Tae-an, Republic of Korea

  • Heo, Yoonjeong;Lee, Hyohyemi
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.3 no.2
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    • pp.115-121
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    • 2022
  • The Yezo sika deer (Cervus nippon yesoensis) is a subspecies of sika deer originated from Hokkaido, Japan. This paper is a study on the ecological impact caused by large mammals invading the ecosystem. Two pairs of deer were donated to the Agency for Defense Development in Taean in the late 1980s, and the population expanded to over 280 in 2018. The thermal imaging camera showed that the population ranged from 8 to 53 herds, divided into approximately 10 groups. It was confirmed that some of the herds had escaped the management area and invaded the nearby natural ecosystem, causing damage to cultivated land and natural vegetation. Herds of over 50 individuals have been studied in large grassland areas near drinking water sources such as streams and ponds. In places with excessive deer concentration, 1) feeding damage to herbs, shrubs and sub-trees, 2) tree withering due to antler-rubbing, and their habit of migrating along forest edges 3) excessive soil loss on slopes, 4) destruction of herbaceous layers due to compaction, and finally 5) damage to infrastructure were also investigated. As such, it is expected that the results of this study on the ecological and economic damage of Yezo sika deer can be used to predict the impact of other exotic sika deer in South Korea with similar behavioral characteristics and to establish a management plan.

Particle Size Effect: Ru-Modified Pt Nanoparticles Toward Methanol Oxidation

  • Kim, Se-Chul;Zhang, Ting;Park, Jin-Nam;Rhee, Choong-Kyun;Ryu, Ho-Jin
    • Bulletin of the Korean Chemical Society
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    • v.33 no.10
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    • pp.3331-3337
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    • 2012
  • Ru-modified Pt nanoparticles of various sizes on platelet carbon nanofiber toward methanol oxidation were investigated in terms of particle size effect. The sizes of Pt nanoparticles, prepared by polyol method, were in the range of 1.5-7.5 nm and Ru was spontaneously deposited by contacting Pt nanoparticles with the Ru precursor solutions of 2 and 5 mM. The Ru-modified Pt nanoparticles were characterized using transmission electron microscopy, X-ray photoelectron spectroscopy and cyclic voltammetry. The methanol oxidation activities of Ru-modified Pt nanoparticles, measured using cyclic voltammetry and chronoamperometry, revealed that when the Pt particle size was less than 4.3 nm, the mass specific activity was fairly constant with an enhancement factor of more than 2 at 0.4 V. However, the surface area specific activity was maximized on Pt nanoparticles of 4.3 nm modified with 5 mM Ru precursor solution. The observations were discussed in terms of the enhancement of poison oxidation by Ru and the population variation of Pt atoms at vertices and edges of Pt nanoparticles due to selective deposition of Ru on the facets of (111) and (100).

Internet Governance & Politics of Expertise (인터넷 거버넌스와 전문성의 정치)

  • Kim, Ji-Yeon
    • Review of Korean Society for Internet Information
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    • v.14 no.3
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    • pp.5-20
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    • 2013
  • ICANN has been governing the Domain Name System(DNS) "technically" since 1998. The architecture is called Internet Governance, and it brings about many different discourses; "What does that govern?", "Who delegate its role to ICANN?"," How could the regime ensure fairness?" etc. This article will analyze on Internet Governance by applying the government approach of Foucault, and try to compare two parts, the 'core' and the 'edge' of Internet Governance for method. Whereas the 'core' of it refers the site that be governed by the formal contract directly, the 'edge' as the rest of it means informal friendly relations with ICANN. The 'core' rule was stemmed from technological community such as IAB or IETF historically. They had invented new world and its population to integrate the technical order as protocol and the semiotic order as language, that be based on new government mode. On the other hand, ".KR" domain, one of the 'edges', has been evolved into more heterogeneous system, through contest and conflict between traditional state and Internet Governance. The governed object of ".KR" domain is situated in the crossing of each other the 'protocol user', the 'language-semiotic user' and the' geographical resident'. Here the 'geographical resident' rule was weird for DNS, so that shows the internal lack of Internet Governance. It needs to move to the concept of 'Hangeul(Korean-language) user' rather than the 'geographical resident'.

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Regenwurmpopulationen in ackerbaulich ge-nutzten Flachen und deren Randbereichen. I.Ostliches Harzvorland

  • christine Hemmann;Leithold, und-Gunter
    • Korean Journal of Organic Agriculture
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    • v.3 no.1
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    • pp.23-42
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    • 1994
  • This paper studied earthworm populations in fields under practical cultivation in the Eastern Harzforeland (Germany). The examined sites differed insignificantly in their climatic and soil conditions. The examination was a comparison between a field and a narrow edge or meadow. A combination of Oktett method and handsortin was used. The five different habitates seven earthworm species were discoverd. The most frequently foundd were A. rosea, A. caliginosa, and A. chlorotica. There were clear differences in species between the habitates of each site. Generally the edge or the meadow contained one (Zoeberitz) or two (Zscherben) more species than the field. The composition of species differed between 1990 and 1992. In the dry Autumn of 1991 there were less species found at both sites. The occurance of earthworm species depends on the weather. Moisture influencing similiarity of abundance and bio-mass were recorded in three out of four habitates. Starting on a high level in Autumn 1990 the abundance as well as biomass decreased until Autumn 1991 and increased the following year. The number from 1990 were never reached again during the examination. One year of normal precipita-tion was not enough to return the population to the beginning level. Great differences in the number of earthworms between the compared habitats suggest that the edges and meadows are a potential immigration source into a field which is poor on earthworms. Structrues of distribution near the edge refer to a migration from a high populated edge into an almost empty field.

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Digital Divide in Riyadh Neighborhoods: A Spatial Analysis

  • Rawan, Almutlaq;Shuruq, Alshamrani;Ohoud, Alhaqbani;Fatimah, Altamimi;Ghadah, Alammaj;Omer, Alrwais
    • International Journal of Computer Science & Network Security
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    • v.23 no.1
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    • pp.17-24
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    • 2023
  • The objective of this paper is to use Geographical Information Systems for identifying Digital Divide in Riyadh Neighborhoods, Saudi Arabia. Geo-database was created that includes Streets, Neighborhoods, ICT Access Data and Coverage Map for Riyadh. We used QGIS and overlay for analysis, intersection selected as tool for this paper. The results indicate that after analyzing the use of information communication technology in all regions of the Kingdom it turns that Riyadh, Ash Sharqiyyah and Makkah in average with percentage 50%, While Al Jawf, Al Madinah, and Najran are the least with percentage 42%. Then we focused on Riyadh to analyze the digital divide because it is the capital of Saudi Arabia and occupations the highest percent of communications towers in the KSA due to population density. Regarding coverage of the 4G, the neighborhoods at the center have recorded very high coverage score. While neighborhoods at the edges of the city have low values of coverage score. Same for 3G, it is more intense in the center and the coverage percentage is higher than 4G. For 2G we found it had the highest coverage compared to 3G or 4G

Elite Ant System for Solving Multicast Routing Problem (멀티캐스트 라우팅 문제 해결을 위한 엘리트 개미 시스템)

  • Lee, Seung-Gwan
    • Journal of the Korea Society of Computer and Information
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    • v.13 no.3
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    • pp.147-152
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    • 2008
  • Ant System(AS) is new meta heuristic for hard combinatorial optimization problem. It is a population based approach that uses exploitation of positive feedback as well as greedy search. It was first proposed for tackling the well known Traveling Salesman Problem. In this paper, AS is applied to the Multicast Routing Problem. Multicast Routing is modeled as the NP-complete Steiner tree problem. This is the shortest path from source node to all destination nodes. We proposed new AS to resolve this problem. The proposed method selects the neighborhood node to consider all costs of the edge and the next node in state transition rule. Also, The edges which are selected elite agents are updated to additional pheromone. Simulation results of our proposed method show fast convergence and give lower total cost than original AS and $AS_{elite}$.

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Ant Colony System for solving the traveling Salesman Problem Considering the Overlapping Edge of Global Best Path (순회 외판원 문제를 풀기 위한 전역 최적 경로의 중복 간선을 고려한 개미 집단 시스템)

  • Lee, Seung-Gwan;Kang, Myung-Ju
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.3
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    • pp.203-210
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    • 2011
  • Ant Colony System is a new meta heuristics algorithms to solve hard combinatorial optimization problems. It is a population based approach that uses exploitation of positive feedback as well as greedy search. It was first proposed for tackling the well known Traveling Salesman Problem. In this paper, we propose the searching method to consider the overlapping edge of the global best path of the previous and the current. This method is that we first determine the overlapping edge of the global best path of the previous and the current will be configured likely the optimal path. And, to enhance the pheromone for the overlapping edges increases the probability that the optimal path is configured. Finally, the performance of Best and Average-Best of proposed algorithm outperforms ACS-3-opt, ACS-Subpath and ACS-Iter algorithms.