• Title/Summary/Keyword: Trees

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Embedding Complete binary trees in Binomial trees (완전이진트리의 이항트리에 대한 임베딩)

  • 윤수민;최정임형석
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.289-292
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    • 1998
  • Trees are the underlying structure for divide-and-conquer algorithms and the graphs that provide the solution spaces for NP-complete problems. Complete binary trees are the basic structure among trees. Therefore, if complete binary trees can be embedded in binomial trees, the algorithms which are provided by complete binary trees can be performed efficiently on the interconnection networks which have binomial trees as their subgraphs or in which binomial trees can be embedded easily. In this paper, we present dilation 2 embedding of complete binary trees in binomial trees.

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Embedding Binomial Trees in Complete Binary Trees (이항트리의 완전이진트리에 대한 임베딩)

  • 윤수만;최정임형석
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.479-482
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    • 1998
  • Whether a given tree is a subgraph of the interconnection network topology is one of the important problem in parallel computing. Trees are used as the underlying structure for divide and conquer algorithms and provide the solution spaces for NP-complete problems. Complete binary trees are the basic structure among those trees. Binomial trees play an important role in broadcasting messages in parallel networks. If binomial trees can be efficiently embedded in complex binary trees, broadcasting algorithms can be effeciently performed on the interconnection networks. In this paper, we present average dilation 2 embedding of binomial trees in complete binary trees.

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The Present Conditions and Remedial Measures of Street Trees in Miryang City (밀양시 가로수 현황과 개선방안)

  • 백재봉;조재우;최송현
    • Journal of Environmental Science International
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    • v.12 no.6
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    • pp.565-572
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    • 2003
  • The aim of this research is to survey the census of street trees and to provide remedial measures for street trees management to Miryang City. To do this, survey was carried out 16 region units in Miryang City. Through the survey, the current status of street trees’ map was made using automated map. From the results, it is turned out that 17,079 trees have been planted in Miryang City. The major species of street trees are Prunus serrulata var. spontanea(41.6%), Ginkgo biloba(26.1%), Pinus thunbergiana(13.3%) and the others are 12 species(19.0%). By the region units, Samrangjin-Eub is the most that 2,308 street trees are planted, and the next is Chodong-Myon(2,206 trees). The littlest street trees planted region is Cheongdo-Myon. In the results of comparison the component of street trees with other municipal cities, e.g. Seoul, Incheon, Kwangyang etc., only a few street trees have been planted so many in Miryang City. So, Miryang City indicated high proportionate street trees planting ratio. The suggested remedial measures are consisted with identifying the each street, increasing the green area by accepting the suitable street tree planting model, improving the physiological growth condition and systematic management with GIS.

Low-delay Node-disjoint Multi-path Routing using Complementary Trees for Industrial Wireless Sensor Networks

  • Liu, Luming;Ling, Zhihao;Zuo, Yun
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.11
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    • pp.2052-2067
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    • 2011
  • Complementary trees are two spanning trees rooted at the sink node satisfying that any source node's two paths to the sink node on the two trees are node-disjoint. Complementary trees routing strategy is a special node-disjoint multi-path routing approach. Several complementary trees routing algorithms have been proposed, in which path discovery methods based on depth first search (DFS) or Dijkstra's algorithm are used to find a path for augmentation in each round of path augmentation step. In this paper, a novel path discovery method based on multi-tree-growing (MTG) is presented for the first time to our knowledge. Based on this path discovery method, a complementary trees routing algorithm is developed with objectives of low average path length on both spanning trees and low complexity. Measures are employed in our complementary trees routing algorithm to add a path with nodes near to the sink node in each round of path augmentation step. The simulation results demonstrate that our complementary trees routing algorithm can achieve low average path length on both spanning trees with low running time, suitable for wireless sensor networks in industrial scenarios.

Structure of Secondary Xylem and Cambial Initials in Pinus koraiensis S. et Z. Grown in Arid Soil (건지에서 자란 잣나무(Pinus koraiensis S. et Z.)의 이기목부 및 형성층구조의 변화)

  • 임동옥
    • Journal of Plant Biology
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    • v.36 no.1
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    • pp.35-42
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    • 1993
  • This study deals with the effect of dwarf growth for the wood and the structural changes of cambium in Pinus koraiensis subjected to water stress. The length and wall thickness of tracheary elements in dwarf trees was shorter and thicker than that in normal trees. The redial width and cell number of the annual rings are narrower and smaller in dwarf trees than those in normal trees. In serial tangential sections, the frequency of anticlinal division is low and loss of cambial initials is small in dwarf trees. The length of cambial initials in water deficit, trees are slightly shorter than that in normal trees, and the instructive growth of cambial initials during differentiation of xylem mother cells is inactive in dwarf trees. Thus, it is interpreted that the shortening of tracheary elements in dwarf trees is due to the fact that the length of cambial initials are shortened and the intrusive growth of those during differentiation of xylem mother cells is inactive. The structural variations in the wood of naturally occurring dwarf trees are similar to those of trees subjected to artificial water stress. Therefore, it is suggested that the variation of xylem element in dwarf trees are related to water conditions.

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A Study on the Preserving, Replanting and Recycling of Reconstruction Estates' Existing Trees for Sustainable Conversion - Focused on the Case of Greenbank System by UR Agency in Japan - (주거단지의 지속전환을 위한 기존 수목 보존과 활용 - 일본 UR도시기구의 그린뱅크 시스템을 중심으로 -)

  • Yoo, Soon Seon
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.36 no.2
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    • pp.109-116
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    • 2020
  • There are many existing trees are to be damaged by reconstruction of large housing estates. The purpose of this study was to find out sustainable conversion methods of Greenbank system by UR Agency. Greenbank system is divided 3 parts as Preserving, Replanting, Recycling of Existing trees. Literature and institutional review and site survey of 5 reconstruction housing estate were the methods for the following findings. The results are follows. Firstly, Because of feasibility of reconstruction, existing trees are preserving at boundary space of reconstruction housing estates. Secondly, existing trees are preserving at inner space for remember of resettlement as symbolic trees. It is conformed by residents participation with UR Agency and city official. Thirdly, Preserving and replanting trees are recorded signboard in the reconstruction housing estates, and preserving of trees are developed as Green workshop by residents. Fourthly, Besides Preserving and Replanting trees, the other trees are recycling as bench, play equipment, planter, etc. And it is remained symbol of reconstruction housing estates. Fifthly, District planning as a institutional, Guidelines as a noninstitutional method are very efficiently for preserving trees. But a part of this study can be adapt reconstruction housing estates in Korea. The results of this study are expected to serve some clue for dealing with the practice of sustainable conversion in housing estates.

An Analysis of Permanantly Shaded Areas and the Defect Rate of Landscape Trees in Apartment Complexes Using Daylight Simulations

  • Park, Sang Wook
    • Journal of People, Plants, and Environment
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    • v.23 no.3
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    • pp.333-345
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    • 2020
  • Background and objective: The purpose of this study was to provide basic data on trees that can be used for planting design and construction for permanently shaded areas by grasping the growth status of trees according to the daylight conditions of the outdoor spaces of apartment complexes. Methods: On the recently completed apartment complexes, daylight conditions were analyzed by using daylight simulations utilizing Solar Access Analysis of Ecotect Analysis. With a criteria for assessment of tree condition, the defect rate of trees planted in permanently shaded areas and green spaces with good daylight conditions was analyzed to suggest trees applicable to permanently shaded areas. The first tree survey was conducted from November 18, 2019 to February 15, 2020, focusing on trees planted in permanently shaded areas, and the second tree survey of all the trees planted on the study sites including permanently shaded areas was conducted from March 16 to March 30, 2020. Results: Evergreen trees which are classified as shade intolerant trees including Pinus densiflora, Thuja occidentalis, and Abies holophylla showed a higher defect rate of trees among the trees planted in permanently shaded areas. Taxus cuspidata, Zelkova serrata, Cornus kousa, Chionanthus retusus and Acer palmatum which are classified as shade tolerant trees and shade moderate tolerance trees seemed to be able to be used in the plant design of permanently shaded areas in apartment complexes because the trees showed good growth and a low tree defect rate. In addition, although it was excluded from the analysis due to a small number of samples, Sorbus commixta and Prunus cerasifera var. atropurpurea also can be used for planting in permanently shaded areas. Conclusion: The daylight simulation technique used to analyze permanent shaded areas in this study can be used as an analysis tool considering the daylight environment at the stages of design and construction, and additional research will be required to analyze tree growth according to daylight conditions through data accumulation and monitoring by managing records throughout the entire life cycle of trees in the process of planting and maintenance.

Induction of Decision Tress Using the Threshold Concept (Threshold를 이용한 의사결정나무의 생성)

  • 이후석;김재련
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.45
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    • pp.57-65
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    • 1998
  • This paper addresses the data classification using the induction of decision trees. A weakness of other techniques of induction of decision trees is that decision trees are too large because they construct decision trees until leaf nodes have a single class. Our study include both overcoming this weakness and constructing decision trees which is small and accurate. First, we construct the decision trees using classification threshold and exception threshold in construction stage. Next, we present two stage pruning method using classification threshold and reduced error pruning in pruning stage. Empirical results show that our method obtain the decision trees which is accurate and small.

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A Study of Effective Methods for the Formation of Calluses on Trees after Surgical Operation (외구수술 후 수목의 효율적인 Callus 형성 방법에 관한 연구)

  • Ha, Tae-Joo;Lee, Jae-Keun;Kwon, Oh-Bok
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.7 no.6
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    • pp.29-38
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    • 2004
  • This study validated the effect of Vaseline and the vegetable hormone-added medicine that can influence the formation of new calluses on the injured part, with the subjects of natural monument trees and large old trees. The medicines can help in the treatment of the pored or injured parts and promote the formation of new callus on natural monument trees and large old trees, which can help vigorous growth activities and prevent any secondary infection by pathogens at the same time. It turned out that the Vaseline that is used for the protection of cambiums after surgical operations on the trees did not have any significant effect on the formation of calluses. However, since it was found that new calluses formed rapidly when applying the medicine using a vegetable hormone, the medicine is highly recommended for use. If further studies should determine proper medicines for the trees according to the kinds of trees and if the medicine is applied in proper concentrations to the injured part for rapid formation of calluses on the trees when the trees undergo surgical operations, it then should be helpful in preventing the sound part(s) of the trees from decay caused by secondary infection and treatment of the injured part.

Growth Environment and Management Status of Legally Protected Trees in Gwangju, Gyeonggi-do (경기도 광주시 보호수의 생육환경 및 관리실태 조사 연구)

  • Jun, HyungSoon
    • Journal of Environmental Science International
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    • v.29 no.4
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    • pp.371-382
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    • 2020
  • This study was conducted to suggest a management plan for legally protected trees in Gwangju, Gyeonggi-do by examining their distribution and growth. A literature review and field survey of these trees were conducted to derive problems and usage plans, with a number of key results. Among the legally protected trees (77 species in total) in 74 locations within Gwangju, Gyeonggi-do, the growth status of 74 species (96.10%) was above average, indicating that most legally protected trees were growing without any issues. Despite the results, analysis of the function of these legally protected trees indicated that there was low diversity and utilization of these trees as only trees in 33.77% were used as resting places or pavilions while those in 66.23% were used for landscaping or other purposes. It was assumed that these legally protected trees and the areas surrounding them in Gwangju, Gyeonggi-do will be used as community spaces if the environment is improved. This includes converting these areas into small parks or resting places for residents. In addition, further research should be carried out to maintain good growth conditions for these legally protected trees in general and to explore various plans that allow utilization of the surrounding natural ecosystem, human environment, and cultural elements in order to enhance the quality of the region and improve it as a living space for residents.