• Title/Summary/Keyword: Cluster Tree

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The Estimation of Tree Form Index for Major Canopy Species in the Natural Deciduous Forest (천연활엽수림(天然闊葉樹林) 주요(主要) 상층(上層) 임관(林冠) 수종(樹種)의 임목(林木) 형질(形質) 지수(指數) 추정(推定))

  • Kim, Ji Hong;Yang, Hee Moon
    • Journal of Forest and Environmental Science
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    • v.15 no.1
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    • pp.1-9
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    • 1999
  • Noticing the intrinsic growing habit variations of hardwood species which is indigenous to the natural deciduous forest, eighteen tree species in overstory were selected for comparative evaluating tree form so as to develop the tree form index (TFI). Selected six tree form attributes were arbitrarily divided four assessment criteria and given appropriate scores. Eighteen tree species were undergone corresponding scores, converted to percentage base, and estimated TFI by the summation of the six scoring values. Cluster analysis was carried out to review which attribute would have been shared among species based on dissimilarity of scores for each pair of species in $18{\times}6$ data matrix. The result showed that Populus davidiana had the highest TFI value of 80.8 and Carpinus cordata had the lowest TFI va1ue of 46.3. The species which received more than 70 of TFI are Populus davidiana, Betula costata, Fraxinus mandshurica, and Ulmus davidiana var. japonica, characterized by the advantage of straight and longer bole, the narrower crown, and the thinner branch. On the contrary, such species as Sorbus alnifolia. Prunus sargentii, Acer mandshuricum, Juglans mandshurica, and Carpinus cordata received less than 60 of TFI, characterized by the disadvantage of the crooked or forked stem. the wider or deeper crown. and the thicker branch. In the dendrogram produced by cluster analysis, arbitrary value of Euclidean distance 10 divided eighteen species into four distinctive groups. and the typical characteristics of each group were discussed.

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An Efficient Cluster Routing Protocol Based on 2-level Tree for Wireless Ad Hoc Networks (무선 애드 혹 네트워크에서 에너지 효율적인 2-level 트리 기반의 클러스터 라우팅 프로토콜)

  • Lee, Young Joon;Kim, Sung Chun
    • KIPS Transactions on Computer and Communication Systems
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    • v.3 no.5
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    • pp.155-162
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    • 2014
  • We proposed a 2 level tree based cluster based routing protocol for mobile ad hoc networks. it is our crucial goal to establish improved clustering's structure in order to extend average node life-time and elevate the average packet delivery ratio. Because of insufficient wireless resources and energy, the method to form and manage clusters is useful for increasing network stability. but cluster-head fulfills roles as a host and a router in clustering protocol of Ad hoc networks environment. Therefore energy exhaustion of cluster-head causes communication interruption phenomenon. Effective management of cluster-head is key-point which determines the entire network performance. The scheme focuses on improving the performance the life time of the network and throughput through the management of cluster-heads and its neighbor nodes. In simulation, we demonstrated that it would obtain averagely better 17% performance than LS2RP.

A Minimum Interference Channel Assignment Algorithm for Performance Improvement of Large-Scale Wireless Mesh Networks (대규모 무선 메쉬 네트워크의 성능 향상을 위한 최소 간섭 채널 할당 알고리즘)

  • Ryu, Min-Woo;Cha, Si-Ho;Cho, Kuk-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.10B
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    • pp.964-972
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    • 2009
  • Wireless mesh network (WMN) is emerging a future core technology to resolve many problems derived from exist wireless networks by employing multi-interface and multi-channel. Ability to utilize multiple channels in WMNs substantially increases the effective bandwidth available to wireless network nodes. However, minimum interference channel assignment algorithms are required to use the effective bandwidth in multi-channel environments. This paper proposes a cluster-based minimum interference channel assignment (MI-CA) algorithm to improve the performance of WMN. The MI-CA algorithm is consists of Inter-Cluster and Intra-Cluster Intrchannel assignment between clusters and in the internal clusters, respectively. The Inter-Cluster channel assignment assigns a barebone channel to cluster heads and border nodes based on minimum spanning tree (MST) and the Intra-Cluster channel assignment minimizes channel interference by reassigning ortasgonal channels between cluster mespann. Our simheation results show that MI-CA can improve the performance of WMNs by minimizing channel interference.

A Study on the Development of Fruit Tree Experience Programs Based on User Segmentation

  • Kwon, O Man;Lee, Junga;Jeong, Daeyoung;Lee, Jin Hee
    • Journal of Environmental Science International
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    • v.27 no.10
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    • pp.865-874
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    • 2018
  • Fruit trees are a key part of agriculture in rural areas and have recently been a part of ecotourism or agrotourism. This study analyzes user segmentation based on user motivation to determine characteristics of potential customers in fruit tree farms, and thereby develop fruit tree experience and educational programs. We conducted a survey of 253 potential customers of fruit tree experience programs in September 2017. Data were evaluated using factor and cluster analyses. The results of the cluster analysis identified four distinct segments based on potential customers' motivations, that is, activity-oriented, learning-oriented, leisure-oriented, and purchase-oriented. These clusters showed that significant differences in the preference of potential customers exist. Different markets were segmented based on the benefits sought by users. The segments' characteristics were identified and activities relevant to each segment were proposed for rural tourism. Lastly, this study suggests directions for development of fruit tree farm experience and educational programs.

Solving Cluster Based Multicast Routing Problems Using A Simulated Annealing Algorithm (시뮬레이티디 어닐링 알고리즘을 이용한 클러스터 기반의 멀티캐스트 라우팅 문제 해법)

  • Kang Myung-Ju
    • Journal of the Korea Society of Computer and Information
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    • v.9 no.3
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    • pp.189-194
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    • 2004
  • This paper proposes a Simulated Annealing(SA) algorithm for cluster-based Multicast Routing problems. Multicasting, the transmission of data to a group, can be solved from constructing multicast tree, that is. the whole network is partitioned to some clusters and the clusters are constructed by multicast tree. Multicast tree can be constructed by minimum-cost Steiner tree. In this paper, an SA algorithm is used in the minimum-cost Steiner tree. Especially, in SA, the cooling schedule is an important factor for the algorithm. Hence, in this paper, a cooling schedule is proposed for SA for multicast routing problems and analyzed the simulation results.

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Development of a Forensic Analyzing Tool based on Cluster Information of HFS+ filesystem

  • Cho, Gyu-Sang
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.3
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    • pp.178-192
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    • 2021
  • File system forensics typically focus on the contents or timestamps of a file, and it is common to work around file/directory centers. But to recover a deleted file on the disk or use a carving technique to find and connect partial missing content, the evidence must be analyzed using cluster-centered analysis. Forensics tools such as EnCase, TSK, and X-ways, provide a basic ability to get information about disk clusters, but these are not the core functions of the tools. Alternatively, Sysinternals' DiskView tool provides a more intuitive visualization function, which makes it easier to obtain information around disk clusters. In addition, most current tools are for Windows. There are very few forensic analysis tools for MacOS, and furthermore, cluster analysis tools are very rare. In this paper, we developed a tool named FACT (Forensic Analyzer based Cluster Information Tool) for analyzing the state of clusters in a HFS+ file system, for digital forensics. The FACT consists of three features, a Cluster based analysis, B-tree based analysis, and Directory based analysis. The Cluster based analysis is the main feature, and was basically developed for cluster analysis. The FACT tool's cluster visualization feature plays a central role. The FACT tool was programmed in two programming languages, C/C++ and Python. The core part for analyzing the HFS+ filesystem was programmed in C/C++ and the visualization part is implemented using the Python Tkinter library. The features in this study will evolve into key forensics tools for use in MacOS, and by providing additional GUI capabilities can be very important for cluster-centric forensics analysis.

Adaptive Beacon Scheduling Algorithm to Reduce End-to-End Delay in Cluster-tree based LR-WPAN (클러스터-트리 기반 LR-WPAN에서 End-to-End 지연시간을 줄이기 위한 적응적 Beacon 스케줄링 알고리즘)

  • Kang, Jae-Eun;Park, Hak-Rae;Lee, Jong-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.3B
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    • pp.255-263
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    • 2009
  • In this paper, we propose an adaptive beacon scheduling algorithm to control a reception period of actual data according to variation of amount of traffic in IEEE 802.15.4 LR-WPAN(Low Rate-Wireless Personal Area Network) with the cluster-tree topology. If a beacon interval is shortened, the amount of the traffic a node receives can be increased while consumption of the energy can be also increased. In this sense, we can achieve optimal on orgy consumption by controlling the beacon interval when the amount of data to be received is being decreased. The result of simulation using NS-2 shows that the proposed algorithm improves performances in terms of packet loss rate and end-to-end delay compared with algorithm using a fixed beacon interval. For a design of cluster-tree based LR-WPAN managing delay-sensitive services, the proposed algorithm and the associated results can be applied usefully.

Data Modeling using Cluster Based Fuzzy Model Tree (클러스터 기반 퍼지 모델트리를 이용한 데이터 모델링)

  • Lee, Dae-Jong;Park, Jin-Il;Park, Sang-Young;Jung, Nahm-Chung;Chun, Meung-Geun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.16 no.5
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    • pp.608-615
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    • 2006
  • This paper proposes a fuzzy model tree consisting of local linear models using fuzzy cluster for data modeling. First, cluster centers are calculated by fuzzy clustering method using all input and output attributes. And then, linear models are constructed at internal nodes with fuzzy membership values between centers and input attributes. The expansion of internal node is determined by comparing errors calculated in parent node with ones in child node, respectively. As a final step, data prediction is performed with a linear model having the highest fuzzy membership value between input attributes and cluster centers in leaf nodes. To show the effectiveness of the proposed method, we have applied our method to various dataset. Under various experiments, our proposed method shows better performance than conventional model tree and artificial neural networks.

Maximum Node Interconnection by a Given Sum of Euclidean Edge Lengths in a Cluster Node Distribution

  • Kim, Yeonsoo;Kim, Minkwon;Hwang, Byungyeon
    • Journal of information and communication convergence engineering
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    • v.20 no.2
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    • pp.90-95
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    • 2022
  • This paper proposes a method to find a tree with the maximum number of terminals that can be connected by a given length when numerous terminals distributed in a cluster form are given to the Euclidean plane R2 with several constraints. First constraint is that a given terminal is distributed in a cluster form, second is that a given length cannot connect all terminals in the tree, and third is that there is no curved connection between each terminal. This paper proposes a method to establish more efficient interconnections within terminals distributed in a cluster form by improving a randomly distributed memetic genetic algorithm. The construction of interconnections has been extensively used in design-related fields, from networking to architecture. Additionally, in real life, the construction of interconnections is mostly distributed in the form of clusters. Therefore, the heuristic algorithm proposed in this paper can be effectively utilized in real life and is expected to provide various cost savings.

A Design of TNA(Traceback against Network Attacks) Based on Multihop Clustering using the depth of Tree structure on Ad-hoc Networks (애드혹 네트워크 상에 트리구조 깊이를 이용한 다중홉 클러스터링 기반 TNA(Traceback against Network Attacks) 설계)

  • Kim, Ju-Yung;Lee, Byung-Kwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37A no.9
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    • pp.772-779
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    • 2012
  • In the current MANET, DOS or DDOS attacks are increasing, but as MANET has limited bandwidth, computational resources and battery power, the existing traceback mechanisms can not be applied to it. Therefore, in case of traceback techniques being applied to MANET, the resource of each node must be used efficiently. However, in the traceback techniques applied to an existing ad hoc network, as a cluster head which represents all nodes in the cluster area manages the traceback, the overhead of the cluster head shortens each node's life. In addition, in case of multi-hop clustering, as one Cluster head manages more node than one, its problem is getting even worse. This paper proposes TNA(Traceback against Network Attacks) based on multihop clustering using the depth of tree structure in order to reduce the overhead of distributed information management.