• Title/Summary/Keyword: tree pruning

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Cycle Detection Using Single Edge Node Pruning (단일 간선 노드 전정 사이클 검출)

  • Sang-Un Lee
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.1
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    • pp.149-154
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    • 2024
  • This paper proposes an algorithm that remedy Floyd's the tortoise and the hare algorithm (THA) shortcomings which is specialized in singly linked list (SLL), so this algorithm fails to detect the cycle in undirected graph, digraph, and tree with multiple inputs or outputs. The proposed algorithm simply pruning the source and sink with only one edge using cycle detection of single edge node pruning. As a result of the experimental of various list, undirected graph, digraph, and tree, the proposed algorithm can be successively detect the cycle all of them. Thus, the proposed algorithm has the simplest and fastest advantage in the field of cycle detection.

Sparse Signal Recovery via Tree Search Matching Pursuit

  • Lee, Jaeseok;Choi, Jun Won;Shim, Byonghyo
    • Journal of Communications and Networks
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    • v.18 no.5
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    • pp.699-712
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    • 2016
  • Recently, greedy algorithm has received much attention as a cost-effective means to reconstruct the sparse signals from compressed measurements. Much of previous work has focused on the investigation of a single candidate to identify the support (index set of nonzero elements) of the sparse signals. Well-known drawback of the greedy approach is that the chosen candidate is often not the optimal solution due to the myopic decision in each iteration. In this paper, we propose a tree search based sparse signal recovery algorithm referred to as the tree search matching pursuit (TSMP). Two key ingredients of the proposed TSMP algorithm to control the computational complexity are the pre-selection to put a restriction on columns of the sensing matrix to be investigated and the tree pruning to eliminate unpromising paths from the search tree. In numerical simulations of Internet of Things (IoT) environments, it is shown that TSMP outperforms conventional schemes by a large margin.

Studies on the Forestation of Useful Broad Leaf Tree and the Development of Some Special Trees - Practice Application for Tending of Natural Forest I - (유용 활엽수림 조성을 위한 특수림 개발에 관한 기초연구 - 천연림 보육을 위한 시업적용 I -)

  • Kim, Young Chai
    • Journal of Korean Society of Forest Science
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    • v.82 no.4
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    • pp.406-419
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    • 1993
  • In spite of the economical and sivicultural importance, tending methods of natural broad leaf tree have not been established in Korea. In the present study, the structure of crown and biomass of Quercus variabilis were analyzed to obtain the basic information on pruning practice. There was not correlated between clear length of sample tree and tree height and D.B.H. The stratum with the largest leaf and branch weight was lower part of the stratum with the largest branch increment. The degree of contribution of branch to knotless trunk production (${\Delta}{\omega}_B(Z)/{\omega}_B(Z)$ and ${\omega}_L(Z)/{\omega}_B(Z)$) decreased from the upper part to the lower part. As an example of the application of the ecological data to pruning practice, the author attempted to estimate the effect of pruning with this experimental stand. Two methods of pruning were investigated. One is the removal of branches according to a definite external indication such as clear length rate of branch, and the other is the removal of barnches according to a definite height.

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Computerization for Management of Street Tree Using CAD (CAD를 이용한 가로수 관리 전산화에 관한 연구)

  • 허상현;심경구
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.2
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    • pp.68-76
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    • 2001
  • The purpose of this study is to computerize street tree management using a CAD program in order to manage the drawing record of street trees systematically and concurrently. The configuration of this program is composed of Reference Data, Data Inquiry, and Cost Assessment. The Reference Data includes characteristics of trees, monthly managements records, damage by blight and insects and usage of pesticides. The Data Inquiry includes an individual search of the tree index, simple searches and multiple searches. The Cost Assessment includes two main components, the data input with labor cost, manure ocst and pesticide cost and the assesment of management cost for prevention of blight and insects, pruning and fertilization. The results of this study are as follows: 1) When there are practices such as transplanting and removing of street trees it is immediately updated with the various situation. By creating an in progress a tree management system, up to the date information can be given to the manager for decision making. 2) To identify individual tree at the site or in drawing, the street name and numbers were used instead of coordinates. Tree tags are attached to the street trees individually. It can make DB management simple and easy. 3) By doing simple or multiple search with constructed DB, data can be provided quickly. 4) The result of this type of search are useful in the assessment of management cost very useful in regards to items such as the pruning, pesticides scattering and fertilization. 5) By using the AutoCAD software and existing PC without purchasing new equipment, the cost of system implementation can be minimized.

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Korean Agrammatic Production : Testing The Tree-Pruning Hypothesis

  • Kim SuJung;Halliwell John F.
    • Proceedings of the Acoustical Society of Korea Conference
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    • autumn
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    • pp.337-340
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    • 1999
  • The most salient and discussed features of speech production in agrammatic aphasia are the omission and substitution of grammatical morphemes. Cross-linguistic studies have shown that the pattern of omission/substitution is not random but occurs in a systematic and highly constrained way. Although these descriptions are important, they do not explain why all grammatical morphemes are not equally impaired. Friedmann and Grodzinsky (1997) proposed the Tree-Pruning Hypothesis (TPH) to account for these patterns of sparing and loss. The TPH claims that in an agrammatic representation, an impaired functional node is underspecified, thus allowing inappropriate affixation to occur. Additionally, whenever a node is impaired, all nodes above it will also be impaired. Using four types of narratives collected from two Korean agrammatic patients, We test the claim that the impairment in agrammatism is based on such hierarchical representation. It was found that these patients consistently produced appropriate grammatical morphemes that are higher in a syntactic tree than the impaired morphemes. The finding that an intact node exists higher than an impaired node refutes the TPH.

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A Hierarchical Packet Classification Algorithm Using Set-Pruning Binary Search Tree (셋-프루닝 이진 검색 트리를 이용한 계층적 패킷 분류 알고리즘)

  • Lee, Soo-Hyun;Lim, Hye-Sook
    • Journal of KIISE:Information Networking
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    • v.35 no.6
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    • pp.482-496
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    • 2008
  • Packet classification in the Internet routers requires multi-dimensional search for multiple header fields for every incoming packet in wire-speed, hence packet classification is one of the most important challenges in router design. Hierarchical packet classification is one of the most effective solutions since search space is remarkably reduced every time a field search is completed. However, hierarchical structures have two intrinsic issues; back-tracking and empty internal nodes. In this paper, we propose a new hierarchical packet classification algorithm which solves both problems. The back-tracking is avoided by using the set-pruning and the empty internal nodes are avoided by applying the binary search tree. Simulation result shows that the proposed algorithm provides significant improvement in search speed without increasing the amount of memory requirement. We also propose an optimization technique applying controlled rule copy in set-pruning.

Performance Evaluation of the FP-tree and the DHP Algorithms for Association Rule Mining (FP-tree와 DHP 연관 규칙 탐사 알고리즘의 실험적 성능 비교)

  • Lee, Hyung-Bong;Kim, Jin-Ho
    • Journal of KIISE:Databases
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    • v.35 no.3
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    • pp.199-207
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    • 2008
  • The FP-tree(Frequency Pattern Tree) mining association rules algorithm was proposed to improve mining performance by reducing DB scan overhead dramatically, and it is recognized that the performance of it is better than that of any other algorithms based on different approaches. But the FP-tree algorithm needs a few more memory because it has to store all transactions including frequent itemsets of the DB. This paper implements a FP-tree algorithm on a general purpose UNK system and compares it with the DHP(Direct Hashing and Pruning) algorithm which uses hash tree and direct hash table from the point of memory usage and execution time. The results show surprisingly that the FP-tree algorithm is poor than the DHP algorithm in some cases even if the system memory is sufficient for the FP-tree. The characteristics of the test data are as follows. The site of DB is look, the number of total items is $1K{\sim}7K$, avenrage length of transactions is $5{\sim}10$, avergage size of maximal frequent itemsets is $2{\sim}12$(these are typical attributes of data for large-scale convenience stores).

M-tree based Indexing Method for Effective Image Browsing (효과적인 이미지 브라우징을 위한 M-트리 기반의 인덱싱 방법)

  • Yu, Jeong-Soo;Nang, Jong-Ho
    • Journal of KIISE:Computing Practices and Letters
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    • v.16 no.4
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    • pp.442-446
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    • 2010
  • In this paper we propose an indexing method supporting the browsing scheme for effective image search on large photo database. The proposed method is based on M-tree, a representative indexing scheme on matrix space. While M-tree focuses on the searching efficiency by pruning, it did not consider browsing efficiency directly. This paper proposes node selection method, node splitting method and node splitting conditions for browsing efficiency. According to test results, node cohesion and clustering precision improved 1.5 and twice the original respectively and searching speed also increased twice the original speed.

Postural Risk Assessment of Young Tree Tending Operations in for Managing Pinus Densiflora and Larix Kaempferi Plantations (소나무와 일본잎갈나무 조림지 관리를 위한 어린나무가꾸기의 작업 자세 위험도 분석)

  • Lee, Eun-Jai;Lee, Sang-Tae;Han, Sang-Kyun;Cho, Koo-Hyun
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.3
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    • pp.271-281
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    • 2021
  • Pinus densiflora and Larix kaempferi forests not only extended the plantation management area but also cultivated to the sustainable wood supply chain during the last 5-years. These prescriptions are primarily done by manual operation activities, particularly in young tree tending. Two types of tending activities, brashing by brush cutter(BB) and pruning by pruning shear and saw(PP), were selected for the investigate of musculoskeletal disorders' level and postural risks using Ovako Working Posture Analysis System (OWAS). The postural risk indexes (BB and PP) ranged from 115 to 125 and 102 to 105, respectively. There is no significant difference between the species. The young tree tending operations had low postural risks. The results may be used as basic data to develop technical guideline for safe young trees.

Modeling strength of high-performance concrete using genetic operation trees with pruning techniques

  • Peng, Chien-Hua;Yeh, I-Cheng;Lien, Li-Chuan
    • Computers and Concrete
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    • v.6 no.3
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    • pp.203-223
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    • 2009
  • Regression analysis (RA) can establish an explicit formula to predict the strength of High-Performance Concrete (HPC); however, the accuracy of the formula is poor. Back-Propagation Networks (BPNs) can establish a highly accurate model to predict the strength of HPC, but cannot generate an explicit formula. Genetic Operation Trees (GOTs) can establish an explicit formula to predict the strength of HPC that achieves a level of accuracy in between the two aforementioned approaches. Although GOT can produce an explicit formula but the formula is often too complicated so that unable to explain the substantial meaning of the formula. This study developed a Backward Pruning Technique (BPT) to simplify the complexity of GOT formula by replacing each variable of the tip node of operation tree with the median of the variable in the training dataset belonging to the node, and then pruning the node with the most accurate test dataset. Such pruning reduces formula complexity while maintaining the accuracy. 404 experimental datasets were used to compare accuracy and complexity of three model building techniques, RA, BPN and GOT. Results show that the pruned GOT can generate simple and accurate formula for predicting the strength of HPC.