• Title/Summary/Keyword: tree pruning

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A Context-based Fast Encoding Quad Tree Plus Binary Tree (QTBT) Block Structure Partition

  • Marzuki, Ismail;Choi, Hansol;Sim, Donggyu
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2018.06a
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    • pp.175-177
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    • 2018
  • This paper proposes an algorithm to speed up block structure partition of quad tree plus binary tree (QTBT) in Joint Exploration Test Model (JEM) encoder. The proposed fast encoding of QTBT block partition employs three spatially neighbor coded blocks, such as left, top-left, and top of current block, to early terminate QTBT block structure pruning. The propose algorithm is organized based on statistical similarity of those spatially neighboring blocks, such as block depths and coded block types, which are coded with overlapped block motion compensation (OBMC) and adaptive multi transform (AMT). The experimental results demonstrate about 30% encoding time reduction with 1.3% BD-rate loss on average compared to the anchor JEM-7.1 software under random access configuration.

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A Lifetime-Preserving and Delay-Constrained Data Gathering Tree for Unreliable Sensor Networks

  • Li, Yanjun;Shen, Yueyun;Chi, Kaikai
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.6 no.12
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    • pp.3219-3236
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    • 2012
  • A tree routing structure is often adopted for many-to-one data gathering and aggregation in sensor networks. For real-time scenarios, considering lossy wireless links, it is an important issue how to construct a maximum-lifetime data gathering tree with delay constraint. In this work, we study the problem of lifetime-preserving and delay-constrained tree construction in unreliable sensor networks. We prove that the problem is NP-complete. A greedy approximation algorithm is proposed. We use expected transmissions count (ETX) as the link quality indicator, as well as a measure of delay. Our algorithm starts from an arbitrary least ETX tree, and iteratively adjusts the hierarchy of the tree to reduce the load on bottleneck nodes by pruning and grafting its sub-tree. The complexity of the proposed algorithm is $O(N^4)$. Finally, extensive simulations are carried out to verify our approach. Simulation results show that our algorithm provides longer lifetime in various situations compared to existing data gathering schemes.

Improved Decision Tree-Based State Tying In Continuous Speech Recognition System (연속 음성 인식 시스템을 위한 향상된 결정 트리 기반 상태 공유)

  • ;Xintian Wu;Chaojun Liu
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.6
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    • pp.49-56
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    • 1999
  • In many continuous speech recognition systems based on HMMs, decision tree-based state tying has been used for not only improving the robustness and accuracy of context dependent acoustic modeling but also synthesizing unseen models. To construct the phonetic decision tree, standard method performs one-level pruning using just single Gaussian triphone models. In this paper, two novel approaches, two-level decision tree and multi-mixture decision tree, are proposed to get better performance through more accurate acoustic modeling. Two-level decision tree performs two level pruning for the state tying and the mixture weight tying. Using the second level, the tied states can have different mixture weights based on the similarities in their phonetic contexts. In the second approach, phonetic decision tree continues to be updated with training sequence, mixture splitting and re-estimation. Multi-mixture Gaussian as well as single Gaussian models are used to construct the multi-mixture decision tree. Continuous speech recognition experiment using these approaches on BN-96 and WSJ5k data showed a reduction in word error rate comparing to the standard decision tree based system given similar number of tied states.

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Selection of the Optimal Decision Tree Model Using Grid Search Method : Focusing on the Analysis of the Factors Affecting Job Satisfaction of Workplace Reserve Force Commanders (격자탐색법을 이용한 의사결정나무 분석 최적 모형 선택 : 직장예비군 지휘관의 직장만족도에 대한 영향 요인 분석을 중심으로)

  • Jeong, Chulwoo;Jeong, Won Young;Shin, David
    • Journal of the Korean Operations Research and Management Science Society
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    • v.40 no.2
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    • pp.19-29
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    • 2015
  • The purpose of this study is to suggest the grid search method for selecting an optimal decision tree model. It chooses optimal values for the maximum depth of tree and the minimum number of observations that must exist in a node in order for a split to be attempted. Therefore, the grid search method guarantees building a decision tree model that shows more precise and stable classifying performance. Through empirical analysis using data of job satisfaction of workplace reserve force commanders, we show that the grid search method helps us generate an optimal decision tree model that gives us hints for the improvement direction of labor conditions of Korean workplace reserve force commanders.

A Study on the Korean Continuous Speech Recognition using Adaptive Pruning Algorithm and PDT-SSS Algorithm (적응 프루닝 알고리즘과 PDT-SSS 알고리즘을 이용한 한국어 연속음성인식에 관한 연구)

  • 황철준;오세진;김범국;정호열;정현열
    • Journal of Korea Multimedia Society
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    • v.4 no.6
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    • pp.524-533
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    • 2001
  • Efficient continuous speech recognition system for practical applications requires that the processing be carried out in real time and high recognition accuracy. In this paper, we study the acoustic models by adopting the PDT-SSS algorithm and the language models by iterative learning so as to improve the speech recognition accuracy. And the adaptive pruning algorithm is applied to the continuous speech. To verify the effectiveness of proposed method, we carried out the continuous speech recognition for the Korean air flight reservation task. Experimental results show that the adopted algorithm has the average 90.9% for continuous speech recognition and the average 90.7% for word recognition accuracy including continuous speech. And in case of adopting the adaptive pruning algorithm to continuous speech, it reduces the recognition time of about 1.2 seconds(15%) without any loss of accuracy. From the result, we proved the effectiveness of the PDT-SSS algorithm and the adaptive pruning algorithm.

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A study on data mining techniques for soil classification methods using cone penetration test results

  • Junghee Park;So-Hyun Cho;Jong-Sub Lee;Hyun-Ki Kim
    • Geomechanics and Engineering
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    • v.35 no.1
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    • pp.67-80
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    • 2023
  • Due to the nature of the conjunctive Cone Penetration Test(CPT), which does not verify the actual sample directly, geotechnical engineers commonly classify the underground geomaterials using CPT results with the classification diagrams proposed by various researchers. However, such classification diagrams may fail to reflect local geotechnical characteristics, potentially resulting in misclassification that does not align with the actual stratification in regions with strong local features. To address this, this paper presents an objective method for more accurate local CPT soil classification criteria, which utilizes C4.5 decision tree models trained with the CPT results from the clay-dominant southern coast of Korea and the sand-dominant region in South Carolina, USA. The results and analyses demonstrate that the C4.5 algorithm, in conjunction with oversampling, outlier removal, and pruning methods, can enhance and optimize the decision tree-based CPT soil classification model.

Performance Enhancement of Tree Kernel-based Protein-Protein Interaction Extraction by Parse Tree Pruning and Decay Factor Adjustment (구문 트리 가지치기 및 소멸 인자 조정을 통한 트리 커널 기반 단백질 간 상호작용 추출 성능 향상)

  • Choi, Sung-Pil;Choi, Yun-Soo;Jeong, Chang-Hoo;Myaeng, Sung-Hyon
    • Journal of KIISE:Software and Applications
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    • v.37 no.2
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    • pp.85-94
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    • 2010
  • This paper introduces a novel way to leverage convolution parse tree kernel to extract the interaction information between two proteins in a sentence without multiple features, clues and complicated kernels. Our approach needs only the parse tree alone of a candidate sentence including pairs of protein names which is potential to have interaction information. The main contribution of this paper is two folds. First, we show that for the PPI, it is imperative to execute parse tree pruning removing unnecessary context information in deciding whether the current sentence imposes interaction information between proteins by comparing with the latest existing approaches' performance. Secondly, this paper presents that tree kernel decay factor can play an pivotal role in improving the extraction performance with the identical learning conditions. Consequently, we could witness that it is not always the case that multiple kernels with multiple parsers perform better than each kernels alone for PPI extraction, which has been argued in the previous research by presenting our out-performed experimental results compared to the two existing methods by 19.8% and 14% respectively.

Sap Outflow Characteristics of Walnut Tree (Juglans sinensis Dode) (호두나무 수액의 유출특성)

  • Kim, Chul-Woo;Kim, Mahn-Jo;Park, Youngki
    • Korean Journal of Plant Resources
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    • v.27 no.2
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    • pp.188-193
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    • 2014
  • The sap outflow characteristics of Juglans sinensis and J. mandshurica were investigated to evaluate the optimum pruning period of walnut tree that there is a sap spill on dormant. The total period of sap outflow were 34 days for both J. sinensis and J. mandshurica. Total amount of sap outflow per tree in J. sinensis and J. mandshurica were 2,922 mL/tree and 3,135 mL/tree, respectively and the period of sap outflow and non sap outflow between two species were similar. ANOVA analysis showed that the amount of sap outflow was significant differences with day of sap outflow but there were no significant differences between species. From the correlation analysis between air-temperature and sap outflow, daily minimum temperature showed a positive correlation at the 1% level of significance (r=0.56 and r=0.46) for both J. sinensis and J. mandshurica. When branch of walnut tree that diameter is 5 cm cut on the period of sap outflow, the sap flowed down the longest period (48 days) but the sap outflow was not observed after budburst. Therefore, our study supported that the pruning have to avoid the period of sap outflow to reduce sap outflow of walnut tree.

A Study of the Planting Characteristics of Street Trees and Herbaceous Plants in Gangwon-do (강원도 내 가로수와 가로녹지대 초화류의 식재 특성에 관한 연구)

  • Jeong Jin-Hyung;Lee Ki-Eui
    • Journal of the Korean Institute of Landscape Architecture
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    • v.33 no.5 s.112
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    • pp.57-68
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    • 2005
  • This study surveyed planting areas along streets in Gangwon-do to find out how to improve the planting and use of street trees and herbaceous plants. There were 301,491 trees of 41 species on the streets of Gangwon-do in 2004. The predominant species of street trees were Ginkgo biloba ($40\%$), Prunus spp. (Prunus yedoensis and Prunus sargentii) ($25\%$), Platanus occidentalis ($5\%$), followed by Betula platyphylla var. japonica, Zelkova serrata, Prunus armeniaca var. ansu, Acer palmatum, and Pinus thunbergii. Eighty-four herbaceous plant species were found in the Youngseo district (the southern area of Gangwon-do); the ratio of native species to exotic was 51:33. The predominant species were Cosmos bipinnatus, Petunia hybrida, Tagetes spp., Aster koraiensis, and Fagopyrum esculentum. Eighty-nine herbaceous plant species were found in the Youngdong district (the eastern area of Gangwon-do); the ratio of native species to exotic was 55:33. The predominant herbaceous plants were Aster koraiensis, Tagetes spp., Petunia hybrida, Rudbeckia bicolor, Cosmos bipinnatus, Salvia splendens, Brassica oleraceae var. acephala, Aquilegia buergeriana var. oxysepala, Coreopsis drummondii, Viola tricolor, and Dianthus superbus var. longicalycinus. Appropriate pruning adds to the aesthetic value of trees and prolongs their useful life; it also maintains good health and thereby reduces the need to control insects and diseases. Street trees had not been properly pruned due to the presence of power lines and a shortage of pruning information. The pruning was controlled by Korea Electric Power Company, which has no pruning information. Pruning must be maintained by a professional landscape company in order to maintain good shape, such as that which is done for bonsai. In order to improve the planting, use and maintenance of landscape plants in Gangwon-do, the following recommendations are made: street tree species should be diversified, suitable street trees should be selected for each space, native species should generally be used, trees should be appropriately pruned and properly fertilized, pests and diseases should be controlled, plantings should be done in multiple layers, spatial arrangements should be improved, larger trees should be planted, and drainage and underground electric wires should be considered when planting.

Study of germination for none seasonal pruning mulberry farm and their insective diseases (순상전 춘기말벌채고조의 발아상태와 충해 발생 관계)

  • 도경화
    • Journal of Sericultural and Entomological Science
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    • v.3
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    • pp.13-21
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    • 1963
  • 1. In the mulberry groves for both rearing of spring and fall, the rate of germination was 74.3 percent and the rate of the unfinished bud was 25.7 percent. 2. When the summer pruning after spring rearing was not worked, new sprouted leaves from the axillary buds of an age old branches was 74.88 percent of germination and the rest from unfinished bud during the spring showed 28.12 percent. 3. In the furrows running from north to south, new buds facing the due north were the worst but towards south-east and north-east were the best in their sprouts. 4. One year-old branches which had been raised without the summer pruning in the bush types of Morus Lhou (ser) Koidz offered a habitat where Apriona Rugico1lis Cherr could live. 5. On the grove of Morus Lhou Koidz cultivated at lower zone under a higher humidity and the shortage of sun light the appearance of Anomoneura Mori Schw was likely to happen very much. 6. One year old branches without the summer pruning produced more leaves owing to a long period of growth than branches with the summer pruning in the fall crops. 7. It is necessary to reconsider a certain distance of planting because of causing, when the summer pruning was not made in the bush plantation, a obstacle of fertilizer operation or the forth coming year's management. 8. It can not be thought the ideal method for us to raise mulberry tree such as Morus Lhou Koidz under natural form and at a short distance of planting (one another). 9. Among the species, Morus alba L. had a great deal of leaves and of the rate of germination per unit length of branch.

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