• Title/Summary/Keyword: k-d tree

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Development of Interactive 3D Volume Visualization Techniques Using Contour Trees (컨투어 트리를 이용한 삼차원 볼륨 영상의 대화형 시각화 기법 개발)

  • Sohn, Bong-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.16 no.11
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    • pp.67-76
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    • 2011
  • This paper describes the development of interactive visualization techniques and a program that allow us to visualize the structure of the volume data and interactively select and visualize the isosurface components using contour tree. The main characteristic of this technique is to provide an algorithm that draws the contour tree in 2D plane in a way that users easily understand the tree, and to provide an algorithm that can efficiently extract an isosurface component utilizing GPU's parallel architecture. The main characteristic of the program we developed through implementing the algorithms is to provide us with an interactive user interface based on the contour tree for extracting an isosurface component and visualization that integrates with previous isosurface and volume rendering techniques. To show the excelland vof our methods, we applied 3D biomedical volume data to our algorithms. The results show that we could interactively select the isosurface components that represent a polypeptide chain, a ventricle and a femur respectively using the user interface based on our contour tree layout method, and extract the isosurface components with 3x-4x higher speed compared to previous methods.

Development of Boolean Operations for CAD System Kernel Supporting Non-manifold Models (비다양체 모델을 수용하는 CAD 시스템 커널을 위한 불리안 조직의 개발)

  • 김성환;이건우;김영진
    • Korean Journal of Computational Design and Engineering
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    • v.1 no.1
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    • pp.20-32
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    • 1996
  • The boundary evaluation technique for Boolean operation on non-manifold models which is regarded as the most popular and powerful method to create and modify 3-D CAD models has been developed. This technique adopted the concept of Merge and Selection in which the CSG tree for Boolean operation can be edited quickly and easily. In this method, the merged set which contains complete information about primitive models involved is created by merging primitives one by one, then the alive entities are selected following the given CSG tree. This technique can support the hybrid representation of B-rep(Boundary Representation) and CSG(Constructive Solid Geometry) tree in a unified non-manifold model data structure, and expected to be used as a basic method for many modeling problems such as data representation of form features, and the interference between them, and data representation of conceptual models in design process, etc.

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Performance Analysis of Layer Pruning on Sphere Decoding in MIMO Systems

  • Karthikeyan, Madurakavi;Saraswady, D.
    • ETRI Journal
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    • v.36 no.4
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    • pp.564-571
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    • 2014
  • Sphere decoding (SD) for multiple-input and multiple-output systems is a well-recognized approach for achieving near-maximum likelihood performance with reduced complexity. SD is a tree search process, whereby a large number of nodes can be searched in an effort to find an estimation of a transmitted symbol vector. In this paper, a simple and generalized approach called layer pruning is proposed to achieve complexity reduction in SD. Pruning a layer from a search process reduces the total number of nodes in a sphere search. The symbols corresponding to the pruned layer are obtained by adopting a QRM-MLD receiver. Simulation results show that the proposed method reduces the number of nodes to be searched for decoding the transmitted symbols by maintaining negligible performance loss. The proposed technique reduces the complexity by 35% to 42% in the low and medium signal-to-noise ratio regime. To demonstrate the potential of our method, we compare the results with another well-known method - namely, probabilistic tree pruning SD.

Studies on the Determination of the Breast-Height Form Factors for Stem of Pinus thunbergii and Cryptomeria japonica (곰솔 및 삼나무의 흉고형수(胸高形數) 결정(決定)에 관한 연구(硏究))

  • Park, Nam Chang;Chung, Young Gwan
    • Journal of Korean Society of Forest Science
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    • v.70 no.1
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    • pp.28-37
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    • 1985
  • In order to estimate breast-height form factors of Pinus thunbergii and Cryptomeria japonica, 8 models based on tree age, diameter at breast height and tree height were suggested and evaluated. It was the following equations that turned out to be most fit for estimating them; for Pinus thunbergii, $F=0.553-4.567\;1/A+71.409\;1/A^2$ ($R^2=0.928$), based on tree age, ($6.727^{**}$) ($14.100^{**}$) $F=0.356+1.774\;1/D-0.770\;1/D^2$ ($R^2=0.944$), based on diameter at breast height, ($15.102^{**}$) ($2.908^{**}$) $F=0.316+1.546\;1/H+0.397\;1/H^2$ ($R^2=0.941$), based on tree height, ($8.380^{**}$) ($3.896^{**}$) for Cryptomeria japonica, $F=0.400+2.348\;1/A+17.053\;1/A^2$ ($R^2=0.889$), based on tree age, ($3.501^{**}$) ($3.298^{**}$) $F=0.353+2.118\;1/D-1.462\;1/D^2$ ($R^2=0.923$), based on diameter at breast height, ($14.873^{**}$) ($3.545^{**}$) $F=0.403+0.427\;1/H+2.843\;1/H^2$ ($R^2=0.887$), based on tree height. ($3.254^{**}$) ($5.742^{**}$) The above estimated breast-height form factors proved to be overestimated for young trees and small diameter trees, and to be underestimated for old trees and large diameter trees, in comparison to generally accepted figure in Korea, that is, the form factor of 0.45.

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K-d Tree Structured Representation for MusicXML Music Scores (MusicXML 전자악보를 위한 K-d 트리 구조 표현)

  • Kim, Taek-Hun;Yang, Sung-Bong
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.06c
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    • pp.252-257
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    • 2007
  • MusicXML은 다양한 전자악보 형식들이 음악을 악보로 표현하는데 있어 지니는 한계를 잘 극복하면서 응용성, 확장성 및 공개성 등의 장점으로 인해 현재 전자악보의 표준으로 가장 적합한 것으로 평가되고 있는 악보 형식이다. 그러나 MusicXML은 XML을 기반으로 한 텍스트 데이터이기 때문에 이러한 악보 형식을 실제 악보로 변환하거나 연주하는 것은 물론 실제 악보 내용을 기반으로 한 악보 검색이 용이하도록 적절한 데이터 구조로 표현하는 것이 필요하다. 본 논문에서는 MusicXML 악보에 대하여 다차원 속성 정보를 가진 데이터의 표현에 용이한 k-d 트리 기반 데이터 구조로 표현하는 방법을 제안한다. 논문은 또한 악보에 대한 k-d 트리 구조를 보다 다양한 응용에 활용할 수 있도록 k-d 트리를 확장하여 구조화하는 방법을 제시한다. 본 논문에서 제안한 방법은 특히 내용을 기반으로 한 악보 정보 검색에 유용하게 이용될 수 있다.

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The Determination of the Partial 28S Ribosomal DNA Sequences and Rapid Detection of Phellinus linteus and Related species

  • Park, Hyung-Sik;Kim, Gi-Young;Nam, Byung-Hyouk;Lee, Sang-Joon;Lee, Jae-Dong
    • Mycobiology
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    • v.30 no.2
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    • pp.82-87
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    • 2002
  • Species of Phellinus were known to harmful fungi causing white pocket rot and severe plant disease such as canker or heartrot in living trees in the West, but some species have been used to traditional medicines in the Orient for a long time. In this study the partial D1-D2 nucleotide sequences of 28S ribosomal DNA from 13 Phellinus strains were determined and compared with the sequences of 21 strains obtained from GenBank database. According to the neighbor-joining(NJ) method comparing the sequence data the phylogenetic tree was constructed. The phylogenetic tree displayed the presence of four groups. Group I includes P. ferreus, P. gilvus and P. johnsonianus, Group II contains P. laevigatus, P. conchatus and P. tremulae, Group III possesses P. linteus, P. weirianus, P. baumii, P. rhabarbarinus and P. igniarius, and Group IV comprises P. pini, P. chrysoloma. P. linteus and P. baumii, which were used mainly in traditional medicine, belong to the same group, but exactly speaking both were split into two different subgroups. To detect P. linteus only, we developed the PCR primer, D12HR. The primer showed the specific amplification of P linteus, which is permitted to medicinal mushroom in the East. The results make a potential to be incorporated in a PCR identification system that could be used for the rapid identification of this species from its related species, P. linteus especially.

Development of Wound-treatment Formulation Using Plant Growth Regulators for Wound Healing of Some Tree Species (수피상처치료를 위한 식물생장조절물질 기반 상처유합제 개발)

  • Min, Hojung;Kim, Byeongkwan;Cha, Byeongjin
    • The Korean Journal of Pesticide Science
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    • v.20 no.2
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    • pp.83-92
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    • 2016
  • New tree wound-treatment formulations (WTF) were developed in this study. Stimulating effects of plant growth regulating substance on callus formation were evaluated in vivo twig disc culture of Zelkova serrata, Ziziphus jujuba, Pinus densiflora, Ginkgo biloba. and Aesculus turbinata. Based on the evaluation, WTF were prepared with 2,4-D, NAA, and IBA using xanthan gum as an extending agent. WTF were pasted on $2{\times}10cm$ artificial wound on the stem and the effects were evaluated 12 weeks later with the thickness of new callus-tissues. The effects varied with tree species and the growth regulators. In Z. serrata and A. turbinata, 2 mg/L of 2,4-D was the best WTF. In P. koraiensis and G. biloba, 8 mg/L of NAA and 1 mg/L of IBA were the best, respectively. Callus formation was quite lower in G. biloba compared to other species. Stimulating effect of thiophanate-methyl paste was excellent only in Z. serrata and lower than certain WTF in other species. Vaseline, which was used generally as an WTF, remained longer on the wound and causing decay. From the results, it could be recommended that 2,4-D, NAA and IBA were the best WTF for Z. serrata/A. turbinata, P. koraiensis and G. biloba, respectively.

Sound Absorption Property of the Leaves of Two Evergreen Broad-Leaved Tree Species, Dendropanax morbiferus and Fatsia japonica

  • JUNG, Su Young;YEOM, Da-Hye;KONG, Ree-Keun;SHIN, Gab Gyun;LEE, Kwang Soo;BYEON, Hee Seop
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.5
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    • pp.631-640
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    • 2020
  • In this study, the effect of specimen size and layer thickness on the sound absorption of the leaves of two evergreen broad-leaved tree species, Dendropanax morbiferus and Fatsia japonica, was investigated. The specimen sizes of 0.5 × 0.5, 1.0 × 1.0, and 2.0 × 2.0 ㎠ and layer thicknesses of 1.00, 1.75, and 2.50 cm were considered. At the layer thickness of 2.5 cm, the leaf of the D. morbiferus showed no significant difference in sound absorption coefficients (SACs) as the sample size varied, however, a significant change in SACs was recorded in that of the F. japonica. At 1.0-cm thickness, the SACs of the F. japonica leaf varied more remarkably with the sample size. The 2.50-cm-thick F. japonica leaf with the specimen size 0.5 × 0.5 ㎠ exhibited the highest sound absorption effect among all samples investigated.