• Journal of applied mathematics & informatics
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• 제42권3호
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• pp.511-520
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• 2024

In this paper, we introduce the concept of split and non-split tree (D, C)- set of a connected graph G and its associated color variable, namely split tree (D, C) number and non-split tree (D, C) number of G. A subset S ⊆ V of vertices in G is said to be a split tree (D, C) set of G if S is a tree (D, C) set and ⟨V - S⟩ is disconnected. The minimum size of the split tree (D, C) set of G is the split tree (D, C) number of G, γ_χST (G) = min{|S| : S is a split tree (D, C) set}. A subset S ⊆ V of vertices of G is said to be a non-split tree (D, C) set of G if S is a tree (D, C) set and ⟨V - S⟩ is connected and non-split tree (D, C) number of G is γ_χST (G) = min{|S| : S is a non-split tree (D, C) set of G}. The split and non-split tree (D, C) number of some standard graphs and its compliments are identified.

• 한국산림과학회지
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• 제101권4호
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• pp.648-655
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• 2012

본 연구는 치유의 숲의 치유효과 증진을 위해 대중의 시각적 선호도에 기반 한 적정 임목밀도 관리 방향을 제시하는데 그 목적이 있다. 잣나무, 편백, 소나무, 낙엽송의 4개 침엽수종에 대해서 3개 주요 직경급별로 임목밀도 시뮬레이션을 이용하여 시각적 선호도를 조사 분석하였다. 그 결과, 잣나무의 경우, 일반소경재(D<25)는 임목밀도 약 816본/ha, 우량중경재($25{\leq}D$ <40)는 임목밀도 약 400본/ha, 우량대경재($40{\leq}D$)는 임목밀도 약 277본/ha을 가장 높게 선호하였다. 편백의 경우, 일반소경재(D<25)는 임목밀도 약 625본/ha, 우량중경재($25{\leq}D$ <40)는 임목밀도 약 625본/ha, 우량대경재($40{\leq}D$)는 임목밀도 약 400본/ha의 선호도가 가장 높게 나타났다. 소나무의 경우, 일반소경재(D<25)는 임목밀도 약 816본/ha, 우량중경재($25{\leq}D$ <40)는 임목밀도 약 625본/ha, 우량대경재($40{\leq}D$)는 임목밀도 약 400본/ha의 선호도가 가장 높게 나타났다. 낙엽송의 경우, 일반소경재(D<25)는 임목밀도 약 625본/ha, 우량중경재($25{\leq}D$ <40)는 임목밀도 약 625본/ha, 우량대경재($40{\leq}D$)는 임목밀도 약 277본/ha을 가장 선호하는 것으로 나타났다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.295-295
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• 2008

Water tree experiments were done for several types of cross-linked polyethylenes. Test method is followed by ASTM D6097. Polyethylene is divided for four subgroup. First One is chemically cross-linked general XLPE, and second one is chemically cross-linked tree-retardant XLPE, and the third one is silane cross-linked polyethylene made by monosil process, and the last one is silane cross-linked polythylene made by copolymer. Tree retardant XLPE shows the shortest water tree length. Cahemcally cross-linked general XLPE shows the longest water tree length. Silane cross-linked polyethylene by copolymer is similar to tree retardant XLPE and similar breakdown strength. So silane cross-linked XLPE by copolymer could be used for the the medium voltage cable which should have tree retardant characteristics.

• 한국정보과학회논문지:시스템및이론
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• 제35권3호
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• pp.133-140
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• 2008

본 논문은 GPU상에서 작동되는 ray tracing을 위한 효과적인 k-D tree 탐색 알고리즘을 제안한다. 기존의 k-D tree를 위한 GPU 기반 탐색 알고리즘은 임의의 단말노드에서 교차되는 primitive를 찾지 못한 경우. root 노드 방향으로 bottom-up 탐색하여 부모 노드에서 bounding box 교차검사를 이용해 형제 노드의 기 방문 여부를 판단한다. 이러한 방법은 이미 방문한 부모 노드의 방문과 bounding box 교차검사를 중복적으로 수행한다. 본 논문에서 제안하는 알고리즘은 bottom-up 탐색을 수행 할 때 형제노드가 이전에 방문했는지를 확인할 수 있는 효율적인 방법을 제시함으로써 형제노드 및 부모로드의 방문을 생략하도록 하고, 또한 아직 방문하지 않은 노드에 대해서만 bounding box 교차검사를 수행함으로써 중복된 연산을 피한다. 결과적으로 본 논문의 실험은 기존 알고리즘 대비 제안하는 알고리즘이 약 30%의 성능 향상이 있음을 보여 준다.

• 한국가구학회지
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• 제23권1호
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• pp.95-102
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• 2012

The objective of this study was to conduct the species identification and tree-ring dating of Lotus Pedestal of the Amitabha Statue at Ssangbong-Temple in Hwasun. The six wood blocks used for the Lotus Pedestal were hard pines (Pinus spp.; diploxilon) except one piece which was ginkgo (Ginkgo biloba L.). The lotus leaves surrounding the pedestal body were also made of ginkgo. Tree-ring patterns of 3 blocks were synchronized and a 133 years chronology was made. The chronology was crossdated well with the master chronology of Japanese red pine in South Korea. It dated back to A. D. 1551~1683, i.e. the last ring dated A. D. 1683. Through the estimation of the number of sapwood rings removed during carving, the felling year was calculated A. D. $1704{\pm}10$. The calligraphic writing on the Pedestal indicated that this statue was made in A. D. 1694. Therefore, the accuracy of the tree-ring dating has been proven.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권7호
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• pp.3284-3306
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• 2018

This study proposes a method to develop an authoring system(GeoMaTree) for diverse trees that constitute a virtual landscape. The GeoMaTree system enables the simple, intuitive production of an efficient structure, and supports real-time processing. The core of the proposed system is a procedural modeling based on a mathematical model and an application that supports digital content creation on diverse platforms. The procedural modeling allows users to control the complex pattern of branch propagation through an intuitive process. The application is a multi-resolution 3D model that supports appropriate optimization for a tree structure. The application and a compatible function, with commercial tools for supporting the creation of realistic synthetic images and virtual landscapes, are implemented, and the proposed system is applied to a variety of 3D image content.

• 한국가구학회지
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• 제18권3호
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• pp.188-194
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• 2007

Tree-ring dating can be used to date scientifically prehistoric timbers, historical buildings or woodcrafts. It can give a calendar year to each tree ing and produces the felling dates of logs or wood panels. In this study, we applied tree-ring dating to three rice chests, whose dates of manufacturing are unknown. According to the shape of frame, we assumed that they should be made in Cholla Province. The last rings of the woods of three rice chests were dated A.D. 1830, A.D. 1870 and A.D. 1901, respectively. Tree-ring patterns indicated that two of them were collected from Kangwon province.

• 한국게임학회 논문지
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• 제13권4호
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• pp.25-34
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• 2013

3D 게임에서 충돌 탐지를 효과적으로 하기 위해 구성하는 공간 분할 트리는 분할 평면을 결정하는데 트리 밸런스와 분할 평면과 겹치는 폴리곤의 개수 등을 고려해야 한다. 본 논문에서는 3D 게임 공간 분할 트리에서 트리 빌드 조건에 대한 가중치를 제어하는 휴리스틱 알고리즘을 제안하였다. 가중치의 변화에 따라서 트리 빌드 시간, 분할 평면과 겹치는 폴리곤을 쪼갤 때 시각적 불일치를 유발할 수 있는 T-junction 의 제거 시간, 트리 밸런스에 따른 렌더링 속도(frame per second) 등을 3D 게임 시뮬레이션을 통하여 분석하였다.

• 한국산림과학회지
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• 제5권1호
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• pp.27-32
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• 1966

Taking an opportunity of the application of clearcutting method, 140 red pine (Pinus densiflora Sieb. et Zucc.) trees grown at Chon-nam province, the southern part of South Korea, were fellen and the tree height, clear-bole length, D.B.H. diameter at base(0.2m above from the ground line) and the length of the longest branch were measured. The correlation between factors mentioned were analysed. The results are summarized as follows: 1. The correlation between crown length and tree height (r=0.821) was sinificant. 2. The correlation between the diameter at base and D.B.H. was highly significant (r=0.961). D.B.H. can be calculated from multiplying the diameter at base by 0.88. 3. A weak relation between D.B.H and tree height was abserved. 4. The positive correlation between tree height and clear-bole-length was calculated, but it was not sharp between D.B.H. and the length of the longest branch. 5. The height, basal area, D.B.H. and volume increment by tree class calculated from the data of the stem analysis are presented (Tab. 3~10).

• 한국가구학회지
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• 제23권1호
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• pp.84-94
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• 2012

We present the species and the dendrochronological dates of Korean traditional furniture in Forest Museum Collection of Korea National Arboretum. Seven of thirteen were successfully dated. Chest with a flap door (84-55-1) was dated A. D. 1623. Others dated were cabinet (83-41-1: A. D. 1759), Chest with a turnover door (83-39-1; A. D. 1801), Cabinet with two horizontal section (88-39; A. D. 1843), Rice chest (82-27-3; A. D. 1849), Cabinet with two horizontal section (83-40-2; A. D. 1877), Chest with a flap door (84-50; A. D. 1918). Most of existing cabinets were made in 1800s. The 84-55-1 chest was one of the earliest pieces of furniture in the collections of Korea museums. The furniture is usually composed one species. The major species was Pinus densiflora. Bedside cabinet (83-41-1) and Cabinet with two horizontal section (88-39) were made from Korean pine (Pinus koraiensis). Becasue they were dated by the tree-ring chronology of Mt. Bekdu, the timber of their boards could be from the area of Mt. Bekdu.