• Title, Summary, Keyword: 지름

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Minimum-Diameter Spanning Tree with the Bounded Degree (제한된 분지수를 갖는 최소 지름 신장 트리)

  • 안희갑;한요섭;신찬수
    • Proceedings of the Korean Information Science Society Conference
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    • pp.806-808
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    • 2003
  • 이차원 평면에 주어진 n 개의 점을 연결하는 신장 트리(spanning tree) 중에서, 지름이 최소가 되는 최소지름 신장 트리는 특정 점에서의 분지수가 n-1 까지 증가할 수 있다. 본 논문에서는 트리의 분지수(degree)를 입력으로 받아 그 분지수를 넘지 않는 신장 트리를 구성하면서 트리의 지름은 최소 지름의 상수 배를 넘지 않도록 하는 구성 방법을 제안한다.

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Fault Diameter and Mutually Disjoint Paths in Multidimensional Torus Networks (다차원 토러스 네트워크의 고장지름과 서로소인 경로들)

  • Kim, Hee-Chul;Im, Do-Bin;Park, Jung-Heum
    • Journal of KIISE:Computer Systems and Theory
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    • v.34 no.5_6
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    • pp.176-186
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    • 2007
  • An interconnection network can be represented as a graph where a vertex corresponds to a node and an edge corresponds to a link. The diameter of an interconnection network is the maximum length of the shortest paths between all pairs of vertices. The fault diameter of an interconnection network G is the maximum length of the shortest paths between all two fault-free vertices when there are $_k(G)-1$ or less faulty vertices, where $_k(G)$ is the connectivity of G. The fault diameter of an R-regular graph G with diameter of 3 or more and connectivity ${\tau}$ is at least diam(G)+1 where diam(G) is the diameter of G. We show that the fault diameter of a 2-dimensional $m{\times}n$ torus with $m,n{\geq}3$ is max(m,n) if m=3 or n=3; otherwise, the fault diameter is equal to its diameter plus 1. We also show that in $d({\geq}3)$-dimensional $k_1{\times}k_2{\times}{\cdots}{\times}k_d$ torus with each $k_i{\geq}3$, there are 2d mutually disjoint paths joining any two vertices such that the lengths of all these paths are at most diameter+1. The paths joining two vertices u and v are called to be mutually disjoint if the common vertices on these paths are u and v. Using these mutually disjoint paths, we show that the fault diameter of $d({\geq}3)$-dimensional $k_1{\times}k_2{\times}{\cdots}{\times}k_d$ totus with each $k_i{\geq}3$ is equal to its diameter plus 1.

Fault Diameter of Recursive Circulant $G(2^{m},2^{k})$ (재귀원형군 $G(2^{m},2^{k})$의 고장 지름)

  • 김희철;정호영;박정흠
    • Journal of KIISE:Computer Systems and Theory
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    • v.29 no.12
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    • pp.665-679
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    • 2002
  • The fault diameter of a graph G is the maximum of lengths of the shortest paths between all two vertices when there are $\chi$(G) - 1 or less faulty vertices, where $\chi$(G) is connectivity of G. In this paper, we analyze the fault diameter of recursive circulant $G(2^m,2^k)$ with $k{\geq}3$. Let $ dia_{m.k}$ denote the diameter of $G(2^m,2^k)$. We show that if $2{\leq}m,2{\leq}k, the fault diameter of $G(2{\leq}m,2{\leq}k)$ is equal to $2^m-2$, and if m=k+1, it is equal to $2^k-1$. It is also shown that for m>k+1, the fault diameter is equal to di a_$m{\neq}1$(mod 2k); otherwise, it is less than or equal to$dia_{m.k+2}$.

Measurement of 100-nm polystyrene sphere by transmission electron microscope (투과형 전자현미경을 이용한 100nm폴리스티렌 구의 측정)

  • 박병천;정기영;송원영;오범환
    • Proceedings of the Korea Crystallographic Association Conference
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    • pp.57-57
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    • 2002
  • 100 nm 이하의 입자의 크기와 모양을 정확하게 측정할 수 있는 기술개발을 위하여 투과형 전자현미경(TEM)으로 100 nm 지름의 폴리스티렌구의 평균지름을 측정하였다. 기기 표시 배율과 엣지결정불확도에 의한 크기측정오차를 최소화하기 위하여, 지름이 정확히 알려진 300 nm 입자를 내부 기준자로 쓰기 위하여 100 nm 입자와 섞었다. 100 nm 입자들의 지름은 동일한 TEM 필름상의 300 nm 입자와의 비교를 통하여 얻어졌다. 전자빔에 의한 입자축소효과의 보정을 위하여, 가속전압, 빔세기, 그리고 노출시간이 축소량에 미치는 정량적 관계를 조사하고 분석하였다. 그러한 분석과 몇가지 데이터 처리과정에 기초하여, 100 nm 폴리스티렌구의 평균지름을 95 % 신뢰수준에서 확장불확도 2 %로 결정하였다. 측정값은 동일한 쌤플에 대하여, 다른 방법을 사용하는 다른 실험실들과의 결과와도 일치하고 있다.

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Fault Diameter and Fault Tolerance of Gray Cube (그레이 큐브의 고장 지름(Fault Diameter)과 고장 허용도(Fault Tolerance))

  • Lee, Hyeong-Ok;Joo, Nak-Keun;Lim, Hyeong-Seok
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.8
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    • pp.1930-1939
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    • 1997
  • In this paper, we analyze the fault diameter and fault tolerance of Gray cube proposed recently in [12]. fault diameter of an interconnection network is one of the important network measures concerning the distance between nodes when some nodes fail. It is showed that fault diameter of n-dimensional Gray cube having $2^n$ nodes is [(n+1)/2]+2, ($n{\ge}3$). It means the increment of the longest distance between nodes under node-failure is only constant factor. Comparing the result with the fault diameter of well-known hypercube, the longest routing distance of a message in a Gray cube under node-failure is about the half of that hypercube.

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Fault Diameter of Folded Hyper-Star Interconnection Networks FHS(2n,n) (상호연결망 폴디드 하이퍼-스타 연결망 FHS(2n,n)의 고장 지름)

  • Kim, Jong-Seok;Lee, Hyeong-Ok
    • The KIPS Transactions:PartA
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    • v.17A no.1
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    • pp.1-8
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    • 2010
  • The fault diameter is one of the important measures for transmission rate and reliability of interconnection network. H.-O. Lee et al.[Parallel paths in folded hyper-star graph, Journal of KIPS, Vol.6, No.7, pp.1756-1769, 1999] suggested the node-disjoint paths of FHS (2n,n), and proved that the fault diameter of FHS(2n,n) is less than 2n-1. In this paper, we suggest an advanced node-disjoint paths of FHS(2n,n). We also prove that the wide diameter of FHS(2n,n) is dist(U,V)+4, and the fault diameter of FHS(2n,n) is less than n+2.

A Research on the Processing Method to Minimize the Outer Radius(Sharp edge) in Sheet Metal Z-bending Work (박판의 Z-굽힘가공에서 외측 굽힘반지름 치수의 최소화(샤프에지) 가공법에 관한 연구)

  • Yun, Jae-Woong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.2
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    • pp.349-355
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    • 2017
  • Bending work using press dies involves bending a flat blank to a desired angle. The bending produces a flange (the bent part) and a web (the unbent part). The bending line will have a bending angle, and there is an inner and outer bending radius. The minimum inner radius size is determined by the material used. When the inner radius size is too small, there will be excess metal welding, which will cause a crack in the outer radius part. The outer bending radius size cannot be controlled by a bending punch and die block. Types of bending include V-bending, U-bending, O-bending, edge bending, twist bending, and crimping. Z-bending involves two bending lines, which are set on the upper side and under surface of the blank, respectively, and upward or downward bending is used. Z-bending is also called crank bending. Z-bending using this type of die structure will produce a standard inner bending radius. The standard size is the minimum bending radius that represents the angle radius of the bending punch. In industry, there is a need for a sharp edge shape with a very small size (R=0.2mm), but that is not possible when using bending punch and die block. The purpose of this research is to meet the need by development.

Approximation Algorithms for a Minimum-Diameter Spanning Tree (최소 지름 신장 트리를 구하는 근사 알고리즘)

  • 신찬수;박상민
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.5_6
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    • pp.319-323
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    • 2003
  • Let P be a set of n points in the plane. A minimum spanning tree(MST) is a spanning tree connecting n points of P such that the sum of lengths of edges of the tree is minimized. A diameter of a tree is the maximum length of paths connecting two points of a spanning tree of P. The problem considered in this paper is to compute the spanning tree whose diameter is minimized over all spanning trees of P. We call such tree a minimum-diameter spanning tree(MDST). The best known previous algorithm[3] finds MDST in $O(n^2)$ time. In this paper, we suggest an approximation algorithm to compute a spanning tree whose diameter is no more than 5/4 times that of MDST, running in O(n$^2$log$^2$n) time. This is the first approximation algorithm on the MDST problem.

Analysis of Bisection width and Fault Diameter for Hyper-Star Network HS(2n, n) (상호연결망 하이퍼-스타 HS(2n, n)의 이분할 에지수와 고장지름 분석)

  • Kim, Jong-Seok;Lee, Hyeong-Ok
    • The KIPS Transactions:PartA
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    • v.12A no.6
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    • pp.499-506
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    • 2005
  • Recently, Hyper-Star network HS(m,k) which improves the network cost of hypercube has been proposed. In this paper, we show that the bisection width of regular Hyper-Star network HS(2n,n) is maximum (2n-2,n-1). Using the concept of container, we also show that k-wide diameter of HS(2n,n) is less than dist(u,v)+4, and the fault diameter is less than D(HS(2n,n))+2, where dist(u,v) is the shortest path length between any two nodes u and v in HS(2n,n), and D(HS(2n,n)) is its diameter.

Fabrication of a Polishing Machine for 1 m Diameter Aspheric Surface (구경 1 m 정밀 비구면 연마기 제작)

  • 이원용;임동건;이재협;이회윤;송재봉;이윤우;이인원
    • Proceedings of the Optical Society of Korea Conference
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    • pp.36-37
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    • 2002
  • 위성용 천문 망원경의 개발에 있어 광학계는 대구경화되고 회절한계능의 품질이 요구되고 있다. 한국표준과학연구원에서는 위성용 카메라를 위한 지름 1 m 의 비구면 거울의 제작기술을 확보하고자 하는 연구가 진행 중이다. 현재 지름 600 mm 의 비구면 연마기를 확보하여 테스트 중에 있으며, 지름 1m 비구면 가공을 위한 연마기를 제작 중에 있다. 비구면 가공을 위해서는 측정기술 또한 중요하다. (중략)

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