• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(A)
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• pp.11-12
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• 2010

• 한국CDE학회논문집
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• 제11권2호
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• pp.148-155
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• 2006

This paper presents a new method for assessing the efficiency of production process plans using tolerance chart to lower production cost. The tolerance chart is used to predict the accuracy of a part that is to be produced following the process plan, and to carry out the quantitative measurement on the efficiency of the process plan. By comparing the values of design tolerances and their corresponding resultant tolerances calculated using the tolerance chart, the process plan that is incapable of satisfying the design requirements and the faulty production operations can be identified. Similarly, the process plan that imposes unnecessarily high accuracy and wasteful production operations can also be identified. For the latter, a quantitative measure on the efficiency of the process plan is introduced. The higher the unnecessary cost of the production, the poor is the efficiency of the process plan. A coefficient is introduced for measuring the process plan efficiency. The coefficient also incorporates two weighting factors to reflect the difficulty of manufacturing operations and number of dimensional tolerances involved. To facilitate the identification of the machining operations and the machined surfaces, which are related to the unnecessarily tight resultant tolerances caused by the process plan, a rooted tree representation of the tolerance chart is introduced, and its use is demonstrated. An example is presented to illustrate the new method. This research introduces a new quantitative process plan evaluation method that may lead to the optimization of process plans.

• Journal of applied mathematics & informatics
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• 제30권3_4호
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• pp.541-553
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• 2012

In this paper, we study some limit properties of the harmonic mean of random transition probability for a second-order nonhomogeneous Markov chain on the generalized gambling system indexed by a tree by constructing a nonnegative martingale. As corollary, we obtain the property of the harmonic mean and the arithmetic mean of random transition probability for a second-order nonhomogeneous Markov chain indexed by a double root tree.

• 한국전산응용수학회:학술대회논문집
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• 한국전산응용수학회 2003년도 KSCAM 학술발표회 프로그램 및 초록집
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• pp.16.1-16
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• 2003

A subset S of vertices of a graph G is independent if no two vertices of S are adjacent by an edge in G. Also we say that S is maximal independent if it is contained In no larger independent set in G. A planted plane tree is a tree that is embedded in the plane and rooted at an end-vertex. A (k＋1) -valent tree is a planted plane tree in which each vertex has degree one or (k＋1). We classify maximal independent sets of (k＋1) -valent trees into two groups, namely, type A and type B maximal independent sets and consider specific independent sets of these trees. We study relations among these three types of independent sets. Using the relations, we count the number of all maximal independent sets of (k＋1) -valent trees with n vertices of degree (k＋1).

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제3권6호
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• pp.612-627
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• 2009

The high-level contribution of this paper is to illustrate the effectiveness of using graph theory tree traversal algorithms (pre-order, in-order and post-order traversals) to generate the chain of sensor nodes in the classical Power Efficient-Gathering in Sensor Information Systems (PEGASIS) data aggregation protocol for wireless sensor networks. We first construct an undirected minimum-weight spanning tree (ud-MST) on a complete sensor network graph, wherein the weight of each edge is the Euclidean distance between the constituent nodes of the edge. A Breadth-First-Search of the ud-MST, starting with the node located closest to the center of the network, is now conducted to iteratively construct a rooted directed minimum-weight spanning tree (rd-MST). The three tree traversal algorithms are then executed on the rd-MST and the node sequence resulting from each of the traversals is used as the chain of nodes for the PEGASIS protocol. Simulation studies on PEGASIS conducted for both TDMA and CDMA systems illustrate that using the chain of nodes generated from the tree traversal algorithms, the node lifetime can improve as large as by 19%-30% and at the same time, the energy loss per node can be 19%-35% lower than that obtained with the currently used distance-based greedy heuristic.

• ETRI Journal
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• 제22권1호
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• pp.30-37
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• 2000

Existing tree construction mechanisms are classified into source-based trees and center-based trees. The source-based trees produce a source-rooted tree with a low delay. However, for the applications with multiple senders, the management overheads for routing tables and resource reservations are too high. The center-based trees are easy to implement and manage, but a priori configuration of candidate center nodes is required, and the optimization mature such as tree cost and delay is not considered. In this paper, we propose a new multicast tree building algorithm. The proposal algorithm basically builds a non-center based shared tree. In particular, any center node is not pre-configured. In the purposed algorithm, a multicast node among current tree nodes is suitably assigned to each incoming user: Such a node is selected in a fashion that tree cost and the maximum end-to-end delay on the tree are jointly minimized. The existing and proposed algorithms are compared by experiments. In the simulation results, it is shown that the proposed algorithm approximately provides the cost saving of 30% and the delay saving of 10%, compared to the existing approaches. In conclusion, we see that the cost and delay aspects for multicast trees can be improved at the cost of additional computations.

• 한국인터넷방송통신학회논문지
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• 제13권4호
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• pp.9-15
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• 2013

데이터센터 네트워크와 관련된 대부분의 최근 연구들은 Fat-Tree와 같은 대칭성 있는 다중루트트리 토포로지를 가정한다. 이러한 네트워크에서는 패킷단위의 분산방식이 매우 효과적이지만 장애가 발생할 경우에는 토포로지의 대칭성이 깨져 TCP의 성능이 저하된다고 알려져 있다. 본 논문에서는 모의실험을 통하여 Fat-Tree에서 링크 장애가 패킷분산방식의 성능에 주는 영향을 다시 조사한다. 모의실험결과는 큰 규모의 Fat-Tree에서는 링크 장애가 발생해도TCP 성능이 저하될 만큼 패킷 순서 바뀜이 심하게 발생하지 않음을 보여주며 링크 장애에 대비한 복잡한 방식이 반드시 필요한 것은 아님을 암시한다.

• 정보처리학회논문지A
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• 제14A권5호
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• pp.263-268
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• 2007

본 논문에서는 Folded 하이퍼-스타 FHS(2n,n)의 위상적 성질들을 분석한다. 먼저, FHS(2n,n)이 최대고장허용도를 가짐을 보이고, double rooted 스패닝 트리를 이용한 방송 수행 시간이 2n-1임을 보인다. 그리고 FHS(2n,n)이 Folded 하이퍼큐브에 연장율 1로 임베딩 가능함을 보이고, Folded 하이퍼큐브가 FHS(2n,n)에 연장율 2, 밀집율 1로 임베딩 가능함을 보인다.

• 한국ITS학회 논문지
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• 제11권1호
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• pp.92-97
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• 2012

본 논문은 무선 센서망에서 이동 싱크의 동적 브랜치를 통한 데이터 수집 방안을 제안한다. 데이터 전달에 이용되는 트리는 싱크 노드를 루트 노드로 하고 복수개의 브랜치를 가지며, 싱크의 이동과 함께 노드의 부모가 동적으로 변경된다. 또한, 홉 기반의 필터와 플러딩의 효과적인 제한을 통해 제어 트래픽을 줄이고, 효율적인 데이터 전달을 이루는 트리구성 방안을 다룬다. 시뮬레이션 결과를 통해, 제안된 데이터 수집 방안이 기존의 방안과 비교하여, 높은 데이터 도착율과 낮은 전달 지연, 그리고 효과적인 에너지 절약을 보이는 것은 확인할 수 있었다.

• Journal of applied mathematics & informatics
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• 제41권4호
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• pp.839-848
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• 2023

Let G be a simple undirected graph. A planar graph known as a Halin graph(HG) is characterised by having three connected and pendent vertices of a tree that are connected by an outer cycle. A subset S of V is said to be a dominating set of the graph G if each vertex u that is part of V is dominated by at least one element v that is a part of S. The domination number of a graph is denoted by the γ(G), and it corresponds to the minimum size of a dominating set. A dominating set S is called a secure dominating set if for each v ∈ V＼S there exists u ∈ S such that v is adjacent to u and S₁ = (S＼{v}) ∪ {u} is a dominating set. The minimum cardinality of a secure dominating set of G is equal to the secure domination number γ_s(G). In this article we found the secure domination number of Halin graph(HG) with perfet k-ary tree and also we determined secure domination of rooted product of special trees.