• Title/Summary/Keyword: PRESENT algorithm

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WRR Cell Scheduling Algorithm for Improving Smoothing Scheme (평탄화 기법을 개선한 WRR 셀 스케쥴링 알고리즘)

  • 조해성
    • The Journal of the Korea Contents Association
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    • v.3 no.3
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    • pp.55-62
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    • 2003
  • In this paper, I proposed a new WRR Cell Scheduling algorithm for improving the problem of existing smoothing scheme. in proposed algorithm, when queue of being service VC in present round is emptied, instead VC that difference between assigned weight and length of present buffer is biggest in all VC service. This result efficiency of bandwidth allocation is increased. And above all real-time traffic is serviced, non-real-time to allocate bandwidth of the remainder multimedia-service is possible. In one cycle, number of serviced average cell is increased. And for many eel serviced, length of total Duffer is decreased.

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An Effective Algorithm for Constructing the Dominator Tree from Irreducible Directed Graphs (감축 불가능한 유향그래프로부터 지배자 트리를 구성하기 위한 효과적인 알고리즘)

  • Lee, Dae-Sik;Sim, Son-Kweon;Ahn, Heui-Hak
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.8
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    • pp.2536-2542
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    • 2000
  • The dominator tree presents the dominance frontier from directed graph to the tree. we present the effective algorithm for constructing the dominator tree from arbitrarY directed graph. The reducible flow graph was reduced to dominator tree after dominator calculation. And the irreducible flow graph was constructed to dominator-join graph using join-edge information of information table. For reducing the dominator tree from dominator-join graph, we present the effective sequency reducible algorithm and delay reducible algorithm.

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On Development of Vibrational Analysis Algorithm of Cylindrical Shell Structures With Stiffeners (보강재를 갖는 원통셸 구조물의 진동해석 알고리즘의 개발에 관한 연구)

  • 문덕홍;여동준
    • Journal of KSNVE
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    • v.6 no.4
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    • pp.481-491
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    • 1996
  • In this paper, we formulated algorithm for free vibration analysis of cylindrical shells with stiffeners by applying the transfer influence coefficient method. This was developed as a vibration analysis method suitable for using personal computer(PC). The simple computational results form PC demonstrated the validity of the present algorithm, that is, the computational high accuracy and speed, and the flexibility of programming. We compared with results of the transfer matrix method and the reference. We also confirmed that the present algorithm could provide the solutions of high accuracy for system with a lots of intermediate rigid supports and stiffeners. And all boundary conditions and the intermediate stiff supports between shell and foundation could be treated only by adequately varying the values of the spring constants.

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Fast Parallel Algorithm For Optimal Stack Filter Design (최적 스택필터 설계를 위한 고속병렬기법)

  • Yoo, Ji-Sang
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.36S no.2
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    • pp.88-95
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    • 1999
  • Stack filters are a class of digital nonlinear filters with excellent properties for signal restoration. Unfortunately, present algorithms for designing stack filters with large window size are limited in applications by their computational overhead and serial nature. In this paper, new, highly-parallel algorithm is developed for determining a stack filter which minimizes the mean absolute error criterion. It retains the iterative nature of the present adaptive algorithm, but significantly reduces the number of required to converge to an optima filter. A proof is also give that the proposed algorithm converges to an optimal stack filter.

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Time Historical Response Analysis of Three Dimensional Rectilinear Structure using the TSCM (전달강성계수법을 이용한 3차원 직선형 구조물의 시간이력응답 해석)

  • 문덕홍;강현석;최명수
    • Journal of Advanced Marine Engineering and Technology
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    • v.26 no.1
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    • pp.108-115
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    • 2002
  • This paper suggests a new analysis algorithm for the time historical response of three dimensional rectilinear structure which is frequently found in a pipe line system of plant by the combination of the transfer stiffness coefficient method(TSCM) and the Newmark method. The present analysis algorithm for a time historical response can improve the computational accuracy and time remarkably owing to advantages of the TSCM in comparison with transfer matrix method(TMM). The structural system is modeled as a lumped mass system in this method. The analysis algorithm was formulated far the three dimensional rectilinear structure. We confirmed the validity of the present algorithm by comparing the numerical computation results of TSCM with those of TMM.

Determination of Number of AGVs in Multi-path Systems By Using Genetic Algorithm (GA를 이용한 다중루프 시스템의 AGV 대수 결정 문제)

  • 김환성;이상훈
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.299-299
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    • 2000
  • In this paper, a determination method of number of AGVs fer introducing to the multi-path material handling systems is presented by using genetic algorithm. For serving the raw material to each work stations automatically, there needs to introduce a AGVs for transfer the raw martial. To reduce the overall production cost in the material handling systems, however, a trade off exists between the amount of inventory hold on the shop floor and the number of AGVs needed to provide adequate service. In this paper, firstly a objective function which included the net present fixed costs of each stations and each purchased AGVs, delivering cost. stock inventory cost, and safety stock inventory cost is presented. Secondly by using genetic algorithm, the optimal reorder quantity at each stations is decided, where the number of AGVs is increased step by step. From a simulation with different GA parameters, we can determine a optimal number of AGVs to reduce the overall production cost. Thus, the effectiveness of GA for determining the number of AGVs is verified in automated material handling systems.

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Analysis of Thermal flow Field Uing Equal Order Linear Finite Element and Fractional Step Method (동차선형 유한요소와 Fractional Step방법을 이용한 열유동장의 해석)

  • ;;Yoo, Jung Yul
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.10
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    • pp.2667-2677
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    • 1995
  • A new numerical algorithm using equal order linear finite element and fractional step method has been developed which is capable of analyzing unsteady fluid flow and heat transfer problems. Streamline Upwind Petrov-Galerkin (SUPG) method is used for the weighted residual formulation of the Navier-Stokes equations. It is shown that fractional step method, in which pressure term is splitted from the momentum equation, reduces computer memory and computing time. In addition, since pressure equation is derived without any approximation procedure unlike in the previously developed SIMPLE algorithm based FEM codes, the present numerical algorithm gives more accurate results than them. The present algorithm has been applied preferentially to the well known bench mark problems associated with steady flow and heat transfer, and proves to be more efficient and accurate.

Computing the Dominating-Free Set by Two Point Sets in the Plane

  • Kim, Soo-Hwan
    • Journal of information and communication convergence engineering
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    • v.9 no.1
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    • pp.105-109
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    • 2011
  • In this paper, we study the dominating-free sest which is defined as follows: k points called servers and n points called clients in the plane are given. For a point p in the plane is said to be dominated by a client c if for every server s, the distance between s and p is greater than the distance between s and c. The dominating-free set is the set of points in the plane which aren't dominated by any client. We present an O(nklogk+$n^2k$) time algorithm for computing the dominating-free set under the $L_1$-metric. Specially, we present an O(nlogn) time algorithm for the problem when k=2. The algorithm uses some variables and 1-dimensional arrays as its principle data structures, so it is easy to implement and runs fast.

Finite Element Analysis of Fluid Flows with Moving Boundary

  • Cha, Kyung-Se;Park, Jong-Wook;Park, Chan-Guk
    • Journal of Mechanical Science and Technology
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    • v.16 no.5
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    • pp.683-695
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    • 2002
  • The objective of the present study is to analyze the fluid flow with moving boundary using a finite element method. The algorithm uses a fractional step approach that can be used to solve low-speed flow with large density changes due to intense temperature gradients. The explicit Lax-Wendroff scheme is applied to nonlinear convective terms in the momentum equations to prevent checkerboard pressure oscillations. The ALE (Arbitrary Lagrangian Eulerian) method is adopted for moving grids. The numerical algorithm in the present study is validated for two-dimensional unsteady flow in a driven cavity and a natural convection problem. To extend the present numerical method to engine simulations, a piston-driven intake flow with moving boundary is also simulated. The density, temperature and axial velocity profiles are calculated for the three-dimensional unsteady piston-driven intake flow with density changes due to high inlet fluid temperatures using the present algorithm. The calculated results are in good agreement with other numerical and experimental ones.

A Study on A Rotation Compensation of Person Identification Algorithm Utilizing Hand Vein Pattern (손등 정맥 패턴을 이용한 개인식별 알고리즘의 회전 보상에 관한 연구)

  • 안장용;주일용;최환수
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.251-254
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    • 2000
  • This paper proposes an enhanced algorithm for person identification system utilizing hand vein pattern. The conventional algorithm does not cope with distortion caused by image rotation caused by misplaced hands on the imaging device. A straightforward approach to consider the rotaional compensation required too much computational load, thus, we devised an approach to expect the rotation direction along with image translation, reducing the compuational requirement dramatically In this paper, we present the details of the algorithm with experimental results with the new algorithm.

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