• Title/Summary/Keyword: computational algorithm

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Development of Delaunay Triangulation Algorithm Using Subdivision (분할 Delaunay 삼각화 알고리즘 개발)

  • 박시형;이성수
    • Korean Journal of Computational Design and Engineering
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    • v.7 no.4
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    • pp.248-253
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    • 2002
  • Delaunay triangulation is well balanced in the sense that the triangles tend toward equiangularity. And so, Delaunay triangulation hasn't some slivers triangle. It's commonly used in various field of CAD applications, such as reverse engineering, shape reconstruction, solid modeling and volume rendering. For Example, In this paper, an improved Delaunay triangulation is proposed in 2-dimensions. The suggested algorithm subdivides a uniform grids into sub-quad grids, and so efficient where points are nonuniform distribution. To get the mate from quad-subdivision algorithm, the area where triangulation-patch will be most likely created should be searched first.

Rule of Combination Using Expanded Approximation Algorithm (확장된 근사 알고리즘을 이용한 조합 방법)

  • Moon, Won Sik
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.9 no.3
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    • pp.21-30
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    • 2013
  • Powell-Miller theory is a good method to express or treat incorrect information. But it has limitation that requires too much time to apply to actual situation because computational complexity increases in exponential and functional way. Accordingly, there have been several attempts to reduce computational complexity but side effect followed - certainty factor fell. This study suggested expanded Approximation Algorithm. Expanded Approximation Algorithm is a method to consider both smallest supersets and largest subsets to expand basic space into a space including inverse set and to reduce Approximation error. By using expanded Approximation Algorithm suggested in the study, basic probability assignment function value of subsets was alloted and added to basic probability assignment function value of sets related to the subsets. This made subsets newly created become Approximation more efficiently. As a result, it could be known that certain function value which is based on basic probability assignment function is closely near actual optimal result. And certainty in correctness can be obtained while computational complexity could be reduced. by using Algorithm suggested in the study, exact information necessary for a system can be obtained.

An Adaptive Motion Estimation Algorithm Using Spatial Correlation (공간 상관성을 이용한 적응적 움직임 추정 알고리즘)

  • 박상곤;정동석
    • Proceedings of the IEEK Conference
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    • 2000.06d
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    • pp.43-46
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    • 2000
  • In this paper, we propose a fast adaptive diamond search algorithm(FADS) for block matching motion estimation. Fast motion estimation algorithms reduce the computational complexity by using the UESA (Unimodal Error Search Assumption) that the matching error monotonically increases as the search moves away from the global minimum error. Recently many fast BMAs(Block Matching Algorithms) make use of the fact that the global minimum points in real world video sequences are centered at the position of zero motion. But these BMAs, especially in large motion, are easily trapped into the local minima and result in poor matching accuracy. So, we propose a new motion estimation algorithm using the spatial correlation among the adjacent blocks. We change the origin of search window according to the spatially adjacent motion vectors and their MAE(Mean Absolute Error). The computer simulation shows that the proposed algorithm has almost the same computational complexity with UCBDS(Unrestricted Center-Biased Diamond Search)〔1〕, but enhance PSNR. Moreover, the proposed algorithm gives almost the same PSNR as that of FS(Full Search), even for the large motion case, with half the computational load.

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Flood Impact Pressure Analysis of Vertical Wall Structures using PLIC-VOF Method with Lagrangian Advection Algorithm

  • Phan, Hoang-Nam;Lee, Jee-Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.23 no.6
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    • pp.675-682
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    • 2010
  • The flood impact pressure acting on a vertical wall resulting from a dam-breaking problem is simulated using a navier-Stokes(N-S) solver. The N-S solver uses Eulerian Finite Volume Method(FVM) along with Volume Of Fluid(VOF) method for 2-D incompressible free surface flows. A Split Lagrangian Advection(SLA) scheme for VOF method is implemented in this paper. The SLA scheme is developed based on an algorithm of Piecewise Linear Interface Calculation(PLIC). The coupling between the continuity and momentum equations is affected by using a well-known Semi-Implicit Method for Pressure-Linked Equations (SIMPLE) algorithm. Several two-dimensional numerical simulations of the dam-breaking problem are presented to validate the accuracy and demonstrate the capability of the present algorithm. The significance of the time step and grid resolution are also discussed. The computational results are compared with experimental data and with computations by other numerical methods. The results showed a favorable agreement of water impact pressure as well as the global fluid motion.

Improvement of Computational Speed for the SVD Background Clutter Signal Subtraction Algorithm in IR-UWB Radar Systems (IR-UWB Radar 시스템에서 특이값 분해를 이용한 클러터 신호 제거 알고리즘의 연산속도 향상 기법)

  • Baek, In Seok;Jung, Moon Kwun;Cho, Sung Ho
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.38C no.1
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    • pp.89-96
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    • 2013
  • This paper presents an improved clutter signal removal algorithm using Singular Value Decomposition(SVD). For indoor positioning system using IR-UWB Radar, the target signal is extracted from received signal. We use clutter signal removal algorithm using SVD for target signal extraction. Clutter signal removal algorithm using SVD has the advantage of operation but the disadvantage of high computational complexity. In this paper, we propose a method to improve computational complexity. As the experimental results, it is confirmed that the method presented in this paper improve the computational complexity of clutter removal algorithm using SVD.

Design Centering by Genetic Algorithm and Coarse Simulation

  • Jinkoo Lee
    • Korean Journal of Computational Design and Engineering
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    • v.2 no.4
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    • pp.215-221
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    • 1997
  • A new approach in solving design centering problem is presented. Like most stochastic optimization problems, optimal design centering problems have intrinsic difficulties in multivariate intergration of probability density functions. In order to avoid to avoid those difficulties, genetic algorithm and very coarse Monte Carlo simulation are used in this research. The new algorithm performs robustly while producing improved yields. This result implies that the combination of robust optimization methods and approximated simulation schemes would give promising ways for many stochastic optimizations which are inappropriate for mathematical programming.

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Maneuvering Target Tracking Using Multiresolutional Interacting Multiple Model Filter

  • Yu, C,H.;Choi, J.W.;Song, T.L.
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2340-2344
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    • 2003
  • This paper considers a tracking filter algorithm which can track a maneuvering target. Multiresolutional Interacting Multiple Model (MRIMM) algorithm is proposed to reduce computational burden. In this paper multiresolutional state space model equation and multiresolutional measurement equation are derived by using wavelet transform. This paper shows the outline of MRIMM algorithm. Simulation results show that MRIMM algorithm maintains a good tracking performance and reduces computational burden.

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Adaptive C-GSC Algorithm for Reducing the Computational Complexity (계산량 감소를 위한 적응 C-GSC 알고리듬)

  • 문성훈;한동석이규만조명제
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.1187-1190
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    • 1998
  • In this paper we propose a new efficient generalized sidelobe canceller(GSC) algorithm, using the efficient frequency domain LMS algorithm, which has much less weights to update. We only update part of all the weights according to magnitude of each frequency bin. So, the new proposed GSC algorithm, which is called censored GSC(C-GSC), can greatly reduce the computational complexity.

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Simulated Annealing Algorithm for Optimum Design of Space Truss Structures (입체 트러스구조물의 최적설계를 위한 SA기법)

  • 정제원;박효선
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1999.04a
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    • pp.102-109
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    • 1999
  • Two phase simulated annealing algorithm is presented as a structural optimization technique and applied to minimum weight design of space trusses subjected to stress and displacement constraints under multiple loading conditions. Univariate searching algorithm is adopted for automatic selection of initial values of design variables for SA algorithm. The proper values of cooling factors and reasonable stopping criteria for optimum design of space truss structures are proposed to enhance the performance of optimization process. Optimum weights and design solutions are presented for two well-blown example structures and compared with those reported in the literature.

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