• Title/Summary/Keyword: splitting algorithms

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A Loop Transformation for Parallelism from Single Loops

  • Jeong, Sam-Jin
    • International Journal of Contents
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    • v.2 no.4
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    • pp.8-11
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    • 2006
  • This paper describes several loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops into parallel loops.

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Parallelism for Single Loops with Multiple Dependences

  • Jeong, Sam-Jin
    • International Journal of Contents
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    • v.3 no.3
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    • pp.15-19
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    • 2007
  • We review some loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the iteration and distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops with one dependence as well as with multiple dependences into parallel loops.

Interpretability Comparison of Popular Decision Tree Algorithms (대표적인 의사결정나무 알고리즘의 해석력 비교)

  • Hong, Jung-Sik;Hwang, Geun-Seong
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.44 no.2
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    • pp.15-23
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    • 2021
  • Most of the open-source decision tree algorithms are based on three splitting criteria (Entropy, Gini Index, and Gain Ratio). Therefore, the advantages and disadvantages of these three popular algorithms need to be studied more thoroughly. Comparisons of the three algorithms were mainly performed with respect to the predictive performance. In this work, we conducted a comparative experiment on the splitting criteria of three decision trees, focusing on their interpretability. Depth, homogeneity, coverage, lift, and stability were used as indicators for measuring interpretability. To measure the stability of decision trees, we present a measure of the stability of the root node and the stability of the dominating rules based on a measure of the similarity of trees. Based on 10 data collected from UCI and Kaggle, we compare the interpretability of DT (Decision Tree) algorithms based on three splitting criteria. The results show that the GR (Gain Ratio) branch-based DT algorithm performs well in terms of lift and homogeneity, while the GINI (Gini Index) and ENT (Entropy) branch-based DT algorithms performs well in terms of coverage. With respect to stability, considering both the similarity of the dominating rule or the similarity of the root node, the DT algorithm according to the ENT splitting criterion shows the best results.

Estimation of splitting tensile strength of modified recycled aggregate concrete using hybrid algorithms

  • Zhu, Yirong;Huang, Lihua;Zhang, Zhijun;Bayrami, Behzad
    • Steel and Composite Structures
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    • v.44 no.3
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    • pp.389-406
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    • 2022
  • Recycling concrete construction waste is an encouraging step toward green and sustainable building. A lot of research has been done on recycled aggregate concretes (RACs), but not nearly as much has been done on concrete made with recycled aggregate. Recycled aggregate concrete, on the other hand, has been found to have a lower mechanical productivity compared to conventional one. Accurately estimating the mechanical behavior of the concrete samples is a most important scientific topic in civil, structural, and construction engineering. This may prevent the need for excess time and effort and lead to economic considerations because experimental studies are often time-consuming, costly, and troublous. This study presents a comprehensive data-mining-based model for predicting the splitting tensile strength of recycled aggregate concrete modified with glass fiber and silica fume. For this purpose, first, 168 splitting tensile strength tests under different conditions have been performed in the laboratory, then based on the different conditions of each experiment, some variables are considered as input parameters to predict the splitting tensile strength. Then, three hybrid models as GWO-RF, GWO-MLP, and GWO-SVR, were utilized for this purpose. The results showed that all developed GWO-based hybrid predicting models have good agreement with measured experimental results. Significantly, the GWO-RF model has the best accuracy based on the model performance assessment criteria for training and testing data.

Parallelism for Single Loops with Non-uniform Dependences (비균일 단일루프에서의 병렬화)

  • Jeong, Sam-Jin
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.565-569
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    • 2006
  • This paper reviews some loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops into parallel loops.

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Fast Algorithms to Generate the Codebook for Vector Quantization in Image Coding (화상 벡터 양자화의 코드북 구성을 위한 고속 알고리즘)

  • 이주희;정해묵;이충웅
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.1
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    • pp.105-111
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    • 1990
  • In this paper, fast algorithms to generate the codebook of vector quantization in image coding, are proposed. And an efficient algorithm to guess a initial codebook, namely, binary splitting method, is proposed. We generated the initial codebook by binary splitting method and then reduced the searching time using Iterative Optimization algorithm as an alternate to the generalized Lloyd algorithm and several information from binary splitting method. And the searching time and performance can be traded off by varying the searching range. With this proposed algorithm, the computation time can be reduced by a factor of 60 Without any degradation of image quality.

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Experimental Evaluation of Routing Algorithms for Optimal Load Balancing on SONET Rings with Demand Splitting (분할이 허용된 SONET 링의 루팅 해법들에 대한 비교 분석)

  • 명영수;김후곤
    • Korean Management Science Review
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    • v.18 no.2
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    • pp.107-116
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    • 2001
  • In the ring leading problem with demand splitting, traffic demands are given for each pair of nodes in an undirected ring network and a flow is routed in either of the two directions, clockwise and counter-clockwise. The load of a link is the sum of the flows routed through the link and the objective of the problem is to minimize the maximum link load on the ring. Recently, four different optimal a1gorithms have been developed for solving the problem. In this paper, we compare those algorithms in a single framework and conduct a computational study to evaluate the practical performance of those algorithms.

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Parallelism for Nested Loops with Simple Subscripts

  • Jeong, Sam-Jin
    • International Journal of Contents
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    • v.4 no.4
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    • pp.1-6
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    • 2008
  • In this paper, we propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the iteration and distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences (MPSL). By the extension of the MPSL method, we also apply to exploit parallelism from nested loops with simple subscripts, based on cycle shrinking and loop interchanging method. The algorithms generalize how to transform general single loops with non-uniform dependences as well as nested loops with simple subscripts into parallel loops.

RELAXED PROXIMAL POINT ALGORITHMS BASED ON A-AXIMAL RELAXED MONOTONICITY FRAMEWORKS WITH APPLICATIONS

  • Agarwal, Ravi P.;Verma, Ram U.
    • East Asian mathematical journal
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    • v.27 no.5
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    • pp.545-555
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    • 2011
  • Based on the A-maximal(m)-relaxed monotonicity frameworks, the approximation solvability of a general class of variational inclusion problems using the relaxed proximal point algorithm is explored, while generalizing most of the investigations, especially of Xu (2002) on strong convergence of modified version of the relaxed proximal point algorithm, Eckstein and Bertsekas (1992) on weak convergence using the relaxed proximal point algorithm to the context of the Douglas-Rachford splitting method, and Rockafellar (1976) on weak as well as strong convergence results on proximal point algorithms in real Hilbert space settings. Furthermore, the main result has been applied to the context of the H-maximal monotonicity frameworks for solving a general class of variational inclusion problems. It seems the obtained results can be used to generalize the Yosida approximation that, in turn, can be applied to first- order evolution inclusions, and can also be applied to Douglas-Rachford splitting methods for finding the zero of the sum of two A-maximal (m)-relaxed monotone mappings.

STUDY ON THE SPLITTING ALGORITHMSOF THE INCOMPRESSIBLE NAVIER-STOKES EQUATIONS USING P1P1/P2P1 FINITE ELEMENT FORMULATION (P2P1/P1P1 유한요소 공식을 이용한 비압축성 Navier-Stokes 방정식의 분리 해법에 대한 연구)

  • Cho Myung H.;Choi Hyoung G.;Yoo Jung Y.;Park Jae I.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.10a
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    • pp.117-124
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    • 2005
  • Splitting algorithms of the incompressible Navier-Stokes equations using P1P1/P2P1 finite element formulation are newly proposed. P1P1 formulation allocates velocity and pressure at the same nodes, while P2P1 formulation allocates pressure only at the vertex nodes and velocity at both the vertex and mid nodes. For comparison of the elapsed time and accuracy of the two methods, they have been applied to the well-known benchmark problems. The three cases chosen are the two-dimensional steady and unsteady flows around a fixed cylinder, decaying vortex, and impinging slot jet. It is shown that the proposed P2P1 semi-splitting method performs better than the conventional P1P1 splitting method in terms of both accuracy and computation time.

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