The determination of flow directions is an essential step for drainage network extraction, and flat surfaces are common features in flow direction determination. With the challenge of a massive volume of digital eleva...
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We propose a novel algorithm for extracting data from images of tabular documents having a specific structure. Our proposed method is able to maintain the original table format and structure, and offers better efficie...
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With regard to the research on financial risk management, Value-at-Risk(VaR) has been widely accepted as a standard approach to financial risk management. There are various ways applicable to calculate VaR, of which M...
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Several leading-edge applications such as pathology detection, biometric identification, and face recognition are based mainly on blob and line detection. To address this problem, Eigen value computing has been common...
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Several leading-edge applications such as pathology detection, biometric identification, and face recognition are based mainly on blob and line detection. To address this problem, Eigen value computing has been commonly employed due to its accuracy and robustness. However, Eigen value computing requires a raised computational processing, intensive memory data access, and data overlapping, which involve higher execution times. To overcome these limitations, we propose in this paper a new parallel strategy to implement Eigen value computing using a graphics processing unit (GPU). Our contributions are (1) to optimize instruction scheduling to reduce the computation time, (2) to efficiently partition processing into blocks to increase the occupancy of streaming multiprocessors, (3) to provide efficient input data splitting on shared memory to benefit from its lower access time, and (4) to propose new data management of shared memory to avoid access memory conflict and reduce memory bank accesses. Experimental results show that our proposed GPU parallel strategy for Eigen value computing achieves speedups of 27 compared with a multithreaded implementation, of 16 compared with a predefined function in the OpenCV library, and of eight compared with a predefined function in the Cublas library, all of which are performed into a quad core multi-central-processing unit platform. Next, our parallel strategy is evaluated through an Eigen value-based method for retinal thick vessel segmentation, which is essential for detecting ocular pathologies. Eigen value computing is executed in 0.017 s when using Structured Analysis of the Retina database images. Accordingly, we achieved real-time thick retinal vessel segmentation with an average execution time of about 0.039 s. (C) 2020 SPIE and IS&T
Many real-world domains contain multiple agents behaving strategically with probabilistic transitions and uncertain (potentially infinite) duration. Such settings can be modeled as stochastic games. While algorithms h...
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The paper introduces a novel model of parallel metaheuristic optimization algorithms. The hierarchical graph model of a parallel optimization algorithm is proposed. It consists of the model for a parallel optimization...
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The paper introduces a novel model of parallel metaheuristic optimization algorithms. The hierarchical graph model of a parallel optimization algorithm is proposed. It consists of the model for a parallel optimization algorithm at the top level of the hierarchy and the model for a sequential optimization algorithm at the bottom level. The unified representation of a metaheuristic optimization algorithm, which allows representing a class of metaheuristic algorithms, is used. The extension of the proposed model to the parametric hierarchical model is proposed. Graph model transformations for a parallel algorithm analysis and synthesis are introduced. The representation of several metaheuristic algorithms with the proposed model is discussed.
Determinants has been used intensively in a variety of applications through history. It also influenced many fields of mathematics like linear algebra. Finding the determinants of a squared matrix can be done using a ...
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ISBN:
(纸本)9781479904624
Determinants has been used intensively in a variety of applications through history. It also influenced many fields of mathematics like linear algebra. Finding the determinants of a squared matrix can be done using a variety of methods, including well-known methods of Leibniz formula and Laplace expansion which calculate the determinant of any NxN matrix in O(n!). However, decomposition methods, such as: LU decomposition, Cholesky decomposition and QR decomposition, have replaced the native methods with a significantly reduced complexity of O(n boolean AND 3). In this paper, we introduce two parallel algorithms for Laplace expansion and LU decomposition. Then, we analyze them and compare them with their perspective sequential algorithms in terms of run time, speed-up and efficiency, where new algorithms provided better results. At maximum, in Laplace expansion, it became 129% faster, whereas in LU Decomposition, it became 44% faster.
In this work, we present a WZ factorization for a nonsingular diagonally dominant banded matrix. With little modifications in the structures of W and Z, we construct a stable parallel algorithm suitable for solving na...
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ISBN:
(纸本)9781665410175
In this work, we present a WZ factorization for a nonsingular diagonally dominant banded matrix. With little modifications in the structures of W and Z, we construct a stable parallel algorithm suitable for solving narrow banded nonsingular diagonally dominant linear systems using divide and conquer technique. Partition the coefficient matrix along the main diagonal; also partition the unknown vector and the right hand side vector accordingly. The coefficient matrix of the ‘reduced system’ which is obtained by collecting the first ß and last ß equations from each partition, where ß is semibadwidth of the given banded linear system, is proved to be nonsingular diagonally dominant. The backward error analysis of the algorithm is presented and the algorithm is proved to be numerically stable. Numerical experiments are conducted to check the performance of the parallel algorithm and to compare the present parallel algorithm with the corresponding subroutines of ScaLAPACK. The performance of the parallel algorithm is evaluated in terms of speedup and scalability.
In recent years, filter bank multicarrier (FBMC) has recaptured widespread interests for its possible applications in cognitive radio and dynamic spectrum access. A distinctive feature for cognitive radio is its adapt...
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ISBN:
(纸本)9781467362351
In recent years, filter bank multicarrier (FBMC) has recaptured widespread interests for its possible applications in cognitive radio and dynamic spectrum access. A distinctive feature for cognitive radio is its adaptivity to environment. When environment changes, a cognitive radio will change its parameters to optimize the transmission and receiving. Thus it is desirable to design a unified structure and algorithm for FBMC that needs little change for different parameters. In this paper, we propose a unified structure and parallel algorithms to implement the FBMC. The FBMC system and parallel algorithms are constructed based on the normalized prototype filter. The coefficients of the normalized prototype filter can be pre-computed and stored. The proposed parallel algorithms have the same structure for various choices of time duration, subcarrier spacing and bandwidth. Combined with known parallel algorithms for the fast Fourier transform (FFT), the proposed algorithms fully parallelize the computations for the transmitter and receiver, which can run much faster than conventional serial algorithms as modern processors usually have massive parallel capability.
In the last two decades we observed a considerably improvement in algorithms' performances and their ability to solve hard combinatorial optimization problems. One of these problems is the knapsack sharing problem...
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ISBN:
(纸本)9781665442329
In the last two decades we observed a considerably improvement in algorithms' performances and their ability to solve hard combinatorial optimization problems. One of these problems is the knapsack sharing problem (KSP). The latter problem is a challenging variant of the well-known NP-hard single knapsack problem. In fact, we can find in the literature several exact and heuristic resolution approaches to solve the (KSP). We mainly propose here an improvement and an adaptation to parallel computing of one of the existing and most recent algorithm in the literature. The approach is a constructive tree search that runs in two phases: the initial solution construction phase and the second phase where we build the optimal solution through a customized branch and bound. We applied a parallel computing on this second phase in order to improve the overall computational time. Finally we present a comparative study on instances from literature to show the positive effect of parallel processing on the computing time.
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