In this paper we deal withthe problem of finding an optimal query execution plan in database systems. We improve the analysis of a polynomial-time approximation algorithm due to Makino et al. for designing query exec...
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In this paper we deal withthe problem of finding an optimal query execution plan in database systems. We improve the analysis of a polynomial-time approximation algorithm due to Makino et al. for designing query execution plans with almost optimal number of parallel steps. this algorithm is based on the concept of edge ranking of graphs. We use a new upper bound for the edge ranking number of a tree to derive a better worst-case performance guarantee for this algorithm. We also present some experimental results obtained during the tests of the algorithm on random graphs in order to compare the quality of both approximation ratios on average. Boththeoretical analysis and experimental results indicate the superiority of our approach.
Computer simulation is a versatile and commonly used tool for the design and evaluation of systems with different degrees of complexity. Power distribution systems and electric railway network are areas for which comp...
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ISBN:
(纸本)0852967918
Computer simulation is a versatile and commonly used tool for the design and evaluation of systems with different degrees of complexity. Power distribution systems and electric railway network are areas for which computer simulations are being heavily applied. A dominant factor in evaluating the performance of a software simulator is its processing time, especially in the cases of real-time simulation. parallelprocessing provides a viable mean to reduce the computing time and is therefore suitable for building real-time simulators. In this paper, we present different issues related to solving the power distribution system withparallel computing based on a multiple-CPU server and we will concentrate, in particular, on the speedup performance of such an approach.
In this paper parallel solving symmetric eigenproblems, which include standard and generalized eigenvalue problems, is discussed. For standard eigenvalue problem and tridiagonal eigenvalue problem is not the key point...
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Fast implementation of stereo depth estimation algorithms on low-cost processors is demanding both insight of the algorithmic architecture and efficient parallelization techniques. this paper proposes an ARM-base Open...
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ISBN:
(纸本)9781728133263
Fast implementation of stereo depth estimation algorithms on low-cost processors is demanding both insight of the algorithmic architecture and efficient parallelization techniques. this paper proposes an ARM-base OpenMP parallel implementation method of ELAS (Efficient Large-Scale Stereo Algorithms), which is very promising for fast computation on embedded systems. Our experiments were conducted under multi-core environments, both on an 8-core computer and an 8-core ARM ODROID-XU4. the parallel performance was examined in two ways: single image's parallelprocessing and batch processing of an image set containing seven pictures. Experimental results demonstrate the efficiency of our acceleration method, which can achieve a speeding-up for more than four times compared withthe original sequential implementation.
Focusing on the Wavelet Transform, the paper explores four parallel Wavelet Transform algorithms and techniques from the perspectives of data parallel and algorithm parallel for remote sensing images. Among them, the ...
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ISBN:
(纸本)9781728199283
Focusing on the Wavelet Transform, the paper explores four parallel Wavelet Transform algorithms and techniques from the perspectives of data parallel and algorithm parallel for remote sensing images. Among them, the algorithm based on "Working Pool parallel" achieves dynamic load balance without any limits to the scale of the data and the number of the Slaves. therefore, this algorithm is easier to achieve the goal of processingthe vast data of remote sensing images rapidly in the distributed network systems.
Raman spectrometry is a technique that allows detecting chemical products through a number of representative peaks found in an image spectrum or numeric series of data. Raman spectrometry is a necessary technic in man...
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ISBN:
(纸本)9781538606865
Raman spectrometry is a technique that allows detecting chemical products through a number of representative peaks found in an image spectrum or numeric series of data. Raman spectrometry is a necessary technic in many fields such as physics, chemistry and Biology. the Raman spectrometry machine analyses a product and generates images as a curve. the interpretation of the curves peaks permits to detect the chemical origin of the analyzed product. Scientists do this operation manually, which makes it hard and long in terms of time. the aim of the present paper is to automate the molecule detection operation using image-processing techniques. We propose a parallel solution to detect the peaks using OpenCL on Graphics processing Unit (GPU). GPUs allow us to make the application faster and more efficient, thanks to its multicore architecture.
this paper describes an insertion opportunity for optical interconnection technology in embedded massively parallel processors for radar signal processing.
ISBN:
(纸本)0818685727
this paper describes an insertion opportunity for optical interconnection technology in embedded massively parallel processors for radar signal processing.
To accelerate the execution of most DSP(Digital Signal processing) algorithms such as FFT, FIR, Vector operations, while keeping the flexibility of the chip, a reconfigurable architecture (named ReDAr) for DSP is prop...
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ISBN:
(纸本)078037889X
To accelerate the execution of most DSP(Digital Signal processing) algorithms such as FFT, FIR, Vector operations, while keeping the flexibility of the chip, a reconfigurable architecture (named ReDAr) for DSP is proposed and implemented, and finally will be applied to the Radar system of Automatic Navigation Equipment. By analyzing these algorithms, the structure of Reconfigurable processing Element (RPE), the Crossbar interconnect network, the Memory organization. the host controlling strategy, and the data sequencing scheme of the architecture are conceived. and parts of them, including the RPE, Crossbar. data sequencer, are reconfigurable. After configuration. it can be interconnected into a parallel and pipelined framework. closely matching the algorithms and like a dedicated hardware. By simulation. the performances of these algorithms mapped onto this architecture are comparative to algorithm-specific chips in market, and satisfy the requirement of the targeted application.
mpF is a new parallel extension of Fortran 90. It was developed on base of experience of development and use of the mpC parallel programming language. the paper compares programming models of mpC and mpF.
ISBN:
(纸本)3540341412
mpF is a new parallel extension of Fortran 90. It was developed on base of experience of development and use of the mpC parallel programming language. the paper compares programming models of mpC and mpF.
Text classification is a classic topic in natural language processing. In this study, we propose an attention model with multi-layer supervision for this task. In our model, the previous context vector is directly use...
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ISBN:
(纸本)9781450377072
Text classification is a classic topic in natural language processing. In this study, we propose an attention model with multi-layer supervision for this task. In our model, the previous context vector is directly used as attention to select the required features, and multi-layer supervision is used for text classification, i.e., the prediction losses are combined across all layers in the global cost function. the main contribution of our model is that the context vector is not only used as attention but also as a representation of an input text for classification at each layer. We conducted experiments based on five benchmark text classification data sets and the results indicate that our model can improve classification performance when applied to most of the data sets.
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