This paper concerns about modeling of tethered satellites systems (TSS). In this paper, tethers of TSS are modeled as chains of elastic rods connected by rigid joints. A group of spatial vectors are used to describe d...
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The optimal linear attitude estimation algorithm takes Rodrigues parameters as the attitude description, which has advantages of small computation volume and high accuracy. Based on the optimal linear attitude estimat...
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We present a high performance Cholesky factorization algorithm, called BPC for Blocked Packed Cholesky, which performs better or equivalent to the LAPACK DPOTRF subroutine, but with about the same memory requirements ...
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ISBN:
(纸本)354041729X
We present a high performance Cholesky factorization algorithm, called BPC for Blocked Packed Cholesky, which performs better or equivalent to the LAPACK DPOTRF subroutine, but with about the same memory requirements as the LAPACK DPPTRF subroutine, which runs at level 2 BLAS speed. algorithm BPC only calls DGEMM and level 3 kernel routines. It combines a recursive algorithm with blocking and a recursive packed data format. A full analysis of overcoming the non-linear addressing overhead imposed by recursion is given and discussed. Finally, since BPC uses GEMM to a great extent, we easily get a considerable amount of SMP parallelism from an SMP GEMM.
System structure optimization is a well-studied problem in the field of reliability engineering, which aims to achieve the best possible reliability versus cost solutions for the system design. This problem is usually...
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System structure optimization is a well-studied problem in the field of reliability engineering, which aims to achieve the best possible reliability versus cost solutions for the system design. This problem is usually solved for systems that do not change their task and configuration during the mission. However, many practical systems are phased-mission systems (PMS), where the mission involves multiple, consecutive, and nonoverlapping phases of operation. An accurate analysis of PMS must consider the dynamics in system configuration, success criteria, and element behavior as well as statistical dependence of element states across phases. In this paper, we propose a method for solving the structure optimization problem of multistate PMS consisting of nonidentical nonrepairable binary elements. The system configuration and demand as well as the failure distributions of system elements can change from phase to phase. The proposed approach is based on a recursive algorithm for the reliability evaluation of PMS and a genetic algorithm for the structure optimization of PMS. The method is illustrated using an example of a six-phased mission running on an airborne distributed computing system.
We describe the construction of accurate panoramic mosaics from multiple images taken with a rotating camera, or alternatively of a planar scene. The novelty of the approach lies in (i) the transfer of photogrammetric...
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We describe the construction of accurate panoramic mosaics from multiple images taken with a rotating camera, or alternatively of a planar scene. The novelty of the approach lies in (i) the transfer of photogrammetric bundle adjustment techniques to mosaicing;(ii) a new representation of image line measurements enabling the use of lines in camera self-calibration, including computation of the radial and other non-linear distortion;and (iii) the application of the variable state dimension filter to obtain efficient sequential updates of the mosaic as each image is added. We demonstrate that our method achieves better results than the alternative approach of optimising over pairs of images. (C) 2002 Elsevier Science B.V. All rights reserved.
In recent years, along with the further study in incomplete information chess-military chess. How to express and address the incomplete information during the process of game, deciding certain moves strategies to obta...
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ISBN:
(纸本)9781479970162
In recent years, along with the further study in incomplete information chess-military chess. How to express and address the incomplete information during the process of game, deciding certain moves strategies to obtain higher winning rate increasingly become a new issue. An approach using digit to express incomplete information in military chess is proposed in this paper, a model based on guessing probability to address incomplete information in military chess game is designed, and the programming process is provided. In the National Computer Games Tournament, the game program using this model is stronger than the others. Results are shown as 6 wins, 1 draw, and 1 lost. The average time of each moving step is shorter than opponent 2 second.
In this paper,a new multi-dimentional recursive algorithm is given for multi-input, multi-output ARMAX systems. Satisfactory results can all be obtained in many simulation experiments.
ISBN:
(纸本)0780372689
In this paper,a new multi-dimentional recursive algorithm is given for multi-input, multi-output ARMAX systems. Satisfactory results can all be obtained in many simulation experiments.
We compare the results given by different methods to reconstruct cortical sources activity in order to classify EEG in real time. Two motor imagery experiments were performed. The aim was to retrieve from 1 windows of...
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ISBN:
(纸本)9781424441242
We compare the results given by different methods to reconstruct cortical sources activity in order to classify EEG in real time. Two motor imagery experiments were performed. The aim was to retrieve from 1 windows of signal which motor imagery task the subjects were performing. The use of cortical activity reconstruction was compared to Laplacian filtering, which is often used in BCI. A recursive algorithm using Student's t-test was used to select relevant cortical sources. The Beamformer method led to an improvement of the classification for the first experiment, which included six motor imagery tasks. The weighted Minimum-Norm method required the use of a specific head model, extracted from the subject's MRI, to improve the classification. It then gave the best results on the second experiment, achieving a classification rate of 77% compared to 71% for direct use of electrode data and 75% for Laplacian filtering and Beamformer.
In this paper, we propose a recursive and a parallel algorithms, respectively, for constructing independent spanning trees in alternating group networks. The recursive algorithm is BFS-based, while the parallel algori...
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ISBN:
(纸本)9781728189154
In this paper, we propose a recursive and a parallel algorithms, respectively, for constructing independent spanning trees in alternating group networks. The recursive algorithm is BFS-based, while the parallel algorithm is BFS-based and rule-based. Both algorithms are accurate, and furthermore, the parallel algorithm is more efficient than the recursive one.
There are several approaches for computing the inverse of a dense square matrix, say A, namely Gaussian elimination, block wise inversion, and LU factorization (LUF). The latter is used in mathematical software librar...
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ISBN:
(纸本)9781538632505
There are several approaches for computing the inverse of a dense square matrix, say A, namely Gaussian elimination, block wise inversion, and LU factorization (LUF). The latter is used in mathematical software libraries such as SCALAPACK, PBLAS and MATLAB. The inversion routine in SCALAPACK library (called PDGETRI) consists, once the two factors L and U are known (where A=LU), in first inverting U (PDGETRF) then solving a triangular matrix system giving A(-1). A symmetric way consists in first inverting L, then solving a matrix system giving A(-1). Alternatively, one could compute the inverses of both U and L, then their product and get A(-1). On the other hand, the Strassen fast matrix inversion algorithm is known as an efficient alternative for solving our problem. We propose in this paper a series of different versions for parallel dense matrix inversion based on the 'Divide and Conquer' paradigm. A theoretical performance study permits to establish an accurate comparison between the designed algorithms. We achieved a series of experiments that permit to validate the contribution and lead to efficient performances obtained for large matrix sizes i.e. up to 40% faster than SCALAPACK.
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