关键词： Relation algebra   Prime fields   Representation  

摘要： A proper (simple) relation algebra is a collection A of binary relations on a set U such that the top element of the algebra is U x U, and A is closed under union, intersection, complementation, composition, converse and contains the identity relation on U. Proper relation algebras can be constructed using U = Z/pZ as a base set using a method due to Corner. The cycle structure of such an algebra must, in general, be determined a posteriori, normally with the aid of a computer. In this paper, we give an improved algorithm for checking the cycle structure that reduces the time complexity from O(p(2)) to O(p). (C) 2019 Elsevier B.V. All rights reserved.

关键词： walking workers   multi-manned   assembly line balancing   electromagnetic field optimisation  

摘要： Assembly lines are widely used in industrial environments that produce standardised products in high volumes. Multi-manned assembly line is a special version of them that allows simultaneous operation of more than one worker at the same workstation. These lines are widely used in large-sized product manufacturing since they have many advantages over the simple one. This article has dealt with multi-manned assembly line balancing problem with walking workers for minimising the number of workers and workstations as the first and second objectives, respectively. A linear mixed-integer programming formulation of the problem has been firstly addressed after the problem definition is given. Besides that, a metaheuristic based on electromagnetic field optimisation algorithm has been improved. In addition to the classical electromagnetic field optimisation algorithm, a regeneration strategy has been applied to enhance diversification. A particle swarm optimisation algorithm from assembly line balancing literature has been modified to compare with the proposed algorithm. A group of test instances from many precedence diagrams were generated for evaluating the performances of all solution methods. Deviations from lower bound values of the number of workers/workstations and the number of optimal solutions obtained by these methods are concerned as performance criteria. The results obtained by the proposed programming formulations have been also compared with the solutions obtained by the traditional mathematical model of the multi-manned assembly line. Through the experimental results, the performance of the metaheuristic has been found very satisfactory according to the number of obtained optimal solutions and deviations from lower bound values.

关键词： 小学数学   计算教学   优化策略  

摘要： 在小学数学教学中,为了使学生的计算正确率有所提升,教师需要使学生的计算能力得到培养。为了实现这一目的,教师可以对学生进行有效的引导,使他们对计算方法进行灵活的选择,最终使得学生的计算效果得到提升。一旦学生的计算更具个性化,那么他们的数学思维也能够得到发展,进而使得整个数学教学得到优化。

关键词： 非地面点去除   二阶差分   坡度   数学形态学  

摘要： 针对传统点云滤波算法在对大规模无序点云进行非地面点去除时,存在滤波结果误差较大且滤波效率较低的问题,提出一种基于坡度的数学形态学改进滤波算法.该算法首先对点云数据坡度值进行分析,选用二阶差分模型计算格网内坡度值,然后根据最大坡度设置高差阈值,与形态学滤波前后的高差值比较,分离出非地面点.为了验证算法的有效性,选用两个不同区域的无序点云数据进行实验.结果表明:改进算法能较好地以真实局部地形坡度为依据,对地物较多、地形较复杂的区域准确、高效地分离出非地面点,并且能有效保留原始地形特征,且误差相比其他方法较小.

关键词： 数字图像处理   形态学   牌照识   几何特征  

摘要： 在智能交通系统中牌照的自动识别成为关键,由于获取的机动车牌照受天气等因素的影响,存在定位不准。针对上述问题,利用直方图进行图像增强和分段阈值法对牌照图像进行预处理,在通过Sobel算子进行边缘检测,然后根据牌照的几何特征及数学形态学对机动车牌照区域进行精确定位,最后利用LabVIEW平台实现模板匹配和神经网络方法的字符识别。通过仿真实验,能够实现对机动车牌照的准确定位,表明该方法简单有效。

关键词： 数学算法   计算机编程   优化方式   具体分析  

摘要： 以数学算法和计算机编程概述,数学算法对计算机编程优化的重要性为切入点,展开具体分析,并以此为依据,提出了数学算法优化计算机编程的有效方式、数学算法模型思想在计算机编程中的实际运用、数学算法在不同计算机编程语言上的实际运用等内容。希望在今后实际开展计算机编程优化工作时,能够注重数学算法的运用,将实际状况与数学算法模型进行全面结合,为今后信息时代健康长远发展奠定基础。

关键词： Locality of Reference   Multi-Core CPU   Petrinet Modelling   Pipelined Parallelism   POSIX Threads   Processor Affinity   Thomas Algorithm /TDMA   Tridiagonal System  

摘要： Fast and efficient tridiagonal solvers are highly appreciated in scientific and engineering domain, but challenging optimization task for computer engineers. The state-of-the-art developments in multi-core computing paves the way to meet this challenge to an extent. The technical advances in multi-core computing provide opportunities to exploit lower levels of parallelism and concurrency for inherently sequential algorithms. In this article, the authors present an optimal performance pipelined parallel variant of the conventional Tridiagonal Matrix Algorithm (TDMA), aka the Thomas algorithm, on a multi-core CPU platform. The implementation, analysis and performance comparison of the proposed pipelined parallel TDMA and the conventional version are performed on an Intel SIMD multi-core architecture. The results are compared in terms of elapsed time, speedup, cache miss rate. For a system of 'n' linear equations where n = 2<^>36 in presented pipelined parallel TDMA achieves speedup of 1.294X with a parallel efficiency of 43% initially and inclines towards linear speed up as the system grows.

关键词： 小学   “算法多样化”   计算能力  

摘要： 算法多样化的思想强调的是尊重学生的独立思考,鼓励学生探索不同的方法,并不是让学生掌握多种方法,教师应该在课堂中鼓励、尊重学生思维的结果,引导学生进行讨论和交流,适时点拨,肯定有价值、有创意的方法,从而培养学生良好的思维习惯和探索创新的精神。?小学阶段是培养学生计算能力的关键时期,因此,在教学过程中,教师应格外注重落实“算法多样化”教学策略,引导学生运用进位法、联想法、乘法口诀和四则运算法进行计算,进一步活跃学生的思维,提高思维的灵活性和严谨性,促使学生计算过程更认真更快速,并提高计算正确率和计算機能力,取得较好的教学效果。