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通用地质坐标系的似螺线法和圆弧线法为设计弯曲和定向钻孔提供了全定量计算的基础,并能在钻孔施工发生偏离时,指导选择钻孔纠斜方案. 相似文献
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分析当前普通高校信息与计算科学专业学生实习实训模式存在的主要问题,并针对这些问题提出一些解决方案;探讨适合学生实习实训要求的企业实训模式,以安庆师范学院信息与计算科学专业学生实习实训模式为例,对学生实习实训的计划和实施过程进行了阐述。实践表明,新的实训模式能够使学生取得良好的实习实训效果。 相似文献
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In this paper, we introduce a new iterative algorithm by hybrid method for finding a common element of the set of solutions of finite general mixed equilibrium problems and the set of solutions of a general variational inequality problem for finite inverse strongly monotone mappings and the set of common fixed points of infinite family of strictly pseudocontractive mappings in a real Hilbert space. Then we prove strong convergence of the scheme to a common element of the three above described sets. Our result improves and extends the corresponding results announced by many others. 相似文献
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We first consider a finite-buffer single server queue where arrivals occur according to batch Markovian arrival process (BMAP). The server serves customers in batches of maximum size ‘b’ with a minimum threshold size ‘a’. The service time of each batch follows general distribution independent of each other as well as the arrival process. We obtain queue length distributions at various epochs such as, pre-arrival, arbitrary, departure, etc. Some important performance measures, like mean queue length, mean waiting time, probability of blocking, etc. have been obtained. Total expected cost function per unit time is also derived to determine the optimal value N* of N at a minimum cost for given values of a and b. Secondly, we consider a finite-buffer single server queue where arrivals occur according to BMAP and service process in this case follows a non-renewal one, namely, Markovian service process (MSP). Server serves customers according to general bulk service rule as described above. We derive queue length distributions and important performance measures as above. Such queueing systems find applications in the performance analysis of communication, manufacturing and transportation systems. 相似文献
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在西门子S7—200PLC系统中,通常所配置的人机界面大多采用西门子专用的TP170、TP27、OP37等系列触摸屏。一旦这些触摸屏发生故障和损坏,难以采购和维修,且备件成本较高。本案例采用当今流行的通用PC机来代替TP27和OP37等专用HMI设备,并实现了PC机与S7—200PLC之间的数据通信,为PLC系统触摸屏的通用化改造提供了一个应用实例。 相似文献
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Stuart D.C. Walsh Martin O. Saar Peter Bailey David J. Lilja 《Computers & Geosciences》2009,35(12):2353-2364
Many complex natural systems studied in the geosciences are characterized by simple local-scale interactions that result in complex emergent behavior. Simulations of these systems, often implemented in parallel using standard central processing unit (CPU) clusters, may be better suited to parallel processing environments with large numbers of simple processors. Such an environment is found in graphics processing units (GPUs) on graphics cards.This paper discusses GPU implementations of three example applications from computational fluid dynamics, seismic wave propagation, and rock magnetism. These candidate applications involve important numerical modeling techniques, widely employed in physical system simulations, that are themselves examples of distinct computing classes identified as fundamental to scientific and engineering computing. The presented numerical methods (and respective computing classes they belong to) are: (1) a lattice-Boltzmann code for geofluid dynamics (structured grid class); (2) a spectral-finite-element code for seismic wave propagation simulations (sparse linear algebra class); and (3) a least-squares minimization code for interpreting magnetic force microscopy data (dense linear algebra class). Significant performance increases (between 10× and 30× in most cases) are seen in all three applications, demonstrating the power of GPU implementations for these types of simulations and, more generally, their associated computing classes. 相似文献