Reducing structural changes in van Emde Boas' data structure to the lower bound for the dynamic predecessor problem

We consider the problem of maintaining a dynamic ordered set of n integers in a universe U under the operations of insertion, deletion and predecessor queries. The computation model used is a unit-cost RAM, with a word length of w bits, and the universe size is |U|=2^w. We present a data structure that uses O(|U|/log|U|+n) space, performs all the operations in O(loglog|U|) time and needs O(loglog|U|/logloglog|U|) structural changes per update operation. The data structure is a simplified version of the van Emde Boas' tree introducing, in its construction and functioning, new concepts, which help to keep the important information for searching along the path of the tree, in a more compact and organized way.     

Learning to See: Making Sense of the Mathematics of Change in Middle School

In this article, we will describe the results of a study of 6th grade students learning about the mathematics of change. The students in this study worked with software environments for the computer and the graphing calculator that included a simulation of a moving elevator, linked to a graph of its velocity vs. time. We will describe how the students and their teacher negotiated the mathematical meanings of these representations, in interaction with the software and other representational tools available in the classroom. The class developed ways of selectively attending to specific features of stacks of centimeter cubes, hand-drawn graphs, and graphs (labeled velocity vs. time) on the computer screen. In addition, the class became adept at imagining the motions that corresponded to various velocity vs. time graphs. In this article, we describe this development as a process of learning to see mathematical representations of motion. The main question this article addresses is: How do students learn to see mathematical representations in ways that are consistent with the discipline of mathematics? This revised version was published online in July 2006 with corrections to the Cover Date.     

Transmission of a Gaussian beam after incidenting nonnormally on a Fabry–Perot etalon: a nonresonant case

Under the nonresonant case where the carrier frequency of a Gaussian beam deviates from the resonant frequency of a Fabry–Perot etalon, the transmission of a Gaussian beam after incidenting nonnormally on a Fabry–Perot etalon has been investigated. The results show that under the nonresonant case, variations of the peak intensity, the position of the peak intensity and the spot size of the transmitted beam with the input angle behave differently and even with a reversed tendency compared with those obtained under the resonant case.     

辨析企业人才的"留"与"流"

论述了辨证认识与处理好人才的“留”与“流”的关系，指出了只有做好人才管理工作，慎重地考虑人才的留用，才能使企业长期、持续、健康、稳定地发展。     

On the convergence rate and optimization of a numerical method with splitting of boundary conditions for the stokes system in a spherical layer in the axisymmetric case: Modification for thick layers

The convergence rate of a fast-converging second-order accurate iterative method with splitting of boundary conditions constructed by the authors for solving an axisymmetric Dirichlet boundary value problem for the Stokes system in a spherical gap is studied numerically. For R/r exceeding about 30, where r and R are the radii of the inner and outer boundary spheres, it is established that the convergence rate of the method is lower (and considerably lower for large R/r) than the convergence rate of its differential version. For this reason, a really simpler, more slowly converging modification of the original method is constructed on the differential level and a finite-element implementation of this modification is built. Numerical experiments have revealed that this modification has the same convergence rate as its differential counterpart for R/r of up to 5 × 10³. When the multigrid method is used to solve the split and auxiliary boundary value problems arising at iterations, the modification is more efficient than the original method starting from R/r ～ 30 and is considerably more efficient for large values of R/r. It is also established that the convergence rates of both methods depend little on the stretching coefficient η of circularly rectangular mesh cells in a range of η that is well sufficient for effective use of the multigrid method for arbitrary values of R/r smaller than ～ 5 × 10³.     

基于蓝牙Profiles的互连测试系统的研究和实现

对蓝牙通信软件的互连性测试进行了研究,提出了测试模型和测试方法.     

用随机模糊方法研究合理确定工程项目工期

站在兼顾业主与建造商的公正立场,基于网络优化技术基础上并以系统的观点,采用随机模糊数学方法研究合理确定项目工期,进而用实际项目进行分析验证,是一种科学合理确定工期的方法.     

高职思想品德课案例教学效果的显现化

高职思想品德课的现代案例教学的效果显现化,可以帮助和指导学生思想品德的发展。对思想品德课效果显现化的内容应包括认知目标、情感目标、心因目标,其显现化的手段已不能用简单、传统的“考试”来测评,而应考虑用一些更综合的方式进行。     

哈夫曼编码的JAVA实现

叙述了哈夫曼编码的思想以及用JAVA语言实现其程序设计的详细过程     

三维动画课件在案例教学中的应用

《生产与运作管理》案例教学的案例一般均为实际问题,涉及的因素广泛、复杂.受单纯文字表达或平面图形静态表达的限制,加之缺乏实践经验,使学生对案情的理解往往产生较大的偏差,以至于难以充分发挥案例的作用.本文对采用三维动画课件的形式,立体、动态地表达案情,建立更为接近实际情况的动态模型,开展案例教学进行了探讨.结论是三维动画课件特别适合于运作管理案例教学,有利于显著提高MBA学员的教学参与程度,提高案例分析和方案设计的水平.