Blocking optimized SIMD tree search on modern processors

Tree search is a widely used fundamental algorithm. Modern processors provide tremendous computing power by integrating multiple cores, each with a vector processing unit. This paper reviews some studies on exploiting single instruction multiple date (SIMD) capacity of processors to improve the performance of tree search, and proposes several improvement methods on reported SIMD tree search algorithms. Based on blocking tree structure, blocking for memory alignment and dynamic blocking prefetch are proposed to optimize the overhead of memory access. Furthermore, as a way of non-linear loop unrolling, the search branch unwinding shows that the number of branches can exceed the data width of SIMD instructions in the SIMD search algorithm. The experiments suggest that blocking optimized SIMD tree search algorithm can achieve 1.6 times response speed faster than the un-optimized algorithm.     

Novel algorithm for complex bit reversal: employing vector permutation and branch reduction methods

We present novel vector permutation and branch reduction methods to minimize the number of execution cycles for bit reversal algorithms. The new methods are applied to single instruction multiple data （SIMD） parallel implementation of complex data floating-point fast Fourier transform （FFT）. The number of operational clock cycles can be reduced by an average factor of 3.5 by using our vector permutation methods and by 1.1 by using our branch reduction methods, compared with conventional implementations. Experiments on MPC7448 （a well-known SIMD reduced instruction set computing processor） demonstrate that our optimal bit-reversal algorithm consistently takes fewer than two cycles per element in complex array operations.     

IF转换实现方法分析

IF转换是一种能够充分利用现代微处理器提供的谓词执行功能来提高程序性能的编译手段，它能够将程序中的条件分支代码转换为谓词执行的顺序代码，有效地增加基本块的大小，扩大指令调度的范围，从而增加基本块中的指令级并行性。RK算法是一个非常有效的算法，它能够将谓词的使用和谓词定义指令的数目最小化。     

多媒体教学的误区及应对措施

多媒体教学是在传统教学基础上发展起来的，在现代教学中起着非常重要的作用，但是当前的教学模式仍不可能脱离传统的教学手段，多媒体教学手段只能作为“辅助”的作用。多煤体教学只是教学的一种手段，我们不能停留在形式，要使多媒体教学为教学目的服务，就必须有选择的使用多媒体教学，避免走入多媒体教学的怪圈。     

课堂教学活动化：特征、意义及偏误矫正

“活动性”是当代课堂教学的突显特征和共同追求,具有教学改革意义和课堂实践价值。但是,课堂教学如果一味地追求“动”而缺失“静”,将会给教学带来诸多的危害,课堂教学的理想境界应是动与静的有机结合。     

PLC功能指令在程序设计中的应用

介绍了功能指令,重点阐述了触点比较指令和传送指令的特点,并以交通信号灯的控制为例,提出了运用触点比较指令和传送指令进行程序设计的方法,使程序结构紧凑、语句简洁,可方便地完成控制要求．     

20世纪前期语文课程分合论——兼说“阅读教学”的含义

与传统语文教育不同的是,现代语文教育中的识字、写字、听说、阅读、写作教学往往是在借助一本由单篇选文组成的课本进行＂集成教学＂,在实施过程中往往几项教学相互掣肘,这是造成语文教学少慢差费的一个重要原因。从1902-1904年语文独立设科至20世纪40年代,关于这几项课程的分与合的探讨就一直没有停止过。通过对不同时代关于此问题的观点的梳理、分析,可为当下的语文课程改革提供一个思考的路径。另外,＂阅读教学＂的含义也需要重新界定。     

数控车削固定循环指令和单一指令的应用技巧

通过对单一和复合循环编程指令的介绍,阐述了单一指令的编程方式以及其应用特点。在复合循环指令编程方面,通过实例,详细介绍了编程的方法和在实际应用方面的技巧,并指出了两种指令的适用条件。     

多媒体辅助大学英语教学的利弊分析

多媒体教学具有多方面的优越特点,但它仅仅是一种先进的辅助教学手段,既为我们建构新的教学模式提供一个有力的工具,也给大学英语教师带来了挑战与更高的要求.要想实现大学英语课堂教学的最优化,需要用先进的教学思想指导,合理地运用这种教学手段,师生互动,最大限度地开发它的优越性,服务于大学英语教学.     

A combined approach to strengthen children’s scientific thinking: direct instruction on scientific reasoning and training of teacher’s verbal support

Inquiry-based lessons have been demonstrated to improve children’s scientific thinking (i.e. reasoning abilities and domain-specific knowledge). Although empirical evidence shows that inquiry-based learning requires instruction, research comes from two approaches that have not been bridged yet: direct instruction of scientific reasoning and teacher training of verbal support. We investigated how these two types of instruction separately or combined strengthened children’s scientific thinking by comparing four conditions: baseline, direct instruction, verbal support, and a combined approach. Effectiveness of an inquiry-based lesson series on scientific reasoning abilities, vocabulary, and domain-specific knowledge (near and far transfer) were studied among 301 fourth graders. Results showed that both approaches strengthened different components of scientific reasoning abilities, and that a combination of instructions was most effective for scientific reasoning abilities, vocabulary, and domain-specific knowledge. Domain-specific knowledge acquisition was strengthened only when both instructions were provided. It can thus be concluded that each type of instruction has unique contributions to children’s science learning and that these instructions complement each other. Our study thus showed that inquiry-based lesson series when preceded by direct instruction of scientific reasoning and scaffolded with verbal support are most effective.     

现代教育媒体中的第二课堂：大学英语教学

在高等学校对大学英语教学的期望越来越高的历史时刻，固守传统的“一本教材、一张嘴和一只粉笔”的课堂模式只能使我们生活在“过去”。只有将现代教育媒体用于大学英语教学，使现代教育媒体与传统教育媒体相结合，才能使我们生活在“未来”。     

支架式教学模式在大学英语写作中的应用

支架式教学是建构主义理论指导下的一种教学模式。将支架式教学运用于大学英语写作课堂,可以让学生树立对写作的兴趣和信心,有效地提高英语写作水平。主要介绍支架式教学的内涵和在英语写作课堂教学中应用的基本环节,以及该模式对大学英语写作教学的启示。     

网络教育研究中的基本问题

网络教育是当前教育技术学研究的重要方向。网络教育理论研究中的三个基本问题是:网络教育中WEB(互联网)的教育技术学本质、媒体对学习的影响、网络学习环境中的学习控制。在网络教育中WEB在本质上是一种学习环境;媒体并不是学习效果的决定性因素,而媒体运用的方法和教与学过程中的媒体策略才是影响学习效果的因素;在网络学习环境中,完全的学习者控制是不适当的,应通过创设有效的认知支架,帮助学习者作出合理的学习决策。     

个别化教学的校本实践

坚信每个学生都有某一方面或某几方面的发展潜能,只要提供合适的教育都能成才。实施个别化课堂教学,目的在于促进学生心理健康,主导措施为把握差异,因材施教。不仅对不同学业成绩的学生进行分类教学,而且加强学习技能和学生策略指导;不仅关注学习活动,更要关注学生参与的动机、态度,给予心理支持与辅导;不仅研究如何选择最好的学习方式,更要研究如何让各类不同的学生主动参与其中,并且学有成效;不仅研究课堂教学个别化,还要对个别学生进行教育策划。     

电机控制数字信号处理器最小测试指令集的分析和寻找

The relativity of instructions of motor control digital signal processor (MCDSP) in the design is analyzed. A method for obtaining a minimum instruction set in place of the complete instruction set during generation of testing procedures is given in terms of the processor presentation matrix between micro-operators and instructions of MCDSP.     

Scaffold instruction at the workplace from a situated perspective

This article proposes the need to address scaffold instructions from a situated learning perspective. Based on an empirical study of how apprentice bakers learn their trade, it is claimed that studies of learning at the workplace yield important insights into our understanding of scaffold instructions. Seen from the perspective of the apprentices, scaffold instruction represents access to more responsibility in practice, it supports their identities as future bakers and they learn bodily know-how. When scaffold instruction failed, it was often in relation to situations where the apprentices were placed in marginal positions in the community of practice or in relation to a central workplace situation.     

需求引导教育是德育创新的重要内容

需求引导教育是德育创新的重要内容。新形势下的德育创新要关注学生的需求,关注对学生需求的引导,探索需求引导教育的方法和途径。文章从个性张扬引导、咨询服务引导、性健康引导等方面论述了开展需求引导教育、实现高校德育创新的重要意义,并就开展个性张扬引导、咨询服务引导、性健康引导的方式、方法以及应注意的问题进行初步探讨。     

支架式教学模式对英语写作教学的启示

支架式教学模式是建构主义教学模式之一,支架式教学模式及其在英语写作教学中的运用,可以降低学生英语写作中的困惑度,以及在写作过程中了解写作、学习写作和解决写作问题的作用。     

口腔内科学实验教学改革

口腔内科学的实验教学是深化理论课的重要手段，是由课堂进入临床的桥梁，也是把医学生转化为医生的必经阶段，学生在实验课中获益多少，直接影响到临床工作的质量与水平，为此，作者围绕实验教学改革做了一些探索，从思想上强化学生对实验课重要性的认识，是口内实验教学改革的首要前提；充分发挥教师的主导作用，是口内实验教学改革的重要条件；加强基本操作训练，注重理论联系实际，是口内实验教学改革的显著标志；实现教学手段的现代化是口内实验教学改革的必然途径。