分而治之为上策:数据结构课程的反思与变革

在大学计算机专业课程中,"数据结构"被学生广泛认为是一门难学、难懂、难实践的课程.造成这种现象的原因很多,除了数据结构本身抽象,有一定的难度外,其与"算法"内容的混杂是一个重要原因.众所周知,数据结构常与算法混在一起进行讲授,有的学校的课程名就叫"数据结构与算法".数据结构这种与算法的缠绕由于时间已久,大家已习以为常,并没有细想其合理性.但我们经过多年的实践发现,此种缠绕带来的利益十分有限,却给数据结构课程的教学带来了障碍.本文详细分析了这些缺陷并提出了分而治之的解决之道.     

C语言程序—指针算法分析

指针算法分析是C语言教学中非常难解的一个知识模块,文章从C语言指针算法的概念出发,分析了指针算法教学中的几个关键点问题,对在教学中存在的一些问题进行探讨。     

数学幽默笑话选编

1.负数数学家、生物学家和物理学家坐在街头的咖啡屋里,看着人们从街对面的一间房子进进出出.他们先看到两个人进去,过了一会,他们又看到三个人出来.物理学家:"测量不够准确."生物学家:"他们进行了繁殖."数学家:"如果现在再进去一个人,那房子就空了."     

基于神经网络的双小波混沌信号降噪

根据信号和噪声的特性不同,提出了一种基于神经网络的双小波混沌信号降噪方法。该方法结合奇异谱和梯度下降算法,分别对小波变换后的近似部分和细节部分进行了分析。一方面,奇异谱分析更大程度地去除了代表噪声的较小奇异值;另一方面,神经网络对非线性阈值的自学习,实现了小波系数的自适应选取,提高了信号的定位精度。通过对Lorenz模型和月太阳黑子时序进行仿真,证实了本文所提方法能够对实际观测的混沌信号进行有效的降噪。     

对一年级数学新教材的实践与思考

从初涉课改的喜悦和激动到如今的理性和思考,我们在与新教材"亲密接触"的一年多时间里,发现新教材在教学目标、内容、呈现方式、编排的顺序、渗透数学思想方法等诸多方面都有了许多新的特色.     

设计中重引导体验中促优化——“用乘法分配律进行简便计算”的实践体会

案例背景: 当前,“以生为本”的课堂教学理念早已被教师们推崇与实践.以计算教学来说,课堂上已不再像过去那样,教师只教学教材上的算法,甚至要求学生只能按某种算法去算.现在经常可以看见这样的现象:一道计算题出来后,教师常常鼓励、引导学生思考采用不同的算法.很多教师会对学生说:“可以用你自己喜欢的方法计算.”于是问题就出现了,学生用的方法往往不是教师事先估计的“基本方法”或比较好的方法(即教师心里希望学生用的方法).教师的疑问也由此产生,如要不要对多样的算法进行优化、怎样进行算法优化等等.我在教学实践中也同样有过这样的情况和疑问,为此,专门针对算法优化的问题进行了课题研究.     

FARMER: A novel approach to file access correlation mining and evaluation reference model

File semantic has proven effective in optimizing large scale distributed file system. As a consequence of the elaborate and rich I/O interfaces between upper layer applications and file systems, file system can provide useful and insightful information about semantic. Hence, file semantic mining has become an increasingly important practice in both engineering and research community. Unfortunately, it is a challenge to exploit file semantic knowledge because a variety of factors could affect this information exploration process. Even worse, the challenges are exacerbated due to the intricate interdependency between these factors, and make it difficult to fully exploit the potentially important correlation among various semantic knowledges. This article proposes a file access correlation miming and evaluation reference (FARMER) model, where file is treated as a multivariate vector space, and each item within the vector corresponds a separate factor of the given file. The selection of factor depends on the application, examples of factors are file path, creator and executing program. If one particular factor occurs in both files, its value is non-zero. It is clear that the extent of inter-file relationships can be measured based on the likeness of their factor values in the semantic vectors. Benefit from this model, FARMER represents files as structured vectors of identifiers, and basic vector operations can be leveraged to quantify file correlation between two file vectors. FARMER model leverages linear regression model to estimate the strength of the relationship between file correlation and a set of influencing factors so that the “bad knowledge” can be filtered out. To demonstrate the ability of new FARMER model, FARMER is incorporated into a real large-scale object-based storage system as a case study to dynamically infer file correlations. In addition FARMER-enabled optimize service for metadata prefetching algorithm and object data layout algorithm is implemented. Experimental results show that is FARMER-enabled prefetching algorithm is shown to reduce the metadata operations latency by approximately 30%–40% when compared to a state-of-the-art metadata prefetching algorithm and a commonly used replacement policy.     

CORDIC algorithm based on FPGA

It is an important problem that we implement floating point trigonometric functions of high precision with suitable hardware cost for high performance in digit image processing.The coordinate rotational digital computer (CORDIC) arithmetic to is used to solve the above problem in this paper.In order to increase the speed of operation,it chooses the pipeline architecture.The results are disposed by IEEE-754 standard.The CORDIC architecture is modeled by using the verilog HDL and verified with MATLAB program ...     

Adaptive early termination of fast mode decision in MVC based on inter-view correlation

Variable size motion estimation (ME) and disparity estimation (DE) are employed to select the best coding mode for each macroblock (MB) in the current joint multiview video model (JMVM).This technique achieves the highest possible coding efficiency,but it results in extremely large computation complexity which obstructs the multiview video coding (MVC) from practical application.This paper proposes an adaptive early termination of fast mode decision algorithm for MVC.It makes use of the coding information o...     

关于高中数学必修模块教学顺序的建议

2009年秋季开始,赤峰市红山区高中进入了新一轮课改,选用了人教B版作为数学教材。并且规定沿着自然顺序教学,即按照1→2→3→4→5的顺序。经过了一个学年的