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关键词： 二叉排序树   平衡因子   平衡二叉树  

摘要： 平衡二叉树是对二叉排序树的一种改进,又被称为AVL树,平衡二叉树的结构较好,可以提高查找运算的速度.本文分析了权威教材和相关论文中平衡二叉树的调整方法,这些方法学生普遍反映理解和掌握较困难.据此,本文依据平衡因子和二叉排序树的特性,设计出一种基于平衡因子和二叉排序树的平衡二叉树的调整方法,该方法易于理解和掌握.

关键词： 数据结构   课程设计   创新模式   创新能力  

摘要： 《数据结构》课程设计可以使学生巩固数据结构的理论、方法和应用,激发学生学习和研究的兴趣。通过《数据结构》课程设计综合创新型实验科研培养学生的创新能力、竞争意识和团队精神。为了提高《数据结构》课程设计的教学效果,从课程设计项目的提出、项目的组织与实施、项目的验收与考核等方面提出一些可行方法和建议。重点对《数据结构》课程设计的实际教学过程进行探讨和实践研究。

关键词： 数据结构   教学   改革   探讨  

摘要： 在计算机科学中,《数据结构》是一门核心的、综合性专业基础课。课程学习的效果将直接影响到后续课程的学习以及软件设计水平和能力的培养。本文针对课程的特点,结合教学实践经验。

关键词： Data analysis   Genetic parameters   Weaning weight   Weight gain  

摘要： The objective of the present study was to investigate the effect of data structure on estimated genetic parameters and predicted breeding values of direct and maternal genetic effects for weaning weight (WW) and weight gain from birth to weaning (BWG), including or not the genetic covariance between direct and maternal effects. Records of 97,490 Nellore animals born between 1993 and 2006, from the Jacarezinho cattle raising farm, were used. Two different data sets were analyzed: DI_all, which included all available progenies of dams without their own performance;DII_all, which included DI_all + 20% of recorded progenies with maternal phenotypes. Two subsets were obtained from each data set (DI_all and DII_all): DI_1 and DII_1, which included only dams with three or fewer progenies;DI_5 and DII_5, which included only dams with five or more progenies. (Co)variance components and heritabilities were estimated by Bayesian inference through Gibbs sampling using univariate animal models. In general, for the population and traits studied, the proportion of dams with known phenotypic information and the number of progenies per dam influenced direct and maternal heritabilities, as well as the contribution of maternal permanent environmental variance to phenotypic variance. Only small differences were observed in the genetic and environmental parameters when the genetic covariance between direct and maternal effects was set to zero in the data sets studied. Thus, the inclusion or not of the genetic covariance between direct and maternal effects had little effect on the ranking of animals according to their breeding values for WW and BWG. Accurate estimation of genetic correlations between direct and maternal genetic effects depends on the data structure. Thus, this covariance should be set to zero in Nellore data sets in which the proportion of dams with phenotypic information is low, the number of progenies per dam is small, and pedigree relationships are poorly known. (c) 2

关键词： Memory contention   Data structure   Cell-probe model  

摘要： We consider the problem of minimizing contention in static (read-only) dictionary data structures, where contention is measured with respect to a fixed query distribution by the maximum expected number of probes to any given cell. The query distribution is known by the algorithm that constructs the data structure but not by the algorithm that queries it. Assume that the dictionary has n items. When all queries in the dictionary are equiprobable, and all queries not in the dictionary are equiprobable, we show how to construct a data structure in O(n) space where queries require O(1) probes and the contention is O(1/n). Asymptotically, all of these quantities are optimal. For arbitrary query distributions, we construct a data structure in O(n) space where each query requires O(log n/log log n) probes and the contention is O(log n/(n log log n)). The lack of knowledge of the query distribution by the query algorithm prevents perfect load leveling in this case: for a large class of algorithms, we present a lower bound, based on VC-dimension, that shows that for a wide range of data structure problems, achieving contention even within a polylogarithmic factor of optimal requires a cell-probe complexity of Omega(log log n). (C) 2012 Elsevier Inc. All rights reserved.

关键词： 最短路径   有向图   数据结构  

摘要： 对任意图,选择合适的数据结构表示图,在此基础上实现求解最短路径的Dijkstra算法。对所设计的图的数据结构,提供必要的基本功能。建立图的表示模块,顶点的插入和删除操作模块;在建立图之后从单源点开始求最短路径并显示。实现的功能有建立有向图,排除和增加目的地,方便找出最短路径,在建立好的有向图中,显示出来从顶点到各个顶点的最短路径。

关键词： Focal Region   Discordant Pair   High Throughput Sequencing Data   Exact Breakpoint   Split Read  

摘要： Background: Recent advances in sequencing technologies make it possible to comprehensively study structural variations (SVs) using sequence data of large-scale populations. Currently, more efforts have been taken to develop methods that call SVs with exact breakpoints. Among these approaches, split-read mapping methods can be applied on low-coverage sequence data. With increasing amount of data generated, more efficient split-read mapping methods are still needed. Also, since sequence errors can not be avoided for the current sequencing technologies, more accurate split-read mapping methods are still needed to better handle sequence errors. Results: In this paper, we present a split-read mapping method implemented in the program SVseq2 which improves our previous work SVseq1. Similar to SVseq1, SVseq2 calls deletions (and insertions) with exact breakpoints. SVseq2 achieves more accurate calling through split-read mapping within focal regions. SVseq2 also has a much desired feature: there is no need to specify the maximum deletion size, while some existing split-read mapping methods need more memory and longer running time when larger maximum deletion size is chosen. SVseq2 is also much faster because it only needs to examine a small number of ways of splitting the reads. Moreover, SVseq2 supports insertion calling from low-coverage sequence data, while SVseq1 only supports deletion finding. The program SVseq2 can be downloaded at http://***/similar to jiz08001/. Conclusions: SVseq2 enables accurate and efficient SV calling through split-read mapping within focal regions using paired-end reads. For many simulated data and real sequence data, SVseq2 outperforms some other existing approaches in accuracy and efficiency, especially when sequence coverage is low.

关键词： 数据结构   2路插入排序   算法  

摘要： 提出了一种非循环2路插入排序算法,给出了算法思想及其实现,该算法与传统2路插入排序算法相比,时间效率得到了改善,空间复杂度由原来的O(n)降低为O(1)。

关键词： DNA计算机   队列数据结构   设计   实现  

摘要： 近些年,生物信息技术的发展有效的促进了DNA计算机的提出,DNA计算机作为模拟生物分子DNA的结构并借助生物分子技术进行DNA计算的一种新型计算机,需要有相关的数据结构来合理有效的组织DNA计算机所要处理的相关数据信息。本文从对DNA计算机的相关概念的介绍谈起,然后就队列数据结构的概念进行说明,最后对DNA计算机中队列数据结构的设计与实现进行分析。

关键词： 数据结构   实践性教学模式   形成性考核  

摘要： 针对数据结构课程特点,提出一种实践性教学模式。通过课堂理论教学、实验设计及实施、课程课外实践活动、形成性考核等教学实践中的四个环节,详细阐述培养学生运用数据结构知识提高实践能力的方法。