基于树型结构的可扩展标记语言查询增量维护算法研究

在进行数据统计归纳过程中,可能出现的数据系统结构变化、数据库接口标准的变换等情况,都会对现有的数据查询过程形成影响.为了满足数据查询过程发展要求的提升,本文对基于树型结构的可扩展标记语言增量维护算法进行了研究,研究了增量维护算法的输入设计、输出设计、逻辑设计等内容,完善了现有的数据查询过程应用结构.     

基于FP-Growth算法构造批量增量的FP-tree

提出了一种利用FP树表示增量数据库,然后进行增量挖掘的方法,即IA_FP-Growth算法.算法重构和合并两个小的时间上连续的FP树,以获得由FP-Growth算法生成的FP树.与其他从数据库读取事务的顺序增量算法不同,IA_FP-Growth算法使用原FP-tree作为预处理数据库来获取项目集,因此其花费较少的时间来构建新的增量FP-tree项目.实验结果表明,随着数据库大小的增加,IA_FP-Growth的运行时间的增加要少得多,而且与其他算法比较也是最少的.     

基于Spark Streaming的增量协同过滤算法

针对协同过滤算法处理大数据流时响应慢的缺陷,在改善推荐准确度的情况下,提出增量更新算法以加快响应速度,提高推荐系统性能。介绍了当前协同过滤算法以及KNN和Spark的相关知识,阐述了协同过滤算法的增量模型。采用Group Lens网站提供的Movie Lens数据集作为实验数据,应用Socket模拟流和Spark并行计算技术实现增量模型。实验结果显示,在保证推荐准确度的前提下,响应时间明显缩短,说明增量模型适合实时处理大数据流,可缓解数据处理不及时问题。     

加权三支决策增量软聚类算法及性能分析

现有的增量聚类算法虽然解决了数据增量和类簇重叠问题,但在距离度量时没有考虑属性重要度不同,且普遍拥有较高的时间复杂度。针对以上问题,提出一种基于属性重要度的加权三支决策增量软聚类算法（W-TIOC-TWD算法）,将属性重要度考虑到距离度量中,弥补了现有算法在聚类过程中将所有属性的重要程度视为相等的不足。该算法还引入离群点概念,降低了算法的时间复杂度。基于人工数据集和UCI数据集的实验结果表明,W-TIOC-TWD算法的聚类准确率优于比较算法。     

数据仓库增量ETL的设计及优化

数据增量更新是数据仓库应用领域的重要问题。设计增量数据的获取方式。对增量数据的冗余问题进行了重点研究,提出了预处理方法并设计了相应算法,该方法实现了增量数据的压缩,提高了增量数据的质量及ETL过程的处理效率。给出了增量ETL过程的具体实现。     

关联规则中一种负增量更新算法的探讨

针对关联规则负增量更新的挖掘问题,提出了一种高效的关联规则负增量更新算法,即NIUA。该算法充分利用原数据库中已有的频繁项集、所有1-项集来生成最小非频繁项集;并采用选样等策略求出删减数据后的频繁项集。整个算法只需扫描删减后的事务数据库一遍,从而提高了关联规则的更新效率。     

基于增量学习算法的混合课程学生成绩预测模型研究

基于在线学习行为预测学生成绩可以辅助教师动态掌握学情,制定差异化的教学策略,然而在混合课程中仅仅依据在线数据对学生成绩迸行预测难度很大,尚处于探索中.文章选取某高校2018秋季学期和2020春季学期的"高活跃型混合课程"学生在线行为数据,采用增量学习的随机森林算法构建学生成绩预测模型,研究发现:(1)增量学习随机森林算法在混合课程样本最多的数据集中,获得预测结果准确率最高(75.1％);(2)相较于批量学习随机森林算法,增量学习算法在数据样本量较多的数据集中预测结果准确率更高;(3)当样本数量达到一定规模后,预测结果准确率波动减小、稳定性增强.本研究采用增量学习随机森林算法预测混合课程中的学生成绩,不仅取得了较好的预测准确率,而且解决了新增数据后模型的稳定性问题,将有助于模型的迭代优化,提高模型的通用性,以及可持续追踪学生在不同学期的学习行为特征.     

基于增量学习SVM的Android恶意应用检测方法

针对传统Android恶意应用检测方法在处理大规模样本时存在的训练时间长、存储空间消耗大的问题,提出一种基于增量学习SVM的Android恶意应用检测方法.该方法提取Android应用的权限申请和API函数调用特征,利用增量学习SVM理论将训练样本集随机划分为初始样本集和若干个增量样本集,利用循环迭代方法训练SVM分类器,每次新的训练仅保留上一轮训练得到的支持向量集并合并到新增样本集中,舍弃大量对分类结果不产生影响的样本以提高分类器学习效率,同时产生新的支持向量集,并最终得到一个高精度的SVM分类器.通过将增量学习SVM算法与基本SVM算法进行对比实验,结果表明,该算法可以有效降低分类器学习时间,减少样本存储的空间占用,同时随着样本规模的积累逐步提高分类精度.     

Context 模型奇异测度及其在量化中的应用

使用聚类算法实现 Context 量化不仅可以推广量化器的应用范围,而且可以获得编码性能较理想的优化量化器。然而,聚类算法依赖于相似测度。前期研究中采用的描述长度增量不能完全满足相似测度的各项属性,从而导致聚类结果的性能偏差。因此,提出数学描述特性更好的奇异测度增量作为两个计数向量的相似测度,并说明其相应性质。实验结果证明,使用奇异测度增量作为相似测度,不仅能够保证 Context 量化器的稳定性,而且还获得更佳的编码结果。     

多层多维关联规则的增量更新算法

数据挖掘要在实际应用中发挥作用,高性能挖掘算法和数据挖掘软件平台是重要的技术基础。通过实例验证,提出了一种快速有效的多层多维关联规则增量更新算法。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.