共查询到20条相似文献，搜索用时 156 毫秒
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针对现有的XML文档树编码方案均不能很好地支持XML文档动态更新问题,提出一种基于分数的动态前缀编码DPEF.在保留Dewey编码优秀特性的基础上,利用分数的无限扩展性,实现了在无需二次编码的情况下对XML文档进行动态更新.实验结果表明,该编码相对于已有的前缀编码方案具有更好的时间和空间性能. 相似文献
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与标准的方法XQuery查询语言不同,XML文档的关键字查询能使用户方便地访问XML数据,不必考虑数据复杂模式和掌握复杂查询描述语言。文章对关键字查询中索引技术进行研究,提出了一种基于Dewey编码的查询索引进行解决,以综合分析XML数据的值信息和结构信息,达到子树返回和路径返回的精确查询的目标。 相似文献
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门爱华 《赤峰学院学报(自然科学版)》2007,23(5):53-54,64
XML文档采用了树型的数据模型,对其查询通常是用带有选择谓词的模式树在XML数据中进行匹配,因此找出XML文档中所有符合模式树结构的元素是XML查询处理的核心操作.本文提出了一种新的XML模式匹配算法,算法思想是利用第一个结点的编码和最后一个结点的编码得到中间结点,用中间结点的begin与DList表结点的begin比较进行连接. 相似文献
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对当前的XML索引需要改进的地方进行分析,给出了一个较通用的索引机制。首先提出一种XML文档编码规则,在此基础上设计支持路径查询和信息检索的索引结构,并给出了对文档重复元素和文本节点索引词汇进行归并处理的索引算法。索引算法只需对文档遍历一次,所得到的索引文件占用空间也比GUID和倒排文档少,并且利用这些索引文件能实现任意粒度、任意形式的内容、结构和属性查询。 相似文献
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逆向Skyline查询能够应用到诸如决策支持、用户偏好支持以及市场行为分析等方面.由于参考对象q的存在,在执行逆向Skyline查询的过程中数据空间被划分成许多分区.然而,存在的算法都没有考虑这个问题的影响,直接使用原始数据集建立索引结构.本文提出了一种新的逆向Skyline查询方法CRSQ,它考虑了这个问题.CRSQ首先根据查询对象q对数据进行聚类,然后建立R-tree索引,最后利用高效修剪策略修剪索引搜索空间.实验结果表明CRSQ算法是有效的,它相对于没有聚类技术的算法获得了50 %以上的性能提高. 相似文献
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在Web数据挖掘研究领域中,数据预处理在Web日志挖掘中起着至关重要的作用,在介绍了数据挖掘的概念、分类和结构体系的基础上,阐述了对网站大量Web日志数据进行预处理所采用的算法和处理过程,即先将已知IP地址与物理地址的对应关系保存在HashMap中,然后综合运用折半与顺序查找算法,可以显著减少查找次数,提高查询效率. 相似文献
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在教学网站的设计与开发中,各类教学资源的组织与分类至为关键。顺序编码算法是当前最常使用的一种简单分类方法,然而,顺序编码算法在进行资源分类时存在很多缺点。本文向大家介绍了一种能有效避免顺序编码算法缺点的高效分类算法：位编码算法。 相似文献
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针对云计算环境下分布式存储系统的数据索引不支持复杂查询的问题,笔者提出了云环境下聚类分解的高维数据混合索引方法.首先,采用聚类分解方法对分割数据建立树状索引;然后,以叶节点为单位,通过扫描线算法来获取节点内部所有对象的局部最近邻结果;最后,依据计算的结果得出启发式的裁剪距离.在单节点最近邻计算中,第二个阶段获取外部的最近邻对象采用范围查询算法.实验分析表明,在查询效率上该索引方法高于单纯的聚类方法.与M-tree、顺序查找、iDisance相比,基于聚类分解的混合索引方法在高维查询模式下具有良好的查询效率和负载均衡. 相似文献
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Finding all occurrences of a twig pattern is a core operation of extensible markup language （XML） query processing. Holistic twig join algorithms, which avoid a large number of intermediate results, represent the state-of-the-art algorithms. However, ordered XML twig join is mentioned rarely in the literature and previous algorithms developed in attempts to solve the problem of ordered twig pattern （OTP） matching have poor performance. In this paper, we first propose a novel children linked stacks encoding scheme to represent compactly the partial ordered twig join results. Based on this encoding scheme and extended Dewey, we design a novel holistic OTP matching algorithm, called OTJFast, which needs only to access the labels of the leaf query nodes. Furthermore, we propose a new algorithm, named OTJFaster, incorporating three effective optimization rules to avoid unnecessary computations. This works well on available indices （such as B~-tree）, skipping useless elements. Thus, not only is disk access reduced greatly, but also many unnecessary computations are avoided. Finally, our extensive experiments over both real and synthetic datasets indicate that our algorithms are superior to previous approaches. 相似文献
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屠毅力 《广播电视大学学报》2014,(2):37-41
杜威的社群主义民主理想和设计深刻地影响了胡适30年代议政时期的政治态度。在《独立评论》"民主与独裁"的论争中,胡适一方面以其所接受的杜威的民主话语抗衡"独裁派",另一方面则迫于当时形势,不得不重新面对杜威思想中最核心的命题:社群民主与民族国家之间的矛盾,相比于杜威的理想化方案,胡适其时则选择了与对立派达成某种程度的和解,即将民主的效率寄托于政治改良。 相似文献
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《Journal of moral education》2012,41(2):221-237
John Dewey and Emile Durkheim are philosophical giants in the field of moral education. This paper compares and contrasts their respective visions for moral education and contextualizes the comparison in the profound intellectual and social changes modernity was casting throughout the world. They were transitional figures that attempted to make education responsive to those novel conditions and forces. Toward this end, Dewey and Durkheim, though they differed in key areas, articulated the moral sources and authority on which their respective visions for education depended. In as much as the contemporary discourse on moral education lacks this articulation, there is much to be learned from examining their work. Though the current cultural context differs from that of Dewey and Durkheim, their approach to addressing these questions can inform our task in the present. 相似文献
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Xu Xu 《Children‘s Literature in Education》2013,44(3):222-237
This essay examines how John Dewey’s child-centered educational philosophy was adopted and adapted in the early twentieth century in China to create a Chinese children’s literature. Chinese intellectuals applied Dewey’s educational philosophy, which values children’s interests and needs, to formulate a new concept of modern childhood that influenced emerging Chinese children’s literature. Underlying the apparently faithful borrowing of Dewey’s theory, though, is a fundamental contradiction between Dewey and his Chinese counterparts in terms of the nature of children. While Dewey was rejecting the notion that human beings possess innate characteristics, Chinese intellectuals were attempting to do the opposite, namely they were endeavoring to make “children” an essentialist category. By emphasizing this intersection of both foreign and indigenous influences in modern Chinese children’s literature, this essay also suggests that Chinese children’s literature is a hybrid product. 相似文献
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盖青 《顺德职业技术学院学报》2003,1(1):74-76
杜威实用主义经验哲学继承了近代以来经验主义哲学传统,他对赫尔巴特的批判着重显示了经验主义认识论与德国古典哲学的冲突。另一方面,杜威经验主义拆解了卢梭思想的核心:主体价值。形成了从古典到近代的形而上学与近代到现代的经验主义哲学之间的深刻分野,展开了意义世界与工具理性之间的重大冲突。 相似文献
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《Journal of moral education》2012,41(2):127-144
Many conservatives, including some conservative scholars, blame the ideas and influence of John Dewey for what has frequently been called a crisis of character, a catastrophic decline in moral behavior in the schools and society of North America. Dewey’s critics claim that he is responsible for the undermining of the kinds of instruction that could lead to the development of character and the strengthening of the will, and that his educational philosophy and example exert a ubiquitous and disastrous influence on students’ conceptions of moral behavior. This article sets forth the views of some of these critics and juxtaposes them with what Dewey actually believed and wrote regarding character education. The juxtaposition demonstrates that Dewey neither called for nor exemplified the kinds of character-eroding pedagogy his critics accuse him of championing; in addition, this paper highlights the ways in which Dewey argued consistently and convincingly that the pedagogical approaches advocated by his critics are the real culprits in the decline of character and moral education. 相似文献
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教师实践性知识的"知识"地位一直是一个颇具争议的问题。杜威的实用主义知识论在理论层面为教师实践性知识的"合理合法性"提供了支持。这种知识论视角超越了传统的心灵—世界二元知识论框架,在人类行动范畴中看知识,揭示了人类是不断变化的世界的参与者,而不是独立于意识之外的世界的旁观者。这种知识论认为知识源自探究,由认知性经验而获得,是关于行动及其导致的结果之间关系的知识,体现在教师身上是有关教育教学行动及其带来的结果之间的关系的"实践性知识",具有引导未来行动的功能。杜威关于知识的工具性观点,还在一定程度上化解了教师的理论性知识与实践性知识孰高孰低之争,因为二者都来自经验,并最终服务于实践,这也使得教师的"知性主动性"显得尤为重要。 相似文献
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John E. Petrovic 《牛津教育评论》2013,39(4):513-520
ABSTRACT In her recent book, All Must Have Prizes, Melanie Phillips makes several claims about the ‘disastrous’ influence that John Dewey had on education in the UK. The problem is that Phillips gets Dewey quite wrong. She is, of course, not alone in her misreading of Dewey. Using Phillips as a point of departure, I present several misinterpretations of Dewey. Specifically, Phillips and others make the following claims: (1) Dewey promoted ahistoric and cultureless education; (2) Dewey sacrificed knowledge, facts, and subject matter to skills and processes; (3) Dewey rejected the authority of teachers. I point out how Dewey speaks explicitly to each of these assertions. 相似文献
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20世纪以来,苏联及俄罗斯对杜威及其教学论思想的认知与评价经过了一个大起大落的曲折历程:从20年代的极力推崇,到30年代开始猛烈批判,50—60年代的评价落入低谷,80年代至世纪末又开始回暖。进入21世纪,俄罗斯学者在新的历史条件下,以更加客观的态度研究与解析杜威的教学论思想,对其进行重新解读和再认识。出现这种曲折认识的重要原因是:苏联曾一度过分注重以意识形态为标准对人进行评价,乃至将这一评价标准推向极端,从而对杜威及其教育教学思想的评价有失客观与公正。在新的时代,教育理论研究和教育实践健康发展的基石是“寻找契合点(或平衡点)”,这要求教育工作者摒弃那种非此即彼的思维方式。 相似文献
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Robin L. Zebrowski 《Educational theory》2008,58(3):305-320
A bstract . In educational scholarship, a number of comparisons have been made between the work of John Dewey and Herbert Spencer, many claiming that Spencer's influence is unmistakable in Dewey's theories or even that Dewey is derivative of Spencer. However, one must look beyond the surface similarities of Dewey and Spencer and recognize the drastically divergent views that each held on those very foundational notions upon which each built his educational program. In this essay, Robin Zebrowksi examines the theories of evolution, the directionality of organism and environment interaction, the agency of the individual, and the conceptualizations of progress in the respective works of Dewey and Spencer. Their underlying beliefs about the world and how it operates show that their philosophies cannot be reconciled. The educational theories that follow from these discrepancies, Zebrowski concludes, have incompatible and distinct implications for the classroom. 相似文献