基于多语义关系的个性化查询扩展方法*

随着数字内容不断增长,信息检索技术已经不能满足不同用户对高精度信息内容获取的需求.文中提出基于多语义关系的个性化查询扩展方法,并应用于基于社会化标签的个性化搜索系统.模型使用标签-主题模型对用户兴趣模型进行建模,能够更有效地表达语义和提升搜索效果.在此基础上,进一步提出基于多语义关系的个性化查询扩展方法,利用社会化标签的多重语义特征进行扩展词的选择.在大规模真实社会化标签数据集上的实验表明,文中方法优于非个性化搜索及其它基于社会化标签系统的个性化查询扩展方法.     

个性化的社会标签查询扩展技术研究

随着互联网上的信息日益增长,个性化的搜索需求越来越迫切,由于用户兴趣的不同和行为的差异,如何为不同的用户提供不同的检索结果成为一个具有挑战性的问题。首先对现有搜索引擎的个性化信息检索和查询扩展技术进行了分类总结,分析了它们各自的优缺点。然后提出了基于社会化标签的个性化查询词扩展方法。这些方法通过从用户所收藏的社会化标签或标签所对应的网页中提取出和用户查询词相关的词,来对用户的初始查询进行扩展。最后利用Delicious网站上的用户数据,对比研究了这几种个性化查询扩展算法。通过与Google进行对比分析实验,结果表明所提出的社会化标签的个性化查询词扩展方法能够较好地满足用户的个性化需求,检索结果比Google的检索结果更接近用户需求。     

基于本体和局部上下文分析的查询扩展

在信息检索过程中,因查询词短少而引起的检索歧义性是影响检索效率的主要原因之一,而查询扩展方法和本体扩展方法能有效改善这一问题.提出一种基于本体和局部上下文分析的查询扩展方法:本体扩展根据本体推理规则对短查询词进行推理,得到与查询词有逻辑关联的推理结果集,为查询词加入了标准化的关联信息.局部上下文分析通过对文档库的分析,在与用户查询词最相关的前m篇文档中抽取与用户查询词最相关的n个扩展词,为查询词加入了统计扩展信息.将两部分扩展查询词合并,再通过扩展查询词相关度计算对搜索结果集进行排序.该方法结合了这两种方法的各自优势,从语义角度扩展关键词.实验分析表明,该方法能有效提高检索查全率和查准率.     

基于粗糙集的个性化Web搜索系统

本文提出了一种基于粗糙集理论的个性化web搜索系统。用户偏好文件中对关键字进行分组以表示用户兴趣类别。利用粗糙集理论处理自然语言的内在含糊性,根据用户偏好文件对查询条件进行扩展。搜索组件使用扩展后的查询条件搜索相关信息。为了进一步排除不相关信息,排序组件计算查询条件和搜索结果之间的相似程度,根据计算值对搜索结果进行排序。与传统搜索引擎进行了比较,实验结果表明,该系统有效地提高了搜索结果的精度,满足了用户的个性化需求。     

XML图书搜索中基于用户社会关系的查询推荐方法

基于关键词的图书搜索系统由于用户输入查询词的模糊性和简单性往往需要利用查询推荐技术对查询词进行扩展。目前的图书查询推荐方法不能辨别出不同用户在不同时期的图书请求意图和兴趣。提出一种基于用户社会关系的查询推荐方法,首先通过分析用户个人资料信息建立用户社会关系对象集合;其次获取用户社会关系对象对图书的标记词,计算输入查询词与标记词之间的共现率并建立用户社会关系标记词推荐集合,选取与查询词共现率最高的标注词进行查询词扩展。在实际图书数据集上的实验表明,该方法大大提高了查询结果的NDCG@10值,提高用户的满意度,表明该方法具有可行性。     

基于网络知识库与通用搜索引擎的查询词扩展方法

对查询词进行扩展是为了进一步理解用户的搜索意图,使得搜索引擎返回更加准确的信息。已有的方法主要研究如何寻找与查询词相似的词,然而相似的户的词并一定能真正反映用意图。从网络知识库中抽取查询词的待扩展词,并利用通用搜索引擎对待扩展词进行排序,这样的查询词扩展方法充分利用了网络群体智慧,使得扩展词更加贴近用户的搜索期望。通过进行实验对比发现,该方法有较好的结果。     

混合P2P环境下有效的查询扩展及其搜索算法

查询扩展是解决信息获取领域中用词歧义性问题的关键技术,并被广泛应用于搜索引擎中,获得了巨大的成功.然而,由于P2P(peer-to-peer)系统是一个分散的、动态的系统,在P2P环境下进行有效的查询扩展具有一定的挑战性.首先,利用查询与文档的关联关系构建了LEM(local expansion method)查询扩展方法;然后,基于查询与文档用词的直接关联,提出了HEM(history_based expansion method)查询扩展方法.在此基础上,提出了一种基于查询扩展的混合P2P环境下的搜索算法.实验及分析结果表明,查询扩展及其搜索算法能够极大地提高搜索的效果.     

融合位置相关和概率排序的Lucene排序算法改进

文档检索结果的排序和文本分类技术是解决垂直搜索、个性化信息检索、信息过滤等相关问题的核心技术。为了提高检索系统的性能,针对Lucene的基础排序算法,提出了一种融合位置相关和概率排序的改进方法。考虑到查询词在文档中出现的位置信息和概率排序对文档相关性的影响,利用位置相关的查询词权值和基于朴素贝叶斯分类算法的文档相关性概率值,对Lucene基础排序算法的评分公式进行改进。实验表明,该改进方法能够有效提高垂直搜索的准确率,使用户拥有更好的垂直搜索体验。     

提高检索性能的朝鲜语布尔查询词生成及扩展

为了提高信息检索系统的检索性能,同时方便用户的操作,本文提出一种新的方法将用户输入的朝鲜自然语句自动转换成扩展的布尔查询词.首先基于句法信息将用户输入的朝鲜自然语句生成布尔查询词,然后对查询词进行句法分析,利用句法树组合或分离结构上相互联系的复合名词,并以扩展多样标记和简略标记用语扩展检索.同普通的检索方法和手动提取布尔查询词检索方法相比,本文提出的方法在准确率上分别高出8％和12％.     

基于地理时间意图和偏好的个性化Web搜索框架GT WSearch

基于Web查询的地理位置、时间查询意图和用户偏好的个性化Web搜索可以改善Web搜索结果,更好地满足不同用户的信息需求。提出了GT-WSearch个性化Web搜索框架,它通过挖掘搜索结果、用户点击数据和对查询进行分析得到的用户概貌和查询概貌,来捕捉用户的地理-时间的意图和偏好,提高搜索质量。用户概貌表明了查询自身的地理-时间的特性。 GT-WSearch框架在排序函数中利用文档的地理位置、时间的相关度来进行个性化搜索。 最后将使用线性的相关度排序函数进行重新排序的搜索结果返回给用户。大量实验结果表明,所提出的个性化方法在提高Web搜索结果的质量中取得了明显的效果。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.