基于互信息的问句语义扩展研究

用户习惯用很少的关键字来检索所需的信息,这必然会导致出现用户所检索的信息与得到的信息有所偏差.针对这一现象,提出了基于互信息的问句语义扩展模型(QSE_BMI).它的好处在于可以根据用户自己制定的兴趣模型和输入的查询问句,检索出与用户兴趣相匹配的并且符合用户需要的相关信息.     

基于本体的林业领域语义查询扩展模型

传统信息检索模型仅考虑考虑关键词本身的匹配程度,在林业领域信息检索时得到的检索结果不全面或不准确.为了改善检索质量,提出了一种基于本体的林业领域语义查询扩展模型.该模型利用了本体的语义推理的能力和语义结构对关键词进行语义查询扩展,最终实现提高检索查全率和查准率的目的,是对传统基于关键词匹配的信息检索模型的语义补充.结果表明该模型在一定程度上改善了林业领域信息检索结果的查准率和查全率.     

基于领域本体的贝叶斯网络检索模型研究

针对传统的信息检索方法无法实现用户查询的语义理解、检索效率低等问题,本文提出基于领域本体进行查询扩展的贝叶斯网络检索模型。该模型首先将用户查询通过领域本体进行语义扩展,然后将扩展后的查询作为证据在贝叶斯网络检索模型中进行传播,进而得到查询结果,实验表明本文提出的贝叶斯网络检索模型能提高检索效率。     

基于语义模型的信息检索机制研究

提出了一种基于本体语义模型的信息检索方法。该方法充分利用领域本体提供的概念之间的语义相关性，从语义模型扩展、概念相似度、相关度计算，并以用户反馈等角度探讨了基于语义模型的自动推理方法在信息检索中的应用，文章介绍了系统实现框架。该系统将应用在学习资源的智能检索中。     

基于主题图的本体信息检索模型研究

针对本体在定义领域概念时具有规范性、明确性和可共享性等特点,结合主题图对文档资源组织方式具有语义可导航性,提出了一种基于主题图的本体信息检索模型,并给出了模型的形式化定义。选择旅游领域作为研究对象,定义了旅游本体和旅游文档资源主题图,分析了在信息检索模型中利用本体来规范用户自然语言查询输入,识别用户检索意图和扩展查询语义方面的作用,并展示了主题图在语义导航和用户相关度排序方面的价值。最后通过实验表明基于主题图的本体信息检索模型较传统的检索系统有较好的性能。     

Ontology在Web中的研究与应用

文章提出了一种基于本体论的Web信息检索模型,它利用领域本体知识库对用户的查询要求进行语义扩展,并且将检索到的文档在语义层模型中根据概念层的概念匹配提出了一种概念关联匹配算法.从而克服了目前的检索工具中仅仅提供基于关键字的检索,但忽视了关键字本身语义信息所造成的错检和漏检.     

基于推理的语义网检索模型及关键技术研究

为解决语义网检索过程中缺少推理导致语义检索性能不高的问题,提出一个基于推理的语义网检索模型,并介绍了该模型实现的关键技术.针对构建的领域本体,使用SWRL规则语言进行本体完善把本体中的隐性知识表示出来;在信息抽取过程中,对于识别出的实体,利用推理规则,获得更加丰富的实例知识库;对于用户输入的查询条件,利用完善的本体知识库及规则得到更多的相似概念实现查询扩展;进行语义匹配,获得更为精准的检索结果.实验结果表明,该模型能提高信息检索的语义性,得到较满意的信息检索结果.     

基于语义的查询扩展研究

用户查询与文档之间语义匹配但词法不匹配现象是影响信息检索效果的重要原因之一.本文提出了一种基于本体的信息检索查询扩展方法,这种方法中,通过建立本体模型并计算本体中概念间的语义相似度来确定扩展查询词.此外,本文还给出了组合向量空间模型,作为引入查询扩展后的查询结果相关度评价方法.     

基于领域本体的语义查询扩展

在信息检索研究领域,资源与查询词的匹配决定信息检索质量。现有检索方法的检索结果存在过多不相关信息,不能很好满足用户需求。针对传统信息检索存在的问题与当前语义查询扩展方法的特点,本文在分析各种语义查询扩展方法及其相关研究的基础上,提出一种改进的基于领域本体的语义查询扩展方法。该方法论通过本体模型和概念相似度的计算对检索信息进行检索意图树的构建并扩展;然后在资源本体中以最短路径的方式搜索资源。实验结果表明,本文方法相较其他查询扩展方法能得到更好的检索结果。     

基于本体的个性化信息检索技术研究

针对传统的采用关键词的信息检索方式在个性化方面的不足,提出了一种根据领域本体的个性化信息检索模型.首先获取用户的特征信息,接着利用用户的特征信息构建基于本体的用户兴趣模型,在检索过程中通过领域本体概念和用户兴趣模型对检索请求进行分析并对其进行扩展,获得符合检索意图的结果,在此基础上按兴趣度大小处理后将最终个性化信息检索结果反馈给用户.通过搭建关于本体的个性化检索原型系统,仿真结果验证了改进模型的有效性.     

Application of Evolutionary Strategies to Optimal Design of Multibody Systems

This paper is concerned with the application of evolutionary strategiesto the optimization of the kinematic or dynamic behaviour of mechanicalsystems. Although slower than classical deterministic, gradient-basedmethods, they represent an interesting alternative: they are global,they should be more robust as they do not rely on continuity andderivability conditions and they can use the simulation software as is.They are inspired from natural evolution: the design variablescorresponding to the genes of an individual mutate from generation togeneration and the ones who survive are those that are the best fittedto their environment, that's to say with the best objective function.The implementation of evolutionary strategies is presented as well assome guidelines to choose the most important parameters. Two examplesare developed for the sake of illustration: the kinematic optimizationof a suspension and the dynamic optimization of the comfort of a railwayvehicle. Finally, the performances are compared with respect todeterministic methods and genetic algorithms.     

Editorial: Communication channels

"34. The objective of piloting superhighways in education, as with any other new technologies, is to establish whether they offer the potential to enrich the delivery and experience of education, are likely to help young people meet the challenges which they will face when they enter employment, and provide them with the skills which they will need for lifetime learning."*     

Scoresynth: a system for the synthesis of music scores based onPetri nets and a music algebra

The authors show that they have chosen and organized symbols depending on instrumental needs within common music notations. The new kind of representation they propose makes up a conceptual music framework with as many different levels of abstraction as the musician needs. It allows them to explicitly describe and process what they call music objects (both traditional and nontraditional music objects), by which they mean anything that could have a musical meaning and can be thought of as an entity with a name and some relationship with other music objects. They describe a tool called Scoresynth, which uses Petri nets to describe, process, and synthesize music scores. They examine Scoresynth's features and explain how it works     

Student engagement with assessment and feedback: Some lessons from short-answer free-text e-assessment questions

Students were observed directly, in a usability laboratory, and indirectly, by means of an extensive evaluation of responses, as they attempted interactive computer-marked assessment questions that required free-text responses of up to 20 words and as they amended their responses after receiving feedback. This provided more general insight into the way in which students actually engage with assessment and feedback, which is not necessarily the same as their self-reported behaviour. Response length and type varied with whether the question was in summative, purely formative, or diagnostic use, with the question itself, and most significantly with students’ interpretation of what the question author was looking for. Feedback was most effective when it was understood by the student, tailored to the mistakes that they had made and when it prompted students rather than giving the answer. On some occasions, students appeared to respond to the computer as if it was a human marker, supporting the ‘computers as social actors’ hypothesis, whilst on other occasions students seemed very aware that they were being marked by a machine.     

Hackers Profiled — Who Are They and What Are Their Motivations?

A great many people see all hackers as immature, spotty teenagers with good computer skills and no regard for the damage they do when they hack systems. The truth is very different. The hacker community as a whole is a very broad church. This article will aim to define a number of different groups of hackers, analyse their motivations and look at the sort of threats they pose to businesses.     

Refactoring Tools: Fitness for Purpose

Refactoring tools can improve the speed and accuracy with which developers create and maintain software—but only if they are used. In practice, tools are not used as much as they could be; this seems to be because sometimes they do not align with the refactoring tactic preferred by most programmers, a tactic the authors call "floss refactoring." They propose five principles that characterize successful floss-refactoring tools—principles that can help programmers to choose the most appropriate refactoring tools and also help toolsmiths to design tools that fit the programmer's purpose.     

Microdisplay‐based industrial 3‐D and microstructure measurement systems

Abstract— Microdisplays, whether they are of the liquid‐crystal‐on‐silicon (LCOS) or organic light‐emitting diode (OLED) type, have been, up until now, mainly used in multimedia applications or head‐mounted displays. Due to their interesting possibilities, these displays open more and more alternative applications; for example, in optical metrology. Projection lenses for this application area need to be specially designed because the requirements on these systems differ completely from those for multimedia applications. The lenses must have very low geometrical image distortion and they have to be adapted to small objects and/or image distances. On the other hand, they often work with light sources with small spectral bandwidths; consequently, they do not need to be corrected for chromatic aberrations. In addition, the numerical aperture has to be large enough to collect and transfer as much light as possible, but also the size of the projection lens has to be as small as possible to ensure compact measurement systems. All these requirements lead to a compromise in optical lens design. Three optical system designs and realizations — one with an OLED microdisplay and two with an LCOS microdisplay — are presented.     

Media multitasking during political news consumption: A relationship with factual and subjective political knowledge

Growth of digital, social, and mobile media has enabled engagement with multiple media activities during news consumption in a more efficient and synchronous fashion than before. This study investigates whether media multitasking activities while consuming political news affects individuals' levels of subjective and factual political knowledge. Results from a Web survey of online panel members show that on the whole, pairwise and bundled forms of media multitasking are negatively related to factual political knowledge. Also, those who engage in media multitasking are more likely to report that they are politically knowledgeable but they do not know about politics as much as they think they do. Implications are discussed for media multitasking and an informed citizenry.     

Digital akrasia: a qualitative study of phubbing

The present article focuses on the issue of ignoring conversational partners in favor of one’s phone, or what has also become known as phubbing. Prior research has shown that this behavior is associated with a host of negative interpersonal consequences. Since phubbing by definition entails adverse effects, however, it is interesting to explore why people continue to engage in this hurtful behavior: Are they unaware that phubbing is hurtful to others? Or do they simply not care? Building on interviews with students in a Danish business college, the article reveals a pronounced discrepancy in young people’s relationship to phubbing: While they emphatically denounce phubbing as both annoying and disrespectful, they readily admit to phubbing others. In other words, they often act against their own moral convictions. Importantly, participants describe this discrepancy as a result of an unintentional inclination to divert attentional engagement. On the basis of these results, the article develops the notion of digital akrasia, which can be defined as a tendency to become swept up by ones digital devices in spite of better intentions. It is proposed that this phenomenon may be the result of bad technohabits. Further implications are discussed.

     

一种三角形网格模型数字水印算法

随着3D模型技术的发展,3D模型的版权保护问题越来越被重视.提出了一种基于三角域上V系统的3D网格模型数字水印算法.该算法首先将模型上的顶点到模型中心的距离进行三角域上的一次V变换,然后对变换后的系数进行量化来嵌入水印.由于该距离是一种全局几何特征,且算法将足够多的比特水印信息分布到模型各处,从而使得该水印方案具有一定的鲁棒性.实验结果表明该算法能够抵抗一般的平移、旋转等类型的攻击和随机噪声攻击.