一种基于混合粒度的微博用户标签推荐模型

针对已有的标签推荐模型在实际微博场景运用中存在的多样性、相关性较差等不足,提出了一种基于混合粒度的标签推荐模型。将微博用户的可分析资源分解成由用户信息、标签和微博正文组成的混合粒度,在不同粒度上分别进行个人信息过滤及个性标签分析,从而计算用户标签的熵值与内联度和分类标注标签词汇,提取微博正文主题等,最终为用户推荐具有较强关联性的个性化标签。与一般LDA模型的对比实验证明,该模型可以有效解决新用户的冷启动、标签推荐的准确度等问题,同时保证了推荐的多样性。     

基于LDA模型的多角度个性化微博推荐算法

通过基于概率的主题挖掘模型隐含狄利克雷分布(LDA)挖掘用户兴趣主题,是目前最常用的用户兴趣主题挖掘方法。为进一步改善用户体验,推荐其感兴趣且质量好、新鲜度高的微博,提出一种新的多角度个性化微博推荐算法。通过微博发布时间、转发数、评论数等特征计算微博重要度,利用LDA模型生成的用户-主题矩阵以及主题-词汇矩阵计算用户对微博的兴趣度,综合考虑微博本身的重要度以及用户对微博的兴趣度对微博进行评分,根据评分结果推荐微博。实验结果表明,该算法与主题模型相结合可有效够提高微博推荐的精准度。     

面向微博用户标签推荐的关系约束主题模型

社会化标签系统允许用户使用个性化的词汇对网络中的资源进行标注而被用户广泛接受。在微博网络中,用户可以为自己加注标签以推广自己或者方便别人找到自己。深入分析了微博用户数据,总结了微博用户标签的特点,针对LDA（latent Dirichlet allocation）主题模型在处理短文本时存在的不足,提出了一种基于好友关系约束主题模型。在此基础上对微博用户标签进行主题分析,计算用户的主题分布,对标签词进行聚类,并最终为用户推荐标签。通过对比实验证明了该方法可以提高标签推荐的准确度。     

结合微博关注特性的UF_AT模型用户兴趣挖掘研究

微博作为国内主流社交网站,信息量与日俱增.目前微博用户兴趣挖掘方法大多停留在研究用户浏览网页时点击行为、用户所发微博内容或所在社区等表象层面,尚未深入到微博用户使用特性层面.从用户微博内容出发,结合用户关注对象微博,提出一种改进作者主题模型UF_AT(users focus-author topic).最后对真实数据进行实验得出,模型在用户兴趣主题以及主题词概率值上均高于AT模型,而且用户兴趣主题准确、全面,同时验证了UF_AT模型在挖掘用户兴趣中的有效性.     

LDA模型在微博用户推荐中的应用

潜在狄利克雷分配(LDA)主题模型可用于识别大规模文档集中潜藏的主题信息,但是对于微博短文本的应用效果并不理想。为此,提出一种基于LDA的微博用户模型,将微博基于用户进行划分,合并每个用户发布的微博以代表用户,标准的文档-主题-词的三层LDA模型变为用户-主题-词的用户模型,利用该模型进行用户推荐。在真实微博数据集上的实验结果表明,与传统的向量空间模型方法相比,采用该方法进行用户推荐具有更好的效果,在选择合适的主题数情况下,其准确率提高近10%。     

MB-HL模型的微博主题挖掘研究*

为了解决传统的文本主题模型对微博主题挖掘准确率低及不考虑主题之间关联的问题,针对中文微博语料本身的特点,分析LDA和HMM模型优缺点,提出了微博主题挖掘模型MB-HL(Microblog-Hidden Markov Model Latent Dirichlet Allocation)。该模型用逐条微博作为处理单元,建立分布主题-词语矩阵并进行优化,通过LDA模型对微博用户不同的行为建模并提取特征,利用HMM模型强大的时序状态建模能力弥补LDA在主题相关性上的不足,采用Gibbs采样进行推理求解。在真实的新浪微博数据上对比实验表明MB-HL模型能提高近9%主题关键词的准确度,并能有效地发现主题之间的关联关系。     

基于LDA的微博用户粉丝亲密度评价模型

用户关系是目前微博研究的热门方向,微博用户亲密度评价在对用户隐含亲密粉丝的发现、微博网络环境优化等方面具有重要意义。目前微博用户群体庞大且关系复杂,仅从用户自身出发,以用户特征和关系网络等为依据对用户关系亲密度评价的准确率太低。针对这一问题,提出基于LDA的微博用户粉丝亲密度评价模型。首先,对用户粉丝集中非活跃粉丝过滤剔除,获取其活跃粉丝。然后,利用LDA主题模型对用户某时间段所发微博集进行训练,获取用户阶段性微博的主题分布;同时通过主题分布推断其兴趣取向分布,并利用余弦相似方法计算用户与其粉丝之间的兴趣相似度。最后,结合用户的背景相似度和关系紧密度,为用户建立综合的亲密度评价标准。通过新浪API接口抓取微博近期相关数据,组成实验数据集。在数据集上基于评价的推荐实验结果表明,所提出的模型方法具有较高的准确率和有效性。     

基于增量主题模型的微博在线事件分析

为更好地利用微博结构化社会网络方面的信息,提出一种基于增量主题模型的微博在陑事件分析算法。通过设计增量过程,保留已有的训练信息,采用自适应非对称学习算法融入新微博内容与用户关系。实验结果表明,该算法可在短暂的时间内建模,并有效提高事件分析的性能。     

基于加权动态兴趣度的微博个性化推荐

针对微博信息量大、用户兴趣随时间变化特征,提出一种基于加权动态兴趣度(WDDI)的微博个性化推荐模型。WDDI模型考虑微博转发特征,并引入时间因子,利用微博主题模型基于转发的狄利克雷分配(RT-LDA)对用户微博进行研究,建立用户对主题的个体动态兴趣模型。通过用户与其关注用户的相似度和交互频率获取用户的群体动态兴趣,将用户个体兴趣与群体兴趣加权结合得到加权动态主题兴趣模型。对用户接收的新微博按动态兴趣度降序排列,实现微博动态个性化推荐。实验表明,WDDI模型较之传统推荐模型,在微博服务中能够更准确地反映用户动态兴趣。     

基于HDP模型的领域微博主题演化研究

领域微博中包含较多的专业领域信息,并且随时间表现出较强的演化性。为分析领域的主题演化情况,构建一个基于分层Dirichlet过程(HDP)的DM-HDP模型。以用户为单位抽取领域相关的微博,利用微博的领域特征和时间特征,提取领域相关带有明显时间特征的微博并自动挖掘其主题分布,最终构建领域主题演化分析过程。实验结果表明,基于DM-HDP模型的分析方法能够表现领域微博主题的演化过程,与基于LDA和HDP模型的方法相比,在内容困惑度和模型复杂度等方面均具有明显优势。     

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.