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。     

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.     

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。     

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。     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

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.     

A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.