个性化推荐系统中用户兴趣模型的研究

针对现有用户兴趣模型在模型建立和更新阶段的缺陷,文章设计了一种基于用户浏览内容和浏览行为的隐式自反馈用户兴趣模型。采用短期和长期兴趣来建立和表达用户兴趣,并采用基于时间窗口机制来更新短期兴趣,时间遗忘机制来更新长期兴趣。同时发现用户的关联兴趣,克服单集模式下的不足,更加全面的反映用户的多方面兴趣。     

基于用户隐式兴趣模型的信息推荐

信息推荐技术能够帮助用户从海量网络信息中提取有用信息,因而得到研究者的广泛关注。通过建立用户隐式特征兴趣模型,即将用户-行为矩阵分解为用户-隐式兴趣-行为矩阵,在充分挖掘用户隐式兴趣的基础上,研究并实现了基于隐式特征兴趣模型的协同过滤算法。在Movielens语料集上进行测试的结果表明,隐式特征能够更加精准地表述用户兴趣,有效提升信息推荐性能。     

WEB文本挖掘中用户兴趣模型的建立和更新

面对因特网的海量信息,为实现web文本挖掘,可建立用户兴趣模型,使用户很方便地获取所需的有用信息,排除无用信息。在建立这一模型之初,要通过观察用户行为,分析web页面与用户兴趣的相关度,利用静态和动态相结合方法给出一个“兴趣指数”,在此基础上,运用Web文本挖掘技术,通过计算与文本的匹配程度,将满足约定条件的文本推荐给用户,从而利用相关反馈建立和更新用户兴趣模型。     

智能用户接口的用户模型及规划识别器的研究

对于交互式软件的用户知识和信息获取方法进行了分析和讨论，指出显式和隐式用户模型的两种建模方法的特点以及对智能用户接口的适应性，并给出一个基于智能用户接口的规划识别器，以描述实现用户目标规划识别系统的一般体系结构．     

基于自适应用户模型的RSS内容过滤

为更好地解决用户如何从过载信息中快速获取需要的信息，利用RSS标准与内容过滤技术，提出了一种使用Rocchio单次反馈和多次反馈相结合的方法，此方法可以准确、快速地追踪用户兴趣的概念漂移，自适应用户模型的变化，更好地实现用户的个性化需求．为验证该方法的可行性，实现了一个基于RSS新闻的内容过滤系统（RSS News Filtering）．     

基于加权概念网络的用户兴趣建模

提出了一种基于加权概念网络(WCN)的用户兴趣建模方法，该方法利用动态学习算法，挖掘蕴含在用户反馈文档中的概念及其概念关系，建立WCN的用户模型，从而捕捉和表述用户兴趣偏好．基于WCN用户兴趣模型，提出了检索提问个性化理解以及文档个性化重评价的实现方法．为了检验提出方法的建模性能，设计了信息过滤仿真试验．测试结果表明，WCN有较好的用户建模性能．     

面向个性化需求的用户建模技术研究

从用户需求多样性和随机性出发探讨了用户建模技术。对模型表示和模型更新两项关键技术进行了研究。基于向量空间模型表示用户模型,采用重心向量分类算法建立用户模型。分析用户浏览行为隐性地获取反馈信息,计算文档反馈度,提出了一种基于Rocchio算法的周期性自适应学习机制更新用户模型。以用户满意度为评价指标,通过实验,验证了对用户需求变化的动态追踪能力。     

基于用户兴趣模型的信息推送系统研究

为了满足民航监管部门对庞大的各类民航信息有效、及时获取的需求,提出了基于多Agent的信息推送系统模型,通过显式和隐式的建模技术构建和完善向量空间模型描述的用户兴趣特征,并据此使用基于内容和向量空间相结合的方法实现信息的过滤和推荐,使系统提供的个性化信息服务尽可能满足用户真正需要。     

基于用户偏好的智能数据源选择

当前搜索引擎用户个性化的研究是搜索引擎优化的一个研究分支.当前检索模型的主要弊端就是搜索引擎用户提供的信息很少.目前主要借助于用户在和元搜索引擎交互的过程中提供的隐反馈信息对成员搜索引擎的数据源选择算法进行优化,利用语言模型对用户检索行为建模,用户与元搜索引擎交互的过程中动态更新用户行为模型,自适应的满足不同检索动机的用户的信息需求.     

WEB数据挖掘中用户兴趣模型设计

通过跟踪用户的兴趣与行为提出一种采用显示和隐式相结合的方式创建用户兴趣模型的方法.对用户浏览的WEB页面和用户浏览网页的浏览行为进行分析,得到用户兴趣模型.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.