基于时滞相关负反馈的用户信任网络控制推荐模型

由于网络用户数据呈现稀疏状导致对用户信任值评价控制不准确,难以实现有效推荐。传统方法中使用语义Web结合协同过滤方法进行用户信任网络控制,在协同过滤中由于冷启动和不确定时延导致相似用户发现较为困难。提出一种基于Lyapunov稳定性理论的用户信任度评价渐进控制算法,完成用户信任网络控制器设计,并进行用户推荐模型构建,实现对用户信任度的准确评价。仿真实验表明,使用该算法和模型进行网络交易用户信任评价,能解决评价系统中存在的不确定误差、干扰和时滞等问题,用户推荐模型鲁棒性好。     

网络动态干扰监控的信任感知推荐算法设计

网络用户信任感知推荐的准确性设计是提高用户间的社交网络辅助信息信任度的重要依据。传统的网络用户信任感知推荐算法采用的是基于社交网络服务和用户评分的推荐系统,主观性较大,协同过滤效果不好。提出一种基于网络动态干扰监控的信任感知推荐算法设计新方法,设计自适应神经模糊系统网络动态干扰监测算法,构建基于向量空间模型的信任度评价指标体系结构,通过调整网络拓扑权重向量设置信任度周期响应加权变量自适应函数,有效降低迭代算法的运算成本,避免了自适应神经模糊系统网络动态干扰监测加权权重成固化状态,提高抗干扰性能。实验结果表明,算法能使社交网络感知推荐模型的预测误差减少,推荐可靠性优于传统方法。     

基于互相关准则的电子物流信任渐进控制模型

通过对电子商务的物流信任度渐进控制模型设计,进行网络实体对象的信任度评级,提高对商家的定量评估性能。传统的电子物流信任度控制模型采用自相关函数分析的模型设计方法,由于自相关特征分析的主观性较大,评价效果不好。提出一种基于互相关准则的电子物流信任度渐进控制模型。首先构建电子物流的资源数据库结构模型,构建用户信任评估机制与网络控制模型。采用DOI(Degree of Interest)互相关准则描述用户对资源的信任度评价,基于互相关准则,两个用户共同作出对彼此信任值模型的归一化评价。仿真实验表明,采用该模型,对电子物流信任度具有较好的渐进控制性能,信任度评价准确,估计精度较高,实现了基于互相关准则的电子物流信任度渐进控制,提高对电子物流商家的监管能力。     

引入多主体协商频率分析的云信任数据推荐算法

通过对电子商务网络交易中的云信任度数据的准确推荐算法设计,提高对商家的定量评估性能。传统的云信任数据推荐模型采用单自由度协商模型,主观性较大,推荐效果不好。在云计算环境下,提出一种基于多主体协商频率分析的云信任数据推荐算法。利用了正向和逆向云发生器进行定性与定量概念的相互转换。构建多主体协商频率分析模型,采用信任属性云逆向生成器生成信任属性云,对属性云进行综合评定得到综合属性云,同时运用相似度计算原理给出信任度评定等级。采用方差作为标准测度函数,计算信任云权重,实现商家云信任数据推荐算法改进。仿真结果表明,采用该算法进行多主体协商,得到的电子商务商家的云信任数据推荐的收敛性较好,对商家的信任评价准确,有效降低复杂虚拟的网络交易所带来的交易风险,更加完善了信任度评估机制。     

引入多模判决反馈提升B2C忠诚度特征挖掘算法

在B2C模式下对客户的忠诚度特征挖掘是对商户交易信任度评价的基础,进而促进用户忠诚度的提升。传统的B2C忠诚度特征挖掘算法采用基于负反馈动态的渐进控制算法,当用户数据呈现稀疏状特征时,挖掘效果不好。提出一种基于多模判决反馈的特征挖掘算法以提升B2C忠诚度。构建B2C模式下的忠诚度特征分析评估机制,根据B2C模式下多模判决反馈忠诚度控制稳定性理论,提出一种电子商务用户忠诚度评价渐进提升控制算法,这里选取Lyapunov函数构建提升目标函数,实现特征挖掘算法改进。仿真结果表明,采用该算法进行B2C模式下的商户忠诚度特征挖掘和评价,忠诚度评价准确度有所提高,用户的数据信息特征预测性能较好,特征挖掘精度提升,提高了对B2C模式下的商户的定量评价精度。     

网络拓扑变权重信任度云模型定量评估仿真

针对复杂网络环境不同网络交易的特点,提出了采用变权重云模型网络拓扑理论对网上交易信任度及信任度变化量化评估方法。首先构建了基于云模型的信任度评估模型的总体结构,研究标准信任云生成器网络拓扑算法,通过调整网络拓扑权重向量,提出使用标准信任云生成器系统迭代的信息相似度为定量评估参数,设置信任云信息点的响应的频率计数器从而有效降低迭代算法的运算成本,构建标准信任云逆向生成器对网上交易信息进行完整逆向跟踪评价体系。结合淘宝网真实数据进行实验仿真,仿真结果表明该算法能更真实定量地反映商家信任度,有效降低复杂虚拟的网络交易所带来的交易风险,一定程度上完善了信任度评估机制。     

基于约束校对的协同过滤推荐算法

根据用户的个性化需求进行网络信息推荐,在电子商务商品推荐和网络信息推送中具有应用价值。本文针对传统的语义关键词推荐方法的指向性精度不高的问题,提出一种基于协同过滤融合和个性化特征约束校对的信息推荐算法,首先构建P2P网络模型下的信息传输模型,对用户的个性化需求信息进行信息融合和语义信息素特征提取,然后采用自相关匹配滤波方法进行信息融合和滤波,实现对个性化特征的协同过滤和信息推荐,最后通过仿真实现进行性能测试。仿真结果表明,采用该算法进行信息推荐的数据召回率和配准度较高,耗时较短,实现个性化信息定制和推荐。     

融合用户画像与协同过滤的知识付费平台个性化推荐模型

[目的/意义]为提高知识付费平台用户感知服务质量,文章构建了融合用户画像与协同过滤的个性化推荐模型。[方法/过程]首先根据用户特性构建画像标签体系,利用TF-IDF、熵值法、k-means等方法确定用户特征标签;其次分别基于用户画像与改进后的协同过滤算法计算用户相似度,通过调和权重得到用户综合相似度;最后利用Top-N进行个性化推荐。[结果/讨论]通过知乎live付费用户信息进行验证,发现本文算法在推荐结果的准确率以及召回率上,相比其单一方法均有较大提升,且满意度高于知乎live平台。     

一种基于隐式信任感知的MOOCs推荐方法

[目的/意义]随着MOOCs迅猛发展和普及,如何利用智能推荐技术为学习者从海量的MOOC中"寻找最佳课程"成为MOOC发展中需要解决的重要课题。[方法/过程]基于自我知觉理论和学习行为投入框架,充分利用学习行为日志和评分数据挖掘学习者之间的隐式信任关系,并通过信任传播建立MOOC社区信任网络,从而构建动态结合兴趣和隐式信任感知的混合推荐方法。为解决数据稀疏问题,提出基于信任的联合概率矩阵分解模型(TA-PMF),将课程评分矩阵、信任关系矩阵的分解相结合来挖掘用户及课程潜在特征,进而实现评分预测。[结果/结论]真实数据集测试结果表明,与显性评分值相比,学习行为投入信息对信任度构建贡献权重达到0.7;TA-PMF方法对MOOC推荐具有较好的适用性,且能在一定程度上缓解冷启动问题。     

基于个性化情景的移动商务信任推荐模型研究

【目的/意义】移动互联网时代,移动电子商务用户的个性化信息需求具有极强的情景依赖性与感知信任 性,针对目前移动商务信息服务个性化和准确性较低,提出融入用户个性化情景与用户间信任关系的推荐模型。 【方法/过程】首先,通过用户当前情景和历史评分数据计算出对每个用户即时信息需求影响最大的K个情景要素, 以此构造用户个性化情景,然后结合不同信任环境下的用户信任度矩阵改进已有的不同信任信息环境下用户情景 兴趣推荐方法,进而进行项目推荐。【结果/结论】通过Movie lens与Book-Crossing数据集对本文提出的算法和其 它两种算法进行比较,实验结果表明：本模型具有较高的推荐准确率,可有效地解决移动商务环境下的个性化推 荐问题。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.     

Rough Justice: A Statistical Assessment of ICANN's Uniform Dispute Resolution Policy

Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.     

Prevalence of soft neurological signs in Chinese people

Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.     

Monoculture Rubber Plantations Have Negative Ef ects on Controlling Splash Erosion

<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence     

Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels

<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese     

More than Skin Deep – Understand Skin Biology by Means of Dermatogenomics

<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages.