Authors in the Mathematical Reviews/MathSciNet Database

The Physics-Astronomy-Mathematics Division Vendor Update Session at the Special Libraries Association 2010 Annual Conference in New Orleans had a panel of four representatives of organizations involved in author authority work. In my presentation I described the involvement of Mathematical Reviews/MathSciNet in author authority work, from the hand work done with file cards in 1940 through the present day work combining computer systems and hand work. This article is an expanded version of my comments.     

Conceptions of Biology and Approaches to Learning of First Year Biology Students: Introducing a technique for tracking changes in learner profiles over time

We surveyed first year students at the start and at the end of their first semester of university biology (n?=?285) as to their approaches to study (surface, deep) and their conceptions of biology (fragmented, cohesive). Hierarchical cluster analysis was used to group students who responded similarly to the survey; this resolved four Learner Profiles based on specific combinations of approach to study and conception of biology. By comparing cluster membership at the start and end of the semester we could assess whether students (1) maintained their incoming approach to study and conception of the discipline of biology, i.e. their ‘Learner Profile’ and (2) whether certain Learner Profiles were more persistent than others. Approximately half the student cohort did not alter their approach to study or conceptions of biology by semester's end. Students in the disengaged profile, i.e. who returned mostly negative responses to survey items, appeared the most resistant to changing their Learner Profile; while the greatest migration occurred towards less than desirable learning strategies (particularly to the disengaged profile). We were able to confirm the significant migration patterns by assessing the heterogeneity of each cluster at the start of semester clusters with respect to the students' approaches and conceptions at the end of semester. Thus we present a process to accurately track Learner Profile changes that may tell us more about how we can enhance students' learning and provide a means by which to gather the empirical data to support decisions relating to curriculum change.     

Taylor中值定理的一个几何注释

讨论当n>0(n为整数)时,Taylor中值定理的一个几何注释。     

面向情境兴趣的文本信息过滤系统

随着对信息过滤技术研究的深入和展开,信息过滤系统的推荐质量不断得到提高。但长期以来文本信息过滤系统都是用来推荐符合用户长期兴趣的信息,而忽略了用户对短期突发信息的需求。针对这种情况,本文提出了面向个人情境兴趣的文本信息过滤系统。模拟实验显示,这种过滤系统可以更好的适用用户信息需求快速变化的情况。     

基于浏览行为和浏览内容的用户兴趣建模

面对因特网的海量信息，为了更好地实现基于用户兴趣的个性化信息服务，提出一种隐式地获取用户兴趣模型和更新用户兴趣模型的方法。这种方法不需要用户显式地提供兴趣信息，只需要用户浏览页面时的动作和浏览的内容来获取有用的信息，随后利用这些信息建立和更新用户兴趣模型。该模型能较好地描述用户的兴趣类型及兴趣度，提高个性化信息服务的效率。     

基于网络结构和文本内容的群体画像构建方法研究

[目的/意义] 在基于社会网络的用户画像研究中，针对传统用户建模难以处理复杂网络关系，群体构建多基于内容，以及群体相似度低或紧密性差的问题，提出基于网络结构和文本内容的群体画像构建方法。[方法/过程] 首先，采用卷积神经网络方法，融合网络结构和文本内容两方面特征将网络用户表示成空间向量，其次，在k-means算法基础上结合模块度计算方法，对空间向量进行聚类，然后，在爬取的中英文数据集上分别进行对比研究，最后，从中文数据集中选取1 000名重要性用户进行实例分析。[结果/结论] 实验结果表明，该方法的密度值比基于内容的方法平均增加0.105，熵值比基于结构（含基于结构和内容）的方法平均减少0.955，实例分析进一步说明文中方法的可行性。     

Development and field validation of an omni-domain power-duration model

ABSTRACT

Purpose: To validate and compare a novel model based on the critical power (CP) concept that describes the entire domain of maximal mean power (MMP) data from cyclists.

Methods: An omni-domain power-duration (OmPD) model was derived whereby the rate of W? expenditure is bound by maximum sprint power and the power at prolonged durations declines from CP log-linearly. The three-parameter CP (3CP) and exponential (Exp) models were likewise extended with the log-linear decay function (Om3CP and OmExp). Each model bounds W? using a different nonconstant function, W?eff (effective W?). Models were fit to MMP data from nine cyclists who also completed four time-trials (TTs).

Results: The OmPD and Om3CP residuals (4 ± 1%) were smaller than the OmExp residuals (6 ± 2%; P < 0.001). W?eff predicted by the OmPD model was stable between 120–1,800 s, whereas it varied for the Om3CP and OmExp models. TT prediction errors were not different between models (7 ± 5%, 8 ± 5%, 7 ± 6%; P = 0.914).

Conclusion: The OmPD offers similar or superior goodness-of-fit and better theoretical properties compared to the other models, such that it best extends the CP concept to short-sprint and prolonged-endurance performance.     

Using a Heuristic-Systematic Model to assess the Twitter user profile’s impact on disaster tweet credibility

Journalists, emergency responders, and the general public use Twitter during disasters as an effective means to disseminate emergency information. However, there is a growing concern about the credibility of disaster tweets. This concern negatively influences Twitter users’ decisions about whether to retweet information, which can delay the dissemination of accurate—and sometimes essential—communications during a crisis. Although verifying information credibility is often a time-consuming task requiring considerable cognitive effort, researchers have yet to explore how people manage this task while using Twitter during disaster situations.To address this, we adopt the Heuristic-Systematic Model of information processing to understand how Twitter users make retweet decisions by categorizing tweet content as systematically processed information and a Twitter user’s profile as heuristically processed information. We then empirically examine tweet content and Twitter user profiles, as well as how they interact to verify the credibility of tweets collected during two disaster events: the 2011 Queensland floods, and the 2013 Colorado floods. Our empirical results suggest that using a Twitter profile as source-credibility information makes it easier for Twitter users to assess the credibility of disaster tweets. Our study also reveals that the Twitter user profile is a reliable source of credibility information and enhances our understanding of timely communication on Twitter during disasters.     

急性太极拳运动对原发性高血压患者血压和血脂的影响

目的:探讨急性太极拳运动对原发性高血压患者血压和血脂的影响及其可能的作用机制。方法:以原发性高血压患者14人为研究对象,采用自身对照法,用DS-250型动态血压测量仪(美国产),观察休息日和运动日24小时动态血压变化。测定运动结束后即刻、24小时、48小时血清总胆固醇(TC)、高密度脂蛋白胆固醇(HDL-C)、甘油三酯(TG)、低密度脂蛋白胆固醇(LDL-C)的动态变化。结果:与运动前相比,一次急性太极拳运动后,原发性高血压患者收缩压和舒张压都呈下降趋势,舒张压下降的程度更加明显(P<0.05)且更为持久,这种降压效应可持续18个小时以上,24小时后基本恢复到运动前水平。一次急性太极拳运动后即刻TC、LDL-C浓度明显下降(P<0.05),HDL-C浓度显著上升(P<0.05);运动后24小时HDL-C浓度持续升高(P<0.01),TG浓度明显下降(P<0.05),LDL-C回升并超过运动前水平;48小时后TC、TG、LDL-C的浓度基本恢复到运动前水平,HDL-C浓度仍然较高,但与运动前相比没有达到显著性差异。     

一个基于反馈的信息过滤系统的设计与实现

随着互联网上信息的迅速增长 ,信息过滤技术得到越来越广泛的应用。本文论述了一个基于反馈的内容信息过滤系统的设计和实现。它采用向量空间模型 ,使用类重心分类算法来形成用户兴趣文件 ,采用余弦算法比较待过滤文档和用户兴趣文件的相似度 ,并使用Rocchio反馈模型来重建用户兴趣文件。实验表明 ,本文提出的策略和方法是切实可行的