Inverted Index Compression Using Word-Aligned Binary Codes

We examine index representation techniques for document-based inverted files, and present a mechanism for compressing them using word-aligned binary codes. The new approach allows extremely fast decoding of inverted lists during query processing, while providing compression rates better than other high-throughput representations. Results are given for several large text collections in support of these claims, both for compression effectiveness and query efficiency.     

数学化对学生学习数学概念的影响——以“小数”概念学习为例

"数学化"这一概念最初是由荷兰数学家和数学教育家弗赖登塔尔(H.Freudenthal,1905—1990)提出的。"数学化"既是数学教学的过程,也是数学教学的结果。以"小数"概念学习为例,将数学化的过程呈现在数学概念的教学中,第一次学习是水平数学化,即由现实问题到数学问题的学习;第二次学习是垂直数学化,即由具体问题到抽象概念的学习。在这两次教学实践过程中,生活经验、模型支撑、多种表征都对学生"小数"概念数学化有一定的帮助。     

政府网站信息资源知识元模型与可视化表征研究

[目的/意义]利用知识元模型理论研究政府网站知识服务效果的优化路径,辅以可视化表征技术,以降低大数据环境下政务用户信息获取的操作负载和知识加工的认知负荷。[方法/过程]依据相关知识元模型研究推理出符合政府网站信息资源属性特征的六元组知识元表示方法和四元组知识元本体结构,采用TextRank与HDP算法分别抽取政府网站信息资源关键词和主题词,并由领域专家根据抽取结果确定知识元,构建包含知识元本体库生成和可视化知识服务的政府网站信息资源领域知识元可视化表征模型。[结果/结论]通过政府网站发布的共享单车实例检验知识元可视化表征模型的有效性和可行性,为实现政府网站粗粒度信息服务转向以知识元为单位的细粒度知识服务范式开辟了新的研究思路,可视化知识服务模式增强了政务信息导航的结构化和用户解读领域文本语义的效果。     

信息表征对移动医疗APP隐私政策阅读效果的影响研究——基于认知负荷理论

[目的 /意义]移动医疗场景下的隐私保护是当下亟待解决的重要课题,对其用户隐私政策阅读效果的研究不仅可以激发用户隐私政策阅读意愿、提高用户隐私保护意识,且有利于移动医疗的普及和应用.[方法/过程]尝试从便于用户阅读和理解的视角出发,以认知负荷理论为基础,通过虚拟实验和多因素方差分析对不同类型的用户阅读不同形式的隐私政策...     

生师比评价的一个数学模型及其在教学评估中的应用

本文在生师比评价实际问题的基础上,提出了一种基于模糊数学原则的数学模型,将该模型应用于一个实际的教学评估案例中,对评估结果进行分析并给出了建议。     

两个代数不等式的简证及推广

本文通过例子对[1]中不等式猜想给出了肯定的回答。找到了这个不等式成立的另一个充分条件,并给出了它的一个新的推广．     

正确培养大学生的数学思维品质

以发展个性思维为目的，探讨了培养学生思维的精度、速度、新度、深度、广度等五个方面的思维品质。     

高师数学教学中如何实施素质教育的几点探讨

本简述数学素质教训在素质教育中的作用及实施素质教育进行的五种转变。     

Effects of power variation on cycle performance during simulated hilly time-trials

It has previously been shown that cyclists are unable to maintain a constant power output during cycle time-trials on hilly courses. The purpose of the present study is therefore to quantify these effects of power variation using a mathematical model of cycling performance. A hypothetical cyclist (body mass: 70?kg, bicycle mass: 10?kg) was studied using a mathematical model of cycling, which included the effects of acceleration. Performance was modelled over three hypothetical 40-km courses, comprising repeated 2.5-km sections of uphill and downhill with gradients of 1%, 3%, and 6%, respectively. Amplitude (5–15%) and distance (0.31–20.00?km) of variation were modelled over a range of mean power outputs (200–600?W) and compared to sustaining a constant power. Power variation was typically detrimental to performance; these effects were augmented as the amplitude of variation and severity of gradient increased. Varying power every 1.25?km was most detrimental to performance; at a mean power of 200?W, performance was impaired by 43.90?s (±15% variation, 6% gradient). However at the steepest gradients, the effect of power variation was relatively independent of the distance of variation. In contrast, varying power in parallel with changes in gradient improved performance by 188.89?s (±15% variation, 6% gradient) at 200?W. The present data demonstrate that during hilly time-trials, power variation that does not occur in parallel with changes in gradient is detrimental to performance, especially at steeper gradients. These adverse effects are substantially larger than those previously observed during flat, windless time-trials.     

在远程网络教程编制中关于有效教学策略的应用

随着利用 Internet进行远程教育的日渐深入 ,网络教学资源的开发与利用显得越来越重要。本文以高师《公共心理学》网上教程为例 ,从信息的组织结构、内容的表现、支持自主学习的策略等几方面 ,探讨了在远程网络教程编制中有效教学策略的应用