融合用户行为和内容的微博用户影响力方法

为了模拟信息在微博环境中的传播情况,根据微博用户行为(发布、关注、转发和评论等)和微博内容,提出一种融合用户行为和内容的微博用户影响力算法。通过对微博用户行为的分析,得到行为因子数据,进而计算出用户影响力的权值。利用微博用户内容建立词共现矩阵,继而运用狄利克雷分配(LDA)模型进行潜在主题分布的识别,通过KL(Kullback Leibler)散度的方法得到用户之间的相似性,最后结合用户影响力权值,得到用户的影响力。实验表明,此算法较为有效。     

基于PageRank的社交网络影响最大化传播模型与算法研究

社交网络中影响最大化问题是指找出最具有影响力的k个节点,使得最终社交网络中被影响的节点最多,信息传播范围最大。针对影响最大化问题,目前已存在一些基本传播模型,但是这些模型没有考虑网络中节点的相关性和重要性,而网络中节点的相关性和重要性是衡量其影响力的一个重要指标,因此,提出了一种基于网页排名算法的信息传播模型(PageRank-based Propagation Model,PRP),然后利用贪心算法来近似求解影响最大化问题。实验结果表明,基于PageRank的传播模型解决影响最大化问题的效果比传统的线性阈值模型、加权级联模型和独立级联模型的效果更好,影响力范围更大。     

大学生生活方式二重性研究——基于网络二重属性的影响

网络自然属性与社会属性既相互联系又相互区别;大学生生活方式自然属性与社会属性也相互联系并相互区别;网络二重性对大学生生活方式二重性产生直接的影响。网络的自然属性重塑大学生的社会结构,二重地改变着大学生生活的时空结构。网络的社会属性削弱大学生现实社会关系的不平等性;改变大学生生活的社交范围,并为其提供更新的社交方式;二重地影响着大学生的思想与心理。     

微地形对输电线路影响的探讨

利用国内外输电线路通过微地形地段风速研究的方法,通过微地形地段调查及确定,进行微地形地段气候成因分析,研究微地型对风速的影响,提出在福建沿海输电线路工程中应用的关键。     

气相色谱法测定卷烟烟气中烟碱的影响因素

为提高气相色谱法测定卷烟烟气中烟碱含量的准确性,依据行业标准YC/T156-2001对各种影响因素进行了考察,发现标准品配置方法、纯度是主要影响因素。根据试验结果,确定了用直接称重法制作标准工作曲线,采用校正标样的气相色谱法测定卷烟烟气中的烟碱。结果表明,改进后方法的准确度高、检测结果稳定,监测卷烟的测定结果与标定值基本一致。     

电子图书的发展及其对图书馆工作的影响

文章分析了电子图书的优势和存在的问题，以及给图书馆工作带来的影响，并对图书馆积极面对电子图书的挑战提出了建议。     

变压器第三线圈漏抗对滤波效果的影响及其解决方法

本文通过阻抗频率特性仿真,分析了变压器漏抗对滤波效果的影响,并从理论上提出了解决上述问题的方法.     

短路电流分流系数的计算与测试方法

本文以220kV变电站及输电线路为研究对象,对接地短路电流的分流系数进行了分析,提出了计算与测试方法,并通过对实际工程的验证,得出了适用的结论。     

Learning a decision maker's utility function from (possibly) inconsistent behavior

When modeling a decision problem using the influence diagram framework, the quantitative part rests on two principal components: probabilities for representing the decision maker's uncertainty about the domain and utilities for representing preferences. Over the last decade, several methods have been developed for learning the probabilities from a database. However, methods for learning the utilities have only received limited attention in the computer science community.

A promising approach for learning a decision maker's utility function is to take outset in the decision maker's observed behavioral patterns, and then find a utility function which (together with a domain model) can explain this behavior. That is, it is assumed that decision maker's preferences are reflected in the behavior. Standard learning algorithms also assume that the decision maker is behavioral consistent, i.e., given a model of the decision problem, there exists a utility function which can account for all the observed behavior. Unfortunately, this assumption is rarely valid in real-world decision problems, and in these situations existing learning methods may only identify a trivial utility function. In this paper we relax this consistency assumption, and propose two algorithms for learning a decision maker's utility function from possibly inconsistent behavior; inconsistent behavior is interpreted as random deviations from an underlying (true) utility function. The main difference between the two algorithms is that the first facilitates a form of batch learning whereas the second focuses on adaptation and is particularly well-suited for scenarios where the DM's preferences change over time. Empirical results demonstrate the tractability of the algorithms, and they also show that the algorithms converge toward the true utility function for even very small sets of observations.     

Design of a Medical Non‐Linear Drilling Device: The Influence of Twist and Wear on the Fatigue Behaviour of NiTi Wires Subjected to Bending Rotation

This paper considers fundamental and experimental aspects associated with the engineering design of a medical, non‐linear drilling device which exploits shape memory pseudoelasticity of NiTi wires. For this application it is important that the NiTi wires have a good fatigue resistance. This is why the present authors have previously determined the influence of various parameters on cyclic life, crack growth and stress state of pseudoelastic wires subjected to bending rotation fatigue. The actual drilling device has to withstand twist in addition to bending rotation because the free rotation is constrained by friction between the drill head and the bone material. In addition, friction between the wire and a NiTi guiding tube results in wear and this may well promote fatigue crack nucleation. In this paper, we explain the function of the medical drill. We then report results on the effect of the additional parameters (1) twist and (2) wear on the fatigue life of thin pseudoelastic NiTi wires. We finally discuss the implications of our experimental results for the design process of the medical drilling device.