基于ⅡG和LSI组合特征提取方法的文本聚类研究

本文利用改进的信息增益特征选择方法和潜在语义索引技术组合的特征提取方法,对文本进行了有效的自动聚类.从语料库中抽取了250篇文本,首先利用向量空间模型和改进的信息增益特征选择方法,构造文本特征向量,利用C-均值方法聚类,聚类结果准确率、查全率、F-measure分别达到0.82、0.88、0.83.在此基础上,对最优的特征选择结果运用潜在语义索引方法,对奇异值分解的结果进行截断处理,发现奇异值K取40时聚类结果的准确率、查全率、F-measure达到0.95、0.57、0.78,在有效地降维的同时,大幅度地提高了聚类的准确率.     

公共图书馆商业数字资源的管理与开发利用

随着计算机、互联网及现代通讯技术的发展,信息化环境已经形成,信息的表现形式多样化,数字信息的比重在不断增加.商业数字资源大大丰富了公共图书馆的馆藏,也为公共图书馆的可持续发展提供了广阔的空间.如何对海量信息资源进行有效的管理,使之最大限度地满足信息用户的需要,是当代公共图书馆所面临的重要课题.本文论述了公共图书馆商业数字资源管理的方法以及商业数字资源开发与利用的思路.     

网络版权保护之基础法律问题探析

随着网络技术的飞速发展,互联网已给著作权法领域带来了诸多我们亟待解决的新问题.本文旨在探讨网络著作权的确认及侵权等一些重要的法律问题,并提出个人的思考和建议.     

我国综合档案事业发展水平及其趋势的定量评价研究

论文应用熵权法和AR(1)模型分析了我国1991-2015年的综合档案事业发展水平及其演化趋势.结果发现:档案资源建设水平、档案开放利用水平和组织建设水平发展的步调不尽相同并表现出明显的阶段性特征;国家综合档案事业发展水平总体上呈稳步上升势态,但阶段性发展特征同样明显;国家综合档案事业发展水平滞后于同期经济发展水平;综合档案事业发展水平的绝对发展速度受制于上年度的绝对发展速度.     

企业知识管理策略

针对知识管理的特征和内容,企业应从如下七个方面来发展知识管理的对策:建立企业知识库 建立知识库的目的是为了提高企业智商(Corporate IQ)。比尔·盖茨认为企业智商就是企业拥有的学习能力。企业不但要从错误中学习,也要从成功的经验中学习。在全球拥有六万个顾问的安达信顾问公司,过去几年     

Understanding the Nature,Uses, and Gratifications of Social Television: Implications for Developing Viewer Engagement and Network Loyalty

This study employed an online survey (N = 310) to explore how viewers’ motivations for social TV participation influence their involvement in social TV activities, their program commitment, and network loyalty. Findings show that social infotainment and social companionship are the primary motivations of social TV participation. However, only social infotainment significantly predicts the intensity of viewers’ social TV usage, which has a positive influence on program commitment and network loyalty. Additionally, the relationship between social TV usage and network loyalty is partially mediated by program commitment. These findings demonstrate the value of social TV to broadcasters and provide directions for initiating and maintaining long-term relationships with viewers.     

Serrated lithium fluoride nanofibers-woven interlayer enables uniform lithium deposition for lithium-metal batteries

The uncontrollable formation of Li dendrites has become the biggest obstacle to the practical application of Li-metal anodes in high-energy rechargeable Li batteries. Herein, a unique LiF interlayer woven by millimeter-level, single-crystal and serrated LiF nanofibers (NFs) was designed to enable dendrite-free and highly efficient Li-metal deposition. This high-conductivity LiF interlayer can increase the Li⁺ transference number and induce the formation of ‘LiF–NFs-rich’ solid–electrolyte interface (SEI). In the ‘LiF–NFs-rich’ SEI, the ultra-long LiF nanofibers provide a continuously interfacial Li⁺ transport path. Moreover, the formed Li–LiF interface between Li-metal and SEI film renders low Li nucleation and high Li⁺ migration energy barriers, leading to uniform Li plating and stripping processes. As a result, steady charge–discharge in a Li//Li symmetrical cell for 1600 h under 4 mAh cm⁻² and 400 stable cycles under a high area capacity of 5.65 mAh cm⁻² in a high-loading Li//rGO–S cell at 17.9 mA cm⁻² could be achieved. The free-standing LiF–NFs interlayer exhibits superior advantages for commercial Li batteries and displays significant potential for expanding the applications in solid Li batteries.     

Magnetically encoded 3D mesostructure with high-order shape morphing and high-frequency actuation

Inspired by origami/kirigami, three-dimensional (3D) mesostructures assembled via a mechanics-guided approach, with reversible and maneuverable shape-morphing capabilities, have attracted great interest with regard to a broad range of applications. Despite intensive studies, the development of morphable 3D mesostructures with high-order (multi-degree-of-freedom) deformation and untethered high-frequency actuation remains challenging. This work introduces a scheme for a magnetically encoded transferable 3D mesostructure, with polyethylene terephthalate (PET) film as the skeleton and discrete magnetic domains as actuation units, to address this challenge. The high-order deformation, including hierarchical, multidirectional and blending shape morphing, is realized by encoding 3D discrete magnetization profiles on the architecture through ultraviolet curing. Reconfigurable 3D mesostructures with a modest structural modulus (∼3 GPa) enable both high-frequency (∼55 Hz) and large-deformation (∼66.8%) actuation under an alternating magnetic field. Additionally, combined with the shape-retention and adhesion property of PET, these 3D mesostructures can be readily transferred and attached to many solid substrates. On this basis, diverse functional devices, including a switchable colour letter display, liquid mixer, sequential flashlight and biomimetic sliding robot, are demonstrated to offer new perspectives for robotics and microelectronics.     

基于ASP.NET 3.5+AJAX在线测试功能的实现

随着网络的普及,在线测试这一方式在各种测试场合中起着越来越重要的作用。实现在线测试的技术和方法很多,本文给出一种基于ASP.NET AJAX技术的Web在线测试实现方法。