数字水印技术综述

简单介绍了数字水印技术的概念、原理和特点,根据水印所附载体不同,将数字水印分为图像水印、音频水印、视频水印、文本水印、网格水印和软件水印,并描述了其原理和各种不同的实现方法.最后介绍了数字水印技术目前在各个领域的应用,并指出数字水印技术的发展方向.     

提高馆员素质 适应时代需要

知识经济的崛起,对作为社会主义事业的图书馆产生了巨大的冲击.在新的时期,传统图书馆不会消亡,它将和数字图书馆互补共存,并且从文化素质和思想素质两个方面对馆员提出了更高的要求.     

高职院校《数字通信原理》课程教学改革的探讨

《数字通信原理》是高职院校通信类专业的一门重要专业基础课,其教学改革的目的是提高教学水平和完善教学质量。针对目前教学中存在的一些问题及高职院校学生实际情况,该文对教学内容、教学方法及教学实践环节进行了改革探讨。教学实践结果表明,其教学效果良好。     

基于XML与Web服务的图书馆资源整合与集成模式的探讨

通过分析XML与Web服务技术,设计了一种基于XML和Web服务技术的数字图书馆资源整合和集成模型体系:以XML为标准的数据交换格式,以Web服务为分布式计算机制.通过该模型解决了新形势下分布、异构和自主的数字图书馆资源给读者检索和利用带来的困难.     

Students and society in the 2020s. Three future ‘histories’ of education and technology

ABSTRACT

As social science fiction, this paper imagines three possible futures for education and technology. Among the most important technologies emerging today are data-aggregating technologies such as AI, affective computing, adaptive or predictive software, clouds and platforms. The paper is not, however, directed at specific technologies, but at indeterminate sociotechnical configurations. Set in 2040, it offers three ‘histories’ of the 2020s. Might students become (i) ‘smooth users’, improving themselves in the pursuit of frictionless efficiency within a post-democratic frame created by large corporations, (ii) ‘digital nomads’, seeking freedom, individualism and aesthetic joy as solopreneurs exploiting state regulations and algorithmic rules while stepping out of the state and deeply into the capitalist new economy, or (iii) participatory, democratic, ecological humans embedded in ‘collective agency’ that see institutions as spaces for exploring more equitable ways of living? The paper reflects on the future research and the political, educational and technological decisions which would make each of these three fictional future histories more or less likely.     

数字化测图中偏心测量用法的改进探讨

在数字化采集过程中,当遇到棱镜难于直接安置在目标点时,采用偏心测量方法能够获得较好的测量效果。本文对偏心测量方法进行了一些改进,对实际测量有指导意义。     

The Information Seeking Strategies of High School Science Students

This study focused on the use of the Artemis web-based interface http://artemis.goknow.com/artemis/index.adp). This program provides a digital library for students to search, organise, and evaluation science information related to project-based investigations. The primary feature of the Artemis interface is a focused search tool. Key scaffolding features in Artemis include the collections of web sites, driving question folders, a persistent workspace for notes, cataloging of past search results, and the viewing of sites shared by other students. The primary goal of this study was to describe high school science students' use of the scaffolding features embedded in the Artemis interface. The researchers were interested in identifying the scaffolding features students use and describing how they use them in the context of finding science information related to investigations. In addition, to look at scaffolding interaction, relationships between feature use and student learning were examined. The context of this study was a four-week science investigation conducted by 43 high school biology students. Students worked in dyads to answer driving questions related to their topics of study (e.g., What do the conditions need to be in order for green algae to survive?). It was found that students relied heavily upon Organisational Feature scaffolds (persistent workspace) to help them organise information that was ultimately used by the students to produce domain specific artifacts. In addition, students spent much of their time conducting searches and saving results. However, classroom performance success was only significantly correlated with the use of Organizational Feature scaffolds – scaffolding features that students use to create driving questions, write notes about the information they found as a result of their searches, and keep track of their investigations. No other search tool used by the students possessed this important scaffolding feature. The students did not automatically use Collaborative Features – scaffolding features hypothesised to be powerful cognitive tools.     

试论特色数字图书馆的建设

随着信息技术和网络技术的进步 ,我国数字化图书馆应向特色化发展。应充分认识数字地球图书馆所具有的核心竞争力和发展的必然性。     

用数码技术研究抛射体的运动规律

利用数码相机拍摄小球运动的短片,利用Premiere,Photoshop和Excel等计算机软件合成轨迹图、处理数据和拟合运动曲线,从而探索抛射体的运动规律,并求得重力加速度值。最后分析了表差法处理结果的不确定度。     

一种基于视觉模型的DCT数字水印算法

如何解决不可见性和鲁棒性之间的矛盾一直是数字水印算法的关键问题。提出了一种基于视觉模型的DCT域盲水印算法，该方法通过对视觉模型的亮度遮蔽特性和对比度遮蔽特性的研究和使用，优化了水印的嵌入位置和水印的嵌入强度，确保了水印信号能够在合适的嵌入位置上以尽可能大的嵌入强度嵌入，使得水印保持了较好不可见性的同时，其鲁棒性也得到了一定的提高。实验结果表明，该水印算法对噪音、裁剪以及压缩攻击具有较强的鲁棒性，算法是有效的。