基于P-Grid的数字媒体信息共享研究

文中总结了网络环境中的数字媒体使用现状,分析了在传统的数字媒体应用中存在的问题。为了解决这些问题,基于对等计算(P2P Computing)的思想,作者提出了一个基于P-Grid的数字信息共享模型,以基于XML的数字媒体生命周期为基础,利用P-Grid网络信息共享技术对Metadata进行有向发布和检索,实现数字媒体信息的有效使用。     

Optimising Publications for Google Users

Abstract

Librarians should think explicitly about Google users whenever they publish on the Web, and should update their policies and procedures accordingly. The article describes procedures that libraries can adopt to ensure that their publications are optimised for access by users of Google and other Web search engines. The aim of these procedures is to enhance resource discovery and information retrieval, and to enhance the reputation of libraries as valued custodians of published information, as well as exemplars of good practice in information management.     

数字图书馆元数据互操作机制的研究

元数据是数字图书馆建设的关键技术之一,随着越来越多的元数据标准的出现,元数据的互操作问题已成为数字图书馆互操作的一个重要方面。分析元数据互操作产生的原因,从技术角度总结和研究元数据互操作的主要解决途径, 指出存在的问题,最后给出利用网格技术实现元数据互操作的思路。     

Finding Geographic Information: Collection-Level Metadata

Certain types of information are associated with specific locations on Earths surface, and can be retrieved using location as the primary search key. The combination of a collection of such information and a location-based search mechanism is termed a geolibrary. A search for specific information over multiple collections is more efficient if one knows where to look. Information about the contents of a collection is termed collection-level metadata (CLM). Several conceptual designs for the process of search are reviewed, and the U.S. National Geospatial Data Clearinghouse is discussed. The Alexandria Digital Library provides an example of a large digital collection. Its geographic coverage is analyzed to determine whether its CLM can be modeled effectively. The difficulties of describing CLM are discussed from the perspective of institutional change, as library collections attempt to make themselves more accessible through the Internet.     

Realist Activity Theory for Digital Library Evaluation: Conceptual Framework and Case Study

A critical yet largely unexamined facet of digital library design anduse is how library content is assembled and vetted, which in turn hasprofound implications for ongoing digital library usefulness and usability.This article presents a social realist evaluation framework for anactivity theoretic case study of the Flora of North America digitallibrary. Social realist evaluation is a relatively new evaluationparadigm, positing that outcomes follow from mechanisms acting incontingently configured contexts. Because this study focuses on thedigital library content vetting process, a significant part of thepresent analysis concerns the publication subsystem of the Flora ofNorth America digital library – Collaborative Publishing Services –and how problems related to its design and use facilitates our abilityto explain the Flora of North America not only as a functioning digitallibrary project, but as a contradiction-driven organizational form inexpansive development. Activity theory is a philosophical and cross-disciplinaryframework for studying different forms of human practices in a multi-level,stratified manner, developmentally in time and through space. This intensivecase study of the Flora of North America digital library illustrates thatwhile social realism, itself content-neutral mechanics of explanation,provides a real foundation for activity theoretic analyses of workand technology, activity theory supplies a conceptually and substantivelyrich vocabulary for explanatory reasoning about technologically mediatedsocial practices, such as digital library assemblage and use.     

报业媒体资产管理系统规划研究

由新技术应用带来的媒体资产管理,是目前报业传媒关注的热点。新媒体的发展,数字报业战略的规划实施,又对媒体资产管理提出了新的要求。从媒体资产管理系统分析入手,结合国内媒体资产管理发展现况以及集团自身发展实际,提出安徽日报报业集团媒体资产管理系统整体规划方案;最后,对规划实施和未来媒体资产管理的发展趋势进行了探讨。     

The Continuous Media Web: a distributed multimedia information retrieval architecture extending the World Wide Web

The World Wide Web, with its paradigms of surfing and searching for information, has become the predominant system for computer-based information retrieval. Media resources, however information-rich, only play a minor role in providing information to Web users. While bandwidth (or the lack thereof) may be an excuse for this situation, the lack of surfing and searching capabilities on media resources are the real issue. We present an architecture that extends the Web to media, enabling existing Web infrastructures to provide seamless search and hyperlink capabilities for time-continuous Web resources, with only minor extensions. This makes the Web a true distributed information system for multimedia data. The article provides an overview of the specifications that have been developed and submitted to the IETF for standardization. It also presents experimental results with prototype applications.     

高校数字图书馆数字资源检索系统的研究与设计

文章首先简单介绍了数字图书馆的概念与发展,研究了高校数字图书馆的特点和资源检索的基本技术,介绍了当前数字资源元数据的流行规范Dublin Core,最后实现了高校数字图书馆资源检索系统的设计,并特别论述了资源统一检索平台和元数据库的设计。     

多媒体数字水印技术研究进展

作为数字媒体版权保护的重要手段,数字水印技术近年来已成为国内外研究的热点。回顾了数字水印技术的发展情况,讨论了如下问题:(1)数字水印系统模型;(2)数字水印的基本要求;(3)数字水印技术的应用前景;(4)数字水印的分类,包括各类水印的基本概念,相关算法,性能及发展趋势的分析与讨论;(5)数字水印的关键技术;(6)数字水印技术目前存在的问题和未来的研究重点。     

Prioritized Admission Strategies to Improve User-Perceived Performance in Interactive VOD Servers

In the past, much emphasis has been given to the data throughput of VOD servers. In Interactive Video-on-Demand (IVOD) applications, such as digital libraries, service availability and response times are more visible to the user than the underlying data throughput. Data throughput is a measure of how efficiently resources are utilized. Higher throughput may be achieved at the expense of deteriorated user-perceived performance metrics such as probability of admission and queuing delay prior to admission. In this paper, we propose and evaluate a number of strategies to sequence the admission of pending video requests. Under different request arrival rates and buffer capacities, we measure the probability of admission, queueing delay and data throughput of each strategy. Results of our experiments show that simple hybrid strategies can improve the number of admitted requests and reduce the queuing time, without jeopardizing the data throughput. The techniques we propose are independent of the underlying disk scheduling techniques used. So, they can be employed to improve the user-perceived performance of VOD servers, in general.