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1.
This paper presents major technical requirements for designing and developing future distributed multimedia information system using Internet technology. The key requirements of this system are to allow users to search, access, and communicate multimedia documents consisting of text, audio, video and image. We emphasize the role of object-oriented technology for information management and real-time communication protocols to guarantee QoS. it presents a reference architecture for Web-based real-time distributed multimedia system which provides several functionalities including real-time distributed multimedia system which provides several functionalities including real-time streaming, multimedia indexing and searching, and distributed object management.  相似文献   

2.
The next generation of interactive multimedia documents can contain both static media, e.g., text, graph, image, and continuous media, e.g., audio and video, and can provide user interactions in distributed environments. However, the temporal information of multimedia documents cannot be described using traditional document structures, e.g., Open Document Architecture (ODA) and Standard Generalized Mark-up Language (SGML); the continuous transmission of media units also raises some new synchronization problems, which have not been met before, for processing user interactions. Thus, developing a distributed interactive multimedia document system should resolve the issues of document model, presentation control architecture, and control scheme. In this paper, we (i) propose a new multimedia document model that contains the logical structure, the layout structure, and the temporal structure to formally describe multimedia documents, and (ii) point out main interaction-based synchronization problems, and propose a control architecture and a token-based control scheme to solve these interaction-based synchronization problems. Based on the proposed document model, control architecture, and control scheme, a distributed interactive multimedia document development mechanism, which is called MING-I, is developed on SUN workstations.  相似文献   

3.
The huge volume of distributed information that is nowadays available in electronic multimedia documents forces a lot of people to consume a significant percentage of their time looking for documents that contain information useful to them. The filtering of electronic documents seems hard to automate, partly because of document heterogeneity, but mainly because it is difficult to train computers to have an understanding of the contents of these documents and make decisions based on user-subjective criteria. In this paper, we suggest a model for the automation of content-based electronic document filtering, supporting multimedia documents in a wide variety of forms. The model is based on multi-agent technology and utilizes an adaptive knowledge base organized as a set of logical rules. Implementations of the model using the client-server architecture should be able to efficiently access documents distributed over an intranet or the Internet.  相似文献   

4.
A multimedia document is composed of different media objects. ISO's Open Document Architecture (ODA) proposes a standard multimedia document model. However, the current ODA profile only includes static media, e.g. text, geometric graphics and images. Because the future multimedia documents not only include static media but also continuous media, e.g. video and audio, continuous media document parts should be added to have a complete multimedia document model. In this paper, we propose a multimedia document model, which is derived from ODA's concept. The proposed model is based on the object-oriented approach. Objects in the proposed document model are divided into two types: data objects and pseudo objects. Data objects are data structures of a document; pseudo objects are used to manage data objects. Based on the proposed model, a multimedia document authoring and presenting system (MMDS) is also developed on SUN SPARC workstations using the Solaris 2.X operating system  相似文献   

5.
Protection and administration of XML data sources   总被引:3,自引:0,他引:3  
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6.
Today, important information is scattered in so many places, formats, and media, that getting the right information at the right time and place is an extremely difficult task. Developing a single software product, for example, includes the creation of documents ranging from the requirements specification and project schedules to marketing presentations, multimedia tutorials, and more. Each document may be created by a different person using a different tool, and each may be stored in a different place. InfoHarness is an information integration system, platform, and tool set that addresses these problems, managing huge amounts of herterogeneous information in a distributed environment. Through a powerful, consistent user interface, InfoHarness provides rapid search of and access to information assets including documents and parts of documents, mail messages, images, code files, video clips, Web pages with URLs, InfoHarness queries, and views of relational tables. The system makes all these artifacts available without relocating, restructuring, or reformatting the data  相似文献   

7.
Knowledge management has become a challenge for almost all e-government applications where the efficient processing of large amounts of data is still a critical issue. In the last years, semantic techniques have been introduced to improve the full automatic digitalization process of documents, in order to facilitate the access to the information embedded in very large document repositories. In this paper, we present a novel model for multimedia digital documents aiming at improve effectiveness of digitalization activities within an information system supporting e-government organizations. At the best of our knowledge, the proposed model is one of the first attempts to give a single and unified characterization of multimedia documents managed by e-government applications, whereas semantic procedures and multimedia facilities are used for the transformation of unstructured documents into structured information. Furthermore, we define an architecture for the management of multimedia documents “life cycle”, which provides advanced functionalities for information extraction, semantic retrieval, indexing, storage, presentation, together with long-term preservation. Preliminary experiments concerning an e-health scenario are finally presented and discussed.  相似文献   

8.
9.
随着信息化社会的不断发展,文档的电子化成为大势所趋.电子文档在给我们提供便利的同时,也带来了诸多安全隐患.涉密电子文档面临的安全威胁有非授权访问、知密范围难控和泄密主体难追踪等,而目前关于涉密电子文档的解决方案仅满足了身份认证、访问控制等安全需求,未能实现对用户身份的实时认证和涉密文档的有效控制.针对以上安全威胁及用户需求,通过对面部认证、单向传输和眼球追踪等技术的研究,文章设计了一款基于面部认证的涉密文档阅读器.使用OpenCV实现的面部认证技术用于完成对用户的身份认证和阅读权限的实时认证,可有效防止非授权访问、偷窥等行为,实现可靠的访问控制.专用接口提供对USB移动存储数据的安全处理,提供单向数据传输功能,通过专用接口向涉密文档阅读器单向传输涉密文档,可有效解决阅读器丢失、拷贝复制等造成的安全隐患.文中设计的阅读器在提高数据安全性和可靠性的同时,为用户提供一个安全便携的涉密文档阅读平台.系统采用技术手段弥补制度上的漏洞,实现涉密电子文档管控的安全性和实用性的平衡.  相似文献   

10.
This paper describes the system design and the components of a web-based multimedia interactive Telelearning system (MITS) with emphasis on metadata and media content management mechanisms. Metadata model is defined and exploited in designing the overall architecture to support courseware creating, management, delivery, and learner performance evaluation. Multimedia document architecture is used to describe the media contents which represent the course material. Metadata and media contents are generated, stored, and utilized to facilitate the search and on-demand presentation of learning objects. Learner preference, performance and progress information is maintained by profile database to make courseware presentation adaptable and more interactive. The system provides a multimedia interactive learning environment with easy-to-search and highly reusable learning objects.  相似文献   

11.
基于网络用户行为的搜索引擎系统SISI   总被引:1,自引:0,他引:1  
郭岩 《计算机工程》2004,30(16):9-11,13
提出了一种基于网络用户行为的搜索引擎SISl(Similar Interest,Similar access on Internet)。SISI的查询输入是一个Web文档的URL。SISI的检索模型是使用统计的方法基于网络日志中用户对文档的访问频率挖掘相关文档,充分利用了用户在相关文档判定上的潜在意识。模型的假设基础是一组兴趣相似的人访问的文档有可能相关。与传统的搜索引擎相比较,搜索引擎SISI具有系统初始化时间代价小、空间代价小等优点。同时SISI的检索优势在于可以查找那些没有显式相似内容的相关文档,尤其是在检索处理时避开了文档的类型,将文本文档和多媒体文档一视同仁。  相似文献   

12.
This paper describes the design and implementation of MPRES, a Multimedia Presentation Toolkit for the WWW. The WWW has seen phenomenal growth over the last couple of years. It has become a vast repository of multimedia information that is accessible to virtually anyone having a browser. MPRES is a multimedia presentation system that allows a user to compose and render a presentation consisting of objects referenced by their URLs (Uniform Resource Locators). It uses the concept of dynamic documents to render on a WWW browser, a sequence of multimedia scenarios, having objects of types such as audio, image, plaintext, HTML (Hypertext Markup Language) document and animation. MPRES Author, the authoring subsystem, allows the user to interactively test and compose such a presentation, using the Netscape Navigator to collect multimedia resources from the WWW. A presentation database stores the presentations and provides a convenient frontend for accessing them. © 1997 John Wiley & Sons,Ltd.  相似文献   

13.
The rapid growth of multimedia documents has raised huge demand for sophisticated multimedia knowledge discovery systems. The knowledge extraction of the documents mainly relies on the data representation model and the document representation model. As the multimedia document comprised of multimodal multimedia objects, the data representation depends on modality of the objects. The multimodal objects require distinct processing and feature extraction methods resulting in different features with different dimensionalities. Managing multiple types of features is challenging for knowledge extraction tasks. The unified representation of multimedia document benefits the knowledge extraction process, as they are represented by same type of features. The appropriate document representation will benefit the overall decision making process by reducing the search time and memory requirements. In this paper, we propose a domain converting method known as Multimedia to Signal converter (MSC) to represent the multimodal multimedia document in an unified representation by converting multimodal objects as signal objects. A tree based approach known as Multimedia Feature Pattern (MFP) tree is proposed for the compact representation of multimedia documents in terms of features of multimedia objects. The effectiveness of the proposed framework is evaluated by performing the experiments on four multimodal datasets. Experimental results show that the unified representation of multimedia documents helped in improving the classification accuracy for the documents. The MFP tree based representation of multimedia documents not only reduces the search time and memory requirements, also outperforms the competitive approaches for search and retrieval of multimedia documents.  相似文献   

14.
The Internet and related technologies have seen tremendous growth in distributed applications such as medicine, education, e-commerce, and digital libraries. As demand increases for online content and integrated, automated services, various applications employ Web services technology for document exchange among data repositories. Web services provide a mechanism to expose data and functionality using standard protocols, and hence to integrate many features that enhance Web applications. XML, a well-established text format, is playing an increasingly important role in supporting Web services. XML separates data from style and format definition and allows uniform representation, interchange, sharing, and dissemination of information content over the Internet. XML and Web services provide a simplified application integration framework that drives demand for models that support secure information interchange. Providing document security in XML-based Web services requires access control models that offer specific capabilities. Our XML-based access control specification language addresses a new set of challenges that traditional security models do not address.  相似文献   

15.
基于角色的访问控制(RBAC)被普遍认为是当前最具有发展潜力的访问控制策略,已经成为信息安全等领域研究的热点之一。本文对典型RBAC模型进行了扩展,增加了对用户组、访问客体以及访问模式等概念的抽象。在有多用户参与以及多客体的大型分布式信息管理系统中该模型具有更好的可用性以及与现实世界更接近。  相似文献   

16.
面向XML文档的细粒度强制访问控制模型   总被引:25,自引:0,他引:25  
李斓  何永忠  冯登国 《软件学报》2004,15(10):1528-1537
XML文档存放的信息需要受到访问控制策略的保护.现有的一些面向XML文档的访问控制模型都是基于自主访问控制策略或基于角色的访问控制.高安全等级系统需要强制访问控制来保证系统内信息的安全.首先扩展了XML文档模型使其包含标签信息,并给出了扩展后的文档模型需要满足的规则.然后通过讨论XML文档上的4种操作,描述了面向XML文档的细粒度强制访问控制模型的详细内容.该模型基于XML模式技术,它的控制粒度可以达到文档中的元素或者属性.最后讨论了该模型的体系结构和一些实现机制.  相似文献   

17.
Concepts and principles of TINA (Telecommunications Information Networking Architecture) are introduced with the objective of correcting problems of the current centralized service control and service data model in an IN (Intelligent Network). It is becoming increasingly clear that the future sophisticated telecommunication services, e.g., multimedia, and multi-party conferencing, breaking away from the traditional telephony call model will need the solutions for rapid and efficient introduction, deployment, operations, and management.In this paper, we discuss accounting features and requirements, as well as security services in the TINA management context. We will introduce and present an implementation of a model for a security management, based on secure objects, cryptography and certificate distribution. In order to provide secure services, secure objects that have security functionality, such as authentication and access control, have been defined. Secure objects in our model are CORBA objects. The security domain is also called SBS (Security Base Server), provides security services and has an SMIB (Security Management Information Base) that contains security policies, cryptographic algorithms, and other relevant information. A prototype has been implemented and some experimental results are presented.  相似文献   

18.
Information flow control in object-oriented systems   总被引:4,自引:0,他引:4  
We describe a high assurance discretionary access control model for object oriented systems. The model not only ensures protection against Trojan horses leaking information, but provides the flexibility of discretionary access control at the same time. The basic idea of our approach is to check all information flows among objects in the system in order to block possible illegal flows. An illegal flow arises when information is transmitted from one object to another object in violation of the security policy. The interaction modes among objects are taken into account in determining illegal flows. We consider three different interaction modes that are standard interaction modes found in the open distributed processing models. The paper presents formal definitions and proof of correctness of our flow control algorithm  相似文献   

19.
何明  邹建华 《计算机工程与应用》2003,39(28):122-124,232
文章根据人造复杂系统的特性和人的认知规律,提出了一个基于对象的多媒体认知软件系统数据模型。数据模型由媒体存取层、多媒体对象层和多媒体表现层和多媒体应用层构成。这种层次模型将媒体异构环境存取、多媒体对象处理和语义合成表现以及各种时序关系等问题在不同层次分别进行处理,使软件系统具有很好的灵活性和可复用性。  相似文献   

20.
We describe the design of a multimedia database management system for a distributed news-on-demand multimedia information system. News-on-demand is an application that uses broadband network services to deliver news articles to subscribers in the form of multimedia documents. Different news providers insert articles into the database, which are then accessed by users remotely, over a broadband, asynchronous transfer-mode (ATM) network. The particulars of our design are an object-oriented approach and strict adherence to international standards, in particular the Standard Generalized Mark-up Language (SGML) and Hy-Time. The multimedia database system has a visual query facility, which is also described in this paper. The visual query interface provides three major facilities for end users: presentation, navigation, and querying of multimedia news documents. The main focus, however, is the querying of multimedia objects stored in the database.  相似文献   

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