%0 Journal Article %J Telecommunication Information Management Journal, Volume 2, Issue 4 %D 2002 %T An Architecture for Interactive Distributed Multimedia Information Services %A Christos Bouras %A Vaggelis Kapoulas %A Paul Spirakis %A D Moiras %A V Ouzounis %X In this work, we present an architecture for interactive distributed multimedia information services. The service consists of three basic parts, the clients, the access servers, and the content servers. Clients manage the presentation of the requested multimedia documents, while also ensure the synchronization among various involved media. Special policies for the synchronized presentation of multimedia documents and user interactions management are discussed. Access servers authorize the users for legitimate use of the service, while also provide various searching capabilities Content servers manage the transportation of multimedia documents over a broadband network and the user interactions. The proposed architecture preserves scalability, flexibility and modularity due to the distributed nature of the architecture, while also results in good performance due to the dynamic allocation of resources. %B Telecommunication Information Management Journal, Volume 2, Issue 4 %P 3 - 10 %G eng %0 Journal Article %J Networking and Information Systems Journal, Hermes Science Publishing, Volume 2, No. 5-6 %D 1999 %T On-Demand Hypermedia/Mutimedia Service using Pre-Orcestrated Scenarios over the Internet %A Christos Bouras %A Vaggelis Kapoulas %A Paul Spirakis %A D Moiras %A V Ouzounis %A A Tatakis %X In this paper we present a unified approach for delivering hypermedia/multimedia objects over broadband networks. The described service consists of several multimedia servers and a set of functions that intend to present to the end user interactive information in real-time. The hypermedia documents are structured using a hypermedia markup language that keeps information of the spatiotemporal relationships among document’s media components. In order to deal with the variant network behavior, buffering manipulation mechanisms and grading of the transmitted media quality techniques are proposed to smooth presentation and synchronization anomalies. %B Networking and Information Systems Journal, Hermes Science Publishing, Volume 2, No. 5-6 %P 741 - 762 %G eng %0 Conference Paper %B 10th International Conference on Parallel and Distributed Computing and Systems-Special Session on Communication and Computing for Distributed Multimedia Systems, Las Vegas, Nevada, USA %D 1998 %T A Framework for a Distributed Information Service Using Hypermedia/Multimedia Pre-Orchestrated Scenarios %A Christos Bouras %A Vaggelis Kapoulas %A D Moiras %A V Ouzounis %X Real time delivery of multimedia objects based on preorchestrated scenarios, seems to have several difficulties due to presentation deadlines that should be satisfied, and network’s unpredictable behavior which may lead to synchronization anomalies among related media streams. Beyond these, a structural model that represents such scenarios is required. In this paper, we present a general framework that addresses the above mentioned issues, and we attempt to describe a unified approach for delivering hypermedia/ multimedia objects over network connections preserving their timing constraints. We mainly concentrate on the study and development of a markup language that models the presentational structure of a multimedia object and provides primitives that assure playout synchronization of the different media streams that compose these hypermedia objects. Methods for keeping a constant quality level of presentation in times of network load are discussed. %B 10th International Conference on Parallel and Distributed Computing and Systems-Special Session on Communication and Computing for Distributed Multimedia Systems, Las Vegas, Nevada, USA %P 226 - 229 %8 28 - 31 October %G eng %0 Conference Paper %B Workshop on Internet Programming Languages(in conjunction with 1998 IEEE International Conference on Programming Languages), Chicago, Illinois, USA %D 1998 %T Implementing spatio-temporal relations for hypermedia presentations using an HTML-like language %A Christos Bouras %A Vaggelis Kapoulas %A Paul Spirakis %A D Moiras %A V Ouzounis %A A Tatakis %X Hypermedia is currently the trend in delivering information composed of various forms of media. Up to now most systems lack the ability to present the user with hypermedia information containing various media that have specific spatio-temporal relations. In this paper we propose and describe a model that can describe such kinds of hypermedia presentations. The core of the model is an HTML-like language that supports tags for the description of timing relations between the information objects that compose a hypermedia presentation. %B Workshop on Internet Programming Languages(in conjunction with 1998 IEEE International Conference on Programming Languages), Chicago, Illinois, USA %8 13 May %G eng %0 Conference Paper %B ED-MEDIA/ED-TELECOM 97, Calgary, Canada %D 1997 %T Hermes Service: Distributed Hypermedia Educational Services on Demand %A Christos Bouras %A Vaggelis Kapoulas %A Paul Spirakis %A D Moiras %A V Ouzounis %A I Antoniou %A D Karageorgopoylos %X In this paper we present a distributed HypERMEdia SERVICE (HERMES SERVICE) which supports integrated capabilities for distance education and learning purposes. Hermes service consists of hermes servers and hermes browsers. The users are connected with the service using hermes browsers and retrieve hypermedia lessons organised in thematical units. The lessons are stored in various distributed Hermes servers which retrieve the requested lesson and transmit it to the corresponding browser on on-demand basis. The requested lesson is presented to the user according to a well defined presentation scenario. The media objects are rendered in a synchronized manner according to the spatio-temporal relationships existing among them. Finally, special monitoring mechanism controls the state of the network and adjusts the presentation process so as to improve presentation quality. %B ED-MEDIA/ED-TELECOM 97, Calgary, Canada %P 19 - 24 %8 14 - 19 Jne %G eng %0 Conference Paper %B 3rd Workshop on Open Hypermedia Systems, Southampton, UK %D 1997 %T HY-MOST: HYpermedia MOdel for Synchronised presenTations %A Christos Bouras %A Paul Spirakis %A D Moiras %A V Ouzounis %A I Antoniou %X A brief abstract. In this paper we present a new model for hypermedia presentations. This model is based on an HTML-like language which provides the necessary modules for the intermedia synchronisation of the inline media that comprise the hypermedia document. The model also enables a distributed approach in the storage of the hypermedia documents. Additionally, it is capable of incorporating the necessary protocols needed for the real-time delivery of continuous media such as audio and video. %B 3rd Workshop on Open Hypermedia Systems, Southampton, UK %P 18 - 23 %8 6 - 11 April %G eng %0 Conference Paper %B 5th IEEE International Symposium On High Performance Distributed Computing-HPDC-5, Syracuse, New York, USA %D 1996 %T On-Demand Hypermedia/Multimedia Service over Broadband Networks %A Christos Bouras %A Vaggelis Kapoulas %A Paul Spirakis %A D Moiras %A V Ouzounis %A A Tatakis %X In this paper we present a uni ed approach for de- livering hypermedia/multimedia objects over broadband networks. Documents are stored in various multimedia servers, while the inline data may reside in their own media servers, attached to the multimedia servers. The described service consists of several multimedia servers and a set of functions that intend to present to the end user interactive information in real-time. Users interact with the service requesting multimedia docu- ments on demand. Various media streams are trans- mitted over di erent parallel connections according to their transmission requirements. The hypermedia doc- uments are structured using a hypermedia markup lan- guage that keeps information of the spatiotemporal re- lationships among document's media components. In order to deal with the variant network behavior, bu ering manipulation mechanisms and grading of the transmitted media quality techniques are proposed to smooth presentation and synchronization anomalies. %B 5th IEEE International Symposium On High Performance Distributed Computing-HPDC-5, Syracuse, New York, USA %P 224 - 231 %8 6 - 9 August %G eng