Browsing by Author "Candan, K. Selcuk"
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Item AVIS: An Advanced Video Information System(1997) Adali, Sibel; Candan, K. Selcuk; Erol, Kutluhan; Subrahmanian, V.S.; ISRDuring the last few years, the advent of the CD-Rom, and the introduction of high bandwidth communications networks has caused a spectacular explosion in the availability of large video- libraries. While a great deal of effort has been invested in problems of how to effectively utilize bandwidth to communicate large bodies of data across the network, relatively little effort has gone into how to organize, and access, video databases. In this paper, we describe how video data may be organized and structured so as to facilitate queries. We develop a formal model of video data and show how spatial data structures, suitably modified, provide an elegant way of storing such data. We develop algorithms to process various kinds of video queries and show that in most cases, the complexity of these algorithms is linear. We develop algorithms to update these video databases. A prototype system called AVIS ("Advanced Video Information System") has been designed at the University of Maryland based on these concepts.Item CHIMP: A Framework for Multimedia Documents(1997) Candan, K. Selcuk; Prabhakaran, B.; Subrahmanian, V.S.; ISRA multimedia document consists of different types of media objects that are to be presented at different instants of time and for different durations. The media objects may be stored in computer systems connected by a network, thereby rendering the document distributed. The authors may wish to collaborate in a distributed manner to edit a multimedia document. Hence, an authoring system needs to identify a retrieval schedule that describes the time instants at which the objects have to be retrieved as well as the logical paths to be followed by the objects. In this paper, we consider a collaborative multimetia document authoring system with the above mentioned features. We propose a difference constraints based temporal specification for the multimedia document. This approach allows us to generate flexible schedules for retrieving objects over the computer network. This flexible retrieval schedule can handle variations in system parameters such as available network throughput and buffer resources.Item Resource Lock Commit Protocol (RLCP) for Multimedia Object Retrieval(1998-10-15) Candan, K. Selcuk; Hwang, Eenjun; Prabhakaran, B.; Subrahmanian, V.S.Many multimedia presentation applications involve retrieval of objects from more than one collaborating server. Presentations of objects from different collaborating servers might be inter-dependent. For instance, we can consider distributed video servers where blocks of movies are distributed over a set of servers. Here, blocks of a movie from different video servers have to be retrieved and presented continuously without any gaps in the presentation. Such applications first need an estimate of the available network resources to each of the collaborating server in order to identify a schedule for retrieving the objects composing the presentation. A collaborating server can suggest modifications of the retrieval schedule depending on its load. These modifications can potentially affect the retrieval schedule for other collaborating applications. Hence, a sequence of negotiations have to be carried out with the collaborating servers in order to commit for a retrieval schedule of the objects composing the multimedia presentation. In this paper, we propose an application sub-layer protocol, Resource Lock Commit Protocol (RLCP), for handling the negotiation and commitment of the resources required for a collaborative multimedia presentation application. (Also cross-referenced as UMIACS-TR-97-08)Item Retrieval Schedules Based on Resource Availibility and Flexible Presentation Specifications(1998-10-15) Candan, K. Selcuk; Prabhakaran, B.; Subrahmanian, V. S.A distributed multimedia document presentation involves retrieval of objects from the document server(s) and their presentation at the client system. The presentation of the multimedia objects have to be carried out in accordance with the specification of temporal relationships among the objects. The retrieval of multimedia objects from the document server(s) is influenced by the factors such as: temporal specification of objects presentations, throughput offered by the network service provider, and the buffer resources on the client system. Flexibility in the temporal specification of the multimedia document can help in deriving an object retrieval schedule that can handle variations in the network throughput and buffer resources availability. In this paper, we develop techniques for deriving a flexible object retrieval schedule for a distributed multimedia document presentation. The schedule is based on flexible temporal specification of the multimedia document using the difference constraints approach. We show how the derived retrieval schedule can be validated and modified to ensure that it can work with the offered network throughput and the available buffer resources. (Also cross-referenced as UMIACS-TR-96-21)