Legacy buffer cache management schemes for multimedia server are grounded at the assumption that the application sequentially accesses the multimedia file. However, user access pattern may not be sequential in some ci...
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ISBN:
(纸本)0819446408
Legacy buffer cache management schemes for multimedia server are grounded at the assumption that the application sequentially accesses the multimedia file. However, user access pattern may not be sequential in some circumstances, for example, in distance learning application, where the user may exploit the VCR-like function(rewind and play) of the system and accesses the particular segments of video repeatedly in the middle of sequential playback. Such a looping reference can cause a significant performance degradation of interval-based caching algorithms. And thus an appropriate buffer cache management scheme is required in order to deliver desirable performance even under the workload that exhibits looping reference behavior. We propose Adaptive Buffer cache Management(ABM) scheme which intelligently adapts to the file access characteristics. For each opened file, ABM applies either the LRU replacement or the interval-based caching depending on the Looping Reference Indicator, which indicates that how strong temporally localized access pattern is. According to our experiment, ABM exhibits better buffer cache miss ratio than interval-based caching or LRU, especially when the workload exhibits not only sequential but also looping reference property.
The number of terminals that have access to multimediacontent by means of a network is rapidly increasing. More and more, the characteristics of different terminals are increasing in variety. In addition, their users...
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ISBN:
(纸本)0819446416
The number of terminals that have access to multimediacontent by means of a network is rapidly increasing. More and more, the characteristics of different terminals are increasing in variety. In addition, their users can have different preferences. Therefore, the adaptation of multimediacontent to a specific terminal and/or its user has become an important research issue. Such an adaptation is mainly based on two aspects: the description of the multimediacontent and the description of the user environment. Both can be considered as metadata, and can be formatted in an XML language (e.g., MPEG-7 and CC/PP). However, it is not yet clear how we can realize a generic mapping mechanism between two such vocabularies. We feel that such a mechanism is necessary to accomplish a mature content adaptation framework. This paper describes how such a mechanism can be achieved. We attach requirements and preferences of the user environment to specific aspects of the description of multimediacontent. Based on this information, we try to maximize the value of the adapted content, while making it appropriate for the terminal. We also take into account the extensibility of the existing vocabularies we focus on, because this means our mechanism will also be extensible.
E-health is greatly impacting on information distribution and availability within the health services, hospitals and to the public. Previous research has addressed the development of system architectures with the aim ...
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This paper presents an approach based on wireless web and dialogue system convergence for multimodal, multimedia communication services over converged networks. It uses a unique event-triggered service delivery method...
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ISBN:
(纸本)078037553X
This paper presents an approach based on wireless web and dialogue system convergence for multimodal, multimedia communication services over converged networks. It uses a unique event-triggered service delivery method that separates service interaction and wireless web-based service delivery. Our approach results in an architecture of WAP-based, location-independent, wireless service monitoring, notification and service access for mobile users that can be applied over various network bearers in enterprise environment. A new wireless secure server (WSS) provides secure connections to dialogue systems. It allows one-key switching to retrieve the multimediacontent. A prototype system was implemented and performance advantages were demonstrated on several enterprise service applications.
The current explosive expansion of mobile communication systems will lead to an increased demand for multimedia applications. However, due to the large variety of mobile terminals (such as mobile phones, laptops...) a...
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ISBN:
(纸本)0819446416
The current explosive expansion of mobile communication systems will lead to an increased demand for multimedia applications. However, due to the large variety of mobile terminals (such as mobile phones, laptops...) and, because of this, a wide collection of different terminal possibilities and terminal characteristics, it is difficult to create a mobile multimedia application which can be used on mobile devices of different types. In this paper, we propose a mobile multimedia application that adapts its content to the possibilities of the mobile terminal and to the end-user preferences. Also the application takes changing device characteristics into account. To make this possible, a software framework is set up to enable negotiation between the mobile terminal and the content server. During the initial negotiation, the concept of the Universal multimediaaccess framework is used. Subsequent negotiations take place after changing terminal characteristics or end-user preferences, and this by means of time-dependent metadata. This newly created flexible and extendable framework makes it possible that multimedia applications interact with the content provider in order to deliver an optimal multimedia presentation for any arbitrary mobile terminal at any given time.
This paper describes the MPEG-7 compliant indexing and retrieval system iFinder based on XML and open source database technology. The iFinder system automatically extracts metadata from A/V-content and allows access t...
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ISBN:
(纸本)9781581136203
This paper describes the MPEG-7 compliant indexing and retrieval system iFinder based on XML and open source database technology. The iFinder system automatically extracts metadata from A/V-content and allows access to the enriched content by means of a client/server-based retrieval engine. This multimedia retrieval system allows for search and retrieval of short video segments in huge multimedia archives. As a reference application, the iFinder system is used to index speeches from the German Parliament. The user can search for fragments of political speeches and receives matching video segments through a video streaming service.
This paper discusses the problem of content overload in the home environment. We describe the various domains where the problem manifests itself, and we analyse which user activities could benefit from software assist...
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ISBN:
(纸本)9781581136203
This paper discusses the problem of content overload in the home environment. We describe the various domains where the problem manifests itself, and we analyse which user activities could benefit from software assistance. In particular, we focus on the problem of searching for information, and we introduce the concept of Conversational Search as the means to tackle it. We also introduce a framework to test several heuristics related to Conversational Search, and show how using a model of the user can significantly improve the results of purely information-theoretical heuristics.
The proceedings contains 119 papers from the conference on ACM multimedia 2002: 10th International conference on multimedia. The topics discussed include: in-home access to multimediacontent;generating TV summaries f...
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The proceedings contains 119 papers from the conference on ACM multimedia 2002: 10th International conference on multimedia. The topics discussed include: in-home access to multimediacontent;generating TV summaries for CE-devices;rate adaptation transcoding for precoded video streams;mining video editing rules in video streams;and complexity management for video encoders.
There are numerous contexts in which systems need to buffer multimedia signal content. If such a buffer overflows, signal data are lost in an uncontrolled manner, which can lead to large end-to-end distortions. Howeve...
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ISBN:
(纸本)0780374029
There are numerous contexts in which systems need to buffer multimedia signal content. If such a buffer overflows, signal data are lost in an uncontrolled manner, which can lead to large end-to-end distortions. However, if the queued signals are distortion-tolerant, overflows can be avoided, and significant performance gains realized, by reducing the fidelity of the signals in a gradual, controlled, manner. Based on ideas of successive-approximation source coding, we design an adaptive-buffering algorithm to minimize end-to-end distortion. This algorithm performs nearly as well as a performance bound on all possible algorithms. Perhaps most importantly, the algorithm's performance remains robust across a wide range of (unpredictable) utilization rates (input rate/output rate).
Automatically partitioning instructional videos into topic sections is a challenging problem in e-learning environments for efficient content management and cataloging. This paper addresses this problem by proposing a...
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ISBN:
(纸本)9781581136203
Automatically partitioning instructional videos into topic sections is a challenging problem in e-learning environments for efficient content management and cataloging. This paper addresses this problem by proposing a novel density function to delineate sections underscored by changes in topics in instructional and training videos. The content density function draws guidance from the observation that topic boundaries coincide with the ebb and flow of the 'density' of content shown in these videos. Based on this function, we propose two methods for high-level segmentation by determining topic boundaries. We study the performance of the two methods on eight training videos, and our experimental results demonstrate the effectiveness and robustness of the two proposed high-level segmentation algorithms for learning media.
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