The paper describes the data model used to implement the SIM content Management Server an SGML/XML-native content server designed to support extremely fast data access to and dynamic update of 100Gb collections under ...
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ISBN:
(纸本)0769505775
The paper describes the data model used to implement the SIM content Management Server an SGML/XML-native content server designed to support extremely fast data access to and dynamic update of 100Gb collections under high load. The paper describes requirements for supporting text intensive applications and for building XML/SGML document management solutions. The SIM CMS employs a data model designed to directly support SGML and XML;this model is described, and a comparison to other models based on general purpose data base management systems is made.
When multimedia traffic is introduced into code division multiple access (CDMA) mobile networks, power should be assigned to users according to different bit rate and quality of service (QoS) requirements, in order to...
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Current multimedia databases contain a wealth of information in the form of audiovisual, as well as text data. Even though efficient search algorithms have been developed for either media, there still exists the need ...
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There are many system proposals for satellite-based multimedia communications that promise high capacity and ease of access. Many of these proposals require advanced switching technology and signal processing on-board...
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ISBN:
(纸本)0780362837
There are many system proposals for satellite-based multimedia communications that promise high capacity and ease of access. Many of these proposals require advanced switching technology and signal processing on-board satellites that will directly impact their cast, performance, availability, and time-to-market. Given the amount of commercial and technical ris involved in such complex systems, satellite operators have been leaking for solutions that are simpler, yet flexible. One solution is based on a geosynchronous (GEO) satellite system equipped with simple on-board processing and switching. The satellite network is ATM-based and carries heterogeneous traffic. An important feature of this system is allowing for a maximum number of simultaneous users, hence, requiring effective connection admission control (CAC) and bandwidth an demand(BOD) algorithms. Nortel Networks has already developed an innovative CAC and BOD algorithm for the system In this paper, we present the BOD performance evaluations of the integrated algorithm. By detailed simulations, we show that the BOD scheme is able to efficiently utilize all available bandwidth and to gain high throughput. We also find that the end-to-end delays for voice traffic in the system falls well within ITU's QoS specification for GEO-based satellite systems. The application buffer sizes observed in the simulations can serve as a guideline for ground station and satellite on-board memory design.
The increase of bandwidth and streaming technology has made video on the Web the current "killer-app" of the dot-com world. However, users still face many problems. Users have to find the right video and the...
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ISBN:
(纸本)9781581131987
The increase of bandwidth and streaming technology has made video on the Web the current "killer-app" of the dot-com world. However, users still face many problems. Users have to find the right video and the right segment within the video. Locally stored files provide easy (but still not very sophisticated) access to individual points in the video by utilizing a seek slider. If the video is streamed over the Internet, this slider loses much of its attraction. Every accessed point in the video requires the video player to buffer, which causes a time lag. The mediacaptain is a system that addresses this issue by using supplementary material like text and graphics to provide indices. This time-aligned material is used to help the user make an informed decision on whether they want to watch a video and if so, what portions. This web-enabled prototype called mediacaptain emerged from user surveys and is demonstrated on several content types and represents an advanced experience with video on the Web.
As packet-mode communications become prevalent in upcoming generations of wireless communications systems, the need to investigate the performance of advanced adaptive signal processing techniques in such context beco...
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As packet-mode communications become prevalent in upcoming generations of wireless communications systems, the need to investigate the performance of advanced adaptive signal processing techniques in such context becomes exigent. In this paper, we evaluate the impact of some of these schemes, namely the adaptive antenna, the adaptive equalization and the decorrelator multiuser detector, in a comparative performance assessment of an uplink joint CDMA/PRMA and a CDMA/ALOHA protocol. Besides single resource allocation policy for voice-only traffic, it is considered the use of multislot and multicode multirate approaches for continuous bit rate (CBR) and variable bit rate video (VBR) traffic transmission. The presented results permit to analyze the tradeoffs existing between performance and complexity among the different options, allowing then for an integrated design of the medium access control protocols and advanced receiver algorithms.
Whereas current debate concerns more object-oriented technologies, such as the MPEG-4 standardization process, this paper adresses the state of the art of MPEG-2 technology. The MPEG-2 standard was adopted four years ...
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Whereas current debate concerns more object-oriented technologies, such as the MPEG-4 standardization process, this paper adresses the state of the art of MPEG-2 technology. The MPEG-2 standard was adopted four years ago and is currently used for broadcasting digital television worldwide. Some comments and requirements from the first field trials require a new generation of MPEG-2 compression systems, and it was the objective of this paper to try to give some inputs for them. Whereas the first generations were mainly an optimization of the TM5 model with new motion estimators, new bit-rate control strategies and sometimes new mode selection algorithms, this new generation will be adaptive to the picture content and complexity. This adaptation concerns not only the input data (such as picture resolution, noise reduction) or the encoder itself(GOP structure, local adaptation, multipass encoding), but also the bandwidth (statistical multiplexing). From the results presented here, a 20 to 30% bit savings can be expected on average, and locally more than 50% (for special cases where the encoders fails, i.e,. noise, scene cuts, fading). After being in the cost and system software, the competition is now clearly on compression efficiency to add as many programs as possible into one single channel. The new techniques developed and introduced in this phase of optimization will certainly be exploited in future standards such as MPEG-4 or MPEG-7 where segmentation and scene characterization, respectively, will be key technologies.
Image data is a very commonly used multimedia data type and usually have visual characteristics that have imprecise descriptions. Fuzzy retrieval of images that are stored in an image database is a natural and effecti...
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The retrieval of stored images matching an input configuration is an important form of content-based retrieval. Exhaustive processing (i.e., retrieval of the best solutions) of configuration similarity queries is, in ...
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ISBN:
(纸本)9781581132267
The retrieval of stored images matching an input configuration is an important form of content-based retrieval. Exhaustive processing (i.e., retrieval of the best solutions) of configuration similarity queries is, in general, exponential and fast search for sub-optimal solutions is the only way to deal with the vast (and ever increasing) amounts of multimedia information in several real-time applications. In this paper we discuss the utilization of hill climbing heuristics that can provide very good results within limited processing time. We propose several heuristics, which differ on the way that they search through the solution space, and identify the best ones depending on the query and image characteristics. Finally we develop new algorithms that take advantage of the specific structure of the problem to improve performance.
The proceedings contain 43 papers. The special focus in this conference is on Data Warehouses, Computer Networks and Constraint Programming. The topics include: Model of summary tables selection for data warehouses;mo...
ISBN:
(纸本)3540411844
The proceedings contain 43 papers. The special focus in this conference is on Data Warehouses, Computer Networks and Constraint Programming. The topics include: Model of summary tables selection for data warehouses;modeling the behavior of OLAP applications using an UML compliant approach;conceptual multidimensional data model based on metacube;using portfolio theory for automatically processing information about data quality in data warehouse environments;representative sample data for data warehouse environments;an intrinsic element in database systems;estimating proximity of metric ball regions for multimedia data indexing;a technique for upgrading database machines online;automatic semantic object discovery and mapping from non-normalised relational database systems;estimation of uncertain relations between indeterminate temporal points;comparison of genetic and tabu search algorithms in multiquery optimization in advanced database systems;interval optimization of correlated data items in data broadcasting;a packet routing protocol for frequently changing topology with ad-hoc networks;throughput stability of reliable multicast protocols;on the rearrangeability of multistage networks employing uniform connection pattern;combining constraints and consistency techniques in knowledge-based expert systems;declarative modelling of constraint propagation strategies;clustering of texture features for content-based image retrieval;fuzzy content-based retrieval in image databases;fuzzy signatures for multimedia databases;application of metadata concepts to discovery of internet resources;evaluation of the object-orientation of a multi-agent system;development of a component oriented garment design library and an agent-based information retrieval system.
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