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IEEE conference on Vehicular Technology (VTC)

作者： Xin Tang Y. Bar-Ness N.J.M. Van Waes Center for Communications and Signal Processing Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA

With the demand for high capacity (multimedia) services, wideband CDMA (WCDMA) has become an attractive multiple access scheme for 3rd generation wireless systems. Coming with higher data rate, the application of WCDMA brings with it new challenges in terms of multiple access interference (MAI) and intersymbol interference (ISI) suppression due to the fact that compared to the "regular" CDMA, the delay spread is no longer only a few chips. Most of the literature on multiuser detection so far focused on algorithms which, due to high computational/hardware complexity, are unsuitable for large delay spread channels. We present an adaptive symbol-based signal separator based on multishot matched filtering which is suitable for the asynchronous large delay spread fading channels characteristics.

关键词： Wideband Multiaccess communication Delay Multiple access interference Intersymbol interference multimedia systems Multiuser detection Hardware Particle separators Adaptive filters

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Connection admission control for a high capacity multimedia satellite communication system

Connection admission control for a high capacity multimedia ...

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Seamless Interconnection for Universal Services. Global Telecommunications conference. GLOBECOM'99. (Cat. No.99CH37042)

作者： Yi Qian R. Hu H. Abu-Amara P. Maveddat Nortel Networks Limited Richardson TX USA

With their tremendous success in broadcasting entertainment services, digital satellite systems are rapidly being viewed as viable service delivery vehicles. In parallel, both the demand for Internet and multimedia services and the subsequent end-user demand for higher bandwidth are forcing network operators to search for mechanisms that can cost effectively provide high speed access to end-users. Network operators are seriously considering satellite based networks to offer broadband and multimedia services to supplement and enhance their existing terrestrial networks. One solution is based on a geosynchronous (GEO) satellite system equipped with on-board processing and switching. Allowing for a maximum number of simultaneous users is an important element of this system, hence requiring effective connection admission control (CAC) and bandwidth on demand (BOD) algorithms. A CAC scheme is studied for the uplink segment of a broadband GEO satellite network with an on-board ATM-like switch. A MF-TDMA scheme is used for the uplink access. The CAC algorithm investigated is ATM-based with heterogeneous traffic traversing the satellite network. Performance evaluations of the CAC algorithm are done by detailed simulations. Connection blocking performance results are given for each type of traffic in the system.

关键词： Admission control multimedia communication multimedia systems Satellite communication Satellite broadcasting Bandwidth Switches Traffic control Vehicles IP networks

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An efficient graphical shot verifier incorporating visual rhythm

An efficient graphical shot verifier incorporating visual rh...

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IEEE International conference on multimedia Computing and systems (ICMCS)

作者： Hyeokman Kim Jinho Lee S. Moon-Ho Song Department of Computer Science Kookmin University Seoul South Korea Multimedia Tech. Research Lab Korea Telecom Seoul South Korea School of Electrical Engineering Korea University Seoul South Korea

Recent publications regarding video shot change detection algorithms show that abrupt shot changes are detected fairly well. However, gradual shot changes, including wipes and dissolves, are often missed or falsely detected. A robust shot change detection system, therefore, must include a shot verification step to further enhance the overall system performance. In this paper, we introduce the concept of a visual rhythm, an abstraction of the video. A visual rhythm is a single image, a sub-sampled version of a full video in which the sampling is performed in a pre-determined and in a systematic fashion. It is basically a representation of the video which includes the overall content of the video, but most importantly, the visual rhythm contains patterns or visual features that allow the viewer/operator to distinguish and classify many different types of video effects (edits and otherwise): cuts, wipes, dissolves, fades, camera motions, object motions, flashlights, zooms, etc. The different video effects manifest themselves as different patterns on the visual rhythm. Using the visual rhythm, it becomes possible, without sequentially playing the entire video, to find false positive shots as well as undetected shots. Thus, inclusion of the visual rhythm in the shot verification process will aid the operator to verify detected shots as well as to find undetected shots fast and efficiently. For this purpose, we have developed a new tool, a shot verifier that includes the visual rhythm. The usefulness of the visual rhythm during the shot verification process is presented.

关键词： Rhythm Gunshot detection systems Layout Indexing Cameras Streaming media Computer science Telecommunications Detection algorithms Robustness

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content adaptation framework: bringing the Internet to information appliances

Content adaptation framework: bringing the Internet to infor...

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IEEE conference and Exhibition on Global Telecommunications (GLOBECOM)

作者： R. Mohan J.R. Smith Chung-Sheng Li IBM Thomas J. Watson Research Center Yorktown Heights NY USA

The deployment of information appliances is predicted to exceed that of personal computers in the next few years. However, due to the wide range of communication, processing, storage and display capabilities of information appliances, the multimedia content on the Internet needs to be adapted before it can be efficiently delivered to these devices. We present content adaptation framework (CAF), a general framework for customizing Internet content for diverse client devices. The system first analyzes the content to be customized. Next, a variety of transcoders generate multi-resolution, multimodal versions of the content. The transcoded versions of the multimedia content are represented in a novel multi-modal, multi-resolution representation hierarchy called the InfoPyramid. Finally, a selection module uses an extended rate-distortion framework to pick the best content versions from the InfoPyramid while meeting the client device characteristics and resources. The content adaptation system can be deployed at various nodes in the Internet topology, such as at the server, at the client device or at an intermediate proxy. We present examples of proxy and server content adaptation systems based on CAF. Based on the content adaptation framework, we present a description scheme for multimedia and Internet content. This description scheme enables universal access to content. It has been proposed to various standards bodies.

关键词： Internet Home appliances Network servers File servers Transcoding Roads Sliding mode control Focusing Automatic voltage control Videoconference

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Adaptive QoS resource management in dynamic environments

Adaptive QoS resource management in dynamic environments

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IEEE International conference on multimedia Computing and systems (ICMCS)

作者： S. Chatterjee M. Brown SRI International Inc. Menlo Park CA USA

As greater numbers of end users run both multimedia applications and traditional desktop applications (word processing, spreadsheets, etc.) on the same distributed system (e.g., an office intranet or the Internet), the issue of how to provide adaptive quality of service (QoS) in a highly dynamic, shared, and heterogeneous resource environment becomes very important. While Java/spl dagger/ is an elegant solution to the heterogeneity problem, it lacks adaptive QoS support, which is critical to multimedia and other real-time applications. Our ERDoS (End-to-End Resource Management of Distributed systems) project presents solutions to the adaptation problem. We will demonstrate our innovative content-based adaptation algorithm, embedded within the Java Virtual Machine (JVM) using a set of multimedia applications on a laptop computer running Linux. If the underlying infrastructure provides real-time support, it becomes much easier to extend the support to the application layers. However, the underlying infrastructure for most common systems (whether it is an intranetwork, extranetwork or the Internet) is non-real time. The problem is exacerbated because these newer multimedia applications have to co-reside within the same distributed infrastructure with current desktop applications, which are non-real time and have unpredictable resource usage patterns. Therefore, our objective is to provide adaptive QoS support to these new multimedia applications within a best-effort infrastructure. We are not trying to extend Java to support real-time guarantees for applications because of the inherent non-real-time properties of Java (e.g., its dynamic loading and linking, and garbage collection). Instead, our goal is to insert sophisticated multiapplication, multidimensional QoS adaptation algorithms inside the JVM, to enable it to gracefully adapt multimedia applications as system state changes, in a manner that minimizes the adverse visual effect on these applications' users.

关键词： Resource management Quality of service Java Application software multimedia systems Text processing Web and internet services Virtual machining Portable computers Embedded computing

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Deriving communication sub-graph and optimal synchronizing interval for a distributed virtual environment system

Deriving communication sub-graph and optimal synchronizing i...

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IEEE International conference on multimedia Computing and systems (ICMCS)

作者： J.C.S. Lui O.K.Y. So T.S. Tam Department of Computer Science & Engineering Chinese University of Hong Kong Hong Kong China

Advances in multimedia and networking technologies allow the realization of the distributed virtual environment (DVE). DVE is a distributed system which allows many clients who are located in different locations (within a LAN or across a WAN) to concurrently explore and interact with each other in a high resolution, three-dimensional graphical virtual environment. Some of the potential applications of DVE are: teleconferencing, distributed games, distributed interactive simulation, collaborative groupware environments, etc. One challenging issue in designing a DVE is to guarantee that each participating client has the same consistent view of the virtual world. To provide this consistent view, the DVE needs to perform synchronization actions periodically. We present a methodology for deriving an optimal synchronizing interval. Our work is divided into two parts. In the first part, algorithms are presented to construct a suitable communication sub-graph for the clients. In the second part, we present the outline of how to derive the optimal synchronizing interval based on the proposed communication sub-graph using Markov chain theory and the fundamental matrix.

关键词： Virtual environment Relational databases Spatial databases Computer science Local area networks Wide area networks Teleconferencing Collaboration Data mining User-generated content

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Hierarchical video-on-demand servers for TV-anytime services

Hierarchical video-on-demand servers for TV-anytime services

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International conference on Computer Communications and Networks (ICCCN)

作者： R. Luling Paderborn Center for Parallel Computing-PC University of Paderborn Germany

This paper presents algorithms and principles for the implementation of a novel broadband multimedia service called "TV-anytime". The basic idea of this service is to store broadcast media assets on media server systems and allow people to access this information at any time. Using a given user profile the recording of media assets can be personalized allowing the implementation of "personal TV" in this way. Within this paper we present the basic mechanisms for the implementation of TV-anytime services on an hierarchical network of media servers. The basic question of how to handle and manage the broadband media assets on such a hierarchical network of media servers is addressed in this paper. We present methods that take up concepts from a graph for the mangement of media assets and verify these methods using sample applications. The results show that the methods provide near to optimal performance in terms of the "quality of service" for the TV-daytime scenario.

关键词： Network servers TV broadcasting multimedia communication Parallel processing multimedia computing Asset management Councils Digital multimedia broadcasting Quality of service Indexing

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Video content extraction and representation using a joint audio and video processing

ICASSP, IEEE International Conference on Acoustics, Speech a...

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ICASSP, IEEE International conference on Acoustics, Speech and Signal Processing - Proceedings 1999年 6卷 3033-3036页

作者： Saraceno, Caterina Vienna Univ of Technology Vienna Austria

Computer technology allows for large collections of digital archived material. At the same time, the increasing availability of potentially interesting data makes difficult the retrieval of desired information. Currently, access to such information is limited to textual queries or characteristics such as color or texture. The demand for new solutions allowing common users to easily access, store and retrieve relevant audio-visual information is becoming urgent. One possible solution to this problem is to hierarchically organize the audio-visual data so as to create a nested indexing structure which provides efficient access to relevant information at each level of the hierarchy. This work presents an automatic methodology to extract and hierarchically represent the semantic of the contents, based on a joint audio and visual analysis. Descriptions on each media (audio, video) will be used to recognize higher level of meaningful structures, such as specific types of scenes, or, at the highest level, correlations beyond the temporal organization of information, allowing to reflect classes of visual or audio or audio-visual types. Once a hierarchy is extracted from the data analysis, a nested indexing structure can be created to access relevant information at a specific level of detail, according to the user requirements.

关键词： multimedia systems

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Query processing issues in image (multimedia) databases

Query processing issues in image (multimedia) databases

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International conference on Data Engineering

作者： S. Nepal M.V. Ramakrishna Department of Computer Science RMIT University Melbourne VIC Australia

multimedia database systems are essential for the effective and efficient use of large collections of image data. The aim of such systems is to enable retrieval of images based on their contents. As part of our research in this area, we are building a prototype content-based image retrieval system called CHITRA. This uses a four-level data model, and we have defined a fuzzy object query language (FOQL) for this system. This system enables retrieval based on high-level concepts, such as "retrieve images of mountains and sunset". A problem faced in this system is the processing of complex queries such as "retrieve all images that have a similar color histogram and a similar texture to the given example image". Such problems have attracted research attention in recent times. R. Fagin (1996) has given an algorithm for processing such queries and provided a probabilistic upper bound for the complexity of the algorithm (which has been implemented in IBM's Garlic project). In this paper, we provide a theoretical (probabilistic) analysis of the expected cost of this algorithm. We propose a new multi-step query processing algorithm and prove that it performs better than Fagin's algorithm in all cases. Our algorithm requires fewer database accesses. We have evaluated both algorithms against an image database of 1000 images on our CHITRA system. We have used both color histogram and Gabor texture features. Our analysis is presented and the reported experimental results validate our algorithm (which has a significant performance improvement).

关键词： multimedia databases Query processing Image databases Image retrieval content based retrieval Histograms Algorithm design and analysis Prototypes Data models Fuzzy systems

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A database approach for modeling and querying video data

A database approach for modeling and querying video data

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International conference on Data Engineering

作者： C. Decleir M.-S. Hacid J. Kouloumdjian LISI-INSA Bât 501 Villeurbanne France LuFG Theoretical Computer Science RWTH Aachen Aachen Germany

Indexing video data is essential for providing content based access. We consider how database technology can offer an integrated framework for modeling and querying video data. We develop a data model and a rule-based query language for video content based indexing and retrieval. The data model is designed around the object and constraint paradigms. A video sequence is split into a set of fragments. Each fragment can be analyzed to extract the information (i.e., symbolic descriptions) of interest that can be put into a database. This database can then be searched to find information of interest. Two types of information are considered: the entities (i.e., objects) of interest in the domain of a video sequence; video frames which contain these entities. To represent this information, our data model allows facts as well as objects and constraints. We present a declarative, rule-based, constraint query language that can be used to infer relationships about information represented in the model. The language has a clear declarative and operational semantics.

关键词： Video on demand Video compression Application software Indexing Electrical capacitance tomography multimedia databases Computer science multimedia systems Database languages Contracts

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