delay-constrained streaming of fully-scalable video over IEEE 802.11a/e wireless (WLANs) is of great interest for many emerging multimedia applications. In this paper, we consider the problem of video transmission ove...
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delay-constrained streaming of fully-scalable video over IEEE 802.11a/e wireless (WLANs) is of great interest for many emerging multimedia applications. In this paper, we consider the problem of video transmission over HCF controlled channel access (HCCA), which is part of the new medium access control (MAC) protocol of IEEE 802.11e. A cross-layer optimization across the MAC and application layers is used in order to exploit the features provided by the new HCCA standard, as well as by the versatility of new state-of-the-art scalable video coding algorithms. Under pre-determineddelay constraints for streaming, the proposed cross-layer strategy leads to a larger number of stations being simultaneously admitted (without any loss in the video quality) than in systems that utilize application-layer only optimizations. At the same time, the fine-grain layering provided by the scalable bitstream facilitates prioritization and unequal retransmissions of packets at the MAC layer thereby enabling graceful quality degradation under channel-capacity limitations anddelay constraints. The expected gains offered by the optimized solutions proposed in this paper are established through simulations
There are lots of attempts in automotive field to supersede mechanical parts with electrical ones owing to increasing needs of drivers' safety, comfort and convenience as well as recent tightened environmental reg...
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There are lots of attempts in automotive field to supersede mechanical parts with electrical ones owing to increasing needs of drivers' safety, comfort and convenience as well as recent tightened environmental regulation. In addition, continuous improvements of semiconductor technology make it speed up to use electric components instead of conventional mechanical and hydraulic ones. In accordance with these tendencies, the demand of electric power and energy used in vehicle has been increasing steadily, and it will cause overburden of conventional 14 V power generation anddistribution system. A research on higher voltage system started in early 1990s and 42 V powersystem has been introduced for a future automotive power-net. In this paper, technical trend in energy storage system which implies one of the key technologies to implement 42 V power-net is reviewed, anddevelopment results of the improved energy storage system consisted of ultracapacitor, battery and management controllers are presented
The image sequence of a static scene includes similar orredundant information over time. Hence, motion-discontinuous instants can efficiently characterize a video shot or event. However, such instants (key frames) ar...
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The image sequence of a static scene includes similar orredundant information over time. Hence, motion-discontinuous instants can efficiently characterize a video shot or event. However, such instants (key frames) are differently identified according to the change of velocity and acceleration of motion, and such scales of change might be different on each sequence of the same event. In this paper, we present a scalable video abstraction in which the key frames are obtained by the maximum curvature of camera motion at each temporal scale. The scalability means dealing with the velocity and acceleration change of motion. In the temporal neighborhooddetermined by the scale, the scene features (motion, color, and edge) can be used to index and classify the video events. Therefore, those key frames provide temporal interest points (TIPs) for the abstraction and classification of video events.
The needs of automated inspection system are grown for the flat panel displays (FPd). However, it is so difficult to detect the defects on the surface of FPddue to non-uniform intensity distribution through the whole...
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The needs of automated inspection system are grown for the flat panel displays (FPd). However, it is so difficult to detect the defects on the surface of FPddue to non-uniform intensity distribution through the whole panel. Especially, curve-type defects such as micro sized thread and scratch are too difficult to detect with the conventional methods. In this paper, we propose a robust detection algorithm for curve-type defects. The proposed algorithm is composed of flattening, segmentation, and classification. The flattening makes intensity distribution likely to be uniform. The segmentation extracts candidates of curve-type defect and the classification selects real defects from candidates. The experimental result verifies the performance of the proposed method.
This article demonstrates results and experiences gained in the area of multilayer internetworking, with emphasis on bandwidth on-demand provisioning as well as resource andrestoration management. Behavioral characte...
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This article demonstrates results and experiences gained in the area of multilayer internetworking, with emphasis on bandwidth on-demand provisioning as well as resource andrestoration management. Behavioral characteristics and numerical results were obtained from a management system prototype implemented and tested in an appropriately adapted commercial WdM environment enhanced with multivendor gigabit IP routers. The management solution, the testbed environment, and a representative evaluation scenario are presented as a means of explaining in detail the results that finally allow a global system assessment.
We propose a non-data-aided (NdA) signal-to-noise-ratio (SNr) estimation algorithm for quadrature amplitude modulation (QAM) signals in an additive white Gaussian noise (AWGN) channel. The NdA SNr estimation algorithm...
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ISBN:
(纸本)0780386477
We propose a non-data-aided (NdA) signal-to-noise-ratio (SNr) estimation algorithm for quadrature amplitude modulation (QAM) signals in an additive white Gaussian noise (AWGN) channel. The NdA SNr estimation algorithm for QAM signals is derived based on a statistical ratio of observables over a block of data. The simple analysis andcomputer simulation for some kinds of QAM signals have been done, the results of which have proved that all the tested QAM signals can be effectively estimated by this algorithm.
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