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FPGA Prototyping of a Watermarking Algorithm for MPEG-4 (open access)

FPGA Prototyping of a Watermarking Algorithm for MPEG-4

In the immediate future, multimedia product distribution through the Internet will become main stream. However, it can also have the side effect of unauthorized duplication and distribution of multimedia products. That effect could be a critical challenge to the legal ownership of copyright and intellectual property. Many schemes have been proposed to address these issues; one is digital watermarking which is appropriate for image and video copyright protection. Videos distributed via the Internet must be processed by compression for low bit rate, due to bandwidth limitations. The most widely adapted video compression standard is MPEG-4. Discrete cosine transform (DCT) domain watermarking is a secure algorithm which could survive video compression procedures and, most importantly, attacks attempting to remove the watermark, with a visibly degraded video quality result after the watermark attacks. For a commercial broadcasting video system, real-time response is always required. For this reason, an FPGA hardware implementation is studied in this work. This thesis deals with video compression, watermarking algorithms and their hardware implementation with FPGAs. A prototyping VLSI architecture will implement video compression and watermarking algorithms with the FPGA. The prototype is evaluated with video and watermarking quality metrics. Finally, it is seen that the video qualities …
Date: May 2007
Creator: Cai, Wei
System: The UNT Digital Library
Preliminary design of a cryogenic thermoelectric generator. (open access)

Preliminary design of a cryogenic thermoelectric generator.

A cryogenic thermoelectric generator is proposed to increase the efficiency of a vehicle propulsion system that uses liquid nitrogen as its fuel. The proposed design captures some of the heat required for vaporizing or initial heating of the liquid nitrogen to produce electricity. The thermoelectric generator uses pressurized liquid nitrogen as its cold reservoir and ambient air as the high-temperature reservoir to generate power. This study concentrated on the selection of thermoelectric materials whose properties would result in the highest efficiency over the operating temperature range and on estimating the initial size of the generator. The preliminary selection of materials is based upon their figure of merit at the operating temperatures. The results of this preliminary design investigation of the cryogenic thermoelectric generator indicate that sufficient additional energy can be used to increase overall efficiency of the thermodynamic cycle of a vehicle propulsion system.
Date: May 2007
Creator: Sivapurapu, Sai Vinay Kumar
System: The UNT Digital Library