H.264/AVC, the result of the collaboration between the ISO/IEC Moving Picture Experts Group and the ITU-T Video Coding Experts Group, is the latest standard for video coding. The goals of this standardization effort were enhanced compression efficiency, network friendly video representation for interactive (video telephony) and non-interactive applications (broadcast, streaming, storage, video on demand). H.264/AVC provides gains in compression efficiency of up to 50％ over a wide range of bit rates and video resolutions compared to previous standards. Compared to previous standards, the decoder complexity is about four times that of MPEG-2 and two times that of MPEG-4 Visual Simple Profile. This paper provides an overview of the new tools, features and complexity of H.264/AVC.
标签： the collaboration between Experts
上传时间： 2013-12-30
上传用户：dongbaobao
SuperLU is a general purpose library for the direct solution of large, sparse, nonsymmetric systems of linear equations on high performance machines. The library is written in C and is callable from either C or Fortran. The library routines will perform an LU decomposition with partial pivoting and triangular system solves through forward and back substitution. The LU factorization routines can handle non-square matrices but the triangular solves are performed only for square matrices. The matrix columns may be preordered (before factorization) either through library or user supplied routines. This preordering for sparsity is completely separate from the factorization. Working precision iterative refinement subroutines are provided for improved backward stability. Routines are also provided to equilibrate the system, estimate the condition number, calculate the relative backward error, and estimate error bounds for the refined solutions.
标签： nonsymmetric solution SuperLU general
上传时间： 2017-02-20
上传用户：lepoke
In an electromagnetic cloak based on a transformation approach, reduced sets of material properties are generally favored due to their easier implementation in reality, although a seemingly inevitable drawback of undesired reflection exists in such cloaks. Here we suggest using high-order transformations to create smooth moduli at the outer boundary of the cloak, therefore completely eliminating the detrimental scattering within the limit of geometric optics. We apply this scheme to a non-magnetic cylindrical cloak and demonstrate that the scattered field is reduced substantially in a cloak with optimal quadratic transformation as compared to its linear counterpart.
标签： electromagnetic transformation properties approach
上传时间： 2017-03-30
上传用户：pkkkkp
We simulate uncoded BER of BPSK modulated data as a function of SNR -in an AWGN channel -in a Rayleigh fading channel -in an AWGN channel when direct sequence spreading is used and compare results to the theoretical ones. We assume coherent receiver and perfect synchronization.
标签： modulated simulate function channel
上传时间： 2014-01-11
上传用户：1109003457
Watermarking schemes evaluation Abstract鈥擠igital watermarking has been presented as a solution to copy protection of multimedia objects and dozens of schemes and algorithms have been proposed. Two main problems seriously darken the future of this technology though. Firstly, the large number of attacks and weaknesses which appear as fast as new algorithms are proposed, emphasizes the limits of this technology and in particu-lar the fact that it may not match users expectations. Secondly, the requirements, tools and methodologies to assess the current technologies are almost non-existent. The lack of benchmarking of current algorithms is bla-tant. This confuses rights holders as well as software and hardware manufacturers and prevents them from using the solution appropriate to their needs. Indeed basing long-lived protection schemes on badly tested watermarking technology does not make sense.
标签： Watermarking watermarking evaluation presented
上传时间： 2013-12-04
上传用户：thinode
This is a code of Pseudo-Arc Length Continuation Method , the method can be used for solving the nonlinear equations, the principle can re found in some text books. In the code,I prove the agreement of the code with other methods
标签： Continuation Pseudo-Arc the solving
上传时间： 2013-12-03
上传用户：xzt
The Hilbert Transform is an important component in communication systems, e.g. for single sideband modulation/demodulation, amplitude and phase detection, etc. It can be formulated as filtering operation which makes it possible to approximate the Hilbert Transform with a digital filter. Due to the non-causal and infinite impulse response of that filter, it is not that easy to get a good approximation with low hardware resource usage. Therefore, different filters with different complexities have been implemented. The detailed discussion can be found in "Digital Hilbert Transformers or FPGA-based Phase-Locked Loops" (http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=4629940). The design is fully pipelined for maximum throughput.
标签： e.g. communication Transform important
上传时间： 2017-06-25
上传用户：gxf2016
This project features a full-hardware sound compressor using the well known algorithm: IMA ADPCM. The core acts as a slave WISHBONE device. The output is perfectly compatible with any sound player with the IMA ADPCM codec (included by default in every Windows). Includes a testbench that takes an uncompressed PCM 16 bits Mono WAV file and outputs an IMA ADPCM compressed WAV file. Compression ratio is fixed for IMA-ADPCM, being 4:1. PLEASE NOTICE THAT THIS CORE IS LICENSED UNDER http://creativecommons.org/licenses/by-nc-sa/3.0/ (Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported). That means you may use it only for NON-COMMERCIAL purposes.
标签： full-hardware compressor algorithm features
上传时间： 2014-01-14
上传用户：Shaikh
The FPGA can realize a more optimized Digital controller in DC/DC Converters when compare to DSPs. In this paper, based on the FPGA platform, The theoretical analysis, characteristics, simulation and design consideration are given. The methods to implement the digital DC/DC Converters have been researched. The function module, state machine of digital DC/DC controller and high resolution DPWM with Sigma- Delta dither has been introduced. They are verified by experiments on a 20 W, 300 KHz non-isolated synchronous buck converters.
标签： Converters controller optimized Digital
上传时间： 2013-12-31
上传用户：tzl1975
This is a paper describing Pulse Compression technique implemented in the Weather Radar system. This paper presents data examples from the radars and contrasts the use of pulse compression waveforms with more traditional non-modulated pulsed waveforms.
标签： This Compression implemented describing
上传时间： 2017-08-25
上传用户：问题问题
