cordic methods describe essentially the same algorithm that with suitably chosen inputs can be used to calculate a whole range of scientific functions including sin, cos, tan, arctan, arcsin, arccos, sinh, cosh, tanh, arctanh, log, exp, square root and even multiply and divide. the method dates back to volder [1959], and due to its versatility and compactness, it made possible the microcoding of the hp35 pocket scientific calculator in 1972. here is some code to illustrate the techniques. ive split the methods into three parts linear, circular and hyperbolic. in the hp35 microcode these would be unified into one function (for space reasons). because the linear mode can perform multiply and divide, you only need add/subtract and shift to complete the implementation. you can select in the code whether to do the multiples and divides also by cordic means. other multiplies and divides are all powers of 2 (these dont count). to eliminate these too, would involve ieee hackery.
標簽： essentially algorithm describe suitably
上傳時間： 2017-03-02
上傳用戶：litianchu
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.
標簽： electromagnetic transformation properties approach
上傳時間： 2017-03-30
上傳用戶：pkkkkp
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.
標簽： Watermarking watermarking evaluation presented
上傳時間： 2013-12-04
上傳用戶：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
標簽： Continuation Pseudo-Arc the solving
上傳時間： 2013-12-03
上傳用戶：xzt
/*請分別定義圖形類Shape（抽象基類），繼承類矩形類Rectangle、正方形類Square、 圓形類Circle；它們具有的方法是計算周長和面積。在另一個類的main函數中分別創建矩形、 正方形和圓形對象，設置所需的屬性值，打印其周長和面積。*/
上傳時間： 2014-01-16
上傳用戶：lili123
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.
標簽： e.g. communication Transform important
上傳時間： 2017-06-25
上傳用戶：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.
標簽： full-hardware compressor algorithm features
上傳時間： 2014-01-14
上傳用戶：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.
標簽： Converters controller optimized Digital
上傳時間： 2013-12-31
上傳用戶：tzl1975
分別定義圖形類Shape（抽象基類），繼承類矩形類Rectangle、正方形類Square、 圓形類Circle；并且計算周長和面積。在另一個main函數中分別創建矩形、 正方形和圓形對象，設置所需的屬性值，打印其周長和面積。（備注：只要把該文件解壓，把里面的東東COPY去即可使用）
上傳時間： 2017-07-25
上傳用戶：wuyuying
The radially averaged power spectrum (RAPS) is the direction-independent mean spectrum, i.e. the average of all possible directional power spectra. This function computes and plots the RAPS of an input image. The function was written to produce the RAPS for square weather radar reflectivity images so you will have to relabel the plot axes and title to suit your needs. The radially averaged power spectrum provides a convenient means to view and compare information contained in 2D spectra in 1D
標簽： spectrum direction-independent i.e. the
上傳時間： 2013-12-17
上傳用戶：watch100
