Misc DVB standards including en50221 conditional access module standard
标签： conditional standards including standard
上传时间： 2013-12-03
上传用户：wendy15
conditional Entropy of a function
标签： conditional function Entropy of
上传时间： 2017-08-08
上传用户：阿四AIR
随着数字视频广播的发展，观众将会面对越来越多综合或专门频道的选择，欣赏到更高品质，更多服务的节目。而广播业者则要为这些节目的版权购买，制作而承受更高的成本，单纯的广告收入已经不够。要求对用户收取一定的收视费用，而另一方面，调查也显示用户是愿意预付一定费用以获得更好服务的。条件接受系统(conditional Access system)就是为了商业目的而对某些广播服务实施接入控制，决定一个数字接受设备能否将特定的广播节目展现给最终用户的系统。CA技术要求既能使用户自由选择收看节目又能保护广播业者的利益，确算只有已支付了或即将支付费用的用户才能收看到所选的电视节目。在数字电视领域中，CA系统无疑将成为发展新服务的必需条件。但是在不同的运营商可能会使用不同的CA系统，在不同的CA系统之间进行互操作所必需共同遵守的最基本条件是：通用的加扰算法。每个用户接收设备中应集成相应的解扰模块。在我国国家标准--数字电视条件接收系统GY/Z 175-2001的附录H中有详细的描述。 FPGA是英文Field Programmable Gate Array的缩写，即现场可编程门阵列，它是在PAL、GAL、EPLD等可编程器件的基础上进一步发展的产物。它是作为专用集成电路(ASIC)领域中的一种半定制电路而出现的，既解决了定制电路的不足，又克服了原有可编程器件门电路数有限的缺点。可以说，FPGA芯片是小批量系统提高系统集成度、可靠性的最佳选择之一。 首先本文简要介绍CA系统的目的和组成，FPGA的结构和原理，优势。然后介绍了利用FPGA来实现CA系统主要组成部分即加扰的原理和步骤，分析算法，划分逻辑结构，软件仿真，划分硬件模块，硬件性能分析，验证平台构建，硬件实现等。 然后对以上各个部分做详细的阐述。同时为了指导FPGA设计，给出了FPGA的结构和原理与FPGA设计的基本原则、设计的基本技巧、设计的基本流程； 最后给出了该加扰系统的测试与验证方法以及验证和测试结果。
上传时间： 2013-06-22
上传用户：chongchong2016
在现代通信系统中，电话语音的频带被限制在300 Hz～4 kHz的范围内，带来了语音可懂度和自然度的降低。为了在不增加额外成本的前提下提高语音的可懂度和自然度，进行了电话语音频带扩展的研究。提出了一种改进的基于码本映射的语音带宽扩展算法：在码本映射的过程中，使用加权系数来得到映射码本。客观测试结果表明，用此算法得到的宽带语音的谱失真度比用一般的码本映射降低至少2%。主观测试结果表明，用此算法得到的宽带语音具有更好的可懂度和自然度。 Abstract: In modern communication systems， the bandwidth of telephone speech is limited from 300Hz to 4 kHz， which reduces the intelligibility and naturalness of speech. Telephone speech bandwidth extension is researched to get wideband speech and to improve its intelligibility and naturalness， without increasing extra costs. This paper put forward an improved algorithm of speech bandwidth extension based on codebook mapping. In the process of codebook mapping， weighted coefficients were used to get mapping codebook. Objective tests show that spectral distortion of wideband speech obtained by this algorithm reduces at least 2%， comparing to conditional codebook mapping. Subjective tests show that the wideband speech obtained by this algorithm has better intelligibility and naturalness.
上传时间： 2014-12-29
上传用户：15501536189
This book is for students and Linux System Administrators. It provides the skills to read, write, and debug Linux shell scripts using bash shell. The book begins by describing Linux and simple scripts to automate frequently executed commands and continues by describing conditional logic, user interaction, loops, menus, traps, and functions.
上传时间： 2014-12-30
上传用户：黄蛋的蛋黄
内容如下： 1.The history of the computerized database 2.SQL Data Statements--those used to create, manipulate, and retrieve data stored in your database example statements include select, update, insert, and delete 3.SQL Schema Statements--those used to create database objects, such as tables, indexes, and constraints 4.How data sets can interact with queries 5.The importance of subqueries 6.Data conversion and manipulation via SQL s built-in functions 7.How conditional logic can be used in Data Statements
标签： computerized Statements database history
上传时间： 2015-04-25
上传用户：ardager
Hieu Xuan Phan & Minh Le Nguyen 利用CRF统计模型写的可用于英文命名实体识别、英文分词的工具（开放源码）。CRF模型最早由Lafferty提出，全名conditional random fields，该模型后来被广泛地应用在语言和图像处理领域，并随之出现了很多的变体。FlexCRF就是对CRF模型的一个实现应用工具，可用于文本信息处理
上传时间： 2014-01-07
上传用户：ggwz258
SharpZipLib之前叫做NZipLib，完全由 C# 开发的压缩库，支持Zip, GZip, Tar and BZip2 ，为2007年8月最新0852release版的源文件和文档说明！ Changes for v0.85.2 release Minor tweaks for CF, ZipEntryFactory and ZipFile. Fix for zip testing and Zip64 local header patching. FastZip revamped to handle file attributes on extract + other fixes Null ref in path filter fixed. Extra data handling fixes Revamped build and conditional compilation handling Many bug fixes for Zip64. Minor improvements to C# samples. ZIP-1341 Non ascii zip password handling fix. ZIP-355 Fix for zip compression problem at low levels
标签： SharpZipLib NZipLib
上传时间： 2015-12-11
上传用户：84425894
SharpZipLib之前叫做NZipLib，完全由 C# 开发的压缩库，支持Zip, GZip, Tar and BZip2 ，为2007年8月最新0852release版的代码实例！ Changes for v0.85.2 release Minor tweaks for CF, ZipEntryFactory and ZipFile. Fix for zip testing and Zip64 local header patching. FastZip revamped to handle file attributes on extract + other fixes Null ref in path filter fixed. Extra data handling fixes Revamped build and conditional compilation handling Many bug fixes for Zip64. Minor improvements to C# samples. ZIP-1341 Non ascii zip password handling fix. ZIP-355 Fix for zip compression problem at low levels
标签： SharpZipLib NZipLib
上传时间： 2015-12-11
上传用户：love_stanford
Rao-Blackwellised Particle Filters (RBPFs) are a class of Particle Filters (PFs) that exploit conditional dependencies between parts of the state to estimate. By doing so, RBPFs can improve the estimation quality while also reducing the overall computational load in comparison to original PFs. However, the computational complexity is still too high for many real-time applications. In this paper, we propose a modified RBPF that requires a single Kalman Filter (KF) iteration per input sample. Comparative experiments show that while good convergence can still be obtained, computational efficiency is always drastically increased, making this algorithm an option to consider for real-time implementations.
标签： Particle Filters Rao-Blackwellised exploit
上传时间： 2016-01-02
上传用户：refent
