Misc DVB standards including en50221 conditional access module standard
標(biāo)簽： conditional standards including standard
上傳時間： 2013-12-03
上傳用戶：wendy15
conditional Entropy of a function
標(biāo)簽： conditional function Entropy of
上傳時間： 2017-08-08
上傳用戶：阿四AIR
隨著數(shù)字視頻廣播的發(fā)展，觀眾將會面對越來越多綜合或?qū)ｉT頻道的選擇，欣賞到更高品質(zhì)，更多服務(wù)的節(jié)目。而廣播業(yè)者則要為這些節(jié)目的版權(quán)購買，制作而承受更高的成本，單純的廣告收入已經(jīng)不夠。要求對用戶收取一定的收視費用，而另一方面，調(diào)查也顯示用戶是愿意預(yù)付一定費用以獲得更好服務(wù)的。條件接受系統(tǒng)(conditional Access system)就是為了商業(yè)目的而對某些廣播服務(wù)實施接入控制，決定一個數(shù)字接受設(shè)備能否將特定的廣播節(jié)目展現(xiàn)給最終用戶的系統(tǒng)。CA技術(shù)要求既能使用戶自由選擇收看節(jié)目又能保護廣播業(yè)者的利益，確算只有已支付了或即將支付費用的用戶才能收看到所選的電視節(jié)目。在數(shù)字電視領(lǐng)域中，CA系統(tǒng)無疑將成為發(fā)展新服務(wù)的必需條件。但是在不同的運營商可能會使用不同的CA系統(tǒng)，在不同的CA系統(tǒng)之間進行互操作所必需共同遵守的最基本條件是：通用的加擾算法。每個用戶接收設(shè)備中應(yīng)集成相應(yīng)的解擾模塊。在我國國家標(biāo)準(zhǔn)--數(shù)字電視條件接收系統(tǒng)GY/Z 175-2001的附錄H中有詳細的描述。 FPGA是英文Field Programmable Gate Array的縮寫，即現(xiàn)場可編程門陣列，它是在PAL、GAL、EPLD等可編程器件的基礎(chǔ)上進一步發(fā)展的產(chǎn)物。它是作為專用集成電路(ASIC)領(lǐng)域中的一種半定制電路而出現(xiàn)的，既解決了定制電路的不足，又克服了原有可編程器件門電路數(shù)有限的缺點。可以說，F(xiàn)PGA芯片是小批量系統(tǒng)提高系統(tǒng)集成度、可靠性的最佳選擇之一。 首先本文簡要介紹CA系統(tǒng)的目的和組成，F(xiàn)PGA的結(jié)構(gòu)和原理，優(yōu)勢。然后介紹了利用FPGA來實現(xiàn)CA系統(tǒng)主要組成部分即加擾的原理和步驟，分析算法，劃分邏輯結(jié)構(gòu)，軟件仿真，劃分硬件模塊，硬件性能分析，驗證平臺構(gòu)建，硬件實現(xiàn)等。 然后對以上各個部分做詳細的闡述。同時為了指導(dǎo)FPGA設(shè)計，給出了FPGA的結(jié)構(gòu)和原理與FPGA設(shè)計的基本原則、設(shè)計的基本技巧、設(shè)計的基本流程； 最后給出了該加擾系統(tǒng)的測試與驗證方法以及驗證和測試結(jié)果。
上傳時間： 2013-06-22
上傳用戶：chongchong2016
在現(xiàn)代通信系統(tǒng)中，電話語音的頻帶被限制在300 Hz～4 kHz的范圍內(nèi)，帶來了語音可懂度和自然度的降低。為了在不增加額外成本的前提下提高語音的可懂度和自然度，進行了電話語音頻帶擴展的研究。提出了一種改進的基于碼本映射的語音帶寬擴展算法：在碼本映射的過程中，使用加權(quán)系數(shù)來得到映射碼本。客觀測試結(jié)果表明，用此算法得到的寬帶語音的譜失真度比用一般的碼本映射降低至少2%。主觀測試結(jié)果表明，用此算法得到的寬帶語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.
上傳時間： 2014-12-29
上傳用戶：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.
上傳時間： 2014-12-30
上傳用戶：黃蛋的蛋黃
內(nèi)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
標(biāo)簽： computerized Statements database history
上傳時間： 2015-04-25
上傳用戶：ardager
Hieu Xuan Phan & Minh Le Nguyen 利用CRF統(tǒng)計模型寫的可用于英文命名實體識別、英文分詞的工具（開放源碼）。CRF模型最早由Lafferty提出，全名conditional random fields，該模型后來被廣泛地應(yīng)用在語言和圖像處理領(lǐng)域，并隨之出現(xiàn)了很多的變體。FlexCRF就是對CRF模型的一個實現(xiàn)應(yīng)用工具，可用于文本信息處理
標(biāo)簽： CRF Lafferty Nguyen Hieu
上傳時間： 2014-01-07
上傳用戶：ggwz258
SharpZipLib之前叫做NZipLib，完全由 C# 開發(fā)的壓縮庫，支持Zip, GZip, Tar and BZip2 ，為2007年8月最新0852release版的源文件和文檔說明！ 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
標(biāo)簽： SharpZipLib NZipLib
上傳時間： 2015-12-11
上傳用戶：84425894
SharpZipLib之前叫做NZipLib，完全由 C# 開發(fā)的壓縮庫，支持Zip, GZip, Tar and BZip2 ，為2007年8月最新0852release版的代碼實例！ 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
標(biāo)簽： SharpZipLib NZipLib
上傳時間： 2015-12-11
上傳用戶：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.
標(biāo)簽： Particle Filters Rao-Blackwellised exploit
上傳時間： 2016-01-02
上傳用戶：refent
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