無遲延通信 的英文怎麼說
中文拼音 [wúchíyántōngxìn]
無遲延通信
英文
no delay service-
Although uml activity diagram is magnitude component in uml, which agrees with modeling system dynamic process and describing workflow, it is immature in itself with the characteristic of non - oriented - object and essentially different from other uml diagram, and need to be ameliorated especially when applicated in workflow, own to the following limitation : firstly, activity diagram describes the behaviors of object class that response the inner action, so uml activity diagram is generally on the assumption of that there is no interruption caused by outer events during the process and no time defer, which limits the ability of uml activity diagram discribing complicated process ; secondly, user cannot obtain enough information of object data, and cannot make sure the character of mutual objects because of actually complicated object and relatively simple object expression in uml activity diagram ; lastly, owe to lacking rigorous mathematical basis and strict, effective methods of validation and analysis, uml activity diagram cannot support the simulation and optimization of workflow, let alone optimizating the model based on the result
Uml活動圖是uml的重要組成部分，適用於系統動態行為建模和描述工作流，與uml的其他圖形工具不同，它本質上是非面向對象的，而且其本身並不成熟，仍在改進之中，特別是在工作流應用方面。首先， uml活動圖描述的是響應內部處理的對象類的行為， uml活動圖通常假定在整個計算處理的過程中沒有外部事件引起的中斷，也沒有時間的延遲，這就限制了uml活動圖對一些復雜過程描述能力。第二，現實世界業務過程涉及的對象數據十分復雜，但是uml活動圖的對象語義卻非常簡略，用戶基本上無法從uml活動圖中獲取關于對象數據的信息，也不能確定參與交互的對象的特徵。The microwave delaylines using hts thin films have the advantages of small size and mass and low insertion lose. these characters are much better than the delaylines using surface acoustic wave, coaxial - line, magetostatic wave or conventional metal planar structures. these merits benefit a lot in largely reduction the mass and volume of communication systems
利用高溫超導（ htsc ）薄膜材料研製的微波延遲線具有體積小、重量輕、插損小等優點，這是利用聲表面波、同軸線、靜磁波或常規金屬平面結構設計的延遲線所無法比擬的。這些優點對于減輕通信系統的重量和縮小體積都是非常有利的。The proposed md mesh - based motion coding methodis then combined with the pairwise correlating transform, and acomplete md video coding scheme is proposed. further measures are takento reduce the mismatch between the encoder and decoder that occurs whenonly one description is received and the decoder reconstruction isdifferent from the encoder. the performance of the proposed scheme isevaluated using computer simulations, and the results show, compared toreibman s md transform coding mdtc method, the proposed schemeachieves better redundancy rate distortion performance
數據重傳必然會引起延遲，因而在需要很短延遲的應用中是行不通的，如雙向無線通信同時在以廣播方式進行數據傳輸時也是行不通的當有大量突發錯誤時，糾錯碼如分組糾錯碼block code及卷積碼convolutional code無法在不產生額外延遲及需要額外運算的前提下對數據提供足夠的保護而錯誤掩蔽的性能則受接收到數據與丟失數據之間的殘留相關性大小的影響。In a multiple sensor tracking system, out - of - sequence measurement ( oosm ) always occurs due to communication delays
摘要由於通信時間的延遲性，在多傳感器系統中常常會出現無序量測情況。The standard is designed to give a new technical solution to a broad range of applications, such as very low bit rate conversational services and entertainment quality broadcast, interactive video on demand services etc. so this standard obtains much attention from academic and industrial fields
H . 264標準支持從低帶寬、高誤碼率的無線移動視頻通信到高碼率、低延遲的視頻廣播及在線流媒體等多種應用，因此日益受到業界的關注。Arq ( auto repeat on request ) is used in data communication to garauntee error - free transmission, but it is not suitable for video communication because video communication has stringent delay requirement and limitless retransmission is not allowed
傳統的數據通信通過出錯重傳的方法保證數據的無差錯傳輸，但是這種方法不適合實時視頻通信。因為視頻通信對延遲有嚴格的要求，不可能使用無限制的重傳。Due to a variety of its advantages such as high bandwidth efficiency and robustness against multi - path delay, it has been widely used in the fields of digital audio broadcasting, digital television and wireless local area networks and is likely to become one of key technologies of fourth generation mobile communications
由於具有很高的頻譜利用率，很強的抗多徑延遲能力，它已經廣泛的應用在數字音頻廣播、數字電視以及無線局域網當中，並有望成為第四代移動通信的關鍵技術之一。As the application of distributed computing is used much more widely ， distributed database becomes a significant part of information management it avoids a lot of disadvantages of conventional centralized database ， and is applicable to many situations distributed database is a set of data which is the unity logic ， but in fact these data is located on different sites it is of high availability ， easy expansibility ， high concurrency ， high efficiency and etc in distributed system ， data redundancy is a method to improve the speed of query and the availability of system distributed query should shield the lower level details of data redundancy from end users ， distributed transaction should ensure data from disaccord this paper introduces basic conceptions of distributed database firstly ， discusses distributed transaction and concurrent control ， describes the development prototype mysql ’ s characters ， architecture and executive mechanism ， then shows the skeleton model of dpsql and exposes the strategy and algorithm of distributed query and distributed transaction ， at last analyzes the extra expenses and response delay of distributed processes this paper exposes the implementation mechanism of distributed query and distributed transaction emphatically distributed query uses the strategy of “ read one ， write a11 ” s0 in such a system if user ’ s requests are read - - only for the most part and the distribution of data redundancy is plausible ， efficiency is very high distributed transaction uses two - 。 phase commit protocol to ensure the consistency of global data ， which has less communication overhead
分散式查詢需要向用戶屏蔽數據冗餘分散的底層細節，分散式事務處理要保證全局數據完整，這都是傳統集中式數據庫不曾面臨的問題。本文首先介紹了分散式數據庫的概念性問題；接著討論了分散式事務涉及的定義及演算法；然後描述了dpsql的原型mysql的特性、結構和執行機制；繼而給出了dpsql的梗概模型，闡述了實現分散式查詢和分散式事務處理的策略及演算法；最後分析了進行分散式處理給系統增加的額外開銷和客戶端的額外響應延遲。本文重點描述了分散式查詢和分散式事務處理的實現機制，分散式查詢採用」讀一個寫全部」的本地優先策略，在讀操作頻繁的系統中，只要庫的分佈合理，單機效率極高，幾乎無任何附加開銷和延遲，而以整個系統的角度看來，吞吐量就更是優于單機系統；分散式事務處理採用兩階段提交協議，通信次數較少並能確實保證副本一致。分享友人