The standard that governs the design of avioniccomponents and systems, DO-254, is one of the mostpoorly understood but widely applicable standardsin the avionic industry. While information on thegeneral aspects of the standard is easy to obtain, thedetails of exactly how to implement the standard aresketchy. And once an entity develops a process thatachieves compliance, the details of how compliancewas achieved become part of the intellectualproperty of that entity. This white paper focuses onthe details of developing a DO-254 compliantprocess for the design of FPGAs.
The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. Frequently the messages have meaning; that is they refer to or are correlated according to some system with certain physical or conceptual entities.
為了在CDMA系統中更好地應用QDPSK數字調制方式，在分析四相相對移相（QDPSK)信號調制解調原理的基礎上，設計了一種QDPSK調制解調電路，它包括串并轉換、差分編碼、四相載波產生和選相、相干解調、差分譯碼和并串轉換電路。在MAX+PLUSⅡ軟件平臺上，進行了編譯和波形仿真。綜合后下載到復雜可編程邏輯器件EPM7128SLC84-15中，測試結果表明，調制電路能正確選相，解調電路輸出數據與QDPSK調制輸入數據完全一致，達到了預期的設計要求。
Abstract:
In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase，and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.
在Multisim 10軟件環境下，設計一種由運算放大器構成的精確可控矩形波信號發生器，結合系統電路原理圖重點闡述了各參數指標的實現與測試方法。通過改變RC電路的電容充、放電路徑和時間常數實現了占空比和頻率的調節，通過多路開關投入不同數值的電容實現了頻段的調節，通過電壓取樣和同相放大電路實現了輸出電壓幅值的調節并提高了電路的帶負載能力，可作為頻率和幅值可調的方波信號發生器。Multisim 10仿真分析及應用電路測試結果表明，電路性能指標達到了設計要求。
Abstract:
Based on Multisim 10， this paper designed a kind of rectangular-wave signal generator which could be controlled exactly composed of operational amplifier， the key point was how to implement and test the parameter indicators based on the circuit diagram. The duty and the frequency were adjusted by changing the time constant and the way of charging and discharging of the capacitor， the width of frequency was adjusted by using different capacitors provided with multiple switch， the amplitude of output voltage was adjusted by sampling voltage and using in-phase amplifier circuit，the ability of driving loads was raised， the circuit can be used as squarewave signal generator whose frequency and amplitude can be adjusted. The final simulation results of Multisim 10 and the tests of applicable circuit show that the performance indicators of the circuit meets the design requirements.
21天學會用JAVA開發網絡游戲
書籍語言： 簡體中文
書籍類型： 程序設計
授權方式： 免費軟件
書籍大小： 287 KB
書籍等級：
整理時間： 2004-11-3 20:41:10
With all of the media attention that is focused on the Internet and the World Wide Web, figuring out exactly what they are all about is sometimes difficult. Are they just a neat new way to market products or will they truly offer us a new medium of communication that will someday surpass even televisions and telephones? The answer is, who knows? Unfortunately, the ultimate use for the Internet is still unknown. This is because it is still in such a state of flux that it s pretty much impossible to accurately predict where it will end up. However, you can look at the evidence of what is there now and gain some insight into what the Internet might become, at least in terms of games.
JDiff is a Javadoc doclet which generates an HTML report of all the packages, classes, constructors, methods, and fields which have been removed, added or changed in any way, including their documentation, when two APIs are compared. This is very useful for describing exactly what has changed between two releases of a product. Only the API (Application Programming Interface) of each version is compared. It does not compare what the source code does when executed.
this m file can Find a (near) optimal solution to the Traveling Salesman Problem (TSP) by setting up a Genetic Algorithm (GA) to search for the shortest path (least distance needed to travel to each city exactly once)
Notes:
1. Input error checking included
2. Inputs can be specified in any order, so long as the parameter pairs are specified as a parameter , value
American Gladiator,You are consulting for a game show in which n contestants are pitted against n gladiators in order to see which contestants are the best. The game show aims to rank the contestants in order of strength this is done via a series of 1-on-1 matches between contestants and gladiators. If the contestant is stronger than the gladiator, then the contestant wins the match otherwise, the gladiator wins the match. If the contestant and gladiator have equal strength, then they are “perfect equals” and a tie is declared. We assume that each contestant is the perfect equal of exactly one gladiator, and each gladiator is the perfect equal of exactly one contestant. However, as the gladiators sometimes change from one show to another, we do not know the ordering of strength among the gladiators.
With the release of PHP 5 web developers need a guide to developing with PHP 5 to both learn its complex new features and more fully implement the long-standing features on which PHP s success is built. PHP 5 in Practice is a reference guide that provides developers with easy-to-use and easily extensible code to solve common PHP problems. It focuses on providing real code solutions to problems, allowing the reader to learn by seeing exactly what is happening behind the scenes to get your solution. Because a real-life situation will rarely match the book s example problems precisely, PHP 5 in Practice explains the solution well enough that you will understand it and can learn how to truly solve your own problem.
