See Appendix B for a description of the programs included
on this companion disk. RESOURCE.WRI identifies other books
and resources for Internet programming. WEBHELP.HLP contains
an introduction to the World Wide Web. TCPMAN.HLP provides
detailed instructions to help you use the Trumpet Winsock
included on this disk. Use the Program Manager s File menu
Run option to execute the SETUP.EXE program found on this
disk. SETUP.EXE will install the programs on your hard drive
and create an Internet Programming group window.
Internet編程技術 [配套程序]
[涉及平臺] VC
[作者] void
[文件大小] 1032K
加密算法
Test Driver for Crypto++, a C++ Class Library of Cryptographic Primitives:
- To generate an RSA key
cryptest g
- To encrypt and decrypt a string using RSA
cryptest r
- To calculate MD5, SHS, and RIPEMD-160 message digests:
cryptest m file
- To encrypt and decrypt a string using DES-EDE in CBC mode:
cryptest t
- To encrypt or decrypt a file
cryptest e|d input output
- To share a file into shadows:
cryptest s <pieces> <pieces-needed> file
(make sure file has no extension, if you re running this under DOS)
- To reconstruct a file from shadows:
cryptest j output file1 file2 [....]
- To gzip a file:
cryptest z <compression-level> input output
- To gunzip a file:
cryptest u input output
- To run validation tests:
cryptest v
- To run benchmarks:
cryptest b [time for each benchmark in seconds]
Verilog HDL: Magnitude
For a vector (a,b), the magnitude representation is the following:
A common approach to implementing these arithmetic functions is to use the Coordinate Rotation Digital Computer (CORDIC) algorithm. The CORDIC algorithm calculates the trigonometric functions of sine, cosine, magnitude, and phase using an iterative process. It is made up of a series of micro-rotations of the vector by a set of predetermined constants, which are powers of two. Using binary arithmetic, this algorithm essentially replaces multipliers with shift and add operations. In a Stratix™ device, it is possible to calculate some of these arithmetic functions directly, without having to implement the CORDIC algorithm.
design LP,HP,B S digital Butterworth and Chebyshev
filter. All array has been specified internally,so user only need to
input f1,f2,f3,f4,fs(in hz), alpha1,alpha2(in db) and iband (to specify
the type of to design). This program output hk(z)=bk(z)/ak(z),k=1,2,...,
ksection and the freq.
About:
hamsterdb is a database engine written in ANSI C. It supports a B+Tree index structure, uses memory mapped I/O (if available), supports cursors, and can create in-memory databases.
Release focus: Major feature enhancements
Changes:
This release comes with many changes and new features. It can manage multiple databases in one file. A new flag (HAM_LOCK_EXCLUSIVE) places an exclusive lock on the file. hamsterdb was ported to Windows CE, and the Solution file for Visual Studio 2005 now supports builds for x64. Several minor bugs were fixed, performance was improved, and small API changes occurred. Pre-built libraries for Windows (32-bit and 64-bit) are available for download.
Author:
cruppstahl
結合單片機和M a t l a b 兩者的優點，基于事件驅動的中斷通信機制，提出一種Matlab 環境下PC 機與
單片機實時串行通信及數據處理的方法；完成單片機數據采集系統與PC 機的RS-232/RS-485 串行通
信及其通信數據的分析處理、文件存儲、F I R 濾波及圖形顯示；簡化系統開發流程，提高開發效率。
該方法已成功應用于一個P I C 1 6 F 8 7 6 單片機應用系統實例之中
Floyd-Warshall算法描述
1)適用范圍：
a)APSP(All Pairs Shortest Paths)
b)稠密圖效果最佳
c)邊權可正可負
2)算法描述：
a)初始化：dis[u,v]=w[u,v]
b)For k:=1 to n
For i:=1 to n
For j:=1 to n
If dis[i,j]>dis[i,k]+dis[k,j] Then
Dis[I,j]:=dis[I,k]+dis[k,j]
c)算法結束：dis即為所有點對的最短路徑矩陣
3)算法小結：此算法簡單有效，由于三重循環結構緊湊，對于稠密圖，效率要高于執行|V|次Dijkstra算法。時間復雜度O(n^3)。
考慮下列變形：如(I,j)∈E則dis[I,j]初始為1,else初始為0，這樣的Floyd算法最后的最短路徑矩陣即成為一個判斷I,j是否有通路的矩陣。更簡單的，我們可以把dis設成boolean類型，則每次可以用“dis[I,j]:=dis[I,j]or(dis[I,k]and dis[k,j])”來代替算法描述中的藍色部分，可以更直觀地得到I,j的連通情況。
實現最優二叉樹的構造；在此基礎上完成哈夫曼編碼器與譯碼器。 假設報文中只會出現如下表所示的字符：
字符 A B C D E F G H I J K L M N
頻度 186 64 13 22 32 103 21 15 47 57 1 5 32 20 57
字符 O P Q R S T U V W X Y Z ， ．
頻度 63 15 1 48 51 80 23 8 18 1 16 1 6 2
要求完成的系統應具備如下的功能：
1．初始化。從終端（文件）讀入字符集的數據信息，。建立哈夫曼樹。
2．編碼：利用已建好的哈夫曼樹對明文文件進行編碼，并存入目標文件（哈夫曼碼文件）。
3．譯碼：利用已建好的哈夫曼樹對目標文件（哈夫曼碼文件）進行編碼，并存入指定的明文文件。
4．輸出哈夫曼編碼文件：輸出每一個字符的哈夫曼編碼。
