伸展樹，基本數據結構，The tree is drawn in such a way that both of the edges down from a node are the same length. This length is the minimum such that the two subtrees are separated by at least two blanks.
AdaBoost, Adaptive Boosting, is a well-known meta machine learning algorithm that was proposed by Yoav Freund and Robert Schapire. In this project there two main files
1. ADABOOST_tr.m
2. ADABOOST_te.m
to traing and test a user-coded learning (classification) algorithm with AdaBoost. A demo file (demo.m) is provided that demonstrates how these two files can be used with a classifier (basic threshold classifier) for two class classification problem.
AdaBoost, Adaptive Boosting, is a well-known meta machine learning algorithm that was proposed by Yoav Freund and Robert Schapire. In this project there two main files
Watermarking schemes evaluation
Abstract鈥擠igital watermarking has been presented as a solution to copy protection of multimedia objects and dozens of schemes and algorithms have been proposed. Two main problems seriously darken the future of this technology though.
Firstly, the large number of attacks and weaknesses which appear as fast as new algorithms are proposed, emphasizes the limits of this technology and in particu-lar the fact that it may not match users expectations.
Secondly, the requirements, tools and methodologies to assess the current technologies are almost non-existent. The lack of benchmarking of current algorithms is bla-tant. This confuses rights holders as well as software and hardware manufacturers and prevents them from using the solution appropriate to their needs. Indeed basing long-lived protection schemes on badly tested watermarking technology does not make sense.
Video-DVM is a very cheap DVM that shows how an output as complex as a videocomposite signal can be generated entirely in software: two I/O pins and three resistors are all the hardware required. Connected to any TV set it displays voltages, included max and min peaks, using both giant digits and an analog bar-display . A serial data output for computer data logging is provided, too.
Playfair Cipher
1.not even the large number of keys in a monoalphabetic cipher provides security
2.one approach to improving security was to encrypt multiple letters
3.the Playfair Cipher is an example
4.invented by Charles Wheatstone in 1854,but named after his friend Baron Playfair
Playfair Key Matrix
1.a 5X5 matrix of letters based on a keyword
2.fill in letters of keyword (sans duplicates)
3.fill rest of matrix with other letters
Encrypting and Decrypting
-plaintext is encrypted two letters at a time
1. if a pair is a repeated letter, insert filler like X’
2. if both letters fall in the same row, replace each with letter to right (wrapping back to start from end)
3. if both letters fall in the same column, replace each with the letter below it (again wrapping to top from
bottom)
4. otherwise each letter is replaced by the letter in the same row and in the column of the other letter of the pair
Heapsort
1.A heap is a binary tree satisfying the followingconditions:
-This tree is completely balanced.
-If the height of this binary tree is h, then leaves can be at level h or level h-1.
-All leaves at level h are as far to the left as possible.
-The data associated with all descendants of a node are smaller than the datum associated with this node.
Implementation
1.using a linear array not a binary tree.
-The sons of A(h) are A(2h) and A(2h+1).
2.time complexity: O(n log n)
Please read your package and describe it at least 40 bytes.
System will automatically delete the directory of debug and release, so please do not put files on these two directory.
Jpeg Steganography
Please read your package and describe it at least 40 bytes.
System will automatically delete the directory of debug and release, so please do not put files on these two directory.
