离散数学的二元关系判断（源与再…

应用背景PBKDF2(Password-Based Key Derivation Function)，PBKDF2简单而言就是将salted hash进行多次重复计算，这个次数是可选择的。如果计算一次所需要的时间是1微秒，那么计算1百万次就需要1秒钟。假如攻击一个密码所需的rainbow table有1千万条，建立所对应的rainbow table所需要的时间就是115天关键技术 PBKDF2应用一个伪随机函数以导出密钥。导出密钥的长度本质上是没有限制的。(但是，导出密钥的最大有效搜索空间受限于基本伪随机函数的结构。其实还有PBKDF1算法，但它只用于已有应用的兼容因为它产生的密钥对某些应用来说不够大，对新的应用推荐使用PBKDF2。

平均因子分解法，适用于正定矩阵First, let s recall the definition of the Cholesky decomposition: Given a symmetric positive definite square matrix X, the Cholesky decomposition of X is the factorization X=U U, where U is the square root matrix of X, and satisfies: (1) U U = X (2) U is upper triangular (that is, it has all zeros below the diagonal). It seems that the assumption of positive definiteness is necessary. Actually, it is "positive definite" which guarantees the existence of such kind of decomposition. -Average factor decomposition method applied to positive definite matrix First, let s recall the definition of the Cholesky decomposition: Given a symmetric positive definite square matrix X, the Cholesky decomposition of X is the factorization X = UU, where U is the square root matrix of X, and satisfies: (1) UU = X (2) U is upper triangular (that is, it has all zeros below the diagonal). It seems that the assumption of positive definiteness is necessary. Actually, it is positive

采用了基本的蚁群算法来求解0-1背包问题，该算法不仅可以对0-1背包问题进行求解，还可以对多维背包问题进行求解。-Using the basic ant colony algorithm to solve the 0-1 knapsack problem, the algorithm not only for the 0-1 knapsack problem can be solved, but also multi-dimensional knapsack problem can be solved.

输出wav文件的所有信息,输出size段,输出编码方式,输出声道数目,输出采样频率,输出每秒所需字节数,输出数据块对齐单位,输出每个采样所需bit数,/输出附加信息,输出

二维稳态导热问题。设材料物性均为常数，均质无内热源。已知它的左边界是温度为T2的等温边界，其他三个边界均为温度为T1的等温边界。导热区域为边长L的正方形。-two-dimensional steady-state heat conduction problems. Based material properties are constant, no heterogeneity within the heat source. It is known to have a threefold T2 is the temperature of the isothermal boundary, the other three border are temperature T1 isothermal boundary. Regional conduction length L of the square.

分水岭算法分割彩色图片，使用时只需要更改处理图片的路径即可，属于Matlab程序，压缩文件中含有原始图片

该8位乘法器采用冗余二进制编码。0或1需要用2位bit表示。 冗余二进制使得部分积压缩部分速度更快，不受到进位的影响 编程语言为verilog

采用C语言，编写了矩阵计算常用的一些函数，比如矩阵转置，矩阵求逆，矩阵的加减乘除等

本文是一程序源代码，描述的是在一维条件下用FDTD计算模拟波在与频率有关的介质中传播时E的变化。-This article is a source code, describing 1D FDTD simulation of a frequency dependent material for E field changes.

与上一个程序的不同之处在于，此程序计算的是强制对流的问题，上一个为自然对流-With a different procedure is that this procedure is the calculation of the problem of forced convection, natural convection on a