运算符号

The m-sequence with Cyclic Prefix is inserted between OFDM symbols in time domain as training sequence. The cross-correlation is calculated between the received sequence with CP removed and the appointed circular shifted m-sequence, which takes reliability of the estimation of channel impulse response on account of the two-valued auto-correlation property of the m-sequence, thereby the channel frequency response can be advisably decided.

在时域OFDM符号之间插入附加循环前缀的m序列作为训练序列，在接收端将去掉循环前缀的接收序列与指定的循环移位m序列作相关运算，然后利用m序列的二值自相关特性获得信道的冲激响应估计，从而得到信道的频率响应估计。

In this paper, they have not only illustrated the practical approaches and methods of modern mathematical analysis used in anode baking and thermotechnical procedure, but also provided computational techniques for the approximate solution to thermotechnical differential equations.

它的创新之处在于借助Mathematica系统的强大的符号运算功能与该系统提供的控制语句，能实现系统有效渐近解的自动求解，到目前为止，还很少见到用计算机实现其自动求解过程。

In order to analyze the general astigmatism of laser resonator cavities, the general analytical formula of misalignment sensitivity for complex astigmatic resonator cavities with several optical components has been derived by adopting augmented 8×8 misaligned matrix and symbol operation functions of MATLAB.

为了分析激光谐振腔的一般复杂像散特性，采用了8×8失调增广矩阵和MATLAB的符号运算的方法，推导出了复杂像散腔失调灵敏度的一般解析表达式。

Grasp the basic symbol operations in calculus of linear algebra applications, control of the equation solution.

掌握MATLAB的基本符号运算，在微积分中的应用，在线性代数中的应用，同时掌握方程的求解方法。

Digital signature operates the born and a series of sign and codes to constitute the electronics password to carry on the signature through a certain password , replace to the writing signature or an official seals , to confirm the body , the data source and integrities of signs , keeping data from burglarize to take , distort and break , thus to attain the purpose of protecting the data

数字签名是通过某种密码运算生成一系列符号及代码组成电子密码进行签名，来代替书写签名或印章，确认签名者的身份、数据来源和完整性，防止数据被窃取、篡改和破坏，从而达到保护数据的目的。

The soundness and completeness theorem of this method were proved at last. This part consists of the following points: 1. The properties of the indecomposable extremely simple form of LP were discussed, the theorem shown that every logical formula of LP was equals of a generalized conjunction normal form. 2. The method for judging a logical formula is a indecomposable extremely simple form or not was discussed, the necessary and sufficient conditions of a logical formula with not more than three implicative connective being a indecomposable extremely simple form was given. 3. The α-resolution fields of the indecomposable extremely simple form of LP were discussed, some elementary results were obtained. 4. The automated reasoning method based on the resolution principle of classical logic was discussed, the author given a method to describe the set of clauses by using a matrix, and translated the resolution of two clauses to column operations of this matrix.

二、关于格值命题逻辑系统LP中α-自动推理方法的研究 1、对LP中不可分极简式的性质进行了研究，证明了LP中任何一个格值逻辑公式等值于一个广义合取范式； 2、对LP中不可分极简式的判定方法进行了研究，讨论了含有不超过3个蕴涵运算的格值逻辑式为不可分极简式的充分必要条件； 3、对LP中不可分极简式的α-归结域进行了研究，得到了一些基本结果； 4、对经典逻辑中基于归结原理的自动推理方法进行了研究，给出了用符号矩阵表示子句集合的一种方法，把不同的归结过程转换成矩阵的列变换。

Aiming at these problems, an expectation maximum based MAP algorithm is proposed and the performance is analyzed. The proposed algorithm avoids large matrix operations by using the EM algorithm to decompose the MIMO channel estimation problem into a series of single input single output problems. Besides, a joint estimation is carried out over multiple OFDM symbols in order to enhance the data transmission efficiency and the estimative performance of the proposed algorithm.

该算法利用EM算法把多输入输出信道估计问题化简为一系列独立的单输入输出问题，避免了大规模矩阵运算，降低了MAP算法的计算复杂度；为进一步改善MAP算法的数据传输效率及其估计性能，可通过对多个连续的OFDM符号进行联合信道估计。

MatLab the book from the start of basic knowledge in detail on the various orders, to the readers of MatLab in higher mathematics, linear algebra, symbolic operation, graphics and image processing. data processing and the application of the external interface design.

本书从MatLab的基础知识入手，在详细介绍各种命令的同时，向读者介绍了MatLab在高等数学、线性代数、符号运算、图形图像处理、数据处理等方面的应用和外部接口程序设计。

Is scientifically same as imaginary number i. They are all symbols.

∞在科学上可以和虚数 i 一样，都只是一个符号，当我们利用虚数进行运算的时候，0、∞也同样可以。

According to the characteristic of tight correlation between memory overrun and loop induction variable arithmetic,extended algebra for chains of recurrences is combined with detection methods based on symbolic execution,for the first time,to design defect detection guide information as to multi-loop,while locality characteristic of software updates and their impact is used.

针对内存访问越界缺陷与循环归纳变量运算紧密关联的特点，首次将递推链扩展代数与符号执行类缺陷检测方法相结合，设计了面向多重循环的缺陷检测指导信息，同时利用软件更新影响的局部性特点，实现了基于路径指导的定向检测和基于更新影响的增量检测。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。