单向的

In this paper we firstly discuss the general concepts of compter security and cryptology, and then describe the mostly used modern encryption methods and technologies. We detail the advantages and disadvantages of symmetric algorithm, public-key algorithm and one-way hash function. At last we put forward a new block cipher - permutation code, and describe the secret hash digital signature and online electronic contracting with the trusted third party system.

本文首先讨论计算机安全和密码学的一般概念，然后介绍现代加密手段常用的方法和技术，详细讨论了对称加密方法、公开密钥加密方法和单向散列加密方法的优点和不足，进而提出了一种新型的分组加密算法—排列码加密算法，并在此基础上实现了保密散列数字签名算法和有可信第三方参与的网上电子签约。

Firstly, this paper puts forward an improved authentication and key distribution scheme for internet environment, in which we adhibit multilevel authentication center, encryption technology of DES, RSA and one-way function to actualize the safety of communication among the different user on network and reduces the workload of the authentication institution; at the same time, this scheme can also assure the security of network. Besides, it use the temporary symbol and the responds" sign of both-side correspondent to replace time stamp and applies them to internet communication to countercheck "rebroadcast attack and accordingly resolves the problem that it needs synchronization for network clock.

本文在首先提出一种改进的Internet网络环境下的认证及密钥分配方案，该方案考虑采用了多级认证中心，DES、RSA和单向函数加密机制，实现了网络上不同用户间的安全通信，降低了网上认证机构的工作量，同时也能够保证网络的安全性；并用通信双方的临时标志和响应者标识来代替时间戳应用于Internet通信中以防止"重播"攻击，从而解决了以往需要网络时钟同步这一难题。

On the base of the single-diameter laser-scanned measuring technology, a double direction laser-scanned measuring system is presented. Which combinate the laser-scanned measuring technology with special optical system. In the system, the collimation semiconductor laser-scanned beam scanning two perpendiculars direct of one plane of the measured workpiece at the same time is made. The beams with the dimension information of two perpendiculars direct are processed by the scanning receive system, the high-speed photoelectric transition and electronic data process. Two measured results of the diametric directs and ellipse tolerance,etc, parameter, of the turning workpiece on the same plane are obtained by non-contact automatic measurement. The problem of non-contact measurement of two perpendiculars direct of one plane of turning workpiece is settled. It processes many peculiarities, such as high speed, high accuracy and non-contact automatic measurement, etc.

在单向激光扫描检测技术的基础之上，提出了一种双向激光扫描检测系统，其采用激光扫描检测技术与特殊光学系统相结合，用准直半导体激光扫描光束对被测工件径向某一截面的两个相互垂直方向同时扫描，经扫描接收光学系统、高速光电变换、电子学系统和微机数据处理系统，对将携带有垂直方向被测量信息的光束进行处理，实现了回转体工件同一截面两个垂直方向的径向尺寸和椭圆度等参数的非接触自动测量，解决了同时非接触测量回转体零件同一截面两个径向尺寸的难题，它具有高速，高精度和非接触自动测量等特点。

In the system , the collimation semiconductor laser - scanned beam scanning two perpendiculars direct of one plane of the measured workpiece at the same time is made . the beams with the dimension information of two perpendiculars direct are processed by the scanning receive system , the high - speed photoelectric transition and electronic data process . two measured results of the diametric directs and ellipse tolerance , etc , parameter , of the turning workpiece on the same plane are obtained by non - contact automatic measurement

在单向激光扫描检测技术的基础之上，提出了一种双向激光扫描检测系统，其采用激光扫描检测技术与特殊光学系统相结合，用准直半导体激光扫描光束对被测工件径向某一截面的两个相互垂直方向同时扫描，经扫描接收光学系统、高速光电变换、电子学系统和微机数据处理系统，对将携带有垂直方向被测量信息的光束进行处理，实现了回转体工件同一截面两个垂直方向的径向尺寸和椭圆度等参数的非接触自动测量，解决了同时非接触测量回转体零件同一截面两个径向尺寸的难题，它具有高速，高精度和非接触自动测量等特点。

The labor force in the tertiary industry disperses from urban core to its edge area within a distance of 15 km; oppositely it has a centralizing trend to inner city out of a distance of 15 km, especially in exurban area.

第二、三产业从业劳动力的分布变动互不相同：第二产业主要表现为由中心城区向郊区扩散的较大范围的单向均衡化变动；第三产业从业劳动力空间分布的变动则相对更向中心城区集聚，表现为在距离市中心15km圈内由都心区向其边缘区扩散、15km圈以外地区特别是远郊区则反呈趋向中心城区的集中化变动。

As for the outflow of human capital, the higher level of human capital, the lower possibility of returning as countryside owing to the frailness of agriculture and the inherent wage disparity between urban and rural areas. That is that this flow way of the rural human capital, generally is a state of unidirectional loss or net loss, which leads to an existence of serious"misplaced effect"in rural human capital investment.

对于流出去的人力资本来说，由于农业的弱质性以及城乡固有的工资差异，其人力资本水平越高返回农村的可能性越小，也就是说，农村人力资本的这种流动基本上呈一种单向流失和净流失状态，这就决定了我国农村人力资本投资存在着严重的投资收益"错位效应"。

On the basis of gas migration equation -Darcy Law,coal seam gas content equation -parabola equation ,ideal gas state equation and the continuity equation s of the gas flow,a dynamic model of gas unilateral flow in the coal seam is set .

根据基本假设，对煤层瓦斯流动规律进行了研究，运用瓦斯运动方程—达西定律、煤层瓦斯含量方程—抛物线方程、理想气体状态方程以及气体流动的连续性方程，建立了煤层单向瓦斯流动的动力学模型，并根据边界条件和初始条件，对动力学模型进行了求解，推导出煤壁单位面积的瓦斯涌出量的计算公式，分析了瓦斯涌出量的影响因素，利用测得的数据，进行了实例计算，并用vc编制了计算机程序。

The weight that is because of such B2B platform inside Internet search engine is taller, the link that you keep and it is one-way return chain, have very good implicative sex to your website.

因为这样的B2B平台在互联网搜索引擎里面的权重比较高，你留下的链接而且都是单向反链，对你的网站有很好的连带性。

At the end of this paper, we investigate the invertible problem with the watermarking algorithms, and analyze the situation of image ownership dispute caused by the possible counterfeit attack for the reason of invertibility. Then we discuss one method based on one-way hash function to make the watermarking algorithms non-invertible, and another one using the time stamping protocol, to prevent the counterfeit attacks.

本文随后研究了水印算法的可逆性问题，对于由此可能发生的伪造攻击致使对图象所有权产生争议的情况作了分析，并且讨论了基于单向Hash函数的使水印算法不可逆的方法，以及采用时间戳协议以阻止伪造攻击的方法。

Following are the main results of this thesis: Detailedly analyze some related schemes concerning group key management, We reconstruct a tree key management scheme, in comparison with Logical Key Hierarchy and One-way Function Tree schemes, we find that it has good performance of key storage, re-key communication costs and calculation of group manager.

本论文的主要研究成果如下：对目前存在的多播组密钥管理方案进行了详细的研究分析，提出了一种改进的树型管理方案，与逻辑密钥分层方案和单向函数树方案进行分析比较，它在密钥存储、密钥更新、通信量以及组管理者的计算量方面均有较好的性能。

But we don't care about Battlegrounds.

但我们并不在乎沙场中的显露。

Ah! don't mention it, the butcher's shop is a horror.

啊！不用提了。提到肉，真是糟透了。