可构造性

In the thesis, two constructible definitions for DAG are put forward to make it intuitive and operable.

本文提出了有向无回路图的两种构造性定义，使DAG直观化、可操作化。

Chaikin algorithm is the simplest discrete curve modeling method.In thepaper planar Chaikin algorithm is generalized into sphere,and the practicability ofthe algorithm as well as the continuous differentiable property of the generatingcurve is proved.It is shown that the curve generated by Chaikin algorithm is apiecewise spherical Bezier curve of second kind of order two.Furthermore,generalspherical corner-cutting algorithms are discussed,and it is pointed out that thecurve generated through corner-cutting has"Spherical Variation DiminishingProperty".3Curve interpolation method restricted on a smooth surface based ontransformation.

Chaikin算法是最简单的离散曲线造型方法，文中将Chaikin算法推广到球面，证明了算法的可行性和生成曲线的连续可微性，指出球面Chaikin算法得到的曲线是分段的二次第二类球面Bezier曲线，并给出了用球面Chaikin算法构造球面插值曲线的算法；进一步，文中讨论了一般的球面割角算法，指出由球面割角算法得到的曲线具有"球面变差缩减性质"。3基于变换的约束在光滑曲面上的曲线插值方法。

A similarly jointed framework,such as a power - collecting trolley on an electric locomotive or an extensible telephone arm.

动臂装置同样构造的有活节的结构，如电力火车上的电力机车或可伸性电话臂收藏反馈

This type is accompanied by the structure-salt dissolution breccias,being vein or flamboyancy in cross section while some of them shot through the lead and zinc ore. In fact,the breccias were lead and zinc orebodies themselves.

其角砾成分单一(主要为沥青质灰岩、晶质灰岩)、大小混杂(nmm～nX10m)、无分选，角砾多呈不规则状和次棱角状或次浑圆状，部分角砾具有可拼性，角砾间为砂质充填或无充填，表明它是一套构造和膏溶共同作用形成的角砾岩。

Based on two algebra Riccati equation method especially the structure of the system Hamilton matrix and system observability theory, the role of invariant zeros in constructing system reduced order controllers was given. That is, by the suitable selection of free parameters of the system H(subscript ∞) controller, some points which were symmetry with the unstable invariant zeros about the imaginary axis became the stable poles of the system controller which were not observable and could be reduced from the system, thus could get further reduced order controller.

基于2代数黎卡提方程方法，特别是系统Hamilton矩阵的结构特点和系统可观测性理论，论述了不变零点在构造系统降阶控制器中所起的作用，即通过选择控制器的自由参量，使某些不稳定的不变零点关于虚轴对称的点构成系统控制器不可观的稳定极点，从而实现了控制器进一步降阶。

These constructional methods can be used to treat many problems, the numerical results show that the given interval extension has smaller excessive width relative to the range of the functions over a domain. For univariate differentiable functions, the definition of interval slope is extended from the first order to high order according to their differentiability, and iterative formula of high-order interval slope computation is also developed.

对多元函数，在不要求函数的可微性及有关Lipschitz常数的条件下，给出了分量函数区间展开的斜率算术运算规则；利用函数局部凸或凹的运算特点，通过递归计算建立了多元函数区间扩张的构造方法。

Furthermore, when the system is a periodic system, sufficient conditions are obtained that guarantee the existence, uniqueness and global attractivity of the positive periodic solution by applying the Brouwer fixed theorem and the method of constructing Liapunov function.

利用比较原理给出了系统一致持久性的充分条件；当系统是周期系统时，应用Brouwer不动点原理和构造Liapunov函数的方法给出其存在惟一且全局吸引的ω-周期正解的充分条件，并通过实例验证了文中定理条件的可实现性。

Then, we set up the double-row monodromy matrix of the Hamiltonian, the transfer matrix and the reflection equation of the system with the help of the scattering matrix and the reflecting matrix.

接着借助量子反散射方法，运用两体散射矩阵和反射矩阵，构造了双行monodromy矩阵、转移矩阵和系统的边界反射方程，从而详细证明了系统的精确可解性。

This paper first analyses and summarizes the ststus quo and evolution trend of encryption, some common used cryptograph are introduced, including the algorithms used in symmetric cryptosystem and asymmetirc cryptosystem. We describe the theory of each algorithms and compare the elliptic curve cryptosystem with the other two asymmetric cryptosystems to show the advantages of this algorithm. Second, the principle of ECC is discussed, including the math foundation of ECC, basic conception of elliptic curves, constructiong idea of ECC, operation on the elliptic curve and so on. Third, the current attacks of ECC were analyzed deeply, and an algorithm based on limited prime number field was constructed. We analyzed its realizability in theory, and implement it by using certain function of MIRACL software package. Latter half in this paper, the implementation model of a simple elliptic curve encryption system which based on GF has been introduced. The paper also put a deep analysis on the algorithm of point addition and point multiplication.

本文首先对密码技术的发展现状及其发展趋势进行了分析和综述，详细的介绍了私钥密码系统和公钥密码系统的发展，说明各种算法的原理和优缺点，并给出了一些典型的密码体制的简要分析，重点将椭圆曲线算法与其它几种公钥密码算法比较，说明椭圆曲线算法的优势；其次，探讨了椭圆曲线密码体制的原理，包括椭圆曲线密码的数学基础、基本概念、椭圆曲线密码体制的构造思想等问题；第三作者对椭圆曲线的攻击现状作了详细的分析，针对所使用的大素数域F_p，设计了素数域上安全椭圆曲线产生的算法，从理论上做了可实施性分析，从软件上做了具体实现；在本文的后半部分，提出了一个简单的基于有限素数域上的椭圆曲线加密方按算实现模型，并对SECES中设计的点加和点乘运算进行了深入分析。

From the above theorem,（1） compositional invariant security properties and constructive security properties are proved to exist, and （2） security properties are degraded under operators of process algebra, which is known as "bucket principle", i.e, a composed system cannot be securer than the weakest link of the system.

根据这一结果证明了复合不变性质和可构造安全性质在安全性质集上的存在性，并且在安全性质集合上证明了安全性质的"木桶原理"，即复合系统的整体安全性不强于系统中最弱的部分。

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。