It is hard to guarantee that the signatory cannot deny his/her operation in the trade through digital signature because it cannot provide a "proof-of-existence" for the particular datum at an instant in time.
仅仅依靠传统的数字签名技术无法提供数据的存在性证明,进而就无法保证活动的不可抵赖性。
A constructive proof of a class of nonconvex Brouwer fixed point problems is pre-sented, and the theoretical base of homotopy method to the problem has been created.
一类非凸Ｂｒｏｕｗｅｒ不动点问题的同伦算法于波，林正华（吉林大学数学研究所，长春１３００２３）关键词不动点定理，构造性证明，同伦算法在７０年代，文［１，２］就提出了求Ｒ￣ｎ中有界闭凸集上连续可微自映射的不动点的同伦算法，这是非线性问题数值解法的突破性。
The Abstract Space of Existence of General Equilibrium
一般均衡存在性证明的空间抽象过程研究
Study on existence of eigenvalue for sub-laplacian on Heisenberg group
Heisenberg群上的次拉普拉斯算子特征值存在性证明
He proved the existence of parallel lines.
他证明了平行线的存在性。
Analysis Technique of the Existence of Mid-Value in the Differential;
微分中值点存在性命题证明技巧分析
Summary on direct methods of large scale system;
用对偶原理证明线性不等式组的解的存在性
The Application of Construction Method in Graph Theory--On proof of existence;
“构造法”在图论中的应用——关于存在性的证明
Proof of Existence and Uniqueness for the Solution of Integrated Equation;
关于一个积分方程解的存在唯一性证明
A Simple Proof for the Existence of Continuous Utility FunctionAn Application of Countable Dense Set;
利用可数稠密集证明连续效用函数存在性
A Simple Proof on Existence of Limit of Sequence of Number {(1+1/n)~n};
数列{(1+1/n)~n}极限存在性的一种简单证明
A Constructive Proof of Periodic Boundary Value Problems of One Class of Second Order Linear ODE
一类二阶线性周期边值问题解的存在唯一性的构造性证明(英文)
What evidence do astronomers have that black holes exist?
天文学家有何证据证明黑洞的存在呢？
Existence results are shown for a class of beam equation under the resonance condition.
在共振条件下，对一类梁方程解的存在性给出证明.
It is shown that there is the nonlocal body moment in the nonlocal elastic solids.
证明了在非局部弹性固体中存在着非局部体力矩.
Mathematics had to free itself of a narrow technique for establishing existence.
数学必须在证明存在性的问题上不受狭隘的几何方法的束缚。
Application of Method of Undetermined Coefficient in Proof of Existence of Differential Coefficient Median;
待定系数法在证明微分中值存在性问题中的应用
On every confidence level, we use the degree of departure from central point as the measure of risk.
当预期收益率给定时，证明最小风险选择组合的存在性。
Hopf Differential and a Direct Proof of Non-existence of λ_2-eigenmap S~2→S~2;
Hopf微分以及二维球面到自身的特征映射的不存在性的直接证明
Ontological Proof of Artistic Truth;
对艺术真实性的存在论证明——论海德格尔美学的意义及缺憾