一种灵活的基于身份的签名方案

在基于身份的密钥提取过程中,使密钥生成器在私钥中嵌入随机数,从而使得密钥提取具有较好的灵活性,使得用户对一个身份可具备多个私钥,这无疑会增加密钥使用的安全性;基于这种新的密钥提取思路,给出一个基于身份的签名体制,新的密钥提取方式使得它具有更好的安全性和灵活性;新的基于身份的签名体制中具有最少对运算,因此,与类似的方案相比,其具备较好的计算效率;新签名体制的安全性依赖于k-合谋攻击问题(k-CAAP)的困难性,其在适应性选择消息和ID攻击下具备强不可伪造性,并且其安全性证明具有紧规约性.     

Comparisons of mixed systems with decreasing failure rate component lifetimes using dispersive order

Because lifetimes of systems are not deterministic, partially, orders are used for comparison purposes which lead us to provide optimal system configurations. This paper deals with a signature‐based dispersive ordering of mixed systems. It is assumed that component lifetimes are independent and identically distributed, and the common distribution has a decreasing failure rate function. Some illustrative examples are also given.     

多重边融合复杂动态网络的自适应同步

基于网络拆分的思想对多重边融合复杂动态网络局部和全局的自适应同步进行了研究.通过给出严格的数学定义及假设,运用Lyapunov稳定理论得出了网络局部和全局的同步准则,给出了更为简单的网络同步的控制器.最后以Lorenz 系统为例进行数值仿真,验证了结论的正确性和有效性. 关键词： 多重边融合复杂动态网络 自适应同步 网络拆分 时滞     

Generalized Seifert surfaces and signatures of colored links

In this paper, we use `generalized Seifert surfaces' to extend the Levine-Tristram signature to colored links in . This yields an integral valued function on the -dimensional torus, where is the number of colors of the link. The case corresponds to the Levine-Tristram signature. We show that many remarkable properties of the latter invariant extend to this -variable generalization: it vanishes for achiral colored links, it is `piecewise continuous', and the places of the jumps are determined by the Alexander invariants of the colored link. Using a -dimensional interpretation and the Atiyah-Singer -signature theorem, we also prove that this signature is invariant by colored concordance, and that it provides a lower bound for the `slice genus' of the colored link.

     

时滞速度反馈作用下弹性梁的主共振分析

采用时滞速度反馈控制策略对轴力作用下的弹性梁进行振动控制.根据Newton第二定律建立压电耦合弹性梁的非线性振动控制模型,运用直接法得到时滞反馈作用下弹性梁主共振的一阶近似解,得出系统响应与控制参数的关系.结果表明,主共振的响应存在多解和跳跃现象,调节控制增益和时滞值可以有效抑制大幅振动.     

Infinite horizon quadratic control of linear singularly perturbed systems with small state delays: an asymptotic solution of Riccati-type equations

Email: valery{at}techunix.technion.ac.il Received on January 31, 2006; Accepted on October 5, 2006 An infinite horizon linear-quadratic optimal control problemfor a singularly perturbed system with multiple point-wise anddistributed small delays in the state variable is considered.The set of Riccati-type equations, associated with this problemby the control optimality conditions, is studied. Since thesystem in the control problem is singularly perturbed, the equationsof this set are also perturbed by a small parameter of the singularperturbations. The zero-order asymptotic solution to this setof equations is constructed and justified. Based on this asymptoticsolution, parameter-free sufficient conditions for the existenceand uniqueness of solution to the original optimal control problemare established.     

More generalized hybrid variational principle and corresponding finite element model

According to recent studies of the generalized variational principle by Professor Chien Weizang, the more generalized hybrid variational principle for finite element method is given, from which a new kind of the generalized hybrid element model is etablished.Using the thin plate bending element with varying thickness as an example, we compare various hybrid elements based on different generalized variational principles.     

Efficient Rabin-type Digital Signature Scheme

Rabin's cryptosystem was proved to be as hard as factorization. However, Rabin's digital signature schemes is probabilistic. This paper shows two efficient Rabin type digital signature schemes, a basic scheme and an improved scheme. Both schemes run much faster than Rabin's scheme. They are deterministic and the size of a signature is much smaller than that of a signature in Rabin's scheme. Furthermore, it is proved that, by applying the technique of Bellare and Rogaway, the proposed scheme is secure against chosen plaintext attack. More precisely, breaking the proposed digital signature scheme by chosen plaintext attack is as hard as factoring N.     

Description of all observed rotational bands in ~(128)Pr

The configuration-dependent cranked Nilsson-Strutinsky approach was used to investigate the rotational structures in ¹²⁸Pr and signature splittings of some observed bands could be well described quantitatively at high spin. Its modified model was used to calculate special configurations in order to distinguish the N=4 d_3/2s_1/2 and g_7/2d_5/2 orbitals. All observed bands were compared with the calculated configuration assigned to the band and the agreement between experiment and theory is remarkable.