一种基于IDEA和ECC算法的数字化防伪认证新方案的研究与实现

商品防伪是一项系统工程，现有防伪措施在有效性和易操作性之间不能达到很好的统一，本文在研究商品防伪机制的基础上提出了一种有效解决上述问题的新方案．该方案通过IDEA比特流重组的加密算法对商品信息进行加密，以主密钥机制采用椭圆曲线密码算法ECC实现对IDEA密钥的自动化安全管理，而客户可依据加密产生的防伪码通过电话或网站快速准确认证其对应商品的真伪．理论分析和系统的实际运行表明该方案是一种有效、安全的新型实用方案．     

Approximation by fat arcs and fat biarcs

A general discussion of the including approximation of a curve by a fat arc is given followed by an algorithm for constructing an including fat arc for a parametric Bézier curve. An example of applying the algorithm is given. The results for a fat arc are then used to develop an including approximation for a curve segment using a fat biarc. An algorithm for a fat biarc including approximation is provided followed by examples of Bézier curves being included by a fat biarc.     

Preserving computational topology by subdivision of quadratic and cubic Bézier curves

Non-self-intersection is both a topological and a geometric property. It is known that non-self-intersecting regular Bézier curves have non-self-intersecting control polygons, after sufficiently many uniform subdivisions. Here a sufficient condition is given within ℝ³ for a non-self-intersecting, regular C ² cubic Bézier curve to be ambient isotopic to its control polygon formed after sufficiently many subdivisions. The benefit of using the control polygon as an approximant for scientific visualization is presented in this paper.     

IDEA加密标准在开发系统时的一些改进

分析介绍了IDEA国际数据加密标准,提出了解决明文最后一个不完整分组的新方法(适用于其他分组加密算法),简化了用户密钥管理(适用于所有加密算法),并在其他方面也提出了有实际意义的处理方法。     

Multiresolution morphing for planar curves

We present a multiresolution morphing algorithm using ``as-rigid-as-possible' shape interpolation combined with an angle-length based multiresolution decomposition of simple 2D piecewise curves. This novel multiresolution representation is defined intrinsically and has the advantage that the details' orientation follows any deformation naturally. The multiresolution morphing algorithm consists of transforming separately the coarse and detail coefficients of the multiresolution decomposition. Thus all LoD (level of detail) applications like LoD display, compression, LoD editing etc. can be applied directly to all morphs without any extra computation. Furthermore, the algorithm can robustly morph between very large size polygons with many local details as illustrated in numerous figures. The intermediate morphs behave natural and least-distorting due to the particular intrinsic multiresolution representation.     

Some fixed point theorems in 1-M-complete fuzzy metric-like spaces

Very recently, in order to unify the notions of fuzzy metric space and metric-like space, Shukla and Abbas introduced the concept of fuzzy metric-like space and proved some fixed-point results in this setting. In this article, we modify the notion of Cauchy sequence and completeness to generalize their results. Thus, we extend their theorems to a more general framework, which is also appropriate to generalize some recent, well-known results in this line of research. Furthermore, several examples are presented to illustrate the significance of our results.     

Input-output properties of the Page-Hinkley detector

We consider the stochastic input-output properties of a simple non-linear dynamical system, the so-called Page-Hinkley detector, playing a key role in change detection, and also in queuing theory. We show that for L-mixing inputs with negative expectation the output process of this system is L-mixing. The result is applied to get an upper bound for the false alarm rate. The proof is then adapted to get a similar result for the case of random i.i.d. inputs. Possible extensions and open problems are given in the discussion.     

C3I系统信息加密技术研究

对C^3I系统的信息安全性进行了分析，讨论了安全体系结构及数据保密的实现途径，建立了C^3I系统的安全模型，综合使用IDEA类算法、RSA相关算法、HAVAL杂凑算法设计了一个C^3I数据加密系统。     

Controller synthesis with guaranteed closed-loop phase constraints

In this paper, we present an analysis and synthesis approach for guaranteeing that the phase of a single-input, single-output closed-loop transfer function is contained in the interval [−α,α] for a given α>0 at all frequencies. Specifically, we first derive a sufficient condition involving a frequency domain inequality for guaranteeing a given phase constraint. Next, we use the Kalman–Yakubovich–Popov theorem to derive an equivalent time domain condition. In the case where , we show that frequency and time domain sufficient conditions specialize to the positivity theorem. Furthermore, using linear matrix inequalities, we develop a controller synthesis approach for guaranteeing a phase constraint on the closed-loop transfer function. Finally, we extend this synthesis approach to address mixed gain and phase constraints on the closed-loop transfer function.