Who needs QP for linear MPC anyway?

Conventional MPC uses quadratic programming (QP) to minimise, on-line, a cost over n linearly constrained control moves. However, stability constraints often require the use of large n thereby increasing the on-line computation, rendering the approach impracticable in the case of fast sampling. Here, we explore an alternative that requires a fraction of the computational cost (which increases only linearly with n), and propose an extension which, in all but a small class of models, matches to within a fraction of a percent point the performance of the optimal solution obtained through QP. The provocative title of the paper is intended to point out that the proposed approach offers a very attractive alternative to QP-based MPC.     

混沌非线性反馈密码序列的理论设计和有限精度实现

本文利用一类特殊的一维分段线性混沌系统，来产生具有均匀不变分布函数和δ自相关函数特性的连续混沌信号，这类连续混信号经过不可逆变换可生成具有理想保密性的二进制混 列。本文分析了该混沌系统的有限精度效应并提出一类ｍ序列扰动实现方法，，与传统密码序列相比，混沌非线性反馈密码序列不仅具有丰富的源泉，而且设计异常方便，性能易于控制。     

An Analysis of SAFER

We investigate some of the algebraic properties of the SAFER block cipher when the message space is considered as a Z -module. In particular, we consider the invariant Z -submodules of the PHT layer and show how these invariant Z -submodules give potential cryptographic weaknesses. Received 12 June 1995 and revised 22 July 1997     

建立Hopfield网络的一般方法

讨论了用离散的带反馈的Hopfield网络的极限环来表达概念,以及在给定不动点、极限 环或迭代序列等限制下,用线性规划和遗传算法通过求解不等式组一般性地建立Hopfield网 络的方法,从而也解决了网络联结的稀释问题.最后给出了几个实例,     

A predictivistic interpretation of the multivariatet distribution

Summary De Finetti type theorems characterize models in terms of invariance. The idea is to take observables, postulate symmetry and then represent the model as a mixture of standard parametric models. If additional conditions are specified, then the mixing measure can be determined. Invariance under the action of special groups of orthogonal transformations may give results on mixtures of parametric normal distributions (Diaconis, Eaton and Lauritzen, 1992). The additional conditions required to determine the mixing measure in this case can be obtained using results in Diaconis and Ylvisaker (1979, 1985). From these results, we obtain a predictivistic characterization of the multivariatet distribution. Furthermore, we state conditions under which then-dimensional law of sequences of random variables is a location mixture of multivariatet distributions. The results are extended to the case of sequences of orthogonally invariant random vectors.     

电光晶体光学性质的折射率椭球分析法

本文利用折射率椭球一般性地讨论了电光晶体的光学性质,给出了电光晶体光轴方位和折射率分布的普遍公式。根据这些公式,可以很方便地分析一个具体的电光晶体的光学性质。     

Recognizing algebraic surfaces from their outlines

The outline in a single picture of a generic algebraic surface of degree three or greater completely determines the projective geometry of the surface. The result holds for a generic perspective view of a generic algebraic surface, where the camera calibration parameters and the focal point are unknown. Known camera calibration appears not to reduce the projective ambiguity. The result is constructive.     

On the decentralized control of interconnected systems

Recently, it was shown [1] how to reduce the order of the decentralized control problem for interconnected systems by using local dynamic feedback. The analysis was carried out with polynomial matrices. In this letter, these results are reproduced in state space using the Generalized Hessenberg Representation (GHR). This analysis shows how the interaction between the interconnection structure and the local system structure generates the result above. In addition, this analysis leads directly to numerical algorithms.