An alternative Kalman-Yakubovich-Popov lemma and some extensions

This paper introduces an alternative formulation of the Kalman-Yakubovich-Popov (KYP) Lemma, relating an infinite dimensional Frequency Domain Inequality (FDI) to a pair of finite dimensional Linear Matrix Inequalities (LMI). It is shown that this new formulation encompasses previous generalizations of the KYP Lemma which hold in the case the coefficient matrix of the FDI does not depend on frequency. In addition, it allows the coefficient matrix of the frequency domain inequality to vary affinely with the frequency parameter. One application of this results is illustrated in an example of computing upper bounds to the structured singular value with frequency-dependent scalings.     

LPV重复过程的H_∞滤波新方法

将时滞线性参数变化(LPV)思想应用于重复过程中,研究了其H∞滤波问题。基于参数依赖Lyapunov函数方法推出了该重复过程的稳定性和滤波器设计的充分条件。通过投影定理引入两个附加矩阵,解除了重复过程矩阵和依赖于参数的Lyapunov函数矩阵之间的耦合,使得到的条件便于求解。仿真实例证实了该设计方法的有效性。     

沥青路面摊铺不平整的机械性原因分析及对策

分析了机械造成沥青路面摊铺不平整的原因，探讨了处理措施。     

具有概率分布时滞的神经网络稳定性新判据

基于概率理论和Lyapunov稳定性理论,研究一类具有概率分布时滞神经网络稳定性问题。通过构造合适的Lyapunov-Krasovskii（LK）泛函,运用Wirtinger不等式和倒凸技术来估计LK泛函导数的上界,得到了确保该类时滞神经网络在均方意义下的全局渐近稳定的新判据。该判据以LMIs形式表出,它不但依赖于时滞的上界,而且依赖于时滞的概率分布。给出两个数值例子,仿真表明所提方法的有效性和较弱的保守性。     

A sliding mode observer design for uncertain fractional Ito stochastic systems with state delay

This paper addresses the robust observer design problem for uncertain time-delay fractional Ito stochastic systems. A sliding surface is proposed and it is shown that state estimates converge towards it and remain there for the subsequent time. Additionally, by constructing a novel Lyapunov functional, a sufficient condition for the stability of the sliding motion of the estimated states is given in the form of Linear Matrix Inequalities (LMIs). It is demonstrated that the state estimates are stabilizable in probability provided that the LMI is feasible. Moreover, a finite-time sliding mode control law based on the estimated states is proposed. Simulation examples are given to show the validity and effectiveness of the results.     

Regional Variations In Housing And Wealth Accumulation In New Zealand

This paper reviews and empirically examines the debate about the role of housing in wealth generation and wealth distribution in New Zealand over the past twenty five years. The article is structured around four parts. The first explores the theoretical debate regarding housing wealth accumulation and situates the paper within this debate as a contribution to the exploration of regional housing price shifts and the links to economic and social restructuring. The second part addresses the methodological issues in the analysis of financial gains from housing. The third reviews previous New Zealand empirical work covering the period from 1970–1988 to provide a background for the fourth section which examines changes over the period from 1990–94. The data is interpreted in the paper against the background of the economic and social restructuring of the regions which has taken place since 1970.     

MULTIMODEL DISCRETE CONTROL WITH ONLINE UPDATING OF THE FRACTIONAL ORDER HOLD GAINS

A multiestimation scheme for adaptive discrete-time control is presented. The different models of the scheme to be estimated are obtained from a set of different discretizations of a continuous-time unknown transfer function under a fractional order hold of correcting gain (β-FROH) which leads to distinct associate discrete-time models for the given continuous-time plant. The objective is to design a scheme being able to find the most appropriate value for the gain β to enhance the identification and tracking performances. The scheme chooses online the value of β with the best reference tracking performance by implementing eventually switches through time among a prefixed set of values characterizing the discrete models of the plant in a parallel multiestimation scheme. The switching rule is subjected to a minimum residence time in order to guarantee the closed loop stability. Simulations for two different practical cases, a controlled DC motor and a resonant circuit, are presented.     

Complexity of Clausal Constraints Over Chains

We investigate the complexity of the satisfiability problem of constraints over finite totally ordered domains. In our context, a clausal constraint is a disjunction of inequalities of the form x≥d and x≤d. We classify the complexity of constraints based on clausal patterns. A pattern abstracts away from variables and contains only information about the domain elements and the type of inequalities occurring in a constraint. Every finite set of patterns gives rise to a (clausal) constraint satisfaction problem in which all constraints in instances must have an allowed pattern. We prove that every such problem is either polynomially decidable or NP-complete, and give a polynomial-time algorithm for recognizing the tractable cases. Some of these tractable cases are new and have not been previously identified in the literature.