Algebraic criteria for positive realness relative to the unit circle

A purely algebraic algorithm is developed for testing positive real character of real rational functions and matrices relative to the unit circle in the complex plane. Since the algorithm is entirely recursive and is performed in finite number of steps, it is suitable for machine computations.     

New approaches to positive observer design for discrete-time positive linear systems

This paper aims at providing new design approaches for positive observers of discrete-time positive linear systems based on a construction method of linear copositive Lyapunov function for positive systems. First, an efficient positive observer design approach is proposed by using linear programming such that the observer error system is exponentially stable. Furthermore, an interval observer design is proposed for uncertain positive systems. Then, the results are extended to positive time delay systems. In contrast with the previous design approaches, the new design method provides a general observer design with lower computational burden. Finally, three comparison examples are given to show the merit of the new design approach.     

代数偏微分方程组的对合特征集方法分析（英文）

基于Wu-Ritt特征集方法和V.Gerdt的对合除法, 我们定义了非线性偏微分方程组的关于一般延拓方向的对合特征集 (ICS). 影响ICS方法的两个主要因素为: 延拓方向和变量的序. 本文中, 应用ICS方法处理在计算偏微分方程组的对称群过程中产生的大型偏微分方程组. 在实验的基础上, 总结了对于ICS方法较好的延拓方向和变量的序.     

Some augmented approaches to the improved stability criteria for linear systems with time-varying delays

This work investigates the improved stability conditions for linear systems with time-varying delays via various augmented approaches. Some augmented approaches are augmented Lyapunov-Krasovskii functionals, augmented zero equalities, and the augmented zero equality approach. At first, by constructing augmented Lyapunov-Krasovskii functionals including the state vectors which were not considered in the previous works and augmented zero equalities, a stability criterion is proposed in the forms of linear matrix inequalities. Through the proposed Lyapunov-Krasovskii functionals and an additional functional derived from the integral inequality, a slightly improved result is derived. The proposed results do not consider the increase in the computational complexity to achieve a larger delay bound. So, by applying the augmented zero equality approach, which is a method of grafting the proposed augmented zero equality proposed in Finsler Lemma, to the proposed result, an enhanced stability result was derived. Also, the computational complexity is reduced by appropriately adjusting any vector of the integral inequality utilized in the proposed criteria. By applying some numerical examples to the proposed conditions, the effectiveness and superiority of the results are confirmed.     

Improved approaches to stability criteria for neural networks with time-varying delays

In this paper, the problem of stability analysis for neural networks with time-varying delays is considered. By the use of a newly augmented Lyapunov functional and some novel techniques, sufficient conditions to guarantee the asymptotic stability of the concerned networks are established in terms of linear matrix inequalities (LMIs). Three numerical examples are given to show the improved stability region of the proposed works.     

A novel approach to stability analysis for switched positive linear systems

This paper is concerned with exploring less conservative stability conditions for a class of switched positive linear systems. A switched matrix-parameterized copositive Lyapunov function (SMPCLF) is first introduced, where “matrix-parameterized” implies that the parameters of the constructed Lyapunov function are distributed in a matrix, which is different from the traditional vector-parameterized copositive Lyapunov function. Based on the proposed SMPCLF, a new stability criterion is derived for the underlying systems under arbitrary switching. Furthermore, by performing higher order relaxations in the SMPCLF and its time difference by positive states, the conservativeness can be further reduced. A numerical example is given to demonstrate the effectiveness and advantages of the obtained theoretical results.     

A universal unit for the electrical differential analyzer

This article describes an electromechanical unit which performs various mathematical operations occurring in the solution of differential equations by analog methods.     

Affine matched parameterization approach to sampled-data stabilization criteria for T-S fuzzy systems with variable sampling

This paper presents new parameterized sampled-data stabilization criteria using affine transformed membership functions for T-S fuzzy systems. To deal with the sampled control input having aperiodic sampling intervals, the proposed method adopts new looped functionals, and employs a modified free weighting matrix inequality. A relaxed condition for the controller design is derived by formulating the constraint conditions of the membership functions in the proposed controller with affinely matched weighting parameter vectors. Based on a newly devised lemma for handling affinely matched vectors, the stabilization and guaranteed cost performance criteria are given in terms of linear matrix inequalities (LMIs). The superiority of the presented method is demonstrated via significantly improved results in numerical examples.     

二次相对评价法在企业技术创新能力中的应用

给出了测算企业技术创新能力的二次相对评价法，首先利用层次分析法(AHP)测算综合指数状态，再用数据包络分析(DEA)方法中的BCC模型测算二次相对评价值；该方法消除了客观基础条件优劣的影响，从而可真正反映人的有效主观努力在增强企业技术创新能力中所起的作用。     

Inside the source selection process: Selection criteria for human information sources

Co-workers are an important source of information in organizations. Consequently, information managers seek to facilitate the use of such human information sources. Although various studies about what influences the use of human information sources in organizations exist, it is difficult for information managers to utilize insights from this research body. The studies have provided contradictory results regarding the role of accessibility and quality and suffer from various weaknesses. To address these weaknesses, several studies are employing other research methods. This study aims to contribute to the methodological development of this emerging new line of research by exploring the value of a think aloud approach to such studies. In addition, it aims to provide more insight into the role of accessibility and quality in the selection of human information sources in organizations. Fifty-six employees from four governmental organizations were asked to think aloud while selecting human information sources. The findings of this study corroborate those of studies taking a similar approach: source quality is the most dominant factor in the selection of human information sources. The think aloud approach seems a valuable contribution to available research methods to assess the role of accessibility and quality in human source selection in organizations.     

状态依赖时滞型微分方程正周期解的存在性

本文利用Krasnoselskii不动点定理,考虑了状态依赖时滞性微分方程x′(t) = &;#8722;A(t, x(t))x(t) + B(x(t))F(x(t &;#8722;  (t, x(t))))正周期解的存在性, 得到了该方程存在与不存在正周期解的充分条件.     

基于卓越绩效准则的企业动态管理模式研究

在动态管理模式研究的基础上,将卓越绩效评价准则引入到管理模式中,研究了基于卓越绩效准则的动态管理模式的构成,并对构成该模式的各子系统进行了描述,提出了卓越绩效动态管理模式系统运行效果的监控方式.