A new excitation scheme for closed-loop subspace identification using additional sampling outputs and its extension to instrumental variable method

It is known that feedback from outputs to inputs causes non-identifiability in many subspace identification algorithms. In this paper, a new excitation method is proposed for closed-loop subspace identification. By adding an output sampling point within two adjacent control times, a difficult closed loop identification issue is recast into an open loop identification. Uncorrelation between the process inputs and the noises in closed loop is obtained, and the persistently exciting condition is proven to be satisfied based on spectral analysis and innovation state space models so that the consistent estimates with no demand for external exciting signals can be guaranteed. Simultaneously, the additional sampling scheme offers different selections of instrumental variables for the non-error-in-variable case and the error-in-variable case in some instrumental variables-based identification algorithms. A simulation is performed to test the identification efficiency of the new scheme.     

A new set of orthogonal functions and its application to the analysis of dynamic systems

The present work proposes a complementary pair of orthogonal triangular function (TF) sets derived from the well-known block pulse function (BPF) set. The operational matrices for integration in TF domain have been computed and their relation with the BPF domain integral operational matrix is shown. It has been established with illustration that the TF domain technique is more accurate than the BPF domain technique as far as integration is concerned, and it provides with a piecewise linear solution.As a further study, the newly proposed sets have been applied to the analysis of dynamic systems to prove the fact that it introduces less mean integral squared error (MISE) than the staircase solution obtained from BPF domain analysis, without any extra computational burden. Finally, a detailed study of the representational error has been made to estimate the upper bound of the MISE for the TF approximation of a function f(t) of Lebesgue measure.     

A new feat of powerful laser system

CAS physicists have recently developed an intense femtosecond (fs) laser system with a peak output power     

A new feat of powerful laser system

CAS physicists have recently developed an intense femtosecond (fs) laser system with a peak output power of more than 350 TW. Dubbed Jiguang-Ⅲ (or XLite-Ⅲ), the work passed the acceptance check by a 10-member panel of experts under the auspices of CAS on last 27December. It was regarded as one of the best results of its kind in open literature so far.     

A new approach for constrained chaos synchronization with application to secure data communication

In this paper, a new technique is introduced for chaos secure data communication. In this approach, in addition to the usually used techniques for data encryption, the concept of carrier encryption is introduced to increase the security level of the secure communication scheme. To fulfill this objective, at the transmitting end, two chaotic oscillators are coupled, and a set of inequality time dependent constraints with time dependent bounds is imposed on the generated chaotic signals. Moreover, to increase system complexity and its security level, the imposed set of constraints and their bounds are allowed to be changeable from one time period to another during the transmission process. As a result, the patterns of the generated chaotic signals are completely changed and the chaotic oscillator is completely encrypted. At the receiving end, the newly developed Constrained Smoothed Regularized Least Square (CSRLS) observer is used to synchronize the received constrained chaotic signals and hence retrieve the transmitted data. Using such an approach, the quality of the received information, measured by the Bit Error Rate (BER), is highly improved due to the superior performance of the developed CSRLS observer. The stability of the observer is analyzed, and simulation results are presented to show the efficiency and effectiveness of the proposed secure communication scheme.     

基于点阵码的新型人机互动方式及应用

点阵码是以信息编码和图像处理为核心的基础信息技术,基于点阵码的新型人机互动方式是服务于"智慧城市"的一项新技术。文章对点阵码的分类、特点、现状进行了研究归纳,重点阐述Grid Onput点阵码技术。进而将之与电子射频标签技术进行比较,并提出基于Grid Onput点阵码的UU-POINT技术在电子书包、防伪溯源等领域创新性的应用实例。最后对基于点阵码的新型人机互动方式做出展望。     

On rectangular systems of differential equations and their application to circuit theory

A system of differential equations A(d/dt) x = Bx+f, along with the initial condition x(0) = k, is considered where A and B are m x n matrices. Generalized inverses of the matrix A are used to derive algebraic conditions for the existence and uniqueness of a solution. An example is presented to illustrate application of the results to circuit theory.     

A Zipfian model of an automatic bibliographic system: an application to MEDLINE.

A Zipfian model of an automatic bibliographic system is developed using parameters describing the contents of it database and its inverted file. The underlying structure of the Zipf distribution is derived, with particular emphasis on its application to work frequencies, especially with regard to the inverted flies of an automatic bibliographic system. Andrew Booth developed a form of Zipf's law which estimates the number of words of a particular frequency for a given author and text. His formulation has been adopted as the basis of a model of term dispersion in an inverted file system. The model is also distinctive in its consideration of the proliferation of spelling errors in free text, and the inclusion of all searchable elements from the system's inverted file. This model is applied to the National Library of Medicine's MEDLINE. The model carries implications for the determination of database storage requirements, search response time, and search exhaustiveness.     

一种面向服务的数字校园体系结构

基于Web服务技术,针对信息孤岛问题设计了数字校园的面向服务应用集成平台,实现服务即插即用的同时,利用事件模型作为对应用集成过程进行流程级管理,从而实现对业务过程的集成,提供应用集成个性化门户服务,实现统一用户与权限管理,提供了一个强大的扩展平台,提高用户使用校园内各种应用系统的体验。     

一种新的产业集聚分类方法及其在江苏特色产业集聚中的应用研究

首先对已有产业集聚分类成果进行综述.接着从增强微观企业竞争力的角度,提出了一种新的产业集聚分类方法;这种新的分类包括五种类型,每种类型的划分依据是其主要形成条件.随后,将提出的分类方法应用于江苏特色产业基地的分析,应用结果表明提出的分类方法具有简约、实际指导的和针对性强的特点.最后,提出了推进产业集聚的若干政策建议.     

Multiple summation inequalities and their application to stability analysis of discrete-time delay systems

This paper is devoted to stability analysis of discrete-time delay systems based on a set of Lyapunov–Krasovskii functionals. New multiple summation inequalities are derived that involve the famous discrete Jensen?s and Wirtinger?s inequalities, as well as the recently presented inequalities for single and double summation in [16]. The present paper aims at showing that the proposed set of sufficient stability conditions can be arranged into a bidirectional hierarchy of LMIs establishing a rigorous theoretical basis for the comparison of conservatism of the investigated methods. Numerical examples illustrate the efficiency of the method.     

新型数据库(PowerBuilder)在计量管理中的应用

使用企业级数据库前端开发工具PowerBuilder，对某企业计量管理系统进行了改造，证明使用PB这种面向对象编程的新型数据库系统的快速与方便，实现的计量管理系统既准确又稳定，提高了企业的经济效益。     

从专利申请看城市的技术创新与新技术发展——以江苏省无锡市为例

通过对1998—2008年无锡市专利申请情况的统计分析,发现无锡市近十年来专利申请总量及发明专利申请比例均迅速提高,专利构成得到了优化;对无锡市专利申请的IPC分布情况进行了统计分析,得出无锡市技术创新能力的强势区为作业、运输、机械、化工、生活需要等方面,而纺织、建筑、物理、电技术等是其弱势区;根据专利申请的总体情况,从宏观上分析了无锡市新技术的发展趋势;最后对无锡市如何进一步完善科技创新体系以不断促进其技术创新与发展提出了具体的措施。