Recursive identification for EIV ARMAX systems

The input u _k and output y _k of the multivariate ARMAX system A(z)y _k = B(z)u _k + C(z)w _k are observed with noises: u _k ^ob ≜ u _k + ε _k ^u and y _k ^ob ≜ y _k + ε _k ^y , where ε _k ^u and ε _k ^y denote the observation noises. Such kind of systems are called errors-in-variables (EIV) systems. In the paper, recursive algorithms based on observations are proposed for estimating coefficients of A(z), B(z), C(z), and the covariance matrix Rw of w _k without requiring higher than the second order statistics. The algorithms are convenient for computation and are proved to converge to the system coefficients under reasonable conditions. An illustrative example is provided, and the simulation results are shown to be consistent with the theoretical analysis.     

工业数据挖掘中应用最小二乘法的缺陷

工业数据建模常常使用最小二乘法进行参数估计,在数据满足一定条件的前提下,可得到被估计参数的无偏估计值。但是工业数据一般含有测量误差,当基于误差数据作为自变量进行最小二乘回归时,得到的参数估计值往往是有偏的,其结果不能正确反映数据变量之间的结构关系。因此,对二元变量模型进行了深入分析,通过对测量误差进行合理假设,建立了在统计意义下被估计参数真值与测量误差和参数有偏估计值之间的解析关系式,为进一步参数校正奠定了理论基础。仿真实例表明了该方法的有效性。     

基于叩齿声音的身份确认方法

为了克服语音身份确认中语音分割、特征提取和鲁棒性差的困难,文中分析叩齿声音波形特性,提出一种利用叩齿声音进行身份确认的方法。使用二阶微分方程建立齿震动发声的近似模型,以此为基础提出基于叩齿声音信号的身份确认方法。实验结果表明,叩齿声音信号稳定性强,处理复杂度低于声纹信号,应用于身份识别性能优良。该方法和经典的支持向量机、最近邻算法相比,运算量低,所需训练样本少。     

闭环变量带误差系统的控制器设计

针对目前大多数系统的研究中,只考虑输出被误差干扰的情况,提出了一种闭环变量带误差系统模型(输入和输出信号均被噪声干扰),并对该系统的控制器进行设计。采用最小方差控制来对控制器进行设计,设计完成最小方差控制器以及自校正最小方差控制器。然后应用最小方差性能指标来评估控制器性能,并通过仿真验证控制器性能。     

热电偶动态响应的带外部输入自回归模型

热电偶测量动态温度受到热电偶自身动态特性的制约和影响。为了评价热电偶的动态特性,建立了一种双气流环境下的热电偶动态响应实验系统,测量热电偶在两种不同温度气流交替激励下的响应。由于激励温度本身也存在测量误差,当用回归方法分析热电偶响应过程时,响应过程构成了一种变量带误差问题。为了获得热电偶动态响应的无偏估计,建立了热电偶动态响应的状态空间方程,用随机扰动与确定性模型结合的方式描述热电偶动态响应过程,采用一种带外部输入自回归模型对响应过程进行辨识。以一种工业中常用的露端式镍铬镍硅热电偶为对象,给出了一个算例。实验和计算结果表明,带外部输入自回归模型适用于双气流环境下热电偶动态响应能力的评价。     

Basic program for identification of an unknown with presence-absence data against an identification matrix of percent positive characters

A program named MATIDEN in BASIC is given for online computer-assisted identification of an unknown sample scored for presence-absence properties. The properties of the unknown are input at a terminal. They then are compared with a previously prepared identification matrix that contains the percentage of positives for each property in each of the groups to which the unknown might belong. It is not necessary to enter all properties: the program will determine the best identities of a sample with incomplete data.The program calculates the identification scores of the unknown against the groups, and offers a choice of five polythetic identification coefficients: (1) Willcox probability, (2) taxonomic distance, (3) standard error of this distance, (4) the Gaussian integral corresponding to this standard error, and (5) pattern distance.The best identifications are printed with their scores, followed by properties in which the unknown is atypical. These are followed by additional properties (that have not been scored for the unknown) which assist in separating the best identification from the next best alternatives, thus permitting rerunning with additional properties scored.Brief discussion of interpretation of the results also is given.     

Identification of EIV models by compensated PEM

This paper deals with identification of discrete-time errors-in-variables models where the input and output data are both perturbed by different additive noises. The goal is to study the effects of input noise on the model which is estimated based on the prediction error method. The obtained model is then improved by modifying the results and implementing the instrumental variable method. It is proved that the identification of the errors-in-variables models based on the proposed approach could result in an unbiased estimation in the presence of independent colour noises on the input and output data with adequate accuracy and mediocre complexity.     

System of personal identification by using tactile stimuli

This paper proposes a personal identification system that uses tactile stimuli. Recently, scientists have been conducting research in biometrics using biomedical information. However, there is the problem that biomedical information is unchangeable. For example, if a thief steals another user’s biomedical information, that person has no information to register. Due to the problems of sight information and unchangeable biomedical information, we propose a solution that uses the sense of tactile stimuli. Tactile information is difficult to steal and relies on human memory, which is unchangeable. This paper proposes a system that uses a pattern formed by a tactile stimuli time series instead of a password number as the identification key. We also discuss the results of an identification experiment and a memory property experiment. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Triggering of Cathode or Emitter Coupled Univibrators Connected into a Chain†

The possibility of direct triggering of one cathode or emitter coupled univibrator by the differentiated cathode or emitter voltage jump of the other is discussed and analysed, for univibrators connected into a chain. Simple approximate relations are derived for the univibrator optimum trigger pulse nominal threshold voltage and for the maximum permissible deviation from their nominal parameters, which show that this way of triggering is suitable both for transistor and for tube circuits.     

Identification of EIV models with coloured input–output noise: combining PEM and covariance matching method

In this paper, a novel identification method for discrete-time linear systems when input–output observations are contaminated by coloured noise (errors-in-variables models) is proposed. To develop the new approach, modified prediction error and covariance matching methods are utilised. It is proved that the proposed approach leads to a consistent estimation. System identification through the proposed approach entails the existence of a flat frequency interval in power spectra of input and ratio of noise-free input to input signals which is a somewhat mild assumption. Two Monte Carlo simulations are provided to explain the efficiency, numerical complexity and the application of the proposed method.     

指纹识别及 PDF417二维码在考试管理中的应用

从我国美术专业招生考试实际情况出发,结合指纹识别和二维条码技术的各自特点和优势,将其应用在考试身份验证中,实现符合美术招生考试要求的身份验证模型。简要来说就是利用二维条码的信息存储能力及防伪特性,将考生的各类信息包括指纹特征信息存储在条码图形中,通过条码识别设备和指纹采集设备,将现场采集的考生指纹信息与条码中存储的信息进行比对,以此来确认考生身份的真假。     

指纹识别技术在电子商务认证系统中的应用

本文在简单介绍生物识别技术的基础上,着重介绍了生物识别技术中指纹识别技术在电子商务认证系统中的应用,包括指纹识别技术的优势、原理以及指纹识别技术在电子商务认证系统中应用时的要求、原理和实施步骤等。     

Basic program for determining the best identification scores possible from the most typical examples when compared with an identification matrix of percent positive characters

A BASIC program entitled MOSTTYP is given for evaluation of the quality of identification matrices by calculating the best identification scores that an entirely typical example of each group could achieve. The program is intended to supplement the method of identification of unknowns with presence-absence properties by comparison with a matrix of percent positive characters.     

基于模糊辨识算法的蓄电池荷电状态测量方法与模块设计

针对蓄电池荷电状态在线监测中对准确度和测量速度的要求,本文提出采用模糊辨识算法对蓄电池进行系统辨识。并通过对蓄电池的荷电状态与内阻、端电压数据的分析,建立了蓄电池荷电状态的模糊规则模型,并以此进行蓄电池荷电状态的测量,得到均方误差为0.0052。测量结果表明基于模糊辨识算法的蓄电池荷电状态测量能够满足蓄电池在线监测的要求,且易于硬件实现。文章还使用DSP Builder设计了蓄电池荷电状态测量模块,其中内阻测量采用了特征分解谱估计的信号提取方法,荷电状态测量则实现了模糊辨识算法所得出的模糊规则模型的运用。     

Basic program for printing a coding sheet for unknowns that are to be identified against an identification matrix of percent positive characters

A BASIC program is given, entitled IDEFORM, that prints a coding sheet for use in computer-assisted identification. The coding sheet is intended for use with the program MATIDEN by which unknowns scored for presence-absence properties or characters are compared with an identification matrix of percent positive characters of a number of groups or taxa. The coding sheet is prepared from the particular identification matrix for use with that matrix.