Bicriterial Design of Digital Filters

A problem of technical interest is the solution of approximation problems which make a tradeoff between the L ₂ norm and the L norm error criteria. This problem is investigated in the framework of filter design with respect to two conflicting optimality goals. The particular interest in L ₂-L norm compromise filters has been raised by a paper of Adams (IEEE Trans. on Circuits and Systems vol. 39, pp. 376–388, 1991), who suggested to compute such FIR filters by solution of certain constrained L ₂ approximation problems which require a proper choice of weights. It is shown in this paper that bicriterial filter design problems can be approached by classical methods from multicriteria optimization and that especially reference point approximation with the ideal point as reference point is a suitable tool to deal with Adams' problem. Solutions from this latter approach do especially not depend on the choice of weights and yield the best possible compromise filters with respect to a prescribed measure. The resulting optimization problems can be solved with (semi-infinite) programming methods having proven convergence under standard assumptions. Examples of L ₂-L norm compromise designs of a linear-phase FIR and an IIR filter are presented.     

自适应跟踪数字陷波滤波器的设计与应用

本文采用自适应跟踪数字陷波滤波器自动跟踪被测信号中干扰信号的频率 ,并利用该频率设计相应的数字陷波滤波器去除被测信号中的干扰信号。试验表明 ,该方法具有设计简单、应用方便、实时性强等特点 ,可以有效去除被测信号中频率缓慢变化的干扰信号     

光学薄膜的数字滤波器设计方法

本文给出利用数字滤波器的设计方法设计光学薄膜的具体过程.由数字滤波器设计软件,按照光学薄膜的设计要求给出光学薄膜目标谱传递函数,将光学薄膜传榆矩阵表示为格型数字滤波器传输矩阵的数学形式,导出等光学厚度光学薄膜传递函数的递归关系式.利用光学薄膜传递函数递归关系,采用剥层算法计算出各膜层的折射率,得到满足目标谱传递函数的膜...     

图片彩色参数数字滤波设计

颜色和形状信息是识别物体的重要信息．本文提出用数字滤波器将图象空间分割为H包含M和M/H空间的一种方法．该方法进一步将分析彩色图象为众所周知的测量分割部分几何特征的算法，包括通过节点的阶数确定分割部分的分布及动态特征，包括速度和移动方向的分布等．     

A Technique for Synthesizing Digital Filters

In designing digital systems, one often faces the task of replacing a given analog filter by an equivalent digital filter. This paper proposes a method for synthesizing such digital filters in the time domain. It is assumed that the pulsed transfer function of the digital filter is a ratio of two rational polynomials. The coefficients are then determined by least-square fitting the digital filter to the analog filter's sampled input and output data. The resulting equations for computing the coefficients are linear. It is shown that the digital filter is essentially related to the analog filter, the sampling time, and the power spectrum of the signal being processed. If the signal is band-limited and the sampling frequency is sufficiently high, the digital filter can then be simply approximated by the Z transform of the analog filter multiplied by the sampling period.     

包络检波的数字滤波算法

介绍了用包络分析技术诊断设备零件损伤类故障的原理，提出用一对垂直数字滤波器进行垂直滤波分解，将传统包络分析中信号的窄带带通滤波和包络检波过程合二为一，算法具有较强的实时性，另外包络分析信号的长度也不受限制。     

有源模拟滤波器的MATLAB辅助设计方法

在简要概述传统有源模拟滤波器设计方法的同时给出利用MATLAB进行有源模拟滤波器设计的方法,通过对有源模拟滤波器两种设计方法关键步骤的比较,给出了MATLAB能有效地简化有源模拟滤波器设计的结论。结合有源模拟滤波器的特性,给出了零极点分配原则和级联原则;同时介绍了如何用MATLAB给出滤波器总体和局部幅/相频特性,为滤波器调试提供了参考。通过设计实例,验证了本文提出的设计方案的便捷性、直观性、可行性。     

畸变不变空间滤波器的理论设计

本文给出畸变不变空间滤波器的一种理论设计。使用这个空间滤波器,可以实现平移、旋转、比例和强度不变模式识别。     

Design of Trimmingless Narrowband Planar HTS Filters

The use of high temperature superconductor (HTS) films provides a higher selectivity of planar filters. The lower out-of-band interference increases the sensitivity of receiving systems and allows reduction of transmitter radiated power. Our goal was to show how these filters can be designed with a desired accuracy, and to give evidence for a real possibility of designing the trimmingless planar HTS filters. The analysis of filter performance is based on accurate models of the characteristics of the HTS planar transmission lines. The HTS film and substrate characteristic tolerance sensitivity is investigated. The design procedure of the trimmingless filter is proposed. Mass production of such filters requires a specific certification of the substrate materials and HTS films used.     

Approximate Design of Alloy Composition of Cathode Target

An empirical formula for composition demixing analysis in cathodic arc ion plating using alloy target is established based on the concepts of average charged state and relative demixing parameter. The level of composition demixing effect is presented by demixing degree of one element. For binary constituent alloy target, the composition change trend in coating is discussed and the limit of demixing degree for each element is determined. The content of one element with higher average charged state gets larger in coating than in alloy target, at meantime, the content of one element with lower average charged state gets less. For each one of the two constituents, the less the atom percent in alloy target, the larger the difference of its contents between the coating and the target. For triple constituent alloy target, the content change of one element with moderate average charged state is discussed in detail. Its content in coating getting larger or less is determined by the combination result of the contents of the other two elements in alloy target. For a given content of the element with moderate average charged state in triple alloy target, the content deviation level of that element from coating to alloy target will be not larger than that using binary alloy target containing only that element and one of the two others. According to the wanted coating composition, the composition design of alloy target is easily deduced from the formula.     

Approximate Model Spaces for Model-Robust Experiment Design

Optimal designs depend upon a prespecified model form. A popular and effective model-robust alternative is to design with respect to a set of models instead of just one. However, model spaces associated with experiments of interest are often prohibitively large and so algorithmically generated designs are infeasible. Here, we present a simple method that largely eliminates this problem by choosing a small set of models that approximates the full set and finding designs that are explicitly robust for this small set. We build our procedure on a restricted columnwise-pairwise algorithm, and explore its effectiveness for two model spaces in the literature. For smaller full model spaces, we find that the designs constructed with the new method compare favorably with robust designs that use the full model space, with construction times reduced by orders of magnitude. We also construct designs that heretofore have been unobtainable due to the size of their model spaces. Supplementary material (available online) includes code, designs, and additional results.     

Bayesian Design of Experiments Using Approximate Coordinate Exchange

The construction of decision-theoretical Bayesian designs for realistically complex nonlinear models is computationally challenging, as it requires the optimization of analytically intractable expected utility functions over high-dimensional design spaces. We provide the most general solution to date for this problem through a novel approximate coordinate exchange algorithm. This methodology uses a Gaussian process emulator to approximate the expected utility as a function of a single design coordinate in a series of conditional optimization steps. It has flexibility to address problems for any choice of utility function and for a wide range of statistical models with different numbers of variables, numbers of runs and randomization restrictions. In contrast to existing approaches to Bayesian design, the method can find multi-variable designs in large numbers of runs without resorting to asymptotic approximations to the posterior distribution or expected utility. The methodology is demonstrated on a variety of challenging examples of practical importance, including design for pharmacokinetic models and design for mixed models with discrete data. For many of these models, Bayesian designs are not currently available. Comparisons are made to results from the literature, and to designs obtained from asymptotic approximations. Supplementary materials for this article are available online.     

A Novel Single-Multiplier Implementation of IIR and FIR Digital Filters Using Tri-State Logic

A new implementation of digital FIR and IIR filters which takes advantage of the availability of tri-state logic for modularity and extensibility is outlined. The filter is a time-based design and uses a single multiplier. The sequence of operations for a second-order IIR filter with such an implementation is illustrated with the aid of a block diagram.     

Design of a Mechanical Tuning for Superconducting Microwave Power Filters

We have been studying microwave superconducting power filters with dynamic tunable mechanism. This paper reports estimation of superconducting microstrip patch resonators using piezoelectric actuators as parts of the electrically tunable mechanism. We carried out electromagnetic (EM) simulations on the proposed tunable patch resonators. The main conditions of the EM simulations were that the superconducting material was YBCO, the patch pattern with TM₁₁ or TM₀₁-resonant mode was disk shape, and so on. From the EM simulation results, it was estimated that the resonant mode differences of the unloaded-Q, the power handling capability, and the resonant frequency tunability related with the PZT bimorph element as the actuator candidate.     

包装设计与数字化的设计手段

论述了在数字化技术的支持下,产品包装设计的设计方法与程序,探讨了以Pro/Engineer等多种设计软件在包装设计中的介入,以某消毒剂产品的包装设计为实例,说明了塑料包装设计构思及应用数字化技术的设计过程,以及产品包装设计的发展趋势.     

A Simple Method for Design of Adaptive Filters for Sinusoidal Signals

Filtering of input signals in algorithms for measurement of power system electrical parameters is very important. Filters are used to minimize the noise effect and eliminate the presence of higher order harmonics. In addition to that, a number of measurement algorithms apply orthogonal signal components obtained by two orthogonal finite-impulse response filters. The frequency response of the filters must have nulls at the higher order harmonic frequencies that are expected to be present in the signal and must have a unity gain at the main harmonic frequency. In the case of a time-varying frequency, the filter parameters have to be adapted during frequency estimation. In this paper, a simple method for online design of digital filters for sinusoidal signals is proposed. It is based on closed-form solutions for calculating filter coefficients. A simple linear algorithm for frequency estimation was used, and a derived algorithm for online adaptation of the filter coefficients is computationally very efficient. The number of subsections in the cascade and data window lengths can also be changed, depending on the frequency variations during measurement.      

适用于微机电系统的自适应红外探测器的可调谐滤光器设计与开发

微机电系统与高品质红外探测技术联合运用为国防、商业、通信、生物医学检测及环境监测等许多应用领域面临的一系列具有挑战性的问题提供了唯一可行的解决方案．可调谐法布里．玻罗滤光片是适用于微机电系统的红外探测器的核心部件．滤光片的结构设计和关键结构件的材料对于滤光片的性能和整个装置的完善性有重要影响．阐述了利用有限元建模进行法布里-玻罗滤光片机械设计和分析的方法．报告了滤光片的结构材料——用低温等离子增强化学沉积法制造的氮化硅的结构表征和机械性能测定方法和结果．最后展示了一些所制作的滤光片阵列．