A comparative numerical study between the adaptive finite-impulse-response and Fourier transform techniques to monitor structural integrity

2015 ◽  
Vol 25 (4) ◽  
pp. 449-467 ◽  
Author(s):  
Matthew J Lamb ◽  
Vincent Rouillard
Keyword(s):  
Fourier Transform ◽  
Impulse Response ◽  
Structural Integrity ◽  
Finite Impulse Response ◽  
Numerical Study

The Spectra of Filters

2021 ◽  
pp. 204-268
Author(s):  
Victor Lazzarini
Keyword(s):  
Fourier Transform ◽  
Impulse Response ◽  
Discrete Time ◽  
Filter Design ◽  
Finite Impulse Response ◽  
Infinite Impulse Response ◽  
Main Body ◽  
Analysis Tool ◽  
The Fourier Transform ◽  
Definition Of

This chapter now turns to the discussion of filters, which extend the notion of spectrum beyond signals into the processes themselves. A gentle introduction to the concept of delaying signals, aided by yet another variant of the Fourier transform, the discrete-time Fourier transform, allows the operation of filters to be dissected. Another analysis tool, in the form of the z-transform, is brought to the fore as a complex-valued version of the discrete-time Fourier transform. A study of the characteristics of filters, introducing the notion of zeros and poles, as well as finite impulse response (FIR) and infinite impulse response (IIR) forms, composes the main body of the text. This is complemented by a discussion of filter design and applications, including ideas related to time-varying filters. The chapter conclusion expands once more the definition of spectrum.

Design of optimized finite impulse response digital filters for use with passive Fourier transform infrared interferograms

1990 ◽  
Vol 62 (17) ◽  
pp. 1768-1777 ◽  
Author(s):  
Gary W. Small ◽  
Amy C. Harms ◽  
Robert T. Kroutil ◽  
John T. Ditillo ◽  
William R. Loerop
Keyword(s):  
Fourier Transform ◽  
Impulse Response ◽  
Digital Filters ◽  
Finite Impulse Response ◽  
Fourier Transform Infrared

Signal Processing Techniques for Ultrasonic Waves to Measure Stresses in Oil Pipelines

2013 ◽  
Author(s):  
Paulo Pereira ◽  
Cleudiane S. Santos ◽  
Auteliano A. dos Santos
Keyword(s):  
Impulse Response ◽  
Structural Integrity ◽  
Finite Impulse Response ◽  
Ultrasonic Waves ◽  
Economic Losses ◽  
Infinite Impulse Response ◽  
Environmental Damage ◽  
Discrete Wavelet ◽  
Material Sources ◽  
Oil Pipelines

Ensuring the structural integrity of oil pipelines is vital to prevent environmental damage and economic losses. In that sense, it is important to know the magnitude of the stress in the pipe, which must be done using non-destructive techniques. Measuring stress using ultrasonic longitudinal critically refracted waves (LCR) has been applied to pipelines with very promising results. The technique is based on the acoustoelastic theory that relates speed variation of elastic waves traveling in the material with its state of strain. Nevertheless, the signals acquired from piezoelectric transducers in such application may show high levels of noise coming mainly from material sources (grain boundaries, irregularities). The noise makes the measurement of wave velocity difficult, resulting in imprecise evaluations of the stress in the pipeline. The aim of this study is to evaluate techniques for filtering digital signals of LCR waves propagating in an oil pipe fabricated with API 5L X70 steel. We analyzed the signal-to-noise ratio (SNR) of digitalized acquired signals in four circumstances: without treatment; signals treated with successive averages; treated with FIR (Finite Impulse Response) and IIR (Infinite Impulse Response) digital filters, and with the Discrete Wavelet Transform (DWT). The results show that the signals treated with DWT present better SNR compared to the other techniques.

Finite‐impulse‐response reduction‐to‐the‐pole filter

Geophysics ◽  
1998 ◽  
Vol 63 (6) ◽  
pp. 1958-1964 ◽  
Author(s):  
Richard S. Lu
Keyword(s):  
Fourier Transform ◽  
Frequency Response ◽  
Impulse Response ◽  
Fourier Transforms ◽  
Finite Impulse Response ◽  
Fir Filter ◽  
Data Set ◽  
Linear Convolution ◽  
Reduction To The Pole ◽  
Anomaly Map

Convolving a finite‐impulse‐response (FIR) filter with a magnetic anomaly map produces a reduction‐to‐the‐pole (RTP) that is superior to that of the conventional Fourier‐transform approach. The conventional approach, in which the map’s Fourier transform is multiplied by the frequency response of the RTP filter, is flawed by not accounting properly for the dimensions of the respective Fourier transforms. The resultant wraparound effect of circular convolution degrades the RTP map. The FIR filter, combined with linear convolution and appropriate choices for dimensions of data and filter, eliminates the wraparound effect, minimizes contamination of the result by noise, and improves stability. These properties are illustrated by a synthetic example and by application to an actual data set.

scholarly journals NANO-studio, the design environment of filter banks implemented in standard CMOS technology

2021 ◽  
Author(s):  
Andrzej Handkiewicz ◽  
Mariusz Naumowicz
Keyword(s):  
Impulse Response ◽  
Filter Banks ◽  
Finite Impulse Response ◽  
Infinite Impulse Response ◽  
Cmos Process ◽  
Digital Cmos ◽  
Additional Advantage ◽  
Analysis And Synthesis ◽  
Optimization Parameters ◽  
Synthesis Filter

AbstractThe paper presents a method of optimizing frequency characteristics of filter banks in terms of their implementation in digital CMOS technologies in nanoscale. Usability of such filters is demonstrated by frequency-interleaved (FI) analog-to-digital converters (ADC). An analysis filter present in these converters was designed in switched-current technique. However, due to huge technological pitch of standard digital CMOS process in nanoscale, its characteristics substantially deviate from the required ones. NANO-studio environment presented in the paper allows adjustment, with transistor channel sizes as optimization parameters. The same environment is used at designing a digital synthesis filter, whereas optimization parameters are input and output conductances, gyration transconductances and capacitances of a prototype circuit. Transition between analog s and digital z domains is done by means of bilinear transformation. Assuming a lossless gyrator-capacitor (gC) multiport network as a prototype circuit, both for analysis and synthesis filter banks in FI ADC, is an implementation of the strategy to design filters with low sensitivity to parameter changes. An additional advantage is designing the synthesis filter as stable infinite impulse response (IIR) instead of commonly used finite impulse response (FIR) filters. It provides several dozen-fold saving in the number of applied multipliers.. The analysis and synthesis filters in FI ADC are implemented as filter pairs. An additional example of three-filter bank demonstrates versatility of NANO-studio software.

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