scholarly journals Transverse Shape Analysis of Xylem Ground Tissues by the Fourier Transform Image Analysis: III. Shape reconstruction of earlywood tracheids in 22 species and some parameters for normalizing cell shapes

2005 ◽  
Vol 51 (4) ◽  
pp. 218-226 ◽  
Author(s):  
Yoko MIDORIKAWA ◽  
Minoru FUJITA
Keyword(s):  
Image Analysis ◽  
Fourier Transform ◽  
Shape Analysis ◽  
Shape Reconstruction ◽  
Cell Shapes ◽  
The Fourier Transform

scholarly journals Evaluation of Particle Orientation by the Fourier Transform Image Analysis.

1995 ◽  
Vol 44 (498) ◽  
pp. 267-272 ◽  
Author(s):  
Minoru FUJITA ◽  
Hiromu KAJITA ◽  
Tomoyuki MAEKAWA ◽  
Hiroshi SAIKI
Keyword(s):  
Image Analysis ◽  
Fourier Transform ◽  
Particle Orientation ◽  
The Fourier Transform

Measuring Fiber Orientation in Nonwovens Part III: Fourier Transform

1997 ◽  
Vol 67 (2) ◽  
pp. 143-151 ◽  
Author(s):  
B. Pourdeyhimi ◽  
R. Dent ◽  
H. Davis
Keyword(s):  
Image Analysis ◽  
Fourier Transform ◽  
Fiber Orientation ◽  
Image Analysis Technique ◽  
Tracking Method ◽  
Analysis Technique ◽  
The Fourier Transform ◽  
Simulated Images

This paper addresses the development of an image analysis technique using the Fourier transform of the image to evaluate orientation in a fibrous assembly. The algorithms are evaluated using simulated images presented in Part I of the series. The results are compared with those for the tracking method presented in Part II.

scholarly journals Strain Sensitivity Enhancement of Broadband Ultrasonic Signals in Plates Using Spectral Phase Filtering

2021 ◽  
Vol 11 (6) ◽  
pp. 2582
Author(s):  
Lucas M. Martinho ◽  
Alan C. Kubrusly ◽  
Nicolás Pérez ◽  
Jean Pierre von der Weid
Keyword(s):  
Fourier Transform ◽  
Guided Waves ◽  
Strain Level ◽  
Energy Concentration ◽  
Short Time Fourier Transform ◽  
Time Frequency ◽  
Frequency Representation ◽  
The Fourier Transform ◽  
Short Time ◽  
Sensitivity Gain

The focused signal obtained by the time-reversal or the cross-correlation techniques of ultrasonic guided waves in plates changes when the medium is subject to strain, which can be used to monitor the medium strain level. In this paper, the sensitivity to strain of cross-correlated signals is enhanced by a post-processing filtering procedure aiming to preserve only strain-sensitive spectrum components. Two different strategies were adopted, based on the phase of either the Fourier transform or the short-time Fourier transform. Both use prior knowledge of the system impulse response at some strain level. The technique was evaluated in an aluminum plate, effectively providing up to twice higher sensitivity to strain. The sensitivity increase depends on a phase threshold parameter used in the filtering process. Its performance was assessed based on the sensitivity gain, the loss of energy concentration capability, and the value of the foreknown strain. Signals synthesized with the time–frequency representation, through the short-time Fourier transform, provided a better tradeoff between sensitivity gain and loss of energy concentration.

Determination of starch crystallinity with the Fourier-transform terahertz spectrometer

2021 ◽  
Vol 262 ◽  
pp. 117928
Author(s):  
Shusaku Nakajima ◽  
Shuhei Horiuchi ◽  
Akifumi Ikehata ◽  
Yuichi Ogawa
Keyword(s):  
Fourier Transform ◽  
The Fourier Transform ◽  
Starch Crystallinity
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