Results 211 to 220 of about 2,149,393 (281)

Fourier Transform vs Hadamard Transform Spectroscopy

Applied Optics, 1973
Recent articles have claimed a significant S/N advantage of Hadamard transform spectroscopy over Fourier transform spectroscopy. The scanty published data does not support this assertion, and the possibility that the claim is valid in theory is examined.
T, Hirschfeld, G, Wyntjes
openaire   +2 more sources

Hadamard transform spectroscopy

Journal of Optics, 1992
The authors show the ability to record simultaneously several lines with a single channel detector and to increase the signal to noise ratio thanks to Hadamard transform techniques. A 63 element mask is used to encode neon spectral emission in the range 580-650 nm.
A Chapput, J Barbillat, C Allet
openaire   +1 more source

Adaptive fast Walsh-Hadamard transform for magnetic flux leakage signal of broken wire damage extraction under noise background

Nondestructive Testing and Evaluation
Steel wire rope usually works in harsh environments, making it prone to damage during frequent use. Magnetic flux leakage testing is an important way of non-destructive testing, preventing some major accidents of hoist equipment by identifying the damage
Shengping Huang, Zhongqiu Wang, Jianhua Yang, Tao Gong, Zhen Shan, Yan Yang   +5 more
semanticscholar   +1 more source

Cal-sal Walsh-Hadamard transform

IEEE Transactions on Acoustics, Speech, and Signal Processing, 1978
Walsh-Hadamard matrices are rearranged such that the first half of the rows represents cal functions in increasing order of sequency whereas the second half represents sal functions in decreasing order of sequency. The transform based on this rearrangement is called the Cal-Sal Walsh-Hadamard transform or (WHT) cs .
Rao, K. R., Devarajan, V., Vlasenko, V., Narasimhan, M. A.   +3 more
openaire   +2 more sources

Hadamard–Transform Image Scanning

Applied Optics, 1970
We point out the applicability of optical Hadamard-transform coding to detector-noise-limited image scanning and give approximate signal-to-noise ratio gains over conventional point-by-point scanning for several whole-image multiplex scanning schemes.
openaire   +2 more sources

Hadamard Transform Ion Mobility Spectrometry

Analytical Chemistry, 2006
A detection scheme that makes use of the Hadamard transform has been employed with an atmospheric-pressure ion mobility spectrometer fitted with an electrospray ionization source. The Hadamard transform was implemented through the use of a linear-feedback shift register to produce a pseudorandom sequence of 1023 points.
Andrew W, Szumlas, Steven J, Ray, Gary M, Hieftje   +2 more
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Hadamard Transform Ion Mobility Spectrometry

Analytical Chemistry, 2005
Traditionally, the spectrum acquired using ion mobility spectrometry (IMS) is an average of multiple experimental cycles. Each cycle is initiated by passing a short burst of ions into a drift tube containing a homogeneous electric field. Prior to starting the subsequent cycle, all ions in the system must arrive at the detector or spectral overlap may ...
Brian H, Clowers, William F, Siems, Herbert H, Hill, Steven M, Massick   +3 more
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Simulating, Predicting, and Minimizing False Peaks for Hadamard Transform Ion Mobility Spectrometry.

Journal of the American Society for Mass Spectrometry, 2020
Multiplexing techniques, including the Hadamard Transform, are widely used in the recovery of weak signals from high-level noise. Hadamard transform ion mobility spectrometry (HT-IMS), however, can suffer serious drawbacks due to false peaks. False peaks
Jianna Yu, Guoxing Jing, Wenshan Li, Wenjie Liu, Okonkwo Juliet Nwadiuso, Wenjie Liu, H. Hill   +6 more
semanticscholar   +1 more source

Modified Hadamard transform microchip electrophoresis

ELECTROPHORESIS, 2005
AbstractSensitivity is a crucial point in the development applications for medicine or environmental samples in which the analytes are present in the nanomolar range. Besides further technical development of detection systems, the multiplex sample injection technique can be applied for enhancing the signal‐to‐noise ratio.
Renato, Guchardi, Maria A, Schwarz
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Real-Time Walsh-Hadamard Transformation

IEEE Transactions on Computers, 1972
A technique for obtaining the digital Walsh-Hadamard transform of two-dimensional discrete pictures in real time is presented. A considerable reduction in total time for the transformation of a picture results since the process of scanning and digitizing one picture line overlaps with computations on the previous line. This is accomplished by operating
Alexandridis, Nikitas A., Klinger, Allen
openaire   +1 more source