Results 241 to 250 of about 2,157,914 (307)

BIFORE or Hadamard transform

IEEE Transactions on Audio and Electroacoustics, 1971
BIFORE or Hadamard transform is defined and several of its properties are developed. BIFORE power and phase spectra are developed and their frequency-sequency composition is explored. Using matrix partitioning, fast algorithms for efficient computation of BIFORE coefficients and power and phase spectra are developed.
N. Ahmed, K. Rao, A. Abdussattar
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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
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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.
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Discrete Pseudo-Fractional Hadamard Transform and its Fast Algorithm

IEEE Signal Processing Letters, 2020
In this paper a new discrete fractional transform for data vectors whose size $N$ is a power of two is proposed. The basic operation of the introduced transform is a discrete fractional Hadamard transform. Since the described transform is not a classical
D. Majorkowska-Mech, A. Cariow
semanticscholar   +1 more source

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

The Hadamard Transform in Statistics

1997
Use of the Hadamard transform, and the devisement of a fast algorithm for its implementation, goes back to Yates (1937) who used the transform to determine what factors were contributory in a factorial experiment, ie, to uncover the dependencies within a multivariable data set.
R. K. Rao Yarlagadda, John E. Hershey
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Large symmetric π transformations for Hadamard transforms

Applied Optics, 1983
Many multiplexing instruments utilize the fast Hadamard transform (FHT) to demultiplex the signal. In the past, the FHT includes the π1 and π2 transformations to reorder vectors before and after a Sylvester-type Hadamard transform. Although the computational effort involved in the π1 and the Sylvester-type Hadamard transform scales as n log2n ...
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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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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
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Lossless quantization of Hadamard transform coefficients

IEEE Transactions on Image Processing, 2000
This paper shows that an n x 1 integer vector can be exactly recovered from its Hadamard transform coefficients, even when 0.5 n log(2)(n) of the (less significant) bits of these coefficients are removed. The paper introduces a fast "lossless" dequantization algorithm for this purpose. To investigate the usefulness of the procedure in data compression,
Philips, Wilfried, Denecker, Koen, De Neve, Peter, Van Assche, Steven   +3 more
openaire   +3 more sources