Results 171 to 180 of about 35,175 (225)

Hadamard Transform Capillary Electrophoresis

Analytical Chemistry, 1999
This paper reports the first demonstration of a multiplex sample injection technique in capillary electrophoresis. The sample was injected into a capillary (effective length, 4 cm) as a pseudorandam Hadamard sequence by a photodegradation technique using a high-power gating laser, and the fluorescence signal, which was measured using a probe excitation
T, Kaneta, Y, Yamaguchi, T, Imasaka
openaire   +2 more sources

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

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
openaire   +2 more sources

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
openaire   +2 more sources

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
openaire   +2 more sources

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

High Resolution Hadamard Transform Spectrometer

Applied Optics, 1972
The ir spectrometer described employs alkaline halide lenses, an echelle grating, and a cryogenically cooled doped germanium bolometer as a detector. It is provided for two possible modes of operation: one is a single slit or conventional scan, the other is a multiplex or Hadamard scan.
Hansen, Peter, Strong, John
openaire   +2 more sources