نتایج جستجو برای: signal saturation correction filter

تعداد نتایج: 720932  

Journal: :iranian journal of nuclear medicine 2007
kourosh ebrahim nejad gorgi hossein rajabi ebrahim hajizadeh faraz kalantari hadi taleshi

introduction: there are several technical features that make pet an ideal device for the noninvasive evaluation of cardiac physiology. organ motion due to respiration is a major challenge in diagnostic imaging, especially in cardiac pet imaging. these motions reduce image quality by spreading the radiotracer activity over an increased volume, distorting apparent lesion size and shape and reduci...

2015
Lin-Tao Duan Bing Guo Yan Shen Ji-He Wang Wen-Li Zhang

Organic Light Emitting Diode (OLED) displays have matured into current smartphones. How to prolong the lifetime of displays while preserving the display quality becomes a primary issue. In this paper, we propose a low image distortion constrained power-saving approach for OLED displays based on gamma correction and saturation scaling. We first investigate the impact of gamma correction and satu...

2016
K Shafqat P A Kyriacou R M Langford

The oesophagus has been found to be a reliable monitoring site for blood oxygen saturation (SpO2) in anaesthetised patients. Despite it being a very well perfused organ, it was not possible to estimate SpO2 in the lower to deep oesophagus due to movement artefact caused by the mechanical ventilator. This limitation made the measurements more difficult since the probe had to be placed carefully ...

2004
Peter Singerl Christian Vogel

Wireless communication receivers work with radio frequency (RF) input signals with a huge dynamic range of 50dB and more. In order to provide the analog-to-digital converters (ADCs) in the receivers with an optimal signal strength, the gains of the RF and IF (intermediate frequency) stages have to be tuned according to the strength of the RF input signal. The RF input signal strength can be est...

2015
Robert A. Corns Vicky W. Huang Steven D. Thomas

Flattening filter-free radiation beams have higher dose rates that significantly increase the ion recombination rate in an ion chamber's volume and lower the signal read by the chamber-electrometer pair. The ion collection efficiency correction (P(ion)) accounts for the loss of signal and subsequently changes dosimetric quantities when applied. We seek to characterize the changes to the percent...

2015
Jacob U. Fluckiger Brandon C. Benefield Lara Bakhos Kathleen R. Harris Daniel C. Lee

OBJECTIVES To evaluate the impact of correcting myocardial signal saturation on the accuracy of absolute myocardial blood flow (MBF) measurements. MATERIALS AND METHODS We performed 15 dual bolus first-pass perfusion studies in 7 dogs during global coronary vasodilation and variable degrees of coronary artery stenosis. We compared microsphere MBF to MBF calculated from uncorrected and correct...

Journal: :Journal of theoretical biology 2006
Serge Smidtas Vincent Schächter François Képès

In the yeast Saccharomyces cerevisiae, the interplay between galactose, Gal3p, Gal80p and Gal4p determines the transcriptional status of the genes required for galactose utilization. After an increase in galactose concentration, galactose molecules bind onto Gal3p. This event leads via Gal80p to the activation of Gal4p, which then induces GAL3 and GAL80 gene transcription. Here we propose a qua...

Journal: :iranian journal of basic medical sciences 0
shabnam oloomi department of medical physics, mashhad university of medical science, mashhad, iran hadi noori eskandari department of applied mathematics, school of mathematical sciences, ferdowsi university of mashhad, mashhad, iran seyed rasoul zakavi nuclear medicine research center, imam reza hospital, faculty of medicine, mashhad university of medical sciences, mashhad, iran peter knoll department of nuclear medicine wilhelminenspital vienna, austria faraz kalantari research center for nuclear medicine, tehran university of medical sciences, tehran, iran mohsen hajizadeh saffar department of medical physics, mashhad university of medical science, mashhad, iran

objective(s): in spect, the sinogram contains scatter and lack of attenuated counts that degrade the reconstructed image quality and quantity. many techniques for attenuation and scatter correction have been proposed. an acceptable method of correction is to incorporate effects into an iterative statistical reconstruction. here, we propose new maximum likelihood expectation maximization (mlem) ...

In this paper, a model for MEMS capacitive microphone is presented for integrated circuits.  The microphone has a diaphragm thickness of 1 μm, 0.5 × 0.5 mm2 dimension, and an air gap of 1.0 μm. Using the analytical and simulation results, the important features of MEMS capacitive microphone such as pull-in voltage and sensitivity are obtained 3.8v and 6.916 mV/Pa, respectively while there is no...

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