نتایج جستجو برای: spectral contrast

تعداد نتایج: 550643  

Journal: :Optics express 2016
Bosheng Zhang Dennis F Gardner Matthew H Seaberg Elisabeth R Shanblatt Christina L Porter Robert Karl Christopher A Mancuso Henry C Kapteyn Margaret M Murnane Daniel E Adams

We report a proof-of-principle demonstration of a new scheme of spectromicroscopy in the extreme ultraviolet (EUV) spectral range, where the spectral response of the sample at different wavelengths is imaged simultaneously. This scheme is enabled by combining ptychographic information multiplexing (PIM) with a tabletop EUV source based on high harmonic generation, where four spectrally narrow h...

Journal: :Applied optics 2011
Jean Minet Jean Taboury François Goudail Michel Péalat Nicolas Roux Jacques Lonnoy Yann Ferrec

The matched filter is a widely used detector in hyperspectral detection applications because of its simplicity and its efficiency in practical situations. We propose to estimate its performance with respect to the number of spectral bands. These spectral bands are selected thanks to a genetic algorithm in order to optimize the contrast between the target and the background in the detection plan...

2013
Nicolas Catz Arnaud J. Noreña

The role of early auditory processing may be to extract some elementary features from an acoustic mixture in order to organize the auditory scene. To accomplish this task, the central auditory system may rely on the fact that sensory objects are often composed of spectral edges, i.e., regions where the stimulus energy changes abruptly over frequency. The processing of acoustic stimuli may benef...

Spectral analysis considers the problem of determining (the art of recovering) the spectral content (i.e., the distribution of power over frequency) of a stationary time series from a finite set of measurements, by means of either nonparametric or parametric techniques. This paper introduces the spectral analysis problem, motivates the definition of power spectral density functions, and reviews...

2012
K. L. Donaldson Hanna I. R. Thomas N. E. Bowles B. T. Greenhagen C. M. Pieters J. F. Mustard C. R. M. Jackson M. B. Wyatt

[1] New laboratory thermal infrared emissivity measurements of the plagioclase solid solution series over the 1700 400 cm 1 (6–25 mm) spectral range are presented. Thermal infrared (TIR) spectral changes for fine-particulate samples (0–25 mm) are characterized for the first time under different laboratory environmental conditions: ambient (terrestrial-like), half-vacuum (Mars-like), vacuum, and...

Journal: :Journal of neurophysiology 2007
Lina A J Reiss Sharba Bandyopadhyay Eric D Young

Neurons in the dorsal cochlear nucleus (DCN) exhibit strong nonlinearities in spectral processing. Low-order models that transform the stimulus spectrum into discharge rate using a combination of first- and second-order weighting of the spectrum (quadratic models) usually fail to predict responses to novel stimuli for principal neurons in the DCN, even though they work well in ventral cochlear ...

Journal: :Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics 2015
Marie Müllner Helmut Schlattl Christoph Hoeschen Olaf Dietrich

PURPOSE To demonstrate the feasibility of gold-specific spectral CT imaging for the detection of liver lesions in humans at low concentrations of gold as targeted contrast agent. METHODS A Monte Carlo simulation study of spectral CT imaging with a photon-counting and energy-resolving detector (with 6 energy bins) was performed in a realistic phantom of the human abdomen. The detector energy t...

2007
Niranjan Thatte Roberto Abuter Matthias Tecza Eric L. Nielsen Fraser J. Clarke

We present an extension of the spectral deconvolution method (Sparks & Ford 2002) to achieve very high contrast at small inner working radii. We apply the method to the specific case of ground based adaptive optics fed integral field spectroscopy (without a coronagraph). Utilising the wavelength dependence of the Airy and speckle patterns, we make an accurate estimate of the PSF that can be sca...

2017
Tong Yu Jun Gao Zhi-Min Liu Qi-Feng Zhang Yong Liu Ling Jiang Yun Peng

BACKGROUND Contrast dose and radiation dose reduction in computerized tomography (CT) scan for adult has been explored successfully, but there have been few studies on the application of low-concentration contrast in pediatric abdominal CT examinations. This was a feasibility study on the use of dual-energy spectral imaging and adaptive statistical iterative reconstruction (ASiR) for the reduct...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید