Results 111 to 120 of about 101,437 (150)
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Medical Physics, 1995
The proper understanding of modulation transfer function (MTF), noise power spectra (NPS), and noise equivalent quanta (NEQ) in digital systems is significantly hampered when the systems are undersampled. Undersampling leads to three significant complications: (1) MTF and NPS do not behave as transfer amplitude and variance, respectively, of a single ...
James T Dobbins
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The proper understanding of modulation transfer function (MTF), noise power spectra (NPS), and noise equivalent quanta (NEQ) in digital systems is significantly hampered when the systems are undersampled. Undersampling leads to three significant complications: (1) MTF and NPS do not behave as transfer amplitude and variance, respectively, of a single ...
James T Dobbins
exaly +3 more sources
Sb-Heterostructure Millimeter-Wave Detectors With Reduced Capacitance and Noise Equivalent Power
IEEE Electron Device Letters, 2008InAs/AlSb/GaSb backward diodes are used for millimeter-wave square-law power detection. A new heterostructure design with low capacitance, low resistance, and high curvature coefficient as compared to previous designs is presented. Voltage sensitivity, which is directly proportional to curvature coefficient, is improved by 31% as compared to prior ...
R Rajavel, P Deelman, J N Schulman
exaly +2 more sources
Physics in Medicine and Biology, 2007
Dose reduction efforts in diagnostic CT have brought the tradeoff of dose versus image quality to the forefront. The need for meaningful characterization of image noise beyond that offered by pixel standard deviation is becoming increasingly important.
K L, Boedeker +2 more
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Dose reduction efforts in diagnostic CT have brought the tradeoff of dose versus image quality to the forefront. The need for meaningful characterization of image noise beyond that offered by pixel standard deviation is becoming increasingly important.
K L, Boedeker +2 more
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Theoretical Expression for the Noise Equivalent Power of Pyroelectric Detectors
Journal of Applied Physics, 1966An equivalent circuit appropriate for pyroelectric materials is derived without assuming a unidirectional polarization vector. This circuit is used to obtain a theoretical expression for the noise equivalent power (NEP) for detectors using pyroelectric sensing elements. It is found that a good figure of merit for pyroelectric materials is given by Fp=p/
Glenn A. Burdick, Roy T. Arnold
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Noise Equivalent Power of Graphene–Superconductor-Based Optical Sensor
Fluctuation and Noise Letters, 2017In this paper, the noise equivalent power (NEP) of optical sensors based on graphene–superconductor junctions in the voltage bias operation mode has been calculated. The effects of device parameters such as temperature, magnetic field and device resistance on the NEP of these detectors have been thoroughly investigated.
B. Afkhami Aghda +2 more
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The Effects of Gaussian Noise on the Videokeratoscopic Measurement of Spherical Equivalent Power
Vision Science and its Applications, 1997One of the questions surrounding the use of videokeratoscopic height data is the ability to extract useful parameters in the presence of noise. Parameters such as spherical equivalent power, radius of curvature and conic constant need to be accurately calculated from noisy height data.
Jim Schwiegerling, John E. Greivenkamp
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Infrared Black Phosphorus Phototransistor with Tunable Responsivity and Low Noise Equivalent Power
ACS Applied Materials & Interfaces, 2017The narrow band gap property of black phosphorus (BP) that bridges the energy gap between graphene and transition metal dichalcogenides holds great promise for enabling broadband optical detection from ultraviolet to infrared wavelengths. Despite its rich potential as an intriguing building block for optoelectronic applications, however, very little ...
Li Huang +5 more
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Noise-equivalent power and response time of TlSe bolometer at 15 K*
Journal of the Optical Society of America, 1975A far-infrared bolometer detector using p-type thallium selenide (TlSe) single crystal as the temperature-sensitive element has been operated at 1.5 K with a noise-equivalent power (NEP) of 8.3 × 10−15 W/Hz1/2 and a response time constant of 8 × 10−3 s. The bolometer could be made faster without increasing NEP by reducing the thickness of the element.
P. S. Nayar, W. O. Hamilton
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An acoustooptic method of measuring the noise equivalent power of optical heterodyne systems
Optical and Quantum Electronics, 1975The noise equivalent power of optical heterodyne detection at 10.6 μm has been measured with a method based on Raman-Nath diffraction of a CO2 laser beam. One of the frequency shifted first order diffracted beams is used as the signal radiation. The local oscillator radiation is obtained by splitting off a part of the laser beam incident upon the ...
H. Eklund, S. T. Eng, E. Daniels
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Noise Equivalent Power of Background Limited Thermal Detectors at Submillimeter Wavelengths
International Journal of Infrared and Millimeter Waves, 1998With the advent of large submillimeter telescopes at high, dry sites, the atmospheric background noise in a moderate bandwidth can be low enough to challenge the ability of instrument designers to produce sufficiently low noise bolometers to be background limited.
D. J. Benford +2 more
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