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Search results for: GAIN CORRECTION
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Gain Correction for Nearly Optimal Variable Fractional Sample Delay Filter Design
PublicationJedną z najbardziej efektywną numerycznie metodą projektowania filtrów jest metoda okien. Sprawia to, że takie podejście bardzo dobrze nadaje się do implementacji filtrów ułamkowoopóźniających o zmiennym opóźnieniu, gdzie wymagana jest częsta aktualizacja współczynników takiego filtru. Z drugiej strony, jeżeli wymagane są filtry wysokiej jakości wybór okna jest najczęściej problematyczny. Z tego powodu w pracy rozpatrzono użycie...
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A CMOS Pixel With Embedded ADC, Digital CDS and Gain Correction Capability for Massively Parallel Imaging Array
PublicationIn the paper, a CMOS pixel has been proposed for imaging arrays with massively parallel image acquisition and simultaneous compensation of dark signal nonuniformity (DSNU) as well as photoresponse nonuniformity (PRNU). In our solution the pixel contains all necessary functional blocks: a photosensor and an analog-to-digital converter (ADC) with built-in correlated double sampling (CDS) integrated together. It is implemented in...
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A Power-Efficient Digital Technique for Gain and Offset Correction in Slope ADCs
PublicationIn this brief, a power-efficient digital technique for gain and offset correction in slope analog-to-digital converters (ADCs) has been proposed. The technique is especially useful for imaging arrays with massively parallel image acquisition where simultaneous compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. The presented approach is based on stopping the ADC clock by...
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Time-varied-gain correction for digital echosounders. W: [CD-ROM] Forum A-custicum Sevilla 2002. 3rd European Congres on Acoustics. XXXIII Spanish Congress on Acoustics - TECNIACUSTICA 2002. European and Japanese Symposium on Acoustics. Sevilla, Spain 16-20 September 2002. Madrid: Sociedad Espano- la de Acustica**2002 vol. 33, [6 s.] 6 rys. bibliogr. 2 poz. ISBN: 84-87985-06-8 Special Issue of the Journal Revista de Acustica, vol.XXXIII, ano 2002. Korekcja zasięgowej regulacji wzmocnienia dla echosond cyfrowych.
PublicationW pracy przedstawiono modyfikację statystycznej metody EMS stosowanej w za-gadnieniach odwrotnych, polegającą na iteracyjnym rozwiązaniu równania Fred-holma. Pokazano jej zastosowanie do pośredniej estymacji siły celu ryb sto-sowanej dla danych pozyskanych przez hydrakustyczne systemy jednowiązkowewykorzystywane w przeszukiwaniach akustycznych. Wyniki porównano z rezulta-tami uzyskanymi technikami dekompozycji SVD.
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Variable Fractional Delay Filter Design Using a Symmetric Window
PublicationIn this paper a numerically efficient method for designing a nearly optimal variable fractional delay (VFD) filter based on a simple and well-known window method is presented. In the proposed method a single window extracted from the optimal filter with fixed fractional delay (FD) is divided into even and odd part. Subsequently, the odd part is discarded and symmetric even part of the extracted window is used to design a family...
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Fixed Pattern Noise Reduction and Linearity Improvement in Time-Mode CMOS Image Sensors
PublicationIn the paper, a digital clock stopping technique for gain and offset correction in time-mode analog-to-digital converters (ADCs) has been proposed. The technique is dedicated to imagers with massively parallel image acquisition working in the time mode where compensation of dark signal non-uniformity (DSNU) as well as photo-response non-uniformity (PRNU) is critical. Fixed pattern noise (FPN) reduction has been experimentally validated...
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Multi-objective design optimization of antennas for reflection, size, and gain variability using kriging surrogates and generalized domain segmentation
PublicationCost-efficient multi-objective design optimization of antennas is presented. The framework exploits auxiliary data-driven surrogates, a multi-objective evolutionary algorithm for initial Pareto front identification, response correction techniques for design refinement, as well as generalized domain segmentation. The purpose of this last mechanism is to reduce the volume of the design space region that needs to be sampled in order...
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Three-objective antenna optimization by means of kriging surrogates and domain segmentation
PublicationIn this paper, an optimization framework for multi-objective design of antenna structures is discussed which exploits data-driven surrogates, a multi-objective evolutionary algorithm, response correction techniques for design refinement, as well as generalized domain segmentation. The last mechanism is introduced to constrain the design space region subjected to sampling, which permits reduction of the number of training data samples...
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Fast surrogate-assisted frequency scaling of planar antennas with circular polarisation
PublicationIn this work, the problem of computationally efficient frequency scaling (re-design) of circular polarisation antennas is addressed using surrogate-assisted techniques. The task is challenging and requires the identification of the optimum geometry parameters to enable the operation of the re-designed structure at a selected (required) centre frequency. This involves handling several performance figures such as the antenna gain,...
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Measurement of Seafloor Acoustic Backscatter Angular Dependence at 150 kHz Using a Multibeam Echosounder
PublicationAcoustic seafloor measurements with multibeam echosounders (MBESs) are currently often used for submarine habitat mapping, but the MBESs are usually not acoustically calibrated for backscattering strength (BBS) and cannot be used to infer absolute seafloor angular dependence. We present a study outlining the calibration and showing absolute backscattering strength values measured at a frequency of 150 kHz at around 10–20 m water...