Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Time Domain Response of the ARIANNA Detector  [PDF]
S. W. Barwick,E. C. Berg,D. Z. Besson,J. C. Hanson,S. R. Klein,S. A. Kleinfelder,M. Piasecki,K. Ratzlaff,C. Reed,M. Roumi,T. Stezelberger,J. Tatar,J. Walker,R. Young,L. Zou
Physics , 2014, DOI: 10.1016/j.astropartphys.2014.09.002
Abstract: The Antarctic Ross Ice Shelf Antenna Neutrino Array (ARIANNA) is a high-energy neutrino detector designed to record the Askaryan electric field signature of cosmogenic neutrino interactions in ice. To understand the inherent radio-frequency (RF) neutrino signature, the time-domain response of the ARIANNA RF receiver must be measured. ARIANNA uses Create CLP5130-2N log-periodic dipole arrays (LPDAs). The associated effective height operator converts incident electric fields to voltage waveforms at the LDPA terminals. The effective height versus time and incident angle was measured, along with the associated response of the ARIANNA RF amplifier. The results are verified by correlating to field measurements in air and ice, using oscilloscopes. Finally, theoretical models for the Askaryan electric field are combined with the detector response to predict the neutrino signature.
Investigation Into Time- and Frequency-Domain Emi-Induced Noise in Bistable Multivibrator
Han-Chang Tsai
PIER , 2010, DOI: 10.2528/PIER09112904
Abstract: Electromagnetic interference (EMI) has a negative effect upon the performance of circuit communication systems. The present study considers the case of EMI induced in a conducting wire, and derives equations to establish the effect of the EMI on a bistable multivibrator. The validity of the equations is verified experimentally. The results indicate that the degree of influence of the EMI on the bistable oscillator depends on the interference power, the interference frequency, the induced power, the output resistance of the circuit, and the parasitic capacitance. Moreover, it is shown that the harmonic noise increases with an increasing interference amplitude and frequency. The theoretical results are found to be in good agreement with the experimental data.
A Reduced Complexity Quasi-1D Viterbi Detector  [PDF]
Rabi N. Panda, Siba P. Panigrahi, Sasmita Kumari Padhy
Journal of Signal and Information Processing (JSIP) , 2011, DOI: 10.4236/jsip.2011.21004
Abstract: This paper develops a reduced complexity quasi-1D detector for optical storage devices and digital communication system. Superior performance of the proposed detector is evidenced by simulation results.
Signal Peak-Tracker based on the Teager-Kaiser Energy (TKE) Operator  [PDF]
Randall D. Peters
Physics , 2010,
Abstract: Described is a modification of the TKE operator from its usual `energy form'. The resulting `peak-tracker' (or peak-detector) is especially useful in studies that involve the frequency domain.
A New Precision Peak Detector/Full-Wave Rectifier  [PDF]
Predrag B. Petrovi?
Journal of Signal and Information Processing (JSIP) , 2013, DOI: 10.4236/jsip.2013.41009

A new precision peak detector/full-wave rectifier of input sinusoidal signals, based on usage of dual-output current conveyors, is presented in this paper. The circuit gives a DC output voltage that is the peak input voltage over a wide frequency range, with a very low ripple voltage and low harmonic distortion. The proposed circuits use an all-pass filter as a 90° phase shifter of the processed input signal. To verify the theoretical analysis, the circuit SPICE simulations results have also been included, showing good agreement with the theory. Inherently, the circuit is well suited for IC implementation.

Shifted Quasi-Symmetric Functions and the Hopf algebra of peak functions  [PDF]
Nantel Bergeron,Stefan Mykytiuk,Frank Sottile,Stephanie van Willigenburg
Mathematics , 1999,
Abstract: In his work on P-partitions, Stembridge defined the algebra of peak functions Pi, which is both a subalgebra and a retraction of the algebra of quasi-symmetric functions. We show that Pi is closed under coproduct, and therefore a Hopf algebra, and describe the kernel of the retraction. Billey and Haiman, in their work on Schubert polynomials, also defined a new class of quasi-symmetric functions --- shifted quasi-symmetric functions --- and we show that Pi is strictly contained in the linear span Xi of shifted quasi-symmetric functions. We show that Xi is a coalgebra, and compute the rank of the n-th graded component.
Subspace Alignment Based Domain Adaptation for RCNN Detector  [PDF]
Anant Raj,Vinay P. Namboodiri,Tinne Tuytelaars
Computer Science , 2015,
Abstract: In this paper, we propose subspace alignment based domain adaptation of the state of the art RCNN based object detector. The aim is to be able to achieve high quality object detection in novel, real world target scenarios without requiring labels from the target domain. While, unsupervised domain adaptation has been studied in the case of object classification, for object detection it has been relatively unexplored. In subspace based domain adaptation for objects, we need access to source and target subspaces for the bounding box features. The absence of supervision (labels and bounding boxes are absent) makes the task challenging. In this paper, we show that we can still adapt sub- spaces that are localized to the object by obtaining detections from the RCNN detector trained on source and applied on target. Then we form localized subspaces from the detections and show that subspace alignment based adaptation between these subspaces yields improved object detection. This evaluation is done by considering challenging real world datasets of PASCAL VOC as source and validation set of Microsoft COCO dataset as target for various categories.
Measurement of electromagnetic interference in time-domain  [PDF]
S. Braun,A. Frech,P. Russer
Advances in Radio Science : Kleinheubacher Berichte , 2008,
Abstract: Time-domain EMI measurement systems allow measurement time to be reduced by several orders of magnitude. In this paper a novel real-time operating time-domain EMI measurement system is presented. By the use of several analog-to-digital converters the dynamic range requested by the international EMC standards is achieved. A real-time operating digital signal processing unit is presented. The frequency band that is investigated is subdivided into several sub-bands. A novel implementation of the 9 kHz IF filter for the frequency 150 kHz to 1 GHz is presented. By this way the measurement time has been reduced by a factor of 8000 in comparison to conventional EMI receivers. During emission measurements performed with a modelled IF-bandwidth of 9 kHz the noise floor is decreased to 19 dBμV in the average detector mode by the implemented low noise power splitter. Measurements have been performed with the improved measurement system in the frequency range 30 MHz–1 GHz.
Twin peak quasi-periodic oscillations as signature of oscillating cusp torus  [PDF]
Gabriel T?r?k,Kate?ina Goluchová,Ji?í Horák,Eva ?rámková,Martin Urbanec,Tomá? Pechá?ek,Pavel Bakala
Physics , 2015,
Abstract: Serious theoretical effort has been devoted to explain the observed frequencies of twin-peak quasi-periodic oscillations (HF QPOs) observed in low-mass X-ray neutron star binaries. Here we propose a new model of HF QPOs. Within its framework we consider an oscillating torus with cusp that changes location $r_0$ of its centre around radii very close to innermost stable circular orbit. The observed variability is assigned to global modes of accreted fluid motion that may give strong modulation of both accretion disc radiation and the accretion rate. For a given spacetime geometry, the model predicts that QPO frequencies are function of single parameter $r_0$. We illustrate that the model can provide fits of data comparable to those reached by other models, or even better. In particular it is compared to relativistic precession model. Moreover, we also illustrate that the model consideration is compatible with consideration of models of a rotating neutron star in the atoll source 4U~1636-53.
Optimum Signal Linear Detector in the Discrete Wavelet Transform-Domain  [PDF]
Ignacio Melgar,Jaime Gomez,Juan Seijas
Mathematics , 2005,
Abstract: The problem of known signal detection in Additive White Gaussian Noise is considered. In this paper a new detection algorithm based on Discrete Wavelet Transform pre-processing and threshold comparison is introduced. Current approaches described in [7] use the maximum value obtained in the wavelet domain for decision. Here, we use all available information in the wavelet domain with excellent results. Detector performance is presented in Probability of detection curves for a fixed probability of false alarm.
Page 1 /100
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.