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202
A Frequency-Domain Entropy-Based Detector for Robust Spectrum Sensing in Cognitive Radio Networks
"... Abstract—Sensitivity to noise uncertainty is a fundamental limitation of current spectrum sensing strategies in cognitive radio networks (CRN). Because of noise uncertainty, the performance of traditional detectors such as matched filters, energy detectors, and even cyclostationary detectors deterio ..."
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Cited by 2 (0 self)
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deteriorates rapidly at low Signal-to-Noise Ratios (SNR). To counteract noise uncertainty, a new entropy-based spectrum sensing scheme is introduced in this letter. The entropy of the sensed signal is estimated in the frequency domain with a probability space partitioned into fixed dimensions. It is proven
Activity recognition from user-annotated acceleration data
, 2004
"... In this work, algorithms are developed and evaluated to detect physical activities from data acquired using five small biaxial accelerometers worn simultaneously on different parts of the body. Acceleration data was collected from 20 subjects without researcher supervision or observation. Subjects ..."
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Cited by 515 (7 self)
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. Subjects were asked to perform a sequence of everyday tasks but not told specifically where or how to do them. Mean, energy, frequency-domain entropy, and correlation of acceleration data was calculated and several classifiers using these features were tested. Decision tree classifiers showed the best
Entropy Based Measure of Camera Focus
, 2004
"... A new measure for assessing camera focusing via recorded image is presented in this paper. The proposed measure bases on calculating entropy in image frequency domain, and we call it frequency domain entropy or FDE. First an intuitive explanation of measure is presented, and next tests for some clas ..."
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A new measure for assessing camera focusing via recorded image is presented in this paper. The proposed measure bases on calculating entropy in image frequency domain, and we call it frequency domain entropy or FDE. First an intuitive explanation of measure is presented, and next tests for some
Robust Entropy-Enhanced Frequency-Domain Genomic Analysis Under Uncertainties
, 2004
"... Lyshevski, Sergey and Krueger, Frank, "Robust entropy-enhanced frequency-domain genomic analysis under uncertainties " (2004). ..."
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Lyshevski, Sergey and Krueger, Frank, "Robust entropy-enhanced frequency-domain genomic analysis under uncertainties " (2004).
Physical Activity Recognition from Acceleration Data under SemiNaturalistic Conditions
, 2003
"... Achieving context-aware computer systems requires that computers can automatically recognize what people are doing. In this work, algorithms are developed and evaluated to detect physical activities from data acquired using five small accelerometers worn simultaneously on different parts of the body ..."
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Cited by 22 (2 self)
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of the body. Acceleration data was collected from twenty subjects in both laboratory and semi-naturalistic environments. For semi-naturalistic data, subjects were asked to perform a sequence of everyday tasks outside of the laboratory. Mean, energy, frequency-domain entropy, and correlation of acceleration
Frequency-domain study of α-relaxation in the Random Orthogonal Model
, 2003
"... The time-dependent susceptibility for the finite-size mean-field Random Orthogonal model (ROM) is studied numerically for temperatures above the mode-coupling temperature. The results show that the imaginary part of the susceptibility χ ′ ′ (ν) obeys the scaling form proposed for glass-forming liqui ..."
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-forming liquids with the peak frequency decreasesing as the temperature is lowered consistently with the Vogel-Fulcher law with a critical temperature remarkably close to the known critical temperature Tc of the model where the configurational entropy vanishes. PACS: 64.40.-i, 64.60.Cn, 75.10.Nr The spectral
A comparative study of advanced frequency-domain coding techniques in compression of infrared line-scan images
- QIRT 1998, Lodz Poland
"... Abstract A comparative study of transform coding techniques in data compression of IRLS (InfraRed LineScanner) images is described in this paper. In performance evaluation of block transform and wavelet image coders, we first carefully formed two sets of "good" basis functions: 4 types of ..."
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Cited by 1 (0 self)
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of generalized overlapped block transform (LOT) and 3 types of biorthonormal discrete wavelets transform (OWT). We found by extensive computer simulation on IRLS representative test-images, type and order of transform in the most efficient scalar quantized-entropy coder in each set for compression ratio from 10
Proper complex random processes with applications to information theory
- 152 tel-00906143, version 1 - 19 Nov 2013
, 1993
"... Abstract- The “covariance ” of complex random variables and processes, when defined consistently with the corresponding notion for real random variables, is shown to be determined by the usual (complex) covariance together with a quantity called the pseudo-covariance. A characterization of uncorrela ..."
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Cited by 192 (0 self)
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-mean. The notion of circular stutionarity is introduced. For the class of proper complex random processes, a discrete Fourier transform correspondence is derived relating circular stationarity in the time domain to uncorrelatedness in the frequency domain. As an application of the theory, the capacity of a
Prediction of Atrial Fibrillation Termination by Approximate Entropy in the Time-Frequency Domain
"... Given the high prevalence of Atrial Fibrillation (AF) among adult population, to distinguish between these AF episodes that terminate spontaneously and those that persist if no external action is carried out becomes a subject of great clinical interest. In this matter, the complexity analysis of mat ..."
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of the sequences have been made using the Approximate Entropy, repeating the same procedure for nine distinct time-frequency distributions. The possibility of classifying correctly the AF episodes depends directly on the selected time-frequency distribution. 1.
Results 1 - 10
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202