| Calculation of Entropy and Mutual Information for Sinusoids |
28-Jan-2009 |
11 pages |
| Authors:
Joseph V Michalowicz; Jonathan M Nichols; Frank Bucholtz; NAVAL RESEARCH LAB WASHINGTON DC PHOTONICS TECHNOLOGY BRANCH
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 | In this work, an analytical expression is developed for the differential entropy of a sinusoid. The mutual information between two sinusoids with different amplitudes and phase is then derived using both continuous and discrete entropies. |
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| Modeling Magnetic Core Loss for Sinusoidal Waveforms |
01-Jun-2008 |
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| Authors:
Colin J Dunlop; MASSACHUSETTS INST OF TECH CAMBRIDGE
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 | Among the challenging unsolved technical problems that have plagued the minds of scientist and engineers throughout the 20th and 21st century is the development of a quantifiable model to accurately estimate or explain Core Power Losses (CPL). Theoretical advances in magnets led to many model proposals, but as these models were experimentally examined, they quickly lost their validation. Many of the current models use manufacturer's material estimates to form limited ... |
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| Sinusoidal Vertical Motion of a Sonobuoy Suspension: Experimental Data and a Theoretical Model |
Jun-2008 |
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| Authors:
David M F Chapman; Dusko B A Kezele; DEFENCE RESEARCH AND DEVELOPMENT ATLANTIC DARTMOUTH (CANADA)
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| To isolate its acoustic sensor from the large vertical motions of the buoy at the ocean surface, a typical sonobuoy employs a low-pass mechanical filter comprising a bungee cord (spring) and a damper disk (hydrodynamic added mass and damping). If the system were to behave as a driven simple harmonic oscillator, the transfer function of vertical motion would roll off at 40 dB/decade above resonance; however, experimental systems of this ... |
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| Binary Chirped Grating Diffractive Element for Sinusoidal to Linear Scanning Conversion: The Beam Propagation Design (Preprint) |
28-Jan-2008 |
15 pages |
| Authors:
Bahareh Haji-saeed; William Bailey; John Kierstead; Jed Khoury; Charles L Woods; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
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| We fabricated and tested our previously designed optical correction element with zoom capability to convert nonlinear sinusoidal scans into linear scans. The design methodology is based on derivating a graded index of refraction device as a reference design and converting the graded index of refraction into an amplitude or phase binarized diffractive element. Our graded index of refraction derivation is based on the propagation of an electromagnetic wave in an ... |
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| A Refractive-Diffractive Element Design for Resonant Scanner Angular Correction: The Symmetric Beam Retardation Approach (Preprint) |
18-Jan-2008 |
31 pages |
| Authors:
Bahareh Haji-saeed; Jed Khoury; Charles L Woods; John Kierstead; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
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| We propose a new approach for designing diffractive optical corrective elements with zooming capability to convert nonlinear sinusoidal scanning into linear scanning. Such devices will be useful for linearizing the angular scan of a resonant mirror scanner. The design methodology is to create a graded index of refraction device as the reference design, with its index of refraction parameters based on beam retardation through propagation in an inhomogeneous media. In ... |
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| Analysis of Time-History data of Forces and Motions Measured at Towing Facilities |
SEP 2007 |
41 pages |
| Authors:
Young S. Hong; Anne Fullerton; NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD
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| Methods to filter and to analyze measured data are described and the numerical results are validated with the generated data. A lowpass filter is used to eliminate the noise of the measured data. The methods of zero crossing, sine function and spectral analysis are applied to compute the amplitudes, periods and phase angles. The numerical results of the measured data are compared with those of different methods. When the measured ... |
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| An Experimental Investigation of Guided Wave Propagation in Corrugated Plates Showing Stop Bands and Pass Bands (PREPRINT) |
FEB 2006 |
29 pages |
| Authors:
T. Kundu; S. Banerjee; Kumar V. Jata; ARIZONA UNIV TUCSON DEPT OF CIVIL ENGINEERING
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| For health monitoring of structures with periodic geometry a good understanding of the elastic wave propagation through such periodic structures is necessary. Although a number of research papers on the wave propagation through periodic structures are available in the literature hardly anyone investigated experimentally the guided wave propagation through plates with periodic plate boundaries and compared the experimental data with theoretical predictions. In this paper the elastic wave propagation in ... |
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| Air Ejector Pumping Enhancement Through Pulsing Primary Flow |
DEC 2005 |
33 pages |
| Authors:
Peter J. Vermeulen; Venkataramanayya Ramesh; Guang C. Meng; Daniel N. Miller; Neal Domel; CALGARY UNIV (ALBERTA) DEPT OF MECHANICAL ENGINEERING
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| Improving the performance of an ejector is a flow control problem. Passive methods such as changing the geometry of the mixing tube showed that, for a simple mixing tube geometry of a concentric cone-tube combination, the diameter of the tube had to be at least 4 times the diameter of the primary nozzle. Thus for a 5.13 mm dia. primary jet, a 22.7 mm dia. tube was 27% better than ... |
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| Measurements and Modeling of Combustion Dynamics for Control of Combustion Instabilities |
10 DEC 2004 |
56 pages |
| Authors:
Fred Culick; Albert Ratner; Dal M. Kang; Konstantin I. Matveev; Winston Pun; CALIFORNIA INST OF TECH PASADENA
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| This report is the final report of a six-month program with a six- month NCE comprising experimental work on problems arising with unsteady combustion of gases intended for use in propulsion systems. The experimental work comprises measurements providing the basis for inferring the local response function of a reacting mixture and is based on great extended equipment purchased before this program began, with a DURIP grant from AFOSR. The basic ... |
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| A Motion Description Language and a Hybrid Architecture for Motion Planning with Nonholonomic Robots |
1995 |
23 pages |
| Authors:
Vikram Manikonda; P. S. Krishnaprasad; James Hendler; MARYLAND UNIV COLLEGE PARK INST FOR SYSTEMS RESEARCH
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| This paper puts forward a formal basis for behavior-based robotics, using techniques that have been successful in control-theory-based approaches for steering and stabilizing robots that are subject to nonholonomic constraints. In particular, behaviors for robots are formalized in terms of kinetic state machines, a motion description language, and the interaction of the kinetic state machine with real-time information from (limited range) sensors. This formalization allows us to create a mathematical ... |
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| Estimation of Multiple Sinusoids by Parametric Filtering |
JAN 1992 |
49 pages |
| Authors:
Ta-Hsin Li; Benjamin Kedem; MARYLAND UNIV COLLEGE PARK SYSTEMS RESEARCH CENTER
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| The problem of estimating the frequencies of multiple sinusoids from noisy observations is addressed in this paper. A parametric filtering approach, called the PF method, is proposed that leads to a consistent estimator of the AR representation of the sinusoidal signal, given the number of sinusoids. It is accomplished by using an iterative procedure to find a fixed point of the parametrized least squares estimator (from the filtered data) that ... |
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| Detecting Periodic Components in a White Gaussian Time Series |
SEP 1986 |
18 pages |
| Authors:
Shean-Tsong Chiu; RICE UNIV HOUSTON TX DEPT OF MATHEMATICAL SCIENCES
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| A family of tests for periodic components in a white Gaussian series is proposed. The test is based on a statistic which is proportional to the ratio of the maximum periodogram to the trimmed mean of the periodograms. The asymptotic distribution of the statistic is obtained. It is shown that the test proposed and Fisher's test have the same asymptotic powers at the alternative hypotheses that the series contains a ... |
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Reports by Keyword(s)
SINUSOIDAL FUNCTIONS
