Remedial Action Plan for the codisposal and stabilization of the Monument Valley and Mexican Hat uranium mill tailings at Mexican Hat, Utah: Appendices C--E. Final report

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-02-01

This document provides appendices C, D, and E this Remedial Action Plan (RAP) which is a revision of the original Mexican Hat Remedial Action Plan and RAP Modification submitted in July 1988 and January 1989, respectively, along with updated design documents. Appendix C provide the Radiological Support Plan, Appendix D provides the Site Characterization, and Appendix E provides the Water Resources Protection Strategy.

Radiologic characterization of the Mexican Hat, Utah, uranium mill tailings remedial action site: Appendix D, Addenda D1--D7

Energy Technology Data Exchange (ETDEWEB)

Ludlam, J.R.

1985-01-01

This radiologic characterization of the inactive uranium millsite at Mexican Hat, Utah, was conducted by Bendix Field Engineering Corporation foe the US Department of Energy (DOE), Grand Junction Project Office, in response to and in accord with a Statement of Work prepared by the DOE Uranium Mill tailings Remedial Action Project (UMTRAP) Technical Assistance Contractor, Jacobs Engineering Group, Inc. the objective of this project was to determine the horizontal and vertical extent of contamination that exceeds the US Environmental Protection Agency (EPA) standards at the Mexican Hat site. The data presented in this report are required for characterization of the areas adjacent to the Mexican Hat tailings piles and for the subsequent design of cleanup activities. Some on-pile sampling was required to determine the depth of the 15-pCi/g Ra-226 interface in an area where wind and water erosion has taken place.

Final audit report of remedial action construction at the UMTRA Project Mexican Hat, Utah -- Monument Valley, Arizona, sites

International Nuclear Information System (INIS)

1995-10-01

The final audit report for remedial action at the Mexican Hat, Utah, Monument Valley, Arizona, Uranium Mill Tailings Remedial Action (UMTRA) Project sites consists of a summary of the radiological surveillances/audits, quality assurance (QA) in-process surveillances, and QA remedial action close-out inspections performed by the US Department of Energy (DOE) and the Technical Assistance Contractor (TAC); on-site construction reviews (OSCR) performed by the US Nuclear Regulatory Commission (NRC); and a surveillance performed by the Navajo Nation. This report refers to remedial action activities performed at the Mexican Hat, Utah--Monument Valley, Arizona, Uranium Mill Tailings Remedial Action (UMTRA) Project sites

The boson and the Mexican hat

International Nuclear Information System (INIS)

Cohen-Tannoudji, Gilles; Spiro, Michel

2013-01-01

This document contains a brief presentation and the table of contents of a book in which the authors who reports the evolutions of the contemporary astrophysics theories, and the scientific, technological and human adventure of the CERN until the discovery of the Higgs boson by means of the LHC. The Mexican hat is the name given to the mechanism by which the boson reports the origin of the elementary particle masses. The first part reports the boson genealogy: the law of universal gravitation, the relativity and the limits of the rational mechanics, quantum mechanics, and particle physics at the end of the 1960's. The second part addresses the necessary existence of the boson: quantum electrodynamics, from the quark model to quantum chromo-dynamics, from intermediate bosons to the Brout, Englert and Higgs boson, the standard cosmology model. The third part deals with the perspectives opened by the existence and evidence of the boson: the search for physics theory and models beyond standard models

Phase II, Title I engineering assessment of inactive uranium mill tailings, Mexican Hat site, Mexican Hat, Utah

International Nuclear Information System (INIS)

1977-01-01

An engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at the Mexican Hat millsite in Utah is presented. Topographic maps, data on core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and other radium-contaminated materials, the evaluation of resulting radiation exposures of individuals residing nearby, the investigation of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions are presented. Radon gas release from the 2,200,000 tons of tailings on the site constitutes the most significant environmental impact. T he six alternative actions presented are directed towards restricting access to the site, returning the windblown tailings to the piles and stabilizing the piles with cover material, and consolidating the two piles into one pile and stabilizing it with cover material. Fencing around the site or the tailings and the decontamination of mill buildings is included in all options. Costs of the options range from $370,000 to $4,390,000

Assessment of seeps in the vicinity of the Mexican Hat tailings disposal cell

International Nuclear Information System (INIS)

1990-10-01

The Phase II remedial action at the Mexican Hat site began in September 1988, and involved the excavation, transportation, and placement of contaminated materials onto the lower tailings pile. These materials were from the upper tailings pile, portions of the lower tailings pile, off-pile contaminated areas, and demolition material stockpiled at the former-mill site. By December 1989, all of the contaminated soils on the upper tailings pile area and most of the off-pile windblown and waterborne contamination had been removed and placed on the lower pile. Since that time, several seeps have been observed near the site. These seeps and some previously identified seeps may be related to remedial action construction activities or the past disposal of mill tailings at the Mexican Hat site. The objectives of this report are to: summarize the geology and hydrostratigraphy of the site; discuss field investigation of the locations, chronology, and flow rates of the seeps; discuss background groundwater quality, tailings pore fluid characterization, and water quality of the seeps; identify possible sources of the seeps; interpret the data; make recommendations for continued site characterization and assessment

UMTRA Project Site Observational Work Plan, Mexican Hat, Utah

International Nuclear Information System (INIS)

1994-09-01

Surface cleanup activities at the Mexican Hat UMTRA processing site are nearing completion. Ground Water contamination at the Mexican Hat site is a result of uranium milling operations. The extent of residual process water has been identified, and it is limited to the uppermost aquifer in the vicinity of the site. Deeper aquifers are not affected because of an upward hydraulic gradient and the presence of a confining unit (the deeper aquifers are protected by hydrogeologic isolation). The uppermost unit is returning to its pre-milling, mainly unsaturated state. The unit that contains the contaminated water is not a ground water resource because it qualifies as Class III (limited use) based on limited yield. Ground water in the uppermost unit is currently not used and is not anticipated to be used as a ground water resource. The nearby San Juan River and a converted oil exploration well provide all of the water needs for the area. There are no current threats to human health or livestock; and, because the zone of contamination does not represent a ground water resource, none are anticipated in the future. There are, however, seeps where contaminated water is exposed at land surface. The seeps create potential exposure pathways for plants and wildlife. It is not known at this time if there is a risk to the environment. Additional investigations are needed and are described in this document to confirm the presence or absence of potential environmental risks. Additional hydrogeologic investigations are not required. The proposed ground water compliance strategy for the site is no remediation, because the ground water in the uppermost aquifer (which is also the zone of contamination) qualifies for supplemental standards based on Class III, limited yield, and because there are no threats to human health. Domestic and agricultural water is pumped from a deeper aquifer that is isolated from the contaminated zone

Wavelet based analysis of multi-electrode EEG-signals in epilepsy

Science.gov (United States)

Hein, Daniel A.; Tetzlaff, Ronald

2005-06-01

For many epilepsy patients seizures cannot sufficiently be controlled by an antiepileptic pharmacatherapy. Furthermore, only in small number of cases a surgical treatment may be possible. The aim of this work is to contribute to the realization of an implantable seizure warning device. By using recordings of electroenzephalographical(EEG) signals obtained from the department of epileptology of the University of Bonn we studied a recently proposed algorithm for the detection of parameter changes in nonlinear systems. Firstly, after calculating the crosscorrelation function between the signals of two electrodes near the epileptic focus, a wavelet-analysis follows using a sliding window with the so called Mexican-Hat wavelet. Then the Shannon-Entropy of the wavelet-transformed data has been determined providing the information content on a time scale in subject to the dilation of the wavelet-transformation. It shows distinct changes at the seizure onset for all dilations and for all patients.

A wavelet-based Gaussian method for energy dispersive X-ray fluorescence spectrum

Directory of Open Access Journals (Sweden)

Pan Liu

2017-05-01

Full Text Available This paper presents a wavelet-based Gaussian method (WGM for the peak intensity estimation of energy dispersive X-ray fluorescence (EDXRF. The relationship between the parameters of Gaussian curve and the wavelet coefficients of Gaussian peak point is firstly established based on the Mexican hat wavelet. It is found that the Gaussian parameters can be accurately calculated by any two wavelet coefficients at the peak point which has to be known. This fact leads to a local Gaussian estimation method for spectral peaks, which estimates the Gaussian parameters based on the detail wavelet coefficients of Gaussian peak point. The proposed method is tested via simulated and measured spectra from an energy X-ray spectrometer, and compared with some existing methods. The results prove that the proposed method can directly estimate the peak intensity of EDXRF free from the background information, and also effectively distinguish overlap peaks in EDXRF spectrum.

Mexican hat curve for hydrogen and antihydrogen-states in natural atom H

CERN Document Server

Van Hooydonk, G

2004-01-01

Molecular band spectra as well as atomic line spectra reveal a left-right symmetry for atoms (Van Hooydonk, Spectrochim. Acta A, 2000, 56, 2273 and CERN-Ext-2002-041). We now extract a Mexican hat shaped or double well curve from the line spectrum (Lyman ns1/2 singlets) of natural atom H. An H CSB theory and its oscillator contribution (1-0.5pi/n)esp2/nexp2 lead to unprecedented results for antihydrogen physics, ahead of the CERN AD-project on artificial antihydrogen.

Development of Wavelet Based Tools for Improving the γ-ray Spectrometry

International Nuclear Information System (INIS)

Hamzaoui, E-M.; El Badri, L.; Laraki, K.; Cherkaoui-Elmorsli, R.

2013-06-01

In this article, we propose a wavelet transform based tool to improve the use of gamma ray spectrometry as a nuclear technique. First, we attempt to study the problem of filtering the preamplifier's output signals of HPGe detector used in the measurements chain. Thus, we developed a nonlinear method based on discrete Coiflet transform combined to principal component analysis, which allows a significant improvement of the signal to noise ratio (SNR) at the output of the HPGe preamplifier. In a second step, the continuous wavelet transform, based on the Mexican Hat mother function, is used to achieve an automatic processing of the spectrometric data. This method permits us to get an alternative representation of the gamma energy spectrum. The results of different tests, performed in both the presence and the absence of a gamma radiation source, are illustrated. (authors)

Bayesian estimation inherent in a Mexican-hat-type neural network

Science.gov (United States)

Takiyama, Ken

2016-05-01

Brain functions, such as perception, motor control and learning, and decision making, have been explained based on a Bayesian framework, i.e., to decrease the effects of noise inherent in the human nervous system or external environment, our brain integrates sensory and a priori information in a Bayesian optimal manner. However, it remains unclear how Bayesian computations are implemented in the brain. Herein, I address this issue by analyzing a Mexican-hat-type neural network, which was used as a model of the visual cortex, motor cortex, and prefrontal cortex. I analytically demonstrate that the dynamics of an order parameter in the model corresponds exactly to a variational inference of a linear Gaussian state-space model, a Bayesian estimation, when the strength of recurrent synaptic connectivity is appropriately stronger than that of an external stimulus, a plausible condition in the brain. This exact correspondence can reveal the relationship between the parameters in the Bayesian estimation and those in the neural network, providing insight for understanding brain functions.

Sadhana | Indian Academy of Sciences

Indian Academy of Sciences (India)

Modelling spatial density using continuous wavelet transforms ... Space debris; wavelets; Mexican hat; Laplace distribution; random search; parameter estimation. ... of peaks and peak locations of spatial density model using continuous wavelets. ... Department of Mathematics, Osmania University, Hyderabad 500 007, India ...

Engineering assessment of inactive uranium mill tailings, Mexican Hat site, Mexican Hat, Utah. A summary of the Phase II, Title I

International Nuclear Information System (INIS)

1977-01-01

Ford, Bacon and Davis Utah Inc. has performed an engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at the Mexican Hat millsite in Utah. The Phase II, Title I services include the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and other radium-contaminated materials, the evaluation of resulting radiation exposures of individuals residing nearby, the investigation of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas release from the 2,200,000 tons of tailings on the site constitutes the most significant environmental impact. The six alternative actions presented are directed towards restricting access to the site (Option I), returning the windblown tailings to the piles and stabilizing the piles with cover material (Options II, III, and IV), and consolidating the two piles into one pile and stabilizing it with cover material (Options V and VI). Fencing around the site or the tailings and the decontamination of mill buildings is included in all options. Options II and V provide 2 ft of cover material on the tailings, Options III, IV, and VI provide 4 ft, 13 ft, and 10 ft of cover, respectively. Costs of the options range from $370,000 to $4,390,000. Reprocessing the tailings for uranium is not feasible at present

Radiological audit of remedial action activities at the processing sites Mexican Hat, Utah and Monument Valley, Arizona. Audit date: May 3--7, 1993, Final report

International Nuclear Information System (INIS)

1993-05-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project's Technical Assistance Contractor (TAC) performed a radiological audit of the Remedial Action Contractor (RAC), MK-Ferguson and CWM Federal Environmental Services, Inc., at the processing sites in Mexican Hat, Utah, and Monument Valley, Arizona. This audit was conducted May 3--7, 1993, by Bill James and Gerry Simiele of the TAC. Three site-specific findings and four observations were identified during the audit and are presented in this report. The overall conclusion from the audit is that the majority of the radiological aspects of the Mexican Hat, Utah, and Monument Valley, Arizona, remedial action programs are performed adequately. However, the findings identify that there is some inconsistency in following procedures and meeting requirements for contamination control, and a lack of communication between the RAC and the DOE on variances from the published remedial action plan (RAP)

INTRODUCING MEXICAN NEEDLETS FOR CMB ANALYSIS: ISSUES FOR PRACTICAL APPLICATIONS AND COMPARISON WITH STANDARD NEEDLETS

International Nuclear Information System (INIS)

Scodeller, S.; Rudjord, Oe.; Hansen, F. K.; Marinucci, D.; Geller, D.; Mayeli, A.

2011-01-01

Over the last few years, needlets have emerged as a useful tool for the analysis of cosmic microwave background (CMB) data. Our aim in this paper is first to introduce into the CMB literature a different form of needlets, known as Mexican needlets, first discussed in the mathematical literature by Geller and Mayeli. We then proceed with an extensive study of the properties of both standard and Mexican needlets; these properties depend on some parameters which can be tuned in order to optimize the performance for a given application. Our second aim in this paper is then to give practical advice on how to adjust these parameters for WMAP and Planck data in order to achieve the best properties for a given problem in CMB data analysis. In particular, we investigate localization properties in real and harmonic space and propose a recipe for quantifying the influence of galactic and point-source masks on the needlet coefficients. We also show that for certain parameter values, the Mexican needlets provide a close approximation to the Spherical Mexican Hat Wavelets (whence their name), with some advantages concerning their numerical implementation and derivation of their statistical properties.

Assessment of the radiological impact of the inactive uranium-mill tailings at Mexican Hat, Utah

Energy Technology Data Exchange (ETDEWEB)

Haywood, F.F.; Goldsmith, W.A.; Ellis, B.S.; Hubbard, H.M. Jr.; Fox, W.F.; Shinpaugh, W.H.

1980-03-01

High surface soil concentrations of /sup 226/Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health effect of exposure to gamma rays during a 2000-hr work year in the area represents an increase of 0.1% in the risk of death from cancer. Exposure of less than 600 persons within 1.6 km of the tailings to radon daughters results in an estimated 0.2%/year increase in risk of lung cancer.

Assessment of the radiological impact of the inactive uranium-mill tailings at Mexican Hat, Utah

International Nuclear Information System (INIS)

Haywood, F.F.; Goldsmith, W.A.; Ellis, B.S.; Hubbard, H.M. Jr.; Fox, W.F.; Shinpaugh, W.H.

1980-03-01

High surface soil concentrations of 226 Ra and high above-ground measurements of gamma-ray intensity in the vicinity of the inactive uranium-mill tailings at Mexican Hat show both wind and water erosion of the tailings. The former mill area, occupied by a trade school at the time of this survey, shows a comparatively high level of contamination, probably from unprocessed ore on the surface of the ore storage area near the location of the former mill buildings. However, the estimated health effect of exposure to gamma rays during a 2000-hr work year in the area represents an increase of 0.1% in the risk of death from cancer. Exposure of less than 600 persons within 1.6 km of the tailings to radon daughters results in an estimated 0.2%/year increase in risk of lung cancer

A Wavelet-Based Algorithm for the Spatial Analysis of Poisson Data

Science.gov (United States)

Freeman, P. E.; Kashyap, V.; Rosner, R.; Lamb, D. Q.

2002-01-01

Wavelets are scalable, oscillatory functions that deviate from zero only within a limited spatial regime and have average value zero, and thus may be used to simultaneously characterize the shape, location, and strength of astronomical sources. But in addition to their use as source characterizers, wavelet functions are rapidly gaining currency within the source detection field. Wavelet-based source detection involves the correlation of scaled wavelet functions with binned, two-dimensional image data. If the chosen wavelet function exhibits the property of vanishing moments, significantly nonzero correlation coefficients will be observed only where there are high-order variations in the data; e.g., they will be observed in the vicinity of sources. Source pixels are identified by comparing each correlation coefficient with its probability sampling distribution, which is a function of the (estimated or a priori known) background amplitude. In this paper, we describe the mission-independent, wavelet-based source detection algorithm ``WAVDETECT,'' part of the freely available Chandra Interactive Analysis of Observations (CIAO) software package. Our algorithm uses the Marr, or ``Mexican Hat'' wavelet function, but may be adapted for use with other wavelet functions. Aspects of our algorithm include: (1) the computation of local, exposure-corrected normalized (i.e., flat-fielded) background maps; (2) the correction for exposure variations within the field of view (due to, e.g., telescope support ribs or the edge of the field); (3) its applicability within the low-counts regime, as it does not require a minimum number of background counts per pixel for the accurate computation of source detection thresholds; (4) the generation of a source list in a manner that does not depend upon a detailed knowledge of the point spread function (PSF) shape; and (5) error analysis. These features make our algorithm considerably more general than previous methods developed for the

Synchrony, waves and ripple in spatially coupled Kuramoto oscillators with Mexican hat connectivity.

Science.gov (United States)

Heitmann, Stewart; Ermentrout, G Bard

2015-06-01

Spatiotemporal waves of synchronized activity are known to arise in oscillatory neural networks with lateral inhibitory coupling. How such patterns respond to dynamic changes in coupling strength is largely unexplored. The present study uses analysis and simulation to investigate the evolution of wave patterns when the strength of lateral inhibition is varied dynamically. Neural synchronization was modeled by a spatial ring of Kuramoto oscillators with Mexican hat lateral coupling. Broad bands of coexisting stable wave solutions were observed at all levels of inhibition. The stability of these waves was formally analyzed in both the infinite ring and the finite ring. The broad range of multi-stability predicted hysteresis in transitions between neighboring wave solutions when inhibition is slowly varied. Numerical simulation confirmed the predicted transitions when inhibition was ramped down from a high initial value. However, non-wave solutions emerged from the uniform solution when inhibition was ramped upward from zero. These solutions correspond to spatially periodic deviations of phase that we call ripple states. Numerical continuation showed that stable ripple states emerge from synchrony via a supercritical pitchfork bifurcation. The normal form of this bifurcation was derived analytically, and its predictions compared against the numerical results. Ripple states were also found to bifurcate from wave solutions, but these were locally unstable. Simulation also confirmed the existence of hysteresis and ripple states in two spatial dimensions. Our findings show that spatial synchronization patterns can remain structurally stable despite substantial changes in network connectivity.

WARM SPITZER PHOTOMETRY OF THREE HOT JUPITERS: HAT-P-3b, HAT-P-4b AND HAT-P-12b

Energy Technology Data Exchange (ETDEWEB)

Todorov, Kamen O. [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Deming, Drake [Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 (United States); Knutson, Heather A. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Fortney, Jonathan J.; Laughlin, Gregory [Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Lewis, Nikole K. [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Cowan, Nicolas B. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Desert, Jean-Michel [Astronomy Department, California Institute of Technology, Pasadena, CA 91125 (United States); Sada, Pedro V. [Department of Physics and Mathematics, University of Monterrey, Monterrey (Mexico); Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Langton, Jonathan [Department of Physics, Principia College, Elsah, IL 62028 (United States); Showman, Adam P. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

2013-06-20

We present Warm Spitzer/IRAC secondary eclipse time series photometry of three short-period transiting exoplanets, HAT-P-3b, HAT-P-4b and HAT-P-12b, in both the available 3.6 and 4.5 {mu}m bands. HAT-P-3b and HAT-P-4b are Jupiter-mass objects orbiting an early K and an early G dwarf star, respectively. For HAT-P-3b we find eclipse depths of 0.112%+0.015%-0.030% (3.6 micron) and 0.094%+0.016%-0.009% (4.5 {mu}m). The HAT-P-4b values are 0.142%+0.014%-0.016% (3.6 micron) and 0.122%+0.012%-0.014% 4.5 {mu}m). The two planets' photometry is consistent with inefficient heat redistribution from their day to night sides (and low albedos), but it is inconclusive about possible temperature inversions in their atmospheres. HAT-P-12b is a Saturn-mass planet and is one of the coolest planets ever observed during secondary eclipse, along with the hot Neptune GJ 436b and the hot Saturn WASP-29b. We are able to place 3{sigma} upper limits on the secondary eclipse depth of HAT-P-12b in both wavelengths: <0.042% (3.6 {mu}m) and <0.085% (4.5 {mu}m). We discuss these results in the context of the Spitzer secondary eclipse measurements of GJ 436b and WASP-29b. It is possible that we do not detect the eclipses of HAT-P-12b due to high eccentricity, but find that weak planetary emission in these wavelengths is a more likely explanation. We place 3{sigma} upper limits on the |e cos {omega}| quantity (where e is eccentricity and {omega} is the argument of periapsis) for HAT-P-3b (<0.0081) and HAT-P-4b (<0.0042), based on the secondary eclipse timings.

The Illustrated Wavelet Transform Handbook: Introductory Theory and Applications in Science, Engineering, Medicine and Finance

Energy Technology Data Exchange (ETDEWEB)

Kingsbury, J Ng and N G [Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

2004-02-06

This book provides an overview of the theory and practice of continuous and discrete wavelet transforms. Divided into seven chapters, the first three chapters of the book are introductory, describing the various forms of the wavelet transform and their computation, while the remaining chapters are devoted to applications in fluids, engineering, medicine and miscellaneous areas. Each chapter is well introduced, with suitable examples to demonstrate key concepts. Illustrations are included where appropriate, thus adding a visual dimension to the text. A noteworthy feature is the inclusion, at the end of each chapter, of a list of further resources from the academic literature which the interested reader can consult. The first chapter is purely an introduction to the text. The treatment of wavelet transforms begins in the second chapter, with the definition of what a wavelet is. The chapter continues by defining the continuous wavelet transform and its inverse and a description of how it may be used to interrogate signals. The continuous wavelet transform is then compared to the short-time Fourier transform. Energy and power spectra with respect to scale are also discussed and linked to their frequency counterparts. Towards the end of the chapter, the two-dimensional continuous wavelet transform is introduced. Examples of how the continuous wavelet transform is computed using the Mexican hat and Morlet wavelets are provided throughout. The third chapter introduces the discrete wavelet transform, with its distinction from the discretized continuous wavelet transform having been made clear at the end of the second chapter. In the first half of the chapter, the logarithmic discretization of the wavelet function is described, leading to a discussion of dyadic grid scaling, frames, orthogonal and orthonormal bases, scaling functions and multiresolution representation. The fast wavelet transform is introduced and its computation is illustrated with an example using the Haar

Optimal Matched Filter in the Low-number Count Poisson Noise Regime and Implications for X-Ray Source Detection

Science.gov (United States)

Ofek, Eran O.; Zackay, Barak

2018-04-01

Detection of templates (e.g., sources) embedded in low-number count Poisson noise is a common problem in astrophysics. Examples include source detection in X-ray images, γ-rays, UV, neutrinos, and search for clusters of galaxies and stellar streams. However, the solutions in the X-ray-related literature are sub-optimal in some cases by considerable factors. Using the lemma of Neyman–Pearson, we derive the optimal statistics for template detection in the presence of Poisson noise. We demonstrate that, for known template shape (e.g., point sources), this method provides higher completeness, for a fixed false-alarm probability value, compared with filtering the image with the point-spread function (PSF). In turn, we find that filtering by the PSF is better than filtering the image using the Mexican-hat wavelet (used by wavdetect). For some background levels, our method improves the sensitivity of source detection by more than a factor of two over the popular Mexican-hat wavelet filtering. This filtering technique can also be used for fast PSF photometry and flare detection; it is efficient and straightforward to implement. We provide an implementation in MATLAB. The development of a complete code that works on real data, including the complexities of background subtraction and PSF variations, is deferred for future publication.

Adaptive image denoising based on support vector machine and wavelet description

Science.gov (United States)

An, Feng-Ping; Zhou, Xian-Wei

2017-12-01

Adaptive image denoising method decomposes the original image into a series of basic pattern feature images on the basis of wavelet description and constructs the support vector machine regression function to realize the wavelet description of the original image. The support vector machine method allows the linear expansion of the signal to be expressed as a nonlinear function of the parameters associated with the SVM. Using the radial basis kernel function of SVM, the original image can be extended into a MEXICAN function and a residual trend. This MEXICAN represents a basic image feature pattern. If the residual does not fluctuate, it can also be represented as a characteristic pattern. If the residuals fluctuate significantly, it is treated as a new image and the same decomposition process is repeated until the residuals obtained by the decomposition do not significantly fluctuate. Experimental results show that the proposed method in this paper performs well; especially, it satisfactorily solves the problem of image noise removal. It may provide a new tool and method for image denoising.

The Illustrated Wavelet Transform Handbook: Introductory Theory and Applications in Science, Engineering, Medicine and Finance

International Nuclear Information System (INIS)

Kingsbury, J Ng and N G

2004-01-01

This book provides an overview of the theory and practice of continuous and discrete wavelet transforms. Divided into seven chapters, the first three chapters of the book are introductory, describing the various forms of the wavelet transform and their computation, while the remaining chapters are devoted to applications in fluids, engineering, medicine and miscellaneous areas. Each chapter is well introduced, with suitable examples to demonstrate key concepts. Illustrations are included where appropriate, thus adding a visual dimension to the text. A noteworthy feature is the inclusion, at the end of each chapter, of a list of further resources from the academic literature which the interested reader can consult. The first chapter is purely an introduction to the text. The treatment of wavelet transforms begins in the second chapter, with the definition of what a wavelet is. The chapter continues by defining the continuous wavelet transform and its inverse and a description of how it may be used to interrogate signals. The continuous wavelet transform is then compared to the short-time Fourier transform. Energy and power spectra with respect to scale are also discussed and linked to their frequency counterparts. Towards the end of the chapter, the two-dimensional continuous wavelet transform is introduced. Examples of how the continuous wavelet transform is computed using the Mexican hat and Morlet wavelets are provided throughout. The third chapter introduces the discrete wavelet transform, with its distinction from the discretized continuous wavelet transform having been made clear at the end of the second chapter. In the first half of the chapter, the logarithmic discretization of the wavelet function is described, leading to a discussion of dyadic grid scaling, frames, orthogonal and orthonormal bases, scaling functions and multiresolution representation. The fast wavelet transform is introduced and its computation is illustrated with an example using the Haar

Association with the origin recognition complex suggests a novel role for histone acetyltransferase Hat1p/Hat2p

Directory of Open Access Journals (Sweden)

Greenblatt Jack F

2007-09-01

Full Text Available Abstract Background Histone modifications have been implicated in the regulation of transcription and, more recently, in DNA replication and repair. In yeast, a major conserved histone acetyltransferase, Hat1p, preferentially acetylates lysine residues 5 and 12 on histone H4. Results Here, we report that a nuclear sub-complex consisting of Hat1p and its partner Hat2p interacts physically and functionally with the origin recognition complex (ORC. While mutational inactivation of the histone acetyltransferase (HAT gene HAT1 alone does not compromise origin firing or initiation of DNA replication, a deletion in HAT1 (or HAT2 exacerbates the growth defects of conditional orc-ts mutants. Thus, the ORC-associated Hat1p-dependent histone acetyltransferase activity suggests a novel linkage between histone modification and DNA replication. Additional genetic and biochemical evidence points to the existence of partly overlapping histone H3 acetyltransferase activities in addition to Hat1p/Hat2p for proper DNA replication efficiency. Furthermore, we demonstrated a dynamic association of Hat1p with chromatin during S-phase that suggests a role of this enzyme at the replication fork. Conclusion We have found an intriguing new association of the Hat1p-dependent histone acetyltransferase in addition to its previously known role in nuclear chromatin assembly (Hat1p/Hat2p-Hif1p. The participation of a distinct Hat1p/Hat2p sub-complex suggests a linkage of histone H4 modification with ORC-dependent DNA replication.

BOOK REVIEW: The Illustrated Wavelet Transform Handbook: Introductory Theory and Applications in Science, Engineering, Medicine and Finance

Science.gov (United States)

Ng, J.; Kingsbury, N. G.

2004-02-01

This book provides an overview of the theory and practice of continuous and discrete wavelet transforms. Divided into seven chapters, the first three chapters of the book are introductory, describing the various forms of the wavelet transform and their computation, while the remaining chapters are devoted to applications in fluids, engineering, medicine and miscellaneous areas. Each chapter is well introduced, with suitable examples to demonstrate key concepts. Illustrations are included where appropriate, thus adding a visual dimension to the text. A noteworthy feature is the inclusion, at the end of each chapter, of a list of further resources from the academic literature which the interested reader can consult. The first chapter is purely an introduction to the text. The treatment of wavelet transforms begins in the second chapter, with the definition of what a wavelet is. The chapter continues by defining the continuous wavelet transform and its inverse and a description of how it may be used to interrogate signals. The continuous wavelet transform is then compared to the short-time Fourier transform. Energy and power spectra with respect to scale are also discussed and linked to their frequency counterparts. Towards the end of the chapter, the two-dimensional continuous wavelet transform is introduced. Examples of how the continuous wavelet transform is computed using the Mexican hat and Morlet wavelets are provided throughout. The third chapter introduces the discrete wavelet transform, with its distinction from the discretized continuous wavelet transform having been made clear at the end of the second chapter. In the first half of the chapter, the logarithmic discretization of the wavelet function is described, leading to a discussion of dyadic grid scaling, frames, orthogonal and orthonormal bases, scaling functions and multiresolution representation. The fast wavelet transform is introduced and its computation is illustrated with an example using the Haar

Inference of strata separation and gas emission paths in longwall overburden using continuous wavelet transform of well logs and geostatistical simulation

Science.gov (United States)

Karacan, C. Özgen; Olea, Ricardo A.

2014-06-01

Prediction of potential methane emission pathways from various sources into active mine workings or sealed gobs from longwall overburden is important for controlling methane and for improving mining safety. The aim of this paper is to infer strata separation intervals and thus gas emission pathways from standard well log data. The proposed technique was applied to well logs acquired through the Mary Lee/Blue Creek coal seam of the Upper Pottsville Formation in the Black Warrior Basin, Alabama, using well logs from a series of boreholes aligned along a nearly linear profile. For this purpose, continuous wavelet transform (CWT) of digitized gamma well logs was performed by using Mexican hat and Morlet, as the mother wavelets, to identify potential discontinuities in the signal. Pointwise Hölder exponents (PHE) of gamma logs were also computed using the generalized quadratic variations (GQV) method to identify the location and strength of singularities of well log signals as a complementary analysis. PHEs and wavelet coefficients were analyzed to find the locations of singularities along the logs. Using the well logs in this study, locations of predicted singularities were used as indicators in single normal equation simulation (SNESIM) to generate equi-probable realizations of potential strata separation intervals. Horizontal and vertical variograms of realizations were then analyzed and compared with those of indicator data and training image (TI) data using the Kruskal-Wallis test. A sum of squared differences was employed to select the most probable realization representing the locations of potential strata separations and methane flow paths. Results indicated that singularities located in well log signals reliably correlated with strata transitions or discontinuities within the strata. Geostatistical simulation of these discontinuities provided information about the location and extents of the continuous channels that may form during mining. If there is a gas

"Work smart, wear your hard hat"

CERN Multimedia

2003-01-01

Falling objects and collisions are frequent occurrences in work sites and hazardous areas. Hard hats can help prevent many types of accident and can even save lives. Just imagine an 800 g spanner falling from a 13 m high scaffold onto the head of someone standing below - a nightmare scenario! The impact to the head is equivalent to that of a 5 kg weight falling from 2 metres. That is just what happened to Gerd Fetchenhauer when he was working on the UA1 experiment. Fortunately, he was wearing a hard hat at the time. "That hat saved my life," he explains. "It punched a hole right through the hat and I was a bit dazed for a couple of hours but otherwise I was OK." Since that day, Gerd Fetchenhauer, now working on CMS, is never seen on a work site without his hard hat on. Work sites have proliferated at CERN with the construction of the LHC and its detectors, and the wearing of hard hats is compulsory (not to mention life-saving). In the underground caverns and experiment halls, where gantry cranes and other h...

Certain problems concerning wavelets and wavelets packets

Energy Technology Data Exchange (ETDEWEB)

Siddiqi, A H

1995-09-01

Wavelets is the outcome of the synthesis of ideas that have emerged in different branches of science and technology, mainly in the last decade. The concept of wavelet packets, which are superpositions of wavelets, has been introduced a couple of years ago. They form bases which retain many properties of wavelets like orthogonality, smoothness and localization. The Walsh orthornomal system is a special case of wavelet packet. The wavelet packets provide at our disposal a library of orthonormal bases, each of which can be used to analyze a given signal of finite energy. The optimal choice is decided by the entropy criterion. In the present paper we discuss results concerning convergence, coefficients, and approximation of wavelet packets series in general and wavelets series in particular. Wavelet packet techniques for solutions of differential equations are also mentioned. (author). 117 refs.

Certain problems concerning wavelets and wavelets packets

International Nuclear Information System (INIS)

Siddiqi, A.H.

1995-09-01

Wavelets is the outcome of the synthesis of ideas that have emerged in different branches of science and technology, mainly in the last decade. The concept of wavelet packets, which are superpositions of wavelets, has been introduced a couple of years ago. They form bases which retain many properties of wavelets like orthogonality, smoothness and localization. The Walsh orthornomal system is a special case of wavelet packet. The wavelet packets provide at our disposal a library of orthonormal bases, each of which can be used to analyze a given signal of finite energy. The optimal choice is decided by the entropy criterion. In the present paper we discuss results concerning convergence, coefficients, and approximation of wavelet packets series in general and wavelets series in particular. Wavelet packet techniques for solutions of differential equations are also mentioned. (author). 117 refs

Hard-hat day

CERN Multimedia

2003-01-01

CERN will be organizing a special information day on Friday, 27th June, designed to promote the wearing of hard hats and ensure that they are worn correctly. A new prevention campaign will also be launched.The event will take place in the hall of the Main Building from 11.30 a.m. to 2.00 p.m., when you will be able to come and try on various models of hard hat, including some of the very latest innovative designs, ask questions and pass on any comments and suggestions.

Hat cycle dynamic simulation

International Nuclear Information System (INIS)

Trucco, A.; Corallo, C.; Pini Prato, A.; Porro, S.

1999-01-01

Among the innovative cycle recently proposed in literature, the Humid Air Turbine Cycle - Hat better seems to fulfil the main energy market requirements of today: High efficiency in a large power ranger, low pollution, low specific capital cost. The previous results of an analysis at partial load and transient conditions are here presented, where the Hat plant has been simulated using the original model implemented in LEGO environment [it

Performance comparison of novel WNN approach with RBFNN in navigation of autonomous mobile robotic agent

Directory of Open Access Journals (Sweden)

Ghosh Saradindu

2016-01-01

Full Text Available This paper addresses the performance comparison of Radial Basis Function Neural Network (RBFNN with novel Wavelet Neural Network (WNN of designing intelligent controllers for path planning of mobile robot in an unknown environment. In the proposed WNN, different types of activation functions such as Mexican Hat, Gaussian and Morlet wavelet functions are used in the hidden nodes. The neural networks are trained by an intelligent supervised learning technique so that the robot makes a collision-free path in the unknown environment during navigation from different starting points to targets/goals. The efficiency of two algorithms is compared using some MATLAB simulations and experimental setup with Arduino Mega 2560 microcontroller in terms of path length and time taken to reach the target as an indicator for the accuracy of the network models.

Discovering Wavelets

CERN Document Server

Aboufadel, Edward

1999-01-01

An accessible and practical introduction to wavelets. With applications in image processing, audio restoration, seismology, and elsewhere, wavelets have been the subject of growing excitement and interest over the past several years. Unfortunately, most books on wavelets are accessible primarily to research mathematicians. Discovering Wavelets presents basic and advanced concepts of wavelets in a way that is accessible to anyone with only a fundamental knowledge of linear algebra. The basic concepts of wavelet theory are introduced in the context of an explanation of how the FBI uses wavelets

Image processing for quantifying fracture orientation and length scale transitions during brittle deformation

Science.gov (United States)

Rizzo, R. E.; Healy, D.; Farrell, N. J.

2017-12-01

We have implemented a novel image processing tool, namely two-dimensional (2D) Morlet wavelet analysis, capable of detecting changes occurring in fracture patterns at different scales of observation, and able of recognising the dominant fracture orientations and the spatial configurations for progressively larger (or smaller) scale of analysis. Because of its inherited anisotropy, the Morlet wavelet is proved to be an excellent choice for detecting directional linear features, i.e. regions where the amplitude of the signal is regular along one direction and has sharp variation along the perpendicular direction. Performances of the Morlet wavelet are tested against the 'classic' Mexican hat wavelet, deploying a complex synthetic fracture network. When applied to a natural fracture network, formed triaxially (σ1>σ2=σ3) deforming a core sample of the Hopeman sandstone, the combination of 2D Morlet wavelet and wavelet coefficient maps allows for the detection of characteristic scale orientation and length transitions, associated with the shifts from distributed damage to the growth of localised macroscopic shear fracture. A complementary outcome arises from the wavelet coefficient maps produced by increasing the wavelet scale parameter. These maps can be used to chart the variations in the spatial distribution of the analysed entities, meaning that it is possible to retrieve information on the density of fracture patterns at specific length scales during deformation.

Measurements of the UVR protection provided by hats used at school.

Science.gov (United States)

Gies, Peter; Javorniczky, John; Roy, Colin; Henderson, Stuart

2006-01-01

The importance of protection against solar ultraviolet radiation (UVR) in childhood has lead to SunSmart policies at Australian schools, in particular primary schools, where children are encouraged and in many cases required to wear hats at school. Hat styles change regularly and the UVR protection provided by some of the hat types currently used and recommended for sun protection by the various Australian state cancer councils had not been previously evaluated. The UVR protection of the hats was measured using UVR sensitive polysulphone film badges attached to different facial sites on rotating headforms. The sun protection type hats included in this study were broad-brimmed hats, "bucket hats" and legionnaires hats. Baseball caps, which are very popular, were also included. The broad-brimmed hats and bucket hats provided the most UVR protection for the six different sites about the face and head. Legionnaires hats also provided satisfactory UVR protection, but the caps did not provide UVR protection to many of the facial sites. The highest measured UVR protection factors for facial sites other than the forehead were 8 to 10, indicating that, while some hats can be effective, they need to be used in combination with other forms of UVR protection.

James J. Gallagher: Man in the White Hat

Science.gov (United States)

Jolly, Jennifer L.; Robinson, Ann

2014-01-01

In classic Western movies, the good guy could be frequently identified by his trademark white Stetson hat, whereas the bad guy always wore black. James J. Gallagher wore many hats during his career that spanned over six decades; he too would be known as the "man in the white hat,"--trusted to do the right thing. From 1967 to 1970,…

HATS-50b through HATS-53b: Four Transiting Hot Jupiters Orbiting G-type Stars Discovered by the HATSouth Survey

Science.gov (United States)

Henning, Th.; Mancini, L.; Sarkis, P.; Bakos, G. Á.; Hartman, J. D.; Bayliss, D.; Bento, J.; Bhatti, W.; Brahm, R.; Ciceri, S.; Csubry, Z.; de Val-Borro, M.; Espinoza, N.; Fulton, B. J.; Howard, A. W.; Isaacson, H. T.; Jordán, A.; Marcy, G. W.; Penev, K.; Rabus, M.; Suc, V.; Tan, T. G.; Tinney, C. G.; Wright, D. J.; Zhou, G.; Durkan, S.; Lazar, J.; Papp, I.; Sari, P.

2018-02-01

We report the discovery of four close-in transiting exoplanets (HATS-50b through HATS-53b), discovered using the HATSouth three-continent network of homogeneous and automated telescopes. These new exoplanets belong to the class of hot Jupiters and orbit G-type dwarf stars, with brightness in the range V = 12.5–14.0 mag. While HATS-53 has many physical characteristics similar to the Sun, the other three stars appear to be metal-rich ([{Fe}/{{H}}]=0.2{--}0.3), larger, and more massive. Three of the new exoplanets, namely HATS-50b, HATS-51b, and HATS-53b, have low density (HATS-50b: 0.39+/- 0.10 {M}{{J}}, 1.130+/- 0.075 {R}{{J}}; HATS-51b: 0.768+/- 0.045 {M}{{J}}, 1.41+/- 0.19 {R}{{J}}; HATS-53b: 0.595+/- 0.089 {M}{{J}}, 1.340+/- 0.056 {R}{{J}}) and similar orbital periods (3.8297 days, 3.3489 days, 3.8538 days, respectively). Instead, HATS-52b is more dense (mass 2.24+/- 0.15 {M}{{J}} and radius 1.382+/- 0.086 {R}{{J}}) and has a shorter orbital period (1.3667 days). It also receives an intensive radiation from its parent star and, consequently, presents a high equilibrium temperature ({T}{eq}=1834+/- 73 K). HATS-50 shows a marginal additional transit feature consistent with an ultra-short-period hot super Neptune (upper mass limit 0.16 {M}{{J}}), which will be able to be confirmed with TESS photometry. The HATSouth network is operated by a collaboration consisting of Princeton University (PU), the Max Planck Institute für Astronomie (MPIA), the Australian National University (ANU), and the Pontificia Universidad Católica de Chile (PUC). The station at Las Campanas Observatory (LCO) of the Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. Based in part on observations made with the ESO 3.6 m, the NTT, the MPG 2.2 m and Euler 1.2 m Telescopes at the ESO Observatory in

Detection of seismic phases by wavelet transform. Dependence of its performance on wavelet functions; Wavelet henkan ni yoru jishinha no iso kenshutsu. Wavelet ni yoru sai

Energy Technology Data Exchange (ETDEWEB)

Zeng, X; Yamazaki, K [Tokyo Gakugei University, Tokyo (Japan); Oguchi, Y [Hosei University, Tokyo (Japan)

1997-10-22

A study has been performed on wavelet analysis of seismic waves. In the wavelet analysis of seismic waves, there is a possibility that the results according to different wavelet functions may come out with great difference. The study has carried out the following analyses: an analysis of amplitude and phase using wavelet transform which uses wavelet function of Morlet on P- and S-waves generated by natural earthquakes and P-wave generated by an artificial earthquake, and an analysis using continuous wavelet transform, which uses a constitution of complex wavelet function constructed by a completely diagonal scaling function of Daubechies and the wavelet function. As a result, the following matters were made clear: the result of detection of abnormal components or discontinuity depends on the wavelet function; if the Morlet wavelet function is used to properly select angular frequency and scale, equiphase lines in a phase scalogram concentrate on the discontinuity; and the result of applying the complex wavelet function is superior to that of applying the wavelet function of Morlet. 2 refs., 5 figs.

TCUP: A novel hAT transposon active in maize tissue culture

Directory of Open Access Journals (Sweden)

Alan eSmith

2012-01-01

Full Text Available Transposable elements are capable of inducing heritable de novo genetic variation. The sequences capable of reactivation, and environmental factors that induce mobilization, remain poorly defined even in well-studied genomes such as maize. We treated maize tissue culture with the demethylating agent 5-aza-2-deoxcytidine and examined long-term tissue culture lines to discover silenced transposable elements that have the potential to induce heritable genetic variation. Through these screens we have identified a novel low copy number hAT transposon, Tissue Culture Up-Regulated (TCUP, which is transcribed at high levels in long-term maize Black Mexican Sweet (BMS tissue culture and up-regulated in response to treatment with 5-aza-2-deoxycytidine. Analysis of the TIGR Maize Gene Index revealed that this element is the most frequently represented EST from the BMS cell culture library and is not represented in other tissue libraries, which is the basis for its name. A full-length sequence was assembled in inbred B73 that contains the putative functional motifs required for autonomous movement of a hAT transposon. Transposon display detected movement of TCUP in two long-term tissue cultured cell lines of the genotype Hi-II AxB and BMS. This research implicates TCUP as a transposon that is capable of reactivation and which may also be particularly sensitive to the stress of the tissue culture environment. Our findings are consistent with the hypothesis that epigenetic alterations potentiate genomic responses to stress during clonal propagation of plants.

Spitzer Secondary Eclipses of HAT-P-13b

Science.gov (United States)

Hardy, Ryan A.; Harrington, J.; Hardin, M. R.; Madhusudhan, N.; Cubillos, P.; Blecic, J.; Bakos, G.; Hartman, J. D.

2013-10-01

HAT-P-13 b is a transiting hot Jupiter with a slightly eccentric orbit (e = 0.010) inhabiting a two-planet system. The two-planet arrangement provides an opportunity to probe the interior structure of HAT-P-13b. Under equilibrium-tide theory and confirmation that the apsides of planets b and c are in alignment, a measurement of the planet's eccentricity can be related to the planet's tidal Love number k2, which describes the central condensation of the planet's mass and its deformation under tidal effects. A measurement of k2 could constrain interior models of HAT-P-13b. HAT-P-13b's orbit is configured favorably for refinement of the eccentricity by secondary eclipse timing observations, which provide direct measurements of ecosω. In 2010, Spitzer observed two secondary eclipses of HAT-P-13b in the 3.6- and 4.5-μm IRAC bandpasses. We present secondary eclipse times and depths; joint models of the HAT-P-13 system that incorporate transit photometry and radial velocity data; and constraints on the atmospheric chemistry of HAT-P-13b that suggest solar-abundance composition without a thermal inversion. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA, which provided support for this work. This work was supported in part by NASA Planetary Atmospheres Grant NNX13AF38G.

WARM SPITZER OBSERVATIONS OF THREE HOT EXOPLANETS: XO-4b, HAT-P-6b, AND HAT-P-8b

Energy Technology Data Exchange (ETDEWEB)

Todorov, Kamen O. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Deming, Drake [Planetary Systems Laboratory, NASA' s Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Knutson, Heather A. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 05844 (United States); Sada, Pedro V. [Department of Physics and Mathematics, University of Monterrey, Monterrey (Mexico); Cowan, Nicolas B. [Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Agol, Eric [Department of Astronomy, University of Washington, Box 351580, Seattle, WA 98195 (United States); Desert, Jean-Michel; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Fortney, Jonathan J.; Laughlin, Gregory [Department of Astronomy and Astrophysics, University of California at Santa Cruz, Santa Cruz, CA 95064 (United States); Langton, Jonathan [Department of Physics, Principia College, Elsah, IL 62028 (United States); Showman, Adam P.; Lewis, Nikole K. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

2012-02-10

We analyze Warm Spitzer/Infrared Array Camera observations of the secondary eclipses of three planets, XO-4b, HAT-P-6b, and HAT-P-8b. We measure secondary eclipse amplitudes at 3.6 {mu}m and 4.5 {mu}m for each target. XO-4b exhibits a stronger eclipse depth at 4.5 {mu}m than at 3.6 {mu}m, which is consistent with the presence of a temperature inversion. HAT-P-8b shows a stronger eclipse amplitude at 3.6 {mu}m and is best described by models without a temperature inversion. The eclipse depths of HAT-P-6b can be fitted with models with a small or no temperature inversion. We consider our results in the context of a postulated relationship between stellar activity and temperature inversion and a relationship between irradiation level and planet dayside temperature, as discussed by Knutson et al. and Cowan and Agol, respectively. Our results are consistent with these hypotheses, but do not significantly strengthen them. To measure accurate secondary eclipse central phases, we require accurate ephemerides. We obtain primary transit observations and supplement them with publicly available observations to update the orbital ephemerides of the three planets. Based on the secondary eclipse timing, we set upper boundaries for ecos ({omega}) for HAT-P-6b, HAT-P-8b, and XO-4b and find that the values are consistent with circular orbits.

Wavelet analysis

CERN Document Server

Cheng, Lizhi; Luo, Yong; Chen, Bo

2014-01-01

This book could be divided into two parts i.e. fundamental wavelet transform theory and method and some important applications of wavelet transform. In the first part, as preliminary knowledge, the Fourier analysis, inner product space, the characteristics of Haar functions, and concepts of multi-resolution analysis, are introduced followed by a description on how to construct wavelet functions both multi-band and multi wavelets, and finally introduces the design of integer wavelets via lifting schemes and its application to integer transform algorithm. In the second part, many applications are discussed in the field of image and signal processing by introducing other wavelet variants such as complex wavelets, ridgelets, and curvelets. Important application examples include image compression, image denoising/restoration, image enhancement, digital watermarking, numerical solution of partial differential equations, and solving ill-conditioned Toeplitz system. The book is intended for senior undergraduate stude...

Atmospheric Retrievals of HAT-P-16b and WASP-11b/HAT-P-10b

Science.gov (United States)

McIntyre, Kathleen; Harrington, Joseph; Challener, Ryan; Lenius, Maria; Hartman, Joel D.; Bakos, Gaspar A.; Blecic, Jasmina; Cubillos, Patricio E.; Cameron, Andrew

2018-01-01

We report Bayesian atmospheric retrievals performed on the exoplanets HAT-P-16b and WASP-11b/HAT-P-10b. HAT-P-16b is a hot (equilibrium temperature 1626 ± 40 K, assuming zero Bond albedo and efficient energy redistribution), 4.19 ± 0.09 Jupiter-mass exoplanet orbiting an F8 star every 2.775960 ± 0.000003 days (Buchhave et al 2010). WASP-11b/HAT-P-10b is a cooler (1020 ± 17 K), 0.487 ± 0.018 Jupiter-mass exoplanet orbiting a K3 star every 3.7224747 ± 0.0000065 days (Bakos et al. 2009, co-discovered by West et al. 2008). We observed secondary eclipses of both planets using the 3.6 μm and 4.5 μm channels of the Spitzer Space Telescope's Infrared Array Camera (program ID 60003). We applied our Photometry for Orbits, Eclipses, and Transits (POET) code to produce normalized eclipse light curves, and our Bayesian Atmospheric Radiative Transfer (BART) code to constrain the temperature-pressure profiles and atmospheric molecular abundances of the two planets. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

ERRATUM: Work smart, wear your hard hat

CERN Multimedia

2003-01-01

An error appeared in the article «Work smart, wear your hard hat» published in Weekly Bulletin 27/2003, page 5. The impact which pierced a hole in the hard hat worn by Gerd Fetchenhauer was the equivalent of a box weighing 5 kg and not 50 kg.

Significance tests for the wavelet cross spectrum and wavelet linear coherence

Directory of Open Access Journals (Sweden)

Z. Ge

2008-12-01

Full Text Available This work attempts to develop significance tests for the wavelet cross spectrum and the wavelet linear coherence as a follow-up study on Ge (2007. Conventional approaches that are used by Torrence and Compo (1998 based on stationary background noise time series were used here in estimating the sampling distributions of the wavelet cross spectrum and the wavelet linear coherence. The sampling distributions are then used for establishing significance levels for these two wavelet-based quantities. In addition to these two wavelet quantities, properties of the phase angle of the wavelet cross spectrum of, or the phase difference between, two Gaussian white noise series are discussed. It is found that the tangent of the principal part of the phase angle approximately has a standard Cauchy distribution and the phase angle is uniformly distributed, which makes it impossible to establish significance levels for the phase angle. The simulated signals clearly show that, when there is no linear relation between the two analysed signals, the phase angle disperses into the entire range of [−π,π] with fairly high probabilities for values close to ±π to occur. Conversely, when linear relations are present, the phase angle of the wavelet cross spectrum settles around an associated value with considerably reduced fluctuations. When two signals are linearly coupled, their wavelet linear coherence will attain values close to one. The significance test of the wavelet linear coherence can therefore be used to complement the inspection of the phase angle of the wavelet cross spectrum. The developed significance tests are also applied to actual data sets, simultaneously recorded wind speed and wave elevation series measured from a NOAA buoy on Lake Michigan. Significance levels of the wavelet cross spectrum and the wavelet linear coherence between the winds and the waves reasonably separated meaningful peaks from those generated by randomness in the data set. As

Criticality in the configuration-mixed interacting boson model (1) $U(5)-\\hat{Q}(\\chi)\\cdot\\hat{Q}(\\chi)$ mixing

CERN Document Server

Hellemans, V; De Baerdemacker, S; Heyde, K

2008-01-01

The case of U(5)--$\\hat{Q}(\\chi)\\cdot\\hat{Q}(\\chi)$ mixing in the configuration-mixed Interacting Boson Model is studied in its mean-field approximation. Phase diagrams with analytical and numerical solutions are constructed and discussed. Indications for first-order and second-order shape phase transitions can be obtained from binding energies and from critical exponents, respectively.

FACTORS & ELEMENTAL ANALYSIS OF SIX THINKING HATS TECHNIQUE USING ABCD FRAMEWORK

OpenAIRE

Dr. P. S. Aithal; V. T. Shailashree; Dr. P. M. Suresh Kumar

2017-01-01

De Bono's Six Thinking Hats technique suggests different types of thinking corresponding to six thinking roles for the analyst, associated with hats of six different colors. The technique correlates different thinking styles used in a systematic problem solving procedure with different coloured hats. Alternately, by conceptualizing each type of hat, the person focuses on the style of thinking associated with each colour so that the problem can be analysed from different angles and frame of re...

'Nederlandismes' in HAT

Directory of Open Access Journals (Sweden)

F. van Houwelingen

1998-04-01

Full Text Available Dutch influence in HAT (1994 Although there is consensus among linguists that Afrikaans and Dutch are related languages, and that Afrikaans originated from 17th century Dutch, the differences between present-day varieties of Afrikaans and Dutch serve as proof that we are dealing with two separate languages. These differences should be clearly visible in descriptive as well as normative sources of the two languages. However, the third edition of Verklarende Handewoordeboek van die Afrikaanse Taal (HAT, one of the leading Afrikaans standard monolingual dictionaries, contains headwords as well as microstructural information that do not agree with the reality of the Afrikaans of today. An empirical investigation conducted among Afrikaans-speaking dictionary users has proven that a significant Dutch influence is still prominent - in the micro- as well as the macrostructure of the dictionary. It is believed that the Dutch "thread" of many Afrikaans dictionaries has indirectly contributed towards the creation of a super-standard norm, which is partially responsible for the estrangement between the cultural language and the vernacular.

Novel insect leaf-mining after the end-Cretaceous extinction and the demise of cretaceous leaf miners, Great Plains, USA.

Directory of Open Access Journals (Sweden)

Michael P Donovan

Full Text Available Plant and associated insect-damage diversity in the western U.S.A. decreased significantly at the Cretaceous-Paleogene (K-Pg boundary and remained low until the late Paleocene. However, the Mexican Hat locality (ca. 65 Ma in southeastern Montana, with a typical, low-diversity flora, uniquely exhibits high damage diversity on nearly all its host plants, when compared to all known local and regional early Paleocene sites. The same plant species show minimal damage elsewhere during the early Paleocene. We asked whether the high insect damage diversity at Mexican Hat was more likely related to the survival of Cretaceous insects from refugia or to an influx of novel Paleocene taxa. We compared damage on 1073 leaf fossils from Mexican Hat to over 9000 terminal Cretaceous leaf fossils from the Hell Creek Formation of nearby southwestern North Dakota and to over 9000 Paleocene leaf fossils from the Fort Union Formation in North Dakota, Montana, and Wyoming. We described the entire insect-feeding ichnofauna at Mexican Hat and focused our analysis on leaf mines because they are typically host-specialized and preserve a number of diagnostic morphological characters. Nine mine damage types attributable to three of the four orders of leaf-mining insects are found at Mexican Hat, six of them so far unique to the site. We found no evidence linking any of the diverse Hell Creek mines with those found at Mexican Hat, nor for the survival of any Cretaceous leaf miners over the K-Pg boundary regionally, even on well-sampled, surviving plant families. Overall, our results strongly relate the high damage diversity on the depauperate Mexican Hat flora to an influx of novel insect herbivores during the early Paleocene, possibly caused by a transient warming event and range expansion, and indicate drastic extinction rather than survivorship of Cretaceous insect taxa from refugia.

Novel insect leaf-mining after the end-Cretaceous extinction and the demise of cretaceous leaf miners, Great Plains, USA.

Science.gov (United States)

Donovan, Michael P; Wilf, Peter; Labandeira, Conrad C; Johnson, Kirk R; Peppe, Daniel J

2014-01-01

Plant and associated insect-damage diversity in the western U.S.A. decreased significantly at the Cretaceous-Paleogene (K-Pg) boundary and remained low until the late Paleocene. However, the Mexican Hat locality (ca. 65 Ma) in southeastern Montana, with a typical, low-diversity flora, uniquely exhibits high damage diversity on nearly all its host plants, when compared to all known local and regional early Paleocene sites. The same plant species show minimal damage elsewhere during the early Paleocene. We asked whether the high insect damage diversity at Mexican Hat was more likely related to the survival of Cretaceous insects from refugia or to an influx of novel Paleocene taxa. We compared damage on 1073 leaf fossils from Mexican Hat to over 9000 terminal Cretaceous leaf fossils from the Hell Creek Formation of nearby southwestern North Dakota and to over 9000 Paleocene leaf fossils from the Fort Union Formation in North Dakota, Montana, and Wyoming. We described the entire insect-feeding ichnofauna at Mexican Hat and focused our analysis on leaf mines because they are typically host-specialized and preserve a number of diagnostic morphological characters. Nine mine damage types attributable to three of the four orders of leaf-mining insects are found at Mexican Hat, six of them so far unique to the site. We found no evidence linking any of the diverse Hell Creek mines with those found at Mexican Hat, nor for the survival of any Cretaceous leaf miners over the K-Pg boundary regionally, even on well-sampled, surviving plant families. Overall, our results strongly relate the high damage diversity on the depauperate Mexican Hat flora to an influx of novel insect herbivores during the early Paleocene, possibly caused by a transient warming event and range expansion, and indicate drastic extinction rather than survivorship of Cretaceous insect taxa from refugia.

Wavelet basics

CERN Document Server

Chan, Y T

1995-01-01

Since the study of wavelets is a relatively new area, much of the research coming from mathematicians, most of the literature uses terminology, concepts and proofs that may, at times, be difficult and intimidating for the engineer. Wavelet Basics has therefore been written as an introductory book for scientists and engineers. The mathematical presentation has been kept simple, the concepts being presented in elaborate detail in a terminology that engineers will find familiar. Difficult ideas are illustrated with examples which will also aid in the development of an intuitive insight. Chapter 1 reviews the basics of signal transformation and discusses the concepts of duals and frames. Chapter 2 introduces the wavelet transform, contrasts it with the short-time Fourier transform and clarifies the names of the different types of wavelet transforms. Chapter 3 links multiresolution analysis, orthonormal wavelets and the design of digital filters. Chapter 4 gives a tour d'horizon of topics of current interest: wave...

Wavelets in neuroscience

CERN Document Server

Hramov, Alexander E; Makarov, Valeri A; Pavlov, Alexey N; Sitnikova, Evgenia

2015-01-01

This book examines theoretical and applied aspects of wavelet analysis in neurophysics, describing in detail different practical applications of the wavelet theory in the areas of neurodynamics and neurophysiology and providing a review of fundamental work that has been carried out in these fields over the last decade. Chapters 1 and 2 introduce and review the relevant foundations of neurophysics and wavelet theory, respectively, pointing on one hand to the various current challenges in neuroscience and introducing on the other the mathematical techniques of the wavelet transform in its two variants (discrete and continuous) as a powerful and versatile tool for investigating the relevant neuronal dynamics. Chapter 3 then analyzes results from examining individual neuron dynamics and intracellular processes. The principles for recognizing neuronal spikes from extracellular recordings and the advantages of using wavelets to address these issues are described and combined with approaches based on wavelet neural ...

Multivariate wavelet frames

CERN Document Server

Skopina, Maria; Protasov, Vladimir

2016-01-01

This book presents a systematic study of multivariate wavelet frames with matrix dilation, in particular, orthogonal and bi-orthogonal bases, which are a special case of frames. Further, it provides algorithmic methods for the construction of dual and tight wavelet frames with a desirable approximation order, namely compactly supported wavelet frames, which are commonly required by engineers. It particularly focuses on methods of constructing them. Wavelet bases and frames are actively used in numerous applications such as audio and graphic signal processing, compression and transmission of information. They are especially useful in image recovery from incomplete observed data due to the redundancy of frame systems. The construction of multivariate wavelet frames, especially bases, with desirable properties remains a challenging problem as although a general scheme of construction is well known, its practical implementation in the multidimensional setting is difficult. Another important feature of wavelet is ...

Application of Six Thinking Hats with the Theme „Profession of Sociologist”. Transcript of the Sequence of Green Hat

Directory of Open Access Journals (Sweden)

Gheorghe Onuţ

2009-12-01

Full Text Available The study is the transcription of the sequence of green hat from the application of the creative technique Six Thinking Hats (Edward de Bono’s creation that I did at the workshop with the theme „Profession of Sociologist”, of the international colloquium of social sciences ACUM 2008. The colloquium ACUM is the most important of the scientific manifestations organized by the Faculty of Law and Sociology of „Transilvania” University of Braşov.

Wavelets and their uses

International Nuclear Information System (INIS)

Dremin, Igor M; Ivanov, Oleg V; Nechitailo, Vladimir A

2001-01-01

This review paper is intended to give a useful guide for those who want to apply the discrete wavelet transform in practice. The notion of wavelets and their use in practical computing and various applications are briefly described, but rigorous proofs of mathematical statements are omitted, and the reader is just referred to the corresponding literature. The multiresolution analysis and fast wavelet transform have become a standard procedure for dealing with discrete wavelets. The proper choice of a wavelet and use of nonstandard matrix multiplication are often crucial for the achievement of a goal. Analysis of various functions with the help of wavelets allows one to reveal fractal structures, singularities etc. The wavelet transform of operator expressions helps solve some equations. In practical applications one often deals with the discretized functions, and the problem of stability of the wavelet transform and corresponding numerical algorithms becomes important. After discussing all these topics we turn to practical applications of the wavelet machinery. They are so numerous that we have to limit ourselves to a few examples only. The authors would be grateful for any comments which would move us closer to the goal proclaimed in the first phrase of the abstract. (reviews of topical problems)

Adaptive Wavelet Transforms

Energy Technology Data Exchange (ETDEWEB)

Szu, H.; Hsu, C. [Univ. of Southwestern Louisiana, Lafayette, LA (United States)

1996-12-31

Human sensors systems (HSS) may be approximately described as an adaptive or self-learning version of the Wavelet Transforms (WT) that are capable to learn from several input-output associative pairs of suitable transform mother wavelets. Such an Adaptive WT (AWT) is a redundant combination of mother wavelets to either represent or classify inputs.

Become a CERN WhiteHat

CERN Multimedia

CERN. Geneva

2014-01-01

Discovering CERN's weaknesses is as important as ever. Become a CERN WhiteHat and help us poking around CERN computing services and web applications. All you need is to apply and get the appropriate training...

Incidence of Hospital Acquired Thrombosis (HAT) in a Tertiary Care Hospital.

LENUS (Irish Health Repository)

Khan, MI

2017-04-01

Venous thromboembolism (VTE) is a major cause of preventable morbidity and mortality in hospitalized patients. In spite of guidelines, VTE prophylaxis continues to be underutilised, and hospital acquired thrombosis (HAT) continues to be a problem. This study was conducted to estimate the incidence of HAT in a tertiary referral centre and to examine whether VTE risk assessment and thromboprophylaxis (TP) were implemented. Patients 18 years and above, with a radiologically-confirmed acute VTE during the study period of 15 weeks were included. Acute VTE was diagnosed in 100 patients and HAT was diagnosed in 48. There were 12,024 admissions over the study period, therefore the incidence of HAT was 0.4%. TP was prescribed in only 35% of patients, and 65% did not receive any or appropriate TP. Hospitals without active implementation of a formal risk assessment tool and TP policy are likely to continue to have increased incidence of HAT.

The GAPS programme with HARPS-N at TNG. XVI. Measurement of the Rossiter-McLaughlin effect of transiting planetary systems HAT-P-3, HAT-P-12, HAT-P-22, WASP-39, and WASP-60

Science.gov (United States)

Mancini, L.; Esposito, M.; Covino, E.; Southworth, J.; Biazzo, K.; Bruni, I.; Ciceri, S.; Evans, D.; Lanza, A. F.; Poretti, E.; Sarkis, P.; Smith, A. M. S.; Brogi, M.; Affer, L.; Benatti, S.; Bignamini, A.; Boccato, C.; Bonomo, A. S.; Borsa, F.; Carleo, I.; Claudi, R.; Cosentino, R.; Damasso, M.; Desidera, S.; Giacobbe, P.; González-Álvarez, E.; Gratton, R.; Harutyunyan, A.; Leto, G.; Maggio, A.; Malavolta, L.; Maldonado, J.; Martinez-Fiorenzano, A.; Masiero, S.; Micela, G.; Molinari, E.; Nascimbeni, V.; Pagano, I.; Pedani, M.; Piotto, G.; Rainer, M.; Scandariato, G.; Smareglia, R.; Sozzetti, A.; Andreuzzi, G.; Henning, Th.

2018-05-01

Context. The measurement of the orbital obliquity of hot Jupiters with different physical characteristics can provide clues to the mechanisms of migration and orbital evolution of this particular class of giant exoplanets. Aims: We aim to derive the degree of alignment between planetary orbit and stellar spin angular momentum vectors and look for possible links with other orbital and fundamental physical parameters of the star-planet system. We focus on the characterisation of five transiting planetary systems (HAT-P-3, HAT-P-12, HAT-P-22, WASP-39, and WASP-60) and the determination of their sky-projected planet orbital obliquity through the measurement of the Rossiter-McLaughlin effect. Methods: We used HARPS-N high-precision radial velocity measurements, gathered during transit events, to measure the Rossiter-McLaughlin effect in the target systems and determine the sky-projected angle between the planetary orbital plane and stellar equator. The characterisation of stellar atmospheric parameters was performed by exploiting the HARPS-N spectra, using line equivalent width ratios and spectral synthesis methods. Photometric parameters of the five transiting exoplanets were re-analysed through 17 new light curves, obtained with an array of medium-class telescopes, and other light curves from the literature. Survey-time-series photometric data were analysed for determining the rotation periods of the five stars and their spin inclination. Results: From the analysis of the Rossiter-McLaughlin effect we derived a sky-projected obliquity of λ = 21.2° ± 8.7°, λ = -54°-13°+41°, λ = -2.1° ± 3.0°, λ = 0° ± 11°, and λ = -129° ± 17° for HAT-P-3 b, HAT-P-12 b, HAT-P-22 b, WASP-39 b, and WASP-60 b, respectively. The latter value indicates that WASP-60 b is moving on a retrograde orbit. These values represent the first measurements of λ for the five exoplanetary systems under study. The stellar activity of HAT-P-22 indicates a rotation period of 28.7 ± 0

The elliptic quantum algebra Uq,p(sl-hatN) and its vertex operators

International Nuclear Information System (INIS)

Chang Wenjing; Ding Xiangmao

2009-01-01

We construct a realization of the elliptic quantum algebra U q,p (sl-hat N ) for any given level k in terms of free boson fields and their twisted partners. It can be considered as the elliptic deformation of the Wakimoto realization of the quantum affine algebra U q (sl-hat N ). We also construct a family of screening currents, which commute with the currents of U q,p (sl-hat N ) up to total q-differences. And we give explicit twisted expressions for the type I and type II vertex operators of U q,p (sl-hat N ) by twisting the known results of the type I vertex operators of the quantum affine algebra U q (sl-hat N ) and the new results of the type II vertex operators of U q (sl-hat N ) we obtained in this paper.

Wavelet Transforms using VTK-m

Energy Technology Data Exchange (ETDEWEB)

Li, Shaomeng [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Sewell, Christopher Meyer [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-09-27

These are a set of slides that deal with the topics of wavelet transforms using VTK-m. First, wavelets are discussed and detailed, then VTK-m is discussed and detailed, then wavelets and VTK-m are looked at from a performance comparison, then from an accuracy comparison, and finally lessons learned, conclusion, and what is next. Lessons learned are the following: Launching worklets is expensive; Natural logic of performing 2D wavelet transform: Repeat the same 1D wavelet transform on every row, repeat the same 1D wavelet transform on every column, invoke the 1D wavelet worklet every time: num_rows x num_columns; VTK-m approach of performing 2D wavelet transform: Create a worklet for 2D that handles both rows and columns, invoke this new worklet only one time; Fast calculation, but cannot reuse 1D implementations.

Wavelets in scientific computing

DEFF Research Database (Denmark)

Nielsen, Ole Møller

1998-01-01

the FWT can be used as a front-end for efficient image compression schemes. Part II deals with vector-parallel implementations of several variants of the Fast Wavelet Transform. We develop an efficient and scalable parallel algorithm for the FWT and derive a model for its performance. Part III...... supported wavelets in the context of multiresolution analysis. These wavelets are particularly attractive because they lead to a stable and very efficient algorithm, namely the fast wavelet transform (FWT). We give estimates for the approximation characteristics of wavelets and demonstrate how and why...... is an investigation of the potential for using the special properties of wavelets for solving partial differential equations numerically. Several approaches are identified and two of them are described in detail. The algorithms developed are applied to the nonlinear Schrödinger equation and Burgers' equation...

HATS-43b, HATS-44b, HATS-45b, and HATS-46b: Four Short-period Transiting Giant Planets in the Neptune–Jupiter Mass Range

Science.gov (United States)

Brahm, R.; Hartman, J. D.; Jordán, A.; Bakos, G. Á.; Espinoza, N.; Rabus, M.; Bhatti, W.; Penev, K.; Sarkis, P.; Suc, V.; Csubry, Z.; Bayliss, D.; Bento, J.; Zhou, G.; Mancini, L.; Henning, T.; Ciceri, S.; de Val-Borro, M.; Shectman, S.; Crane, J. D.; Arriagada, P.; Butler, P.; Teske, J.; Thompson, I.; Osip, D.; Díaz, M.; Schmidt, B.; Lázár, J.; Papp, I.; Sári, P.

2018-03-01

We report the discovery of four short-period extrasolar planets transiting moderately bright stars from photometric measurements of the HATSouth network coupled to additional spectroscopic and photometric follow-up observations. While the planet masses range from 0.26 to 0.90 {M}{{J}}, the radii are all approximately a Jupiter radii, resulting in a wide range of bulk densities. The orbital period of the planets ranges from 2.7 days to 4.7 days, with HATS-43b having an orbit that appears to be marginally non-circular (e = 0.173 ± 0.089). HATS-44 is notable for having a high metallicity ([{Fe}/{{H}}] = 0.320 ± 0.071). The host stars spectral types range from late F to early K, and all of them are moderately bright (13.3 Carnegie Institute is operated by PU in conjunction with PUC, the station at the High Energy Spectroscopic Survey (H.E.S.S.) site is operated in conjunction with MPIA, and the station at Siding Spring Observatory (SSO) is operated jointly with ANU. This paper includes data gathered with the MPG 2.2 m and ESO 3.6 m telescopes at the ESO Observatory in La Silla. This paper includes data gathered with the 6.5 meter Magellan Telescopes located at Las Campanas Observatory, Chile.

Lecture notes on wavelet transforms

CERN Document Server

Debnath, Lokenath

2017-01-01

This book provides a systematic exposition of the basic ideas and results of wavelet analysis suitable for mathematicians, scientists, and engineers alike. The primary goal of this text is to show how different types of wavelets can be constructed, illustrate why they are such powerful tools in mathematical analysis, and demonstrate their use in applications. It also develops the required analytical knowledge and skills on the part of the reader, rather than focus on the importance of more abstract formulation with full mathematical rigor.  These notes differs from many textbooks with similar titles in that a major emphasis is placed on the thorough development of the underlying theory before introducing applications and modern topics such as fractional Fourier transforms, windowed canonical transforms, fractional wavelet transforms, fast wavelet transforms, spline wavelets, Daubechies wavelets, harmonic wavelets and non-uniform wavelets. The selection, arrangement, and presentation of the material in these ...

The "Burgundian" hat from Herjolfsnes, Greenland: new discoveries, new dates

DEFF Research Database (Denmark)

Smith, Michèle Hayeur; Arneborg, Jette; Smith, Kevin

2016-01-01

of the Greenland Norse colony but also its enduring cultural links with continental European fashions, following a comment to this effect published by Nørlund himself. In 1996, the hat was dated to the early fourteenth century by Arneborg, a century earlier than Nørlund’s dating, based on stylistic comparisons...... with European examples. Recent research on North Atlantic textiles led to a re-examination of the hat, with different sections sampled and resubmitted for accelerated mass spectrometry dating. The results suggest that the body of the hat and its crown are of different periods with c. 100 years between them...

HAT-P-25b

DEFF Research Database (Denmark)

Quinn, S.N.; Bakos, G. 'A; Hartman, J.

2012-01-01

We report the discovery of HAT-P-25b, a transiting extrasolar planet orbiting the V = 13.19 G5 dwarf star GSC 1788-01237, with a period P = 3.652836 +/- 0.000019 days, transit epoch Tc = 2455176.85173 +/- 0.00047 (BJD), and transit duration 0.1174 +/- 0.0017 days. The host star has mass of 1.01 +...

WAVELET ANALYSIS OF ABNORMAL ECGS

Directory of Open Access Journals (Sweden)

Vasudha Nannaparaju

2014-02-01

Full Text Available Detection of the warning signals by the heart can be diagnosed from ECG. An accurate and reliable diagnosis of ECG is very important however which is cumbersome and at times ambiguous in time domain due to the presence of noise. Study of ECG in wavelet domain using both continuous Wavelet transform (CWT and discrete Wavelet transform (DWT, with well known wavelet as well as a wavelet proposed by the authors for this investigation is found to be useful and yields fairly reliable results. In this study, Wavelet analysis of ECGs of Normal, Hypertensive, Diabetic and Cardiac are carried out. The salient feature of the study is that detection of P and T phases in wavelet domain is feasible which are otherwise feeble or absent in raw ECGs.

Fractional Calculus and Shannon Wavelet

Directory of Open Access Journals (Sweden)

Carlo Cattani

2012-01-01

Full Text Available An explicit analytical formula for the any order fractional derivative of Shannon wavelet is given as wavelet series based on connection coefficients. So that for any 2(ℝ function, reconstructed by Shannon wavelets, we can easily define its fractional derivative. The approximation error is explicitly computed, and the wavelet series is compared with Grünwald fractional derivative by focusing on the many advantages of the wavelet method, in terms of rate of convergence.

Wavelets, vibrations and scalings

CERN Document Server

Meyer, Yves

1997-01-01

Physicists and mathematicians are intensely studying fractal sets of fractal curves. Mandelbrot advocated modeling of real-life signals by fractal or multifractal functions. One example is fractional Brownian motion, where large-scale behavior is related to a corresponding infrared divergence. Self-similarities and scaling laws play a key role in this new area. There is a widely accepted belief that wavelet analysis should provide the best available tool to unveil such scaling laws. And orthonormal wavelet bases are the only existing bases which are structurally invariant through dyadic dilations. This book discusses the relevance of wavelet analysis to problems in which self-similarities are important. Among the conclusions drawn are the following: 1) A weak form of self-similarity can be given a simple characterization through size estimates on wavelet coefficients, and 2) Wavelet bases can be tuned in order to provide a sharper characterization of this self-similarity. A pioneer of the wavelet "saga", Meye...

Mexican Perspectives on Mexican-U.S. Relations

Science.gov (United States)

1993-04-01

while serving in the United States military, working in the Bracero program and in American factories. By working with Americans, Mexicans learned that...Mexican government blames the problem on the United States. During the history of the Bracero Program (1942 -1964) 4.6 million Mexicans traveled to...and became familiar to Mexican migrants.ŕ The termination of the Bracero Program did not discourage Mexican agricultural workers from entering the

Application of Human-Autonomy Teaming (HAT) Patterns to Reduce Crew Operations (RCO)

Science.gov (United States)

Shively, R. Jay; Brandt, Summer L.; Lachter, Joel; Matessa, Mike; Sadler, Garrett; Battiste, Henri

2016-01-01

Unmanned aerial systems, robotics, advanced cockpits, and air traffic management are all examples of domains that are seeing dramatic increases in automation. While automation may take on some tasks previously performed by humans, humans will still be required, for the foreseeable future, to remain in the system. The collaboration with humans and these increasingly autonomous systems will begin to resemble cooperation between teammates, rather than simple task allocation. It is critical to understand this human-autonomy teaming (HAT) to optimize these systems in the future. One methodology to understand HAT is by identifying recurring patterns of HAT that have similar characteristics and solutions. This paper applies a methodology for identifying HAT patterns to an advanced cockpit project.

HAT-P-16b

DEFF Research Database (Denmark)

Buchhave, Lars A.; Bakos, G. A.; Hartman, J. D.

2010-01-01

We report the discovery of HAT-P-16b, a transiting extrasolar planet orbiting the V = 10.8 mag F8 dwarf GSC 2792-01700, with a period P = 2.775960 ± 0.000003 days, transit epoch Tc = 2455027.59293 ± 0.00031 (BJD10), and transit duration 0.1276 ± 0.0013 days. The host star has a mass of 1.22 ± 0.0...

HAT-P-38h

DEFF Research Database (Denmark)

Sato, Bun'ei; Hartman, Joel D.; Bakos, Gaspar Á.

2012-01-01

We report on the discovery of HAT-P-38b, a Saturn-mass exoplanet, transiting the V = 12.56 dwarf star GSC 2314-00559 on a P = 4.6404 d circular orbit. The host star is a 0.89 M-circle dot late G dwarf, with solar metallicity and a radius of 0.92 R-circle dot. The planetary companion has a mass of...

Home Automated Telemanagement (HAT System to Facilitate Self-Care of Patients with Chronic Diseases

Directory of Open Access Journals (Sweden)

Joseph Finkelstein

2003-06-01

Full Text Available Successful patient self-management requires a multidisciplinary approach that includes regular patient assessment, disease-specific education, control of medication adherence, implementation of health behavior change models and social support. Existing systems for computer-assisted disease management do not provide this multidisciplinary patient support and do not address treatment compliance issues. We developed the Home Automated Telemanagement (HAT system for patients with different chronic health conditions to facilitate their self-care. The HAT system consists of a home unit, HAT server, and clinician units. Patients at home use a palmtop or a laptop connected with a disease monitor on a regular basis. Each HAT session consists of self-testing, feedback, and educational components. The self-reported symptom data and objective results obtained from disease-specific sensors are automatically sent from patient homes to the HAT server in the hospital. Any web-enabled device can serve as a clinician unit to review patient results. The HAT system monitors self-testing results and patient compliance. The HAT system has been implemented and tested in patients receiving anticoagulation therapy, patients with asthma, COPD and other health conditions. Evaluation results indicated high level of acceptance of the HAT system by the patients and that the system has a positive impact on main clinical outcomes and patient satisfaction with medical care.

Broad-band spectrophotometry of HAT-P-32 b

DEFF Research Database (Denmark)

Mallonn, M.; Bernt, I.; Herrero, E.

2016-01-01

Multicolour broad-band transit observations offer the opportunity to characterize the atmosphere of an extrasolar planet with small- to medium-sized telescopes. One of the most favourable targets is the hot Jupiter HAT-P-32 b. We combined 21 new transit observations of this planet with 36 previou...... makes a recent tentative detection of a scattering feature less likely. Instead, the available spectral measurements of HAT-P-32 b favour a completely flat spectrum from the near-UV to the near-IR. A plausible interpretation is a thick cloud cover at high altitudes....

Probing the parameters of the HAT-P-2 system

Science.gov (United States)

Bailey, Elizabeth; Naoz, Smadar; Batygin, Konstantin

2018-04-01

The HAT-P-2 system contributes an exceptional set of parameters to the exoplanetary inventory. HAT-P-2b weighs in at approximately 9 Jupiter masses, residing on one of the most eccentric, close-in orbits of any hot Jupiter (e~0.5, a~0.07). The identification of an RV trend points to the existence of an additional, long-period companion, which may have facilitated Kozai-Lidov cycles in the system over its multi-Gyr history. The well-constrained parameters of HAT-P-2b present an opportunity to predict the parameters of the perturber, and furthermore, to assess the tidal dissipation involved in the system's evolution. In this work, we employ an octupole-level secular model to account for the interaction of the two massive planets, thus classifying the system's deviations away from purely quadrupolar dynamics.

Wavelets in physics

CERN Document Server

Fang, Li-Zhi

1998-01-01

Recent advances have shown wavelets to be an effective, and even necessary, mathematical tool for theoretical physics. This book is a timely overview of the progress of this new frontier. It includes an introduction to wavelet analysis, and applications in the fields of high energy physics, astrophysics, cosmology and statistical physics. The topics are selected for the interests of physicists and graduate students of theoretical studies. It emphasizes the need for wavelets in describing and revealing structure in physical problems, which is not easily accomplishing by other methods.

Cross-section crushing behaviour of hat-sections (Part II: Analytical modelling)

NARCIS (Netherlands)

Hofmeyer, H.

2005-01-01

Hat-sections are often used to experimentally investigate building sheeting subject to a concentrated load and bending. In car doors, hat-sections are used for side-impact protection. Their crushing behaviour can partly be explained by only observing their cross-sectional behaviour [1]. This

Epigenetic control of learning and memory in Drosophila by Tip60 HAT action.

Science.gov (United States)

Xu, Songjun; Wilf, Rona; Menon, Trisha; Panikker, Priyalakshmi; Sarthi, Jessica; Elefant, Felice

2014-12-01

Disruption of epigenetic gene control mechanisms in the brain causes significant cognitive impairment that is a debilitating hallmark of most neurodegenerative disorders, including Alzheimer's disease (AD). Histone acetylation is one of the best characterized of these epigenetic mechanisms that is critical for regulating learning- and memory- associated gene expression profiles, yet the specific histone acetyltransferases (HATs) that mediate these effects have yet to be fully characterized. Here, we investigate an epigenetic role for the HAT Tip60 in learning and memory formation using the Drosophila CNS mushroom body (MB) as a well-characterized cognition model. We show that Tip60 is endogenously expressed in the Kenyon cells, the intrinsic neurons of the MB, and in the MB axonal lobes. Targeted loss of Tip60 HAT activity in the MB causes thinner and shorter axonal lobes while increasing Tip60 HAT levels cause no morphological defects. Functional consequences of both loss and gain of Tip60 HAT levels in the MB are evidenced by defects in immediate-recall memory. Our ChIP-Seq analysis reveals that Tip60 target genes are enriched for functions in cognitive processes, and, accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, we find that both learning and immediate-recall memory deficits that occur under AD-associated, amyloid precursor protein (APP)-induced neurodegenerative conditions can be effectively rescued by increasing Tip60 HAT levels specifically in the MB. Together, our findings uncover an epigenetic transcriptional regulatory role for Tip60 in cognitive function and highlight the potential of HAT activators as a therapeutic option for neurodegenerative disorders. Copyright © 2014 by the Genetics Society of America.

Application of wavelet transform to seismic data; Wavelet henkan no jishin tansa eno tekiyo

Energy Technology Data Exchange (ETDEWEB)

Nakagami, K; Murayama, R; Matsuoka, T [Japan National Oil Corp., Tokyo (Japan)

1996-05-01

Introduced herein is the use of the wavelet transform in the field of seismic exploration. Among applications so far made, there are signal filtering, break point detection, data compression, and the solution of finite differential equations in the wavelet domain. In the field of data compression in particular, some examples of practical application have been introduced already. In seismic exploration, it is expected that the wavelet transform will separate signals and noises in data in a way different from the Fourier transform. The continuous wavelet transform displays time change in frequency easy to read, but is not suitable for the analysis and processing large quantities of data. On the other hand, the discrete wavelet transform, being an orthogonal transform, can handle large quantities of data. As compared with the conventional Fourier transform that handles only the frequency domain, the wavelet transform handles the time domain as well as the frequency domain, and therefore is more convenient in handling unsteady signals. 9 ref., 8 figs.

Wavelets in functional data analysis

CERN Document Server

Morettin, Pedro A; Vidakovic, Brani

2017-01-01

Wavelet-based procedures are key in many areas of statistics, applied mathematics, engineering, and science. This book presents wavelets in functional data analysis, offering a glimpse of problems in which they can be applied, including tumor analysis, functional magnetic resonance and meteorological data. Starting with the Haar wavelet, the authors explore myriad families of wavelets and how they can be used. High-dimensional data visualization (using Andrews' plots), wavelet shrinkage (a simple, yet powerful, procedure for nonparametric models) and a selection of estimation and testing techniques (including a discussion on Stein’s Paradox) make this a highly valuable resource for graduate students and experienced researchers alike.

Signal Analysis by New Mother Wavelets

International Nuclear Information System (INIS)

Niu Jinbo; Qi Kaiguo; Fan Hongyi

2009-01-01

Based on the general formula for finding qualified mother wavelets [Opt. Lett. 31 (2006) 407] we make wavelet transforms computed with the newly found mother wavelets (characteristic of the power 2n) for some optical Gaussian pulses, which exhibit the ability to measure frequency of the pulse more precisely and clearly. We also work with complex mother wavelets composed of new real mother wavelets, which offer the ability of obtaining phase information of the pulse as well as amplitude information. The analogy between the behavior of Hermite-Gauss beams and that of new wavelet transforms is noticed. (general)

Giant Paperclip Necklaces, Soup-Can Rings and Cherry-Pie Hats

Science.gov (United States)

Winters, Laurel A.

2011-01-01

In this article, the author describes an art project inspired by the wearable sculpture art created by artist Marjorie Schick. Students used wallpaper paste and newspapers to create papier-mache for a mountain hat, a cherry-pie mask/hat, a "dress" shoe and a Cubistic mask. Cardboard was used in many of these things, in addition to being used as…

Application of Shannon Wavelet Entropy and Shannon Wavelet Packet Entropy in Analysis of Power System Transient Signals

Directory of Open Access Journals (Sweden)

Jikai Chen

2016-12-01

Full Text Available In a power system, the analysis of transient signals is the theoretical basis of fault diagnosis and transient protection theory. Shannon wavelet entropy (SWE and Shannon wavelet packet entropy (SWPE are powerful mathematics tools for transient signal analysis. Combined with the recent achievements regarding SWE and SWPE, their applications are summarized in feature extraction of transient signals and transient fault recognition. For wavelet aliasing at adjacent scale of wavelet decomposition, the impact of wavelet aliasing is analyzed for feature extraction accuracy of SWE and SWPE, and their differences are compared. Meanwhile, the analyses mentioned are verified by partial discharge (PD feature extraction of power cable. Finally, some new ideas and further researches are proposed in the wavelet entropy mechanism, operation speed and how to overcome wavelet aliasing.

Maximizing prosthetic valve size with the Top Hat supra-annular aortic valve

DEFF Research Database (Denmark)

Aagaard, Jan; Geha, Alexander S.

2007-01-01

BACKGROUND AND AIM OF THE STUDY: The CarboMedics Top Hat supra-annular aortic valve allows a one-size (and often two-size) increase over the standard intra-annular valve. This advantage should minimize the risk of patient-prosthesis mismatch, where the effective prosthetic valve orifice area....... This study evaluates the authors' clinical experience with Top Hat supra-annular aortic valve size selection, and the technical aspects of implantation. METHODS: Between January 1999 and October 2005, a total of 251 consecutive patients underwent 252 aortic valve replacements with Top Hat supra...... required unplanned coronary bypass, and 30-day mortality was 2.0% (5/251), indicating a good safety profile for the valves implanted in this series. CONCLUSION: The general distribution of implant sizes in the US indicates that cardiac surgeons may be under-sizing the Top Hat supra-annular aortic valve...

Application of Human-Autonomy Teaming (HAT) Patterns to Reduced Crew Operations (RCO)

Science.gov (United States)

Shively, R. Jay; Brandt, Summer L.; Lachter, Joel; Matessa, Mike; Sadler, Garrett; Battiste, Henri

2016-01-01

As part of the Air Force - NASA Bi-Annual Research Council Meeting, slides will be presented on recent Reduced Crew Operations (RCO) work. Unmanned aerial systems, robotics, advanced cockpits, and air traffic management are all examples of domains that are seeing dramatic increases in automation. While automation may take on some tasks previously performed by humans, humans will still be required, for the foreseeable future, to remain in the system. The collaboration with humans and these increasingly autonomous systems will begin to resemble cooperation between teammates, rather than simple task allocation. It is critical to understand this human-autonomy teaming (HAT) to optimize these systems in the future. One methodology to understand HAT is by identifying recurring patterns of HAT that have similar characteristics and solutions. A methodology for identifying HAT patterns to an advanced cockpit project is discussed.

An Introduction to Wavelet Theory and Analysis

Energy Technology Data Exchange (ETDEWEB)

Miner, N.E.

1998-10-01

This report reviews the history, theory and mathematics of wavelet analysis. Examination of the Fourier Transform and Short-time Fourier Transform methods provides tiormation about the evolution of the wavelet analysis technique. This overview is intended to provide readers with a basic understanding of wavelet analysis, define common wavelet terminology and describe wavelet amdysis algorithms. The most common algorithms for performing efficient, discrete wavelet transforms for signal analysis and inverse discrete wavelet transforms for signal reconstruction are presented. This report is intended to be approachable by non- mathematicians, although a basic understanding of engineering mathematics is necessary.

A wavelet phase filter for emission tomography

International Nuclear Information System (INIS)

Olsen, E.T.; Lin, B.

1995-01-01

The presence of a high level of noise is a characteristic in some tomographic imaging techniques such as positron emission tomography (PET). Wavelet methods can smooth out noise while preserving significant features of images. Mallat et al. proposed a wavelet based denoising scheme exploiting wavelet modulus maxima, but the scheme is sensitive to noise. In this study, the authors explore the properties of wavelet phase, with a focus on reconstruction of emission tomography images. Specifically, they show that the wavelet phase of regular Poisson noise under a Haar-type wavelet transform converges in distribution to a random variable uniformly distributed on [0, 2π). They then propose three wavelet-phase-based denoising schemes which exploit this property: edge tracking, local phase variance thresholding, and scale phase variation thresholding. Some numerical results are also presented. The numerical experiments indicate that wavelet phase techniques show promise for wavelet based denoising methods

Wavelets y sus aplicaciones

OpenAIRE

Castro, Liliana Raquel; Castro, Silvia Mabel

1995-01-01

Se presenta una introducción a la teorfa de wavelets. Ademas, se da una revisión histórica de cómo fueron introducidas las wavelets para la representación de funciones. Se efectúa una comparación entre la transformada wavelet y la transformada de Fourier. Por último, se presentan también algunas de los múltiples aplicaciones de esta nueva herramienta de análisis armónico.

HAT-P-11: Discovery of a Second Planet and a Clue to Understanding Exoplanet Obliquities

Science.gov (United States)

Yee, Samuel W.; Petigura, Erik A.; Fulton, Benjamin J.; Knutson, Heather A.; Batygin, Konstantin; Bakos, Gáspár Á.; Hartman, Joel D.; Hirsch, Lea A.; Howard, Andrew W.; Isaacson, Howard; Kosiarek, Molly R.; Sinukoff, Evan; Weiss, Lauren M.

2018-06-01

HAT-P-11 is a mid-K dwarf that hosts one of the first Neptune-sized planets found outside the solar system. The orbit of HAT-P-11b is misaligned with the star’s spin—one of the few known cases of a misaligned planet orbiting a star less massive than the Sun. We find an additional planet in the system based on a decade of precision radial velocity (RV) measurements from Keck/High Resolution Echelle Spectrometer. HAT-P-11c is similar to Jupiter in its mass ({M}P\\sin i=1.6+/- 0.1 M J ) and orbital period (P={9.3}-0.5+1.0 year), but has a much more eccentric orbit (e = 0.60 ± 0.03). In our joint modeling of RV and stellar activity, we found an activity-induced RV signal of ∼7 {{m}} {{{s}}}-1, consistent with other active K dwarfs, but significantly smaller than the 31 {{m}} {{{s}}}-1 reflex motion due to HAT-P-11c. We investigated the dynamical coupling between HAT-P-11b and c as a possible explanation for HAT-P-11b’s misaligned orbit, finding that planet–planet Kozai interactions cannot tilt planet b’s orbit due to general relativistic precession; however, nodal precession operating on million year timescales is a viable mechanism to explain HAT-P-11b’s high obliquity. This leaves open the question of why HAT-P-11c may have such a tilted orbit. At a distance of 38 pc, the HAT-P-11 system offers rich opportunities for further exoplanet characterization through astrometry and direct imaging.

Estimating q-hat in Quenched Lattice SU(2) Gauge Theory

International Nuclear Information System (INIS)

Majumder, Abhijit

2013-01-01

The propagation of a virtual quark in a thermal medium is considered. The non-perturbative jet transport coefficient q -hat is estimated in quark less SU(2) lattice gauge theory. The light like correlator which defines q -hat , defined in the regime where the jet has small virtuality compared to its energy, is analytically related to a series of local operators in the deep Euclidean region, where the jet's virtuality is of the same order as its energy. It is demonstrated that in this region, for temperatures in the range of T=400–600 MeV, and for jet energies above 20 GeV, the leading term in the series is dominant over the next-to-leading term and thus yields an estimate of the value of q -hat . In these proceedings we discuss the details of the numerical calculation

Target recognition by wavelet transform

International Nuclear Information System (INIS)

Li Zhengdong; He Wuliang; Zheng Xiaodong; Cheng Jiayuan; Peng Wen; Pei Chunlan; Song Chen

2002-01-01

Wavelet transform has an important character of multi-resolution power, which presents pyramid structure, and this character coincides the way by which people distinguish object from coarse to fineness and from large to tiny. In addition to it, wavelet transform benefits to reducing image noise, simplifying calculation, and embodying target image characteristic point. A method of target recognition by wavelet transform is provided

Modeling Network Traffic in Wavelet Domain

Directory of Open Access Journals (Sweden)

Sheng Ma

2004-12-01

Full Text Available This work discovers that although network traffic has the complicated short- and long-range temporal dependence, the corresponding wavelet coefficients are no longer long-range dependent. Therefore, a "short-range" dependent process can be used to model network traffic in the wavelet domain. Both independent and Markov models are investigated. Theoretical analysis shows that the independent wavelet model is sufficiently accurate in terms of the buffer overflow probability for Fractional Gaussian Noise traffic. Any model, which captures additional correlations in the wavelet domain, only improves the performance marginally. The independent wavelet model is then used as a unified approach to model network traffic including VBR MPEG video and Ethernet data. The computational complexity is O(N for developing such wavelet models and generating synthesized traffic of length N, which is among the lowest attained.

Tip off the HAT- Epigenetic control of learning and memory by Drosophila Tip60.

Science.gov (United States)

Xu, Songjun; Elefant, Felice

2015-01-01

Disruption of epigenetic gene control mechanisms involving histone acetylation in the brain causes cognitive impairment, a debilitating hallmark of most neurodegenerative disorders. Histone acetylation regulates cognitive gene expression via chromatin packaging control in neurons. Unfortunately, the histone acetyltransferases (HATs) that generate such neural epigenetic signatures and their mechanisms of action remain unclear. Our recent findings provide insight into this question by demonstrating that Tip60 HAT action is critical for morphology and function of the mushroom body (MB), the learning and memory center in the Drosophila brain. We show that Tip60 is robustly produced in MB Kenyon cells and extending axonal lobes and that targeted MB Tip60 HAT loss results in axonal outgrowth disruption. Functional consequences of loss and gain of Tip60 HAT levels in the MB are evidenced by defects in memory. Tip60 ChIP-Seq analysis reveals enrichment for genes that function in cognitive processes and accordingly, key genes representing these pathways are misregulated in the Tip60 HAT mutant fly brain. Remarkably, increasing levels of Tip60 in the MB rescues learning and memory deficits resulting from Alzheimer's disease associated amyloid precursor protein (APP) induced neurodegeneration. Our studies highlight the potential of HAT activators as a therapeutic option for cognitive disorders.

Wavelet frames and their duals

DEFF Research Database (Denmark)

Lemvig, Jakob

2008-01-01

frames with good time localization and other attractive properties. Furthermore, the dual wavelet frames are constructed in such a way that we are guaranteed that both frames will have the same desirable features. The construction procedure works for any real, expansive dilation. A quasi-affine system....... The signals are then represented by linear combinations of the building blocks with coefficients found by an associated frame, called a dual frame. A wavelet frame is a frame where the building blocks are stretched (dilated) and translated versions of a single function; such a frame is said to have wavelet...... structure. The dilation of the wavelet building blocks in higher dimension is done via a square matrix which is usually taken to be integer valued. In this thesis we step away from the "usual" integer, expansive dilation and consider more general, expansive dilations. In most applications of wavelet frames...

USING SIX THINKING HATS AS A TOOL FOR LATERAL THINKING IN ORGANIZATIONAL PROBLEM SOLVING

OpenAIRE

Dr. P. S. Aithal; Dr. P. M. Suresh Kumar

2016-01-01

Six thinking hats is recently introduced technique which outlines different thinking styles required by an individual while analysing a given problem in an effective way. The technique correlates different thinking styles used in a systematic problem-solving procedure with different coloured hats. Alternately, by conceptualizing each type of hat, the person focuses on the style of thinking associated with each colour so that the problem can be analysed from different angles and frame of refer...

Wavelet-based moment invariants for pattern recognition

Science.gov (United States)

Chen, Guangyi; Xie, Wenfang

2011-07-01

Moment invariants have received a lot of attention as features for identification and inspection of two-dimensional shapes. In this paper, two sets of novel moments are proposed by using the auto-correlation of wavelet functions and the dual-tree complex wavelet functions. It is well known that the wavelet transform lacks the property of shift invariance. A little shift in the input signal will cause very different output wavelet coefficients. The autocorrelation of wavelet functions and the dual-tree complex wavelet functions, on the other hand, are shift-invariant, which is very important in pattern recognition. Rotation invariance is the major concern in this paper, while translation invariance and scale invariance can be achieved by standard normalization techniques. The Gaussian white noise is added to the noise-free images and the noise levels vary with different signal-to-noise ratios. Experimental results conducted in this paper show that the proposed wavelet-based moments outperform Zernike's moments and the Fourier-wavelet descriptor for pattern recognition under different rotation angles and different noise levels. It can be seen that the proposed wavelet-based moments can do an excellent job even when the noise levels are very high.

The elliptic quantum algebra U{sub q,p}(sl-hat{sub N}) and its vertex operators

Energy Technology Data Exchange (ETDEWEB)

Chang Wenjing [School of Mathematical Science, Capital Normal University, Beijing 100048 (China); Ding Xiangmao [Institute of Applied Mathematics, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100190 (China)], E-mail: wjchang@amss.ac.cn, E-mail: xmding@amss.ac.cn

2009-10-23

We construct a realization of the elliptic quantum algebra U{sub q,p}(sl-hat{sub N}) for any given level k in terms of free boson fields and their twisted partners. It can be considered as the elliptic deformation of the Wakimoto realization of the quantum affine algebra U{sub q}(sl-hat{sub N}). We also construct a family of screening currents, which commute with the currents of U{sub q,p}(sl-hat{sub N}) up to total q-differences. And we give explicit twisted expressions for the type I and type II vertex operators of U{sub q,p}(sl-hat{sub N}) by twisting the known results of the type I vertex operators of the quantum affine algebra U{sub q}(sl-hat{sub N}) and the new results of the type II vertex operators of U{sub q}(sl-hat{sub N}) we obtained in this paper.

Wavelet entropy characterization of elevated intracranial pressure.

Science.gov (United States)

Xu, Peng; Scalzo, Fabien; Bergsneider, Marvin; Vespa, Paul; Chad, Miller; Hu, Xiao

2008-01-01

Intracranial Hypertension (ICH) often occurs for those patients with traumatic brain injury (TBI), stroke, tumor, etc. Pathology of ICH is still controversial. In this work, we used wavelet entropy and relative wavelet entropy to study the difference existed between normal and hypertension states of ICP for the first time. The wavelet entropy revealed the similar findings as the approximation entropy that entropy during ICH state is smaller than that in normal state. Moreover, with wavelet entropy, we can see that ICH state has the more focused energy in the low wavelet frequency band (0-3.1 Hz) than the normal state. The relative wavelet entropy shows that the energy distribution in the wavelet bands between these two states is actually different. Based on these results, we suggest that ICH may be formed by the re-allocation of oscillation energy within brain.

A generalized wavelet extrema representation

Energy Technology Data Exchange (ETDEWEB)

Lu, Jian; Lades, M.

1995-10-01

The wavelet extrema representation originated by Stephane Mallat is a unique framework for low-level and intermediate-level (feature) processing. In this paper, we present a new form of wavelet extrema representation generalizing Mallat`s original work. The generalized wavelet extrema representation is a feature-based multiscale representation. For a particular choice of wavelet, our scheme can be interpreted as representing a signal or image by its edges, and peaks and valleys at multiple scales. Such a representation is shown to be stable -- the original signal or image can be reconstructed with very good quality. It is further shown that a signal or image can be modeled as piecewise monotonic, with all turning points between monotonic segments given by the wavelet extrema. A new projection operator is introduced to enforce piecewise inonotonicity of a signal in its reconstruction. This leads to an enhancement to previously developed algorithms in preventing artifacts in reconstructed signal.

iHAT: interactive Hierarchical Aggregation Table for Genetic Association Data

Directory of Open Access Journals (Sweden)

Heinrich Julian

2012-05-01

Full Text Available Abstract In the search for single-nucleotide polymorphisms which influence the observable phenotype, genome wide association studies have become an important technique for the identification of associations between genotype and phenotype of a diverse set of sequence-based data. We present a methodology for the visual assessment of single-nucleotide polymorphisms using interactive hierarchical aggregation techniques combined with methods known from traditional sequence browsers and cluster heatmaps. Our tool, the interactive Hierarchical Aggregation Table (iHAT, facilitates the visualization of multiple sequence alignments, associated metadata, and hierarchical clusterings. Different color maps and aggregation strategies as well as filtering options support the user in finding correlations between sequences and metadata. Similar to other visualizations such as parallel coordinates or heatmaps, iHAT relies on the human pattern-recognition ability for spotting patterns that might indicate correlation or anticorrelation. We demonstrate iHAT using artificial and real-world datasets for DNA and protein association studies as well as expression Quantitative Trait Locus data.

Wavelet theory and its applications

Energy Technology Data Exchange (ETDEWEB)

Faber, V.; Bradley, JJ.; Brislawn, C.; Dougherty, R.; Hawrylycz, M.

1996-07-01

This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). We investigated the theory of wavelet transforms and their relation to Laboratory applications. The investigators have had considerable success in the past applying wavelet techniques to the numerical solution of optimal control problems for distributed- parameter systems, nonlinear signal estimation, and compression of digital imagery and multidimensional data. Wavelet theory involves ideas from the fields of harmonic analysis, numerical linear algebra, digital signal processing, approximation theory, and numerical analysis, and the new computational tools arising from wavelet theory are proving to be ideal for many Laboratory applications. 10 refs.

HAT-P-10b: A LIGHT AND MODERATELY HOT JUPITER TRANSITING A K DWARF

International Nuclear Information System (INIS)

Bakos, G. A.; Pal, A.; Torres, G.; Sipocz, B.; Latham, D. W.; Noyes, R. W.; Hartman, J.; Esquerdo, G. A.; Sasselov, D. D.; Kovacs, Gabor; Stefanik, R. P.; Kovacs, Geza; Fischer, D. A.; Johnson, J. A.; Marcy, G. W.; Howard, A. W.; Butler, R. P.; Lazar, J.; Papp, I.; Sari, P.

2009-01-01

We report on the discovery of HAT-P-10b, one of the lowest mass (0.487 ± 0.018 M J ) transiting extrasolar planets (TEPs) discovered to date by transit searches. HAT-P-10b orbits the moderately bright V = 11.89 K dwarf GSC 02340-01714, with a period P = 3.7224747 ± 0.0000065 days, transit epoch T c = 2454759.68683 ± 0.00016 (BJD), and duration 0.1090 ± 0.0008 days. HAT-P-10b has a radius of 1.005 +0.032 -0.027 R J yielding a mean density of 0.594 ± 0.052 g cm -3 . Comparing these observations with recent theoretical models we find that HAT-P-10b is consistent with a ∼4.5 Gyr, almost pure hydrogen and helium gas giant planet with a 10 M + core. With an equilibrium temperature of T eq = 1020 ± 17 K, HAT-P-10b is one of the coldest TEPs. Curiously, its Safronov number θ = 0.053 ± 0.002 falls close to the dividing line between the two suggested TEP populations.

Construction of wavelets with composite dilations

International Nuclear Information System (INIS)

Wu Guochang; Li Zhiqiang; Cheng Zhengxing

2009-01-01

In order to overcome classical wavelets' shortcoming in image processing problems, people developed many producing systems, which built up wavelet family. In this paper, the notion of AB-multiresolution analysis is generalized, and the corresponding theory is developed. For an AB-multiresolution analysis associated with any expanding matrices, we deduce that there exists a singe scaling function in its reducing subspace. Under some conditions, wavelets with composite dilations can be gotten by AB-multiresolution analysis, which permits the existence of fast implementation algorithm. Then, we provide an approach to design the wavelets with composite dilations by classic wavelets. Our way consists of separable and partly nonseparable cases. In each section, we construct all kinds of examples with nice properties to prove our theory.

Wavelets a tutorial in theory and applications

CERN Document Server

1992-01-01

Wavelets: A Tutorial in Theory and Applications is the second volume in the new series WAVELET ANALYSIS AND ITS APPLICATIONS. As a companion to the first volume in this series, this volume covers several of the most important areas in wavelets, ranging from the development of the basic theory such as construction and analysis of wavelet bases to an introduction of some of the key applications, including Mallat's local wavelet maxima technique in second generation image coding. A fairly extensive bibliography is also included in this volume.Key Features* Covers several of the

Boosted bosons and wavelets

CERN Document Server

Søgaard, Andreas

For the LHC Run 2 and beyond, experiments are pushing both the energy and the intensity frontier so the need for robust and efficient pile-up mitigation tools becomes ever more pressing. Several methods exist, relying on uniformity of pile-up, local correlations of charged to neutral particles, and parton shower shapes, all in $y − \\phi$ space. Wavelets are presented as tools for pile-up removal, utilising their ability to encode position and frequency information simultaneously. This allows for the separation of individual hadron collision events by angular scale and thus for subtracting of soft, diffuse/wide-angle contributions while retaining the hard, small-angle components from the hard event. Wavelet methods may utilise the same assumptions as existing methods, the difference being the underlying, novel representation. Several wavelet methods are proposed and their effect studied in simple toy simulation under conditions relevant for the LHC Run 2. One full pile-up mitigation tool (‘wavelet analysis...

Explanatory Emotion Talk in Mexican Immigrant and Mexican American Families.

Science.gov (United States)

Cervantes, Christi A.

2002-01-01

Mother-child conversations during story-telling play were analyzed for patterns of emotion talk. Subjects were 48 Mexican immigrant and Mexican American mothers and their children aged 3-4. Contrary to previous findings, Mexican immigrant mothers used more explanations of emotions than labels. Mexican American mothers used both, equally. Results…

How a hat may affect 3-month-olds' recognition of a face: an eye-tracking study.

Science.gov (United States)

Bulf, Hermann; Valenza, Eloisa; Turati, Chiara

2013-01-01

Recent studies have shown that infants' face recognition rests on a robust face representation that is resilient to a variety of facial transformations such as rotations in depth, motion, occlusion or deprivation of inner/outer features. Here, we investigated whether 3-month-old infants' ability to represent the invariant aspects of a face is affected by the presence of an external add-on element, i.e. a hat. Using a visual habituation task, three experiments were carried out in which face recognition was investigated by manipulating the presence/absence of a hat during face encoding (i.e. habituation phase) and face recognition (i.e. test phase). An eye-tracker system was used to record the time infants spent looking at face-relevant information compared to the hat. The results showed that infants' face recognition was not affected by the presence of the external element when the type of the hat did not vary between the habituation and test phases, and when both the novel and the familiar face wore the same hat during the test phase (Experiment 1). Infants' ability to recognize the invariant aspects of a face was preserved also when the hat was absent in the habituation phase and the same hat was shown only during the test phase (Experiment 2). Conversely, when the novel face identity competed with a novel hat, the hat triggered the infants' attention, interfering with the recognition process and preventing the infants' preference for the novel face during the test phase (Experiment 3). Findings from the current study shed light on how faces and objects are processed when they are simultaneously presented in the same visual scene, contributing to an understanding of how infants respond to the multiple and composite information available in their surrounding environment.

Wavelet transforms as solutions of partial differential equations

Energy Technology Data Exchange (ETDEWEB)

Zweig, G.

1997-10-01

This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Wavelet transforms are useful in representing transients whose time and frequency structure reflect the dynamics of an underlying physical system. Speech sound, pressure in turbulent fluid flow, or engine sound in automobiles are excellent candidates for wavelet analysis. This project focused on (1) methods for choosing the parent wavelet for a continuous wavelet transform in pattern recognition applications and (2) the more efficient computation of continuous wavelet transforms by understanding the relationship between discrete wavelet transforms and discretized continuous wavelet transforms. The most interesting result of this research is the finding that the generalized wave equation, on which the continuous wavelet transform is based, can be used to understand phenomena that relate to the process of hearing.

Wavelet spectra of JACEE events

International Nuclear Information System (INIS)

Suzuki, Naomichi; Biyajima, Minoru; Ohsawa, Akinori.

1995-01-01

Pseudo-rapidity distributions of two high multiplicity events Ca-C and Si-AgBr observed by the JACEE are analyzed by a wavelet transform. Wavelet spectra of those events are calculated and compared with the simulation calculations. The wavelet spectrum of the Ca-C event somewhat resembles that simulated with the uniform random numbers. That of Si-AgBr event, however, is not reproduced by simulation calculations with Poisson random numbers, uniform random numbers, or a p-model. (author)

Parsimonious Wavelet Kernel Extreme Learning Machine

Directory of Open Access Journals (Sweden)

Wang Qin

2015-11-01

Full Text Available In this study, a parsimonious scheme for wavelet kernel extreme learning machine (named PWKELM was introduced by combining wavelet theory and a parsimonious algorithm into kernel extreme learning machine (KELM. In the wavelet analysis, bases that were localized in time and frequency to represent various signals effectively were used. Wavelet kernel extreme learning machine (WELM maximized its capability to capture the essential features in “frequency-rich” signals. The proposed parsimonious algorithm also incorporated significant wavelet kernel functions via iteration in virtue of Householder matrix, thus producing a sparse solution that eased the computational burden and improved numerical stability. The experimental results achieved from the synthetic dataset and a gas furnace instance demonstrated that the proposed PWKELM is efficient and feasible in terms of improving generalization accuracy and real time performance.

Wavelet analysis in neurodynamics

International Nuclear Information System (INIS)

Pavlov, Aleksei N; Hramov, Aleksandr E; Koronovskii, Aleksei A; Sitnikova, Evgenija Yu; Makarov, Valeri A; Ovchinnikov, Alexey A

2012-01-01

Results obtained using continuous and discrete wavelet transforms as applied to problems in neurodynamics are reviewed, with the emphasis on the potential of wavelet analysis for decoding signal information from neural systems and networks. The following areas of application are considered: (1) the microscopic dynamics of single cells and intracellular processes, (2) sensory data processing, (3) the group dynamics of neuronal ensembles, and (4) the macrodynamics of rhythmical brain activity (using multichannel EEG recordings). The detection and classification of various oscillatory patterns of brain electrical activity and the development of continuous wavelet-based brain activity monitoring systems are also discussed as possibilities. (reviews of topical problems)

Wavelet-LMS algorithm-based echo cancellers

Science.gov (United States)

Seetharaman, Lalith K.; Rao, Sathyanarayana S.

2002-12-01

This paper presents Echo Cancellers based on the Wavelet-LMS Algorithm. The performance of the Least Mean Square Algorithm in Wavelet transform domain is observed and its application in Echo cancellation is analyzed. The Widrow-Hoff Least Mean Square Algorithm is most widely used algorithm for Adaptive filters that function as Echo Cancellers. The present day communication signals are widely non-stationary in nature and some errors crop up when Least Mean Square Algorithm is used for the Echo Cancellers handling such signals. The analysis of non-stationary signals often involves a compromise between how well transitions or discontinuities can be located. The multi-scale or multi-resolution of signal analysis, which is the essence of wavelet transform, makes Wavelets popular in non-stationary signal analysis. In this paper, we present a Wavelet-LMS algorithm wherein the wavelet coefficients of a signal are modified adaptively using the Least Mean Square Algorithm and then reconstructed to give an Echo-free signal. The Echo Canceller based on this Algorithm is found to have a better convergence and a comparatively lesser MSE (Mean Square error).

Targeting Specific HATs for Neurodegenerative Disease Treatment: Translating Basic Biology to Therapeutic Possibilities

Directory of Open Access Journals (Sweden)

Sheila K. Pirooznia

2013-03-01

Full Text Available Dynamic epigenetic regulation of neurons is emerging as a fundamental mechanism by which neurons adapt their transcriptional responses to specific developmental and environmental cues. While defects within the neural epigenome have traditionally been studied in the context of early developmental and heritable cognitive disorders, recent studies point to aberrant histone acetylation status as a key mechanism underlying acquired inappropriate alterations of genome structure and function in post-mitotic neurons during the aging process. Indeed, it is becoming increasingly evident that chromatin acetylation status can be impaired during the lifetime of neurons through mechanisms related to loss of function of histone acetyltransferase (HATs activity. Several HATs have been shown to participate in vital neuronal functions such as regulation of neuronal plasticity and memory formation. As such, dysregulation of such HATs has been implicated in the pathogenesis associated with age-associated neurodegenerative diseases and cognitive decline. In order to counteract the loss of HAT function in neurodegenerative diseases, the current therapeutic strategies involve the use of small molecules called histone deacetylase (HDAC inhibitors that antagonize HDAC activity and thus enhance acetylation levels. Although this strategy has displayed promising therapeutic effects, currently used HDAC inhibitors lack target specificity, raising concerns about their applicability. With rapidly evolving literature on HATs and their respective functions in mediating neuronal survival and higher order brain function such as learning and memory, modulating the function of specific HATs holds new promises as a therapeutic tool in neurodegenerative diseases. In this review, we focus on the recent progress in research regarding epigenetic histone acetylation mechanisms underlying neuronal activity and cognitive function. We discuss the current understanding of specific HDACs and

Wavelet analysis for nonstationary signals

International Nuclear Information System (INIS)

Penha, Rosani Maria Libardi da

1999-01-01

Mechanical vibration signals play an important role in anomalies identification resulting of equipment malfunctioning. Traditionally, Fourier spectral analysis is used where the signals are assumed to be stationary. However, occasional transient impulses and start-up process are examples of nonstationary signals that can be found in mechanical vibrations. These signals can provide important information about the equipment condition, as early fault detection. The Fourier analysis can not adequately be applied to nonstationary signals because the results provide data about the frequency composition averaged over the duration of the signal. In this work, two methods for nonstationary signal analysis are used: Short Time Fourier Transform (STFT) and wavelet transform. The STFT is a method of adapting Fourier spectral analysis for nonstationary application to time-frequency domain. To have a unique resolution throughout the entire time-frequency domain is its main limitation. The wavelet transform is a new analysis technique suitable to nonstationary signals, which handles the STFT drawbacks, providing multi-resolution frequency analysis and time localization in a unique time-scale graphic. The multiple frequency resolutions are obtained by scaling (dilatation/compression) the wavelet function. A comparison of the conventional Fourier transform, STFT and wavelet transform is made applying these techniques to: simulated signals, arrangement rotor rig vibration signal and rotate machine vibration signal Hanning window was used to STFT analysis. Daubechies and harmonic wavelets were used to continuos, discrete and multi-resolution wavelet analysis. The results show the Fourier analysis was not able to detect changes in the signal frequencies or discontinuities. The STFT analysis detected the changes in the signal frequencies, but with time-frequency resolution problems. The wavelet continuos and discrete transform demonstrated to be a high efficient tool to detect

Analysis of transient signals by Wavelet transform

International Nuclear Information System (INIS)

Penha, Rosani Libardi da; Silva, Aucyone A. da; Ting, Daniel K.S.; Oliveira Neto, Jose Messias de

2000-01-01

The objective of this work is to apply the Wavelet Transform in transient signals. The Wavelet technique can outline the short time events that are not easily detected using traditional techniques. In this work, the Wavelet Transform is compared with Fourier Transform, by using simulated data and rotor rig data. This data contain known transients. The wavelet could follow all the transients, what do not happen to the Fourier techniques. (author)

Wavelets for Sparse Representation of Music

DEFF Research Database (Denmark)

Endelt, Line Ørtoft; Harbo, Anders La-Cour

2004-01-01

We are interested in obtaining a sparse representation of music signals by means of a discrete wavelet transform (DWT). That means we want the energy in the representation to be concentrated in few DWT coefficients. It is well-known that the decay of the DWT coefficients is strongly related...... to the number of vanishing moments of the mother wavelet, and to the smoothness of the signal. In this paper we present the result of applying two classical families of wavelets to a series of musical signals. The purpose is to determine a general relation between the number of vanishing moments of the wavelet...

Wavelet-based prediction of oil prices

International Nuclear Information System (INIS)

Yousefi, Shahriar; Weinreich, Ilona; Reinarz, Dominik

2005-01-01

This paper illustrates an application of wavelets as a possible vehicle for investigating the issue of market efficiency in futures markets for oil. The paper provides a short introduction to the wavelets and a few interesting wavelet-based contributions in economics and finance are briefly reviewed. A wavelet-based prediction procedure is introduced and market data on crude oil is used to provide forecasts over different forecasting horizons. The results are compared with data from futures markets for oil and the relative performance of this procedure is used to investigate whether futures markets are efficiently priced

30 CFR 75.1720-1 - Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced...

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats, or hard caps... STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1720-1 Distinctively colored hard hats, or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color...

Bi-Directional Communication: A Critical Component of HAT

Science.gov (United States)

Shively, Robert J.

2016-01-01

Known problems with automation include lack of mode awareness, automation brittleness, and risk of miscalibrated trust. Human-Autonomy Teaming (HAT) is essential for improving these problems. This presentation outlines critical components for Human-Autonomy Teaming.

Wavelets a primer

CERN Document Server

Blatter, Christian

1998-01-01

The Wavelet Transform has stimulated research that is unparalleled since the invention of the Fast Fourier Transform and has opened new avenues of applications in signal processing, image compression, radiology, cardiology, and many other areas. This book grew out of a short course for mathematics students at the ETH in Zurich; it provides a solid mathematical foundation for the broad range of applications enjoyed by the wavelet transform. Numerous illustrations and fully worked out examples enhance the book.

30 CFR 77.1710-1 - Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced...

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Distinctively colored hard hats or hard caps... Distinctively colored hard hats or hard caps; identification for newly employed, inexperienced miners. Hard hats or hard caps distinctively different in color from those worn by experienced miners shall be worn at...

Comparison between wavelet and wavelet packet transform features for classification of faults in distribution system

Science.gov (United States)

Arvind, Pratul

2012-11-01

The ability to identify and classify all ten types of faults in a distribution system is an important task for protection engineers. Unlike transmission system, distribution systems have a complex configuration and are subjected to frequent faults. In the present work, an algorithm has been developed for identifying all ten types of faults in a distribution system by collecting current samples at the substation end. The samples are subjected to wavelet packet transform and artificial neural network in order to yield better classification results. A comparison of results between wavelet transform and wavelet packet transform is also presented thereby justifying the feature extracted from wavelet packet transform yields promising results. It should also be noted that current samples are collected after simulating a 25kv distribution system in PSCAD software.

Planet-induced Stellar Pulsations in HAT-P-2's Eccentric System

International Nuclear Information System (INIS)

Wit, Julien de; Lewis, Nikole K.; Knutson, Heather A.; Batygin, Konstantin; Fuller, Jim; Antoci, Victoria; Fulton, Benjamin J.; Laughlin, Gregory; Deming, Drake; Shporer, Avi; Cowan, Nicolas B.; Agol, Eric; Burrows, Adam S.; Fortney, Jonathan J.; Langton, Jonathan; Showman, Adam P.

2017-01-01

Extrasolar planets on eccentric short-period orbits provide a laboratory in which to study radiative and tidal interactions between a planet and its host star under extreme forcing conditions. Studying such systems probes how the planet’s atmosphere redistributes the time-varying heat flux from its host and how the host star responds to transient tidal distortion. Here, we report the insights into the planet–star interactions in HAT-P-2's eccentric planetary system gained from the analysis of ∼350 hr of 4.5 μ m observations with the Spitzer Space Telescope . The observations show no sign of orbit-to-orbit variability nor of orbital evolution of the eccentric planetary companion, HAT-P-2 b. The extensive coverage allows us to better differentiate instrumental systematics from the transient heating of HAT-P-2 b’s 4.5 μ m photosphere and yields the detection of stellar pulsations with an amplitude of approximately 40 ppm. These pulsation modes correspond to exact harmonics of the planet’s orbital frequency, indicative of a tidal origin. Transient tidal effects can excite pulsation modes in the envelope of a star, but, to date, such pulsations had only been detected in highly eccentric stellar binaries. Current stellar models are unable to reproduce HAT-P-2's pulsations, suggesting that our understanding of the interactions at play in this system is incomplete.

A wavelet ridge extraction method employing a novel cost function in two-dimensional wavelet transform profilometry

Science.gov (United States)

Wang, Jianhua; Yang, Yanxi

2018-05-01

We present a new wavelet ridge extraction method employing a novel cost function in two-dimensional wavelet transform profilometry (2-D WTP). First of all, the maximum value point is extracted from two-dimensional wavelet transform coefficient modulus, and the local extreme value points over 90% of maximum value are also obtained, they both constitute wavelet ridge candidates. Then, the gradient of rotate factor is introduced into the Abid's cost function, and the logarithmic Logistic model is used to adjust and improve the cost function weights so as to obtain more reasonable value estimation. At last, the dynamic programming method is used to accurately find the optimal wavelet ridge, and the wrapped phase can be obtained by extracting the phase at the ridge. Its advantage is that, the fringe pattern with low signal-to-noise ratio can be demodulated accurately, and its noise immunity will be better. Meanwhile, only one fringe pattern is needed to projected to measured object, so dynamic three-dimensional (3-D) measurement in harsh environment can be realized. Computer simulation and experimental results show that, for the fringe pattern with noise pollution, the 3-D surface recovery accuracy by the proposed algorithm is increased. In addition, the demodulation phase accuracy of Morlet, Fan and Cauchy mother wavelets are compared.

Some applications of wavelets to physics

International Nuclear Information System (INIS)

Thompson, C.R.

1992-01-01

A thorough description of a fast wavelet transform algorithm (FWT) and its inverse (IFWT) are given. The effects of noise in the wavelet transform are studied, in particular the effects on signal reconstruction. A model for additive white noise on the coefficients is presented along with two methods that can help to suppress the effects of noise corruption of the signal. Problems of improper sampling are studied, including the propagation of uncertainty through the FWT and IFWT. Interpolation techniques and data compression are also studied. The FWT and IFWT are generalized for analysis of two dimensional images. Methods for edge detection are discussed as well as contrast improvement and data compression. Finally, wavelets are applied to electromagnetic wave propagation problems. Formulas relating the wavelet and Fourier transforms are given, and expansions of time-dependent electromagnetic fields using both fixed and moving wavelet bases are studied

Cross wavelet analysis: significance testing and pitfalls

Directory of Open Access Journals (Sweden)

D. Maraun

2004-01-01

Full Text Available In this paper, we present a detailed evaluation of cross wavelet analysis of bivariate time series. We develop a statistical test for zero wavelet coherency based on Monte Carlo simulations. If at least one of the two processes considered is Gaussian white noise, an approximative formula for the critical value can be utilized. In a second part, typical pitfalls of wavelet cross spectra and wavelet coherency are discussed. The wavelet cross spectrum appears to be not suitable for significance testing the interrelation between two processes. Instead, one should rather apply wavelet coherency. Furthermore we investigate problems due to multiple testing. Based on these results, we show that coherency between ENSO and NAO is an artefact for most of the time from 1900 to 1995. However, during a distinct period from around 1920 to 1940, significant coherency between the two phenomena occurs.

From Fourier analysis to wavelets

CERN Document Server

Gomes, Jonas

2015-01-01

This text introduces the basic concepts of function spaces and operators, both from the continuous and discrete viewpoints.  Fourier and Window Fourier Transforms are introduced and used as a guide to arrive at the concept of Wavelet transform.  The fundamental aspects of multiresolution representation, and its importance to function discretization and to the construction of wavelets is also discussed. Emphasis is given on ideas and intuition, avoiding the heavy computations which are usually involved in the study of wavelets.  Readers should have a basic knowledge of linear algebra, calculus, and some familiarity with complex analysis.  Basic knowledge of signal and image processing is desirable. This text originated from a set of notes in Portuguese that the authors wrote for a wavelet course on the Brazilian Mathematical Colloquium in 1997 at IMPA, Rio de Janeiro.

Wavelet based free-form deformations for nonrigid registration

Science.gov (United States)

Sun, Wei; Niessen, Wiro J.; Klein, Stefan

2014-03-01

In nonrigid registration, deformations may take place on the coarse and fine scales. For the conventional B-splines based free-form deformation (FFD) registration, these coarse- and fine-scale deformations are all represented by basis functions of a single scale. Meanwhile, wavelets have been proposed as a signal representation suitable for multi-scale problems. Wavelet analysis leads to a unique decomposition of a signal into its coarse- and fine-scale components. Potentially, this could therefore be useful for image registration. In this work, we investigate whether a wavelet-based FFD model has advantages for nonrigid image registration. We use a B-splines based wavelet, as defined by Cai and Wang.1 This wavelet is expressed as a linear combination of B-spline basis functions. Derived from the original B-spline function, this wavelet is smooth, differentiable, and compactly supported. The basis functions of this wavelet are orthogonal across scales in Sobolev space. This wavelet was previously used for registration in computer vision, in 2D optical flow problems,2 but it was not compared with the conventional B-spline FFD in medical image registration problems. An advantage of choosing this B-splines based wavelet model is that the space of allowable deformation is exactly equivalent to that of the traditional B-spline. The wavelet transformation is essentially a (linear) reparameterization of the B-spline transformation model. Experiments on 10 CT lung and 18 T1-weighted MRI brain datasets show that wavelet based registration leads to smoother deformation fields than traditional B-splines based registration, while achieving better accuracy.

Wavelet Radiosity on Arbitrary Planar Surfaces

OpenAIRE

Holzschuch , Nicolas; Cuny , François; Alonso , Laurent

2000-01-01

Colloque avec actes et comité de lecture. internationale.; International audience; Wavelet radiosity is, by its nature, restricted to parallelograms or triangles. This paper presents an innovative technique enabling wavelet radiosity computations on planar surfaces of arbitrary shape, including concave contours or contours with holes. This technique replaces the need for triangulating such complicated shapes, greatly reducing the complexity of the wavelet radiosity algorithm and the computati...

Optical Aperture Synthesis Object's Information Extracting Based on Wavelet Denoising

International Nuclear Information System (INIS)

Fan, W J; Lu, Y

2006-01-01

Wavelet denoising is studied to improve OAS(optical aperture synthesis) object's Fourier information extracting. Translation invariance wavelet denoising based on Donoho wavelet soft threshold denoising is researched to remove Pseudo-Gibbs in wavelet soft threshold image. OAS object's information extracting based on translation invariance wavelet denoising is studied. The study shows that wavelet threshold denoising can improve the precision and the repetition of object's information extracting from interferogram, and the translation invariance wavelet denoising information extracting is better than soft threshold wavelet denoising information extracting

Comparison on Integer Wavelet Transforms in Spherical Wavelet Based Image Based Relighting

Institute of Scientific and Technical Information of China (English)

WANGZe; LEEYin; LEUNGChising; WONGTientsin; ZHUYisheng

2003-01-01

To provide a good quality rendering in the Image based relighting (IBL) system, tremendous reference images under various illumination conditions are needed. Therefore data compression is essential to enable interactive action. And the rendering speed is another crucial consideration for real applications. Based on Spherical wavelet transform (SWT), this paper presents a quick representation method with Integer wavelet transform (IWT) for the IBL system. It focuses on comparison on different IWTs with the Embedded zerotree wavelet (EZW) used in the IBL system. The whole compression procedure contains two major compression steps. Firstly, SWT is applied to consider the correlation among different reference images. Secondly, the SW transformed images are compressed with IWT based image compression approach. Two IWTs are used and good results are showed in the simulations.

Curcumin and its demethoxy derivatives possess p300 HAT inhibitory activity and suppress hypertrophic responses in cardiomyocytes

Directory of Open Access Journals (Sweden)

Yoichi Sunagawa

2018-04-01

Full Text Available The natural compound, curcumin (CUR, possesses several pharmacological properties, including p300-specific histone acetyltransferase (HAT inhibitory activity. In our previous study, we demonstrated that CUR could prevent the development of cardiac hypertrophy by inhibiting p300-HAT activity. Other major curcuminoids isolated from Curcuma longa including demethoxycurcumin (DMC and bisdemethoxycurcumin (BDMC are structural analogs of CUR. In present study, we first confirmed the effect of these three curcuminoid analogs on p300-HAT activity and cardiomyocyte hypertrophy.Our results showed that DMC and BDMC inhibited p300-HAT activity and cardiomyocyte hypertrophy to almost the same extent as CUR. As the three compounds have structural differences in methoxy groups at the 3-position of their phenol rings, our results suggest that these methoxy groups are not involved in the inhibitory effects on p300-HAT activity and cardiac hypertrophy. These findings provide useful insights into the structure–activity relationship and biological activity of curcuminoids for p300-HAT activity and cardiomyocyte hypertrophy. Keywords: Curcumin, Demethoxycurcumin, Bisdemethoxycurcumin, p300, Cardiomyocyte hypertrophy

Visualization of a Turbulent Jet Using Wavelets

Institute of Scientific and Technical Information of China (English)

Hui LI

2001-01-01

An application of multiresolution image analysis to turbulence was investigated in this paper, in order to visualize the coherent structure and the most essential scales governing turbulence. The digital imaging photograph of jet slice was decomposed by two-dimensional discrete wavelet transform based on Daubechies, Coifman and Baylkin bases. The best choice of orthogonal wavelet basis for analyzing the image of the turbulent structures was first discussed. It is found that these orthonormal wavelet families with index N＜10 were inappropriate for multiresolution image analysis of turbulent flow. The multiresolution images of turbulent structures were very similar when using the wavelet basis with the higher index number, even though wavelet bases are different functions. From the image components in orthogonal wavelet spaces with different scales, the further evident of the multi-scale structures in jet can be observed, and the edges of the vortices at different resolutions or scales and the coherent structure can be easily extracted.

Wavelet analysis in two-dimensional tomography

Science.gov (United States)

Burkovets, Dimitry N.

2002-02-01

The diagnostic possibilities of wavelet-analysis of coherent images of connective tissue in its pathological changes diagnostics. The effectiveness of polarization selection in obtaining wavelet-coefficients' images is also shown. The wavelet structures, characterizing the process of skin psoriasis, bone-tissue osteoporosis have been analyzed. The histological sections of physiological normal and pathologically changed samples of connective tissue of human skin and spongy bone tissue have been analyzed.

What's Values Got to Do with It? Thriving among Mexican/Mexican American College Students

Science.gov (United States)

Morgan Consoli, Melissa L.; Llamas, Jasmín; Consoli, Andrés J.

2016-01-01

The authors examined traditional Mexican/Mexican American and perceived U.S. mainstream cultural values as predictors of thriving. One hundred twenty-four (37 men, 87 women) self-identified Mexican/Mexican American college students participated in the study. The traditional Mexican/Mexican American cultural values of family support and religion…

A new fractional wavelet transform

Science.gov (United States)

Dai, Hongzhe; Zheng, Zhibao; Wang, Wei

2017-03-01

The fractional Fourier transform (FRFT) is a potent tool to analyze the time-varying signal. However, it fails in locating the fractional Fourier domain (FRFD)-frequency contents which is required in some applications. A novel fractional wavelet transform (FRWT) is proposed to solve this problem. It displays the time and FRFD-frequency information jointly in the time-FRFD-frequency plane. The definition, basic properties, inverse transform and reproducing kernel of the proposed FRWT are considered. It has been shown that an FRWT with proper order corresponds to the classical wavelet transform (WT). The multiresolution analysis (MRA) associated with the developed FRWT, together with the construction of the orthogonal fractional wavelets are also presented. Three applications are discussed: the analysis of signal with time-varying frequency content, the FRFD spectrum estimation of signals that involving noise, and the construction of fractional Harr wavelet. Simulations verify the validity of the proposed FRWT.

Numerical shaping of the ultrasonic wavelet

International Nuclear Information System (INIS)

Bonis, M.

1991-01-01

Improving the performance and the quality of ultrasonic testing requires the numerical control of the shape of the driving signal applied to the piezoelectric transducer. This allows precise shaping of the ultrasonic field wavelet and corrections for the physical defects of the transducer, which are mainly due to the damper or the lens. It also does away with the need for an accurate electric matching. It then becomes feasible to characterize, a priori, the ultrasonic wavelet by means of temporal and/or spectral specifications and to use, subsequently, an adaptative algorithm to calculate the corresponding driving wavelet. Moreover, the versatility resulting from the numerical control of this wavelet allows it to be changed in real time during a test

Wavelet analysis and its applications an introduction

CERN Document Server

Yajnik, Archit

2013-01-01

"Wavelet analysis and its applications: an introduction" demonstrates the consequences of Fourier analysis and introduces the concept of wavelet followed by applications lucidly. While dealing with one dimension signals, sometimes they are required to be oversampled. A novel technique of oversampling the digital signal is introduced in this book alongwith necessary illustrations. The technique of feature extraction in the development of optical character recognition software for any natural language alongwith wavelet based feature extraction technique is demonstrated using multiresolution analysis of wavelet in the book.

Forecasting of particulate matter time series using wavelet analysis and wavelet-ARMA/ARIMA model in Taiyuan, China.

Science.gov (United States)

Zhang, Hong; Zhang, Sheng; Wang, Ping; Qin, Yuzhe; Wang, Huifeng

2017-07-01

Particulate matter with aerodynamic diameter below 10 μm (PM 10 ) forecasting is difficult because of the uncertainties in describing the emission and meteorological fields. This paper proposed a wavelet-ARMA/ARIMA model to forecast the short-term series of the PM 10 concentrations. It was evaluated by experiments using a 10-year data set of daily PM 10 concentrations from 4 stations located in Taiyuan, China. The results indicated the following: (1) PM 10 concentrations of Taiyuan had a decreasing trend during 2005 to 2012 but increased in 2013. PM 10 concentrations had an obvious seasonal fluctuation related to coal-fired heating in winter and early spring. (2) Spatial differences among the four stations showed that the PM 10 concentrations in industrial and heavily trafficked areas were higher than those in residential and suburb areas. (3) Wavelet analysis revealed that the trend variation and the changes of the PM 10 concentration of Taiyuan were complicated. (4) The proposed wavelet-ARIMA model could be efficiently and successfully applied to the PM 10 forecasting field. Compared with the traditional ARMA/ARIMA methods, this wavelet-ARMA/ARIMA method could effectively reduce the forecasting error, improve the prediction accuracy, and realize multiple-time-scale prediction. Wavelet analysis can filter noisy signals and identify the variation trend and the fluctuation of the PM 10 time-series data. Wavelet decomposition and reconstruction reduce the nonstationarity of the PM 10 time-series data, and thus improve the accuracy of the prediction. This paper proposed a wavelet-ARMA/ARIMA model to forecast the PM 10 time series. Compared with the traditional ARMA/ARIMA method, this wavelet-ARMA/ARIMA method could effectively reduce the forecasting error, improve the prediction accuracy, and realize multiple-time-scale prediction. The proposed model could be efficiently and successfully applied to the PM 10 forecasting field.

A study of non-binary discontinuity wavelet

International Nuclear Information System (INIS)

Lin Hai; Liu Lianshou

2006-01-01

This paper gives a study of non-binary discontinuity wavelet, put forward the theory and method of constituting basic wavelet functions, and has constituted concretely a wavelet function using λ=3.4 as an example. It also conducts a theoretical inference on the decomposition algorithm and reconstruction algorithm of non-binary wavelet, and gives a concrete study of the change of matrix in connection with λ=3.4. In the end, it shows the future of application of the result to the study of high energy collision. (authors)

Wavelet analysis of the nuclear phase space

International Nuclear Information System (INIS)

Jouault, B.; Sebille, F.; De La Mota, V.

1997-01-01

The description of complex systems requires to select and to compact the relevant information. The wavelet theory constitutes an appropriate framework for defining adapted representation bases obtained from a controlled hierarchy of approximations. The optimization of the wavelet analysis depend mainly on the chosen analysis method and wavelet family. Here the analysis of the harmonic oscillator wave function was carried out by considering a Spline bi-orthogonal wavelet base which satisfy the symmetry requirements and can be approximated by simple analytical functions. The goal of this study was to determine a selection criterion allowing to minimize the number of elements considered for an optimal description of the analysed functions. An essential point consists in utilization of the wavelet complementarity and of the scale functions in order to reproduce the oscillating and peripheral parts of the wave functions. The wavelet base representation allows defining a sequence of approximations of the density matrix. Thus, this wavelet representation of the density matrix offers an optimal base for describing both the static nuclear configurations and their time evolution. This information compacting procedure is performed in a controlled manner and preserves the structure of the system wave functions and consequently some of its quantum properties

Wavelets and multiscale signal processing

CERN Document Server

Cohen, Albert

1995-01-01

Since their appearance in mid-1980s, wavelets and, more generally, multiscale methods have become powerful tools in mathematical analysis and in applications to numerical analysis and signal processing. This book is based on "Ondelettes et Traitement Numerique du Signal" by Albert Cohen. It has been translated from French by Robert D. Ryan and extensively updated by both Cohen and Ryan. It studies the existing relations between filter banks and wavelet decompositions and shows how these relations can be exploited in the context of digital signal processing. Throughout, the book concentrates on the fundamentals. It begins with a chapter on the concept of multiresolution analysis, which contains complete proofs of the basic results. The description of filter banks that are related to wavelet bases is elaborated in both the orthogonal case (Chapter 2), and in the biorthogonal case (Chapter 4). The regularity of wavelets, how this is related to the properties of the filters and the importance of regularity for t...

Detecting microcalcifications in digital mammogram using wavelets

International Nuclear Information System (INIS)

Yang Jucheng; Park Dongsun

2004-01-01

Breast cancer is still one of main mortality causes in women, but the early detection can increase the chance of cure. Microcalcifications are small size structures, which can indicate the presence of cancer since they are often associated to the most different types of breast tumors. However, they very small size and the X-ray systems limitations lead to constraints to the adequate visualization of such structures, which means that the microcalcifications can be missed many times in mammogram visual examination. In addition, the human eyes are not able to distinguish minimal tonality differences, which can be another constraint when mammogram image presents poor contrast between microcalcifications and the tissues around them. Computer-aided diagnosis (CAD) schemes are being developed in order to increase the probabilities of early detection. To enhance and detect the microcalcifications in the mammograms we use the wavelets transform. From a signal processing point of view, microcalcifications are high frequency components in mammograms. Due to the multi-resolution decomposition capacity of the wavelet transform, we can decompose the image into different resolution levels which sensitive to different frequency bands. By choosing an appropriate wavelet and a right resolution level, we can effectively enhance and detect the microcalcifications in digital mammogram. In this work, we describe a new four-step method for the detection of microcalcifications: segmentation, wavelets transform processing, labeling and post-processing. The segmentation step is to split the breast area into 256x256 segments. For each segmented sub-image, wavelet transform is operated on it. For comparing study wavelet transform method, 4 typical family wavelets and 4 decomposing levels is discussed. We choose four family wavelets for detecting microcalcifications, that is, Daubechies, Biothgonai, Coieflets and Symlets wavelets, for simply, bd4, bior3.7, coif3, sym2 are chosen as the

Applications of a fast, continuous wavelet transform

Energy Technology Data Exchange (ETDEWEB)

Dress, W.B.

1997-02-01

A fast, continuous, wavelet transform, based on Shannon`s sampling theorem in frequency space, has been developed for use with continuous mother wavelets and sampled data sets. The method differs from the usual discrete-wavelet approach and the continuous-wavelet transform in that, here, the wavelet is sampled in the frequency domain. Since Shannon`s sampling theorem lets us view the Fourier transform of the data set as a continuous function in frequency space, the continuous nature of the functions is kept up to the point of sampling the scale-translation lattice, so the scale-translation grid used to represent the wavelet transform is independent of the time- domain sampling of the signal under analysis. Computational cost and nonorthogonality aside, the inherent flexibility and shift invariance of the frequency-space wavelets has advantages. The method has been applied to forensic audio reconstruction speaker recognition/identification, and the detection of micromotions of heavy vehicles associated with ballistocardiac impulses originating from occupants` heart beats. Audio reconstruction is aided by selection of desired regions in the 2-D representation of the magnitude of the transformed signal. The inverse transform is applied to ridges and selected regions to reconstruct areas of interest, unencumbered by noise interference lying outside these regions. To separate micromotions imparted to a mass-spring system (e.g., a vehicle) by an occupants beating heart from gross mechanical motions due to wind and traffic vibrations, a continuous frequency-space wavelet, modeled on the frequency content of a canonical ballistocardiogram, was used to analyze time series taken from geophone measurements of vehicle micromotions. By using a family of mother wavelets, such as a set of Gaussian derivatives of various orders, features such as the glottal closing rate and word and phrase segmentation may be extracted from voice data.

A Comparative Study on Optimal Structural Dynamics Using Wavelet Functions

Directory of Open Access Journals (Sweden)

Seyed Hossein Mahdavi

2015-01-01

Full Text Available Wavelet solution techniques have become the focus of interest among researchers in different disciplines of science and technology. In this paper, implementation of two different wavelet basis functions has been comparatively considered for dynamic analysis of structures. For this aim, computational technique is developed by using free scale of simple Haar wavelet, initially. Later, complex and continuous Chebyshev wavelet basis functions are presented to improve the time history analysis of structures. Free-scaled Chebyshev coefficient matrix and operation of integration are derived to directly approximate displacements of the corresponding system. In addition, stability of responses has been investigated for the proposed algorithm of discrete Haar wavelet compared against continuous Chebyshev wavelet. To demonstrate the validity of the wavelet-based algorithms, aforesaid schemes have been extended to the linear and nonlinear structural dynamics. The effectiveness of free-scaled Chebyshev wavelet has been compared with simple Haar wavelet and two common integration methods. It is deduced that either indirect method proposed for discrete Haar wavelet or direct approach for continuous Chebyshev wavelet is unconditionally stable. Finally, it is concluded that numerical solution is highly benefited by the least computation time involved and high accuracy of response, particularly using low scale of complex Chebyshev wavelet.

Wavelet-based verification of the quantitative precipitation forecast

Science.gov (United States)

Yano, Jun-Ichi; Jakubiak, Bogumil

2016-06-01

This paper explores the use of wavelets for spatial verification of quantitative precipitation forecasts (QPF), and especially the capacity of wavelets to provide both localization and scale information. Two 24-h forecast experiments using the two versions of the Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS) on 22 August 2010 over Poland are used to illustrate the method. Strong spatial localizations and associated intermittency of the precipitation field make verification of QPF difficult using standard statistical methods. The wavelet becomes an attractive alternative, because it is specifically designed to extract spatially localized features. The wavelet modes are characterized by the two indices for the scale and the localization. Thus, these indices can simply be employed for characterizing the performance of QPF in scale and localization without any further elaboration or tunable parameters. Furthermore, spatially-localized features can be extracted in wavelet space in a relatively straightforward manner with only a weak dependence on a threshold. Such a feature may be considered an advantage of the wavelet-based method over more conventional "object" oriented verification methods, as the latter tend to represent strong threshold sensitivities. The present paper also points out limits of the so-called "scale separation" methods based on wavelets. Our study demonstrates how these wavelet-based QPF verifications can be performed straightforwardly. Possibilities for further developments of the wavelet-based methods, especially towards a goal of identifying a weak physical process contributing to forecast error, are also pointed out.

Joint Time-Frequency And Wavelet Analysis - An Introduction

Directory of Open Access Journals (Sweden)

Majkowski Andrzej

2014-12-01

Full Text Available A traditional frequency analysis is not appropriate for observation of properties of non-stationary signals. This stems from the fact that the time resolution is not defined in the Fourier spectrum. Thus, there is a need for methods implementing joint time-frequency analysis (t/f algorithms. Practical aspects of some representative methods of time-frequency analysis, including Short Time Fourier Transform, Gabor Transform, Wigner-Ville Transform and Cone-Shaped Transform are described in this paper. Unfortunately, there is no correlation between the width of the time-frequency window and its frequency content in the t/f analysis. This property is not valid in the case of a wavelet transform. A wavelet is a wave-like oscillation, which forms its own “wavelet window”. Compression of the wavelet narrows the window, and vice versa. Individual wavelet functions are well localized in time and simultaneously in scale (the equivalent of frequency. The wavelet analysis owes its effectiveness to the pyramid algorithm described by Mallat, which enables fast decomposition of a signal into wavelet components.

A study of biorthogonal multiple vector-valued wavelets

International Nuclear Information System (INIS)

Han Jincang; Cheng Zhengxing; Chen Qingjiang

2009-01-01

The notion of vector-valued multiresolution analysis is introduced and the concept of biorthogonal multiple vector-valued wavelets which are wavelets for vector fields, is introduced. It is proved that, like in the scalar and multiwavelet case, the existence of a pair of biorthogonal multiple vector-valued scaling functions guarantees the existence of a pair of biorthogonal multiple vector-valued wavelet functions. An algorithm for constructing a class of compactly supported biorthogonal multiple vector-valued wavelets is presented. Their properties are investigated by means of operator theory and algebra theory and time-frequency analysis method. Several biorthogonality formulas regarding these wavelet packets are obtained.

Flexural fatigue life prediction of closed hat-section using materially nonlinear axial fatigue characteristics

Science.gov (United States)

Razzaq, Zia

1989-01-01

Straight or curved hat-section members are often used as structural stiffeners in aircraft. For instance, they are employed as stiffeners for the dorsal skin as well as in the aerial refueling adjacent area structure in F-106 aircraft. The flanges of the hat-section are connected to the aircraft skin. Thus, the portion of the skin closing the hat-section interacts with the section itself when resisting the stresses due to service loads. The flexural fatigue life of such a closed section is estimated using materially nonlinear axial fatigue characteristics. It should be recognized that when a structural shape is subjected to bending, the fatigue life at the neutral axis is infinity since the normal stresses are zero at that location. Conversely, the fatigue life at the extreme fibers where the normal bending stresses are maximum can be expected to be finite. Thus, different fatigue life estimates can be visualized at various distances from the neural axis. The problem becomes compounded further when significant portions away from the neutral axis are stressed into plastic range. A theoretical analysis of the closed hat-section subjected to flexural cyclic loading is first conducted. The axial fatigue characteristics together with the related axial fatigue life formula and its inverted form given by Manson and Muralidharan are adopted for an aluminum alloy used in aircraft construction. A closed-form expression for predicting the flexural fatigue life is then derived for the closed hat-section including materially nonlinear action. A computer program is written to conduct a study of the variables such as the thicknesses of the hat-section and the skin, and the type of alloy used. The study has provided a fundamental understanding of the flexural fatigue life characteristics of a practical structural component used in aircraft when materially nonlinear action is present.

Planet-induced Stellar Pulsations in HAT-P-2's Eccentric System

Energy Technology Data Exchange (ETDEWEB)

Wit, Julien de [Department of Earth, Atmospheric and Planetary Sciences, MIT, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Lewis, Nikole K. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Knutson, Heather A.; Batygin, Konstantin [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Fuller, Jim [TAPIR, Walter Burke Institute for Theoretical Physics, Mailcode 350-17, California Institute of Technology, Pasadena, CA 91125 (United States); Antoci, Victoria [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Fulton, Benjamin J. [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States); Laughlin, Gregory [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Deming, Drake [Department of Astronomy, University of Maryland at College Park, College Park, MD 20742 (United States); Shporer, Avi [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91009 (United States); Cowan, Nicolas B. [Department of Physics, Department of Earth and Planetary Sciences, McGill University, 3550 rue University, Montreal, QC H3A 2A7 (Canada); Agol, Eric [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Burrows, Adam S. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Langton, Jonathan [Department of Physics, Principia College, Elsah, IL 62028 (United States); Showman, Adam P. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

2017-02-20

Extrasolar planets on eccentric short-period orbits provide a laboratory in which to study radiative and tidal interactions between a planet and its host star under extreme forcing conditions. Studying such systems probes how the planet’s atmosphere redistributes the time-varying heat flux from its host and how the host star responds to transient tidal distortion. Here, we report the insights into the planet–star interactions in HAT-P-2's eccentric planetary system gained from the analysis of ∼350 hr of 4.5 μ m observations with the Spitzer Space Telescope . The observations show no sign of orbit-to-orbit variability nor of orbital evolution of the eccentric planetary companion, HAT-P-2 b. The extensive coverage allows us to better differentiate instrumental systematics from the transient heating of HAT-P-2 b’s 4.5 μ m photosphere and yields the detection of stellar pulsations with an amplitude of approximately 40 ppm. These pulsation modes correspond to exact harmonics of the planet’s orbital frequency, indicative of a tidal origin. Transient tidal effects can excite pulsation modes in the envelope of a star, but, to date, such pulsations had only been detected in highly eccentric stellar binaries. Current stellar models are unable to reproduce HAT-P-2's pulsations, suggesting that our understanding of the interactions at play in this system is incomplete.

Texture analysis using Gabor wavelets

Science.gov (United States)

Naghdy, Golshah A.; Wang, Jian; Ogunbona, Philip O.

1996-04-01

Receptive field profiles of simple cells in the visual cortex have been shown to resemble even- symmetric or odd-symmetric Gabor filters. Computational models employed in the analysis of textures have been motivated by two-dimensional Gabor functions arranged in a multi-channel architecture. More recently wavelets have emerged as a powerful tool for non-stationary signal analysis capable of encoding scale-space information efficiently. A multi-resolution implementation in the form of a dyadic decomposition of the signal of interest has been popularized by many researchers. In this paper, Gabor wavelet configured in a 'rosette' fashion is used as a multi-channel filter-bank feature extractor for texture classification. The 'rosette' spans 360 degrees of orientation and covers frequencies from dc. In the proposed algorithm, the texture images are decomposed by the Gabor wavelet configuration and the feature vectors corresponding to the mean of the outputs of the multi-channel filters extracted. A minimum distance classifier is used in the classification procedure. As a comparison the Gabor filter has been used to classify the same texture images from the Brodatz album and the results indicate the superior discriminatory characteristics of the Gabor wavelet. With the test images used it can be concluded that the Gabor wavelet model is a better approximation of the cortical cell receptive field profiles.

HAT-P-16b: A Bayesian Atmospheric Retrieval

Science.gov (United States)

McIntyre, Kathleen; Harrington, Joseph; Blecic, Jasmina; Cubillos, Patricio; Challener, Ryan; Bakos, Gaspar

2017-10-01

HAT-P-16b is a hot (equilibrium temperature 1626 ± 40 K, assuming zero Bond albedo and efficient energy redistribution), 4.19 ± 0.09 Jupiter-mass exoplanet orbiting an F8 star every 2.775960 ± 0.000003 days (Buchhave et al 2010). We observed two secondary eclipses of HAT-P-16b using the 3.6 μm and 4.5 μm channels of the Spitzer Space Telescope's Infrared Array Camera (program ID 60003). We applied our Photometry for Orbits, Eclipses, and Transits (POET) code to produce normalized eclipse light curves, and our Bayesian Atmospheric Radiative Transfer (BART) code to constrain the temperature-pressure profiles and atmospheric molecular abundances of the planet. Spitzer is operated by the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. This work was supported by NASA Planetary Atmospheres grant NNX12AI69G and NASA Astrophysics Data Analysis Program grant NNX13AF38G.

Solution of wave-like equation based on Haar wavelet

Directory of Open Access Journals (Sweden)

Naresh Berwal

2012-11-01

Full Text Available Wavelet transform and wavelet analysis are powerful mathematical tools for many problems. Wavelet also can be applied in numerical analysis. In this paper, we apply Haar wavelet method to solve wave-like equation with initial and boundary conditions known. The fundamental idea of Haar wavelet method is to convert the differential equations into a group of algebraic equations, which involves a finite number or variables. The results and graph show that the proposed way is quite reasonable when compared to exact solution.

Wavelets: Applications to Image Compression-II

Indian Academy of Sciences (India)

Wavelets: Applications to Image Compression-II. Sachin P ... successful application of wavelets in image com- ... b) Soft threshold: In this case, all the coefficients x ..... [8] http://www.jpeg.org} Official site of the Joint Photographic Experts Group.

Effective implementation of wavelet Galerkin method

Science.gov (United States)

Finěk, Václav; Šimunková, Martina

2012-11-01

It was proved by W. Dahmen et al. that an adaptive wavelet scheme is asymptotically optimal for a wide class of elliptic equations. This scheme approximates the solution u by a linear combination of N wavelets and a benchmark for its performance is the best N-term approximation, which is obtained by retaining the N largest wavelet coefficients of the unknown solution. Moreover, the number of arithmetic operations needed to compute the approximate solution is proportional to N. The most time consuming part of this scheme is the approximate matrix-vector multiplication. In this contribution, we will introduce our implementation of wavelet Galerkin method for Poisson equation -Δu = f on hypercube with homogeneous Dirichlet boundary conditions. In our implementation, we identified nonzero elements of stiffness matrix corresponding to the above problem and we perform matrix-vector multiplication only with these nonzero elements.

Application of Improved Wavelet Thresholding Function in Image Denoising Processing

Directory of Open Access Journals (Sweden)

Hong Qi Zhang

2014-07-01

Full Text Available Wavelet analysis is a time – frequency analysis method, time-frequency localization problems are well solved, this paper analyzes the basic principles of the wavelet transform and the relationship between the signal singularity Lipschitz exponent and the local maxima of the wavelet transform coefficients mold, the principles of wavelet transform in image denoising are analyzed, the disadvantages of traditional wavelet thresholding function are studied, wavelet threshold function, the discontinuity of hard threshold and constant deviation of soft threshold are improved, image is denoised through using the improved threshold function.

International Conference and Workshop on Fractals and Wavelets

CERN Document Server

Barnsley, Michael; Devaney, Robert; Falconer, Kenneth; Kannan, V; PB, Vinod

2014-01-01

Fractals and wavelets are emerging areas of mathematics with many common factors which can be used to develop new technologies. This volume contains the selected contributions from the lectures and plenary and invited talks given at the International Workshop and Conference on Fractals and Wavelets held at Rajagiri School of Engineering and Technology, India from November 9-12, 2013. Written by experts, the contributions hope to inspire and motivate researchers working in this area. They provide more insight into the areas of fractals, self similarity, iterated function systems, wavelets and the applications of both fractals and wavelets. This volume will be useful for the beginners as well as experts in the fields of fractals and wavelets.

ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

Energy Technology Data Exchange (ETDEWEB)

Lewis, Nikole K.; Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Knutson, Heather A.; Desert, Jean-Michel; Kao, Melodie [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Cowan, Nicolas B. [Center for Interdisciplinary Exploration and Research in Astrophysics and Department of Physics and Astronomy, Northwestern University, 2131 Tech Drive, Evanston, IL 60208 (United States); Laughlin, Gregory; Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Burrows, Adam; Bakos, Gaspar A.; Hartman, Joel D. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ 08544 (United States); Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Crepp, Justin R. [Department of Physics, University of Notre Dame, Notre Dame, IN 46556 (United States); Mighell, Kenneth J. [National Optical Astronomy Observatories, Tucson, AZ 85726 (United States); Agol, Eric [Department of Astronomy, University of Washington, Seattle, WA 98195 (United States); Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Hinkley, Sasha; Johnson, John Asher [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Howard, Andrew W., E-mail: nklewis@mit.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); and others

2013-04-01

We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 {mu}m bands of the Spitzer Space Telescope. The 3.6 and 4.5 {mu}m data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest continuous phase curve observations obtained to date and the first full-orbit observations of a planet with an eccentricity exceeding 0.2. We present an improved non-parametric method for removing the intrapixel sensitivity variations in Spitzer data at 3.6 and 4.5 {mu}m that robustly maps position-dependent flux variations. We find that the peak in planetary flux occurs at 4.39 {+-} 0.28, 5.84 {+-} 0.39, and 4.68 {+-} 0.37 hr after periapse passage with corresponding maxima in the planet/star flux ratio of 0.1138% {+-} 0.0089%, 0.1162% {+-} 0.0080%, and 0.1888% {+-} 0.0072% in the 3.6, 4.5, and 8.0 {mu}m bands, respectively. Our measured secondary eclipse depths of 0.0996% {+-} 0.0072%, 0.1031% {+-} 0.0061%, 0.071%{sub -0.013%}{sup +0.029,} and 0.1392% {+-} 0.0095% in the 3.6, 4.5, 5.8, and 8.0 {mu}m bands, respectively, indicate that the planet cools significantly from its peak temperature before we measure the dayside flux during secondary eclipse. We compare our measured secondary eclipse depths to the predictions from a one-dimensional radiative transfer model, which suggests the possible presence of a transient day side inversion in HAT-P-2b's atmosphere near periapse. We also derive improved estimates for the system parameters, including its mass, radius, and orbital ephemeris. Our simultaneous fit to the transit, secondary eclipse, and radial velocity data allows us to determine the eccentricity (e = 0.50910 {+-} 0.00048) and argument of periapse ({omega} = 188. Degree-Sign 09 {+-} 0. Degree-Sign 39) of HAT-P-2b's orbit with a greater precision than has been achieved for any other eccentric extrasolar planet. We also find evidence for a long

Signal-dependent independent component analysis by tunable mother wavelets

International Nuclear Information System (INIS)

Seo, Kyung Ho

2006-02-01

The objective of this study is to improve the standard independent component analysis when applied to real-world signals. Independent component analysis starts from the assumption that signals from different physical sources are statistically independent. But real-world signals such as EEG, ECG, MEG, and fMRI signals are not statistically independent perfectly. By definition, standard independent component analysis algorithms are not able to estimate statistically dependent sources, that is, when the assumption of independence does not hold. Therefore before independent component analysis, some preprocessing stage is needed. This paper started from simple intuition that wavelet transformed source signals by 'well-tuned' mother wavelet will be simplified sufficiently, and then the source separation will show better results. By the correlation coefficient method, the tuning process between source signal and tunable mother wavelet was executed. Gamma component of raw EEG signal was set to target signal, and wavelet transform was executed by tuned mother wavelet and standard mother wavelets. Simulation results by these wavelets was shown

Quantum dynamics and electronic spectroscopy within the framework of wavelets

International Nuclear Information System (INIS)

Toutounji, Mohamad

2013-01-01

This paper serves as a first-time report on formulating important aspects of electronic spectroscopy and quantum dynamics in condensed harmonic systems using the framework of wavelets, and a stepping stone to our future work on developing anharmonic wavelets. The Morlet wavelet is taken to be the mother wavelet for the initial state of the system of interest. This work reports daughter wavelets that may be used to study spectroscopy and dynamics of harmonic systems. These wavelets are shown to arise naturally upon optical electronic transition of the system of interest. Natural birth of basis (daughter) wavelets emerging on exciting an electronic two-level system coupled, both linearly and quadratically, to harmonic phonons is discussed. It is shown that this takes place through using the unitary dilation and translation operators, which happen to be part of the time evolution operator of the final electronic state. The corresponding optical autocorrelation function and linear absorption spectra are calculated to test the applicability and correctness of the herein results. The link between basis wavelets and the Liouville space generating function is established. An anharmonic mother wavelet is also proposed in the case of anharmonic electron–phonon coupling. A brief description of deriving anharmonic wavelets and the corresponding anharmonic Liouville space generating function is explored. In conclusion, a mother wavelet (be it harmonic or anharmonic) which accounts for Duschinsky mixing is suggested. (paper)

Early detection of rogue waves by the wavelet transforms

International Nuclear Information System (INIS)

Bayındır, Cihan

2016-01-01

Highlights: • The advantages of wavelet analysis over the Fourier analysis for the early detection of rogue waves are discussed. • The triangular wavelet spectra can be detected at early stages of the development of rogue waves. • The wavelet analysis is capable of detecting not only the emergence but also the location of a rogue wave. • Wavelet analysis is also capable of predicting the characteristic distances between successive rogue waves. - Abstract: We discuss the possible advantages of using the wavelet transform over the Fourier transform for the early detection of rogue waves. We show that the triangular wavelet spectra of the rogue waves can be detected at early stages of the development of rogue waves in a chaotic wave field. Compared to the Fourier spectra, the wavelet spectra are capable of detecting not only the emergence of a rogue wave but also its possible spatial (or temporal) location. Due to this fact, wavelet transform is also capable of predicting the characteristic distances between successive rogue waves. Therefore multiple simultaneous breaking of the successive rogue waves on ships or on the offshore structures can be predicted and avoided by smart designs and operations.

Early detection of rogue waves by the wavelet transforms

Energy Technology Data Exchange (ETDEWEB)

Bayındır, Cihan, E-mail: cihan.bayindir@isikun.edu.tr

2016-01-08

Highlights: • The advantages of wavelet analysis over the Fourier analysis for the early detection of rogue waves are discussed. • The triangular wavelet spectra can be detected at early stages of the development of rogue waves. • The wavelet analysis is capable of detecting not only the emergence but also the location of a rogue wave. • Wavelet analysis is also capable of predicting the characteristic distances between successive rogue waves. - Abstract: We discuss the possible advantages of using the wavelet transform over the Fourier transform for the early detection of rogue waves. We show that the triangular wavelet spectra of the rogue waves can be detected at early stages of the development of rogue waves in a chaotic wave field. Compared to the Fourier spectra, the wavelet spectra are capable of detecting not only the emergence of a rogue wave but also its possible spatial (or temporal) location. Due to this fact, wavelet transform is also capable of predicting the characteristic distances between successive rogue waves. Therefore multiple simultaneous breaking of the successive rogue waves on ships or on the offshore structures can be predicted and avoided by smart designs and operations.

Temporal and spatial characteristics of wet-dry climate variation in the northern slope of Tianshan Mountains, Xinjiang

Science.gov (United States)

Yu, Meiyan; Xi, Chen; Bao, Anming

2008-10-01

Based on the monthly temperature and rainfall data of 1961-2006, aridity is calculated and its multi-time scales characteristics in different divisions in the northern slope of Tianshan Mountains have been analyzed using Mexican Hat wavelet analysis in this article. The periodic oscillation of aridity variation and the points of abrupt change at different time scales along the time series are discovered. Also the trend of climate change is tested. Additionally, possible association of climate variation in this area with ENSO is explored using SOI date series. The research results indicate that there exist obvious regional characteristics of wet-dry climate variation in the northern slope of Tianshan Mountains. Wavelet analysis shows that there mainly exits two modes of scales (12-24 years and 4-8 years) in every division, while catastrophe point differs in different zones. To predict on the scale of 12-24 years, it will be relatively dry in mountain division and desert area in a period after 2006. In addition, the transition from warm-dry to warm-wet appears in oasis area. Correlation analysis indicted that aridity variation of the northern slope of Tianshan Mountains is affected by ENSO, while influence degree is different between areas; furthermore, this influence is one-year lagging behind ENSO in the whole area.

Wavelets and quantum algebras

International Nuclear Information System (INIS)

Ludu, A.; Greiner, M.

1995-09-01

A non-linear associative algebra is realized in terms of translation and dilation operators, and a wavelet structure generating algebra is obtained. We show that this algebra is a q-deformation of the Fourier series generating algebra, and reduces to this for certain value of the deformation parameter. This algebra is also homeomorphic with the q-deformed su q (2) algebra and some of its extensions. Through this algebraic approach new methods for obtaining the wavelets are introduced. (author). 20 refs

Noise reduction by wavelet thresholding

National Research Council Canada - National Science Library

Jansen, Maarten

2001-01-01

.... I rather present new material and own insights in the que stions involved with wavelet based noise reduction . On the other hand , the presented material does cover a whole range of methodologies, and in that sense, the book may serve as an introduction into the domain of wavelet smoothing. Throughout the text, three main properties show up ever again: spar...

Wavelets for the stimulation of turbulent incompressible flows

International Nuclear Information System (INIS)

Deriaz, E.

2006-02-01

This PhD thesis presents original wavelet methods aimed at simulating incompressible fluids. In order to construct 2D and 3D wavelets designed for incompressible flows, we resume P-G Lemarie-Rieussets and K. Urbans works on divergence free wavelets. We show the existence of associated fast algorithms. In the following, we use divergence-free wavelet construction to define the Helmholtz decomposition of 2D and 3D vector fields. All these algorithms provide a new method for the numerical resolution of the incompressible Navier-Stokes equations. (author)

Implementation of Texture Based Image Retrieval Using M-band Wavelet Transform

Institute of Scientific and Technical Information of China (English)

LiaoYa-li; Yangyan; CaoYang

2003-01-01

Wavelet transform has attracted attention because it is a very useful tool for signal analyzing. As a fundamental characteristic of an image, texture traits play an important role in the human vision system for recognition and interpretation of images. The paper presents an approach to implement texture-based image retrieval using M-band wavelet transform. Firstly the traditional 2-band wavelet is extended to M-band wavelet transform. Then the wavelet moments are computed by M-band wavelet coefficients in the wavelet domain. The set of wavelet moments forms the feature vector related to the texture distribution of each wavelet images. The distances between the feature vectors describe the similarities of different images. The experimental result shows that the M-band wavelet moment features of the images are effective for image indexing.The retrieval method has lower computational complexity, yet it is capable of giving better retrieval performance for a given medical image database.

Detection of the Secondary Eclipse of Exoplanet HAT P-11b

Science.gov (United States)

Barry, R. K.; Deming, L. D.; Bakos, G.; Harrington, J.; Madhusudhan, N.; Noyes, R.; Seager, S.

2010-01-01

We have successfully conducted secondary eclipse observations of exoplanet HAT-P-11b using the Spitzer Space Telescope. HAT-P-11b was, until very recently, the smallest transiting extrasolar planet yet found and one of only two known exo-Neptunes. We observed the system at 3.6 microns for a period of 22 hours centered on the anticipated secondary eclipse time, to detect the eclipse and determine its phase. Having detected the secondary eclipse, we are at present making a more focused series of observations in both the 3.6 and 4.5 micron bands to fully characterize it. HAT-P-11b has a period of 4.8878 days, radius of 0.422 RJ, mass of 0.081 MJ and semi-major axis 0.053 AU. Measurements of the secondary eclipse will serve to clarify two key issues; 1) the planetary brightness temperature and the nature of its atmosphere, and 2) the eccentricity of its orbit, with implications for its dynamical evolution. A precise determination of the orbit phase for the secondary eclipse will also be of great utility for Kepler observations of this system at visible wavelengths.

Selection of the wavelet function for the frequencies estimation; Seleccion de la funcion wavelet para la estimacion de frecuencias

Energy Technology Data Exchange (ETDEWEB)

Garcia R, A. [ININ, Carretera Mexico-Toluca S/N, 52750 La Marquesa, Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: ramador@nuclear.inin.mx

2007-07-01

At the moment the signals are used to diagnose the state of the systems, by means of the extraction of their more important characteristics such as the frequencies, tendencies, changes and temporary evolutions. This characteristics are detected by means of diverse analysis techniques, as Autoregressive methods, Fourier Transformation, Fourier transformation in short time, Wavelet transformation, among others. The present work uses the one Wavelet transformation because it allows to analyze stationary, quasi-stationary and transitory signals in the time-frequency plane. It also describes a methodology to select the scales and the Wavelet function to be applied the one Wavelet transformation with the objective of detecting to the dominant system frequencies. (Author)

Optimization of wavelet decomposition for image compression and feature preservation.

Science.gov (United States)

Lo, Shih-Chung B; Li, Huai; Freedman, Matthew T

2003-09-01

A neural-network-based framework has been developed to search for an optimal wavelet kernel that can be used for a specific image processing task. In this paper, a linear convolution neural network was employed to seek a wavelet that minimizes errors and maximizes compression efficiency for an image or a defined image pattern such as microcalcifications in mammograms and bone in computed tomography (CT) head images. We have used this method to evaluate the performance of tap-4 wavelets on mammograms, CTs, magnetic resonance images, and Lena images. We found that the Daubechies wavelet or those wavelets with similar filtering characteristics can produce the highest compression efficiency with the smallest mean-square-error for many image patterns including general image textures as well as microcalcifications in digital mammograms. However, the Haar wavelet produces the best results on sharp edges and low-noise smooth areas. We also found that a special wavelet whose low-pass filter coefficients are 0.32252136, 0.85258927, 1.38458542, and -0.14548269) produces the best preservation outcomes in all tested microcalcification features including the peak signal-to-noise ratio, the contrast and the figure of merit in the wavelet lossy compression scheme. Having analyzed the spectrum of the wavelet filters, we can find the compression outcomes and feature preservation characteristics as a function of wavelets. This newly developed optimization approach can be generalized to other image analysis applications where a wavelet decomposition is employed.

Nuclear data compression and reconstruction via discrete wavelet transform

Energy Technology Data Exchange (ETDEWEB)

Park, Young Ryong; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1998-12-31

Discrete Wavelet Transforms (DWTs) are recent mathematics, and begin to be used in various fields. The wavelet transform can be used to compress the signal and image due to its inherent properties. We applied the wavelet transform compression and reconstruction to the neutron cross section data. Numerical tests illustrate that the signal compression using wavelet is very effective to reduce the data saving spaces. 7 refs., 4 figs., 3 tabs. (Author)

Nuclear data compression and reconstruction via discrete wavelet transform

Energy Technology Data Exchange (ETDEWEB)

Park, Young Ryong; Cho, Nam Zin [Korea Advanced Institute of Science and Technology, Taejon (Korea, Republic of)

1997-12-31

Discrete Wavelet Transforms (DWTs) are recent mathematics, and begin to be used in various fields. The wavelet transform can be used to compress the signal and image due to its inherent properties. We applied the wavelet transform compression and reconstruction to the neutron cross section data. Numerical tests illustrate that the signal compression using wavelet is very effective to reduce the data saving spaces. 7 refs., 4 figs., 3 tabs. (Author)

Construction of a class of Daubechies type wavelet bases

International Nuclear Information System (INIS)

Li Dengfeng; Wu Guochang

2009-01-01

Extensive work has been done in the theory and the construction of compactly supported orthonormal wavelet bases of L 2 (R). Some of the most distinguished work was done by Daubechies, who constructed a whole family of such wavelet bases. In this paper, we construct a class of orthonormal wavelet bases by using the principle of Daubechies, and investigate the length of support and the regularity of these wavelet bases.

Online Wavelet Complementary velocity Estimator.

Science.gov (United States)

Righettini, Paolo; Strada, Roberto; KhademOlama, Ehsan; Valilou, Shirin

2018-02-01

In this paper, we have proposed a new online Wavelet Complementary velocity Estimator (WCE) over position and acceleration data gathered from an electro hydraulic servo shaking table. This is a batch estimator type that is based on the wavelet filter banks which extract the high and low resolution of data. The proposed complementary estimator combines these two resolutions of velocities which acquired from numerical differentiation and integration of the position and acceleration sensors by considering a fixed moving horizon window as input to wavelet filter. Because of using wavelet filters, it can be implemented in a parallel procedure. By this method the numerical velocity is estimated without having high noise of differentiators, integration drifting bias and with less delay which is suitable for active vibration control in high precision Mechatronics systems by Direct Velocity Feedback (DVF) methods. This method allows us to make velocity sensors with less mechanically moving parts which makes it suitable for fast miniature structures. We have compared this method with Kalman and Butterworth filters over stability, delay and benchmarked them by their long time velocity integration for getting back the initial position data. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Visibility of wavelet quantization noise

Science.gov (United States)

Watson, A. B.; Yang, G. Y.; Solomon, J. A.; Villasenor, J.

1997-01-01

The discrete wavelet transform (DWT) decomposes an image into bands that vary in spatial frequency and orientation. It is widely used for image compression. Measures of the visibility of DWT quantization errors are required to achieve optimal compression. Uniform quantization of a single band of coefficients results in an artifact that we call DWT uniform quantization noise; it is the sum of a lattice of random amplitude basis functions of the corresponding DWT synthesis filter. We measured visual detection thresholds for samples of DWT uniform quantization noise in Y, Cb, and Cr color channels. The spatial frequency of a wavelet is r 2-lambda, where r is display visual resolution in pixels/degree, and lambda is the wavelet level. Thresholds increase rapidly with wavelet spatial frequency. Thresholds also increase from Y to Cr to Cb, and with orientation from lowpass to horizontal/vertical to diagonal. We construct a mathematical model for DWT noise detection thresholds that is a function of level, orientation, and display visual resolution. This allows calculation of a "perceptually lossless" quantization matrix for which all errors are in theory below the visual threshold. The model may also be used as the basis for adaptive quantization schemes.

Application of wavelets in speech processing

CERN Document Server

Farouk, Mohamed Hesham

2014-01-01

This book provides a survey on wide-spread of employing wavelets analysis  in different applications of speech processing. The author examines development and research in different application of speech processing. The book also summarizes the state of the art research on wavelet in speech processing.

From cardinal spline wavelet bases to highly coherent dictionaries

International Nuclear Information System (INIS)

Andrle, Miroslav; Rebollo-Neira, Laura

2008-01-01

Wavelet families arise by scaling and translations of a prototype function, called the mother wavelet. The construction of wavelet bases for cardinal spline spaces is generally carried out within the multi-resolution analysis scheme. Thus, the usual way of increasing the dimension of the multi-resolution subspaces is by augmenting the scaling factor. We show here that, when working on a compact interval, the identical effect can be achieved without changing the wavelet scale but reducing the translation parameter. By such a procedure we generate a redundant frame, called a dictionary, spanning the same spaces as a wavelet basis but with wavelets of broader support. We characterize the correlation of the dictionary elements by measuring their 'coherence' and produce examples illustrating the relevance of highly coherent dictionaries to problems of sparse signal representation. (fast track communication)

Wavelet series approximation using wavelet function with compactly ...

African Journals Online (AJOL)

The Wavelets generated by Scaling Function with Compactly Support are useful in various applications especially for reconstruction of functions. Generally, the computational process will be faster if Scaling Function support descends, so computational errors are summarized from one level to another level. In this article, the ...

Thermodynamic studies of a HAT cycle and its components

International Nuclear Information System (INIS)

Nyberg, Bjoern; Thern, Marcus

2012-01-01

Highlights: → Performance maps for HAT cycles with different complexity are shown. → A suggestion, where to extract cooling air for the turbine is presented. → The influence of the makeup water on total efficiency is shown. → The optimal pressure level for intercooling is described. -- Abstract: The electric power grid contains more and more renewable power production such as wind and solar power. The use of renewable power sources increases the fluctuations in the power grid which increase the demand for highly efficient, fast-starting power-producing units that can cope with sudden production losses. One of the more innovative power plant cycles, that have the potential of competing with conventional combined power plants in efficiency but has a higher availability and faster start up time, is the Evaporative Gas Turbine (EvGT) or Humid Air Turbine (HAT). A thermodynamic evaluation of different HAT cycle layouts has been done in this paper. Each layout is evaluated separately which makes it possible to study different components individual contribution to the efficiency and specific power. The thermodynamic evaluation also shows that it is important to look at different cool-flow extracting positions. The effect of water temperature entering the cycle, called make-up water, and where it is introduced into the cycle has been evaluated. The make-up water temperature also affects the optimal pressure level for intercooling and it is shown that an optimal position can be decided considering design parameters of the compressor and the water circuit.

Wavelet tree structure based speckle noise removal for optical coherence tomography

Science.gov (United States)

Yuan, Xin; Liu, Xuan; Liu, Yang

2018-02-01

We report a new speckle noise removal algorithm in optical coherence tomography (OCT). Though wavelet domain thresholding algorithms have demonstrated superior advantages in suppressing noise magnitude and preserving image sharpness in OCT, the wavelet tree structure has not been investigated in previous applications. In this work, we propose an adaptive wavelet thresholding algorithm via exploiting the tree structure in wavelet coefficients to remove the speckle noise in OCT images. The threshold for each wavelet band is adaptively selected following a special rule to retain the structure of the image across different wavelet layers. Our results demonstrate that the proposed algorithm outperforms conventional wavelet thresholding, with significant advantages in preserving image features.

Kavunda ebeveyn hat ile melezlerinin bazı tohum ve tohum çıkışı özelliklerinin belirlenmesi

OpenAIRE

TUR, Ayşegül; SEYMEN, Musa; TÜRKMEN, Önder

2018-01-01

Bu çalışma, 2015-2016 yıllarında yürütülmüş ve bitkisel materyal olarak, 13 genotip (SÇ-1: Sel-1-1. SÇ-2: Sel-1-2. SÇ-3: Sel-2. SÇ-4: Sel-3. SÇ-5: Sel-4. SÇ-6: Sel-6-1. SÇ-7: Sel-6-2. SÇ-8: Sel-7. SÇ-9: Sel-8. SÇ-10: Sel-9. SÇ-11: Sel-10. SÇ-12: Sel-11. SÇ-13: Pop. Diyarbakır). 4 ebeveyn hat (EB-1: saf hat-7. EB-2: saf hat-A4. EB-3: saf hat-G22. EB-4: saf hat-136) ve 9 melez (M-1: safhat 7xsafhat-136. M-2: safhat-7xsafhat-A4. M-3: safhat-7xsafhat-G22. M-4: safhat-G22xsafhat-136. M-5: safhat-G...

ORBITAL PHASE VARIATIONS OF THE ECCENTRIC GIANT PLANET HAT-P-2b

International Nuclear Information System (INIS)

Lewis, Nikole K.; Showman, Adam P.; Knutson, Heather A.; Désert, Jean-Michel; Kao, Melodie; Cowan, Nicolas B.; Laughlin, Gregory; Fortney, Jonathan J.; Burrows, Adam; Bakos, Gáspár Á.; Hartman, Joel D.; Deming, Drake; Crepp, Justin R.; Mighell, Kenneth J.; Agol, Eric; Charbonneau, David; Fischer, Debra A.; Hinkley, Sasha; Johnson, John Asher; Howard, Andrew W.

2013-01-01

We present the first secondary eclipse and phase curve observations for the highly eccentric hot Jupiter HAT-P-2b in the 3.6, 4.5, 5.8, and 8.0 μm bands of the Spitzer Space Telescope. The 3.6 and 4.5 μm data sets span an entire orbital period of HAT-P-2b (P = 5.6334729 d), making them the longest continuous phase curve observations obtained to date and the first full-orbit observations of a planet with an eccentricity exceeding 0.2. We present an improved non-parametric method for removing the intrapixel sensitivity variations in Spitzer data at 3.6 and 4.5 μm that robustly maps position-dependent flux variations. We find that the peak in planetary flux occurs at 4.39 ± 0.28, 5.84 ± 0.39, and 4.68 ± 0.37 hr after periapse passage with corresponding maxima in the planet/star flux ratio of 0.1138% ± 0.0089%, 0.1162% ± 0.0080%, and 0.1888% ± 0.0072% in the 3.6, 4.5, and 8.0 μm bands, respectively. Our measured secondary eclipse depths of 0.0996% ± 0.0072%, 0.1031% ± 0.0061%, 0.071% -0.013% +0.029, and 0.1392% ± 0.0095% in the 3.6, 4.5, 5.8, and 8.0 μm bands, respectively, indicate that the planet cools significantly from its peak temperature before we measure the dayside flux during secondary eclipse. We compare our measured secondary eclipse depths to the predictions from a one-dimensional radiative transfer model, which suggests the possible presence of a transient day side inversion in HAT-P-2b's atmosphere near periapse. We also derive improved estimates for the system parameters, including its mass, radius, and orbital ephemeris. Our simultaneous fit to the transit, secondary eclipse, and radial velocity data allows us to determine the eccentricity (e = 0.50910 ± 0.00048) and argument of periapse (ω = 188.°09 ± 0.°39) of HAT-P-2b's orbit with a greater precision than has been achieved for any other eccentric extrasolar planet. We also find evidence for a long-term linear trend in the radial velocity data. This trend suggests the presence of

Wavelet processing techniques for digital mammography

Science.gov (United States)

Laine, Andrew F.; Song, Shuwu

1992-09-01

This paper introduces a novel approach for accomplishing mammographic feature analysis through multiresolution representations. We show that efficient (nonredundant) representations may be identified from digital mammography and used to enhance specific mammographic features within a continuum of scale space. The multiresolution decomposition of wavelet transforms provides a natural hierarchy in which to embed an interactive paradigm for accomplishing scale space feature analysis. Similar to traditional coarse to fine matching strategies, the radiologist may first choose to look for coarse features (e.g., dominant mass) within low frequency levels of a wavelet transform and later examine finer features (e.g., microcalcifications) at higher frequency levels. In addition, features may be extracted by applying geometric constraints within each level of the transform. Choosing wavelets (or analyzing functions) that are simultaneously localized in both space and frequency, results in a powerful methodology for image analysis. Multiresolution and orientation selectivity, known biological mechanisms in primate vision, are ingrained in wavelet representations and inspire the techniques presented in this paper. Our approach includes local analysis of complete multiscale representations. Mammograms are reconstructed from wavelet representations, enhanced by linear, exponential and constant weight functions through scale space. By improving the visualization of breast pathology we can improve the chances of early detection of breast cancers (improve quality) while requiring less time to evaluate mammograms for most patients (lower costs).

Application of wavelet transform in seismic signal processing

International Nuclear Information System (INIS)

Ghasemi, M. R.; Mohammadzadeh, A.; Salajeghe, E.

2005-01-01

Wavelet transform is a new tool for signal analysis which can perform a simultaneous signal time and frequency representations. Under Multi Resolution Analysis, one can quickly determine details for signals and their properties using Fast Wavelet Transform algorithms. In this paper, for a better physical understanding of a signal and its basic algorithms, Multi Resolution Analysis together with wavelet transforms in a form of Digital Signal Processing will be discussed. For a Seismic Signal Processing, sets of Orthonormal Daubechies Wavelets are suggested. when dealing with the application of wavelets in SSP, one may discuss about denoising from the signal and data compression existed in the signal, which is important in seismic signal data processing. Using this techniques, EL-Centro and Nagan signals were remodeled with a 25% of total points, resulted in a satisfactory results with an acceptable error drift. Thus a total of 1559 and 2500 points for EL-centro and Nagan seismic curves each, were reduced to 389 and 625 points respectively, with a very reasonable error drift, details of which are recorded in the paper. Finally, the future progress in signal processing, based on wavelet theory will be appointed

Virtual Screening of Phytochemicals to Novel Target (HAT) Rtt109 in Pneumocystis Jirovecii using Bioinformatics Tools.

Science.gov (United States)

Sugumar, Ramya; Adithavarman, Abhinand Ponneri; Dakshinamoorthi, Anusha; David, Darling Chellathai; Ragunath, Padmavathi Kannan

2016-03-01

Pneumocystis jirovecii is a fungus that causes Pneumocystis pneumonia in HIV and other immunosuppressed patients. Treatment of Pneumocystis pneumonia with the currently available antifungals is challenging and associated with considerable adverse effects. There is a need to develop drugs against novel targets with minimal human toxicities. Histone Acetyl Transferase (HAT) Rtt109 is a potential therapeutic target in Pneumocystis jirovecii species. HAT is linked to transcription and is required to acetylate conserved lysine residues on histone proteins by transferring an acetyl group from acetyl CoA to form e-N-acetyl lysine. Therefore, inhibitors of HAT can be useful therapeutic options in Pneumocystis pneumonia. To screen phytochemicals against (HAT) Rtt109 using bioinformatics tool. The tertiary structure of Pneumocystis jirovecii (HAT) Rtt109 was modeled by Homology Modeling. The ideal template for modeling was obtained by performing Psi BLAST of the protein sequence. Rtt109-AcCoA/Vps75 protein from Saccharomyces cerevisiae (PDB structure 3Q35) was chosen as the template. The target protein was modeled using Swiss Modeler and validated using Ramachandran plot and Errat 2. Comprehensive text mining was performed to identify phytochemical compounds with antipneumonia and fungicidal properties and these compounds were filtered based on Lipinski's Rule of 5. The chosen compounds were subjected to virtual screening against the target protein (HAT) Rtt109 using Molegro Virtual Docker 4.5. Osiris Property Explorer and Open Tox Server were used to predict ADME-T properties of the chosen phytochemicals. Tertiary structure model of HAT Rtt 109 had a ProSA score of -6.57 and Errat 2 score of 87.34. Structure validation analysis by Ramachandran plot for the model revealed 97% of amino acids were in the favoured region. Of all the phytochemicals subjected to virtual screening against the target protein (HAT) Rtt109, baicalin exhibited highest binding affinity towards the

Denoising in Wavelet Packet Domain via Approximation Coefficients

Directory of Open Access Journals (Sweden)

Zahra Vahabi

2012-01-01

Full Text Available In this paper we propose a new approach in the wavelet domain for image denoising. In recent researches wavelet transform has introduced a time-Frequency transform for computing wavelet coefficient and eliminating noise. Some coefficients have effected smaller than the other's from noise, so they can be use reconstruct images with other subbands. We have developed Approximation image to estimate better denoised image. Naturally noiseless subimage introduced image with lower noise. Beside denoising we obtain a bigger compression rate. Increasing image contrast is another advantage of this method. Experimental results demonstrate that our approach compares favorably to more typical methods of denoising and compression in wavelet domain.100 images of LIVE Dataset were tested, comparing signal to noise ratios (SNR,soft thresholding was %1.12 better than hard thresholding, POAC was %1.94 better than soft thresholding and POAC with wavelet packet was %1.48 better than POAC.

Pseudo-stochastic signal characterization in wavelet-domain

International Nuclear Information System (INIS)

Zaytsev, Kirill I; Zhirnov, Andrei A; Alekhnovich, Valentin I; Yurchenko, Stanislav O

2015-01-01

In this paper we present the method for fast and accurate characterization of pseudo-stochastic signals, which contain a large number of similar but randomly-located fragments. This method allows estimating the statistical characteristics of pseudo-stochastic signal, and it is based on digital signal processing in wavelet-domain. Continuous wavelet transform and the criterion for wavelet scale power density are utilized. We are experimentally implementing this method for the purpose of sand granulometry, and we are estimating the statistical parameters of test sand fractions

Wavelet library for constrained devices

Science.gov (United States)

Ehlers, Johan Hendrik; Jassim, Sabah A.

2007-04-01

The wavelet transform is a powerful tool for image and video processing, useful in a range of applications. This paper is concerned with the efficiency of a certain fast-wavelet-transform (FWT) implementation and several wavelet filters, more suitable for constrained devices. Such constraints are typically found on mobile (cell) phones or personal digital assistants (PDA). These constraints can be a combination of; limited memory, slow floating point operations (compared to integer operations, most often as a result of no hardware support) and limited local storage. Yet these devices are burdened with demanding tasks such as processing a live video or audio signal through on-board capturing sensors. In this paper we present a new wavelet software library, HeatWave, that can be used efficiently for image/video processing/analysis tasks on mobile phones and PDA's. We will demonstrate that HeatWave is suitable for realtime applications with fine control and range to suit transform demands. We shall present experimental results to substantiate these claims. Finally this library is intended to be of real use and applied, hence we considered several well known and common embedded operating system platform differences; such as a lack of common routines or functions, stack limitations, etc. This makes HeatWave suitable for a range of applications and research projects.

Characterization of the Micro-shell Surface Using Holographic Measurements

Energy Technology Data Exchange (ETDEWEB)

Sandras, F.; Hermerel, C.; Choux, A.; Merillot, P.; Pin, G.; Jeannot, L. [CEA Valduc, Dept Rech Mat Nucl, Serv Microcibles, 21 - Is-sur-Tille (France)

2009-05-15

To characterize the shape, the quality, and the roughness of micro-shells, typically used technologies are scanning electron microscopy, scanning interferometric microscopy, or atomic force microscopy. One of the drawbacks of these techniques is that they are generally slow because of their scanning process. Digital holographic microscopy technology is an innovation that can offer ability adapted to these studies. It captures holograms instead of intensity images, as done by conventional microscopes. The holograms are then digitally interpreted (10 per second) to reconstruct a double image, one for the intensity and another one for the phase. Using a rotation axis, the bump counting for the complete micro-shell surface is possible with a very high speed. Using an image stitching software, mapping can be done in a few minutes. Wavelets such as 'Mexican hat' are used to model the bumps. Each bump can then be characterized on the map by its position, diameter, and height. (authors)

Separated Flow over Wind Turbines

Science.gov (United States)

Brown, David; Lewalle, Jacques

2015-11-01

The motion of the separation point on an airfoil under unsteady flow can affect its performance and longevity. Of interest is to understand and control the performance decrease in wind turbines subject to turbulent flow. We examine flow separation on an airfoil at a 19 degree angle of attack under unsteady flow conditions. We are using a DU-96-W180 airfoil of chord length 242 mm. The unsteadiness is generated by a cylinder with diameter 203 mm located 7 diameters upstream of the airfoil's leading edge. The data comes from twenty surface pressure sensors located on the top and bottom of the airfoil as well as on the upstream cylinder. Methods of analysis include Mexican hat transforms, Morlet wavelet transforms, power spectra, and various cross correlations. With this study I will explore how the differences of signals on the pressure and suction sides of an airfoil are related to the motion of the separation point.

WAVELET TRANSFORM AND LIP MODEL

Directory of Open Access Journals (Sweden)

Guy Courbebaisse

2011-05-01

Full Text Available The Fourier transform is well suited to the study of stationary functions. Yet, it is superseded by the Wavelet transform for the powerful characterizations of function features such as singularities. On the other hand, the LIP (Logarithmic Image Processing model is a mathematical framework developed by Jourlin and Pinoli, dedicated to the representation and processing of gray tones images called hereafter logarithmic images. This mathematically well defined model, comprising a Fourier Transform "of its own", provides an effective tool for the representation of images obtained by transmitted light, such as microscope images. This paper presents a Wavelet transform within the LIP framework, with preservation of the classical Wavelet Transform properties. We show that the fast computation algorithm due to Mallat can be easily used. An application is given for the detection of crests.

From Calculus to Wavelets: ANew Mathematical Technique

Indian Academy of Sciences (India)

Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 4. From Calculus to Wavelets: A New Mathematical Technique Wavelet Analysis Physical Properties. Gerald B Folland. General Article Volume 2 Issue 4 April 1997 pp 25-37 ...

On transforms between Gabor frames and wavelet frames

DEFF Research Database (Denmark)

Christensen, Ole; Goh, Say Song

2013-01-01

We describe a procedure that enables us to construct dual pairs of wavelet frames from certain dual pairs of Gabor frames. Applying the construction to Gabor frames generated by appropriate exponential Bsplines gives wavelet frames generated by functions whose Fourier transforms are compactly...... supported splines with geometrically distributed knot sequences. There is also a reverse transform, which yields pairs of dual Gabor frames when applied to certain wavelet frames....

Application of wavelets to singular integral scattering equations

International Nuclear Information System (INIS)

Kessler, B.M.; Payne, G.L.; Polyzou, W.N.

2004-01-01

The use of orthonormal wavelet basis functions for solving singular integral scattering equations is investigated. It is shown that these basis functions lead to sparse matrix equations which can be solved by iterative techniques. The scaling properties of wavelets are used to derive an efficient method for evaluating the singular integrals. The accuracy and efficiency of the wavelet transforms are demonstrated by solving the two-body T-matrix equation without partial wave projection. The resulting matrix equation which is characteristic of multiparticle integral scattering equations is found to provide an efficient method for obtaining accurate approximate solutions to the integral equation. These results indicate that wavelet transforms may provide a useful tool for studying few-body systems

Coresident sensor fusion and compression using the wavelet transform

Energy Technology Data Exchange (ETDEWEB)

Yocky, D.A.

1996-03-11

Imagery from coresident sensor platforms, such as unmanned aerial vehicles, can be combined using, multiresolution decomposition of the sensor images by means of the two-dimensional wavelet transform. The wavelet approach uses the combination of spatial/spectral information at multiple scales to create a fused image. This can be done in both an ad hoc or model-based approach. We compare results from commercial ``fusion`` software and the ad hoc, wavelet approach. Results show the wavelet approach outperforms the commercial algorithms and also supports efficient compression of the fused image.

Framelets and wavelets algorithms, analysis, and applications

CERN Document Server

Han, Bin

2017-01-01

Marking a distinct departure from the perspectives of frame theory and discrete transforms, this book provides a comprehensive mathematical and algorithmic introduction to wavelet theory. As such, it can be used as either a textbook or reference guide. As a textbook for graduate mathematics students and beginning researchers, it offers detailed information on the basic theory of framelets and wavelets, complemented by self-contained elementary proofs, illustrative examples/figures, and supplementary exercises. Further, as an advanced reference guide for experienced researchers and practitioners in mathematics, physics, and engineering, the book addresses in detail a wide range of basic and advanced topics (such as multiwavelets/multiframelets in Sobolev spaces and directional framelets) in wavelet theory, together with systematic mathematical analysis, concrete algorithms, and recent developments in and applications of framelets and wavelets. Lastly, the book can also be used to teach on or study selected spe...

Scalets, wavelets and (complex) turning point quantization

Science.gov (United States)

Handy, C. R.; Brooks, H. A.

2001-05-01

Despite the many successes of wavelet analysis in image and signal processing, the incorporation of continuous wavelet transform theory within quantum mechanics has lacked a compelling, first principles, motivating analytical framework, until now. For arbitrary one-dimensional rational fraction Hamiltonians, we develop a simple, unified formalism, which clearly underscores the complementary, and mutually interdependent, role played by moment quantization theory (i.e. via scalets, as defined herein) and wavelets. This analysis involves no approximation of the Hamiltonian within the (equivalent) wavelet space, and emphasizes the importance of (complex) multiple turning point contributions in the quantization process. We apply the method to three illustrative examples. These include the (double-well) quartic anharmonic oscillator potential problem, V(x) = Z2x2 + gx4, the quartic potential, V(x) = x4, and the very interesting and significant non-Hermitian potential V(x) = -(ix)3, recently studied by Bender and Boettcher.

WASP-12b AND HAT-P-8b are members of triple star systems

Energy Technology Data Exchange (ETDEWEB)

Bechter, Eric B.; Crepp, Justin R.; Matthews, Christopher T. [Department of Physics, University of Notre Dame, 225 Nieuwland Science Hall, Notre Dame, IN 46556 (United States); Ngo, Henry; Knutson, Heather A.; Batygin, Konstantin; Johnson, John Asher [Department of Planetary Science, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Hinkley, Sasha; Muirhead, Philip S.; Montet, Benjamin T.; Morton, Timothy D. [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Howard, Andrew W., E-mail: ebechter@nd.edu [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States)

2014-06-10

We present high spatial resolution images that demonstrate that WASP-12b and HAT-P-8b orbit the primary stars of hierarchical triple star systems. In each case, two distant companions with colors and brightnesses consistent with M dwarfs co-orbit the hot Jupiter planet host as well as one another. Our adaptive optics images spatially resolve the secondary around WASP-12, previously identified by Bergfors et al. and Crossfield et al. into two distinct sources separated by 84.3 ± 0.6 mas (21 ± 3 AU). We find that the secondary to HAT-P-8, also identified by Bergfors et al., is in fact composed of two stars separated by 65.3 ± 0.5 mas (15 ± 1 AU). Our follow-up observations demonstrate physical association through common proper motion. HAT-P-8 C has a particularly low mass, which we estimate to be 0.18 ± 0.02 M {sub ☉} using photometry. Due to their hierarchy, WASP-12 BC and HAT-P-8 BC will enable the first dynamical mass determination for hot Jupiter stellar companions. These previously well studied planet hosts now represent higher-order multi-star systems with potentially complex dynamics, underscoring the importance of diffraction-limited imaging and providing additional context for understanding the migrant population of transiting hot Jupiters.

WASP-12b and HAT-P-8b are Members of Triple Star Systems

Science.gov (United States)

Bechter, Eric B.; Crepp, Justin R.; Ngo, Henry; Knutson, Heather A.; Batygin, Konstantin; Hinkley, Sasha; Muirhead, Philip S.; Johnson, John Asher; Howard, Andrew W.; Montet, Benjamin T.; Matthews, Christopher T.; Morton, Timothy D.

2014-06-01

We present high spatial resolution images that demonstrate that WASP-12b and HAT-P-8b orbit the primary stars of hierarchical triple star systems. In each case, two distant companions with colors and brightnesses consistent with M dwarfs co-orbit the hot Jupiter planet host as well as one another. Our adaptive optics images spatially resolve the secondary around WASP-12, previously identified by Bergfors et al. and Crossfield et al. into two distinct sources separated by 84.3 ± 0.6 mas (21 ± 3 AU). We find that the secondary to HAT-P-8, also identified by Bergfors et al., is in fact composed of two stars separated by 65.3 ± 0.5 mas (15 ± 1 AU). Our follow-up observations demonstrate physical association through common proper motion. HAT-P-8 C has a particularly low mass, which we estimate to be 0.18 ± 0.02 M ⊙ using photometry. Due to their hierarchy, WASP-12 BC and HAT-P-8 BC will enable the first dynamical mass determination for hot Jupiter stellar companions. These previously well studied planet hosts now represent higher-order multi-star systems with potentially complex dynamics, underscoring the importance of diffraction-limited imaging and providing additional context for understanding the migrant population of transiting hot Jupiters.

WASP-12b AND HAT-P-8b are members of triple star systems

International Nuclear Information System (INIS)

Bechter, Eric B.; Crepp, Justin R.; Matthews, Christopher T.; Ngo, Henry; Knutson, Heather A.; Batygin, Konstantin; Johnson, John Asher; Hinkley, Sasha; Muirhead, Philip S.; Montet, Benjamin T.; Morton, Timothy D.; Howard, Andrew W.

2014-01-01

We present high spatial resolution images that demonstrate that WASP-12b and HAT-P-8b orbit the primary stars of hierarchical triple star systems. In each case, two distant companions with colors and brightnesses consistent with M dwarfs co-orbit the hot Jupiter planet host as well as one another. Our adaptive optics images spatially resolve the secondary around WASP-12, previously identified by Bergfors et al. and Crossfield et al. into two distinct sources separated by 84.3 ± 0.6 mas (21 ± 3 AU). We find that the secondary to HAT-P-8, also identified by Bergfors et al., is in fact composed of two stars separated by 65.3 ± 0.5 mas (15 ± 1 AU). Our follow-up observations demonstrate physical association through common proper motion. HAT-P-8 C has a particularly low mass, which we estimate to be 0.18 ± 0.02 M ☉ using photometry. Due to their hierarchy, WASP-12 BC and HAT-P-8 BC will enable the first dynamical mass determination for hot Jupiter stellar companions. These previously well studied planet hosts now represent higher-order multi-star systems with potentially complex dynamics, underscoring the importance of diffraction-limited imaging and providing additional context for understanding the migrant population of transiting hot Jupiters.

Time-frequency analysis of phonocardiogram signals using wavelet transform: a comparative study.

Science.gov (United States)

Ergen, Burhan; Tatar, Yetkin; Gulcur, Halil Ozcan

2012-01-01

Analysis of phonocardiogram (PCG) signals provides a non-invasive means to determine the abnormalities caused by cardiovascular system pathology. In general, time-frequency representation (TFR) methods are used to study the PCG signal because it is one of the non-stationary bio-signals. The continuous wavelet transform (CWT) is especially suitable for the analysis of non-stationary signals and to obtain the TFR, due to its high resolution, both in time and in frequency and has recently become a favourite tool. It decomposes a signal in terms of elementary contributions called wavelets, which are shifted and dilated copies of a fixed mother wavelet function, and yields a joint TFR. Although the basic characteristics of the wavelets are similar, each type of the wavelets produces a different TFR. In this study, eight real types of the most known wavelets are examined on typical PCG signals indicating heart abnormalities in order to determine the best wavelet to obtain a reliable TFR. For this purpose, the wavelet energy and frequency spectrum estimations based on the CWT and the spectra of the chosen wavelets were compared with the energy distribution and the autoregressive frequency spectra in order to determine the most suitable wavelet. The results show that Morlet wavelet is the most reliable wavelet for the time-frequency analysis of PCG signals.

A New Formula for the Inverse Wavelet Transform

OpenAIRE

Sun, Wenchang

2010-01-01

Finding a computationally efficient algorithm for the inverse continuous wavelet transform is a fundamental topic in applications. In this paper, we show the convergence of the inverse wavelet transform.

Adapted wavelet analysis from theory to software

CERN Document Server

Wickerhauser, Mladen Victor

1994-01-01

This detail-oriented text is intended for engineers and applied mathematicians who must write computer programs to perform wavelet and related analysis on real data. It contains an overview of mathematical prerequisites and proceeds to describe hands-on programming techniques to implement special programs for signal analysis and other applications. From the table of contents: - Mathematical Preliminaries - Programming Techniques - The Discrete Fourier Transform - Local Trigonometric Transforms - Quadrature Filters - The Discrete Wavelet Transform - Wavelet Packets - The Best Basis Algorithm - Multidimensional Library Trees - Time-Frequency Analysis - Some Applications - Solutions to Some of the Exercises - List of Symbols - Quadrature Filter Coefficients

Time-localized wavelet multiple regression and correlation

Science.gov (United States)

Fernández-Macho, Javier

2018-02-01

This paper extends wavelet methodology to handle comovement dynamics of multivariate time series via moving weighted regression on wavelet coefficients. The concept of wavelet local multiple correlation is used to produce one single set of multiscale correlations along time, in contrast with the large number of wavelet correlation maps that need to be compared when using standard pairwise wavelet correlations with rolling windows. Also, the spectral properties of weight functions are investigated and it is argued that some common time windows, such as the usual rectangular rolling window, are not satisfactory on these grounds. The method is illustrated with a multiscale analysis of the comovements of Eurozone stock markets during this century. It is shown how the evolution of the correlation structure in these markets has been far from homogeneous both along time and across timescales featuring an acute divide across timescales at about the quarterly scale. At longer scales, evidence from the long-term correlation structure can be interpreted as stable perfect integration among Euro stock markets. On the other hand, at intramonth and intraweek scales, the short-term correlation structure has been clearly evolving along time, experiencing a sharp increase during financial crises which may be interpreted as evidence of financial 'contagion'.

Effectiveness Of Six Thinking Hats Training In Improving The ...

African Journals Online (AJOL)

This study investigated the effectiveness of Six Thinking Hats Training in improving the psychological well- being of prisoners. The study consisted of 24 convicted prisoners whose ages ranged from 19-60 years with a mean of 22.50 years. A 2x2 experimental group design was adopted, and subjects were randomly ...

Mexican Parenting Questionnaire (MPQ)

Science.gov (United States)

Halgunseth, Linda C.; Ispa, Jean M.

2012-01-01

The present study was conducted in four phases and constructed a self-report parenting instrument for use with Mexican immigrant mothers of children aged 6 to 10. The 14-item measure was based on semistructured qualitative interviews with Mexican immigrant mothers (N = 10), was refined by a focus group of Mexican immigrant mothers (N = 5), and was…

Wavelet transform analysis of transient signals: the seismogram and the electrocardiogram

Energy Technology Data Exchange (ETDEWEB)

Anant, K.S.

1997-06-01

In this dissertation I quantitatively demonstrate how the wavelet transform can be an effective mathematical tool for the analysis of transient signals. The two key signal processing applications of the wavelet transform, namely feature identification and representation (i.e., compression), are shown by solving important problems involving the seismogram and the electrocardiogram. The seismic feature identification problem involved locating in time the P and S phase arrivals. Locating these arrivals accurately (particularly the S phase) has been a constant issue in seismic signal processing. In Chapter 3, I show that the wavelet transform can be used to locate both the P as well as the S phase using only information from single station three-component seismograms. This is accomplished by using the basis function (wave-let) of the wavelet transform as a matching filter and by processing information across scales of the wavelet domain decomposition. The `pick` time results are quite promising as compared to analyst picks. The representation application involved the compression of the electrocardiogram which is a recording of the electrical activity of the heart. Compression of the electrocardiogram is an important problem in biomedical signal processing due to transmission and storage limitations. In Chapter 4, I develop an electrocardiogram compression method that applies vector quantization to the wavelet transform coefficients. The best compression results were obtained by using orthogonal wavelets, due to their ability to represent a signal efficiently. Throughout this thesis the importance of choosing wavelets based on the problem at hand is stressed. In Chapter 5, I introduce a wavelet design method that uses linear prediction in order to design wavelets that are geared to the signal or feature being analyzed. The use of these designed wavelets in a test feature identification application led to positive results. The methods developed in this thesis; the

Wavelets in medical imaging

International Nuclear Information System (INIS)

Zahra, Noor e; Sevindir, Huliya A.; Aslan, Zafar; Siddiqi, A. H.

2012-01-01

The aim of this study is to provide emerging applications of wavelet methods to medical signals and images, such as electrocardiogram, electroencephalogram, functional magnetic resonance imaging, computer tomography, X-ray and mammography. Interpretation of these signals and images are quite important. Nowadays wavelet methods have a significant impact on the science of medical imaging and the diagnosis of disease and screening protocols. Based on our initial investigations, future directions include neurosurgical planning and improved assessment of risk for individual patients, improved assessment and strategies for the treatment of chronic pain, improved seizure localization, and improved understanding of the physiology of neurological disorders. We look ahead to these and other emerging applications as the benefits of this technology become incorporated into current and future patient care. In this chapter by applying Fourier transform and wavelet transform, analysis and denoising of one of the important biomedical signals like EEG is carried out. The presence of rhythm, template matching, and correlation is discussed by various method. Energy of EEG signal is used to detect seizure in an epileptic patient. We have also performed denoising of EEG signals by SWT.

Wavelets in medical imaging

Energy Technology Data Exchange (ETDEWEB)

Zahra, Noor e; Sevindir, Huliya A.; Aslan, Zafar; Siddiqi, A. H. [Sharda University, SET, Department of Electronics and Communication, Knowledge Park 3rd, Gr. Noida (India); University of Kocaeli, Department of Mathematics, 41380 Kocaeli (Turkey); Istanbul Aydin University, Department of Computer Engineering, 34295 Istanbul (Turkey); Sharda University, SET, Department of Mathematics, 32-34 Knowledge Park 3rd, Greater Noida (India)

2012-07-17

The aim of this study is to provide emerging applications of wavelet methods to medical signals and images, such as electrocardiogram, electroencephalogram, functional magnetic resonance imaging, computer tomography, X-ray and mammography. Interpretation of these signals and images are quite important. Nowadays wavelet methods have a significant impact on the science of medical imaging and the diagnosis of disease and screening protocols. Based on our initial investigations, future directions include neurosurgical planning and improved assessment of risk for individual patients, improved assessment and strategies for the treatment of chronic pain, improved seizure localization, and improved understanding of the physiology of neurological disorders. We look ahead to these and other emerging applications as the benefits of this technology become incorporated into current and future patient care. In this chapter by applying Fourier transform and wavelet transform, analysis and denoising of one of the important biomedical signals like EEG is carried out. The presence of rhythm, template matching, and correlation is discussed by various method. Energy of EEG signal is used to detect seizure in an epileptic patient. We have also performed denoising of EEG signals by SWT.

BALTIMORE’S M.S. LEVY AND SONS: Straw Hat Makers to the World, 1870-1960

Directory of Open Access Journals (Sweden)

Jessica I. Elfenbein

2008-01-01

Full Text Available From 1860 to 1960, Baltimore was an important center of the men’s ready-to- wear clothing industries. German-speaking Jews created many businesses that manufactured and sold underwear, men’s suits, and specialty items like hats and umbrellas. The straw hat making firm started by M.S. Levy is an interesting example of a Baltimore-based, family-owned niche business that existedfor 90 years, through three generations ofa singlefamily. The M.S. Levy and Sons story has two main chapters. The first covers the period from its founding by Michael Simon Levy in the 1870s through his son Julius’ death in 1926. This is the story of ascension. A premonition about the coming popularity of straw hats, together with a small but important technological breakthrough, positioned a family and a small industry for significant expansion. The second period began in 1930 with the introduction of wool felt hats and the death of William, M.S. Levy’s oldest son, and includes the Great Depression, unionization, merger, third generation leadership, and finally, in 1959, the family’s withdrawal from the industry. This later period, as told by grandsons of the founder, is the story of struggle followed by decline.

Digital transceiver implementation for wavelet packet modulation

Science.gov (United States)

Lindsey, Alan R.; Dill, Jeffrey C.

1998-03-01

Current transceiver designs for wavelet-based communication systems are typically reliant on analog waveform synthesis, however, digital processing is an important part of the eventual success of these techniques. In this paper, a transceiver implementation is introduced for the recently introduced wavelet packet modulation scheme which moves the analog processing as far as possible toward the antenna. The transceiver is based on the discrete wavelet packet transform which incorporates level and node parameters for generalized computation of wavelet packets. In this transform no particular structure is imposed on the filter bank save dyadic branching, and a maximum level which is specified a priori and dependent mainly on speed and/or cost considerations. The transmitter/receiver structure takes a binary sequence as input and, based on the desired time- frequency partitioning, processes the signal through demultiplexing, synthesis, analysis, multiplexing and data determination completely in the digital domain - with exception of conversion in and out of the analog domain for transmission.

Multiscale wavelet representations for mammographic feature analysis

Science.gov (United States)

Laine, Andrew F.; Song, Shuwu

1992-12-01

This paper introduces a novel approach for accomplishing mammographic feature analysis through multiresolution representations. We show that efficient (nonredundant) representations may be identified from digital mammography and used to enhance specific mammographic features within a continuum of scale space. The multiresolution decomposition of wavelet transforms provides a natural hierarchy in which to embed an interactive paradigm for accomplishing scale space feature analysis. Choosing wavelets (or analyzing functions) that are simultaneously localized in both space and frequency, results in a powerful methodology for image analysis. Multiresolution and orientation selectivity, known biological mechanisms in primate vision, are ingrained in wavelet representations and inspire the techniques presented in this paper. Our approach includes local analysis of complete multiscale representations. Mammograms are reconstructed from wavelet coefficients, enhanced by linear, exponential and constant weight functions localized in scale space. By improving the visualization of breast pathology we can improve the changes of early detection of breast cancers (improve quality) while requiring less time to evaluate mammograms for most patients (lower costs).

Mexican Society of Bioelectromagnetism

International Nuclear Information System (INIS)

Canedo, Luis

2008-01-01

In July 2007 physicians, biologists and physicists that have collaborated in previous meetings of the medical branch of the Mexican Physical Society constituted the Mexican Society of Bioelectromagnetism with the purpose of promote scientific study of the interaction of electromagnetic energy (at frequencies ranging from zero Hertz through those of visible light) and acoustic energy with biological systems. A second goal was to increase the contribution of medical and biological professionals in the meetings of the medical branch of the Mexican Physical Society. The following paragraphs summarize some objectives of the Mexican Society of Bioelectromagnetism for the next two years

Multi-Level Wavelet Shannon Entropy-Based Method for Single-Sensor Fault Location

Directory of Open Access Journals (Sweden)

Qiaoning Yang

2015-10-01

Full Text Available In actual application, sensors are prone to failure because of harsh environments, battery drain, and sensor aging. Sensor fault location is an important step for follow-up sensor fault detection. In this paper, two new multi-level wavelet Shannon entropies (multi-level wavelet time Shannon entropy and multi-level wavelet time-energy Shannon entropy are defined. They take full advantage of sensor fault frequency distribution and energy distribution across multi-subband in wavelet domain. Based on the multi-level wavelet Shannon entropy, a method is proposed for single sensor fault location. The method firstly uses a criterion of maximum energy-to-Shannon entropy ratio to select the appropriate wavelet base for signal analysis. Then multi-level wavelet time Shannon entropy and multi-level wavelet time-energy Shannon entropy are used to locate the fault. The method is validated using practical chemical gas concentration data from a gas sensor array. Compared with wavelet time Shannon entropy and wavelet energy Shannon entropy, the experimental results demonstrate that the proposed method can achieve accurate location of a single sensor fault and has good anti-noise ability. The proposed method is feasible and effective for single-sensor fault location.

Electromagnetic spatial coherence wavelets

International Nuclear Information System (INIS)

Castaneda, R.; Garcia-Sucerquia, J.

2005-10-01

The recently introduced concept of spatial coherence wavelets is generalized for describing the propagation of electromagnetic fields in the free space. For this aim, the spatial coherence wavelet tensor is introduced as an elementary amount, in terms of which the formerly known quantities for this domain can be expressed. It allows analyzing the relationship between the spatial coherence properties and the polarization state of the electromagnetic wave. This approach is completely consistent with the recently introduced unified theory of coherence and polarization for random electromagnetic beams, but it provides a further insight about the causal relationship between the polarization states at different planes along the propagation path. (author)

Fast generation of computer-generated holograms using wavelet shrinkage.

Science.gov (United States)

Shimobaba, Tomoyoshi; Ito, Tomoyoshi

2017-01-09

Computer-generated holograms (CGHs) are generated by superimposing complex amplitudes emitted from a number of object points. However, this superposition process remains very time-consuming even when using the latest computers. We propose a fast calculation algorithm for CGHs that uses a wavelet shrinkage method, eliminating small wavelet coefficient values to express approximated complex amplitudes using only a few representative wavelet coefficients.

Daily water level forecasting using wavelet decomposition and artificial intelligence techniques

Science.gov (United States)

Seo, Youngmin; Kim, Sungwon; Kisi, Ozgur; Singh, Vijay P.

2015-01-01

Reliable water level forecasting for reservoir inflow is essential for reservoir operation. The objective of this paper is to develop and apply two hybrid models for daily water level forecasting and investigate their accuracy. These two hybrid models are wavelet-based artificial neural network (WANN) and wavelet-based adaptive neuro-fuzzy inference system (WANFIS). Wavelet decomposition is employed to decompose an input time series into approximation and detail components. The decomposed time series are used as inputs to artificial neural networks (ANN) and adaptive neuro-fuzzy inference system (ANFIS) for WANN and WANFIS models, respectively. Based on statistical performance indexes, the WANN and WANFIS models are found to produce better efficiency than the ANN and ANFIS models. WANFIS7-sym10 yields the best performance among all other models. It is found that wavelet decomposition improves the accuracy of ANN and ANFIS. This study evaluates the accuracy of the WANN and WANFIS models for different mother wavelets, including Daubechies, Symmlet and Coiflet wavelets. It is found that the model performance is dependent on input sets and mother wavelets, and the wavelet decomposition using mother wavelet, db10, can further improve the efficiency of ANN and ANFIS models. Results obtained from this study indicate that the conjunction of wavelet decomposition and artificial intelligence models can be a useful tool for accurate forecasting daily water level and can yield better efficiency than the conventional forecasting models.

Noise removal for medical X-ray images in wavelet domain

International Nuclear Information System (INIS)

Wang, Ling; Lu, Jianming; Li, Yeqiu; Yahagi, Takashi; Okamoto, Takahide

2006-01-01

Many important problems in engineering and science are well-modeled by Poisson noise, the noise of medical X-ray image is Poisson noise. In this paper, we propose a method of noise removal for degraded medical X-ray image using improved preprocessing and improved BayesShrink (IBS) method in wavelet domain. Firstly, we pre-process the medical X-ray image, Secondly, we apply the Daubechies (db) wavelet transform to medical X-ray image to acquire scaling and wavelet coefficients. Thirdly, we apply the proposed IBS method to process wavelet coefficients. Finally, we compute the inverse wavelet transform for the thresholded coefficeints. Experimental results show that the proposed method always outperforms traditional methods. (author)

An introduction to random vibrations, spectral & wavelet analysis

CERN Document Server

Newland, D E

2005-01-01

One of the first engineering books to cover wavelet analysis, this classic text describes and illustrates basic theory, with a detailed explanation of the workings of discrete wavelet transforms. Computer algorithms are explained and supported by examples and a set of problems, and an appendix lists ten computer programs for calculating and displaying wavelet transforms.Starting with an introduction to probability distributions and averages, the text examines joint probability distributions, ensemble averages, and correlation; Fourier analysis; spectral density and excitation response relation

Characterization of the atmosphere of the hot Jupiter HAT-P-32Ab and the M-dwarf companion HAT-P-32B

Energy Technology Data Exchange (ETDEWEB)

Zhao, Ming; Wright, Jason T.; Curtis, Jason [Department of Astronomy and Astrophysics, Pennsylvania State University, PA 16802 (United States); O' Rourke, Joseph G.; Knutson, Heather A.; Ngo, Henry [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Princeton, NJ 08544 (United States); Fortney, Johnathan [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Fulton, Benjamin J.; Baranec, Christoph [Institute for Astronomy, University of Hawai' i at Mānoa, Hilo, HI 96720-2700 (United States); Riddle, Reed; Hinkley, Sasha [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Law, Nicholas M. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3255 (United States); Muirhead, Philip S. [Department of Astronomy, Boston University, 725 Commonwealth Avenue, Boston, MA 02215 (United States); Showman, Adam P. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, Tucson, AZ 85721 (United States); Burruss, Rick, E-mail: mingzhao@psu.edu [Jet Propulsion Laboratory, California Institute of Technology, CA 91109 (United States)

2014-12-01

We report secondary eclipse photometry of the hot Jupiter HAT-P-32Ab, taken with Hale/Wide-field Infra-Red Camera (WIRC) in H and K{sub S} bands and with Spitzer/IRAC at 3.6 and 4.5 μm. We carried out adaptive optics imaging of the planet host star HAT-P-32A and its companion HAT-P-32B in the near-IR and the visible. We clearly resolve the two stars from each other and find a separation of 2.''923 ± 0.''004 and a position angle 110.°64 ± 0.°12. We measure the flux ratios of the binary in g'r'i'z' and H and K{sub S} bands, and determine T {sub eff}= 3565 ± 82 K for the companion star, corresponding to an M1.5 dwarf. We use PHOENIX stellar atmosphere models to correct the dilution of the secondary eclipse depths of the hot Jupiter due to the presence of the M1.5 companion. We also improve the secondary eclipse photometry by accounting for the non-classical, flux-dependent nonlinearity of the WIRC IR detector in the H band. We measure planet-to-star flux ratios of 0.090% ± 0.033%, 0.178% ± 0.057%, 0.364% ± 0.016%, and 0.438% ± 0.020% in the H, K{sub S} , 3.6 and 4.5 μm bands, respectively. We compare these with planetary atmospheric models, and find they prefer an atmosphere with a temperature inversion and inefficient heat redistribution. However, we also find that the data are equally well described by a blackbody model for the planet with T {sub p} = 2042 ± 50 K. Finally, we measure a secondary eclipse timing offset of 0.3 ± 1.3 minutes from the predicted mid-eclipse time, which constrains e = 0.0072{sub −0.0064}{sup +0.0700} when combined with radial velocity data and is more consistent with a circular orbit.

Directional dual-tree rational-dilation complex wavelet transform.

Science.gov (United States)

Serbes, Gorkem; Gulcur, Halil Ozcan; Aydin, Nizamettin

2014-01-01

Dyadic discrete wavelet transform (DWT) has been used successfully in processing signals having non-oscillatory transient behaviour. However, due to the low Q-factor property of their wavelet atoms, the dyadic DWT is less effective in processing oscillatory signals such as embolic signals (ESs). ESs are extracted from quadrature Doppler signals, which are the output of Doppler ultrasound systems. In order to process ESs, firstly, a pre-processing operation known as phase filtering for obtaining directional signals from quadrature Doppler signals must be employed. Only then, wavelet based methods can be applied to these directional signals for further analysis. In this study, a directional dual-tree rational-dilation complex wavelet transform, which can be applied directly to quadrature signals and has the ability of extracting directional information during analysis, is introduced.

An Extension of Fourier-Wavelet Volume Rendering by View Interpolation

NARCIS (Netherlands)

Westenberg, Michel A.; Roerdink, Jos B.T.M.

2001-01-01

This paper describes an extension to Fourier-wavelet volume rendering (FWVR), which is a Fourier domain implementation of the wavelet X-ray transform. This transform combines integration along the line of sight with a simultaneous 2-D wavelet transform in the view plane perpendicular to this line.

Abnormal traffic flow data detection based on wavelet analysis

Directory of Open Access Journals (Sweden)

Xiao Qian

2016-01-01

Full Text Available In view of the traffic flow data of non-stationary, the abnormal data detection is difficult.proposed basing on the wavelet analysis and least squares method of abnormal traffic flow data detection in this paper.First using wavelet analysis to make the traffic flow data of high frequency and low frequency component and separation, and then, combined with least square method to find abnormal points in the reconstructed signal data.Wavelet analysis and least square method, the simulation results show that using wavelet analysis of abnormal traffic flow data detection, effectively reduce the detection results of misjudgment rate and false negative rate.

Option pricing from wavelet-filtered financial series

Science.gov (United States)

de Almeida, V. T. X.; Moriconi, L.

2012-10-01

We perform wavelet decomposition of high frequency financial time series into large and small time scale components. Taking the FTSE100 index as a case study, and working with the Haar basis, it turns out that the small scale component defined by most (≃99.6%) of the wavelet coefficients can be neglected for the purpose of option premium evaluation. The relevance of the hugely compressed information provided by low-pass wavelet-filtering is related to the fact that the non-gaussian statistical structure of the original financial time series is essentially preserved for expiration times which are larger than just one trading day.

Wavelet-domain de-noising of OCT images of human brain malignant glioma

Science.gov (United States)

Dolganova, I. N.; Aleksandrova, P. V.; Beshplav, S.-I. T.; Chernomyrdin, N. V.; Dubyanskaya, E. N.; Goryaynov, S. A.; Kurlov, V. N.; Reshetov, I. V.; Potapov, A. A.; Tuchin, V. V.; Zaytsev, K. I.

2018-04-01

We have proposed a wavelet-domain de-noising technique for imaging of human brain malignant glioma by optical coherence tomography (OCT). It implies OCT image decomposition using the direct fast wavelet transform, thresholding of the obtained wavelet spectrum and further inverse fast wavelet transform for image reconstruction. By selecting both wavelet basis and thresholding procedure, we have found an optimal wavelet filter, which application improves differentiation of the considered brain tissue classes - i.e. malignant glioma and normal/intact tissue. Namely, it allows reducing the scattering noise in the OCT images and retaining signal decrement for each tissue class. Therefore, the observed results reveals the wavelet-domain de-noising as a prospective tool for improved characterization of biological tissue using the OCT.

Analysis on Behaviour of Wavelet Coefficient during Fault Occurrence in Transformer

Science.gov (United States)

Sreewirote, Bancha; Ngaopitakkul, Atthapol

2018-03-01

The protection system for transformer has play significant role in avoiding severe damage to equipment when disturbance occur and ensure overall system reliability. One of the methodology that widely used in protection scheme and algorithm is discrete wavelet transform. However, characteristic of coefficient under fault condition must be analyzed to ensure its effectiveness. So, this paper proposed study and analysis on wavelet coefficient characteristic when fault occur in transformer in both high- and low-frequency component from discrete wavelet transform. The effect of internal and external fault on wavelet coefficient of both fault and normal phase has been taken into consideration. The fault signal has been simulate using transmission connected to transformer experimental setup on laboratory level that modelled after actual system. The result in term of wavelet coefficient shown a clearly differentiate between wavelet characteristic in both high and low frequency component that can be used to further design and improve detection and classification algorithm that based on discrete wavelet transform methodology in the future.

Joint Markov Blankets in Feature Sets Extracted from Wavelet Packet Decompositions

Directory of Open Access Journals (Sweden)

Gert Van Dijck

2011-07-01

Full Text Available Since two decades, wavelet packet decompositions have been shown effective as a generic approach to feature extraction from time series and images for the prediction of a target variable. Redundancies exist between the wavelet coefficients and between the energy features that are derived from the wavelet coefficients. We assess these redundancies in wavelet packet decompositions by means of the Markov blanket filtering theory. We introduce the concept of joint Markov blankets. It is shown that joint Markov blankets are a natural extension of Markov blankets, which are defined for single features, to a set of features. We show that these joint Markov blankets exist in feature sets consisting of the wavelet coefficients. Furthermore, we prove that wavelet energy features from the highest frequency resolution level form a joint Markov blanket for all other wavelet energy features. The joint Markov blanket theory indicates that one can expect an increase of classification accuracy with the increase of the frequency resolution level of the energy features.

On variable geometric factor systems for top-hat electrostatic space plasma analyzers

International Nuclear Information System (INIS)

Collinson, Glyn A; Kataria, Dhiren O

2010-01-01

Even in the relatively small region of space that is the Earth's magnetosphere, ion and electron fluxes can vary by several orders of magnitude. Top-hat electrostatic analyzers currently do not possess the dynamic range required to sample plasma under all conditions. The purpose of this study was to compare, through computer simulation, three new electrostatic methods that would allow the sensitivity of a sensor to be varied through control of its geometric factor (GF) (much like an aperture on a camera). The methods studied were inner filter plates, split hemispherical analyzer (SHA) and top-cap electrode. This is the first discussion of the filter plate concept and also the first study where all three systems are studied within a common analyzer design, so that their relative merits could be fairly compared. Filter plates were found to have the important advantage that they facilitate the reduction in instrument sensitivity whilst keeping all other instrument parameters constant. However, it was discovered that filter plates have numerous disadvantages that make such a system impracticable for a top-hat electrostatic analyzer. It was found that both the top-cap electrode and SHA are promising variable geometric factor system (VGFS) concepts for implementation into a top-hat electrostatic analyzer, each with distinct advantages over the other

Wavelet-Based Methodology for Evolutionary Spectra Estimation of Nonstationary Typhoon Processes

Directory of Open Access Journals (Sweden)

Guang-Dong Zhou

2015-01-01

Full Text Available Closed-form expressions are proposed to estimate the evolutionary power spectral density (EPSD of nonstationary typhoon processes by employing the wavelet transform. Relying on the definition of the EPSD and the concept of the wavelet transform, wavelet coefficients of a nonstationary typhoon process at a certain time instant are interpreted as the Fourier transform of a new nonstationary oscillatory process, whose modulating function is equal to the modulating function of the nonstationary typhoon process multiplied by the wavelet function in time domain. Then, the EPSD of nonstationary typhoon processes is deduced in a closed form and is formulated as a weighted sum of the squared moduli of time-dependent wavelet functions. The weighted coefficients are frequency-dependent functions defined by the wavelet coefficients of the nonstationary typhoon process and the overlapping area of two shifted wavelets. Compared with the EPSD, defined by a sum of the squared moduli of the wavelets in frequency domain in literature, this paper provides an EPSD estimation method in time domain. The theoretical results are verified by uniformly modulated nonstationary typhoon processes and non-uniformly modulated nonstationary typhoon processes.

Wavelet transform of generalized functions in K ′{Mp} spaces

Indian Academy of Sciences (India)

Using convolution theory in K{Mp} space we obtain bounded results for the wavelet transform. Calderón-type reproducing formula is derived in distribution sense as an application of the same. An inversion formula for the wavelet transform of generalized functions is established. Keywords. Continuous wavelet transform ...

A research on the postural stability of a person wearing the lower limb exoskeletal robot by the HAT model.

Science.gov (United States)

Chang, Minsu; Kim, Yeongmin; Lee, Yoseph; Jeon, Doyoung

2017-07-01

This paper proposes a method of detecting the postural stability of a person wearing the lower limb exoskeletal robot with the HAT(Head-Arm-Trunk) model. Previous studies have shown that the human posture is stable when the CoM(Center of Mass) of the human body is placed on the BoS(Base of Support). In the case of the lower limb exoskeletal robot, the motion data, which are used for the CoM estimation, are acquired by sensors in the robot. The upper body, however, does not have sensors in each segment so that it may cause the error of the CoM estimation. In this paper, the HAT(Head-Arm-Trunk) model which combines head, arms, and torso into a single segment is considered because the motion of head and arms are unknown due to the lack of sensors. To verify the feasibility of HAT model, the reflecting markers are attached to each segment of the whole human body and the exact motion data are acquired by the VICON to compare the COM of the full body model and HAT model. The difference between the CoM with full body and that with HAT model is within 20mm for the various motions of head and arms. Based on the HAT model, the XCoM(Extrapolated Center of Mass) which includes the velocity of the CoM is used for prediction of the postural stability. The experiment of making unstable posture shows that the XCoM of the whole body based on the HAT model is feasible to detect the instance of postural instability earlier than the CoM by 20-250 msec. This result may be used for the lower limb exoskeletal robot to prepare for any action to prevent the falling down.

Energy-Based Wavelet De-Noising of Hydrologic Time Series

Science.gov (United States)

Sang, Yan-Fang; Liu, Changming; Wang, Zhonggen; Wen, Jun; Shang, Lunyu

2014-01-01

De-noising is a substantial issue in hydrologic time series analysis, but it is a difficult task due to the defect of methods. In this paper an energy-based wavelet de-noising method was proposed. It is to remove noise by comparing energy distribution of series with the background energy distribution, which is established from Monte-Carlo test. Differing from wavelet threshold de-noising (WTD) method with the basis of wavelet coefficient thresholding, the proposed method is based on energy distribution of series. It can distinguish noise from deterministic components in series, and uncertainty of de-noising result can be quantitatively estimated using proper confidence interval, but WTD method cannot do this. Analysis of both synthetic and observed series verified the comparable power of the proposed method and WTD, but de-noising process by the former is more easily operable. The results also indicate the influences of three key factors (wavelet choice, decomposition level choice and noise content) on wavelet de-noising. Wavelet should be carefully chosen when using the proposed method. The suitable decomposition level for wavelet de-noising should correspond to series' deterministic sub-signal which has the smallest temporal scale. If too much noise is included in a series, accurate de-noising result cannot be obtained by the proposed method or WTD, but the series would show pure random but not autocorrelation characters, so de-noising is no longer needed. PMID:25360533

Fundamental papers in wavelet theory

CERN Document Server

Walnut, David F

2006-01-01

This book traces the prehistory and initial development of wavelet theory, a discipline that has had a profound impact on mathematics, physics, and engineering. Interchanges between these fields during the last fifteen years have led to a number of advances in applications such as image compression, turbulence, machine vision, radar, and earthquake prediction. This book contains the seminal papers that presented the ideas from which wavelet theory evolved, as well as those major papers that developed the theory into its current form. These papers originated in a variety of journals from differ

On extensions of wavelet systems to dual pairs of frames

DEFF Research Database (Denmark)

Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

2015-01-01

It is an open problem whether any pair of Bessel sequences with wavelet structure can be extended to a pair of dual frames by adding a pair of singly generated wavelet systems. We consider the particular case where the given wavelet systems are generated by the multiscale setup with trigonometric...

Big data extraction with adaptive wavelet analysis (Presentation Video)

Science.gov (United States)

Qu, Hongya; Chen, Genda; Ni, Yiqing

2015-04-01

Nondestructive evaluation and sensing technology have been increasingly applied to characterize material properties and detect local damage in structures. More often than not, they generate images or data strings that are difficult to see any physical features without novel data extraction techniques. In the literature, popular data analysis techniques include Short-time Fourier Transform, Wavelet Transform, and Hilbert Transform for time efficiency and adaptive recognition. In this study, a new data analysis technique is proposed and developed by introducing an adaptive central frequency of the continuous Morlet wavelet transform so that both high frequency and time resolution can be maintained in a time-frequency window of interest. The new analysis technique is referred to as Adaptive Wavelet Analysis (AWA). This paper will be organized in several sections. In the first section, finite time-frequency resolution limitations in the traditional wavelet transform are introduced. Such limitations would greatly distort the transformed signals with a significant frequency variation with time. In the second section, Short Time Wavelet Transform (STWT), similar to Short Time Fourier Transform (STFT), is defined and developed to overcome such shortcoming of the traditional wavelet transform. In the third section, by utilizing the STWT and a time-variant central frequency of the Morlet wavelet, AWA can adapt the time-frequency resolution requirement to the signal variation over time. Finally, the advantage of the proposed AWA is demonstrated in Section 4 with a ground penetrating radar (GPR) image from a bridge deck, an analytical chirp signal with a large range sinusoidal frequency change over time, the train-induced acceleration responses of the Tsing-Ma Suspension Bridge in Hong Kong, China. The performance of the proposed AWA will be compared with the STFT and traditional wavelet transform.

EEG Artifact Removal Using a Wavelet Neural Network

Science.gov (United States)

Nguyen, Hoang-Anh T.; Musson, John; Li, Jiang; McKenzie, Frederick; Zhang, Guangfan; Xu, Roger; Richey, Carl; Schnell, Tom

2011-01-01

!n this paper we developed a wavelet neural network. (WNN) algorithm for Electroencephalogram (EEG) artifact removal without electrooculographic (EOG) recordings. The algorithm combines the universal approximation characteristics of neural network and the time/frequency property of wavelet. We. compared the WNN algorithm with .the ICA technique ,and a wavelet thresholding method, which was realized by using the Stein's unbiased risk estimate (SURE) with an adaptive gradient-based optimal threshold. Experimental results on a driving test data set show that WNN can remove EEG artifacts effectively without diminishing useful EEG information even for very noisy data.

Wavelets an elementary treatment of theory and applications

CERN Document Server

Koornwinder, T H

1993-01-01

Nowadays, some knowledge of wavelets is almost mandatory for mathematicians, physicists and electrical engineers. The emphasis in this volume, based on an intensive course on Wavelets given at CWI, Amsterdam, is on the affine case. The first part presents a concise introduction of the underlying theory to the uninitiated reader. The second part gives applications in various areas. Some of the contributions here are a fresh exposition of earlier work by others, while other papers contain new results by the authors. The areas are so diverse as seismic processing, quadrature formulae, and wavelet

Traffic characterization and modeling of wavelet-based VBR encoded video

Energy Technology Data Exchange (ETDEWEB)

Yu Kuo; Jabbari, B. [George Mason Univ., Fairfax, VA (United States); Zafar, S. [Argonne National Lab., IL (United States). Mathematics and Computer Science Div.

1997-07-01

Wavelet-based video codecs provide a hierarchical structure for the encoded data, which can cater to a wide variety of applications such as multimedia systems. The characteristics of such an encoder and its output, however, have not been well examined. In this paper, the authors investigate the output characteristics of a wavelet-based video codec and develop a composite model to capture the traffic behavior of its output video data. Wavelet decomposition transforms the input video in a hierarchical structure with a number of subimages at different resolutions and scales. the top-level wavelet in this structure contains most of the signal energy. They first describe the characteristics of traffic generated by each subimage and the effect of dropping various subimages at the encoder on the signal-to-noise ratio at the receiver. They then develop an N-state Markov model to describe the traffic behavior of the top wavelet. The behavior of the remaining wavelets are then obtained through estimation, based on the correlations between these subimages at the same level of resolution and those wavelets located at an immediate higher level. In this paper, a three-state Markov model is developed. The resulting traffic behavior described by various statistical properties, such as moments and correlations, etc., is then utilized to validate their model.

Selection of the wavelet function for the frequencies estimation

International Nuclear Information System (INIS)

Garcia R, A.

2007-01-01

At the moment the signals are used to diagnose the state of the systems, by means of the extraction of their more important characteristics such as the frequencies, tendencies, changes and temporary evolutions. This characteristics are detected by means of diverse analysis techniques, as Autoregressive methods, Fourier Transformation, Fourier transformation in short time, Wavelet transformation, among others. The present work uses the one Wavelet transformation because it allows to analyze stationary, quasi-stationary and transitory signals in the time-frequency plane. It also describes a methodology to select the scales and the Wavelet function to be applied the one Wavelet transformation with the objective of detecting to the dominant system frequencies. (Author)

Wavelet Transforms: Application to Data Analysis - I -10 ...

Indian Academy of Sciences (India)

from 0 to 00, whereas translation index k takes values from -00 .... scaling function in any wavelet basis set. ..... sets derived from diverse sources like stock market, cos- ... [4] G B Folland, From Calculus to Wavelets: A New Mathematical Tech-.

Anisotropy in wavelet-based phase field models

KAUST Repository

Korzec, Maciek; Mü nch, Andreas; Sü li, Endre; Wagner, Barbara

2016-01-01

When describing the anisotropic evolution of microstructures in solids using phase-field models, the anisotropy of the crystalline phases is usually introduced into the interfacial energy by directional dependencies of the gradient energy coefficients. We consider an alternative approach based on a wavelet analogue of the Laplace operator that is intrinsically anisotropic and linear. The paper focuses on the classical coupled temperature/Ginzburg--Landau type phase-field model for dendritic growth. For the model based on the wavelet analogue, existence, uniqueness and continuous dependence on initial data are proved for weak solutions. Numerical studies of the wavelet based phase-field model show dendritic growth similar to the results obtained for classical phase-field models.

Anisotropy in wavelet-based phase field models

KAUST Repository

Korzec, Maciek

2016-04-01

When describing the anisotropic evolution of microstructures in solids using phase-field models, the anisotropy of the crystalline phases is usually introduced into the interfacial energy by directional dependencies of the gradient energy coefficients. We consider an alternative approach based on a wavelet analogue of the Laplace operator that is intrinsically anisotropic and linear. The paper focuses on the classical coupled temperature/Ginzburg--Landau type phase-field model for dendritic growth. For the model based on the wavelet analogue, existence, uniqueness and continuous dependence on initial data are proved for weak solutions. Numerical studies of the wavelet based phase-field model show dendritic growth similar to the results obtained for classical phase-field models.

Trajectories of Mexican American and mainstream cultural values among Mexican American adolescents.

Science.gov (United States)

Knight, George P; Basilio, Camille D; Cham, Heining; Gonzales, Nancy A; Liu, Yu; Umaña-Taylor, Adriana J

2014-12-01

Mexican Americans are one of the largest and fastest growing ethnic groups in the United States, yet we have limited knowledge regarding changes (i.e., developmental trajectories) in cultural orientation based upon their exposure to the Mexican American and mainstream cultures. We examined the parallel trajectories of Mexican American and mainstream cultural values in a sample of 749 Mexican American adolescents (49 % female) across assessments during the fifth grade (approximately 11 years of age), the seventh grade (approximately 13 years of age) and the tenth grade (approximately 16 years of age). We expected that these values would change over this developmental period and this longitudinal approach is more appropriate than the often used median split classification to identify distinct types of acculturation. We found four distinct acculturation trajectory groups: two trajectory groups that were increasing slightly with age in the endorsement of mainstream cultural values, one of which was relatively stable in Mexican American cultural values while the other was declining in their endorsement of these values; and two trajectory groups that were declining substantially with age in their endorsement of mainstream cultural values, one of which was also declining in Mexican American cultural values and the other which was stable in these values. These four trajectory groups differed in expected ways on a number of theoretically related cultural variables, but were not highly consistent with the median split classifications. The findings highlight the need to utilize longitudinal data to examine the developmental changes of Mexican American individual's adaptation to the ethnic and mainstream culture in order to understand more fully the processes of acculturation and enculturation.

Wavelet Analysis of Ultrasonic Echo Waveform and Application to Nondestructive Evaluation

International Nuclear Information System (INIS)

Park, Ik Keun; Park, Un Su; Ahn, Hyung Keun; Kwun, Sook In; Byeon, Jai Won

2000-01-01

Recently, advanced signal analysis which is called 'time-frequency analysis' has been used widely in nondestructive evaluation applications. Wavelet transform(WT) and Wigner Distribution are the most advanced techniques for processing signals with time-varying spectra. Wavelet analysis method is an attractive technique for evaluation of material characterization nondestructively. Wavelet transform is applied to the time-frequency analysis of ultrasonic echo waveform obtained by an ultrasonic pulse-echo technique. In this study, the feasibility of noise suppression of ultrasonic flaw signal and frequency-dependent ultrasonic group velocity and attenuation coefficient using wavelet analysis of ultrasonic echo waveform have been verified experimentally. The Gabor function is adopted the analyzing wavelet. The wavelet analysis shows that the variations of ultrasonic group velocity and attenuation coefficient due to the change of material characterization can be evaluated at each frequency. Furthermore, to assure the enhancement of detectability and new sizing performance, both computer simulated results and experimental measurements using wavelet signal processing are used to demonstrate the effectiveness of the noise suppression of ultrasonic flaw signal obtained from austenitic stainless steel weld including EDM notch

Islanding detection technique using wavelet energy in grid-connected PV system

Science.gov (United States)

Kim, Il Song

2016-08-01

This paper proposes a new islanding detection method using wavelet energy in a grid-connected photovoltaic system. The method detects spectral changes in the higher-frequency components of the point of common coupling voltage and obtains wavelet coefficients by multilevel wavelet analysis. The autocorrelation of the wavelet coefficients can clearly identify islanding detection, even in the variations of the grid voltage harmonics during normal operating conditions. The advantage of the proposed method is that it can detect islanding condition the conventional under voltage/over voltage/under frequency/over frequency methods fail to detect. The theoretical method to obtain wavelet energies is evolved and verified by the experimental result.

Ideologiekritik des E-Learnings. Welchen Nutzen hat die Einführung von E-Learning?

Directory of Open Access Journals (Sweden)

Katharina Kaiser-Müller

2015-03-01

Full Text Available Vor etwa sieben Jahren hat das damalige Bundesministerium für Unterricht, Kunst und Kultur (bm:ukk, das seit 2014 Bundesministerium für Bildung und Frauen (BMBF genannt wird, verschiedene Maßnahmen im Blick auf neuen Medien – insbesondere im Blick auf das E-Learning – gesetzt, um einen Beitrag zur Vorbereitung der Lernenden auf eine Informations- und Wissensgesellschaft zu leisten. E-Learning wurde als Erfolgsfaktor für die Zukunft gesehen und mit der Begründung, es fördere das individuelle und selbst gesteuerte Lernen, gefördert. Die zentrale Frage ist dabei: Welchen Nutzen hat die Einführung von E-Learning? In diesem Artikel wird dahingehend aufgezeigt, dass E-Learning nicht wegen pädagogischem Bedarf, sondern durch ministeriell gesetzte Maßnahmen eingeführt wurde und dadurch – wenn auch nicht bewusst und schon gar nicht als solches kommuniziert – neoliberale Strukturen durchgesetzt wurden. Die Einführung von E-Learning hat somit für deren Akzeptanz gesorgt.

Wavelet neural networks with applications in financial engineering, chaos, and classification

CERN Document Server

Alexandridis, Antonios K

2014-01-01

Through extensive examples and case studies, Wavelet Neural Networks provides a step-by-step introduction to modeling, training, and forecasting using wavelet networks. The acclaimed authors present a statistical model identification framework to successfully apply wavelet networks in various applications, specifically, providing the mathematical and statistical framework needed for model selection, variable selection, wavelet network construction, initialization, training, forecasting and prediction, confidence intervals, prediction intervals, and model adequacy testing. The text is ideal for

HAT-P-26b: A Neptune-mass exoplanet with a well-constrained heavy element abundance.

Science.gov (United States)

Wakeford, Hannah R; Sing, David K; Kataria, Tiffany; Deming, Drake; Nikolov, Nikolay; Lopez, Eric D; Tremblin, Pascal; Amundsen, David S; Lewis, Nikole K; Mandell, Avi M; Fortney, Jonathan J; Knutson, Heather; Benneke, Björn; Evans, Thomas M

2017-05-12

A correlation between giant-planet mass and atmospheric heavy elemental abundance was first noted in the past century from observations of planets in our own Solar System and has served as a cornerstone of planet-formation theory. Using data from the Hubble and Spitzer Space Telescopes from 0.5 to 5 micrometers, we conducted a detailed atmospheric study of the transiting Neptune-mass exoplanet HAT-P-26b. We detected prominent H 2 O absorption bands with a maximum base-to-peak amplitude of 525 parts per million in the transmission spectrum. Using the water abundance as a proxy for metallicity, we measured HAT-P-26b's atmospheric heavy element content ([Formula: see text] times solar). This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime, with little contamination from metal-rich planetesimals. Copyright © 2017, American Association for the Advancement of Science.

HAT-P-68b: A Transiting Hot Jupiter Around a K5 Dwarf Star

Science.gov (United States)

Lindor, Bethlee; Hartman, Joel D.

2018-01-01

One of the main goals of the astrophysical society has been to detect sources of life outside of Earth. To aid this search, astronomers have spent the last 2 decades focused on the discovery and characterization of exoplanets. The most effective method for doing so has been transit photometry, wherein we measure the brightness of stars over periods of time. These measurements, or light curves, are later analyzed for dips in brightness caused by objects passing in front of the star. However, variations in these time series can also occur due to non-planetary systems and a meticulous process is needed to distinguish the planets from the various false positives that are detected. HATNet is one of many surveys involved in this endeavor, and in this work I analyze HAT-P-68. First, I model the system as a single star with a transiting planet and derive estimates of the stellar and planetary physical parameters. I also model HAT-P-68 as a number of a false positives such as a pair of stars in an eclipsing binary blended with a background star, and a planet-sized star orbiting a Sun-like star. In order to rule out the possibility that HAT-P-68 is a blend, I carried out a statistical blend analysis of the photometric data and find that all blend models tested can be ruled out. Thus, I conclude that HAT-P-68 is a system with a transiting hot jupiter and consider what future observations would be most promising to further characterize the system.

Regularization of EIT reconstruction based on multi-scales wavelet transforms

Directory of Open Access Journals (Sweden)

Gong Bo

2016-09-01

Full Text Available Electrical Impedance Tomography (EIT intends to obtain the conductivity distribution of a domain from the electrical boundary conditions. This is an ill-posed inverse problem usually solved on finite element meshes. Wavelet transforms are widely used for medical image reconstruction. However, because of the irregular form of the finite element meshes, the canonical wavelet transforms is impossible to perform on meshes. In this article, we present a framework that combines multi-scales wavelet transforms and finite element meshes by viewing meshes as undirected graphs and applying spectral graph wavelet transform on the meshes.

Processing of pulse oximeter data using discrete wavelet analysis.

Science.gov (United States)

Lee, Seungjoon; Ibey, Bennett L; Xu, Weijian; Wilson, Mark A; Ericson, M Nance; Coté, Gerard L

2005-07-01

A wavelet-based signal processing technique was employed to improve an implantable blood perfusion monitoring system. Data was acquired from both in vitro and in vivo sources: a perfusion model and the proximal jejunum of an adult pig. Results showed that wavelet analysis could isolate perfusion signals from raw, periodic, in vitro data as well as fast Fourier transform (FFT) methods. However, for the quasi-periodic in vivo data segments, wavelet analysis provided more consistent results than the FFT analysis for data segments of 50, 10, and 5 s in length. Wavelet analysis has thus been shown to require less data points for quasi-periodic data than FFT analysis making it a good choice for an indwelling perfusion monitor where power consumption and reaction time are paramount.

Fast reversible wavelet image compressor

Science.gov (United States)

Kim, HyungJun; Li, Ching-Chung

1996-10-01

We present a unified image compressor with spline biorthogonal wavelets and dyadic rational filter coefficients which gives high computational speed and excellent compression performance. Convolutions with these filters can be preformed by using only arithmetic shifting and addition operations. Wavelet coefficients can be encoded with an arithmetic coder which also uses arithmetic shifting and addition operations. Therefore, from the beginning to the end, the while encoding/decoding process can be done within a short period of time. The proposed method naturally extends form the lossless compression to the lossy but high compression range and can be easily adapted to the progressive reconstruction.

The use of wavelet transforms in the solution of two-phase flow problems

International Nuclear Information System (INIS)

Moridis, G.J.; Nikolaou, M.; You, Yong

1994-10-01

In this paper we present the use of wavelets to solve the nonlinear Partial Differential.Equation (PDE) of two-phase flow in one dimension. The wavelet transforms allow a drastically different approach in the discretization of space. In contrast to the traditional trigonometric basis functions, wavelets approximate a function not by cancellation but by placement of wavelets at appropriate locations. When an abrupt chance, such as a shock wave or a spike, occurs in a function, only local coefficients in a wavelet approximation will be affected. The unique feature of wavelets is their Multi-Resolution Analysis (MRA) property, which allows seamless investigational any spatial resolution. The use of wavelets is tested in the solution of the one-dimensional Buckley-Leverett problem against analytical solutions and solutions obtained from standard numerical models. Two classes of wavelet bases (Daubechies and Chui-Wang) and two methods (Galerkin and collocation) are investigated. We determine that the Chui-Wang, wavelets and a collocation method provide the optimum wavelet solution for this type of problem. Increasing the resolution level improves the accuracy of the solution, but the order of the basis function seems to be far less important. Our results indicate that wavelet transforms are an effective and accurate method which does not suffer from oscillations or numerical smearing in the presence of steep fronts

Motion compensation via redundant-wavelet multihypothesis.

Science.gov (United States)

Fowler, James E; Cui, Suxia; Wang, Yonghui

2006-10-01

Multihypothesis motion compensation has been widely used in video coding with previous attention focused on techniques employing predictions that are diverse spatially or temporally. In this paper, the multihypothesis concept is extended into the transform domain by using a redundant wavelet transform to produce multiple predictions that are diverse in transform phase. The corresponding multiple-phase inverse transform implicitly combines the phase-diverse predictions into a single spatial-domain prediction for motion compensation. The performance advantage of this redundant-wavelet-multihypothesis approach is investigated analytically, invoking the fact that the multiple-phase inverse involves a projection that significantly reduces the power of a dense-motion residual modeled as additive noise. The analysis shows that redundant-wavelet multihypothesis is capable of up to a 7-dB reduction in prediction-residual variance over an equivalent single-phase, single-hypothesis approach. Experimental results substantiate the performance advantage for a block-based implementation.

Fair Start Program: Outreach to Mexican and Mexican American Farmworker Families.

Science.gov (United States)

Winters-Smith, Carol; Larner, Mary

This presentation describes a home visiting health education program serving Mexican and Mexican-American migrant farmworkers in Florida. The purposes of the program were to educate farmworker families about pregnancy, childbirth, nutrition, and child development, and to encourage the use of preventive health care services. Home visitors were…

Adaptive Filtering in the Wavelet Transform Domain via Genetic Algorithms

Science.gov (United States)

2004-08-06

wavelet transforms. Whereas the term “evolved” pertains only to the altered wavelet coefficients used during the inverse transform process. 2...words, the inverse transform produces the original signal x(t) from the wavelet and scaling coefficients. )()( ,, tdtx nk n nk k ψ...reconstruct the original signal as accurately as possible. The inverse transform reconstructs an approximation of the original signal (Burrus

Path representation of su-hat (2){sub k} states I: Operators and particles for k=1,2

Energy Technology Data Exchange (ETDEWEB)

Lamy-Poirier, Joel, E-mail: jlamypoirier@perimeterinstitute.c [Departement de physique, de genie physique et d' optique, Universite Laval, Quebec, G1K 7P4 (Canada); Mathieu, Pierre, E-mail: pmathieu@phy.ulaval.c [Departement de physique, de genie physique et d' optique, Universite Laval, Quebec, G1K 7P4 (Canada)

2011-04-11

This is the first of two articles devoted to the analysis of the path description of the states in su-hat (2){sub k} WZW models, a representation well suited for constructive derivations of the fermionic characters. In this first article, the cases k=1,2 are treated in detail, emphasizing a different description in each case (operators vs particles). For k=1, we first prove, as a side result, the equivalence of two known path representations for the finitized su-hat (2){sub 1} states by displaying an explicit bijection. An immediate offshoot is the gain of a new and simple weighting for the (Kyoto) path representation that generalizes to level k. The bijection also suggests two operator constructions for the su-hat (2){sub 1} paths, a local and a nonlocal one, both interrelated. These are formal operators that map a path to another path, so that any path can be obtained by successive applications of these operators on a simple reference (ground-state) path. The nonlocal operator description is the starting point for a direct and elementary derivation of the su-hat (2){sub 1} spinon character. The second part presents an extensive study of the su-hat (2){sub 2} paths from their particle point of view, where the particles are defined as the path building blocks. The resulting generating functions appear to provide new (at least superficially) fermionic forms of the characters. In particular, a nice relationship between the sum of the j=0,1 characters at k=2 and the two ones at k=1 is unraveled.

Multiresolution signal decomposition schemes. Part 2: Morphological wavelets

NARCIS (Netherlands)

H.J.A.M. Heijmans (Henk); J. Goutsias (John)

1999-01-01

htmlabstractIn its original form, the wavelet transform is a linear tool. However, it has been increasingly recognized that nonlinear extensions are possible. A major impulse to the development of nonlinear wavelet transforms has been given by the introduction of the lifting scheme by Sweldens. The

Wavelet modeling of signals for non-destructive testing of concretes

International Nuclear Information System (INIS)

Shao, Zhixue; Shi, Lihua; Cai, Jian

2011-01-01

In a non-destructive test of concrete structures, ultrasonic pulses are commonly used to detect damage or embedded objects from their reflections. A wavelet modeling method is proposed here to identify the main reflections and to remove the interferences in the detected ultrasonic waves. This method assumes that if the structure is stimulated by a wavelet function with good time–frequency localization ability, the detected signal is a combination of time-delayed and amplitude-attenuated wavelets. Therefore, modeling of the detected signal by wavelets can give a straightforward and simple model of the original signal. The central time and amplitude of each wavelet represent the position and amplitude of the reflections in the detected structure. A signal processing method is also proposed to estimate the structure response to wavelet excitation from its response to a high-voltage pulse with a sharp leading edge. A signal generation card with a compact peripheral component interconnect extension for instrumentation interface is designed to produce this high-voltage pulse. The proposed method is applied to synthesized aperture focusing technology of concrete specimens and the image results are provided

Characterization and Simulation of Gunfire with Wavelets

Directory of Open Access Journals (Sweden)

David O. Smallwood

1999-01-01

Full Text Available Gunfire is used as an example to show how the wavelet transform can be used to characterize and simulate nonstationary random events when an ensemble of events is available. The structural response to nearby firing of a high-firing rate gun has been characterized in several ways as a nonstationary random process. The current paper will explore a method to describe the nonstationary random process using a wavelet transform. The gunfire record is broken up into a sequence of transient waveforms each representing the response to the firing of a single round. A wavelet transform is performed on each of these records. The gunfire is simulated by generating realizations of records of a single-round firing by computing an inverse wavelet transform from Gaussian random coefficients with the same mean and standard deviation as those estimated from the previously analyzed gunfire record. The individual records are assembled into a realization of many rounds firing. A second-order correction of the probability density function is accomplished with a zero memory nonlinear function. The method is straightforward, easy to implement, and produces a simulated record much like the measured gunfire record.

Watermarking on 3D mesh based on spherical wavelet transform.

Science.gov (United States)

Jin, Jian-Qiu; Dai, Min-Ya; Bao, Hu-Jun; Peng, Qun-Sheng

2004-03-01

In this paper we propose a robust watermarking algorithm for 3D mesh. The algorithm is based on spherical wavelet transform. Our basic idea is to decompose the original mesh into a series of details at different scales by using spherical wavelet transform; the watermark is then embedded into the different levels of details. The embedding process includes: global sphere parameterization, spherical uniform sampling, spherical wavelet forward transform, embedding watermark, spherical wavelet inverse transform, and at last resampling the mesh watermarked to recover the topological connectivity of the original model. Experiments showed that our algorithm can improve the capacity of the watermark and the robustness of watermarking against attacks.

Constructing New Biorthogonal Wavelet Type which Matched for Extracting the Iris Image Features

International Nuclear Information System (INIS)

Isnanto, R Rizal; Suhardjo; Susanto, Adhi

2013-01-01

Some former research have been made for obtaining a new type of wavelet. In case of iris recognition using orthogonal or biorthogonal wavelets, it had been obtained that Haar filter is most suitable to recognize the iris image. However, designing the new wavelet should be done to find a most matched wavelet to extract the iris image features, for which we can easily apply it for identification, recognition, or authentication purposes. In this research, a new biorthogonal wavelet was designed based on Haar filter properties and Haar's orthogonality conditions. As result, it can be obtained a new biorthogonal 5/7 filter type wavelet which has a better than other types of wavelets, including Haar, to extract the iris image features based on its mean-squared error (MSE) and Euclidean distance parameters.

Dual-tree complex wavelet for medical image watermarking

International Nuclear Information System (INIS)

Mavudila, K.R.; Ndaye, B.M.; Masmoudi, L.; Hassanain, N.; Cherkaoui, M.

2010-01-01

In order to transmit medical data between hospitals, we insert the information for each patient in the image and its diagnosis, the watermarking consist to insert a message in the image and try to find it with the maximum possible fidelity. This paper presents a blind watermarking scheme in wavelet transform domain dual tree (DTT), who increasing the robustness and preserves the image quality. This system is transparent to the user and allows image integrity control. In addition, it provides information on the location of potential alterations and an evaluation of image modifications which is of major importance in a medico-legal framework. An example using head magnetic resonance and mammography imaging illustrates the overall method. Wavelet techniques can be successfully applied in various image processing methods, namely in image de noising, segmentation, classification, watermarking and others. In this paper we discussed the application of dual tree complex wavelet transform (D T-CWT), which has significant advantages over classic discrete wavelet transform (DWT), for certain image processing problems. The D T-CWT is a form of discreet wavelet transform which generates complex coefficients by using a dual tree of wavelet filters to obtain their real and imaginary parts. The main part of the paper is devoted to profit the exceptional quality for D T-CWT, compared to classical DWT, for a blind medical image watermarking, our schemes are using for the performance bivariate shrinkage with local variance estimation and are robust of attacks and favourably preserves the visual quality. Experimental results show that embedded watermarks using CWT give good image quality and are robust in comparison with the classical DWT.

Schrödinger like equation for wavelets

Directory of Open Access Journals (Sweden)

A. Zúñiga-Segundo

2016-01-01

Full Text Available An explicit phase space representation of the wave function is build based on a wavelet transformation. The wavelet transformation allows us to understand the relationship between s − ordered Wigner function, (or Wigner function when s = 0, and the Torres-Vega-Frederick’s wave functions. This relationship is necessary to find a general solution of the Schrödinger equation in phase-space.

Thin film description by wavelet coefficients statistics

Czech Academy of Sciences Publication Activity Database

Boldyš, Jiří; Hrach, R.

2005-01-01

Roč. 55, č. 1 (2005), s. 55-64 ISSN 0011-4626 Grant - others:GA UK(CZ) 173/2003 Institutional research plan: CEZ:AV0Z10750506 Keywords : thin films * wavelet transform * descriptors * histogram model Subject RIV: BD - Theory of Information Impact factor: 0.360, year: 2005 http://library.utia.cas.cz/separaty/2009/ZOI/boldys-thin film description by wavelet coefficients statistics .pdf

Signatures of rocky planet engulfment in HAT-P-4. Implications for chemical tagging studies

Science.gov (United States)

Saffe, C.; Jofré, E.; Martioli, E.; Flores, M.; Petrucci, R.; Jaque Arancibia, M.

2017-07-01

Aims: We aim to explore the possible chemical signature of planet formation in the binary system HAT-P-4 by studying the trends of abundance vs. condensation temperature Tc. The star HAT-P-4 hosts a planet detected by transits, while its stellar companion does not have any detected planet. We also study the lithium content, which might shed light on the problem of Li depletion in exoplanet host stars. Methods: We derived for the first time both stellar parameters and high-precision chemical abundances by applying a line-by-line full differential approach. The stellar parameters were determined by imposing ionization and excitation equilibrium of Fe lines, with an updated version of the FUNDPAR program, together with ATLAS9 model atmospheres and the MOOG code. We derived detailed abundances of different species with equivalent widths and spectral synthesis with the MOOG program. Results: The exoplanet host star HAT-P-4 is found to be 0.1 dex more metal rich than its companion, which is one of the highest differences in metallicity observed in similar systems. This could have important implications for chemical tagging studies. We rule out a possible peculiar composition for each star, such as is the case for λ Boötis and δ Scuti, and neither is this binary a blue straggler. The star HAT-P-4 is enhanced in refractory elements relative to volatile when compared to its stellar companion. Notably, the Li abundance in HAT-P-4 is greater than that of its companion by 0.3 dex, which is contrary to the model that explains the Li depletion by the presence of planets. We propose a scenario where at the time of planet formation, the star HAT-P-4 locked the inner refractory material in planetesimals and rocky planets, and formed the outer gas giant planet at a greater distance. The refractories were then accreted onto the star, possibly as a result of the migration of the giant planet. This explains the higher metallicity, the higher Li content, and the negative Tc trend we

Higher risk for obesity among Mexican-American and Mexican immigrant children and adolescents than among peers in Mexico.

Science.gov (United States)

Hernández-Valero, María A; Bustamante-Montes, L Patricia; Hernández, Mike; Halley-Castillo, Elizabeth; Wilkinson, Anna V; Bondy, Melissa L; Olvera, Norma

2012-08-01

We conducted a cross-sectional study among 1,717 children and adolescents of Mexican origin ages 5-19 years living in Mexico and Texas to explore the influence of country of birth and country of longest residence on their overweight and obesity status. Descriptive statistics were used to compare demographic and anthropometric characteristics of participants born and raised in Mexico (Mexicans), born in Mexico and raised in the United States (Mexican immigrants), and born and raised in the United States (Mexican-Americans). Univariate and multivariate nominal logistic regression was used to determine the demographic predictors of obesity adjusted by country of birth, country of residence, age, and gender. Almost half (48.8%) of the Mexican-Americans and 43.2% of the Mexican immigrants had body mass index at the 85th percentile or above, compared to only 29.3% of the Mexicans (P obese than their Mexican peers [Mexican-Americans: odds ratio (OR) = 2.5 (95% confidence interval [CI] 1.8-3.4); Mexican immigrants: OR = 2.2 (95% CI 1.6-3.0)]. In addition, males were more likely than females to be obese [OR = 1.6 (95% CI 1.2-2.1)], and adolescents 15-19 years of age were less likely than their younger counterparts [OR = 0.5 (95% CI 0.4-0.7)] to be obese. The high prevalence of obesity among children of Mexican origin in the United States is of great concern and underscores the urgent need to develop and implement obesity preventive interventions targeting younger children of Mexican origin, especially newly arrived immigrant children. In addition, future obesity research should take into consideration the country of origin of the study population to develop more culturally specific obesity interventions.

Wavelet Based Diagnosis and Protection of Electric Motors

OpenAIRE

Khan, M. Abdesh Shafiel Kafiey; Rahman, M. Azizur

2010-01-01

In this chapter, a short review of conventional Fourier transforms and new wavelet based faults diagnostic and protection techniques for electric motors is presented. The new hybrid wavelet packet transform (WPT) and neural network (NN) based faults diagnostic algorithm is developed and implemented for electric motors. The proposed WPT and NN

Evaluation of the wavelet image two-line coder

DEFF Research Database (Denmark)

Rein, Stephan Alexander; Fitzek, Frank Hanns Paul; Gühmann, Clemens

2015-01-01

This paper introduces the wavelet image two-line (Wi2l) coding algorithm for low complexity compression of images. The algorithm recursively encodes an image backwards reading only two lines of a wavelet subband, which are read in blocks of 512 bytes from flash memory. It thus only requires very ...

The Mexican American.

Science.gov (United States)

Rowan, Helen

The purpose of this paper, prepared for the U. S. Commission on Civil Rights, is to indicate the types and ranges of problems facing the Mexican American community and to suggest ways in which these problems are peculiar to Mexican Americans. Specific examples are cited to illustrate major problems and personal experiences. Topics covered in the…

Improvement of electrocardiogram by empirical wavelet transform

Science.gov (United States)

Chanchang, Vikanda; Kumchaiseemak, Nakorn; Sutthiopad, Malee; Luengviriya, Chaiya

2017-09-01

Electrocardiogram (ECG) is a crucial tool in the detection of cardiac arrhythmia. It is also often used in a routine physical exam, especially, for elderly people. This graphical representation of electrical activity of heart is obtained by a measurement of voltage at the skin; therefore, the signal is always contaminated by noise from various sources. For a proper interpretation, the quality of the ECG should be improved by a noise reduction. In this article, we present a study of a noise filtration in the ECG by using an empirical wavelet transform (EWT). Unlike the traditional wavelet method, EWT is adaptive since the frequency spectrum of the ECG is taken into account in the construction of the wavelet basis. We show that the signal-to-noise ratio increases after the noise filtration for different noise artefacts.

Multiresolution wavelet-ANN model for significant wave height forecasting.

Digital Repository Service at National Institute of Oceanography (India)

Deka, P.C.; Mandal, S.; Prahlada, R.

Hybrid wavelet artificial neural network (WLNN) has been applied in the present study to forecast significant wave heights (Hs). Here Discrete Wavelet Transformation is used to preprocess the time series data (Hs) prior to Artificial Neural Network...

A CMOS Morlet Wavelet Generator

Directory of Open Access Journals (Sweden)

A. I. Bautista-Castillo

2017-04-01

Full Text Available The design and characterization of a CMOS circuit for Morlet wavelet generation is introduced. With the proposed Morlet wavelet circuit, it is possible to reach a~low power consumption, improve standard deviation (σ control and also have a small form factor. A prototype in a double poly, three metal layers, 0.5 µm CMOS process from MOSIS foundry was carried out in order to verify the functionality of the proposal. However, the design methodology can be extended to different CMOS processes. According to the performance exhibited by the circuit, may be useful in many different signal processing tasks such as nonlinear time-variant systems.

Generalized Wavelet Fisher’s Information of 1/fα Signals

Directory of Open Access Journals (Sweden)

Julio Ramírez-Pacheco

2015-01-01

Full Text Available This paper defines the generalized wavelet Fisher information of parameter q. This information measure is obtained by generalizing the time-domain definition of Fisher’s information of Furuichi to the wavelet domain and allows to quantify smoothness and correlation, among other signals characteristics. Closed-form expressions of generalized wavelet Fisher information for 1/fα signals are determined and a detailed discussion of their properties, characteristics and their relationship with wavelet q-Fisher information are given. Information planes of 1/f signals Fisher information are obtained and, based on these, potential applications are highlighted. Finally, generalized wavelet Fisher information is applied to the problem of detecting and locating weak structural breaks in stationary 1/f signals, particularly for fractional Gaussian noise series. It is shown that by using a joint Fisher/F-Statistic procedure, significant improvements in time and accuracy are achieved in comparison with the sole application of the F-statistic.

Mexican Revolution

OpenAIRE

Scheuzger, Stephan

2016-01-01

It was the complex and far-reaching transformation of the Mexican Revolution rather than the First World War that left its mark on Mexican history in the second decade of the 20th century. Nevertheless, although the country maintained its neutrality in the international conflict, it was a hidden theatre of war. Between 1914 and 1918, state actors in Germany, Great Britain and the United States defined their policies towards Mexico and its nationalist revolution with a view not only to improve...

A novel neural-wavelet approach for process diagnostics and complex system modeling

Science.gov (United States)

Gao, Rong

Neural networks have been effective in several engineering applications because of their learning abilities and robustness. However certain shortcomings, such as slow convergence and local minima, are always associated with neural networks, especially neural networks applied to highly nonlinear and non-stationary problems. These problems can be effectively alleviated by integrating a new powerful tool, wavelets, into conventional neural networks. The multi-resolution analysis and feature localization capabilities of the wavelet transform offer neural networks new possibilities for learning. A neural wavelet network approach developed in this thesis enjoys fast convergence rate with little possibility to be caught at a local minimum. It combines the localization properties of wavelets with the learning abilities of neural networks. Two different testbeds are used for testing the efficiency of the new approach. The first is magnetic flowmeter-based process diagnostics: here we extend previous work, which has demonstrated that wavelet groups contain process information, to more general process diagnostics. A loop at Applied Intelligent Systems Lab (AISL) is used for collecting and analyzing data through the neural-wavelet approach. The research is important for thermal-hydraulic processes in nuclear and other engineering fields. The neural-wavelet approach developed is also tested with data from the electric power grid. More specifically, the neural-wavelet approach is used for performing short-term and mid-term prediction of power load demand. In addition, the feasibility of determining the type of load using the proposed neural wavelet approach is also examined. The notion of cross scale product has been developed as an expedient yet reliable discriminator of loads. Theoretical issues involved in the integration of wavelets and neural networks are discussed and future work outlined.

Subjective Social Status, Mental and Psychosocial Health, and Birth Weight Differences in Mexican-American and Mexican Immigrant Women.

Science.gov (United States)

Fleuriet, K Jill; Sunil, T S

2015-12-01

Recent Mexican immigrant women on average have an unexpectedly low incidence of low birth weight (LBW). Birth weights decline and LBW incidence increases in post-immigrant generations. This pilot project tested the hypothesis that subjective social status (SSS) of pregnant women predicts variation in birth weight between Mexican immigrant and Mexican-American women. 300 low-income pregnant Mexican immigrant and Mexican-American women in South Texas were surveyed for SSS, depression, pregnancy-related anxiety, perceived social stress and self-esteem and subsequent birth weight. No significant difference in SSS levels between pregnant Mexican immigrant and Mexican-American women were found. However, SSS better predicted variation in birth weight across both groups than mental and psychosocial health variables. Results suggest distinct relationships among SSS, mental and psychosocial health that could impact birth weight. They underscore the relevance of a multilevel, biopsychosocial analytical framework to studying LBW.

DIY teleport hats - the consolation of technology

DEFF Research Database (Denmark)

Hansen, Lone Koefoed

2009-01-01

or biking there. This particular set is made in the free-form crochet style: there is no exact pattern to crochet from, instead you crochet in an iterative process alternating between crocheting and trying the hat on for size and pattern adaptations. Disclaimer: It is of course not a functioning device...... but it works well as a gift for someone you miss or someone who misses another person madly as it provides an opportunity to take some kind of action when ordinary options like driving, jetting or biking are not feasible even if the action is only symbolic....

Optimization and Assessment of Wavelet Packet Decompositions with Evolutionary Computation

Directory of Open Access Journals (Sweden)

Schell Thomas

2003-01-01

Full Text Available In image compression, the wavelet transformation is a state-of-the-art component. Recently, wavelet packet decomposition has received quite an interest. A popular approach for wavelet packet decomposition is the near-best-basis algorithm using nonadditive cost functions. In contrast to additive cost functions, the wavelet packet decomposition of the near-best-basis algorithm is only suboptimal. We apply methods from the field of evolutionary computation (EC to test the quality of the near-best-basis results. We observe a phenomenon: the results of the near-best-basis algorithm are inferior in terms of cost-function optimization but are superior in terms of rate/distortion performance compared to EC methods.

Non-stationary dynamics in the bouncing ball: A wavelet perspective

Energy Technology Data Exchange (ETDEWEB)

Behera, Abhinna K., E-mail: abhinna@iiserkol.ac.in; Panigrahi, Prasanta K., E-mail: pprasanta@iiserkol.ac.in [Department of Physical Sciences, Indian Institute of Science Education and Research (IISER) Kolkata, Mohanpur 741246 (India); Sekar Iyengar, A. N., E-mail: ansekar.iyengar@saha.ac.in [Plasma Physics Division, Saha Institute of Nuclear Physics (SINP), Sector 1, Block-AF, Bidhannagar, Kolkata 700064 (India)

2014-12-01

The non-stationary dynamics of a bouncing ball, comprising both periodic as well as chaotic behavior, is studied through wavelet transform. The multi-scale characterization of the time series displays clear signatures of self-similarity, complex scaling behavior, and periodicity. Self-similar behavior is quantified by the generalized Hurst exponent, obtained through both wavelet based multi-fractal detrended fluctuation analysis and Fourier methods. The scale dependent variable window size of the wavelets aptly captures both the transients and non-stationary periodic behavior, including the phase synchronization of different modes. The optimal time-frequency localization of the continuous Morlet wavelet is found to delineate the scales corresponding to neutral turbulence, viscous dissipation regions, and different time varying periodic modulations.

The Mexican oil industry

International Nuclear Information System (INIS)

Marcos-Giacoman, E.

1991-01-01

In the environment of growing domestic demand and enhanced international competitiveness, Petroleos Mexicanos (PEMEX)-the Mexican national oil company-faces the challenge of not only responding adequately to the rapid changes taking place in the Mexican economy, but making a significant contribution towards solid and stable growth. This paper reports that the relevant concern is how PEMEX is going to live up to these expectations. The Mexican oil industry, especially including the petrochemical sector, has great potential in terms of an ample domestic market as well as external foreign-currency-generating markets

Implications of the Secondary Eclipse of Exoplanet HAT-P-11b

Science.gov (United States)

Barry, Richard K.; Deming, L. D.; Bakos, G.; Harrington, J.; Madhusudhan, N.; Noyes, R.; Seager, S.

2010-01-01

We observed exoplanet HAT-P-11b and have successfully detected its secondary eclipse. We conducted observations using the Spitzer Space Telescope in the post-cryo mission at 3.6 microns for a period of 22 hours centered on the anticipated secondary eclipse time, to detect the eclipse and determine its phase. Having detected the secondary eclipse, we are at present making a more focused series of observations in both the 3.6 and 4.5 micron bands to fully characterize it. HAT-P-11b is one of only two known exo-Neptunes and has a period of 4.8878 days, radius of 0.422 RJ, mass of 0.081 MJ and semi-major axis 0.053 AU. Measurements of the secondary eclipse will serve to clarify two key issues; 1) the planetary brightness temperature and the nature of its atmosphere, and 2) the eccentricity of its orbit, with implications for its dynamical evolution. We discuss implications of these observations.

A hybrid video compression based on zerotree wavelet structure

International Nuclear Information System (INIS)

Kilic, Ilker; Yilmaz, Reyat

2009-01-01

A video compression algorithm comparable to the standard techniques at low bit rates is presented in this paper. The overlapping block motion compensation (OBMC) is combined with discrete wavelet transform which followed by Lloyd-Max quantization and zerotree wavelet (ZTW) structure. The novel feature of this coding scheme is the combination of hierarchical finite state vector quantization (HFSVQ) with the ZTW to encode the quantized wavelet coefficients. It is seen that the proposed video encoder (ZTW-HFSVQ) performs better than the MPEG-4 and Zerotree Entropy Coding (ZTE). (author)

Wavelet entropy of BOLD time series: An application to Rolandic epilepsy.

Science.gov (United States)

Gupta, Lalit; Jansen, Jacobus F A; Hofman, Paul A M; Besseling, René M H; de Louw, Anton J A; Aldenkamp, Albert P; Backes, Walter H

2017-12-01

To assess the wavelet entropy for the characterization of intrinsic aberrant temporal irregularities in the time series of resting-state blood-oxygen-level-dependent (BOLD) signal fluctuations. Further, to evaluate the temporal irregularities (disorder/order) on a voxel-by-voxel basis in the brains of children with Rolandic epilepsy. The BOLD time series was decomposed using the discrete wavelet transform and the wavelet entropy was calculated. Using a model time series consisting of multiple harmonics and nonstationary components, the wavelet entropy was compared with Shannon and spectral (Fourier-based) entropy. As an application, the wavelet entropy in 22 children with Rolandic epilepsy was compared to 22 age-matched healthy controls. The images were obtained by performing resting-state functional magnetic resonance imaging (fMRI) using a 3T system, an 8-element receive-only head coil, and an echo planar imaging pulse sequence ( T2*-weighted). The wavelet entropy was also compared to spectral entropy, regional homogeneity, and Shannon entropy. Wavelet entropy was found to identify the nonstationary components of the model time series. In Rolandic epilepsy patients, a significantly elevated wavelet entropy was observed relative to controls for the whole cerebrum (P = 0.03). Spectral entropy (P = 0.41), regional homogeneity (P = 0.52), and Shannon entropy (P = 0.32) did not reveal significant differences. The wavelet entropy measure appeared more sensitive to detect abnormalities in cerebral fluctuations represented by nonstationary effects in the BOLD time series than more conventional measures. This effect was observed in the model time series as well as in Rolandic epilepsy. These observations suggest that the brains of children with Rolandic epilepsy exhibit stronger nonstationary temporal signal fluctuations than controls. 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2017;46:1728-1737. © 2017 International Society for Magnetic

WAVELET-BASED ALGORITHM FOR DETECTION OF BEARING FAULTS IN A GAS TURBINE ENGINE

Directory of Open Access Journals (Sweden)

Sergiy Enchev

2014-07-01

Full Text Available Presented is a gas turbine engine bearing diagnostic system that integrates information from various advanced vibration analysis techniques to achieve robust bearing health state awareness. This paper presents a computational algorithm for identifying power frequency variations and integer harmonics by using wavelet-based transform. The continuous wavelet transform with  the complex Morlet wavelet is adopted to detect the harmonics presented in a power signal. The algorithm based on the discrete stationary wavelet transform is adopted to denoise the wavelet ridges.

Polarized spectral features of human breast tissues through wavelet ...

Indian Academy of Sciences (India)

Abstract. Fluorescence characteristics of human breast tissues are investigated through wavelet transform and principal component analysis (PCA). Wavelet transform of polar- ized fluorescence spectra of human breast tissues is found to localize spectral features that can reliably differentiate different tissue types.

A Wavelet-Based Approach to Fall Detection

Directory of Open Access Journals (Sweden)

Luca Palmerini

2015-05-01

Full Text Available Falls among older people are a widely documented public health problem. Automatic fall detection has recently gained huge importance because it could allow for the immediate communication of falls to medical assistance. The aim of this work is to present a novel wavelet-based approach to fall detection, focusing on the impact phase and using a dataset of real-world falls. Since recorded falls result in a non-stationary signal, a wavelet transform was chosen to examine fall patterns. The idea is to consider the average fall pattern as the “prototype fall”.In order to detect falls, every acceleration signal can be compared to this prototype through wavelet analysis. The similarity of the recorded signal with the prototype fall is a feature that can be used in order to determine the difference between falls and daily activities. The discriminative ability of this feature is evaluated on real-world data. It outperforms other features that are commonly used in fall detection studies, with an Area Under the Curve of 0.918. This result suggests that the proposed wavelet-based feature is promising and future studies could use this feature (in combination with others considering different fall phases in order to improve the performance of fall detection algorithms.

Six Thinking Hats and Social Workers' Innovative Competence: An Experimental Study

Science.gov (United States)

Azeez, Razaq Olugbenga

2016-01-01

Employees, no doubt, are the main force in organizations, and their innovative behaviours are vital for outcome efficacy. Innovative organisations, therefore, need creative employees who generate new ideas for product or process of innovation. This study investigated the effect of six thinking hats creativity technique on innovative competence of…

A note on the standard dual frame of a wavelet frame with three-scale

International Nuclear Information System (INIS)

Chen Qingjiang; Wei Zongtian; Feng Jinshun

2009-01-01

In this paper, it is shown that there exist wavelet frames generated by two functions which have good dual wavelet frames, but for which the standard dual wavelet frame does not consist of wavelets. That is to say, the standard dual wavelet frame cannot be generated by the translations and dilations of a single function. Relation to some physical theories such as entropy and E-infinity theory is also discussed.

Construction and decomposition of biorthogonal vector-valued wavelets with compact support

International Nuclear Information System (INIS)

Chen Qingjiang; Cao Huaixin; Shi Zhi

2009-01-01

In this article, we introduce vector-valued multiresolution analysis and the biorthogonal vector-valued wavelets with four-scale. The existence of a class of biorthogonal vector-valued wavelets with compact support associated with a pair of biorthogonal vector-valued scaling functions with compact support is discussed. A method for designing a class of biorthogonal compactly supported vector-valued wavelets with four-scale is proposed by virtue of multiresolution analysis and matrix theory. The biorthogonality properties concerning vector-valued wavelet packets are characterized with the aid of time-frequency analysis method and operator theory. Three biorthogonality formulas regarding them are presented.

Research on fault diagnosis for RCP rotor based on wavelet analysis

International Nuclear Information System (INIS)

Chen Zhihui; Xia Hong; Wang Taotao

2008-01-01

Wavelet analysis is with the characteristics of noise reduction and multiscale resolution, and can be used to effectively extract the fault features of the typical failures of the main pumps. Simulink is used to simulate the typical faults: Misalignment Fault, Crackle Fault of rotor, and Initial Bending Fault, then the Wavelet method is used to analyze the vibration signal. The result shows that the extracted fault feature from wavelet analysis can effectively identify the fault signals. The Wavelet analysis is a practical method for the diagnosis of main coolant pump failure, and is with certain value for application and significance. (authors)

Study of Denoising in TEOAE Signals Using an Appropriate Mother Wavelet Function

Directory of Open Access Journals (Sweden)

Habib Alizadeh Dizaji

2007-06-01

Full Text Available Background and Aim: Matching a mother wavelet to class of signals can be of interest in signal analy­sis and denoising based on wavelet multiresolution analysis and decomposition. As transient evoked otoacoustic emissions (TEOAES are contaminated with noise, the aim of this work was to pro­vide a quantitative approach to the problem of matching a mother wavelet to TEOAE signals by us­ing tun­ing curves and to use it for analysis and denoising TEOAE signals. Approximated mother wave­let for TEOAE signals was calculated using an algorithm for designing wavelet to match a specified sig­nal.Materials and Methods: In this paper a tuning curve has used as a template for designing a mother wave­let that has maximum matching to the tuning curve. The mother wavelet matching was performed on tuning curves spectrum magnitude and phase independent of one another. The scaling function was calcu­lated from the matched mother wavelet and by using these functions, lowpass and highpass filters were designed for a filter bank and otoacoustic emissions signal analysis and synthesis. After signal analyz­ing, denoising was performed by time windowing the signal time-frequency component.Results: Aanalysis indicated more signal reconstruction improvement in comparison with coiflets mother wavelet and by using the purposed denoising algorithm it is possible to enhance signal to noise ra­tio up to dB.Conclusion: The wavelet generated from this algorithm was remarkably similar to the biorthogonal wave­lets. Therefore, by matching a biorthogonal wavelet to the tuning curve and using wavelet packet analy­sis, a high resolution time-frequency analysis for the otoacoustic emission signals is possible.

Optimization design of biorthogonal wavelets for embedded image coding

NARCIS (Netherlands)

Lin, Z.; Zheng, N.; Liu, Y.; Wetering, van de H.M.M.

2007-01-01

We present here a simple technique for parametrization of popular biorthogonal wavelet filter banks (BWFBs) having vanishing moments (VMs) of arbitrary multiplicity. Given a prime wavelet filter with VMs of arbitrary multiplicity, after formulating it as a trigonometric polynomial depending on two

On Parseval Wavelet Frames with Two or Three Generators via the Unitary Extension Principle

DEFF Research Database (Denmark)

Christensen, Ole; Kim, Hong Oh; Kim, Rae Young

2014-01-01

The unitary extension principle (UEP) by A. Ron and Z. Shen yields a sufficient condition for the construction of Parseval wavelet frames with multiple generators. In this paper we characterize the UEP-type wavelet systems that can be extended to a Parseval wavelet frame by adding just one UEP......-type wavelet system. We derive a condition that is necessary for the extension of a UEP-type wavelet system to any Parseval wavelet frame with any number of generators and prove that this condition is also sufficient to ensure that an extension with just two generators is possible....

HAT-P-13b,c: A TRANSITING HOT JUPITER WITH A MASSIVE OUTER COMPANION ON AN ECCENTRIC ORBIT

International Nuclear Information System (INIS)

Bakos, G. A.; Noyes, R. W.; Hartman, J.; Torres, G.; Latham, D. W.; Sasselov, D. D.; Stefanik, R. P.; Sipocz, B.; Kovacs, Gabor; Esquerdo, G. A.; Pal, A.; Howard, A. W.; Marcy, G. W.; Kovacs, Geza; Fischer, D. A.; Johnson, J. A.; Lazar, J.; Papp, I.; Sari, P.

2009-01-01

We report on the discovery of a planetary system with a close-in transiting hot Jupiter on a near circular orbit and a massive outer planet on a highly eccentric orbit. The inner planet, HAT-P-13b, transits the bright V = 10.622 G4 dwarf star GSC 3416 - 00543 every P = 2.916260 ± 0.000010 days, with transit epoch T c = 2454779.92979 ± 0.00038 (BJD) and duration 0.1345 ± 0.0017 days. The outer planet HAT-P-13c orbits the star every P 2 = 428.5 ± 3.0 days with a nominal transit center (assuming zero impact parameter) of T 2c = 2454870.4 ± 1.8 (BJD) or time of periastron passage T 2,peri = 2454890.05 ± 0.48 (BJD). Transits of the outer planet have not been observed, and may not be present. The host star has a mass of 1.22 +0.05 -0.10 M sun , radius of 1.56 ± 0.08 R sun , effective temperature of 5653 ± 90 K, and is rather metal-rich with [Fe/H] = +0.41 ± 0.08. The inner planetary companion has a mass of 0.853 +0.029 -0.046 M J , and radius of 1.281 ± 0.079 R J , yielding a mean density of 0.498 +0.103 -0.069 g cm -3 . The outer companion has m 2 sin i 2 = 15.2 ± 1.0 M J , and orbits on a highly eccentric orbit of e 2 = 0.691 ± 0.018. While we have not detected significant transit timing variations of HAT-P-13b, due to gravitational and light-travel time effects, future observations will constrain the orbital inclination of HAT-P-13c, along with its mutual inclination to HAT-P-13b. The HAT-P-13 (b, c) double-planet system may prove extremely valuable for theoretical studies of the formation and dynamics of planetary systems.

Quality Variation Control for Three-Dimensional Wavelet-Based Video Coders

Directory of Open Access Journals (Sweden)

Vidhya Seran

2007-02-01

Full Text Available The fluctuation of quality in time is a problem that exists in motion-compensated-temporal-filtering (MCTF- based video coding. The goal of this paper is to design a solution for overcoming the distortion fluctuation challenges faced by wavelet-based video coders. We propose a new technique for determining the number of bits to be allocated to each temporal subband in order to minimize the fluctuation in the quality of the reconstructed video. Also, the wavelet filter properties are explored to design suitable scaling coefficients with the objective of smoothening the temporal PSNR. The biorthogonal 5/3 wavelet filter is considered in this paper and experimental results are presented for 2D+t and t+2D MCTF wavelet coders.

Quality Variation Control for Three-Dimensional Wavelet-Based Video Coders

Directory of Open Access Journals (Sweden)

Seran Vidhya

2007-01-01

Full Text Available The fluctuation of quality in time is a problem that exists in motion-compensated-temporal-filtering (MCTF- based video coding. The goal of this paper is to design a solution for overcoming the distortion fluctuation challenges faced by wavelet-based video coders. We propose a new technique for determining the number of bits to be allocated to each temporal subband in order to minimize the fluctuation in the quality of the reconstructed video. Also, the wavelet filter properties are explored to design suitable scaling coefficients with the objective of smoothening the temporal PSNR. The biorthogonal 5/3 wavelet filter is considered in this paper and experimental results are presented for 2D+t and t+2D MCTF wavelet coders.

The relationship between Mexican American cultural values and resilience among Mexican American college students: a mixed methods study.

Science.gov (United States)

Morgan Consoli, Melissa L; Llamas, Jasmin D

2013-10-01

The current study investigated the role of cultural values in the resilience of Mexican American college students. Utilizing mixed methodology, 124 self-identified Mexican American college students were asked to complete an online survey, including a demographic questionnaire, the Resilience Scale, Mexican American Cultural Values Scale, and 2 open-ended questions concerning overcoming adversity and cultural values. As hypothesized, Mexican American traditional cultural values (Familismo, Respeto, Religiosidad, and Traditional Gender Roles) predicted resilience, with Familismo accounting for the majority of the variance. Consensual qualitative research (Hill, Thompson, & Nutt Williams, 1997) was used to identify emergent domains and themes within the open-ended question responses. Traditional Mexican American Value themes included Familismo, Ethnic Identity, Religiosidad, Perseverance, and Respeto. Results highlight the important role that certain Mexican American cultural values play in providing strength for overcoming adversities.

Perceived social stress, pregnancy-related anxiety, depression and subjective social status among pregnant Mexican and Mexican American women in south Texas.

Science.gov (United States)

Fleuriet, K Jill; Sunil, T S

2014-05-01

The purpose of this study was to determine differences in subjective social status, perceived social stress, depressive symptoms, and pregnancy-related anxiety between pregnant Mexican American and Mexican immigrant women. Three hundred pregnant Mexican immigrant and Mexican American women in South Texas were surveyed for pregnancy-related anxiety, perceived social stress, depressive symptoms, and subjective social status. Pregnant Mexican immigrant women had higher levels of pregnancy-related anxiety and lower levels of depression and perceived social stress than pregnant Mexican American women. Change in these variables among Mexican immigrant women was relatively linear as time of residence in the United States increased. Mexican immigrant and Mexican American women had significantly different correlations between subjective social status, self-esteem and perceived social stress. Results indicate that subjective social status is an important psychosocial variable among pregnant Hispanic women. Results contribute to ongoing efforts to provide culturally responsive prenatal psychosocial support services.

Analysis and removing noise from speech using wavelet transform

Science.gov (United States)

Tomala, Karel; Voznak, Miroslav; Partila, Pavol; Rezac, Filip; Safarik, Jakub

2013-05-01

The paper discusses the use of Discrete Wavelet Transform (DWT) and Stationary Wavelet Transform (SWT) wavelet in removing noise from voice samples and evaluation of its impact on speech quality. One significant part of Quality of Service (QoS) in communication technology is the speech quality assessment. However, this part is seriously overlooked as telecommunication providers often focus on increasing network capacity, expansion of services offered and their enforcement in the market. Among the fundamental factors affecting the transmission properties of the communication chain is noise, either at the transmitter or the receiver side. A wavelet transform (WT) is a modern tool for signal processing. One of the most significant areas in which wavelet transforms are used is applications designed to suppress noise in signals. To remove noise from the voice sample in our experiment, we used the reference segment of the voice which was distorted by Gaussian white noise. An evaluation of the impact on speech quality was carried out by an intrusive objective algorithm Perceptual Evaluation of Speech Quality (PESQ). DWT and SWT transformation was applied to voice samples that were devalued by Gaussian white noise. Afterwards, we determined the effectiveness of DWT and SWT by means of objective algorithm PESQ. The decisive criterion for determining the quality of a voice sample once the noise had been removed was Mean Opinion Score (MOS) which we obtained in PESQ. The contribution of this work lies in the evaluation of efficiency of wavelet transformation to suppress noise in voice samples.

Wavelet denoising method; application to the flow rate estimation for water level control

International Nuclear Information System (INIS)

Park, Gee Young; Park, Jin Ho; Lee, Jung Han; Kim, Bong Soo; Seong, Poong Hyun

2003-01-01

The wavelet transform decomposes a signal into time- and frequency-domain signals and it is well known that a noise-corrupted signal could be reconstructed or estimated when a proper denoising method is involved in the wavelet transform. Among the wavelet denoising methods proposed up to now, the wavelets by Mallat and Zhong can reconstruct best the pure transient signal from a highly corrupted signal. But there has been no systematic way of discriminating the original signal from the noise in a dyadic wavelet transform. In this paper, a systematic method is proposed for noise discrimination, which could be implemented easily into a digital system. For demonstrating the potential role of the wavelet denoising method in the nuclear field, this method is applied to the steam or feedwater flow rate estimation of the secondary loop. And the configuration of the S/G water level control system is proposed for incorporating the wavelet denoising method in estimating the flow rate value at low operating powers

ACO-Initialized Wavelet Neural Network for Vibration Fault Diagnosis of Hydroturbine Generating Unit

Directory of Open Access Journals (Sweden)

Zhihuai Xiao

2015-01-01

Full Text Available Considering the drawbacks of traditional wavelet neural network, such as low convergence speed and high sensitivity to initial parameters, an ant colony optimization- (ACO- initialized wavelet neural network is proposed in this paper for vibration fault diagnosis of a hydroturbine generating unit. In this method, parameters of the wavelet neural network are initialized by the ACO algorithm, and then the wavelet neural network is trained by the gradient descent algorithm. Amplitudes of the frequency components of the hydroturbine generating unit vibration signals are used as feature vectors for wavelet neural network training to realize mapping relationship from vibration features to fault types. A real vibration fault diagnosis case result of a hydroturbine generating unit shows that the proposed method has faster convergence speed and stronger generalization ability than the traditional wavelet neural network and ACO wavelet neural network. Thus it can provide an effective solution for online vibration fault diagnosis of a hydroturbine generating unit.

Determination of phase from the ridge of CWT using generalized Morse wavelet

Science.gov (United States)

Kocahan, Ozlem; Tiryaki, Erhan; Coskun, Emre; Ozder, Serhat

2018-03-01

The selection of wavelet is an important step in order to determine the phase from the fringe patterns. In the present work, a new wavelet for phase retrieval from the ridge of continuous wavelet transform (CWT) is presented. The phase distributions have been extracted from the optical fringe pattern by choosing the zero order generalized morse wavelet (GMW) as a mother wavelet. The aim of the study is to reveal the ways in which the two varying parameters of GMW affect the phase calculation. To show the validity of this method, an experimental study has been conducted by using the diffraction phase microscopy (DPM) setup; consequently, the profiles of red blood cells have been retrieved. The results for the CWT ridge technique with GMW have been compared with the results for the Morlet wavelet and the Paul wavelet; the results are almost identical for Paul and zero order GMW because of their degree of freedom. Also, for further discussion, the Fourier transform and the Stockwell transform have been applied comparatively. The outcome of the comparison reveals that GMWs are highly applicable to the research in various areas, predominantly biomedicine.

Fringe pattern information retrieval using wavelets

Science.gov (United States)

Sciammarella, Cesar A.; Patimo, Caterina; Manicone, Pasquale D.; Lamberti, Luciano

2005-08-01

Two-dimensional phase modulation is currently the basic model used in the interpretation of fringe patterns that contain displacement information, moire, holographic interferometry, speckle techniques. Another way to look to these two-dimensional signals is to consider them as frequency modulated signals. This alternative interpretation has practical implications similar to those that exist in radio engineering for handling frequency modulated signals. Utilizing this model it is possible to obtain frequency information by using the energy approach introduced by Ville in 1944. A natural complementary tool of this process is the wavelet methodology. The use of wavelet makes it possible to obtain the local values of the frequency in a one or two dimensional domain without the need of previous phase retrieval and differentiation. Furthermore from the properties of wavelets it is also possible to obtain at the same time the phase of the signal with the advantage of a better noise removal capabilities and the possibility of developing simpler algorithms for phase unwrapping due to the availability of the derivative of the phase.

Wavelet-based compression of pathological images for telemedicine applications

Science.gov (United States)

Chen, Chang W.; Jiang, Jianfei; Zheng, Zhiyong; Wu, Xue G.; Yu, Lun

2000-05-01

In this paper, we present the performance evaluation of wavelet-based coding techniques as applied to the compression of pathological images for application in an Internet-based telemedicine system. We first study how well suited the wavelet-based coding is as it applies to the compression of pathological images, since these images often contain fine textures that are often critical to the diagnosis of potential diseases. We compare the wavelet-based compression with the DCT-based JPEG compression in the DICOM standard for medical imaging applications. Both objective and subjective measures have been studied in the evaluation of compression performance. These studies are performed in close collaboration with expert pathologists who have conducted the evaluation of the compressed pathological images and communication engineers and information scientists who designed the proposed telemedicine system. These performance evaluations have shown that the wavelet-based coding is suitable for the compression of various pathological images and can be integrated well with the Internet-based telemedicine systems. A prototype of the proposed telemedicine system has been developed in which the wavelet-based coding is adopted for the compression to achieve bandwidth efficient transmission and therefore speed up the communications between the remote terminal and the central server of the telemedicine system.

Using the Dual-Tree Complex Wavelet Transform for Improved Fabric Defect Detection

Directory of Open Access Journals (Sweden)

Hermanus Vermaak

2016-01-01

Full Text Available The dual-tree complex wavelet transform (DTCWT solves the problems of shift variance and low directional selectivity in two and higher dimensions found with the commonly used discrete wavelet transform (DWT. It has been proposed for applications such as texture classification and content-based image retrieval. In this paper, the performance of the dual-tree complex wavelet transform for fabric defect detection is evaluated. As experimental samples, the fabric images from TILDA, a textile texture database from the Workgroup on Texture Analysis of the German Research Council (DFG, are used. The mean energies of real and imaginary parts of complex wavelet coefficients taken separately are identified as effective features for the purpose of fabric defect detection. Then it is shown that the use of the dual-tree complex wavelet transform yields greater performance as compared to the undecimated wavelet transform (UDWT with a detection rate of 4.5% to 15.8% higher depending on the fabric type.

Potential ground water resources of Hat Yai Basin in Peninsular Thailand by gravity study

Directory of Open Access Journals (Sweden)

Warawutti Lohawijarn

2005-05-01

Full Text Available Residual gravity anomaly with a minimum of about -140 mm s-2 with approximately NS trend and a limited axial length was observed over Hat Yai Basin in Peninsular Thailand. The modeled Hat Yai basin is about 1 km deep at its deepest, 60 km long and 20 km wide. The porosity of basin sediment and the amount of potential ground water reserves within the basin are estimated to be 39% and 121.7±0.8 km3 respectively, assuming full saturation. Within the topmost 80 m of ground where the present extraction is concentrated, the estimated ground water reserve is 12.5±0.5 km3.

Auditory ERB like admissible wavelet packet features for TIMIT phoneme recognition

Directory of Open Access Journals (Sweden)

P.K. Sahu

2014-09-01

Full Text Available In recent years wavelet transform has been found to be an effective tool for time–frequency analysis. Wavelet transform has been used as feature extraction in speech recognition applications and it has proved to be an effective technique for unvoiced phoneme classification. In this paper a new filter structure using admissible wavelet packet is analyzed for English phoneme recognition. These filters have the benefit of having frequency bands spacing similar to the auditory Equivalent Rectangular Bandwidth (ERB scale. Central frequencies of ERB scale are equally distributed along the frequency response of human cochlea. A new sets of features are derived using wavelet packet transform's multi-resolution capabilities and found to be better than conventional features for unvoiced phoneme problems. Some of the noises from NOISEX-92 database has been used for preparing the artificial noisy database to test the robustness of wavelet based features.

Another Mexican birthweight paradox? The role of residential enclaves and neighborhood poverty in the birthweight of Mexican-origin infants.

Science.gov (United States)

Osypuk, Theresa L; Bates, Lisa M; Acevedo-Garcia, Dolores

2010-02-01

Examining whether contextual factors influence the birth outcomes of Mexican-origin infants in the US may contribute to assessing rival explanations for the so-called Mexican health paradox. We examined whether birthweight among infants born to Mexican-origin women in the US was associated with Mexican residential enclaves and exposure to neighborhood poverty, and whether these associations were modified by nativity (i.e. mother's place of birth). We calculated metropolitan indices of neighborhood exposure to Mexican-origin population and poverty for the Mexican-origin population, and merged with individual-level, year 2000 natality data (n=490,332). We distinguished between neighborhood exposure to US-born Mexican-origin population (i.e. ethnic enclaves) and neighborhood exposure to foreign-born (i.e. Mexico-born) Mexican-origin population (i.e. immigrant enclaves). We used 2-level hierarchical linear regression models adjusting for individual, metropolitan, and regional covariates and stratified by nativity. We found that living in metropolitan areas with high residential segregation of US-born Mexican-origin residents (i.e. high prevalence of ethnic enclaves) was associated with lower birthweight for infants of US-born Mexican-origin mothers before and after covariate adjustment. When simultaneously adjusting for exposure to ethnic and immigrant enclaves, the latter became positively associated with birthweight and the negative effect of the former increased, among US-born mothers. We found no contextual birthweight associations for mothers born in Mexico in adjusted models. Our findings highlight a differential effect of context by nativity, and the potential health effects of ethnic enclaves, which are possibly a marker of downward assimilation, among US-born Mexican-origin women. Copyright 2009 Elsevier Ltd. All rights reserved.

Wavelet-Coded OFDM for Next Generation Mobile Communications

DEFF Research Database (Denmark)

Cavalcante, Lucas Costa Pereira; Vegas Olmos, Juan José; Tafur Monroy, Idelfonso

2016-01-01

In this work, we evaluate the performance of Wavelet-Coding into offering robustness for OFDM signals against the combined effects of varying fading and noise bursts. Wavelet-Code enables high diversity gains with a low complex receiver, and, most notably, without compromising the system’s spectr......-wave frequencies in future generation mobile communication due to its robustness against multipath fading....

Evolutive Optimization of Wavelets and Shapelets for Bioelectrical Signal Analysis

OpenAIRE

Pinzón Morales, Rubén Dario

2011-01-01

análisis Wavelet es una poderosa herramienta para el procesamiento de señal digital. Ha sido ampliamente utilizado en señales bioeléctricas incluyendo evocar potenciales relacionados (ERP), señales de electromiografía (EMG), grabaciones de microelectrodos (MER), electrocardiograma (ECG), electroencefalogramas (EEG), entre otros. Algunas de las principales ventajas de la wavelet transform son el soporte compacto, y la concentración de la energía. Básicamente, la transformada wavelet es una con...

Multiscale peak detection in wavelet space.

Science.gov (United States)

Zhang, Zhi-Min; Tong, Xia; Peng, Ying; Ma, Pan; Zhang, Ming-Jin; Lu, Hong-Mei; Chen, Xiao-Qing; Liang, Yi-Zeng

2015-12-07

Accurate peak detection is essential for analyzing high-throughput datasets generated by analytical instruments. Derivatives with noise reduction and matched filtration are frequently used, but they are sensitive to baseline variations, random noise and deviations in the peak shape. A continuous wavelet transform (CWT)-based method is more practical and popular in this situation, which can increase the accuracy and reliability by identifying peaks across scales in wavelet space and implicitly removing noise as well as the baseline. However, its computational load is relatively high and the estimated features of peaks may not be accurate in the case of peaks that are overlapping, dense or weak. In this study, we present multi-scale peak detection (MSPD) by taking full advantage of additional information in wavelet space including ridges, valleys, and zero-crossings. It can achieve a high accuracy by thresholding each detected peak with the maximum of its ridge. It has been comprehensively evaluated with MALDI-TOF spectra in proteomics, the CAMDA 2006 SELDI dataset as well as the Romanian database of Raman spectra, which is particularly suitable for detecting peaks in high-throughput analytical signals. Receiver operating characteristic (ROC) curves show that MSPD can detect more true peaks while keeping the false discovery rate lower than MassSpecWavelet and MALDIquant methods. Superior results in Raman spectra suggest that MSPD seems to be a more universal method for peak detection. MSPD has been designed and implemented efficiently in Python and Cython. It is available as an open source package at .

Partially coherent imaging and spatial coherence wavelets

International Nuclear Information System (INIS)

Castaneda, Roman

2003-03-01

A description of spatially partially coherent imaging based on the propagation of second order spatial coherence wavelets and marginal power spectra (Wigner distribution functions) is presented. In this dynamics, the spatial coherence wavelets will be affected by the system through its elementary transfer function. The consistency of the model with the both extreme cases of full coherent and incoherent imaging was proved. In the last case we obtained the classical concept of optical transfer function as a simple integral of the elementary transfer function. Furthermore, the elementary incoherent response function was introduced as the Fourier transform of the elementary transfer function. It describes the propagation of spatial coherence wavelets form each object point to each image point through a specific point on the pupil planes. The point spread function of the system was obtained by a simple integral of the elementary incoherent response function. (author)

Wavelet theory and belt finishing process, influence of wavelet shape on the surface roughness parameter values

International Nuclear Information System (INIS)

Khawaja, Z; Mazeran, P-E; Bigerelle, M; Guillemot, G; Mansori, M El

2011-01-01

This article presents a multi-scale theory based on wavelet decomposition to characterize the evolution of roughness in relation with a finishing process or an observed surface property. To verify this approach in production conditions, analyses were developed for the finishing process of the hardened steel by abrasive belts. These conditions are described by seven parameters considered in the Tagushi experimental design. The main objective of this work is to identify the most relevant roughness parameter and characteristic length allowing to assess the influence of finishing process, and to test the relevance of the measurement scale. Results show that wavelet approach allows finding this scale.

Wavelet applications for modeling in the atmospheric sciences: Current status and potential extensions. Final report

International Nuclear Information System (INIS)

Envair, J.H.; Ekstrom, P.

1995-11-01

Wavelets are elementary mathematical functions used to construct, transform, and analyze higher functions and observational data. This report describes the results of an exploratory research effort to evaluate wavelet applications for numerically integrating differential equations associated with air pollution transport and conversion models. It is intended to provide a primer on wavelets, and specifically outlines the use of wavelets in a model that addresses derivative-evaluation and boundary-condition problems. Several factors complicate the use of wavelets for integrating differential equations. First, an enormous range of different wavelet types exists, making the choice of wavelet family for a given application challenging. Moreover, in contrast to the Fourier series, the functional derivatives necessary for numerical approximation are difficult to evaluate and consolidate in terms of wavelet expansions, introducing appreciable complexity into any attempt at wavelet-based integration. On the positive side, wavelet techniques do hold promise for effectively interfacing plume and other subgrid-scale phenomena in grid models. Moreover, workable techniques for derivative evaluation and simulation of boundary features appear feasible. Wavelet use may provide a viable, advantageous option for numerically integrating model equations describing fields on all scales of time and distance, especially where inhomogeneous fields exist, and provide a computationally efficient method of focusing on high-variability regions. The potential for wavelets to conduct integrations totally in transform space contrasts with Fourier-based approaches, which essentially preclude such treatments whenever nonlinear chemical processes occur in the modeled system

Clifford Continuous Wavelet Transforms in Ll0,2 and Ll0,3

International Nuclear Information System (INIS)

Bernstein, S.

2008-01-01

We consider Clifford-valued functions defined on R n . From the viewpoint of square integrable group representations a continuous wavelet transform is an irreducible continuous unitary representation of the affin group on the real line but also on R n . We will demonstrate that different Clifford continuous wavelet transforms can be obtained inside the calculus with similar properties than the real valued transform. Nevertheless, the Clifford wavelet transform is neither just a special vector transform nor just a wavelet transform applied to each component of the Clifford-valued function.

A cross-over in Mexican and Mexican-American fertility rates: Evidence and explanations for an emerging paradox

Directory of Open Access Journals (Sweden)

Patrick Heuveline

2005-03-01

Full Text Available Against a backdrop of two new developments in the fertility behavior of the Mexican- Origin population in the U.S., the present discussion will update contemporary Mexican-Origin fertility patterns and address several theoretical weaknesses in the current approach to minority group fertility. Data come from six national surveys (three from Mexico and three from the U.S. that cover a twenty-five year period (1975-2000. The findings demonstrate dramatic decreases in the fertility rates in Mexico at the same time that continuous increases have been documented in the fertility rates of third-or-later generation Mexican-Americans in the U.S., particularly at younger ages. These changes necessitate a reexamination of the ubiquitous theory that Mexican pronatalist values are responsible for the high fertility rates found within the Mexican-Origin population in the U.S. Instead, they point to the increasing relevance of framing the fertility behavior of the Mexican-Origin population within a racial stratification perspective that stresses the influence of U.S. social context on fertility behavior. As a step in this direction, the analysis examines fertility patterns within the Mexican-Origin population in the U.S. Special attention is given to the role of nativity/generational status in contributing to within group differences.

A comparison between wavelet based static and dynamic neural network approaches for runoff prediction

Science.gov (United States)

Shoaib, Muhammad; Shamseldin, Asaad Y.; Melville, Bruce W.; Khan, Mudasser Muneer

2016-04-01

In order to predict runoff accurately from a rainfall event, the multilayer perceptron type of neural network models are commonly used in hydrology. Furthermore, the wavelet coupled multilayer perceptron neural network (MLPNN) models has also been found superior relative to the simple neural network models which are not coupled with wavelet. However, the MLPNN models are considered as static and memory less networks and lack the ability to examine the temporal dimension of data. Recurrent neural network models, on the other hand, have the ability to learn from the preceding conditions of the system and hence considered as dynamic models. This study for the first time explores the potential of wavelet coupled time lagged recurrent neural network (TLRNN) models for runoff prediction using rainfall data. The Discrete Wavelet Transformation (DWT) is employed in this study to decompose the input rainfall data using six of the most commonly used wavelet functions. The performance of the simple and the wavelet coupled static MLPNN models is compared with their counterpart dynamic TLRNN models. The study found that the dynamic wavelet coupled TLRNN models can be considered as alternative to the static wavelet MLPNN models. The study also investigated the effect of memory depth on the performance of static and dynamic neural network models. The memory depth refers to how much past information (lagged data) is required as it is not known a priori. The db8 wavelet function is found to yield the best results with the static MLPNN models and with the TLRNN models having small memory depths. The performance of the wavelet coupled TLRNN models with large memory depths is found insensitive to the selection of the wavelet function as all wavelet functions have similar performance.

Evaluation of the Use of Second Generation Wavelets in the Coherent Vortex Simulation Approach

Science.gov (United States)

Goldstein, D. E.; Vasilyev, O. V.; Wray, A. A.; Rogallo, R. S.

2000-01-01

The objective of this study is to investigate the use of the second generation bi-orthogonal wavelet transform for the field decomposition in the Coherent Vortex Simulation of turbulent flows. The performances of the bi-orthogonal second generation wavelet transform and the orthogonal wavelet transform using Daubechies wavelets with the same number of vanishing moments are compared in a priori tests using a spectral direct numerical simulation (DNS) database of isotropic turbulence fields: 256(exp 3) and 512(exp 3) DNS of forced homogeneous turbulence (Re(sub lambda) = 168) and 256(exp 3) and 512(exp 3) DNS of decaying homogeneous turbulence (Re(sub lambda) = 55). It is found that bi-orthogonal second generation wavelets can be used for coherent vortex extraction. The results of a priori tests indicate that second generation wavelets have better compression and the residual field is closer to Gaussian. However, it was found that the use of second generation wavelets results in an integral length scale for the incoherent part that is larger than that derived from orthogonal wavelets. A way of dealing with this difficulty is suggested.

An adaptive wavelet-network model for forecasting daily total solar-radiation

International Nuclear Information System (INIS)

Mellit, A.; Benghanem, M.; Kalogirou, S.A.

2006-01-01

The combination of wavelet theory and neural networks has lead to the development of wavelet networks. Wavelet-networks are feed-forward networks using wavelets as activation functions. Wavelet-networks have been used successfully in various engineering applications such as classification, identification and control problems. In this paper, the use of adaptive wavelet-network architecture in finding a suitable forecasting model for predicting the daily total solar-radiation is investigated. Total solar-radiation is considered as the most important parameter in the performance prediction of renewable energy systems, particularly in sizing photovoltaic (PV) power systems. For this purpose, daily total solar-radiation data have been recorded during the period extending from 1981 to 2001, by a meteorological station in Algeria. The wavelet-network model has been trained by using either the 19 years of data or one year of the data. In both cases the total solar radiation data corresponding to year 2001 was used for testing the model. The network was trained to accept and handle a number of unusual cases. Results indicate that the model predicts daily total solar-radiation values with a good accuracy of approximately 97% and the mean absolute percentage error is not more than 6%. In addition, the performance of the model was compared with different neural network structures and classical models. Training algorithms for wavelet-networks require smaller numbers of iterations when compared with other neural networks. The model can be used to fill missing data in weather databases. Additionally, the proposed model can be generalized and used in different locations and for other weather data, such as sunshine duration and ambient temperature. Finally, an application using the model for sizing a PV-power system is presented in order to confirm the validity of this model

Wavelet and Spectral Analysis of Some Selected Problems in Reactor Diagnostics

Energy Technology Data Exchange (ETDEWEB)

Sunde, Carl

2004-12-01

Both spectral and wavelet analysis were successfully used in various diagnostic problems involving non-stationary core processes in nuclear power reactors. Three different problems were treated: two-phase flow identification, detector tube impacting and core-barrel vibrations. The first two problems are of non-stationary nature, whereas the last one is not. In the first problem, neutron radiographic and visible light images of four different vertical two-phase flow regimes, bubbly, slug, chum and annular flow, were analysed and classified with a neuro-wavelet algorithm. The algorithm consists of a wavelet part, using the 2-D discrete wavelet transform and of an artificial neural network. It classifies the different flow regimes with up to 99% efficiency. Detector tubes in a Boiling Water Reactor may execute vibrations and may also impact on nearby fuel-assemblies. Signals from in-core neutron detectors in Ringhals-1 were analysed, for detection of impacting, with both a classical spectral method and wavelet-based methods. The wavelet methods include both the discrete and the continuous 1-D wavelet transform. It was found that there is agreement between the different methods as well as with visual inspections made during the outage at the plant. However, the wavelet technique has the advantage that it does not require expert judgement for the interpretation of the analysis. In the last part two analytical calculations of the neutron noise, induced by shell-mode core-barrel vibrations, were carried out. The results are in good agreement with calculations from a numerical simulator. An out-of-phase behaviour between in-core and ex-core positions was found, which is in agreement with earlier measurements from the Pressurised Water Reactor Ringhals-3. The results from these calculations are planned to be used when diagnosing the shell-mode core-barrel vibrations in an operating plant.

Wavelet and Spectral Analysis of Some Selected Problems in Reactor Diagnostics

International Nuclear Information System (INIS)

Sunde, Carl

2004-12-01

Both spectral and wavelet analysis were successfully used in various diagnostic problems involving non-stationary core processes in nuclear power reactors. Three different problems were treated: two-phase flow identification, detector tube impacting and core-barrel vibrations. The first two problems are of non-stationary nature, whereas the last one is not. In the first problem, neutron radiographic and visible light images of four different vertical two-phase flow regimes, bubbly, slug, chum and annular flow, were analysed and classified with a neuro-wavelet algorithm. The algorithm consists of a wavelet part, using the 2-D discrete wavelet transform and of an artificial neural network. It classifies the different flow regimes with up to 99% efficiency. Detector tubes in a Boiling Water Reactor may execute vibrations and may also impact on nearby fuel-assemblies. Signals from in-core neutron detectors in Ringhals-1 were analysed, for detection of impacting, with both a classical spectral method and wavelet-based methods. The wavelet methods include both the discrete and the continuous 1-D wavelet transform. It was found that there is agreement between the different methods as well as with visual inspections made during the outage at the plant. However, the wavelet technique has the advantage that it does not require expert judgement for the interpretation of the analysis. In the last part two analytical calculations of the neutron noise, induced by shell-mode core-barrel vibrations, were carried out. The results are in good agreement with calculations from a numerical simulator. An out-of-phase behaviour between in-core and ex-core positions was found, which is in agreement with earlier measurements from the Pressurised Water Reactor Ringhals-3. The results from these calculations are planned to be used when diagnosing the shell-mode core-barrel vibrations in an operating plant

ACO-Initialized Wavelet Neural Network for Vibration Fault Diagnosis of Hydroturbine Generating Unit

OpenAIRE

Xiao, Zhihuai; He, Xinying; Fu, Xiangqian; Malik, O. P.

2015-01-01

Considering the drawbacks of traditional wavelet neural network, such as low convergence speed and high sensitivity to initial parameters, an ant colony optimization- (ACO-) initialized wavelet neural network is proposed in this paper for vibration fault diagnosis of a hydroturbine generating unit. In this method, parameters of the wavelet neural network are initialized by the ACO algorithm, and then the wavelet neural network is trained by the gradient descent algorithm. Amplitudes of the fr...

Orthonormal Wavelet Bases for Quantum Molecular Dynamics

International Nuclear Information System (INIS)

Tymczak, C.; Wang, X.

1997-01-01

We report on the use of compactly supported, orthonormal wavelet bases for quantum molecular-dynamics (Car-Parrinello) algorithms. A wavelet selection scheme is developed and tested for prototypical problems, such as the three-dimensional harmonic oscillator, the hydrogen atom, and the local density approximation to atomic and molecular systems. Our method shows systematic convergence with increased grid size, along with improvement on compression rates, thereby yielding an optimal grid for self-consistent electronic structure calculations. copyright 1997 The American Physical Society

Wavelet and Blend maps for texture synthesis

OpenAIRE

Du Jin-Lian; Wang Song; Meng Xianhai

2011-01-01

blending is now a popular technology for large realtime texture synthesis .Nevertheless, creating blend map during rendering is time and computation consuming work. In this paper, we exploited a method to create a kind of blend tile which can be tile together seamlessly. Note that blend map is in fact a kind of image, which is Markov Random Field, contains multiresolution signals, while wavelet is a powerful way to process multiresolution signals, we use wavelet to process the traditional ble...

Digital Correlation based on Wavelet Transform for Image Detection

International Nuclear Information System (INIS)

Barba, L; Vargas, L; Torres, C; Mattos, L

2011-01-01

In this work is presented a method for the optimization of digital correlators to improve the characteristic detection on images using wavelet transform as well as subband filtering. It is proposed an approach of wavelet-based image contrast enhancement in order to increase the performance of digital correlators. The multiresolution representation is employed to improve the high frequency content of images taken into account the input contrast measured for the original image. The energy of correlation peaks and discrimination level of several objects are improved with this technique. To demonstrate the potentiality in extracting characteristics using the wavelet transform, small objects inside reference images are detected successfully.

Obesity and central adiposity in Mexican adults: results from the Mexican National Health and Nutrition Survey 2006.

Science.gov (United States)

Barquera, Simón; Campos-Nonato, Ismael; Hernández-Barrera, Lucía; Flores, Mario; Durazo-Arvizu, Ramón; Kanter, Rebecca; Rivera, Juan A

2009-01-01

To estimate the prevalence of overweight, obesity and central adiposity in Mexico, and to explore trends compared to the previous Mexican National Health Survey (ENSA 2000) and to Mexican-Americans. The Mexican National Health and Nutrition Survey 2006 (ENSANUT 2006) was used to describe overweight, obesity and central adiposity. Trends over time were assessed using the ENSA 2000 and by comparing the ENSANUT 2006 results to those of Mexican-Americans using the United States National Health and Nutrition Examination Survey (NHANES) 1999-2000 and 2005-2006. A total of 33023 adults > 20 years old were included; 39.7% were found to be overweight and 29.9% were found to be obese; 75.9% of all adults had abdominal obesity. In Mexico between 2000 and 2006, the combined prevalence of overweight and obesity in adults increased approximately 12%. Mexican-Americans showed a higher prevalence of morbid obesity compared to native Mexicans. Mexico has experienced a rapid increase in the number of adults who have experienced excess weight gain between the years 2000 and 2006.

Wavelet-based ground vehicle recognition using acoustic signals

Science.gov (United States)

Choe, Howard C.; Karlsen, Robert E.; Gerhart, Grant R.; Meitzler, Thomas J.

1996-03-01

We present, in this paper, a wavelet-based acoustic signal analysis to remotely recognize military vehicles using their sound intercepted by acoustic sensors. Since expedited signal recognition is imperative in many military and industrial situations, we developed an algorithm that provides an automated, fast signal recognition once implemented in a real-time hardware system. This algorithm consists of wavelet preprocessing, feature extraction and compact signal representation, and a simple but effective statistical pattern matching. The current status of the algorithm does not require any training. The training is replaced by human selection of reference signals (e.g., squeak or engine exhaust sound) distinctive to each individual vehicle based on human perception. This allows a fast archiving of any new vehicle type in the database once the signal is collected. The wavelet preprocessing provides time-frequency multiresolution analysis using discrete wavelet transform (DWT). Within each resolution level, feature vectors are generated from statistical parameters and energy content of the wavelet coefficients. After applying our algorithm on the intercepted acoustic signals, the resultant feature vectors are compared with the reference vehicle feature vectors in the database using statistical pattern matching to determine the type of vehicle from where the signal originated. Certainly, statistical pattern matching can be replaced by an artificial neural network (ANN); however, the ANN would require training data sets and time to train the net. Unfortunately, this is not always possible for many real world situations, especially collecting data sets from unfriendly ground vehicles to train the ANN. Our methodology using wavelet preprocessing and statistical pattern matching provides robust acoustic signal recognition. We also present an example of vehicle recognition using acoustic signals collected from two different military ground vehicles. In this paper, we will

Applications of wavelet transforms for nuclear power plant signal analysis

International Nuclear Information System (INIS)

Seker, S.; Turkcan, E.; Upadhyaya, B.R.; Erbay, A.S.

1998-01-01

The safety of Nuclear Power Plants (NPPs) may be enhanced by the timely processing of information derived from multiple process signals from NPPs. The most widely used technique in signal analysis applications is the Fourier transform in the frequency domain to generate power spectral densities (PSD). However, the Fourier transform is global in nature and will obscure any non-stationary signal feature. Lately, a powerful technique called the Wavelet Transform, has been developed. This transform uses certain basis functions for representing the data in an effective manner, with capability for sub-band analysis and providing time-frequency localization as needed. This paper presents a brief overview of wavelets applied to the nuclear industry for signal processing and plant monitoring. The basic theory of Wavelets is also summarized. In order to illustrate the application of wavelet transforms data were acquired from the operating nuclear power plant Borssele in the Netherlands. The experimental data consist of various signals in the power plant and are selected from a stationary power operation. Their frequency characteristics and the mutual relations were investigated using MATLAB signal processing and wavelet toolbox for computing their PSDs and coherence functions by multi-resolution analysis. The results indicate that the sub-band PSD matches with the original signal PSD and enhances the estimation of coherence functions. The Wavelet analysis demonstrates the feasibility of application to stationary signals to provide better estimates in the frequency band of interest as compared to the classical FFT approach. (author)

Applications of wavelets in morphometric analysis of medical images

Science.gov (United States)

Davatzikos, Christos; Tao, Xiaodong; Shen, Dinggang

2003-11-01

Morphometric analysis of medical images is playing an increasingly important role in understanding brain structure and function, as well as in understanding the way in which these change during development, aging and pathology. This paper presents three wavelet-based methods with related applications in morphometric analysis of magnetic resonance (MR) brain images. The first method handles cases where very limited datasets are available for the training of statistical shape models in the deformable segmentation. The method is capable of capturing a larger range of shape variability than the standard active shape models (ASMs) can, by using the elegant spatial-frequency decomposition of the shape contours provided by wavelet transforms. The second method addresses the difficulty of finding correspondences in anatomical images, which is a key step in shape analysis and deformable registration. The detection of anatomical correspondences is completed by using wavelet-based attribute vectors as morphological signatures of voxels. The third method uses wavelets to characterize the morphological measurements obtained from all voxels in a brain image, and the entire set of wavelet coefficients is further used to build a brain classifier. Since the classification scheme operates in a very-high-dimensional space, it can determine subtle population differences with complex spatial patterns. Experimental results are provided to demonstrate the performance of the proposed methods.

Image encryption using the fractional wavelet transform

International Nuclear Information System (INIS)

Vilardy, Juan M; Useche, J; Torres, C O; Mattos, L

2011-01-01

In this paper a technique for the coding of digital images is developed using Fractional Wavelet Transform (FWT) and random phase masks (RPMs). The digital image to encrypt is transformed with the FWT, after the coefficients resulting from the FWT (Approximation, Details: Horizontal, vertical and diagonal) are multiplied each one by different RPMs (statistically independent) and these latest results is applied an Inverse Wavelet Transform (IWT), obtaining the encrypted digital image. The decryption technique is the same encryption technique in reverse sense. This technique provides immediate advantages security compared to conventional techniques, in this technique the mother wavelet family and fractional orders associated with the FWT are additional keys that make access difficult to information to an unauthorized person (besides the RPMs used), thereby the level of encryption security is extraordinarily increased. In this work the mathematical support for the use of the FWT in the computational algorithm for the encryption is also developed.

ECG denoising with adaptive bionic wavelet transform.

Science.gov (United States)

Sayadi, Omid; Shamsollahi, Mohammad Bagher

2006-01-01

In this paper a new ECG denoising scheme is proposed using a novel adaptive wavelet transform, named bionic wavelet transform (BWT), which had been first developed based on a model of the active auditory system. There has been some outstanding features with the BWT such as nonlinearity, high sensitivity and frequency selectivity, concentrated energy distribution and its ability to reconstruct signal via inverse transform but the most distinguishing characteristic of BWT is that its resolution in the time-frequency domain can be adaptively adjusted not only by the signal frequency but also by the signal instantaneous amplitude and its first-order differential. Besides by optimizing the BWT parameters parallel to modifying a new threshold value, one can handle ECG denoising with results comparing to those of wavelet transform (WT). Preliminary tests of BWT application to ECG denoising were constructed on the signals of MIT-BIH database which showed high performance of noise reduction.

Video steganography based on bit-plane decomposition of wavelet-transformed video

Science.gov (United States)

Noda, Hideki; Furuta, Tomofumi; Niimi, Michiharu; Kawaguchi, Eiji

2004-06-01

This paper presents a steganography method using lossy compressed video which provides a natural way to send a large amount of secret data. The proposed method is based on wavelet compression for video data and bit-plane complexity segmentation (BPCS) steganography. BPCS steganography makes use of bit-plane decomposition and the characteristics of the human vision system, where noise-like regions in bit-planes of a dummy image are replaced with secret data without deteriorating image quality. In wavelet-based video compression methods such as 3-D set partitioning in hierarchical trees (SPIHT) algorithm and Motion-JPEG2000, wavelet coefficients in discrete wavelet transformed video are quantized into a bit-plane structure and therefore BPCS steganography can be applied in the wavelet domain. 3-D SPIHT-BPCS steganography and Motion-JPEG2000-BPCS steganography are presented and tested, which are the integration of 3-D SPIHT video coding and BPCS steganography, and that of Motion-JPEG2000 and BPCS, respectively. Experimental results show that 3-D SPIHT-BPCS is superior to Motion-JPEG2000-BPCS with regard to embedding performance. In 3-D SPIHT-BPCS steganography, embedding rates of around 28% of the compressed video size are achieved for twelve bit representation of wavelet coefficients with no noticeable degradation in video quality.

Wavelet Types Comparison for Extracting Iris Feature Based on Energy Compaction

Science.gov (United States)

Rizal Isnanto, R.

2015-06-01

Human iris has a very unique pattern which is possible to be used as a biometric recognition. To identify texture in an image, texture analysis method can be used. One of method is wavelet that extract the image feature based on energy. Wavelet transforms used are Haar, Daubechies, Coiflets, Symlets, and Biorthogonal. In the research, iris recognition based on five mentioned wavelets was done and then comparison analysis was conducted for which some conclusions taken. Some steps have to be done in the research. First, the iris image is segmented from eye image then enhanced with histogram equalization. The features obtained is energy value. The next step is recognition using normalized Euclidean distance. Comparison analysis is done based on recognition rate percentage with two samples stored in database for reference images. After finding the recognition rate, some tests are conducted using Energy Compaction for all five types of wavelets above. As the result, the highest recognition rate is achieved using Haar, whereas for coefficients cutting for C(i) < 0.1, Haar wavelet has a highest percentage, therefore the retention rate or significan coefficient retained for Haaris lower than other wavelet types (db5, coif3, sym4, and bior2.4)

Sparse data structure design for wavelet-based methods

Directory of Open Access Journals (Sweden)

Latu Guillaume

2011-12-01

Full Text Available This course gives an introduction to the design of efficient datatypes for adaptive wavelet-based applications. It presents some code fragments and benchmark technics useful to learn about the design of sparse data structures and adaptive algorithms. Material and practical examples are given, and they provide good introduction for anyone involved in the development of adaptive applications. An answer will be given to the question: how to implement and efficiently use the discrete wavelet transform in computer applications? A focus will be made on time-evolution problems, and use of wavelet-based scheme for adaptively solving partial differential equations (PDE. One crucial issue is that the benefits of the adaptive method in term of algorithmic cost reduction can not be wasted by overheads associated to sparse data management.

Properties of wavelet discretization of Black-Scholes equation

Science.gov (United States)

Finěk, Václav

2017-07-01

Using wavelet methods, the continuous problem is transformed into a well-conditioned discrete problem. And once a non-symmetric problem is given, squaring yields a symmetric positive definite formulation. However squaring usually makes the condition number of discrete problems substantially worse. This note is concerned with a wavelet based numerical solution of the Black-Scholes equation for pricing European options. We show here that in wavelet coordinates a symmetric part of the discretized equation dominates over an unsymmetric part in the standard economic environment with low interest rates. It provides some justification for using a fractional step method with implicit treatment of the symmetric part of the weak form of the Black-Scholes operator and with explicit treatment of its unsymmetric part. Then a well-conditioned discrete problem is obtained.

Comparative study of wavelets of the first and second generation

International Nuclear Information System (INIS)

Ososkov, G.A.; Shitov, A.B.; Stadnik, A.V.

2001-01-01

In order to compare efficiency a comprehensive set of benchmarking tests is developed, which is used to compare abilities of continuous wavelet transform of the vanishing momenta type as well as the second generation wavelets constructed on the basis of the lifting scheme. It is based on processing of various types of pure and contaminated harmonic signals, delta-function, study of the signal phase dependence and the gain-frequency characteristics. The results of a comparative multiscale analysis allow one to reveal advantages and flaws of the considered types of wavelets

Multidimensional filter banks and wavelets research developments and applications

CERN Document Server

Levy, Bernard

1997-01-01

Multidimensional Filter Banks and Wavelets: Reserach Developments and Applications brings together in one place important contributions and up-to-date research results in this important area. Multidimensional Filter Banks and Wavelets: Research Developments and Applications serves as an excellent reference, providing insight into some of the most important research issues in the field.

Adaptive wavelet collocation methods for initial value boundary problems of nonlinear PDE's

Science.gov (United States)

Cai, Wei; Wang, Jian-Zhong

1993-01-01

We have designed a cubic spline wavelet decomposition for the Sobolev space H(sup 2)(sub 0)(I) where I is a bounded interval. Based on a special 'point-wise orthogonality' of the wavelet basis functions, a fast Discrete Wavelet Transform (DWT) is constructed. This DWT transform will map discrete samples of a function to its wavelet expansion coefficients in O(N log N) operations. Using this transform, we propose a collocation method for the initial value boundary problem of nonlinear PDE's. Then, we test the efficiency of the DWT transform and apply the collocation method to solve linear and nonlinear PDE's.

Wavelets in self-consistent electronic structure calculations

International Nuclear Information System (INIS)

Wei, S.; Chou, M.Y.

1996-01-01

We report the first implementation of orthonormal wavelet bases in self-consistent electronic structure calculations within the local-density approximation. These local bases of different scales efficiently describe localized orbitals of interest. As an example, we studied two molecules, H 2 and O 2 , using pseudopotentials and supercells. Considerably fewer bases are needed compared with conventional plane-wave approaches, yet calculated binding properties are similar. Our implementation employs fast wavelet and Fourier transforms, avoiding evaluating any three-dimensional integral numerically. copyright 1996 The American Physical Society

Multiresolution signal decomposition transforms, subbands, and wavelets

CERN Document Server

Akansu, Ali N; Haddad, Paul R

2001-01-01

The uniqueness of this book is that it covers such important aspects of modern signal processing as block transforms from subband filter banks and wavelet transforms from a common unifying standpoint, thus demonstrating the commonality among these decomposition techniques. In addition, it covers such ""hot"" areas as signal compression and coding, including particular decomposition techniques and tables listing coefficients of subband and wavelet filters and other important properties.The field of this book (Electrical Engineering/Computer Science) is currently booming, which is, of course

Numerical simulation for fractional order stationary neutron transport equation using Haar wavelet collocation method

Energy Technology Data Exchange (ETDEWEB)

Saha Ray, S., E-mail: santanusaharay@yahoo.com; Patra, A.

2014-10-15

Highlights: • A stationary transport equation has been solved using the technique of Haar wavelet collocation method. • This paper intends to provide the great utility of Haar wavelets to nuclear science problem. • In the present paper, two-dimensional Haar wavelets are applied. • The proposed method is mathematically very simple, easy and fast. - Abstract: In this paper the numerical solution for the fractional order stationary neutron transport equation is presented using Haar wavelet Collocation Method (HWCM). Haar wavelet collocation method is efficient and powerful in solving wide class of linear and nonlinear differential equations. This paper intends to provide an application of Haar wavelets to nuclear science problems. This paper describes the application of Haar wavelets for the numerical solution of fractional order stationary neutron transport equation in homogeneous medium with isotropic scattering. The proposed method is mathematically very simple, easy and fast. To demonstrate about the efficiency and applicability of the method, two test problems are discussed.

Value-at-risk estimation with wavelet-based extreme value theory: Evidence from emerging markets

Science.gov (United States)

Cifter, Atilla

2011-06-01

This paper introduces wavelet-based extreme value theory (EVT) for univariate value-at-risk estimation. Wavelets and EVT are combined for volatility forecasting to estimate a hybrid model. In the first stage, wavelets are used as a threshold in generalized Pareto distribution, and in the second stage, EVT is applied with a wavelet-based threshold. This new model is applied to two major emerging stock markets: the Istanbul Stock Exchange (ISE) and the Budapest Stock Exchange (BUX). The relative performance of wavelet-based EVT is benchmarked against the Riskmetrics-EWMA, ARMA-GARCH, generalized Pareto distribution, and conditional generalized Pareto distribution models. The empirical results show that the wavelet-based extreme value theory increases predictive performance of financial forecasting according to number of violations and tail-loss tests. The superior forecasting performance of the wavelet-based EVT model is also consistent with Basel II requirements, and this new model can be used by financial institutions as well.

Dependence and risk assessment for oil prices and exchange rate portfolios: A wavelet based approach

Science.gov (United States)

Aloui, Chaker; Jammazi, Rania

2015-10-01

In this article, we propose a wavelet-based approach to accommodate the stylized facts and complex structure of financial data, caused by frequent and abrupt changes of markets and noises. Specifically, we show how the combination of both continuous and discrete wavelet transforms with traditional financial models helps improve portfolio's market risk assessment. In the empirical stage, three wavelet-based models (wavelet-EGARCH with dynamic conditional correlations, wavelet-copula, and wavelet-extreme value) are considered and applied to crude oil price and US dollar exchange rate data. Our findings show that the wavelet-based approach provides an effective and powerful tool for detecting extreme moments and improving the accuracy of VaR and Expected Shortfall estimates of oil-exchange rate portfolios after noise is removed from the original data.

Analysis of the tennis racket vibrations during forehand drives: Selection of the mother wavelet.

Science.gov (United States)

Blache, Y; Hautier, C; Lefebvre, F; Djordjevic, A; Creveaux, T; Rogowski, I

2017-08-16

The time-frequency analysis of the tennis racket and hand vibrations is of great interest for discomfort and pathology prevention. This study aimed to (i) to assess the stationarity of the vibratory signal of the racket and hand and (ii) to identify the best mother wavelet to perform future time-frequency analysis, (iii) to determine if the stroke spin, racket characteristics and impact zone can influence the selection of the best mother wavelet. A total of 2364 topspin and flat forehand drives were performed by fourteen male competitive tennis players with six different rackets. One tri-axial and one mono-axial accelerometer were taped on the racket throat and dominant hand respectively. The signal stationarity was tested through the wavelet spectrum test. Eighty-nine mother wavelet were tested to select the best mother wavelet based on continuous and discrete transforms. On average only 25±17%, 2±5%, 5±7% and 27±27% of the signal tested respected the hypothesis of stationarity for the three axes of the racket and the hand respectively. Regarding the two methods for the detection of the best mother wavelet, the Daubechy 45 wavelet presented the highest average ranking. No effect of the stroke spin, racket characteristics and impact zone was observed for the selection of the best mother wavelet. It was concluded that alternative approach to Fast Fourier Transform should be used to interpret tennis vibration signals. In the case where wavelet transform is chosen, the Daubechy 45 mother wavelet appeared to be the most suitable. Copyright © 2017 Elsevier Ltd. All rights reserved.

Standard filter approximations for low power Continuous Wavelet Transforms.

Science.gov (United States)

Casson, Alexander J; Rodriguez-Villegas, Esther

2010-01-01

Analogue domain implementations of the Continuous Wavelet Transform (CWT) have proved popular in recent years as they can be implemented at very low power consumption levels. This is essential for use in wearable, long term physiological monitoring systems. Present analogue CWT implementations rely on taking mathematical a approximation of the wanted mother wavelet function to give a filter transfer function that is suitable for circuit implementation. This paper investigates the use of standard filter approximations (Butterworth, Chebyshev, Bessel) as an alternative wavelet approximation technique. This extends the number of approximation techniques available for generating analogue CWT filters. An example ECG analysis shows that signal information can be successfully extracted using these CWT approximations.

Wavelet Based Hilbert Transform with Digital Design and Application to QCM-SS Watermarking

Directory of Open Access Journals (Sweden)

S. P. Maity

2008-04-01

Full Text Available In recent time, wavelet transforms are used extensively for efficient storage, transmission and representation of multimedia signals. Hilbert transform pairs of wavelets is the basic unit of many wavelet theories such as complex filter banks, complex wavelet and phaselet etc. Moreover, Hilbert transform finds various applications in communications and signal processing such as generation of single sideband (SSB modulation, quadrature carrier multiplexing (QCM and bandpass representation of a signal. Thus wavelet based discrete Hilbert transform design draws much attention of researchers for couple of years. This paper proposes an (i algorithm for generation of low computation cost Hilbert transform pairs of symmetric filter coefficients using biorthogonal wavelets, (ii approximation to its rational coefficients form for its efficient hardware realization and without much loss in signal representation, and finally (iii development of QCM-SS (spread spectrum image watermarking scheme for doubling the payload capacity. Simulation results show novelty of the proposed Hilbert transform design and its application to watermarking compared to existing algorithms.

Complex Wavelet transform for MRI

International Nuclear Information System (INIS)

Junor, P.; Janney, P.

2004-01-01

Full text: There is a perpetual compromise encountered in magnetic resonance (MRl) image reconstruction, between the traditional elements of image quality (noise, spatial resolution and contrast). Additional factors exacerbating this trade-off include various artifacts, computational (and hence time-dependent) overhead, and financial expense. This paper outlines a new approach to the problem of minimizing MRI image acquisition and reconstruction time without compromising resolution and noise reduction. The standard approaches for reconstructing magnetic resonance (MRI) images from raw data (which rely on relatively conventional signal processing) have matured but there are a number of challenges which limit their use. A major one is the 'intrinsic' signal-to-noise ratio (SNR) of the reconstructed image that depends on the strength of the main field. A typical clinical MRI almost invariably uses a super-cooled magnet in order to achieve a high field strength. The ongoing running cost of these super-cooled magnets prompts consideration of alternative magnet systems for use in MRIs for developing countries and in some remote regional installations. The decrease in image quality from using lower field strength magnets can be addressed by improvements in signal processing strategies. Conversely, improved signal processing will obviously benefit the current conventional field strength MRI machines. Moreover, the 'waiting time' experienced in many MR sequences (due to the relaxation time delays) can be exploited by more rigorous processing of the MR signals. Acquisition often needs to be repeated so that coherent averaging may partially redress the shortfall in SNR, at the expense of further delay. Wavelet transforms have been used in MRI as an alternative for encoding and denoising for over a decade. These have not supplanted the traditional Fourier transform methods that have long been the mainstay of MRI reconstruction, but have some inflexibility. The dual

Wavelet analysis of epileptic spikes

Science.gov (United States)

Latka, Miroslaw; Was, Ziemowit; Kozik, Andrzej; West, Bruce J.

2003-05-01

Interictal spikes and sharp waves in human EEG are characteristic signatures of epilepsy. These potentials originate as a result of synchronous pathological discharge of many neurons. The reliable detection of such potentials has been the long standing problem in EEG analysis, especially after long-term monitoring became common in investigation of epileptic patients. The traditional definition of a spike is based on its amplitude, duration, sharpness, and emergence from its background. However, spike detection systems built solely around this definition are not reliable due to the presence of numerous transients and artifacts. We use wavelet transform to analyze the properties of EEG manifestations of epilepsy. We demonstrate that the behavior of wavelet transform of epileptic spikes across scales can constitute the foundation of a relatively simple yet effective detection algorithm.

Wavelet analysis of epileptic spikes

CERN Document Server

Latka, M; Kozik, A; West, B J; Latka, Miroslaw; Was, Ziemowit; Kozik, Andrzej; West, Bruce J.

2003-01-01

Interictal spikes and sharp waves in human EEG are characteristic signatures of epilepsy. These potentials originate as a result of synchronous, pathological discharge of many neurons. The reliable detection of such potentials has been the long standing problem in EEG analysis, especially after long-term monitoring became common in investigation of epileptic patients. The traditional definition of a spike is based on its amplitude, duration, sharpness, and emergence from its background. However, spike detection systems built solely around this definition are not reliable due to the presence of numerous transients and artifacts. We use wavelet transform to analyze the properties of EEG manifestations of epilepsy. We demonstrate that the behavior of wavelet transform of epileptic spikes across scales can constitute the foundation of a relatively simple yet effective detection algorithm.

A New Wavelet Threshold Function and Denoising Application

Directory of Open Access Journals (Sweden)

Lu Jing-yi

2016-01-01

Full Text Available In order to improve the effects of denoising, this paper introduces the basic principles of wavelet threshold denoising and traditional structures threshold functions. Meanwhile, it proposes wavelet threshold function and fixed threshold formula which are both improved here. First, this paper studies the problems existing in the traditional wavelet threshold functions and introduces the adjustment factors to construct the new threshold function basis on soft threshold function. Then, it studies the fixed threshold and introduces the logarithmic function of layer number of wavelet decomposition to design the new fixed threshold formula. Finally, this paper uses hard threshold, soft threshold, Garrote threshold, and improved threshold function to denoise different signals. And the paper also calculates signal-to-noise (SNR and mean square errors (MSE of the hard threshold functions, soft thresholding functions, Garrote threshold functions, and the improved threshold function after denoising. Theoretical analysis and experimental results showed that the proposed approach could improve soft threshold functions with constant deviation and hard threshold with discontinuous function problems. The proposed approach could improve the different decomposition scales that adopt the same threshold value to deal with the noise problems, also effectively filter the noise in the signals, and improve the SNR and reduce the MSE of output signals.

Wie viel Kapazität hat ein Mobilfunknetz?

Science.gov (United States)

Eisenblätter, Andreas; Geerdes, Hans-Florian

Wer hat das noch nicht erlebt? Der Akku ist aufgeladen und reichlich Guthaben vorhanden, doch das Telefonieren mit dem Handy klappt trotzdem nicht. Meist liegt das daran, dass man sich in einem Funkloch befindet. Aber manchmal ist auch das Netz überlastet. Anders gesagt: das Funknetz des Mobilfunkanbieters, das viele Antennen auf Hausdächern oder Masten umfasst, bietet entweder nicht genügend Abdeckung oder nicht genügend Kapazität. Genau das will der Anbieter natürlich vermeiden. Mathematik hilft, diese Herausforderungen mit einer guten Planung des Mobilfunknetzes zu bewältigen.

Wavelet Filter Banks for Super-Resolution SAR Imaging

Science.gov (United States)

Sheybani, Ehsan O.; Deshpande, Manohar; Memarsadeghi, Nargess

2011-01-01

This paper discusses Innovative wavelet-based filter banks designed to enhance the analysis of super resolution Synthetic Aperture Radar (SAR) images using parametric spectral methods and signal classification algorithms, SAR finds applications In many of NASA's earth science fields such as deformation, ecosystem structure, and dynamics of Ice, snow and cold land processes, and surface water and ocean topography. Traditionally, standard methods such as Fast-Fourier Transform (FFT) and Inverse Fast-Fourier Transform (IFFT) have been used to extract Images from SAR radar data, Due to non-parametric features of these methods and their resolution limitations and observation time dependence, use of spectral estimation and signal pre- and post-processing techniques based on wavelets to process SAR radar data has been proposed. Multi-resolution wavelet transforms and advanced spectral estimation techniques have proven to offer efficient solutions to this problem.

Wavelet methods in mathematical analysis and engineering

CERN Document Server

Damlamian, Alain

2010-01-01

This book gives a comprehensive overview of both the fundamentals of wavelet analysis and related tools, and of the most active recent developments towards applications. It offers a stateoftheart in several active areas of research where wavelet ideas, or more generally multiresolution ideas have proved particularly effective. The main applications covered are in the numerical analysis of PDEs, and signal and image processing. Recently introduced techniques such as Empirical Mode Decomposition (EMD) and new trends in the recovery of missing data, such as compressed sensing, are also presented.

Racial Identity and Racial Treatment of Mexican Americans.

Science.gov (United States)

Ortiz, Vilma; Telles, Edward

2012-04-01

How racial barriers play in the experiences of Mexican Americans has been hotly debated. Some consider Mexican Americans similar to European Americans of a century ago that arrived in the United States with modest backgrounds but were eventually able to participate fully in society. In contrast, others argue that Mexican Americans have been racialized throughout U.S. history and this limits their participation in society. The evidence of persistent educational disadvantages across generations and frequent reports of discrimination and stereotyping support the racialization argument. In this paper, we explore the ways in which race plays a role in the lives of Mexican Americans by examining how education, racial characteristics, social interactions, relate to racial outcomes. We use the Mexican American Study Project, a unique data set based on a 1965 survey of Mexican Americans in Los Angeles and San Antonio combined with surveys of the same respondents and their adult children in 2000, thereby creating a longitudinal and intergenerational data set. First, we found that darker Mexican Americans, therefore appearing more stereotypically Mexican, report more experiences of discrimination. Second, darker men report much more discrimination than lighter men and than women overall. Third, more educated Mexican Americans experience more stereotyping and discrimination than their less-educated counterparts, which is partly due to their greater contact with Whites. Lastly, having greater contact with Whites leads to experiencing more stereotyping and discrimination. Our results are indicative of the ways in which Mexican Americans are racialized in the United States.

Solution of neutron transport equation using Daubechies' wavelet expansion in the angular discretization

International Nuclear Information System (INIS)

Cao Liangzhi; Wu Hongchun; Zheng Youqi

2008-01-01

Daubechies' wavelet expansion is introduced to discretize the angular variables of the neutron transport equation when the neutron angular flux varies very acutely with the angular directions. An improvement is made by coupling one-dimensional wavelet expansion and discrete ordinate method to make two-dimensional angular discretization efficient and stable. The angular domain is divided into several subdomains for treating the vacuum boundary condition exactly in the unstructured geometry. A set of wavelet equations coupled with each other is obtained in each subdomain. An iterative method is utilized to decouple the wavelet moments. The numerical results of several benchmark problems demonstrate that the wavelet expansion method can provide more accurate results by lower-order expansion than other angular discretization methods

Wavelet-transform-based time–frequency domain reflectometry for reduction of blind spot

International Nuclear Information System (INIS)

Lee, Sin Ho; Park, Jin Bae; Choi, Yoon Ho

2012-01-01

In this paper, wavelet-transform-based time–frequency domain reflectometry (WTFDR) is proposed to reduce the blind spot in reflectometry. TFDR has a blind spot problem when the time delay between the reference signal and the reflected signal is short enough compared with the time duration of the reference signal. To solve the blind spot problem, the wavelet transform (WT) is used because the WT has linearity. Using the characteristics of the WT, the overlapped reference signal at the measured signal can be separated and the blind spot is reduced by obtaining the difference of the wavelet coefficients for the reference and reflected signals. In the proposed method, the complex wavelet is utilized as a mother wavelet because the reference signal in WTFDR has a complex form. Finally, the computer simulations and the real experiments are carried out to confirm the effectiveness and accuracy of the proposed method. (paper)

Identification Method of Mud Shale Fractures Base on Wavelet Transform

Science.gov (United States)

Xia, Weixu; Lai, Fuqiang; Luo, Han

2018-01-01

In recent years, inspired by seismic analysis technology, a new method for analysing mud shale fractures oil and gas reservoirs by logging properties has emerged. By extracting the high frequency attribute of the wavelet transform in the logging attribute, the formation information hidden in the logging signal is extracted, identified the fractures that are not recognized by conventional logging and in the identified fracture segment to show the “cycle jump”, “high value”, “spike” and other response effect is more obvious. Finally formed a complete wavelet denoising method and wavelet high frequency identification fracture method.

Fast, large-scale hologram calculation in wavelet domain

Science.gov (United States)

Shimobaba, Tomoyoshi; Matsushima, Kyoji; Takahashi, Takayuki; Nagahama, Yuki; Hasegawa, Satoki; Sano, Marie; Hirayama, Ryuji; Kakue, Takashi; Ito, Tomoyoshi

2018-04-01

We propose a large-scale hologram calculation using WAvelet ShrinkAge-Based superpositIon (WASABI), a wavelet transform-based algorithm. An image-type hologram calculated using the WASABI method is printed on a glass substrate with the resolution of 65 , 536 × 65 , 536 pixels and a pixel pitch of 1 μm. The hologram calculation time amounts to approximately 354 s on a commercial CPU, which is approximately 30 times faster than conventional methods.

Hydrological model performance and parameter estimation in the wavelet-domain

Directory of Open Access Journals (Sweden)

B. Schaefli

2009-10-01

Full Text Available This paper proposes a method for rainfall-runoff model calibration and performance analysis in the wavelet-domain by fitting the estimated wavelet-power spectrum (a representation of the time-varying frequency content of a time series of a simulated discharge series to the one of the corresponding observed time series. As discussed in this paper, calibrating hydrological models so as to reproduce the time-varying frequency content of the observed signal can lead to different results than parameter estimation in the time-domain. Therefore, wavelet-domain parameter estimation has the potential to give new insights into model performance and to reveal model structural deficiencies. We apply the proposed method to synthetic case studies and a real-world discharge modeling case study and discuss how model diagnosis can benefit from an analysis in the wavelet-domain. The results show that for the real-world case study of precipitation – runoff modeling for a high alpine catchment, the calibrated discharge simulation captures the dynamics of the observed time series better than the results obtained through calibration in the time-domain. In addition, the wavelet-domain performance assessment of this case study highlights the frequencies that are not well reproduced by the model, which gives specific indications about how to improve the model structure.

Exploring an optimal wavelet-based filter for cryo-ET imaging.

Science.gov (United States)

Huang, Xinrui; Li, Sha; Gao, Song

2018-02-07

Cryo-electron tomography (cryo-ET) is one of the most advanced technologies for the in situ visualization of molecular machines by producing three-dimensional (3D) biological structures. However, cryo-ET imaging has two serious disadvantages-low dose and low image contrast-which result in high-resolution information being obscured by noise and image quality being degraded, and this causes errors in biological interpretation. The purpose of this research is to explore an optimal wavelet denoising technique to reduce noise in cryo-ET images. We perform tests using simulation data and design a filter using the optimum selected wavelet parameters (three-level decomposition, level-1 zeroed out, subband-dependent threshold, a soft-thresholding and spline-based discrete dyadic wavelet transform (DDWT)), which we call a modified wavelet shrinkage filter; this filter is suitable for noisy cryo-ET data. When testing using real cryo-ET experiment data, higher quality images and more accurate measures of a biological structure can be obtained with the modified wavelet shrinkage filter processing compared with conventional processing. Because the proposed method provides an inherent advantage when dealing with cryo-ET images, it can therefore extend the current state-of-the-art technology in assisting all aspects of cryo-ET studies: visualization, reconstruction, structural analysis, and interpretation.

Steerable dyadic wavelet transform and interval wavelets for enhancement of digital mammography

Science.gov (United States)

Laine, Andrew F.; Koren, Iztok; Yang, Wuhai; Taylor, Fred J.

1995-04-01

This paper describes two approaches for accomplishing interactive feature analysis by overcomplete multiresolution representations. We show quantitatively that transform coefficients, modified by an adaptive non-linear operator, can make more obvious unseen or barely seen features of mammography without requiring additional radiation. Our results are compared with traditional image enhancement techniques by measuring the local contrast of known mammographic features. We design a filter bank representing a steerable dyadic wavelet transform that can be used for multiresolution analysis along arbitrary orientations. Digital mammograms are enhanced by orientation analysis performed by a steerable dyadic wavelet transform. Arbitrary regions of interest (ROI) are enhanced by Deslauriers-Dubuc interpolation representations on an interval. We demonstrate that our methods can provide radiologists with an interactive capability to support localized processing of selected (suspicion) areas (lesions). Features extracted from multiscale representations can provide an adaptive mechanism for accomplishing local contrast enhancement. By improving the visualization of breast pathology can improve changes of early detection while requiring less time to evaluate mammograms for most patients.

Comparative study on γ energy spectrum denoise by fourier and wavelet transforms

International Nuclear Information System (INIS)

Shi Dongsheng; Di Yuming; Zhou Chunlin

2007-01-01

This paper introduces the basic principle of wavelet and Fourier transforms, applies wavelet transform method to denoise γ energy spectrum of 60 Co and compares it with Fourier transform method. The result of simulation with MATLAB software tool showed that as compared with traditional Fourier transform, wavelet transform has comparatively higher accuracy for γ energy spectrum denoising and is more feasible to γ energy spectrum denoising. (authors)

A STUDY OF WAVELET ENTROPY MEASURE DEFINITION AND ITS APPLICATION FOR FAULT FEATURE PICK-UP AND CLASSIFICATION

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

Shannon entropy in time domain is a measure of signal or system uncertainty. When based on spectrum entropy, Shannon entropy can be taken as a measure of signal or system complexity.Therefore, wavelet analysis based on wavelet entropy measure can signify the complexity of non-steady signal or system in both time and frequency domain. In this paper, in order to meet the requirements of post-analysis on abundant wavelet transform result data and the need of information mergence, the basic definition of wavelet entropy measure is proposed, corresponding algorithms of several wavelet entropies, such as wavelet average entropy, wavelet time-frequency entropy, wavelet distance entropy,etc. are put forward, and the physical meanings of these entropies are analyzed as well. The application principle of wavelet entropy measure in ElectroEncephaloGraphy (EEG) signal analysis, mechanical fault diagnosis, fault detection and classification in power system are analyzed. Finally, take the transmission line fault detection in power system for example, simulations in two different systems, a 10kV automatic blocking and continuous power transmission line and a 500kV Extra High Voltage (EHV) transmission line, are carried out, and the two methods, wavelet entropy and wavelet modulus maxima, are compared, the results show feasibility and application prospect of the six wavelet entropies.

A Comparative Analysis for Selection of Appropriate Mother Wavelet for Detection of Stationary Disturbances

Science.gov (United States)

Kamble, Saurabh Prakash; Thawkar, Shashank; Gaikwad, Vinayak G.; Kothari, D. P.

2017-12-01

Detection of disturbances is the first step of mitigation. Power electronics plays a crucial role in modern power system which makes system operation efficient but it also bring stationary disturbances in the power system and added impurities to the supply. It happens because of the non-linear loads used in modern day power system which inject disturbances like harmonic disturbances, flickers, sag etc. in power grid. These impurities can damage equipments so it is necessary to mitigate these impurities present in the supply very quickly. So, digital signal processing techniques are incorporated for detection purpose. Signal processing techniques like fast Fourier transform, short-time Fourier transform, Wavelet transform etc. are widely used for the detection of disturbances. Among all, wavelet transform is widely used because of its better detection capabilities. But, which mother wavelet has to use for detection is still a mystery. Depending upon the periodicity, the disturbances are classified as stationary and non-stationary disturbances. This paper presents the importance of selection of mother wavelet for analyzing stationary disturbances using discrete wavelet transform. Signals with stationary disturbances of various frequencies are generated using MATLAB. The analysis of these signals is done using various mother wavelets like Daubechies and bi-orthogonal wavelets and the measured root mean square value of stationary disturbance is obtained. The measured value obtained by discrete wavelet transform is compared with the exact RMS value of the frequency component and the percentage differences are presented which helps to select optimum mother wavelet.

Comparisons between two wavelet functions in extracting coherent structures from solar wind time series

International Nuclear Information System (INIS)

Bolzani, M.J.A.; Guarnieri, F.L.; Vieira, Paulo Cesar

2009-01-01

Nowadays, wavelet analysis of turbulent flows have become increasingly popular. However, the study of geometric characteristics from wavelet functions is still poorly explored. In this work we compare the performance of two wavelet functions in extracting the coherent structures from solar wind velocity time series. The data series are from years 1996 to 2002 (except 1998 and 1999). The wavelet algorithm decomposes the annual time-series in two components: the coherent part and non-coherent one, using the daubechies-4 and haar wavelet function. The threshold assumed is based on a percentage of maximum variance found in each dyadic scale. After the extracting procedure, we applied the power spectral density on the original time series and coherent time series to obtain spectral indices. The results from spectral indices show higher values for the coherent part obtained by daubechies-4 than those obtained by the haar wavelet function. Using the kurtosis statistical parameter, on coherent and non-coherent time series, it was possible to conjecture that the differences found between two wavelet functions may be associated with their geometric forms. (author)

Method and system for progressive mesh storage and reconstruction using wavelet-encoded height fields

Science.gov (United States)

Baxes, Gregory A. (Inventor); Linger, Timothy C. (Inventor)

2011-01-01

Systems and methods are provided for progressive mesh storage and reconstruction using wavelet-encoded height fields. A method for progressive mesh storage includes reading raster height field data, and processing the raster height field data with a discrete wavelet transform to generate wavelet-encoded height fields. In another embodiment, a method for progressive mesh storage includes reading texture map data, and processing the texture map data with a discrete wavelet transform to generate wavelet-encoded texture map fields. A method for reconstructing a progressive mesh from wavelet-encoded height field data includes determining terrain blocks, and a level of detail required for each terrain block, based upon a viewpoint. Triangle strip constructs are generated from vertices of the terrain blocks, and an image is rendered utilizing the triangle strip constructs. Software products that implement these methods are provided.

Assessment of Haar Wavelet-Quasilinearization Technique in Heat Convection-Radiation Equations

Directory of Open Access Journals (Sweden)

Umer Saeed

2014-01-01

Full Text Available We showed that solutions by the Haar wavelet-quasilinearization technique for the two problems, namely, (i temperature distribution equation in lumped system of combined convection-radiation in a slab made of materials with variable thermal conductivity and (ii cooling of a lumped system by combined convection and radiation are strongly reliable and also more accurate than the other numerical methods and are in good agreement with exact solution. According to the Haar wavelet-quasilinearization technique, we convert the nonlinear heat transfer equation to linear discretized equation with the help of quasilinearization technique and apply the Haar wavelet method at each iteration of quasilinearization technique to get the solution. The main aim of present work is to show the reliability of the Haar wavelet-quasilinearization technique for heat transfer equations.

Wavelet Packet Transform Based Driver Distraction Level Classification Using EEG

Directory of Open Access Journals (Sweden)

Mousa Kadhim Wali

2013-01-01

Full Text Available We classify the driver distraction level (neutral, low, medium, and high based on different wavelets and classifiers using wireless electroencephalogram (EEG signals. 50 subjects were used for data collection using 14 electrodes. We considered for this research 4 distraction stimuli such as Global Position Systems (GPS, music player, short message service (SMS, and mental tasks. Deriving the amplitude spectrum of three different frequency bands theta, alpha, and beta of EEG signals was based on fusion of discrete wavelet packet transform (DWPT and FFT. Comparing the results of three different classifiers (subtractive fuzzy clustering probabilistic neural network, -nearest neighbor was based on spectral centroid, and power spectral features extracted by different wavelets (db4, db8, sym8, and coif5. The results of this study indicate that the best average accuracy achieved by subtractive fuzzy inference system classifier is 79.21% based on power spectral density feature extracted by sym8 wavelet which gave a good class discrimination under ANOVA test.

Image Denoising Using Singular Value Difference in the Wavelet Domain

Directory of Open Access Journals (Sweden)

Min Wang

2018-01-01

Full Text Available Singular value (SV difference is the difference in the singular values between a noisy image and the original image; it varies regularly with noise intensity. This paper proposes an image denoising method using the singular value difference in the wavelet domain. First, the SV difference model is generated for different noise variances in the three directions of the wavelet transform and the noise variance of a new image is used to make the calculation by the diagonal part. Next, the single-level discrete 2-D wavelet transform is used to decompose each noisy image into its low-frequency and high-frequency parts. Then, singular value decomposition (SVD is used to obtain the SVs of the three high-frequency parts. Finally, the three denoised high-frequency parts are reconstructed by SVD from the SV difference, and the final denoised image is obtained using the inverse wavelet transform. Experiments show the effectiveness of this method compared with relevant existing methods.

Green Medicine: Traditional Mexican-American Herbal Remedies.

Science.gov (United States)

Torres, Eliseo

Traditional Mexican American herbal potions and remedies and their history are explained in an introductory book for the general reader. The importance of curanderismo, or green medicine, in Mexican and Mexican American cultures is explored. A brief history traces the herbal aspects of curanderismo through Mayan and Aztec cultures, the Spanish…

Experimental study on the crack detection with optimized spatial wavelet analysis and windowing

Science.gov (United States)

Ghanbari Mardasi, Amir; Wu, Nan; Wu, Christine

2018-05-01

In this paper, a high sensitive crack detection is experimentally realized and presented on a beam under certain deflection by optimizing spatial wavelet analysis. Due to the crack existence in the beam structure, a perturbation/slop singularity is induced in the deflection profile. Spatial wavelet transformation works as a magnifier to amplify the small perturbation signal at the crack location to detect and localize the damage. The profile of a deflected aluminum cantilever beam is obtained for both intact and cracked beams by a high resolution laser profile sensor. Gabor wavelet transformation is applied on the subtraction of intact and cracked data sets. To improve detection sensitivity, scale factor in spatial wavelet transformation and the transformation repeat times are optimized. Furthermore, to detect the possible crack close to the measurement boundaries, wavelet transformation edge effect, which induces large values of wavelet coefficient around the measurement boundaries, is efficiently reduced by introducing different windowing functions. The result shows that a small crack with depth of less than 10% of the beam height can be localized with a clear perturbation. Moreover, the perturbation caused by a crack at 0.85 mm away from one end of the measurement range, which is covered by wavelet transform edge effect, emerges by applying proper window functions.

Wavelet analysis deformation monitoring data of high-speed railway bridge

Science.gov (United States)

Tang, ShiHua; Huang, Qing; Zhou, Conglin; Xu, HongWei; Liu, YinTao; Li, FeiDa

2015-12-01

Deformation monitoring data of high-speed railway bridges will inevitably be affected because of noise pollution, A deformation monitoring point of high-speed railway bridge was measurd by using sokkia SDL30 electronic level for a long time,which got a large number of deformation monitoring data. Based on the characteristics of the deformation monitoring data of high-speed railway bridge, which contain lots of noise. Based on the MATLAB software platform, 120 groups of deformation monitoring data were applied to analysis of wavelet denoising.sym6,db6 wavelet basis function were selected to analyze and remove the noise.The original signal was broken into three layers wavelet,which contain high frequency coefficients and low frequency coefficients.However, high frequency coefficient have plenty of noise.Adaptive method of soft and hard threshold were used to handle in the high frequency coefficient.Then,high frequency coefficient that was removed much of noise combined with low frequency coefficient to reconstitute and obtain reconstruction wavelet signal.Root Mean Square Error (RMSE) and Signal-To-Noise Ratio (SNR) were regarded as evaluation index of denoising,The smaller the root mean square error and the greater signal-to-noise ratio indicate that them have a good effect in denoising. We can surely draw some conclusions in the experimental analysis:the db6 wavelet basis function has a good effect in wavelet denoising by using a adaptive soft threshold method,which root mean square error is minimum and signal-to-noise ratio is maximum.Moreover,the reconstructed image are more smooth than original signal denoising after wavelet denoising, which removed noise and useful signal are obtained in the original signal.Compared to the other three methods, this method has a good effect in denoising, which not only retain useful signal in the original signal, but aiso reach the goal of removing noise. So, it has a strong practical value in a actual deformation monitoring

Wavelet analysis of MR functional data from the cerebellum

Energy Technology Data Exchange (ETDEWEB)

Karen, Romero Sánchez, E-mail: alphacentauri-hp@hotmail.com, E-mail: marcos-vaquezr@hotmail.com, E-mail: isabeldgg@hotmail.com; Vásquez Reyes Marcos, A., E-mail: alphacentauri-hp@hotmail.com, E-mail: marcos-vaquezr@hotmail.com, E-mail: isabeldgg@hotmail.com; González Gómez Dulce, I., E-mail: alphacentauri-hp@hotmail.com, E-mail: marcos-vaquezr@hotmail.com, E-mail: isabeldgg@hotmail.com; Hernández López, Javier M., E-mail: javierh@fcfm.buap.mx [Faculty of Physics and Mathematics, BUAP, Puebla, Pue (Mexico); Silvia, Hidalgo Tobón, E-mail: shidbon@gmail.com [Infant Hospital of Mexico, Federico Gómez, Mexico DF. Mexico and Physics Department, Universidad Autónoma Metropolitana. Iztapalapa, Mexico DF. (Mexico); Pilar, Dies Suarez, E-mail: pilydies@yahoo.com, E-mail: neurodoc@prodigy.net.mx; Eduardo, Barragán Pérez, E-mail: pilydies@yahoo.com, E-mail: neurodoc@prodigy.net.mx [Infant Hospital of Mexico, Federico Gómez, Mexico DF. (Mexico); Benito, De Celis Alonso, E-mail: benileon@yahoo.com [Faculty of Physics and Mathematics, BUAP, Puebla, Pue. Mexico and Foundation for Development Carlos Sigüenza. Puebla, Pue. (Mexico)

2014-11-07

The main goal of this project was to create a computer algorithm based on wavelet analysis of BOLD signals, which automatically diagnosed ADHD using information from resting state MR experiments. Male right handed volunteers (infants with ages between 7 and 11 years old) were studied and compared with age matched controls. Wavelet analysis, which is a mathematical tool used to decompose time series into elementary constituents and detect hidden information, was applied here to the BOLD signal obtained from the cerebellum 8 region of all our volunteers. Statistical differences between the values of the a parameters of wavelet analysis was found and showed significant differences (p<0.02) between groups. This difference might help in the future to distinguish healthy from ADHD patients and therefore diagnose ADHD.

Wavelet analysis of MR functional data from the cerebellum

International Nuclear Information System (INIS)

Karen, Romero Sánchez; Vásquez Reyes Marcos, A.; González Gómez Dulce, I.; Hernández López, Javier M.; Silvia, Hidalgo Tobón; Pilar, Dies Suarez; Eduardo, Barragán Pérez; Benito, De Celis Alonso

2014-01-01

The main goal of this project was to create a computer algorithm based on wavelet analysis of BOLD signals, which automatically diagnosed ADHD using information from resting state MR experiments. Male right handed volunteers (infants with ages between 7 and 11 years old) were studied and compared with age matched controls. Wavelet analysis, which is a mathematical tool used to decompose time series into elementary constituents and detect hidden information, was applied here to the BOLD signal obtained from the cerebellum 8 region of all our volunteers. Statistical differences between the values of the a parameters of wavelet analysis was found and showed significant differences (p<0.02) between groups. This difference might help in the future to distinguish healthy from ADHD patients and therefore diagnose ADHD

REFINED SYSTEM PARAMETERS AND TTV STUDY OF TRANSITING EXOPLANETARY SYSTEM HAT-P-20

Energy Technology Data Exchange (ETDEWEB)

Sun, Leilei; Gu, Shenghong; Wang, Xiaobin; Cao, Dongtao; Wang, Yibo; Xiang, Yue [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Cameron, Andrew Collier [School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS (United Kingdom); Hui, Ho-Keung; Kwok, Chi-Tai [Ho Koon Nature Education cum Astronomical Centre, Sik Sik Yuen, Hong Kong (China); Yeung, Bill; Ng, Eric [Hong Kong Astronomical Society, Hong Kong (China); Horta, Ferran Grau, E-mail: wangxb@ynao.ac.cn [Observatori Ca l’Ou, C/de Dalt 18, Sant Martí Sesgueioles (Spain)

2017-01-01

We report new photometric observations of the transiting exoplanetary system HAT-P-20, obtained using CCD cameras at Yunnan Observatories and Ho Koon Nature Education cum Astronomical Centre, China, from 2010 to 2013, and Observatori Ca l’Ou, Sant Marti Sesgueioles, Spain, from 2013 to 2015. The observed data are corrected for systematic errors according to the coarse de-correlation and SYSREM algorithms, so as to enhance the signal of the transit events. In order to consistently model the star spots and transits of this exoplanetary system, we develop a highly efficient tool STMT based on the analytic models of Mandel and Agol and Montalto et al. The physical parameters of HAT-P-20 are refined by homogeneously analyzing our new data, the radial velocity data, and the earlier photometric data in the literature with the Markov chain Monte Carlo technique. New radii and masses of both host star and planet are larger than those in the discovery paper due to the discrepancy of the radius among K-dwarfs between predicted values by standard stellar models and empirical calibration from observations. Through the analysis of all available mid-transit times calculated with the normal model and spotted model, we conclude that the periodic transit timing variations in these transit events revealed by employing the normal model are probably induced by spot crossing events. From the analysis of the distribution of occulted spots by HAT-P-20b, we constrain the misaligned architecture between the planetary orbit and the spin of the host star.

SeismicWaveTool: Continuous and discrete wavelet analysis and filtering for multichannel seismic data

Science.gov (United States)

Galiana-Merino, J. J.; Rosa-Herranz, J. L.; Rosa-Cintas, S.; Martinez-Espla, J. J.

2013-01-01

A MATLAB-based computer code has been developed for the simultaneous wavelet analysis and filtering of multichannel seismic data. The considered time-frequency transforms include the continuous wavelet transform, the discrete wavelet transform and the discrete wavelet packet transform. The developed approaches provide a fast and precise time-frequency examination of the seismograms at different frequency bands. Moreover, filtering methods for noise, transients or even baseline removal, are implemented. The primary motivation is to support seismologists with a user-friendly and fast program for the wavelet analysis, providing practical and understandable results. Program summaryProgram title: SeismicWaveTool Catalogue identifier: AENG_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AENG_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC license, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 611072 No. of bytes in distributed program, including test data, etc.: 14688355 Distribution format: tar.gz Programming language: MATLAB (MathWorks Inc.) version 7.8.0.347 (R2009a) or higher. Wavelet Toolbox is required. Computer: Developed on a MacBook Pro. Tested on Mac and PC. No computer-specific optimization was performed. Operating system: Any supporting MATLAB (MathWorks Inc.) v7.8.0.347 (R2009a) or higher. Tested on Mac OS X 10.6.8, Windows XP and Vista. Classification: 13. Nature of problem: Numerous research works have developed a great number of free or commercial wavelet based software, which provide specific solutions for the analysis of seismic data. On the other hand, standard toolboxes, packages or libraries, such as the MathWorks' Wavelet Toolbox for MATLAB, offer command line functions and interfaces for the wavelet analysis of one-component signals. Thus, software usually is focused on very specific problems

Wavelets and Sentiment in the Heterogeneous Agents Model

Czech Academy of Sciences Publication Activity Database

Vácha, Lukáš; Vošvrda, Miloslav

2008-01-01

Roč. 15, č. 25 (2008), s. 41-56 ISSN 1212-074X R&D Projects: GA ČR GP402/08/P207; GA ČR GA402/07/1113; GA ČR(CZ) GA402/06/0990 Institutional research plan: CEZ:AV0Z10750506 Keywords : heterogeneous agents model * market sentiment * Hurst exponent * wavelets Subject RIV: AH - Economics http://library.utia.cas.cz/separaty/2008/E/vacha-wavelets and sentiment in the heterogeneous agents model.pdf

Controlled wavelet domain sparsity for x-ray tomography

Science.gov (United States)

Purisha, Zenith; Rimpeläinen, Juho; Bubba, Tatiana; Siltanen, Samuli

2018-01-01

Tomographic reconstruction is an ill-posed inverse problem that calls for regularization. One possibility is to require sparsity of the unknown in an orthonormal wavelet basis. This, in turn, can be achieved by variational regularization, where the penalty term is the sum of the absolute values of the wavelet coefficients. The primal-dual fixed point algorithm showed that the minimizer of the variational regularization functional can be computed iteratively using a soft-thresholding operation. Choosing the soft-thresholding parameter \

Diagnostics of detector tube impacting with wavelet techniques

Energy Technology Data Exchange (ETDEWEB)

Racz, A. [KFKI-AEKI Applied Reactor Physics, Budapest (Hungary); Pazsit, I. [Chalmers Univ. of Tech., Goeteborg (Sweden). Dept. of Reactor Physics

1997-12-08

A neutron noise based method is proposed for the detection of impacting of detector tubes in BWRs. The basic idea relies on the assumption that non-stationary transients (e.g. fuel box vibrations) may be induced at impacting. Such short-lived transients are difficult to detect by spectral analysis methods. However, their presence in the detector signal can be detected by wavelet analysis. A simple wavelet technique, the so-called Haar transform, is suggested for the detection of impacting. Tests of the proposed method have been performed with success on both simulated data with controlled impacting as well as with real measurement data. The simulation model as well as the results of the wavelet analysis are reported in this paper. The source code written in MATLAB are available at a public ftp site. The necessary information to reproduce the simulation results is also reported. (author).

Diagnostics of detector tube impacting with wavelet techniques

Energy Technology Data Exchange (ETDEWEB)

Racz, A.; Pazsit, I

1998-04-01

A neutron noise based method is proposed for the detection of impacting of detector tubes in BWRs. The basic idea relies on the assumption that non-stationary transients (e.g. fuel box vibrations) may be induced at impacting. Such short-lived transients are difficult to detect by spectral analysis methods. However, their presence in the detector signal can be detected by wavelet analysis. A simple wavelet technique, the so-called Haar transform, is suggested for the detection of impacting. Tests of the proposed method have been performed with success on both simulated data with controlled impacting as well as with real measurement data. The simulation model as well as the results of the wavelet analysis are reported in this paper. The source codes written in MATLAB[reg] are available at a public ftp site. The necessary information to reproduce the simulation results is also reported.

Wavelet regression model in forecasting crude oil price

Science.gov (United States)

Hamid, Mohd Helmie; Shabri, Ani

2017-05-01

This study presents the performance of wavelet multiple linear regression (WMLR) technique in daily crude oil forecasting. WMLR model was developed by integrating the discrete wavelet transform (DWT) and multiple linear regression (MLR) model. The original time series was decomposed to sub-time series with different scales by wavelet theory. Correlation analysis was conducted to assist in the selection of optimal decomposed components as inputs for the WMLR model. The daily WTI crude oil price series has been used in this study to test the prediction capability of the proposed model. The forecasting performance of WMLR model were also compared with regular multiple linear regression (MLR), Autoregressive Moving Average (ARIMA) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH) using root mean square errors (RMSE) and mean absolute errors (MAE). Based on the experimental results, it appears that the WMLR model performs better than the other forecasting technique tested in this study.

The cross wavelet and wavelet coherence analysis of spatio-temporal rainfall-groundwater system in Pingtung plain, Taiwan

Science.gov (United States)

Lin, Yuan-Chien; Yu, Hwa-Lung

2013-04-01

The increasing frequency and intensity of extreme rainfall events has been observed recently in Taiwan. Particularly, Typhoon Morakot, Typhoon Fanapi, and Typhoon Megi consecutively brought record-breaking intensity and magnitude of rainfalls to different locations of Taiwan in these two years. However, records show the extreme rainfall events did not elevate the amount of annual rainfall accordingly. Conversely, the increasing frequency of droughts has also been occurring in Taiwan. The challenges have been confronted by governmental agencies and scientific communities to come up with effective adaptation strategies for natural disaster reduction and sustainable environment establishment. Groundwater has long been a reliable water source for a variety of domestic, agricultural, and industrial uses because of its stable quantity and quality. In Taiwan, groundwater accounts for the largest proportion of all water resources for about 40%. This study plans to identify and quantify the nonlinear relationship between precipitation and groundwater recharge, find the non-stationary time-frequency relations between the variations of rainfall and groundwater levels to understand the phase difference of time series. Groundwater level data and over-50-years hourly rainfall records obtained from 20 weather stations in Pingtung Plain, Taiwan has been collected. Extract the space-time pattern by EOF method, which is a decomposition of a signal or data set in terms of orthogonal basis functions determined from the data for both time series and spatial patterns, to identify the important spatial pattern of groundwater recharge and using cross wavelet and wavelet coherence method to identify the relationship between rainfall and groundwater levels. Results show that EOF method can specify the spatial-temporal patterns which represents certain geological characteristics and other mechanisms of groundwater, and the wavelet coherence method can identify general correlation between

Generalized exact holographic mapping with wavelets

Science.gov (United States)

Lee, Ching Hua

2017-12-01

The idea of renormalization and scale invariance is pervasive across disciplines. It has not only drawn numerous surprising connections between physical systems under the guise of holographic duality, but has also inspired the development of wavelet theory now widely used in signal processing. Synergizing on these two developments, we describe in this paper a generalized exact holographic mapping that maps a generic N -dimensional lattice system to a (N +1 )-dimensional holographic dual, with the emergent dimension representing scale. In previous works, this was achieved via the iterations of the simplest of all unitary mappings, the Haar mapping, which fails to preserve the form of most Hamiltonians. By taking advantage of the full generality of biorthogonal wavelets, our new generalized holographic mapping framework is able to preserve the form of a large class of lattice Hamiltonians. By explicitly separating features that are fundamentally associated with the physical system from those that are basis specific, we also obtain a clearer understanding of how the resultant bulk geometry arises. For instance, the number of nonvanishing moments of the high-pass wavelet filter is revealed to be proportional to the radius of the dual anti-de Sitter space geometry. We conclude by proposing modifications to the mapping for systems with generic Fermi pockets.

HATS-36b and 24 Other Transiting/Eclipsing Systems from the HATSouth-K2 Campaign 7 Program

Science.gov (United States)

Bayliss, D.; Hartman, J. D.; Zhou, G.; Bakos, G. Á.; Vanderburg, A.; Bento, J.; Mancini, L.; Ciceri, S.; Brahm, R.; Jordán, A.; Espinoza, N.; Rabus, M.; Tan, T. G.; Penev, K.; Bhatti, W.; de Val-Borro, M.; Suc, V.; Csubry, Z.; Henning, Th.; Sarkis, P.; Lázár, J.; Papp, I.; Sári, P.

2018-03-01

We report on the result of a campaign to monitor 25 HATSouth candidates using the Kepler space telescope during Campaign 7 of the K2 mission. We discover HATS-36b (EPIC 215969174b, K2-145b), an eccentric (e=0.105+/- 0.028) hot Jupiter with a mass of 3.216+/- 0.062 {M}{{J}} and a radius of 1.235+/- 0.043 {R}{{J}}, which transits a solar-type G0V star (V = 14.386) in a 4.1752-day period. We also refine the properties of three previously discovered HATSouth transiting planets (HATS-9b, HATS-11b, and HATS-12b) and search the K2 data for TTVs and additional transiting planets in these systems. In addition, we also report on a further three systems that remain as Jupiter-radius transiting exoplanet candidates. These candidates do not have determined masses, however pass all of our other vetting observations. Finally, we report on the 18 candidates that we are now able to classify as eclipsing binary or blended eclipsing binary systems based on a combination of the HATSouth data, the K2 data, and follow-up ground-based photometry and spectroscopy. These range in periods from 0.7 day to 16.7 days, and down to 1.5 mmag in eclipse depths. Our results show the power of combining ground-based imaging and spectroscopy with higher precision space-based photometry, and serve as an illustration as to what will be possible when combining ground-based observations with TESS data.

Analysis of Ultrasonic Transmitted Signal for Apple using Wavelet Transform

International Nuclear Information System (INIS)

Kim, Ki Bok; Lee, Sang Dae; Choi, Man Yong; Kim, Man Soo

2005-01-01

This study was conducted to analyze the ultrasonic transmitted signal for apple using wavelet transform. Fruit consists of nonlinear visco-elastic properties such as flesh, an ovary and rind and lienee most ultrasonic wave is attenuated and its frequency is shifted during passing the fruit. Thus it is not easy to evaluate the internal quality of the fruit using typical ultrasonic parameters such as wave velocity, attenuation, and frequency spectrum. The discrete wavelet transform was applied to the ultrasonic transmitted signal for apple. The magnitude of the first peak frequency of the wavelet basis from the ultrasonic transmitted signal showed a close correlation to the storage time of apple

Haar wavelets, fluctuations and structure functions: convenient choices for geophysics

Directory of Open Access Journals (Sweden)

S. Lovejoy

2012-09-01

Full Text Available Geophysical processes are typically variable over huge ranges of space-time scales. This has lead to the development of many techniques for decomposing series and fields into fluctuations Δv at well-defined scales. Classically, one defines fluctuations as differences: (Δv_diff = v(x+Δx-v(x and this is adequate for many applications (Δx is the "lag". However, if over a range one has scaling Δv ∝ Δx^H, these difference fluctuations are only adequate when 0 < H < 1. Hence, there is the need for other types of fluctuations. In particular, atmospheric processes in the "macroweather" range ≈10 days to 10–30 yr generally have −1 < H < 0, so that a definition valid over the range −1 < H < 1 would be very useful for atmospheric applications. A general framework for defining fluctuations is wavelets. However, the generality of wavelets often leads to fairly arbitrary choices of "mother wavelet" and the resulting wavelet coefficients may be difficult to interpret. In this paper we argue that a good choice is provided by the (historically first wavelet, the Haar wavelet (Haar, 1910, which is easy to interpret and – if needed – to generalize, yet has rarely been used in geophysics. It is also easy to implement numerically: the Haar fluctuation (Δv_Haar at lag Δx is simply equal to the difference of the mean from x to x+ Δx/2 and from x+Δx/2 to x+Δx. Indeed, we shall see that the interest of the Haar wavelet is this relation to the integrated process rather than its wavelet nature per se.

Using numerical multifractal simulations, we show that it is quite accurate, and we compare and contrast it with another similar technique, detrended fluctuation analysis. We find that, for estimating scaling exponents, the two methods are very similar, yet

Application of 3D wavelet transforms for crack detection in rotor ...

Indian Academy of Sciences (India)

Vijayawada 520 007. bAll India Council for Technical Education (AICTE), New Delhi 110 001 ... rotor system the transient analysis has been applied. ... In the present work a new wavelet plot called cross wavelet transform (XWT) has been.

Detection of Early Faults in Rotating Machinery Based on Wavelet Analysis

Directory of Open Access Journals (Sweden)

Meng Hee Lim

2013-01-01

Full Text Available This paper explores the application of wavelet analysis for the detection of early changes in rotor dynamics caused by common machinery faults, namely, rotor unbalance and minor blade rubbing conditions. In this paper, the time synchronised wavelet analysis method was formulated and its effectiveness to detect machinery faults at the early stage was evaluated based on signal simulation and experimental study. The proposed method provides a more standardised approach to visualise the current state of rotor dynamics of a rotating machinery by taking into account the effects of time shift, wavelet edge distortion, and system noise suppression. The experimental results showed that this method is able to reveal subtle changes of the vibration signal characteristics in both the frequency content distribution and the amplitude distortion caused by minor rotor unbalance and blade rubbing conditions. Besides, this method also appeared to be an effective tool to diagnose and to discriminate the different types of machinery faults based on the unique pattern of the wavelet contours. This study shows that the proposed wavelet analysis method is promising to reveal machinery faults at early stage as compared to vibration spectrum analysis.

A Wavelet-Based Optimization Method for Biofuel Production

Directory of Open Access Journals (Sweden)

Maurizio Carlini

2018-02-01

Full Text Available On a global scale many countries are still heavily dependent on crude oil to produce energy and fuel for transport, with a resulting increase of atmospheric pollution. A possible solution to obviate this problem is to find eco-sustainable energy sources. A potential choice could be the use of biodiesel as fuel. The work presented aims to characterise the transesterification reaction of waste peanut frying oil using colour analysis and wavelet analysis. The biodiesel production, with the complete absence of mucilages, was evaluated through a suitable set of energy wavelet coefficients and scalograms. The physical characteristics of the biodiesel are influenced by mucilages. In particular the viscosity, that is a fundamental parameter for the correct use of the biodiesel, might be compromised. The presence of contaminants in the samples can often be missed by visual analysis. The low and high frequency wavelet analysis, by investigating the energy change of wavelet coefficient, provided a valid characterisation of the quality of the samples, related to the absence of mucilages, which is consistent with the experimental results. The proposed method of this work represents a preliminary analysis, before the subsequent chemical physical analysis, that can be develop during the production phases of the biodiesel in order to optimise the process, avoiding the presence of impurities in suspension in the final product.

Alcohol Use Disorders in National Samples of Mexicans and Mexican-Americans: The Mexican National Addiction Survey and the U.S. National Alcohol Survey

Science.gov (United States)

Borges, Guilherme; Medina-Mora, Maria Elena; Lown, Anne; Ye, Yu; Robertson, Marjorie J.; Cherpitel, Cheryl; Greenfield, Tom

2006-01-01

The authors show associations between immigration and alcohol disorders using data from the 1995 and 2000 U.S. National Alcohol Surveys and the 1998 Mexico National Household Survey on Addictions. The prevalence of alcohol dependence was 4.8% for the Mexicans, 4.2% for the Mexico-born immigrants, and 6.6% for the U.S.-born Mexican Americans. They…

An NMR log echo data de-noising method based on the wavelet packet threshold algorithm

International Nuclear Information System (INIS)

Meng, Xiangning; Xie, Ranhong; Li, Changxi; Hu, Falong; Li, Chaoliu; Zhou, Cancan

2015-01-01

To improve the de-noising effects of low signal-to-noise ratio (SNR) nuclear magnetic resonance (NMR) log echo data, this paper applies the wavelet packet threshold algorithm to the data. The principle of the algorithm is elaborated in detail. By comparing the properties of a series of wavelet packet bases and the relevance between them and the NMR log echo train signal, ‘sym7’ is found to be the optimal wavelet packet basis of the wavelet packet threshold algorithm to de-noise the NMR log echo train signal. A new method is presented to determine the optimal wavelet packet decomposition scale; this is within the scope of its maximum, using the modulus maxima and the Shannon entropy minimum standards to determine the global and local optimal wavelet packet decomposition scales, respectively. The results of applying the method to the simulated and actual NMR log echo data indicate that compared with the wavelet threshold algorithm, the wavelet packet threshold algorithm, which shows higher decomposition accuracy and better de-noising effect, is much more suitable for de-noising low SNR–NMR log echo data. (paper)

Discrete wavelet transform: a tool in smoothing kinematic data.

Science.gov (United States)

Ismail, A R; Asfour, S S

1999-03-01

Motion analysis systems typically introduce noise to the displacement data recorded. Butterworth digital filters have been used to smooth the displacement data in order to obtain smoothed velocities and accelerations. However, this technique does not yield satisfactory results, especially when dealing with complex kinematic motions that occupy the low- and high-frequency bands. The use of the discrete wavelet transform, as an alternative to digital filters, is presented in this paper. The transform passes the original signal through two complementary low- and high-pass FIR filters and decomposes the signal into an approximation function and a detail function. Further decomposition of the signal results in transforming the signal into a hierarchy set of orthogonal approximation and detail functions. A reverse process is employed to perfectly reconstruct the signal (inverse transform) back from its approximation and detail functions. The discrete wavelet transform was applied to the displacement data recorded by Pezzack et al., 1977. The smoothed displacement data were twice differentiated and compared to Pezzack et al.'s acceleration data in order to choose the most appropriate filter coefficients and decomposition level on the basis of maximizing the percentage of retained energy (PRE) and minimizing the root mean square error (RMSE). Daubechies wavelet of the fourth order (Db4) at the second decomposition level showed better results than both the biorthogonal and Coiflet wavelets (PRE = 97.5%, RMSE = 4.7 rad s-2). The Db4 wavelet was then used to compress complex displacement data obtained from a noisy mathematically generated function. Results clearly indicate superiority of this new smoothing approach over traditional filters.

Object-Oriented Wavelet-Layered Digital Watermarking Technique

Institute of Scientific and Technical Information of China (English)

LIU Xiao-yun; YU Jue-bang; LI Ming-yu

2005-01-01

In this paper, an object-oriented digital watermarking technique is proposed in the wavelet domain for still images. According to the difference of recognition degree of the human eye to the different region of the image, the image is divided into the interested region and uninterested region of human eye vision in this scheme. Using the relativity of position and the difference to ocular sensitivity of the multiresolution wavelet among each subband, the image is processed with layered watermarking append technique. Experimental results show that the proposed technique successfully survives image processing operations, additive noise and JPEG compression.

Idioms of Distress Among Depressed White-Non-Mexican and Mexican-Origin Older Men.

Science.gov (United States)

Apesoa-Varano, Ester Carolina; Barker, Judith C; Unutzer, Jurgen; Aguilar-Gaxiola, Sergio; Johnson, Megan Dwight; Tran, Cindy; Guarnaccia, Peter; Hinton, Ladson

2015-09-01

Older men are less likely than older women to receive depression treatment. Latino older men in particular have been found to have significantly lower rates of depression treatment than their white-non-Mexican (WNM) counterparts. Prior research has shown that men are less likely than women to express overt affect and/or report depression symptoms that may prompt primary care physicians' inquiry about depression. Previous studies have overlooked the idioms of distress common among older men. This study investigates: a) the range of idioms of distress that emerge in the narratives of depressed older men, and b) the use of these idioms among depressed WNM and Mexican-origin older men. The present report is based on qualitative data collected through the Men's Health and Aging Study (MeHAS), a mixed-method study of clinically depressed WNM and Mexican-origin older (65 and above) men recruited in primary care settings. Qualitative analysis of 77 interviews led to identification of idioms of distress and informed idiom categories. Study findings show that: a) both groups of men utilized a range of idioms of distress that met current DSM criteria for depression, b) both groups were also likely to utilize idioms that feel outside clinical depression criteria, and c) there were similarities as well as differences between WNM and Mexican-origin men. This study provides a larger vocabulary that clinicians might consider in recognizing depression and initiating depression care for older men from diverse ethnic backgrounds. This is important to improve depression care among older men in general and those of Mexican-origin in particular.

El Arte Culinario Mexicano (Mexican Culinary Art).

Science.gov (United States)

Card, Michelle

This unit in Mexican cooking can be used in Junior High School home economics classes to introduce students to Mexican culture or as a mini-course in Spanish at almost any level. It is divided into two parts. Part One provides historical background and information on basic foods, the Mexican market, shopping tips, regional cooking and customs.…

A Hybrid Model Based on Wavelet Decomposition-Reconstruction in Track Irregularity State Forecasting

Directory of Open Access Journals (Sweden)

Chaolong Jia

2015-01-01

Full Text Available Wavelet is able to adapt to the requirements of time-frequency signal analysis automatically and can focus on any details of the signal and then decompose the function into the representation of a series of simple basis functions. It is of theoretical and practical significance. Therefore, this paper does subdivision on track irregularity time series based on the idea of wavelet decomposition-reconstruction and tries to find the best fitting forecast model of detail signal and approximate signal obtained through track irregularity time series wavelet decomposition, respectively. On this ideology, piecewise gray-ARMA recursive based on wavelet decomposition and reconstruction (PG-ARMARWDR and piecewise ANN-ARMA recursive based on wavelet decomposition and reconstruction (PANN-ARMARWDR models are proposed. Comparison and analysis of two models have shown that both these models can achieve higher accuracy.

Sparsity guided empirical wavelet transform for fault diagnosis of rolling element bearings

Science.gov (United States)

Wang, Dong; Zhao, Yang; Yi, Cai; Tsui, Kwok-Leung; Lin, Jianhui

2018-02-01

Rolling element bearings are widely used in various industrial machines, such as electric motors, generators, pumps, gearboxes, railway axles, turbines, and helicopter transmissions. Fault diagnosis of rolling element bearings is beneficial to preventing any unexpected accident and reducing economic loss. In the past years, many bearing fault detection methods have been developed. Recently, a new adaptive signal processing method called empirical wavelet transform attracts much attention from readers and engineers and its applications to bearing fault diagnosis have been reported. The main problem of empirical wavelet transform is that Fourier segments required in empirical wavelet transform are strongly dependent on the local maxima of the amplitudes of the Fourier spectrum of a signal, which connotes that Fourier segments are not always reliable and effective if the Fourier spectrum of the signal is complicated and overwhelmed by heavy noises and other strong vibration components. In this paper, sparsity guided empirical wavelet transform is proposed to automatically establish Fourier segments required in empirical wavelet transform for fault diagnosis of rolling element bearings. Industrial bearing fault signals caused by single and multiple railway axle bearing defects are used to verify the effectiveness of the proposed sparsity guided empirical wavelet transform. Results show that the proposed method can automatically discover Fourier segments required in empirical wavelet transform and reveal single and multiple railway axle bearing defects. Besides, some comparisons with three popular signal processing methods including ensemble empirical mode decomposition, the fast kurtogram and the fast spectral correlation are conducted to highlight the superiority of the proposed method.

Reproductive habitus, psychosocial health, and birth weight variation in Mexican immigrant and Mexican American women in south Texas.

Science.gov (United States)

Fleuriet, K Jill; Sunil, T S

2015-08-01

The Latina Paradox, or persistent, unexplained variation in low birth weight rates in recently immigrated Mexican women and the trend toward higher rates in subsequent generations of Mexican American women, is most often attributed to unidentified sociocultural causes. We suggest herein that different disciplinary approaches can be synthesized under the constructs of reproductive habitus and subjective social status to identify influences of sociocultural processes on birth weight. Reproductive habitus are "modes of living the reproductive body, bodily practices, and the creation of new subjects through interactions between people and structures" (Smith-Oka, 2012: 2276). Subjective social status infers comparison of self to others based on community definitions of status or socioeconomic status (Adler 2007). We present results from a prospective study of low-income Mexican immigrant and Mexican American women from south Texas that tested the ability of reproductive habitus and subjective social status to elucidate the Latina Paradox. We hypothesized that reproductive habitus between Mexican immigrant women and Mexican American women inform different subjective social statuses during pregnancy, and different subjective social statuses mediate responses to psychosocial stressors known to correlate with low birth weight. Six hundred thirty-one women were surveyed for psychosocial health, subjective social status, and reproductive histories between 2011 and 2013. Eighty-three women were interviewed between 2012 and 2013 for status during pregnancy, prenatal care practices, and pregnancy narratives and associations. Birth weight was extracted from medical records. Results were mixed. Subjective social status and pregnancy-related anxiety predicted low birth weight in Mexican immigrant but not Mexican American women. Mexican immigrant women had significantly lower subjective social status scores but a distinct reproductive habitus that could explain improved psychosocial

Construction of Interval Wavelet Based on Restricted Variational Principle and Its Application for Solving Differential Equations

OpenAIRE

Mei, Shu-Li; Lv, Hong-Liang; Ma, Qin

2008-01-01

Based on restricted variational principle, a novel method for interval wavelet construction is proposed. For the excellent local property of quasi-Shannon wavelet, its interval wavelet is constructed, and then applied to solve ordinary differential equations. Parameter choices for the interval wavelet method are discussed and its numerical performance is demonstrated.

Multifractal Cross Wavelet Analysis

Science.gov (United States)

Jiang, Zhi-Qiang; Gao, Xing-Lu; Zhou, Wei-Xing; Stanley, H. Eugene

Complex systems are composed of mutually interacting components and the output values of these components usually exhibit long-range cross-correlations. Using wavelet analysis, we propose a method of characterizing the joint multifractal nature of these long-range cross correlations, a method we call multifractal cross wavelet analysis (MFXWT). We assess the performance of the MFXWT method by performing extensive numerical experiments on the dual binomial measures with multifractal cross correlations and the bivariate fractional Brownian motions (bFBMs) with monofractal cross correlations. For binomial multifractal measures, we find the empirical joint multifractality of MFXWT to be in approximate agreement with the theoretical formula. For bFBMs, MFXWT may provide spurious multifractality because of the wide spanning range of the multifractal spectrum. We also apply the MFXWT method to stock market indices, and in pairs of index returns and volatilities we find an intriguing joint multifractal behavior. The tests on surrogate series also reveal that the cross correlation behavior, particularly the cross correlation with zero lag, is the main origin of cross multifractality.

Two Decades of Mexican Particle Physics at Fermilab

International Nuclear Information System (INIS)

Rubinstein, R.

2003-01-01

This report is a view from Fermilab of Mexican particle physics at the Laboratory since about 1980; it is not intended to be a history of Mexican particle physics: that topic is outside the expertise of the writer. The period 1980 to the present coincides with the growth of Mexican experimental particle physics from essentially no activity to its current state where Mexican groups take part in experiments at several of the world's major laboratories

Multi-dimensional medical images compressed and filtered with wavelets

International Nuclear Information System (INIS)

Boyen, H.; Reeth, F. van; Flerackers, E.

2002-01-01

Full text: Using the standard wavelet decomposition methods, multi-dimensional medical images can be compressed and filtered by repeating the wavelet-algorithm on 1D-signals in an extra loop per extra dimension. In the non-standard decomposition for multi-dimensional images the areas that must be zero-filled in case of band- or notch-filters are more complex than geometric areas such as rectangles or cubes. Adding an additional dimension in this algorithm until 4D (e.g. a 3D beating heart) increases the geometric complexity of those areas even more. The aim of our study was to calculate the boundaries of the formed complex geometric areas, so we can use the faster non-standard decomposition to compress and filter multi-dimensional medical images. Because a lot of 3D medical images taken by PET- or SPECT-cameras have only a few layers in the Z-dimension and compressing images in a dimension with a few voxels is usually not worthwhile, we provided a solution in which one can choose which dimensions will be compressed or filtered. With the proposal of non-standard decomposition on Daubechies' wavelets D2 to D20 by Steven Gollmer in 1992, 1D data can be compressed and filtered. Each additional level works only on the smoothed data, so the transformation-time halves per extra level. Zero-filling a well-defined area alter the wavelet-transform and then performing the inverse transform will do the filtering. To be capable to compress and filter up to 4D-Images with the faster non-standard wavelet decomposition method, we have investigated a new method for calculating the boundaries of the areas which must be zero-filled in case of filtering. This is especially true for band- and notch filtering. Contrary to the standard decomposition method, the areas are no longer rectangles in 2D or cubes in 3D or a row of cubes in 4D: they are rectangles expanded with a half-sized rectangle in the other direction for 2D, cubes expanded with half cubes in one and quarter cubes in the

Two-dimensional wavelet transform for reliability-guided phase unwrapping in optical fringe pattern analysis.

Science.gov (United States)

Li, Sikun; Wang, Xiangzhao; Su, Xianyu; Tang, Feng

2012-04-20

This paper theoretically discusses modulus of two-dimensional (2D) wavelet transform (WT) coefficients, calculated by using two frequently used 2D daughter wavelet definitions, in an optical fringe pattern analysis. The discussion shows that neither is good enough to represent the reliability of the phase data. The differences between the two frequently used 2D daughter wavelet definitions in the performance of 2D WT also are discussed. We propose a new 2D daughter wavelet definition for reliability-guided phase unwrapping of optical fringe pattern. The modulus of the advanced 2D WT coefficients, obtained by using a daughter wavelet under this new daughter wavelet definition, includes not only modulation information but also local frequency information of the deformed fringe pattern. Therefore, it can be treated as a good parameter that represents the reliability of the retrieved phase data. Computer simulation and experimentation show the validity of the proposed method.

Imbalance between HAT and HDAC activities in the PBMCs of patients with ankylosing spondylitis or rheumatoid arthritis and influence of HDAC inhibitors on TNF alpha production.

Directory of Open Access Journals (Sweden)

Eric Toussirot

Full Text Available OBJECTIVE: Acetylation or deacetylation of histone proteins may modulate cytokine gene transcription such as TNF alpha (TNF. We evaluated the balance between histone deacetytlase (HDAC and histone acetyltransferase (HAT in patients with rheumatoid arthritis (RA or ankylosing spondylitis (AS compared to healthy controls (HC and determined the influence of HDAC inhibitors (trichostatin A -TSA- or Sirtinol -Sirt- on these enzymatic activities and on the PBMC production of TNF. METHODS: 52 patients with RA, 21 with AS and 38 HC were evaluated. HAT and HDAC activities were measured on nuclear extracts from PBMC using colorimetric assays. Enzymatic activities were determined prior to and after ex vivo treatment of PBMC by TSA or Sirt. TNF levels were evaluated in PBMC culture supernatants in the absence or presence of TSA or Sirt. RESULTS: HAT and HDAC activities were significantly reduced in AS, while these activities reached similar levels in RA and HC. Ex vivo treatment of PBMC by HDACi tended to decrease HDAC expression in HC, but Sirt significantly reduced HAT in RA. TNF production by PBMC was significantly down-regulated by Sirt in HC and AS patients. CONCLUSION: HAT and HDAC were disturbed in AS while no major changes were found in RA. HDACi may modulate HDAC and HAT PBMC expression, especially Sirt in RA. Sirtinol was able to down regulate TNF production by PBMC in HC and AS. An imbalance between HAT and HDAC activities might provide the rationale for the development of HDACi in the therapeutic approach to inflammatory rheumatic diseases.

Decompositions of bubbly flow PIV velocity fields using discrete wavelets multi-resolution and multi-section image method

International Nuclear Information System (INIS)

Choi, Je-Eun; Takei, Masahiro; Doh, Deog-Hee; Jo, Hyo-Jae; Hassan, Yassin A.; Ortiz-Villafuerte, Javier

2008-01-01

Currently, wavelet transforms are widely used for the analyses of particle image velocimetry (PIV) velocity vector fields. This is because the wavelet provides not only spatial information of the velocity vectors, but also of the time and frequency domains. In this study, a discrete wavelet transform is applied to real PIV images of bubbly flows. The vector fields obtained by a self-made cross-correlation PIV algorithm were used for the discrete wavelet transform. The performances of the discrete wavelet transforms were investigated by changing the level of power of discretization. The images decomposed by wavelet multi-resolution showed conspicuous characteristics of the bubbly flows for the different levels. A high spatial bubble concentrated area could be evaluated by the constructed discrete wavelet transform algorithm, in which high-leveled wavelets play dominant roles in revealing the flow characteristics

Image Registration Using Redundant Wavelet Transforms

National Research Council Canada - National Science Library

Brown, Richard

2001-01-01

.... In our research, we present a fundamentally new wavelet-based registration algorithm utilizing redundant transforms and a masking process to suppress the adverse effects of noise and improve processing efficiency...

The HAT Score-A Simple Risk Stratification Score for Coagulopathic Bleeding During Adult Extracorporeal Membrane Oxygenation.

Science.gov (United States)

Lonergan, Terence; Herr, Daniel; Kon, Zachary; Menaker, Jay; Rector, Raymond; Tanaka, Kenichi; Mazzeffi, Michael

2017-06-01

The study objective was to create an adult extracorporeal membrane oxygenation (ECMO) coagulopathic bleeding risk score. Secondary analysis was performed on an existing retrospective cohort. Pre-ECMO variables were tested for association with coagulopathic bleeding, and those with the strongest association were included in a multivariable model. Using this model, a risk stratification score was created. The score's utility was validated by comparing bleeding and transfusion rates between score levels. Bleeding also was examined after stratifying by nadir platelet count and overanticoagulation. Predictive power of the score was compared against the risk score for major bleeding during anti-coagulation for atrial fibrillation (HAS-BLED). Tertiary care academic medical center. The study comprised patients who received venoarterial or venovenous ECMO over a 3-year period, excluding those with an identified source of surgical bleeding during exploration. None. Fifty-three (47.3%) of 112 patients experienced coagulopathic bleeding. A 3-variable score-hypertension, age greater than 65, and ECMO type (HAT)-had fair predictive value (area under the receiver operating characteristic curve [AUC] = 0.66) and was superior to HAS-BLED (AUC = 0.64). As the HAT score increased from 0 to 3, bleeding rates also increased as follows: 30.8%, 48.7%, 63.0%, and 71.4%, respectively. Platelet and fresh frozen plasma transfusion tended to increase with the HAT score, but red blood cell transfusion did not. Nadir platelet count less than 50×10 3 /µL and overanticoagulation during ECMO increased the AUC for the model to 0.73, suggesting additive risk. The HAT score may allow for bleeding risk stratification in adult ECMO patients. Future studies in larger cohorts are necessary to confirm these findings. Copyright © 2017 Elsevier Inc. All rights reserved.

National Mexican Tourism Policy and North American Second Homeowners In Mexico: Local Tourism Development and Mexican Identity (Chapter 6)

DEFF Research Database (Denmark)

Clausen, Helene Balslev

2018-01-01

. Still the Mexican state does not seize the second home owners as a resource and ‘producers’ rather only as consumers of different Mexican objects, food etc. The chapter addresses this research gap and proposes rather than only perceive North American second home owners as part of tourism development...... participate in reshaping and reconfigure public policy and Mexican culture/identity construction. The purpose of the chapter is to explore the role of the North American second home owners and their impact on the planning and regulation of Mexican state policies, and how they might reconfigure practices and...

Wavelet Packet Entropy in Speaker-Independent Emotional State Detection from Speech Signal

OpenAIRE

Mina Kadkhodaei Elyaderani; Seyed Hamid Mahmoodian; Ghazaal Sheikhi

2015-01-01

In this paper, wavelet packet entropy is proposed for speaker-independent emotion detection from speech. After pre-processing, wavelet packet decomposition using wavelet type db3 at level 4 is calculated and Shannon entropy in its nodes is calculated to be used as feature. In addition, prosodic features such as first four formants, jitter or pitch deviation amplitude, and shimmer or energy variation amplitude besides MFCC features are applied to complete the feature vector. Then, Support Vect...

Response of Autonomic Nervous System to Body Positions: Fourier and Wavelet Analysis

OpenAIRE

Xu, Aiguo; Gonnella, G.; Federici, A.; Stramaglia, S.; Simone, F.; Zenzola, A.; Santostasi, R.

2003-01-01

Two mathematical methods, the Fourier and wavelet transforms, were used to study the short term cardiovascular control system. Time series, picked from electrocardiogram and arterial blood pressure lasting 6 minutes, were analyzed in supine position (SUP), during the first (HD1), and the second parts (HD2) of $90^{\\circ}$ head down tilt and during recovery (REC). The wavelet transform was performed using the Haar function of period $T=2^j$ ($% j=1$,2,$... $,6) to obtain wavelet coefficients. ...

Wavelet neural network load frequency controller

International Nuclear Information System (INIS)

Hemeida, Ashraf Mohamed

2005-01-01

This paper presents the feasibility of applying a wavelet neural network (WNN) approach for the load frequency controller (LFC) to damp the frequency oscillations of two area power systems due to load disturbances. The present intelligent control system trained the wavelet neural network (WNN) controller on line with adaptive learning rates, which are derived in the sense of a discrete type Lyapunov stability theorem. The present WNN controller is designed individually for each area. The proposed technique is applied successfully for a wide range of operating conditions. The time simulation results indicate its superiority and effectiveness over the conventional approach. The effects of consideration of the governor dead zone on the system performance are studied using the proposed controller and the conventional one

Implementation of Wavelet-Based Robust Differential Control for Electric Vehicle Application

DEFF Research Database (Denmark)

Daya, Febin; Padmanaban, Sanjeevikumar; Blaabjerg, Frede

2015-01-01

This research letter presents the modeling and simulation of electronic differential, employing a novel wavelet controller for two brushless dc motors. The proposed controller uses discrete wavelet transform to decompose the error between actual and reference speed. Error signal that is actually...

Pricing early-exercise and discrete barrier options by Shannon wavelet expansions

NARCIS (Netherlands)

Maree, S. C.; Ortiz-Gracia, L.; Oosterlee, C. W.

2017-01-01

We present a pricing method based on Shannon wavelet expansions for early-exercise and discretely-monitored barrier options under exponential L,vy asset dynamics. Shannon wavelets are smooth, and thus approximate the densities that occur in finance well, resulting in exponential convergence.

Structure of the Hat Creek graben region: Implications for the structure of the Hat Creek graben and transfer of right-lateral shear from the Walker Lane north of Lassen Peak, northern California, from gravity and magnetic anomalies

Science.gov (United States)

Langenheim, Victoria; Jachens, Robert C.; Clynne, Michael A.; Muffler, L. J. Patrick

2016-01-01

Interpretation of magnetic and new gravity data provides constraints on the geometry of the Hat Creek Fault, the amount of right-lateral offset in the area between Mt. Shasta and Lassen Peak, and confirmation of the influence of pre-existing structure on Quaternary faulting. Neogene volcanic rocks coincide with short-wavelength magnetic anomalies of both normal and reversed polarity, whereas a markedly smoother magnetic field occurs over the Klamath Mountains and its Paleogene cover. Although the magnetic field over the Neogene volcanic rocks is complex, the Hat Creek Fault, which is one of the most prominent normal faults in the region and forms the eastern margin of the Hat Creek Valley, is marked by the eastern edge of a north-trending magnetic and gravity high 20-30 km long. Modeling of these anomalies indicates that the fault is a steeply dipping (~75-85°) structure. The spatial relationship of the fault as modeled by the potential-field data, the youngest strand of the fault, and relocated seismicity suggests that deformation continues to step westward across the valley, consistent with a component of right-lateral slip in an extensional environment. Filtered aeromagnetic data highlight a concealed magnetic body of Mesozoic or older age north of Hat Creek Valley. The body’s northwest margin strikes northeast and is linear over a distance of ~40 km. Within the resolution of the aeromagnetic data (1-2 km), we discern no right-lateral offset of this body. Furthermore, Quaternary faults change strike or appear to end, as if to avoid this concealed magnetic body and to pass along its southeast edge, suggesting that pre-existing crustal structure influenced younger faulting, as previously proposed based on gravity data.

A wavelet analysis of co-movements in Asian gold markets

Science.gov (United States)

Das, Debojyoti; Kannadhasan, M.; Al-Yahyaee, Khamis Hamed; Yoon, Seong-Min

2018-02-01

This study assesses the cross-country co-movements of gold spot returns among the major gold consuming countries in Asia using wavelet-based analysis for a dataset spanning over 26 years. Wavelet-based analysis is used since it allows measuring co-movements in a time-frequency space. The results suggest intense and positive co-movements in Asia after the Asian financial crisis of 1997 at all frequencies. In addition, the Asian gold spot markets depict a state of impending perfect market integration. Finally, Thailand emerges as the potential market leader in all wavelet scales except one, which is led by India. The study has important implications for international diversification of a single-asset (gold) portfolio.

Wavelet Filtering to Reduce Conservatism in Aeroservoelastic Robust Stability Margins

Science.gov (United States)

Brenner, Marty; Lind, Rick

1998-01-01

Wavelet analysis for filtering and system identification was used to improve the estimation of aeroservoelastic stability margins. The conservatism of the robust stability margins was reduced with parametric and nonparametric time-frequency analysis of flight data in the model validation process. Nonparametric wavelet processing of data was used to reduce the effects of external desirableness and unmodeled dynamics. Parametric estimates of modal stability were also extracted using the wavelet transform. Computation of robust stability margins for stability boundary prediction depends on uncertainty descriptions derived from the data for model validation. F-18 high Alpha Research Vehicle aeroservoelastic flight test data demonstrated improved robust stability prediction by extension of the stability boundary beyond the flight regime.

Feature Extraction on Brain Computer Interfaces using Discrete Dyadic Wavelet Transform: Preliminary Results

International Nuclear Information System (INIS)

Gareis, I; Gentiletti, G; Acevedo, R; Rufiner, L

2011-01-01

The purpose of this work is to evaluate different feature extraction alternatives to detect the event related evoked potential signal on brain computer interfaces, trying to minimize the time employed and the classification error, in terms of sensibility and specificity of the method, looking for alternatives to coherent averaging. In this context the results obtained performing the feature extraction using discrete dyadic wavelet transform using different mother wavelets are presented. For the classification a single layer perceptron was used. The results obtained with and without the wavelet decomposition were compared; showing an improvement on the classification rate, the specificity and the sensibility for the feature vectors obtained using some mother wavelets.

Reversible wavelet filter banks with side informationless spatially adaptive low-pass filters

Science.gov (United States)

Abhayaratne, Charith

2011-07-01

Wavelet transforms that have an adaptive low-pass filter are useful in applications that require the signal singularities, sharp transitions, and image edges to be left intact in the low-pass signal. In scalable image coding, the spatial resolution scalability is achieved by reconstructing the low-pass signal subband, which corresponds to the desired resolution level, and discarding other high-frequency wavelet subbands. In such applications, it is vital to have low-pass subbands that are not affected by smoothing artifacts associated with low-pass filtering. We present the mathematical framework for achieving 1-D wavelet transforms that have a spatially adaptive low-pass filter (SALP) using the prediction-first lifting scheme. The adaptivity decisions are computed using the wavelet coefficients, and no bookkeeping is required for the perfect reconstruction. Then, 2-D wavelet transforms that have a spatially adaptive low-pass filter are designed by extending the 1-D SALP framework. Because the 2-D polyphase decompositions are used in this case, the 2-D adaptivity decisions are made nonseparable as opposed to the separable 2-D realization using 1-D transforms. We present examples using the 2-D 5/3 wavelet transform and their lossless image coding and scalable decoding performances in terms of quality and resolution scalability. The proposed 2-D-SALP scheme results in better performance compared to the existing adaptive update lifting schemes.

Application of Bipartite Entangled States to Quantum Mechanical Version of Complex Wavelet Transforms

International Nuclear Information System (INIS)

Fan Hongyi; Lu Hailiang; Xu Xuefen

2006-01-01

We introduce the bipartite entangled states to present a quantum mechanical version of complex wavelet transform. Using the technique of integral within an ordered product of operators we show that the complex wavelet transform can be studied in terms of various quantum state vectors in two-mode Fock space. In this way the creterion for mother wavelet can be examined quantum-mechanically and therefore more deeply.

Robust pricing of european options with wavelets and the characteristic function

NARCIS (Netherlands)

Ortiz-Gracia, L.; Oosterlee, C.W.

2013-01-01

We present a novel method for pricing European options based on the wavelet approximation method and the characteristic function. We focus on the discounted expected payoff pricing formula and compute it by means of wavelets. We approximate the density function associated to the underlying asset

Denoising solar radiation data using coiflet wavelets

Energy Technology Data Exchange (ETDEWEB)

Karim, Samsul Ariffin Abdul, E-mail: samsul-ariffin@petronas.com.my; Janier, Josefina B., E-mail: josefinajanier@petronas.com.my; Muthuvalu, Mohana Sundaram, E-mail: mohana.muthuvalu@petronas.com.my [Department of Fundamental and Applied Sciences, Faculty of Sciences and Information Technology, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak Darul Ridzuan (Malaysia); Hasan, Mohammad Khatim, E-mail: khatim@ftsm.ukm.my [Jabatan Komputeran Industri, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia); Sulaiman, Jumat, E-mail: jumat@ums.edu.my [Program Matematik dengan Ekonomi, Universiti Malaysia Sabah, Beg Berkunci 2073, 88999 Kota Kinabalu, Sabah (Malaysia); Ismail, Mohd Tahir [School of Mathematical Sciences, Universiti Sains Malaysia, 11800 USM Minden, Penang (Malaysia)

2014-10-24

Signal denoising and smoothing plays an important role in processing the given signal either from experiment or data collection through observations. Data collection usually was mixed between true data and some error or noise. This noise might be coming from the apparatus to measure or collect the data or human error in handling the data. Normally before the data is use for further processing purposes, the unwanted noise need to be filtered out. One of the efficient methods that can be used to filter the data is wavelet transform. Due to the fact that the received solar radiation data fluctuates according to time, there exist few unwanted oscillation namely noise and it must be filtered out before the data is used for developing mathematical model. In order to apply denoising using wavelet transform (WT), the thresholding values need to be calculated. In this paper the new thresholding approach is proposed. The coiflet2 wavelet with variation diminishing 4 is utilized for our purpose. From numerical results it can be seen clearly that, the new thresholding approach give better results as compare with existing approach namely global thresholding value.

JPEG and wavelet compression of ophthalmic images

Science.gov (United States)

Eikelboom, Robert H.; Yogesan, Kanagasingam; Constable, Ian J.; Barry, Christopher J.

1999-05-01

This study was designed to determine the degree and methods of digital image compression to produce ophthalmic imags of sufficient quality for transmission and diagnosis. The photographs of 15 subjects, which inclined eyes with normal, subtle and distinct pathologies, were digitized to produce 1.54MB images and compressed to five different methods: (i) objectively by calculating the RMS error between the uncompressed and compressed images, (ii) semi-subjectively by assessing the visibility of blood vessels, and (iii) subjectively by asking a number of experienced observers to assess the images for quality and clinical interpretation. Results showed that as a function of compressed image size, wavelet compressed images produced less RMS error than JPEG compressed images. Blood vessel branching could be observed to a greater extent after Wavelet compression compared to JPEG compression produced better images then a JPEG compression for a given image size. Overall, it was shown that images had to be compressed to below 2.5 percent for JPEG and 1.7 percent for Wavelet compression before fine detail was lost, or when image quality was too poor to make a reliable diagnosis.

Estimation of Handgrip Force from SEMG Based on Wavelet Scale Selection.

Science.gov (United States)

Wang, Kai; Zhang, Xianmin; Ota, Jun; Huang, Yanjiang

2018-02-24

This paper proposes a nonlinear correlation-based wavelet scale selection technology to select the effective wavelet scales for the estimation of handgrip force from surface electromyograms (SEMG). The SEMG signal corresponding to gripping force was collected from extensor and flexor forearm muscles during the force-varying analysis task. We performed a computational sensitivity analysis on the initial nonlinear SEMG-handgrip force model. To explore the nonlinear correlation between ten wavelet scales and handgrip force, a large-scale iteration based on the Monte Carlo simulation was conducted. To choose a suitable combination of scales, we proposed a rule to combine wavelet scales based on the sensitivity of each scale and selected the appropriate combination of wavelet scales based on sequence combination analysis (SCA). The results of SCA indicated that the scale combination VI is suitable for estimating force from the extensors and the combination V is suitable for the flexors. The proposed method was compared to two former methods through prolonged static and force-varying contraction tasks. The experiment results showed that the root mean square errors derived by the proposed method for both static and force-varying contraction tasks were less than 20%. The accuracy and robustness of the handgrip force derived by the proposed method is better than that obtained by the former methods.

Harmonic analysis of electric locomotive and traction power system based on wavelet singular entropy

Science.gov (United States)

Dun, Xiaohong

2018-05-01

With the rapid development of high-speed railway and heavy-haul transport, the locomotive and traction power system has become the main harmonic source of China's power grid. In response to this phenomenon, the system's power quality issues need timely monitoring, assessment and governance. Wavelet singular entropy is an organic combination of wavelet transform, singular value decomposition and information entropy theory, which combines the unique advantages of the three in signal processing: the time-frequency local characteristics of wavelet transform, singular value decomposition explores the basic modal characteristics of data, and information entropy quantifies the feature data. Based on the theory of singular value decomposition, the wavelet coefficient matrix after wavelet transform is decomposed into a series of singular values that can reflect the basic characteristics of the original coefficient matrix. Then the statistical properties of information entropy are used to analyze the uncertainty of the singular value set, so as to give a definite measurement of the complexity of the original signal. It can be said that wavelet entropy has a good application prospect in fault detection, classification and protection. The mat lab simulation shows that the use of wavelet singular entropy on the locomotive and traction power system harmonic analysis is effective.

Rate-distortion analysis of directional wavelets.

Science.gov (United States)

Maleki, Arian; Rajaei, Boshra; Pourreza, Hamid Reza

2012-02-01

The inefficiency of separable wavelets in representing smooth edges has led to a great interest in the study of new 2-D transformations. The most popular criterion for analyzing these transformations is the approximation power. Transformations with near-optimal approximation power are useful in many applications such as denoising and enhancement. However, they are not necessarily good for compression. Therefore, most of the nearly optimal transformations such as curvelets and contourlets have not found any application in image compression yet. One of the most promising schemes for image compression is the elegant idea of directional wavelets (DIWs). While these algorithms outperform the state-of-the-art image coders in practice, our theoretical understanding of them is very limited. In this paper, we adopt the notion of rate-distortion and calculate the performance of the DIW on a class of edge-like images. Our theoretical analysis shows that if the edges are not "sharp," the DIW will compress them more efficiently than the separable wavelets. It also demonstrates the inefficiency of the quadtree partitioning that is often used with the DIW. To solve this issue, we propose a new partitioning scheme called megaquad partitioning. Our simulation results on real-world images confirm the benefits of the proposed partitioning algorithm, promised by our theoretical analysis. © 2011 IEEE

Weight status of Mexican immigrant women: a comparison with women in Mexico and with US-born Mexican American women.

Science.gov (United States)

Guendelman, Sylvia D; Ritterman-Weintraub, Miranda L; Fernald, Lia C H; Kaufer-Horwitz, Martha

2013-09-01

We assessed the association between birthplace, residence, or years in the United States and actual weight (body mass index), perceived weight accuracy, or provider screens for overweight or obesity among Mexican immigrant women. We used linked data from Health and Nutrition Examination Survey waves 2001-2006 and 2006 National Mexican Health and Nutrition Survey to compare 513 immigrants with 9527 women in Mexico and 342 US-born Mexican American women. Immigrants were more likely than women in Mexico to be obese and to perceive themselves as overweight or obese after adjustment for confounders. Recent immigrants had similar weight-related outcomes as women in Mexico. Immigrants were less likely to be obese than were US-born Mexican Americans. Within the overweight or obese population, reported provider screens were higher among immigrants than among women in Mexico, but lower than among US-born Mexican Americans. US residency of at least 5 years but less than 20 years and reporting insufficient provider screens elevated obesity risk. Mexican-origin women in the United States and Mexico are at risk for overweight and obesity. We found no evidence of a "healthy immigrant" effect.

Adaptive Image Transmission Scheme over Wavelet-Based OFDM System

Institute of Scientific and Technical Information of China (English)

GAOXinying; YUANDongfeng; ZHANGHaixia

2005-01-01

In this paper an adaptive image transmission scheme is proposed over Wavelet-based OFDM (WOFDM) system with Unequal error protection (UEP) by the design of non-uniform signal constellation in MLC. Two different data division schemes: byte-based and bitbased, are analyzed and compared. Different bits are protected unequally according to their different contribution to the image quality in bit-based data division scheme, which causes UEP combined with this scheme more powerful than that with byte-based scheme. Simulation results demonstrate that image transmission by UEP with bit-based data division scheme presents much higher PSNR values and surprisingly better image quality. Furthermore, by considering the tradeoff of complexity and BER performance, Haar wavelet with the shortest compactly supported filter length is the most suitable one among orthogonal Daubechies wavelet series in our proposed system.

Wavelet Domain Radiofrequency Pulse Design Applied to Magnetic Resonance Imaging.

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Andrew M Huettner

Full Text Available A new method for designing radiofrequency (RF pulses with numerical optimization in the wavelet domain is presented. Numerical optimization may yield solutions that might otherwise have not been discovered with analytic techniques alone. Further, processing in the wavelet domain reduces the number of unknowns through compression properties inherent in wavelet transforms, providing a more tractable optimization problem. This algorithm is demonstrated with simultaneous multi-slice (SMS spin echo refocusing pulses because reduced peak RF power is necessary for SMS diffusion imaging with high acceleration factors. An iterative, nonlinear, constrained numerical minimization algorithm was developed to generate an optimized RF pulse waveform. Wavelet domain coefficients were modulated while iteratively running a Bloch equation simulator to generate the intermediate slice profile of the net magnetization. The algorithm minimizes the L2-norm of the slice profile with additional terms to penalize rejection band ripple and maximize the net transverse magnetization across each slice. Simulations and human brain imaging were used to demonstrate a new RF pulse design that yields an optimized slice profile and reduced peak energy deposition when applied to a multiband single-shot echo planar diffusion acquisition. This method may be used to optimize factors such as magnitude and phase spectral profiles and peak RF pulse power for multiband simultaneous multi-slice (SMS acquisitions. Wavelet-based RF pulse optimization provides a useful design method to achieve a pulse waveform with beneficial amplitude reduction while preserving appropriate magnetization response for magnetic resonance imaging.

Reversible Integer Wavelet Transform for the Joint of Image Encryption and Watermarking

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Bin Wang

2015-01-01

Full Text Available In recent years, signal processing in the encrypted domain has attracted considerable research interest, especially embedding watermarking in encrypted image. In this work, a novel joint of image encryption and watermarking based on reversible integer wavelet transform is proposed. Firstly, the plain-image is encrypted by chaotic maps and reversible integer wavelet transform. Then the lossless watermarking is embedded in the encrypted image by reversible integer wavelet transform and histogram modification. Finally an encrypted image containing watermarking is obtained by the inverse integer wavelet transform. What is more, the original image and watermarking can be completely recovered by inverse process. Numerical experimental results and comparing with previous works show that the proposed scheme possesses higher security and embedding capacity than previous works. It is suitable for protecting the image information.

Cross dynamics of oil-stock interactions: A redundant wavelet analysis

International Nuclear Information System (INIS)

Jammazi, Rania

2012-01-01

The main aim of the present paper is to explore how the interactions between crude oil (CO) price changes and stock returns of five developed countries namely U.S.A, Canada, Germany, Japan and U.K., evolve simultaneously over time and frequency, in light of the conflicting evidence provided by much of recent studies on the sign and the direction of this relationship. To this end, we apply a more efficient wavelet tool, namely Haar à trous wavelet transform that helps circumvent the problems of the standard regression techniques and proves its effectiveness in encircling the real data features. In order to provide more credible conclusions, the wavelet variance, correlation and cross-correlation are implemented. In general, we extend the existing empirical works by providing more generalized and convincing results inherent to the stock-oil markets interactions which are usually reputed to be complicated. First, we find evidence that the wavelet variances of all the variables decrease with increasing scales. Second, from the analysis of the wavelet correlation, changes in CO and almost all the stock prices do not move together up to the intermediate scale, but since they abruptly shift their direction in unison. Third, results for the wavelet CCF at scales 2, 3 and/or 4 generally illustrate no transmission mechanism between CO and the stock market returns although we provide support for massive CO variations at these scales. In contrast, the CO-equity market relationships at higher scales become interconnected in a negative unidirectional pattern running from CO to stock market returns for only two oil importing countries but also Canada. For oil exporting countries, we have seen that while highly transient (scale 1) positive/negative causalities flowing from TSX stock market to CO changes are detected, highly persistent (scale 6) positive causality running from FTSE to the CO changes are rather found. Finally, the implications of the study's results vary depending

Craniofacial Secular Change in Recent Mexican Migrants.

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Spradley, Katherine; Stull, Kyra E; Hefner, Joseph T

2016-01-01

Research by economists suggests that recent Mexican migrants are better educated and have higher socioeconomic status (SES) than previous migrants. Because factors associated with higher SES and improved education can lead to positive secular changes in overall body form, secular changes in the craniofacial complex were analyzed within a recent migrant group from Mexico. The Mexican group represents individuals in the act of migration, not yet influenced by the American environment, and thus can serve as a starting point for future studies of secular change in this population group. The excavation of a historic Hispanic cemetery in Tucson, Arizona, also allows for a comparison between historic Hispanics and recent migrants to explore craniofacial trends over a broad time period, as both groups originate from Mexico. The present research addresses two main questions: (1) Are cranial secular changes evident in recent Mexican migrants? (2) Are historic Hispanics and recent Mexican migrants similar? By studying secular changes within a migrant population group, secular trends may be detected, which will be important for understanding the biological variation of the migrants themselves and will serve as a preliminary investigation of secular change within Mexican migrants. The comparison of a sample of recent Mexican migrants with a historic Hispanic sample, predominantly of Mexican origin, allows us to explore morphological similarities and differences between early and recent Mexicans within the United States. Vault and face size and a total of 82 craniofacial interlandmark distances were used to explore secular changes within the recent Mexican migrants (females, n = 38; males, n = 178) and to explore the morphological similarities between historic Hispanics (females, n = 54; males, n = 58) and recent migrants. Sexes were separated, and multivariate adaptive regression splines and basis splines (quadratic with one knot) were used to assess the direction and magnitude

Secured Data Transmission Using Wavelet Based Steganography and cryptography

OpenAIRE

K.Ravindra Reddy; Ms Shaik Taj Mahaboob

2014-01-01

Steganography and cryptographic methods are used together with wavelets to increase the security of the data while transmitting through networks. Another technology, the digital watermarking is the process of embedding information into a digital (image) signal. Before embedding the plain text into the image, the plain text is encrypted by using Data Encryption Standard (DES) algorithm. The encrypted text is embedded into the LL sub band of the wavelet decomposed image using Le...

Using Wavelets in Economics. An Application on the Analysis of Wage-Price Relation

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Vasile-Aurel Caus

2017-03-01

Full Text Available In the last decades, more and more approaches of economic issues have used mathematical tools, and among the most recent ones, spectral and wavelet methods are to be distinguished. If in the case of spectral analysis the approaches and results are sufficiently clear, while the use of wavelet decomposition, especially in the analysis of time series, is not fully valorized. The purpose of this paper is to emphasize how these methods are useful for time series analysis. After theoretical considerations on Fourier transforms versus wavelet transforms, we have presented the methodology we have used and the results obtained by using wavelets in the analysis of wage-price relation, based on some empirical data. The data we have used is concerning the Romanian economy - the inflation and the average nominal wage denominated in US dollars, between January 1991 and May 2016, highlighting that the relation between nominal salary and prices can be revealed more accurately by use of wavelets.

Wavelet-enhanced convolutional neural network: a new idea in a deep learning paradigm.

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Savareh, Behrouz Alizadeh; Emami, Hassan; Hajiabadi, Mohamadreza; Azimi, Seyed Majid; Ghafoori, Mahyar

2018-05-29

Manual brain tumor segmentation is a challenging task that requires the use of machine learning techniques. One of the machine learning techniques that has been given much attention is the convolutional neural network (CNN). The performance of the CNN can be enhanced by combining other data analysis tools such as wavelet transform. In this study, one of the famous implementations of CNN, a fully convolutional network (FCN), was used in brain tumor segmentation and its architecture was enhanced by wavelet transform. In this combination, a wavelet transform was used as a complementary and enhancing tool for CNN in brain tumor segmentation. Comparing the performance of basic FCN architecture against the wavelet-enhanced form revealed a remarkable superiority of enhanced architecture in brain tumor segmentation tasks. Using mathematical functions and enhancing tools such as wavelet transform and other mathematical functions can improve the performance of CNN in any image processing task such as segmentation and classification.

APPLICATIONS OF WAVELETS IN INDUCTION MACHINE FAULT DETECTION APLICACIONES DE WAVELETS EN LA DETECCIÓN DE FALLAS DE MÁQUINAS DE INDUCCIÓN

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Erick Schmitt

2010-08-01

Full Text Available This paper presents a new wavelet-based algorithm for three-phase induction machine fault detection. This new method uses the standard deviation of wavelet coefficients, obtained from n-level decomposition of each phase voltage and current, to identify single-phasing faults or unbalanced stator resistance faults in induction machines. The proposed algorithm can operate independent of the operational frequency, fault type and loading conditions. Results show that this algorithm has better detection response than the Fourier transform-based techniques.Este trabajo presenta un nuevo algoritmo basado en wavelets para la detección de fallas en máquinas de inducción de tres fases. Este nuevo método utiliza la desviación estándar de los coeficientes wavelet, que se obtiene de la descomposición de n-niveles de cada fase, para identificar fallas en el voltaje en una fase o fallas en la resistencia del estator en máquinas de inducción. El algoritmo propuesto puede funcionar independiente de la frecuencia de operación, tipo de falla y condiciones de carga. Los resultados muestran que este algoritmo tiene una mejor respuesta de detección que las técnicas basadas en la transformada de Fourier.

Wigner functions from the two-dimensional wavelet group.

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Ali, S T; Krasowska, A E; Murenzi, R

2000-12-01

Following a general procedure developed previously [Ann. Henri Poincaré 1, 685 (2000)], here we construct Wigner functions on a phase space related to the similitude group in two dimensions. Since the group space in this case is topologically homeomorphic to the phase space in question, the Wigner functions so constructed may also be considered as being functions on the group space itself. Previously the similitude group was used to construct wavelets for two-dimensional image analysis; we discuss here the connection between the wavelet transform and the Wigner function.

Los Dos Mundos: Rural Mexican Americans, Another America.

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Baker, Richard

This book explores race relations between Mexican Americans and Anglo Americans in "Middlewest," a fictitious name for an actual rural Idaho community with the highest proportion of Mexican Americans in the state. Many Mexican Americans in this predominantly agricultural area are current or former migrant workers. The first chapter…

Protein structure analysis using the resonant recognition model and wavelet transforms

International Nuclear Information System (INIS)

Fang, Q.; Cosic, I.

1998-01-01

An approach based on the resonant recognition model and the discrete wavelet transform is introduced here for characterising proteins' biological function. The protein sequence is converted into a numerical series by assigning the electron-ion interaction potential to each amino acid from N-terminal to C-terminal. A set of peaks is found after performing a wavelet transform onto a numerical series representing a group of homologous proteins. These peaks are related to protein structural and functional properties and named characteristic vector of that protein group. Further more, the amino acids contributing mostly to a protein's biological functions, the so-called 'hot spots' amino acids, are predicted by the continuous wavelet transform. It is found that the hot spots are clustered around the protein's cleft structure. The wavelets approach provides a novel methods for amino acid sequence analysis as well as an expansion for the newly established macromolecular interaction model: the resonant recognition model. Copyright (1998) Australasian Physical and Engineering Sciences in Medicine

Iris image recognition wavelet filter-banks based iris feature extraction schemes

CERN Document Server

Rahulkar, Amol D

2014-01-01

This book provides the new results in wavelet filter banks based feature extraction, and the classifier in the field of iris image recognition. It provides the broad treatment on the design of separable, non-separable wavelets filter banks, and the classifier. The design techniques presented in the book are applied on iris image analysis for person authentication. This book also brings together the three strands of research (wavelets, iris image analysis, and classifier). It compares the performance of the presented techniques with state-of-the-art available schemes. This book contains the compilation of basic material on the design of wavelets that avoids reading many different books. Therefore, it provide an easier path for the new-comers, researchers to master the contents. In addition, the designed filter banks and classifier can also be effectively used than existing filter-banks in many signal processing applications like pattern classification, data-compression, watermarking, denoising etc.  that will...

Using wavelet denoising and mathematical morphology in the segmentation technique applied to blood cells images.

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Boix, Macarena; Cantó, Begoña

2013-04-01

Accurate image segmentation is used in medical diagnosis since this technique is a noninvasive pre-processing step for biomedical treatment. In this work we present an efficient segmentation method for medical image analysis. In particular, with this method blood cells can be segmented. For that, we combine the wavelet transform with morphological operations. Moreover, the wavelet thresholding technique is used to eliminate the noise and prepare the image for suitable segmentation. In wavelet denoising we determine the best wavelet that shows a segmentation with the largest area in the cell. We study different wavelet families and we conclude that the wavelet db1 is the best and it can serve for posterior works on blood pathologies. The proposed method generates goods results when it is applied on several images. Finally, the proposed algorithm made in MatLab environment is verified for a selected blood cells.

Accelerometer North Finding System Based on the Wavelet Packet De-noising Algorithm and Filtering Circuit

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LU Yongle

2014-07-01

Full Text Available This paper demonstrates a method and system for north finding with a low-cost piezoelectricity accelerometer based on the Coriolis acceleration principle. The proposed setup is based on the choice of an accelerometer with residual noise of 35 ng•Hz-1/2. The plane of the north finding system is aligned parallel to the local level, which helps to eliminate the effect of plane error. The Coriolis acceleration caused by the earth’s rotation and the acceleration’s instantaneous velocity is much weaker than the g-sensitivity acceleration. To get a high accuracy and a shorter time for north finding system, in this paper, the Filtering Circuit and the wavelet packet de-nosing algorithm are used as the following. First, the hardware is designed as the alternating currents across by filtering circuit, so the DC will be isolated and the weak AC signal will be amplified. The DC is interfering signal generated by the earth's gravity. Then, we have used a wavelet packet to filter the signal which has been done through the filtering circuit. Finally, compare the north finding results measured by wavelet packet filtering with those measured by a low-pass filter. Wavelet filter de-noise data shows that wavelet packet filtering and wavelet filter measurement have high accuracy. Wavelet Packet filtering has stronger ability to remove burst noise and higher engineering environment adaptability than that of Wavelet filtering. Experimental results prove the effectiveness and project implementation of the accelerometer north finding method based on wavelet packet de-noising algorithm.

A Quantitative Analysis of an EEG Epileptic Record Based on MultiresolutionWavelet Coefficients

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Mariel Rosenblatt

2014-11-01

Full Text Available The characterization of the dynamics associated with electroencephalogram (EEG signal combining an orthogonal discrete wavelet transform analysis with quantifiers originated from information theory is reviewed. In addition, an extension of this methodology based on multiresolution quantities, called wavelet leaders, is presented. In particular, the temporal evolution of Shannon entropy and the statistical complexity evaluated with different sets of multiresolution wavelet coefficients are considered. Both methodologies are applied to the quantitative EEG time series analysis of a tonic-clonic epileptic seizure, and comparative results are presented. In particular, even when both methods describe the dynamical changes of the EEG time series, the one based on wavelet leaders presents a better time resolution.

Study on critical heat flux based on wavelet transform in rectangular narrow channels

International Nuclear Information System (INIS)

Zhou Tao; Ju Zhongyun; Zhang Lei; Li Jingjing; Sheng Cheng; Xiao Zejun

2014-01-01

Critical heat flux is very important for nuclear reactor safety, and observing temperature rise rate is a feasible method. Through using the wavelet transform to analyze the CHF temperature rise curves in rectangular narrow channels, it can remove relative weaker interference and effectively judge CHF. Rectangular narrow channel can strengthen heat transfer and reduce CHF, whose characteristics are proved by, temperature rise curves analyzed by wavelet transform. Respectively applying Daubechies function and Haar function is for guarantee the accuracy of the wavelet analysis, and Daubechies function is more accurate than Haar function in the detail signal processing from results. While the wavelet analysis and experimental results are compared and found in good agreement with the experimental results. (authors)

Multidimensional signaling via wavelet packets