14 Hits in 5.6 sec

Using topography statistics to help phase unwrapping

A. Monti Guarnieri
2003 IEE Proceedings - Radar Sonar and Navigation  
This model provides useful statistic information for phase unwrapping.  ...  Conventional techniques approach Phase Unwrapping (PU) as an optimization problem, where figures of merit like the total branch-cut length, the number of cuts, etc, is to be minimized.  ...  Average cut length and direction Current PU techniques are designed to provide the minimal cut length or the minimal average cut height (L0, L1 norm respectively).  ... 
doi:10.1049/ip-rsn:20030565 fatcat:dwfdmxtszzgz3el6twnnkng3ri

Quantitative susceptibility mapping (QSM): Decoding MRI data for a tissue magnetic biomarker

Yi Wang, Tian Liu
2014 Magnetic Resonance in Medicine  
Deconvolution of the MRI signal phase can determine tissue susceptibility but is challenged by the lack of MRI signal in the background and by the zeroes in the dipole kernel.  ...  However, the study of tissue magnetic susceptibility has been hindered by poor molecular specificities of hitherto used methods based on MRI signal phase and T2* contrast, which depend convolutedly on  ...  ACKNOWLEDGMENTS We thank the members and collaborators of Professor Wang  ... 
doi:10.1002/mrm.25358 pmid:25044035 pmcid:PMC4297605 fatcat:zall27kgbnaezl4glzp7kwalfq

Pitched Instrument Onset Detection Based On Auditory Spectra

Emmanouil Benetos, Andre Holzapfel, Yannis Stylianou
2009 Zenodo  
seed bandpass filter where h[n, l] = αh[αn, l 0 ], with scaling factor α = 2 l−l0 and l = 1, . . . , 129.  ...  The spectral flux in the auditory spectrum is defined using the L1 norm: AU D SF [n] = l HW (X A [n, l] − X A [n − 1, l]). (6) For the auditory spectral flux, the original signal is resampled to 8kHz and  ...  The group delay function and spectral flux in the auditory domain were introduced as features for onset detection, and a system was proposed.  ... 
doi:10.5281/zenodo.1416173 fatcat:bz5vevu5rvdhpmr4lkqy2lxrpm

Auditory Spectrum-Based Pitched Instrument Onset Detection

E Benetos, Y Stylianou
2010 IEEE Transactions on Audio, Speech, and Language Processing  
Here, the spectral flux and phase slope features are derived in the auditory framework and a novel fundamental frequency estimation algorithm based on auditory spectra is introduced.  ...  Recent work on onset detection employs DFT-based features describing spectral energy and phase differences, as well as pitchbased features.  ...  seed bandpass filter where h[n, l] = αh[αn, l 0 ], with scaling factor α = 2 l−l0 and l = 1, . . . , 129.  ... 
doi:10.1109/tasl.2010.2040785 fatcat:ycesxbueafearknnis2anot2eq

Monitoring of Expansive Clays over Drought-Rewetting Cycles Using Satellite Remote Sensing

André Burnol, Michael Foumelis, Sébastien Gourdier, Jacques Deparis, Daniel Raucoules
2021 Atmosphere  
Moreover, the relative phase difference between the vertical displacement and surface soil moisture show local variations that are interpreted in terms of depth and thickness of the clay layer, as visualized  ...  With regard to future works, a similar treatment relying fully on remote sensing observations may be scaled up to map larger areas in order to better assess the shrink-swell risk.  ...  XWT image is the 2-D representation of the absolute value and the phase of the complex number in the time-frequency space.  ... 
doi:10.3390/atmos12101262 fatcat:5fg3zqn2fndknblkvyayu5fxmi

Multivariate MR Biomarkers Better Predict Cognitive Dysfunction in Mouse Models of Alzheimers Disease [article]

Alexandra Badea, Natalie A Delpratt, RJ Anderson, Russell Dibb, Yi Qi, Hongjiang Wei, Chunlei Liu, William C Wetsel, Brian B Avants, Carol Colton
2018 arXiv   pre-print
In particular, we aimed to understand the relationship between vulnerable brain circuits and memory deficits measured in the Morris water maze, and we tested several predictive modeling approaches.  ...  To understand multifactorial conditions such as Alzheimers disease (AD) we need brain signatures that predict the impact of multiple pathologies and their interactions.  ...  We thank all CIVM-ers for their efforts to build and maintain this resource, and a collaborative learning environment.  ... 
arXiv:1812.11001v1 fatcat:x4bog23b2nf27gcemorkepugda

Joint inversion of seismic PP- and PS-waves in the ray parameter domain

Feng Zhang, Yanghua Wang, Mike Warner, The Sponsors Of The Centre For Reservoir Geophysics, NERC University Collaboration Scheme
I estimate mixed-phase wavelets for each constant ray-parameter (CRP) pro [...]  ...  Therefore, PP and PS-wave calibration transforms PS-wave reflection events from PS-wave time to the corresponding PP-wave time, and reflections events in a pair of PP- and calibrated PS-wave traces with  ...  Considering that in practice data always have non-Gaussian additive noise, we adopt the minimum L0-norm unwrapping method to deal with the noisy wrapped phase in the 2D domain.  ... 
doi:10.25560/6123 fatcat:jng7epdboffzhdgtxzc3yw4dza

Computational Methods for Enhancing Sensitivity to MRI Cell-Tracking Agents

Parker H. Mills
The third method, called Phase Map Cross-Correlation Detection and Quantification (PDQ), detects isolated magnetic dipoles that indicate the presence of an iron oxide-labeled cell or cell cluster.  ...  The second method, called Phase Slope Magnitude Imaging (PSM), highlights arbitrary distributions of iron oxide CA in tissue.  ...  patchy appearance of some TV-L1 reconstructed images [153] ; and L0 norm minimization to large elements above a user-specified threshold (and regular L1-norm minimization to below-threshold small elements  ... 
doi:10.1184/r1/6715250.v1 fatcat:66kffhlnkfe6nalmv2i3bf2ksq

Image splicing detection with local illumination estimation

Yu Fan, Philippe Carre, Christine Fernandez-Maloigne
2015 2015 IEEE International Conference on Image Processing (ICIP)  
Our approach is data-driven, on both mobile and cloud platforms, leveraging large data-sets and parallel computing clusters to solve problems at scale .  ...  E F G T U V Avenu e Hono ré-Me rcier HALL 2000 FOYER 2000 2 000 D 2 000 C 2 000 B 2 000 A 2 101 2 10 2 A 2 10 2 B 2 0 7 20 2 2 04 A 2 05 A 2  ...  The sensory gap will then be the focus, and its causes (e .g ., resolution, perspective, scale, field of view) will be highlighted with a visual demonstration .  ... 
doi:10.1109/icip.2015.7351341 dblp:conf/icip/FanCF15 fatcat:7ja5gjnp5rafvedc2nman7xcru

Multiple membranes in M-theory

Jonathan Bagger, Neil Lambert, Sunil Mukhi, Constantinos Papageorgakis
2013 Physics reports  
Different choices of 3-algebras lead to distinct classes of 2+1 dimensional theories with varying degrees of supersymmetry.  ...  After discussing the inherent difficulties pertaining to a maximally supersymmetric lagrangian formulation with the appropriate field content and symmetries, we discuss how introducing the concept of 3  ...  This formula nicely reconciles the n 3 2 scaling at fixed k (in particular k = 1) that was predicted long ago in [140] , and the n 2 scaling for the free energy of a large-n gauge theory at fixed 't Hooft  ... 
doi:10.1016/j.physrep.2013.01.006 fatcat:c2ra56s7qbbh7efgkyzzoa65ze

Sampling strategies and reconstruction techniques for magnetic resonance imaging [article]

Nicholas D. Blakeley, University Of Canterbury
These types of sampling schemes are applicable to 3-D Cartesian MRI, MRSI, and other modalities that measure a single point in 2-D k-space per echo.  ...  The two issues considered are where to position the samples (sampling strategies) and how to form an image (reconstruction techniques).  ...  columns indexed by sets a and ,8 submatrix of A with rows indexed by the set a and all columns subvector of x with rows indexed by the set a 2-norm (or spectral norm) of a matrix or vector Frobenius norm  ... 
doi:10.26021/2930 fatcat:6yplpxtptbconphgmnuxl7znii

Zero-based ensemble deconvolution and EEG spectral topography [article]

Brenda Lee Satherley, University Of Canterbury
Given sufficient knowledge of a zero sheet, it is possible to reconstruct, to within a complex scaling factor, the image from which the zero sheet was derived.  ...  This thesis presents theoretical and practical aspects of two distinctly different topics - zero­ based two-dimensional ensemble blind deconvolution and spectral topography of the electroencephalogram.  ...  ACKNOWLEDGEMENTS I deeply appreciate the guidance, encouragement, support and friendship that many people have extended to me throughout the period of my PhD.  ... 
doi:10.26021/2528 fatcat:yt6qkat4lvgoxgv5a7i2iwwrm4

Aalborg Universitet Guidance, Navigation, Control and Relative Dynamics for Spacecraft Proximity Maneuvers Ankersen, Finn FINN ANKERSEN Guidance, Navigation, Control and Relative Dynamics for Spacecraft Proximity Maneuvers Guidance, Navigation, Control and Relative Dynamics for Spacecraft Proximity Maneuvers in Denmark Preface and Acknowledgments

Finn Ankersen, Thesis, Finn Ankersen, Finn Ankersen, Finn Ankersen, Finn Ankersen
2010 unpublished
Secondly control methods and designed Guidance, Navigation and Control for the 6 degree of freedom systems will be compared and traded off.  ...  This will form the basis for developing the expressions for general ∆V maneuvers and the special properties of radial and tangential ones.  ...  F L = F L1 + F L0 and F S = F S1 + F S0 (3.33) As F L0 = F S0 Equation (3.32) yield F P = F L1 − F S1 (3.34) and F L1 = k s x 1 + c sẋ1 (3.35) F S1 = m 1 γ tank (3.36) where x 1 is the displacement of  ... 

The Price of Bananas" 189-194 Pooja

M Thirumalai, B Mallikarjun, Sam, B A Sharada, A R Fatihi, Lakhan, Marie Jennifer, S M Bayer, G Ravichandran, L Baskaran, C Ramamoorthy, Subburaman (+26 others)
2015 Thoughts on Mulk Raj Anand's Story   unpublished
Community, Aspirations and English: A Sociolinguistic Study of a West Bengal Village 91-99 Michael Leeming, M.A. (Biblical Studies), M.  ...  D. for helping us with the statistical analysis. And also our sincere thanks to all our friends who participated in this study.  ...  We acknowledge the help of our participants and family members for their cooperation during this study.  ...