New York could as well have been Dutch. In 1609, English explorer Henry Hudson (according to wikipedia):
re-discovered the region, sailing for his employer the Dutch East India Company. He proceeded to sail up what he named the North River, also called the Mauritis River, and now known as the Hudson River, to the site of the present-day New York State capital of Albany in the belief that it might represent an oceanic tributary. When the river narrowed and was no longer saline,
he realized it wasn't a sea passage and sailed back downriver. He made a
ten-day exploration of the area and claimed the region for his
employer. In 1614 the area between Cape Cod and Delaware Bay would be claimed by the Netherlands and called Nieuw-Nederland (New Netherland).
There are many good reasons to go to New York City and send a lot of time strolling through this amazing city. One of the reasons that led me to first ride on Greyhound on 1998 from Boston to New York is the album Nits in concert, which i bought earlier in a second-hand record shop in Boston. A relatively rare promo-CD where the Nits (a Dutch band) explain some of their songs' lyrics meanings. Which is a neat way to dive into their song writing atmosphere.
On Nits in concert, there is a track called "A touch of Henry Moore", where they allude (lyrics) to a sculpture called "Reclining figure" (1965). It was 15 years ago at UNO headquarters, it now dwells at the Lincoln Center. Here i was back again this Tuesday (picture on the top left). I like this instrumentally minimalist version of "A touch of Henry Moore" (from album Omsk), which still evokes the hammering of a brass being. Another version used a large tube & pipe wall, My second best remains this one, in a more visually appealing vision with percussions on a blocky squared wall.
Detailed knowledge of petroleum products at molecular scale has always been essential to
understand the mechanisms leading to their formation, to design thermodynamic and kinetic models employed in the refining processes and to predict their physical properties. In view of the complexity of petroleum products, very significant research efforts have been made over the past 15 years for improving relevant analytical techniques, especially in the field of Gas Chromatography in order to improve its separation power. The advent of comprehensive Two-dimensional Gas Chromatography (GC×GC) at the end of 1990's constitutes a true revolution allowing an unprecedented insight into very complex mixture at the molecular level.
This book aims at providing a complete review of the implementation of Gas Chromatography in the field of oil industry, with an important focus on GC×GC and related multidimensional systems. It is therefore organised into 8 chapters dealing with fundamental and experimental aspects as well as data processing challenges. Recent progress in the development of these chromatographic systems are discussed according to various applications: detailed molecular analysis of hydrocarbons, speciation of hetero-element, global properties calculation based on chromatographic data and simulated distillation. Specialists from IFP Energies nouvelles, CNRS and major companies leading important research in this field have contributed, reporting a synthesis of the knowledge acquired from research these last 15 years.
Thus, this book will be useful for anyone involved in the separation of oil and derivatives: the student starting a research project, the academic researcher and the refinery engineer willing to deepen their knowledge on advanced multidimensional Gas Chromatography, as well as molecular analysis of petroleum products.
Contents: 1. Molecular analysis for petroleum products: challenges and future needs. 2. GCxGC: a disruptive technique. 3. Data processing applied to GCxGC. Applications to the petroleum industry. 4. Coupled systems with a CG or GCxGC dimension. 5. Detailed analysis of hydrocarbons. 6. Calculating properties from chromatographic data. 7. Speciation of heteroelements. 8. Simulated distillation. Index.
Comprehensive two-dimensional gas chromatography (GC
xGC or GC2D) is a major
advance for the detailed characterisation of petroleum products. This technique is based on two
orthogonal dimensions of separation achieved by two chromatographic capillary columns of different
chemistries and selectivities. High-frequency sampling between the two columns is achieved by a
modulator, ensuring that the whole sample is transferred and analysed continuously in both separations.
Thus, the peak capacity and the resoluting power dramatically increase. Besides, highly structured 2D
chromatograms are obtained upon the volatility and the polarity of the solute to provide more accurate
molecular identification of hydrocarbons. In this paper fundamental and practical considerations for
implementation of GCxGC are reviewed. Selected applications obtained using a prototype of a GCxGC
chromatograph developed in-house highlight the potential of the technique for molecular
characterisation of middle distillates, sulphur speciation in diesel and analysis of effluents frompetrochemical processes
The detailed characterisation of middle distillates is
essential for a better understanding of reactions involved in refining
process. Owing
to higher resolution power and enhanced sensitivity, comprehensive
two-dimensional gas chromatography (GCxGC) is a powerful tool
for improving characterisation of petroleum samples. The aim of this
paper is to compare GCxGC and various ASTM methods – gas
chromatography (GC), liquid chromatography (LC) and mass spectrometry
(MS) – for group type separation and detailed hydrocarbon
analysis. Best features of GCxGC are demonstrated and compared to these
techniques in terms of cost, time consumption and accuracy. In
particular, a new approach of simulated distillation (SimDis-GCxGC) is
proposed: compared to the standard method ASTM D2887 it gives
unequal information for better understanding of conversion process.
Comprehensive two-dimensional gas chromatography (GCxGC) has
been investigated for the characterization of high valuable
petrochemical samples from dehydrogenation of n-paraffins,
Fischer–Tropsch and oligomerization processes. GCxGC separations,
performed
using a dual-jets CO2 modulator, were optimized using a test mixture
representative of the hydrocarbons found in petrochemicals. For complex
samples, a comparison of GCxGC qualitative and quantitative results with
conventional gas chromatography (1D-GC) has demonstrated an
improved resolution power of major importance for the processes: the
group type separation has permitted the detection of aromatic compounds
in the products from dehydrogenation of n-paraffins and from
oligomerization, and the separation of alcohols from other hydrocarbons
in
Fischer–Tropsch products.
ICASSP 2013 (International conference on acoustic, speech and signal processing) takes place at the end of May 2013 in Vancouver, Canada. The technical program is online.
Summary of the Special Session:
This special session aims at showing some relevant problems in chemical engineering that can be addressed with classical or advanced methods of signal and image processing. It will be introduced by a tutorial paper, presented by the organizers, who will offer a large overview of issues which have been addressed in this application domain, like chemical analysis leading to PARAFAC/tensor methods, hyper spectral imaging, ion-sensitive sensors, artificial nose, chromatography, mass spectrometry, TEP imaging, etc. For enlarging and illustrating the points of view of the tutorial, the invited papers of the session consider other applications (NMR, Raman spectroscopy, recognition of explosive compounds, etc.) addressed by various methods, e.g. source separation, Bayesian or EMD, and exploiting priors like positivity, unit-concentration or sparsity.
Typical chemical signals: 2D comprehensive gas chromatogram (GCxGC)
Motivation and rationale of the Special Session:
With the advent of more affordable, higher resolution or innovative data acquisition techniques, chemical analysis has been using progressively advanced signal and image processing tools. This crucial need is exemplified in the Savitzky-Golay filter, which recently was thoroughly revisited by R. W. Schafer ("What Is a Savitzky-Golay Filter?", Signal Processing Magazine, Jul. 2011). Indeed, both specialities (analytical chemistry and signal processing) share similar values of best practice in carrying out identifications and comprehensive characterizations, albethey of chemical samples or of numerical data. Signal and image processing, for instance, often breaks down data into atoms, molecules, with specific decompositions and priors, as common in chemistry.
This special session will gather a representative sample of recent works in chemical sensing, aiming at introducing its specific challenges to a broader signal processing audience, for the benefits of both domains.
Abstract: This tutorial paper aims at summarizing some problems, ranging from analytical chemistry to novel chemical sensors, that can be addressed with classical or advanced methods of signal and image processing. We gather them under the denomination of "chemical sensing". It is meant to introduce the special session "Signal Processing for Chemical Sensing" with a large overview of issues which have been and remain to be addressed in this application domain, including chemical analysis leading to PARAFAC/tensor methods, hyper spectral imaging, ion-sensitive sensors, artificial nose, chromatography, mass spectrometry, etc. For enlarging and illustrating the points of view of this tutorial, the invited papers of the session consider other applications (NMR, Raman spectroscopy, recognition of explosive compounds, etc.) addressed by various methods, e.g. source separation, Bayesian, and exploiting typical chemical signal priors like positivity, linearity, unit-concentration or sparsity. Keywords: Chemical analysis, Chemical sensors, Gas chromatography, Signal processing algorithms, Spectroscopy
Abstract: This paper deals with the reconstruction of relaxation time distributions in Nuclear Magnetic Resonance (NMR) spectroscopy. This large scale and ill-posed inverse problem is solved by the iterative minimization of a regularized objective function allowing to encode some prior assumptions on the sought distribution. The numerical optimization of the criterion is performed using a primal-dual interior point algorithm allowing to handle the non-negativity constraint. The performances of the proposed approach are illustrated through the processing of real data from a two-dimensional NMR experiment. Keywords: T1-T2 relaxation times, Laplace transform inversion, interior-point, primal-dual, preconditioning
Abstract: We propose a sparse modal estimation approach for analyzing 2-D NMR signals. It consists in decomposing the 2-D problem into two 1-D modal estimations. Each 1-D problem is formulated in terms of simultaneous sparse approximation which is efficiently solved using the Simultaneous Orthogonal Matching Pursuit method associated with a multi-grid dictionary refinement. Then, we propose a new criterion for mode pairing which comes down to solve a sparse approximation problem involving a low dimensional dictionary. The effectiveness of the method is demonstrated on real NMR data. Keywords: Modal retrieval, sparse approximation, multi-grid, 2-D NMR
Abstract: New sensor technologies such as Fabry-Pérot interferometers (FPI) offer low-cost and portable alternatives to traditional infrared absorption spectroscopy for chemical analysis. However, with FPIs the absorption spectrum has to be measured one wavelength at a time. In this work, we propose an active-sensing framework to select a subset of wavelengths that best separates the specific components of a chemical mixture. Compared to passive feature selection approaches, in which the subset is selected offline, active sensing selects the next feature on-the-fly based on previous measurements so as to reduce uncertainty. We propose a novel multi-modal non-negative least squares method (MM-NNLS) to solve the underlying linear system, which has multiple near optimal solutions. We tested the framework on mixture problems of up to 10 components from a library of 100 chemicals. MMNNLS can solve complex mixtures using only a small number of measurements, and outperforms passive approaches in terms of sensing efficiency and stability. Keywords: Active sensing, tunable sensors, multi-modal optimization, chemical mixture analysis
Abstract: In this paper, a novel gas identification approach based on the Recursive Least Squares (RLS) algorithm is proposed. We detail some adaptations of RLS to be applied to a sensor matrix of several technologies in optimal conditions. The low complexity of the algorithm and its ability to process online samples from multi-sensor make the real-time identification of volatile compounds possible. The effectiveness of this approach to early detect and recognize explosive compounds in the air has been successfully demonstrated on an experimentally obtained dataset. Keywords: Electronic nose, Pattern recognition, Multidimensional analysis, Recursive Least Squares
Two others ICASSP 2013 papers are something related to the topic:
Assuming you have a standard Gaussian bell curve (in blue). Suppose that you want to cut it into two parts of equal area, horizontally.
Which fraction of the Gaussian peak height provides you with the red and the green curves, with equal surface integral?
It turns out that, numerically, the fraction, on the y-axis, is about 0.3063622804625085, or one over 3.26410940175247 of the peak height. If one looks at the x-axis, one has to cut at +/- 1.538172262286592.\sigma, if \sigma is the usual Gaussian scale parameter. In practice, cutting the Gaussian at 3/10 of the height would be good enough, assuming sufficient sampling. Yet out of curiosity, i looked at numerical constant tables, or even Plouffe's constant inverter, and did not find any of these three. Once again:
0.3063622804625085
1.538172262286592
3.26410940175247
Does anybody knows whether this Gaussian split is "common practice" in some field, or if these constants are listed somewhere?
Résumé : La quête de représentations optimales en traitement d'images et vision par ordinateur se heurte à la richesse et la diversité des données bidimensionnelles. De nombreux travaux se sont cependant attelés aux tâches de séparation de zones régulières, de contours et de textures, à la recherche d'un compromis entre complexité et efficacité de représentation. La prise en compte des aspects multi-échelles, dans le siècle de l'invention des ondelettes, a joué pour l'analyse d'images un rôle important. La dernière décennie a ainsi vu apparaître une série de méthodes efficaces, combinant des aspects multi-échelle à des aspects directionnels et fréquentiels, permettant de mieux prendre en compte l'orientation des éléments d'intérêt des images (curvelets, contourlets et autres shearlets). Leur fréquente redondance leur permet d'obtenir des représentations plus parcimonieuses et parfois quasi-invariantes pour certaines transformations usuelles (translation, rotation). Ces méthodes sont la motivation d'une revue thématique, incluant quelques incursions sur des domaines non-euclidiens (sphère, maillages, graphes).
Abstract: The richness of natural images makes the quest for optimal representations in image processing and computer vision challenging. The latter observation has not prevented the design of image representations, which trade off between efficiency and complexity, while achieving accurate rendering of smooth regions as well as reproducing faithful contours and textures. The most recent ones, proposed in the past decade, share a hybrid heritage highlighting the multiscale and oriented nature of edges and patterns in images. This paper presents a panorama of the aforementioned literature on decompositions in multiscale, multi-orientation bases or dictionaries. They typically exhibit redundancy to improve sparsity in the transformed domain and sometimes its invariance with respect to simple geometric deformations (translation, rotation). Oriented multiscale dictionaries extend traditional wavelet processing and may offer rotation invariance. Highly redundant dictionaries require specific algorithms to simplify the search for an efficient (sparse) representation. We also discuss the extension of multiscale geometric decompositions to non-Euclidean domains such as the sphere or arbitrary meshed surfaces. The etymology of panorama suggests an overview, based on a choice of partially overlapping “pictures”. We hope that this paper will contribute to the appreciation and apprehension of a stream of current research directions in image understanding.
After about a hundred starlets or wavelets in *let, the newborn ERBlet borrows from the auditory scale, namely the Equivalent Rectanguar Bandwidth and the non-stationary Gabor transforms (NSGT). See more at WITS: where is the Starlet. The attendant Matlab toolbox is there (ICASSP 2013).
ERBlet
In short:
A linear and invertible time-frequency transformation adapted to human auditory perception, for masking and perceptual sparsity
Time-frequency representations are widely used in audio applications involving sound analysis-synthesis. For such applications, obtaining a time-frequency transform that accounts for some aspects of human auditory perception is of high interest. To that end, we exploit the theory of non-stationary Gabor frames to obtain a perception-based, linear, and perfectly invertible time-frequency transform. Our goal is to design a non-stationary Gabor transform (NSGT) whose time-frequency resolution best matches the time-frequency analysis properties by the ear. The peripheral auditory system can be modeled in a first approximation as a bank of bandpass filters whose bandwidth increases with increasing center frequency. These so-called “auditory filters” are characterized by their equivalent rectangular bandwidths (ERB) that follow the ERB scale. Here, we use a NSGT with resolution evolving across frequency to mimic the ERB scale, thereby naming the resulting paradigm "ERBlet transform". Preliminary results will be presented. Following discussion shall focus on finding the "best" transform settings allowing to achieve perfect reconstruction while minimizing redundancy.
Thibaud Necciari with P. Balazs, B. Laback, P. Soendergaard, R. Kronland-Martinet, S. Meunier, S. Savel, and S. Ystad, The ERBlet transform, auditory time-frequency masking and perceptual sparsity, 2nd SPLab Workshop, October 24–26, 2012, Brno
The ERBlet transform, time-frequency masking and perceptual sparsity
Time-frequency (TF) representations are widely used in audio applications involving sound analysis-synthesis. For such applications, obtaining an invertible TF transform that accounts for some aspects of human auditory perception is of high interest. To that end, we combine results of non-stationary signal processing and psychoacoustics. First, we exploit the theory of non-stationary Gabor frames to obtain a linear and perfectly invertible non-stationary Gabor transform (NSGT) whose TF resolution best matches the TF analysis properties by the ear. The peripheral auditory system can be modeled in a first approximation as a bank of bandpass filters whose bandwidth increases with increasing center frequency. These so-called “auditory filters” are characterized by their equivalent rectangular bandwidths (ERB) that follow the ERB scale. Here, we use a NSGT with resolution evolving across frequency to mimic the ERB scale, thereby naming the resulting paradigm “ERBlet transform”.
Second, we exploit recent psychoacoustical data on auditory TF masking to find an approximation of the ERBlet that keeps only the audible components (perceptual sparsity criterion). Our long-term goal is to obtain a perceptually relevant signal representation, i.e., as close as possible to “what we see is what we hear”. Auditory masking occurs when the detection of a sound (referred to as the “target” in psychoacoustics) is degraded by the presence of another sound (the “masker”). To accurately predict auditory masking in the TF plane, TF masking data for masker and target signals with a good localization in the TF plane are required. To our knowledge, these data are not available in the literature. Therefore, we conducted psychoacoustical experiments to obtain a measure of the TF spread of masking produced by a Gaussian TF atom.
The ERBlet transform and the psychoacoustical data on TF masking will be presented. The implementation of the perceptual sparsity criterion in the ERBlet will be discussed.
The ranking, which measures innovation in intellectual property, is determined using a variety of patent-related criteria. This includes application success (the ratio of published applications to granted patents), the volume of patents in innovative areas like new technologies, global coverage (inventions patented with all "quadrilateral" patent authorities, i.e. in Europe, Japan, China and the US) and the patents' impact (the number of times they are cited by competitors).
The award is due recognition of IFPEN's policy of innovation and industrial development, aimed at protecting research, promoting technology transfer to industry, and creating wealth and jobs.
It is not the first time IFPEN has been rewarded for innovation. In 2011 the French institute for intellectual property (INPI) ranked it 11th in France by number of published patents. That puts IFPEN among the top three research bodies in France, with the French Atomic Energy Commission (CEA), and the French National Scientific Research Center (CNRS). When adjusted to account for workforce (1,700 staff), IFPEN climbs to number one.
According to a researcher (hic) at Salonic University, it doesn't matter in what order the letters in a word are, the only important thing is the quantity of Beaujolais Nouveau wine you have drunk before. This external advertising panel outside a Nicolas shop distills: "Le Beaujolais nouveau est arrivé" in a drunkard anagram: "Le beuajolias nuovaeu est avriré". See what it does to the poor Alan Parsons Project.
The ad takes on the September 2003 hoax on the unimportance of the order of letters, according to a forged researcher (sic) at Cambridge University (Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy).
Original: Uit de wiskundige analyse volgde dat de integraal van deze functie nul moet zijn en dat deze functie naar nul moet convergeren als het argument naar oneindig gaat. M.a.w. deze functie moet een beetje "schommelen" en dan geleidelijk uitsterven; het is een soort "lokaal golfje".
Scrambled: Uit de wskngdiuie aaslyne vdogle dat de igtanaerl van deze ficntue nul meot zijn en dat deze ficntue naar nul meot ceervongern als het agnumert naar oineindg gaat. M.a.w. deze ficntue meot een bteeje "seoemmhcln" en dan gileeeiljdk uirsteevtn; het is een sroot "lakaol gfojle".
It works with Dutch. I cannot equally read both texts. Here are two interesting texts, with studies in different languages, pertaining to the case. None from Cambridge university.
This paper describes a novel theoretical framework of how the position of a letter within a string is encoded, the SERIOL model (sequential encoding regulated by inputs to oscillations within letter units). Letter order is represented by a temporal activation pattern across letter units, as is consistent with current theories of information coding based on the precise timing of neural spikes. The framework specifies how this pattern is invoked via an activation gradient that interacts with subthreshold oscillations and how it is decoded via contextual units that activate word units. Using mathematical modeling, this theoretical framework is shown to account for the experimental data from a wide variety of string-processing studies, including hemispheric asymmetries, the optimal viewing position, and positional priming effects.
In the last decade, reading research has seen a paradigmatic shift. A new wave of computational models of orthographic processing that offer various forms of noisy position or context-sensitive coding have revolutionized the field of visual word recognition. The influx of such models stems mainly from consistent ?ndings, coming mostly from European languages, regarding an apparent insensitivity of skilled readers to letter order. Underlying the current revolution is the theoretical assumption that the insensitivity of readers to letter order reflects the special way in which the human brain encodes the position of letters in printed words. The present article discusses the theoretical shortcomings and misconceptions of this approach to visual word recognition. A systematic review of data obtained from a variety of languages demonstrates that letter-order insensitivity is neither a general property of the cognitive system nor a property of the brain in encoding letters. Rather, it is a variant and idiosyncratic characteristic of some languages, mostly European, reflecting a strategy of optimizing encoding resources, given the specific structure of words. Since the main goal of reading research is to develop theories that describe the fundamental and invariant phenomena of reading across orthographies, an alternative approach to model visual word recognition is offered. The dimensions of a possible universal model of reading, which outlines the common cognitive operations involved in orthographic processing in all writing systems, are discussed.
Do not "Drunk in the gutter", "Greet unkind truth".
ICASSP 2013 (to to held in Vancouver, Canada, May 2013) deadline has been nicely extended to November 30th, 2012.(Rare) updates on Twitter. From the grapevine, the accepted special session list includes the following:
Organizers: Mark Plumbley, Dimitris Giannoulis, Mathieu Lagrange
Title: Acoustic Event Detection and Scene Analysis.
Organizers: Mauro Barni, Fernando Pérez-González
Title: Advances in adversary-aware signal processing.
Organizers: Tao Zhang and Philip Loizou
Title: Challenges, Solutions and Future Directions in Signal Processing Research for Hearing Instruments.
Organizers: Ali N. Akansu and Ilya Pollak
Title: Financial Signal Processing and Electronic Trading.
Organizers: Li Deng, Geoff Hinton, Brian Kingsbury
Title: New types of deep neural network learning for speech recognition and related applications.
Back in 2002 ICASSP, i thought Orlando had a little something... artificial. Fake trees, weird hotels. Ten years later in 2012 SEG (Society of Explorations Geophysicists) annual meeting in Las Vegas, well the fake fragrance mixes even more with air conditioned, and the weather is really cool. No need to keep twitting on the event because Matt Hall at Agile* does it already. The papers i'll have to study a little deeper are the following:
I'm keeping a last word for Generalized windowed transforms for seismic processing and imaging (Charles C. Mosher). Having worked with wavelets in geophysics for decades, Chuck comes up with a 20 years' work on developing a slighly redundant windowed transform, based on finite support filters in the frequency domain associated with fractional subsampling, to reduce the aliasing, and moving artifacts to some form of blending. This ends up in a non tight frame, mostly implemented in the Fourier transformed domain.
This transform is meant to be used in blended acquistion, or even compressing sensing, two of the current trends in geophysical meetings. No wonder, the cost of data acquisition is so high in seismic exploration that one may expect huge savings if they succeed in reducing the acquisition rate by just a factor of two. What puzzles me, still, is that the same petroleum industry which could not loose 1-bit out of 24-integer or 32-bit float data in lossy compression, now looked at blended acquisition (followed by source separation) or compressive sensing has potential data deluge saviors. I even have the feeling that a few people cannot yet tell the difference between those two.
Who compressively senses the compressive sensing folks (cf. Quis custodiet ipsos custodes?)? In an exchange among technical chairs for a conference with a close deadline, we notice the following mention:
Please pay particular attention to reviewers who can deal with compressed sensing papers. Extrapolating from previous years, there are typically almost a 100 papers in compressed sensing - and so we need a lot of capable reviewers in the area.
Impressive. So who does compressively sense the compressive sensing community? Nuit Blanche does sense it, maybe not quite compressively (hence, its audience). I guess there exists redundancy in the published stuff, should one try to reduce drastically the selection on compressive sensing, not based on "peer evaluation", maybe on random picking? Or assuming some Finite Rate of Innovation in a period of time? Hurry up, rumors are the NSF (not NFS nor NHS, thank you Igor) may shrink the funding on such topics...
All along the watch tower (Bob Dylan) by Calvin Russell
The November-December 2012 issue of Geophysics (Volume 77, Issue 6) features (at last) a recent work performed on model-based, adaptive multiple removal in seismic. The concept is illustrated on the figure to the left. Signal obtained from direct reflections of interest (blue) are mixing with other waves bouncing between layers (red). They look alike except for differential attenuation in the frequency domains, different slopes in CMP gathers. Those interested could have a look at the booklet Seismic multiple removal techniques: past, present and future by Eric J. (Dirk) Verschuur. Those more patient may want to waiting for Seismic Multiple Elimination Techniques, by the same author, which should be published in June 2013.As the problem is quite complex per se, hundred of papers have been devoted to multiple elimination techniques, since the January 1948 special issue of Geophysics. A common approach consists in first computing one or several approximate models of the multiple reflections, and then trying to adaptively substract the model from the data. Such techniques usually combine an adapted representation (Fourier, Radon, different breeds of wavelets) and a matching or separation technique. The one we finally published resides at one end of the representation/matching spectrum, to cope with the industrial partner requirements. A somewhat redundant complex wavelet tranform (and yes, combining a Morlet wavelet frame and the complex trace, so to say) and a very simple sliding window 1-tap adaptive filter estimation on the complex scalogram, to adapt and remove a template disturbance signal from the original seismic trace. Maybe not the most theoretically proven approach, but a decent, fancy blend of complex wavelets and adaptive filtering, and some industrialized code that works. And a milestone in a nice collaborative venture, especially with Sergi Ventosa, now at IPGP. And finally published (took 1.5 years). So here it is:
Sergi Ventosa, Sylvain Le Roy, Irène Huard, Antonio Pica, Hérald Rabeson, Patrice Ricarte, Laurent Duval
Abstract:Adaptive subtraction is a key element in predictive multiple-suppression methods. It minimizes misalignments and amplitude differences between modeled and actual multiples , and thus reduces multiple contamination in the dataset after subtraction. The challenge consists in attenuating multiples without distorting primaries, despite the high cross-correlation between their waveform. For this purpose, this complicated wide-band problem is decomposed into a set of more tractable narrow-band problems using a 1D complex wavelet frame. This decomposition enables a single-pass adaptive subtraction via single-sample (unary) complex Wiener filters, consistently estimated on overlapping windows in a complex wavelet transformed domain. Each unary filter compensates amplitude differences within its frequency support, and rectifies more robustly small and large misalignment errors through phase and integer delay corrections . This approach greatly simplifies the matching filter estimation and, despite its simplicity, compares promisingly with standard adaptive 2D methods, on both synthetic and field data.
The preprint version is available, with nice color figures, under the umbrella of Arxiv. Next in line: explore other ends of the matching/transform spectrum. Comments welcome.
Typical the kind of image that makes me (still) love image processing. So the "light green" spiraled stripelets have the same color corrdinates (yes, R,G,B) as the "light blue" ones. I have checked it with XnView.
There is still room for image processing algorithms that meet vision stimuli.
The two-penny philosophical question: do these two colors actually merge at the aliased warped end in the center? Indeed, the phenomenon is related to the scale of observation, as one may obseve by zooming in and see how the green and the blue reduce there perceptual distance. Funnily enough, the illusion also works with at least one color blind and image processing specialist colleague (Frédéric Morain-Nicolier @ Pixel Shaker) who has been kind enough to discuss these issues. So here is the thumbnail and an enlarged version. Of course, youcannot fully trust the present image renderer, but try by yourself.
Although conferences = concern fees (with the anagram equivalence) for a few organizers, they allow to grab a few call for papers to other conferences. Grabbed from EUSIPCO 2012, along with cfp1 and cfp2 (on time-frequency theory and applications), and after a couple of proofs from a finally painfully published paper in Geophysics, the recent opening of GRETSI 2013 website in Brest, France, provides a good opportunity to release the latest updates on Signal, Image and Volume Analysis (SIVA) Conferences:
Eurographics 2013 (Annual conference of the European Association for Computer Graphics) calls for papers on 21/09/2013. CVPR 2015 (IEEE Conference on Computer Vision and Pattern Recognition) is announced in Boston, Massachussetts, USA; ICIP 2016 (IEEE International Conference on Image Processing) in Phoenix, Arizona, USA; ICCV 2015 (International Conference on Computer Vision) in Santiago, Chile.
In recent years, research in the area of Condition-Based Maintenance
(CBM) and Modal Analysis (MA) has been growing rapidly benefiting from
the development of more advanced and accurate time-frequency methods.
CBM is a decision making strategy which was introduced to recommend
maintenance actions when the output of the sensors placed on the
physical equipment fulfill a set of predefined criteria defining
abnormal behaviors. CBM is based on using real-time data to prioritize
and to optimize maintenance resources. It enables real-time diagnosis of
impending failures and prognosis of remaining useful life of equipment
without interrupting normal operations through analyzing and
interpreting the measured data. Intensively used in CBM, the MA is
concerned with the identification of the natural mode shapes and
frequencies of structures or fluids under vibrational excitation.
Multi-purpose time-frequency methods like the short-time Fourier
transform, the Wigner-Ville distribution or wavelets etc. are signal
processing techniques which are applied in mechanical structures
analysis for investigating functional parameters that are evolving in
time like structural damages, cracks or deformations. Their usefulness
in practice consists mainly in the fact that they are non-invasive
techniques. This call for papers is aiming to stimulate not only new
insides on the standard time-frequency techniques for signal processing
but also recently developed methods like non-stationary Gabor frames,
curvelets, adaptive wavelet families, sparse decompositions etc. with
potential applications to dynamic data processing in manufacturing,
mechanical structures and acoustics. Therefore, the main objective of
this special issue is to bring the ideas of worldwide research community
to present the latest developments and to advance the fields of CBM and
MA through applications of the modern time-frequency processing
techniques.
The following topics are of main interest:
Time-frequency methods for diagnostics, prognostics and features extraction
Time-frequency methods for modal analysis
Wavelet-based vibration monitoring and control
Natural frequencies identification
Sparse signal analysis
Online, segment-wise and parallel time-frequency implementations
Assessment studies of different signal processing techniques
Hardware and application constraints when building CBM systems
Applications in radar, mechanics, acoustics, etc.
The specified topics should be viewed as guidelines but any original
interpretation of the signal processing methods for CBM and MA will be
considered.
Important dates:
Manuscript due: November 30, 2012
First Round of Reviews: January 31, 2013
Second Round of Reviews: March 31, 2013
Publication date: June 1, 2013
Submission Guidelines:
Authors are invited to submit their papers via the Elsevier submission web site at http://ees.elsevier.com/sigpro/login.asp and please select the Item: “Time-frequency for CBM&MA” after you log in as an author. Please also refer to the complete Author Guidelines.
The 4-page white paper should address: the motivations, importance, timeliness of the topics, an outline of the paper structure and content, some words about the authors (for the special issue editors). No style imposed: 4-page one-column would be enough.
The special issue (not yet on the special issue page) seeks to present recent advances in time-frequency (TF) signal analysis, using both linear and nonlinear decompositions.
Topics include:
advances in detection, estimation and classification using TF signatures
instantaneous frequency estimation
robust TF signal representations
new advances in TF localization and uncertainty principles
Ingrid Daubechies (wiki page) has just been granted? awarded? made a baroness title by the King of Belgium. She is has a PhD in Physics from Vrije Universiteit Brussel (VUB), teaches at Princeton and Duke universities, and is the present president of the "International Mathematical Union". She is famous to waveleters for many progresses, among others, in frame sampling, wavelet design (e.g. daublets & coiflets), (two-scale) difference equations, orthogonal and biorthogonal bases design, fast, integer, lifting, irregular and signal edge-aware implementation, time-frequency reassignment, inverse problems, fractal properties, compression, with a recent brush(let)strocke towards artist (van Gogh) identification, to mention a few. Have a look... Soon, she will be another distinguished line on http://fr.wikipedia.org/wiki/Cat%C3%A9gorie:Baron_belge.
http://www.mortati.com/glusker/fowler/
The ternary calculating machine of Thomas Fowler
[In a word: e (2.71828...) is the most efficient base for storing digital information. Not two. Three would be the best practical information base. Ternary arithmetic rulez]
This short post is inspired by Igor Carron's The 2-bit Aggie weather station. Igor proposes us the three-valued (bbl) system for assessing weather conditions, with a brick put outside: brown, bright, left
If brick is dark brown, it's a sure sign that it's raining outside.
If the brick is bright, then it's sunny outside.
If the brick is not there anymore, it's a tornado.
The weird machine on the right is not a brick, and is better described in The ternary calculating machine of Thomas Fowler, IEEE Annals of the History of Computing, 2005, by Glusker, Hogan, and Vass.
Bender: Ahhh, what an awful dream. Ones and zeroes everywhere... and I thought I saw a two.
Fry: Don't worry, Bender: there's no such thing ...
Futurama
Among the very few scientific results i can grasp, a very few simple ones jump to my mind and keep me amazed:
the fact that the Wiles-Fermat theorem is almost trivial in polynomial ring (see Mason-Stothers ABC theorem, based on Wronskians for complex coefficients, showing that max(deg(A(a),deg(B(x),deg(C(x))) + 1 <= # roots (A(x)B(x)C(x))
The most radical one, pertaining to signal acquisition and representation, lies between the binary and the ternary systems: from bits to trits, from bytes to trytes. It states that the "most efficient" storing system is "e", from Euler's number, not to confuse with Mascheroni-Euler constant, gamma, (the one from the natural logarithm). I am quite surprised the binary system pervades so much the present digital world that this "fact" is quite often ignored. Indeed, when i try to gather some information on that topic, i generally do not remember where to start from. Which keywords (trit for "ternary digits" similar to bits for "binary digits", or "tryte" versus "byte" for the "words" themselves, trinary or ternary), what sources?
The basic idea is that, when trying to represent a number in concise or sparse form on d-digits (or number byte-width), one could choose the biggest b-base (or bit-depth, the number of symbols per "digit") for representation. In a similar way for signal or image processing, the sparsest base or frame for a specific signal or image has this signal or image data as a vector. The simplest idea comes from minimizing the product width x depth, or e(d,b) = = db, considered as a loss function.Let us compute it for all numbers from 0 to decimal N = 999999, in different numeral systems?
Decimal: b = 10, d = 6 = ceil(log(N+1)/log(b)), db = 60,
Binary: b = 2, d = 20, db = 40,
Ternary: b = 3, d = 13, db = 39,
Quaternary: b = 4, d = 10, db = 40.
Here we have a very local minimum at b = 3. More generalized, the objective minimizes the loss function e(b) = b/log(b) (at WolframAlpha). The non-negative real minimum is "e". The two potential contenders for practical arithmetics, or even physics, are 2 (binary) or 3 (ternary), the two closest integers. It is easy to note that e(2) = 2.885... while e(3) = 2.731... and e(4) = 5.771 (compare to 2.718...). This confirms the preceding decimal/binary/ternary/quaternary local minimum at 3, 2 becoming second, the ternary numeral system, is closer to the absolute minimum. So we need to add 2 and 3 and propose a "Generalized"-) Euler formula:
and, more interesting, 3 should be more compact, even for three-valued logic in computer systems. The chapter Ternary computers: the setun and the setun 70, by N. P. Brusentov and J. R. Alvarez from Moscow state university (at Google books), indicates that this is an old story:
"It is known that the ternary arithmetic has essential advantages as compared with the binary one that is used in present-day computers. In connection with this Donald Knuth assumed that the replacement of "flip-flop" for "flip-flap-flop" one a "good" day will nevertheless happen [1]. Now, when the binary computers predominate, it is hard to believe in a reality of such assumption, but if it would happen not only the computer arithmetic, but the informatics on the whole would become most simple and most perfect. The third value (Aristotle named it snmbebhkoV – attendant) what is very actual but hidden in binary logic, will become obvious and direct manipulated. Ternary logic has better accordance with the Nature and human informal thinking [2]. Unfortunately, the modern researches of the multivalued (non-binary) logic are formal and are not associated with practical requests.A remarkable exclusion is the experience of creating the ternary computers "Setun" and "Setun 70" at Moscow State University [3,4,5,6]. This experience convincingly confirms practical preferences of ternary digital technique.
The design of small digital machine "Setun" (Setun is the little river which flows into the river "Moscow" near the University) was initiated by member of the academy of Sciences S. L. Sobolev at 1956. It was assumed to create small, inexpensive computer, simple in use and service for schools, research laboratories, design offices and for manufacture control. For such goal at the computer center of the University there was formed a group of young men (4 MS and 5 BA). The joint seminar for engineers and programmers was organized and S. L. Sobolev, K. A. Semendjev, M. R. Shura-Bura, I. S. Berezin were its permanent participants. The problems of optimization of computer architecture and technical realization were examined and the variants of future computer were discussed."
I especially like the flip-flap-flop mnemonic. "Perhaps the prettiest number system of all," writes Donald E. Knuth in
The Art of Computer Programming, "is the balanced ternary notation."This reminds of the derivatives of position. Velocity and acceleration are well known, jerk is the 3rd. Jounce is sometimes given for the fourth derivative. Jounce is the rate of change of jerk, over the time. But some call the 4th, 5th and 6th derivatives "Snap, "Crackle" and "Pop" (as for the RiceCrispies, as for those interested in wavelets).
"When base 2 is too small and base 10 is too big, base 3 is just right. "
It even recalls the following conjecture:
More than 20 years ago, Paul Erdös and Ronald L. Graham published a conjecture about the ternary representation of powers of 2. They observed that 2^2 and 2^8 can be written in ternary without any 2s (the ternary numerals are 11 and 100111 respectively). But every other positive power of 2 seems to have at least one 2 in its ternary expansion; in other words, no other power of 2 is a simple sum of powers of 3. Ilan Vardi of the Institut des hautes études scientifiques has searched up to 2^6973568802 without finding a counterexample, but the conjecture remains open.
Yet, even-though the first attempts have met difficulties (check out the early 1950 High Speed Computing Devices in djvu), people are still working towards ternary physical systems: Klein M., Mol J. A., Verduijn J., Levine R. D., et al. Ternary logic
implemented on a single dopant atom field effect silicon transistor.
APPLIED PHYSICS LETTERS. 2010; 96(4) (see Raphael Levine).
So yes Igor, this brick-like technology does (almost) exist. Or probably in a near future. Maybe it is not practical enough yet, or the world is not ready for that. A while ago (30 years), i learned how to count in binary with my fingers (thanks to a mormon American, CF, thinking of you), and we have three phalanges, so i can easily switch. But the ternary politic system still does not yet exist in France.
Additional links on ternary arithmetics and trits (trytes or trybbles):
The Ternary Manifesto: Douglas W. Jones proposes (quite interesting) "An alternative basis for development of a completely incompatible digital infrastructure is presented here. This minimizes the potential for leakage of information, particularly malware and other covert content from our existing digital infrastructure. This effort can be described as taking security through obscurity as a fundamental design principle."
