October 1, 2010

Cucu fraternel - are there such things as french maths?

For french listening folks only: "Mathématiques : quelle pérennité pour le prestige français ?" on France Culture today. Following the recent Fields medals, the discussion goes along the following tracks:
  • How long does it take to become a mathematician?
  • Has a 3-year long project some sense in mathematics?
  • Why is a paper outdated after 3 years in biology, while only after 30 years in maths?
  • Why a Minister of Higher Education and Research is so booked (s)he cannot attend such a debate?

Panel: Michel Broué, mathématicien, professeur à l’université Paris Diderot, Pierre Cartier, mathématicien, CNRS/IHES, Dominique Leglu, directrice de la rédaction de la revue Sciences et Avenir, Bertrand Monthubert,  mathématicien, Institut de mathématiques de Toulouse, with interviews of Cédric Villani, mathématicien, professeur à l’Institut Camille Jordan, directeur de l’Institut Henri Poincaré et médaille Fields 2010 and Wendelin Werner, professeur de mathématiques, université Paris-Sud et Ecole normale supérieure Médaille Fields 2006 et membre de l’Académie des sciences.

Musical intermede: Gov't mule, Thorazine shuffle



September 30, 2010

Upcoming conferences (concern Fees) - The latent ones

Saint-Malo Intra-Muros.
I went like an "animal sot" to Saint-Malo (Brittany) and returned enchanted by the 2010 edition of the Latent Variable Analysis and Independant Component Analysis (LVA-ICA 2010). The four excellent keynote/plenary speeches:
  • When tensor decomposition meets compressed sensing, by Pierre Comon (University of Nice, France), admittedly with an ad-like title, more akin to coherence than CS;
  • Discrimination with deformation for classification, by Stéphane Mallat (Ecole Polytechnique, France), when mapping complex wavelet coefficients to the lower frequencies yields a scattering metric;
  • Bayesian non-negative matrix factorisation methods to detect dye labelled DNA oligonucleotides in multiplexed Raman spectra, by Mark Girolami (University of Glasgow, UK);
  • 2nd order statistics + A 3rd data dimension = Just weight and see!, by Arie Yeredor (Tel-Aviv University, Israel);
should be webcasted soon (stay tuned, i got audio bootlegs for personal use). Meanwhile, the next LVA/ICA 2012 will be held in Spring 2012 in Tel Aviv, Israel (see SIVA conferences). An internship is proposed in 2011 at IFP Energies nouvelles on that peculiar domain.

Among other latent events recently announced:
SPARS 2011 (Workshop: Signal Processing with Adaptive Sparse Structured Representations) in Edinburgh, Scotland (DL: 27/06/2011) from 30/06/2011 to 30/08/2010;
SSP 2011 (IEEE Workshop on Statistical Signal Processing) in Nice, France (DL: 15/01/2011) for  28/06/2011 to 30/06/2011;
ICCV 2013 (International Conference on Computer Vision) is announced in Barcelona, Spain;
GenSIPS 2010 (IEEE International Workshop on Genomic Signal Processing and Statistics) at Cold Spring Harbor USA-NY from  10/11/2010 to 12/11/2010;
DSP 2011 (International Conference on Digital Signal Processing) in Corfu, Greece (DL: 14/01/2011) from 06/07/2011 to 08/07/201;

August 19, 2010

See my very appreciation to Yves Meyer's price

Emys turtle from http://en.wikipedia.org/wiki/Emys
While a decent anagram with two "y" and four "e" still hides under the carpet (much better ones related to Alain Connes, Fields medalist), see my very appreciation to Yves Meyer's Carl Friedrich Gauss price (here in French), four years after Kiyoshi Itō. At ICM 2010, it is said that, along with his work on wavelets ("wavelet theory has become the new name for Fourier analysis", gosh!),
[...] he has found a surprising connection between his early work on the model sets used to construct quasicrystals — the ‘Meyer Sets’ — and ‘compressed sensing’, a technique used for acquiring and reconstructing a signal utilizing the prior knowledge that it is sparse or compressible.
Which should please Igor Carron, of course. Every emys knows that every four years, Fields medals are attributed to talented mathematicians. The country of course honors Ngô Bao Châu (fundamental Lemma in the theory of automorphic forms through the introduction of new algebro-geometric methods) and Cédric Villani (proofs of nonlinear Landau damping and convergence to equilibrium for the Boltzmann equation, yet  being director of IHP), along with Elon Lindenstrauss (results on measure rigidity in ergodic theory, and their applications to number theory) and Stanislas Smirnov (proof of conformal invariance of percolation and the planar Ising model in statistical physics). The Nevanlinna Prize and the Chern Prize go to Daniel Spielman  and Louis Nirenberg respectively.

Let us end this with a typical mathanagram:
  • What’s an anagram of Banach-Tarski?
  • Banach-Tarski Banach-Tarski.

July 23, 2010

The turn of a friendly card - Train numbering trick

Coming back from Orléans (France) on March 2010 for the Second conference  "Mathematics and Image processing" (Deuxième colloque "Méthodes mathématiques pour l’image") organized at MAPMO. Having presented stuff on Statistical estimators based on Stein's principle for  M-band wavelets and filter banks (abstract, slides, codes). Waiting in a train, staring again (and pixing) at the eight-seat compartment  numbering once discussed here

Since Igor Carron posted this Magic trick for summer vacations on Nuit Blanche (constest won by Laurent Jacques), I propose the following one again. Pictures attest the realness of the data, in contrast to Igor thought experiment (vicious tackle). Seat numbering is split in odd and even (unlike in six-seat cars), face-to-face, as:
.1 .3 .7 .5
.2 .8 .4 .6
The 3 (mod 8) sum is obvious. Easy enough for front-to-front booking by ancient computers. So why not the simple child Gauss-like arrangement?
.1 .3 .5 .7
.8 .6 .4 .2
Suspect some kind of compressive coding of seat booking? Contributions welcome. 

One good reason to listen on Nits again - The train. TGIF; my train of thoughts is leaving (le train de mes pensées s'égare).






Or Alan Parson's project - Turn of the friendly card:




July 21, 2010

Leurrer ? Détrompez-vous ! - Dompterez-vous l'erreur ?

Source : http://cereales.lapin.org/ (705)
On doit à René Thom (médaille Fields 1958) : "ce qui limite le vrai n’est pas le faux, mais l’insignifiant" [Paraboles et Catastrophes, Champs Flammarion, p. 127] (citation déjà évoquée à propos de l'antienne sur l'infobésité, ou la surabondance d'information de notre monde). On attribue à Wolfgang Pauli, pestant contre un article de physique sans  intérêt,  "ce n’est pas juste et, pire, ce n’est même pas faux !" (cf. WikiQuote on Pauli).

Cette idée n'est pas toujours évidente (voire contre intuitive) pour les élèves, étudiants, le grand public et - voire - pour une partie des contributeurs à la recherche scientifique.

Le festival "Science jeune public" (et peut-êre même les moins jeunes) oeuvre cette année dans le sens de cet éclaircissement sous le titre : Détrompez-vous (du 21 au 24 juillet 2010 à l'Ecole normale supérieure)

La Journée Grand Public qui aura lieu le samedi 24 juillet est ouverte à tous, sans réservation préalable. Extrait :
Les intervenants du festival vont s’efforcer cette année de faire tomber une idée reçue : l’erreur serait négative ! Dans tout processus d’apprentissage, comme dans la recherche, c’est en remettant en question des conceptions fausses que l’on progresse : il y a des erreurs nécessaires. Sur ce thème, qui vise à inciter chacun à oser entreprendre, de nombreux chercheurs, artistes, médiateurs, passionnés de sciences feront de ce festival un moment d’échanges intenses.

 Alors, négative, l'erreur ? Résolument pas ! L'erreur a pour racine latine l'errance... Et s'égarer, sortir des sentiers battus : n'est-ce pas la voie de la créativité ? Osons donc explorer les chemins broussailleux où mènent les errances... Pour mieux rebondir, prenons le risque de nous tromper !
A diffuser aux ames curieuses : ateliers, animations, spectacles... On se quitte pour ce soir sur Jorge Ben : Errare humanum est ["A Tábua de esmeralda", 1972].



July 19, 2010

Upcoming SIVA signal and image conferences - Concern fees

Today we update on the SIVA: Signal, Image, Video and Applications conferences page.


Long time ahead is ICASSP 2014 website running. Not much information yet, execpt in this information pdf file, like a call to image processing tools like inpainting. ICIP 2013 (Melbourne, Australia), ICASSP 2013 (Vancouver, Canada) are open but scarse as well.

Closer from us, SAMPTA 2011 held in Singapore (deadline on 01/10/2010), ISCAS 2011 in Rio de Janeiro, Brazil (deadline on 29/09/2011, sooner for Special sessions), ICASSP 2011 in Prague, Czech Rebublic (deadline on 20/10/2010), ICCV 2011 in Barcelona, Spain (deadline on 01/03/2011). ICIP 2011 in Brussels, Belgium, has no deadline for now. MWSCAS 2011, once believed in Brazil, will be in fabulous Seoul, South Korea (deadline 04/03/2010). SIVA would not be complete without the annual Conference on Digital Image Content Knowledge, held in Chicago, Illinois, USA. For myself, i will try to enjoy the shores of Saint-Malo at LVA/ICA 2010, the ninth conference on latent variable analysis and signal separation.


All this comes with a nomade gift: Skype version 5.0 for a portable use on a usb key.For people who like to do it themselves, look here.

July 10, 2010

Time is the simplest (non-commutative) thing


One of the most elegant theorems of all times is 4-word: every finite field commutes (Wedderburn's little theorem). While having life-long interests in anagrams and questions about time, i never thought they were related. They are. Thanks to the conference: Un espace non-commutatif engendre son propre temps, by Alain Connes on 06 November 2007 in Metz, France (downloadable video, 220 Mb, flv format, since i failed in embedding it into the blog).





Alain Connes is both a tremendous mathematician and wonderful, passionate story-teller. A cryptic message by a friend's child:
Je suis Alençonnais, et non alsacien, si tu veux un conseil nana, rendez-vous au coin annales
and a story about book reading by japanese mathematician Minoru Tomita (and related results) lead us to a lesson on associativity and commutativity rules. Anagrams are possible only because written language is associative and non-commutative (no alternative!). Meaningful anagrams (such as seen in Remaniement) are seen as a commutative breach. What is important, says Alain Connes, is poetic spirit (not foreign to mathematics) and a clue on where you are heading (if you do not change direction, see Lao Tzu). Without too much mathematics, Connes conveys those insights (with Carlo Rovelli) that the sense of duration may well arises from the statistical state of a system, quite like temperature. A relic of the antic  3 K radiation of the Universe. Funny enough, both French and Italian languages have very close words for time (temps/tempo) and temperature (température/temperatura). Could they be physically closely related, as real and imaginery parts of a complex number? Do algebra have periods? Look at the audience questions at the end of the talk. See also: Alain Connes : une autre vision de l’espace.

Arte also proposes a series of questions to Carlo Rovelli, interestingly pertaining to the life of a physicist. Alain Connes book on Noncommutative Geometry is freely available in pdf. Clifford D. Simak (not the - associative - algebra) wrote one of the most poetic sci-fi book on time travel, Time is the simplest thing (Le pêcheur en langue française). M. Dhenin shares a series of radio broadcast in a Mindmap for time (in French).

July 3, 2010

Dimension-reduction, High-dimensional problems and solutions, Workshop, June 2010

In epochs of information overload (or overlook), salvation comes from conferences like the HDPS 2010 workshop organized on 21 and 22 of June 2010 on High Dimensional Problems and Solutions, with Ron DeVore (Dep. of Mathematics,Texas A&M University, USA, recipient of the Foundation's Research Chaire of Excellence 2009) and Albert Cohen (UPMC, LJLL). Indeed:
Several important areas of science are confronted with the having to recover a functions of many variables either from large data sets or from complex mathematical models. Such recovery is inhibited by what is commonly called the 'curse of dimensionality' which says the numerical approximation of such a function will require inordinately more computation as the number of active variables increases. This workshop bring together the world's leading experts on high dimensional problems to discuss their recent research in areas such as manifold learning, stochastic and parametric PDEs, and optimal recovery.
The program was terrific:
  • Steve Smale (City University of Hong Kong) "Hodge Theory"
  • Mauro Maggioni (Duke) "Multiscale geometric methods for the analysis of points clouds"
  • Gilad Lerman (Univ. of Minnesota) "Multi-Manifold Data Modeling: Foundations and Applications"
  • Christoph Schwab (ETH Zurich) "Sparse Tensor Approximations of PDEs on high-dimensional parameter spaces"
  • Yvon Maday (Paris VI) "Reduced basis and magic point for high dimensional approximation problems"
  • Wolfgang Dahmen (RWTH Aachen) "A greedy approach for the reduced basis method - Convergence rates"
  • Emmanuel Vasquez (Supelec) "Gaussian processes, RKHS and their applications to computer experiments" 
  • Przemek Wojtaszczyk (Univ. Warsaw) "Approximation of functions of few variables in high dimension "
  • Dominique Picard (Paris VII) "LOL: thresholdings and high dimensions"
  • Rob Nowak (Univ. of Wisconsin) "Adaptive and Nonlinear Designs for Large-Scale Multiple Hypothesis Testing"
  • Martin Wainwright (Berkeley) "Recovery problems in high dimensions: A unified analysis of estimators with decomposable regularizers"
  • Stephane Mallat (Polytechnique) "High dimensional classification by recursive interferometry"

As i could not attend, i am glad that most of it is now available as webcasts (gather at Foundation Sciences Mathématiques de Paris), as potential take-aways for summer holidays:

Mauro Maggioni (Duke): "Multiscale geometric methods for the analysis of points clouds",

Steve Smale (City University of Hong Kong): "Hodge Theory",

Stephane Mallat (Polytechnique): "High dimensional classification by recursive interferometry",

Martin Wainwright (Berkeley): "Recovery problems in high dimensions: A unified analysis of estimators with decomposable regularizers",

Rob Nowak (Univ. du Wisconsin): "Adaptive and Nonlinear Designs for Large-Scale Multiple Hypothesis Testing",

Wolfgang Dahmen (RWTH Aachen, joint work with Peter Binev, Albert Cohen, Ronald DeVore, Guergana Petrova, and Przemyslaw Wojtaszczyk): Convergence Rates for Greedy Algorithms in Reduced Basis Methods,

Peter Binev (Univ. Caroline du Sud): "Sparse Occupancy Trees",

Gilad Lerman (Univ. of Minnesota): "Multi-Manifold Data Modeling: Foundations and Applications",

Emmanuel Vazquez (Supelec): "Gaussian processes, RKHS and their applications to computer experiments",

Yvon Maday (UPMC): "Reduced basis and magic point for high dimensional approximation problems",

Przemek Wojtaszczyk (Univ. de Varsovie): "Approximation of functions of few variables in high dimension",

Dominique Picard (Université Paris-Diderot Paris-7): "LOL: thresholdings and high dimensions", http://www.dailymotion.com/video/xds3nm_lol-thresholdings-and-high-dimensio_tech
For dessert, a smoother video on "are soap bubbles all round?"



Thank you Igor for referencing.

June 25, 2010

Minotaure, tu dois finir ta thèse (Simon Berjeaut), paroles

MAJ20121116 : Simon Berjeaut est invité de Grantanfi (doctorants, l'avenir dure longtemps) sur France Culture le mercredi 21/11/2012.

Simon Berjeaut est l'auteur du Minotaure, ou "Tu dois finir ta thèse", message d'espoir en chanson pour les doctorants et doctorantes en mal de manuscrit, dont je vous avais parlé il y a deux mois, et qu'Igor Carron avait proposé de rendre viral sur YouTube. La vidéo se télécharge . Et les paroles sont un peu plus bas... 






Maurits Cornelis Escher : Angels and Demons (1942)
C'était à l'époque cendreuse de Eyjafjallajökull, et cette chanson évoque le piton de la Fournaise. Pourquoi le Minotaure ? Pour Thésée, l'homme perdu dans le labyrinthe que seul un fil ténu rappelle vers l'issue, une métaphore taurine illustrative du parcours de rédigeant de chaque doctorant. Thêseús comme Odysseus tant la parcours semble voyage sans fin, mais borné, comme l'univers Lorentzien de M. C. Escher de "anges et démons", ou disque hyperbolique de Poncaré. Mais aussi l'évocation de cette période surréaliste, par Minotaure, revue d'avant-guerre (la seconde) qui a fait diffuser des Roberto Matta, Alberto Giacometti, Hans Bellmer, Victor Brauner ou Tristan Tzara. Les deux derniers me rappelant un voyage en Roumanie. Roumanie + T = Minotaure (anagramme faible).

Les paroles ? Les paroles !

Victor Brauner, Hypergenesse de la Reapparition (1932)
Où est ton regard de braise
Et tes airs conquérants
Tes épaules en trapèze
Et ta belle énergie
Tu as le regard qui biaise
De tous les doctorants
Et tu deviens obèse
Pris dans ta léthargie

Tu dois finir ta thèse
Tu dois finir ta thèse

Ton esprit de synthèse
Ta volonté de fer
Et ton désir d'acèse
Se sont-ils envolés ?
Au pied de la falaise
Tu ne sais plus comment faire
Ta volonté de glaise
Il faut la remodeler

Tu dois finir ta thèse
Tu dois finir ta thèse

Ce soir c'est repartit
Tu t'enfermes chez toi
Tu vas finir ta thèse
Ta décision est ferme
Ou au moins une partie
Ou bien le petit trois
Ou bien la parenthèse
Qu'il faut que je referme

Tu dois finir ta thèse

Tu vas finir demain
Tu dois finir le seize
Tu vas finir en juin
Bon, tu reprends une 16
Tu fumes un dernier joint
Et soudain tu t'apaises
Et doucement tu rejoins
Le mouvement des sans-thèse (x3)

Comme le dit Marie-Thérèse
Ta voisine martiniquaise
C'est comme le piton de la fournaise
Ça prendra comme une mayonnaise
C'est des foutaises
Tu vas finir ta thèse

Comme le dit Madame Hernandes
Dans sa sagesse toute portuguaise
Si aujourd'hui "nada se fez" (rien ne se fait)
"vai ficar para outra vez" (ça sera pour une autre fois)

C'est des fadaises !
Tu vas finir ta thèse

Tu aimerais trouver un max de pèze
Caché dans une attaché-case
Tu partirais à Saint-Tropez
Tu irais faire du steeple-chase

Tu ferais pas ta thèse
Tu ferais plus du tout ta thèse

Même si la vie te pèse
Écarte l'hypothèse
De finir ta thèse
Au père Lachaise
Enfile tes charentaises
Rassied-toi sur ta chaise
Pas besoin de chanter la Marseillaise
Mets-toi à l'aise
Tu vas finir ta thèse

Et ne vous en déplaise
Et tant pis si j'ai tord
Mais il me semble plus aisé
De poursuivre une thèse
Plutôt qu'un Minotaure
Tout le monde peut pas être Thésée
Tout le monde peut pas être Thésée
Thésée, Thésée

Mais taisez-vous
Punaise !
[Quelle prise de thèse ?]

Tu vas finir ta thèse
Tu vas finir ta thèse

C'est infinissable
... Mais tu vas la finir
C'est insoutenable
... Mais tu vas la soutenir

Tu vas la finir
Tu vas la soutenir
Tu vas la publier, qui sait ?

Tu vas finir ta thèse
Tu vas finir ta thèse

June 10, 2010

Information overload - And no more trivia, fool!

[Update 2014/05/20 with Ann Blair publications] There is a recent concern about information overload. Or is there? According to the following independent sources:
the problem is not so recent. Ann Blair already informed us in 2003 that there were Reading Strategies for Coping with Information Overload ca. 1550-1700:
The "multitude of books" was a subject of wonder and anxiety for authors who reflected on the scholarly condition in the sixteenth through the eighteenth centuries. In the preface to his massive project of cataloguing all known books in the Bibliotheca univeralis (1545) Conrad Gesner complained of that "confusing and harmful abundance of books," a problem which he called on kings and princes and the learned to solve.  By 1685 the situation seemed absolutely dire to Adrien Baillet, who warned:
"We have reason to fear that the multitude of books which grows every day in a prodigious fashion will make the following centuries fall into a state as barbarous as that of the centuries that followed the fall of the Roman Empire. Unless we try to prevent this danger by separating those books which we must throw out or leave in oblivion from those which one should save and within the latter between what is useful and what is not."
In this way Baillet claimed to have warded off barbarity itself with his collection of judgments on the learned in his nine-volume (and still only half-completed) Jugemens des sçavans
The "information overload" or "scholar big data" is push further in: Too Much to Know. Managing Scholarly Information before the Modern Age (2010):
The flood of information brought to us by advancing technology is often accompanied by a distressing sense of “information overload,” yet this experience is not unique to modern times. In fact, says Ann M. Blair in this intriguing book, the invention of the printing press and the ensuing abundance of books provoked sixteenth- and seventeenth-century European scholars to register complaints very similar to our own. Blair examines methods of information management in ancient and medieval Europe as well as the Islamic world and China, then focuses particular attention on the organization, composition, and reception of Latin reference books in print in early modern Europe. She explores in detail the sophisticated and sometimes idiosyncratic techniques that scholars and readers developed in an era of new technology and exploding information.
Listen to 23' of Clay Shirky at Web 2.0 Expo NY, 19 September 2008, where you learn, along  the movie narration flood, "It's Not Information Overload. It's Filter Failure":




The "multitude of books" was a subject of wonder and anxiety for authors who reflected on the scholarly condition in the sixteenth through the eighteenth centuries. In the preface to his massive project of cataloguing all known books in the Bibliotheca univeralis (1545) Conrad Gesner complained of that "confusing and harmful abundance of books," a problem which he called on kings and princes and the learned to solve.1 By 1685 the situation seemed absolutely dire to Adrien Baillet, who warned [...]

So apparently, the information overload problem is no novelty. Looks like information is riding an exponential wave, as in the standard chart (left), whose derivative is just about an exponential. Reminds me of the following joke: $1$ and $e^x$ sit in an old favorite room of a restaurant. Waiting for food arrival - noontime. Suddenly, $1$ gets terrified and cry at $e^x$: "hide me, hide me, here enters a derivative operator!". Proud and fierce,  $e^x$ hides the constant behind her back, and defies the operator: "i am $e^x$, i don't fear you". "Sure!" the operator replies, "i am $\frac{\partial}{\partial y}$". 
As Clay Shirky says, "If you have a problem for a long time, it's not a problem... Maybe it's a fact!" (IMHO probably emphasized by the Internet/media mode of "content creation", more than often a mere duplication (pure redundancy) or basic distorsion (jamming) of pre-existing content, with reduced added value), to fill the media tubes and pipes (forlorn media ovation). Since more and more people write, blog, tweet and buzz about IO, further adding low valued load. IO might just be neither a true problem nor a false one. René Thom (in Paraboles et Catastrophes, Champs Flammarion, p. 127) reminds us that "Ce qui limite le vrai n’est pas le faux, mais l’insignifiant", approximately translated to "What limits truth, it is not forgery but trifle/insignificance" (quote courtesy of Olivier Rey, whose Itinéraire de l'égarement deserves close reading, admiration of no lover). IO as an inane vomit flood roar (sounds like a death metal song title, but only an anagram).

Yet still assuming that "more data = better decisions", some argue that the "real problem is the lack of efficient strategies to index, summarize, filter, cross-reference and archive information", or propose "A Framework for Information Overload Research in Organizations Insights from Organization Science, Accounting, Marketing, MIS, and Related Disciplines" (Eppler, Mengis, 2003). But more insignificant data may as well lead to zero decisions, as gaussian disturbances may vanish as the square root on the number of observations. Second thought, not so much with rounding, see Statistical Analysis for Rounding Data (Zhidong Bai, 2006). The current trend in signal or image processing is generally similar: acquire more data, at higher frequency, with more precision (watch out, formation on evil road), hoping signal processing, statistics and data mining will cope with the flood and deliver precious information. An extreme example arises in seismic processing, where petabytes of data ("but also storage systems that can handle petabytes of data daily") are gathered. Yet, due to the computational burden and memory footprint, the relative time spent on "fine processing" with respect to data reading, loading, handling, sorting seems tiny.

Thank to the availability of low cost sensors and band-width, the data overload plague is spreading. More and more data, less and less time to process it properly, massive low-quality batch filtering are favored. Signal and image processing enter the dark area of weak signals and information overlook. I pray everyday (no variation of me, Lord) for my colleagues to tell me: next step, we are going to acquire much less signals (and favor no more dilation of disk space), to spend the remaining time on their processing.

April 13, 2010

All PhDs unite: une chanson pour les thésard(e)s du monde entier (francophone)

[Mise à jour : la vidéo du Minotaure (ou "tu dois finir ta thèse) de Simon Berjeaut, mais surtout les paroles, sont à Minotaure, tu dois finir ta thèse (again)] Pour les doctorants du monde entier, une ode à la fin de thèse : "Tu dois finir ta thèse". La vidéo est téléchargeable ici :
http://www.laurent-duval.eu/_Share/Tu_dois_finir_ta_these.mp4
et mise sur You Tube, car elle ne semblait pas y être (http://www.youtube.com/watch?v=rbfse8Af_Ps) par Igor Carron (de Nuit Blanche). Merci à Elodie Jeandel pour l'info (sur Facebook).






January 21, 2010

Raah - Haar year (toute)


Today a call for paper, a celebration of Haar centenary, codes for multivariate denoising and a thought.

2010 is the centenary (with 1 % imprecision) of the Haar wavelet (or Haarlet). Oddly, it possesses an anagram, raah. According to Urban Dictionary, raah denotes:
A richly dressed person, usually with big hair and are commonly situated in Surrey. They enjoy prancing around in Ralph Lauren, Jack Wills and Abercrombie & Fitch. Their grooming and hair can be described as messy, but stylish.

To celebrate such a birthday, everybody is invited to contribute to the call for paper to Elevier Signal Processing: Advances in Multirate Filter Bank Structures and Multiscale Representations, with a 15 February 2010 deadline.

The CfP is featured at several other places:
http://www.elsevier.com/wps/find/journaldescription.cws_home/505662/description#description
http://www.elsevier.com/inca/publications/misc/sigpromultirate.pdf
http://www.wikicfp.com/
http://www.ee.cuhk.edu.hk/~tblu/monsite/pdfs/CFPSigPro.pdf
and last but not least at Nuit Blanche:
http://nuit-blanche.blogspot.com/2010/01/cs-advances-in-multirate-filter-bank.html
Thank you Igor.

Not exclusive topics: Sampling theory, compressive sensing . Sparse representations . Multiscale models . Multiscale processing: interpolation, inpainting, restoration . Wavelet shrinkage and denoising . Oversampled filter banks, discrete frames . Rational and non-uniform multirate systems . Directional, steerable filter banks and wavelets . Nonlinear filter banks . (Multidimensional) filter bank design and optimization . Hybrid analog/digital filter banks . Fast and low-power schemes (lifting, integer design) . Multiscale and multirate applications to source and channel coding, equalization, adaptive filtering,...

The english version of the founding paper On the Theory of Orthogonal Function Systems (Zur Theorie der orthogonalen Funktionen-Systeme), translated for the magnificent collection of papers in Fundamental Papers in Wavelet Theory edited by Christopher Heil and David F. Walnut, is made available at WITS: Haarlet.

Matlab codes for Multivariate Dual Tree Wavelet Denoising (based on Stein's principle), were created to illustrate and reproduce the results presented in:



A nonlinear Stein-based estimator for multichannel image denoising
DOI:10.1109/TSP.2008.921757
Arxiv  
Caroline Chaux, Laurent Duval, Amel Benazza-Benyahia and Jean-Christophe Pesquet
IEEE Transactions on Signal Processing, August 2008, Volume 56, Issue 8, p. 3855-3870

They have been made available at Research codes, and can be used them freely for research purposes.



Finally, in homophonia memoriam, to Ar-lette Duval, in loving memory to her vanishing souvenirs (thanks Alois), totally ceased today.