The project Algorithms of INRIA runs a seminar devoted to the analysis of algorithms and related topics. The subjects covered include combinatorics, symbolic computation, asymptotic analysis, average-case analysis of algorithms and data structures, and computational number theory.
The talks are held in the conference room of Building 9 at INRIA-Rocquencourt, near Paris. Contact information is given below, and directions are available on how to get to Rocquencourt.
July 9, 2007
Équations différentielles pour les séries algébriques
Il s'agit d'un travail en commun avec Alin Bostan, Frédéric Chyzak, Grégoire Lecerf et Éric Schost.
Comment utiliser l'algorithme de Wiedemann pour le calcul de l'immunité d'une fonction booléenne contre les attaques algébriques
June 12, 2007
Some Recent Results on Solving and Factoring Differential and Difference Equations
Approximation polynomiale de fonctions continues et nombres flottants
Les coefficients du polynôme doivent être stockés dans la mémoire de l'ordinateur et doivent donc être représentables sous forme de nombres-machine. Nous nous intéressons au problème de la recherche d'un très bon polynôme à coefficients représentables en machine, pour approcher une fonction continue. En utilisant la théorie des réseaux de points (et l'algorithme LLL de A. Lenstra, H. Lenstra et L. Lovász, que nous présenterons au cours de l'exposé) nous proposons un algorithme permettant d'obtenir un tel polynôme. Nous illustrerons les avantages et les défauts de l'algorithme sur un exemple complet.
Comptages probabilistes, de l'analyse aux programmes
Counting first-order correlation-immune functions
We first show that the exact number of $1$-resilient boolean functions with $7$ variables is $23478015754788854439497622689296$ and we obtain a tight estimation of their number with $8$ variables, between $4\;10^{67}$ and $5.6\;10^{68}$. We then present a general lower bound for the number of $1$-resilient boolean functions and improve Schneider's upper bound. We also propose a general lower bound for the number of $k$-resilient functions. Most of the bounds presented in this paper, substantially improve the best known bounds in the literature. We finally establish that the probability of a Boolean function being $1$-resilient is asymptotically between $\frac{\left(n\pi\right)^{n/2}}{2^{n^2-\frac{3}{2}n-1}e^{n-1/2}}$ and $2^{-\frac{n^2}{4}+\frac{n}{4}}$. We also present some ideas about how we may be able to find the exact asymptotic value of this probability.
This is joint work with Jean-Marie Le Bars from University of Caen.
May 21, 2007
Compositional Average-Case Timing.
We show how distribution tracking can be achieved based on a redesign of standard data structuring operations. We outline the theory of Random Bags which formalizes the distributions of the data states. Random Bag Preservation of the operations guarantees the capacity to track the distributions throughout the computations.
This approach has enabled the specification of the novel programming language MOQA (MOdular Quantitative Analysis), implemented in Java 5.0, and its associated timing tool DISTRI-TRACK.
MOQA, essentially a suite of data structure operations for modular design, is guaranteed to be compositional w.r.t. the average-case time measure. This is not the case for general purpose programming languages and in particular for current languages geared towards automated average-case analysis.
The approach links several, thus far largely separate, areas together, including Semantics, Complexity, Analysis of Algorithms and Real-Time Language design. The corresponding unified foundation for algorithmic analysis has led to the solution of bottle-neck problems in automated average-case timing (open problems on dynamic algorithms such as heapsort and deletions and insertions in binary search trees) and has given rise to novel algorithms. In this talk we focus on the analysis of the exact average-case time of heapsort as an application of the new approach.
The talk focuses on the intuitions underlying the approach and should be accessible to anyone with a standard undergraduate background in the Analysis of Algorithms. The talk touches on some core issues which will be discussed in the book ``A Modular Calculus for the Average Cost of Data Structuring'', to appear with Springer.
(Semi-)automated analysis via MOQA.
February 26, 2007
December 11, 2006
November 27, 2006
November 20, 2006
October 23 2006
October 20, 2006
September 25, 2006
June 26, 2006
May 29, 2006
May 15, 2006
March 27, 2006
March 13, 2006
January 30, 2006
January 16, 2006
December 5, 2005
November 14, 2005
November 7, 2005
October 3, 2005
LaTeX style files and guidelines on manuscript preparation can be accessed here.
We publish every year Seminar Proceedings that contain summaries of the talks. The seminar proceedings for the years 1991-2005 can be accessed here.
Virginie Collette