This year, ENS-Lyon is hosting visiting professors who are leading experts in two aspects of numerical computing.
Nick Trefethen (University of Oxford) is a well-known numerical analyst and the inventor of Chebfun, a MATLAB-based tool that solves all kinds of problems of rootfinding, integration, and differential equations fast and typically to 15 digits of accuracy.
Warwick Tucker (Uppsala University) is a leader in the area of rigorous numerical computing, where instead of computing numbers with no guarantees, one applies interval analysis and other methods to obtain guaranteed results — and even to rigorously prove mathematical theorems with the aid of the computer.
In this week, using a mixture of lectures and hand-on computer laboratories, the two professors will showcase some of the highlights of these two sides of numerical computing.
software: Chebfun, a freely available package written in Matlab.
Teachers: Joel Ouaknine, Ben Worrell et Stefan Kiefel (Oxford).
Tuesday: 9 – 11:30 am, 1:30-3:30 pm and 4-6 pm.
Wednesday: 9-11:30 am and 1:30-3:30 pm.
External participants who has no access to the building should contact Marton Karsai (marton.karsai@ens-lyon.fr) in advance.
The main page of the course can be found here.
The course aims to provide basic skills for analysis and statistical modeling of data, with special attention to machine learning both supervised and unsupervised. An important objective of the course is the operational knowledge of the techniques and algorithms treated, and for this aim the lectures will focus on both theoretical and practical aspects of machine learning, and for the practical part it is required to have a good knowledge of programming, preferentially in Python language. The expected outcomes include (1) understanding the theoretical foundations of machine learning and (2) ability to use some Python libraries for machine learning in the context of simple applications.
– Score functions and optimization techniques. Gradient descent and stochastic gradient descent.
– Overfitting and Regularization: model complexity and overfitting, commonly used regularizers, Lasso.
Overview of the theoretical aspects of machine learning will be followed by the application of algorithms in real problems such as: image classification, text mining, spam detection… The exercises will be implemented with the help of an interactive Python environment, with the use of standard tools for data analysis and visualization, such as the Scientific Python stack, Scikit­Learn, Pandas and NLTK.
Organizer : Nicolas Thiéry and Thierry Monteil.
Local contact : Frédéric Vivien.
Registration is free, but the number of participants is limited. Registration includes neither housing nor meals (though for lunch the attendees will be granted access to the student cafeteria). Registration should be made before … (to be decided later) by clicking on this link, filling the form and sending the e-mail message. You will receive a confirmation as soon as possible.
wishes to attend the research school “ER01: Algorithmic Game Theory”, taking place at ENS Lyon, from Jan. 12 to Jan. 16, 2015.
wishes to attend the research school “ER02: “, taking place at ENS Lyon, from Jan. 19 to Jan. 23, 2015.
wishes to attend the research school “ER03: Static Analysis and Compilation”, taking place at ENS Lyon, from Jan. 26 to Jan. 30, 2015.
Please contact Yves Bertot (Yves.Bertot@sophia.inria.fr) to know the registration instructions.
Please contact Jean-Daniel Boissonat (Jean-Daniel.Boissonnat@inria.fr) to know the registration instructions.
School outline and timetable .
Registration is free, but the number of participants is limited. Registration includes neither housing nor meals (though for lunch the attendees will be granted access to the student cafeteria). Registration should be made before November 29, 2013 by clicking on this link, filling the form and sending the e-mail message. You will receive a confirmation as soon as possible.
wishes to attend the research school “Algorithmic Game Theory”, taking place at ENS Lyon, from Dec. 9 to Dec. 13, 2013.
Local contact : Laure Gonnord.
Registration is free, but the number of participants is limited. Registration includes neither housing nor meals (though for lunch the attendees will be granted access to the student cafeteria). Registration should be made before January 3, 2014 by clicking on this link, filling the form and sending the e-mail message. You will receive a confirmation as soon as possible.
wishes to attend the research school “Synchronous Approaches for Embedded Systems”, taking place at ENS Lyon, from Jan. 13 to Jan. 17, 2014.
Speakers: André Platzer and Sarah Loos.
Registration is free, but the number of participants is limited. Registration includes neither housing nor meals (though for lunch the attendees will be granted access to the student cafeteria). Registration should be made before January 10, 2014 by clicking on this link, filling the form and sending the e-mail message. You will receive a confirmation as soon as possible.
wishes to attend the research school “Logic for Dynamical Systems”, taking place at ENS Lyon, from Jan. 20 to Jan. 24, 2014.
January 21-25, 2013, ENS Lyon.
Speakers: Manuel Bodirsky, Michael Pinsker.
A Constraint Satisfaction Problem (CSP) is a computational problem where the task is to decide for a given finite set of variables and constraints whether there is an assignment to the variables that satisfies all constraints. Many computational problems in various areas of theoretical computer science can be modeled in this way.
If the variables take their values in some finite domain, there is a rich universal-algebraic theory that describes those constraint languages whose CSP is NP-hard, and those whose CSP is in P. In this course, we present a powerful generalization of this approach to CSPs where the underlying domain is infinite.
After introducing the necessary background in model theory, the course will also cover recent applications of structural Ramsey theory that have led to complexity classification results for large classes of CSPs.
Monday: Examples of CSPs from Artificial Intelligence. Primitive positive formulas and NP-hardness proofs. Some efficient algorithms. The Feder-Vardi conjecture.
Tuesday: The universal-algebraic approach. The Inv-Pol Galois correspondence. The core of a structure. The tractability conjecture. Cyclic operations. Exercices.
Wednesday: CSPs on infinite domains. Fraïssé limits, the Ryll-Nardzewski theorem. The Inv-Pol correspondence on infinite domains. The topology of simple convergence. Henson digraphs and other examples.
Thirsday: Introduction to Ramsey theory. Canonical functions. The classification of Graph-SAT problems.
Friday: Open problems, proposals of research projects. Exam and discussion.
Registration is free, but there is a limit on the number of participants and it does include neither housing nor meals (though for lunch the attendees will be granted access to the student cafeteria). Registration should be made before Monday, December 3, by clicking on this link and filling in and sending the e-mail form. You shall receive a confirmation as soon as possible.
wishes to attend the research school ‘Constraint satisfaction problems’, taking place at ENS Lyon, from Jan. 21 to Jan. 25.
January 14-18, 2013, ENS Lyon.
Optimisations performed by the hardware or by high-level language compilers can reorder memory accesses in various subtle ways. These reorderings can sometimes be observed by concurrent programs, exacerbating the usual problems of concurrent programming. The situation is even worse when we abandon traditional shared memory concurrency in favor of graphics processing units (GPUs) or exotic hardware. In these lectures we will cover recent progress in understanding and specifying the behaviour of some major processor architectures and the impact of optimisations performed by high-level programming language compilers, stablishing a solid basis for shared memory programming. We will then explore techniques which can help programmers develop reliable concurrent software by automatically discovering the necessary synchronization. We will also discuss techniques for verification of multicore software, including GPU kernels.
Please bring your laptop with you. In case you do not have one, please get in contact with Filippo Bonchi (ens-lyon.fr).
Registration is free, but there is a limit on the number of participants and it does include neither housing nor meals (though for lunch the attendees will be granted access to the student cafeteria). Registration should be made before Monday, January 8, by clicking on this link and filling in and sending the e-mail form. You shall receive a confirmation as soon as possible.
wishes to attend the research school ‘Semantics and tools for low-level concurrent programming’, taking place at ENS Lyon, from Jan. 14 to Jan. 18.
December 10-14, 2012, ENS Lyon.
During this course, we will discuss fault tolerance techniques for high performance computing systems.
drive or network card) has a drastic and lasting effect on the computation. Even without accounting for the implicit energy costs, in front of the evolving expectations for the next generation computing platforms MTTI, such approaches cannot reasonably lead to sustainable software solutions.
This course will highlight the existing solutions, and present parallel algorithms designed to provide correct solutions despite the presence of failures. We will show how the programming environment can be modified to increase the system reliability and sustainability. The course will start with an introduction to High Performance Programming, its challenges and typical algorithms.
Then we present theoretical as well as practical studies of the many fault-tolerant approaches that have been proposed over the years.
The course assumes a general knowledge of algorithms and operating system, as well as a basic understanding of machine architecture and network systems.
Update: bring your laptop! Some exercises on machine will be proposed along the course. Attendants are expected to bring a laptop with a possibility to establish a connection to a distant machine (typically, ssh): please write to the local contact (Yves Robert) if this is not possible for you — we should be able to lend a few laptops to participants.