Together with Alexandre Borghi and Jérome Darbon, we wrote a paper entitled Exact Optimization for the $latex l^1$-Compressive Sensing problem using a Modified Dantzig-Wolfe method. the paper is available as a UCLA CAM Report here: cam09-101.pdf Here is the abstract: This paper considers the $latex l^1$-Compressive Sensing problem and presents an efficient algorithm that computes an exact solution. The idea consists in reformulating the problem such that it yields a modified Dantzig-Wolfe decomposition that allows to efficiently apply all standard simplex pivoting rules. Experimental results show the superiority of our approach compared to standard linear programming methods. Comments are more […]

I am part of the ANR MIDAS project, and we’re hiring: We search for a dedicated individual to work on an implementation of a numerical library devised for the purpose of the data analysis of Cosmic Microwave Background (CMB) data sets. CMB is one of the most exciting and dynamically developing areas of modern cosmology as it provides a unique opportunity to explore the very early Universe. The data analysis of CMB data sets is central to its successful exploration. New CMB data sets of unprecedented quality and volume are anticipated within the next few years and their analysis will […]

Qest is a conference that I like for many reasons, and here is the call for papers for the 2010 edition of the conference. The conference website is here. Scope and Topics The International Conference on Quantitative Evaluation of SysTems (QEST) is the leading forum on evaluation and verification of computer systems and networks, through stochastic models and measurements. QEST has a broad range of interest — the common thread is that the evaluation be quantitative. The range of performance metrics of interest spans classical measures involving performance and reliability, as well as quantification of properties that are classically qualitative, […]

I am currently in the US for a few days, and today it’s turkey day. To stay on the thanksgiving topic, here is a nice infographic find on mint.com: A wide version is here. And now, it’s time to cook the turkey, and the mash potatoes…

First International Workshop on Quantitative Stochastic Models in the Verification and Design of Software Systems (QUOVADIS) Workshop at the ICSE 2010 3rd May 2010, Cape Town, South Africa http://deepse.dei.polimi.it/quovadis/ Motivation and Objectives: ========================== Modern software systems are increasingly complex and pervasive. They are often offered to clients as services, which must meet high level expectations in terms of predictability. They are embedded in a fluid environment that is constantly evolving, because of changes in the requirements, in the operating environment, and in usage profiles. Traditional software development processes and methods are unable to cope with the challenges posed by this […]

To find the beginning of the triangular adventure, you should read this post. To prove the lemma we use the following theorem that I am not proving in this post (if you want the proof, just let me know). Theorem Consider $latex N$ urns each filled with $latex m$ balls, and the following process: pick a ball in an urn chosen uniformly at random until the chosen urn is empty. The probability that one had to pick more than $latex O(N^{\frac{m-1}{m}})$ balls tends to a nonzero constant as $latex N$ goes to infinity. Proof (of the lemma) To each triangle […]

======================================================================= SPAA 2010 Call for Papers 22nd ACM Symposium on Parallelism in Algorithms and Architectures Santorini, Greece June 13-15, 2010 http://www.spaa-conference.org ======================================================================= SCOPE: Contributed papers are sought in all areas of parallel algorithms and architectures. SPAA defines the term « parallel » broadly, encompassing any computational system that can perform multiple operations or tasks simultaneously. Topics of interest include, but are not limited to: – Parallel and Distributed Algorithms and Applications – Parallel and Distributed Data Structures – Parallel Complexity Theory – Parallel and Distributed Architectures – Multi-Core Architectures – Instruction Level Parallelism and VLSI – Compilers and Tools for Concurrent Programming […]

I found on this blog this infographic that shows the internet speeds and costs around the world.

The trend today is towards Business Intelligence and Customer Relationship Management (CRM) and I think we have all realised that for any capable web marketer, the three vital statistics are:  the KPI (Key performance Indicator), ROI (Return on Investment) and Web Analytics. So, let’s dive into the (customer) Marketing adventure, a field  which can be applied to most sales contexts including  the online, which don’t differ much from a more traditional ‘Brick and Mortar’ situation. Customer Life Cycle Who is a company’s good customer?  He/she is firstly loyal, and always returns to the company for a purchase to the point […]

This is an interactive nice infographic that shows percentages of total budgets allocated for Military, Healthcare and Education. To see it follow this link.