LEPISME

We present a first version of a software dedicated to an application of a classical nonlinear control theory problem to the study of compartmental models in biology. The software is being developed over a new free computer algebra library dedicated to differential and algebraic elimination

Représentation par jeux du chaos de séquences d'ADN

Le jeu du chaos est une technique permettant de dessiner facilement des images fractales. Cette technique a été adaptée aux séquences d'ADN et permet de représenter des génomes par des images, révélant des structures fractales différentes suivant les génomes. Une question fondamentale est de savoir d'où viennent ces structures fractales, et de les caractériser. Dans ce travail, nous montrons que ces structures sont la conséquence directe de la présence de langages réguliers au sein de la séquence. Nous proposons ensuite une méthode de quantification de cette présence et de caractérisation des structures fractales à l'aide d'automates finis probabilistes. Nous montrons également que l'on peut utiliser ces structures et ces automates pour discriminer des génomes. Nous ouvrons par cette technique un certain nombre de pistes de représentations de séquences et leurs applications à diverses problématiques

QuiGon: the First Tool Against Clone Attack on Internet Relay Chat

Abstract. Clone attacks are a way to perform DDOS attack on Internet Relay Chat networks. There is no tool which prevent an IRC network against such attacks despite some handcrafted methods which are not so efficient. Here, we present qui-gon, the first tool which defeat clones attacks. It use a temporal oracle which detect attacks by measuring the connection rate; and another oracle which distinguish clones using probabilistic automata. These oracles learn the characteristic of the network in order to fit better to the network.

Modelling to Simulate Botnet Command and Control Protocols for the Evaluation of Network Intrusion Detection Systems

National audienceThe purpose of this paper is the modelization and simulation of zombie machines for the evaluation of Network Intrusion Detection Systems (NIDS), used to detect botnets. We propose an automatic method to infer zombies behaviors through the analysis of messages exchanged with their masters. Once computed, a model provides a solution to generate realistic and manageable traffic, which is mandatory for an NIDS evaluation. We propose to use a Stochastic Mealy Machine to model zombies behavior, and an active inference algorithm to learn it. With our approach, it is possible to generate a realistic traffic corresponding to the communications of botnets while ensuring its controllability in the context of an NIDS evaluation

GC×GC-HRTOFMS for untargeted screening of exhaled breath

In the galaxy of Omics Science, breathomics (i.e., exhaled breath analysis) knows an exponential growth. The full characterization of the breath composition and the understanding of the origin of these chemicals could have a gigantic impact for clinical research. Indeed, the potential of using non-invasive breath testing for patient status evaluation could be a game changer in disease monitoring and personalized medicine. Following that goal, there are numerous applications under development from cancer detection to diet adjustment. However, the complete characterization of the exhaled breath composition represents a complex analytical quest. From the exhaustive and reliable sampling, through robust untargeted analysis, to validated markers identification, the playground is large and require the development of new analytical workflows. To ensure the robustness of the entire process, every step must be carefully optimized and controlled with a robust QA/QC system. In order to resolve the complex composition of such samples, a powerful analytical technique is required. To obtain an untargeted screening of exhaled breath sample comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) is a go to analytical solution. GC×GC-MS provides high separation resolution and orthogonal compounds identification metrics. Indeed, the retention times combined to the MS fragmentogram and potentially to the high-resolution MS provide strong identification confidence, which can reach level 2 MSI (metabolomics standard initiative) classification in a single analysis. The organic and biological analytical chemistry group (OBiAChem) from Liège University has been dedicating a lot of effort to tackle the challenges on the road of robust breath test. In this webinar, we will cover the different technological aspects of exhaled breath research including sampling, analysis, data processing, and QA/QC. In addition, we will cover some clinical applications and discuss the transferability of breath testing for large scale population screening