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17120
29/05/2017

L'aspect topologique des recommandations

E.LE MERRER, G.TREDAN

Technicolor France, TSF

Manifestation avec acte : Rencontres Francophones sur les Aspects Algorithmiques des Télécommunications ( ALGOTEL ) 2017 du 29 mai au 02 juin 2017, Quiberon (France), Mai 2017, 4p. , N° 17120

Lien : https://hal.archives-ouvertes.fr/hal-01517738

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Résumé

La recommandation joue un rôle central dans le e-commerce et dans l'industrie du divertissement. L'intérêt croissant pour la transparence algorithmique nous motive dans cet article à observer les résultats de recommandations sous la forme d'un graphe capturant les navigations proposées dans l'espace des items. Nous argumentons qu'une telle approche en "boite noire" est utile dans le cas d'une exploration limitée à un utilisateur: nous illustrons une topologie tirée de recommandations à un utilisateur de Youtube, fournissons ses caractéristiques clés, et montrons qu'elle renseigne sur la connaissance de cet utilisateur par le système. Nous montrons ensuite que l'analyse de cette topologie d'aborder la question du \text{biais} potentiel dans ces recommandations. Nous postulons que les systèmes de recommandation produisent naturellement des topologies cohérentes, et qu'une manipulation de ces résultats par l'ajout de liens biaisés a toutes les chances de violer cette cohérence (à la manières des liens longs d'un modèle "petit monde"). Ce postulat est supporté par l'analyse d'un modèle génératif basé sur les kNN et par l'exploitation du crawl Youtube, en ciblant la prédiction de liens "Recommandé pour vous" (i.e., biaisés ou non par Youtube).

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17109
27/04/2017

State of the art of network protocol reverse engineering tools

J.DUCHENE, C.LE GUERNIC, E.ALATA, V.NICOMETTE, M.KAANICHE

TSF, INRIA Rennes

Rapport LAAS N°17109, doi 10.1007/s11416-016-0289-8, Avril 2017, 27p.

Lien : https://hal.inria.fr/hal-01496958

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Abstract

Communication protocols enable structured information exchanges between different entities. A description, at different levels of detail, is necessary for many applications, such as interoperability or security audits. When such a description is not available, one can resort to protocol reverse engineering to infer the format of exchanged messages or a model of the protocol. During the past 12 years, several tools have been developed in order to automate, entirely or partially, the protocol inference process. Each of those tools has been developed with a specific application goal for the inferred model, leading to specific needs, and thus different strengths and limitations. After identifying key challenges, the paper presents a survey of protocol reverse engineering tools developed in the last decade. We consider tools focusing on the inference of the format of individual messages or of the grammar of sequences of messages. Finally, we propose a classification of these tools according to different criteria, that is aimed at providing relevant insights about the techniques used by each of these tools and comparatively to other tools, for the classification of messages, the inference of their format or of the grammar of the protocol. This classification also permits to identify technical areas that are not sufficiently explored so far and that require further development in the future.

139658
17104
25/04/2017

A toolset for mobile systems testing

P.ANDRE, N.RIVIERE, H.WAESELYNCK

TSF

Rapport LAAS N°17104, Avril 2017, 8p.

Lien : https://hal.laas.fr/hal-01499518

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Abstract

Validation of mobile applications needs taking account of context (such network topology) and interactions between mobile nodes. Scenario-based approaches are well-suited to describe the behavior and interactions to observe in distributed systems. The difficulty to control accurately the execution context of such applications has led us to use passive testing. This paper presents a toolset which supports specification and verification of scenarios. A UML-based formal language, called TERMOS, has been implemented for specifying scenarios in mobile computing systems. These scenarios capture the key properties which are automatically checked on the traces, considering both the spatial configuration of nodes and their communication. We give an overview of the language design choices, its semantics and the implementation of the tool chain. The approach is demonstrated on a case study.

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17031
10/04/2017

Synthesis of safety rules for active monitoring: application to an airport light measurement robot

L.MASSON, J.GUIOCHET, H.WAESELYNCK, A.DESFOSSES, M.LAVAL

TSF, Sterela

Manifestation avec acte : IEEE International Conference on Robotic Computing ( IRC ) 2017 du 10 avril au 12 avril 2017, Taichung (Taiwan), Avril 2017, 8p. , N° 17031

Lien : https://hal.archives-ouvertes.fr/hal-01465734

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Abstract

Safety-critical autonomous systems, like robots working in collaboration with humans, are about to be used in diverse environments such as industry but also public spaces or hospitals. Those systems evolve in complex and dynamic environments and are exposed to a wide variety of hazards. Several techniques may be used to ensure that their misbehavior cannot cause unacceptable damage or harm. One of them is active safety monitoring. A safety monitor is a component responsible for maintaining the system in a safe state despite the occurrence of hazardous situations. In this paper, we study the introduction of safety monitoring into an airport light measurement robot. The specification of the monitor follows a principled approach that starts with a hazard analysis and ends with a set of safety rules synthesized based on formal methods. This study illustrates the benefits of the approach, and shows the impact of safety on the development of an autonomous system.

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17073
03/04/2017

Refined exponential stability analysis of a coupled system

M.SAFI, L.BAUDOUIN, A.SEURET

ISI, MAC

Rapport LAAS N°17073, Avril 2017, 6p.

Lien : https://hal.laas.fr/hal-01496136

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Abstract

The objective of this contribution is to improve recent stability results for a system coupling ordinary differential equations to a vectorial transport partial differential equation by proposing a new structure of Lyapunov functional. Following the same process of most of the investigations in literature, that are based on an a priori selection of Lyapunov functionals and use the usual integral inequalities (Jensen, Wirtinger, Bessel...), we will present an efficient method to estimate the exponential decay rate of this coupled system leading to a tractable test expressed in terms of linear matrix inequalities. These LMI conditions stem from the new design of a candidate Lyapunov functional, but also the inherent properties of the Legendre polynomials, that are used to build a projection of the infinite dimensional part of the state of the system. Based on these polynomials and using the appropriate Bessel-Legendre inequality, we will prove an exponential stability result and in the end, we will show the efficiency of our approach on academic example.

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16018
01/03/2017

Quantifying interdependent privacy risks with location data

A.M.OLTEANU, K.HUGUENIN, R.SHOKRI, M.HUMBERT, J.P.HUBAUX

EPFL, TSF, University of Texas, Max Planck

Revue Scientifique : IEEE Transactions on Mobile Computing, Vol.16, N°3, pp.829-842, Mars 2017 , N° 16018

Lien : https://hal.archives-ouvertes.fr/hal-01266229

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Abstract

Co-location information about users is increasingly available online. For instance, mobile users more and more frequently report their co-locations with other users in the messages and in the pictures they post on social networking websites by tagging the names of the friends they are with. The users' IP addresses also constitute a source of co-location information. Combined with (possibly obfuscated) location information, such co-locations can be used to improve the inference of the users' locations, thus further threatening their location privacy: As co-location information is taken into account, not only a user's reported locations and mobility patterns can be used to localize her, but also those of her friends (and the friends of their friends and so on). In this paper, we study this problem by quantifying the effect of co-location information on location privacy, considering an adversary such as a social network operator that has access to such information. We formalize the problem and derive an optimal inference algorithm that incorporates such co-location information, yet at the cost of high complexity. We propose some approximate inference algorithms, including a solution that relies on the belief propagation algorithm executed on a general Bayesian network model, and we extensively evaluate their performance. Our experimental results show that, even in the case where the adversary considers co-locations of the targeted user with a single friend, the median location privacy of the user is decreased by up to 62% in a typical setting. We also study the effect of the different parameters (e.g., the settings of the location-privacy protection mechanisms) in different scenarios.

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17035
01/02/2017

Architecting resilient computing systems: A component-based approach for adaptive fault tolerance

M.STOICESCU, J.C.FABRE, M.ROY

ESOC, TSF

Revue Scientifique : Journal of Systems Architecture, Vol.73, pp.6-16, Février 2017 , N° 17035

Lien : https://hal.archives-ouvertes.fr/hal-01472877

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Abstract

Evolution of systems during their operational life is mandatory and both updates and upgrades should not impair their dependability properties. Dependable systems must evolve to accommodate changes, such as new threats and undesirable events, application updates or variations in available resources. A system that remains dependable when facing changes is called resilient. In this paper, we present an innovative approach taking advantage of component-based software engineering technologies for tackling the on-line adaptation of fault tolerance mechanisms. We propose a development process that relies on two key factors: designing fault tolerance mechanisms for adaptation and leveraging a reflective component-based middleware enabling fine-grained control and modification of the software architecture at run-time. We thoroughly describe the methodology, the development of adaptive fault tolerance mechanisms and evaluate the approach in terms of performance and agility.

139257
17013
31/01/2017

SMOF - A Safety MOnitoring Framework for Autonomous Systems

M.MACHIN, J.GUIOCHET, H.WAESELYNCK, J.P.BLANQUART, M.ROY, L.MASSON

TSF, ASTRIUM

Rapport LAAS N°17013, doi 10.1109/TSMC.2016.2633291, Janvier 2017

Lien : https://hal.archives-ouvertes.fr/hal-01394139

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Abstract

Safety critical systems with decisional abilities, such as autonomous robots, are about to enter our everyday life. Nevertheless, confidence in their behavior is still limited, particularly regarding safety. Considering the variety of hazards that can affect these systems, many techniques might be used to increase their safety. Among them, active safety monitors are a means to maintain the system safety in spite of faults or adverse situations. The specification of the safety rules implemented in such devices is of crucial importance, but has been hardly explored so far. In this paper, we propose a complete framework for the generation of these safety rules based on the concept of safety margin. The approach starts from a hazard analysis, and uses formal verification techniques to automatically synthesize the safety rules. It has been successfully applied to an industrial use case, a mobile manipulator robot for co-working.

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16465
31/01/2017

From requirements to UML using NLP and requirements management tools

O.S.DAWOOD, A.E.K.SAHRAOUI

SUST, ISI

Revue Scientifique : European Journal of Engineering Research & Science, Vol.2, N°1, pp.44-50, Janvier 2017 , N° 16465

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Abstract

In the paper process of moving from software requirements to UML diagrams has been studied. It shows the importance of this process and discusses many comparative studies in the field. A questionnaire related to the study was distributed worldwide to many research groups, academia, and industry to know the current status of using requirement management tools, knowledge of using UML in software development, frequently used UML diagrams, and the methodology used to generate UML diagrams from requirements. The paper emphasises that there is a need to do some important research in the area of requirements NLP to obtain UML diagrams, and generalize process of using automatic or semi-automatic methodology to generate UML diagrams from requirements.

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17071
22/01/2017

An abstraction model and a comparative analysis of Intel and ARM hardware isolation mechanisms

G.AVERLANT, B.MORGAN, E.ALATA, V.NICOMETTE, M.KAANICHE

TSF

Manifestation avec acte : IEEE Pacific Rim International Symposium on Dependable Computing ( PRDC ) 2017 du 22 janvier au 25 janvier 2017, Christchurch (Nouvelle Zélande), Janvier 2017, 10p. , N° 17071

Lien : https://hal.laas.fr/hal-01493597

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Abstract

Computer systems software and hardware architec- tures have become increasingly complex today. Meanwhile, cyber- attacks are becoming more and more sophisticated and target any software or hardware components of these systems. Several isolation mechanisms, at the software and the hardware layers, are now available to provide the best protection against these widespread attacks. This paper is aimed at reviewing especially hardware segregation mechanisms available in today’s CPU in order to provide better insights about the intended scope of the protection and the different threats that could be addressed by such mechanisms. An abstraction model presenting the main components of current architectures and their interactions through different communication channels is proposed to support such analysis. The study focuses on Intel and ARM architectures, and outlines various hardware isolation resources that provide a security layer to the software running on these architectures. A comparative analysis of these architectures is also presented together with a discussion of open issues and future challenges.

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