LIG Laboratory

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Denmark
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Hunold S.,LIG Laboratory | Lepping J.,TU Dortmund
Proceedings - IEEE International Conference on Cluster Computing, ICCC | Year: 2011

Parallel task graphs (PTGs) arise when parallel programs are combined to larger applications, e.g., scientific workflows. Scheduling these PTGs onto clusters is a challenging problem due to the additional degree of parallelism stemming from moldable tasks. Most algorithms are based on the assumption that the execution time of a parallel task is monotonically decreasing as the number of processors increases. But this assumption does not hold in practice since parallel programs often perform better if the number of processors is a multiple of internally used block sizes. In this article, we introduce the Evolutionary Moldable Task Scheduling (EMTS) algorithm for scheduling static PTGs onto homogeneous clusters. We apply an evolutionary approach to determine the processor allocation of each task. The evolutionary strategy ensures that EMTS can be used with any underlying model for predicting the execution time of moldable tasks. With the purpose of finding solutions quickly, EMTS considers results of other heuristics (e.g., HCPA, MCPA) as starting solutions. The experimental results show that EMTS significantly reduces the make span of PTGs compared to other heuristics for both non-monotonically and monotonically decreasing models. © 2011 IEEE.


Fleury A.,University of Lille Nord de France | Noury N.,University of Lyon | Vacher M.,LIG Laboratory
International Journal of E-Health and Medical Communications | Year: 2011

The increase in life expectancy is producing a bottleneck at the entry in institutions. Therefore, telemedicine becomes a timely solution, which is largely explored to care after elderly people living independently at home. It requires identifying the behaviors and activities of the person at home, with non-intrusive sensors and to process data to detect the main trends in the health status. This paper presents the results of the study of prior introduction, in Support Vector Machine, to improve the automatic recognition of Activities of Daily Living. From a set of activities, performed in the experimental smart home in Grenoble, the authors obtained models for seven activities of Daily Living and tested the performances of this classification with introduction of spatial and temporal priors. Eventually, different results are discussed. Copyright © 2011, IGI Global.


Rawat S.,Indian Institute of Technology Hyderabad | Richier J.-L.,LIG Laboratory | Groz R.,LIG Laboratory
CODASPY 2014 - Proceedings of the 4th ACM Conference on Data and Application Security and Privacy | Year: 2014

Fuzz testing consists in automatically generating and sending malicious inputs to an application in order to hopefully trigger a vulnerability. Fuzzing entails such questions as: Where to fuzz? Which parameter to fuzz? Where to observe its effects? etc. In this paper, we specifically address the questions: How to fuzz a parameter? How to observe its effects? To address these questions, we propose KameleonFuzz, a blackbox Cross Site Scripting (XSS) fuzzer for web applications. KameleonFuzz can not only generate malicious inputs to exploit XSS, but also detect how close it is revealing a vulnerability. The malicious inputs generation and evolution is achieved with a genetic algorithm, guided by an attack grammar. A double taint inference, up to the browser parse tree, permits to detect precisely whether an exploitation attempt succeeded. Our evaluation demonstrates no false positives and high XSS revealing capabilities: KameleonFuzz detects several vulnerabilities missed by other black-box scanners. Copyright is held by the owner/author(s).


Clausen A.,University of Southern Denmark | Demazeau Y.,LIG Laboratory | Jorgensen B.N.,University of Southern Denmark
Communications in Computer and Information Science | Year: 2014

Distributed energy resources (DER) offer an economically attractive alternative to traditional centralized generation. However, the unpredictable and scattered nature of DER prevents them from replacing traditional centralized generator capacity. Aggregating DER under a virtual power plant (VPP) addresses this issue by exposing the combined capabilities of connected DER as a single controllable entity towards the utility. In this paper we propose an architecture that supports multi-level aggregation of DER under VPPs. In this architecture, DER submit energy profiles to a VPP. The VPP may then control the DER within the boundaries defined in the energy profiles. The proposed architecture is hosted in an agent-based framework, Controleum, and is to be demonstrated at a primary school in Denmark, first quarter 2014. © Springer International Publishing Switzerland 2014.


Nejma G.B.,LIUPPA Laboratory | Roose P.,LIUPPA Laboratory | Dalmau M.,LIUPPA Laboratory | Gensel J.,LIG Laboratory | Ghorbali M.A.,LIG Laboratory
Energy Procedia | Year: 2014

The field of temporary social network has grown quickly in the last years giving the user a social spontaneous experience. Most existing applications focused on the ephemeral life span of the multimedia contents exchanged between people and forsaken other important aspects. In our work, we put the emphasis on some aspects as the location and the sense of group and we try to incorporate others innovative aspects like context awareness and semantic technologies. In this demonstration we present Taldea, community's application that facilitates user's access to spontaneous communities. It provides multiple services in order to satisfy the needs of users gathered by a common interest or purpose. Copyright © 2014 The Authors. Published by Elsevier B.V.


Caillouet C.,LIG Laboratory | Perennes S.,French Institute for Research in Computer Science and Automation | Rivano H.,INSA Lyon
Computer Communications | Year: 2011

In this paper, we address the problem of computing the transport capacity of Wireless Mesh Networks (WMNs) dedicated to Internet access. Routing and transmission scheduling have a major impact on the capacity provided to the clients. A cross-layer optimization of these problems allows the routing to take into account contentions due to radio interference. We present a generic mixed integer linear programing description of the configurations of a given WMN, addressing gateway placement, routing, and scheduling optimizations. We then develop new optimization models that can take into account a large variety of radio interference models, and QoS requirements on the routing. We also provide efficient resolution methods that deal with realistic size instances. It allows to work around the combinatoric of simultaneously achievable transmissions and point out a critical region in the network bounding the network achievable capacity. Based upon strong duality arguments, it is then possible to restrict the computation to a bounded area. It allows for computing solutions very efficiently on large networks. © 2011 Elsevier B.V.


Molle C.,LIG Laboratory | Voge M.-E.,LIG Laboratory
IEEE Communications Letters | Year: 2010

Evaluating wireless mesh network performances has become a specific challenge since the emergence of ubiquitous computing. In this article, we consider the network capacity as the performance measure and study its behaviour under two different interference models: (i) usual IEEE 802.11 MAC layer with acknowledgments at each hop, and (ii) block acknowledgments reported at the transport layer that can be included in the IEEE 802.16 standard. We derive a linear program modeling crosslayer characteristics of the wireless mesh network that is solved using column generation. We quantify the capacity gain induced by the move of the MAC acknowledgments into the transport layer, and show that a better load distribution is also obtained. © 2010 IEEE.


Emeras J.,LIG Laboratory | Ruiz C.,LIG Laboratory | Vincent J.-M.,LIG Laboratory | Richard O.,LIG Laboratory
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

In HPC community the System Utilization metric enables to determine if the resources of the cluster are efficiently used by the batch scheduler. This metric considers that all the allocated resources (memory, disk, processors, etc.) are full-time utilized. To optimize the system performance, we have to consider the effective physical consumption by jobs regarding the resource allocations. This information gives an insight into whether the cluster resources are efficiently used by the jobs. In this work we propose an analysis of production clusters based on the jobs resource utilization. The principle is to collect simultaneously traces from the job scheduler (provided by logs) and jobs resource consumptions. The latter has been realized by developing a job monitoring tool, whose impact on the system has been measured as lightweight (0.35 % speed-down). The key point is to statistically analyze both traces to detect and explain underutilization of the resources. This could enable to detect abnormal behavior, bottlenecks in the cluster leading to a poor scalability, and justifying optimizations such as gang scheduling or besteffort scheduling. This method has been applied to two medium sized production clusters on a period of eight months. © 2014 Springer-Verlag.


Serna A.,LIG Laboratory | Calvary G.,LIG Laboratory | Scapin D.L.,French Institute for Research in Computer Science and Automation
EICS'10 - Proceedings of the 2010 ACM SIGCHI Symposium on Engineering Interactive Computing Systems | Year: 2010

In Human Computer Interaction, plasticity refers to the capacity of User Interfaces (UIs) to withstand variations of context of use while preserving quality in use. Frequently, insuring more or less smooth transition from one context of use to the other (from the end-user perspective) is conducted ad hoc. To support a more systematic approach for characterizing UI tuning in terms of quality in use along context of use variations, we present an exploratory study focused deliberately on platform aspects. The design process of this particular case study is detailed and all design decisions have been recorded in terms of their influence on UI ergonomic quality, using Ergonomic Criteria. The interesting result is that most design choices when changing the platform lead to the reexamination of the initial designs. Ongoing work is done to support the insight that considering plasticity seems to help in explicitly broadening UI design choices and sharpening the solution. © 2010 ACM.


Nguyen T.B.,Danang University of Technology | Delaunay M.,LIG Laboratory | Robach C.,Grenoble Institute of Technology
Proceedings - 2011 IEEE International Conference on Computer Science and Automation Engineering, CSAE 2011 | Year: 2011

Reactive systems are often designed as two parts: computation part and control part. The computation part is modeled by operator diagrams, while the control part is modeled by transition-based models. In this paper, we concentrate on analyzing testability of control part by basing upon transition-based models. We first transform transition-based models into Markov chains by augmenting probability information. Then, testability measures are proposed from Markov chains as an estimate of testing effort for reaching state coverage and path coverage. The approach is applied to a case study and the obtained measures are compared to the testing effort required by a test generation tool. The results shows some interesting perspectives. © 2011 IEEE.

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