Article de revue avec comité de lecture (3)
CASTRO-JUL Fátima, DÍAZ-REDONDO Rebeca P. , FERNÁNDEZ VILAS Ana, CHABRIDON Sophie, CONAN Denis
Fog architectures and sensor location certification in distributed event-based systems. Sensors, january 2019, vol. 19, n° 1, pp. 104-1-104-26
URL: https://www.mdpi.com/1424-8220/19/1/104/pdf
abstract
Since smart cities aim at becoming self-monitoring and self-response systems, their deployment relies on close resource monitoring through large-scale urban sensing. The subsequent gathering of massive amounts of data makes essential the development of event-filtering mechanisms that enable the selection of what is relevant and trustworthy. Due to the rise of mobile event producers, location information has become a valuable filtering criterion, as it not only offers extra information on the described event, but also enhances trust in the producer. Implementing mechanisms that validate the quality of location information becomes then imperative. The lack of such strategies in cloud architectures compels the adoption of new communication schemes for Internet of Things (IoT)-based urban services. To serve the demand for location verification in urban event-based systems (DEBS), we have designed three different fog architectures that combine proximity and cloud communication. We have used network simulations with realistic urban traces to prove that the three of them can correctly identify between 73% and 100% of false location claims
LIAO Jianwei, TRAHAY François, CAI Zhigang, XIONG Hailing, CHEN Shanxiong, ISHIKAWA Yutaka
Fine granularity and adaptive cache update mechanism for client caching. IEEE systems journal, june 2019, vol. 13, n° 2, pp. 1587 -1598
abstract
Distributed file systems have been commonly used as the back end to provide high-performance I/O services for hosting complicated data processing, such as database workloads. By buffering the frequently used data in the local file cache, which is called the client caching mechanism, can reduce the I/O latency and improve the performance of file access. However, the overhead and complexity for ensuring data consistency may offset the performance benefits caused by data caching. This paper proposes an adaptive, per-block cache update mechanism, which can ensure data consistency of block data in a distributed file system, with low synchronization overhead. Specifically, based on the recent history of read/write requests, the proposed scheme can adaptively select the best-suited consistency update policy for each data block at run time. The experiments on database applications show that our newly proposed mechanism can greatly reduce the overhead resulted by maintaining cache consistency, especially for the workloads having fluctuating read/write ratios. As a consequence, the system performance can be also enhanced
SELLAMI Mohamed, MAAMAR Zakaria, LEFEBVRE Sylvain, FACI Noura
Logs and enterprise networks for overcoming obstacles in business processes. Computing, march 2019, vol. 101, n° 3, pp. 263-288
abstract
This paper discusses obstacle tackling in the context of business processes, in general, and social business processes, in particular. Obstacles are situations that could evolve into exceptions, if they are not efficiently and promptly (i.e., no preventive measures taken) tackled. Compared to obstacles, exceptions put a business process in a suspension mode until corrective measures are taken, which does not help ensure operation continuity. To address this lack of continuity, a two-stage approach for obstacle tackling using specialized enterprise networks is presented. The approach consists of (i) an early business-process obstacle detection technique based on logs and enterprise networks, and (ii) obstacle tackling technique based on solutions that result from network crawling. A system demonstrating the feasibility and efficiency of the approach through a real dataset, is presented in the paper as well
Communication dans une conférence à comité de lecture (3)
JABBOUR Saïd, MA Yue, RADDAOUI Badran
Handling disagreement in ontologies-based reasoning via argumentation. WISE 2019: 20th International Conference on Web Information Systems Engineering, ACM, 26-30 november 2019, Hong-Kong, China, 2019 (document in press)
abstract
Ontologies are at the heart of the Semantic Web technologies. This paper introduces a framework for reasoning under uncertainty in the context of ontologies represented in description logics; these ontologies could be inconsis- tent or incoherent. Conflicts are addressed through a form of logic-based argu- mentation. We examine how the number of attacks and the weights of arguments can be used to define various labelling functions that identify the justification statuses of arguments. Then, different inference relations are distinguished to obtain meaningful answers to queries from imperfect ontologies without extra computational costs compared to classical DL reasoning. Lastly, we study the properties of these new entailment relations and their relationships with other well-known existing ones.
MEBREK Wafaa, RADDAOUI Badran, ALBILANI Mohamad
On relaxing failing queries over RDF databases. Big Data 2019: IEEE International Conference on Big Data, IEEE Computer Society, 09-12 december 2019, Los Angeles, United States, 2019 (document in press)
abstract
Database users can be frustrated by having an empty answer to a query. In particular, querying RDF triple-stores are prone to failure due to the nature of RDF data. The problem of query relaxation is thus a helpful technique for efficiently querying RDF databases by providing users with alternative answers instead of an empty result. The main shortcoming of most prior researches is that they focus on the relaxation itself rather than the causes of failure. Yet, determining possible explanations, i.e. diagnoses, for an unexpected behavior of the system under observation is crucial to the user. In this paper, we present CADER, a novel approach for computing relaxations for failed queries over RDF databases. We show how the number of required database queries for determining all the possible relaxations can be limited to the search of failed subqueries of the user query. Then, we point out how the hitting set problem can be applied for determining the possible relaxed queries in an efficient way without querying the RDF database. Finally, the efficiency and scalability of CADER against existing solutions are shown through extensive experiments on the well-known RDF benchmarks with a variety of queries of different shapes.
OUDART David, CANTENOT Jérôme, BOULANGER Frédéric, CHABRIDON Sophie
An approach to design smart grids and their IT system by cosimulation. MODELSWARD 2019: 7th International Conference on Model-Driven Engineering and Software Development, Setúbal : SCITEPRESS, 20-22 february 2019, Prague, Czech Republic, 2019, pp. 372-379, ISBN 978-989-758-358-2
abstract
Smart grids are the oncoming generation of power grids, which rely on information and communication technologies to tackle decentralized and intermittent energy sources such as wind farms and photovoltaic plants. They integrate electronics, software information processing and telecommunications technical domains. Therefore the design of smart grids is complex because of the various technical domains and modeling tools at stake. In this article, we present an approach to their design, which relies on model driven engineering, executable models and FMI based cosimulation. This approach is illustrated on the use case of an insular power grid and allows to study the impact of power production decisions
