| L'Elimination de la subjectivité dans la recommandation de confiance | | BIBAK | Full-Text | 3-10 | |
| Omar Hasan; Lionel Brunie; Jean-Marc Pierson; Elisa Bertino | |||
| In ubiquitous environments, a party who wishes to make a transaction often
requires that it has a certain level of trust in the other party. It is
frequently the case that the parties are unknown to each other and thus share
no preexisting trust. Trust-based systems enable users to establish trust in
unknown users through trust recommendation from known users. For example, Bob
may choose to trust an unknown user Carol when he receives a recommendation
from his friend Alice that Carol's trustworthiness is 0.8 on the interval [0,
1].
In this paper we highlight the problem that when a trust value is recommended by one user to another it may lose its real meaning due to subjectivity. Bob may regard 0.8 as a very high value of trust but it is possible that Alice perceived this same value as only average. We present a solution for the elimination of subjectivity from trust recommendation. We run experiments to compare our subjectivity-eliminated trust recommendation method with the unmodified method. In a random graph based web of trust with high subjectivity, it is observed that the novel method can give better results up to 95% of the time. Keywords: social networks, subjectivity, trust, ubiquitous environments | |||
| CBay: encheres pour le redéploiement de composants sur l'internet des machines | | BIBAK | Full-Text | 11-18 | |
| Charbel El Kaed; François Gael Ottogali; Yves Denneulin | |||
| Internet of machines also known as Machine-To-Machine is a system composed
of thousands of interconnected machines that inter operate to run an
application that meets a specific need. Such an application can be implemented
by the encapsulation and the cooperation of several software entities called
component. These components will be distributed on nodes with different
resources in terms of memory, capacity of calculation, bandwidth, battery
dependent, etc.
The placement of these components on the nodes is a crucial step for both the application and the target machines. The choice of placement actually influences their performance. Such a deployment algorithm has to take into account the functional needs, constraints and properties as well as the available resources and performance of the whole system. Many algorithms have been proposed for this, including one based on a principle of auction, DecAp [13], which allows the dynamic redeployment of components in order to take into account the evolution of the system's resources. We present in this article an extension of this algorithm by adding the management of available resources on each node: memory, bandwidth and computing capacity. Keywords: Machine-To-Machine, auction, deployment, software components | |||
| Record & replay: expérimentation d'un service multimodal | | BIBAK | Full-Text | 19-23 | |
| Antoine Bouyer; Florent Chuffart | |||
| This paper presents the conception of a multimodal platform, and analyses
the results of a user experimentation. Keywords: multimodality, user experimentation | |||
| Vers la définition du contexte d'un utilisateur mobile de système de recherche d'information | | BIBAK | Full-Text | 25-31 | |
| Ourdia Bouidghaghen; Lynda Tamine-Lechani; Mohand Boughanem | |||
| The mobile user differs from the desktop user in that his handheld device is
truly personal. It roams with him and allows him access to information at any
time from anywhere. Contextual information access in mobile environments aims
to tackle the problem of information overload by providing appropriate results
according to the resource constraints on the one hand and user's location, time
and interests on the other hand. In this paper, we describe a general approach
for building a context-aware user profile for a mobile user for search engines
using evidence issued from retrieval situations. The basic idea is to learn the
user's interests for each user's situation. A situation refers to an
aggregation of the spatio-temporel context within his past search activities.
User's interests are inferred from past search activities related to the
identified situations. Keywords: context-aware profile, contextuel information retrieval, location, mobile
user, personalization, situation, time | |||
| Caractérisation de la densité de trafic et de son évolution à partir de trajectoires d'objets mobiles | | BIBAK | Full-Text | 33-40 | |
| Ahmed Kharrat; Iulian Sandu Popa; Karine Zeitouni; Sami Faiz | |||
| Managing and mining data derived from moving objects is becoming an
important issue in the last years. In this paper, we are interested in mining
trajectories of moving objects such as vehicles in the road network. We propose
a method for dense route discovery by clustering similar road sections
according to both traffic and location in each time period. The traffic
estimation is based on the collected spatiotemporal trajectories. We also
propose a characterization approach of the temporal evolution of dense routes
by a graph of route connection over consecutive time periods. This graph is
labelled by a degree of evolution. We have implemented and tested the proposed
algorithms, which have shown their effectiveness and efficiency. Keywords: clustering, moving object databases, road traffic, similarity,
spatiotemporal data mining | |||
| Opérations d'administration pour SStreaMWare | | BIBAK | Full-Text | 41-44 | |
| Levent Gürgen; Cyril Labbé; Shinichi Honiden | |||
| SStreaMWare is a data management middleware that allows building declarative
queries on heterogeneous sensors. This paper illustrates how to extend
SStreaMWare, in addition to its querying capabilities, with management
capabilities, such as configuration, software update and performance
monitoring, in order to increase the efficiency of networked sensing systems.
In fact, with the emergence of sensors in applications in which the quality of
service requirements are high (e.g., industrial, medical, domotic), management
of these sensing devices gains an increasing importance. Keywords: management, middleware, sensors, ubiquitous networks | |||
| Historical data storage for large scale sensor networks | | BIBAK | Full-Text | 45-52 | |
| Loïc Petit; Abdelhamid Nafaa; Raja Jurdak | |||
| Wireless sensor networks are rapidly finding their way through a plethora of
new applications like precision farming and forestry, with increasing network
scale, system complexity, and data rate. While scalable MAC and routing
protocols for sensor networks have been well addressed in recent years, the
scalability of the back-end storage architecture has been largely overlooked.
As a result, current storage and retrieval architectures usually lead to an
excessive I/O cost when it comes to improving the scalability and
responsiveness of the system. In this paper, we present a scalable backend
storage and retrieval architecture to support very large volumes of real-time
measurements from wireless sensor networks. In particular, our contribution
provides: (i) a database partitioning and structuring scheme coupled with a
double-buffering technique to reduce the end-to-end delay while minimizing the
processing power, and (ii) an optimized historical measurement data query
format tailored for superior performance in terms of data retrieval
responsiveness. Through a realistic emulator for large scale sensor network, we
evaluate this storage and retrieval system to illustrates its delay and I/O
benefits in both high and low traffic rate scenarios. The evaluation guides our
design of an adaptive design, that applies batch insert method for smaller
deployments to reduce insertion delay, and double-buffering for larger
deployments to reduce I/O cost and avoid saturation, at the cost of higher
delay. Keywords: database partitioning, double-buffer, historical storage, sensor | |||
| Résumé de flux d'événements dans les réseaux inter-véhiculaires | | BIBAK | Full-Text | 53-60 | |
| Bruno Defude; Thierry Delot; Dorsaf Zekri | |||
| In this article, we focus en inter-vehicle ad hoc networks. In such
networks, data are usually exchanged between vehicles to warn or inform the
drivers when an event is detected (e.g., accident, emergency braking, available
parking space, etc.).
In this article, we propose de store and aggregate the data once used to produce a warning to the driver. We therefore use Flajolet-Martin sketches. Our goal is here to generate additional knowledge to assist drivers by detecting news road hazards (e.g., dangerous areas, etc.). Keywords: V2V, data aggregation, event streams, inter-vehicles ad hoc networks,
spatio-temporal data, storage and data aggregation | |||
| Support d'adaptation dynamique et distribuée dans la conception de systèmes de réplication de données | | BIBAK | Full-Text | 61-64 | |
| Mohamed Zouari; Françoise André; Maria-Teresa Segarra | |||
| The distributed and mobile environments are characterized by high
heterogeneity and suffer from important variations. Mobile and geographically
dispersed users who collaborate together may access shared data. Data
replication can be used to improve data availability and query latency. In
order to ensure quality of service, a replication system should be adaptive to
context. However, making such system adaptive can be a complex and costly task,
in particular because of its distributed nature. This article presents our
model-based approach to structure the mechanisms that ensure a dynamic and
distributed adaptation. We propose a specialization of the model to build an
adaptable data replication system. We have chosen to illustrate our approach
through a telemedicine application. Keywords: data replication, dynamic and distributed adaptation, telemedicine | |||
| Cache sémantique pour grilles pervasives | | BIBAK | Full-Text | 65-72 | |
| Laurent d'Orazio; Mamadou Kaba Traoré | |||
| Pervasive grids present a new trend to distributed computing, for
coordinating large-scale resources enabling access to small and smart devices.
In this paper, we propose a caching approach for improving querying on
pervasive grids. The proposed solution, called semantic pervasive dual cache,
follows a semantic oriented approach. It is based on the one hand on a clear
separation between the analysis and the evaluation process, and on the other
hand on the cooperation between client caches considering light analysis and
proxy caches including evaluation capabilities. Such an approach helps load
balancing, making the system more scalable. Our proposal has been validated
thanks to analytic models and simulations and seems promising as showed by the
results obtained. Keywords: pervasive grid, semantic caching | |||
| MANET: modèle de mobilité planifiée | | BIBAK | Full-Text | 75-78 | |
| Frédéric Guinand; Brice Onfroy | |||
| With the common availability of mobile communicating devices like PDA or
smartphones, mobile ad hoc networks (a.k.a MANET) are rising as an interesting
domain of research. They are now ready for a wide development. These
infrastructureless networks are composed of wireless-enable communicating
devices, which moves entail frequent changes in their own neighborhood.
Consequently, obtaining real data on this kind of networks in order to observe
the dynamic of their topology is rather complicated. Thus, it is critical to be
able to simulate human mobility in various environments for the purpose of
recreating, in a global way, a dynamic network close to reality. Many mobility
models have already been used for analyzing the viability of new protocols for
routing, communicating or broadcasting. The purpose of this demonstration is
present a simulation plateform for mobility models within urban environments. A
new type of mobility model implementing the planification of moves will
illustrate the way of using such simulator. Keywords: MANET, dynamic graph, metropolitan mobile ad hoc network, mobile ad hoc
network, mobility model, planned mobility, urban environment | |||
| Une architecture sensible au contexte pour le développement des systèmes d'administration pour l'enseignement | | BIBAK | Full-Text | 79-82 | |
| Gaël Bergeret; Windson Viana; José Bringel Filho; José C. F. Junior; Marlène Villanova-Oliver; Jérôme Gensel; Hervé Martin | |||
| The increasing use of mobile devices and wireless communication technologies
has improved the access to web information systems. However, the development of
these systems imposes new challenges mainly due to the heterogeneity of mobile
devices, the management of context information, and the complexity of
adaptation process. Especially in this case, these systems should be runable on
a great number of mobile devices models. In this article, we describe a
context-aware architecture that provides solutions to the challenges presented
above for the development of education administration systems. Keywords: context-awareness, mobile computing, web applications | |||
| SimplyEngine-WComp: plate-forme de prototypage rapide pour l'Informatique ambiante basée sur une approche orientée services pour dispositifs réels/virtuels | | BIBAK | Full-Text | 83-86 | |
| V. Maurin; N. Dalmasso; B. Copigneaux; S. Lavirotte; G. Rey; J.-Y. Tigli | |||
| In this paper, we describe the joint research between Simplysim company and
the Rainbow research group to lead to SimplyEngine-WComp platform as a web
service for device oriented platform to rapidly and dynamically prototype
applications in a 3D virtual environment using physical devices to interact
with. This experimental product is the result of the dual expertise of both
organizations in the fields of 3D environment real time simulation and services
for devices oriented approaches to design ubiquitous applications. The SLCA
model and WComp middleware, made by the Rainbow research group are already
validated by prototypes of multi-devices systems, complete the SimplyEngine
made by Simplysim to propose a complete platform to prototype dynamic physical
and virtual systems. All the conditions are met for prototyping incremental and
scalable applications for ubiquitous world. Then the accuracy of the prototype
depends on the number of virtual devices replaced by physical devices. This
replacement is realized by a simple research, discovery and substitution of
services. Keywords: composite web services, input/output devices, ubiquitous computing, virtual
and augmented reality | |||
| SoCQ: a pervasive environment management system | | BIBAK | Full-Text | 87-90 | |
| Yann Gripay; Frédérique Laforest; Jean-Marc Petit | |||
| Pervasive systems give an overview of what digital environments should look
like in the future. SoCQ takes a data-oriented perspective on the pervasive
environment through a unified view of available data and services. Pervasive
applications can then be created in a declarative fashion using
service-oriented continuous queries. We tackle the following challenges: 1) a
homogeneous representation for data sources and services from the pervasive
environment, 2) a query language over pervasive environments, 3) a Pervasive
Environment Management System (PEMS). This demonstration shows our PEMS
prototype in action, allowing the user to visualize the environment and define
pervasive applications. Keywords: continuous queries, pervasive systems, services | |||
| SWooki: supporting disconnection in a peer-to-peer semantic wiki | | BIBAK | Full-Text | 91-94 | |
| Hala Skaf-Molli; Pascal Molli; Gérôme Canals | |||
| SWooki is a P2P semantic wiki. A SWooki network is a set of interconnected
semantic wiki servers. Each server hosts a replica of semantically annotated
wiki pages. The replicated architecture allows to support mobile work. Mobile
work is characterized by the alternate of connection and disconnection phases.
During disconnection phase, the different replicas can be modified in parallel
so they diverge. Later, upon reconnection they are synchronized. SWooki uses an
optimistic replication mechanism to maintain the consistency of the replicated
wiki pages and the replicated RDF repositories. This demonstration shows
various functionalities of SWooki. Keywords: disconnected work, peer-to-peer, replication, semantic wiki | |||