Sylvain Lecomte is Full Professor at LAMIH-University of Valenciennes. He has obtained a HDR in Computer Science at the University of Valenciennes (Title: Conception and adaptation of technical services dedicated to ambient computing , 2005) and a PhD in Computer Science at the University of Lille 1 (Title: COST-STIC : Smart Card embedded into transactional services and transactional services embedded into smart Card, 1998). Relevant Work Experience: Strong background in Context aware computing, Mobile services and Component model
Abstract: Nowadays there are many applications that users can benefit from on their handheld devices: localization, navigation, e-commerce, social networks and many others. Such capabilities are reaching our vehicles, offering drivers help for driving safely and more efficiently, thanks to the numerous services provided by applications on their devices. To simplify application assembly and reactivity according to transportation constraints (lack of communication infrastructure, high mobility...), we propose a framework that hosts multiple applications at once, offering at the same time management functions for context-awareness. Our framework is intended for mobile devices such as smartphones or in-car devices, which can range from stationary to highly mobile. We propose a service-oriented architecture able to compose applications out of services. This makes our framework flexible and allows for easier adaptation to context changes through the use of a Context Manager for all services (instead of having each service or application monitor the context). In this paper we present our proposition as well as some initial evaluations.
Abstract: The recent emergence of handheld devices
and wireless networks has provoked an exponential
increase in the number of mobile users. These users are
potential consumers of new applications, such as the
Location-Dependent Applications (LDA) examined in this
article. As their name implies, these applications depend
on location information, which is used to adapt and
customize the application for each user. In this article,
we focus on the problem of information localization,
particularly the evaluation of Location-Dependent Queries
(LDQ). Such queries allow, for example, a mobile user
who is in an airport to locate the closest bus stop to go to
the university. To evaluate these queries, the client
position must be retrieved. Often, positioning systems
such as GPS are used for this purpose; however, not all
mobile clients are equipped with such systems and these
systems are not well suited in every environments. To
remedy this lack, we propose a positioning solution based
on environment metadata, that can provide an
approximate client position, sufficient for evaluating LDQs.
This paper presents both the positioning system, and its
optimization with regard to minimizing response time and
economizing mobile device resources.
Abstract: The transportation domain brings particular needs dealing with the specificities of the environment (highly mobile, distributed, unstable network connection, ...). In this paper, we propose a first step in providing a dynamic adaptable framework responding to the non-functional needs of transportation’s applicative services. Among the most important services we can name positioning, time or communication capabilities. To achieve both this flexibility and automate context adaptation, we rely on a Service Oriented architecture and experiment our proposition on the inter-vehicular communication system, VESPA.
Abstract: The query service is the key element enabling users to identify
and access data or services. If the growth of mobility
in recent years makes it necessary to support different types
of queries (continuous, location dependent, spatio-temporal,
etc..), it has also resulted in the emergence of new and dedicated
evaluation and optimization techniques. These different
types of queries or techniques are useful and efficient depending
on the usage conditions in which the user is located.
Today, it is necessary to have, in pervasive environments, a
query service that adapts to context changes (application
constraints, user preferences, connectivity profile mobility,
etc.). In this paper we propose an architecture of a query
service dynamically adaptable to the context. This adaptability
is managed and controlled by an adaptation manager
by use of rules. Our solution not only allows the addition
and removal of new features dynamically, it also allows the
change of used evaluation techniques in order to use the
adapted one to the environment.
Abstract: These last years, the evolution of nomadic terminals and mobile
networks has yield to the development of the ubiquitous
computing. In this context, actual query evaluation and optimization
techniques in distributed databases based on the
use of a global schema and a cost model are no more relevant.
Furthermore, a query processor deployed in this type
of environment must face a significant heterogeneity, in particular
mobile terminals, communication networks and different
data sources. In order to cope with this heterogeneity,
such service should have the capability to adapt itself dynamically.
In this paper, we describe the problems related
to query processing in mobile environment and the needs for
adaptability.
Abstract: Nowadays, execution environments of applications are more and more heterogeneous: from powerful servers to smart cards. In order to assume the heterogeneity and the portability of applications, the component–based model has emerged as a model to develop new distributed applications. Thus, these applications are built as an assembly of interchangeable software blocks. Nevertheless, the gain of adaptability that comes from the use of component does not stretch to non-functional services (such as transaction management, security, etc). So, we suggest complementing the existing solution by facilitating the adaptability of non-functional services to their environment. Therefore, we propose to design a non-functional service as composition of small components. Besides, it is possible to supply the most appropriate version of a non-functional service to an application. So, in our approach, the application is composed by assembling both business components and non-functional components.
Abstract: The recent emergence of handheld devices and wireless networks has implied an exponential increase of terminals users. So, today, service providers have to propose new applications adapted to mobile environments. In this paper, we propose and describe a new class of distributed applications called the proximity applications. In such applications, two or more handheld devices, physically close to each other, can communicate and exchange data in a secure way. Proximity applications rely on the use of both different mobile devices and heterogeneous wireless networks. Thus, these applications need a high degree of flexibility, for an easy and rapid application development. In this context, our purpose is to study the interest of the Hybrid Peer-To-Peer (P2P) architecture model use specially for the extensibility, the fault-tolerance management and the scalability of proximity applications. Moreover, thanks to this model, proximity applications can easily face to the heterogeneity of devices and networks.
