Laboratory STICC

Saint-Cyr-l'École, France

Laboratory STICC

Saint-Cyr-l'École, France
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Rajaonarivo L.,Laboratory STICC | Courgeon M.,Laboratory STICC | Maisel E.,Laboratory STICC | De Loor P.,Laboratory STICC
International Conference on Intelligent User Interfaces, Proceedings IUI | Year: 2017

This paper presents an intelligent user interface model dedicated to the exploration of complex databases. This model is implemented on a 3D metaphor : A virtual museum. In this metaphor, the database elements are embodied as museum objects. The objects are grouped in rooms according to their semantic properties and relationships and the rooms organization forms the museum. Rooms organization is not predefined but defined incrementally by taking into account not only the relationships between objects, but also the users centers of interest. The latter are evaluated in real-Time through user interactions within the virtual museum. This interface allows for a personal reading and favors the discovery of unsuspected links between data. In this paper, we present our model's formalization as well as its application to the context of cultural heritage. © 2017 ACM.

Even C.,Laboratory STICC | Bosser A.-G.,Laboratory STICC | Buche C.,Laboratory STICC
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2017

Recently, the development of believable agents has gained a lot of interest and many solutions have been proposed by the research community to implement such bots. However, in order to make advances in this field, a generic and rigorous evaluation that would allow the comparison of new systems against existing ones is needed. This paper provides a summary of the existing believability assessments. Seven features characterising the protocols are identified. After a comprehensive analysis, recommendations and prospects for improvement are provided. © Springer International Publishing AG 2017.

Duan J.,IMT Atlantique | Lagrange X.,IMT Atlantique | Guilloud F.,Laboratory STICC
IEEE International Conference on Communications | Year: 2017

Centralized/Cloud Radio Access Network (C-RAN) separates Baseband Units (BBUs) away from Remote Radio Heads (RRHs) and centralizes BBUs into a BBU pool. This new architecture can facilitate the cooperation between different cells. We apply zero-forcing (ZF) for joint transmission in a C-RAN downlink system. A number of User Elements (UEs) are assigned to be served into different subframes for serving. This paper proposes two user grouping algorithms denoted Global Greedy User Grouping Algorithm (GGUGA) and User Division Algorithm (UDA) to maximize the average achievable sum rate. GGUGA is a typical greedy algorithm. UDA restricts the random selection of UEs groupings into a certain region which increases the chance to make a good choice. GGUGA achieves a similar performance compared to exhaustive enumeration of all possible UEs groupings. The complexity of UDA is much less than the one of GGUGA when the number of UEs for grouping is large at the expense of a small loss in performance. © 2017 IEEE.

Salzenstein F.,University of Strasbourg | Boudraa A.O.,CNRS Naval Academy Research Institute | Chonavel T.,Laboratory STICC
Multidimensional Systems and Signal Processing | Year: 2013

This work aims at introducing some energy operators linked to Teager-Kaiser energy operator (TKEO) (Kaiser in On a simple algorithm to calculate the energy of a signal, pp 381-384, 1990), its associated higher order versions and expanding them to multi-dimensional signals. These operators are very useful for analysing oscillatory signals with time-varying amplitude and frequency (AM-FM). We first propose a new mathematical expression of these operators using directional derivatives along any n-D vector and Kronecker powers (Proposition 1, Sect. 3). This mathematical formulation allows us to extend to n-D case some properties of the classical TKEO such as tracking of AM envelope and instantaneous frequency of a multi-dimensional AM-FM signal. In addition, we have introduced a new scalar function using the directional derivative along a vector to recover the "sign" of the frequency components. Applications of this model to a local n-D AM-FM signal and the related demodulation errors are presented. To show the effectiveness and the robustness of the new class of operators in term of envelope and frequency tracking, results obtained on synthetic and real data are compared to multi-dimensional energy separation algorithm (Maragos and Bovik in J Opt Soc Am A 12:1867-1876, 1995) and to our previously developed method (Salzenstein and Boudraa in Signal Process 89(4):623-640, 2009). Finally, the performances of these methods are investigated in the presence of an additive noise. © 2012 Springer Science+Business Media, LLC.

Rolland A.,CNRS Institute of Electronics and Telecommunications, Rennes | Boriskin A.V.,CNRS Institute of Electronics and Telecommunications, Rennes | Person C.,Laboratory STICC | Quendo C.,Laboratory STICC | And 2 more authors.
IEEE Antennas and Wireless Propagation Letters | Year: 2012

A lens-corrected smooth-walled axis-symmetrical dielectric-loaded horn antenna is designed and characterized in Ka-band using the bodies of revolution finite-difference time domain (BoR-FDTD) technique and genetic algorithm. The joint optimization of the horn and dielectric loading profiles enables us to develop a horn with a very good gain performance achieved in a frequency range of about 18%. Compared to earlier results, the bandwidth improvement exceeds a factor two. A lightweight prototype is fabricated in metallized foam. A very good agreement between the numerical and measured data is obtained. © 2012 IEEE.

Rolland A.,CNRS Institute of Electronics and Telecommunications, Rennes | Nguyen N.T.,CNRS Institute of Electronics and Telecommunications, Rennes | Sauleau R.,CNRS Institute of Electronics and Telecommunications, Rennes | Person C.,Laboratory STICC | Le Coq L.,CNRS Institute of Electronics and Telecommunications, Rennes
IEEE Transactions on Antennas and Propagation | Year: 2012

Several smooth-walled axis-symmetrical dielectric-loaded horn antennas with large flare angles have been designed and characterized in Ka-band. They have been optimized using an in-house CAD tool based on the BoR-FDTD technique and genetic algorithms. Two antenna configurations have been compared: in the first case, only the metallic profile of the horn is shaped and the radiating aperture remains flat, whereas in the second one, the shapes of the horn profile and the aperture are simultaneously optimized. The impact of both techniques in terms of antenna size and performance is discussed. An original fabrication process (metallized foam) has been developed to produce monolithic prototypes. Two prototypes with optimized shapes have been fabricated, and their main characteristics (radiation characteristics, bandwidth, compactness, weight) are compared to those of a standard conical horn used as a reference (same flare angle, same diameter, but without shaped profile). Our results show that the proposed design and fabrication procedures enable us to produce reduced-size horns with high radiation efficiency; the total loss, including the transition loss, is lower than 1 dB in average around 29.5 GHz. © 2006 IEEE.

Tchakaloff B.,Embedded Systems Team | Tchakaloff B.,Laboratory STICC | Saudrais S.,Embedded Systems Team | Babau J.-P.,Laboratory STICC
QoSA 2013 - Proceedings of the 9th International ACM Sigsoft Conference on the Quality of Software Architectures | Year: 2013

Electric vehicles embed a low amount of energy, so their devices need to be managed efficiently to optimize the vehicle autonomy. A vehicle management is achieved by the embedded systems, modeled following the Autosar standard. Autosar covers most of the automotive concerns, but it lacks energy consumption and user-oriented Quality of Service models. This paper presents Orqa, a framework to model and manage the electric vehicle devices through energy consumption and user-oriented Quality of Service. At design time, the architects choose and tune the actual vehicle device models through their power requirements and, if appropriate, quality levels. The generated implementation is then embedded in the existing Autosar models. Thus, at run-time, the vehicle's system is able to evaluate the global consumption of a trip and to propose the user a specific driving strategy. The optional devices are managed throughout the trip, based on the driver preferences. Orqa is illustrated with a classic use-case: a work to home trip. Copyright 2013 ACM.

Courgeon M.,Laboratory STICC | Hoareau C.,University of South Brittany | Duhaut D.,University of South Brittany
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

The MoCA project aims to design and study children-companion relationship through virtual agents, personal robots and communicating devices. In this article, we present an exploratory study of the free 30 min long interactions between children and a set of artificial, robot-like and virtual companions. We present a preliminary overview of the results obtained pending further analyses. © Springer International Publishing AG 2016.

Polceanu M.,Laboratory STICC | Parenthoen M.,Laboratory STICC | Buche C.,Laboratory STICC
Proceedings of the 28th International Florida Artificial Intelligence Research Society Conference, FLAIRS 2015 | Year: 2015

Using mental simulation as a means of selecting actions for an agent is not new to the scientific community, but implementations from literature focus on specific scenarios and strategies built by domain-experts. In this paper, we propose a generic decision-making agent architecture which uses mental simulation. Our architecture allows an agent to predict both physical phenomena and behavior of other entities simultaneously, in real time, and to pursue its goal without additional builtin strategies. The experimental results show its performance in a dynamic nature-inspired scenario where our agent changes its behavior based on how it anticipates others will act. Copyright © 2015, Association for the Advancement of Artificial Intelligence ( All rights reserved.

Barange M.,Laboratory STICC | Kabil A.,Laboratory STICC | De Keukelaere C.,Laboratory STICC | Chevaillier P.,Laboratory STICC
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

Coordination is an essential ingredient for human-agent teamwork. It requires team members to share knowledge to establish common grounding and mutual awareness among them. This paper proposes a behavioral architecture C 2 BDI that enhances the knowledge sharing using natural language communication between team members. Collaborative conversation protocols and resource allocation mechanism have been defined that provide proactive behavior to agents for coordination. This architecture has been applied to a real scenario in a collaborative virtual environment for learning. The solution enables users to coordinate with other team members. © 2014 Springer International Publishing Switzerland.

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