Dominique Vaufreydaz

Dr. Dominique Vaufreydaz

University of Grenoble, Grenoble, France

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 March 2017 in Sensors
Verified
Journal Article
Open access
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Joaquín Torres-SospedraJoaquín Torres-Sospedra
Joaquín Torres-Sospedra
ARAntonio Ramon Jimenez Ruiz
Antonio Ramon Jimenez Ruiz
SKStefan Knauth
Stefan Knauth
AMAdriano J. C. Moreira
Adriano J. C. Moreira
YBYair Beer
Yair Beer
ECEric Castelli
Eric Castelli
This paper presents the analysis and discussion of the off-site localization competition track, which took place during the Seventh International Conference on Indoor Positioning and Indoor Navigation (IPIN 2016). Five international teams proposed different strategies for smartphone-based indoor positioning using the same reference data. The competitors were provided with several smartphone-collected signal datasets, some of which were used for training (known trajectories), and others for evaluating (unknown trajectories). The competition permits a coherent evaluation method of the competitors’ estimations, where inside information to fine-tune their systems is not offered, and thus provides, in our opinion, a good starting point to introduce a fair comparison between the smartphone-based systems found in the literature. The methodology, experience, feedback from competitors and future working lines are described.

10 January 2020 in Sensors
Verified
Journal Article
Open access
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VTViet-Cuong Ta
Viet-Cuong Ta
TDTrung Kien Dao
Trung Kien Dao
DVDominique Vaufreydaz
Dominique Vaufreydaz
ECEric Castelli
Eric Castelli
For the localization of multiple users, Bluetooth data from the smartphone is able to complement Wi-Fi-based methods with additional information, by providing an approximation of the relative distances between users. In practice, both positions provided by Wi-Fi data and relative distance provided by Bluetooth data are subject to a certain degree of noise due to the uncertainty of radio propagation in complex indoor environments. In this study, we propose and evaluate two approaches, namely Non-temporal and Temporal ones, of collaborative positioning to combine these two cohabiting technologies to improve the tracking performance. In the Non-temporal approach, our model establishes an error observation function in a specific interval of the Bluetooth and Wi-Fi output. It is then able to reduce the positioning error by looking for ways to minimize the error function. The Temporal approach employs an extended error model that takes into account the time component between users’ movements. For performance evaluation, several multi-user scenarios in an indoor environment are set up. Results show that for certain scenarios, the proposed approaches attain over 40% of improvement in terms of average accuracy.

Verified
Journal Article
Open access
PDF file
TGThomas Guntz
Thomas Guntz
RBRaffaella Balzarini
Raffaella Balzarini
DVDominique Vaufreydaz
Dominique Vaufreydaz
JCJames Crowley
James Crowley
In this paper we present the first results of a pilot experiment in the interpretation of multimodal observations of human experts engaged in solving challenging chess problems. Our goal is to investigate the extent to which observations of eye-gaze, posture, emotion and other physiological signals can be used to model the cognitive state of subjects, and to explore the integration of multiple sensor modalities to improve the reliability of detection of human displays of awareness and emotion. Domains of application for such cognitive model based systems are, for instance, healthy autonomous ageing or automated training systems. Abilities to observe cognitive abilities and emotional reactions can allow artificial systems to provide appropriate assistance in such contexts. We observed chess players engaged in problems of increasing difficulty while recording their behavior. Such recordings can be used to estimate a participant’s awareness of the current situation and to predict ability to respond effectively to challenging situations. Feature selection has been performed to construct a multimodal classifier relying on the most relevant features from each modality. Initial results indicate that eye-gaze, body posture and emotion are good features to capture such awareness. This experiment also validates the use of our equipment as a general and reproducible tool for the study of participants engaged in screen-based interaction and/or problem solving.

12 October 2017 in arXiv
Verified
Preprint
Open access
PDF file
TGThomas Guntz
Thomas Guntz
RBRaffaella Balzarini
Raffaella Balzarini
DVDominique Vaufreydaz
Dominique Vaufreydaz
JCJames Crowley
James Crowley
In this paper we present the first results of a pilot experiment in the capture and interpretation of multimodal signals of human experts engaged in solving challenging chess problems. Our goal is to investigate the extent to which observations of eye-gaze, posture, emotion and other physiological signals can be used to model the cognitive state of subjects, and to explore the integration of multiple sensor modalities to improve the reliability of detection of human displays of awareness and emotion. We observed chess players engaged in problems of increasing difficulty while recording their behavior. Such recordings can be used to estimate a participant's awareness of the current situation and to predict ability to respond effectively to challenging situations. Results show that a multimodal approach is more accurate than a unimodal one. By combining body posture, visual attention and emotion, the multimodal approach can reach up to 93% of accuracy when determining player's chess expertise while unimodal approach reaches 86%. Finally this experiment validates the use of our equipment as a general and reproducible tool for the study of participants engaged in screen-based interaction and/or problem solving.