Search results for " Computer Science"
showing 10 items of 3983 documents
Effect of Footstep Vibrations and Proprioceptive Vibrations Used with an Innovative Navigation Method
2017
This study proposes to investigate the effect of adding vibration feedback to a navigation task in virtual environment. Previous study used footstep vibrations and proprioceptive vibrations in order to decrease the cyber-sickness and increase the sense of presence. In this study, we experiment the same vibration modalities but with a new navigation method. The results show that proprioceptive vibrations do not impact the sense of presence neither the cyber-sickness while footstep vibrations increase sense of presence and decrease in a certain way cyber-sickness. Burgundy region through the JCE funding project
Testbed evaluation of optimized REACT over multi-hop paths
2018
REACT is a distributed resource allocation protocol that computes a max-min allocation of airtime for mesh networks. The allocation adapts automatically to changes in local traffic load and in local network views. SALT, a new contention window tuning algorithm, ensures that each node secures the airtime allocated to it by REACT. REACT and SALT are extended to the multi-hop flow scenario with the introduction of a new airtime reservation algorithm. With a reservation in place, multi-hop TCP flows show increased throughput when running over SALT and REACT compared to running over 802.11 DCF. All results are obtained from experimentation on the w-iLab.t wireless network testbed in Belgium.
An improvement of NFC-SEC with signed exchanges for an e-prescription-based application
2013
International audience; In the context of an aging population, drug intake can be a potential source of errors leading to death in some cases. Almost all of these errors are unintentional and come from incorrect prescriptions, unsuitable dosages for the patient or incompatibility with other treatments. To limit these risks which are especially important in the elderly or pre-dependency, we propose a secure system for drug treatment through the NFC (Near Field Communication) contact-less communication technology. The proposed system provides security mechanisms such as integrity, authentication, encryption and non-repudiation. To ensure this security, an extension of the international standa…
The Athena X-ray Integral Field Unit (X-IFU)
2016
Event: SPIE Astronomical Telescopes + Instrumentation, 2016, Edinburgh, United Kingdom.
Tracking Hands in Interaction with Objects: A Review
2017
Markerless vision-based 3D hand motion tracking is a key and popular component for interaction studies in many domains such as virtual reality and natural human-computer interfaces. While this research field has been well studied in the last decades, most approaches have considered the human hand in isolation and not in action or in interaction with the environment or the other articulated human body parts. Employing contextual information about the surrounding environment (e.g. the shape, the texture, and the posture of the object in the hand) can remarkably constrain the tracking problem. The goal of this survey is to develop an up-to-date taxonomy of existing vision-based hand tracking m…
Efficient Skin Detection under Severe Illumination Changes and Shadows
2011
International audience; This paper presents an efficient method for human skin color detection with a mobile platform. The proposed method is based on modeling the skin distribution in a log-chromaticity color space which shows good invariance properties to changing illumination. The method is easy to implement and can cope with the requirements of real-world tasks such as illumination variations, shadows and moving camera. Extensive experiments show the good performance of the proposed method and its robustness against abrupt changes of illumination and shadows.
Multimodal 2D Image to 3D Model Registration via a Mutual Alignment of Sparse and Dense Visual Features
2018
International audience; Many fields of application could benefit from an accurate registration of measurements of different modalities over a known 3D model. However, aligning a 2D image to a 3D model is a challenging task and is even more complex when the two have a different modality. Most of the 2D/3D registration methods are based on either geometric or dense visual features. Both have their own advantages and their own drawbacks. We propose, in this paper, to mutually exploit the advantages of one feature type to reduce the drawbacks of the other one. For this, an hybrid registration framework has been designed to mutually align geometrical and dense visual features in order to obtain …
Real-Time Human Pose Estimation from Body-Scanned Point Clouds
2015
International audience; This paper presents a novel approach to estimate the human pose from a body-scanned point cloud. To do so, a predefined skeleton model is first initialized according to both the skeleton base point and its torso limb obtained by Principal Component Analysis (PCA). Then, the body parts are iteratively clustered and the skeleton limb fitting is performed, based on Expectation Maximization (EM). The human pose is given by the location of each skeletal node in the fitted skeleton model. Experimental results show the ability of the method to estimate the human pose from multiple point cloud video sequences representing the external surface of a scanned human body; being r…
A mechanism of coalition formation in the metaphor of politics multiagent architecture
2003
Hybrid Multi-Agent Architectures allow the support of mobile robots colonies moving in dynamic, not predictable and time variable environments in order to achieve distributed solving strategies that develop collective team-oriented behaviors for solving complicate and difficult tasks. The development of a new robotic architecture for the coordination of a robot colonies in dangerous, unknown and dynamic environment is outlined. The name of this new architecture is Metaphor of Politics (MP), because it loosely takes inspiration from the political organizations of democratic governments.
Line reconstruction using prior knowledge in single non-central view
2016
International audience; Line projections in non-central systems contain more geometric information than in central systems. The four degrees of freedom of the 3D line are mapped to the line-image and the 3D line can be theoretically recovered from 4 projecting rays (i.e. line-image points) from a single non-central view. In practice, extraction of line-images is consid- erably more difficult and the resulting reconstruction is imprecise and sensitive to noise. In this paper we present a minimal solution to recover the geometry of the 3D line from only three line-image points when the line is parallel to a given plane. A second minimal solution allows to recover the 3D line from two points w…