Abstract:
The invention lies within the field of wireless communications systems with several transmitting antennas, corresponding to MIMO (Multiple Input Multiple Output) systems or to MISO (Multiple Input Single Output) systems. According to the invention, the symbols to be transmitted are pre-encoded with a particular linear pre-encoding matrix then coded according to space-time block coding so as to benefit to the full from temporal and spatial diversities allowing at reception for particularly easy and efficient linear decoding.
Abstract:
The invention relates to modelling individual head related transfer functions (HRTFs) with respect to an individual audition in a three-dimensional space. The inventive method consists in picking up morphological parameters of several individuals for roughly estimating the HRTFs by finite elements and building the database thereof roughly estimated by comparing/training on said database and on another database containing several HRTFs measured in all directions of space and in building, for the same individuals, a model based on an artificial neurone network which is capable to calculate the HRTFs for all directions of space from a series of measurements of morphological parameters of any individuals.
Abstract:
A method of processing the presence status of a user at at least one terminal connected to a telecommunications network on the basis of presence status information provided by at least one status source of said terminal. The presence status is weighted as a function of a pertinence value that is calculated as a function of time. The invention makes it possible over time to correct the pertinence of presence information to as maximize the reliability of a presence status calculated on the basis of said information.
Abstract:
A video image sequence including coefficients of frequency sub-bands with different spatial resolutions is coded. A data stream including at least one restitution level (Niv N−2, Niv N−1, Niv N) is formed. The restitution levels have coefficients of frequency sub-bands whose spatial resolution equals a spatial resolution of the restitution level. There are inserted, in at least one restitution level, coefficients of frequency sub-bands with a spatial resolution higher than the spatial resolution or resolutions of the restitution level.
Abstract:
A method is provided for evaluating quantity PQ representing a quality, as perceived by a recipient, of a signal OFx carrying data representing at least one stimulus intended to be produced on said recipient. The method includes a step of quantification of parameters Sqm and Tqm representing a spatial quality and a temporal quality of the signal, and a step of weighting during which a weighted product of the parameters Sqm and Tqm is computed and raised to a power C strictly below one. The method can be used to take account of a correlation that will be made by a person exposed to the stimulus between its spatial and temporal qualities, in applying an automatic technique in real time.
Abstract:
A method identifying faces from facial images called query images, associated with at least one person, including a learning phase using learning images and a recognition phase used to identify the faces appearing in query images. The learning phase includes filtering the images, applied on the basis of a group of at least two learning facial images associated with the at least one person, enabling selection of at least one learning image representing the face to be identified. The recognition phase uses only the learning images selected during the learning phase. Filtering is performed using at least one of the thresholds belonging to the group including: a maximum distance taking at least account of the membership of the vectors in a cloud constituted by the vectors; and a maximum distance between the vectors and vectors rebuilt after projection of the vectors on a space associated with said cloud of vectors.
Abstract:
The present invention sets out to combine a calculation of visibility from a viewpoint, with the selection of a level of detail for each of the nodes in a tree representing the geometry of the objects in a scene, so as increase the level of geometric detail of the visible objects and to reduce this level for all the obscured objects.
Abstract:
The invention concerns a method for demodulating a digital signal received via a transmission channel, comprising a step which consists in associating with each value received of said received signal a point of the corresponding modulation constellation, on the basis of the decision boundaries taking into account the potential effect of a phase shift on at least one of said points of the modulation constellation and of the potential effect of an Gaussian additive noise applied on said point, said Gaussian additive noise being represented by a generating surface associated with said point, and said phase shift by a rotation on an angular range based so that said swept surface belongs essentially to the region of decision associated with the corresponding point of the modulation constellation, plotted on the basis of at least one phase and/or amplitude characteristic of said modulation, so as to associate with each of said points of the constellation a portion of a reception space, called corresponding region of decision.
Abstract:
The present system relates to a method for indexing a document comprising the acts of retrieving in the content of the document true landmarks associated with said content, selecting one true landmark as representing the document, indexing the document to include a reference to the selected true landmark, wherein the retrieving act further comprises the act of identifying landmarks through the comparison of the content of the document to a landmark database, and, retaining only true landmarks among the identified landmark using a natural language approach, and wherein the selecting act further comprising the acts of assigning a weight to each true landmark based on at least one criterion, selecting the true landmark that represents the document based on the assigned weights.
Abstract:
To evaluate the use of services accessible from a user terminal via a telecommunication network, an authentication sever authenticates the user of the terminal and transmits identifiers of the services to a control device to authorize the user terminal to access the services. In response to the service identifiers triggering an opening of control sessions for accessible services from the user terminal, an evaluation module evaluates the data traffics exchanged between the user terminal and service servers dispensing the services accessible in traffic accounts, and transmits to a management server, service control messages each including a service identifier and a traffic account relating to an accessible service after the closure of control sessions relating to the services.