Search results for "InGaN"
showing 10 items of 1214 documents
The Light Side of Passwords : Turning Motivation from the Extrinsic to the Intrinsic
2019
There are many good and bad aspects to password authentication. They are mostly without cost, securing many accounts and systems, and allowing users access from anywhere in the world. However, passwords can elicit dark side phenomena, including security technostress; with many users feeling negatively towards them, as they struggle to cope with the sheer numbers required in their everyday lives. Much research has attempted to understand users’ interactions with passwords, examining the trade-off between security, memorability, user convenience, and suggesting techniques to manage them better. However, users continue to struggle. Many studies have shown that users are more concerned with goa…
A Velocity Estimation Technique for a Monocular Camera Using mmWave FMCW Radars
2021
Perception in terms of object detection, classification, and dynamic estimation (position and velocity) are fundamental functionalities that autonomous agents (unmanned ground vehicles, unmanned aerial vehicles, or robots) have to navigate safely and autonomously. To date, various sensors have been used individually or in combination to achieve this goal. In this paper, we present a novel method for leveraging millimeter wave radar’s (mmW radar’s) ability to accurately measure position and velocity in order to improve and optimize velocity estimation using a monocular camera (using optical flow) and machine learning techniques. The proposed method eliminates ambiguity in optical flow veloci…
Motility analysis by means of video tracked markers
2018
Abstract The motility of the gastrointestinal tract is crucial for digestive activity and dysfunction can lead to severe disease pattern. A method for analysing the motility is needed when treatment approaches shall be evaluated. Therefore markers attached to different locations on the stomach and the bowel of pigs are video tracked in this research study. The markers are designed to provide a high contrast and have an adhesive side for fixation. Above the operation field a video camera has been placed to film the markers during the procedure. To analyse the video data a special algorithm has been implemented. The algorithm requires a registration process at the beginning of each recording …
Sensors based on MultiSpectral Filter Arrays
2014
International audience; Spectral Filter arrays (SFA) is an emerging technology for multispectral image acquisition. SFAs make possible the use of a compact multispectral sensor to acquire still images or video. One part of this talk will present and compare typical multispectral and color image acquisition systems in order to clearly identify differences underlying SFA technologies. The other part of this talk will show the difficulties and advances that we have made at the University of Bourgogne in the building of such sensors from the design of filters to data processing, such as demosaicing.
Use of accelerometers and gyros for hip and knee angle estimation
2013
In this paper a wearable sensor system, consisting of accelerometers and gyros, has been studied to estimate hip and knee angles. The proposed algorithm, developed in order to avoid the error accumulation due to gyroscopes drift, has been tested on angle measurement of the hip and knee of a commercial device for assisted gait. The results have shown a good accuracy of the angles estimation, also in high angle rate movement
Composición, estructura interna y transporte electrónico de nanohilos individuales de In1-xGaxN e InN
2014
La posibilidad de sintonizar la banda prohibida de las aleaciones de In1-xGaxN desde el UV al IR variando x desde 0 a 1 es la base para potenciales aplicaciones de esta aleación como diodos emisores de luz (LEDs), del inglés “light emitting diodes”, diodos láser (LDs), del inglés “laser diodes” o células solares. Sin embargo, las inhomogeneidades en la composición y la segregación de fases, debido no sólo a la fata de sustratos con coeficientes de expansión térmica que se ajusten a los del InN y el GaN, sino también a la baja temperatura de disociación del InN comparada con la del GaN, dificulta el crecimiento de capas de alta calidad en todo el rango de composiciones. Con el objetivo de su…
Optical flow estimation from multichannel spherical image decomposition
2011
International audience; The problem of optical flow estimation is largely discussed in computer vision domain for perspective images. It was also proven that, in terms of optical flow analysis from these images, we have difficulty distinguishing between some motion fields obtained with little camera motion. The omnidirectional cameras provided images with large filed of view. These images contain global information about motion and allow to remove the ambiguity present in perspective case. Nevertheless, these images contain significant radial distortions that is necessary to take into account when treating these images to estimate the motion. In this paper, we shall describe new way to comp…
HDR-ARtiSt: a FPGA-based Smart Camera for High Dynamic Range color video from multiple exposures
2014
International audience; A camera is able to capture only a part of a high dynamic range scene information. The same scene can be fully perceived by the human visual system. This is true especially for real scenes where the difference in light intensity between the dark areas and bright areas is high. The imaging technique which can overcome this problem is called HDR (High Dynamic Range). It produces images from a set of multiple LDR images (Low Dynamic Range), captured with different exposure times. This technique appears as one of the most appropriate and a cheap solution to enhance the dynamic range of captured environments. We developed an FPGA-based smart camera that produces a HDR liv…
UNE APPROCHE PARALLELE D'EVALUATION DES PARAMETRES DE TEXTURE POUR L'ANALYSE D'IMAGES DE GRANDE TAILLE
2011
International audience; The main objective of this paper is to develop a new image processing technique that could better be adapted to the processing of large and complex images, especially SAR images, in relation to the former methods of our works. We propose here a new approach of textural parameters evaluation which is about (Ng+1)n-1 times faster than the co-occurrence matrix approach considered as classical, where n is the order of the textural parameter and Ng being the maximum grey level in the image. This approach is based on a new modeling of textural parameters of a generic order n>1 equivalent to the classical formulation, but which is no longer based on frequency matrix (co-occ…
Visual saliency by keypoints distribution analysis
2011
In this paper we introduce a new method for Visual Saliency detection. The goal of our method is to emphasize regions that show rare visual aspects in comparison with those showing frequent ones. We propose a bottom up approach that performs a new technique based on low level image features (texture) analysis. More precisely, we use SIFT Density Maps (SDM), to study the distribution of keypoints into the image with different scales of observation, and its relationship with real fixation points. The hypothesis is that the image regions that show a larger distance from the mode (most frequent value) of the keypoints distribution over all the image are the same that better capture our visual a…