Search results for "threshold"

Rigidity of random networks of stiff fibers in the low-density limit.

2001

Rigidity percolation is analyzed in two-dimensional random networks of stiff fibers. As fibers are randomly added to the system there exists a density threshold ${q=q}_{\mathrm{min}}$ above which a rigid stress-bearing percolation cluster appears. This threshold is found to be above the connectivity percolation threshold ${q=q}_{c}$ such that ${q}_{\mathrm{min}}=(1.1698\ifmmode\pm\else\textpm\fi{}{0.0004)q}_{c}.$ The transition is found to be continuous, and in the universality class of the two-dimensional central-force rigidity percolation on lattices. At percolation threshold the rigid backbone of the percolating cluster was found to break into rigid clusters, whose number diverges in the…

Effectiveness of Self-Hypnosis on the Relief of Experimental Dental Pain: A Randomized Trial.

2016

This randomized, controlled clinical trial evaluates the effectiveness of self-hypnosis on pain perception. Pain thresholds were measured, and a targeted, standardized pain stimulus was created by electrical stimulation of the dental pulp of an upper anterior tooth. Pain stimulus was rated by a visual analogue scale (VAS). The pain threshold under self-hypnosis was higher (57.1 ± 17.1) than without hypnotic intervention (39.5 ± 11.8) (p < .001). Pain was rated lower on the VAS with self-hypnosis (4.0 ± 3.8) than in the basal condition without self-hypnosis (7.1 ± 2.7) (p < .001). Self-hypnosis can be used in clinical practice as an adjunct to the gold standard of local anesthesia for pain m…

Digital information receiver based on stochastic resonance

2003

International audience; An electronic receiver based on stochastic resonance is presented to rescue subthreshold modulated digital data. In real experiment, it is shown that a complete data restoration is achieved for both uniform and Gaussian white noise.

Microwave response properties of epoxy resin composites filled with graphitic fillers

2014

Composite materials based on epoxy resin filled with various kinds of graphite particles: exfoliated graphite (EG), natural graphite, and coarse, medium and fine artificial graphites have been prepared. The dielectric permittivity strongly increases with graphite particle size. This effect is related to the distance of the investigated filler concentrations to the composites' percolation threshold. Microwave experiments show that exfoliated graphite is, out of investigated graphite particles, the only one being a really effective additive for producing electromagnetic (EM) interference (EMI) shielding: 2 wt.% epoxy/EG is absolutely opaque to electromagnetic radiation at 30 GHz.

Multilevel preconditioning and adaptive sparse solution of inverse problems

2012

Unsupervised image processing scheme for transistor photon emission analysis in order to identify defect location

2015

International audience; The study of the light emitted by transistors in a highly scaled complementary metal oxide semiconductor (CMOS) integrated circuit (IC) has become a key method with which to analyze faulty devices, track the failure root cause, and have candidate locations for where to start the physical analysis. The localization of defective areas in IC corresponds to a reliability check and gives information to the designer to improve the IC design. The scaling of CMOS leads to an increase in the number of active nodes inside the acquisition area. There are also more differences between the spot’s intensities. In order to improve the identification of all of the photon emission sp…

Extracting cloud motion from satellite image sequences

2004

This paper present a new technique for the estimation of cloud motion, using a sequence of infrared satellite images. It can be considered a challenging task due to the complexity of phenomena implied, as non-linear events and a non-rigid motion. In this circumstances most motion models are not suitable and new algorithms have to be developed. We propose a novel method, combining an Automatic Multilevel Thresholding for image segmentation, a Block Matching Algorithm (BMA) and a best candidate block search along with a vector median regularization.

Gabor filtering for feature extraction on complex images: application to defect detection on semiconductors

2006

AbstractThis paper is an extension of previous work on the image segmentation of electronic structures on patterned wafers to improve the defect detection process on optical inspection tools. Die-to-die wafer inspection is based upon the comparison of the same area on two neighbourhood dies. The dissimilarities between the images are a result of defects in this area of one of the dies. The noise level can vary from one structure to the other, within the same image. Therefore, segmentation is needed to create a mask and apply an optimal threshold in each region. Contrast variation on the texture can affect the response of the parameters used for the segmentation. This paper shows a method of…

Real-time people counting system using a single video camera

2008

This is the copy of journal's version originally published in Proc. SPIE 6811. Reprinted with permission of SPIE: http://spie.org/x10.xml?WT.svl=tn7 There is growing interest in video-based solutions for people monitoring and counting in business and security applications. Compared to classic sensor-based solutions the video-based ones allow for more versatile functionalities, improved performance with lower costs. In this paper, we propose a real-time system for people counting based on single low-end non-calibrated video camera. The two main challenges addressed in this paper are: robust estimation of the scene background and the number of real persons in merge-split scenarios. The latter…

Bag of words representation and SVM classifier for timber knots detection on color images

2015

Knots as well as their density have a huge impact on the mechanical properties of wood boards. This paper addresses the issue of their automatic detection. An image processing pipeline which associates low level processing (contrast enhancement, thresholding, mathematical morphology) with bag-of-words approach is developed. We propose a SVM classification based on features obtained by SURF descriptors on RGB images, followed by a dictionary created using the bag-of-words approach. Our method was tested on color images from two different datasets with a total number of 640 knots. The mean recall (true positive) rate achieved was (92%) and (97%) for a single dictionary (built only on samples …