Search results for " processing"
showing 10 items of 7549 documents
Blow-up collocation solutions of nonlinear homogeneous Volterra integral equations
2011
In this paper, collocation methods are used for detecting blow-up solutions of nonlinear homogeneous Volterra-Hammerstein integral equations. To do this, we introduce the concept of "blow-up collocation solution" and analyze numerically some blow-up time estimates using collocation methods in particular examples where previous results about existence and uniqueness can be applied. Finally, we discuss the relationships between necessary conditions for blow-up of collocation solutions and exact solutions.
Collocation Method for Linear BVPs via B-spline Based Fuzzy Transform
2018
The paper is devoted to an application of a modified F-transform technique based on B-splines in solving linear boundary value problems via the collocation method. An approximate solution is sought as a composite F-transform of a discrete function (which allows the solution to be compactly stored as the values of this discrete function). We demonstrate the effectiveness of the described technique with numerical examples, compare it with other methods and propose theoretical results on the order of approximation when the fuzzy partition is based on cubic B-splines.
The Cone-to-Cone Interconversion of Partially O-Methylated Calix[4]arenes: First Experimental Values for the Energy Barriers
1999
Laser speckle imaging for early detection of microbial colony forming units
2021
In this study, an optical contactless laser speckle imaging technique for the early identification of bacterial colony-forming units was tested. The aim of this work is to compare the laser speckle imaging method for the early assessment of microbial activity with standard visual inspection under white light illumination. In presented research, the growth of Vibrio natriegens bacterial colonies on the solid medium was observed and analyzed. Both – visual examination under white light illumination and laser speckle correlation analysis were performed. Based on various experiments and comparisons with the theoretical Gompertz model, colony radius growth curves were obtained. It was shown that…
Laser speckle time-series correlation analysis for bacteria activity detection
2020
The study aims at development and laboratory approbation of non-contact optical technique for early evaluation of microbial activity. Microorganisms’ activity is estimated by laser speckle contrast imaging technique in combination with image processing of obtained time varying speckle patterns. Laser speckle patterns were captured by CMOS sensor during illumination of growing bacteria colonies by low power (<30 mW, 635 nm) stabilized coherent light source. To validate proposed technique and image processing algorithm the vibrio natriegens bacteria are used. After analysis of several different experiments the following results were obtained: In the central part of the colony activity can be …
Behavior of four main dairy pathogenic bacteria during manufacturing and ripening of pecorino siciliano cheese
2020
Background: Consumption of raw cheese may be associated with different diseases. This study aimed to evaluate behavior of four pathogenic bacteria during manufacture and ripening of Protected Designation of Origin (PDO) Pecorino Siciliano cheese.
 Methods: The experimental cheese groups were inoculated with pathogenic bacteria, including Escherichia coli O157, Listeria monocytogenes, Salmonella Enteritidis, and Staphylococcus aureus. The cheese making processes were monitored from milk curdling until 3 months ripened cheeses and the levels of Lactic Acid Bacteria (LAB) and the four dairy pathogens were evaluated by plate counts. Randomly Amplified Polymorphic DNA (RAPD)-Polymerase Chai…
Improving color correction across camera and illumination changes by contextual sample selection
2012
International audience; In many tasks of machine vision applications, it is important that recorded colors remain constant, in the real world scene, even under changes of the illuminants and the cameras. Contrary to the human vision system, a machine vision system exhibits inadequate adaptability to the variation of lighting conditions. Automatic white bal- ance control available in commercial cameras is not sufficient to pro- vide reproducible color classification. We address this problem of color constancy on a large image database acquired with varying digi- tal cameras and lighting conditions. A device-independent color repre- sentation may be obtained by applying a chromatic adaptation…
Spatio-temporal saliency detection in dynamic scenes using color and texture features
2014
Visual saliency is an important research topic in the field of computer vision due to its numerouspossible applications. It helps to focus on regions of interest instead of processingthe whole image or video data. Detecting visual saliency in still images has been widelyaddressed in literature with several formulations. However, visual saliency detection invideos has attracted little attention, and is a more challenging task due to additional temporalinformation. Indeed, a video contains strong spatio-temporal correlation betweenthe regions of consecutive frames, and, furthermore, motion of foreground objects dramaticallychanges the importance of the objects in a scene. The main objective o…
Multichannel single-output color pattern recognition by use of a joint-transform correlator.
1996
A novel method for performing color image recognition by the use of the coherent joint-transform correlator is introduced. The input plane of the proposed method is a spatial rearrangement of the separation into color channels of both the color input scene and the color target. This input plane is gray scaled and monochromatic, thus it can be displayed by the use of amplitude spatial light modulators to achieve real-time operation. The system provides a single output-plane result of the optical coherent addition of the separate channels’ correlation outputs. At the output plane no electronic postprocessing is needed, and the detection decision is achieved simply by the application of thresh…
Multi-channel chromatic transformations for nonlinear color pattern recognition
2002
We present a new approach for color pattern recognition based on multi-channel nonlinear correlations. High discrimination capability is obtained in comparison with common linear multi-channel detection methods. We apply the nonlinear morphological correlation to different color channel decompositions as RGB and ATD channels. Moreover, in order to improve the discrimination we have introduced a new color transformation. When a high selectivity is required, the combination of the nonlinear correlation and the new color decomposition yields to detect the object using just a single channel. Simulation results are provided.