Search results for "methodologies"
showing 10 items of 2106 documents
A Tutorial on Computational Cluster Analysis with Applications to Pattern Discovery in Microarray Data
2008
Background Inferring cluster structure in microarray datasets is a fundamental task for the so-called -omic sciences. It is also a fundamental question in Statistics, Data Analysis and Classification, in particular with regard to the prediction of the number of clusters in a dataset, usually established via internal validation measures. Despite the wealth of internal measures available in the literature, new ones have been recently proposed, some of them specifically for microarray data. Results We consider five such measures: Clest, Consensus (Consensus Clustering), FOM (Figure of Merit), Gap (Gap Statistics) and ME (Model Explorer), in addition to the classic WCSS (Within Cluster Sum-of-S…
The burden of norovirus disease in children in the European Union.
2015
Supplemental Digital Content is available in the text.
Examining the utility of pinhole-type screens for lightfield display
2021
The use of microlens arrays for lightfield display has the drawback of providing images with strong chromatic aliasing. To overcome this problem, pinhole-type lightfield monitors are proposed. This paper is devoted to evaluating the capability for such lightfield monitors to offer the user a convincing 3D experience with images with enough brightness and continuous aspect. Thus, we have designed a psychophysical test specifically adapted for lightfield monitors, which allowed us to confirm the usability of pinhole-type monitors.
Time-multiplexing Integral Microscopy
2014
Conventional microscopes do not capture the 3D information of thick specimens. In order to avoid this limitation Integral Microscopy was proposed. An integral microscope is implemented by inserting a microlens array between the microscope objective and the camera sensor. Although this device captures multiperspective information of the specimen, the small number of microlenses limits the lateral resolution. In this paper we propose to improve the resolution by time multiplexing. Specifically, we propose an electrically addressable device that permits to obtain three sheared versions of the microscopic plenoptic map. Digital processing algorithm applied to the maps provides images with resol…
Confocal scanning microscope using a CCD camera as a pinhole-detector system
2011
We report a scheme for a detector system of confocal microscopes. In our scheme the pinhole and the large area detector are subtituted by a CCD camera. The numerical integration of the intensities acquired by the active pixels emulates the signal acquired by the detector. To demonstrate the utility of the system we efficiently performed an experiment of substractive-image confocal microscopy
Scanning microscopy with spatial sampling of the detector plane
2013
We present the implementation of a confocal scanning microscope in which the signal detection is performed through a matrix sensor, specifically, a CCD camera. This kind of detection has several advantages over the conventional detection in confocal microscopes. One of those advantages is the possibility to recover information of the sample that vanishes when the confocal image is directly acquired by the integration of light into a signal. We demonstrate the applicability of the system which allows implementing super-resolution techniques in a very easy manner.
One-dimensional wavelength multiplexed microscope without objective lens
2009
A new approach aimed to achieve microscopic imaging without objective lenses and based on wavelength multiplexing of the spatial object information is presented. The proposed method is used to develop, construct and experimentally validate a new type of optical microscope having no objective lens and no numerical reconstruction algorithms to allow imaging process. In order to extract the collected spatial information we use a spectrometer as part of our microscope system. Preliminary results are presented while considering two different types of one-dimensional (1-D) objects.
Fourier-domain lightfield microscopy: a new paradigm in 3D microscopy
2020
Recently, integral (also known as lightfield or plenoptic) imaging concept has been applied successfully to microscopy. The main advantage of lightfield microscopy when compared with conventional 3D imaging techniques is that it offers the possibility of capturing the 3D information of the sample after a single shot. However, integral microscopy is now facing many challenges, like improving the resolution and depth of field of the reconstructed specimens or the development and optimization of specially-adapted reconstruction algorithms. This contribution is devoted to review a new paradigm in lightfield microscopy, namely, the Fourier-domain integral microscope (FiMic), that improves the ca…
Robust Depth Estimation for Light Field Microscopy
2019
Light field technologies have seen a rise in recent years and microscopy is a field where such technology has had a deep impact. The possibility to provide spatial and angular information at the same time and in a single shot brings several advantages and allows for new applications. A common goal in these applications is the calculation of a depth map to reconstruct the three-dimensional geometry of the scene. Many approaches are applicable, but most of them cannot achieve high accuracy because of the nature of such images: biological samples are usually poor in features and do not exhibit sharp colors like natural scene. Due to such conditions, standard approaches result in noisy depth ma…
Novel GaN Based Solid State Power Amplifiers, Results, Advances and Comparison with Vacuum Tubes Based Microwave Power Modules
2018
Power amplifiers based on vacuum tubes or solid state are key items in a number of systems. Solid state technology is growing up for some applications and it may be complementary to the vacuum technology. This paperwork presents SSPA operational principles and performance. The GaN technology available in the market, the technology roadmap, a comparison with the vacuum tubes are introduced