Search results for "SAMPLE"
showing 10 items of 2270 documents
Absolute kinematics of radio source components in the complete S5 polar cap sample
2004
We observed the thirteen extragalactic radio sources of the complete S5 polar cap sample at 15.4 GHz with the Very Long Baseline Array, on 27 July 1999 (1999.57) and 15 June 2000 (2000.46). We present the maps from those two epochs, along with maps obtained from observations of the 2 cm VLBA survey for some of the sources of the sample, making a total of 40 maps. We discuss the apparent morphological changes displayed by the radio sources between the observing epochs. Our VLBA observations correspond to the first two epochs at 15.4 GHz of a program to study the absolute kinematics of the radio source components of the members of the sample, by means of phase delay astrometry at 8.4 GHz, 15.…
Open inquiry-based learning experiences: a case study in the context of energy exchange by thermal radiation
2013
An open inquiry (OI)-based teaching/learning experience, regarding a scientific investigation of the process of energy exchange by thermal radiation, is presented. A sample of upper secondary school physics teachers carried out this experience at the University of Palermo, Italy, in the framework of ESTABLISH, a FP7 European Project aimed at promoting and developing inquiry-based science education. The teachers had the opportunity to personally experience an OI-based learning activity, with the aim of exploring the pedagogical potentialities of this teaching approach to promote both the understanding of difficult concepts and a deeper view of scientific practices. The teachers were firstly …
Modelling Optical Resonators Probed by Subwavelength Sized Optical Detectors
1996
The possibility of mapping the optical field structure inside a Fabry-Perot resonator by using a pointed optical fiber was recently reported [1]. In this contribution, we propose a simulation of such near-field optical experiments by using a two-dimensional self-consistent model. The method based on the discretization of four different domains, i.e. the two mirrors, the glass sample and the tip, allows us a meaningful description of the evolution of the full field pattern when approaching the optical detector. In particular, this computerized work supply a direct illustration of the optical energy tranfer occurring when the tip enters the near-field zone. In this context, different tip desi…
Sub-wavelength and non-periodic holes array based fully lensless imager
2011
Abstract We present a novel concept for microscopic imaging. The proposed microscope-like device does not include an objective lens neither a condenser. Instead, a metallic plate of sub-wavelength hole-array with a varying pitch is used to illuminate the inspected object that is mounted very close to it. As a result, the transmitted spectrum through each hole differs from the others and therefore, each spot of the detected object is illuminated with a unique spectrum. By measuring a single spectrum that is the sum of all the spectra that are transmitted through the sample and by using spectral decomposition algorithms, the spatial transmission pattern of the object can be extracted.
The Performance of Belle II Data Acquisition System in the First Physics Run
2019
The Belle II experiment is a new generation B-factory experiment at KEK in Japan aiming at the search for New Physics in a huge sample of B-meson dacays. The commissioning of the SuperKEKB accelerator was started in 2017 (Phase 1), and then a pilot run with outer detectors was performed in 2018 (Phase 2). From March this year, an operation with the full detector has been started for the physics data taking (Phase 3). The Belle II data acquisiton system (DAQ) is now fully working in the Phase 3 run. The system consists of the trigger timing distribution system, the common readout modules (COPPER) with the unified optical data link to the detector front end, the readout PCs and the network sw…
Dynamic Phase Diagram of the REM
2019
International audience; By studying the two-time overlap correlation function, we give a comprehensive analysis of the phase diagram of the Random Hopping Dynamics of the Random Energy Model (REM) on time-scales that are exponential in the volume. These results are derived from the convergence properties of the clock process associated to the dynamics and fine properties of the simple random walk in the $n$-dimensional discrete cube.
Electrooptic beam deflection with latex
1988
The use of latex in electrooptic devices is proposed. The static non linearity coefficient is shown to be approximatively 200 times the optical one. The theory of a beam deflector is developed and an explicit expression is given for the deflection angle versus the physical parameters of the sample Utilisation de suspensions aqueuses de latex dans un dispositif electro-optique. On montre que le coefficient statique de non-linearite devrait etre 200 fois plus eleve que le coefficient optique. Application a un deflecteur optique
Whither the species? Phytophthora taxa, MOTUs and barcodes in the world of metagenomics
2015
The study of ecosystem diversity is being transformed by high throughput sequencing technology that allows an unparalleled depth of sampling of DNA barcode sequences. The opportunities are great at this fascinating interface of pathology, ecology, taxonomy and molecular biology but there are pitfalls. It is important to consider the potential for bias at all steps in the process from sampling through to data analysis. Increasingly Phytophthora diversity is being examined by metabarcoding of the PCR amplified rDNA ITS regions from soil, water or plant sample DNA. We have applied baiting and isolation, cloning and Sanger sequencing and Illumina MiSeq analysis to a time-series of filtered wate…
(Table 1) Stable oxygen and carbon isotopic ratios of tree rings, and tree ring width of white spruce (Picea glauca), Ennadai Lake
2012
Stable isotope ratios from tree rings and peatland mosses have become important proxies of past climate variations. We here compare recent stable carbon and oxygen isotope ratios in cellulose of tree rings from white spruce (Picea glauca), growing near the arctic tree line; and cellulose of Sphagnum fuscum stems, growing in a hummock of a subarctic peatland, in west-central Canada. Results show that carbon isotopes in S. fuscum correlate significantly with July temperatures over the past ~20 yr. The oxygen isotopes correlate with both summer temperature and precipitation. Analyses of the tree-ring isotopes revealed summer temperatures to be the main controlling factor for carbon isotope var…
Leveraging Uncertainty Estimates to Improve Segmentation Performance in Cardiac MR
2021
In medical image segmentation, several studies have used Bayesian neural networks to segment and quantify the uncertainty of the images. These studies show that there might be an increased epistemic uncertainty in areas where there are semantically and visually challenging pixels. The uncertain areas of the image can be of a great interest as they can possibly indicate the regions of incorrect segmentation. To leverage the uncertainty information, we propose a segmentation model that incorporates the uncertainty into its learning process. Firstly, we generate the uncertainty estimate (sample variance) using Monte-Carlo dropout during training. Then we incorporate it into the loss function t…