Search results for "Measurement"
showing 10 items of 2918 documents
Responsivity measurements of silicon carbide Schottky photodiodes in the UV range
2014
We report on the design and the electro-optical characterization of new classes of 4H-SiC Schottky UV detectors, fabricated employing Ni 2 Si interdigitated strips. We have measured, in dark conditions, the forward and reverse I-V characteristics as a function of temperature and C-V characteristics. Responsivity measurements of the devices, as function of wavelength in the UV range, of package temperature and of applied reverse bias are reported. We also compared devices featuring different strip pitch sizes, discussing their performances, and found the device exhibiting best results.
CNT-based RFID passive gas sensor
2011
Summary form only given, as follows. Single-wall carbon nanotube (CNT) is examined for the design of a passive and maintenance-free wireless RFID sensor. CNT buckypaper is characterized from a dielectric and a sensitivity point of view, using an indirect way, by using antenna measurement and simulations in a controlled medium. A CNT-based prototype RFID tag is then described as the featured maintenance free sensor and experimentally verified for its applicability and sensitivity towards NH3.
Study and design of a controlled oscillator for an embedded system to measure the complex impedance of PEM fuel cell »
2017
We present in this paper the study and the design of a voltage controlled oscillator (VCO) for an embedded system to diagnose the PEM fuel cell. Some problems related to fuel cells used in the electric vehicle field are the management of its efficiency and the lifetime of its membranes. To do this, the diagnosis using measuring the complex impedance is an important phase. It is based on the injection of a perturbation signal at the output of the PEM fuel cell, then we observe its behavior by measuring its impedance. The used measurement method is the electrochemical impedance spectroscopy (EIS) using the load modulation technique, which is implemented in an embedded measurement system based…
A note on the Bregmanized Total Variation and dual forms
2009
This paper considers two approaches to perform image restoration while preserving the contrast. The first one is the Total Variation-based Bregman iterations while the second consists in the minimization of an energy that involves robust edge preserving regularization. We show that these two approaches can be derived form a common framework. This allows us to deduce new properties and to extend and generalize these two previous approaches.
RECOVERY OF THE SOUND SPEED FOR THE ACOUSTIC WAVE EQUATION FROM PHASELESS MEASUREMENTS
2018
We recover the higher order terms for the acoustic wave equation from measurements of the modulus of the solution. The recovery of these coefficients is reduced to a question of stability for inverting a Hamiltonian flow transform, not the geodesic X-ray transform encountered in other inverse boundary problems like the determination of conformal factors. We obtain new stability results for the Hamiltonian flow transform, which allow to recover the higher order terms.
Uncertainty evaluation in the differential measurements of power losses in a power drive system
2021
Abstract In order to guarantee a correct classification in the standardized energy efficiency classes, the current standards concerning the power drive systems prescribe that their power losses must be evaluated with great accuracy. This circumstance involves the usage of expensive measurement systems, since accurate instrumentation, skilled personnel and controlled environments are required. During the design stage of a power drive system, however, the measurement of the absolute value of its power losses is not always needed. Often, in fact, it is enough to assess the power losses variations caused by a modification of either hardware or software sections of the power drive system. In the…
A SYNTHETIC MEASURE FOR THE ASSESSMENT OF THE PROJECT PERFORMANCE
2009
The present paper aims to offer a synthetic project performance indicator (PPI) that aggregates two input parameters obtained by the Earned Value Analysis. The PPI is calculated by using a Fuzzy Inference System (FIS) able to single out a measure based on the input parameters, instead of formulating a mathematical model that could be a troublesome task whenever complex relations among the input variables exist. The purpose is to communicate the project performance to the stakeholders in a clear and complete way, for example, describing the PPI by means of contour lines.
Application of GPS technology to measurements of displacements of high-rise structures due to weak winds
2002
Abstract Global positioning systems (GPS) have been developed for military purposes like single-point positioning and navigation. The first non-military applications have been made for geodetic purposes with base-line measurements using differential methods. We introduce GPS technology as an alternative measurement method of displacements when high-rise structural systems are monitored. In this paper, two tests to evaluate the accuracy of the measurements using GPS are presented. Then the evaluation of ability of GPS to measure small movements of the Stuttgart TV-tower and the industrial chimney of Opole power station due to weak winds are also given.
Performance Measurement and Outperformance Tests
2017
This chapter explains how to evaluate the performance of a trading strategy and how to carry out a statistical test of the hypothesis that a moving average trading strategy outperforms the corresponding buy-and-hold strategy. In particular, it argues that there is no unique performance measure, reviews the most popular performance measures, and points to the limitations of these measures. The chapter then surveys the parametric methods of testing the outperformance hypothesis and the current “state of the art” non-parametric methods.
Psychometric Properties of an Emotional Adjustment Measure
2007
Item response theory (IRT) provides valuable methods for the analysis of the psychometric properties of a psychological measure. However, IRT has been mainly used for assessing achievements and ability rather than personality factors. This paper presents an application of the IRT to a personality measure. Thus, the psychometric properties of a new emotional adjustment measure that consists of a 28-six graded response items is shown. Classical test theory (CTT) analyses as well as IRT analyses are carried out. Samejima's (1969) graded-response model has been used for estimating item parameters. Results show that the bank of items fulfills model assumptions and fits the data reasonably well,…