Search results for "Measurement"
showing 10 items of 2918 documents
Closure to “Testing the Stage-Discharge Relationship in Sloping SMBF Flumes” by Francesco Giuseppe Carollo and Vincenzo Pampalone
2022
This is the closure to the discussions on the paper "Testing the Stage-Discharge Relationship in Sloping SMBF Flumes".
Novel leaf-level measurements of chlorophyll fluorescence for photosynthetic efficiency
2015
Solar induced chlorophyll fluorescence (SIF) from vegetation can now be obtained from satellites as well as ground-based field studies, at select wavelengths associated with atmospheric features. At the leaf level, full spectrum (650–800 nm) chlorophyll emissions (ChlF) can be measured using specialized instrumentation to support interpretation of these SIF observations. We found that ChlF spectra differ for leaf bottoms versus upper leaf surfaces, potentially affecting within-canopy radiative scattering. Our ChlF measurements for leaves of eight tree species (n≥125) obtained during fall 2013 senescence at the Duke Forest in North Carolina, USA and the 2014 growing season (n=72) at the USDA…
Micro-machining
2008
This chapter provides comprehensive knowledge regarding the fabrication of micro-products and element of micro-electromechanical systems using various techniques and processes. Both well-established techniques such as micro-machining and new trends in improving micro-processes taking into account EDM, laser, FIB, LIGA and DRIE processes are overviewed. The background of micro-machining processes, including typical machining operations such as turning, milling and drilling and different construction materials, is outlined. Moreover, a special focus was made on new constructions, control systems and effective applications of micro-machining techniques. In addition, the focus was directed towa…
Exploring the generative power of performance measurement systems design
2019
Abstract Prior studies recognise the enabling power of incompleteness in the design of Performance Measurement Systems (PMS). We add to these studies by exploring the ‘time dimension’ of incompleteness as a way to delve into the generative power of design. To this aim, we rely upon the experience of a knowledge-intensive organization during the design of a new PMS. While knowledge complexity engaged the participants within an open-ended design process, incomplete measures were associated with unfolding memories of the past and confident beliefs in future solutions, which generated effects through the knowledge gaps that they entailed, as well as through the projections in the past and in th…
Towards a test of the weak equivalence principle of gravity using anti-hydrogen at CERN
2016
International audience; The aim of the GBAR (Gravitational Behavior of Antimatter at Rest) experiment is to measure the free fall acceleration of an antihydrogen atom, in the terrestrial gravitational field at CERN and therefore test the Weak Equivalence Principle with antimatter. The aim is to measure the local gravity with a 1% uncertainty which can be reduced to few parts of 10-3.
The Economics of Freedom. Theory, Measure and Policy Implications
2012
What is freedom? Can we measure it? Does it affect policy? This book develops an original measure of freedom called 'Autonomy Freedom', consistent with J. S. Mill's view of autonomy, and applies it to issues in policy and political design. The work pursues three aims. First, it extends classical liberalism beyond exclusive reliance on negative freedom so as to take autonomous behavior explicitly into account. Second, it grounds on firm conceptual foundations a new standard in the measurement of freedom that can be fruitfully coupled with existing gauges. Third, it shows empirically that individual preferences for redistribution and cross-country differences in welfare spending in Organisati…
A passive stabilization solution for camera embedded onboard small planes
2014
Embedded camera is becoming democratized in personal uses like sport. Thus the need for a stabilized video leads to a development of dedicated stabilized systems. However, in professional uses like video protection, stabilization solutions are not yet common. Moreover such a system needs to fit application specific requirements in term of size, weight, amplitude and frequency response.
Partial Discharge Detection Using a Spherical Electromagnetic Sensor
2019
The presence of a partial discharge phenomenon in an electrical apparatus is a warning signal that could determine the failure of the insulation system, terminating the service of the apparatus and/or the network. In this paper, an innovative partial discharge (PD) measurement instrument based on an antenna sensor is presented and analyzed. Being non-intrusive is one of the most relevant features of the sensor. The frequency response of the antenna sensor and the features to recognize different PD sources and automatically synchronize them with the supply voltage are described and discussed in details. The results show the performance of the instrument can make a fast and correct diagnosis …
Improvement of Hall Effect Current Transducer Metrological Performances in the Presence of Harmonic Distortion
2010
The performance of Hall effect current transducers (HECTs), under distorted waveform conditions, is usually characterized by means of a frequency response test. In this paper, it was investigated if frequency response is able to correctly evaluate the ratio and the phase errors under distorted conditions. Two HECTs, with the accuracy class level of 1% and 0.5%, respectively, were experimentally characterized under two conditions: 1) sinusoidal excitation with frequencies ranging from 50 to 750 Hz, which is the well-known frequency response test, and 2) nonsinusoidal excitation using fundamental frequency and one harmonic with adjusted amplitude and phase shift. It was found that ratio and p…
Rogowski coil current transducer compensation method for harmonic active power error
2015
Abstract In the harmonic active power measurement, the highest uncertainties are generally introduced by the current and voltage transducers. In a previous paper, the authors showed that the current transformer (CT) can introduce significant errors in such measurement, especially if the phase shift between voltage and current is close to ±90°. In such condition the errors on harmonic power measurement are mainly due to the CT phase displacement. This paper shows that better results can be achieved with more linear transducers, such as the Rogowski coil current transducers (RCCTs), whose metrological performance in distorted condition can be improved, by means of a proper compensation method…