Search results for " Time measurement"
showing 7 items of 7 documents
Drift Time Measurement in the ATLAS Liquid Argon Electromagnetic Calorimeter using Cosmic Muons
2010
The ionization signals in the liquid argon of the ATLAS electromagnetic calorimeter are studied in detail using cosmic muons. In particular, the drift time of the ionization electrons is measured and used to assess the intrinsic uniformity of the calorimeter gaps and estimate its impact on the constant term of the energy resolution. The drift times of electrons in the cells of the second layer of the calorimeter are uniform at the level of 1.3% in the barrel and 2.8% in the endcaps. This leads to an estimated contribution to the constant term of (0.29-0.04+0.05)% in the barrel and (0.54-0.04+0.06)% in the endcaps. The same data are used to measure the drift velocity of ionization electrons …
Measuring the Rate of Information Transfer in Point-Process Data: Application to Cardiovascular Interactions
2021
We present the implementation to cardiovascular variability of a method for the information-theoretic estimation of the directed interactions between event-based data. The method allows to compute the transfer entropy rate (TER) from a source to a target point process in continuous time, thus overcoming the severe limitations associated with time discretization of event-based processes. In this work, the method is evaluated on coupled cardiovascular point processes representing the heartbeat dynamics and the related peripheral pulsation, first using a physiologically-based simulation model and then studying real point-process data from healthy subjects monitored at rest and during postural …
On the birth and growth of pendulum clocks in the Early on the History Modern Era
2016
Measuring the passage of time has intrigued humankind throughout the centuries. Ancient times witnessed the appearance and development of clepsydras and water clocks, whose place was subsequently taken by mechanical clocks in the Middle Ages. It is really surprising how the general architecture of mechanical clocks has remained almost unchanged in practice up to the present time. Yet the foremost mechanical developments in clock-making date from the 17th century, when the discovery of the laws of pendular isochronism by Galilei and Huygens permitted a higher degree of accuracy in the measuring of time.
A Quantum-Inspired Classifier for Early Web Bot Detection
2022
This paper introduces a novel approach, inspired by the principles of Quantum Computing, to address web bot detection in terms of real-time classification of an incoming data stream of HTTP request headers, in order to ensure the shortest decision time with the highest accuracy. The proposed approach exploits the analogy between the intrinsic correlation of two or more particles and the dependence of each HTTP request on the preceding ones. Starting from the a-posteriori probability of each request to belong to a particular class, it is possible to assign a Qubit state representing a combination of the aforementioned probabilities for all available observations of the time series. By levera…
Transfer Entropy Analysis of Pulse Arrival Time - Heart Period Interactions during Physiological Stress
2022
Although Heart Period (HP) variability is the most widely used measure to assess cardiovascular oscillations, its evaluation combined with that of Pulse Arrival Time (PAT) variability may provide additional information about cardiac dynamics and cardiovascular interactions. In this study, we computed the transfer entropy from PAT to HP in 76 subjects monitored at rest and during orthostatic and mental stress using both a model-free (k- Nearest Neighbors) and a linear parametric estimator. Our results show how the information flow between these two variables depends on the physiological condition and how the nonlinear measure captures more information than the linear one during orthostatic s…
Physical properties of aerosol particles measured from a bubbling fluidized bed boiler
2015
Abstract Increased use of biomass and waste fuels, and the consequent corrosion problem have led to an increased need to study and monitor the combustion processes. This study presents an extensive physical characterization of aerosol particles measured from a bubbling fluidized bed boiler with different fuel mixtures and optional ferric sulfate feeding. The fuel mixtures included bark, sludge, peat and solid recovered fuel. Previously, the characterization of the particles analyzed from a fluidized bed reactor has mainly focused on chemical off-line analysis of collected impactor samples, large coarse mode particles or laboratory-scale reactors. In this study, the focus is in the particle …
VERS UNE ARCHITECTURE UNIFIÉE ET ZÉRO TEMPS MORT POUR L'INSTRUMENTATION NUCLÉAIRE
2014
National audience; Dans l’instrumentation nucléaire, et d’autres domaines tels que les applications de la physique des particules, l’analyse de signaux médicaux (Tomographie par Emission de Positons (TEP), Electro-EncephaloGraphie (EEG)) ou la détection de signaux radar, le signal mesuré est composé d’impulsions dont la date d’arrivée est aléatoire, et dont l’amplitude et la durée sont non-d´eterministes. La grande variété d’applications nécessite de disposer d’une architecture flexible pouvant être aisément reprogrammée. De plus, l’exigence de mesures en temps réel impose de disposer d’une grande capacité de calcul et de bande passante pour la mise en forme et l’extraction des caractéristi…