Search results for "Servo"

Stochastic seismic analysis of hydrodynamic pressure in dam reservoir systems

2002

Hydrodynamic seismic-induced pressure requires careful consideration in the aseismic design of dams. Effects induced by earthquake excitation may cause many-fold increments of hydrostatic pressure. In this study earthquake excitation has been modelled by means of random process theory obtaining the response statistics of a dam-reservoir dynamical system. The analysis has been conducted assuming a rigid retaining wall of the reservoir and dissipative fluid. Copyright © 2002 John Wiley & Sons, Ltd.

Waveguide-QED-based measurement of a reservoir spectral density

2015

The spectral density (SD) function has a central role in the study of open quantum systems (OQSs). We discover a method allowing for a "static" measurement of the SD - i.e., it requires neither the OQS to be initially excited nor its time evolution tracked in time - which is not limited to the weak-coupling regime. This is achieved through one-dimensional photon scattering for a zero-temperature reservoir coupled to the OQS via the rotating wave approximation. We find that the SD profile is a universal simple function of the photon's reflectance and transmittance. As such, it can be straightforwardly inferred from photon's reflection and transmission spectra.

Reservoir Computing with Random Skyrmion Textures

2020

The Reservoir Computing (RC) paradigm posits that sufficiently complex physical systems can be used to massively simplify pattern recognition tasks and nonlinear signal prediction. This work demonstrates how random topological magnetic textures present sufficiently complex resistance responses for the implementation of RC as applied to A/C current pulses. In doing so, we stress how the applicability of this paradigm hinges on very general dynamical properties which are satisfied by a large class of physical systems where complexity can be put to computational use. By harnessing the complex resistance response exhibited by random magnetic skyrmion textures and using it to demonstrate pattern…

Dynamics of a Quantum Particle in Asymmetric Bistable Potential with Environmental Noise

2011

In this work we analyze the dynamics of a quantum particle subject to an asymmetric bistable potential and interacting with a thermal reservoir. We obtain the time evolution of the population distributions in both energy and position eigenstates of the particle, for different values of the coupling strength with the thermal bath. The calculation is carried out using the Feynman-Vernon functional under the discrete variable representation.

The bistable potential: An archetype for classical and quantum systems

2012

In this work we analyze the transient dynamics of three different classical and quantum systems. First, we consider a classical Brownian particle moving in an asymmetric bistable potential, subject to a multiplicative and additive noise source. We investigate the role of these two noise sources on the life time of the metastable state. A nonmonotonic behavior of the lifetime as a function of both additive and multiplicative noise intensities is found, revealing the phenomenon of noise enhanced stability. Afterward, by using a LotkaVolterra model, the dynamics of two competing species in the presence of Lévy noise sources is analyzed. Quasiperiodic oscillations and stochastic resonance pheno…

Using Macroelement Content to Characterize Surficial Water Quality of Artificial Reservoirs

2021

Abstract The quality of surface waters in the territory of Poland, despite the implemented remedial measures, is mostly classified as bad. This article presents the results of research on the composition of water macroelements in 24 artificial reservoirs located in Opole province (southern Poland), searching for the reasons behind their pollution. Concentrations of the anions F−, Cl−, Br−, NO2−, NO3−, PO43− and SO42− and cations Na+, NH4+, K+, Mg2+ and Ca2+ were taken into account. An analysis of seasonal changes was carried out and, on the example of a dam reservoir (Turawa Big Reservoir), a multi-point analysis of the distribution of ion concentrations in water at the reservoir surface w…

DISTRIBUTION OF PONTO-CASPIAN AMPHIPODPONTOGAMMARUS ROBUSTOIDESIN LATVIAN WATERS

2007

Data of the monitoring of inland waters, conducted during 1999–2005, show that the alien Ponto-Caspian amphipod Pontogammarus robustoides is quite widespread in Latvia. The species was detected at 15 monitoring sites. This non-indigenous amphipod occurs in the lower reaches and mouths of rivers emptying into the Baltic Sea, water reservoirs located on the Daugava River, and nearshore lakes which are connected to the brackish waters of the sea. The spread of P. robustoides in the lower reaches of the Daugava River and its water reservoirs must have originated from the intentional introduction of this amphipod into the Keguma Water Reservoir in the 1960s. Meanwhile, the invasion of this amphi…

Rare and threatend pondweed communities in anthropogenic water bodies of Opole Silesia (SW Poland)

2007

Method for improving the contouring accuracy for CNC profiling machines at the shop floor level

2009

Computer Numerically Controlled (CNC) laser cutting machines are capable of producing high-quality precise parts. However, as cutting speeds is increased, in order to achieve higher productivity, the accuracy of the parts is affected. In order to improve the contouring accuracy of these machines, a simple straight-forward joint simulation and experimental strategy is proposed. The position controllers within the feed drives are considered the key factor in improving the dynamic behavior and consequently the contouring accuracy of a CNC laser cutting machine at the shop floor level.

New modes in non-invasive ventilation

2016

IF 2.536; International audience; Non-invasive ventilation is useful to treat some forms of respiratory failure. Hence, the number of patients receiving this treatment is steadily increasing. Considerable conceptual and technical progress has been made in recent years by manufacturers concerning this technique. This includes new features committed to improve its effectiveness as well as patient-ventilator interactions. The goal of this review is to deal with latest advances in ventilatory modes and features available for non-invasive ventilation. We present a comprehensive analysis of new modes of ventilator assistance committed to treat respiratory failure (hybrid modes) and central and co…