Search results for "driven"
showing 10 items of 224 documents
Adiabatic eigenflows in a vertical porous channel
2014
AbstractThe existence of an infinite class of buoyant flows in a vertical porous channel with adiabatic and impermeable boundary walls, called adiabatic eigenflows, is discussed. A uniform heat source within the saturated medium is assumed, so that a stationary state is possible with a net vertical through-flow convecting away the excess heat. The simple isothermal flow with uniform velocity profile is a special adiabatic eigenflow if the power supplied by the heat source is zero. The linear stability analysis of the adiabatic eigenflows is carried out analytically. It is shown that these basic flows are unstable. The only exception, when the power supplied by the heat source is zero, is th…
Steady-state entanglement activation in optomechanical cavities
2014
Quantum discord, and a number of related indicators, are currently raising a relentless interest as a novel paradigm of non-classical correlations beyond entanglement. Beside merely fundamental aspects, various works have shown that discord is a valuable -- so far largely unexplored -- resource in quantum information processing. Along this line, quite a striking scheme is {entanglement activation}. An initial amount of discord between two disentangled parties of a multipartite system affects the dynamics so as to establish entanglement across a bipartition, which would not arise otherwise. To date, such a process was proven to be achievable only dynamically, i.e., with no guarantee of a sta…
Dynamics of Uniaxial Hard Ellipsoids
2007
We study the dynamics of monodisperse hard ellipsoids via a new event-driven molecular dynamics algorithm as a function of volume fraction $\phi$ and aspect ratio $X_0$. We evaluate the translational $D_{trans}$ and the rotational $D_{rot}$ diffusion coefficient and the associated isodiffusivity lines in the $\phi-X_0$ plane. We observe a decoupling of the translational and rotational dynamics which generates an almost perpendicular crossing of the $D_{trans}$ and $D_{rot}$ isodiffusivity lines. While the self intermediate scattering function exhibits stretched relaxation, i.e. glassy dynamics, only for large $\phi$ and $X_0 \approx 1$, the second order orientational correlator $C_2(t)$ sho…
Laser driven structured quantum rings
2015
In this work we study harmonic emission from structured quantum rings (SQRs). In SQRs, electrons trapped in two-dimensional structures are further confined by an external potential composed of N scattering centers arranged on a circle. We build a suitable one-dimensional model Hamiltonian describing this class of systems and analytically solve the associated Schödinger equation. We find that the solution can be expressed in terms of Mathieu functions and focus on the specific case of N = 6. By exactly solving the time-dependent Schödinger equation, we then show how the harmonic response to linearly polarized lasers strongly depends on the ring physical parameters. The results illustrate how…
An empirical approach for evaluating the usability of model-driven tools
2013
MDD tools are very useful to draw conceptual models and to automate code generation. Even though this would bring many benefits, wide adoption of MDD tools is not yet a reality. Various research activities are being undertaken to find why and to provide the required solutions. However, insufficient research has been done on a key factor for the acceptance of MDD tools: usability. With the help of end-users, this paper presents a framework to evaluate the usability of MDD tools. The framework will be used as a basis for a family of experiments to get clear insights into the barriers to usability that prevent MDD tools from being widely adopted in industry. To illustrate the applicability of …
Exploring Process-Modelling Practice: Towards a Conceptual Model
2008
Despite the importance of process modelling for business process management and related tasks, there are few theories and empirical studies of process-modelling practice available that can serve as the basis for understanding and improving this important practice. To contribute to the development of better theory, this paper proposes a model of process modelling practice, focussing on the relations between process modelling purpose, process modelling process, model artefact, process modelling outcome as well as initial and eventual modelling and process maturity. The proposed model is based on the existing literature and validated in a study of 34 Norwegian process-modelling projects. Resul…
Business Process Models and Information System Usability
2015
Abstract The paper describes the use of business process models for effective managing of information system execution processes and transparent representation of execution statuses. Contrary to traditional approaches where business process models are used only in the initial stages of information system development, the proposed approach suggests direct utilization of business process models during the use of information systems. Information system usability can be improved by using new means of representation, and business process models can serve as an efficient way to visualize execution processes in information systems.
Effectiveness and safety of a new helmet CPAP configuration allowing tidal volume monitoring in patients with COVID-19.
2021
Abstract Background High generated tidal volumes (Vt) have been correlated with higher risk of self-induced lung injury and worse clinical outcome. This study aimed to evaluate the effectiveness and safety of a new helmet continuous positive airway pressure delivered (h-CPAP) configuration allowing Vt monitoring in patients affected by COVID-19. Methods This prospective observational study was performed in the respiratory intermediate care unit of University Hospital in Turin, Italy, between March 24th, and June 15th, 2020. Included patients were treated with CPAP via a single-limb intentional leak configuration by a turbine-driven ventilator, provided with a dedicated patch. Effectiveness …
PREDICTION OF THERMODYNAMIC INSTABILITIES OF PROTEIN SOLUTIONS FROM SIMPLE PROTEIN-PROTEIN INTERACTIONS
2013
Statistical thermodynamics of protein solutions is often studied in terms of simple, microscopic models of particles interacting via pairwise potentials. Such modelling can reproduce the short range structure of protein solutions at equilibrium and predict thermodynamics instabilities of these systems. We introduce a square well model of effective protein-protein interaction that embeds the solvent's action. We modify an existing model [45] by considering a well depth having an explicit dependence on temperature, i.e. an explicit free energy character, thus encompassing the statistically relevant configurations of solvent molecules around proteins. We choose protein solutions exhibiting dem…