Search results for "Simulation."
showing 10 items of 4779 documents
Femtosecond parabolic pulse shaping in normally dispersive optical fibers
2013
Formation of parabolic pulses at femtosecond time scale by means of passive nonlinear reshaping in normally dispersive optical fibers is analyzed. Two approaches are examined and compared: the parabolic waveform formation in transient propagation regime and parabolic waveform formation in the steady-state propagation regime. It is found that both approaches could produce parabolic pulses as short as few hundred femtoseconds applying commercially available fibers, specially designed all-normal dispersion photonic crystal fiber and modern femtosecond lasers for pumping. The ranges of parameters providing parabolic pulse formation at the femtosecond time scale are found depending on the initia…
Characterization of Locally Excited and Charge-Transfer States of the Anticancer Drug Lapatinib by Ultrafast Spectroscopy and Computational Studies
2020
[EN] Lapatinib (LAP) is an anticancer drug, which is metabolized to theN- and O-dealkylated products (N-LAP andO-LAP, respectively). In view of the photosensitizing potential of related drugs, a complete experimental and theoretical study has been performed on LAP,N-LAP andO-LAP, both in solution and upon complexation with human serum albumin (HSA). In organic solvents, coplanar locally excited (LE) emissive states are generated; they rapidly evolve towards twisted intramolecular charge-transfer (ICT) states. By contrast, within HSA only LE states are detected. Accordingly, femtosecond transient absorption reveals a very fast switching (ca. 2 ps) from LE (lambda(max)=550 nm) to ICT states (…
Seismically induced, non-stationary hydrodynamic pressure in a dam-reservoir system
2003
Stochastic seismic analysis of hydrodynamic pressure in a dam-reservoir system is presented in this paper. The analysis is conducted assuming infinite reservoir compressible fluid and modeling seismic acceleration as a normal zero-mean stochastic process obtained by Penzien filter. The non-homogeneous boundary conditions associated to the problem have been incorporated into the equation of pressure wave scattering in the form of a forcing function turning the non-homogeneous boundary value problem into an homogeneous one. Solution obtained via modal analysis in time-domain is coupled with the use of classical Ito stochastic differential calculus to characterize the stochastic hydrodynamic p…
Mechanical testing and numerical modelling of pull-wound carbon-epoxy spinnaker poles
2002
The paper deals with experimental testing and numerical simulation of the mechanical behaviour of multi-layer cylindrical coupons, of two different diameters, made in carbon-epoxy composite. The aim of the study is to provide a simple and effective numerical model that can be used as a design tool for structural elements having analogous geometrical and manufacturing characteristics. The numerical analysis, performed in the elastic regime with a standard finite element (FE) code, was strongly correlated with the laboratory determination of fibre-volume fractions and of some elastic parameters of the material system. Other parameters, like the shear modulus values G, were in fact appropriate…
Non-syndromic Mitral Valve Dysplasia Mutation Changes the Force Resilience and Interaction of Human Filamin A
2018
International audience; Filamin A (FLNa), expressed in endocardial endothelia during fetal valve morphogenesis, is key in cardiac development. Missense mutations in FLNa cause non-syndromic mitral valve dysplasia (FLNA-MVD). Here, we aimed to reveal the currently unknown underlying molecular mechanism behind FLNA-MVD caused by the FLNa P637Q mutation. The solved crystal structure of the FLNa3-5 P637Q revealed that this mutation causes only minor structural changes close to mutation site. These changes were observed to significantly affect FLNa's ability to transmit cellular force and to interact with its binding partner. The performed steered molecular dynamics simulations showed that signi…
Optimal Flight Path Determination in Turbulent Air: A Modified EKF Approach
2017
By using the Extended Kalman Filter an accurate path following in turbulent air is performed. The procedure employs simultaneously two different EKFs: the first one estimates disturbances, the second one affords to determine the necessary controls displacements for rejecting those ones. To tune the EKFs an optimization algorithm has been designed to automatically determine Process Noise Covariance and Measurement Noise Covariance matrices. The first filter, by using instrumental measurements gathered in turbulent air, estimates wind components. The second one obtains command laws able to follow the desired flight path. To perform this task aerodynamic coefficients have been modified. Such a…
Forecasting Financial Crises and Contagion in Asia Using Dynamic Factor Analysis
2009
In this paper we use principal components analysis to obtain vulnerability indicators able to predict financial turmoil. Probit modelling through principal components and also stochastic simulation of a Dynamic Factor model are used to produce the corresponding probability forecasts regarding the currency crisis events affecting a number of East Asian countries during the 1997-1998 period. The principal components model improves upon a number of competing models, in terms of out-of-sample forecasting performance.
Commercial and financial policies in family firms: The small business growth management flight simulator
2000
An interactive learning environment (ILE) was built to reproduce the budgeting process of a small family-owned entrepreneurial firm and to capture how current decisions affect business growth in a longer time horizon. The ILE matches the accounting-related perspective through which spreadsheet-based budgets are drawn up, with the system dynamics (SD) view. Such a goal has been pursued through a connection of traditional Excel spreadsheets with POWERSIM SD models. Playing the SMALL BUSINESS GROWTH MANAGEMENT FLIGHT SIMULATOR allows one to learn how (a) to draw up a budget based on an SD perspective, (b) long-term goals may be affected by current decisions, (c) business/family survival and gr…
Operational and financial effectiveness of e-collaboration tools in supply chain integration
2004
This paper develops a comprehensive model of supply chain integration and uses it to analyze and assess the operational and financial effectiveness of different e-collaboration tools at various levels of supply chain integration. This model is also used to evaluate the importance of the sequence in which e-collaboration tools are adopted in supply chain integration. Computational results from a validated system dynamics simulation model with different implementation sequences of e-collaboration tools and different financial scenarios show that local financial constraints can also severely impact operational and financial performance of the entire supply chain. (C) 2003 Elsevier B.V. All rig…
Le renouveau du système éducatif de la République Démocratique du Congo. Priorités et alternatives
2005
International audience