Search results for "Proa"
showing 10 items of 1834 documents
Evaluation of the shakedown limit load multiplier for stochastic seismic actions
2017
A new approach for the evaluation of the shakedown limit load multiplier for structures subjected to a combination of quasi-statically variable loads and seismic actions is presented. The common case of frame structures constituted by elastic perfectly plastic material is considered. The acting load history during the lifetime of the structure will be defined as a suitable combination of never ending quasi-statical loads, variable within an appropriate given domain, and stochastic seismic actions occurring for limited time interval. The proposed approach utilizes the Monte Carlo method in order to generate a suitable large number of seismic acceleration histories and the corresponding shake…
An interactive multi-objective approach to heat exchanger network synthesis
2010
In this work we present a multi-objective approach to heat exchanger network synthesis. The approach solves a modified version of the Synheat model using an interactive multi-objective optimisation method, NIMBUS, which is implemented in GAMS. The results obtained demonstrate the potential of interactive multi-objective optimisation.
Hydrological post-processing based on approximate Bayesian computation (ABC)
2019
[EN] This study introduces a method to quantify the conditional predictive uncertainty in hydrological post-processing contexts when it is cumbersome to calculate the likelihood (intractable likelihood). Sometimes, it can be difficult to calculate the likelihood itself in hydrological modelling, specially working with complex models or with ungauged catchments. Therefore, we propose the ABC post-processor that exchanges the requirement of calculating the likelihood function by the use of some sufficient summary statistics and synthetic datasets. The aim is to show that the conditional predictive distribution is qualitatively similar produced by the exact predictive (MCMC post-processor) or …
Approximate survival probability determination of hysteretic systems with fractional derivative elements
2018
Abstract A Galerkin scheme-based approach is developed for determining the survival probability and first-passage probability of a randomly excited hysteretic systems endowed with fractional derivative elements. Specifically, by employing a combination of statistical linearization and of stochastic averaging, the amplitude of the system response is modeled as one-dimensional Markovian Process. In this manner the corresponding backward Kolmogorov equation which governs the evolution of the survival probability of the system is determined. An approximate solution of this equation is sought by employing a Galerkin scheme in which a convenient set of confluent hypergeometric functions is used a…
An Interactive Evolutionary Multiobjective Optimization Method: Interactive WASF-GA
2015
In this paper, we describe an interactive evolutionary algorithm called Interactive WASF-GA to solve multiobjective optimization problems. This algorithm is based on a preference-based evolutionary multiobjective optimization algorithm called WASF-GA. In Interactive WASF-GA, a decision maker (DM) provides preference information at each iteration simple as a reference point consisting of desirable objective function values and the number of solutions to be compared. Using this information, the desired number of solutions are generated to represent the region of interest of the Pareto optimal front associated to the reference point given. Interactive WASF-GA implies a much lower computational…
Robust model calibration using determinist and stochastic performance metrics
2016
International audience; The aeronautics industry has benefited from the use of numerical models to supplement or replace the costly design-build-test paradigm. These models are often calibrated using experimental data to obtain optimal fidelity-to-data but compensating effects between calibration parameters can complicate the model selection process due to the non-uniqueness of the solution. One way to reduce this ambiguity is to include a robustness requirement to the selection criteria. In this study, the info-gap decision theory is used to represent the lack of knowledge resulting from compensating effects and a robustness analysis is performed to investigate the impact of uncertainty on…
Decision-aid for discrete multiple criteria decision making problems with imprecise data
1999
Abstract We describe ways of aiding decision making with a discrete set of alternatives. In many decision situations, it is not possible to obtain explicit preference information from the decision makers. Instead, useful decision-aid can be provided to the decision makers by describing what kind of weighting of the criteria result in certain choices of the alternatives. The suggested treatment is based on the basic ideas of the ELECTRE III method. The modelling of the preferences by pseudo-criteria is especially helpful in case the data, that is, the criterion values are imprecise. Unlike ELECTRE III, no ranking of the alternatives is produced. Based on a minimum-procedure in the exploitati…
Numerical study of the transverse stability of the Peregrine solution
2020
We generalise a previously published approach based on a multi-domain spectral method on the whole real line in two ways: firstly, a fully explicit 4th order method for the time integration, based on a splitting scheme and an implicit Runge--Kutta method for the linear part, is presented. Secondly, the 1D code is combined with a Fourier spectral method in the transverse variable both for elliptic and hyperbolic NLS equations. As an example we study the transverse stability of the Peregrine solution, an exact solution to the one dimensional nonlinear Schr\"odinger (NLS) equation and thus a $y$-independent solution to the 2D NLS. It is shown that the Peregrine solution is unstable against all…
Career goal-related social ties during two educational transitions: Antecedents and consequences
2010
Abstract This study examined adolescents’ career goal-related social ties during the transition from compulsory to post-compulsory education and during transition from post-compulsory education to working-life or further studies. A total of 687 Finnish adolescents aged 15–16 were surveyed of whom 654 also participated at the second measurement point one year later, and 497 three years later. Differences in career goal-related social ties were found according to gender, GPA, family structure, and SES. Moreover, social ties were associated with educational track after compulsory school above and beyond SES, GPA, and family structure. Adolescents who named a teacher or a romantic partner were …
Promoting Capabilities with a Drama Workshop among Foster Care Adolescents
2021
We assessed the impacts of a drama-based 13-session workshop among adolescents (N = 8) residing in a reform school due to severe conduct problems. The participants were interviewed three times duri...