Search results for "Modelli"

Application of computational fluid dynamics technique in electrodialysis/reverse electrodialysis processes

2022

This Chapter treats the application of CFD technique in ED/RED processes. CFD simulations are able to predict flow and mass transfer in channels filled with spacers or membrane profiles, by providing dimensionless correlations useful for process models. At a larger scale, manifolds of the stack and inlet/ outlet zones of the channel can be simulated. Numerical models can include the computation of the electrical potential, thus characterizing the process performance. Direct numerical simulations can elucidate the complex phenomenology of overlimiting transport and of chaotic electrokinetic flows.

Modelació de sedimentadors en plantes de tractament d’aigües residuals. Aplicació al procés de fermentació – elutriació de fangs primaris

2005

La depuració de les aigües residuals requereix la consumació de molts processos de transformació de forma simultània i/o consecutiva, que fan molt difícil el seu estudi. A més, la complexitat dels processos de depuració va en augment no sols per l'aparició de requisits d’abocament cada vegada més exigents, sinó també per les noves tendències cap al desenvolupament sostenible aplicades a aquest procés i centrades fonamentalment en l’estalvi energètic i la recuperació de nutrients de les aigües residuals per millorar el seu cicle de vida. Per aquest motiu, es fa necessari l'ús d'eines de simulació que tinguen en compte tots aquests processos mitjançant un model matemàtic adequat i ajuden a de…

Statistical Modelling and Risk Analysis of Bitcoins Exchange Rate

2018

Master's thesis Business Administration BE501 - University of Agder 2018 Bitcoin is a phenomenon that is new and there is little information on how and why it behaves as volatile as it does. This thesis uses existing data on Bitcoin’s exchange rate to estimate a model that describes the pattern and use it in a financial risk analysis. We also aim to contribute as a foundation for further studies in this field. The statistical properties of the log-return of the exchange rate are analysed and it is deemed to be iid. From the eleven distributional candidates we study is the fitted skew generalised t distribution proven to represent the data best after evaluation by criteria and statistics. Th…

Bioinspired sensors from olfactory proteins

2011

Impact de la flore adventice sur la rétention des pesticides : développement d’un nouvel indicateur pour l’évaluation des systèmes de culture

2016

Weeds are usually considered as harmful for crops but they are essential for biodiversity. Indicators were already developed using the model FLORSYS (Colbach et al., 2014) to evaluate the cropping system in term of harmfullness or benefits related to weed flora. We thus propose a new indicator to evaluate the potential of pesticide retention by weed flora and its impact on pesticide transfer into the environment. The indicator is divided in two parts i) herbicide application efficiency (herbicides interception by weeds), ii) plant uptake for the others pesticides. Several cropping systems have been simulated with the FLORSYS model. Preliminary results have been analyzed using the tree regre…

Social features, Spatial features, Time features: An urban archaeological data model

2007

http://proceedings.caaconference.org/files/2007/64_Rodier_Saligny_CAA2007.pdf; International audience; The use of GIS to study the spatial evolution of pre-industrial cities over the "longue durée" requires rigorous formalisation of heterogeneous data from different sources into robust entities. An initial model using the HBDS (Hypergraph Based Data Structure) method enabled us to distinguish social and spatial features. In this paper, we develop a specific model for the temporal dimension. The definition of urban objects using social, spatial and temporal features enhances the study of urban dynamics and of change over the "longue durée".

Modelling challenge of small amounts of change: a new sampling strategy in land use science

2016

International audience

Global sensitivity analysis in environmental water quality modelling: Where do we stand?

2014

Global sensitivity analysis (GSA) is a valuable tool to support the use of mathematical models for environmental systems. During the last years the water quality modelling field has embraced the use of GSA. Environmental water quality modellers have tried to transfer the knowledge and experience acquired in other disciplines. The main objective of this paper is to provide an informed problem statement of the issues surrounding GSA applications in the environmental water quality modelling field. Specifically, this paper aims at identifying, for each GSA method, the potential use, the critical issues to be solved and the limits identified in a comprehensive literature review. The paper shows …

Modelling Dynamic Systems: Examples Involving an Iconic Oriented Environment

2005

We present a modelling environment based on the use of iconic representations consisting of elements, as containers and connected flows, able to describe the relationships between relevant variables of dynamic systems. The procedures involved are aimed to make students aware of the reasoning processes to describe, formalise and explain complex system behaviours. Moreover, we show how these strategies may allow the overcoming of some well-known difficulties involved in pupil understanding of mathematical formalisms, such as derivatives and differential equations and their real meaning. Our reported modelling examples were experimented on during some laboratory sessions of the Pre-Service Sch…

Modelling of managerial competences in health care units – preliminary assumptions

2022

Purpose: The aim of the article is to present the theoretical assumptions of the model of managerial competences in health care units. It was assumed that competences are a multidimensional concept and require an integrated approach that allows for the construction of a competency model that reflects their real complexity. A list of managerial competencies will be presented, which will be subject to empirical verification in the course of future research by the authors in order to identify key competencies. Design/methodology/approach: The proposed lists of managerial competencies (six domains) were created and are based on the analysis of healthcare competencies models – the study of the l…