Search results for "modelling"
showing 10 items of 1353 documents
The story of endurance:Biogeography and the evolutionary history of four Holarctic butterflies with different habitat requirements
2021
Aim: Biogeographical studies on the entire ranges of widely distributed species can change our perception of species’ range dynamics. We studied the effects of Pleistocene glacial cycles on current butterfly species distributions, aiming to uncover complex biogeographic patterns in the Holarctic, a region dramatically affected by Cenozoic climate change. Location: Eurasia and North America. Taxon: Boloria chariclea, Agriades optilete, Carterocephalus palaemon, Oeneis jutta. Methods: We reconstructed the biogeographic history of four butterfly species differing in habitat preferences (B. chariclea – tundra, A. optilete – bogs, C. palaemon – temperate grasslands, O. jutta – taiga), using one …
Basis of predictive mycology.
2005
Abstract For over 20 years, predictive microbiology focused on food-pathogenic bacteria. Few studies concerned modelling fungal development. On one hand, most of food mycologists are not familiar with modelling techniques; on the other hand, people involved in modelling are developing tools dedicated to bacteria. Therefore, there is a tendency to extend the use of models that were developed for bacteria to moulds. However, some mould specificities should be taken into account. The use of specific models for predicting germination and growth of fungi was advocated previously [ Dantigny, P., Guilmart, A., Bensoussan, M., 2003. Basis of predictive mycology. In Proceedings of the 4th Internatio…
Fostering growth patterns of SMEs through business model innovation. A tailored dynamic business modelling approach
2021
Abstract In the contemporary complex and fast-changing markets, there is persistent pressure for Small-and-Medium Enterprises (SMEs) to engage in business model innovation to promptly meet customer expectations and successfully compete for survival. In the last decade, multiple approaches to business model development and innovation have been explored. However, they have been primarily designed for large-sized companies, while SMEs display distinctive organizational attributes. Thus, SMEs require a tailored approach to design, experiment and innovate their business models, in order to frame the specific complexity of their value creation processes. This paper aims to explore how a Dynamic B…
A Novel Method to Characterize User Sessions of Educational Software
2013
Abstract Software applications destined for the educational environment have a long history and have evolved side by side with the progress of technology from simple computer assisted instruction programs to sophisticated eLearning platforms. A study that we have conducted on a sample of 395 children aged 6 through 12, coming from both the rural and the urban environments, shows that an increasing number of children use computer related technologies. Given their exposure to these technologies it is imperative that the educational applications be designed in a way that takes into account the children's abilities, interests and the demands for their development. We have proposed a 5-dimension…
Mass appraisal of residential real estate using multilevel modelling
2016
Mass appraisal, or the automatic valuation of a large number of real estate assets, has attracted the attention of many researchers, who have mainly approached this issue employing traditional econometric models such as Ordinary Least Squares (OLS). However, this method does not consider the hierarchical structure of the data and therefore assumes the unrealistic hypothesis of the independence of the individuals in the sample. This paper proposes the use of the Hierarchical Linear Model (HLM) to overcome this limitation. The HLM also gives valuable information on the percentage of the variance error caused by each level in the hierarchical model. In this study HLM was applied to a large dat…
Simplified dynamic pressure method for kLa measurement in aerated bioreactors
2010
Abstract A simplified version of the dynamic pressure method for measuring mass-transfer coefficients in gas–liquid systems is proposed. With this method oxygen concentration in the liquid phase is monitored after a sudden change of total pressure is applied to the system. With respect to the original technique introduced by Linek [14] the simplified version here proposed greatly simplifies the data treatment, yet resulting in good accuracy for most practical purposes. In practice, with the help of a simple mathematical model, it is found that the dynamic oxygen concentration response, when plotted as residual driving force versus time in a semi-log diagram, should be expected to finally se…
11B-MAS NMR approach to the boron adsorption mechanism on a glucose-functionalised mesoporous silica matrix
2018
[EN] Boron chemistry has raised much interest because, despite the difference between necessities and toxicity being very narrow, it is still widely used in industrial processes. In a previous work we reported an adsorbent for boron extraction from water by the functionalisation of a UVM-7 mesoporous silica matrix with gluconamide moieties. The ability of this material to adsorb boron is based on its well-known affinity for coordinating the cis-diols present in attached saccharide. Although much research on the formation of boron esters with sugars and sugar derivatives in solution has been done, very few reports have dealt with the adsorption mechanism of boron onto functionalised material…
Development and analysis of a model based on chirped fiber Bragg gratings employed for cracks characterization in materials
2018
In this work a model was developed that allows to understand the behavior of a chirped fiber Bragg grating for the detection and characterization of cracks in materials. In addition to the amplitude response, we show that the group delay of the grating provides useful information for the characterization of the crack. The position of the crack can be determined thanks to the linear chirp of the grating that fixes a correlation between the spatial position and both, the wavelength and the group delay. However, our analysis shows that this simple approach has a source of error, which can be overcome if a controllable external strain can be applied to the embedded grating, additional to the st…
Numerical simulations of the mechanical characteristics of glass fibre reinforced C-profiles
2006
A mechanical characterisation analysis on pultruded glass fibre reinforced C-shaped profiles, developed as modular construction elements to assemble fastening systems, such as doors, window frames and shutters is presented. The key idea is to perform the analysis, and all the related identification procedures of the material parameters, via a coupled approach, based on a limited number of standard laboratory tests and on the numerical finite element simulations of the same tests. The proposed approach allows one to identify all those material parameters which are difficult to detect, by means of simple laboratory experiments on specimens that are extracted from commercial products. It also …
High-dose behaviour of CaSO4: Dy thermoluminescent phosphors as deduced by a continuous model for trap depths
1978
Abstract The high-dose behaviour of CaSO4: Dy TL dosimeters observed by some authors is compared with the one deduced by the continuous distribution of trap depths previously proposed by us. A general agreement results.