Search results for " modeling"

Common and Domain-specific Metamodel Elements for Problem Description in Simulation Problems

2014

It is well known that the multi-agent system paradigm is well suited for modelling and developing simulations of complex systems belonging to several application domains. Simulation study aims at developing simulation models useful for representing, studying and analyzing entities and their behavior in a system according to specific purposes. With our work we are trying to understand what are the right elements to be considered and included in the description of a simulation problem. In order to root our resulting metamodel in the state of the art of multi-agent simulations we started from the study of twelve papers dealing with four different application domains: Crowd Dynamics, Traffic an…

Nonlocal Second Order Vehicular Traffic Flow Models And Lagrange-Remap Finite Volumes

2011

In this paper a second order vehicular macroscopic model is derived from a microscopic car–following type model and it is analyzed. The source term includes nonlocal anticipation terms. A Finite Volume Lagrange–remap scheme is proposed.

2019

Abstract. The cumulative occurrence of heavy precipitation and flood events during recent years in various Central European locations emphasises the urgent need to improve extreme rainfall observations and forecasts. Precipitation gauges based on a weighing system allow the recording of intense short-term precipitation events with a very high temporal resolution (down to 1 min). In this study, observational data that were collected during the period 2000 to 2016 for 126 stations of two corresponding measuring networks in the Central German state of Hesse were investigated for the first time to answer the following questions: (1) Are the recorded high-resolution precipitation data plausible …

SARS-CoV-2 RNA in wastewater anticipated COVID-19 occurrence in a low prevalence area

2020

Preprint disponible en http://hdl.handle.net/10261/209125

Stochastic dynamic analysis of structures with fractional viscoelastic constitutive laws

The main purpose of this thesis is to provide a new way to correctly perform stochastic analysis of structures with viscoelastic constitutive law. The reason for this kind of problem relates the fact that structures with viscoelastic materials are built in many areas of mechanical, civil and aerospace engineering. To perform this kind of stochastic analysis there are two fundamental problems. That is, the mechanical description of the viscoelastic phenomenon, and the correct representation of the external loads. Both of these problems are addressed and solved by the proposed modeling that involves some advanced mathematical tools. The reason to describe materials as viscoelastic is given by…

Three dimensional numerical simulation of wind driven flows in closed channels and basins

2008

In the paper, a fully 3D finite-volume numerical model is developed and employed for the prediction of wind-induced flows in a regular channel and in a square basin with a complex bathymetry. Numerical results are compared with laboratory experiments.Numerical tests are then performed to investigate whether simplifying assumptions about the pressure distribution and the turbulente stresses representation can be employed in the simulation of wind-driven flows. The hydrostatic pressure assumption, resulting in the use of “quasi-3D” models, proved to be reasonably acceptable in order to obtain the vertical profile of the streamwise velocity component away from the boundaries. The quasi-3D mode…

Is Age Just a Number? Cognitive Reserve as a Predictor of Divergent Thinking in Late Adulthood

2016

The purpose of the study was to test a model of causal relationships among cognitive reserve (CR), personality variables such as Neuroticism and Openness to experience, and divergent thinking (DT), independently evaluating performance in different domains (verbal and graphic). It was hypothesized that CR, Openness, and Neuroticism would each directly influence verbal and graphic DT. A total of 135 subjects between 55 and 84 years old participated in the study and were interviewed in individual sessions. For a correct fit Neuroticism was eliminated from the measurement model. The goodness-of-fit indexes of the measurement model, the adequate composite reliability index and the discriminant v…

Towards an Ontology for Information Systems Development—A Contextual Approach

2007

This chapter presents an ISD ontology, which aims to provide an integrated conceptualization of ISD through anchoring it upon a contextual approach. The ISD ontology is composed of concepts, relationships, and constraints referring to purposes, actors, actions, and objects of ISD. It is presented as a vocabulary with explicit definitions and in meta models in a UML-based ontology representation language. We believe that although not complete the ISD ontology can promote the achievement of a shared understanding of contextual aspects in ISD. It can be used to analyze and compare existing frameworks and meta models and as a groundwork for engineering new ISD methods, and parts thereof. IGI PU…

The Early Years Home Learning Environment – Associations With Parent-Child-Course Attendance and Children’s Vocabulary at Age 3

2020

Although many studies investigated the effects of the home learning environment (HLE) in the preschool years, the constructs that underlie the HLE in the years before the age of three and its effects on language development are still poorly understood. This study therefore investigated the dimensionality of the HLE at age two, its relation to the attendance of low threshold parent-child-courses, and its importance for children's vocabulary development between age 2 and 3 years against the background of differing family background characteristics. Using data from 1,013 children and their families of the Newborn Cohort of the German National Educational Panel Study, structural equation modeli…

Effects of fabrication on the mechanics, microstructure and micromechanical environment of small intestinal submucosa scaffolds for vascular tissue e…

2013

In small intestinal submucosa scaffolds for functional tissue engineering, the impact of scaffold fabrication parameters on success rate may be related to the mechanotransductory properties of the final microstructural organization of collagen fibers. We hypothesized that two fabrication parameters, 1) preservation (P) or removal (R) of a dense collagen layer present in SIS and 2) SIS in a final dehydrated (D) or hydrated (H) state, have an effect on scaffold void area, microstructural anisotropy (fiber alignment) and mechanical anisotropy (global mechanical compliance). We further integrated our experimental measurements in a constitutive model to explore final effects on the micromechanic…