Search results for "Modelling"

Identification of Potential Locations for Run-of-River Hydropower Plants Using a GIS-Based Procedure

2019

The increasing demand for renewable and sustainable energy sources has encouraged the development of small run-of-river plants. Preliminary studies are required to assess the technical and economic feasibility of such plants. In this context, the identification of optimal potential run-of-river sites has become a key issue. In this paper, an approach that is based on GIS tools coupled with a hydrological model has been applied to detect potential locations for a run-of-river plant. A great number of locations has been analyzed to identify those that could assure the achievement of different thresholds of potential power. The environmental and economic feasibility for small hydropower projec…

A systematic comparison of kinetic modelling methods generating parametric maps for [11C]-(R)-PK11195

2006

[(11)C]-(R)-PK11195 is presently the most widely used radiotracer for the monitoring of microglia activity in the central nervous system (CNS). Microglia, the resident immune cells of the brain, play a critical role in acute and chronic diseases of the central nervous system and in host defence against neoplasia. The purpose of this investigation was to evaluate the reliability and sensitivity of five kinetic modelling methods for the formation of parametric maps from dynamic [(11)C]-(R)-PK11195 studies. The methods we tested were the simplified reference tissue model (SRTM), basis pursuit, a simple target-to-reference ratio, the Logan plot and a wavelet based Logan plot. For the reliabilit…

Fluctuation-dissipation relations for Markov processes.

2005

The fluctuation-dissipation relation is calculated for stochastic models obeying a master equation with continuous time. In the general case of a nonstationary process, there appears to be no simple relation between the response and the correlation. Also, if one considers stationary processes, the linear response cannot be expressed via time-derivatives of the correlation function alone. In this case, an additional function, which has rarely been discussed previously, is required. This so-called asymmetry depends on the two times also relevant for the response and the correlation and it vanishes under equilibrium conditions. The asymmetry can be expressed in terms of the propagators and the…

Cost analysis of a vaccination strategy for respiratory syncytial virus (RSV) in a network model

2010

[EN] In this paper an age-structured mathematical model for respiratory syncytial virus (RSV) is proposed where children younger than one year old, who are the most affected by this illness, are specially considered. Real data of hospitalized children in the Spanish region of Valencia are used in order to determine some seasonal parameters of the model. Once the parameters are determined, we propose a complete stochastic network model to study the seasonal evolution of the respiratory syncytial virus (RSV) epidemics. In this model every susceptible individual can acquire the disease after a random encounter with any infected individual in the social network. The edges of a complete graph co…

Simulations of networked critical infrastructures

2018

Master's thesis Information- and communication technology IKT590 - University of Agder 2018 Critical infrastructure (CI) refers to assets that are essential for the functioning of a society and economy, such as telecommunication/ICT; energy generation, transmission and distribution; financial sector; etc. CIs are tightly coupled, creating a complex system where failures propagate from a disrupted CI to other CIs, aggravating and prolonging the societal impact through cascading effects. This thesis extends a system dynamic model by Eliza Canzani describing how a failed critical infrastructure that cannot deliver products and services impacts other critical infrastructures, and how a critical…

Innovative techniques for survey and communication of cultural heritage

2008

This paper deals with the survey and communications of Cultural Heritage through the development of innovative methodologies. The case of study is the polychrome wooden ceiling in the “Magna” Hall of “Palazzo Steri”. The “Steri”, built in the XIVth century by the noble family Chiaromonte, is at the present the headquarter of the Rector’s Office of Palermo University. A 3D model of the wooden ceiling has initially been carried out with laser-scanning and digital photogrammetric techniques; successively a multimodal interactive guide has been realized. The guide is integrated to the 3D model, so that visitors can navigate the virtual representation of the ancient wood ceiling and achieve, int…

3D survey and modelling of the main portico of the Cathedral of Monreale

2018

3D survey and modelling of Cultural Heritage allow to store a great deal of 3D data that can be managed for different purposes. 3D models can be used for documentation, restoration and knowledge of historic architectures and monuments. In this work, a 3D survey of the main portico of the Cathedral of Monreale (Palermo, Italy) was carried out. The paper presents the data acquisition process and the 3D modelling phase. The work is aimed to reconstruct a 3D model that could be used also to set up an HBIM (Heritage or Historic Building Information Modelling) of the main portico. The result of this study could be considered as a first test to implement an HBIM platform for the whole monumental c…

Quantifying and Processing Biomedical and Behavioral Signals

2019

PASSENGER SATISFACTION WITH HYBRID ELECTRIC BUS SERVICE IN NORWAY : A PLS Structural Equation Modelling Approach

2019

Master's thesis Business Administration BE501 - University of Agder 2019 The use of hybrid electric buses (HEBs) in public transit is one of the global attention received topics in this 21st century because of its environment friendly nature. This study focusses on effect of bus service quality dimensions such as bus driver's quality, bus tangible and empathy to determine customer satisfaction level of bus service in Kristiansand region. Structural equation model is used for an empirical investigation to find out the association of perceived bus service quality dimensions with word of mouth mediated by perceived value and customer satisfaction. A total of 276 valid university student respon…

Computational Models That Matter During a Global Pandemic Outbreak

2020

The COVID-19 pandemic is causing a dramatic loss of lives worldwide, challenging the sustainability of our health care systems, threatening economic meltdown, and putting pressure on the mental health of individuals (due to social distancing and lock-down measures). The pandemic is also posing severe challenges to the scientific community, with scholars under pressure to respond to policymakers’ demands for advice despite the absence of adequate, trusted data. Understanding the pandemic requires fine-grained data representing specific local conditions and the social reactions of individuals. While experts have built simulation models to estimate disease trajectories that may be enough to gu…