Search results for "Dynamic"
showing 10 items of 12329 documents
A two-phase insertion technique of unexpected customers for a dynamic dial-a-ride problem
2006
Abstract This work deals with a dynamic dial-a-ride problem with time window constraints. In particular, new unplanned requests for service may arise at a vehicle stop and the driver must decide in real-time whether to accept or reject them. For this problem, we have developed a two-phase insertion algorithm based on route perturbations: the first phase, which is run off-line when the vehicle moves between two successive stops, aims at creating a feasible neighborhood of the current route; while the second phase, which is run in real-time every time a new request occurs, inserts, when possible, the delivery stop of the new customer in the current route.
Parametric sensitivity of a CFD model concerning the hydrodynamics of trickle-bed reactor (TBR)
2016
Abstract The aim of the present study was to investigate the sensitivity of a multiphase Eulerian CFD model with respect to relations defining drag forces between phases. The mean relative error as well as standard deviation of experimental and computed values of pressure gradient and average liquid holdup were used as validation criteria of the model. Comparative basis for simulations was our own data-base obtained in experiments carried out in a TBR operating at a co-current downward gas and liquid flow. Estimated errors showed that the classical equations of Attou et al. (1999) defining the friction factors Fjk approximate experimental values of hydrodynamic parameters with the best agre…
Acid–base properties of functionalised tripodal polyamines and their interaction with nucleotides and nucleic acids
2010
Novel, highly positively charged tripodal polyamines with appended heterocyclic moieties revealed an intriguing panel of protonation species within the biologically relevant range. Studied compounds bind nucleotide monophosphates by mostly electrostatic interactions but only the imidazole analogue showed selectivity toward UMP in respect to other nucleotides. Strong binding of all the studied compounds to both ds-DNA and ds-RNA is to some extent selective toward the latter, showing rather rare RNA over DNA preference.
The two-fluid extended model of superfluid helium
2019
In this paper we perform the first numerical comparison between the two main existing models of superfluid helium: the two-fluid model proposed by Landau and the one-fluid extended model proposed from the extended thermodynamics. The numerical experiments in this paper regard the profiles of the so-called normal and superfluid components in 2D counterflow turbulence.
Ultrafast solvent-assisted level crossing in 1-Naphthol
2013
The nonadiabatic inversion dynamics of the energetic order of the electronic excited states of the photoacid 1-naphthol have been revealed by ultrafast spectroscopy on a femtosecond timescale (see picture; IC=internal conversion). The energetic order of the excited states La and Lb of 1-naphthol is reversed in 60 fs in polar dimethyl sulfoxide solvent.
Læringspotensial i en digital interaktiv matematikkundervisning : en analyse av læringspotensialet i geometriundervisningen på 8. trinn med utstrakt …
2016
Masteroppgave matematikkdidaktikk – Universitetet i Agder 2016 The theme of this master thesis is learning potential in mathematical tasks designed for geometry teaching in GeoGebra in 8th grade. This thesis is written in connection to the project Digital interactive mathematics teaching (DIM), where the goal is to create innovative mathematics teaching by using digital tools in a pedagogic context. Previous research has documented that students learning outcome of the teaching is largely influenced and limited by the tasks that are given. In this context analysis of the tasks learning potential is particular interesting. Therefore, my research question is: What learning potential is it in …
Studying incidental news : Antecedents, dynamics and implications
2020
In light of concerns about decreasing news use, a decline in interest in political news or even active avoidance or resistance of news in general, the idea of ‘incidental news’ has been seen as a possible remedy. Generally, ‘incidental news’ refers to the ways in which people encounter information about current events through media when they were not actively seeking the news. However, scholars studying incidental news through different theoretical and methodological perspectives have been arriving at differing evaluations of the significance and implications of this phenomenon – to the extent of downright contradictory findings. This introductory piece posits the aim of this special issue…
Dynamic Modeling for Environmental Processes: A Case Study of Lake Engure
2014
Abstract This focus of the study was on system dynamic models that could be useful for modelling environmental processes in Lake Engure. The paper considers the system dynamic model development principles, the most important elements and structure. The aim of the study was to describe possible methods of ecosystem process modelling that allow to represent the actual state of ecosystems and provide opportunities to predict further processes. The methods of ecosystem modelling considered in the paper reveal interactive factors of anthropogenic and environmental processes that influence changes in ecosystems. System dynamic models indicate not only interactions between various factors in the e…
The roles of achievement-related behaviours and parental beliefs in children´s mathematical performance
2003
This study aimed to investigate the developmental dynamics between children's mathematical performance, the task-focused versus task-avoidant behaviours they show in the classroom, and their parents' beliefs concerning their school competence. The mathematical performance of 111 six- to seven-year-old children was tested, and their task-focused versus task-avoidant behaviours were rated by their teachers four times during their first school year. Parents filled in questionnaires measuring their skill-specific and general beliefs about their children's school competencies at the beginning and at the end of the school year. The results showed that parents' beliefs in their children's general …