Search results for " Dynamics"
showing 10 items of 4108 documents
Autonomous vehicle with communicative driving for pedestrian crossing: Trajectory optimization
2020
Connected and autonomous vehicles (CAV) is a key technology for this century. One of the main challenges is to define a smart interaction behavior of CAV with the other road users. The challenge is mainly raised at conflicting points where path of CAV intersects with the other users. Recent studies show interaction with humans is a big challenge. It not only requires a collision avoidance system but also more communicative behaviors of the CAV. More precisely, pedestrian needs to understand the intention of the incoming CAV whether it will cross first or not according to its speed profile. One way to overcome this issue is to design optimal trajectory control of the CAV that matches with th…
System Dynamics in the Predictive Analytics of Container Freight Rates
2021
This study proposes a two-tier cross-validation and backtesting procedure, including expanding and rolling-window test metrics in predictive analytics of container freight rates by utilizing the system dynamics approach. The study utilized system dynamics to represent the nonlinear complex structure of container freight rates for predictive analytics and performed univariate and multivariate time-series analysis as benchmarks of the conventional approach. In particular, the China containerized freight index (CCFI) has been investigated through various parametric methodologies (both conventional time-series and system dynamics approaches). This study follows a strict validation process cons…
A stochastic dynamical social model involving a human happiness index
2018
[EN] This paper presents a new human happiness index built through five dimensions: development, freedom, solidarity, justice and peace. These five dimensions are evaluated through quantitative variables obtained from the Human Development Reports, World Data Bank and Eurostat. The new happiness index has been built following the guidelines set by the Human Development Reports of the UN for the construction of quality indices, and it has been compared on a set of 13 EU countries with the Overall Life Satisfaction Index, which is used by the UN. Moreover, the new index has been included in a dynamic mathematical model through the demographic rates to study the evolution of the population. Th…
Nonlinear femtosecond pulse propagation in an all-solid photonic bandgap fiber
2009
Nonlinear femtosecond pulse propagation in an all-solid photonic bandgap fiber is experimentally and numerically investigated. Guiding light in such fiber occurs via two mechanisms: photonic bandgap in the central silica core or total internal reflection in the germanium doped inclusions. By properly combining spectral filtering, dispersion tailoring and pump coupling into the fiber modes, we experimentally demonstrate efficient supercontinuum generation with controllable spectral bandwidth.
Performance Study of Twisted Darrieus Hydrokinetic Turbine With Novel Blade Design
2021
Abstract Twisted Darrieus water turbine is receiving growing attention for small-scale hydropower generation. Accordingly, the need for raised water energy conversion incentivizes researchers to focus on the blade shape optimization of twisted Darrieus turbine. In view of this, experimental analysis has been performed to appraise the efficiency of a spiral Darrieus water rotor in the present work. To better the performance parameters of the studied water rotor with twisted blades, three novel blade shapes, namely U-shaped blade, V-shaped blade, and W-shaped blade, have been numerically tested using a computational fluid dynamics three-dimensional numerical model. The maximum power coefficie…
Talis pater, talis filius: the role of discursive strategies, thematic narratives and ideology in Cosa Nostra
2018
The discursive analysis of criminal organizations’ family dynamics and ideological devices may provide important insights into the inner functioning of these groups. In this article, we describe and analyze a specific set of discursive strategies and the thematic narratives emerging from a TV interview with Giuseppe Riina, a member of Cosa Nostra and the son of one of the most important mafia bosses. Our analyses demonstrate the existence of recurring ideological devices such as reductionism, amoralism, familism, verticalism, normalism, victimism and religious relativism. The results are discussed in light of previous research that examines how discursive strategies and narratives may repre…
Theoretical conditions for the coexistence of viral strains with differences in phenotypic traits : A bifurcation analysis
2019
We investigate the dynamics of a wild-type viral strain which generates mutant strains differing in phenotypic properties for infectivity, virulence and mutation rates. We study, by means of a mathematical model and bifurcation analysis, conditions under which the wild-type and mutant viruses, which compete for the same host cells, can coexist. The coexistence conditions are formulated in terms of the basic reproductive numbers of the strains, a maximum value of the mutation rate and the virulence of the pathogens. The analysis reveals that parameter space can be divided into five regions, each with distinct dynamics, that are organized around degenerate Bogdanov–Takens and zero-Hopf bifurc…
Proactive avoidance behaviour and pace-of-life syndrome in Atlantic salmon
2019
Individuals in a fish population differ in key life-history traits such as growth rate and body size. This raises the question of whether such traits cluster along a fast-slow growth continuum according to a pace-of-life syndrome (POLS). Fish species like salmonids may develop a bimodal size distribution, providing an opportunity to study the relationships between individual growth and behavioural responsiveness. Here we test whether proactive characteristics (bold behaviour coupled with low post-stress cortisol production) are related to fast growth and developmental rate in Atlantic salmon, Salmo salar . Boldness was tested in a highly controlled two-tank hypoxia test were oxygen levels …
Influence of the exchange and correlation functional on the structure of amorphous InSb and In3SbTe2 compounds
2016
We have investigated the structural, vibrational, and electronic properties of the amorphous phase of InSb and In3SbTe2 compounds of interest for applications in phase change non-volatile memories. Models of the amorphous phase have been generated by quenching from the melt by molecular dynamics simulations based on density functional theory. In particular, we have studied the dependence of the structural properties on the choice of the exchange-correlation functional. It turns out that the use of the Becke-Lee-Yang-Parr functional provides models with a much larger fraction of In atoms in a tetrahedral bonding geometry with respect to previous results obtained with the most commonly used P…
Physico-chemical investigation of the state of cyanamide confined in AOT and lecithin reversed micelles
2004
Sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and lecithin reversed micelles containing cyanamide have been investigated by small-angle X-ray scattering, FT-IR, and 1H NMR spectroscopy at various cyanamide-to-surfactant molar ratio (X) and at fixed surfactant concentration (0.1 mol kg-1). Experimental data are consistent with a model of cyanamide molecules confined in reversed micelles, quite uniformly distributed among them and mainly located among surfactant headgroups. SAXS data analysis leads also to hypothesize a unidimensional growth of the reversed micelles with increasing the X value. Moreover, the cyanamide state and the cyanamide/cyanamide interactions in reversed micelles have bee…