Search results for "DISTRIBUTIONS"
showing 10 items of 214 documents
An empirically grounded agent based model for modeling directs, conflict detection and resolution operations in air traffic management
2017
We present an agent based model of the Air Traffic Management socio-technical complex system that aims at modeling the interactions between aircrafts and air traffic controllers at a tactical level. The core of the model is given by the conflict detection and resolution module and by the directs module. Directs are flight shortcuts that are given by air controllers to speed up the passage of an aircraft within a certain airspace and therefore to facilitate airline operations. Conflicts resolution between flight trajectories can arise during the en-route phase of each flight due to both not detailed flight trajectory planning or unforeseen events that perturb the planned flight plan. Our mod…
Land unit definition for potential distribution of endangered species
2010
In Europe several mapping techniques exist to lay out plant distribution. Most of them, however, are focused on actual and not on potential species distribution range. Spatial predictions become more important for rare and endangered taxa because their conservation is related to existing as well as potential biotopes. The large part of detailed distribution models applies advanced statistics on a large data-set of environmental variables. Data-input availability limits the choice of the prediction model for species distribution and application of results in a detailed scale. Distribution pattern accuracy determinates its applicability in environmental management (for tracing edges, defining…
Assessing fat-tailed sequential forecast distributions for the Dow-Jones index with logarithmic scoring rules
2007
We use the logarithmic scoring rule for distributions to assess a variety of fat-tailed sequential forecasting distributions for the Dow-Jones industrial stock index from 1980 to the present. The methodology applies Bruno de Finetti''s contributions to understanding how to compare the quality of different coherent forecasting distributions for the same sequence of observations, using proper scoring rules. Four different forms of forecasting distributions are compared: a mixture Normal, a mixture of convex combinations of three Normal distributions, a mixture exponential power distribution, and a mixture of a convex combination of three exponential power distributions. The mixture linear com…
Tevatron Run II combination of the effective leptonic electroweak mixing angle
2018
The Ministry of Science and Innovation and the Consolider-Ingenio 2010 Program and the European Union community Marie Curie Fellowship Contract No. 302103.
Structure of distributions generated by the scenery flow
2015
We expand the ergodic theory developed by Furstenberg and Hochman on dynamical systems that are obtained from magnifications of measures. We prove that any fractal distribution in the sense of Hochman is generated by a uniformly scaling measure, which provides a converse to a regularity theorem on the structure of distributions generated by the scenery flow. We further show that the collection of fractal distributions is closed under the weak topology and, moreover, is a Poulsen simplex, that is, extremal points are dense. We apply these to show that a Baire generic measure is as far as possible from being uniformly scaling: at almost all points, it has all fractal distributions as tangent …
A CLASS OF MULTIVARIATE TRANSFORMED-EXPONENTIAL DISTRIBUTIONS
2013
In finance it is commonly accepted that heavy-tailed distributions are appropriate for modelling financial asset return variables and part of the financial literature has recently focused on them. Much less attention has been dedicated to the construction of joint models of asset returns unable to describe an adequate dependence structure between all these variables. In this paper we propose a procedure for constructing multivariate distributions with given heterogeneous heavy-tailed marginal distributions as a possible (under certain conditions) alternative to the copula approach. The procedure bases on the marginal transformation method and, for given plausible specifications of the margi…
Culture and team production
2018
Abstract This paper addresses theoretically the question whether culture has an effect on economic performance in team production, and what would be an optimal team culture. The members of a team are guided both by economic incentives and by personal norms, weighed according to their prevailing level of materialism. We assume that personal norms evolve following a dynamic driven by a combination of psychological mechanisms such as consistency and conformism. The different vectors of materialism, consistency and conformism shared by the group result in a continuum of cultures characterized by different combinations of individualism and collectivism. Team culture turns out to be a fundamental…
Determinants of COVID-19 Vaccine Rollouts and Their Effects on Health Outcomes
2022
Background Vaccination against the coronavirus disease (SARS-CoV-2) is understood to be the key way out of the COVID-19 pandemic. Limited evidence exists on the determinants of vaccine rollouts and their health effects at the country level. Objective Examine the determinants of COVID-19 vaccine rollouts and their effects on health outcomes. Methods Ordinary least squares regressions with standard errors clustered at the country level for Cross-section and Panel daily data of vaccinations and various health outcomes (new COVID-19 cases, fatalities, intensive care unit (ICU) admissions) for an unbalanced sample of about 200 countries during the period 16 December 2020 to 20 June 2021. Results…
A new mathematical function for describing electrophoretic peaks.
2005
A new model is proposed for characterizing skewed electrophoretic peaks, which is a combination of leading and trailing edge functions, empirically modified to get a rapid recovery of the baseline. The peak model is a sum of square roots and is called thereby "combined square roots (CSR) model". The flexibility of the model was checked on theoretical and experimental peaks with asymmetries in the range of 0-10 (expressed as the ratio of the distance between the center and the trailing edge, and the center and the leading edge of the chromatographic peak, measured at 10% of peak height). Excellent fits were found in all cases. The new model was compared with other three models that have show…
Dorsal root ganglia neurite outgrowth measured as a function of changes in microelectrode array resistance
2017
Current research in prosthetic device design aims to mimic natural movements using a feedback system that connects to the patient's own nerves to control the device. The first step in using neurons to control motion is to make and maintain contact between neurons and the feedback sensors. Therefore, the goal of this project was to determine if changes in electrode resistance could be detected when a neuron extended a neurite to contact a sensor. Dorsal root ganglia (DRG) were harvested from chick embryos and cultured on a collagen-coated carbon nanotube microelectrode array for two days. The DRG were seeded along one side of the array so the processes extended across the array, contacting a…