Search results for " rando"

Spatio-temporal behaviour of the deep chlorophyll maximum in Mediterranean Sea: Development of a stochastic model for picophytoplankton dynamics

2013

In this paper, by using a stochastic reaction-diffusion-taxis model, we analyze the picophytoplankton dynamics in the basin of the Mediterranean Sea, characterized by poorly mixed waters. The model includes intraspecific competition of picophytoplankton for light and nutrients. The multiplicative noise sources present in the model account for random fluctuations of environmental variables. Phytoplankton distributions obtained from the model show a good agreement with experimental data sampled in two different sites of the Sicily Channel. The results could be extended to analyze data collected in different sites of the Mediterranean Sea and to devise predictive models for phytoplankton dynam…

Evidence of stochastic resonance in the mating behavior of Nezara viridula (L.)

2008

We investigate the role of the noise in the mating behavior between individuals of Nezara viridula (L.), by analyzing the temporal and spectral features of the non-pulsed type female calling song emitted by single individuals. We have measured the threshold level for the signal detection, by performing experiments with the calling signal at different intensities and analyzing the insect response by directionality tests performed on a group of male individuals. By using a sub-threshold signal and an acoustic Gaussian noise source, we have investigated the insect response for different levels of noise, finding behavioral activation for suitable noise intensities. In particular, the percentage…

La “Stimolazione transcranica Random Noise” (tRNS) e la riabilitazione motoria dell’arto superiore nel paziente in fase subacuta di ictus ischemico.

"RANDOM NOISE TRANSCRANIAL STIMULATION" (TRNS) AND MOTOR REHABILITATION OF THE UPPER LIMB IN SUBACUTE ISCHEMIC STROKE PATIENTS. BACKGROUND Upper limb impairment is a common outcome after stroke. New rehabilitative interventions partially failed to show a superior effect compared to standard therapy. The present study focuses on the effect of tNRS in the sub-acute stage after stroke. The primary aim is to evaluate the combined use of TRNS with the GRASP in subacute ischemic stroke patients. METHODS A double-blind RCT, approved by local committee, was performed. Patients with upper-limb impairment were recruited 1 to 6 weeks after stroke. Participants were randomly allocated to two groups: GR…

Conjunction, Disjunction and Iterated Conditioning of Conditional Events

2013

Starting from a recent paper by S. Kaufmann, we introduce a notion of conjunction of two conditional events and then we analyze it in the setting of coherence. We give a representation of the conjoined conditional and we show that this new object is a conditional random quantity, whose set of possible values normally contains the probabilities assessed for the two conditional events. We examine some cases of logical dependencies, where the conjunction is a conditional event; moreover, we give the lower and upper bounds on the conjunction. We also examine an apparent paradox concerning stochastic independence which can actually be explained in terms of uncorrelation. We briefly introduce the…

[Choosing a quality-of-life questionnaire].

2006

International audience; Define the objective of the questionnaire: Discrimination: do you want a questionnaire to enable you to describe the quality of life of patients or to compare the quality of life between groups of patients, for example, to determine who has improved and who has gotten worse? Assessment: do you want a questionnaire to help you measure changes over time (improvement or aggravation) in your patients? Determine the properties of instruments necessary for this objective: If the objective is discrimination, analyze: construct validity, reliability. If the objective is assessment, analyze construct validity, sensitivity to changes. Choose the general category of questionnai…

Efficacy and cost-effectiveness of guided and unguided internet- and mobile-based indicated transdiagnostic prevention of depression and anxiety (ICa…

2019

Background Depression and anxiety are highly prevalent and often co-occur. Several studies indicate the potential of disorder-specific psychological interventions for the prevention of each of these disorders. To treat comorbidity, transdiagnostic treatment concepts seem to be a promising approach, however, evidence for transdiagnostic concepts of prevention remains inconclusive. Internet- and mobile-based interventions (IMIs) may be an effective means to deliver psychological interventions on a large scale for the prevention of common mental disorders (CMDs) such as depression and anxiety. IMIs have been shown to be effective in treating CMDs, e.g. in reducing symptoms of depression and an…

Critical Phenomena and Diffusion in Complex Systems

2008

Level-crossing rate and average duration of fades of the envelope of mobile-to-mobile fading channels in K-parallel dual-hop relay networks

2009

©2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE." Article also available from publisher: http://dx.doi.org/10.1109/WCSP.2009.5371574 This paper studies the fading behavior of narrowband mobile-to-mobile (M2M) fading channels in dual-hop distributed cooperative multi-relay systems under non-line-of-sight (NLOS) propagation conditions. M2M fading channels considered here are associated with amplify-and-forward …

Statistical Analysis of the (In)efficiency of Bitcoin : A comparison of the weak form efficient market hypothesis in the US and Venezuela

2019

Master's thesis Business Administration BE501 - University of Agder 2019 Bitcoin is a phenomenon that has received a lot of attentionduringthe last years. Although the literature on the subject has expanded, there is still need for more research. This paper replicates the work of Urquhart (2016) and examines whether there isevidence ofweak form efficiency in the Bitcoin market. He found that the Bitcoin market in the US showed signs of moving towards weak form efficiency. We contribute to the existing literature by adding recentdata and comparing two different markets;the USand Venezuela. To obtain robustness of the results, the analysis is conducted by performing six different statistical …

Spectral adaptation of hyperspectral flight lines using VHR contextual information

2014

Abstract: Due to technological constraints, hyperspectral earth observation imagery are often a mosaic of overlapping flight lines collected in different passes over the area of interest. This causes variations in aqcuisition conditions such that the reflected spectrum can vary significantly between these flight lines. Partly, this problem is solved by atmospherical correction, but residual spectral differences often remain. A probabilistic domain adaptation framework based on graph matching using Hidden Markov Random Fields was recently proposed for transforming hyperspectral data from one image to better correspond to the other. This paper investigates the use of scale and angle invariant…