Search results for "IAT"

Representation of Stationary Multivariate Gaussian Processes Fractional Differential Approach

2011

In this paper, the fractional spectral moments method (H-FSM) is used to generate stationary Gaussian multivariate processes with assigned power spectral density matrix. To this aim, firstly the N-variate process is expressed as sum of N fully coherent normal random vectors, and then, the representation in terms of HFSM is used.

Modelling Systemic Cojumps with Hawkes Factor Models

2013

Instabilities in the price dynamics of a large number of financial assets are a clear sign of systemic events. By investigating a set of 20 high cap stocks traded at the Italian Stock Exchange, we find that there is a large number of high frequency cojumps. We show that the dynamics of these jumps is described neither by a multivariate Poisson nor by a multivariate Hawkes model. We introduce a Hawkes one factor model which is able to capture simultaneously the time clustering of jumps and the high synchronization of jumps across assets.

Effect of Fe-incorporation on Structural and Optoelectronic Properties of Spin Coated p/n Type ZnO Thin Films

2020

Paschen β line shape studies in low-temperature plasmas

2003

Line shape calculations and measurements of the Paschen β line of hydrogen (λ=12818 Å) are reported. Measurements were performed at electron densities of the plasma between 1015 cm-3 and 1016 cm-3. A wall-stabilized arc operated at atmospheric pressure in a helium-hydrogen gas mixture was applied as the excitation source. The radiation of the plasma, originating from nearly homogeneous plasma layers, in the end-on direction, was analyzed. A grating spectrometer equipped with a CCD detector was used for the radiation detection. The measured line profiles are compared with results of available experimental and theoretical Stark broadening data e.g. based on simulation techniques, applied also…

Minimal walking with Z6 symmetry

2009

Uncertainty analysis and symmetry restoration in nuclear self-consistent methods

2015

This thesis contains two articles, in the following denoted by I and II, and an introduction to them. In Chapter 1, I present the theoretical models of nuclear structure. In Chapter 2, I introduce the basic ideas about the density functional theory (DFT) and self-consistent mean-field (SCMF) calculations. In Chapter 3, I give the formulae for the uncertainty propagation, which is the error analysis method used in article I. As a proper tool to survey the predictive power of theoretical models, the error analysis now has become more and more widely used. By analyzing the propagation of uncertainties, one tries to find out the e ectiveness of the calculation with a given parameter set obtaine…

BIOLOGICAL AND EPIDEMIOLOGICAL EXAMINATION OF TRANSDIAGNOSTIC AND SPECIFIC SYMPTOM DIMENSIONS AT PSYCHOSIS ONSET: FINDINGS FROM THE EUGEI STUDY

2018

Background Current diagnostic models of psychosis have been questioned since Kraepelin’s original dichotomy of dementia praecox and manic depression. Indeed, increasing evidence has suggested that a dimensional approach might be a valid alternative platform for research. However, while an increasing number of studies have investigated how environmental risk factors for affective and non-affective psychosis map onto symptom dimensions, only a few have examined these dimensions in relation to genetic variants as summarised by Polygenic Risk Score (PRS). Furthermore, no studies have examined the putative effect of PRS for Schizophrenia (SZ), Bipolar Disorder (BP), and Major Depressive Disorder…

Synchrotron x-ray transmission measurements and modeling of filters investigated for Athena

2020

International audience; Advanced Telescope for High-Energy Astrophysics is a large-class astrophysics space mission selected by the European Space Agency to study the theme "Hot and Energetic Universe." The mission essentially consists of a large effective area x-ray telescope and two detectors: the X-ray Integral Field Unit (X-IFU) and the Wide Field Imager (WFI). Both instruments require filters to shield from out-of-band radiation while providing high transparency to x-rays. The mission is presently in phase B; thus, to consolidate the preliminary design, investigated filter materials need to be properly characterized by experimental test campaigns. We report results from high-resolution…

Host Searching by Egg Parasitoids: Exploitation of Host Chemical Cues

2010

Insect parasitoids are considered “keystone species” in many ecosystems in terms of biodiversity, ecological impact and economic importance (Vinson 1985, LaSalle and Gauld 1993, Hawkins et al. 1999). In the last decades, several reviews have been published on the relationships among plants, hosts and parasitoids, which reflect a strong interest in these insects both as models for behavioral ecologists and as important organisms for classical and applied biological control programs (Hawkins et al. 1999, Vet 1999, Bale et al. 2008). The majority of these studies have considered the larval parasitoid s, besides the extensive use of egg parasitoids in biological control (Hawkins et al. 1999). I…

Populismin väkevöityminen : populistisesta retoriikasta ideologiseen fantasiaan

2020

Artikkelissa tarkastellaan populismin ideologista väkevöitymistä populistisen radikaalioikeiston herättämänä kysymyksenä. Ernesto Laclaun käsittein kuvataan aluksi argumentaatioltaan heikoksi mainitun populistisen retoriikan liikettä muodostavaa voimaa. Laclaun kuvaamat ”tyhjät” ja ”kelluvat” merkitsijät voivat panostua myös ideologisesti liikkeen luonnetta muuttavalla tavalla. Populismin ytimeltään heikko ideologisuus altistaa uusiin ideologisiin linkityksiin ja panosten väkevöitymiseen sen omassa retoriikassa. Siten ideologiaa ei ymmärretä vain populismia jälkikäteen vahvistavaksi aatteeksi, vaan sen merkitsijöitä muuttavaksi dynaamiseksi mahdollisuudeksi. ”Tyhjän merkitsijän” käsitteen k…