Search results for "Mod"
showing 10 items of 39605 documents
MODELING OF VOLATILITY IN THE ROMANIAN CAPITAL MARKET
2012
This paper aims to analyze the volatility of capital market in Romania by selecting a portfolio of representative indices (BET BET_FI and RASDAQ_C). In this respect, we want to identify the most appropriate model to estimate volatility by using modern econometric tools and useful GARCH models respectively. The study results highlight that EGARCH(1,1) model has managed to eliminate all traces of statistically significant autocorrelation and ARCH effects from the residuals from daily series, giving an accurate image of the Romanian capital market volatility.
Ultraviolet imaging of volcanic plumes: A new paradigm in volcanology
2017
Ultraviolet imaging has been applied in volcanology over the last ten years or so. This provides considerably higher temporal and spatial resolution volcanic gas emission rate data than available previously, enabling the volcanology community to investigate a range of far faster plume degassing processes than achievable hitherto. To date, this has covered rapid oscillations in passive degassing through conduits and lava lakes, as well as puffing and explosions, facilitating exciting connections to be made for the first time between previously rather separate sub-disciplines of volcanology. Firstly, there has been corroboration between geophysical and degassing datasets at â1 Hz, expeditin…
Experimental Validation of Maximum Constant Boost Control and Switching Frequency Optimal for three-phase Quasi-Z-Source Converters
2020
This paper presents a modified modulation scheme for quasi-Z-Source converters, based on the Maximum Constant Boost Control (MCBC) concept and Switching Frequency Optimal (SFO) as reference signal. The effectiveness of the proposed technique is validated by comparing the obtained results (in terms of AC harmonic content and voltage stress) with those carried out from traditional modulation schemes. For this reason, a test bench has been assembled and the benefits of the SFO MCBC modulation scheme have been valuated.
Decoupled control scheme of grid-connected split-source inverters
2017
Grid-connected power conversion systems for renewable energy sources must fulfill several requirements, e.g., the high efficiency, the reduced cost and complexity, and, quite often, the boost capabilities that is usually achieved using a front-end dc–dc boost converter before the inversion stage, leading to a two-stage architecture. Meanwhile, single-stage power conversion systems, which perform the boosting operation within the inversion one, offer some potential advantages, in terms of reducing the complexity and the volume of the whole system. Among several proposed options, the split-source inverter (SSI) has been recently proposed by Abdelhakim et al. as an alternative option with some…
Modellazione numerica del comportamento meccanico delle volte catalane
2010
Il presente lavoro riguarda la modellazione numerica del comportamento costitutivo delle cosiddette volte in foglio (le bóvedas tabicadas) che rappresentano una delle tecniche edilizie tradizionali catalane più diffusamente impiegate da alcuni tra i più grandi architetti spagnoli (primo fra tutti Gaudí) alla fine del XIX secolo [1-3]. Tali volte risultano fondamentalmente costituite da strati alternati di spessore in generale pressoché uguale di mattoni e di malta. Questa particolare caratteristica viene studiata in questo lavoro nel quale si vuole confrontare la modellazione del comportamento costitutivo considerando il materiale come ideale omogeneo con quella ottenuta modellando il mater…
L'utilisation de la pierre ponce volcanique dans la construction de voûtes en Sicile au début de l’âge moderne
2016
La stereotomia della pietra applicata alla costruzione di volte ha in Sicilia una lunga tradizione, documentata a partire dal tempo della dominazione normanna nell’isola (XI-XII secolo). Tale pratica costruttiva prosegue nei secoli successivi, con momenti di apice nella qualità del taglio stereotomico nelle architetture federiciane (prima metà del XIII secolo), un successivo scadimento nel corso del XIV secolo, e il ritorno a una fertile stagione di sperimentazione a partire dal Quattrocento, sotto l’impulso impresso al cantiere locale dall’arrivo di modelli e maestri dalla penisola iberica (soprattutto da Barcellona, Valencia e Palma di Maiorca). Questa lunga tradizione prosegue ancora nel…
Volumes of aqueous block copolymers based on poly(propylene oxides) and poly(ethylene oxides) in a large temperature range: A quantitative description
2006
The focus of this paper was on a quantitative comprehension of temperature effect on the volumes of aqueous di-block and triblock copolymers, based on propylene oxide (PO) and ethylene oxide (EO) units. To this purpose, literature data dealing with (EO316PO94 + water) and (EO13PO30EO13 + water) mixtures were analyzed. The volume vs. temperature trends were rationalized on the basis of the (unimers + aggregate) equilibrium by taking into account the temperature effect on both the partial molar volumes of the unimeric and the aggregated copolymer as well as the equilibrium constant of micellization. The analysis extended to the expansibility allowed to quantify the contribution for the shift …
Relationship between volume and energy of vector fields
2001
Abstract A unified study of energy and volume functionals is presented here by determining the critical points of a functional that extends simultaneously energy and volume and that is defined on the product of the manifold of smooth maps C∞(M,N) times the manifold M of riemannian metrics on M. The restriction of this functional to different submanifolds of the space of vector fields X (M)× M is also considered, and used to study several functionals generalizing volume and energy or total bending of vector fields
Ontology and protocol secure for SCADA
2014
In this work, we present a semantic cyber security system and we study its semantic intelligent systems vulnerabilities, focusing on the semantic attacks. For resolving semantic problems we propose a security global solution for the new generation of SCADA systems. The proposed solution aims at protecting critical semantic SCADA processes from the effects of major failures and semantic vulnerabilities in the modern IT-SCADA network. We used a security block in the global network access point, security protocols deployed in different network (OSI) levels and security ontologies deployed in security devices. We used our mixed coordinates (ECC) cryptography solution, this is an encryption tech…
Measuring Vulnerability of Asylum Seekers and Refugees in Italy
2019
In recent years, a growing number of forced migrants have travelled to Italy across the Mediterranean Sea. While the number of new arrivals has diminished since 2017, the Italian reception system still struggles to process the high number of applications for international protection. A significant proportion of forced migrants who arrive in Italy end up living in informal settlements, such as occupied buildings, shacks, containers and tented camps. In this study, we assess the vulnerability of asylum seekers and refugees living in informal settlements in Italy, using data from the first nationally representative survey of this population. We compare a count measure of vulnerability with a n…