Search results for "Decomposition"
showing 10 items of 766 documents
Has 1997 Asian crisis increased information flows between international markets
2003
Abstract The Asian crisis started on July 2, 1997 and caused turmoil in developed as well as emerging international stock markets. The objective of this paper is to analyse the effects of the crisis on the relationships of the Southeast Asian stock markets with the stock markets of three geographical areas (Europe, North America, and Latin America). We use the Morgan Stanley national and international indexes (MSCI) for two homogeneous and nonoverlapping time intervals. The econometric techniques used in this paper include the cointegration test, vector autoregression analysis, forecast error variance decomposition (FEVD), and impulse–response relationships. Our results show that: (i) there…
A Novel Semi-Supervised Methodology for Extracting Tumor Type-Specific MRS Sources in Human Brain Data
2013
Background: The clinical investigation of human brain tumors often starts with a non-invasive imaging study, providing \ud information about the tumor extent and location, but little insight into the biochemistry of the analyzed tissue. Magnetic \ud Resonance Spectroscopy can complement imaging by supplying a metabolic fingerprint of the tissue. This study analyses \ud single-voxel magnetic resonance spectra, which represent signal information in the frequency domain. Given that a single \ud voxel may contain a heterogeneous mix of tissues, signal source identification is a relevant challenge for the problem of\ud tumor type classification from the spectroscopic signal.\ud Methodology/Princ…
Multiscale Decomposition of Cardiovascular and Cardiorespiratory Information Transfer under General Anesthesia∗
2018
The analysis of short-term cardiovascular and cardiorespiratory regulation during altered conscious states, such as those induced by anesthesia, requires to employ time series analysis methods able to deal with the multivariate and multiscale nature of the observed dynamics. To meet this requirement, the present study exploits the extension to multiscale analysis of recently proposed information decomposition methods which allow to quantify, from short realizations, the amounts of joint, unique, redundant and synergistic information transferred within multivariate time series. These methods were applied to the spontaneous variability of heart period (HP), systolic arterial pressure (SAP) an…
Information decomposition of multichannel EMG to map functional interactions in the distributed motor system
2019
AbstractThe central nervous system needs to coordinate multiple muscles during postural control. Functional coordination is established through the neural circuitry that interconnects different muscles. Here we used multivariate information decomposition of multichannel EMG acquired from 14 healthy participants during postural tasks to investigate the neural interactions between muscles. A set of information measures were estimated from an instantaneous linear regression model and a time-lagged VAR model fitted to the EMG envelopes of 36 muscles. We used network analysis to quantify the structure of functional interactions between muscles and compared them across experimental conditions. Co…
Microscopic properties of liquid water from combined ab initio molecular dynamics and energy decomposition studies
2013
The application of newly developed first-principle modeling techniques to liquid water deepens our understanding of the microscopic origins of its unusual macroscopic properties and behaviour. Here, we review two novel ab initio computational methods: second-generation Car-Parrinello molecular dynamics and decomposition analysis based on absolutely localized molecular orbitals. We show that these two methods in combination not only enable ab initio molecular dynamics simulations on previously inaccessible time and length scales, but also provide unprecedented insights into the nature of hydrogen bonding between water molecules. We discuss recent applications of these methods to water cluste…
Thermal kinetics for the energy valorisation of polylactide/sisal biocomposites
2018
[EN] The thermal stability and decomposition kinetics of PLA/sisal biocomposites was discussed to evaluate the suitability of their use in energy recovery processes such as pyrolysis and combustion. The influence of the addition of sisal up to 30%wt, the presence of coupling agent, and the atmosphere of operation, i.e. inert or oxidative was discussed by means of multi-rate linear non-isothermal thermogravimetric experiments. All biocomposites showed a mean high heating value of 15 MJ/kg indicating their suitability for energy recovery processes. The thermal requirements of PLA/sisal decomposition were assessed in terms of onset decomposition temperature and apparent activation energy. A mi…
Thermal Decomposition and Combustion of Microwave Pre-Treated Biomass Pellets
2021
The objective of the study was to investigate a more effective use of commercially available biomass pellets (wheat straw, wood, peat) using microwave pretreatment to improve heat production. Pellets were pretreated using the originally designed microwave torrefaction device. The effects of microwave (mw) pretreatment were quantified, providing measurements of the weight loss and elemental composition of pellets and estimating the effect of mw pretreatment on their porosity, surface area and calorific values at pretreatment temperatures of T = 448–553 K. Obtained results show that the highest structural variations and elemental composition during mw pretreatment were obtained for wheat stra…
Photoemission study of the reactivity of barium towards SiOx thermal films
2011
Abstract Barium was deposited at room temperature on a thermal silicon oxide layer and the interfacial reaction was monitored by synchrotron induced photoemission (both core level and valence band). The first step of the growth consists of an interfacial reaction which leads to the formation of an interfacial silicate layer. The next step consists in formation of barium oxide while metallic barium occurs subsequently. The deposit can be also homogenized by annealing above 575 K. This results in the formation of several layers of silicate by consumption of silicon oxide. In the case of fractional coverage, subsequent annealing at 975 K induces the decomposition of barium silicate. However, s…
Preparation of mixed oxides MNdO3, with M=Cr, Fe. Comparison of several methods
1993
Abstract Different methods for the formation of NdCrO3 and NdFeO3, having the perovskite-like structure, were studied including the ceramic method, simultaneous precipitation of hydroxides and simultaneous crystallization from aqueous solutions of nitrates. Preparation of mixed oxides from hydroxides simultaneously precipitated lowered the temperature and time required for their formation. In the case of NdCrO3 the formation process from hydroxides and nitrates occurred through the chromate, NdCrO4, without intermediate decomposition of the precursor to metal oxides, which lead to the mixed oxide by 600°C.
Ab initio thermodynamics for the growth of ultra-thin Cu film on a perfect MgO(001) surface
2005
Controlled growth of thin metallic films on oxide substrates is important for numerous micro-and nanoelectronic applications. Our ab initio study is devoted to the periodic slab simulations for a series of ordered 2D Cu superlattices on the regular MgO(001) substrate. Submonolayer and monolayer substrate Cu coverages were calculated using the DFT-GGA method, as implemented into the CRYSTAL-98 code. The results of ab initio calculations have been combined with thermodynamic theory which allows us to predict the growth mode of ultra-thin metal films (spinodal decomposition vs. nucleation-and-growth regime) as a function of the metal coverage and the temperature, and to estimate the metal dens…