102 resultados para decomposition techniques


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This paper analyses the international inequalities in CO2 emissions intensity for the period 1971–2009 and assesses explanatory factors. Multiplicative, group and additive methodologies of inequality decomposition are employed. The first allows us to clarify the separated role of the carbonisation index and the energy intensity in the pattern observed for inequalities in CO2 intensities; the second allows us to understand the role of regional groups; and the third allows us to investigate the role of different fossil energy sources (coal, oil and gas). The results show that, first, the reduction in global emissions intensity has coincided with a significant reduction in international inequality. Second, the bulk of this inequality and its reduction are attributed to differences between the groups of countries considered. Third, coal is the main energy source explaining these inequalities, although the growth in the relative contribution of gas is also remarkable. Fourth, the bulk of inequalities between countries and its decline are explained by differences in energy intensities, although there are significant differences in the patterns demonstrated by different groups of countries. JEL codes: D39; Q43; Q56. Key words: CO2 international distribution, inequality decomposition, CO2 emissions intensity

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The scope of this work is the systematic study of the silicidation process affecting tungsten filaments at high temperature (1900ºC) used for silane decomposition in the hot-wire chemical vapour deposition technique (HWCVD). The correlation between the electrical resistance evolution of the filaments, Rfil(t), and the different stages of the their silicidation process is exposed. Said stages correspond to: the rapid formation of two WSi2 fronts at the cold ends of the filaments and their further propagation towards the middle of the filaments; and, regarding the hot central portion of the filaments: a initial stage of silicon dissolution into the tungsten bulk, with a random duration for as-manufactured filaments, followed by the inhomogeneous nucleation of W5Si3 (which is later replaced by WSi2) and its further growth towards the filaments core. An electrical model is used to obtain real-time information about the current status of the filaments silicidation process by simply monitoring their Rfil(t) evolution during the HWCVD process. It is shown that implementing an annealing pre-treatment to the filaments leads to a clearly repetitive trend in the monitored Rfil(t) signatures. The influence of hydrogen dilution of silane on the filaments silicidation process is also discussed.

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We analyse the use of the ordered weighted average (OWA) in decision-making giving special attention to business and economic decision-making problems. We present several aggregation techniques that are very useful for decision-making such as the Hamming distance, the adequacy coefficient and the index of maximum and minimum level. We suggest a new approach by using immediate weights, that is, by using the weighted average and the OWA operator in the same formulation. We further generalize them by using generalized and quasi-arithmetic means. We also analyse the applicability of the OWA operator in business and economics and we see that we can use it instead of the weighted average. We end the paper with an application in a business multi-person decision-making problem regarding production management

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Methods for the extraction of features from physiological datasets are growing needs as clinical investigations of Alzheimer’s disease (AD) in large and heterogeneous population increase. General tools allowing diagnostic regardless of recording sites, such as different hospitals, are essential and if combined to inexpensive non-invasive methods could critically improve mass screening of subjects with AD. In this study, we applied three state of the art multiway array decomposition (MAD) methods to extract features from electroencephalograms (EEGs) of AD patients obtained from multiple sites. In comparison to MAD, spectral-spatial average filter (SSFs) of control and AD subjects were used as well as a common blind source separation method, algorithm for multiple unknown signal extraction (AMUSE). We trained a feed-forward multilayer perceptron (MLP) to validate and optimize AD classification from two independent databases. Using a third EEG dataset, we demonstrated that features extracted from MAD outperformed features obtained from SSFs AMUSE in terms of root mean squared error (RMSE) and reaching up to 100% of accuracy in test condition. We propose that MAD maybe a useful tool to extract features for AD diagnosis offering great generalization across multi-site databases and opening doors to the discovery of new characterization of the disease.

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This special issue aims to cover some problems related to non-linear and nonconventional speech processing. The origin of this volume is in the ISCA Tutorial and Research Workshop on Non-Linear Speech Processing, NOLISP’09, held at the Universitat de Vic (Catalonia, Spain) on June 25–27, 2009. The series of NOLISP workshops started in 2003 has become a biannual event whose aim is to discuss alternative techniques for speech processing that, in a sense, do not fit into mainstream approaches. A selected choice of papers based on the presentations delivered at NOLISP’09 has given rise to this issue of Cognitive Computation.

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In this paper we present a method for blind deconvolution of linear channels based on source separation techniques, for real word signals. This technique applied to blind deconvolution problems is based in exploiting not the spatial independence between signals but the temporal independence between samples of the signal. Our objective is to minimize the mutual information between samples of the output in order to retrieve the original signal. In order to make use of use this idea the input signal must be a non-Gaussian i.i.d. signal. Because most real world signals do not have this i.i.d. nature, we will need to preprocess the original signal before the transmission into the channel. Likewise we should assure that the transmitted signal has non-Gaussian statistics in order to achieve the correct function of the algorithm. The strategy used for this preprocessing will be presented in this paper. If the receiver has the inverse of the preprocess, the original signal can be reconstructed without the convolutive distortion.

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In this work we explore the multivariate empirical mode decomposition combined with a Neural Network classifier as technique for face recognition tasks. Images are simultaneously decomposed by means of EMD and then the distance between the modes of the image and the modes of the representative image of each class is calculated using three different distance measures. Then, a neural network is trained using 10- fold cross validation in order to derive a classifier. Preliminary results (over 98 % of classification rate) are satisfactory and will justify a deep investigation on how to apply mEMD for face recognition.

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Artifacts are present in most of the electroencephalography (EEG) recordings, making it difficult to interpret or analyze the data. In this paper a cleaning procedure based on a multivariate extension of empirical mode decomposition is used to improve the quality of the data. This is achieved by applying the cleaning method to raw EEG data. Then, a synchrony measure is applied on the raw and the clean data in order to compare the improvement of the classification rate. Two classifiers are used, linear discriminant analysis and neural networks. For both cases, the classification rate is improved about 20%.

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Objectives: Benign Oral Vascular Lesions (BOVLs) are a group of vascular diseases characterized by congenital, inflammatory or neoplastic vascular dilations clinically evidenced as more or less wide masses of commonly dark bluish color. If traumatized BOVLs are characterized by a great risk of hemorrhage and their treatment usually requires great caution to prevent massive bleeding. In the last decades lasers have dramatically changed the way of treatment of BOVLs permitting the application of even peculiar techniques that gave interesting advantages in their management reducing hemorrhage risks. The aim of this study was to evaluate the capabilities and disadvantages of three laser assisted techniques in the management of BOVLs. Study design: In this study 13 BOVLs were treated by three different laser techniques: the traditional excisional biopsy (EB), and two less invasive techniques, the transmucosal thermocoagulation (TMT) and the intralesional photocoagulation (ILP). Two different laser devices were adopted in the study: a KTP laser (DEKA, Florence, Italy, 532nm) and a GaAlAs laser (Laser Innovation, Castelgandolfo, Italy, 808nm) selected since their great effectiveness on hemoglobin. Results: In each case, lasers permitted safe treatments of BOVLs without hemorrhages, both during the intervention and in the post-operative period. The minimally invasive techniques (TMT and ILP) permitted even the safe resolution of big lesions without tissue loss. Conclusions: Laser devices confirm to be the gold standard in BOVLs treatment, permitting even the introduction of minimal invasive surgery principles and reducing the risks of hemorrhage typical of these neoplasms. As usual in laser surgery, it is necessary a clear knowledge of the devices and of the laser-tissue interaction to optimize the results reducing risks and disadvantages

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Ecosystems are complex systems and changing one of their components can alter their whole functioning. Decomposition and biodiversity are two factors that play a role in this stability, and it is vital to study how these two factors are interrelated and how other factors, whether of human origin or not, can affect them. This study has tested different hypotheses regarding the effects of pesticides and invasive species on the biodiversity of the soil fauna and litter decomposition rate. Decomposition was measured using the litterbags technique. Our results indicate that pesticides had a negative effect on decomposition whereas invasive species increased decomposition rate. At the same time, the diversity of the soil biota was unaffected by either factor. These results allow us to better understand the response of important ecosystem functions to human‐induced alterations, in order to mitigate harmful effects or restore them wherever necessary.

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The Water Framework Directive (WFD) defines common objectives for water resources throughout the European Union (EU). Given this general approach to water preservation and water policy, the objective of this paper is to analyse whether common patterns of water consumption exist within Europe. In particular, our study uses two methods to reveal the reasons behind sectoral water use in all EU countries. The first method is based on an accounting indicator that calculates the water intensity of an economy as the sum of sectoral water intensities. The second method is a subsystem input‐output model that divides total water use into different income channels within the production system. The application uses data for the years 2005 and 2009 on water consumption in the production system of the 27 countries of the EU. From our analysis it emerges that EU countries are characterized by very different patterns of water consumption. In particular water consumption by the agriculture sector is extremely high in Central/Eastern Europe, relative to the rest of Europe. In most countries, the water used by the fuel, power and water sector is consumed to satisfy domestic final demand. However, our analysis shows that for some countries exports from this sector are an important driver of water consumption. Focusing on the agricultural sector, the decomposition analysis suggests that water usage in Mediterranean countries is mainly driven by final demand for, and exports of, agricultural products. In Central/Eastern Europe domestic final demand is the main driver of water consumption, but in this region the proportion of water use driven by demand for exports is increasing over time. Given these heterogeneous water consumption patterns, our analysis suggests that Mediterranean and Central/Eastern European countries should adopt specific water policies in order to achieve efficient levels of water consumption in the European Union. JEL codes: N5; C67 Keywords: Water use, Subsystem input–output model; Water intensity, European Union.

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We analyse the use of the ordered weighted average (OWA) in decision-making giving special attention to business and economic decision-making problems. We present several aggregation techniques that are very useful for decision-making such as the Hamming distance, the adequacy coefficient and the index of maximum and minimum level. We suggest a new approach by using immediate weights, that is, by using the weighted average and the OWA operator in the same formulation. We further generalize them by using generalized and quasi-arithmetic means. We also analyse the applicability of the OWA operator in business and economics and we see that we can use it instead of the weighted average. We end the paper with an application in a business multi-person decision-making problem regarding production management

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Background:There is no actual evidence that the ART are directly related to the occurrence of weight discordance. In some studies, ART-­‐conceived twin pregnancies are at greater risk than non-­‐ART-­‐conceived ones for pregnancy complications and adverse perinatal outcome: the incidences of pregnancy-­‐induced hypertension, uterine bleeding, premature contractions, IUGR, fetal death, discordance, and cesarean section were significantly higher. Discordance rate was elevated (25.3% vs.17.0%) among ART twins, which can increase perinatal risk (increased incidence of SGA and NICU admission). Other studies say that perinatal and neonatal morbidity, gestational age at delivery, and birth weight are not affected by ART. Regarding the first trimester ultrasound, some studies didn’t notice significant differences in CRL disparity or birth weight discordance between spontaneous and ART-­‐ conceived dichorionic twin pregnancies. In ART-­‐conceived dichorionic twin pregnancies, CRL disparity may be associated with birth weight discordance. In some studies, CRL discordance in twin pregnancies in the first trimester was a frequent finding. Objectives: To analyze the association of the ART in the occurrence of weight discordance in the pregnancies between 2010 and 2013 in the Hospital Universitari de Girona Doctor Josep Trueta, and to describe the proportion of diagnosis of growth discordance in the first trimester by the ultrasonography technology. Methods: A retrospective cohort study will be performed in those patients with twin pregnancies between 2010 and 2013, within the Hospital Universitari de Girona Doctor Josep Trueta (HUJT). A retrospective and descriptive study will be done in those cases with discordance weight in the moment of the birth, in which the CRL will be studied in the first trimester ultrasound, describing the percentage of discordance detected in that moment. The general characteristics of the sample are going to be analyzed by Logistic RegressionInfluenceof

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Background:There is no actual evidence that the ART are directly related to the occurrence of weight discordance. In some studies, ART-­‐conceived twin pregnancies are at greater risk than non-­‐ART-­‐conceived ones for pregnancy complications and adverse perinatal outcome: the incidences of pregnancy-­‐induced hypertension, uterine bleeding, premature contractions, IUGR, fetal death, discordance, and cesarean section were significantly higher. Discordance rate was elevated (25.3% vs.17.0%) among ART twins, which can increase perinatal risk (increased incidence of SGA and NICU admission). Other studies say that perinatal and neonatal morbidity, gestational age at delivery, and birth weight are not affected by ART. Regarding the first trimester ultrasound, some studies didn’t notice significant differences in CRL disparity or birth weight discordance between spontaneous and ART-­‐ conceived dichorionic twin pregnancies. In ART-­‐conceived dichorionic twin pregnancies, CRL disparity may be associated with birth weight discordance. In some studies, CRL discordance in twin pregnancies in the first trimester was a frequent finding. Objectives: To analyze the association of the ART in the occurrence of weight discordance in the pregnancies between 2010 and 2013 in the Hospital Universitari de Girona Doctor Josep Trueta, and to describe the proportion of diagnosis of growth discordance in the first trimester by the ultrasonography technology. Methods: A retrospective cohort study will be performed in those patients with twin pregnancies between 2010 and 2013, within the Hospital Universitari de Girona Doctor Josep Trueta (HUJT). A retrospective and descriptive study will be done in those cases with discordance weight in the moment of the birth, in which the CRL will be studied in the first trimester ultrasound, describing the percentage of discordance detected in that moment. The general characteristics of the sample are going to be analyzed by Logistic RegressionInfluenceof

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Background:There is no actual evidence that the ART are directly related to the occurrence of weight discordance. In some studies, ART-­‐conceived twin pregnancies are at greater risk than non-­‐ART-­‐conceived ones for pregnancy complications and adverse perinatal outcome: the incidences of pregnancy-­‐induced hypertension, uterine bleeding, premature contractions, IUGR, fetal death, discordance, and cesarean section were significantly higher. Discordance rate was elevated (25.3% vs.17.0%) among ART twins, which can increase perinatal risk (increased incidence of SGA and NICU admission). Other studies say that perinatal and neonatal morbidity, gestational age at delivery, and birth weight are not affected by ART. Regarding the first trimester ultrasound, some studies didn’t notice significant differences in CRL disparity or birth weight discordance between spontaneous and ART-­‐ conceived dichorionic twin pregnancies. In ART-­‐conceived dichorionic twin pregnancies, CRL disparity may be associated with birth weight discordance. In some studies, CRL discordance in twin pregnancies in the first trimester was a frequent finding. Objectives: To analyze the association of the ART in the occurrence of weight discordance in the pregnancies between 2010 and 2013 in the Hospital Universitari de Girona Doctor Josep Trueta, and to describe the proportion of diagnosis of growth discordance in the first trimester by the ultrasonography technology. Methods: A retrospective cohort study will be performed in those patients with twin pregnancies between 2010 and 2013, within the Hospital Universitari de Girona Doctor Josep Trueta (HUJT). A retrospective and descriptive study will be done in those cases with discordance weight in the moment of the birth, in which the CRL will be studied in the first trimester ultrasound, describing the percentage of discordance detected in that moment. The general characteristics of the sample are going to be analyzed by Logistic RegressionInfluenceof