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Models Shows (models + shows)
Selected AbstractsModeling human affective postures: an information theoretic characterization of posture featuresCOMPUTER ANIMATION AND VIRTUAL WORLDS (PREV: JNL OF VISUALISATION & COMPUTER ANIMATION), Issue 3-4 2004P. Ravindra De Silva One of the challenging issues in affective computing is to give a machine the ability to recognize the mood of a person. Efforts in that direction have mainly focused on facial and oral cues. Gestures have been recently considered as well, but with less success. Our aim is to fill this gap by identifying and measuring the saliency of posture features that play a role in affective expression. As a case study, we collected affective gestures from human subjects using a motion capture system. We first described these gestures with spatial features, as suggested in studies on dance. Through standard statistical techniques, we verified that there was a statistically significant correlation between the emotion intended by the acting subjects, and the emotion perceived by the observers. We used Discriminant Analysis to build affective posture predictive models and to measure the saliency of the proposed set of posture features in discriminating between 4 basic emotional states: angry, fear, happy, and sad. An information theoretic characterization of the models shows that the set of features discriminates well between emotions, and also that the models built over-perform the human observers. Copyright © 2004 John Wiley & Sons, Ltd. [source] On the L2 and the H1 couplings for an overlapping domain decomposition method using Lagrange multipliersINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2007P.-A. Guidault Abstract In this paper, a comparison of the L2 and the H1 couplings is made for an overlapping domain decomposition method using Lagrange multipliers. The analysis of the local equations arising from the formulation of the coupling of two mechanical models shows that continuous weight functions are required for the L2 coupling term whereas both discontinuous and continuous weight functions can be used for the H1 coupling. The choice of the Lagrange multiplier space is discussed and numerically studied. The paper ends with some numerical examples of an end-loaded cantilever beam and a cracked plate under tension and shear. It is shown that the continuity enforced with the H1 coupling leads to a link with a flexibility that can be beneficial for coupling a very coarse mesh with a very fine one. To limit the effect of the volume coupling on the global response, a narrow coupling zone is recommended. In this case, volume coupling tends to a surface coupling, especially with a L2 coupling. Copyright © 2006 John Wiley & Sons, Ltd. [source] PARAFASCA: ASCA combined with PARAFAC for the analysis of metabolic fingerprinting dataJOURNAL OF CHEMOMETRICS, Issue 2 2008Jeroen J. Jansen Abstract Novel post-genomics experiments such as metabolomics provide datasets that are highly multivariate and often reflect an underlying experimental design, developed with a specific experimental question in mind. ANOVA-simultaneous component analysis (ASCA) can be used for the analysis of multivariate data obtained from an experimental design instead of the widely used principal component analysis (PCA). This increases the interpretability of the model in terms of the experimental question. Aside from the levels of individual factors, variation that can be described by the experimental design may also depend on levels of multiple (crossed) factors simultaneously, e.g. the interactions. ASCA describes each contribution with a PCA model, but a contribution depending on crossed factors may be described more parsimoniously by multiway models like parallel factor analysis (PARAFAC). The combination of PARAFAC and ASCA, named PARAFASCA, provides a view on the data that is both parsimonious and focused on the experimental question. The novel method is used to analyze a dataset in which the effect of two doses of hydrazine on the urinary chemical composition of rats is investigated by time-resolved metabolic fingerprinting with nuclear magnetic resonance (NMR) spectroscopy. This experiment has been conducted to monitor the dose-specific urine composition changes in time upon hydrazine administration. Comparison of the PCA, the ASCA and the PARAFASCA models shows that ASCA and PARAFASCA describe the data more dedicated to the experimental question than PCA, but that PARAFASCA is more parsimonious than ASCA, and separates the variation underlying different effects better. Copyright © 2008 John Wiley & Sons, Ltd. [source] Modified evolving window factor analysis for process monitoringJOURNAL OF CHEMOMETRICS, Issue 9 2004S. Kamaledin Setarehdan Abstract Reaction process monitoring and control are usually involved with direct measurement or indirect model-based prediction of concentration profiles of the constituents of interest in a chemical reaction at regular time intervals. These approaches are expensive, time-consuming and sometimes impossible. On the other hand, application of so-called ,calibration-free' techniques such as EFA and EWFA to spectral data usually provides important information regarding the structural variations in the chemical system without identification of the chemical components responsible for the variations. In this paper a novel spectral data pre-processing algorithm is presented which helps EWFA to extract the concentration trends of the components of interest within the reaction. The proposed algorithm uses the pure spectrum of the component of interest to develop a so-called ,weighting filter' which is applied to the input spectral information before EWFA. The algorithm was applied to a real Raman spectral data set obtained from a pre-treatment distillation column used for removing unwanted heavy/cyclic hydrocarbons from naphtha in an oil company. Comparison of the concentration trends resulting from the proposed algorithm with those obtained using conventional PLS1 models shows that the new calibration-free and on-line algorithm outperforms the calibration models obtained by difficult and expensive laboratory work. Copyright © 2005 John Wiley & Sons, Ltd. [source] Glacier response in the European Alps to Heinrich Event 1 cooling: the Gschnitz stadial,JOURNAL OF QUATERNARY SCIENCE, Issue 2 2006Susan Ivy-Ochs Abstract The Gschnitz stadial was a period of regionally extensive glacier advance in the European Alps that lies temporally between the breakdown of the Last Glacial Maximum piedmont lobes and the beginning of the Bølling warm interval. Moraines of the Gschnitz stadial are found in medium to small catchments, are steep-walled and blocky, and reflect a snowline lowering of 650,700,m in comparison to the Little Ice Age reference snowline. 10Be surface exposure dating of boulders from the moraine at the type locality at Trins (Gschnitz valley, Tyrol, Austria) shows that it stabilised no later than 15,400,±,1400,yr ago. The overall morphological situation and the long reaction time of the glacier suggest that the climatic downturn lasted about 500,±,300,yr, indicating that the Gschnitz cold period began approximately 15,900,±,1400,yr ago, if not somewhat earlier. This is consistent with published radiocarbon dates that imply that the stadial occurred sometime between 15,400 14C,yr BP (18,020,19,100,cal.,yr) and 13,250 14C,yr BP (15,360,16,015,cal.,yr). A palaeoclimatic interpretation of the Gschnitz glacier based on a simple glacier flow model and statistical glacier-climate models shows that precipitation was about one-third of modern-day precipitation and summer temperatures were about 10,K lower than today. In comparison, during the Younger Dryas, precipitation in this area was only about 10% less and Ts (summer temperature) was only 3.5,4,K lower than modern values. Based on the age of the moraine and the cold and dry climate at that time, we suggest that the Gschnitz stadial was the response of Alpine glaciers to cooling of the North Atlantic Ocean associated with Heinrich Event 1. Copyright © 2005 John Wiley & Sons, Ltd. [source] The Geography of Opportunity and Unemployment: An Integrated Model of Residential Segregation and Spatial MismatchJOURNAL OF URBAN AFFAIRS, Issue 4 2005Michael Howell-Moroney Using National Longitudinal Survey of Youth (1979) data, I estimate a two-step model that separately models the effects of segregation and spatial mismatch. The first model predicts educational attainment as a function of exposure to residential segregation as a youth. The second model predicts unemployment probability as an adult as a function of educational attainment and spatial mismatch. The empirical results show that segregation does have discernable effects on educational attainment for blacks, but not for whites. I also find that spatial mismatch affects unemployment probability for blacks, but such an effect is hardly present for whites. A partial equilibrium analysis using predictions from the models shows that large changes in either segregation levels or the central city/suburban distribution of the black population would yield only moderate decreases in unemployment probability for the black population overall. Yet despite small predicted effects, these results should be viewed with caution because the general equilibrium effects of a large scale movement of blacks and whites across metropolitan space are largely impossible to predict with current data. [source] Spitzer IRAC infrared colours of submillimetre-bright galaxiesMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 1 2008Min S. Yun ABSTRACT High-redshift submillimetre-bright galaxies identified by blank field surveys at millimetre and submillimetre wavelengths appear in the region of the Infra Red Array Camera (IRAC) colour,colour diagrams previously identified as the domain of luminous active galactic nuclei (AGNs). Our analysis using a set of empirical and theoretical dusty starburst spectral energy distribution (SED) models shows that power-law continuum sources associated with hot dust heated by young (,100 Myr old), extreme starbursts at z > 2 also occupy the same general area as AGNs in the IRAC colour,colour plots. A detailed comparison of the IRAC colours and SEDs demonstrates that the two populations are distinct from each other, with submillimetre-bright galaxies having a systematically flatter IRAC spectrum (,1 mag bluer in the observed [4.5],[8.0] colour). Only about 20 per cent of the objects overlap in the colour,colour plots, and this low fraction suggests that submillimetre galaxies powered by a dust-obscured AGN are not common. The red infrared colours of the submillimetre galaxies are distinct from those of the ubiquitous foreground IRAC sources, and we propose a set of infrared colour selection criteria for identifying SMG counterparts that can be used even in the absence of radio or Multiband Imaging Photometer for Spitzer (MIPS) 24 ,m data. [source] Topological properties of hydrogen bonds and covalent bonds from charge densities obtained by the maximum entropy method (MEM)ACTA CRYSTALLOGRAPHICA SECTION B, Issue 5 2009Jeanette Netzel Charge densities have been determined by the Maximum Entropy Method (MEM) from the high-resolution, low-temperature (T, 20,K) X-ray diffraction data of six different crystals of amino acids and peptides. A comparison of dynamic deformation densities of the MEM with static and dynamic deformation densities of multipole models shows that the MEM may lead to a better description of the electron density in hydrogen bonds in cases where the multipole model has been restricted to isotropic displacement parameters and low-order multipoles (lmax = 1) for the H atoms. Topological properties at bond critical points (BCPs) are found to depend systematically on the bond length, but with different functions for covalent C,C, C,N and C,O bonds, and for hydrogen bonds together with covalent C,H and N,H bonds. Similar dependencies are known for AIM properties derived from static multipole densities. The ratio of potential and kinetic energy densities |V(BCP)|/G(BCP) is successfully used for a classification of hydrogen bonds according to their distance d(H...O) between the H atom and the acceptor atom. The classification based on MEM densities coincides with the usual classification of hydrogen bonds as strong, intermediate and weak [Jeffrey (1997). An Introduction to Hydrogen Bonding. Oxford University Press]. MEM and procrystal densities lead to similar values of the densities at the BCPs of hydrogen bonds, but differences are shown to prevail, such that it is found that only the true charge density, represented by MEM densities, the multipole model or some other method can lead to the correct characterization of chemical bonding. Our results do not confirm suggestions in the literature that the promolecule density might be sufficient for a characterization of hydrogen bonds. [source] Refined structures of placental alkaline phosphatase show a consistent pattern of interactions at the peripheral siteACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 8 2010Boguslaw Stec In order to gain deeper insights into the functional sites of human placental alkaline phosphatase, the structures of the enzyme with the putative regulators l -Phe, pNPP and 5,-AMP [Llinas et al. (2005), J. Mol. Biol.350, 441,451] were re-refined. Significant variations in ligand positioning and identity were found compared with the previous report. The multiple corrections to the model improved the phases and the electron-density maps, allowing the modeling of omitted side chains and multiple disordered residues. These improvements led to a change in the position of l -Phe at the peripheral binding site, which appeared to be reversed. The structure with pNPP contained only p -nitrophenol in three distinct sites, while the structure with 5,-AMP contained the p -nitrophenyl group in two of the sites instead of 5,-AMP. Comparison of the re-refined models shows a consistent pattern of interactions at the peripheral site. [source] | |||||||||||||