Glottal source estimation using a sum-of-exponentials model

An algorithm for estimating the glottal source waveform in voiced speech is described. The glottal source waveform is described using the LF model proposed by Fant et al. (1985). The vocal tract filter is modeled as a pole-zero system. The analysis of vowel sounds from several talkers shows that the analysis procedure leads to an accurate estimate of the glottal source     

Religious ritual and dissociation in India and Australia

Bone metastases, together with generalized bone resorption, represent the main complication in patients with advanced prostate cancer, and palliative treatments are required to delay the progression of the metastases and improve the quality of life of these patients. For this reason, the bisphosphonate clodronate was administered to 18 patients (clodronate group) from a total of 30, all of whom were receiving complete androgenic blockade; the remaining 12 formed the control group. Transiliac bone biopsies were taken at the beginning of the study and 6 months later to determine the effect of the bisphosphonate on the skeleton. The results were assessed by bone histomorphometry and showed, although without statistical significance between the groups, an antiresorptive effect of the clodronate expressed as the eroded surface/bone surface and as the osteoclast number/bone surface. However, the bone volume also decreased after 6 months of treatment. Similarly, osteoid formation decreased as indicated by the osteoid surface and by the osteoid volume, probably due to the effect of the drug on the osteoblasts. The mineralization rate was apparently slightly retarded in the clodronate group, although to a lesser degree than in the control group. The results confirm the antiresorptive effect of clodronate and its detrimental effect on osteoblast activity.     

Robust continuous-time smoothers without two-sided stochastic integrals

We consider the problem of fixed-interval smoothing of a continuous-time partially observed nonlinear stochastic dynamical system. Existing results for such smoothers require the use of two-sided stochastic calculus. The main contribution of the paper is to present a robust formulation of the smoothing equations. Under this robust formulation, the smoothing equations are nonstochastic parabolic partial differential equations (with random coefficients) and, hence, the technical machinery associated with two sided stochastic calculus is not required. Furthermore, the robust smoothed state estimates are locally Lipschitz in the observations, which is useful for numerical simulation. As examples, finite dimensional robust versions of the Benes and hidden Markov model smoothers and smoothers for piecewise linear dynamics are derived; these finite-dimensional smoothers do not involve stochastic integrals.     

A reduced-complexity online state sequence and parameter estimatorfor superimposed convolutional coded signals

This paper develops a reduced-complexity online state sequence and parameter estimator for superimposed convolutional coded signals. Joint state sequence and parameter estimation is achieved by iteratively estimating the state sequence via a variable reduced-complexity Viterbi algorithm (VRCVA) and the model parameters via a recursive expectation maximization (EM) approach. The VRCVA is developed from a fixed reduced-complexity Viterbi algorithm (FRCVA). The FRCVA is a special case of the delayed decision-feedback sequence estimation (DDFSE) algorithm. The performance of online versions of the FRCVA, VRCVA, and the standard Viterbi algorithm (VA) are compared when they are used to estimate the state sequence as part of the reduced-complexity online state sequence and parameter estimator     

Stability of Mullite Protective Coatings for Silicon-Based Ceramics

Silicon-based ceramics are prone to severe oxidation and volatilization problems in the presence of water vapor. To address these issues, mullite has been investigated in recent years as a possible protective coating material. To analyze the stability of such coatings, a multi-species diffusion model for ionic species is developed. Onsager reciprocity is assumed for the mobility coefficients and the resulting moving boundary problem is solved numerically. The formulation also accounts for substantial Si volatilization away from the outer surface of the coating. This model is used to analyze an initial transient leading to the formation of an internal silica layer, a second transient period that follows this silica formation, and a steady-state regime that can only be attained if Si diffusion is sufficiently fast.     

Nanocrystal-semiconductor interface: Atomic-resolution cross-sectional transmission electron microscope study of lead sulfide nanocrystal quantum dots on crystalline silicon

We report on a cross-sectional high resolution transmission electron microscope study of lead sulfide nanocrystal quantum dots （NCQDs） dispersed on electron-transparent silicon nanopillars that enables nearly atomically-resolved simultaneous imaging of the entire composite： the quantum dot, the interfacial region, and the silicon substrate. Considerable richness in the nanocrystal shape and orientation with respect to the substrate lattice is observed. The average NCQD-substrate separation is found to be significantly smaller than the length of the ligands on the NCQDs. Complementary photoluminescence measurements show that light emission from PbS NCQDs on silicon is effectively quenched which we attribute to intrinsic mechanisms of energy and charge transfer from PbS NCQDs to Si.     

Mixed convection in wall plumesConvection mixte dans les panaches parietauxErzwungene und freie konvektion bei wandauftriebsströmungenCмeшaннaя кoнвeкция в cвoБoднoкoнвeктивныч cтpyяч нa cтeнкe

An analysis is presented for mixed convection effects in a wall plume flow. The results apply downstream from the source. The method of matched asymptotic expansions has been used to obtain a consistent solution by simultaneously including both the effects of mixed convection and of higher order boundary layer corrections. Several subtle and interesting features of this flow arise and are explained. The unexpected role played by Prandtl number is clearly illustrated. For example, the effect of an aiding imposed forced flow is to reduce surface shear stress, for Pr = 0.7, and to increase it for Pr = 6.7. Further, it has been shown that such a Prandtl number effect on the surface shear stress is dependent on the kind of heating condition imposed at the surface. Results of numerical calculations are presented for two values of Prandtl number, 0.7 and 6.7, as characteristic of air and water, respectively. The overall effect of mixed convection on the downstream decay of surface temperature and on the maximum value of tangential velocity is seen to be greater in air than in water.     

Modelling of attenuation of Lamb waves using Rayleigh damping: Numerical and experimental studies

In this study, the Lamb mode attenuation constants were derived in terms of the attenuation coefficient, group velocity and central frequency of excitation of the Lamb mode, using the Rayleigh damping model. Attenuation of Lamb waves, both fundamental symmetric and anti-symmetric modes, propagating through viscoelastic media (cross-ply glass/epoxy laminate) was modelled using the Finite Element Method. Numerically simulated attenuation of Lamb waves using Lamb mode attenuation constants was found to be in good agreement with the assumed attenuation. Experiments were performed on a quasi-isotropic laminate, employing air-coupled ultrasonic transducers, to measure the attenuation coefficient. Lamb mode attenuation constants, computed using the attenuation coefficient, were used to model the attenuation of the Lamb mode in quasi-isotropic laminates. Numerically simulated amplitude variation was found to be in good agreement with that computed from experiments.