Automatic speech segmentation using probabilistic latent component modeling

Latent variable methods, such as PLCA (Probabilistic Latent Component Analysis) have been successfully used for analysis of non-negative signal representations. In this paper, we formulate PLCS (Probabilistic Latent Component Segmentation), which models each time frame of a spectrogram as a spectral distribution. Given the signal spectrogram, the segmentation boundaries are estimated using a maximum-likelihood approach. For an efficient solution, the algorithm imposes a hard constraint that each segment is modelled by a single latent component. The hard constraint facilitates the solution of ML boundary estimation using dynamic programming. The PLCS framework does not impose a parametric assumption unlike earlier ML segmentation techniques. PLCS can be naturally extended to model coarticulation between successive phones. Experiments on the TIMIT corpus show that the proposed technique is promising compared to most state of the art speech segmentation algorithms.

Fabrication and characterization of sub 100 nm period polymer gratings for photonics applications

We report on the fabrication of polymethylmethacrylate (PMMA) nanogratings on silicon (Si) and glass substrates using electron beam lithography technique. Various aspects of proximity corrections using Monte Carlo simulation have been discussed. The fabrication process parameters such as proximity gap of exposure, exposure dosage and developing conditions have been optimized for high-density PMMA nanogratings structure on Si and glass substrates. Electron beam exposure is adjusted in such a way that PMMA acts as a negative tone resist and at the same time resolution loss due to proximity effect is minimum. Both reflection and transmission-type, nanometre period gratings have been fabricated and their diffraction characteristics are evaluated.

Structural crossover from nonmodulated to long-period modulated tetragonal phase and anomalous change in ferroelectric properties in the lead-free piezoelectric Na1/2Bi1/2TiO3-BaTiO3

The highly complex structure-property interrelationship in the lead-free piezoelectric (x) Na1/2Bi1/2TiO3 - (1 - x) BaTiO3 is a subject of considerable contemporary debate. Using comprehensive x-ray, neutron diffraction, dielectric, and ferroelectric studies, we have shown the existence of a new criticality in this system at x = 0.80, i.e., well within the conventional tetragonal phase field. This criticality manifests as a nonmonotonic variation of the tetragonality and coercivity and is shown to be associated with a crossover from a nonmodulated tetragonal phase (for x < 0.8) to a long-period modulated tetragonal phase (for x > 0.80). It is shown that the stabilization of long-period modulation introduces a characteristic depolarization temperature in the system. While differing qualitatively from the two-phase model often suggested for the critical compositions of this system, our results support the view with regard to the tendency in perovskites to stabilize long-period modulated structures as a result of complex interplay of antiferrodistortive modes Bellaiche and Iniguez, Phys. Rev. B 88, 014104 ( 2013); Prosandeev, Wang, Ren, Iniguez, ands Bellaiche, Adv. Funct. Mater. 23, 234 (2013)].

Sampling Period Selection of Control Application Connected to FlexRay Bus

Flexray is a high speed communication protocol designed for distributive control in automotive control applications. Control performance not only depends on the control algorithm but also on the scheduling constraints in communication. A balance between the control performance and communication constraints must required for the choice of the sampling rates of the control loops in a node. In this paper, an optimum sampling period of control loops to minimize the cost function, satisfying the scheduling constraints is obtained. An algorithm to obtain the delay in service of each task in a node of the control loop in the hyper period has been also developed. (C) 2015 The Authors. Published by Elsevier B.V.

The impact of latent heating on the location and strength of the tropical easterly jet

The tropical easterly jet (TEJ) is a prominent atmospheric circulation feature observed during the Asian summer monsoon. It is generally assumed that sensible heating over the Tibetan Plateau directly influences the location of the TEJ. However, other studies have suggested the importance of latent heating in determining the jet location. In this paper, the relative importance of latent heating on the maintenance of the TEJ is explored through simulations with a general circulation model. The simulation of the TEJ by the Community Atmosphere Model, version 3.1 is discussed in detail. These simulations showed that the location of the TEJ is well correlated with the location of the precipitation. Significant zonal shifts in the location of the precipitation resulted in similar shifts in the zonal location of the TEJ. These zonal shifts had minimal effect on the large-scale structure of the jet. Further, provided that precipitation patterns were relatively unchanged, orography did not directly impact the location of the TEJ. These changes were robust even with changes in the cumulus parameterization. This suggests the potential important role of latent heating in determining the location and structure of the TEJ. These results were used to explain the significant differences in the zonal location of the TEJ in the years 1988 and 2002. To understand the contribution of the latitudinal location of latent heating on the strength of the TEJ, aqua-planet simulations were carried out. It has been shown that for similar amounts of net latent heating, the jet is stronger when heating is in the higher tropical latitudes. This may partly explain the reason for the jet to be very strong during the JJA monsoon season.

Long-period modulated structure and electric-field-induced structural transformation in Na0.5Bi0.5TiO3-based lead-free piezoelectrics

Na0.5Bi0.5TiO3- based lead-free piezoelectrics exhibiting giant piezostrain are technologically interesting materials for actuator applications. The lack of clarity with regard to the structure of the nonpolar phase of this system has hindered the understanding of the structural mechanism associated with the giant piezostrain and other related phenomena. In this paper, we have investigated the structure and field-induced phase transformation behavior of a model system (0.94 - x) Na0.5Bi0.5TiO3-0.06BaTiO(3)-xK(0.5)Na(0.5)NbO(3) (0.0 <= x <= 0.025). A detailed structural analysis using neutron powder diffraction revealed that the nonpolar phase is neither cubic nor a mixture of rhombohedral (R3c) and tetragonal (P4bm) phases as commonly reported in literature but exhibits a long-period modulated structure, which is most probably of the type root 2 x root 2 x n with n = 16. Our results suggest that the giant piezoelectric strain is associated with a field-induced phase transformation of the long-period modulated structure to rhombohedral R3c structure above a critical field. We also demonstrate that the giant piezostrain is lost if the system retains a fraction of the field-induced R3c phase. A possible correlation among depolarization temperature, giant piezostrain, and its electrical fatigue behavior has also been indicated.

A meso elastoplastic constitutive model for polycrystalline metals based on equivalent slip systems with latent hardening

A meso material model for polycrystalline metals is proposed, in which the tiny slip systems distributing randomly between crystal slices in micro-grains or on grain boundaries are replaced by macro equivalent slip systems determined by the work-conjugate principle. The elastoplastic constitutive equation of this model is formulated for the active hardening, latent hardening and Bauschinger effect to predict macro elastoplastic stress-strain responses of polycrystalline metals under complex loading conditions. The influence of the material property parameters on size and shape of the subsequent yield surfaces is numerically investigated to demonstrate the fundamental features of the proposed material model. The derived constitutive equation is proved accurate and efficient in numerical analysis. Compared with the self-consistent theories with crystal grains as their basic components, the present theory is much simpler in mathematical treatment.

Experimental Study of the Earthquake Recurrence Period and the Trend of Post-Seismic Development

In order to study the earthquake recurrence and the characteristics of earthquake series, rupture tests of rock samples and plexiglass samples were made. On rock samples, a number of acoustic emission (AE) and strain measuring points were deployed; the load was one side direct shear. The variation characteristics of AE and strain at different detecting points around the extra large fracture were observed and studied. On plexiglass samples, a series of inclined cracks were prefabricated by a small-scale compressive testing machine. The samples were then loaded on a shockproof platen, when the samples were loaded, the stress intensity factor (SIF) was determined by the laser interferometric technique and shadow optical method of caustics. The fracture conditions such as material toughness around the extra large fracture were also studied. From those experimental results and the theory of fracture mechanics, the earthquake recurrence period and the trend of post-seismic development were studied.

The MBA-LBA I period in the Kourion region : new evidences from Erimi- Laonin tou Porakou (Lemesos, Cyprus)

The evidence from Erimi-Laonin tou Porakou within the Kouris valley settlement system can offer further new data to outline a picture of the development trends from MBA to LBA I periods in the Kourion region. As to this area, such a “transitional” phase could be particularly relevant to better understand the development process of the mature LBA II–III urban centers (in Alassa as well as the most recent discovered in Erimi-Pitharka). In 2008–2009 a focus investigation (an intensive survey, geoperspections and excavations) within the Kouris Valley Project has been addressed to the site of Erimi-Laonin tou Porakou, which lies on one of the highest hilltops facing southward the Kouris dam. The excavations evidenced a double circuit wall which surrounds the top mound and the lower terrace. The top mound (Area A) has been widely occupied by a complex workshop, directly linked with a storage area. The natural limestone bedrock has been worked out to arrange a system of carved deep basins connected each other by a series of flow channels. Southward from the workshop, a large storage area has been cleared, with a relevant assemblage of big pithoi and storage devices. The first lower terrace area (Area B) has been possibly occupied by a domestic quarter; a cemetery area (Area E) has been also evidenced outside the external circuit wall, where a series of five rock-cut tombs (Tombs 228– 232) with single chamber and small incoming dromoi has been excavated.

A possible alchemist apparatus from the early islamic period excavated at Ramla, Israel

Abstract: During extensive salvage excavations carried out during the years 2004-2008 in a large Early Islamic industrial area at the vicinities of Ramla, in Central Israel, an unparalleled industrial device was unearthed. The star-shaped, soil embedded installation, whose lower part was preserved, consisted of a central pottery jar surrounded by five minor jars, linked by ceramic pipes. Evidence of heat was observed mainly around the central vessel, and metal hollow cones perforated in the tip were found inside the surrounding jars. Although the manufacturing procedures and operation techniques of the installation are not completely clear, it is proposed that the installation is part of an industrial workshop or an alchemy laboratory. Both industry and alchemy were well-developed during the Early Islamic period and very often closely related, to the point that sometimes it is difficult to distinguish between them. The identification proposed is based on comparisons with tools described in literary sources, and somewhat later drawings and etchings. Circumstantial ceramic evidence was found, as well as the proximity of a bathhouse whose guests could have been the consumers of perfumes and unguents seem to reinforce this possibility. Due to the poor state of preservation of the device and the lack of available comparisons, the identification proposed here is tentative, and future research coupled with eventual new discoveries is needed in order to clarify this matter.