Abstract

In this problem, the process start with real-valued inputs and are supposed to decide eventually on real-valued outputs. The process is permitted to send real-valued data in messages. Instead of having to agree exactly, as in the ordinary agreement problem, this time the requirement is just that they agree with within a small positive real-valued tolerance ε. In the standard implementation agreement problem converges to a consistent value for each sensor measurement, which is nonfaculty using Byzantine algorithm with at-least n >; 3 faulty sensors. We define a pre-processing BestBasis cost function which allows to find a coherent range, which can be measured using intra-sensor in an ensemble of real-values. The overlap of the range is calculated by using a clique, with a runtime of O(nk) in the worst-case, where the size of clique, k, is a variable. The computation of the pre-processing takes O log(D), where D is the number of levels in a sparse signal basis. Which are some times analogously compared to needle in a hay stack definition.

Abstract

For voiced speech, the most significant excitation takes place around the instant of glottal closure. Glottal closure in-stants (GCI) information is useful for accurate speech analysis.In particular accurate spectrum analysis is performed by con-sidering the speech in the intervals of glottal closure. In this pa-per we propose an approach for detection of GCI by exploring Bessel feature, and the use of AM-FM signal. Using appropri-ate range of Bessel coefficients, the narrow band, band limited signal is obtained for the given signal.The band limited signal isconsidered as AM-FM signal. The signal is band limited for 0-300 Hz to remove effect of formants. Amplitude envelope (AE)function of the AM-FM signal model has been estimated by the discrete energy separation algorithm (DESA). The performance of the method is demonstrated using CMU-Arctic database. The corresponding electro-glottograph (EGG) signals are used as a reference for the validation of the detected GCI locations.

Abstract

Glottal closure instants (GCI) information is useful for accurate speech analysis. In particular accurate spectrum analysis is performed by considering the speech in the intervals of glottal closure. In this paper we propose an approach for detection of GCI based on Bessel features, amplitude and frequency modulated (AM-FM) signal. Using appropriate range of Bessel coefficients, the narrow band, band limited signal is obtained for the given signal. The band limited signal is considered as a AM-FM signal. The signal is band limited for0-300 Hz to remove effect of formants. Amplitude Envelope (AE)function of the AM-FM signal model has been estimated by the discrete energy separation algorithm (DESA). We experimentally evaluated our approach to detect GCI on CMU-Arctic database.The corresponding electro-glottograph (EGG) signals are used as a reference for the validation of the detected GCI locations.

Abstract

Voice onset time is an important temporal feature which is often overlooked in speech perception, speech recognition as well as accent detection. The VOT in unvoiced stops varies with a number of factors, among which the most established one is the place of articulation. In this paper we propose an approach for the automatic detection of VOT. The proposed method uses Bessel expansion to emphasize the vowel and consonant regions of stop consonant vowel units (SCV) such as /ka/, /Ta/, /ta/ and /pa/. AM-FM signal has been emphasized after appropriate consideration of the range of Bessel coefficients,separately for the vowel and consonant regions of SCV units. There constructed signal from the Bessel expansion is a narrow-band AM-FM signal, therefore the amplitude envelope (AE) function for the emphasized signal can be estimated using discrete energy separation algorithm (DESA). For the detection of VOT, both the AE of vowel and consonat emphasized signal has been analyzed.Detection of VOT is analyzed for the continuous speech corpus consisting of recording television broadcast news bulletins.

Abstract

In this paper, we explore Bessel features to determine the number of speakers from multispeaker speech signals collected simultaneously from a pair of spatially separated microphones. The arrival of the speech signals from speaker to microphones gives the time delays of given speaker. The time delays can be estimated by performing the cross-correlation to the band limited multispeaker signals collected at the two microphones. Signals are band limited using a finite number of Bessel coefficients. The computer simulation results demonstrate the proposed method is efficient compared to existing methods.

Abstract

The Independent Component Analysis with Reference (ICA - R) also called as constrained ICA (cICA) extracts only the desired source signals from the mixture of source signals by incorporating some prior information into the separation process. To overcome the problem of designing the reference signal when there is no prior information about the desired signal in the cICA, an improved method is proposed to use a different speech signal generated by the same physical source. The cICA is extended to use Bessel coefficients of the observed signals and the reference signal for processing as they converge faster than the other transformations. Since the Bessel functions provide the desired properties, efficient in representing speech signals, less memory storage they have been exploited in speech processing [1]. The results demonstrate the efficiency of the proposed method

Abstract

In many circumstances in image processing, image resizing is done, either to magnify or to reduce the size of a digital image. The spatial domain based resizing methods such as bilinear interpolation and bi-cubic interpolation are simple and work better for image size magnification. The main drawback in using them is that they are not suitable for image size reduction. In this paper, we propose a new method for image resizing based on Bessel transform (BT). The performance of image resizing based on BT is compared to that of spatial domain based resizing techniques, the results are viewed in terms of Peak Signal to Noise ratio (PSNR) and Mean Square Error (MSE). Experimental results confirm that the proposed method maintains better image quality when image size is enlarged and also when image size is reduced.

Abstract

This paper describes the challenges faced in language learning and use, with a focus on domain-specific vocabulary learning. We focus on the architecture and the presentation model of domain-specific knowledge components. The paper first discusses the significance of assistive mechanisms for vocabulary learning in an academic domain and then outlines two architectures for the presentation model. We suggest how the design of this environment for vocabulary use and learning in the academic domain must adopt different presentations and search strategies to confront the specific challenges in the domain. As this problem can only be solved on a long term basis, we also briefly describe a set of games as a first step in the implementation of the assistive mechanisms.

Abstract

Base pairs involving protonated nucleobases play important roles in mediating global macromolecular conformational changes and in facilitation of catalysis in a variety of functional RNA molecules. Here we present our attempts at understanding the role of such base pairs by detecting possible protonated base pairs in the available RNA crystal structures using BPFind software, in their specific structural contexts, and by the characterization of their geometries, interaction energies, and stabilities using advanced quantum chemical computations. We report occurrences of 18 distinct protonated base pair combinations from a representative data set of RNA crystal structures and propose a theoretical model for one putative base pair combination. Optimization of base pair geometries was carried out at the B3LYP/cc-pVTZ level, and the BSSE corrected interaction energies were calculated at theMP2/aug-ccpVDZ level of theory. The geometries for each of the base pairs were characterized in terms of Hbonding patterns observed, rmsd values observed on optimization, and base pair geometrical parameters. In addition, the intermolecular interaction in these complexes was also analyzed using Morokuma energy decomposition. The gas phase interaction energies of the base pairs range from-24 to-49 kcal/mol and reveal the dominance of Hartree-Fock component of interaction energy constituting 73% to 98%of the total interaction energy values.Onthe basis of our combined bioinformatics and quantum chemical analysis of different protonated base pairs, we suggest resolution of structural ambiguities and correlate their geometric and energetic features with their structural and functional roles. In addition, we also examine the suitability of specific base pairs as key elements in molecular switches and as nucleators for higher order structures such as base triplets and quartets.

Abstract

Riboswitches, typically an integral part of several mRNAs, consist of two domains – a ‘cognate metabolite’ sensing aptamer domain and an expression platform – regulating gene expression at the transcription or in the translation level. Because of their small size and high discriminative ability, p urine riboswitches have been studied extensively both experimentally as well as computationally. Crystal structures of ligand bound aptamer domain of purine riboswitches (Fig. 1) reveal a compact three-way junction architecture consisting of two stem-loops (P2-L2 and P3-L3), held together in parallel orientation by tertiary base pairing interactions between the loops (L2 and L3), converging to a base stem (P1) which communicates with the expression platform. Nucleotides belonging to the three junction loops (J1-2, J2-3 and J3-1) constitute the binding pocket which is lined above and below with double layers of stacked base triples. Though crystal structures of corresponding ligand-free aptamer domains are not available, biophysical and computational studies, including our earlier MD simulations of the add adenine riboswitch1, have provided insights into the functional dynamics connecting the two mechanistic events: discriminative ligand binding and communication with the expression Fig. 1 Ligand bound add platform. Adenine riboswitch In order to gain better insights into the ligand binding induced conformational changes, at the molecular level, and an understanding of the general principles underlying the switching event, we have carried out all-atom explicit solvent molecular dynamics simulations of add adenine riboswitch and xpt-pbuX guanine riboswitch, in ligand-free (APO) state and ligand-bound (HOLO) state, using ff99parmbsc0. Detailed analysis, including principal component analysis and conformational clustering, of the trajectories, reveal interesting insights into changes in conformational dynamics accompanying ligand binding. While confirming the existence of a preformed and ‘binding ready’ APO form and ligand binding induced stabilization of the expression platform linking P1 helices in both aptamers, our studies indicate possible role of stronger L2-L3 interactions in giving rise to fine differences in the functional dynamics of the guanine riboswitch, vis-a-vis the adenine riboswitch.