R. Rajasekaran

The hub and spoke paradigm for CSR evaluation

In this paper, we introduce the new paradigm used in the most recent ARPA-sponsored Continuous Speech Recognition (CSR) evaluation and then discuss the important features of the test design.The 1993 CSR evaluation was organized in a novel fashion in an attempt to accomodate research over a broad variety of important problems in CSR while maintaining a clear program-wide research focus. Furthermore, each test component in the evaluation was designed as an experiment to extract as much information as possible from the results.The evaluation was centered around a large vocabulary speaker-independent (SI) baseline test, which was required of every participating site. This test was dubbed the Hub since it was common to all sites and formed the basis for controlled inter-system comparisons.The Hub test was augmented with a variety of problem-specific optional tests designed to explore a variety of important problems in CSR, mostly involving some kind of mismatch between the training and test conditions. These tests were known as the Spokes since they all could be informatively compared to the Hub, but were otherwise independent.In the first trial of this evaluation paradigm in November, 1993, 11 research groups participated, yielding a rich array of comparative and contrastive results, all calibrated to the current state of the art in large vocabulary CSR.

Enhanced voice services in the telecommunication network using the Texas Instruments multiserve

The paper presents efforts that Texas Instruments is pursuing to place enhanced voice services in the telecommunications network. The authors describe the capabilities of the Texas Instruments multiserve platform, which is a system designed to implement enhanced telecommunication services. The paper discusses an example of some of the technology challenges involved in design of the system. The authors provide results of performance evaluation of the platform on important voice service tasks.<<ETX>>

Structural distortions due to missense mutations in human formylglycine-generating enzyme leading to multiple sulfatase deficiency

The major candidate for multiple sulfatase deficiency is a defective formylglycine-generating enzyme (FGE). Though adequately produced, mutations in FGE stall the activation of sulfatases and prevent their activity. Missense mutations, viz. E130D, S155P, A177P, W179S, C218Y, R224W, N259I, P266L, A279V, C336R, R345C, A348P, R349Q and R349W associated with multiple sulfatase deficiency are yet to be computationally studied. Aforementioned mutants were initially screened through ws-SNPs&GO3D program. Mutant R345C acquired the highest score, and hence was studied in detail. Discrete molecular dynamics explored structural distortions due to amino acid substitution. Therein, comparative analyses of wild type and mutant were carried out. Changes in structural contours were observed between wild type and mutant. Mutant had low conformational fluctuation, high atomic mobility and more compactness than wild type. Moreover, free energy landscape showed mutant to vary in terms of its conformational space as compared to wild type. Subsequently, wild type and mutant were subjected to single-model analyses. Mutant had lesser intra molecular interactions than wild type suggesting variations pertaining to its secondary structure. Furthermore, simulated thermal denaturation showed dissimilar pattern of hydrogen bond dilution. Effects of these variations were observed as changes in elements of secondary structure. Docking studies of mutant revealed less favourable binding energy towards its substrate as compared to wild type. Therefore, theoretical explanations for structural distortions of mutant R345C leading to multiple sulfatase deficiency were revealed. The protocol of the study could be useful to examine the effectiveness of pharmacological chaperones prior to experimental studies.

Speech data base

The Speech Data Base program is in the second phase of a two phase R&D program. In the first phase, we developed speech data bases that fueled and supported the DARPA SCP continuous speech recognition efforts. In cooperation with MIT, an acoustic phonetic base [1] was created consisting of 10 spoken English sentences by each of 630 speakers (dialectically balanced). This data base provided seeds for the development of several speaker independent recognition systems. A resource management data base [2] reflecting query, command and control tasks in naval battle management, was established and provided the evaluation and demonstration infrastructure for the various speech recognizers developed under DARPA SCP program.