Spectral entropy and spectral shape based pre-quantization for real time speaker identification system

Pre-processing is one of the vital steps for developing robust and efficient recognition system. Better pre-processing not only aid in better data selection but also in significant reduction of computational complexity. Further an efficient frame selection technique can improve the overall performance of the system. Pre-quantization (PQ) is the technique of selecting less number of frames in the pre-processing stage to reduce the computational burden in the post processing stages of speaker identification (SI). In this paper, we develop PQ techniques based on spectral entropy and spectral shape to pick suitable frames containing speaker specific information that varies from frame to frame depending on spoken text and environmental conditions. The attempt is to exploit the statistical properties of distributions of speech frames at the pre-processing stage of speaker recognition. Our aim is not only to reduce the frame rate but also to maintain identification accuracy reasonably high. Further we have also analyzed the robustness of our proposed techniques on noisy utterances. To establish the efficacy of our proposed methods, we used two different databases, POLYCOST (telephone speech) and YOHO (microphone speech).     

Chiral resolution of differently substituted racemic acetyl‐1‐phenyl ethanol using lipase from Bacillus subtilis

In the present investigation a Lipase producing strain, Bacillus subtilis (MTCC‐121) was grown on various media containing different sources of carbon, nitrogen and other nutrients. The best media found for the production of lipase was M2 media containing 0.4% peptone, 0.2% beef extract and 1% NaCl. Lipase produced from this culture was used for the kinetic resolution of racemic acetyl‐1‐phenyl ethanol and its derivatives, which are important as chiral auxiliaries and intermediates in the synthesis of natural products, pharmaceuticals and agrochemicals. The lipase resolved these substrates after 48 h with enantiomeric excess of 90–98% and conversion 40–48%. Copyright © 2010 Society of Chemical Industry     

Strength of lime–fly ash compacts using different curing techniques and gypsum additive

Lime–fly ash mixtures are exploited for the manufacture of fly ash bricks finding applications in load bearing masonry. Lime–pozzolana reactions take place at a slow pace under ambient temperature conditions and hence very long curing durations are required to achieve meaningful strength values. The present investigation examines the improvements in strength development in lime–fly ash compacts through low temperature steam curing and use of additives like gypsum. Results of density–strength–moulding water content relationships, influence of lime–fly ash ratio, steam curing and role of gypsum on strength development, and characteristics of compacted lime–fly ash–gypsum bricks have been discussed. The test results reveal that (a) strength increases with increase in density irrespective of lime content, type of curing and moulding water content, (b) optimum lime–fly ash ratio yielding maximum strength is about 0.75 in the normal curing conditions, (c) 24 h of steam curing (at 80°C) is sufficient to achieve nearly possible maximum strength, (d) optimum gypsum content yielding maximum compressive strength is at 2%, (e) with gypsum additive it is possible to obtain lime–fly ash bricks or blocks having sufficient strength (>10 MPa) at 28 days of normal wet burlap curing.     

FAST

We propose Frontier Allocation Synchronized by Token passing (FAST), a distributed algorithm for online terrain coverage using multiple mobile robots, ensuring mutually exclusive selection of frontier cells. Many existing approaches cover the terrain in an irregular fashion, without considering the usability of the already covered region. For instance, in the task of floor cleaning in an office building, these approaches do not guarantee the cleanliness of large unbroken areas until a majority of the task is complete. FAST on the other hand, incrementally traverses the terrain generating structured trajectories for each robot. Following a structured trajectory for coverage path planning is proven to be a very powerful approach in literature. This renders large portions of the terrain usable even before the completion of the coverage task. The novel map representation techniques used in FAST render it scalable to large terrains, without affecting the volume of communication among robots. Moreover, the distributed nature of FAST allows incorporation of fault-tolerance mechanisms. Empirical investigations on maps of varied complexities and sizes both in simulation and on an experimental test-bed demonstrate that the proposed algorithm performs better than some of the benchmark approaches in terms of coverage completion time and less redundant coverage.     

Effect of Processing Variables on WC Nanoparticles Synthesized by Solvothermal Route

In this work, the effect of processing variables on the synthesis of WC nanoparticles by solvothermal route has been reported. Nanoparticles of tungsten carbide (WC) have been prepared by taking metallic magnesium (Mg), acetone (C₃H₆O), and tungsten trioxide (WO₃) in an autoclave at 600°C. The XRD results showed that the optimization of the reaction time facilitates the reduction as well as carburization of the tungsten source. The Williamson-–Hall analysis was used to study the effect of synthesis time on the crystallite size and lattice strain of the sample. Differential thermal analysis/thermogravimetric analysis shows the stability of the synthesized product. It has been observed that the synthesis of WC nanoparticles is a multistep process and the complete carburization reaction occurs at particular carburization time.     

Structural,thermal and electrical properties of Ti4+ substituted Bi2O3 solid systems

In the present study, the effect of TiO₂ doping on (1 ? x) Bi₂O₃ (x)TiO₂ (x = 0.05, 0.10, 0.15, 0.20) materials is investigated using X-ray diffraction (XRD), differential thermal analysis (DTA), ac conductivity, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). XRD results show the formation of single phase Bi₁₂TiO₂₀ at x ≥ 0.15 concentration of TiO₂. It is observed that, the lower concentration of TiO₂ leads to the formation of mixed phase. The x = 0.15 and x = 0.20 samples exhibit regular and uniform distribution of the grains as compared to x = 0.10 sample. The highest conductivity is observed for x = 0.15 specimen, e.g., 9 × 10^?7 S cm^?1.     

An automated algorithm for online detection of fragmented QRS and identification of its various morphologies

Fragmented QRS (f-QRS) has been proven to be an efficient biomarker for several diseases, including remote and acute myocardial infarction, cardiac sarcoidosis, non-ischaemic cardiomyopathy, etc. It has also been shown to have higher sensitivity and/or specificity values than the conventional markers (e.g. Q-wave, ST-elevation, etc.) which may even regress or disappear with time. Patients with such diseases have to undergo expensive and sometimes invasive tests for diagnosis. Automated detection of f-QRS followed by identification of its various morphologies in addition to the conventional ECG feature (e.g. P, QRS, T amplitude and duration, etc.) extraction will lead to a more reliable diagnosis, therapy and disease prognosis than the state-of-the-art approaches and thereby will be of significant clinical importance for both hospital-based and emerging remote health monitoring environments as well as for implanted ICD devices. An automated algorithm for detection of f-QRS from the ECG and identification of its various morphologies is proposed in this work which, to the best of our knowledge, is the first work of its kind. Using our recently proposed time–domain morphology and gradient-based ECG feature extraction algorithm, the QRS complex is extracted and discrete wavelet transform (DWT) with one level of decomposition, using the ‘Haar’ wavelet, is applied on it to detect the presence of fragmentation. Detailed DWT coefficients were observed to hypothesize the postulates of detection of all types of morphologies as reported in the literature. To model and verify the algorithm, PhysioNet''s PTB database was used. Forty patients were randomly selected from the database and their ECG were examined by two experienced cardiologists and the results were compared with those obtained from the algorithm. Out of 40 patients, 31 were considered appropriate for comparison by two cardiologists, and it is shown that 334 out of 372 (89.8%) leads from the chosen 31 patients complied favourably with our proposed algorithm. The sensitivity and specificity values obtained for the detection of f-QRS were 0.897 and 0.899, respectively. Automation will speed up the detection of fragmentation, reducing the human error involved and will allow it to be implemented for hospital-based remote monitoring and ICD devices.     

Instance invariant visual servoing framework for part‐aware autonomous vehicle inspection using MAVs

Visual servoing approaches navigate a robot to the desired pose with respect to a given object using image measurements. As a result, these approaches have several applications in manipulation, navigation and inspection. However, existing visual servoing approaches are instance specific, that is, they control camera motion between two views of the same object. In this paper, we present a framework for visual servoing to a novel object instance. We further employ our framework for the autonomous inspection of vehicles using Micro Aerial Vehicles (MAVs), which is vital for day‐to‐day maintenance, damage assessment, and merchandising a vehicle. This visual inspection task comprises the MAV visiting the essential parts of the vehicle, for example, wheels, lights, and so forth, to get a closer look at the damages incurred. Existing methods for autonomous inspection could not be extended for vehicles due to the following reasons: First, several existing methods require a 3D model of the structure, which is not available for every vehicle. Second, existing methods require expensive depth sensor for localization and path planning. Third, current approaches do not account for the semantic understanding of the vehicle, which is essential for identifying parts. Our instance invariant visual servoing framework is capable of autonomously navigating to every essential part of a vehicle for inspection and can be initialized from any random pose. To the best our knowledge, this is the first approach demonstrating fully autonomous visual inspection of vehicles using MAVs. We have validated the efficacy of our approach through a series of experiments in simulation and outdoor scenarios.     

Method development for optimised green synthesis of gold nanoparticles from Millettia pinnata and their activity in non‐small cell lung cancer cell lines

Green synthesis of gold nanoparticles (GNPs) has received substantial attention, because nanoparticles are produced in an eco‐friendly way using biomolecules present in plant extracts in a single step reaction. This research article highlights GNPs obtained using shade‐dried leaf extracts of Millettia pinnata (L.) with aqueous auric chloride (HAuCl₄) at ambient temperature. In the present study, GNPs with average particle size 37 nm in size were fabricated. Furthermore, the synthesis method to obtain stable and monodispersed GNPs was advanced by optimising enzyme concentration 100 μg/ml, pH 5.4, substrate concentration 0.45 mM and 12 h time of reaction. The confirmation of GNPs formation and characterisation was followed by UV‐vis‐absorption spectroscopy, dynamic light scattering (DLS), and zeta potential (ZP) for the analysis of shape, size, and stability, respectively. TEM images and powder XRD revealed the GNPs synthesis of spherical‐shaped nanoparticles in the face‐centred cubic arrangement. Cytotoxicity of GNPs was studied against A549 lung cancer cells with IC₅₀ 14.76 μg/ml and found lower as compared to doxorubicin IC₅₀ 11.23 μg/ml but significant enough to be used as a vehicle GNPs produced using green source can be used as significant therapeutic agents and drug delivery carriers.Inspec keywords: nanomedicine, molecular biophysics, cancer, electrokinetic effects, pH, transmission electron microscopy, toxicology, gold, cellular biophysics, X‐ray diffraction, lung, biomedical materials, nanofabrication, nanoparticles, particle size, enzymes, visible spectra, ultraviolet spectra, light scattering, biochemistryOther keywords: method development, optimised green synthesis, gold nanoparticles, millettia pinnata, nonsmall cell lung cancer cell lines, plant extracts, single step reaction, shade‐dried leaf extracts, aqueous auric chloride, synthesis method, stable GNPs, monodispersed GNPs, spherical‐shaped nanoparticles, A549 lung cancer cells, green source, particle size, enzyme concentration, substrate concentration, biomolecules, reaction time, UV‐visible‐absorption spectroscopy, dynamic light scattering, zeta potential, TEM images, powder XRD, face‐centred cubic arrangement, cytotoxicity, pH, therapeutic agents, drug delivery carriers, time 12.0 hour, Au