A novel whispered speaker identification system based on extreme learning machine

Whispered speech speaker identification system is one of the most demanding efforts in automatic speaker recognition applications. Due to the profound variations between neutral and whispered speech in acoustic characteristics, the performance of conventional speaker identification systems applied on neutral speech degrades drastically when compared to whisper speech. This work presents a novel speaker identification system using whispered speech based on an innovative learning algorithm which is named as extreme learning machine (ELM). The features used in this proposed system are Instantaneous frequency with probability density models. Parametric and nonparametric probability density estimation with ELM was compared with the hybrid parametric and nonparametric probability density estimation with Extreme Learning Machine (HPNP-ELM) for instantaneous frequency modeling. The experimental result shows the significant performance improvement of the proposed whisper speech speaker identification system.     

Increased microbial fuel cell performance using quaternized poly ether ether ketone anionic membrane electrolyte for electricity generation

A high-performance hydroxide exchange membrane was prepared by the chloromethylation and quaternization of Poly ether ether ketone (PEEK) for microbial fuel cell applications. The study reports on the synthesis of a novel quaternized poly ether ether ketone (QPEEK) membrane and subsequent utilization of the ionomer as an anion exchange membrane (AEM). The structural characterization of chloromethylation and quaternization of PEEK was confirmed by FT-IR and ₁H¹ NMR spectroscopy and the morphologies were viewed by scanning electron microscopy. The effects of oxygen crossover and specific substrate crossover on cathode potential were also studied in detail. The investigation of QPEEK with the commercially available AEM (AMI-7001) revealed that the QPEEK shows excellent static properties, i.e. ion-exchange capacity, water uptake, thickness, etc.; and kinetic properties, i.e. diffusion permeability and better durability over 250 days. Power density obtained from an MFC containing the QPEEK-AEM produced higher value (60 W/m³) than the commercial AMI-7001 AEM (52 W/m³). This study shows that QPEEK could be used as an efficient and a cost effective AEM for an MFC.     

Plant-derived antimicrobials reduce Listeria monocytogenes virulence factors in vitro, and down-regulate expression of virulence genes

Listeria monocytogenes (LM) is a major foodborne pathogen causing septicemia, meningitis and death in humans. LM infection is preceded by its attachment to and invasion of human intestinal epithelium followed by systemic spread. The major virulence factors in LM include motility, hemolysin and lecithinase production. Reducing LM attachment to and invasion of host tissue and production of virulence factors could potentially control listeriosis in humans. This study investigated the efficacy of sub-inhibitory concentrations (SICs, concentrations not inhibiting bacterial growth) of three, generally regarded as safe (GRAS)-status, plant-derived antimicrobial compounds in reducing LM attachment to and invasion of human colon adenocarcinoma (Caco-2) and human brain microvascular endothelial cells (HBMEC). Additionally, the effect of these compounds on the aforementioned LM virulence factors was studied. The compounds and their respective SICs used relative to their MICs were trans-cinnamaldehyde (TC 0.50mM, 0.75mM with the MIC of 0.90mM), carvacrol (CR 0.50mM, 0.65mM with the MIC of 0.75mM), and thymol (TY 0.33mM, 0.50mM with the MIC of 0.60mM). All three-plant antimicrobials reduced LM adhesion to and invasion of Caco-2 and HBMEC (p<0.05). The compounds also decreased LM motility, hemolysin production and lecithinase activity (p<0.05). Real-time PCR data revealed that TC, CR, and TY down-regulated the expression of LM virulence genes by >3.0 folds compared to controls (p<0.05). Results suggest that TC, CR, and TY could potentially be used to control LM infection; however, in vivo studies are necessary to validate these results.     

Fabrication, characterization and invitro bioactivity evaluation of QPSU/TiO2 composite membranes

Quaternized Polysulfone (QPSU) is a widely investigated material in the industry because of its unique properties such as resistance to corrosion and high mechanical properties. The ionic nature of the compound can be exploited for medical applications such as in haemodialysis, drug delivery and tissue engineering. In this study, composite membranes of QPSU with varying concentrations of Titanium oxide (TiO₂) were prepared and characterized using FT-IR, ¹H-NMR, XRD, TGA and SEM. The bioactivity of the membranes was studied by immersing them in simulated body fluid (SBF) for 7 days and subsequently observing under SEM for the formation of calcium-phosphate (Ca–PO₄) layer on the surface of the membranes. The formation of Ca–PO₄ on the samples was confirmed using FT-IR and EDAX. The results were compared with those obtained for QPSU membranes and the effect of TiO₂ concentration on the membrane properties was analyzed. It was observed that the percentage crystallinity of the composites increased upto a filler concentration of 5 wt% beyond which it decreased. TGA studies revealed an increase in the thermal stability of the composites with increasing filler concentrations. While optimum bioactivity was observed in the samples containing 5 wt% of TiO₂, higher filler content resulted in the formation of denser calcium—phosphate layer on the surface of the composites. The study shows that quaternized polysulphone/TiO₂ composites are promising bio composites having great potential for application in health care.     

Facile microwave synthesis of Sn-doped WO3 for pseudocapacitor applications

In the present work, we have successfully synthesized pure tungsten oxide (WO₃) and Sn (3 and 5 wt%)-doped WO₃ nanoparticles using facile microwave irradiation method and studied about the electrochemical performances for supercapacitor electrode material. Structural and morphological studies of the prepared nanomaterials were investigated systematically. The powder XRD analysis reveals that pure WO₃ and Sn-doped WO₃ have monoclinic crystal structure and also crystallite size of the material decreases from 38 to 30 nm with increasing dopant concentration. Micro-Raman analysis confirms the formation of monoclinic phase with υ(O–W–O) stretching and δ(O–W–O) bending mode of vibration. SEM and micrographs show the elongation of the plate-like nanostructure of WO₃ for the doping of Sn. High-resolution transmission electron microscope images depict the morphological change and increased porosity in doped samples. The supercapacitive performance and the electrochemical conductivity of the samples were analysed using cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy measurements. The results demonstrate that the 5 wt% Sn-doped WO₃ electrode has the enhanced electrochemical performance in 1 M KOH with a maximum specific capacitance of 418 F g^?1 at low current density of 1 A g^?1. Also, it shows the increase in energy density from 4.88 to 11.77 Wh kg^?1 with respect to the Sn concentration at the power density of 225 W kg^?1_.

     

Impact of erythromycin on respiratory colonization of Ureaplasma urealyticum and the development of chronic lung disease in extremely low birth weight infants

BACKGROUND: Chronic lung disease (CLD) is a significant cause of neonatal morbidity and mortality despite advances in neonatal care. Ureaplasma urealyticum colonization of the lower respiratory tract has been associated with CLD, particularly in extremely low birth weight infants. Despite numerous studies demonstrating the pathogenicity of this organism, treatment remains controversial. This study examines neonates colonized with U. urealyticum in the lower respiratory tract and treated with erythromycin, as compared with noncolonized neonates. METHODS: A prospective cohort study of 124 neonates weighing <1000 g at birth, requiring endotracheal intubation and ventilation. Endotracheal aspirates were cultured for U. urealyticum and conventional bacteria twice weekly for the duration of endotracheal intubation. Infants colonized with U. urealyticum were treated with intravenous erythromycin. Maximal ventilatory requirements, CLD at Day 28 and 36 weeks postconception, duration of ventilation, oxygen dependency and hospital stay were documented. RESULTS: Twenty-two infants (18%) were identified as being U. urealyticum colonized in endotracheal aspirates. Colonization was significantly associated with younger maternal age, prolonged rupture of membranes, premature labor and vaginal delivery. Of colonized neonates 14% were delivered by cesarean section, with intact membranes. As compared with noncolonized infants, there were no statistically significant differences in chronic lung disease, duration of oxygen therapy or time to discharge. CONCLUSIONS: Seven published cohort studies of similar high risk populations where U. urealyticum-colonized infants did not receive erythromycin therapy, show a consistent association with CLD (pooled relative risk + 5.21; 95% confidence interval, 2.93 to 9.64). This association was not demonstrated in the current study and adds further weight to the need for a randomized controlled trial to be performed to evaluate this treatment regimen.     

Performance analysis of torus optical interconnect with data center traffic

Two-dimensional torus network nodes are typically interconnected using XY routing algorithm for transmitting a packet from a source node to a destination node. In XY routing, if all the paths are used efficiently, the throughput and latency can be improved. In this paper, to utilize all the paths efficiently, we propose a novel binary optical routing algorithm (BORA) to improve the throughput and latency. The throughput is calculated according to the injection rate and number of packets received at the destination. The XY routing algorithm and proposed BORA are implemented using objective modular network testbed in C++ simulation software and the results are analyzed and compared. In this paper, the simulation results show that the network latency reduces to 50% while using the proposed algorithm; moreover, the throughput is also improved.     

User behavior based Insider Threat Detection using a Multi Fuzzy Classifier

Multimedia Tools and Applications - Insider threats are a significant source of security breaches in organizations. They are often identified using machine and deep learning methods. These methods...     

Compact Frequency and Bandwidth Reconfigurable Microwave Filter

This paper details the construction and working of a compound reconfigurable filter capable of frequency and bandwidth reconfiguration in the frequency range from 2 to 3 GHz. The switching between frequency and bandwidth reconfiguration is inherited by two PIN diodes. Bandwidth tuning is facilitated by tuning two transmission zeros individually using varactor diodes, giving flexibility in reconfiguring the upper and lower pass edges. The two transmission zeros are obtained using simple concentric square loop resonators. The maximum bandwidth obtained is 1.5 times the minimum bandwidth offered by the filter. Hence the filter can be used for dynamic bandwidth allocation. This prototype is fabricated and validated in real-time. The simulated and measured results are analogous to each other.

     

Signal integrity analysis on a microstrip ultra-wideband coupled-line coupler

In this paper, a compact, single-section, Ultra-wideband (UWB) coupled-line coupler designed using concentric loop in the signal plane and defect in the ground plane is presented. Bandwidth enhancement is achieved with low coupling at the X-band satellite downlink range to improve the signal strength for defence applications. Return loss greater than 15 dB and isolation greater than 20 dB is achieved over the entire UWB band. The prototype is fabricated and tested to validate the simulation results. Further to detect the quality of the output signal, signal integrity analysis is performed and metrics such as error vector magnitude (EVM), magnitude and phase error, eye pattern, constellation plots and signal to noise ratio are presented for the proposed UWB coupled-line coupler.