Feature-level fusion of mental task’s brain signal for an efficient identification system

In this research, we have explored the canonical correlation analysis (CCA) to improve the performance of the identification system that involves multiple correlated modalities. In particular, we consider the electroencephalogram signal of different mental task performed by the subject such as breathing, mental mathematics, and geometric figure rotation, visual counting and mental letter composing. Our motivation based on the fusion of feature vector of mental task using canonical correlation analysis, where feature set extraction using empirical mode decomposition and information theoretic measure and statistical measurement. In order to classify the fused vector from different mental, we have used linear vector quantization (LVQ) neural network and its extension LVQ2. The results of the experiments testing the performance have been evaluated with two profiles of the database. We have observed canonical correlation-based fusion providing the better results in comparison with simple fusion rule. The novelty of this research is the new feature generation using fused feature of distinct mental task based on CCA.     

A conducting composite based on poly(N‐vinylcarbazole)–formalin resin and acetylene black

A poly(N‐vinylcarbazole) (PNVC)–formalin (FO) resin (PNVC‐FO) was prepared via copolycondensation between N‐vinylcarbazole (NVC) and FO in the presence of dry HCl gas in toluene medium at 110°C. A highly conducting composite of PNVC‐FO resin with nanodimensional acetylene black (AB) was prepared by carrying out the polycondensation reaction in presence of a suspension of acetylene black (AB) in toluene. The inclusion of PNVC in the PNVC‐FO‐AB composite was confirmed by FT‐IR analysis. Scanning electron microscopic analyses of PNVC‐FO resin and PNVC‐FO‐AB composite revealed formation of spherical particles and aggregates of irregular shapes respectively. Thermogravimetric analyses revealed the overall stability order as: AB > PNVC‐FO‐AB composite > PNVC‐FO resin > PNVC homopolymer. In sharp contrast to PNVC and PNVC‐FO resin, which were both nonconducting (10^?12 to 10^?16 S/cm), the conductivity of the composites reached values between 0.75 S/cm and 6.54 S/cm corresponding to AB loading of 28–49 wt % respectively. Temperature versus conductivity studies revealed an initial increase in conductivity upto 200°C and current–voltage characteristics of the PNVC‐FO‐AB composite showed a linear trend consistent with Ohmic behavior. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3837–3843, 2007     

Knoevenagel condensation reaction over acid–base bifunctional nanocrystalline CexZr1−xO2 solid solutions

Highly thermally stable three-dimensional spongelike mesoporous Ce_xZr_1?xO₂ solid solutions consisting of nanometer size particles with different Ce/Zr compositions were synthesized by a modified sol–gel procedure using a triethanolamine/water mixture as a solvent to be used in liquid Knoevenagel condensation reaction. These materials were investigated in detail by means of X-ray diffraction (XRD), Raman spectroscopy, chemical analysis, X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR) and adsorption microcalorimetry. The XRD, HRTEM and XPS studies proved the presence of nanocrystalline Ce_xZr_1?xO₂ solid solutions. These solid solutions showed excellent chemoselectivity in the classical Knoevenagel reaction. The large pore sizes (around 10 nm) highlight the possibility of using Ce_xZr_1?xO₂ as a support material for versatile catalytic systems. The results obtained from NH₃ and SO₂ adsorption microcalorimetry experiments successfully demonstrated the incorporation of ZrO₂ into the CeO₂ lattice resulting in both acidic and basic surface sites in a mixed oxide matrix.     

Microstructural,Optical and Magnetic Study of Ni–Zn Nanoferrites

Journal of Superconductivity and Novel Magnetism - NixZn1-xFe2O4 (x?=?0.0, 0.2, 0.4, 0.5, 0.6, 0.8 and 1.0) nanoferrites were synthesized using the citrate precursor method with...     

A hybrid VQ-GMM approach for identifying Indian languages

Language Identification is the task of identifying a language from a given spoken utterance. Main task of a language identifier is to design an efficient algorithm which helps a machine to identify correctly a particular language from a given audio sample. We have proposed here a hybrid approach for identifying a language which is a combination of Vector Quantization (VQ) and Gaussian Mixture Models (GMM). A brief review of work carried out in the area of Speaker Identification using VQ-GMM hybrid approach is discussed here. We have carried out experiments for identifying four Indian Languages—Assamese, Bengali, Hindi and Indian English. The experiments were carried out on our own recorded standard language database collected from 50 speakers. Speech features were extracted using MFCCs. Results show that after applying hybrid approach, accuracy is best with highest mixture order and with the increase in mixture order, accuracy increases uniformly for all four languages. It is also concluded here that hybrid approach gives better results when compared with the baseline GMM system.     

Recent advances in synthesis,characterization, and applications of nanoparticles for contaminated water treatment- A review

The major issue of consumable water shortage in different parts of the world has piqued the interest of researchers around the globe towards finding out novel, efficient and cost-effective means and techniques for treatment of contaminated water. Towards such efforts, researchers are experimenting with various types of nanoparticles for observing their abilities to treat polluted and/or wastewater. Numerous types of nanoparticles such as carbon-based nanoparticles, semiconductor nanoparticles, ceramic nanoparticles, polymeric nanoparticles, metal nanoparticles, magnetic nanoparticles, etc. are widely tested to confirm their applicability as potential candidates for contaminated as well as wastewater treatment. Different types of nanoparticles offer specific advantages depending on their composition, physical, chemical, electrical, magnetic and structural characteristics. Nanoparticles such as nanoferrites are reported to be easily separated, regenerated and reused up to several runs without incurring any loss in their properties which tend to significantly reduce operations costs. The present study provides a detailed review of the various synthesis and characterization techniques for the production of the nanoparticles. The present study also reviews the current progress, made particularly during the last two decades, in the application of nanoparticles for successful removal of organic, metallic as well as pathogenic pollutants from the water. This review aims to highlight the unlimited potential of nanoparticles and their derivatives in the domain of contaminated and wastewater treatment.     

Conducting nanocomposites of polyacrylamide with acetylene black and polyaniline

A conducting nanocomposite of polyacrylamide (PAA) with acetylene black was prepared via Na₂AsO₃‐K₂CrO₄ redox initiated polymerization of acrylamide in water containing a suspension of acetylene black. FTIR analyses confirmed the presence of PAA in the nanocomposites. The composite possessed lower thermal stability than AB and exhibited three stages of decomposition upto 430°C. DSC thermogram revealed three endotherms due to minor thermal degradation (at ∼100°C), melting and decomposition (at ∼230°C) and major decomposition (at ∼430°C). TEM analyses indicated the formation of globular composite particles with sizes in 30–70 nm range. In contrast to the very low conductivity of the base polymer the composite showed a dramatic increase in conductivity (0.19–6.0 S/cm) depending upon AB loading. Log (conductivity) –1/T plot showed a change in slope at ∼127°C indicating the manifestation of an intrinsic conductivity region and an impurity conductivity region. The activation energy for conduction as estimated from the slope of region I was 0.008 eV/mol. The C–V plot was linear showing a metallic behavior. For comparison in conductivity PAA‐polyaniline composite was also prepared which however displayed much lower conductivity values. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Dielectric characteristics of poly(N-vinylcarbazole) and its nanocomposites with ZnO and acetylene black

Dielectric constant and dielectric loss parameters of poly(N-vinylcarbazole) homopolymer and several nanocomposites of poly(N-vinylcarbazole) with ZnO were studied as a function of frequency. In the low frequency range (0–20 kHz) the dielectric constant values of the base polymer varied from ∼30 to ∼2, and the same for the composite varied from 8500 to 2000 (4.54), 5000 to 1000 (2.63) and 2000 to 500 (1.17), the figures in parenthesis denoting the ratio of ZnO:PNVC in the nanocomposites. Likewise, dielectric loss parameters were found to be (7–10 × 10⁻³) for the homopolymer and 4.0, 2.5 and 1.25 for the three PNVC–ZnO composites respectively. Notably, a mechanical mixture of ZnO and PNVC (1.17) exhibited much lower dielectric constant (400–25) and loss parameters (0.14–0.065). These features imply polarization was differently affected depending on factors such as grain size and grain-boundary interfaces being formed in these systems. Tan δ–temperature variation for the composites revealed the occurrence of a maximum between 60 and 70 °C. These features signified dipole group loss in the composite. Dielectric constant of a conducting nanocomposite of poly(N-vinylcarbazole) with acetylene black revealed very low negative value tending to zero at high frequency.     

Novel dye-substituted polyanilines: conducting and antimicrobial properties

Conducting and antimicrobial properties of chemically synthesized dye-substituted polyanilines were found to be affected by varying the dye moieties. The dye-polyanilines were characterized by various analytical techniques including UV–visible spectroscopy, IR spectroscopy, fluorescence spectroscopy, AC impedance and thermo-gravimetric analysis and X-ray diffraction. The temperature dependence of DC conductivity was studied by two-probe method to learn about the conduction behavior in the synthesized compounds. The conductivity of the dye-substituted polyanilines was found to be in the range of 10^?3–10^?2 Scm^?1. For the study of antimicrobial behavior of the synthesized polyanilines, different microorganisms, including the bacteria Escherichia coli (MTCC 442), Pseudomonas aeurginosa (MTCC 441), Staphylococus aureus (MTCC 96), and S. pyogenus (MTCC 443) and fungal strains Candida albicans (MTCC 227), Aspergillus niger (MTCC 282) and A. clavatus (MTCC 1323), were chosen based on their clinical and pharmacological importance.