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Radhika K.R.,BMS College of Engineering | Venkatesha M.K.,RNS Institute of Technology | Sekhar G.N.,BMS College of Engineering
Pattern Recognition Letters | Year: 2011

In this work, shape analysis of the acceleration plot, using lower order Zernike moments is performed for authentication of on-line signature. The on-line signature uses time functions of the signing process. The lower order Zernike moments represent the global shape of a pattern. The derived feature, acceleration vector is computed for the sample signature which comprises on-line pixels. The Zernike moment represent the shape of the acceleration plot. The summation value of a Zernike moment for a signature sample is obtained on normalized acceleration values. This type of substantiation decreases the influence of primary features with respect to translation, scaling and rotation at preprocessing stage. Zernike moments provide rotation invariance. In this investigation it was evident that the summation of magnitude of a Zernike moment for a genuine sample was less as compared to the summation of magnitude of a imposter sample. The number of derivatives of acceleration feature depends on the structural complexity of the signature sample. The computation of best order by polynomial fitting and reference template of a subject is discussed. The higher order derivatives of acceleration feature are considered. Signatures with higher order polynomial fitting and complex structure require higher order derivatives of acceleration. Each derivative better represents a portion of signature. The best result obtained is 4% of False Rejection Rate [FRR] and 2% of False Acceptance Rate [FAR].© 2010 Elsevier B.V. All rights reserved.


Sumathi S.,RNS Institute of Technology
International Journal of Electrical Power and Energy Systems | Year: 2015

Control of voltage in a power system under varying load conditions can be achieved by varying the generator excitation, changing the tap position of transformers and by varying the reactive power injection or absorption at the shunt compensated buses. Proper coordination of these controllers is essential for the effective operation of the power system. This paper deals with the development of Artificial Neural Network which gives the voltage controller settings, such that the voltage deviations at the load buses are minimum. © 2014 Elsevier Ltd. All rights reserved.


Pandurangappa C.,RNS Institute of Technology | Lakshminarasappa B.N.,Bangalore University
Philosophical Magazine | Year: 2011

Samarium-doped calcium fluoride (CaF2) nanoparticles were synthesized by the co-precipitation method and characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), optical absorption and photoluminescence (PL) techniques. The PXRD patterns confirmed the cubic crystallinity of the synthesized nanoparticles. The average particle size estimated using Scherer's formula was ∼20 nm. The purity of the synthesized nanoparticles was confirmed by the FTIR spectrum. The morphological features studied using SEM revealed that the nanoparticles were agglomerated and porous. The optical absorption spectrum showed a strong and prominent absorption peak at ∼264nm and a weak one at ∼212 nm. The PL spectrum showed broad and prominent emissions with peaks at ∼387 and 532nm along with weak emissions at 573 and 605 nm. © 2011 Taylor & Francis.


Pandurangappa C.,RNS Institute of Technology | Lakshminarasappa B.,Bangalore University
Journal of Nanomedicine and Nanotechnology | Year: 2011

Calcium fluoride (CaF2) nanoparticles were synthesized by co-precipitation method and characterized by powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM). Also, optical absorption (OA) and photoluminescence (PL) studies on gamma irradiated (γ-rayed) CaF2 nanoparticles were carried out. The XRD patterns confirmed the cubic crystallinity of the samples and the particle size was found to be ~25 nm. The purity of the synthesized nanoparticles was confirmed by FTIR spectrum. The morphological features studied using SEM revealed the agglomerated and porous nature of nanoparticles. γ-rayed CaF2 nanoparticles showed a prominent absorption with a peak at ~360 nm besides three weak but well separated absorptions at ~ 267, 442 and 510 nm. The various defect centers responsible for the absorption peaks were identified. The PL studies of samples showed strong emissions at ~396 nm and 425 nm. The observed PL emissions are attributed to defects created in nanocrystalline CaF2. © 2011 Pandurangappa C, et al.


Pandurangappa C.,RNS Institute of Technology | Lakshminarasappa B.N.,Bangalore University | Nagabhushana B.M.,M.S. Ramaiah Institute of Technology
Journal of Alloys and Compounds | Year: 2010

Calcium fluoride nanocrystals (CaF2) were synthesized by two different techniques namely co-precipitation and hydrothermal. The synthesized nanocrystals were characterized by powder X-ray diffraction (PXRD), Fourier transform infrared red spectroscopy (FTIR), scanning electron microscopy (SEM), optical absorption and photoluminescence (PL). The crystallite size estimated using Scherer's formula was found to be in the range 30-35 nm for nanocrystals synthesized by co-precipitation method where as in case of hydrothermally synthesized nanocrystals it is in the range 20-28 nm which is less compared to those obtained by co-precipitation method. The morphological features as studied using SEM revealed that the nanocrystals are agglomerated, crispy with porous. The SEM images of hydrothermally synthesized nanocrystals showed less agglomeration than those obtained by co-precipitation method and the images confirm the formation of nanoparticles. The optical absorption spectrum showed a strong absorption band peaked at 244 nm for nanocrystals synthesized by co-precipitation method and it is 218 nm peak in case of hydrothermally synthesized ones. The PL emission spectrum showed two prominent emission bands peaked at 330 and 600 nm when excited at 218 nm. © 2009 Elsevier B.V. All rights reserved.

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