Srinivasan M.,Saranathan College of Engineering |
Narayanasamy R.,National Institute of Technology Tiruchirappalli |
Senthilkumar V.,National Institute of Technology Tiruchirappalli |
Nguyen Q.B.,National University of Singapore |
Gupta M.,National University of Singapore
Materials and Design | Year: 2013
The hot deformation behavior and microstructural evolution of cast-extruded AZ31B magnesium alloy and nanocomposite have been studied using processing-maps. Compression tests were conducted in the temperature range of 250-400°C and strain rate range of 0.01-1.0s-1. The three-dimensional (3D) processing maps developed in this work, describe the variations of the efficiency of power dissipation and flow instability domains in the strain rate (ε̇) and temperature (T) space. The deformation mechanisms namely dynamic recrystallization (DRX), dynamic recovery (DRY) and instability regions were identified using processing maps. The deformation mechanisms were also correlated with transmission electron microscopy (TEM) and optical microscopy (OM). The optimal region for hot working has been observed at a strain rate (ε̇) of 0.01s-1 and the temperature (T) of 400°C for both magnesium alloy and nanocomposite. Few instability regimes have been identified in this study at higher strain rate (ε̇) and temperature (T). The stability domains have been identified in the lower strain rate regimes. © 2012 Elsevier Ltd.
Arivazhagan M.,AA Government Arts College |
Kavitha R.,Saranathan College of Engineering
Journal of Molecular Structure | Year: 2012
The FT-IR and FT-Raman spectra of 4-methyl-3-nitro benzyl chloride (MNBC) molecule have been recorded in the range of 4000-400 cm -1 and 3500-50 cm -1 respectively. The molecular geometry and vibrational frequencies in the ground state are calculated using the DFT/B3LYP method with 6-311+G (d, p) and 6-311++G (d, p) basis sets. The computed values of frequencies are scaled using a suitable scale factor to yield good coherence with the observed values. Most of the modes have wavenumbers in the expected range. The calculated HOMO-LUMO energy gap shows that charge transfer occur within the molecule. NBO analysis has been performed in order to elucidate charge transfers or conjugative interaction, the intra-molecule rehybridization and delocalization of electron density within the molecule. From the result of Mulliken population analysis, it is clear that the substitution of CH 2Cl atoms in the aromatic ring leads to a redistribution of electron density. The total energy distribution (TED) has also been calculated for each mode of the vibration of the molecule. © 2011 Elsevier B.V. All rights reserved.
Padmaa M.,Saranathan College of Engineering |
Venkataramani Y.,Saranathan College of Engineering |
Amirtharajan R.,SASTRA University
Information Technology Journal | Year: 2011
The study of communication security includes not just encryption but also traffic security, whose essence lies in "Information Hiding". The security of an image can be enhanced by cleverly embedding data without affecting its quality. This can be done by using information hiding techniques like steganography and cryptography. Combining steganography with cryptography becomes an essential facet for secure communication. In present study, enhanced image quality and security is obtained by consorting pixel indicator technique with PVD technique. Here, the raw data is first encrypted to get two different forms of message Tl and T2 using two distinct keys Kl, K2 which is done by using encryption algorithms. As two encrypted messages can be embedded in this process, we have to first extract and then decrypt the message to retrieve the original data. The enhanced level of security is defined by the fact that even if one retrieves the message from the image it's still incomprehensible to get the original message without the two keys Kl and K2. © 2011 Asain Network for Scientific Information.
Kalpana Y.,Saranathan College of Engineering |
Padmaa M.,Saranathan College of Engineering
International Conference on Communication and Signal Processing, ICCSP 2014 - Proceedings | Year: 2014
Edge detection is one of the preprocessing steps in image analysis. Edges characterize boundaries and edge detection is one of the most difficult tasks in image processing. Digital image processing is playing an increasingly vital role in imaging based fire monitoring systems. Since flame images are special class of images, some of the unique features of a flame may be used to identify flame edges. There are some differences between flame images and other general images; the brightness of the flame is generally much higher than the other objects while the background is comparatively dark. The expected flame edge should be clear and uninterrupted. Several known edge detection methods have been tested to identify flame edges but the results achieved are disappointing. Hence this new edge detection algorithm has been proposed for the detection of flame and fire in fire alert systems. This is an improved method which identifies the edges of the flames correctly by removing all the noises in the flames. Some research work shows that the existing methods do not emphasize the continuity and clarity of the flame and fire edges. The proposed method identifies the continuous and clear edges of the flame/fire. This process detects outlines of an object and boundaries between objects and the background in the image. Experimental results for different flame images proved the effectiveness and robustness of the algorithm. © 2014 IEEE.
Hariprasath S.,Saranathan College of Engineering |
Prabakar T.N.,Oxford Engineering College
IEEE-International Conference on Advances in Engineering, Science and Management, ICAESM-2012 | Year: 2012
A Biometric system is essentially a pattern recognition system that makes use of biometric traits to recognize individuals. Authentication systems built on only one biometric modality may not fulfill the requirements of demanding applications in terms of properties such as performance, acceptability and distinctiveness. Most of the unimodal biometrics systems have problems such as noise in collected data, intra-class variations, inter-class variations, non universality etc. Some of these limitations can be overcome by multiple source of information for establishing identity; such systems are known as multimodal biometric systems. In this paper a multi modal biometric system of iris and palm print based on Wavelet Packet Analysis is described. The most unique phenotypic feature visible in a person's face is the detailed texture of each eye's iris. Palm is the inner surface of a hand between the wrist and the fingers. Palmprint is referred to principal lines, wrinkles and ridges on the palm. The visible texture of a person's iris and palm print is encoded into a compact sequence of 2-D wavelet packet coefficients, which generate a "feature vector code". In this paper, we propose a novel multi-resolution approach based on Wavelet Packet Transform (WPT) for texture analysis and recognition of iris and palmprint. The development of this approach is motivated by the observation that dominant frequencies of iris texture are located in the low and middle frequency channels. With an adaptive threshold, WPT sub images coefficients are quantized into 1, 0 or 1 as iris signature. This signature presents the local information of different irises. By using wavelet packets the size of the biometric signature of code attained is 960 bits. The signature of the new pattern is compared against the stored pattern after computing the signature of new input pattern. Identification is performed by computing the hamming distance. © 2012 Pillay Engineering College.
Krishna B.V.,Saranathan College of Engineering |
Baskaran K.,Government College of Technology, Coimbatore
IET Signal Processing | Year: 2013
Fast signal processing implementation techniques for detection and classification of power quality (PQ) disturbances are the need of the hour. Hence in this work, a parallel computing approach has been proposed to speed up the feature extraction of PQ signals to facilitate rapid building of classifier models. Considering that the Fourier, the one-dimensional discrete wavelet, the time-time and the Stockwell transforms have been used extensively to extract pertinent time-frequency features from nonstationary and multi-frequency PQ signals, acceleration approaches using data and task parallelism have been employed for parallel implementation of the above time-frequency transforms. In the first approach, data parallelism was applied to the Stockwell transform and the time-time transform-based feature extraction methods separately to alleviate capability problems. Also, data parallelism was applied to Fourier and wavelet-based feature extraction methods independently to alleviate capacity problems. Secondly, a combination of task and data parallelism was applied to speed up S-transform based three-phase sag feature extraction. Experiments were conducted using shared-memory and distributed memory architectures to try out the effectiveness of the proposed parallel approaches. The performances of these parallel implementations were analysed in terms of computational speed and efficiency in comparison with the sequential approach. © The Institution of Engineering and Technology 2013.
Ganapathy R.,Saranathan College of Engineering
Journal of Heat Transfer | Year: 2012
Free convective heat and mass transfer from a sphere of constant temperature and concentration buried in an unbounded porous medium is studied analytically assuming the validity of the Darcy flow model. Using a regular perturbation analysis, transient and steady-state solutions have been obtained in the form of series expansions in terms of a thermal Rayleigh number, which is based on the temperature of the heated sphere and the medium permeability. The results are exemplified by drawing the streamlines at various times. Of special significance is the emergence of a downward flow in the transient state when the two buoyancy mechanisms are opposed. These results apply as well to the case of buoyancy-induced flows from a sphere generating simultaneously two different chemical components. Copyright © 2012 by American Society of Mechanical Engineers.
Sivakumar P.,Alagappa Chettiar College of Engineering And Technology |
Arutchelvi M.,Saranathan College of Engineering
International Journal of Electrical Power and Energy Systems | Year: 2014
In this paper, a new control algorithm for grid connected inverter fed by Photovoltaic array (PV) excited wind-driven induction generator (IG) for unbalanced nonlinear load at point of common coupling (PCC) is proposed. The proposed composite power controller comprises of multi control loops such as power, voltage and current loops. The power control loop generates positive sequence reference current based on the availability of PV power and the average power demand of the load and negative sequence reference currents to compensate the oscillating power component that appears due to the unbalanced nonlinear load at the PCC and further, drop due to non-fundamental power component is compensated by addition of virtual non-linear impedance to the current control loop. The voltage control loop generates the reactive current reference to compensate the drop due to nonlinear magnetizing reactance of IG to eliminate the machine de-rating effect. The current control loop regulates the average and suppresses the oscillating power in dual decoupled double synchronous reference frame to generate modulating signal to the PV sourced inverter. Exhaustive simulations are carried out for the proposed scheme for varying irradiations, wind speed and load variations at the PCC in MATLAB and compared with direct power control scheme. © 2014 Elsevier Ltd. All rights reserved.
Baritha Begum M.,Saranathan College of Engineering |
Venkataramani Y.,Saranathan College of Engineering
Procedia Engineering | Year: 2012
Compression algorithm is what reduces the redundancy of data representation and decreases the data storage capacity. Data compression plays a vital role in reducing the communication cost making use of available bandwidth. The compressed data from the security aspect is transmitted through internet. It is, however very much vulnerable to a multitude of attacks. To propose a new dictionary based text compression technique for ASCII texts for the purpose of obtaining good performance on various document sizes. Dictionary based compression bits are hidden into the Lsb bit of audio signals and to calculate the signal to noise ratio (SNR). This audio Steganography is conducted for various compression algorithms with dictionary based compression. Audio Steganography based dictionary compression achieves better value of signal to noise ratio (SNR).
Kavitha R.,Saranathan College of Engineering
Indian Journal of Pure and Applied Physics | Year: 2012
The Fourier Transform Infrared (FTIR) and FT-Raman spectra of 4-bromoveratrole (4BV) have been recorded in the region 4000-400 cm -1 and 3500-50 cm -1 , respectively. The experimental vibrational frequencies are compared with the wave numbers obtained theoretically by ab-initio HF and DFT-B3LYP gradient calculations employing the standard 6-31 1++G(d,p) basis set for the optimized geometry of 4BV. The values of the first-order hyperpolarizability (β) of the investigated molecule are computed using DFT quantum mechanical calculations. The calculation results also show that the molecule might have microscopic nonlinear optical (NLO) behaviour with non-zero values.NBO analysis has been carried out at DFT level. NBO study explains charge delocalization of the molecule. Mulliken's net charges have been calculated and compared with the atomic natural charges.