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Reddy V.V.,Kakatiya Institute of Technology and Science
IETE Journal of Research | Year: 2017

A new compact Flared-U-type fractal patch antenna is studied for linear and circular polarization (CP). For linear polarization, patch sides are replaced with symmetrical Flared-U fractal curves. By interchanging the edges of a square structure with asymmetrical Flared-U-type fractal curves in two perpendicular directions, two degenerated orthogonal modes are generated for CP emission. To design compact CP antennas, indentation parameters of the Flared-U-type fractal boundary curves are optimized. All the simulations are carried out using finite-element-method-based HFSS electromagnetic simulation tool. Measured results depict that 10-dB return loss and 3-dB axial ratio bandwidths of the presented iteration order (IO) 1 Flared-U CP antenna 2 are 6.17% and 1.8%, respectively, at operating frequencies of 2300 MHz. Obtained results demonstrate that by deploying fractal boundary curves as sides of the square structure, an excellent CP is achieved. © 2017 IETE

Vankanti V.K.,Kakatiya Institute of Technology and Science
Journal of Materials Research and Technology | Year: 2014

The objective of the present work is to optimize process parameters namely, cutting speed, feed, point angle and chisel edge width in drilling of glass fiber reinforced polymer (GFRP) composites. In this work, experiments were carried out as per the Taguchi experimental design and an L9 orthogonal array was used to study the influence of various combinations of process parameters on hole quality. Analysis of variance (ANOVA) test was conducted to determine the significance of each process parameter on drilling. The results indicate that feed rate is the most significant factor influencing the thrust force followed by speed, chisel edge width and point angle; cutting speed is the most significant factor affecting the torque, speed and the circularity of the hole followed by feed, chisel edge width and point angle. This work is useful in selecting optimum values of various process parameters that would not only minimize the thrust force and torque but also reduce the delimitation and improve the quality of the drilled hole. © 2013 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda. All rights reserved.

Ram M.R.,Kakatiya Institute of Technology and Science | Madhav K.V.,Kakatiya Institute of Technology and Science | Krishna E.H.,Kakatiya University | Komalla N.R.,Government MGM Hospitals | Reddy K.A.,Kakatiya Institute of Technology and Science
IEEE Transactions on Instrumentation and Measurement | Year: 2012

The performance of pulse oximeters is highly influenced by motion artifacts (MAs) in photoplethysmographic (PPG) signals. In this paper, we propose a simple and efficient approach based on adaptive step-size least mean squares (AS-LMS) adaptive filter for reducing MA in corrupted PPG signals. The presented method is an extension to our prior work on efficient use of adaptive filters for reduction of MA in PPG signals. The novelty of the method lies in the fact that a synthetic noise reference signal for an adaptive filtering process, representing MA noise, is generated internally from the MA-corrupted PPG signal itself instead of using any additional hardware such as accelerometer or source-detector pair for acquiring noise reference signal. Thus, the generated noise reference signal is then applied to the AS-LMS adaptive filter for artifact removal. While experimental results proved the efficacy of the proposed scheme, the merit of the method is clearly demonstrated using convergence and correlation analysis, thus making it best suitable for present-day pulse oximeters utilizing PPG sensor head with a single pair of source and detector, which does not have any extra hardware meant for capturing noise reference signal. In addition to arterial oxygen saturation ({SpO}-{2}) estimation, the artifact reduction method facilitated the waveform contour analysis on artifact-reduced PPG, and the conventional parameters were evaluated for assessing the arterial stiffness. © 2012 IEEE.

Nageswara Rao D.K.,Vizag Institute of Technology | Ramesh Babu M.,Christu Jyothi Institute of Technology and Science | Raja Narender Reddy K.,Kakatiya Institute of Technology and Science | Sunil D.,National Thermal Power Corporation
Composite Structures | Year: 2010

The solution presented in this paper is useful for finding the stress distribution around holes in symmetric laminates as well as in isotropic plates and also to determine the failure strength of the laminate on first ply failure basis by Tsai-Hill, Hashin-Rotem and Tsai-Wu criteria. This is a one stop solution for all kinds of in-plane loading on symmetric laminates as well as isotropic plates with any shape of cutout. Using Savin's basic solution for anisotropic plates, the stress functions are derived for generalized mapping function for the hole and arbitrarily oriented in-plane loading. Square and rectangular holes in symmetric laminates of Graphite/epoxy and Glass/epoxy are studied. It is noted that the maximum stress and its location is mainly influenced by the type of loading. Larger stresses are noted for shear loading. The stress results are also obtained by ANSYS for comparison. © 2010 Elsevier Ltd.

Reddy B.S.P.,Kakatiya Institute of Technology and Science | Rao C.S.P.,National Institute of Technology Warangal
International Journal of Simulation Modelling | Year: 2011

In recent times flexible manufacturing systems emerged as a powerful technology to meet the continuous changing customer demands. Increase in the performance of flexible manufacturing systems is expected as a result of integration of the shop floor activities such as machine and vehicle scheduling. The authors made an attempt to integrate machine and vehicle scheduling with an objective to minimize the makespan using Automod. Automod is a discrete event simulation package used to model and simulate a wide variety of issues in automated manufacturing systems. The key issues related to the design and operation of automated guided vehicles such as flow path layout, number of vehicles and traffic control problems are considered in the study. The performance measures like throughput, machine and vehicle utilization are studied for different job dispatching and vehicle assignment rules in different flexible manufacturing system configurations.

Reddy B.S.K.,Kakatiya Institute of Technology and Science
Wireless Personal Communications | Year: 2016

Improved spectral and energy efficiency are two key requirements for the next generation (5G) wireless communication systems. The inefficiency and non-linearity of traditional power amplifiers (PA) pose significant challenges to meet these requirements, especially for multicarrier modulation signals with high peak to average power ratio (PAPR). Orthogonal frequency division multiplexing (OFDM) is currently the most widely used multi carrier modulation technique; it has been adopted in many wireless communication standards including IEEE 802.11, 802.16, 3GPP Long Term Evolution and WiMAX. When a high PAPR signal process through a nonlinear power amplifier (PA), intermodulation distortion is generated, creating out-of-band emission that can interfere with other transmission in adjacent bands. In addition, in-band distortion, which degrades the bit error rate performance, occurs. Hence, I have addressed these problems by employing four different PAPR reduction techniques such as Phase modulation, Rail clipping, Sample and Hold approach and Threshold methods based on amplitude clipping. For practical proof of the proposed concepts, I have chosen software defined radio as an experimental setup that employs USRP N210 as hardware and GNU Radio as software. © 2016 Springer Science+Business Media New York

Balraj U.S.,Kakatiya Institute of Technology and Science
Journal of Physics: Conference Series | Year: 2016

In this paper, mathematical modeling of three performance characteristics namely material removal rate, surface roughness and electrode wear rate in rotary electrical discharge machining RENE80 nickel super alloy is done using regression approach. The parameters considered are peak current, pulse on time, pulse off time and electrode rotational speed. The regression approach is very much effective in mathematical modeling when the performance characteristic is influenced by many variables. The modeling of these characteristics is helpful in predicting the performance under a given set of combination of input process parameters. The adequacy of developed models is tested by correlation coefficient and Analysis of Variance. It is observed that the developed models are adequate in establishing the relationship between input parameters and performance characteristics. Further, multi-criteria optimization of process parameter levels is carried using grey based Taguchi method. The experiments are planned based on Taguchi's L9 orthogonal array. The proposed method employs single grey relational grade as a performance index to obtain optimum levels of parameters. It is found that peak current and electrode rotational speed are influential on these characteristics. Confirmation experiments are conducted to validate optimal parameters and it reveals the improvements in material removal rate, surface roughness and electrode wear rate as 13.84%, 12.91% and 19.42% respectively.

Prabhakar G.S.,Kakatiya Institute of Technology and Science
International Journal of Intelligent Engineering and Systems | Year: 2016

Space-Time Block Coding (STBC) is a MIMO based approach which achieves high reliability and diversity by transmitting multiple copies of data stream across antennas. In this paper, bi-scale based fractional order statistics for blind channel estimation in chaotic STBC systems are proposed. Accordingly, the proposed communication system contains chaotic modulator and transmitter in the transmitter section. Then, the receiver contains the channel equalizer and chaotic demodulator. In the channel equalizer, the signal is transmitted through a channel which is estimated through the proposed channel estimation algorithm. In the proposed channel estimation, the weight updating formulae will be modified based on the comparison of the estimated weighted values and its old weighted value. The analysis of the technique is carried out by finding out the evaluation metrics of BER, MSE and SER with respect to SNR and different antenna array sizeof 4, 5 and 6.

Ganta R.R.,Kakatiya Institute of Technology and Science | Ganta R.R.,Osmania University | Zaheeruddin S.,Kakatiya Institute of Technology and Science | Baddiri N.,Kakatiya Institute of Technology and Science | Rao R.R.,Osmania University
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2012

This paper presents a novel method for segmenting the oil spill regions in the SAR satellite images taken in broad daylight using illumination-reflectance based level set model. These images of oil spills taken in broad daylight appear as a blend of dark areas with scintillations of glitter due to the illumination and reflectance components present. Most of the dark areas in the SAR images are the areas indicating oil spills because the oil dampens the capillary waves on the sea surface. The presence of the glitter induces speckle in SAR images. This does not only reduces the interpreter's ability to resolve fine detail, but also makes automatic segmentation of such images difficult. Segmentation of such images using conventional level set methods makes the process cumbersome and may lead to improper results. The accuracy of segmentation greatly depends on the amount of the illumination and reflectance (IR) components present in the images. To perform segmentation of such images we propose an adaptive level set evolution process based on the IR components in them. This can be achieved by combining a new signed pressure function which is derived from the amount illumination and reflectance present in the image. The IR components present in image are extracted by the process of homomorphic decomposition with the help of filters with specific cut off frequencies. This method is the first application successfully implemented on SAR images and the results are found to be superior when compared with earlier techniques. Comparative analysis is made with the conventional region based level sets in terms of accuracy of segmentation for complex images. © 2008-2012 IEEE.

Kamakshi P.,Kakatiya Institute of Technology and Science
2014 International Conference on Circuits, Power and Computing Technologies, ICCPCT 2014 | Year: 2014

The process of discovering interesting and previously unknown, but potentially useful patterns from large spatial datasets is called spatial data mining. Extracting interesting and useful patterns from spatial datasets is more difficult than extracting the corresponding patterns from traditional numeric and categorical data due to the complication of spatial data types, spatial associations and correlation between them. Spatial Information may not only include spatial or geographical information or symbols but can also contain personal information like a person's name, mobile phone numbers linked with their address. Spatial data mining operation on such databases may not only extract required interesting patterns but may also reveal the sensitive and personal information which are associated with spatial database. An intruder can pose challenges to individual privacy by extracting the spatial data mining results or patterns and linking the data in various situations, previous knowledge and other information obtained from heterogeneous sources. This paper focus on various possibilities through which privacy of an individual can be easily violated in spatial data mining operation. Different techniques are proposed which can preserve the privacy of an individual in spatial data mining operation. © 2014 IEEE.

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