Kaushik A.,Banasthali University |
Dalela B.,SKIT |
Rathore R.,University of Kota |
Vats V.S.,Government College |
And 4 more authors.
Journal of Alloys and Compounds | Year: 2013
A systematic investigation on the synthesis, characterization, optical and magnetic properties of Co doped ZnO nanocrystals have been reported. Nanocrystals of Zn1-xCoxO (where x = 0.05 and 0.10) were synthesized using the Sol-gel technique. Structural, optical and magnetic properties of the samples were investigated by X-ray diffraction (XRD), UV-VIS-NIR spectroscopy, Raman spectroscopy and SQUID magnetometer. Energy dispersive X-ray, Scanning electron microscopic, XRD and Raman measurements showed that the Co ions were successfully doped at the Zn site in the wurtzite type ZnO lattice. An appreciable blue shift in the absorption spectrum was observed, which indicates that the Co doping in ZnO leads to systematic increase in the band-gap with dopant concentration. Magnetization studies showed that the Co doped ZnO nanocrystals display room temperature ferromagnetism and the ferromagnetic ordering strengthens with the Co concentration. © 2013 Elsevier B.V. All rights reserved.
Vijayalaxmi M.,S.K.I.T |
Narayana Reddy S.,S.V.U
Lecture Notes in Electrical Engineering | Year: 2016
In high speed data transmission, Orthogonal Frequency Division Multiplexing (OFDM) is a spectrally proficient method over multipath fading channel. This OFDM signal suffers from high Peak-to-average power ratio (PAPR) and Bit Error Rate (BER) (Van Nee and de Wild, Vehic. Technol. Conf. 3:2072– 2076, 1998) . MIMO OFDM configuration step-up the capacity of the system and diversity gain on frequency selective and time variant channels. Preference is on SFBC-MIMO-OFDM to operate fading channel much more effectively. Constant Modulus Algorithm (CMA) is highly proficient technique for alleviating high PAPR. But the main demerit associated with CMA is slow convergence rate, extensive steady state mean square error (SSMSE), and phase blind nature. We propose an enhanced modified constant modulus algorithm (MCMA) where the step size is carefully assessed to maintain a balancing between convergence rate and final accuracy. Simulations demonstrates the efficiency of proposed MCMA. © Springer India 2016.
Vijayalaxmi M.,S.K.I.T. |
Narayana Reddy S.,S.V.U.
International Journal of Applied Engineering Research | Year: 2015
In this paper, we proposed an iterative receiver for MIMOOFDM systems. Based on this receiver, solutions to two of the most important problems in OFDM systems have been provided, namely, inter carrier interference cancellation and inter symbol interference cancellation over time-selective and frequency-selective fading channels. In this topic we consider an SFBC-OFDM system with timing offset (µ), derive the mathematical expressions for the interference provoked and propose the interference cancelling receiver. The influence of timing offset (µ) on a MIMO OFDM system has been derived theoretically and evaluated from results of bit error rate (BER) simulations. © Research India Publications.
International Conference and Workshop on Emerging Trends in Technology 2011, ICWET 2011 - Conference Proceedings | Year: 2011
This paper reviews the research on expert systems, designed as aids to medical decision making. Because complex medical decisions are often made when major uncertainties are present and when the stakes are extremely high, expert systems are ideally suited for decision analysis. Over the last 50 years, many medical expert systems have been developed. Motivations for the development of expert systems in medicine have been numerous. Assisting physicians in making diagnosis and treatment recommendations is the most commonly found application of expert systems in medical science. Copyright © 2011 ACM.
Siva Subramanyam Reddy R.,SKIT |
Gowri Manohar T.,A.P.S. University
International Journal of Control Theory and Applications | Year: 2016
As the world wide electric utility industry grow up with deregulation; utility transmission systems are reaching their limits, making the need for reliable power greater than ever. Due to ever-growing load demand in the power system witnesses a gradual drop in the system voltage profile. It is precisely the inability of the power system to generate the required reactive power that propounds the cause of voltage collapse, with this effect the losses (Active Power and Reactive Power) in the system gradually increased. The recent developments in power electronics with high power advanced switching devices have introduced Flexible AC Transmission Systems (FACTS), which can facilitate the control of power flow, increase the power transfer capability, decrease the generation cost, improve the security and enhance the stability of the power systems. They allow the operation of the power systems more flexible, secure and economical through controlling various electrical parameters of transmission circuits. The modeling and placement of STATCOM shunt FACTS device is the major task in this type of problems. Earlier many of the engineering conventional optimization techniques applied to real world problems suffers with optimal solutions. In this paper, some of the advanced techniques (Heuristic techniques) like Genetic Algorithm (GA), and Particle Swarm Optimization (PSO) are introduced to find the optimal location of STATCOM shunt FACTS device in a standard IEEE 14,30,57 Bus systems in order to improving the voltage profile and reduce the losses(Active power & Reactive power) in power transmission system. © International Science Press.
Bali R.,University of Rajasthan |
Gravitation and Cosmology | Year: 2015
A tilted cosmological model is studied for a barotropic fluid distribution with heat conduction in the framework of a compact Bianchi Type II space-time. To get a deterministic solution in terms of cosmic time t, we have used the supplementary condition R = Sn between the metric potentials R and S, where n is a constant. The shear tensor σij for the tilted model satisfies the trace-free condition σijvj = 0, where vi is the fluid velocity vector. In a special case, the model becomes non-tilted. The heat conduction vector qi also satisfies the trace-free condition qivi = 0. The spatial volume increases as time increases, and the model represents an inflationary scenario. The model for a barotropic fluid distribution represents decelerating and accelerating phases of the universe, matching with the astronomical observations. Anisotropy is maintained throughout, but in a special case the model isotropizes. The particle horizon and entropy are discussed. We have also discussed the stiff fluid case with physical and geometrical aspects of the models. © 2015, Pleiades Publishing, Ltd.
Mathur D.,Government Engineering College |
Bhatnagar S.K.,SKIT |
Sahula V.,Malaviya National Institute of Technology, Jaipur
IEEE Antennas and Wireless Propagation Letters | Year: 2014
This letter presents a new method for quickly estimating the physical dimensions of a rectangular microstrip antenna (RMSA). This is based on the newly introduced concept of 'Equivalence of Design' for RMSA. Two designs are said to be equivalent if they result in the same resonance frequency. This is an outcome of Bhatnagar's postulate. It relates the classical extension in length ΔL with the length and width of the patch apart from the substrate thickness. This letter emphasizes the importance of substrate thickness normalized with respect to guided wavelength. This is termed as the 'H' parameter. For RMSA, this is the key parameter rather than the individual parameters - dielectric constant (εr), substrate thickness (h), or resonance frequency (fo). A new parameter - the scaling factor (ψ) - has been introduced and defined. Based on these, transformation laws have been put forward. These can be used for quickly estimating the RMSA design parameters from a 'known good design.' The laws have been verified by estimating physical parameters of RMSA and then calculating its resonance frequency. This has been repeated for several hundred designs. The matching has been excellent. Simulation and measurement results of a known good design (Design1) and one of the transformed designs (Design3) are also presented. The results of the transformed design are in good agreement with those of Design1 considering fabrication and measurement tolerances. © 2002-2011 IEEE.
Parashar S.,SKIT |
India International Conference on Power Electronics, IICPE | Year: 2015
In current scenario, renewable energy sources helps to make the environment greener and better. Currently, solar energy is the most available resource of renewable energy. This paper mainly represents the working principle of solar photovoltaic system and way to increase efficiency of the solar system using a method known as the data acquisition system. Data acquisition is a process to monitor changes in system, collect corresponding data and analyze data to make a decision. The data acquisition system has two parts, data acquisition board that contains Microcontroller Kit, ADC, and RS-232 and Zigbee communication modules. Another part is running on a host computer that has a set of software tools as Keil, Proteus, and Visual Basic 6.0 help to analyze and store data. Zigbee communication helps in wireless data transfer without any communication cost. Complete experiment and the result show the data acquisition designed is simple and stable. © 2014 IEEE.
Gupta E.,SKIT |
Journal of Electrical Systems | Year: 2015
This paper presents an application of Grey Wolf Optimizer (GWO) technique to estimate the parameters of the Proportional Integral Controller (PI) for Automatic Generation Control of two area power system. In this work two thermal units with non reheat turbines are considered. The detailed eigenvalue analysis is carried out for exhibiting the philosophy of damping requirement in the complex networks. The parameters namely proportional integral gain, speed regulation, frequency sensitivity coefficient are considered as the modifiable parameters. These parameters are estimated through optimization process with the aim to minimize the Area Control Error (ACE). The comparison between two objective functions namely Integral Square Error (ISE) and Integral Time Absolute Error (ITAE) is presented. Sensitivity analysis advocates the effectiveness of the proposed approach. To draw a fair comparison between the proposed method and the conventional methods (GSA, PSO and GA) convergence characteristics of the optimization techniques are compared and presented. It is observed that the proposed design satisfactorily handle different contingencies and operating conditions. © JES 2015.
Proceedings of the 2011 7th International Conference on Next Generation Web Services Practices, NWeSP 2011 | Year: 2011
This research paper presents a framework, which simplifies the task of developing, deploying, and managing complex, integrated, and standards-compliant OLTP framework solution-an enterprise resource planning software for putting universities online. The framework enables development, configuration, integration, and management of solution at a higher semantic level. It also provides commonly used services such as access to university resources, access control and authentication through biometrics, public key infrastructure, and support for digital signatures. The ability to manage solution at a higher semantic level enables administrators who are not proficient in programming to customize solution in order to address specific needs of the different stakeholders. This includes the ability to customize interfaces for multiple local languages used in university transactions and to customize workflows to conform to the organizational structure and policies to manage access to and retention of university records. © 2011 IEEE.