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Showing papers by "Rajasthan Technical University published in 2011"


Proceedings ArticleDOI
10 Oct 2011
TL;DR: The proposed design is a rectangular patch antenna with slots at the centre frequency 10 GHz that can be reconfigured in the frequency range of 10–10.5 GHz and the simulated are very exciting and show the close agreement with proposed design.
Abstract: Recent developments in the wireless communication industry continue to drive the requirements for small, compatible, and affordable reconfigurable antennas. To overcome the challenges of multi-frequency operation a new scheme of frequency reconfiguration is proposed. In the proposed design a rectangular patch antenna with slots at the centre frequency 10 GHz that can be reconfigured in the frequency range of 10–10.5 GHz. The reconfiguration is carried out by switching the diodes ON/OFF. The antenna is designed on FR4 substrate (e r = 4.54) of thickness (H) 1.50 mm. The proposed structure was simulated by using the electromagnetic (EM) simulation software. The simulated return loss for different configuration are less than −10dB at resonance frequencies. The simulated are very exciting and show the close agreement with proposed design.

17 citations


Journal ArticleDOI
TL;DR: In this paper, a fuzzy logic-based load controller for single-phase self-excited induction generator (SEIG) is proposed to regulate the voltage and frequency of SEIG for standalone operation.
Abstract: This paper presents the design and implementation of a fuzzy logic-based load controller to regulate the voltage and frequency of single phase self-excited induction generator (SEIG), suitable for standalone operation. The SEIG can be used to generate constant voltage and frequency if the load is maintained constant at its terminals. Moreover, under such operation, SEIG requires constant capacitance for excitation resulting in a fixed-point operation. For this purpose, a suitable control scheme is to be developed such that the load on the SEIG remains constant despite the change in the consumer load. A DSP-based fuzzy load controller has been developed based on equal time ratio control (ETRC) AC chopper controllable load which gives non-linear control with fast response and injects minimum harmonics in the system. The transient behaviour of DSP-based SEIG-fuzzy load controller system at different operating conditions such as application and removal of static (resistive and reactive) load is investigated.

9 citations


Journal ArticleDOI
TL;DR: In this article, the correlation between self-trapped exciton luminescence decay time and photocatalytic activity of ZnWO4 powders with grain size in range 20 nm-10 µm was shown.
Abstract: ZnWO4 powders with grain size in range 20 nm–10 µm have been synthesized by a simple combustion method and subsequent calcinations. The photocatalytic activities of powders were tested by degradation of methylene blue solution under UV light. The luminescence spectra and luminescence decay kinetics were studied and luminescence decay time dependence on average powder-grain size was obtained. The correlation between self-trapped exciton luminescence decay time and photocatalytic activity of ZnWO4 powders was shown. A model explaining the excitonic luminescence decay time correlation with photocatalytic activity was proposed.

5 citations


Proceedings ArticleDOI
22 Apr 2011
TL;DR: It is argued that a significant change in motivation for malicious activity has taken place over the past several years: from vandalism and recognition in the hacker community, to attacks and intrusions for financial gain.
Abstract: The continued growth and diversification of the Internet has been accompanied by an increasing prevalence of attacks and intrusions. It can be argued, however, that a significant change in motivation for malicious activity has taken place over the past several years: from vandalism and recognition in the hacker community, to attacks and intrusions for financial gain. This shift has been marked by a growing sophistication in the tools and methods used to conduct attacks, thereby escalating the network security arms race. The reactive methods for network security that are predominant today are ultimately insufficient and that more proactive methods are required. One such approach is to develop a foundational understanding of the mechanisms employed by malicious software (malware) which is often readily available in source form on the Internet. Here is a new network known as BOTNET. A botnet is a group of computers that have been compromised, and run a remote control bot application. The bot herder will send commands to the droves of compromised systems, which will gleefully obey.

5 citations


Journal ArticleDOI
TL;DR: This paper investigates the interest focused on employing parallel connected dc-dc converter with high tracking effectiveness under wide variation in environmental conditions (Insolation) and wide load variation and presents an approach on how duty cycle for maximum power position (MPP) is adjusted by taking care of varying load conditions and without iterative steps.
Abstract: This paper investigates the interest focused on employing parallel connected dc-dc converter with high tracking effectiveness under wide variation in environmental conditions (Insolation) and wide load variation. dc-dc converter is an essential part of the stand alone PV system. Paper also presents an approach on how duty cycle for maximum power position (MPP) is adjusted by taking care of varying load conditions and without iterative steps. Synchronized PWM pulses are employed for the converter. High tracking efficiency is achieved with continuous input and inductor current. In this approach, the converter can he utilized in buck as well in boost mode. The PV system simulation was verified and experimental results were in agreement to the presented scheme.

4 citations


Journal Article
TL;DR: In this paper, a new transformation formula (1 x) 2a 3F2 2 6 a; a + 1 2 ; d + 1 ; x 2 (1x)2 c + 3 ; d 3 7 valid forjxj 0, where A = p 16d 2 16cd 8d + 1.
Abstract: The aim of this research note is to prove the following new transformation formula (1 x) 2a 3F2 2 6 a; a + 1 2 ; d + 1 ; x 2 (1 x)2 c + 3 ; d 3 7 valid forjxj 0, where A = p 16d 2 16cd 8d + 1. For d = c + 1 , we get quadratic transformations due to Kummer. The result is derived with the help of the generalized Gauss's summation theorem available in the literature. AMS subject classications : 33C05, 33D15

3 citations


Book ChapterDOI
28 Jan 2011
TL;DR: In this paper, an audio watermarking technique that utilized the manipulation in high frequency of an audio signal to hide secret message was presented. And the experimented result developed through MATLAB show that the usefulness of this technique.
Abstract: As the technology increases day by day, human dependency increases on technologies. In present scenario everyone wants to do their work, business etc with the help of computer or with internet. Hence this increases the possibility of large-scale unauthorized copying which may lead to undermine the music, film, book and software industries. These concerns over protecting copyright have triggered significant research to find ways to hide copyright messages and serial number into digital media. An important sub discipline of information hiding is Watermarking. Digital Watermarking is an authentication technique which permanently embeds a digital signal (watermark) in text, image, audio, video files (any Data) by slightly modifying the data but in such a way that there are no harmful effects on the data. In this paper, we present audio watermarking technique that utilized the manipulation in high frequency of an audio signal to hide secret message The experimented result developed through MATLAB show that the usefulness of this technique.

2 citations


Proceedings ArticleDOI
10 Oct 2011
TL;DR: In this paper, a tapered slot antenna with added switched band functionality to operate in a wideband or narrowband mode is proposed for wireless applications, which is realized by inserting one pair of switchable square slots into the structure.
Abstract: A tapered slot antenna with added switched band functionality to operate in a wideband or narrowband mode is proposed for wireless applications. The antenna reconfiguration is realized by inserting one pair of switchable square slots into the structure. For switching purpose, PIN diodes are used. The antenna is designed on FR4 substrate that has dielectric constant of 4.9 and the height of the substrate is 1.6 mm. The size of antenna substrate is 72 mm × 70 mm. The structure is simulated on electromagnetic (EM) simulation software. The designed antenna operates over impedance bandwidth (1.9 to 7.5 GHz) for return loss S 11 11 < −10 dB when both diodes are in ON state. The wideband to narrowband frequency reconfigurable can be achieved by switching the diodes in OFF and ON conditions. The proposed antenna performance could be a suitable solution for multimode application requiring wideband and frequency reconfigurable antennas, such as in military applications and cognitive radio.