Showing papers by "Rajasthan Technical University published in 2012"

Energy efficient cluster head selection scheme: A change in node death scenario of LEACH for surveillance wireless sensor networks

Abstract: Wireless sensor networks are energy constraint networks. Energy efficiency, to prolong the network for a longer time is critical issue for wireless sensor network protocols. Clustering is an efficient approach to capitalize the energy of sensor nodes in wireless sensor networks. LEACH is a fully distributed clustering scheme that chooses cluster head randomly from the nodes. In LEACH though node death is random but it is observed that border area nodes die first. But critical field surveillance application requires border nodes to function for much longer time period. In this paper, a cluster head selection scheme is proposed and implemented with LEACH. Proposed scheme divides the network area into two parts: Border area nodes and Inner area nodes. High energy consuming cluster head role is restricted to only inner area nodes. The scheme reduces intra-cluster communication distance and hence increases the energy efficiency of LEACH. Simulation results for proposed scheme shows that border nodes function for longer time as compared to LEACH.

Modeling of a high-performance multimode interference optical switch using reconfigurable image modulated region

Abstract: Modeling and detailed performance analysis is carried out to realize a multimode interferometer optical switch by inserting an appropri- ate image-modulated (IM) region. The concept of self-imaging character- istics of multimode waveguides has been utilized in order to drive the designed device as a photonic switch. Transition losses in the waveguides of the structure are maintained at low levels by selecting appropriate dimensions to increase overall performance of the switch. It has been observed that by inserting an additional IM region, switching losses and corresponding crosstalk levels can be reduced significantly. The device performance is checked for a wider range of index variation in the IM region with respect to other regions for a test wavelengh of 1.55 μm. With rigorous and repetitive simulation, a crosstalk level better than −22.2 dB for either case of polarization state (transverse electric and transverse magnetic) of input has been achieved. The design also possesses a design tolerance in the range of � 0.25 to � 0.5 μm, within which variation in the imaging length and its subsequent adverse effects on device performance remains less than 1.5%. © 2012 Society of Photo-Optical

Dual Band Microstrip-Fed Printed Antennas for Wireless Applications

Abstract: In this paper, the performance of two dual-band printed fed-fed antennas is investigated, which have circular and hexagonal geometrical shapes. The hexagonal antenna shows the centre frequencies 1.6GHz and 3.8GHz and the circular antenna operates on 1.6GHz and 4GHz. These dual band antennas show the good simulated return loss and radiation characteristics. The proposed antenna designs are simulated on electromagnetic (EM) simulation software using FR-4 substrate with dielectric constant of 4.4 and thickness of 1.6 millimeter(mm). The proposed antennas have compact structures, the total size is 60×64 mm2 and fed with 50O micro strip line by optimizing the width of partial ground. With the design, the return loss is lower than-10dB. A single rectangular slot is cut to obtain dual band operation. The proposed antenna is easy to integrate with microwave circuitry for low manufacturing cost. The antenna structure is flat, and its design is simple and straightforward. These antennas can be used in wireless communication.

Computerized detection & classification of ECG signals

Abstract: An electrocardiogram (ECG) is a recorded representation of electrical activity of heart with respect to time Being a very important diagnostic tool for determining various heart functions, computer based ECG interpretation is a computing system that records and automatically detects the variations in important parameters of a given ECG recording These parameters are very critical for doctors while examining the condition of the heart of a patient Identification of the specific area of the heart under problem and the extent of damage done are the basic areas which have been highlighted for proper diagnosis to save patient's life This paper, proposes an approach to determine the values of the amplitude of P, QRS & T together with time durations (PR, RR, QRS, and QT) From these calculations, the heart condition whether it is normal or not, is determined along with amount of variation so that the cardiologist can recommend the amount of dosing required for the medicine for the ailment of the patient It also classifies the ECG into seven major cardiac problems In this thesis, we have introduced a curve mapping technique based on slope method to detect & classify the ECG signals into seven major cardiac problems The accuracy rate arrived in the slope method ranges from 92% to 100%, for seven cardiac conditions with an overall average 9657 %

Database architecture of OLTP in the SaaS-based multi-tenant Educational Enterprise Resource Planning (Java Enterprise Edition(JEE) Based Engineering approach)

Abstract: In conventional delivery mode of Educational Enterprise Resource Planning (EERP) information systems, applications and databases are established for each college in universities independently. It not only causes resources to be wasted, but also brings about a series of problems related to data management. As technologies like virtualization assume important places within the IT landscape, higher education leaders will need to consider which institutional services they wish to leave to customer choice, which ones they wish to outsource "somewhere else: of course cloud," and which services they should operate centrally or locally on campus. In order to solve the problems mentioned above perfectly, Educational Enterprise Resource Planning information system begins to be constructed based on SaaS. In this paper, a schema of distributed database architecture in the SaaS-based multi-tenant Educational Enterprise Resource Planning information systems (OLTP) JEE based application is proposed and a distributed database access process module is implemented.

Design and simulation of Pt-based microhotplate, and fabrication of suspended dielectric membrane by bulk micromachining

Abstract: The paper presents the design and simulation of double spiral Pt-based microhotplate (MHP) for gas sensing application. A platinum resistor of 52 Ω has been designed and simulated on a 0.3 micron thick SiO 2 suspended membrane of size 40 × 40 μm2 using ANSYS. The SiO 2 membrane of size 40 × 40 μμm 2 and thickness 0.3 micron has been fabricated successfully by bulk micromachining in <100< orientation P-type silicon using 25% tetra methyl ammonium hydroxide (TMAH) solution. The simulated temperature and transit time response of microhotplate were obtained as 600.5 °C and 0.2 ms respectively at 4.8 mW power consumption.

Design and mathematical model of a ZnO-based MEMS acoustic sensor

Abstract: The paper presents the design and mathematical model of a ZnO-based MEMS acoustic sensor. The structure consists with a 3.0 μm thick piezoelectric ZnO layer sandwiched between a pair of aluminum electrodes on a 30 μm thick silicon diaphragm. The size of silicon diaphragm is 3.1 x 3.1 mm 2 . Resonance frequency of the structure is determined using harmonic analysis by ANSYS and found to be 41.8 KHz. Sensitivity of acoustic sensor with and without the effect of residual stress are obtained as 334.7μV/Pa and 221.6μV/Pa respectively. The proposed model of the acoustic sensor operated over a wide frequency range from 30 Hz to 8 kHz.

HMM Based Enhanced Dynamic Time Warping Model for Efficient Hindi Language Speech Recognition System

Abstract: Dynamic Time Warping (DTW) is template based cost minimization technique. We propose Hidden Markov Model (HMM) based enhanced DTW technique to efficiently recognize various speaking rate signals and for recognizing closely similar utterances. We extend the derivation of Viterbi and forward algorithms for finding optimized path alignment in new propose technique and extend the Baum-Welch algorithm to optimize the model parameters. The proposed technique is compared with conventional DTW technique, and from comparative results analysis we find that it improves the results from 84% to 94 % using DTW technique for Hindi spoken words for various speech utterances in different environmental conditions or for varying speakers.

Design reconfigurable tapered slot antenna

Abstract: A Tapered slot antenna with reconfigurable frequency band is presented in this paper. This tapered slot antenna contains two switchable rectangular slot. The notch band is achieved by a function of diode. A wide bandwidth mode from 3.2–9.5 GHz and narrowband mode can be selected. The pin diodes are used to reconfigure the impedance match and modify the radiation pattern. Measured results shows good performance of the proposed designs.

MATLAB-Based Investigation of Multiphase Interleaved Buck-Boost Converter for PV System

Abstract: A photovoltaic (PV) generator exhibits nonlinear voltage-current characteristics and its maximum power point varies with solar radiation. Analytical investigations of the new family of switching converters based on a parallel connection of 𝑁(=4) identical buck-boost converters employed in PV system are presented. The interleaving strategy ensures that all the converters operate at the same switching frequency. Mathematical models developed using the state-space average technique are presented in this paper. Various steady-state performance expressions are also derived. The present converter system has the advantages of reduced size of the converter, and ripple in the total inductor current. The effectiveness of the four-phase interleaved dc-dc converter combined with PV system is demonstrated through simulations carried out in MATLAB environment.

Digital Image Steganography: Substitution techniques

Abstract: As the development of internet takes place, variety of digital data ( text, video, images and audio) transmits to worldwide society Problem may arise that the confidential data can be stolen or hacked in many ways To protect the contents from interceptors' attention, the image hiding technology thus emerged Steganography is the art and science of hiding information by embedding secret messages within other, seemingly harmless media Steganography essentially does is exploit human perception, human senses are not trained to look for files that have information hidden inside of them, although there are programs available that can do what is called Steganolysis In this paper we present spatial technique which is also known as Substitution method In this method message bits are embedded into different bits of the pixel grey level values, resulting in increased robustness The robustness would be increased against those attacks which try to reveal the hidden message and also some unintentional attacks like noise addition as well