Department of Electrical Engineering

Indian Institute of Technology Palakkad&nbsp;(IIT Palakkad or IIT PKD) is a public autonomous&nbsp;engineering&nbsp;and&nbsp;research&nbsp;institute located in&nbsp;Palakkad,&nbsp;Kerala. It was&nbsp;one of the five new&nbsp;IITs&nbsp;proposed in the&nbsp;2014 Union budget of India. The campus was inaugurated on 3 August 2015. The institute has 94 faculty, 978 students, and 63 non-teaching staffs.

IT Palakkad currently offers four-year Bachelor of Technology (B.Tech) and two years MS programmes in 8 different engineering disciplines including&nbsp;Computer Science, Electrical, Mechanical, Civil among others.

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IIT Palakkad

This paper deals with a discrete-time Markov jump linear system with a non-homogeneous Markov Chain. In particular, we consider the situation when the transition probability matrix of the non-homogeneous Markov Chain is varying in an interval, and obtained a sufficient condition for the mean square stability of the proposed system. © 2013 EUCA.

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2013 European Control Conference, ECC 2013

Mean square stability of non-homogeneous Markov jump linear systems using interval analysis

Gd2O3-based metal-insulator-metal capacitors have been characterized with single layer (Gd2O3) and bilayer (Gd2O3/Eu2O3 and Eu 2O3/Gd2O3) stacks for analog and DRAM applications. Although single layer Gd2O3 capacitors provide highest capacitance density (15 fF/μm2), they suffer from high leakage current density, poor capacitance density-voltage linearity, and reliability. The stacked dielectrics help to reduce leakage current density (1.2×10-5 A/cm2 and 2.7 × 10-5 A/cm2 for Gd2O3/Eu2O3 and Eu2O3/Gd2O3, respectively, at -1 V), improve quadratic voltage coefficient of capacitance (331 ppm/V2 and 374 ppm/V2 for Gd2O3/Eu2O 3 and Eu2O3/Gd2O3, respectively, at 1 MHz), and improve reliability, with a marginal reduction in capacitance density. This is attributed to lower trap heights as determined from Poole-Frenkel conduction mechanism, and lower defect density as determined from electrode polarization model. © 2013 IEEE.

IEEE Transactions on Electron Devices

Performance and reliability of Gd2O3 and stacked Gd2O3-Eu2O3 metal-insulator-metal capacitors

Thermodynamic properties of the troposphere, particularly water vapor content and temperature, change in response to physical mechanisms, including frictional drag, evaporation, transpiration, heat transfer, pollutant emission and flow modification due to terrain. The planetary boundary layer (PBL) is characterized by a greater rate of change in the thermodynamic state of the atmosphere than at higher altitudes in the troposphere. Measurement of these changes, such as large horizontal gradients in water vapor and vertical profiles, provides very important data for improved weather prediction. Sensitivity studies for severe storm prediction indicate that a lack of accurate observations of water vapor densities throughout the lower troposphere limits the forecasting of severe storms. Therefore, measurements of water vapor density using microwave radiometers may help to improve accuracy of severe weather prediction. The HUMidity EXperiment 2011 (HUMEX11) was conducted to validate remote sensing of tropospheric humidity using ground-based scanning Compact Microwave Radiometers for Humidity profiling (CMR-H). Two microwave radiometers were scanned to sample an atmospheric volume at the U.S. Department of Energy (DOE)'s Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) Climate Research Facility. Scientific objectives of HUMEX11 were to measure water vapor profiles in the lower troposphere with high vertical and temporal resolution and to track rapid variations in water vapor in the lowest 3 km of the troposphere. The principal reason for conducting the campaign at the SGP Climate Research Facility was the ability to compare the water vapor profile results with other measurements like ARM microwave radiometers and Raman lidar. The Raman lidar water vapor profiles were used as truth for comparison with the retrieved profiles. The study also focuses on optimizing the size of the background data set to minimize retrieval error as well as varying the vertical resolution to increase sensitivity to gradients in the water vapor profile. Water vapor profiles were retrieved at various vertical resolutions ranging from 0.1 to 0.5 km. The background data set for the retrieval consisted of radiosondes launched from the DOE ARM SGP site four times daily during the experiment. The accuracy and error statistics of the retrieved profiles is compared for different background data set sizes and different vertical resolutions.

Measurement of Rapid Variations in Lower-Tropospheric Humidity Profiles Using Ground-Based Scanning Compact Microwave Radiometers

Complex bands k(E) in a semiconductor crystal, along a general direction n, can be computed by casting Schrödingers equation as a generalized polynomial eigenvalue problem. When working with primitive lattice vectors, the order of this eigenvalue problem can grow large for arbitrary n. It is, however, possible to always choose a set of non-primitive lattice vectors such that the eigenvalue problem is restricted to be quadratic. The complex bands so obtained need to be unfolded onto the primitive Brillouin zone. In this paper, we present a unified method to unfold real and complex bands. Our method ensures that the measure associated with the projections of the non-primary wavefunction onto all candidate primary wavefunctions is invariant with respect to the energy E. © 2012 IOP Publishing Ltd.

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Journal of Physics Condensed Matter

Brillouin zone unfolding of complex bands in a nearest neighbour tight binding scheme

In this paper, the statistical properties of a change detection algorithm are considered. More specifically, we considered the exponentially weighted moving average (EWMA) algorithm. Analytical expressions for the probability distribution of detection delay and the time between false alarms are proposed, and the results are validated by simulations. The results can be used in examining the abrupt changes in a signal, and also in the design of active fault tolerant control systems. © 2012 IEEE.

Proceedings of the IEEE Conference on Decision and Control

Statistical properties of exponentially weighted moving average algorithm for change detection

In this paper, we present the combined character segmentation algorithm based on the active contour model and nonlinear diffusion techniques. The active contour model is used to perform segmentation of printed characters. The coherence enhancing diffusion technique is proposed to smooth out artifacts and background noises without destroying the edges. The performance of the two character segmentation methods: i) the combined ACM-FGM and CED algorithm, and ii) the ACM-FGM algorithm have been validated using a large scale printed documents in Hindi, Malayalam and Telugu text. The combined algorithm achieves an average segmentation accuracy of 89.08% whereas the ACM-FGM algorithm alone had an average accuracy of 52.63%. The whole character segmentation process time is lesser than that of the ACM-FGM algorithm alone. Experiments show that the combined algorithm provides promising results under scanned documents with different font-size and fond-style characters, and the different artifacts and background noises caused by the aging of the paper and diffusion. © 2012 IEEE.

2012 International Conference on Advances in Computing and Communications …

Performance study of active contour model based character segmentation with nonlinear diffusion

This paper proposes an active soft-switching circuit for bridge converters aiming at improving the power conversion efficiency. The proposed circuit achieves loss-less switching for both main and auxiliary switches without increasing the main device current/voltage rating. It is capable of operating at elevated switching frequencies of several hundreds of kHz, at low and high power levels with a wide range of load variations. A winding coupled to the primary of power transformer ensures soft switching for the auxiliary switches during turn-on and turn-off. Phase Shifted Full Bridge (PSFB) topology is chosen to validate the design. Operation principle with analytical expressions for the proposed circuit are outlined. The proposed active soft switched PSFB DC-DC converter circuit is designed and implemented for 350 W, switching at 100 kHz. The simulation and experimental results are presented. Experimental results are used to validate the analysis. © 2012 IEEE.

PEDES 2012 - IEEE International Conference on Power Electronics, Drives and Energy Systems

A new active soft-switching circuit for full bridge converters

A radio frequency micro-electro-mechanical system (RF-MEMS) phase shifter based on the distributed MEMS transmission line (DMTL) concept towards maximum achievable phase shift with low actuation voltage with good figure of merit (FOM) is presented in this paper. This surface micro-machined analog DMTL phase shifter demonstrates low power consumption for implementation in a Ka-band transmit/receive (T/R) module. The push-pull-type switch has been designed and optimized with an analytical method and validated with simulation, which is the fundamental building block of the design of a true-time-delay phase shifter. Change in phase has been designed and optimized in push and pull states with reference to the up-state performance of the phase shifter. The working principle of this push-pull-type DMTL phase shifter has been comprehensively worked out. A thorough detail of the design and performance analysis of the phase shifter has been carried out with various structural parameters using commercially available simulation tools with reference to a change in phase shift and has been verified using a system level simulation. The phase shifter is fabricated on the alumina substrate, using a suspended gold bridge membrane with a surface micromachining process. Asymmetric behaviour of push-pull bridge configuration has been noted and a corresponding effect on mechanical, electrical and RF performances has been extensively investigated. It is demonstrated 114° dB-1 FOM over 0-40 GHz band, which is the highest achievable FOM from a unit cell on an alumina substrate reported so far. A complete phase shifter contributes to a continuous differential phase shift of 0°-360° over 0-40 GHz band with a minimum actuation voltage of 8.1 V which is the highest achievable phase shift with the lowest actuation voltage as per till date on the alumina substrate with good repeatability and return loss better than 11.5 dB over 0-40 GHz band. © 2012 IOP Publishing Ltd.

Journal of Micromechanics and Microengineering

Design and development of a surface micro-machined push-pull-type true-time-delay phase shifter on an alumina substrate for Ka-band T/R module application

In this paper, we present an automated, adaptive image denoising method for removal of Rician noise from MRI images. The proposed method is based on the discretized total variation (TV) minimization model and the local noise estimation technique. The regularization parameter of the TV-based denoising method is adapted based on the standard deviation of noise in MRI image. The performance of the proposed method is evaluated using the brain MRI images corrupted by Rician noise with standard deviation ranging from 2 to 30. The quality of the denoised image is validated using both subjective visualization tests and objective quality metrics. The experimental results show that the proposed method achieves a significant improvement in the preservation of edges while simultaneously removing the Rician noise from a MR image. The adaptive TV filtering method is reasonably better than existing methods such as non-local filter, bilateral filter and multiscale linear minimum mean square-error estimation (LMMSE) approach. © 2012 Pillay Engineering College.

IEEE-International Conference On Advances In Engineering, Science And …

Adaptive MRI image denoising using total-variation and local noise estimation

Metal-insulator-metal (MIM) capacitors have been fabricated with single dielectric stack (Gd2O3) and bilayer dielectric stacks of Eu2O3 and Gd2O3 (Gd 2O3/Eu2O3 and Eu2O 3/Gd2O3) for analog and DRAM applications. While Pt/Gd2O3/Pt capacitors provide the highest capacitance density (15 fF/μm2), Pt/Gd2O 3/Eu2O3/Pt and Pt/Eu2O 3/Gd2O3/Pt capacitors provide lower leakage current densities (1.2×10-5 A/cm2 and 2.7×10-5 A/cm2, respectively at -1 V) and lower quadratic voltage coefficient of capacitance (VCC) (331 ppm/V2 and 374 ppm/V2, respectively at 1 MHz). The barrier/trap heights and defect densities have been computed for the faricated devices. The improved performance of bilayer dielectric stacks (Gd2O3/Eu 2O3 and Eu2O3/Gd2O 3) is attributed to lower defect densities and higher barrier/trap heights. © 2012 IEEE.