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

World University root node

Department of Electrical Engineering

arXiv e-prints, arXiv: 1512.

Convergence Analysis of Proportionate-type Least Mean Square Algorithms

Managing inter-cell interference is one of the main challenges in current and next generation wireless systems that aggressively reuse the frequency. Cooperation between interfering cells has been sought to mitigate interference. In this paper, we address the problem of jointly optimizing the transmit powers, user scheduling, and user association in a cellular network to maximize the weighted sum rate (WSR). To this end, we develop a distributed interference penalty algorithm in which the cells update their transmit powers and user schedule to maximize its utility minus an interference cost. The proposed algorithm involves only limited exchange of information via backhaul and has convergence guarantees. Furthermore, we propose a sub-optimal algorithm with lower computational and backhaul overhead. In it, the users are first associated to the base stations (BSs) based on their signal-to-interference-plus-noise-ratios (SINRs). It is then followed by joint optimization of BS transmit powers and user scheduling, for which we develop an interference penalty algorithm as well. We show that the proposed algorithms outperform the computationally complex weighted minimum mean squared error (WMMSE) algorithm. © 2015 IFIP.

2015 13th International Symposium on Modeling and Optimization in Mobile, Ad Hoc, and Wireless Networks, WiOpt 2015

Downlink interference penalty algorithm for power control, scheduling, and user association

A capacitance-to-digital converter (CDC) that gives a digital value proportional to the change in the capacitance of a sensor, independent of its nominal capacitance, is presented in this paper. The CDC presented is suitable for single element capacitive sensors. For most of the CDCs, available in the market, the output depends on the nominal value of the sensor. Thus, a manual intervention for appropriate correction in the output is required whenever a new sensor is connected to such CDCs. The proposed CDC uses a simple automatic calibration, employing a digitally controlled reference voltage in a feedback topology, and provides an output independent of the nominal value of the sensor employed. This automatic calibration also removes the dependence on the accuracy of the absolute value of reference capacitor, in the final output. The proposed CDC is based on a switched-capacitor dual-slope technique and possesses the advantages of the dual-slope conversion method. A prototype CDC has been developed and the test results are presented. The results obtained show that the output of the proposed converter is not a function of the nominal capacitance of the sensor for a wide range (50 pF to 1.15 nF). For this range, the worst error noted from the prototype CDC was less than 0.65 %. © 2015 IEEE.

Conference Record - IEEE Instrumentation and Measurement Technology Conference

A novel switched-capacitor capacitance-to-digital converter for single element capacitive sensors

The real contact length during the grinding process is considered as an important subject for researchers, mainly because it reflects the intensity of the responses such as grinding forces and temperature generation. In order to measure and assess the real contact length, many experimental techniques and prediction models are available in the literature. Among all these models, the model developed by Rowe and Qi is being used widely by researchers because of its ability to make close predictions with real values. Rowe and Qi coined the term called roughness factor in their model. This factor varies with grinding environments and wheel-work material combinations. To decide it for a new environment, one has to do the laborious experimental work. In this article, the roughness factor has been analysed from the grinding temperature and the heat partition ratio point of view and expressed so that without experimental work prediction of the roughness factor can be done. For this, a new factor called as the thermal factor has been proposed based on the roughness factor modifications. Its good correlation with dimensionless temperature and heat partition ratio under different grinding environments have been presented and discussed in the current communication. It seems that the thermal factor can be helped in an easy and accurate prediction of the contact length during grinding operations. © 2014 Institution of Mechanical Engineers.

Department of Mechanical Engineering

Fulltext

Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture

A modified model for estimating the contact length in surface grinding

Nanofluid, fluid suspensions of nanometer sized particles are revolutionizing the field of heat transfer area. Addition of nano-particles to the base fluid also alters the lubricating properties by reducing the friction. In grinding process, friction between the abrasive grains and the workpiece is a key issue governing the main grinding output. It has a direct influence on grinding force, power, specific energy and wheel wear. Moreover, high friction force increases the heat generation and lead to thermal damage in the surface layer of the ground work. Hence, any effort towards the friction control will enhance the component quality significantly. In this study, nanofluid as metal working fluid (MWF) is made by adding 0.05, 0.1, 0.5 and 1% volume concentration of Al2O3 and CuO nano-particles to the water during the surface grinding of Ti-6Al-4V in minimum quantity lubrication (MQL) mode. Surface integrity of ground surface, morphology of the wheel, and chip formation characteristics are studied using surface profilometer, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and stereo zoom microscopy (SZM). Coefficient of friction was estimated On-Machine using the measured forces. The results showed that the type of nanoparticle and its concentration in base fluid and the MQL flow rate play a significant role in reducing friction. Application of nanofluid leads to the reduction of tangential forces and grinding zone temperature. The cooling effect is also evident from the short C-type chip formation. MQL application with Al2O3 nanofluid helps in effective flushing of chip material from the grinding zone, thereby solving the main problem during the grinding of Ti-6Al-4V. © 2014 Elsevier Ltd.

International Journal of Machine Tools and Manufacture

Performance evaluation of Ti-6Al-4V grinding using chip formation and coefficient of friction under the influence of nanofluids

This paper proposes a synchrophasors-assisted intelligent relaying scheme for transmission lines compensated by Unified Power Flow Controller (UPFC). The algorithm uses a new relaying signal termed as imaginary part of integrated impedance (IPII). The synchronized phasor measurements at both ends of the transmission line are used to extract voltage and current phasors from instantaneous voltage and current signals. The voltage and current phasors are utilized to derive IPII of each phase. Further, IPII of each phase is used as input to a data-mining model termed as decision tree (DT) which provides the final relaying decision. The proposed algorithm is validated on real-time digital simulator (RTDS) platform, and the results obtained indicate that the proposed scheme is both dependable and secure in protecting transmission system compensated by UPFC. © 2015 Walter de Gruyter GmbH.

International Journal of Emerging Electric Power Systems

Synchrophasors-assisted IPII-based intelligent relaying for transmission lines including UPFC

The paper presents a comprehensive intelligent relaying scheme using phase angle of differential impedance (PAODI) for series compensated double circuit transmission lines. The differential impedance (DI) is the ratio of differential voltage phasors of any phase across two ends of the transmission line to the differential current phasors of the same phase of the same transmission line. The PAODI of each phase are used as inputs to the data mining model known as decision tree (DT) to generate final relaying decision to identify the faulty phase(s) involved. The proposed scheme is extensively validated for different fault scenarios including inter-circuit and cross-country faults on the series-compensated parallel transmission developed on Real Time Digital Simulator (RTDS) platform. The test results obtained indicate that the proposed PAODI based intelligent relaying scheme is both dependable and secure in protecting series compensated double circuit transmission lines with a response time of less than 1 and 1/2 cycles. © 2015 Elsevier Ltd. All rights reserved.

International Journal of Electrical Power and Energy Systems

Intelligent relaying scheme for series-compensated double circuit lines using phase angle of differential impedance

We consider the following weighted eigenvalue problem in the exterior domain: (Formula presented.),where Δp is the p-Laplace operator with p&gt;1, and (Formula presented.) is the exterior of the closed unit ball in RN with N≥1. There is no restriction on the dimension N in terms of $$p, i.e., we allow both 1&lt;p&lt;N and p≥N. The weight function K is locally integrable on (Formula presented.) and is allowed to change its sign. For some appropriate choice of $$w$$w, a positive weight function on the interval (1,∞), we prove that the Beppo-Levi space (Formula presented.) is compactly embedded into the weighted Lebesgue space Lp(Formula presented.). The existence of the positive eigenvalue for the above problem is proved for K such that (Formula presented.) is of non-zero measure and |K|≤w. Further, we discuss the positivity, the regularity and the asymptotic behaviour at infinity of the first eigenfunctions. © 2014, Springer-Verlag Berlin Heidelberg.

Department of Mathematics

Calculus of Variations and Partial Differential Equations

Weighted quasilinear eigenvalue problems in exterior domains

The current work reports quantitative OH species concentration in the cavity of a trapped vortex combustor (TVC) in the context of mixing and flame stabilization studies using both syngas and methane fuels. Planar laser induced fluorescence (PLIF) measurements of OH radical obtained using a Nd:YAG pumped dye laser are quantified using a flat flame McKenna burner. The momentum flux ratio (MFR), defined as the ratio of the cavity fuel jet momentum to that of the guide vane air stream, is observed to be a key governing parameter. At high MFRs ∼4.5, the flame front is observed to form at the interface of the fuel jet and the air jet stream. This is substantiated by velocity vector field measurements. For syngas, as the MFR is lowered to ∼0.3, the fuel-air mixing increases and a flame front is formed at the bottom and downstream edge of the cavity where a stratified charge is present. This trend is observed for different velocities at similar equivalence ratios. In case of methane combustion in the cavity, where the MFRs employed are extremely low at ∼0.01, a different mechanism is observed. A fuel-rich mixture is now observed at the center of the cavity and this mixture undergoes combustion. On further increase of the cavity equivalence ratio, the rich mixture exceeds the flammability limit and forms a thin reaction zone at the interface with air stream. As a consequence, a shear layer flame at the top of the cavity interface with the mainstream is also observed. The equivalence ratio in the cavity also determines the combustion characteristics in the case of fuel-air mixtures that are formed as a result of the mixing. Overall, flame stabilization mechanisms have been proposed, which account for the wide range of MFRs and premixing in the mainstream as well.

Combustion Science and Technology

Quantitative OH Planar Laser Induced Fluorescence Diagnostics of Syngas and Methane Combustion in a Cavity Combustor

The current work reports optical diagnostic measurements of fuel-air mixing and vortex structure in a single cavity trapped vortex combustor (TVC). Specifically, the mixture fraction using acetone PLIF technique in the non-reacting flow and PIV measurements in the reacting flow are reported for the first time in trapped vortex combustors. The fuel-air momentum flux ratio, where the air momentum corresponds to that entering the cavity through a specially-incorporated flow guide vane, is used to characterize the mixing. The acetone PLIF experiments show that at high momentum flux ratios, the fuel-air mixing in the cavity is very minimal and is enhanced as the momentum flux ratio reduces, due to a favourable vortex formation in the cavity. Stoichiometric mixture fraction surfaces show that the mixing causes the reaction surfaces to shift from non-premixed to partially-premixed stratified mixtures. PIV measurements conducted in the non-reacting flow in the cavity further reinforce this observation. The scalar dissipation rates of mixture fraction were compared with the contours of RMS of fluctuating velocity and showed very good agreement. The regions of maximum mixing are observed to be along the fuel air interface. Reacting flow PIV measurements which differ substantially from the non-reacting cases primarily because of the heat release from combustion and the resulting gas expansion show that the vortex is displaced from the centre of the cavity towards the guide vane. Overall, the measurements show interesting features of the flow including the presence of the dual cavity structure and lead to a clear understanding of the underlying physics of the cavity flow highlighting the importance of the fuel-air momentum ratio parameter.