Department of Electrical Engineering

Indian Institute of Technology Hyderabad (IITH) is a premier institute of science and technology established in 2008. IITH has been consistently ranked in the&nbsp;<a href="https://iith.ac.in/reports/" rel="noopener noreferrer">top 10 institutes</a>&nbsp;in India for Engineering&nbsp;<a href="https://www.nirfindia.org/2021/EngineeringRanking.html" rel="noopener noreferrer" target="_blank">according to NIRF</a>&nbsp;making it one of the most coveted schools for science and technology in the country.

IITH offers&nbsp;<a href="https://iith.ac.in/academics/under-graduate/">undergraduate programs</a>&nbsp;in all the classical engineering disciplines, applied sciences, design, as well as several modern interdisciplinary areas. Students are given a flexibility to explore a broad set of areas, and potentially pursue a minor or double major in a discipline that is not their own. Students who wish to seek a deeper understanding of their own discipline are strongly encouraged to get involved in cutting-edge research with the help of a faculty to mentor them, and earn an Honors in their own field.

The very foundation of IIT Hyderabad is based on&nbsp;<a href="https://iith.ac.in/research/">research and innovation</a>. The vibrant research culture is evident from the number of patents and publications that IITH produces consistently every year. IITH offers&nbsp;<a href="https://iith.ac.in/academics/programmes-offered/">graduate programs</a>&nbsp;at both a masters, and a doctoral level, in several diverse areas. There are separate programs for technology, design, science, and liberal arts. The&nbsp;<a href="https://iith.ac.in/academics/post-graduate/">MTech program</a>&nbsp;is offered in various modes and durations to cater to the ever-growing need of postgraduate level professionals in the country.

IITH encourages and supports&nbsp;<a href="https://iic-iith.netlify.app/index.html" rel="noopener noreferrer" target="_blank">innovation and entrepreneurship</a>&nbsp;at every stage. The minor program in entrepreneurship is open to all students of IITH, and many of the courses are offered by industrialists who are entrepreneurs themselves. There are various&nbsp;<a href="https://iith.ac.in/research/centres-incubators/">innovation centers and incubators</a>&nbsp;that promote entrepreneurship and help mentor young innovators. IITH has been very successful in building tie-ups with leading academic institutions around the globe.

IITH enjoys a very special relationship with Japanese universities and industries that goes beyond academic and research collaborations. In fact, some of the iconic buildings in IITH campus will carry the signature of Japanese architecture.

IITH creates a unique holistic ecosystem for education that offers interactive learning, a very flexible academic structure, cutting-edge research, strong industry collaboration, and entrepreneurship. This is an environment which enables students and faculty to translate their dreams into realities.

IIT Hyderabad

In this work, a novel composite constituted by α-MnO2 nanorods and hierarchical MoS2 microspheres is synthesized by a simple, template-cum-catalysis free two-step hydrothermal method for ultra-sensitive and selective detection of nitrite. The nitrite sensor (with optimal MnO2-MoS2 weight ratio)showed a limit of detection of 16 μM, the short response time (&lt;5 s), outstanding selectivity, reproducibility, and sensitivity of 515.84 μA mM−1 cm−2 (R2 = 0.996)in the range of 100–800 μM in an optimized electrolytic pH of 4. The excellent sensing ability of the sensor can be attributed to the heterogeneous interface between two material constituents that results in unimpeded electrical transport due to the presence of intertwined nanosheets in MoS2 and 1D α-MnO2 nanorods, high number of active sites emanating from huge numbers of edges and defects in MoS2, high proportion of metallic (1T)phase than semiconducting (2H)phase in MoS2 and the combined effect of 1D α-MnO2 nanorods and MoS2 nanosheets. The fabricated sensor was also effectively assessed for the detection of nitrite in potable water. This novel, binder-free, MnO2-MoS2 composite based electrode material paves a new way for the development of simple, non-enzymatic and inexpensive electrochemical sensors for analytical applications. © 2019 Elsevier B.V.

World University root node

Journal of Alloys and Compounds

Template-cum-catalysis free synthesis of α-MnO2 nanorods-hierarchical MoS2 microspheres composite for ultra-sensitive and selective determination of nitrite

While all reports on supercapacitors are based on electrodes that are fabricated either using expensive, complex fabrication techniques or multiple steps based synthesis routes, the current work is the first report of one-step hydrothermally grown MoS2 on pencil graphite electrode (PGE) for ultra-high performance supercapacitor application. Field emission scanning electron microscope images revealed MoS2 micro-flower like structure containing interwoven nanosheets whereas chemical characterizations data confirmed the successful growth of few layered (&gt;4 layers) MoS2 on PGE. The performance of the electrode was optimized using various grades of pencil, and it was found that the areal capacitance of the MoS2 grown on 1H PGE(7178.8 mF cm-2) was about 3.4 and 4.1 folds greater than those of the MoS2 grown on 2B, 6H PGE at the same current density respectively. This low cost, binder-free MoS2 based PGE paves a novel way towards the advancement of affordable electrodes for energy storage-conversion and bioanalytical applications. © 2018 IOP Publishing Ltd.

Nanotechnology

Few layered MoS2 grown on pencil graphite: A unique single-step approach to fabricate economical, binder-free electrode for supercapacitor applications

Electronic systems that can respond to the user-defined circumstances from a distant location hold enormous potential in disposable devices, secured memories, restorable environmental monitoring etc. related applications which cannot be achieved by conventional silicon technology. This paper is the first demonstration of wirelessly destructible ultraviolet photodetector based on Itaconic acid functionalized water soluble ZnS on flexible polyvinyl alcohol (PVA) substrate wherein all of the device elements dissolve and/or disintegrate upon immersion in water triggered using smartphone assisted Android application. The user can wirelessly destroy the sensor anytime or the sensor can be programmed to be destroyed after performing its task. Use of graphene as both contacts as well as a transport layer enables superior photodetection while making the fabrication simple, low-cost and cleanroom free which disintegrates from the device upon dissolution in water. The fabricated transient, flexible photodetector exhibited a remarkable responsivity of 1.08 mA/W and rise time and fall times of 6.1 s and 8.23 s respectively which could be ascribed to the large electric field created at the ZnS/graphene schottky barrier. Dissolution and disintegration of the fabricated sensor demonstrate complete transience in 10 mins. The study presented here opens up numerous possibilities for applications of wireless transient photodetectors in environmental monitoring, health care, security and consumer electronics. © 2019 Elsevier Ltd

Materials Science in Semiconductor Processing

Functionalized water soluble nanomaterials and their applications in wirelessly destructible programmed flexible transient photodetectors

Citizens Broadband Radio Service (CBRS) is a new service band in 3550-3700 MHz spectrum with the federal military radars of the United States as the primary users (also called as incumbents). The privacy of location, operation time, operating frequency, and antenna parameters of the incumbents is crucial for national security. Different schemes have been proposed for ensuring location and operation time privacy of incumbents. However, the privacy of operating frequency of incumbents has not been addressed. The termination of non-incumbent device from a frequency on which the incumbent becomes active can reveal the operating frequency of the incumbent. In this work, we propose a scheme to preserve the privacy of operating frequency of the incumbents by introducing dummy incumbent channels. We analyze the probability of incorrectly identifying an actual incumbent channel by the adversary as the privacy metric for incumbents. Further, the optimum probability of faking the presence of incumbents on a channel is obtained through a trade-off between the privacy of incumbents and utility of non-incumbents for different system parameters. Finally, the proposed results are verified through simulations. © 2019 IEEE.

2019 IEEE International Symposium on Dynamic Spectrum Access Networks, DySPAN 2019

Privacy Preserving Scheme for Operating Frequency of Incumbents in Citizens Broadband Radio Service

We study the problem of finding unitary submatrices of the N × N discrete Fourier transform matrix, in the context of interpolating a discrete bandlimited signal using an orthogonal basis. This problem is related to a diverse set of questions on idempotents on ZN and tiling ZN. In this work, we establish a graph-theoretic approach and connections to the problem of finding maximum cliques. We identify the key properties of these graphs that make the interpolation problem tractable when N is a prime power, and we identify the challenges in generalizing to arbitrary N. Finally, we investigate some connections between graph properties and the spectral-tile direction of the Fuglede conjecture. © 1963-2012 IEEE.

IEEE Transactions on Information Theory

Discrete Sampling: A Graph Theoretic Approach to Orthogonal Interpolation

In this paper, we propose a low complexity architecture design methodology for fixed point root and power computations. The state of the art approaches perform the root and power computations based on the natural logarithm-exponential relation using Hyperbolic COordinate Rotation DIgital Computer (CORDIC). In this paper, any root and power computations have been performed using binary logarithm-binary inverse logarithm relation. The designs are modeled using VHDL for fixed point numbers and synthesized under the TSMC 40 -nm CMOS technology @ 1 GHz frequency. The synthesis results shows that the proposed Nth root computation saves 19.38% on chip area and 15.86% power consumption when compared with the state of the art architecture for root computation without compromising the computational accuracy. Similarly, the proposed Nth power computation saves 38% on chip area, 35.67% power consumption when compared with the state of the art power computation with out loss in accuracy. The proposed root and power computation designs save 8 clock cycle latency when compared with the state of the art implementations. © 2004-2012 IEEE.

Fulltext

IEEE Transactions on Circuits and Systems I: Regular Papers

Low Complexity Generic VLSI Architecture Design Methodology for Nth Root and Nth Power Computations

The objective of this study is to identify and eliminate unnecessary iteration loops in the load flow analysis of an active distribution network so as to improve its overall computational efficiency. The number of iteration loops is minimised through the integrated modelling of a distributed generator (DG) and the associated coupling transformer. The DG bus is not preserved in the load flow calculation and the aforementioned DG-transformer assembly is represented in the form of a voltage-dependent negative load at the point of connection to the main distribution network. Thus, the iteration stage that is involved in indirectly preserving the DG in the form of a voltage source or negative constant power load can be eliminated. This, in turn, eliminates the need for multiple rounds of forward-backward sweeps (FBS) iterations to determine the bus voltages. The power characteristics of the DG-transformer assembly are thoroughly investigated through a carefully performed case study so as to assess the general convergence performance of the proposed load flow algorithm Furthermore, extensive comparative studies are carried out to verify the computational efficiency attained via the proposed DG modelling in the load flow analysis of an active distribution network. © The Institution of Engineering and Technology 2018.

IET Generation, Transmission and Distribution

Active distribution network load flow analysis through non-repetitive FBS iterations with integrated DG and transformer modelling

Multicasting K independent messages via multiple-input multiple-output channels to multiple users where each user already has a subset of messages as side information is studied. A general framework of constructing layered space-time index coding (LSTIC) from a large class of space-time block codes (STBC), including perfect STBC, is proposed. We analyze the proposed LSTIC and show that it provides minimum determinant gains that are exponential with the amount of information contained in the side information for any possible side information. When constructed over a perfect STBC, the proposed LSTIC is itself a perfect STBC and hence many desired properties are preserved. To illustrate, we construct LSTIC over the following well-known STBCs: Golden code; 3 × 3, 4 × 4, and 6 × 6 perfect STBCs; and Alamouti code. Simulation results show that the obtained side information gain can be well predicted by our analysis. © 1963-2012 IEEE.

Layered space-time index coding

Conventional Kalman filter (KF) requires matrix inversion. But the pervasive applications of KF cannot at times afford inversion. Especially, embedded implementations do not have the capabilities to compute inverse using methods such as Cholesky decomposition. For large matrices, inversion could be computationally prohibitive even for non-embedded implementations. To address this problem, an inverse free Kalman filter (IFKF) is proposed in this letter. The inverse of innovation covariance matrix required in the update step of the KF is approximated using Taylor series expansion. The approximate inverse has a closed form expression in the elements of the original matrix. Bounds on the error covariance of proposed IFKF are also established. The proposed IFKF does not require any iterations to converge. © 2017 IEEE.

IEEE Control Systems Letters

Inverse Free Kalman Filter Using Approximate Inverse of Diagonally Dominant Matrices

With the emergence of new technologies in power generation methods, microgrids have become a complex system with multiple generators of different types. Sizing of these generators for an economical microgrid has multi-fold challenges. The primary aspect of sizing formulation is incorporating the effects of short-term decision mechanisms, unit commitment and demand side management which significantly impacts the operational cost of the microgrid. Accounting the degradation of the microgridunits and lifetime based on performance are the other important issues that need to be contemplated in sizing methodology. Also, microgrids are associated with uncertainties in load and power generated by renewable sources. Hence, the microgrid sizing problem is a large-scale stochastic optimization problem. In this manuscript, a unified optimization framework for the sizing of an islanded microgrid with features that can simultaneously handle all the challenging issues mentioned above is proposed. Results obtained using the proposed method are compared with the state-of-the-art sizing algorithm. © 2019