(SoE) School of Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

In recent time, third generation solar cells have been developed and become very popular as DYE sensitized solar cells (DSSC). These carbons based DSSC are eco-friendly, having less carbon credit and low in manufacturing cost as compare to second generation thin film solar cells. Overall performance of grid connected PV based electrical systems are affected by the selection of the solar cells and modules. In this work, carbon-based DYE sensitized solar cells have been used for the grid connected PV systems. Here, performance of DSSC based grid connected system is presented in result section. DC link voltage and bidirectional power flow have been shown here to validate the performance of grid connected solar PV system. Simulation work has been done on MATLAB software and different results have been shown in graphical form. © 2019 Elsevier Ltd. All rights reserved.

World University root node

Electrical Engineering

Materials Today: Proceedings

Grid connected solar PV system using carbon material based DYE sensitized solar cells

The groundnuts were dried inside an even span roof type free convection greenhouse dryer with a useful floor area of 1.2×0.8 m2 in the environmental conditions of Rohtak, India (28o54′-N 76o34′E). Wire mesh sieves of sizes 0.15×0.25 m2, 0.25×0.4 m2, and 0.35×0.6 m2 were used to accommodate thin layer samples of groundnuts. The groundnuts were dried till the optimum safe moisture storage level (8%-10%) was attained. Based on experimental (hourly) observations the values of constants (C and n) in the equation of Nusselt number were evaluated. The values of convective and evaporative heat transfer coefficients were calculated which were observed to decrease with the increase in the sieve size. The overall average greenhouse thermal, energy, and exergy efficiencies were evaluated as 8.83%, 22.67%, and 2.75% respectively. The overall average experimental error in terms of % uncertainty for groundnuts drying was evaluated as 37.94%. © 2019, Int. Comm. of Agricultural and Biosystems Engineering. All rights reserved.

Mechanical Engineering

Agricultural Engineering International: CIGR Journal

Experimental free convection thin layer groundnut greenhouse drying

Interdigitated photomixing antennas (PMA), are amongst the most common sources for future terahertz wireless communication systems. In this contribution, a novel and interesting design of a PMA employing graphene as its electrode material has been proposed. The use of graphene provides several potential advantages over conventional metallic electrodes. Variation of the PMA output as a function of various parameters have been discussed and a novel scheme for producing modulation in the PMA output, using an additional signal source, has been introduced. The multiphysical scenario in the functioning of the PMA has been elegantly analyzed with a generalized and simple model. Expressions for the radiated fields from the antenna have been derived using the proposed model and have been validated with full-wave simulations. This paper introduces a procedure for simulating the antenna on commercial EM solvers. Several strategies to modulate the output of antennae, which is crucial for them to be suitable for wireless communications, have also been proposed and discussed with several key findings. The role of some of the antenna parameters have also been investigated. The uniqueness of this analysis lies in its simplicity and generalization along with its capability to combine the multi-physical scenario in the operation of the PMA. © 2018 IOP Publishing Ltd.

Semiconductor Science and Technology

Novel graphene based antennas for the terahertz region

Radiation from a Terahertz Photomixing Antenna (PMA) involves multi-physical phenomena. We introduce a simple analytical model that combines the multi-physical phenomena in the PMA using a conventional 2-ray model. We observe reasonably close agreement between the antenna output obtained from the proposed model and the available measured results. We extend our analytical framework to incorporate the presence of an additional signal source on one of the laser beams, intended towards producing modulation in the PMA output signal. We analytically investigate the active region current density and radiated fields of the PMA. We also present a brief discussion on the efficiency of the PMA and the different factors that impact the efficiency. The output power depends on some key parameters which can be utilized to make PMAs suitable for sensing as well as wireless communication applications. © 2019, © 2019 IETE.

IETE Journal of Research

Analytical Modelling of Terahertz Photomixing Antennas

MassiveMIMO(MaMI) is one of the fiery topics in 5G wireless communications. It is introduced based on the fact that the channel vectors becomes asymptotically orthogonal (as antenna elements tending to infinity). Convergence of frequency selective channel (quasi static block fading) characteristics in terms of favorable propagation and channel hardening (asymptotically orthogonal) conditions are studied using metrics like Eigenvalue Ratio (EVR), Mean Absolute Deviation (MAD) and Diagonal Dominance (DD). Finally, simulations results for convergence metrics EVR, MAD and DD are compared with its limiting behavior. The effect of time delay spread on the channel convergence is studied based on the condition number of channel matrix. © 2019 IEEE.

Physics

(SoNS) School of Natural Sciences

IEEE Region 10 Annual International Conference, Proceedings/TENCON

Convergence of MassiveMIMO Frequency Selective Channels

In this study, a new modulation method defined as Ramanujan periodic subspace division multiplexing (RPSDM) is proposed using Ramanujan subspaces. Each subspace contains an integer-valued Ramanujan sum and its circular downshifts as a basis. The proposed RPSDM decomposes the linear time-invariant wireless channels into a Toeplitz stair block diagonal matrices, whereas orthogonal frequency division multiplexing (OFDM) decompose the same into diagonal. Advantages of such structured subspaces representation are studied and compared with an OFDM representation in terms of a peak-average power ratio and bit error rate. Zero-forcing and minimum mean square error detectors are applied to evaluate the performance of OFDM and RPSDM techniques. Finally, the simulation results show that the proposed design (with an additional receiver complexity) outperforms OFDM under both detectors. © The Institution of Engineering and Technology 2019

IET Communications

Ramanujan periodic subspace division multiplexing

An Ultra-wide band filter is designed in this work. Microstrip lines along with passive components are used to create a wide band filter centered at 5GHz ranging between 3GHz - 9GHz. Shorted stubs are used to remove lower frequency. Detailed design procedure is given in paper. © 2019 IEEE.

2019 IEEE 5th International Conference for Convergence in Technology, I2CT 2019

Tunable Notch Wide Band Filter Using Stubs

The dispersion equation for a planar traveling wave tube with anisotropically conducting open helix structure is derived. Using, the accurate boundary conditions along all the sides of the planar TWT and along the winding direction of the TWT using indicator function, the exact solution of a homogenous boundary value problem for Maxwell's equations is derived. A total number of six different complex constants are derived from a set of six boundary conditions for the proposed cold wave analysis. The presented theoretical analysis will be used in the design of the planar travelling wave tube amplifier (TWTA). © 2019 IEEE.

2019 6th International Conference on Signal Processing and Integrated Networks, SPIN 2019

Modified Dispersion Equation for Planar Open Tape Helix Travelling Wave Tube

By combining several interesting applications of random sampling in geometric algorithms like point location, linear programming, segment intersections, binary space partitioning, Clarkson and Shor [4] developed a general framework of randomized incremental construction (RIC ). The basic idea is to add objects in a random order and show that this approach yields efficient/optimal bounds on expected running time. Even quicksort can be viewed as a special case of this paradigm. However, unlike quicksort, for most of these problems, sharper tail estimates on their running times are not known. Barring some promising attempts in [15, 3, 20], the general question remains unresolved. In this paper we present a general technique to obtain tail estimates for RIC and and provide applications to some fundamental problems like Delaunay triangulations and construction of Visibility maps of intersecting line segments. The main result of the paper is derived from a new and careful application of Freedman’s [9] inequality for Martingale concentration that overcomes the bottleneck of the better known Azuma-Hoeffding inequality. Further, we explore instances, where an RIC based algorithm may not have inverse polynomial tail estimates. In particular, we show that the RIC time bounds for trapezoidal map can encounter a running time of Ω(n log n log log n) with probability exceeding 1n . This rules out inverse polynomial concentration bounds within a constant factor of the O(n log n) expected running time. © Sandeep Sen.

Leibniz International Proceedings in Informatics, LIPIcs

A unified approach to tail estimates for randomized incremental construction

The text covers important algorithm design techniques, such as greedy algorithms, dynamic programming, and divide-and-conquer, and gives applications to contemporary problems. Techniques including Fast Fourier transform, KMP algorithm for string matching, CYK algorithm for context free parsing and gradient descent for convex function minimization are discussed in detail. The book's emphasis is on computational models and their effect on algorithm design. It gives insights into algorithm design techniques in parallel, streaming and memory hierarchy computational models. The book also emphasizes the role of randomization in algorithm design, and gives numerous applications ranging from data-structures such as skip-lists to dimensionality reduction methods. © Sandeep Sen and Amit Kumar 2019.