Mathematics

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Shiv Nadar University

Max-plus algebra has been applied to several fields like matrix algebra, cryptography, transportation, manufacturing, information technology and study of discrete event systems like subway traffic networks, parallel processing systems, telecommunication networks for many years. In this paper, we discuss various optimization problem using methods based on max-plus algebra, which has maximization and addition as its basic arithmetic operations. We present some sub-classes of mathematical optimization problems like linear programming, convex quadratic programming problem, fractional programming problem, bimatrix game problem and some classes of stochastic game problem in max algebraic framework and discuss various connections between max-plus algebra and optimization. © 2020, Springer Nature Singapore Pte Ltd.

(SoNS) School of Natural Sciences

World University root node

Springer Proceedings in Mathematics and Statistics

Max Plus Algebra, Optimization and Game Theory

It is shown that for positive real numbers 0&lt;λ1&lt;…&lt;λn, [Formula presented], where β(⋅,⋅) denotes the beta function, is infinitely divisible and totally positive. For [Formula presented], the Cholesky decomposition and successive elementary bidiagonal decomposition are computed. Let w(n) be the nth Bell number. It is proved that [w(i+j)] is a totally positive matrix but is infinitely divisible only upto order 4. It is also shown that the symmetrized Stirling matrices are totally positive. © 2020 Elsevier Inc.

Fulltext

Linear Algebra and Its Applications

Positivity properties of some special matrices

A novel and strategic green energy production method that utilizes relative wind generated from moving vehicles is presented. A speeding train generates an enormous wake of wind around it, which stocks a substantial amount of kinetic energy. In this study, this freely accessible wind power is harvested by installing a modified savonius wind turbine within the slipstream region of the train. A computer-oriented fluid-solid integrate simulation of wind turbine propelled by train-induced wind is performed by executing all physically realistic boundary conditions. The numerical study is based on open-source CFD toolbox OPENFOAM, and the results were validated against benchmark experimental study. Parametric sensitivity analysis such as optimal turbine performance within the slipstream regime, torque prediction from express trains, two opposite crossing trains, tunnel condition, and turbine wind turbine clusters arrangement has been reported. This study enhances the understanding of the power generation by the turbine from the train slipstream which is not reported in any open literature as far as the authors’ present knowledge goes. Copyright © 2020 by ASME

Mechanical Engineering

(SoE) School of Engineering

Journal of Energy Resources Technology, Transactions of the ASME

A Numerical study toward harvesting power from train slipstream using savonius rotor

Neural codes are collective activity of the neurons which are electrically active cells in our brain. In this paper, We study the openness and closeness of the convex neural codes in one dimension. We discuss the possibilities of a convex code to be realized in dimension 1. That is conditions for the minimal embedding dimension of a neural code to be 1. © 2020 Author(s).

AIP Conference Proceedings

Convex realizations of neural codes in one dimension

Here, an excellent cavitation erosion-corrosion resistance of stainless steel using a novel severe surface deformation technique, reciprocating friction processing (RFP) was demonstrated. The RFP treated stainless steel showed nano-grained, nano-twinned microstructure along with high dislocation density. The RFP treated steel significantly surpassed the performance of advanced structural materials including high entropy alloy (Al0.1CoCrFeNi) and complex concentrated alloy (SiC reinforced Al0.1CoCrFeNi), demonstrating the lowest cavitation erosion and cavitation erosion-corrosion rates for this class of materials. The RFP treated steel demonstrated outstanding corrosion behavior in 3.5\% NaCl solution as well. The unusual performance of RFP treated steel is attributed to its excellent mechanical strength and strong passivating behavior. © 2020 Elsevier B.V.

Wear

Cavitation erosion-corrosion resilient surfaces through reciprocating friction processing

International Game Theory Review

Preface to the Special Issue on-Operations Research and Game Theory: Modeling and Computation

MicroRNAs (miRNAs) and transcription factors (TFs) are the largest families of trans-acting gene regulatory species, which are pivotal players in a complex regulatory network. Recently, extensive research on miRNAs and TFs in agriculture has identified these trans-acting regulatory species, as an effective tool for engineering new crop cultivars to increase yield and quality as well tolerance to environmental stresses but our knowledge of regulatory network is still not sufficient to decipher the exact mechanism. In the current work, stress-specific TF-miRNA-gene network was built for Arabidopsis under drought, cold, salt and waterlogging stress using data from reliable publically available databases; and transcriptome and degradome sequence data analysis by meta-analysis approach. Further network analysis elucidated significantly dense, scale-free, small world and hierarchical backbone of interactions. The various centrality measures highlighted several genes/TF/miRNAs as potential targets for tolerant variety cultivation. This comprehensive regulatory information will accelerate the advancement of current understanding on stress specific transcriptional and post-transcriptional regulatory mechanism and has promising utilizations for experimental biologist who are intended to improve plant crop performance under multiple Abiotic stress environments. © 2019

Life Sciences

Genomics

Abiotic stress induced miRNA-TF-gene regulatory network: A structural perspective

Savonius wind turbines are special class of vertical axis wind turbines (VAWTs). These are low-cost drag-driven turbines and are known to be inefficient. It is proposed in this study that a simple modification to the turbine blade design can yield a significant improvement in power efficiency. The performance of the new design is extensively studied on OPENFOAMv1812, a popular open source computational fluid dynamics (CFD) library. The flow equations coupled with equations of rotation of the turbine are solved on an overset mesh framework. This study also serves as a validation of recently released overset support in OPENFOAM. The turbulence is incorporated by coupling Reynolds-averaged Navier-Stokes (RANS) with shear stress transport (SST) κ-ω eddy viscosity turbulence model. The turbulence parameters are set to produce a flow with the Reynolds number, Re=4.8 × 105. To have better confidence in simulations, this study also presents a comparison of numerical flow over conventional Savonius turbine designs with the published data. It is observed that a majority of CFD analysis on wind turbine designs are performed for the fixed tip speed ratio on a traditional static mesh structure. But, in this CFD study, a winddriven rotation of Savonius turbine is simulated on an overset dynamics approach. The results of the study are compared and discussed based on the predicted moment and power coefficients, pressure variation on the blades, flow velocity field, and wake analysis. The study indicates that the blade design presented here has a potential to increase the power efficiency of a Savonius wind turbine by 10-28\%. © 2020 American Society of Mechanical Engineers (ASME). All rights reserved.

Improvement in savonius wind turbines efficiency by modification of blade designs - A numerical study

In this article, we consider the polynomials of the form f(x) = a0+ a1x + a2X2+ ... + anxn∈ Z[x], where |a0| = |a1| + ... + |a0| and |ao| is a prime. We show that these polynomials have a cyclotomic factor whenever reducible. As a consequence, we give a simple procedure for checking the irreducibility of trinomials of this form and separability criterion for certain quadrinomials. © 2020 Societatea de Stiinte Matematice din Romania. All rights reserved.

Bulletin Mathematique de la Societe des Sciences Mathematiques de Roumanie

An irreducibility criterion for polynomials over integers

Background: There is scarce evidence that tuberculosis (TB) can cause diabetes in those not previously known to be diabetic. Whilst the World Health Organization (WHO) recommends screening for Diabetes Mellitus (DM) at the onset of TB treatment, nevertheless, it remains to be elucidated which patients with TB-associated hyperglycemia are at higher risk for developing DM and stand to benefit from a more regular follow-up. This review aims to firstly quantify the reduction of newly detected hyperglycemia burden in TB patients who are on treatment over time; secondly, determine the burden of TB-associated hyperglycemia after follow-up, and thirdly, synthesize literature on risk factors for unresolved TB-associated hyperglycemia in previously undiagnosed individuals. Methods: We searched PUBMED, EMBASE, SCOPUS, and Global Health for articles on TB-associated hyperglycemia up to September 30th, 2019. Search terms included Tuberculosis and hyperglycemia/DM, and insulin resistance. We appraised studies, extracted data, and conducted a meta-analysis to assess the change of the burden of hyperglycemia in prospective studies. The review is registered in the PROSPERO database (CRD42019118173). Results: Eleven studies were included in the meta-analysis yielding a total of 677 (27,3\%) of patients with newly detected hyperglycemia at baseline. The mean quality score of eligible studies using the Newcastle-Ottawa Quality Assessment Scale was 7.1 out of 9 (range 6-9). The pooled unresolved new cases of hyperglycemia at the end of follow up was 50\% (95\% CI: 36–64\%) and the total pooled burden of hyperglycemia at 3–6 months of follow up was 11\% (95\% CI: 7–16\%), with both estimates displaying a high heterogeneity, which remained significant after performing a sub-analysis by DM diagnostic method and 3 months of follow up. As only 2 studies explored risk factors for unresolved hyperglycemia, no meta-analysis was performed on risk factors. Conclusion: Our meta-analysis showed that although in half of the patients with newly observed hyperglycemia at baseline, it remained unresolved at a follow-up of 3 to 6 months, the total burden of hyperglycemia is slightly above 10\%, 3 months after initiating TB treatment. Studies are warranted to assess whether risk factors including HIV positivity, smoking, and extensive pulmonary TB disease put patients at higher risk for DM. © 2020, The Author(s).

BMC Infectious Diseases

The epidemiology of tuberculosis-associated hyperglycemia in individuals newly screened for type 2 diabetes mellitus: systematic review and meta-analysis