arXiv subjects

Narendra Kumar

Publications and source records attributed to Narendra Kumar.

17 recordsLinked to original sources

arXiv2026

Dynamics of Unemployment with Discouraged Workers: A Nonlinear Mathematical Model

In this article, we formulate and analyze a new non-linear mathematical model to describe the dynamics of unemployment with a discouraged working population. We consider five dynamic variables, namely, unskilled unemployed individuals, skilled unemployed individuals, discouraged individuals, employed persons, and job vacancies. Furthermore, we determine the equilibrium points of the dynamic system and investigate their local stability. To demonstrate the results, we conduct numerical simulations by presenting solution trajectories and analyzing how variations in key parameters influence the states of the dynamical variables.

physics.soc-ph↗

arXiv2025

On a class of coupled fractional nonlinear singular boundary value problems arising in dusty fluid models

In this article, we introduce a new class of coupled fractional Lane-Emden boundary value problems. We employ a novel approach, the fractional Haar wavelet collocation method with the Newton-Raphson method. We analyze the conditions in two cases to present numerical experiments related to the defined system of fractional differential equations. To validate the accuracy of the proposed method we present the convergence of the method, and we demonstrate the method's effectiveness through five numerical experiments, highlighting real-world applications of fractional differential equations. Using figures and tables, we show that the residual error decreases as we increase the value of the maximum level of resolution $J$ while keeping the order of derivatives fixed, and similar trends also observe when $J$ is fixed and vary the order of fractional derivatives. We demonstrate that Mathematica software can be used effectively to solve such nonlinear singular fractional boundary value problems.

math.GM↗

arXiv2025

Bremsstrahlung induced atomic processes

The observed spectra in the collisions of neon (Ne) projectiles of 1.8 and 2.1 MeV with an aluminum target (Al) have been successfully segregated from strong bremsstrahlung backgrounds and then analyzed by comparing the transition energies and rates with the theoretical predictions of the flexible atomic structure code and the general purpose relativistic atomic structure package. The spectra contain K{\alpha}, Kh{\alpha} , and K{\alpha}{\alpha} lines. The K{\alpha}{\alpha} emissions are due to two-electron one-photon transitions. Interestingly, the K{\alpha}{\alpha} lines in projectile ions are only seen with 1.8 MeV energy. In contrast, the K{\alpha}{\alpha} lines in the target ions are also well observed with 2.1 MeV energy. Surprisingly, the Al K x-ray line intensities are strongly suppressed, and the K{\alpha}{\alpha} line intensities are unexpectedly enhanced. The underlying physical process is found to be the photoionization caused by intense bremsstrahlung radiation. This photoionization process converts most of the singly ionized K shell states (\approx 82\% at 2.1 MeV) to doubly ionized K shell states. This phenomenon is silently present on many occasions. We take some of such events to validate this remarkable finding. This bremsstrahlung radiation induced secondary ionization process stands as an eye opening incidence to the plasma physics, astronomy and astrophysics communities; may revolutionize these fields of research.

physics.atom-ph↗

arXiv2024

Uniform Haar Wavelet Solutions for Fractional Regular $\beta$-Singular BVPs Modeling Human Head Heat Conduction under Febrifuge Effects

This paper introduces nonlinear fractional Lane-Emden equations of the form, $$ D^{\alpha} y(x) + \frac{\lambda}{x^\beta}~ D^{\beta} y(x) + f(y) =0, ~ ~1 < \alpha \leq 2, ~~ 0< \beta \leq 1, ~~ 0 < x < 1,$$ subject to boundary conditions, $$ y'(0) =\mathbf{a} , ~~~ \mathbf{c}~ y'(1) + \mathbf{d}~ y(1) = \mathbf{b},$$ where, $D^\alpha, D^\beta$ represent Caputo fractional derivative, $\mathbf{a, b,c,d} \in \mathbb{R}$, $ \lambda = 1, 2$, and $f(y)$ is non linear function of $y.$ We have developed collocation method namely, uniform fractional Haar wavelet collocation method and used it to compute solutions. The proposed method combines the quasilinearization method with the Haar wavelet collocation method. In this approach, fractional Haar integrations is used to determine the linear system, which, upon solving, produces the required solution. Our findings suggest that as the values of $(\alpha, \beta)$ approach $(2,1),$ the solutions of the fractional and classical Lane-Emden become identical.

math.NA↗

arXiv2024

A novel ANROA based control approach for grid-tied multi-functional solar energy conversion system

An adaptive control approach for a three-phase grid-interfaced solar photovoltaic system based on the new Neuro-Fuzzy Inference System with Rain Optimization Algorithm (ANROA) methodology is proposed and discussed in this manuscript. This method incorporates an Adaptive Neuro-fuzzy Inference System (ANFIS) with a Rain Optimization Algorithm (ROA). The ANFIS controller has excellent maximum tracking capability because it includes features of both neural and fuzzy techniques. The ROA technique is in charge of controlling the voltage source converter switching. Avoiding power quality problems including voltage fluctuations, harmonics, and flickers as well as unbalanced loads and reactive power usage is the major goal. Besides, the proposed method performs at zero voltage regulation and unity power factor modes. The suggested control approach has been modeled and simulated, and its performance has been assessed using existing alternative methods. A statistical analysis of proposed and existing techniques has been also presented and discussed. The results of the simulations demonstrate that, when compared to alternative approaches, the suggested strategy may properly and effectively identify the best global solutions. Furthermore, the system's robustness has been studied by using MATLAB/SIMULINK environment and experimentally by Field Programmable Gate Arrays Controller (FPGA)-based Hardware-in-Loop (HLL).

eess.SY↗

arXiv2023

Entropic Stabilization and Descriptors of Structural Transformation in High Entropy Alloys

With first-principles theoretical analysis of the local structure using Bond Orientational Order parameters and Voronoi partitioning, we establish (a) HCP$\rightarrow$BCC structural transformation in high-entropy alloys (HEAs) Nb$_x$(HfZrTi)$_y$ at 16% Nb-concentration, and (b) that the internal lattice distortions (ILDs) peak at the transition. We demonstrate that the relative stability of HCP and BCC structures is driven by energetics, while the overall stability is achieved with contribution from the vibrational entropy that exceeds the configurational entropy of mixing. We show that along with atomic size mismatch, low average number ($< $5) of valence electrons and disparity in the crystal structures of constituent elements are responsible for larger ILDs in Nb$_x$(HfZrTi)$_y$ than in HEAs like Nb$_a$Mo$_b$W$_c$Ta$_d$.

cond-mat.mtrl-sci↗

arXiv2023

Potential energy surface prediction of Alumina polymorphs using graph neural network

The process of design and discovery of new materials can be significantly expedited and simplified if we can learn effectively from available data. Deep learning (DL) approaches have recently received a lot of interest for their ability to speed up the design of novel materials by predicting material properties with precision close to experiments and ab-initio calculations. The application of deep learning to predict materials properties measured by experiments are valuable yet challenging due to the limited amount of experimental data. Most of the existing approaches to predict properties from computational data have also been directed towards specific material properties. In this work, we extend this approach, by proposing Landscape Crystal Graph Convolution Network(LCGCN), an accurate and transferable deep learning framework based on graph convolutional networks. LCGCN directly learns the potential energy surface (PES) from atomic configurations. This approach can enable transferable models that can predict different material properties. We apply this framework to bulk crystals (i.e. Al2O3), and test it by calculating potential energy surfaces at different temperatures and across different phases of crystal.

cond-mat.mtrl-sci↗

arXiv2020

A Cleanroom in a Glovebox

The exploration of new materials, novel quantum phases, and devices requires ways to prepare cleaner samples with smaller feature sizes. Initially, this meant the use of a cleanroom that limits the amount and size of dust particles. However, many materials are highly sensitive to oxygen and water in the air. Furthermore, the ever-increasing demand for a quantum workforce, trained and able to use the equipment for creating and characterizing materials, calls for a dramatic reduction in the cost to create and operate such facilities. To this end, we present our cleanroom-in-a-glovebox, a system which allows for the fabrication and characterization of devices in an inert argon atmosphere. We demonstrate the ability to perform a wide range of characterization as well as fabrication steps, without the need for a dedicated room, all in an argon environment. Connection to a vacuum suitcase is also demonstrated to enable receiving from and transfer to various ultra-high vacuum (UHV) equipment including molecular-beam epitaxy (MBE) and scanning tunneling microscopy (STM).

physics.app-ph↗

arXiv2020

Modulation Doping via a 2d Atomic Crystalline Acceptor

Two-dimensional (2d) nano-electronics, plasmonics, and emergent phases require clean and local charge control, calling for layered, crystalline acceptors or donors. Our Raman, photovoltage, and electrical conductance measurements combined with \textit{ab initio} calculations establish the large work function and narrow bands of $\alpha$-RuCl$_3$ enable modulation doping of exfoliated, chemical vapor deposition (CVD), and molecular beam epitaxy (MBE) materials. Short-ranged lateral doping (${\leq}65\ \text{nm}$) and high homogeneity are achieved in proximate materials with a single layer of \arucl. This leads to the highest monolayer graphene (mlg) mobilities ($4,900\ \text{cm}^2/ \text{Vs}$) at these high hole densities ($3\times10^{13}\ \text{cm}^{-2}$); and yields larger charge transfer to bilayer graphene (blg) ($6\times10^{13}\ \text{cm}^{-2}$). We further demonstrate proof of principle optical sensing, control via twist angle, and charge transfer through hexagonal boron nitride (hBN).

cond-mat.mtrl-sci↗

arXiv2019

System of Lane-Emden equations as IVPs BVPs and Four Point BVPs & Computation with Haar Wavelets

In this work we present Haar wavelet collocation method and solve the following class of system of Lane-Emden equation defined as \begin{eqnarray*} -(t^{k_1} y'(t))'=t^{-\omega_1} f_1(t,y(t),z(t)),\\ -(t^{k_2} z'(t))'=t^{-\omega_2} f_2(t,y(t),z(t)), \end{eqnarray*} where $t>0$, subject to initial values, boundary values and four point boundary values: \begin{eqnarray*} \mbox{Initial Condition:}&&y(0)=\gamma_1,~y'(0)=0,~z(0)=\gamma_2,~z'(0)=0,\\ \mbox{Boundary Condition:}&&y'(0)=0,~y(1)=\delta_1,~z'(0)=0,~z(1)=\delta_2,\\ \mbox{Four~point~Boundary~Condition:}&&y(0)=0,~y(1)=n_1z(v_1),~z(0)=0,~z(1)=n_2y(v_2), \end{eqnarray*} where $n_1$, $n_2$, $v_1$, $v_2$ $\in (0,1)$ and $k_1\geq 0$, $k_2\geq0$, $\omega_1<1$, $\omega_2<1$ are real constants. Results are compared with exact solutions in the case of IVP and BVP. In case of four point BVP we compare the result with other methods. Convergence of these methods is also established and found to be of second order. We observe that as resolution is increased to $J=4$ we get the exact values for IVPs and BVPs. For four point BVPs also at $J=4$, we get highly accurate solutions, e.g., the $L^\infty$ error is of order $10^{-16}$ or $10^{-17}$.

math.NA↗

arXiv2019

Haar wavelets collocation on a class of Emden-Fowler equation via Newton's quasilinearization and Newton-Raphson techniques

In this paper we have considered generalized Emden-Fowler equation, \begin{equation*} y''(t)+\sigma t^\gamma y^\beta(t)=0, ~~~~~~~~t \in ]0,1[ \end{equation*} subject to the following boundary conditions \begin{equation*} y(0)=1,~y(1)=0;~~\&~~y(0)=1,~y'(1)=y(1), \end{equation*} where $\gamma,\beta$ and $\sigma$ are real numbers, $\gamma<-2$, $\beta>1$. We propsoed to solve the above BVPs with the aid of Haar wavelet coupled with quasilinearization approach as well as Newton-Raphson approach. We have also considered the special case of Emden-Fowler equation ($\sigma=-1$,$\gamma=\frac{-1}{2}$ and $\beta=\frac{3}{2}$) which is popularly, known as Thomas-Fermi equation. We have analysed different cases of generalised Emden-Fowler equation and compared our results with existing results in literature. We observe that small perturbations in initial guesses does not affect the the final solution significantly.

math.NA↗

arXiv2019

The Discussion on Hulls of Cyclic Codes over the Ring $\Re =\Z_4+v\Z_4$, $v^2=v$

For odd length $n$, the cyclic codes construction over $\Re= \Z_4[v]/ \langle v^2-v \rangle$ is provided. The hulls of cyclic codes over $\Re$ are studied. The average $2$-dimension $E(n)$ of the hulls of cyclic codes over $\Re$ is also conferred. Among these, the various examples of generators of hulls of cyclic codes over $\Re$ are provided, whose $\Z_4$-images are good $\Z_4$-linear codes with good parameters.

cs.IT↗

arXiv2019

Evidence for Helical Hinge Zero Modes in an Fe-Based Superconductor

Combining topology and superconductivity provides a powerful tool for investigating fundamental physics as well as a route to fault-tolerant quantum computing. There is mounting evidence that the Fe-Based Superconductor FeTe$_{0.55}$Se$_{0.45}$ (FTS) may also be topologically non-trivial. Should the superconducting order be s$^{\pm}$, then FTS could be a higher order topological superconductor with Helical Hinge Zero Modes (HHZM).To test the presence of these modes we developed a new method for making normal metal/superconductor junctions via 2D atomic crystal heterostructures. As expected,junctions in contact with the hinge reveal a sharp zero-bias anomaly whose suppression with temperature and magnetic field only along the c-axis are completely consistent with the presence of HHZM. This feature is completely absent when tunneling purely into the c-axis, and its characteristics are also inconsistent with other origins of zero bias anomalies. Furthermore, additional measurements with soft-point contacts in bulk samples with various Fe interstitial contents demonstrate the intrinsic nature of the observed mode. Thus we provide evidence that FTS is indeed a higher order topological superconductor as well as a new method for probing 2D atomic crystals.

cond-mat.supr-con↗

arXiv2015

On cyclic self-orthogonal codes over Zpm

The purpose of this paper is to study the cyclic self orthogonal codes over $\mathbb{Z}_{p^m}$. After providing the generator polynomial of cyclic self orthogonal codes over $\mathbb{Z}_{p^m}$, we give the necessary and sufficient condition for the existence of non-trivial self orthogonal codes over $\mathbb{Z}_{p^m}$ . We have also provided the number of such codes of length $n$ over $\mathbb{Z}_{p^m}$ for any $ (p,n) = 1 $.

cs.IT↗

arXiv2014

E-Governance in India: Definitions, Challenges and Solutions

The Government of India is transcending from traditional modus operandi of governance towards technological involvement in the process of governance. Currently, the Government of India is in the transition phase and seamlessly unleashing the power of ICT in governance. The government is spending an enormous amount of finances in deployment of e-governance, but, are these efforts are going in the appropriate direction and leads towards intended results? What do the people percept from the concept of e-governance? What is the global perspective about perception of e-governance? What are the major challenges confronting the deployment of e-governance? In this attempt the authors have made an attempt to riposte aforesaid issues. Moreover, the authors have also suggested some plausible suggestions which may help in successful and sustainable deployment of e-governance in India.

cs.CY↗

arXiv2014

ICT in Local Self Governance: A Study of Rural India

The concept of local self-governance is not new as it has its roots in ancient time even before the era of Mauryan emperors. This paper depicts the journey of local self-governance from antediluvian time to 21st century. Further, in the current scenario Information and Communication Technology (ICT) has emerged as a successful tool for dissemination of various e-governance services and in this regard the Government of India has formulated NeGP with adequate service delivery mechanism. With the inculcation of ICT, various applications were designed by central as well as state governments which lead towards strengthening of PRIs for rural reform. This paper also throws some light on necessity of ICT in self-governance along with some case studies.

cs.CY↗

arXiv2013

Improved Service Delivery and Cost Effective Framework for e-Governance in India

In current era, the involvement of technologies like virtualization, consolidation and cloud computing, and adoption of free and open source software in designing and deploying e-governance that can reduce the total cost associated with and hence the financial burden abide by the state and central governments. The success of any e-governance project depends upon its utilization by the intended group and so there accessibility needs to be enhanced drastically by reengineered framework. Here, we design an Improved Service Delivery and Cost Effective Framework for e-Governance that will be useful for success of e-governance projects and the delivery mechanism in India by using free and open access software for development and deployment of e-governance applications, virtualization and consolidation techniques for management of e-services and cloud computing for enhancing the accessibility of services.

cs.CY↗