University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Applied Mathematics

Propagation of water waves over an infinite trench is examined here assuming linear theory where waves are incident from the direction of either negative infinity or positive infinity. For each case, the problem is reduced to solving coupled weakly singular integral equations of first kind involving horizontal component of velocity above the two edges of the trench. The integral equations are solved employing Galerkin approximation in terms of simple polynomials multiplied by appropriate weight functions whose forms are dictated by the edge conditions at the corners of the trench. The numerical estimates for reflection and transmission coefficients are depicted graphically against the wave number for different distance between the trenches and also for different heights of the asymmetric trench

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Zeitschrift für angewandte Mathematik und Physik

Water wave propagation over an infinite trench

Generation of magneto-hydrodynamic surface wave by a moving oscillatory disturbance in a finite depth ocean bounded below by a horizontal porous bottom is presented. The governing initial-boundary value problem is solved using Laplace-Fourier transform and an integral form of the surface elevation is obtained. The asymptotic solutions for the free surface elevation are obtained using stationary phase method. The results show that both the steady-state and transient components exist where the latter decays asymptotically and steady-state is reached. It is seen that the bottom permeability has a significant impact on surface elevation. The dispersion relation is also taken into account and the phase and group velocities for deep water and shallow water are analyzed for different values of the parameters in number of figures. The results for limiting case in which the current speed and the porosity vanishes are compared with the calculations investigated earlier.

Waves in Random and Complex Media

Effects of bottom permeability on wave generation by a moving oscillatory disturbance in magneto- hydrodynamics

Journal of Fluids and Structures

Radiation of water waves by a heaving submerged disc in a three-layer fluid

In this paper, we revisit the problem of clustering 1318 new variable stars found in the Milky way. Our recent work distinguishes these stars based on their light curves which are univariate series of brightness from the stars observed at discrete time points. This work proposes a new approach to look at these discrete series as continuous curves over time by transforming them into functional data. Then, functional principal component analysis is performed using these functional light curves. Clustering based on the significant functional principal components reveals two distinct groups of eclipsing binaries with consistency and superiority compared to our previous results. This method is established as a new powerful light curve-based classifier, where implementation of a simple clustering algorithm is effective enough to uncover the true clusters based merely on the first few relevant functional principal components. Simultaneously we discard the noise from the data study involving the higher order functional principal components. Thus the suggested method is very useful for clustering big light curve data sets which is also verified by our simulation study. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.

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Astrophysics and Space Science

Clustering of eclipsing binary light curves through functional principal component analysis

Subjective classification of spiral galaxies is not sufficient for studying the effect of bars on their physical characteristics. In reality the problem is to comprehend the complex correlations in a multivariate parametric space. Multivariate tools are the best ones for understanding this complex correlation. In this work an objective classification of a large set (26,089) of spiral galaxies was compiled as a value added galaxy catalogue from sdss DR 15 virtual data archive. Initially for dimensionality reduction, Independent Component Analysis is performed to determine a set of Independent Components that are linear combinations of 48 observed features (namely ionized lines, Lick indices, photometric and morphological properties). Subsequently a K-means cluster analysis is carried out on the basis of the 14 best chosen Independent Components to obtain 12 distinct homogeneous groups of spiral galaxies. Amongst these, 3 groups are the oldest ones (1.6 Gyr − 5.9 Gyr), while 5 groups fall in the medium aged category (1.4 Gyr − 1.6 Gyr), 2 groups consist of only unbarred spirals, 1 group is the youngest one and the remaining one is an outlier. In many groups there are clear indication of recurrent bar formation phenomena which is consistent with few previous simulation works. In order to study the robustness of the clusters with respect to the method of clustering, a second method of clustering by Gaussian Mixture Modeling Method (GMMBC) is applied. © 2022 Taylor &amp; Francis Group, LLC.

Communications in Statistics: Simulation and Computation

Investigation of the effect of bars on the properties of spiral galaxies: a multivariate statistical study

European Journal of Mechanics-A/Solids

Vibration analysis of electro-magneto transversely isotropic non-local thermoelastic cylinder with voids material

Journal of Ocean Engineering and Science

Prediction of the stability number of conventional rubble-mound breakwaters using machine learning algorithms

arXiv e-prints

Effect of dark matter halos on the orbital and escape dynamics of barred galaxies

Archive of Applied Mechanics

Generation of waves by moving oscillatory pressure disturbances in presence of porous bottom

Chaos: An Interdisciplinary Journal of Nonlinear Science

Diffusive instability in hyperbolic reaction–diffusion equation with different inertia