arXiv subjects

Ankit Singh

Publications and source records attributed to Ankit Singh.

41 records · Page 3Linked to original sources

arXiv2019

Super-Arrhenius behaviour of molecular glass formers

A theory is developed to calculate values of the potential energy barriers to structural relaxation in molecular glass formers from the data of static pair correlation function. The barrier height is shown to increase due to increase in number of the stable bonds a particle forms with its neighbours and energy of each bond as liquids move deeper into the supercooled (super-compressed) region. We present results for a system of hard-spheres and compare calculated values of the structural relaxation time with experimental and simulation results.

cond-mat.soft↗

arXiv2018

Ultraviolet and optical view of galaxies in the Coma Supercluster

The Coma supercluster (100 Mpc) offers an unprecedented contiguous range of environments in the nearby Universe. In this paper we present a catalogue of spectroscopically confirmed galaxies in the Coma supercluster detected in the ultraviolet (UV) wavebands. We use the arsenal of UV and optical data for galaxies in the Coma supercluster covering ~ 500 square degrees on the sky to study their photometric and spectroscopic properties as a function of environment at various scales. We identify the different components of the cosmic-web: large-scale filaments and voids using Discrete Persistent Structures Extractor, and groups and clusters using Hierarchical Density-based spatial clustering of applications with noise, respectively. We find that in the Coma supercluster the median emission in Halpha inclines, while the g-r and FUV-NUV colours of galaxies become bluer moving further away from the spine of the filaments out to a radius of around 1 Mpc. On the other hand, an opposite trend is observed as the distance between the galaxy and centre of the nearest cluster or group decreases. Our analysis supports the hypothesis that properties of galaxies are not just defined by its stellar mass and large-scale density, but also by the environmental processes resulting due to the intrafilament medium whose role in accelerating galaxy transformations needs to be investigated thoroughly using multi-wavelength data.

astro-ph.GA↗

arXiv2016

BASS Net: Band-Adaptive Spectral-Spatial Feature Learning Neural Network for Hyperspectral Image Classification

Deep learning based landcover classification algorithms have recently been proposed in literature. In hyperspectral images (HSI) they face the challenges of large dimensionality, spatial variability of spectral signatures and scarcity of labeled data. In this article we propose an end-to-end deep learning architecture that extracts band specific spectral-spatial features and performs landcover classification. The architecture has fewer independent connection weights and thus requires lesser number of training data. The method is found to outperform the highest reported accuracies on popular hyperspectral image data sets.

cs.CV↗

arXiv2015

Comparative Stability of Cloned and Non-cloned Code: A Replication Study

Code cloning is an important software engineering aspect. It is a common software reuse principle that consists of duplicating source code within a program or across different systems owned or maintained by the same entity. There are several contradictory claims concerning the impact of cloning on software stability and maintenance effort. Some papers state that cloning is desired since it speeds up the development process and helps stakeholders meet the tight schedule and deliver on time. Other papers argue that code clone leads to code bloat and causes increase software maintenance costs due to copied defects and dead code. In this paper, we are replicating a previous study done on cloning by the original author. We are repeating his work using the same methods and metrics but with different subjects and experimenters. The paper we are addressing evaluates the impact of code cloning on code stability using three different stability-measuring methods. Our team will apply the same stability measurement techniques on a different software system developed in C programming language to determine generalizability, assure that the results are reliable, validate their outcomes, and to inspire new search by combining previous findings from related studies.

cs.SE↗

arXiv2008

Lawn tennis balls, Rolling friction experiment and Trouton viscosity

We took three lawn tennis balls arbitrarily. One was moderately old, one was old and another was new. Fabricating a conveyor belt set-up we have measured rolling friction coefficients, $μ_{r}$, of the three balls as a function of their angular velocities, $ω_{ball}$. In all the three cases, plotting the results and using linear fits, we have obtained relations of the form $μ_{r}= k_{rol} ω_{ball}$ and have deduced the proportionality constant $k_{rol}$. Moreover, core of a lawn tennis ball is made of vulcanised India-rubber. Using the known values of Young modulus and shear viscosity of vulcanised India-rubbers in the theoretical formula for $k_{rol}$, we estimate $k_{rol}$s for the cores made of vulcanised India-rubbers, assuming Trouton ratio as three. The experimental results for the balls and the semi-theoretical estimates for the cores, of $k_{rol}$, are of the same order of magnitudes.

physics.class-ph↗