arXiv subjects

Jahangir Mohammed

Publications and source records attributed to Jahangir Mohammed.

5 recordsLinked to original sources

arXiv2025

On Critical Temperature and Finite Size Scaling of Continuous Spin $2d$ Ising Model

In this paper, we have studied the critical temperature $T_c$ of continuous spin $2d$ square-lattice Ising model using Monte-Carlo simulation. We have considered spins $s$ in a bounded interval, where $s \in [-1,+1]$ in square-lattice configuration with periodic boundary condition. We have observed that the critical temperature $T_c$ is approximately $0.925$, showing a clear second order phase transition. Considering finite size scaling, we have also obtained the critical exponents associated with susceptibility, specific heat, magnetization and we find that these values are in good agreement with the corresponding values obtained for the standard $2d$ Ising universality class.

cond-mat.stat-mech↗

arXiv2020

A comparative study of $2d$ Ising model at different boundary conditions using non-deterministic Hexagonal Cellular Automata

The spin system of the $2d$ Ising model having a hexagonal-lattice is simulated using non-deterministic Cellular Automata. The method to implement this program is outlined and our results show a good approximation to the exact analytic solution. The phase transition in $2d$ Ising model is studied with a $40\times40$ hexagonal-lattice with five different boundary conditions (bcs) i.e., adiabatic, periodic, reflexive, fixed $+1$ and fixed $-1$ with random orientation of spins as initial conditions in the absence of an external applied magnetic field. The critical temperature below which the spontaneous magnetization appears as well as other physical quantities such as the magnetization, energy, specific heat, susceptibility and entropy with each of the bcs are calculated. The phase transition occurs around $T^H_c$ = 1.5 which approximates well with the result obtained from exact analytic solution by Wannier and Houtappel. We compare the behavior of magnetisation per cell for five different types of bcs by calculating the number of points close to the line of zero magnetization for $T>T^H_c$. We find that the periodic, adiabatic and reflexive bcs give closer approximation to the value of $T^H_c$ than fixed $+1$ and fixed $-1$ bcs with all three initial conditions for lattice size less than $50\times50$. However, for lattice size between $50\times50$ and $200\times200$, fixed $+1$ bc and fixed $-1$ bc give closer approximation to the $T^H_c$ with initial conditions in which all spins are in down configuration and all spins are in up configuration respectively.

cond-mat.stat-mech↗

arXiv2018

A comparative study of $2d$ Ising model at different boundary conditions using Cellular Automata

Using Cellular Automata, we simulate spin systems corresponding to $2d$ Ising model with various kinds of boundary conditions (bcs). The appearance of spontaneous magnetization in the absence of magnetic field is studied with a $64\times64$ square lattice with five different bcs, i.e., periodic, adiabatic, reflexive, fixed ($+1$ or $-1$) bcs with three initial conditions (all spins up, all spins down and random orientation of spins). In the context of $2d$ Ising model, we have calculated the magnetisation, energy, specific heat, susceptibility and entropy with each of the bcs and observed that the phase transition occurs around $T_c$ = 2.269 as obtained by Onsager. We compare the behaviour of magnetisation vs temperature for different types of bcs by calculating the number of points close to the line of zero magnetisation after $T>T_c$ at various lattice sizes. We observe that the periodic, adiabatic and reflexive bcs give closer approximation to the value of $T_c$ than fixed +1 and fixed -1 bcs with all three initial conditions for lattice size less than $70\times70$. However, for lattice size between $70\times70$ and $100\times100$, fixed +1 bc and fixed -1 bc give closer approximation to the $T_c$ with initial conditions all spin down configuration and all spin up configuration respectively.

cond-mat.stat-mech↗

arXiv2014

A Cellular Automata based Optimal Edge Detection Technique using Twenty-Five Neighborhood Model

Cellular Automata (CA) are common and most simple models of parallel computations. Edge detection is one of the crucial task in image processing, especially in processing biological and medical images. CA can be successfully applied in image processing. This paper presents a new method for edge detection of binary images based on two dimensional twenty five neighborhood cellular automata. The method considers only linear rules of CA for extraction of edges under null boundary condition. The performance of this approach is compared with some existing edge detection techniques. This comparison shows that the proposed method to be very promising for edge detection of binary images. All the algorithms and results used in this paper are prepared in MATLAB.

cs.CV↗

arXiv2013

An Efficient Edge Detection Technique by Two Dimensional Rectangular Cellular Automata

This paper proposes a new pattern of two dimensional cellular automata linear rules that are used for efficient edge detection of an image. Since cellular automata is inherently parallel in nature, it has produced desired output within a unit time interval. We have observed four linear rules among 512 total linear rules of a rectangular cellular automata in adiabatic or reflexive boundary condition that produces an optimal result. These four rules are directly applied once to the images and produced edge detected output. We compare our results with the existing edge detection algorithms and found that our results shows better edge detection with an enhancement of edges.

cs.CV↗