Raniganj Girls College

West Bengal, India

Raniganj Girls College

West Bengal, India
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Dey B.,Variable Energy Cyclotron Center | Mondal D.,Variable Energy Cyclotron Center | Pandit D.,Variable Energy Cyclotron Center | Mukhopadhyay S.,Variable Energy Cyclotron Center | And 7 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2014

The influence of giant dipole resonance (GDR) induced quadrupole moment on GDR width at low temperatures is investigated experimentally by measuring GDR width systematically in the unexplored temperature range T = 0.8-1.5 MeV, for the first time, in A ~ 100 mass region. The measured GDR widths, using alpha induced fusion reaction, for 97Tc confirm that the GDR width remains constant at the ground state value up to a critical temperature and increases sharply thereafter with increase in T. The data have been compared with the adiabatic Thermal Shape Fluctuation Model (TSFM), phenomenological Critical Temperature Fluctuation Model (CTFM) and microscopic Phonon Damping Model (PDM). Interestingly, CTFM and PDM give similar results and agree with the data, whereas the TSFM differs significantly even after incorporating the shell effects. © 2014 Elsevier B.V.


Sahoo L.,Raniganj Girls College | Banerjee A.,Asansol Engineering College | Bhunia A.K.,University of Burdwan | Chattopadhyay S.,Jadavpur University
Swarm and Evolutionary Computation | Year: 2014

This paper deals with the development of an efficient hybrid approach based on genetic algorithm and particle swarm optimization for solving mixed integer nonlinear reliability optimization problems in series, series-parallel and bridge systems. This approach maximizes the overall system reliability subject to the nonlinear resource constraints arising on system cost, volume and weight. To meet these purposes, a novel hybrid algorithm with the features of advanced genetic algorithm and particle swarm optimization has been developed for determining the best found solutions. To test the capability and effectiveness of the proposed algorithm, three numerical examples have been solved and the computational results have been compared with the existing ones. From comparison, it is observed that the values of the system reliability are better than the existing results in all three examples. Moreover, the values of average computational time and standard deviation are better than the same of similar studies available in the existing literature. The proposed approach would be very helpful for reliability engineers/practitioners for better understanding about the system reliability and also to reach a better configuration. © 2014 Elsevier B.V.


Pandit D.,Variable Energy Cyclotron Center | Dey B.,Variable Energy Cyclotron Center | Mondal D.,Variable Energy Cyclotron Center | Mukhopadhyay S.,Variable Energy Cyclotron Center | And 4 more authors.
Physical Review C - Nuclear Physics | Year: 2013

The first systematic study of the correlation between the experimental giant dipole resonance (GDR) width and the average deformation Œ of the nucleus at finite excitation is presented for the mass region A∼59 to 208. We show that the width of the GDR (Γ) and the quadrupole deformation of the nucleus do not follow a linear relation, as predicted earlier, owing to the GDR-induced quadrupole moment, and the correlation also depends on the mass of the nuclei. The different empirical values of Œ Œ extracted from the experimental GDR width match exceptionally well with the thermal shape fluctuation model. As a result, this universal correlation between Œ Œ and Γ provides a direct experimental probe to determine the nuclear deformation at finite temperature and angular momentum over the entire mass region. © 2013 American Physical Society.


Sahoo L.,Raniganj Girls College | Bhunia A.K.,University of Burdwan | Kapur P.K.,University of Delhi
Computers and Industrial Engineering | Year: 2012

In most of the real world design or decision making problems involving reliability optimization, there are simultaneous optimization of multiple objectives such as the maximization of system reliability and the minimization of system cost, weight and volume. In this paper, our goal is to solve the constrained multi-objective reliability optimization problem of a system with interval valued reliability of each component by maximizing the system reliability and minimizing the system cost under several constraints. For this purpose, four different multi-objective optimization problems have been formulated with the help of interval mathematics and our newly proposed order relations of interval valued numbers. Then these optimization problems have been solved by advanced genetic algorithm and the concept of Pareto optimality. Finally, to illustrate and also to compare the results, a numerical example has been solved.


Pandit D.,Variable Energy Cyclotron Center | Mukhopadhyay S.,Variable Energy Cyclotron Center | Bhattacharya S.,Darjeeling Government College | Pal S.,Variable Energy Cyclotron Center | And 2 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2010

The energy spectrum of the high energy γ-rays in coincidence with the prompt γ-rays has been measured for the spontaneous fission of 252Cf. The nucleus-nucleus coherent bremsstrahlung of the accelerating fission fragments is observed and the result has been substantiated with a theoretical calculation based on the Coulomb acceleration model. The width of the giant dipole resonance (GDR) decay from the excited fission fragments has been extracted for the first time and compared with the thermal shape fluctuation model (TSFM) in the liquid drop formalism. The extracted GDR width is significantly smaller than the predictions of TSFM. © 2010 Elsevier B.V. All rights reserved.


Sahoo L.,Raniganj Girls College | Bhunia A.K.,University of Burdwan | Roy D.,University of Burdwan
International Journal of Systems Assurance Engineering and Management | Year: 2013

This paper deals with redundancy allocation problem in interval environment that maximizes the overall system reliability subject to the given resource constraints and also minimizes the overall system cost subject to the given resources including an additional constraint on system reliability. Here, the reliability of each component is assumed as interval valued and the cost coefficients as well as the amount of resources are imprecise and interval valued. These types of problems have been formulated as an interval valued nonlinear integer programming problem. In this paper, we have formulated two types of redundancy, viz. component level redundancy known as low-level redundancy and the system level redundancy known as high-level redundancy. These problems have been transformed as an unconstrained optimization problem using penalty function technique and solved using genetic algorithm. Finally, two numerical examples (one for low-level redundancy and another for high-level redundancy) have been solved and the computational results have been compared. © 2013, The Society for Reliability Engineering, Quality and Operations Management (SREQOM), India and The Division of Operation and Maintenance, Lulea University of Technology, Sweden.


Pandit D.,Variable Energy Cyclotron Center | Mukhopadhyay S.,Variable Energy Cyclotron Center | Pal S.,Variable Energy Cyclotron Center | De A.,Raniganj Girls College | Banerjee S.R.,Variable Energy Cyclotron Center
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2012

We present the first experimental giant dipole resonance (GDR) width systematics, in the temperature region 0.8-1.2 MeV for 201Tl, a near Pb nucleus, to investigate the evolution of the GDR width in shell effect and pairing dominated region. The extracted GDR widths are well below the predictions of shell effect corrected thermal shape fluctuation model (TSFM) and thermal pairing included phonon damping model. A similar behavior of the GDR width is also observed for 63Cu measured in the present work and 119Sb, measured earlier. This discrepancy is attributed to the GDR induced quadrupole moment leading to a critical point in the increase of the GDR width with temperature. We incorporate this novel idea in the phenomenological description based on the TSFM for a better understanding of the GDR width systematics for the entire range of mass, spin and temperature. © 2012 Elsevier B.V..


Bhunia A.K.,University of Burdwan | Sahoo L.,Raniganj Girls College
Studies in Computational Intelligence | Year: 2011

The objective of this chapter is to develop and solve the reliability optimization problems of series-parallel, parallel-series and complicated system considering the reliability of each component as interval valued number. For optimization of system reliability and system cost separately under resource constraints, the corresponding problems have been formulated as constrained integer/mixed integer programming problems with interval objectives with the help of interval arithmetic and interval order relations. Then the problems have been converted into unconstrained optimization problems by two different penalty function techniques. To solve these problems, two different real coded genetic algorithms (GAs) for interval valued fitness function with tournament selection, whole arithmetical crossover and non-uniform mutation for floating point variables, uniform crossover and uniform mutation for integer variables and elitism with size one have been developed. To illustrate the models, some numerical examples have been solved and the results have been compared. As a special case, taking lower and upper bounds of the interval valued reliabilities of component as same the corresponding problems have been solved and the results have been compared with the results available in the existing literature. Finally, to study the stability of the proposed GAs with respect to the different GA parameters (like, population size, crossover and mutation rates), sensitivity analyses have been shown graphically. © 2011 Springer-Verlag Berlin Heidelberg.


Sarkar B.C.,University of Burdwan | De Sarkar S.S.,Raniganj Girls College | Banerjee T.,University of Burdwan
Signal Processing | Year: 2014

The consequences of unequal propagation delay of the sampled control signals along the two arms of a class of digital tan-lock loops (DTLs) have been studied in this paper. The said delay is considered as a fraction of the basic sampling period and it is modeled by including a discrete time version of a unit-amplitude pure phase shift network in one of the arms of the tan-lock phase detector (PD). The DTL with such unbalanced fractional delay (named as FD-DTL) is studied through bifurcation analysis and time domain numerical simulation of the system equation. Obtained results indicate that for a FD-DTL loop gain values could be taken higher and frequency acquisition ranges (FARs) are wider compared to those for a conventional DTL (CDTL). Thus a deliberate inclusion of a fractional time delay network in one of the arms of a CDTL is a novel technique to improve its dynamical responses. © 2014 Elsevier B.V.


Sarkar B.C.,University of Burdwan | De Sarkar S.S.,Raniganj Girls College | Banerjee T.,University of Burdwan
Signal Processing | Year: 2014

Nonlinear dynamics of a class of symmetric lock range digital phase-locked loops (SLR-DPLLs) has been investigated using nonlinear dynamical theoretical and computational tools. It has been observed that the system shows a period doubling route to chaos. For certain system parameters the loop exhibits intermittent behavior. The analytical bifurcation analysis shows that inspite of the broader frequency acquisition range than a conventional one the stability of the loop degrades appreciably when the input signal frequency is less than the nominal frequency of the digitally controlled oscillator. The system dynamics have been characterized by measuring the Lyapunov exponent and the correlation dimension. Further it has been shown that the stability range of a SLR-DPLL can be extended using a modified loop filter incorporating time delay feedback technique. The modified SLR-DPLL (MSLR-DPLL) with this additional derivative control along with the loop digital filter (LDF) shows faster convergence than the unmodified one for proper choice of system design parameters. Consequently, the MSLR-DPLL becomes more suitable for practical applications. © 2013 Elsevier B.V.

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