Browsing by Author "A.N. Mantri"

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A genetic task allocation algorithm for distributed computing systems incorporating problem specific knowledge
(World Scientific Publishing Co., 1996) Anil Kumar Tripathi; Deo Prakash Vidyarthi; A.N. Mantri
Distributed Computing Systems (DCS) promise a convenient platform for parallel processing and consequently can be expected to provide highly improved throughput and turnaround characteristics for all types of computing jobs. Task allocation in DCS remains to be an important and relevant problem attracting the attention of researchers in the discipline. Genetic Algorithms (GA) have successfully been used to solve various optimization problems. A GA based task allocation model for multiprocessors has been proposed by Hou, Ansari & Ren [3]. We present a Genetic Task Allocation Algorithm for DCS, wherein we have considered the underlying interconnection network of the processors, communication requirements among modules of the tasks apart from the precedence relation of the task graph that has been considered in [3] also. We have also considered multiprogramming at every processing nodes with related characteristic values. We have, intentionally, made use of the finding [4] that the incorporation of the problem specific knowledge in construction of GAs improves the initial population structures. The model and algorithm proposed by us is sufficiently simple and adequately usable for the purpose of simulation experiments and its possible incorporation in future operating systems of DCS.
A geometrical approach to the method of least-squares
(1984) A.N. Mantri
A geometrical approach to the method of least-squares is presented. The results of analytical geometry are used. The expressions for the minimum deviation and the errors for the estimates of the least-squares parameters follow quite naturally in this approach.
A note on the effect of magnetic field on atomic electrons
(1984) A.N. Mantri
[No abstract available]
Backbending feature of rotational spectra in the generalized variable-moment-of-inertia model and its equivalence with the Harris model
(1975) A.N. Mantri
The equivalence of Harris model equations with those of the generalized variable-moment-of-inertia (GVMI) model given by Das et al. is examined in the light of the backbending feature of the rotational states. It is shown that this feature is absent in the Harris model taken to any order. The GVMI model equations are found to be consistent and in one-to-one correspondence with an expansion of the square of the angular velocity in terms of a polynomial in the moment of inertia rather than with the Harris expansion and may give a backbending feature in some cases depending on the relative values of the parameters appearing in the potential energy term. NUCLEAR STRUCTURE Variable moment of inertia, angular velocity, cranking model, backbending, high spin rotational states. © 1975 The American Physical Society.
Comment on the phonon cranking model
(1976) A.N. Mantri
The energy equations in the phonon cranking model of Fogel et al. are shown to be equivalent to those in the centrifugal stretching model. The two models are found to differ, however, in their predictions regarding information about the nuclear shape in the excited states as discussed inthe text. © 1976 IOP Publishing Ltd.
Comments on “Resolving time effect on counting statistics” [Am. J. Phys. 49, 561 (1981)]
(1986) A.N. Mantri
[No abstract available]
Hartree-Fock-Bogolyubov Cranking Analysis of Gyromagnetic Factors of High-Spin States in Yb170, Yb172, and Yb174
(1981) A.N. Mantri; M. Diebel; U. Mosel
We calculate gyrogmagnetic factors of high-spin collective states in three ytterbium isotopes using the Hartree-Fock-Bogolyubov cranking model. Theoretical results for Yb170 and Yb174 are in good agreement with the recent measurements. In Yb172 a greater precision in the measurements is needed to test the calculated decrease of g factors with spin. © 1981 The American Physical Society.
Higher-order cranking calculations in the interacting boson model
(1987) Arpita Mishra; A.N. Mantri
It is shown that IBM cranking calculations, carried out by including a time-odd parameter in the definition of intrinsic states of IBM in the lowest order of angular frequency, give reasonably good estimates for the ground-state moment of inertia, but when extended to higher order they produce an unphysical variation of the moment of inertia with frequency. An alternative expression for the ground-state moment of inertia within the IBM framework without using time-odd parameter is briefly discussed. © 1987 IOP Publishing Ltd.
Higher-order cranking calculations in the interacting boson model
(1987) A. Mishra; A.N. Mantri
It is shown that IBM cranking calculations, carried out by including a time-odd parameter in the definition of intrinsic states of IBM in the lowest order of angular frequency, give reasonably good estimates for the ground-state moment of inertia, but when extended to higher order they produce an unphysical variation of the moment of inertia with frequency. An alternative expression for the ground-state moment of inertia within the IBM framework without using time-odd parameter is briefly discussed.
Is it safe to use the unitary pole expansion for hard core potentials?
(1977) A.N. Mantri; A.V. Lagu
We have examined the various terms in the unitary pole expansion for a hard core potential. It is found that the goodness of the unitary pole expansion depends upon the number of positive and negative eigenvalues in the expansion. It is doubtful if the unitary pole expansion improves over the one term approximation in such a case. NUCLEAR STRUCTURE t matrix, unitary pole expansion, unitary pole approximation, hard core potentials. © 1977 The American Physical Society.
Moment of inertia in the interacting boson model
(Springer-Verlag, 1987) A. Mishra; A.N. Mantri
Defining an intrinsic state for the interacting boson model (IBM) hamiltonian it is possible to obtain expression for the ground state moment of inertia ℐo in terms of IBM hamiltonian parameters and the shape variables. Two such available approaches - one based on correspondence of the IBM hamiltonian with Bohr hamiltonian and the other one based on self-consistent cranking calculations with IBM states - are examined. Results of numerical calculations in both prescriptions are compared with microscopic cranking calculations and also with the "experimental" values as given in the variable moment of inertia (VMI) model. The varying systematics of ℐo values for nuclei in the rare-earth and actinide region is satisfactorily reproduced in the two approaches. © 1987 Springer-Verlag.
On the mass of a charged particle and fine-structure constant in gravity modified field theory using compensation hypothesis
(Società Italiana di Fisica, 1976) A.K. Pandey; A.N. Mantri
[No abstract available]
On the small-angle end of the Rutherford scattering formula
(1977) A.N. Mantri
[No abstract available]
Phenomenological description of new features of rotational spectra
(1974) A.N. Mantri; P.C. Sood
It is shown that the energy expression as a cubic polynomial (CP) in spin I, in addition to giving an excellent fit to the excitation energies of the ground-band levels in all even-even nuclei, also reproduces a critical spin Ic beyond which the squared rotational frequency ω2 decreases although the moment of inertia g keeps on increasing, thus resulting in back bending in g-ω2 plots. This feature is predicted to appear not only in well-deformed nuclei but at quite low spins in nearly spherical nuclei as well. Further, the CP formula predicts the nuclear moment of inertia for the first 2+ state to be smaller than that for the ground state for most of the hard rotors; correspondence of this characteristic with the shrinkage deduced from muonic atom studies and Mössbauer experiments is discussed. © 1974 The American Physical Society.
Relationship between the transition moments of inertia and the intrinsic transition quadrupole moments
(1972) A.N. Mantri; P.C. Sood
In the "variable-moment-of-inertia" model an empirical relation was established between the transition quadrupole moments and the transition moments of inertia for the levels of ground-state bands in even-even nuclei. Later a modification was proposed in the form of introducing an explicit A14 dependence in this relation, and also an alternative expression for the definition of the transition moment of inertia was adopted. We examine these modifications in comparison with the original assumptions through detailed analysis of the experimental data. No significant improvement in the fit to the data is observed as a result of the modified formulation. © 1972 The American Physical Society.
Surface differential operator and electromagnetic field tensor
(1976) A.K. Pandey; A.N. Mantri
In view of the recent work of Ross (see ibid, vol.7, p.705 (1974)) concerning Mandelstam's formulation of gauge-independent quantum electrodynamics, and involving the additional assumption of path independence, the use of a surface differential operator for the electromagnetic field quantities is suggested and some of the results so obtained are discussed.
Unified description of phenomenological models of ground-state bands in even-even nuclei
(1973) A.N. Mantri; P.C. Sood
A generalized stretching model for the description of the ground band levels in even-even nuclei is developed under the provision that the higher-order cranking corrections and Coriolis-antipairing effects, as well as the corrections due to quadrupole centrifugal stretching, are all effectively included in the stretching term expressible in terms of a "generalized stretching variable" t. A basic set of equations is derived by writing the nuclear moment of inertia I as a function of t as I0f(t). It is shown that practically all the successful two- and three-parameter models advanced during the past few years can be obtained from this basic set of equations through appropriate choices for f(t). For example, a linear cutoff in the Taylor's expansion for f(t) gives the equations of the variable moment-of-inertia model. The interrelationships, and the correspondence of respective parameters, in various models are established. Further, it is shown that, for models in which f(t) is also an explicit function of the nuclear spin I, the effective moment of inertia for excited states is renormalized from the value I0f(t) by an additional spin-dependent term. © 1973 The American Physical Society.
Variable moment of inertia in the interacting boson model
(1988) Arpita Mishra; A.N. Mantri
We present a simple prescription for the determination of the nuclear softness parameter, a measure of low-spin variation of the moment of inertia, in the interacting boson model. The formulation makes use of explicit dependence of the moment of inertia on the d-boson mixing parameter. The systematics of the softness parameter are carried out using an effective interacting boson model Hamiltonian approach and results are found to be in excellent agreement. © 1988 The American Physical Society.