1993 (IPP)
Permanent URI for this collectionhttp://localhost:4000/handle/11007/2786
Browse
Item Algorithm for optimally distributing quantized load on transputers with unequal speed: An application to the detection of gravitational wave signals from coalescing binaries(2015-01-13) Pitre, Sangita. N.; Dhurandhar, S.V.In a parallel computing system, we work with a network of a large number of processors wherein the performance characteristics each processer may have are different. This leads to a situation that when there is equal load on all the processer, some complete the job before the others. To make the optimum use of the available computing facility and optimise on time, it is necessary to balance the load on the processers according to there characteristics like speed etc. Here we present an algorithm to optimse to on ‘ time ‘ when difference processer have difference speed and the load is quantised in integral multiples of a given unit of load. The algorithm distribute the load in such a manner that all the processer work optimally and the processing time is minimal. The optimal distribution of the load is achived by employing the well known bisection technique for finding the rots of an equation. We discuss this algorithm in the context of our application for filtering the coalescing binary gravitational wave signals. Numerical result are finally discussed for the 64 transputer machine ( PARAM ) .Item Performance of Newtonian filters in the detection of gravitational radiation from coalescing binaries(2015-01-13) Balasubramanian, R.; Dhurandhar, S.V.Post – Newtonian corrections to the gravitational waveform emitted by coalescing binaries have been found to lead to a secular phase accumulation error as compared with the signals calculated in the Newtonian approximation. The matched filtering process which relies on the correlation between the correlation between the signal and the filter is extremely sensitive to errors in phase. We explore the possibility of compensating for the phase difference caused by the post-Newtonian terms by allowing for a shift in the Newtonian filter parameters. We find that, on the average, we lose by about 30% in the correlation.Item Response of the interferometric antenna to gravitational radiation from pulsars(2015-01-13) Jotania, Kanti; Dhurandhar, S.V.We present here a full calculation of the response of a laser interferometric gravitational wave detector on which gravitational radiation from a continuous source is incident. The observation time is taken to be of the order of few months. The long observation time implies that the motion of the detector is important and must be included in the response as a modulation effect. For simplicity we consider only two motions of the Earth , namely the rotation of the Earth about axis and the orbital motions about the sun. The orbit is assumed to be circular. We consider the detector to be situated and oriented arbitrarily on the Earth, except that we assume the arms of the detector must lie in the tangent plane to the Earth at the point where the detector is situated. The gravitational wave incident on the detector is assumed to be a plane wave having arbitrary direction and polarization. We also present here the computation of the quadrupole wave form of a typical continuous source – a pulsar-which is modelled as an almost spherical object of uniform density, spinning about an arbitrary axis with uniform angular velocity. We use techniques of spherical tensors and Gel’fandfunction developed in the literature to compute the waveformItem Signal analysis of the gravitational waveform of pulsars(2015-01-17) Jotania, Kanti; Dhurandhar, S.V.; Valluri, S.R.