On the Signal Processing Operations in LIGO signals

This article analyzes the data for the five gravitational wave (GW) events detected in Hanford(H1), Livingston(L1) and Virgo(V1) detectors by the LIGO collaboration. It is shown that GW170814, GW170817, GW151226 and GW170104 are very weak signals whose amplitude does not rise significantly during the GW event, and they are indistinguishable from non-stationary detector noise. LIGO software implements cross-correlation funcion(CCF) of H1/L1 signals with the template reference signal, in frequency domain, in a matched filter, using 32 second windows. It is shown that this matched filter misfires with high SNR/CCF peaks, even for very low-amplitude, short bursts of sine wave signals and additive white gaussian noise(AWGN), all the time. It is shown that this erratic behaviour of the matched filter, is due to the error in signal processing operations, such as lack of cyclic prefix necessary to account for circular convolution. It is also shown that normalized CCF method implemented in time domain using short windows, does not have false CCF peaks for sine wave and noise bursts. It is shown that the normalized CCF for GW151226 and GW170104, when correlating H1/L1 and template, is indistinguishable from correlating detector noise and the template. It is also shown that the normalized CCF for GW151226 and GW170104, when correlating H1/L1 and template, is indistinguishable from correlating H1/L1 and bogus chirp templates which are frequency modulated(FM) waveforms which differ significantly from ideal templates. Similar results are shown with LIGO matched filter, which misfires with high Signal to Noise Ratio(SNR) for bogus chirp templates.Comment: Corrected typographical errors, updated names, references and acknowledgement section. Added a subsection on an improved whitening procedur

Generation of supramolecular diversity through self-assembly of multi-dimensional building blocks

Ph.DDOCTOR OF PHILOSOPH

Impact of Covid-19 on Educational Sector – Strategies to Success

The impact of COVID-19 can be felt around the world, especially across the higher education sector. Worldwide closures of educational institutions have impacted over 95% of the world’s student population, with 1.5 billion learners not able to attend classes.  In the wake of this shift, educational institutions have had to quickly adopt new approaches to foster student success in these extraordinary times. In the short term, these measures include delaying start dates, shifting to online course delivery, and offering new forms of financial support. But, what can we do to support the future of Education