id	author	title	date	pages	extension	mime	words	sentences	flesch	summary	cache	txt
cord-310863-jxbw8wl2	PRASAD, J.	A data first approach to modelling Covid-19	2020-05-26		.txt	text/plain	7177	403	64	We use the procedure to fit a set of SIR and SIRD models, with time dependent contact rate, to Covid-19 data for a set of 45 most affected countries. We find that SIR and SIRD models with constant transmission coefficients cannot fit Covid-19 data for most countries (mainly because social distancing, lockdown etc., make those time dependent). Some of the most important problems related to Covid-19 research are (1) estimating the controlling parameters of the pandemic, (2) making short term predictions using mathematical-statistical modeling which can help in mitigating policies (3) simulating the growth of the epidemic by taking into account as many contributing effects as possible and (4) quantifying the impact of mitigation measures, such as lockdown etc [ea20j] . One of the main reasons to consider these models has been that the Covid-19 data is available only for the Susceptible, Infected, Recovered and Dead compartments (for the notations used here and other places in the present work see table (1)).	./cache/cord-310863-jxbw8wl2.txt	./txt/cord-310863-jxbw8wl2.txt