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by Alan
March 30th, 2020, 5:59 pm
Forum: Off Topic
Topic: Good things that come out of this pandemic...
Replies: 40
Views: 915

Re: Good things that come out of this pandemic...

No! These ad delivery systems, probably coupled with google, follow you around on the web. So, that ad is either based on some web site you visited recently or  on just your inferred location. I am seeing ads for California homeowners and local supermarkets. Even though I am used to it (and try to s...
by Alan
March 30th, 2020, 5:12 pm
Forum: Off Topic
Topic: Is the cure worse than the disease?
Replies: 35
Views: 1057

Re: Is the cure worse than the disease?

haha! -- I think that was a Mr. Bean episode.
by Alan
March 30th, 2020, 4:49 pm
Forum: Off Topic
Topic: Good things that come out of this pandemic...
Replies: 40
Views: 915

Re: Good things that come out of this pandemic...

Seems like a week ago worldometer had no ads. Now they have plenty -- good for them! At least somebody is earning some money during this mess. As Louis Pasteur famously said,  "Chance favors the prepared web site".
by Alan
March 30th, 2020, 3:54 pm
Forum: Off Topic
Topic: Gallows humour
Replies: 38
Views: 1650

Re: Gallows humour

Little known side effect: if you watch more than 1hr of corona virus tv coverage --- your head will explode. Also watch out for this problem with your tv.
by Alan
March 30th, 2020, 3:08 pm
Forum: Off Topic
Topic: Good things that come out of this pandemic...
Replies: 40
Views: 915

Re: Good things that come out of this pandemic...

No number because, well, it doesn't deserve one: 
Crime falls sharply in March due to coronavirus restrictions, LAPD and sheriff report


-- duh! 
by Alan
March 30th, 2020, 1:08 pm
Forum: Numerical Methods Forum
Topic: How to solve this ODE?
Replies: 7
Views: 328

Re: How to solve this ODE?

Thank you all for your suggestions. Following Alan’s suggestions to split the integration limits, I can do the integration by a change of variable method to go around the singularity point. However, I am still not sure on the below two questions: (1)      Boundary conditions It seems that as \(x\ri...
by Alan
March 29th, 2020, 9:30 pm
Forum: Off Topic
Topic: Is the cure worse than the disease?
Replies: 35
Views: 1057

Re: Is the cure worse than the disease?

Re badges etc, let's give all recoverees a nice card:
Image
by Alan
March 29th, 2020, 9:10 pm
Forum: Off Topic
Topic: Good things that come out of this pandemic...
Replies: 40
Views: 915

Re: Good things that come out of this pandemic...

21. burkas: not so crazy after all
by Alan
March 29th, 2020, 4:31 pm
Forum: Numerical Methods Forum
Topic: How to solve this ODE?
Replies: 7
Views: 328

Re: How to solve this ODE?

Not sure who 'you' is, but, as I said, the integrals should not be a problem. If you can integrate x^{a-1}, you can integrate these.
by Alan
March 29th, 2020, 2:43 pm
Forum: Numerical Methods Forum
Topic: Models for Covid-19
Replies: 213
Views: 5006

Re: Models for Covid-19

Here's a nice modelling study (Univ. Washington) cited in my local paper (LA Times): Forecasting COVID-19 impact on hospital bed-days, ICU-days, ventilator days and deaths by US state in the next 4 months No differential equations, just fitting a sigmoidal-type ( actually a CumNormal) to the cumulat...
by Alan
March 29th, 2020, 3:42 am
Forum: Off Topic
Topic: News from Outer Space
Replies: 1196
Views: 138255

Re: News from Outer Space

Thanks. That's very interesting and I had no clue. Had never even heard of 'hyperons'.
by Alan
March 28th, 2020, 11:38 pm
Forum: Off Topic
Topic: How should we deal with the coronavirus pandemic?
Replies: 143
Views: 6165

Re: How should we deal with the coronavirus pandemic?

New test device announced by Abbott Labs - the size of a toaster - delivers positive results in 5 minutes, negative results in 13 minutes. Will go out to clinics next week. Can’t say anything about accuracy, but at least R&D efforts and production are moving fast. https://amp.usatoday.com/amp/29327...
by Alan
March 28th, 2020, 11:15 pm
Forum: Off Topic
Topic: News from Outer Space
Replies: 1196
Views: 138255

Re: News from Outer Space

The golden age of neutron star physics has arrived Nature March 4 https://www.nature.com/articles/d41586-020-00590-8 “ Last December, this NASA space observatory provided astronomers with some of the most precise measurements ever made of a neutron star’s mass and radius1,2, as well as unexpected f...
by Alan
March 28th, 2020, 6:41 pm
Forum: Numerical Methods Forum
Topic: How to solve this ODE?
Replies: 7
Views: 328

Re: How to solve this ODE?

(1) Looking at the paper, esp. (3.5), pretty sure  F and G should be ODE solutions that (along with their derivatives) vanish at [$]-\infty[$] and [$]+\infty[$] respectively. (See Borodin & Salminen Handbook, pg 19). For [$]\mu > 0[$] they clearly vanish appropriately. Below I check that they are OD...
by Alan
March 27th, 2020, 11:35 pm
Forum: Numerical Methods Forum
Topic: Models for Covid-19
Replies: 213
Views: 5006

Re: Models for Covid-19

If you set to zero all parameters responsible for recovery then without quarantine you can get the whole population infected from a single case. With quarantine only that household gets infected. So no, it's not just a parameter change. Or rather it's not a parameter change in that limiting case. I...
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