I send my good wishes to all of you and I hope that you, your families, and your friends are faring well in this difficult time.
For those who are interested in modeling populations, such as the current epidemic, there is a logistic equation solver called
“verhulst” in the SU package which you may find of interest.
For example for Covid-19 cases in the US, taking 22 January as day 0 of cases in the US and 29 February as day 0 for deaths. Respective
stepmax= values of 72 for cases and 34 for deaths are both 3 April
verhulst stepmax=72 h=1 a1=.176 y0=1 a2=1e7 mode=x > calculated_cases.bin
verhulst stepmax=35 h=1 a1=.268 y0=1 a2=1e6 mode=x > calculated_deaths.bin
xgraph < calculated_cases.bin n=72 nplot=1 d1=1 &
xgraph < calculated_deaths.bin n=34 nplot=1 d1=1 &
The growth rate a1 values are determined empirically from publicly available data, in this case from the CDC and from the Worldometer site. You will have to make your own estimate of a1 for the data that you are modeling.
Another parameter that is harder to get is an estimate of the carrying capacity of the system a2. Here I am assuming a maximum of 1 million cases in the US and 100 thousand deaths.
The number of new cases or deaths per day is measured by the derivative of the solutions to the verhulst equation
verhulst stepmax=72 h=1 a1=.176 y0=1 a2=1e7 mode=y > delta_cases.bin
verhulst stepmax=35 h=1 a1=.268 y0=1 a2=1e6 mode=y > delta_deaths.bin
xgraph < delta_cases.bin n=72 nplot=1 d1=1 &
xgraph < delta_deaths.bin n=34 nplot=1 d1=1 &
The peak in the change of the population per day occurs when the population reaches the exactly half of the carrying capacity of the system. Thus, raising the carrying capacity will increase the height of the peak and move it out later in time.
Take care, everyone and stay safe.
-John
John Stockwell
Visit: https://wiki.Seismic-Unix.org <https://wiki.seismic-unix.org/>
The new home of Seismic Un*x
Hi all,
We are probably quite a few people using SU for GPR processing.
What do you think of a common (probably poster) presentation of SU and
GPR at the next world GPR meeting in... Boulder, Colorado, at the CSM,
the birth place of SU ?
It would not be a big scientific achievement but may be a way to enlarge
our community. By the way many people in the GPR community have other
background that geophysics and don't know the basics of seismic
processing and imaging.
The author would be « Seismic Unix user group » or something like that...
Quick answer (or moral support) is needed. A short abstract must be
issued in the next days.
The conference WWW site : https://gpr2020.csmspace.com/
Have a nice day !
D.
--
|Dominique Rousset LFCR UMR5150 / E2S UPPA / Dpt des géosciences|
|Univ. Pau et des Pays de l'Adour BP 1155 F-64013 Pau Cedex - France|
|mailto:dominique.rousset@univ-pau.fr http://lfc.univ-pau.fr |
|Off: +33 559 407 423|Cell: +33 660 861 391|xmpp: dominique(a)rousset.nom.fr|
Hello Dominique:
Hmm, that’s odd. Of the few Demos I looked at last night, the models were anisotropic and I could see the surface waves on the images. I haven’t had time to dig into the scripts that generated these Demos so I can’t give you more details.
Best regards,
Jim Gaiser
From: Dominique ROUSSET <dominique.rousset(a)univ-pau.fr>
Date: Friday, January 24, 2020 at 6:11 AM
To: Jggc <kjgaiser(a)gmail.com>
Subject: Re: [Seisunix] Surface wave modeling in seismic unix
Hi,
no.
it's acoustic and you need S waves to generate surface waves...
D.
Le 24/01/2020 à 06:00, Jim Gaiser a écrit :
Hello Paul:
Do the scripts and codes in “./src/demos/Synthetic/Finite_Difference” model surface waves? I haven’t checked.
Regards,
Jim Gaiser
From: Seisunix <seisunix-bounces(a)mailman.seismic-unix.org> on behalf of PAUL GOYES <g.es(a)hotmail.es>
Date: Wednesday, January 22, 2020 at 6:32 AM
To: Seismic Unix <seisunix(a)mailman.seismic-unix.org>
Subject: [Seisunix] Surface wave modeling in seismic unix
Hello colleagues.
In Seismic Unix, there are packages for elastic modeling (trielas, suea2df). I would like to know if there is a way to model surface waves (or ground roll) in seismic UNIX. Or do you know some other package free-open source?
thanks very much.
Sincerely,
Paul Goyes
_______________________________________________ Seisunix mailing list Seisunix(a)mailman.seismic-unix.org https://mailman.seismic-unix.org/listinfo/seisunix
_______________________________________________
Seisunix mailing list
Seisunix(a)mailman.seismic-unix.org
https://mailman.seismic-unix.org/listinfo/seisunix
--
|Dominique Rousset LFCR UMR5150 / E2S UPPA / Dpt des géosciences|
|Univ. Pau et des Pays de l'Adour BP 1155 F-64013 Pau Cedex - France|
|mailto:dominique.rousset@univ-pau.fr http://lfc.univ-pau.fr |
|Off: +33 559 407 423|Cell: +33 660 861 391|xmpp: dominique(a)rousset.nom.fr|
Paul:
I am new to this SU mailing list so I am not sure you are getting my responses.
Look at the demos in “cwp/src/demos/Synthetic/Finite_Difference/Suea2df”, specifically Demo3. It creates a Rayleigh wave because the source sz is only 20. I know nothing about the accuracy or limitations of this code but It is a place to start.
Hope this helps,
Jim Gaiser
From: Seisunix <seisunix-bounces(a)mailman.seismic-unix.org> on behalf of PAUL GOYES <g.es(a)hotmail.es>
Date: Wednesday, January 22, 2020 at 6:32 AM
To: Seismic Unix <seisunix(a)mailman.seismic-unix.org>
Subject: [Seisunix] Surface wave modeling in seismic unix
Hello colleagues.
In Seismic Unix, there are packages for elastic modeling (trielas, suea2df). I would like to know if there is a way to model surface waves (or ground roll) in seismic UNIX. Or do you know some other package free-open source?
thanks very much.
Sincerely,
Paul Goyes
_______________________________________________ Seisunix mailing list Seisunix(a)mailman.seismic-unix.org https://mailman.seismic-unix.org/listinfo/seisunix
Hello Paul:
Do the scripts and codes in “./src/demos/Synthetic/Finite_Difference” model surface waves? I haven’t checked.
Regards,
Jim Gaiser
From: Seisunix <seisunix-bounces(a)mailman.seismic-unix.org> on behalf of PAUL GOYES <g.es(a)hotmail.es>
Date: Wednesday, January 22, 2020 at 6:32 AM
To: Seismic Unix <seisunix(a)mailman.seismic-unix.org>
Subject: [Seisunix] Surface wave modeling in seismic unix
Hello colleagues.
In Seismic Unix, there are packages for elastic modeling (trielas, suea2df). I would like to know if there is a way to model surface waves (or ground roll) in seismic UNIX. Or do you know some other package free-open source?
thanks very much.
Sincerely,
Paul Goyes
_______________________________________________ Seisunix mailing list Seisunix(a)mailman.seismic-unix.org https://mailman.seismic-unix.org/listinfo/seisunix
Hello colleagues.
In Seismic Unix, there are packages for elastic modeling (trielas, suea2df). I would like to know if there is a way to model surface waves (or ground roll) in seismic UNIX. Or do you know some other package free-open source?
thanks very much.
Sincerely,
Paul Goyes
Dear Dominique,
I think your idea to present at the GPR conference is a good idea. You
are right that many users of
GPR people little about seismic processing so some set examples,flows
and data would be useful.
I incorporated the GPR data and flows you and Guy presented at the
summer workshop into a tutorial for the Seismic Unix GUI which I have
been developing for students (on the github).
Please let me know if I can help, although I do not have access to too
many GPR data sets.
Best,
Juan Lorenzo
Hello fellow SU users,
You probably received a monthly reminder of your subscription to this
list with a password (not really secure in my opinion !) . It allows you
to manage your subscription.
Unfortunately, there is a configuration problem that prevents you to use
it. It's the same if you want to see the archives of the lists.
Explanation :
The whole seismic-unix.org platform is run with yunohost (a smart
environment dedicated to self hosting). You can find more information at
https://yunohost.org
It allow to manage a bunch of applications quite easily, including a SSO
(single sign on) authentication process. Presently, we use mainly
- mailman : discussion list manager
- dokuwiki : wiki.seismic-unix.org
- netxcloud : https://netxtcloud.org
These applications can be public or private. A public application can be
used only by a yunohost authenticated user and a public application can
be used by everyone. I installed mailman as a public app and
subscription is public, but there is a bug (in my opinion !) in the
configuration that prevents the users to manage their mailman
subscription (and reading the archives) without being a yunohost user.
I tried without success, until now, to find help to fix the
mailman/yunohost configuration. As a consequence, if you want to manage
your subscription or read the archives, ask for a seismic-unix.org
account !
This account will also allow you to feed the wiki with examples,
tutorials and so on :-)
Enjoy SU !
D.
--
|Dominique Rousset LFCR UMR5150 / E2S UPPA / Dpt des géosciences|
|Univ. Pau et des Pays de l'Adour BP 1155 F-64013 Pau Cedex - France|
|mailto:dominique.rousset@univ-pau.fr http://lfc.univ-pau.fr |
|Off: +33 559 407 423|Cell: +33 660 861 391|xmpp: dominique(a)rousset.nom.fr|
Hello everyone,
Is there a new (active) ftp to download the seismic data (SHOT GATHERS described in Yilmaz (1989) and Yilmaz (2001)?
in the book Seismic Data Processingwith Seismic Un*x was showed a ftp link: ftp://ftp.cwp.mines.edu/pub/data/oz.original/
but it is now broken.
Thanks.
