From daniele.gianni at gmail.com Thu Nov 1 00:30:33 2012 From: daniele.gianni at gmail.com (Daniele Gianni) Date: Thu, 1 Nov 2012 00:30:33 +0100 Subject: [Edu-sig] *** Extended Deadline *** Nov 19 CfP: 3rd International Workshop on Model-driven Approaches for Simulation Engineering (Mod4Sim13) part of the Symposium on Theory of Modeling and Simulation SCS SpringSim 2013) Message-ID: (Please accept our apologies if you receive multiple copies of this CFP) ################################################################# CALL FOR PAPERS 3rd International Workshop on Model-driven Approaches for Simulation Engineering part of the Symposium on Theory of Modeling and Simulation (SCS SpringSim 2013) in technical cooperation with INCOSE San Diego Chapter ################################################################# April 7-10, 2013, San Diego, CA (USA) http://www.sel.uniroma2.it/Mod4Sim13 ################################################################# # Papers Due: *** November 19, 2012 *** Extended ***** # Accepted papers will be published in the conference proceedings # and archived in the ACM Digital Library. ################################################################# The workshop aims to bring together experts in model-based, model-driven and software engineering with experts in simulation methods and simulation practitioners, with the objective to advance the state of the art in model-driven simulation engineering. Model-driven engineering approaches provide considerable advantages to software systems engineering activities through the provision of consistent and coherent models at different abstraction levels. As these models are in a machine readable form, model-driven engineering approaches can also support the exploitation of computing capabilities for model reuse, programming code generation, and model checking, for example. The definition of a simulation model, its software implementation and its execution platform form what is known as simulation engineering. As simulation systems are mainly based on software, these systems can similarly benefit from model-driven approaches to support automatic software generation, enhance software quality, and reduce costs, development effort and time-to-market. Similarly to systems and software engineering, simulation engineering can exploit the capabilities of model-driven approaches by increasing the abstraction level in simulation model specifications and by automating the derivation of simulator code. Further advantages can be gained by using modeling languages, such as UML and SysML ? but not exclusively those. For example, modeling languages can be used for descriptive modeling (to describe the system to be simulated), for analytical modeling (to specify analytically the simulation of the same system), and for implementation modeling (to define the respective simulator). A partial list of topics of interest includes: * model-driven simulation engineering processes * requirements modeling for simulation * domain specific languages for modeling and simulation * model transformations for simulation model building * model transformations for simulation model implementation * model-driven engineering of distributed simulation systems * relationship between metamodeling standards (e.g., MOF, Ecore) and distributed simulation standards (e.g., HLA, DIS) * metamodels for simulation reuse and interoperability * model-driven technologies for different simulation paradigms (discrete event simulation, multi-agent simulation, sketch-based * simulation, etc.) * model-driven methods and tools for performance engineering of simulation systems * simulation tools for model-driven software performance engineering * model-driven technologies for simulation verification and validation * model-driven technologies for data collection and analysis * model-driven technologies for simulation visualization * Executable UML * Executable Architectures * SysML / Modelica integration * Simulation Model Portability and reuse * model-based systems verification and validation * simulation for model-based systems engineering To stimulate creativity, however, the workshop maintains a wider scope and welcomes contributions offering original perspectives on model-driven engineering of simulation systems. +++++++++++++++++++++++++++++++++++ On-Line Submissions and Publication +++++++++++++++++++++++++++++++++++ We invite paper submissions in three forms: 1. Full paper (max 8 pages), describing innovative research results. These papers are eligible for the best paper award and may be invited for an extended version in a special issue of the SCS SIMULATION journal. 2. Work-in-progress paper (max 6 pages), describing novel research ideas and promising work that have not yet been fully evaluated. 3. Short paper (max 6 pages), describing industrial and hands-on experience on any relevant area (i.e. military, government, space, etc.). All the papers must be submitted through the SCS conference management systems (http://www.softconf.com/scs/DEVS13/) and select the Mod4Sim track. The submissions must be in PDF format and conform to the SCS conference template (Word template is available at http://www.scs.org/upload/documents/templates/ConferenceSubmissionWORDTemplate.doc , guidelines are available at http://www.scs.org/PDFs/formattingkit.pdf). All the submitted papers must be original and not submitted else where. Submitted papers will be peer reviewed with respect to their quality, originality and relevance. The authors of the accepted papers must register in advance for inclusion of their paper in the conference proceedings. Authors of accepted papers will be invited to update their papers basing on the reviews, before providing the camera ready. All accepted papers will be included in the conference proceedings and archived in both the ACM Digital Library and IEEE Digital Library. Authors may contact the organizers for expression of interest and content appropriateness at any time. +++++++++++++++ Important Dates +++++++++++++++ * Submission Deadline: November 19, 2012 *** Extended *** * Decision to paper authors: January 10, 2013 * Camera ready due: February 5, 2013 * Conference dates: April 7-10, 2013 ++++++++++++++++++++ Organizing Committee ++++++++++++++++++++ * Andrea D'Ambrogio - University of Rome TorVergata, Italy * Daniele Gianni - European Space Agency, The Netherlands +++++++++++++++++ Program Committee +++++++++++++++++ * Steffen Becker - University of Paderborn, Germany * Paolo Bocciarelli - University of Rome TorVergata, Italy * David Chen - Univeristy of Bordeaux I, France * Cristian Englert - Serco, The Netherlands * Huascar Espinoza - European Software Institute and Tecnalia, Spain * Paul A. Fishwick - University of Florida, USA * Carlos Juiz - University of Balearic Islands, Spain * Cristiano Leorato - Rhea, The Netherlands * Steve McKeever - University of Oxford, UK * Halit Oguzt?z?n - Middle East Technical University, Turkey * Andreas Tolk - Old Dominion University, USA * Hans Vangheluwe - University of Antwerp, Belgium and McGill University, Canada * Anthony Walsh - European Space Agency, Germany * Heming Zhang - Tsinghua University, China *** Contact Information *** Andrea D'Ambrogio and Daniele Gianni (workshop co-chairs) Emails: dambro at uniroma2.it and danielegmail-mod4sim at yahoo.it From jurgis.pralgauskis at gmail.com Tue Nov 13 21:15:03 2012 From: jurgis.pralgauskis at gmail.com (Jurgis Pralgauskis) Date: Tue, 13 Nov 2012 22:15:03 +0200 Subject: [Edu-sig] RurPLE-NG is nice In-Reply-To: References: Message-ID: Some updates: - separated Variables Watch and Output panes, to be seen simultaneusly - implemented Breakpoints :) - beta style Todo: - let enter arbitrary watch expressions http://ftp.akl.lt/users/jurgis/python/rurple-NG053.png http://ftp.akl.lt/users/jurgis/python/rurple-ng-dz0-SplitLogVars_and_Breakpoints_and_funcparams_in_funclist-36c03dee2969.zip for windows one doesn't need to install python separately, just unzip and run :) http://ftp.akl.lt/users/jurgis/python/RURPLE-NG-0.53%20%5bindependent%20exe%5d.zip ps.: RurPLE-NG uses py3 unicode_literals, with_statement, division, print_function so code is generally py3 compliant. when wxpy will work well with py3 it shouldn't be too hard to port fully... >> >> just wanted to mention, >> that http://dev.lshift.net/paul/rurple/ >> is a very nice and lightweit PLE. >> >> what I like most (compared to RurPLE) are: >> 1) variables watch list (if it had breakpoints, it would rock :) From kirby.urner at gmail.com Wed Nov 14 02:18:26 2012 From: kirby.urner at gmail.com (kirby urner) Date: Tue, 13 Nov 2012 17:18:26 -0800 Subject: [Edu-sig] upcoming presentation... Message-ID: I'm shortly to give a 20 min talk, one of two, at our monthly Python Users Group this evening. Usually we meet at Urban Airship but today we've moved to a new location, I think maybe just for this month but I'm not sure. Michelle Rowley, PSF member, is our most visible / public leader and she does an excellent job. Steve Holden, former PSF chairman and still director, would likely be there tonight but he's still out of town as is typical for him. Gary Litvin if you're out there: I just noticed one of our members at this other meetup I attend (not the Python User Group) was a former acting headmaster at Phillips, one Simeon Hyde. You probably don't go back that far (he was in his 90s, I was reading his biography). The presentation features my Tractor Graphics / Art, which moves the turtle (ala LOGO) to a plain ASCII 2x2 list of lists, a Farm class / instance. The idea is not to write advanced code or to replace turtle.py but to sketch an accessible curriculum that alludes to much of the lore. High bandwidth stuff. Tractor subclasses create the Mandelbrot Set in one module, successive generations in Conway's Life in another. We also do the Wolfram patterns. These are all "Systems Science" topics (our Portland State U has a program). http://www.flickr.com/photos/kirbyurner/5583591181/in/set-72157625646071793 (by PSU faculty member, connects the dots) I'll show some source code in PyCharm and my slides if all goes as planned, ya never know. On the Math Forum front I've been using Haskell more. It's somewhat easy to figure out how far along I've gotten in the famous tutorial: http://learnyouahaskell.com/chapters Here's what Haskell looks like (not that different from Python in some of its constructs, but not as imperative or dynamically typed of course): Module (baby.hs): totatives :: (Integral n) => n -> [n] totatives n | n <= 0 = [ ] | n > 1 = filter (\x -> (gcd n x) == 1) [1..n] totient :: Integer -> Int totient = length . totatives Shell: GHCi, version 7.4.1: http://www.haskell.org/ghc/ :? for help Loading package ghc-prim ... linking ... done. Loading package integer-gmp ... linking ... done. Loading package base ... linking ... done. Prelude> :l baby [1 of 1] Compiling Main ( baby.hs, interpreted ) Ok, modules loaded: Main. *Main> totatives 50 [1,3,7,9,11,13,17,19,21,23,27,29,31,33,37,39,41,43,47,49] *Main> totient 50 20 More context: http://mathforum.org/kb/message.jspa?messageID=7921700 (about half way down -- not news to all of us I realize) Kirby From thomas at koch.ro Thu Nov 15 08:22:24 2012 From: thomas at koch.ro (Thomas Koch) Date: Thu, 15 Nov 2012 08:22:24 +0100 Subject: [Edu-sig] RurPLE-NG is nice In-Reply-To: References: Message-ID: <201211150822.25656.thomas@koch.ro> Jurgis Pralgauskis: > Some updates: Hi Mr. Pralgauskis, I also discovered rurple-ng a few weeks ago and will try it the first time today in school. I converted the mercurial repository to a Git repo at https://github.com/thkoch2001/rurple-ng Are you familiar with Git? Would you like to commit your changes to a fork of my Git repo? Paul Crowley has not yet answered to my emails from weeks ago. I'm afraid he does not have time anymore to maintain rurple-ng. But it seems to be a very nice piece of software so we should keep developing it. I've also created a Debian package for rurple-ng. But you're still suffering windows? Best regards, Thomas Koch, http://www.koch.ro From kurner at oreillyschool.com Thu Nov 15 18:42:28 2012 From: kurner at oreillyschool.com (Kirby Urner) Date: Thu, 15 Nov 2012 09:42:28 -0800 Subject: [Edu-sig] more news 'n views Message-ID: In related news (noting RurPL is continuing its advance)... the Visual Python group (VPython.org) have been tackling in earnest the challenge of seamlessly integrating their 3D mini-API to an OpenGL experience within wxPython, the Python adapter for the wx GUI toolkit. I simply subscribe to that list, I'm not in a dev role on that so won't have answers to nitty gritty questions. I'm not up to date on wxPython either. https://github.com/BruceSherwood/vpython-wx (here's the source code) Congratulations to Python for having so many signature educational products. I do not count Blender, which although "educational" is more professional and hard to master without skills unrelated to writing code (more like an ESRI product in that regard, also using Python). Other news: Our user group meeting was packed as usual. The woman who spoke after me had been teaching herself the whole LAMP stack from quasi-zero, with Python her P language. She was living in China when she started, coming from the USA (hazy on the details) and so was already in a mode to want to learn new language / customs / culture. She had come a long way in a relatively short time. She bravely spoke of setbacks and disappointments as well as victories. The audience was empathetic. Here's a link to an editable copy of her talk (shared by Portia): https://docs.google.com/presentation/d/1IgeLis250VcbF-zdwmBlrHOqodB3PNoXU_m1piCZuCM/edit#slide=id.p That talk followed nicely after mine (the first talk) about 'Pythonic Andragogy'. http://4dsolutions.net/presentations/pycon2013.pdf (my slides) I have this slide near the beginning listing various meanings / connotations of Adult, gets wheels turning, and then the next slide is titled 'Trendy / Spoofy' and I call out to the audience for a similar word I'm looking for. "Like 'Breaking Bad' I said, alluding to a popular TV show". "Popular" one guy called out. "Edgy" I said. "For Adults" (as in 'Python for Adults') can be "edgy". Then Portia's talk had some URLs with off color words in them. Some of the best teaching sites use profanity, even right in the URLs. She underlined the word "edgy" as well, alluding to what we had just heard in my talk. Portia has that DIY love-to-make-things-that-work attitude that's so celebrated around O'Reilly (my talk was somewhat a company talk i.e. an ad for OST). We enjoyed the new venue, Idealist, a company on the top floor of what used to be a police headquarters for Portland but the police have long since moved. Urban Airship continues to be our regular host I'm pretty sure. Although I'm listed as an organizer and helped start the meetup presence (on meetup.com), PSF member Michelle Rowley is the chief organizer who makes it all happen in this chapter. Pictures: http://www.flickr.com/photos/kirbyurner/8187740417/in/photostream (police station, see adjacent slides for more meetup) Portland is looking forward to the return of Holden Web (Steve Holden) this Friday from ApacheCon / Europe. He's producing ApacheCon / USA (also an international event) -- in Portland this year (Hilton -- also a former Djangocon venue, great reviews)). (Steve Holden is the author of the Python courses I teach) Kirby From jackie.masloff at newbury.edu Thu Nov 15 21:58:10 2012 From: jackie.masloff at newbury.edu (JACKIE MASLOFF) Date: Thu, 15 Nov 2012 15:58:10 -0500 Subject: [Edu-sig] Problem with Python in Windows Message-ID: Yesterday I was running the Windows version of the Python 2.7.3 shell with IDLE as my editor. I saved a file and ran it and got some error message which unfortunately I don't remember. I then closed Python and when I tried to re-open it, I got the following error message: IDLE's subprocess didn't make a connection. Either IDLE can't start a subprocess or personal firewall software is blocking the connection. I rebooted my computer, thinking that would solve the problem, but it didn't. I then uninstalled and reinstalled Python but got the same message. It's certainly not the firewall because that wasn't changed in the 15-20 minutes' times during which this happened. I am running Windows 7 with the latest service pack. Any suggestions on how I can fix this would be greatly appreciated. Jackie Masloff Adjunct Faculty--Computer Science Newbury College -------------- next part -------------- An HTML attachment was scrubbed... URL: From kirby.urner at gmail.com Thu Nov 15 22:08:18 2012 From: kirby.urner at gmail.com (kirby urner) Date: Thu, 15 Nov 2012 13:08:18 -0800 Subject: [Edu-sig] Problem with Python in Windows In-Reply-To: References: Message-ID: Greeting Jackie: Python's IDLE talks to itself over 127.0.0.1 and sometimes antivirus software can police that circuit. http://stackoverflow.com/questions/8588025/unable-to-load-idle-python-gui I do suggest an experiment where you shut off any antivirus / policing software you can think of, just temporarily. If that does prove to be the problem, must antivirus software has ways to allow exceptions. http://stackoverflow.com/questions/3277946/no-idle-subprocess-connection Also try booting Python with the -n switch per advice in the above post. Kirby On Thu, Nov 15, 2012 at 12:58 PM, JACKIE MASLOFF wrote: > Yesterday I was running the Windows version of the Python 2.7.3 shell with > IDLE as my editor. I saved a file and ran it and got some error message > which unfortunately I don't remember. I then closed Python and when I tried > to re-open it, I got the following error message: > > IDLE's subprocess didn't make a connection. Either IDLE can't start a > subprocess or personal firewall software is blocking the connection. > From PMEDINA at ccisd.net Thu Nov 15 22:20:30 2012 From: PMEDINA at ccisd.net (Medina, Patricia) Date: Thu, 15 Nov 2012 21:20:30 +0000 Subject: [Edu-sig] Problem with Python in Windows In-Reply-To: References: Message-ID: <30BBE65B7E95794F9F4A82F64395F82C4D97176C@TLC-MBX02.ad.ccisd.net> We are having a problem running python 3.x with windows 7 also. It says it can't (no processor or something), then it can. Seems like python and windows don't play well together. From: Edu-sig [mailto:edu-sig-bounces+pmedina=ccisd.net at python.org] On Behalf Of JACKIE MASLOFF Sent: Thursday, November 15, 2012 2:58 PM To: edu-sig at python.org Subject: [Edu-sig] Problem with Python in Windows Yesterday I was running the Windows version of the Python 2.7.3 shell with IDLE as my editor. I saved a file and ran it and got some error message which unfortunately I don't remember. I then closed Python and when I tried to re-open it, I got the following error message: IDLE's subprocess didn't make a connection. Either IDLE can't start a subprocess or personal firewall software is blocking the connection. I rebooted my computer, thinking that would solve the problem, but it didn't. I then uninstalled and reinstalled Python but got the same message. It's certainly not the firewall because that wasn't changed in the 15-20 minutes' times during which this happened. I am running Windows 7 with the latest service pack. Any suggestions on how I can fix this would be greatly appreciated. Jackie Masloff Adjunct Faculty--Computer Science Newbury College -------------- next part -------------- An HTML attachment was scrubbed... URL: From kirby.urner at gmail.com Thu Nov 15 22:52:04 2012 From: kirby.urner at gmail.com (kirby urner) Date: Thu, 15 Nov 2012 13:52:04 -0800 Subject: [Edu-sig] Problem with Python in Windows In-Reply-To: <30BBE65B7E95794F9F4A82F64395F82C4D97176C@TLC-MBX02.ad.ccisd.net> References: <30BBE65B7E95794F9F4A82F64395F82C4D97176C@TLC-MBX02.ad.ccisd.net> Message-ID: Jackie's problem was fixed with the -n switch. I've used Python 3.x extensively with Win7 since 3.x became available, also XP. Python is used with Windows all over the place. Windows is a flagship platform for Python. There can be confusions these days over whether one should run a "64 bit" or "32 bit" Python. Not saying it's always a piece of cake (though it often is and can be). I'm almost exclusively on Lion 10.7.5 with both Python 2.7 and 3.2 with Visual Python, other add ons. My editor is PyCharm. I'm also using Haskell with Xcode but I have done anything with the gonads (strike that), with the monads yet. Kirby On Thu, Nov 15, 2012 at 1:20 PM, Medina, Patricia wrote: > We are having a problem running python 3.x with windows 7 also. It says it > can?t (no processor or something), then it can. Seems like python and > windows don?t play well together. > > > > From: Edu-sig [mailto:edu-sig-bounces+pmedina=ccisd.net at python.org] On > Behalf Of JACKIE MASLOFF > Sent: Thursday, November 15, 2012 2:58 PM > To: edu-sig at python.org > Subject: [Edu-sig] Problem with Python in Windows > From enbody at cse.msu.edu Thu Nov 15 22:57:25 2012 From: enbody at cse.msu.edu (Richard Enbody) Date: Thu, 15 Nov 2012 16:57:25 -0500 Subject: [Edu-sig] Problem with Python in Windows In-Reply-To: <30BBE65B7E95794F9F4A82F64395F82C4D97176C@TLC-MBX02.ad.ccisd.net> References: <30BBE65B7E95794F9F4A82F64395F82C4D97176C@TLC-MBX02.ad.ccisd.net> Message-ID: <50A56545.9070907@cse.msu.edu> I've got a class of 270 students running Python 3.x in a Windows lab (22 machines) with essentially all students running their own copies on a variety of laptops -- mostly windows but many macs. The firewall is a good suggestion, but I haven't seen this problem. -rich enbody at cse.msu.edu On 11/15/12 4:20 PM, Medina, Patricia wrote: > > We are having a problem running python 3.x with windows 7 also. It > says it can't (no processor or something), then it can. Seems like > python and windows don't play well together. > > *From:*Edu-sig [mailto:edu-sig-bounces+pmedina=ccisd.net at python.org] > *On Behalf Of *JACKIE MASLOFF > *Sent:* Thursday, November 15, 2012 2:58 PM > *To:* edu-sig at python.org > *Subject:* [Edu-sig] Problem with Python in Windows > > Yesterday I was running the Windows version of the Python 2.7.3 shell > with IDLE as my editor. I saved a file and ran it and got some error > message which unfortunately I don't remember. I then closed Python and > when I tried to re-open it, I got the following error message: > > IDLE's subprocess didn't make a connection. Either IDLE can't > start a subprocess or personal firewall software is blocking the > connection. > > I rebooted my computer, thinking that would solve the problem, but it > didn't. I then uninstalled and reinstalled Python but got the same > message. It's certainly not the firewall because that wasn't changed > in the 15-20 minutes' times during which this happened. I am running > Windows 7 with the latest service pack. > > Any suggestions on how I can fix this would be greatly appreciated. > > Jackie Masloff > > Adjunct Faculty--Computer Science > > Newbury College > > > > _______________________________________________ > Edu-sig mailing list > Edu-sig at python.org > http://mail.python.org/mailman/listinfo/edu-sig -------------- next part -------------- An HTML attachment was scrubbed... URL: From PMEDINA at ccisd.net Thu Nov 15 23:13:10 2012 From: PMEDINA at ccisd.net (Medina, Patricia) Date: Thu, 15 Nov 2012 22:13:10 +0000 Subject: [Edu-sig] Problem with Python in Windows In-Reply-To: <50A56545.9070907@cse.msu.edu> References: <30BBE65B7E95794F9F4A82F64395F82C4D97176C@TLC-MBX02.ad.ccisd.net> <50A56545.9070907@cse.msu.edu> Message-ID: <30BBE65B7E95794F9F4A82F64395F82C4D97178C@TLC-MBX02.ad.ccisd.net> It is intermittent, and will work the next day. And I am lucky enough to have 30 computers with only 20 students. It doesn't happen enough to worry me, but it frustrates the students. Which depending on the day can be a bonus. :) From: Edu-sig [mailto:edu-sig-bounces+pmedina=ccisd.net at python.org] On Behalf Of Richard Enbody Sent: Thursday, November 15, 2012 3:57 PM To: edu-sig at python.org Subject: Re: [Edu-sig] Problem with Python in Windows I've got a class of 270 students running Python 3.x in a Windows lab (22 machines) with essentially all students running their own copies on a variety of laptops -- mostly windows but many macs. The firewall is a good suggestion, but I haven't seen this problem. -rich enbody at cse.msu.edu On 11/15/12 4:20 PM, Medina, Patricia wrote: We are having a problem running python 3.x with windows 7 also. It says it can't (no processor or something), then it can. Seems like python and windows don't play well together. From: Edu-sig [mailto:edu-sig-bounces+pmedina=ccisd.net at python.org] On Behalf Of JACKIE MASLOFF Sent: Thursday, November 15, 2012 2:58 PM To: edu-sig at python.org Subject: [Edu-sig] Problem with Python in Windows Yesterday I was running the Windows version of the Python 2.7.3 shell with IDLE as my editor. I saved a file and ran it and got some error message which unfortunately I don't remember. I then closed Python and when I tried to re-open it, I got the following error message: IDLE's subprocess didn't make a connection. Either IDLE can't start a subprocess or personal firewall software is blocking the connection. I rebooted my computer, thinking that would solve the problem, but it didn't. I then uninstalled and reinstalled Python but got the same message. It's certainly not the firewall because that wasn't changed in the 15-20 minutes' times during which this happened. I am running Windows 7 with the latest service pack. Any suggestions on how I can fix this would be greatly appreciated. Jackie Masloff Adjunct Faculty--Computer Science Newbury College _______________________________________________ Edu-sig mailing list Edu-sig at python.org http://mail.python.org/mailman/listinfo/edu-sig -------------- next part -------------- An HTML attachment was scrubbed... URL: From thomas at koch.ro Sun Nov 18 19:14:02 2012 From: thomas at koch.ro (Thomas Koch) Date: Sun, 18 Nov 2012 19:14:02 +0100 Subject: [Edu-sig] LearnStreet's Free Online Python Course In-Reply-To: References: Message-ID: <201211181914.03254.thomas@koch.ro> Aakash Prasad: > Hi all, > > I'd like to tell you about a free online Python course that my startup, > LearnStreet (http://www.learnstreet.com), has recently launched (along with > courses on JavaScript and Ruby). Our courses are designed for beginners and > are fun, engaging and interactive through the use of multiple learning > modalities. How is LearnStreet different from other learn-to-code sites you > ask? Hi Aaakash, I just looked at your site and really liked the overall concept. However being a European (German) there are two hurdles for me before I'd consider using your site in my classes: - I can't advise my students to create an account on a foreign site. - Your material is free-as-in-beer but not free-as-in-freedom. I've no idea about your business model but I'm afraid that it's in conflict with my wished for educational material. Thank you anyways for experimenting with new ways of learning! Thomas Koch, http://www.koch.ro