User:Eml4500.f08/HW report table/The best of HW7

Under construction; not final (but close to being stable after a couple of weeks). The intention here is to document the best features in any HW report for the readers (including you); if you see excellent features in any HW report (including your team's) that I may have missed noticing, don't hesitate to let me know. I don't have time to read all HW reports in detail. In fact, due to time constraint, I only selectively looked at a few important features. On the other hand, I also added some annotations (e.g., related to errors) in the HW reports that I looked through for the benefit of everyone. Eml4500.f08 21:26, 9 December 2008 (UTC)

• classnotes graded over 100%
  • 2-D frame elements (truss + beam)
    • 2-D frame model problem
      • FBDs
        • element dofs: displacements, rotations
        • assembly of element stiffness matrices into global stiffness matrix
      • element stiffness matrix $\displaystyle \tilde \bold k ^{(e)}$ in local coordinates
        • dimensional analysis of element stiffness coefficients $\displaystyle \tilde k ^{(e)}_{ij}$
      • transformation of FD relation from local coordinates to global coordinates
    • PVW for elastodynamics of beams
      • stiffness term
      • shape functions for truss and for beam
      • true deformed shape of a frame element (truss + beam)
        • disp components in global coordinates for a point on a frame element in terms of element dofs
        • dimensional analysis of shape functions and overall relation
    • derivation of beam shape functions
  • elastodynamics of trusses, frames, 2-D, 3-D elasticity
    • discrete equations of motion (MDOF; coupled ODEs) and initial conditions
    • unforced vibration problem
      • eigenvalue problem: derivation
        • generalized eigenvalue problem
        • standard eigenvalue problem
        • mass orthogonality property
        • stiffness orthogonality property
    • decouple system of equations of motion into uncoupled ODEs
  • recommended software to improve productivity. Most useful: Team Bike
    • writing wiki articles
    • writing latex equations
    • drawing figures
  • Mediawiki (on Wikiversity) vs. WebCT (on E-learning at UF): To set the proper context for this section, I included below my original e-mail requesting a team consensus on a comparison between Mediawiki vs. WebCT. Best team-consensus comparison: Team Bike. NOTE: Team Delta_6 (with annotations), parallel non-cooperative individual work and comparison. General comment: Non-cooperative work. Some teams even admit that they never met together as instructed per cooperative learning techniques, with each team member taking turn to work on a lecture. Team Aero (with annotations): "the scope of collaboration did not extend as far as was perhaps intended. In general, the assignment was divided based on lecture days and each person made their own posts with little editing." There was not much of a cooperation. Here is a most-telling example. The result is often a mosaic of incoherent pieces put together, without a flowing story. Absenteism and workload. If each student (in a typical team of six) did 1/6 of the work, took care of one lecture once every two weeks, but received 34% credit for the course grade, and yet did not attend all lectures, it is not clear why some of these students said that there was too much work, and what they would use the rest of their freed-up time for !? At least, Mediawiki allowed some students to free up their lecture attendance. Young Einstein was famous for skipping his classes (for thinking about physics), and learned from the math notes of his friend, but he was one in a billion... It would be a wild stretch of imagination to think that we had a Young Einstein in the class... Students who regularly attended lectures would do better in exams than they potentially could otherwise, regardless of their own level. Lecture notes taking seems to be a lost art with in the digital age of powerpoint presentations. While many students continued to take good notes (and even scanned them to e-mail out to their teammates who did not attend lectures), many others just relied either on their teammates' notes, the textbook (some lectures cannot be found in the textbook), or the digital photos they took of my transparencies (hand-written in real time in class) using their cell phones, even though I mentioned in class that it was not possible to do math or mechanics without writing, and did referred to the effect of writing on remembering that I read in Carl Sagan's The Dragons of Eden.
    • collaboration
      • parallel team work across the internet
      • math equations
    • incorporation other media (video, audio)
    • accessibility

Original e-mail re Mediawiki vs. WebCT

From: Loc Vu-Quoc <vu-quoc@ufl.edu> Organization: University of Florida, Gainesville, FL 32611, USA Date: Sat, 6 Dec 2008 15:51:15 -0500 To: fall-0072-l@lists.ufl.edu, Loc Vu-Quoc <vu-quoc@ufl.edu>, fall-3323-l@lists.ufl.edu Subject: Re: AERO+FEAD: we are ahead of UF's E-learning, HW7 (classes, TAs) Sat, 06 Dec 2008, 15:17:03 EST Dear classes (and TAs): Yesterday, for the first time, I contacted the staff of E-learning to explore some features of E-learning (e.g., posting grades), and learned that we were way ahead of UF's E-learning in the use of a wiki for course work (i.e, using Mediawiki on Wikiversity). Here is the story. Actually, "E-learning" is only the name of the service, which is run by WebCT, the software, just like Wikiversity is the name of the wiki site, which is run by Mediawiki, the software. Hence, we should say "Mediawiki vs. WebCT" or "Wikiversity vs. E-learning" (comparing apple to apple), but NOT "Mediawiki vs. E-learning" (comparing apple to orange). WebCT is relative old; the company was bought by another company called Blackboard, which is developing its own software to replace WebCT. UF's E-learning will phase out WebCT in 2 years; they are looking at 5 different programs to replace WebCT. Some universities already phased out WebCT. It is now clear that you cannot list WebCT on your resume as a skill that can help you in your job search, but you can with Mediawiki. In addition, UF's E-learning is exploring the use of a wiki to conduct courses at UF, just like we are using Mediawiki in our courses. They are looking into a proprietary wiki software called Confluence. Below are some interesting related wiki pages: Mediawiki http://en.wikipedia.org/wiki/MediaWiki Confluence http://en.wikipedia.org/wiki/Atlassian_Confluence Comparison of wiki software http://en.wikipedia.org/wiki/Comparison_of_wiki_software where you can see the features of different wiki programs, in particular Mediawiki and Confluence. Another very informative comparison is http://www.wikimatrix.org/compare/Confluence+MediaWiki UF's E-learning staff is still testing the different features of Confluence to tailor it for UF's courses; the web address for their testing wiki site is: https://wiki.courses.ufl.edu/ The UF's E-learning staff member I talked to is interested in looking at our course wiki pages to see how we have been using Mediawiki in our courses. UF will have a wiki for course work on its E-learning service, but perhaps in 2 years or so. We are thus well ahead of UF's E-learning in the use of a wiki for course work. Sincerely, Prof. Vu-Quoc ----- Forwarded message from Loc Vu-Quoc <vu-quoc@ufl.edu> ----- From: Loc Vu-Quoc <vu-quoc@ufl.edu> Organization: University of Florida, Gainesville, FL 32611, USA Date: Mon, 10 Nov 2008 13:58:21 -0500 To: fall-3323-l@LISTS.UFL.EDU, Loc Vu-Quoc <vu-quoc@ufl.edu>, fall-0072-l@LISTS.UFL.EDU Subject: AERO+FEAD: Mediawiki vs. E-Learning in HW7 (classes, TAs) Mon, 10 Nov 2008, 13:34:50 EST Dear classes: Most, if not all, of you are now experts in using Mediawiki. Cheers! In preparation for HW7 (yes, HW7), I ask you to discuss among members of your team to come up with a consensus on the pros and cons of Mediawiki vs. E-Learning for collaborating (remotely) on the type of HW reports that you have been doing. This section should represent the consensus of the team, and not of an individual. I assume that all of you had some familiarity and had used E-learning; if you did not, just mention so. In the team consensus section, list the number of members with familiarity with E-learning, and the number of members without such familiarity. For dissenting views, not agreeing with your team, you can create a sub-section titled "dissenting opinions" to list individual opinions that differ from the consensus of the team and sign under your individual opinion with ~~~~. For example, a few points that I heard from people who know E-learning and some from my own thoughts: - E-learning cannot include equations like Mediawiki (how about figures, videos, audio recordings? Mediawiki accommodates all of these media.) - E-learning system slowed down significantly during crunch time when many students tried to work on and/or upload to E-learning. - E-learning is of course local to UF, whereas Wikiversity (powered by Mediawiki, the software) is open to the whole world, thus allows worldwide access to your work (including yourself when you are on travel anywhere in the world). - it is not clear how long you can access your work on E-learning in the future (sometimes far distant future) after the semester is over. Your work on Wikiversity remains there permanently into the far distant future. - most large companies (Boeing, IBM, etc.) have some form of internal wiki for collaboration; a Mediawiki in-depth experience would be a plus for your resume. How about E-learning experience in terms of job searching? - with an expertise in Mediawiki, you can now contribute (or have been contributing) to Wikiversity, Wikipedia, and any of their sister projects. Of course, an E-learning experience would not be helpful in this matter. etc. You want to brainstorm to come up with a team consensus (and possibly with dissenting views). Feel free to include the above points in your team discussion and in your HW7 section for this comparison. Sincerely, Prof. Vu-Quoc -- US Natl. Congr. Computational Mechanics, San Francisco, 23-26 Jul 2007: Active small (nano) systems: http://clesm.mae.ufl.edu/~vql/conferences/usnccm9/stat.mech/ Shells and thin-walled structures: http://clesm.mae.ufl.edu/~vql/conferences/usnccm9/shells/ ********************************************************************** Loc Vu-Quoc, Professor | Tel: (352) 392-6227 Mechanical and Aerospace | Fax: (352) 392-7303 Engineering Department | E-mail: vu-quoc@ufl.edu P.O. Box 116250 | http://clesm.mae.ufl.edu/~vql/ 231 MAE-A Building, University of Florida, Gainesville, FL 32611 **********************************************************************

• matlab problem graded over 100%
  • 2-bar truss system
    • uniform bar elements
    • tapered bar elements
    • comparison of deformed shapes
  • 2-element frame system
    • boundary conditions: clamped, hinged
    • plot of complete (true) deformed shape
      • comparison with 2-bar truss system
  • electric pylon problem
    • frame model (instead of truss model)
    • finite element analysis
    • plot undeformed and deformed shape
      • compare to deformed shape of truss model
    • frame element with highest nodal bending moment
    • frame element with highest transverse shear force
    • frame model statically determinate?
    • compute reactions from frame model
      • compare to reactions from truss model
    • vibration analysis
      • lumped mass matrix
      • generalized eigenvalue problem
      • lowest three eigenpairs
        • compare with 3 lowest eigenvalues of truss system
        • Results: eigenvalue (period in seconds)
          • Team Bike 132.86 (0.54511 s), 2471.2 (0.12639 s), 2942.6 (0.11583 s); very close to those of the truss model; see The best of HW6; at least 3 teams got the same results.
          • Team ATeam(Sean) (0.54511 s), (0.12639 s), (0.11583 s); too close to those of the truss model (0.54654 s), (0.12647 s), (0.11587 s); at least 3 teams got the same results.
          • Team Delta_6 (with annotations) (0.54511 s), (0.12639 s), (0.11583 s); same comments.
      • plot lowest three eigenvectors: animate these 3 modes. Best animation: Team Bike (gif file) Team ATeam(Sean) (video file)

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EAS 4200C, The best of HW7