- dfdl-wg - lists.ogf.org

Bit/byte order
by Martin Westhead 11 Jul '05

11 Jul '05

Hi all, This is a discussion topic that came up in last weeks telcon. Mike asserted that only byte order was needed. I was not completely comfortable with this and said I'd investigate. After talking it over with various folks and looking a couple of things up, I have reached the conclusion that I agree with Mike. The key observation is that microprocessors handle bytes in parallel, there is no "bit pointer". So, within the context of data on a machine the only ordering over bits is their with respect to significance. Hence, to all intents and purposes, as Mike observes, bit-order==byte-order. It is the case that hardware representations of binary data will have a particular bit-ordering - Ethernet for example is LSB first, representations of data on tapes (or disks) will have a bit ordering. However the conclusion I reached from discussions here was that this is a red-herring for DFDL. Bit-order in this context is one of a number of physical aspects of the data representation which would include frequencies, signal strengths etc. There may be some archival value in recording all that stuff, and you could put it in DFDL, but I think that stuff is safely out of scope for where we are now. As soon as you are looking at your data from software you have bytes. Cheers, Martin

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Nomination of Jim Myers to replace Alan Chappell as co-chair
by Mike Beckerle 06 Jul '05

06 Jul '05

Folks, Alan Chappell has stepped down as co-chair of the DFDL-WG. Jim Myers has been nominated to take his place. Please send any comments on this nomination (e.g., in favor, opposed, don't care) to myself and Martin Westhead, (co-chair) directly. Martin and my emails are on the CC of this email message. Thanks Mike Beckerle

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new forum created
by Mike Beckerle 06 Jul '05

06 Jul '05

I created a "DFDL General" forum for structured discussion. The forum is here: https://forge.gridforum.org/forum/forum.php?forum_id=547 If you are like me you want to receive an email (or email digest) about activity in the forum. To do this you set your monitoring preferences here: https://forge.gridforum.org/monitoring/monitorPreference.php (dont' forget to login first) ...mikeb Mike Beckerle Architect, Scalable Computing IBM Software Group Information Integration Solutions Westborough, MA

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Today's call
by Martin Westhead 06 Jul '05

06 Jul '05

I will be on the call today. Could someone send me the number and access details though - I don't have them here. Thanks, Martin

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Call-in information : There are two GGF DFDL Sessions on Thursday ( 9am and 11am Chicago time)
by Mike Beckerle 06 Jul '05

06 Jul '05

There are two GGF DFDL Sessions on Thursday ( 9am and 11am Chicago time) Please call into this number at 9:00am Chicago on Thursday .... 1-877-950-2442 or 1-203-480-6948 - passcode 575542

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materials for possible discussion during session 2
by Mike Beckerle 30 Jun '05

30 Jun '05

Two slides about DFDL I presented at the Data area summary - Session 1 pre-slides - before the presentation. Session 2 doesn't really have any slides (just a title slide) This represents work on the annotation syntax/model. We took a clean-slate approach to a model for the rep properties with an eye towards enabling annotations "something like" the OMG CAM-model instances approach. Very rough work, but since we might be able to have a conference call today I thought I'd forward these for consideration. Mike Beckerle Architect, Scalable Computing IBM Software Group Information Integration Solutions Westborough, MA

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uploaded to our gridforge page
by Mike Beckerle 22 Jun '05

22 Jun '05

I've uploaded notes and slides from the F2F, and as promised a zip of the examples we walked through from the Ascl (now IBM) prototype my group is working on. In this zip is testCase.xsd, which is the schema of the test-case files that we're using. These are a common format that we could all share for tests of a variety of implementations. http://forge.gridforum.org /projects/dfdl-wg/document/F2F_2005_05_Examples_and_XSDs/en/1. is the URL for the zip file. Sorry for the delay in getting this all up on gridforge. Mike Beckerle Architect, Scalable Computing IBM Software Group Information Integration Solutions Westborough, MA

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Hello everybody!
by Yi Zhu[MSc] 08 Jun '05

08 Jun '05

Hi, My name is Yi Zhu. I am a MSc student of EPCC, majoring in High Performance Computing. I am here because my final project is about DFDL (I am sorry for that as the project has just begun, what exactly will be implemented has not been decided), and I believe this is a interesting, challenging and promising field. However, I am a real beginer in DFDL, so I need all your help. Thanks ever so much! Regards, Yi

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Conference Call on 6/8
by Mike Beckerle 03 Jun '05

03 Jun '05

Unfortunately I can't make the semi-weekly conference call on 6/8. Go ahead without me though! I have the following to report in no particular order of occurance or relevance: 1) MikeB did review ideas on layering and compositionality with Jim Myers. Went well. Jim was supportive of the approach. We have a bit more to do conceptually, but I'm very optimistic right now that we'll be able to advance something to the whole group which will be crisply defined and meet needs without excessive complexity. 2) scoping proposal from F2F was written up and posted to grid forge. Only saw one supportive comment from Martin Westhead. I'm pretty sure this matches what we discussed at the F2F and would only ask that people at least verify if it matches what they expected. 3) other F2F materials were posted on grid forge. Slides, notes, and the testcases and schemas we looked at. Of note, the testcase schema was posted. This will help us all share test/use cases as we move toward having working implementations. 4) Suman sent his latest properties model. Here in westborough we're getting close to where we'll be able to take a look at this. Bear with us Suman, we appreciate your effort, it's just taking some time to get there. 5) I am going to GGF14 in chicago. I've requested two sessions on DFDL there. One to be status/overview as usual, one to be a working session w/conference call if we can swing it. I hope we'll have time before GGF14 to get some more proposals up on grid forge, though we can't ask for any formal comment on anything by GGF14 because we're past the date for that sort of thing. I'm still hoping to have something more on (1) and (4) above in hand (posted to this mailing list or gridforge) before GGF14. Mike Beckerle Architect, Scalable Computing IBM Software Group Information Integration Solutions Westborough, MA

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DFDL Scoping proposal document
by Mike Beckerle 27 May '05

27 May '05

At the F2F we discussed scoping of DFDL annotation properties. This document summarizes the proposal that emerged from the discussion. https://forge.gridforum.org /projects/dfdl-wg/document/DFDL_Scoping_Proposal_v001/en/1. Mike Beckerle Architect, Scalable Computing IBM Software Group Information Integration Solutions Westborough, MA

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