The Bootstrap

buildingSMART ITM/IUG meetings in Oslo

2012-03-20T09:38:00.001+01:00

This week I am in Oslo attending buildingSMART meetings. buildingSMART is the organisation, or federation of regional chapters, which is responsible for the definition of open standards for the representation and exchange of information related to the construction industry.

Nominally, the meetings I'm attending are the ITM and IUG meetings, roughly speaking the technical and user committees, but they seem to have an evolving structure which crosses from those distinctions across to distinction between product (structures for data, in the guise of models and libraries) and process (representing the business processes that create or manipulate that data. I'm certainly more interested in the former, being essentially a technologist (in the context of this community, anyway), but its good to see the focus on the latter, especially considering the worrying tendency amongst BIM adopters to tie themselves to single vendors and formats.

Its interesting to observe how the community here works. It is dramatically less formal than OMG (the standards body I've most dealt with in the past), with very few codified rules on how meetings are run and how their standards are written up and published. There is talk at this meeting about a changing relationship with ISO (who publish the buildingSMART standards), and I wonder whether this will result in changes to the way the organisation is run, but that's kind of by-the-by.

Domain-Specific Model Transformation in Building Quantity Take-Off

2011-10-24T07:52:00.003+02:00

Last week I presented a paper at the ACM/IEEE 14th International Conference on Model Driven Engineering Languages and Systems (or MODELS 2011 to its friends), held in Wellington, New Zealand. The abstract for the paper is as follows:

The two core concepts of model-driven engineering are models and model transformations. Domain-Specific Modelling has become accepted as a powerful means of providing domain experts and end users with the ability to create and manipulate models within the systems that they use. In this paper we argue that there are domains for which it is appropriate to also provide domain experts with the ability to modify and develop model transformations. One such domain is that of quantity surveying, and specifically the taking-off of quantities from a building design. We describe a language for expressing transformations between building models and bills of quantities, and its implementation within an automated quantity take-off tool, reflecting on the commonalities and differences between this language and a general-purpose model transformation language/tool.

The electronic version of the paper is up at the Springer site, and at my university's electronic repository when they get around to putting it up..

The presentation went pretty well, and I was presently surprised throughout the conference by the number of attendees interesting in modelling things that aren't software. The longer I work in modelling, the less I am interested in modelling the software itself, and the more I'm interested in using the models and modelling languages of the domains, and in how making them explicit can shape the software.

A Transformation Workbench for Building Information Models

2011-07-12T07:50:00.002+02:00

Last week I presented a paper at the 4th International Conference on Model Transformation, part of the TOOLS Europe federated conferences, hosted this year by ETH Zurich. The abstract of the paper is/was:

The building industry is undergoing a significant evolution, with increasing use of digital models during the design process and sub- sequent lifecycle of a building. These models, which span multiple de- sign disciplines, multiple stakeholders, and many phases of the build- ing’s life, represent an interesting study for the application of ideas from model-driven engineering, being large, complex, and highly interrelated. Building models are typically represented using the Industry Foundation Classes (IFC), an industry standard supported by many of the popu- lar CAD tools, defined in the STEP/Express technical space. Because the majority of research in MDE has focussed on the Eclipse Modeling Framework (EMF) technical space, it has previously been difficult to experiment with IFC models using model-driven engineering tools and techniques. In this paper we describe a workbench which provides for the integration of the STEP and EMF technical spaces. We also describe a number of initial experiments in bringing model transformation tech- niques and tools to bear on the domain of building models, and propose some future work.

The full paper is available from Springer (it'll be up on my university's publications repository when they get around to it). For the presentation, which I thought went reasonably well, I used the Prezi online presentation system, and the presentation is available here. (Note: I'll be coy about recommending Prezi - it can be cool, but it has some very serious issues).

The ICMT conference, and the TOOLS event as a whole, was very interesting, with an ongoing choice of conferences (4 in total) and workshops (8, including TTC) to get along to across the 5 days. I managed to sample all 4 conferences and 3 of the workshops, and pretty much found something of value in all of them.

Transformation Tools Contest 2011

2011-07-01T09:07:00.002+02:00

Tefkat (with me at the wheel) came in second (of 10) yesterday in the live challenge of the Transformation Tool Challenge workshop at the TOOLS Federated Conferences in Zurich. Congratulations go to the first-place winners, Tassilo Horn and GreTL, who also won awards for the offline problems (along with GrGen.net). The competition was a lot of fun, with lots of useful discussion and feedback amongst the different competition participants and organisers. I'd encourage people who are interested in model transformation and model transformation languages to get along to check it out, on the web site for this year's edition, and also at future events.

Graphical Programming

2011-06-14T08:12:00.003+02:00

Last Thursday I attended the second (well, kind of second) meeting of the Brisbane chapter of the Computational Design Group, kindly hosted by ARUP. There were interesting talks by Steve Downing from ARUP Sydney, Ben Doherty from BVN, and Abdullah Habash from Aurecon. I had been exposed to some of Steve's and Ben's stuff in my former life at QUT, but it was nice to see what they've been up to. It was also nice to see the ways that Abdullah and Aurecon have been using computational techniques for designs of their buildings in Abu Dhabi and Brisbane, including on the building currently under construction next door to me.

One of the thoughts that occurred to me, looking at some of the complex Generative Components and Rhino/Grasshopper models in the presentations, was about graphical programming. People in computer science talk about graphical programming from time to time, but the pointy end of the design industry are doing it for real, on big projects, in these tools.

* I am hoping to revive this blog a little bit. Time will tell whether that ambition yields fruit.

moving on

2011-03-04T01:58:00.002+01:00

Some people who follow me on twitter and had some inside connections already knew this was happening, but it probably warrants a proper announcement for anyone else who's still subscribed here or elsewhere.

A couple of weeks ago I tendered my official resignation to QUT. In just over a week I will be starting a new position as lecturer in the School of ITEE at the University of Queensland.

SoSyM paper on interoperability in BIM

2010-10-11T02:50:00.002+02:00

Last year, Robin and I presented a paper on interoperability of models in the architecture/engineering/construction space. Subsequent to that, with the aid of Bianca (a PhD student of Robin's), we expanded it for a special issue of SoSyM on model interoperability. The final accepted paper is now available online at Springer's site (requires subscription).

Here's the abstract:

The exchange of design models in the design and construction industry is evolving away from 2-dimensional computer-aided design (CAD) and paper towards semantically-rich 3-dimensional digital models. This approach, known as Building Information Modelling (BIM), is anticipated to become the primary means of information exchange between the various parties involved in construction projects. From a technical perspective, the domain represents an interesting study in model-based interoperability, since the models are large and complex, and the industry is one in which collaboration is a vital part of business. In this paper, we present our experiences with issues of model-based interoperability in exchanging building information models between various tools, and in implementing tools which consume BIM models, particularly using the industry standard IFC data modelling format. We report on the successes and challenges in these endeavours, as the industry endeavours to move further towards fully digitised information exchange.

Biden on Copyright

2010-07-05T09:02:00.003+02:00

Last week (or a little longer ago), US vice president Biden claimed

"Piracy is theft, clean and simple"

In fact, not only is "piracy" not theft, plain and simple (as per the US supreme court in Dowling vs United States), nor is copyright infringement, which is what he is talking about. The use of the term "piracy" for copyright infringement, is really very unhelpful, and interferes with any attempts to have any useful debate about intellectual property rights, how they should or shouldn't differ from material property rights, and how they can/should be enforced.

trying the "commercial" software thing

2010-07-01T07:55:00.003+02:00

A couple of friends and I have written an app for the Apple iPad, called Puzzlement. Its a jigsaw puzzle game, selected because we felt it was a good fit for the device's touch interface and form factor (bigger than iPhone). Its development (in which I was the lesser partner of 3) was more difficult than we anticipated, but we put it up in the app store last week.

This is just about the first piece of software that I've worked on that has been sold (actually LCADesign was the first, I think), and certainly the first in whose sales I've had a financial stake. Its been interesting tracking the sales numbers from day to day (and, informally, from hour to hour), and seeing which countries are buying the app and in what numbers. (I've even broken out and engaged in some spreadsheet-fu to track it all.) We had a good first day of sales, but after the initial honeymoon we have realised that making the app successful is going to require some marketing. How we do that remains an open question. The feedback we've had from people who played with the app has been very positive, but we will have to get it into people's hands in order for that to matter.

For the sake of relevance to my usual topics of interest, there is only the slightest bit of model-driven engineering in the app - we used Apple's Core Data framework to manage persistence of puzzle state, and it does quite a nice job of what I guess is the low-hanging fruit for MDE - autogenerated OO-DB bridges for managing application state.

2010-06-29T03:54:00.001+02:00

My paper on bridging STEP and EMF got knocked back from MoDELS'10 this morning. Shame, I really wanted to go. Its been a long time between conferences now.

maybe the NBN will be slower than what we have now

2010-05-07T07:35:00.005+02:00

I enjoy reading about the NBN (most recently here). What I do find frustrating, though, is that although everyone talks about high bandwidth, no-one seems to mention latency.

For those who haven't studied networks at uni, think of a network connection as a pipe (remembering that the internet is a series of tubes). The bandwidth is how many litres of water can flow down the pipe at once. The latency is the time for any give drop to get from one end to another. Replacing a pipe with a fatter pipe might improve your bandwidth, but unless you increase your pressure or reduce the pipe length, then it won't change your latency.

One of the things I use the internet for a lot is online gaming. The way a gamer cares about their connection is like this. They care about bandwidth a lot at first, because it dictates how fast they can download the game data onto their computer (remembering though that it depends on the width). After that, though, provided they have some minimum level of bandwidth (for current games this might be somewhere above modems but short of low-end ADSL), what they really care is latency. It is latency that determines how long it takes them to register that their enemy is doing something, and for the instruction they give in response to that to get back to the server, etc.

Its not just games, either. I'd imagine latency is important for commercial applications, too - realtime share or currency trading, for example. With the NBN, everyone is talking about bandwidth (100Mb/s to the home, etc). No-one is talking about latency.

Australia's at a physical disadvantage, firstly. For our packets to hit an American server, there's the small matter of traversing the Pacific Ocean, but I wonder how much of a factor that actually is. How much of the ping time is actually a packet screaming along a wire or a photon screaming down a fibre, and how much is a factor of how many computers are catching, processing and resending the packet in between?

My understanding is that the signal moving along the wire happens at something like 50-75% the speed of light (depending on whether its fibre, copper, etc), so I would have guessed that the hubs, switches, routers and firewalls (not to mention content filters) would have a much bigger effect on ping. I would also have guessed that new networks probably get more complex rather than simpler, so perhaps the NBN is going to hurt, rather than help, our ping times.

I wonder if one of the goals for the project shouldn't also be simplifying the network topology to try and control latency. Perhaps it is. I'd love it someone could tell me.

EDIT: There are plenty of other ways a gamer (or anyone else) cares about their network connection, obviously. Availability, packet loss, scalability under congestion, etc. Latency is the one I think about most, though :)

Uncertainty

2010-01-11T02:29:00.002+01:00

I am back at work this week, but in a strange position. My present 12-month contract with the university expires this Wednesday, and although my next (6-month) contract has been approved and budgeted within my team, whether it gets through the HR processes before Wednesday remains to be seen. I am fairly zen about it all; I have nothing particularly pressing this week, so a few days extra holiday won't phase me too much. The biggest impact may be on my 7 days of accrued leave from last year. If my contract is renewed, I will have to allocate it in the next few weeks. If not, then I expect it will be paid out, and I'll only have my normal 20 days to spend this year.

I feel like this is a significant year for my future at QUT. My last two years, for various reasons, haven't had the research impact that I would like to have going forward, so this is the year where I think I need to get some papers published, and get some good projects going, to convince myself (and to convince the university) that this is a research direction worth pursuing further.

model interoperability in virtual design and construction

2009-05-06T01:35:00.003+02:00

A couple of weeks ago, I presented a paper at the Knowledge Industry Survival Strategy (KISS) workshop (associated with the ASWEC conference) on the Gold Coast. The conference was about interoperability in domain-specific languages. Our paper (it was written with Professor Robin Drogemuller) was on the IFC language, the standardised language for interoperability in Architecture/Engineering/Construction software, including CAD tools, and on how it performs as an interoperability language. IFC, which I have been working with now for about 16 months, is comfortably the biggest metamodel I have seen or heard of (much bigger than, for example, CWM or UML2), certainly the broadest and among the most complex. The models are enormous - the example I present in the paper included 7.3 computational objects - and also very complex. It is a compelling example of a DSL.

The paper and presentation were very well received, and were singled out for mention in the call for submissions for the followup workshops at Code Generation and ASE. We also got a mention on the website and newsletter of the CRC for Construction Innovation, under whose auspices were conducted the projects that lead to the observations in the paper.

The paper and slides are up on the workshop website,

steal this blog post.

2008-10-13T07:09:00.002+02:00

From the book of xkcd. Amen.

(You really can steal my blog post, but you should say you did.)

refactoring EMF models

2008-10-13T05:59:00.004+02:00

I'm a software engineer now (well, kind of), so I am qualified to espouse great wisdom on my experiences in software engineering.

Last week we had cause for a couple of refactorings in our EMF models.

The first refactoring was very simple. One of our metamodels had a traceability link to source model objects, which needed to be generalised to be able to point to a more structured "assembly" of source model objects. For some reason, I already had a metamodel for these assemblies, so it was a simple matter of moving those metamodel elements into our main metamodel. The generated code for the assemblies hadn't been modified, so I was able to just cut&paste in the EMF editor, and add a reference to allow either single-element or assembly traceability. Then, using eclipse's call hierarchy view, I tracked down all the references to the single-element traceability, and generalised them to handle the new structure.

The second refactoring was more complicated. For one reason or another, we needed/wanted to change the name of one of our metamodel packages (and some other stuff, but let it just be the name). This meant that almost all of our code would change package, and a number of classes would change classname. Unlike the previous refactoring, this would have a huge effect on our generated code, which would need to be moved to new files, in a way that correctly overrode the default generated code. When you generate "over the top" of files, EMF is good at taking care of this, but I wasn't sure it would work when the generated files are "new". (I was pretty sure it wouldn't).

The approach we took was to anticipate all the effects of the metamodel changes we were making. We worked out that these were a number of changes to classnames (where the package prefix forms part of the classname), and a number of package renamings. We carried these out (in that order) using eclipse's Java refactoring (which is very good). Notwithstanding some complaints from SVN, this went smoothly. Then, when it came time to regenerate code from the changed metamodel, EMF found itself "overwriting" existing code, rather than creating new code. The refactoring was completed with only one or two lines of code needing to be hand-modified (for the curious, we had neglected to refactor some inner classes).

A refactoring framework for eclipse would be really nice. I do recall some mention of it on the EMF forum, but I don't know how far they got, or how they were going about it. If I were to go about it, experience like that above would probably lead me to look at essentially mapping eclipse refactorings onto generated Java refactorings (probably implemented as commands, off the top of my head).

In the interim, my advice would be that whenever you are refactoring a metamodel, think about the consequent changes for your non-generated code, and if necessary consider pre-empting the metamodel refactoring with Java refactoring. This way of thinking might not be elegant (the "no-one thinks about bytecode/binary when they're writing Java/C" argument), but it can save you some pain.

(From a more academic, "transformation" point of view, this is probably a good argument for traceability in transformations, and for treating "replay" transformations differently to "green field" transformations).

microsoft oslo

2008-09-30T10:06:00.003+02:00

I'm really impressed to see Microsoft's continuing push towards modelling as important. Their hiring of good people over the years - Jack, Wojtek, Stuart, Steve, etc - and recently of recognising the benefit of playing nicely with others on modelling (which I assume is the reason for Steve Cook being back at an OMG meeting after a long absence).

However, this kind of presentation really makes me cringe. The implication that Microsoft are the real drivers of modelling is kind of rough on the people and companies that have been working on the associated tooling (storing, creating, serialising models, among the things mentioned in the video - no mention of transforming, yet) for a decade or more. I do kind of realise that its not meant for me, and hopefully at some point I'll have the time to check out, or someone will point me towards, what MS are doing. Coming in late does offer them some advantages in terms of cherry-picking the ideas that work from those that maybe don't.

posting hiatus

2008-09-26T03:22:00.003+02:00

Its been a while since I've posted here, and its not the first time I've said that. I've been engineering away, trying to get the estimator feature-complete. I've had a couple of periods of high productivity, particularly when I implemented the rule language and rule engine, and when I was doing some of the traceability (selection sharing, etc) features. In the interim, there have been some slow sections, and some time spent doing non-development things like investigating how the software scales with really large models (not well), and doing some commercialisation- and publicity-motivated demonstrations.

meta-pizza

2008-07-22T01:42:00.001+02:00

Its creator dubbed it "Fractal Pizza", but for this blog, it can only be Meta-Pizza!

What am i reviewing?

2008-05-09T08:52:00.003+02:00

One of the jobs that becomes more prominent upon the completion of PhD is the reviewing of papers. I probably reviewed a half dozen papers a year during my PhD, usually on behalf of one of the full academics in our team. This year, it will probably wind up more like 20 or so, for a mix of conferences, workshops, and journals.

What I'm finding is that about 2 out of 3 papers that I review is riddled with basic grammatical errors. I'm more than happy to overlook a certain density of errors, but perhaps half of these present with errors in a density that would see a university paper sent back to the student with a fail, with little regard for the technical merit of the ideas being presented.

So, do we hold academics to a lower standard than students, on the grounds that a higher proportion are non-native speakers, and that the merits of the ideas outweigh the faults of the presentation?

Personally, I am finding that my critique of the technical merits of these papers is suffering because I am spending too much time correcting, or simply being frustrated by, faults of presentation. The paper is more difficult to read, so the review takes longer to complete, and the lost continuity makes the technical contribution harder to understand. I also spend less time thinking about the science and the relevant technical questions, because I'm instead scribbling down "needs a definite/indefinite article" and "plural: are not is".

I am not unsympathetic to the difficulty of writing in a non-native tongue; the summary chapter of my thesis was riddled with grammatical errors (ed: I confess I did send this chapter to a French journal; I regret doing so, and it was quite rightly rejected because of the poor quality of its writing). However, I also spent a long time correcting the grammar of my colleagues at the lab in France so that their papers might be more legible when they reached reviewers. This is when the majority of such correction should be done. By the time a paper reaches a reviewer, there shouldn't be more than a couple of errors per page, at the most.

Well, there's my rant for the day. It will make me feel 3% less guilty about my review taking so long to get done.

timely change

2008-04-16T08:52:00.003+02:00

I only started using Outlook (or Outrage, as Robin calls it) about 9 months ago, which was about 6 months after I started using Google Calendar. the lack of integration between the two was very frustrating.

I had initially heard a rumour that a bridge was possibly if one had Outlook 2007, but as I didn't, it didn't help me. Of course, I should have realised that it was a better idea to hope for a solution from Google than from Microsoft. Sure enough, Google Calendar Sync!

It's missing a few features - it only syncs to the first google calendar (which isn't my "work" calendar), and I'd like to be able to control the privacy settings of the incoming events - but it essentially works.

STEP/Express

2008-04-16T07:13:00.003+02:00

Over the last couple of weeks I've been getting to know STEP/Express. STEP is the language used to define IFC, which is the standard modelling language interchange format in the world I'm working at the moment.

STEP bears a resemblance to MOF, both in its purpose as a language for defining modeling languages, and structurally, in terms of defining object types, attributes, references (right down to opposites), etc.

The first two days of the course were to do with Jotne's model server, which is essentially like a MOF repository but with domain-specific extensions for model visualization (plugging into a 3-D IFC viewer). There was a fair bit of support for model versioning (versioned at the model level rather than the object level, and with customisable and/or partial checkin/checkout), permissions (although I wasn't very satisfied with their permission model), and even domain-specific merging.

The last few days were to do with associated technologies. There is a language, Express-X, for writing what they call "query functions", which are really just server-side procedures. In many ways, Express-X fits the sort of role Kermeta tries to fill for MDE, a language for the manipulation of models. The similarity ends there, though. Express-X is procedural, with global variables, and various other language design decisions that I've never seen (real literals without trailing 0s ("1."), "++" as a generic insertion operator applicable equally for integer increment, set insertion and string concatenation) or things I wouldn't personally have done (1-relative arrays). I won't be carving out a career as an Express-X programmer.

They also have a bunch of tools that one can imagine for MOF/MDE. They have an ontology-like language which they use for common model elements, much the same way as I've heard MDE people talk about using ontologies. They have a validation framework for people to build model-checking modules, and they're sniffing around some process-modelling stuff.

This isn't the first architecture I've seen with a lot of things in common with MOF/MDA, and I won't be switching, but its interesting to see people in different fields moving in the same direction.

STEPS

2008-03-20T05:54:00.002+01:00

(Via LtU) Viewpoints Research have published the first year's status report on their previously discussed project.

This is a rebadging of the Squeak-Croquet crowd, who do cute enough stuff with Smalltalk, but whom I've always found much more grandiose in their presentation than in their products. I confess I was a little underwhelmed by Squeak/Croquet when I tried it.

What struck me about their progress report was its similarity to a lot of the principles of MDE, in terms of lots of languages and transformations between them.

The central tool – called IS – is a pattern directed transformation system with various levels of
language descriptions from very high level languages in which we write code, all the way to descriptions
of the machine language instructions of our target machines.

If I understand their reference (they don't cite anything, so its hard to tell), they are a bit dismissive of MDE:

Similarly,
the recent work in modeling (too bad this term got co-opted for this) is only convincing to us if
the models can be automatically extracted

... which they can, at least in my envisioning of it all. Nonetheless, beyond the pejorative bits, they're doing some cute stuff, with some striking similarities to things I know about.

IS can instantiate new programming paradigms and systems, including itself. It demonstrates the
power of “extreme late binding” and treats many of the static vs. dynamic choices that are traditionally
rigid (compilation, typing, deployment, etc.) more like orthogonal axes along which design
decisions can be placed.

This gets at the aim of Kermeta as a language engineering workbench - the structural part works well, and the operational part is pretty much there. The idea of compilation, typing, deployment etc as orthogonal design decisions was something that I hinted at in my thesis (modeling type systems as opposed to typing modeling systems) as a direction for Kermeta (one that hasn't yet been explored much, to my knowledge). Indeed, part of the idea of model typing was to enable the implementation of "language aspects", I guess (once again, not yet explored much).

Its a shame, but there seems to be a lot of "turf" differences between crowds like these guys, the graph transformation crowd, the MIC crowd, the MDE crowd (even within the MDE crowd), which leads to a lot of reinvention of the same paradigm.

starting with a trickle

2008-02-15T03:13:00.002+01:00

After four weeks, we now finally have a source code repository, our adopted base framework has been checked in, and stuff from our project is just starting to trickle in. I know we haven't been sitting on our hands up to this point, but it does somehow feel like the project is actually underway now. It's a good feeling.

good gantt

2008-02-05T01:13:00.000+01:00

I've promised to do some Gantt charts. By the end of the week, no less. Honest to blog, what am I becoming?

random notes from a forgotten workshop

2008-01-31T07:14:00.000+01:00

I stumbled across some random notes I took in a workshop a while back.

"W3C does not produce standards" - you just keep tellin' yourself that!

Standards groups as a means for market research.

Cult of TBL

A hundred-pound gorilla is a very small gorilla.

Still no evidence of understanding of conceptual vs representational schemata.

This post may be interesting to no-one. I'm not sure why I'm posting it.