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TLCD Video Analysis using Matlab

19 February, 2011 (00:40) | Engineering, Programming, Research | No comments

To measure the liquid heights in a Tuned Liquid Column Damper, either very expensive wave bob metres are needed, or the researcher can go through video image frame by frame estimating the height of the liquid columns from a scale attached to the TLCD. To avoid this laborious task, and to increase the number of experiments we can do, I developed a video analysis toolkit that processes the image automatically for the liquid heights. Here’s a video of the analysis:

The output can be converted to time and length (in mm say) using the rulers to get a scale (mm per pixel say) and the frame rate of the video. The ‘redness’ of the liquid is the key here: the video is split into RGB and the red channel isolated and converted to black and white once a filter is applied. This image is then scrubbed to get rid of any objects smaller than a threshold size, leaving only the liquid of the column. The image is then split in two at the centre of the bounding box to analyze each column separately. Since a black and white image is represented by a matrix of 1 and 0s, summing the columns of the matrix (ie the vertical direction) gives the column height in pixels. A few other adjustments are needed, but that’s the basic idea.

Build a 15-storey Hotel in 6 days? No Problem!

8 February, 2011 (00:29) | General | No comments

Well worth a look for the prefabrication and impeccable logistical planning evident from the video. But it’s not that new…the Empire State Building took 18 months in total!

Optimization: Himmelblau’s Function

31 August, 2010 (00:18) | General | 1 comment

I just came across Himmelblau’s function for testing optimization routines. It has four local minima and one maxima so it provides a good test:

I’m pleased to say my implementation of the Nelder-Meade Simplex Algorithm (on my C++ page here) was able to optimize it for each minima (depending on the starting locations of course). I did have a weird problem though – starting a solution at (0,0) failed, even though the minima are not equidistant from the origin. Go figure!

Research Opportunities

30 July, 2010 (17:08) | Engineering, Research | No comments

DIT has released details of its new scholarship programme, the DIT Fiosraigh Scholarship Programme 2010 (for more details see here). Of particular interest to recent graduates is the Dean of Graduate Students Award. This will support the successful candidate with €16k+fees+€2k expenses per year, for up to 4 years. A minimum degree of 2:1 is required.The closing date is 15 September 2010.

Candidates interested in pursuing PhD research in Bridge Loading: statistics and dynamics should send a CV to

Candidates interested in self-funding research to MSc level are also invited to send their CVs.

Again, some motivation is given in the chart below, and in this post.

Bridge Collapses as Motivation

18 June, 2010 (13:48) | General | 3 comments

Sometimes its useful to re-motivate ourselves. A sobering TIME magazine photo-essay reminds us why we research and try to continually improve the design process:

The Worst Bridge Collapses in the Past 100 Years

Mianus Bridge, Greenwich, Conn. (June 28, 1983)

Another collection is here:

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