Monthly Archives: October 2015

Recognizing strain

rlpoYou can step off an express train but you can’t speed up a donkey. This is paraphrased from ‘The Fly Trap’ by Fredrik Sjöberg in the context of our adoption of faster and faster technology and the associated life style. Last week we stepped briefly off the ‘express train’ and lowered our strain levels by going to a concert given by the Royal Liverpool Philharmonic Orchestra, including pieces by Dvorak, Chopin and Tchaikovsky. I am not musical at all and so I am unable to tell you much about the performances or compositions, except to say that I enjoyed the performances as did the rest of the audience to judge from the enthusiastic applause. A good deal of my enjoyment arose from the energy of the orchestra and my ability to recognise the musical themes or acoustic features in the pieces. The previous sentence was not intended as a critic’s perspective on the concert but a tenuous link…

Recognising features is one aspect of my recent research, though in strain data rather than music. Modern digital technology allows us to acquire information-rich data maps with tens of thousands of individual data values arranged in arrays or matrices, in which it can be difficult to spot patterns or features. We treat our strain data as images and use image decomposition to compress a data matrix into a feature vector. The diagram shows the process of image decomposition, in which a colour image is converted to a map of intensity in the image. The intensity values can be stored in a matrix and we can fit sets of polynomials to them by ‘tuning’ the coefficients in the polynomials. The coefficients are gathered together in a feature vector. The original data can be reconstructed from the feature vector if you know the set of polynomials used in the decomposition process, so decomposition is also a form of data compression. It is easier to recognise features in the small number of coefficients than in the original data map, which is why we use the process and why it was developed to allow computers to perform pattern recognition tasks such as facial recognition.


Wang W, Mottershead JE, Patki A, Patterson EA, Construction of shape features for the representation of full-field displacement/strain data, Applied Mechanics and Materials, 24-25:365-370, 2010.

Patki, A.S., Patterson, E.A, Decomposing strain maps using Fourier-Zernike shape descriptors, Exptl. Mech., 52(8):1137-1149, 2012.

Nabatchian A., Abdel-Raheem E., and Ahmadi M., 2008, Human face recognition using different moment invariants: a comparative review. Congress on Image and Signal Processing, 661-666.


Engineers, moral compasses and society

Picture1One of my regular correspondents has commented last week about teaching ethics to engineering undergraduate students in order to reduce the probability of repetition of events similar to the Volkswagen emissions scandal (see my post on October 14th, 2015 on ‘Greed overwhelms ethics‘). My experience of talking to professional engineers is that there is nothing wrong with their ethical values but that they feel helpless in the face of corporate intransigence or worse. Many engineers feel unable to shift the moral compass of the organisation in which they work. Ethics is concerned with one’s personal values whereas morality is about what is permissible and forbidden in particular realms of behaviour, according to AC Grayling. The frequent revelations of scandals across a range of industries would suggest that we have a crisis of morality in our society. I don’t know how to resolve it but perhaps a first step would be for everyone, including the rich and powerful, to admit we have a problem.

Greed overwhelms ethics

My car but not my house!

My car but not my house!

The scandal about Volkswagen emissions has already caused journalists and others to wring their hands or to preach sermons, or both, about the ethical standards of the engineering profession, see for example the Editor’s blog in Professional Engineer where he reminds us that professional engineers should conduct their professional work and relationships with “integrity and objectivity and with due regard for the welfare of the people, the organisations and the environment with which they interact”. The quotation is from the Royal Charter of the Institution of Mechanical Engineers. Fine words written to induce good intentions that rarely survive in the face of greed or simply the need to keep your job so that you can feed and house your family.

In my view, the emissions scandal seems to have parallels with the banking scandals of the past decade, in which corporate greed has trampled over ethics and morals in the pursuit of ever larger profits while government regulators through incompetence or acquiescence have allowed it to continue. Volkswagen were wrong to design a device to cheat the Government emission tests, but Government regulators were naive to design a test in which it was so easy to cheat. Senior executives at Volkswagen have blamed their employees following other recent examples.  These company leaders were paid gigantic salaries to provide both leadership and management and, in my opinion, they have failed in both by blaming the people they are supposed to be leading and by allowing the scandals to happen in the first place.

The evidence would suggest that we can trust neither corporations nor governments to take care of the environment. One solution is for all vehicles to provide real-time information on the dashboard about NOX and Carbon emissions as well fuel consumption then we can make our own choices. When I moved to the US more than a decade ago, I was surprised to find that fuel consumption data was not available on the dashboard of most cars as it was already commonplace in Europe. Perhaps its presence was a factor in the development of fuel efficient cars in Europe although clearly higher fuel prices play a large role.  However, in the absence of a tax on emissions, real-time emission data on the dashboard would motivate engineering ingenuity to compete to produce lower emission designs instead of wasting creativity on cheating in useless Government tests.

Here are some of facts to support my statements above about large profits and gigantic salaries:

Volkswagen profits rose 21% in 2014 to more than $12billion on an annual turnover of $230 billion which is comparable to the GDP of Portugal.

The CEO of Volkswagen was paid almost $18million per year which is about 250 times the average salary of a Volkswagen engineer.


Hibbert, L., Editor’s comment: October 2015 The Volkswagen emissions testing scandal has put the issue of professional ethics in the spotlight, Professional Engineer, October 07, 2015.

Wall Street Journal, Feb 27th, 2015

Volkswagen AG Annual Report 2014

World Bank Data Bank

Reuters, March 12th, 2012


Death knell for the lecture?

Author lecturing in Yonsei University, Korea

Author lecturing in Yonsei University, Korea

This week I have started filming short video clips for a MOOC that will be broadcast in February in parallel with my undergraduate course on Thermodynamics. The Massive Online Open Course (MOOC) is provisional titled: ‘Energy – Using it and Losing it: Real-World Thermodynamics for Beginners’ and will be offered through FutureLearn to a worldwide audience. The video clips, which essentially replace the traditional 50-minute lecture, will be about 3 minutes long recognising that this is the longest time period that many young people will focus uninterrupted on a single activity.

Last week was the start of a new academic year in which we have been instructed to use newly-installed software and hardware to record or, in the new terminology, video-stream all of our lectures. The ‘streamed’ lectures will be made available online for students to watch at anytime during the academic year. All of this is happening when attendance at lectures is falling, which leads me to wonder whether these events represent the death knell of the traditional university lecture?

We have known for sometime that people’s maximum attention span was typically fifteen to twenty minutes and yet lectures have remained stubbornly at 50 minutes duration with many double lectures timetabled. Considerable ingenuity, imagination and energy is needed to deliver lectures that engage students for these time periods (see Engage Engineering for tips on how to do this). So it should come as no surprise that many lectures are half empty when students have alternatives such as short video clips available online, streamed lectures that can be fast-forwarded over the boring bits or rewound to repeat important sections, as well as the old-fashioned approach of reading a good textbook and teaching yourself.

Lectures are in many ways a theatrical performance, though factual rather fictional. Theatre has had to evolve and adapt in order to survive the advent of cinema, television and most recently the internet. In the process, some theatres and drama companies have disappeared. I think the same is likely to happen with the university lecture – some will evolve and adapt, for instance by embracing new technology, but others will disappear as students choose more effective means of acquiring knowledge and understanding.