Showing posts with label analysis. Show all posts
Showing posts with label analysis. Show all posts

Thursday, January 23, 2014

Structural Engineering, Computers and Commitment


‘[W]ith the ready availability of powerful computers and highly efficient structural analysis programs, an engineer possessing sound knowledge of structural form and behavior should be able to device and analyze a structure to suit a building of almost any conceivable irregularity’ From the book Tall Building Structures – Analysis and Design by Bryan Stafford Smith and Alex Coull
When I read the above lines in a book on analysis and design of tall buildings, I was transported to seventh heaven. It was a “Beam me up, Scotty…” moment.
The sentiments espoused or implied in the above is what I have beaten my breast about to recent entrants to the profession of structural engineering, of which I consider myself to be a part. But, for whatever reasons, what I say comes off as demagoguery or a harangue, easy to be dismissed or at least brushed under the carpet. When I assemble a group of youngsters to explain certain fundamentals that have either skipped them or they have already forgotten, their reaction is a Grand Canyonesque yawn. “We’ve been there, done that”.
But, when shown that even if they had known what I am telling them, it is time for a recap, they tend to feel I am talking down to them. Rest assured I am not spending time, mine and theirs, to show I am one up on them. It is just that they have a duty to their profession, particularly if they want it to help them keep themselves fed, clothed and sheltered, and that commitment flows through these basics.
The above is the context in which I felt elated upon reading the opening quote of this post.
I want to parse the quote, phrase by phrase. First, I take up, “the ready availability of powerful computers and efficient structural analysis programs.” I am very happy that the changes in how structural engineering is being practiced from a couple of decades ago are acknowledged; very few, if any, engineers use their earlier day’s bread and butter, the slide rule, or even calculators. They have their Excel sheets, besides the specialist software. But …
Yes, there is a twist to my feeling happy. Yes, I want the computers and software to be available to the engineers, but, not too readily. I am neither a Luddite nor an old fogie who feels most comfortable with the tools of yesteryears. I have tried to, and have succeeded to some extent, to keep myself abreast of the new tools of my trade. I appreciate how things have made the life of a structural engineer easy. I do not begrudge that the youngsters are a million times better and faster than I am at working the software. This is Father Time working his way and I respect him for that.
But, to use an old phrase, before the time of GUI, “GIGO” – garbage in garbage out. Perhaps with GUI, the “garbage in” phase has been taken a level deeper. It is not the numbers you input into the computer that nowadays spews out garbage. Rather it is the model you have created that does it. The model is in danger of carrying much less fidelity to what the engineer wants to do, but he is not aware of this disconnect.
I blame the “ready availability” part of the phrase. The 3-D model on the screen overwhelms the engineer instead of illuminating her ideas. The siren song of accelerated output does not fully compensate for the advantages of comprehension. The “readiness” aspect should factor in how ready the engineer is in comprehending the structure and her work.
This leads me to the next phrase I want to focus on: “possessing sound knowledge of structural form and behavior”. In structural engineering the form of a structure plays a major role in how it behaves. Understanding this interrelation is what I would call “comprehension”. So, we now come to the preparedness of the engineer. During studies for graduation, the engineer is taught no more than the truly basics of her profession. When he comes into the field he is deluged with details that he had not of heard of before. Setting things right demands commitment from the graduate.
It goes beyond doing your job well in the profession. It depends on using one’s own time – the time for which one is not paid – to take an interest in the chosen field. I know a few engineers who exemplify this attitude and also aptitude; but, alas they are far too few if the profession has to develop in the country. Such extra-curricular, for want of a better word, commitment is what gives the engineer a “sound knowledge of structural form and behavior”.
This is what I tried to infuse in one of my lectures wherein I showed what looks like a slender column but the designer choosing to call it a shear wall. I asked why. This was a classic case of a form and behavior fusing with each other, the name giving the clue for the fusion.
The next phrase, “should be able to device and analyze a structure.” Note the level of commitment, a mere “should be able to.” That is, sound knowledge alone may not be sufficient. There is something called intuition. There is also value to real life experiences, if only the engineer is equipped to draw parallels.
This I tried to exemplify in one of my brief presentations, on “punching shear”. I took the shards from a punching machine and showed that all of them were cupped rather than flat. I explained why, going beyond the obvious fact that the punching surface was concave outwards, and also its relevance to the topic under discussion. But there were few takers.
The engineer has to be able to visualize the forces coming onto the structure and “feel” the structure responding. No amount of immersing oneself in equations or clicking on the icons is going to help in this. One has to eat and sleep with the structure and in a manner of speaking, mate with it. This obviously takes time. One has to court the profession, get married and then feel fulfilled.
Yes, all these thoughts coursed through my mind as I read the paragraph. Now, you may agree why I felt so elated.
Raghuram Ekambaram
P.S. I have written the above from the perspective of a structural engineer. However, I suspect, one can draw parallels in any field of engineering.



Monday, June 08, 2009

Education enumerated, not evaluated

How does one measure education? By numbers, it would seem. As an engineer I must be most comfortable with this but I am not. I think effectiveness of education cannot be measured solely by numbers.

I started thinking along these lines when I read two articles, Chennai No. 1 in CBSE exams and A jolly good show by Delhi in Class X exams, both in The Hindu of May 30, 2009. If you went through these pieces, I am sure you would be confounded by the plethora of numbers, many of them on a comparative scale. The first thought that should come to your mind is, “They are not talking about education.” But, that is what they ostensibly think they are doing.

An increase of 1.76 pass percentage points in Class X exams in 2009 vis-à-vis 2008, and if you are a sucker for details, from 87.08 to 88.84%. So precise. Does this mean that students have become better over the course of the year by that percentage, in some combinations of hard work, intelligence, sheer luck? Your guess is as good as mine. There is a drop of 29 candidates, from 4,503 to 4,474, in the metric of “above 90% scorers” in Delhi. The total number should be in the tens of thousands. This is a fit case for apoplexy, is it not?

The topper scored 98.8% whereas below him, six students were bunched up at 98.6% (98.7% went unrepresented and unrepented). So, the topper is a genius and others are duds. The overall pass percentage has Chennai at the top, with Ajmer, Allahabad, Panchkula, Delhi and Guwahati trailing, in the order. Never mind that the comparisons are between oranges and apples. CBSE is just one of a number of systems, including the state board of education, in Chennai and it is possible that an implicit selection process is working, of above average achievers into CBSE in Chennai. In Delhi, CBSE is the only game in town. Will this difference not affect the numbers in the aggregate? Even without knowing the details I would venture to guess, yes. Then, does the comparative statement carry any meaning? No.

If anything meaningful at all can be gleaned from such numbers, it will be in a trend, to be discerned over a longer period, say a decade. There indeed is a trend, pass percentage of girls higher than that of boys, seemingly having been established over the “past few years”. Yes, this data deserves to be scrutinized in depth and the trend analyzed.

This year, the population of Class X whose results we are discussing is a veritable pool of budding social scientists. 1,770 candidates, nearly thrice the number of the class of 2008, got a “perfect 100” in Social Science. But, look at science, only six achieved “centums” (100/100) this year as against 287 last year. So, what do we conclude? Two years from now, all the social science courses in colleges will be deluged and the science curricula courses will go begging. A dismal scenario.

Not so fast. You see, there are sort of apologists for this “dismal” (as though 99/100 in science is something to sneeze at) performance of students in science. “One three mark question in the Science theory paper was out of syllabus,” “there was ambiguity in some questions in the 20-mark multiple choice questions of the practicals,” and “for the first time, the MCQ [do not ask me] paper for Class X was based on a list of experiments from Class X as well as Class IX syllabus.”

So, students do not study the subject but only the syllabus. No, I am not asking for an open ended syllabus but peeking minimally out of the syllabus cocoon can be a differentiator; the six versus 287 may be partially explained. If ambiguities are acknowledged how any one could have got full marks? That is, we know for sure that the six students who scored hundred out of hundred reconciled or did not recognize the ambiguity in the exact same way the people who set the papers did. They came out on top in the crap shoot. Ninth is for ninth and tenth is different. Subsequently, tenth is for tenth and eleventh for eleventh, exclusively. So education is pigeonholed into years, no continuity. An array of numbers substitutes meaningful analysis. And, we call this education!

Please hold me back. Otherwise it will be a never ending lament.

Raghuram Ekambaram