Ganesh Swami

It’s only the second week of classes, and I’m already falling behind my reading schedule.

The week started out with some heavy mathematical optimization tricks in my optics class. Based on Fermat’s principle, we did some trajectory tracing problems. The path of a light ray can be traced through any arbitrary medium of varying refractive index.

L is the optical path length, n is the refractive index of the medium which is a function of the position. I like how transferable the solution is to other problem domains.

The other physics course has quickly dived into the depths of heavy theoretical mathematics. This section of the course deals with functions with complex arguments. The prof. kept stressing the point that Riemann sheets are very elegant – I wonder if he was being sarcastic. This becomes very ugly for branch cuts of multi-valued complex functions. Anyone who has used a symbolic program like Maple knows that these programs miss obvious (to a human) simplifications. Read W. Kahan’s “Branch Cuts for Complex Elementary Functions” (in Iserles and Powell (eds.), State of the Art of Numerical Analysis, 1987) to see how zero’s sign bit changes the way we think about math.

My other course Financial Accounting is the most interesting this semester. Just keeping up with the lingo is a full-time job. Operating margin, profit margin, marginal cost, minority interest, etc. The assignments for this course are to be submitted through an online system. I think this is very good – instant feedback. Below is a picture of a balance sheet I completed. Ofcourse, I couldn’t do any Enron-style accounting….(signified by all green.)

Some time back, a colleague introduced me to del.icio.us. Ever since, I’ve been hooked. If you’ve been to the portal section of this website, you’ll see a list of links that I frequently use. This includes links to course home pages, libraries and commonly read websites (that can’t be aggregated.) This list is dynamically generated from specially tagged links on del.icio.us.

The biggest advantage for me is that I don’t have to mess around with the hypertext behind that page. I made the page static as these links don’t change that often. The page is generated by a 10 line script that I wrote in PHP using the MagpieRSS library.

There’s also an Emacs client for del.icio.us. I haven’t used it myself, but the list of features look very tempting.

I’m always looking for ideas on further integration between my website and del.icio.us, so if you think of something, drop me a line.

I recently came across a strategy for stock trading. I won’t promise to make you rich overnight, but I found this trick to be very interesting. The basic idea is to buy the stocks of ten companies from the Dow Jones Industrial Average (DJIA) with the highest dividend yields. Dividend yields are defined as the ratio between the dividends distributed and the stock price. Hold them for a year, and re-evaluate your position after one year. You might have to replace lower performing stocks with newer ones to re-balance your portfolio.

From a modeling perspective, the yield is an inverse indication of the stock’s popularity. High yields typically mean undervalued stocks. Hopefully, by the end of the year, these companies have bounced back increasing stock price and decreasing yield. Of course, as with any investing strategy, the effectiveness scales inversely with the number of people following the strategy. This could explain the decrease in popularity and overall poor performance of this strategy in recent years.

That is all.