Once more unto the breach!

"In peace there's nothing so becomes a man

As modest stillness and humility."

That is what Shakespeare says in Henry V. Does a modest stillness and humility help us survive in today's academic world? I am informed that  it does not. Hence the return to the blog and website.  Let us see how it goes. 

Please have a look also at my reactivated website https://sites.google.com/view/mapcodecomputing/home.

My thanks to our student Mr. Krishna Singh for his help in reactivation of my website and blog. Also to my colleague Mr. K. Sudheendra.

Posting this after a hiatus of more than two years. Have been studying Labelled Transition Systems which is the work of Milner's students and associates. More recently  the work of Paulo Tabuada on labelled transition systems with output. As noted in this blog earlier this model generalizes the models of Knuth, Dijkstra, and Chandy and Misra. A good candidate to explore in the study of formal methods in computer science and software engineering.

The Technology for Education 2012 conference was held  in IIIT, Hyderabad during 18 July to 20 July 2012.  Dr. Shailey Minocha presented two pre-conference tutorials, one on "Evaluating the Effective Use of Emerging Technologies in Education"and one on "Using Social Media Technologies for Teaching and Research".

I will try to say something here about her  second tutorial. It was very comprehensive and at the same time very detailed. She introduced the essential ideas of social media and spoke about their advantages and disadvantages from the perspective of students, educators, and institutions. She talked about ethical considerations, digital scholarship and digital professionalism. She gave advice on how to and how not to maintain a digital presence and stressed the importance of maintaining a distinction between personal and professional presences. She spoke about ethical  considerations to be kept in mind and what digital scholarship and digital professionalism mean.She explained in detail how to use new technologies. Apart from the well known email, Skype, Google chat and texting,
she described how researchers can use wikis,  blogs, Second Life, Twitter, Ning, Facebook, Elluminate, Cloudworks, Social Learn, Mendeley, Delicious, ScoopIt, Slideshare, Dropbox and some other lesser known technologies.

You need to wait for the release next month of her "Handbook of Social Media for Early Career Researchers and Supervisors" to find out more details Meanwhile you could browse her website http://mcs.open.ac.uk/sm5

Three things I learned from my colleagues at TCS

1. I have spent a lifetime studying and teaching mathematics of many different kinds. When I started working with Prof. Kesav Nori's group at Business Systems and Cybernetics Centre, my understanding was that one could make a mathematical model of a system by writing down the differential equations concerned and analysing them. Much as we do in the prey-predator model. However from Prof. P.N.Murthy I learned that for a any social system that we set out to study initially we do not even know which are the independent and which are the dependent ones. We do not know how the dependent ones vary with the independent ones and which are the positive feedback loops and which are the negative feedback loops. So it is necessary for us first to form this understanding by appropriate "cybernetic influence diagrams". A detailed exposition of these is given here.

2. I thought that my model for mathematical computer science was very simple and easy to understand. However I was puzzled that there was not much eagerness to study it. This despite the fact that all my colleagues were doing difficult work and dealing with complex analytical and logical reasoning and all of them were engineers. Then one day talking to Swami I realized that the resistance was not to my method of approach to computer science but really only to the mathematical notation I was using. It was the abstract formulation and the use of symbols that was making the ideas opaque. So I felt that I had to find a different way of expressing my ideas that engineers could work with, not losing the rigour of expression.

3. What language should I use if not  the mathematical language? I saw Doji and Ravi approaching the organizational problems they were dealing with by looking to the manufacturing domain for inspiration. So then can I think of a way of designing an algorithm so that it is similar to  designing an artefact in a factory? Thus was I led to the Management Model of Computing that is explained here. You need to create an account and then go to the pages on Computational Thinking.

Computing with Multiple Discrete Flows

The nearest in the literature to the model of mapcode is the UNITY work of Chandy and Misra. While mapcode considers a set X together with a map F: X -> X, UNITY considers several maps acting on X. The result is a fascinating theory of parallel and distributed programming. UNITY stands for Unbounded Nondeterministic Iterative Transformation theorY. We interpret this theory purely in mathematical terms as with mapcode. Our first paper on this subject dealing with standard sequential programs that are expected to terminate in a finite number of steps and return a value is given in our paper Computing with Multiple Discrete Flows.

Quantum Formalism and Information Retrieval

In 2004 Keith van Rijsbergen published a book with the title "The Geometry of Information Retrieval". In this book he suggested that quantum formalism can be successfully used to model some of the problems of Information Retrieval. This book was given to me by my colleague Dr. Vasudev Varma of the International Institute of Information Technology, Hyderabad with a request to offer a course on the ideas of the book.

Last semester I did so. I had hoped for senior students who already knew Linear Algebra, but none of those who joined was clear about the basics of Linear Algebra. So almost the entire course was spent teaching them linear algebra and then some of the basics of quantum terminology. At the end I was left with only one class to explain how quantum formalism relates to Information Retrieval.

There was another difficulty. The book of Rijsbergen used the physics notation for the inner product according to which it is the second term of the inner product that is linear and the first term antilinear. The mathematics text books have the opposite convention. So there was a need to rewrite the basics of Hilbert Space theory in the mathematical tradition but using the physics notation. This is now summarized in a document and attached here as Review of Hilbert Space Theory. Also attached is my write-up on the Hilbert Space Model for Information Retrieval.

Fifth meeting of the Formal Methods Reading Group

Chapter 3 was concluded by me and Dr. Venkatesh began discussing the concept of concurrency in Chapter 4. My notes of the part of my lecture are here as FMRG-5. Dr. Venkatesh will also put up his notes soon at the wiki of http://enhanceedu.iiit.ac.in. You may send mail to choppell@gmail.com for the login name and password that are necessary to access the wiki.