A friend in Australia was contemplating a move to Singapore and asked me about my experience. We discussed a range of topics — housing, transport, food, work environment, etc — and I’m sharing in this blog piece some practical tips and observations about Singapore while they are still fresh in my mind. Here’s the email to my friend: “The first … More A Guide to Moving to Singapore
Have you noticed more and more shopping malls are offering free wifi? That appears at first sight a puzzling investment, especially in this day and age where everyone has data subscription on their smart phones. But then you start noticing that it’s quite hard to get good signal coverage from your telcos inside those malls that offer … More Data Acquisition for Shopping Research
Before – We came home to this garden after 3.5 years away. During – We decided to do a little project. It took quite a bit longer than we anticipated… After But I think it’s all worth it. Material cost: $1 per paver. Labour cost: $85 per squared meter. A pair of happy birds: Priceless
I spent five years working as a consulting data scientist for EMC/Pivotal. In that time, I have had a chance to help several organisations in Asia Pacific set up their data science practices. Most of these organisations are large traditional enterprises with entrenched corporate practices. In each case, I must admit I wasn’t as successful … More Building a Data Science Practice
Outlier detection is an important tool in risk modelling. In the context where data are distributed across multiple locations and data privacy is a concern, we need to start looking at privacy-preserving techniques for doing outlier detection. Linked here is a tutorial introduction to this topic I recently prepared. Privacy Preserving Outlier Detection The presentation … More Privacy Preserving Outlier Detection: A Tutorial
Suppose we have two entities P1 and P2 and P1 holds a training dataset and P2 holds a dataset . (Assume for simplicity that the x’s all have the same dimension and each y is a real number. We’ll deal with the case when P1 and P2 measure different sets of variables in a different … More Privacy Preserving Support Vector Machines: A Simple Version
I woke up on New Year’s Eve to the sight of an owl perching on top of my air-conditioner condenser unit outside. Now, I’m used to seeing all kinds of wild lives in the backyard of my Canberra home, but a visit from the Wise in my Singapore apartment, which is a stone’s throw away … More An Owl in the House
Most modern big data platforms support parallel execution of (non-native) code written in languages like Python, Perl, R, and Java. On Greenplum and HAWQ, two massively parallel relational database systems, these facilities come in the form of PL/Python, PL/Perl, PL/R, and PL/Java, which are inherited from PostgreSQL. These programming facilities are useful for a range … More PL/Fortran and PL/C++ on PostgreSQL and Greenplum
Most mechanical watches operate at an accuracy of +/- 12 seconds per day. A COSC-certified chronometer, which is what you can expect to get from quality Swiss watch makers like Omega, operates at -4/+6 seconds per day. For most practical uses, these are perfectly acceptable accuracy measures. To get anything more accurate from a mechanical … More Spring Drive 9R15 Movement Accuracy
While doing a project involving survival analysis a while back, I learned a useful technique for reducing survival analysis to binary regression. The following discussion is adapted from Chapter 7 of Survival Analysis by David G. Kleinbaum. To illustrate how the technique works, consider a small data set with three subjects. Subjects 1 and 3 are … More Survival Analysis using Logistic Regression
