Decision Science in Action

Multicollinearity is defined as the linear relationship between two or more independent variables while performing regression analysis between a dependent variables and set of independent variables. Multicollinearity presents a severe problem during regression modelling. Inclusion of independent variables having linear relationship with each other leads to parameter estimation with higher standard error. This in turn leads to inaccurate parameter estimation. Furthermore, due to inaccurate parameters regression model becomes unstable. The unstable models performs badly on the validation and test samples. When model is unstable, its performance deteriorate very fast compared to stable model over the period, though model is scored on the data of sample of same population. In such a situation an analyst must investigate for the multicollinearity, before finalizing the model. Next question is how to investigate and which variable should be kept if some variables are found to ...

Today ‘big data’ has become a buzz word. Everyone is talking about it. Big data are characterized by three attributes, which are high volume, high velocity and high variety. A few researchers also recently proposed "high volatility" as the fourth attribute of big data. We can define big data as the collection of data which are so large, complex and ever growing that they cannot be processed and stored using traditional methods. The size of big data is greater than petabytes. This makes storage of big data very difficult. Examples of the big data are web data, telecom data, sensor data of jet engines, RNA-DNA data etc. The challenges in processing big data led to the development of new technologies such as Hodoop and Map Reduce. People claim that big data can be processed in reasonable time using these technologies. But I have yet to use the above technologies. Hence I cannot judge the efficiency of these technologies. When we deal with any data, then we come across ...

Copying from my own blog @  http://www.gatecounsellor.com/blog/ This law is named after Gordon E. Moore (http://en.wikipedia.org/wiki/Gordon_Moore) who co-founded Intel Corporation to bring revolution in processor industry ultimately leading radical change in life of man kind. Moore’s Law states that  ” Over the history of computing hardware, the number of transistors on integrated circuits doubles approximately every two years”. When I was undergraduate student I remember that I had something called Moore’s Law in most famous and highly recommended book Millaman and Halkias but never tried to understand what’s its significance. I can think of two reasons for  this situation. First topic  was never emphasized in class room teaching and was also not very important for most of exams.  This is in fact a reason many students of Electronics and VLSI do not know it. It was also preferred to understand Transistor/ diode characteristics. The man ...