- Measure twice, average once - Measurement is all about estimation and there is a theory behind it. The blog sheds some light on what the theory is about.
Article:
- Gödel, Escher, Bach: an Eternal Golden Braid - a pholosophical book by Douglas Hofstadter, with many subjects covered, including what i'm interested, such as artificial intelligence.
- How Many Ways Can You Spell V1@gra?
- Brian Hayes analyzed that an legible variation of Viagra has 1,843,200 possible spellings, by varying Viagra and separating the six letters by five copies of space characters. However, studying the 88,324 emails received, the author identified 113 distinct spellings. Based on the information, the author suspected that the spam scheme was not very sophisticated. It seemed a spelling once has been incorporated into a message, it is mailed out repeatedly over a period of a few months, then gave a rest.
- The techniques used to combat spam are must better known thant the methods of spam senders. Three spam-filtering approaches have been used to train a spam-ham classifier, that is, Bayesian, SVM, and HMM. However, a possible attack to Bayesian filtering, Bayesian poisoning, was discussed but could be defended by frequently retraining the filter.
- Introduction to Estimation Theory - The choice of error criterion and optimization heavily influences the form of estimation procedure. The estimation performance can be considered from three aspects.
- Bias - An estimate is said to be unbiased if the expected value of the estimate equals the true value of the parameter.
- Consistency - An estimate is said to be consistent if the mean-squared estimation error tends to zero as the number of observations becomes large.
- Efficiency - An estimate is said to be efficient if its mean-squared error achieves Cramér–Rao bound.
