Cross Entropy
The cross entropy between two probability distributions over the same underlying set of events measures the average number of bits needed to identify an event drawn from the set. The […]
Author Archives: Kostas Hatalis
Massive Opportunity
Artificial Intelligence is the single most important technology in my opinion we’re developing not only in this decade but in the 21st century. Once we realize a level of AI, […]
Softmax Function
The soft-max function is a generalization of the logistic function that normalizes a N-dimensional vector of arbitrary real values to a range of (0,1). It is used to obtain the […]
Bag of Words
The bag-of-words model is a word representation used in natural language processing. A text such as a sentence or a document is represented as the bag of its words, disregarding […]
Swarm Optimization
Particle swarm optimization (PSO) is a swarm intelligence based computational technique that can be used to find an approximate solution to a problem by iteratively trying to search candidate solutions […]
Bayesian Decision Theory
Bayesian Decision Theory (BDT), also known as Bayesian Hypothesis Testing and Bayesian inference, is a fundamental statistical approach that quantifies the tradeoffs between various decisions using distributions and costs that […]
Random Walk Processes
A random walk is defined as a process where the current value of the variable is composed of the past value plus white noise. A white noise process is a […]
Likelihood-Ratio Test
In statistics, a likelihood function is a function of the parameter values, , given outcomes . The likelihood is equal to the probability of those observed outcomes given those parameter […]
Laws of Forecasting
In my study of time series analysis I have summed up three important laws for forecasting. We assume that the future will behave like the past. Even if we know […]
Simple Algo Trading
An algorithm is a specific set of clearly defined instructions aimed to carry out a task or process. Algorithmic trading, also known as automated trading, black-box trading, or simply algo-trading, is the […]
Mad Mind of a PhD Student 