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 Statistical Learning


Clustering Algorithms: From Start To State Of The Art

#artificialintelligence

It's not a bad time to be a Data Scientist. Serious people may find interest in you if you turn the conversation towards "Big Data", and the rest of the party crowd will be intrigued when you mention "Artificial Intelligence" and "Machine Learning". Even Google thinks you're not bad, and that you're getting even better. There are a lot of'smart' algorithms that help data scientists do their wizardry. It may all seem complicated, but if we understand and organize algorithms a bit, it's not even that hard to find and apply the one that we need. Courses on data mining or machine learning will usually start with clustering, because it is both simple and useful. It is an important part of a somewhat wider area of Unsupervised Learning, where the data we want to describe is not labeled.


Big Data Processing with Apache Spark - Part 4: Spark Machine Learning

#artificialintelligence

This is the fourth article of the "Big Data Processing with Apache Spark" series. Please see also: Part 1: Introduction, Part 2: Spark SQL and Part 3: Spark Streaming. Machine learning, predictive analytics, and data science topics are getting a lot of attention in recent years for solving real world problems in different business domains in several organizations. Spark MLlib, Spark's Machine Learning library, includes several different machine learning algorithms for Collaborative Filtering, Clustering, Classification and other machine learning tasks. In the previous articles in "Big Data Processing with Apache Spark" series, we have looked at what Apache Spark framework is (Part 1), how to leverage the SQL interface to access data using Spark SQL library (Part 2) and real-time data processing & analytics of streaming data using Spark Streaming (Part 3). Compose makes it simple to deploy production-ready databases in minutes in the cloud or on your own servers. In this article, we'll discuss machine learning concepts and how to use Apache Spark MLlib library for running predictive analytics.


Book: Predictive Analytics and Data Mining

@machinelearnbot

Put Predictive Analytics into Action Learn the basics of Predictive Analysis and Data Mining through an easy to understand conceptual framework and immediately practice the concepts learned using the open source RapidMiner tool. Whether you are brand new to Data Mining or working on your tenth project, this book will show you how to analyze data, uncover hidden patterns and relationships to aid important decisions and predictions. Data Mining has become an essential tool for any enterprise that collects, stores and processes data as part of its operations. This book is ideal for business users, data analysts, business analysts, business intelligence and data warehousing professionals and for anyone who wants to learn Data Mining. You'll be able to: 1. Gain the necessary knowledge of different data mining techniques, so that you can select the right technique for a given data problem and create a general purpose analytics process.


Home Depot Product Search Relevance, Winners' Interview: 1st Place Alex, Andreas, & Nurlan

@machinelearnbot

A total of 2,552 players on over 2,000 teams participated in the Home Depot Product Search Relevance competition which ran on Kaggle from January to April 2016. Kagglers were challenged to predict the relevance between pairs of real customer queries and products. In this interview, the first place team describes their winning approach and how computing query centroids helped their solution overcome misspelled and ambiguous search terms. Andreas: I have a PhD in Wireless Network Optimization using statistical and machine learning techniques. I worked for 3.5 years as Senior Data Scientist at AGT International applying machine learning in different types of problems (remote sensing, data fusion, anomaly detection) and I hold an IEEE Certificate of Appreciation for winning first place in a prestigious IEEE contest.


Regression Analysis Tutorial and Examples Minitab

#artificialintelligence

I've written a number of blog posts about regression analysis and I've collected them here to create a regression tutorial. This tutorial covers many aspects of regression analysis including: choosing the type of regression analysis to use, specifying the model, interpreting the results, determining how well the model fits, making predictions, and checking the assumptions. At the end, I include examples of different types of regression analyses. If you're learning regression analysis right now, you might want to bookmark this tutorial! Before we begin the regression analysis tutorial, there are several important questions to answer.



On the estimation of initial conditions in kernel-based system identification

arXiv.org Machine Learning

Recent developments in system identification have brought attention to regularized kernel-based methods, where, adopting the recently introduced stable spline kernel, prior information on the unknown process is enforced. This reduces the variance of the estimates and thus makes kernel-based methods particularly attractive when few input-output data samples are available. In such cases however, the influence of the system initial conditions may have a significant impact on the output dynamics. In this paper, we specifically address this point. We propose three methods that deal with the estimation of initial conditions using different types of information. The methods consist in various mixed maximum likelihood--a posteriori estimators which estimate the initial conditions and tune the hyperparameters characterizing the stable spline kernel. To solve the related optimization problems, we resort to the expectation-maximization method, showing that the solutions can be attained by iterating among simple update steps. Numerical experiments show the advantages, in terms of accuracy in reconstructing the system impulse response, of the proposed strategies, compared to other kernel-based schemes not accounting for the effect initial conditions.


Blind system identification using kernel-based methods

arXiv.org Machine Learning

We propose a new method for blind system identification. Resorting to a Gaussian regression framework, we model the impulse response of the unknown linear system as a realization of a Gaussian process. The structure of the covariance matrix (or kernel) of such a process is given by the stable spline kernel, which has been recently introduced for system identification purposes and depends on an unknown hyperparameter. We assume that the input can be linearly described by few parameters. We estimate these parameters, together with the kernel hyperparameter and the noise variance, using an empirical Bayes approach. The related optimization problem is efficiently solved with a novel iterative scheme based on the Expectation-Maximization method. In particular, we show that each iteration consists of a set of simple update rules. We show, through some numerical experiments, very promising performance of the proposed method.


Where does the Sigmoid in Logistic Regression come from?

#artificialintelligence

Note: The title of this post is circular. But I use/abuse it because of the post linked below. I noticed on the Hacker News front page (and via multiple reshares on twitter), a discussion on why logistic regression uses a sigmoid. The article linked in the story talks about the log-odds ratio, and how it leads to the sigmoid (and gives a good intuitive plug on it). However, I think that the more important question is – Why do you care about log-odds?


How To Prepare Your Data For Machine Learning in Python with Scikit-Learn - Machine Learning Mastery

#artificialintelligence

Many machine learning algorithms make assumptions about your data. It is often a very good idea to prepare your data in such way to best expose the structure of the problem to the machine learning algorithms that you intend to use. In this post you will discover how to prepare your data for machine learning in Python using scikit-learn. How To Prepare Your Data For Machine Learning in Python with Scikit-Learn Photo by Vinoth Chandar, some rights reserved. You almost always need to preprocess your data.