When Variable Reduction Doesn’t Work
Posted by Armando Brito Mendes | Filed under estatística, materiais para profissionais
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Um bom exemplo de como os procedimentos habituais nem sempre funcionam
Summary: Exceptions sometimes make the best rules. Here’s an example of well accepted variable reduction techniques resulting in an inferior model and a case for dramatically expanding the number of variables we start with.
of the things that keeps us data scientists on our toes is that the well-established rules-of-thumb don’t always work. Certainly one of the most well-worn of these rules is the parsimonious model; always seek to create the best model with the fewest variables. And woe to you who violate this rule. Your model will over fit, include false random correlations, or at very least will just be judged to be slow and clunky.
Certainly this is a rule I embrace when building models so I was surprised and then delighted to find a well conducted study by Lexis/Nexis that lays out a case where this clearly isn’t true.
Tags: data mining, problemas
Chance Lecture Video Series
Posted by Armando Brito Mendes | Filed under estatística, lições, materiais ensino
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Bons vídeos ainda q antigos de alguns temas em probabilidade e estatística
This page has links to:
The talks featured below require the latest version of the Realplayer software. More particularly, they require that the “Realplayer plug-in” be installed in the plug-ins folder of your browser. If you do not have the “Realplayer plug-in,” a free version of Realplayer (which includes the plug-in) is available here
Tags: inferência, problemas
IFORS Education Resources Project
Posted by Armando Brito Mendes | Filed under estatística, Investigação Operacional, SAD - DSS, software
portal com materal sobre Investigação Operacional, otimização e SADs
Welcome to the International Federation of Operational Research Societies (IFORS) Education Resources Project
- Main Page (19:13, 3 December 2013)
- Biased Random-Key Genetic Algorithms: A Tutorial (21:57, 2 December 2013)
- The Discrete Event System Specification Formalism (19:59, 2 December 2013)
- Urban Operations Research (01:36, 2 December 2013)
- Stochastic Models for Design and Planning (01:34, 2 December 2013)
- Queueing Theory Books Online (01:31, 2 December 2013)
- Practical Queueing Theory in Java (01:31, 2 December 2013)
- Explore Queueing Theory for Scheduling, Resource Allocation and Traffic Flow Applications (01:28, 2 December 2013)
- Stochastic Processes Course Notes (01:26, 2 December 2013)
- Test Problems for Non-Linear Programming (01:23, 2 December 2013)
- OR Notes: Separable Programming (01:21, 2 December 2013)
- OR Notes: Non-Linear Programming (01:20, 2 December 2013)
Tags: decisao em grupo, decisão médica, otimização, previsão, problemas, programação em folha de cálculo, software de otimização, software estatístico
Dictionary of Numbers
Posted by Armando Brito Mendes | Filed under estatística, matemática, materiais para profissionais
um dicionário q associa factos a números
is an award-winning Google Chrome extension that tries to make sense of numbers you encounter on the web by giving you a description of that number in human terms. Like a dictionary describes words you don’t know in terms you do, Dictionary of Numbers puts quantities you’re unfamiliar with in terms you can understand. Because “8 million people” means nothing, but “population of New York City” means everything.
Tags: belo, Estat Descritiva, problemas
Punk Rock Operations Research
Posted by Armando Brito Mendes | Filed under Investigação Operacional, matemática, materiais ensino, materiais para profissionais
Um blogue com modelos e aplicações de técnicas de IO
Punk Rock Operations Research by Laura A. McLay is licensed under a Creative Commons Attribution-NonCommercial 3.0 United States License
Tags: intro IO, otimização, previsão, problemas
VideoLectures.Net
Posted by Armando Brito Mendes | Filed under estatística, Investigação Operacional, matemática, materiais ensino
montes de vídeos sobre imensos temas
VideoLectures.NET is a free and open access educational video lectures repository. The lectures are given by distinguished scholars and scientists at the most important and prominent events like conferences, summer schools, workshops and science promotional events from many fields of Science. All lectures, accompanying documents, information and links are systematically selected and classified through the editorial process taking into account also users’ comments.
Tags: data mining, grafos, inferência, inquéritos, intro IO, otimização, previsão, problemas
Linear Optimization with Applications
Posted by Armando Brito Mendes | Filed under Investigação Operacional, matemática, materiais ensino
Uma boa página sobre programação linear
- Introduction & Summary
- Optimization-Modeling Process
- Ingredients of Optimization Problems and Their Classification
- Linear Programming (LP)
- Dual Problem: Its Construction and Economics Implications
- Learning From the Optimal Strategy
- Goal-Seeking Problem
- Exercise Your Knowledge to Enhance What You Have Learned (PDF)
- Linear Optimization Solvers to Download (free-of-charge),
Tags: otimização, problemas
The Science of Better
Posted by Armando Brito Mendes | Filed under Investigação Operacional
what is O.R.?
In a nutshell, operational research (O.R.) is the discipline of applying advanced analytical methods to help make better decisions.
Tags: análise de sistemas, intro IO, otimização, problemas
