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Book
The gradient test
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ISBN: 0128036133 012803596X 9780128036136 9780128035962 Year: 2016 Publisher: Amsterdam


Book
Regression analysis with Python : learn the art of regression analysis with Python
Authors: ---
ISBN: 1783980745 9781783980741 1785286315 9781785286315 Year: 2016 Publisher: Birmingham : Packt Publishing,

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Abstract

Learn the art of regression analysis with Python About This Book Become competent at implementing regression analysis in Python Solve some of the complex data science problems related to predicting outcomes Get to grips with various types of regression for effective data analysis Who This Book Is For The book targets Python developers, with a basic understanding of data science, statistics, and math, who want to learn how to do regression analysis on a dataset. It is beneficial if you have some knowledge of statistics and data science. What You Will Learn Format a dataset for regression and evaluate its performance Apply multiple linear regression to real-world problems Learn to classify training points Create an observation matrix, using different techniques of data analysis and cleaning Apply several techniques to decrease (and eventually fix) any overfitting problem Learn to scale linear models to a big dataset and deal with incremental data In Detail Regression is the process of learning relationships between inputs and continuous outputs from example data, which enables predictions for novel inputs. There are many kinds of regression algorithms, and the aim of this book is to explain which is the right one to use for each set of problems and how to prepare real-world data for it. With this book you will learn to define a simple regression problem and evaluate its performance. The book will help you understand how to properly parse a dataset, clean it, and create an output matrix optimally built for regression. You will begin with a simple regression algorithm to solve some data science problems and then progress to more complex algorithms. The book will enable you to use regression models to predict outcomes and take critical business decisions. Through the book, you will gain knowledge to use Python for building fast better linear models and to apply the results in Python or in any computer language you prefer. Style and approach This is a practical tutorial-based book. You will be given an example problem and then supplied with the relevant code and how to walk through it. The details are provided in a step by step manner, followed by a thorough explanation of the math underlying the solution. This approach will help you leverage your own data using the same techniques.


Dissertation
An analysis of the impact of connection time on air passenger demand
Authors: --- --- ---
Year: 2016 Publisher: Liège Université de Liège (ULiège)

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Abstract

Although air itinerary demand has been subjected to intensive research for years, few studies specifically analyse the impact on passenger demand of connection time. It is traditionally assumed that passengers prefer to minimise the elapsed time of their trips and hence, connection time. However, it has since been demonstrated that passengers actually avoid short connections.
This paper therefore aims at challenging the assumption that passengers want to minimise connection times. A linear regression model describing air itinerary demand is developed to this end. The issue is then analysed in greater depth by adding new dimensions to the discussion. More particularly, the combined impacts on demand of connection time and trip purpose, departure time of day, past flight on-time performance and flight duration are studied.
Results suggest that aversion to risk of misconnection and discomfort associated with the necessity to rush imply a lower demand for short connection times. Demand appears to be nonlinear, increasing for additional minutes of connection time above the minimum connection time and decreasing afterwards. Results also indicate that the impact of connection time on demand varies depending on the analysed trip and passenger characteristics.
This paper is divided into six parts. It begins with an introduction of the context of the study and the definition of several research questions. An overview of the scientific literature on air itinerary demand is then provided with a focus on connection time analysis. After that, the analytical framework is presented and the methodology followed to build the final linear regression model is detailed. This model is then used to analyse connection time. Results are discussed and interpreted in the fifth chapter and the final chapter, besides summarising key findings and contributions, provides some recommendations based on these findings.


Book
The Birnbaum-Saunders distribution
Author:
ISBN: 0128038276 0128037695 9780128038277 9780128037690 Year: 2016 Publisher: Amsterdam, [Netherlands] : Academic Press,


Book
Is Random Forest a Superior Methodology for Predicting Poverty? : An Empirical Assessment
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Year: 2016 Publisher: Washington, D.C. : The World Bank,

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Random forest is in many fields of research a common method for data driven predictions. Within economics and prediction of poverty, random forest is rarely used. Comparing out-of-sample predictions in surveys for same year in six countries shows that random forest is often more accurate than current common practice (multiple imputations with variables selected by stepwise and Lasso), suggesting that this method could contribute to better poverty predictions. However, none of the methods consistently provides accurate predictions of poverty over time, highlighting that technical model fitting by any method within a single year is not always, by itself, sufficient for accurate predictions of poverty over time.


Book
Applied regression : an introduction
Author:
ISBN: 9781483381473 1483381471 1483396770 1483381463 148338148X Year: 2016 Volume: 22 Publisher: Thousand Oaks, California : Sage,


Book
Applied regression and modeling : a computer integrated approach
Author:
ISBN: 1631573306 Year: 2016 Publisher: New York, New York (222 East 46th Street, New York, NY 10017) : Business Expert Press,

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This book creates a balance between the theory, practical applications, and computer implementation behind Regression--one of the most widely used techniques in analyzing and solving real world problems. The book begins with a thorough explanation of prerequisite knowledge with a discussion of Simple Regression Analysis including the computer applications. This is followed by Multiple Regression--a widely used tool to predict a response variable using two or more predictors. Since the analyses of regression models involve tedious and complex computations, complete computer analysis including the interpretation of multiple regression problems along with the model adequacy tests and residual analysis using widely used computer software are presented. The use of computers relieves the analyst of tedious, repetitive calculations, and allows one to focus on creating and interpreting successful models. Finally, the book extends the concepts to Regression and Modeling. Different models that provide a good fit to a set of data and provide a good prediction of the response variable are discussed. Among models discussed are the nonlinear, higher order, and interaction models, including models with qualitative variables. Computer analysis and interpretation of computer results are presented with real world applications. We also discuss all subset regression and stepwise regression with applications. Several flow charts are presented to illustrate the concepts. The statistical concepts for regression, computer instructions for the software-- Excel and MINITAB--used in the book and all of the data files used can be downloaded from the website link provided.


Book
Adaptive regression for modeling nonlinear relationships
Authors: ---
ISBN: 3319339443 331933946X Year: 2016 Publisher: Cham : Springer International Publishing : Imprint: Springer,

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This book presents methods for investigating whether relationships are linear or nonlinear and for adaptively fitting appropriate models when they are nonlinear. Data analysts will learn how to incorporate nonlinearity in one or more predictor variables into regression models for different types of outcome variables. Such nonlinear dependence is often not considered in applied research, yet nonlinear relationships are common and so need to be addressed. A standard linear analysis can produce misleading conclusions, while a nonlinear analysis can provide novel insights into data, not otherwise possible. A variety of examples of the benefits of modeling nonlinear relationships are presented throughout the book. Methods are covered using what are called fractional polynomials based on real-valued power transformations of primary predictor variables combined with model selection based on likelihood cross-validation. The book covers how to formulate and conduct such adaptive fractional polynomial modeling in the standard, logistic, and Poisson regression contexts with continuous, discrete, and counts outcomes, respectively, either univariate or multivariate. The book also provides a comparison of adaptive modeling to generalized additive modeling (GAM) and multiple adaptive regression splines (MARS) for univariate outcomes. The authors have created customized SAS macros for use in conducting adaptive regression modeling. These macros and code for conducting the analyses discussed in the book are available through the first author's website and online via the book’s Springer website. Detailed descriptions of how to use these macros and interpret their output appear throughout the book. These methods can be implemented using other programs. Provides insight into modeling of nonlinear relationships and also justifications for when to use them, thereby providing novel insights about relationships Addresses not only adaptive generation of additive models but also of models based on nonlinear interactions Discusses adaptive modeling of variances/dispersions as well as of means Highlights both univariate and multivariate outcomes, rather than solely univariate outcomes.

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