Linear Regression Models

concentrated phosphoric acid was added to plastic tubes (50 mL capacity) containing the samples and the suspensions were equilibrated by shaking for 30 min at a minimum of 32 rpm before extraction. The parameter settings in the microwave system (Panasonic Model NN-S62 B) were 10 sec and 100 W. The extraction was performed at 49.8 o C ± 2.8 o C). Each sample was placed in the center of the microwave turntable. Once the extraction was completed, the sample was cooled for 5 min before…

concentration and the water disponibility in certain areas demands to plan how to use this water. Based on these points some statistical methods were used as models of regression and timing series, taking Holt-Winters Methodology as a basic tool to model the water consumption withing coming decades. Index Terms: Holt-Winters, Statistical Model, Timing Series, Water Consumption. RESUMO Sabe-se que 97,5% da água disponível na terra é salgada e se encontram em oceanos e mares. Já a …

calórico, atividade de água, microbiologia e características sensoriais das barras de cereais. Os resultados das variáveis respostas foram tratados por análise de regressão múltipla. E foram utilizados no modelo matemático de segunda ordem os termos lineares, quadráticos e de interação, significativos. A aveia pode ser utilizada como ingrediente na elaboração de barras de cereais por apresentar textura, sabor e aparência adequados. O uso de aveia na formulação possibilita produzir barras…

management through a process of continuous improvement. Thus, this research aims to present a practical model for managing procurement, seeking continuous improvement in performance and results of this area. The proposed model is a facilitator to manage punctually the main basic causes of the problem and constitutes a development of the method QC Story, using the statistical technique of Logistic Regression. A case study is developed to demonstrate how QC Story can be conducted and…

and operational models of based-client brand equity presented in the academic literature. This being the alternative to explore the theme: documenting models of brand equity, as well as differences between the conceptual and empirical models of brand equity, through the eyes of the customer. In this context, there arises the following research problem: The existing models in the literature (theoretical and practical) of based-client brand equity can make a measurement model…

inconvenientes do uso de fotomultiplicadoras e detetores de germânio. A calibração em energia do sistema pode ser feita com fontes radioativas emissoras de raios X e gama, o que torna o método absoluto. O valor do kVp é determinado através da regressão linear na faixa final do espectro, de modo a proporcionar, simultaneamente, um bom ajuste da reta e um desvio padrão baixo do valor do kVp. São apresentados resultados de medições feitas com tubos conectados a um gerador trifásico,…

zero consumption level. The potential bias due to this problem is overcome using Heckit and Tobit models for double-log and semi-log specifications, respectively. It is also estimated an Almost Ideal Demand System (AIDS) directly from the sample of families with non-zero consumption – without the correction for the problem of zero consumption – to compare their results with the two previous models and to test the Consumer Theory‟s restrictions. The socio-demographic characteristics…

various workers [10-19] have p roposed methods for the determination of the pore size distribution of microporous solids, such 40 A. Gil, P. Grange~Colloids Surfaces A: Physicochem. Eng. Aspects 113 (1996) 39-50 as molecular sieves. Several models have been p roposed, taking into account the description of t he energetic heterogeneity of solid surfaces by a t hermodynamic approach [20-22] and as a g eometrical heterogeneity 1-23-26]. Significant p rogress in the…

type II errors and power 6 Confidence intervals for summary statistics of binary data 7 The t tests 8 The χ tests 2 vii 1 12 29 39 44 52 62 78 95 102 111 126 135 145 147 153 9 Exact probability test 10 Rank score tests 11 Correlation and regression 12 Survival analysis 13 Study design and choosing a statistical test Answers to exercises Appendix Index v Preface There are three main upgrades to this 10th edition. The first is to acknowledge that almost everyone now has access to

Predictive models have been increasingly used by the market in order to assist companies in risk mitigation, portfolio growth, customer retention, fraud prevention, among others. During the model development, however, it is usual to have, among the predictive variables, some who have data not filled in (missing values), thus it is necessary to adopt a procedure to treat these variables. Given this scenario, the aim of this study is to discuss frameworks to deal with missing data in…