Regressão Simplex aplicada a delineamentos de mistura e utilização do Algoritmo Boosting

In the composition of this work are present two parts. The first part contains the theory used. The second part contains the two articles. The first article examines two models of the class of generalized linear models for analyzing a mixture experiment, which studied the effect of different diets consist of fat, carbohydrate, and fiber on tumor expression in mammary glands of female rats, given by the ratio mice that had tumor expression in a particular diet. Mixture experiments are characterized by having the effect of collinearity and smaller sample size. In this sense, assuming normality for the answer to be maximized or minimized may be inadequate. Given this fact, the main characteristics of logistic regression and simplex models are addressed. The models were compared by the criteria of selection of models AIC, BIC and ICOMP, simulated envelope charts for residuals of adjusted models, odds ratios graphics and their respective confidence intervals for each mixture component. It was concluded that first article that the simplex regression model showed better quality of fit and narrowest confidence intervals for odds ratio. The second article presents the model Boosted Simplex Regression, the boosting version of the simplex regression model, as an alternative to increase the precision of confidence intervals for the odds ratio for each mixture component. For this, we used the Monte Carlo method for the construction of confidence intervals. Moreover, it is presented in an innovative way the envelope simulated chart for residuals of the adjusted model via boosting algorithm. It was concluded that the Boosted Simplex Regression model was adjusted successfully and confidence intervals for the odds ratio were accurate and lightly more precise than the its maximum likelihood version.

Valores, crenças e comportamentos nas ações e atitudes dos indivíduos de caráter ambiental no município de Lavras -MG

The concept of environment involves social, political and economic aspects, in addition to natural elements. The acknowledgement that the environmental issue is complex highlights the importance of understanding the dynamics of relations that guide the individuals in their interactions with the environment. In this sense, studies have shown the relation between values, beliefs and behaviors. The theory on values developed by Schwartz (1992) identifies the complexity of the relations between values and behavior, organizing the field of human motivation into ten motivational types. Studies conducted by Pato (2004) on environmental beliefs are capable of indicating how the individuals relate to the environment, and its predisposition in acting or not in an ecological manner, allowing an understanding of ecological behavior and its forms of manifestation. Therefore, the objective of this study consisted of analyzing the value perception over environmental beliefs and ecological behavior of the individuals inserted into the environmental theme of the municipality of Lavras, Minas Gerais, Brazil. The research was conducted using a sample of 82 participants, comprised in its majority of male (62.2%), married (54.9%) individuals, and those with age from 31 to 40 years (35.4%). A survey of four segments was conducted: Ecological Behavior Scale (EBS), Environmental Beliefs Scale (EBeS), Schwatz Value Profile (SVP-40) and sociodemographic variables. The participants assumed, first, a value orientation directed to the universalism motivational type, which involves an important set of values for understanding the behaviors in relation to the environment. Furthermore, the results showed that the behaviors related to urban cleaning and economy of water and energy are more easily assimilated, while behaviors oriented to activism/consumerism and recycling were not yet incorporated in a satisfactory manner. On the other hand, the fact of belonging to an institution of which mission is to care for the environment seems to induce the participants to show a greater predisposition to pro-environmental behaviors. The environmental issue, urgent and moved by not always confluent debates, points to the need for reorganizing daily life, which necessarily involves change in values and behaviors. Thus, this study is relevant given that the interaction between the constructs can contribute with the research and the proposition of strategies that promote a reduction of behaviors damaging to the environment, as well as the strengthening of those that contribute for its preservation, sensitizing the actors involved to reorder their roles for benefiting the environment.