Checking the stability of correlation of chronologies over time: an example on Pinus pinea L. rings widths

An exploratory study concerning the variation over time of multidimensional time series allows to check to what extent factors and dendrograms issued by ordination and classification methods, keep stable over time or change – even dramatically. In this paper, using five chronologies of Pinus pinea L. growth rings from literature, principal components analysis and hierarchical factor classification are applied on a ten years window, moving along time-series. These may be resumed through graphics showing the variation of the eigenvalues issued by the principal component analyses and of the correlations between time-series and principal components, through their corresponding time series, as well as through an animation and a compact representation of the time series of dendrograms. The results show that the studied period could be partitioned in seven intervals different in both correlations and groups structure, some of them highly stable: this suggests a second study, where two time intervals, identified as more homogeneous, showed really different structures

Hierarchical Factor Classification of Dendrochronological Time-Series

In this paper, Hierarchical Factor Classification (HFC), an exploratory method of classification of characters is introduced, in comparison with Principal Component Analysis (PCA) in order to show its advantages, in particular when dealing with time series. Exploratory data analysis may play a very relevant role in the understanding of the structure of a data set prior the use of statistical methods – as hypothesis testing and inference, and models. The study of tree-rings time series through exploratory methods may also take advantages, by allowing some interpretation to be further checked via a small number of statistical tests. In particular, while providing overall results close to those of PCA, HFC complements it, by providing a classification of the time-series and estimating a representative chronology for each group, common to the clustered ones. As case study, a data set is taken from literature, composed by five synchronous 79 years-long chronologies of Pinus pinea L., from five different populations scattered along the Tyrrhenian coast in peninsular Italy. HFC suggests how conveniently aggregate the chronologies, by showing similarities and differences between them, otherwise unnoticed, suggesting to limit the aggregation to three chronologies only

The state participatory budgeting in Rio Grande do Sul

The article presents the main results of a survey on voting behavior at the State Participatory Budgeting of Rio Grande do Sul (also known as Consulta popular). The research is based on a sample of 389 respondents, all residents in San Borja, city in the western border of Rio Grande do Sul (Brazil). The article aims to address participation and vote in Consulta popular, considered its role of social inclusion and promotion of political participation. After a brief descriptive analysis, in order to get a better synthetic overview of the data, we submitted the considered characters to two different multidimensional analyses, in search of possible relations among them. The analyses performed were an exploratory one (a Multiple Correspondence Analysis, MCA) and a Generalized Linear Model by hypothesizing a Binomial distribution for the nominal data

Gestão municipal de resíduos e ambiente institucional no Rio Grande do Sul

A Política Nacional de Resíduos Sólidos (pnrs) brasileira assigna aos municípios brasileiros a responsabilidade pela prestação dos serviços de limpeza urbana e a gestão de resíduos, no entanto, as pesquisas destacam as dificuldades, por parte dos próprios municípios, em adotar uma política que cumpra as obrigações da lei antes mencionada. O presente artigo explora o problema de partir das correspondências entre o próprio ambiente institucional municipal (os principais fatores socioeconômicos, políticos e culturais) e a gestão municipal dos resíduos (especificamente, a presença de um Plano de Gestão Integrada de Resíduos Sólidos). Depois de uma breve introdução ao tema, o texto apresenta uma análise descritiva da difusão dos Planos nas microrregiões do Rio Grande do Sul, a continuação, o artigo apresenta uma análise de correspondências múltiplas que proporciona de forma exploratória um quadro geral da gestão municipal de resíduos em seu ambiente institucional.The National Solid Waste Policy (Política Nacional de Resíduos Sólidos, pnrs) assigns Brazilian municipalities the responsibility of providing urban cleaning and waste management services; however, scholars report the difficulty of municipalities in adopting a policy that meets the obligations of the aforementioned law. This article explores the correspondences between the municipal institutional environment itself (the main socioeconomic, political and cultural factors) and municipal waste management (specifically, the presence of an Integrated Solid Waste Management Plan). After a brief introduction to the issue, this paper shows a descriptive analysis of the presence of these plans in the mesoregions of Rio Grande do Sul. The article then presents a multiple correspondence analysis that provides an exploratory overview of municipal waste management in its institutional environment

Exploratory analyses of structured images: a test on different coding procedures and analysis methods

In order to test the ability of textual coding to depict the features of structured images, a corpus of images of Near-Eastern seals of the late IVth millennium B.C. was studied through different exploratory analysis techniques. Two different coding systems were considered: the classical presence/absence coding of iconographical elements present in the images and a new textual coding, based on a formalised text describing the image. These were submitted to Multiple and Textual Correspondence Analyses. The textual analyses were performed according to two different coding systems, and several choices of the items involved. The results of the different analyses are discussed and compared here. In particular, textual analysis proved effective in substituting the classical coding in the description of the iconographic elements appearing in the images. In addition, it allowed us to broaden the investigation to include aspects of the images (occurrence of fixed sub-patterns and composition) which are beyond the capacities of classical coding. The ability of textual coding to select particular elements, and/or element sequences, to be taken into account in the analyses, was also considered an interesting feature for fine-tuning the analyses to the particular characters of specific corpora. Thus, the use of a formalised text as an intermediate between images and analysis tools proved to be a method worth using, in spite of the special care needed, and some still unsolved difficulties