Maintenance Default or Maintenance At Fault?: A Rejoinder

Maintenance default is a large problem and a number of reasons have been suggested for the cause. However, there are also philosophical questions as to whether maintenance is a desirable concept in the first place.     

On the central limit theorem along subsequences of sums of i.i.d. random variables

Let \(\mathbb{N } = \{1, 2, 3, \ldots \}\) . Let \(\{X, X_{n}; n \in \mathbb N \}\) be a sequence of i.i.d. random variables, and let \(S_{n} = \sum _{i=1}^{n}X_{i}, n \in \mathbb N \) . Then \( S_{n}/\sqrt{n} \Rightarrow N(0, \sigma ^{2})\) for some \(\sigma ^{2} < \infty \) whenever, for a subsequence \(\{n_{k}; k \in \mathbb N \}\) of \(\mathbb N \) , \( S_{n_{k}}/\sqrt{n_{k}} \Rightarrow N(0, \sigma ^{2})\) . Motivated by this result, we study the central limit theorem along subsequences of sums of i.i.d. random variables when \(\{\sqrt{n}; n \in \mathbb N \}\) is replaced by \(\{\sqrt{na_{n}};n \in \mathbb N \}\) with \(\lim _{n \rightarrow \infty } a_{n} = \infty \) . We show that, for given positive nondecreasing sequence \(\{a_{n}; n \in \mathbb N \}\) with \(\lim _{n \rightarrow \infty } a_{n} = \infty \) and \(\lim _{n \rightarrow \infty } a_{n+1}/a_{n} = 1\) and given nondecreasing function \(h(\cdot ): (0, \infty ) \rightarrow (0, \infty )\) with \(\lim _{x \rightarrow \infty } h(x) = \infty \) , there exists a sequence \(\{X, X_{n}; n \in \mathbb N \}\) of symmetric i.i.d. random variables such that \(\mathbb E h(|X|) = \infty \) and, for some subsequence \(\{n_{k}; k \in \mathbb N \}\) of \(\mathbb N \) , \( S_{n_{k}}/\sqrt{n_{k}a_{n_{k}}} \Rightarrow N(0, 1)\) . In particular, for given \(0 < p < 2\) and given nondecreasing function \(h(\cdot ): (0, \infty ) \rightarrow (0, \infty )\) with \(\lim _{x \rightarrow \infty } h(x) = \infty \) , there exists a sequence \(\{X, X_{n}; n \in \mathbb N \}\) of symmetric i.i.d. random variables such that \(\mathbb E h(|X|) = \infty \) and, for some subsequence \(\{n_{k}; k \in \mathbb N \}\) of \(\mathbb N \) , \( S_{n_{k}}/n_{k}^{1/p} \Rightarrow N(0, 1)\) .     

Partial Least Squares: A First-order Analysis

We compare the partial least squares (PLS) and the principal component analysis (PCA), in a general case in which the existence of a true linear regression is not assumed. We prove under mild conditions that PLS and PCA are equivalent, to within a first-order approximation, hence providing a theoretical explanation for empirical findings reported by other researchers. Next, we assume the existence of a true linear regression equation and obtain asymptotic formulas for the bias and variance of the PLS parameter estimator     

When community becomes an agent of educational support: communicative research on Learning Communities in Catalonia

Educational support is a key component of any inclusive school. However, many traditional forms of support have been proven ineffective and even exclusionary for the most vulnerable students and their families. This article presents the results of a study conducted over four years by a diverse research team of university professors, PhD students, teachers and head teachers of schools operating as Learning Communities in Catalonia, Spain. The communicative and dialogic approach of these schools offers an alternative understanding of educational support, which is influenced to a great extent by the creation of networks that include participation by diverse agents. The current article provides a theoretical grounding for this approach to support. The article describes the role of different agents from the community and analyses the main effects of this approach and students’ experiences. Finally, a proposal for a dialogic orientation for educational support is discussed.     

On units of Analysis and Creativity Theory: Towards a “Molecular” Perspective

This article addresses the issue of units of analysis and atomistic models in psychology taking creativity research as a case study. A classic typology in this area, initially proposed by Rhodes (1961), distinguishes between the four P's of creativity: person, process, product, and press (environment). Continuing an effort to rewrite this basic language of the discipline from a cultural psychological perspective in the form of five A's (actor, audience, action, artefact, affordances), the discussion here focuses on bringing relationships to the fore within this framework and problematising strict distinctions between each of the five elements. A closer look at the five A's of creativity, drawing on theoretical considerations and illustrated by interviews with creators working in different domains, reveals the permeable borders surrounding these units and challenges clear divisions between actors and audiences, action and artefacts, actors and artefacts. In the end, it is argued that creative phenomena cannot be properly understood and studied outside of their integrated and dynamic totality defined as a creativity complex. Implications of adopting this “molecular” perspective for theory and methodology are discussed.     

A three-dimensional object point process for detection of cosmic filaments

Summary.  We propose to apply an object point process to delineate filaments of the large scale structure in red shift catalogues automatically. We illustrate the feasibility of the idea on an example of the recent 2dF Galaxy Redshift Survey, describe the procedure and characterize the results.     

ABC Shadow algorithm: a tool for statistical analysis of spatial patterns

This paper presents an original ABC algorithm, ABC Shadow, that can be applied to sample posterior densities that are continuously differentiable. The proposed algorithm solves the main condition to be fulfilled by any ABC algorithm, in order to be useful in practice. This condition requires enough samples in the parameter space region, induced by the observed statistics. The algorithm is tuned on the posterior of a Gaussian model which is entirely known, and then, it is applied for the statistical analysis of several spatial patterns. These patterns are issued or assumed to be outcomes of point processes. The considered models are: Strauss, Candy and area-interaction.     

Being other: Intersubjectivity,allocentrism and the possible

This paper engages with the issues of intersubjectivity by raising three main questions about it: What is the status of the other and of the perspective of the other? How would a social ontology that starts from the other look like? and What is the relation between intersubjectivity and the possible? In addressing these questions, I propose four main approaches to self–other relations, each one focused on a different set of theories of intersubjectivity: cognitive (being self), pragmatist (becoming other), dialogical (becoming self), and allocentric (being other). Their main premises, processes, theories and proponents, as well as implications for ethics and the emergence of novelty, are reflected on in turn. Allocentrism emerges as a useful way to shift the focus from self to other in discussions of intersubjectivity, as an ontological condition of the possible, but also as a difficult position to adopt in practice, particularly in polarized societies.