On the asymptotic behavior of solutions of certain second-order differential equations

In this paper, the second order non-linear differential equation

     

Stability and boundedness properties of certain second-order differential equations

In this paper, we investigated the differential equation

     

Ecological dynamics of continuous and categorical decision-making: The regatta start in sailing

Abstract

Ecological dynamics of decision-making in the sport of sailing exemplifies emergent, conditionally coupled, co-adaptive behaviours. In this study, observation of the coupling dynamics of paired boats during competitive sailing showed that decision-making can be modelled as a self-sustained, co-adapting system of informationally coupled oscillators (boats). Bytracing the spatial–temporal displacements of the boats, time series analyses (autocorrelations, periodograms and running correlations) revealed that trajectories of match racing boats are coupled more than 88% of the time during a pre-start race, via continuous, competing co-adaptions between boats. Results showed that both the continuously selected trajectories of the sailors (12 years of age) and their categorical starting point locations were examples of emergent decisions. In this dynamical conception of decision-making behaviours, strategic positioning (categorical) and continuous displacement of a boat over the course in match-race sailing emerged as a function of interacting task, personal and environmental constraints. Results suggest how key interacting constraints could be manipulated in practice to enhance sailors' perceptual attunement to them in competition.     

Crossed looks: globalisations and curriculum in Guinea-Bissau

This article focuses on education in Guinea-Bissau in the context of globalisations, examining the concept of globalisation and its relation to education and the curriculum. It focuses on the relatively neglected area of national education policies in Guinea-Bissau, comparing differences and common points of interference/influence of multilateral (international and regional) and bilateral organisations in these policies. Data collection was based on content analysis of a corpus of documents – the Education Act, the document of Portuguese Cooperation Programme, the Education Sector Policy Paper, the Education for All National Plan of Action, and Policy n. 3/2007/CM/UEMOA – and field notes collected from 2009 to 2012. The article argues that there is a tendency for the homogenisation of curriculum policies, at least at the macro-level, due to the different types of pressures coming from international/regional organisations.     

Choosing the right imaging method in muscle hernias: musculoskeletal ultrasonography

Muscle hernia (MH) is a focal protrusion of muscle into the overlying subcutaneous tissue through an acquired or congenital facial defect. Herniation in the thigh muscles is not common and there are limited reports evaluating this pathology using ultrasonography (US). A 28-year-old amateur football player presented with a palpable mass on the anterior aspect of his right thigh. Sonographic examination demonstrated a MH through a fascial defect, which is called mushroom appearance. Based on the clinical and sonographic findings, the diagnosis of a MH in the rectus femoris muscle was established. Today, there is no doubt anymore on the role of musculoskeletal US in the field of sports injuries. Therefore, with its various advantages (non-invasive, practical and convenient, inexpensive, etc.), US is the key imaging method in the diagnosis of MHs.     

A nonparametric term weighting method for information retrieval based on measuring the divergence from independence

In this article, we introduce an out-of-the-box automatic term weighting method for information retrieval. The method is based on measuring the degree of divergence from independence of terms from documents in terms of their frequency of occurrence. Divergence from independence has a well-establish underling statistical theory. It provides a plain, mathematically tractable, and nonparametric way of term weighting, and even more it requires no term frequency normalization. Besides its sound theoretical background, the results of the experiments performed on TREC test collections show that its performance is comparable to that of the state-of-the-art term weighting methods in general. It is a simple but powerful baseline alternative to the state-of-the-art methods with its theoretical and practical aspects.