Mutual Information, Strange Attractors, and the Optimal Estimation of Dimension

It has been shown that the appropriate setting of data windows is crucial to a successful estimation of a time-series correlation dimension using the Grassberger-Procaccia algorithm [Physica 9D, 189 (1983); Phys. Rev. Lett. 50, 346 (1983)], and it has been proposed that the first minimum of the corresponding mutual-information function may be an appropriate window value. We have tested this hypothesis against data generated by the Rossler equations, the Lorenz equations, and a three-dimensional irrational torus. We conclude that mutual information is not consistently successful in identifying the optimal window

Singular-Value Decomposition and the Grassberger-Procaccia Algorithm

A singular-value decomposition leads to a set of statistically independent variables which are used in the Grassberger-Procaccia algorithm to calculate the correlation dimension of an attractor from a scalar time series. This combination alleviates some of the difficulties associated with each technique when used alone, and can significantly reduce the computational cost of estimating correlation dimensions from a time series

Een 18de-eeuwse wraksite op de Buiten Ratel-zandbank (Belgische territoriale wateren): 1. Multidisciplinair onderzoek van het vondstenmateriaal

In 1996 werd op de Buiten Ratel-zandbank, op 9 mijl van de kust, ter hoogte van Koksijde, een houten scheepswrak gelokaliseerd. Het werd onderzocht door een groep sportduikers, met de naam NATA. Jarenlange verkenning van de wraksite leverde talrijke vondsten op. In 2003 zochten de duikers steun bij het toenmalige IAP (Instituut voor het Archeologisch Patrimonium), nu Vlaams Instituut voor het Onroerend Erfgoed (VIOE), om het onderzoek en de conservatie op wetenschappelijke basis verder te zetten. Het VIOE ontfermde zich over het onderzoek van de tot nu toe geborgen materiële resten van de wraksite. Het eerste hoofdstuk van het artikel geeft een overzicht van de observaties van de wraksite via duikonderzoek en via gespecialiseerde technieken vanop een onderzoeksschip. In hoofdstuk 2 worden de objecten beschreven, hun betekenis aan boord van het schip besproken, evenals hun datering en herkomst. Hoofdstuk 3 brengt alle informatie samen en geeft aan wat er in de toekomst nog aan onderzoek kan gebeuren

Inter-generational transmission in a minority language setting: Stop consonant production by Bangladeshi heritage children and adults

Aims and objectives: The purpose of this study was to gain a better understanding of speech development across successive generations of heritage language users, examining how cross-linguistic, developmental and socio-cultural factors affect stop consonant production. Design: To this end, we recorded Sylheti and English stop productions of two sets of Bangladeshi heritage families: (1) first-generation adult migrants from Bangladesh and their (second-generation) UK-born children, and (2) second-generation UK-born adult heritage language users and their (third-generation) UK-born children. Data and analysis: The data were analysed auditorily, using whole-word transcription, and acoustically, examining voice onset time. Comparisons were then made in both languages across the four groups of participants, and cross-linguistically. Findings: The results revealed non-native productions of English stops by the first-generation migrants but largely target-like patterns by the remaining sets of participants. The Sylheti stops exhibited incremental changes across successive generations of speakers, with the third-generation children’s productions showing the greatest influence from English. Originality: This is one of few studies to examine both the host and heritage language in an ethnic minority setting, and the first to demonstrate substantial differences in heritage language accent between age-matched second- and third-generation children. The study shows that current theories of bilingual speech learning do not go far enough in explaining how speech develops in heritage language settings. Implications: These findings have important implications for the maintenance, transmission and long-term survival of heritage languages, and show that investigations need to go beyond second-generation speakers, in particular in communities that do not see a steady influx of new migrants

Impact of the citizen science project COLLECT on ocean literacy and well-being within a north/west African and south-east Asian context

Plastic pollution is both a societal and environmental problem and citizen science has shown to be a useful tool to engage both the public and professionals in addressing it. However, knowledge on the educational and behavioral impacts of citizen science projects focusing on marine litter remains limited. Our preregistered study investigates the impact of the citizen science project Citizen Observation of Local Litter in coastal ECosysTems (COLLECT) on the participants' ocean literacy, pro-environmental intentions and attitudes, well-being, and nature connectedness, using a pretest-posttest design. A total of 410 secondary school students from seven countries, in Africa (Benin, Cabo Verde, Cote d'Ivoire, Ghana, Morocco, Nigeria) and Asia (Malaysia) were trained to sample plastics on sandy beaches and to analyze their collection in the classroom. Non-parametric statistical tests (n = 239 matched participants) demonstrate that the COLLECT project positively impacted ocean literacy (i.e., awareness and knowledge of marine litter, self-reported litter-reducing behaviors, attitudes towards beach litter removal). The COLLECT project also led to higher pro-environmental behavioral intentions for students in Benin and Ghana (implying a positive spillover effect) and higher well-being and nature connectedness for students in Benin. Results are interpreted in consideration of a high baseline in awareness and attitudes towards marine litter, a low internal consistency of pro-environmental attitudes, the cultural context of the participating countries, and the unique settings of the project's implementation. Our study highlights the benefits and challenges of understanding how citizen science impacts the perceptions and behaviors towards marine litter in youth from the respective regions.info:eu-repo/semantics/publishedVersio