336 research outputs found

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

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    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

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    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

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    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

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    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

    Glycogen Utilization during Running: Intensity, Sex, and Muscle-specific Responses.

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    PURPOSE: To quantify net glycogen utilisation in the vastus lateralis (VL) and gastrocnemius (G) of male (n=11) and female (n=10) recreationally active runners during three outdoor training sessions. METHODS: After 2 days standardisation of carbohydrate (CHO) intakes (6 g.kg body mass per day), glycogen was assessed before and after 1) a 10-mile road run (10-mile) at lactate threshold, 2) 8 x 800 m track intervals (8 x 800 m) at velocity at V[Combining Dot Above]O2max and 3) 3 x 10 minute track intervals (3 x 10 min) at lactate turnpoint. RESULTS: Resting glycogen concentration was lower in the G of females compared with males (P0.05). Net glycogen utilisation was greater in males than females in both VL (P=0.02) and G (P=0.07) during the 10-mile road run. With the exception of males during the 3 x 10 min protocol (P=0.28), greater absolute glycogen utilisation was observed in the G versus the VL muscle in both males and females and during all training protocols (all comparisons, P<0.05). CONCLUSION: Data demonstrate 1) prolonged steady state running necessitates a greater glycogen requirement than shorter but higher intensity track running sessions, 2) females display evidence of reduced resting muscle glycogen concentration and net muscle glycogen utilisation when compared with males and 3), net glycogen utilisation is higher in the gastrocnemius muscle compared with the vastus lateralis
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