August 2022
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14 Reads
Nature
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August 2022
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14 Reads
Nature
July 2007
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20 Reads
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1 Citation
Athletic records represent the best results in a given discipline, thus improving monotonically with time. As has already been shown, this should not be taken as an indication that the athletes' capabilities keep improving. In other words, a new record is not noteworthy just because it is a new record, instead it is necessary to assess by how much the record has improved. In this paper we derive formulae that can be used to show that athletic records continue to improve with time, even if athletic performance remains constant. We are considering two specific examples, the German championships and the world records in several athletic disciplines. The analysis shows that, for the latter, true improvements occur in 20-50% of the disciplines. The analysis is supplemented by an application of our record estimation approach to the prediction of the maximum body length of humans for a specified size of a population respectively population group from a representative sample.
June 2007
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252 Reads
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53 Citations
Athletic records represent the best results in a given discipline, thus improving monotonically with time. As has already been shown, this should not be taken as an indication that the athletes' capabilities keep improving. In other words, a new record is not noteworthy just because it is a new record, instead it is necessary to assess by how much the record has improved. In this paper we derive formulae that can be used to show that athletic records continue to improve with time, even if athletic performance remains constant. We are considering two specific examples, the German championships and the world records in several athletic disciplines. The analysis shows that, for the latter, true improvements occur in 20-50% of the disciplines. The analysis is supplemented by an application of our record estimation approach to the prediction of the maximum body length of humans for a specified size of a population respectively population group from a representative sample.
June 2002
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375 Reads
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75 Citations
Nature
Improvements in the results of athletic competitions are often considered to stem from better training and equipment, but elements of chance are always present in athletics and these also contribute. Here we distinguish between these two effects by estimating the range into which athletic records would have fallen in the absence of systematic progress and then comparing this with actual performance results. We find that only 4 out of 22 disciplines have shown a systematic improvement, and that annual best results worldwide show saturation in some disciplines.
May 2002
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26 Reads
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7 Citations
Improvements in the results of athletic competitions are often considered to stem from better training and equipment, but elements of chance are always present in athletics and these also contribute. Here we distinguish between these two effects by estimating the range into which athletic records would have fallen in the absence of systematic progress and then comparing this with actual performance results. We find that only 4 out of 22 disciplines have shown a systematic improvement, and that annual best results worldwide1 show saturation in some disciplines.
June 2001
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12 Reads
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1 Citation
NeuroImage
January 2001
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7 Reads
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15 Citations
February 2000
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19 Reads
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5 Citations
February 2000
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37 Reads
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121 Citations
Magnetic Resonance in Medicine
New algorithms for correlation analysis are presented that allow the mapping of brain activity from functional MRI (fMRI) data in real time during the ongoing scan. They combine the computation of the correlation coefficients between measured fMRI time-series data and a reference vector with “detrending,” a technique for the suppression of non-stimulus-related signal components, and the “sliding-window technique.” Using this technique, which limits the correlation computation to the last N measurement time points, the sensitivity to changes in brain activity is maintained throughout the whole experiment. For increased sensitivity in activation detection a fast and robust optimization of the reference vector is proposed, which takes into account a realistic model of the hemodynamic response function to adapt the parameterized reference vector to the measured data. Based on the described correlation method, real-time fMRI experiments using visual stimulation paradigms have been performed successfully on a clinical MR scanner, which was linked to an external workstation for image analysis. Magn Reson Med 43:259–268, 2000. © 2000 Wiley-Liss, Inc.
January 1999
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5 Reads
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1 Citation
... One could analyse how world records evolved over time and compare the progress made in given athletic events. 21 To take a view on long-term trends in athletic performances this is certainly a valid methodology. However, to compare the general level of performance in any given year or period looking at the prevailing world records would provide a biased view. ...
July 2007
... It is the study of the statistical properties of particularly large or small values within a data set. EVA is widely applied in various fields where extreme phenomena hold significant importance, such as engineering, meteorology, finance, insurance, and environmental science (Basnayake et al 2019;de Haan and Ferreira 2006;Dong 2016;Einmahl and Magnus 2008;Gembris et al. 2002;Kratz 2017;Rootzen 2017;Songchitruksa and Tarko 2006;Tippett et al. 2016;Tsuduki 2024;Wong and Collins 2020). The central concepts of EVA involve identifying the largest or smallest values in a dataset, determining whether these extremes follow distributions like the Fréchet distribution, Weibull distribution, or Gumbel distribution, and analyzing data points that exceed specific thresholds to estimate their distribution. ...
May 2002
... Correction for temporal correlations was not available. Cummulative correlation analysis (Gembris et al 2000) was performed for comparison. Activation maps were spatially smoothed using a 3×3 median filter. ...
May 1998
NeuroImage
... The physical laws that govern the dynamics of this substance are expressed as a set of partial differential equations (PDEs), which are solved numerically on the diffusion tensor field to produce a metric of connectivity. Early work in this area focused on developing methods modeled on the simple diffusion of heat or water through the image volume, whose dynamics is computed by solving the first order heat equation on the diffusion tensor field [41]- [43]. These methods have the advantages of level set and probabilistic methods and are based the same physical model used to construct the diffusion tensor field. ...
January 2001
... In general, there are several characteristics, such as: The basic gradient technique is often applied to machine learning, as detailed in [22]. Creating a multidimensional plane is an effective classification method [23]. ...
February 2000
Magnetic Resonance in Medicine
... Based on the fact that the concentration (or density) fluctuation of an ideal diffusive medium is governed entirely by the diffusion equation (a partial-derivative description of Fick's law [17]), a natural strategy to reveal the spatio-temporal diffusion process is to obtain the numerical solution of the diffusion equation [18]. Previous attempts to employ this strategy, however, have not been successful due to their limitations in practical implementations, such as the 2-D or partial-brain calculation domain requirements as stated in [18][19][20]. Xu et al. [21] recently employed an improved numerical method to diffusion-weighted Bloch-Torrey equation in simulating diffusion MRI measurements on biological tissues, yet not presented the macroscopic evolution of the diffusive concentration. In this paper, we present a method to map the 3-D spatio-temporal diffusion process in the entire brain based on the numerical solution of the diffusion equation, and then compare with an IOI study. ...
June 2001
NeuroImage
... Applying such methods online would imply that the incremental computation time increases on each new scan, which is clearly a serious drawback when considering real-time constraints. To overcome this problem, some techniques were proposed that compute the correlation between the signal and the model, either in an incremental fashion [2], or by restricting computations to a sliding time window [3]. ...
February 2000
... In competitive sports, achieving a new world record is always gratifying. However, it's not just about representing the pinnacle of a specific sports specialty, it's crucial to assess the valuable information and patterns behind the record [1]. Sports records, over time, follow a monotonic function on a time scale and spatial function [2]. ...
June 2007
... It is the study of the statistical properties of particularly large or small values within a data set. EVA is widely applied in various fields where extreme phenomena hold significant importance (Coles 2001;Gilleland and Katz 2016), such as disaster prevention (de Haan and Ferreira 2006;Tippett et al. 2016), finance (Kratz 2019), safety estimation (Songchitruksa and Tarko 2006), sports (Einmahl and Magnus 2008;Gembris et al. 2002), human lifespan (Dong et al. 2016;Rootzen and Zolud 2017), and the recent pandemic (Wong and Collins 2020). Recently, its applications in the biological data analysis has also become active (Basnayake et al. 2019;Tsuduki 2024). ...
June 2002
Nature