Search results for " VAR"
showing 10 items of 5758 documents
The relationship between leisure-time physical activity and stress on workdays with special reference to heart rate variability analyses
2016
The purpose of this study was to investigate how physical activity (PA), cardio- respiratory fitness, and body composition are associated with objective heart rate variability (HRV)-based indicators of stress and recovery on workdays. Additionally, the association of subjective self-reported stress with HRV-based stress was investigated. Samples of 81 healthy men (age 26–40 years), and 16 275 Finnish employees (6863 men and 9412 women; age 18–65 years) were assessed in the cross-sectional analyses. A sample of 221 overweight psychologically distressed individuals (36 men and 185 women; age 26–60 years) was examined in both cross-sectional and longitudinal analyses. HRV-based stress and reco…
A Stieltjes Approach to Static Hedges
2014
Static hedging of complicated payoff structures by standard instruments becomes increasingly popular in finance. The classical approach is developed for quite regular functions, while for less regular cases, generalized functions and approximation arguments are used. In this note, we discuss the regularity conditions in the classical decomposition formula due to P. Carr and D. Madan (in Jarrow ed, Volatility, pp. 417–427, Risk Publ., London, 1998) if the integrals in this formula are interpreted as Lebesgue integrals with respect to the Lebesgue measure. Furthermore, we show that if we replace these integrals by Lebesgue–Stieltjes integrals, the family of representable functions can be exte…
THE ARITHMETIC BOHR RADIUS
2007
We study the arithmetic Bohr radius of Reinhardt domains in ℂ n which was successfully used in our study of monomial expansions for holomorphic functions in infinite dimensions. We show that this new Bohr radius is different from the radii invented by Boas and Khavinson and Aizenberg. It gives an explicit formula for the n-dimensional hypercone (which means n-dimensional variants of classical results of Bohr and Bombieri), and moreover asymptotically corrects upper and lower estimates for various types of convex and non-convex Reinhardt domains.
Erzwingt die Quantenmechanik eine drastische Änderung unseres Weltbilds? Gedanken und Experimente nach Einstein, Podolsky und Rosen
1989
Von den Anfangen der Quantenmechanik bis heute gibt es Versuche, sie als statistische Theorie uber Ensembles individueller ‚klassischer’ Systeme zu interpretieren. Die Bedingungen, unter denen Theorien verborgener Parameter zu deterministischen Beschreibungen dieser individuellen Systeme als ‚klassisch’ angesehen werden konnen, wurden von Einstein, Podolsky und Rosen 1935 formuliert: 1. Physikalische Systeme sind im Prinzip separierbar. 2. Zu jeder physikalischen Grose, deren Wert man ohne Storung des betrachteten Systems mit Sicherheit voraussagen kann, existiert ein ihr entsprechendes Element der physikalischen Realitat. Zusammen sind sie, wie Bell 1964 gezeigt hat, prinzipiell unvertragl…
Convergence of Measures
2020
One focus of probability theory is distributions that are the result of an interplay of a large number of random impacts. Often a useful approximation can be obtained by taking a limit of such distributions, for example, a limit where the number of impacts goes to infinity. With the Poisson distribution, we have encountered such a limit distribution that occurs as the number of very rare events when the number of possibilities goes to infinity (see Theorem 3.7). In many cases, it is necessary to rescale the original distributions in order to capture the behavior of the essential fluctuations, e.g., in the central limit theorem. While these theorems work with real random variables, we will a…
Assessing game experience: Heart rate variability, in-game behavior and self-report measures
2014
Assessing game experience by means of recordings of physiological reactions elicited during game play is a technique that has gained popularity in recent years in the field of digital games research. However, since physiological signals are typically linked to several psychological processes, the use of some measures such as cardiac activity or heart rate (HR) remains problematic. The goal of the present study is to investigate to what extent game logs and self-report measures of game experience have a predictive value for heart rate variability during game play. Our results showed that the accurate registration of in-game behaviors by means of game logs carries the potential of providing r…
Context–content systems of random variables : The Contextuality-by-Default theory
2016
Abstract This paper provides a systematic yet accessible presentation of the Contextuality-by-Default theory. The consideration is confined to finite systems of categorical random variables, which allows us to focus on the basics of the theory without using full-scale measure-theoretic language. Contextuality-by-Default is a theory of random variables identified by their contents and their contexts, so that two variables have a joint distribution if and only if they share a context. Intuitively, the content of a random variable is the entity the random variable measures or responds to, while the context is formed by the conditions under which these measurements or responses are obtained. A …
Social Collaborative Viewpoint Regression with Explainable Recommendations
2017
A recommendation is called explainable if it not only predicts a numerical rating for an item, but also generates explanations for users' preferences. Most existing methods for explainable recommendation apply topic models to analyze user reviews to provide descriptions along with the recommendations they produce. So far, such methods have neglected user opinions and influences from social relations as a source of information for recommendations, even though these are known to improve the rating prediction. In this paper, we propose a latent variable model, called social collaborative viewpoint regression (sCVR), for predicting item ratings based on user opinions and social relations. To th…
Determining the number of sources in high-density EEG recordings of event-related potentials by model order selection
2011
To high-density electroencephalography (EEG) recordings, determining the number of sources to separate the signal and the noise subspace is very important. A mostly used criterion is that percentage of variance of raw data explained by the selected principal components composing the signal space should be over 90%. Recently, a model order selection method named as GAP has been proposed. We investigated the two methods by performing independent component analysis (ICA) on the estimated signal subspace, assuming the number of selected principal components composing the signal subspace is equal to the number of sources of brain activities. Through examining wavelet-filtered EEG recordings (128…
Early Oral Language Comprehension, Task Orientation, and Foundational Reading Skills as Predictors of Grade 3 Reading Comprehension
2016
The present five-year longitudinal study from preschool to grade 3 examined the developmental associations among oral language comprehension, task orientation, reading precursors, and reading fluency, as well as their role in predicting grade 3 reading comprehension. Ninety Finnish-speaking students participated in the study. The students’ oral language comprehension (vocabulary knowledge, listening comprehension, and inference making) and task orientation were assessed in preschool, kindergarten, and grade 3. Reading precursors (letter knowledge and phonological awareness) were assessed at the first two timepoints and reading fluency at the third timepoint. Structural equation modeling sho…