The stochastic properties of a Langevin-type Markov process can be extracted from a given time series by a Markov analysis. Also processes that obey a stochastically forced second-order differential equation can be analyzed this way by employing a particular embedding approach: To obtain a Markovian process in 2N dimensions from a non-Markovian signal in N dimensions, the system is described in a phase space that is extended by the temporal derivative of the signal. For a discrete time series, however, this derivative can only be calculated by a differencing scheme, which introduces an error. If the effects of this error are not accounted for, this leads to systematic errors in the estimation of the drift and diffusion functions of the process. In this paper we will analyze these errors and we will propose an approach that correctly accounts for them. This approach allows an accurate parameter estimation and, additionally, is able to cope with weak measurement noise, which may be superimposed to a given time series.
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http://dx.doi.org/10.1103/PhysRevE.91.062113 | DOI Listing |
JMIR Med Inform
January 2025
Department of Systems Design Engineering, Faculty of Engineering, University of Waterloo, Waterloo, ON, Canada.
Background: While expert optometrists tend to rely on a deep understanding of the disease and intuitive pattern recognition, those with less experience may depend more on extensive data, comparisons, and external guidance. Understanding these variations is important for developing artificial intelligence (AI) systems that can effectively support optometrists with varying degrees of experience and minimize decision inconsistencies.
Objective: The main objective of this study is to identify and analyze the variations in diagnostic decision-making approaches between novice and expert optometrists.
Phys Rev Lett
December 2024
Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
We introduce an approach for analyzing the responses of dynamical systems to external perturbations that combines score-based generative modeling with the generalized fluctuation-dissipation theorem. The methodology enables accurate estimation of system responses, including those with non-Gaussian statistics. We numerically validate our approach using time-series data from three different stochastic partial differential equations of increasing complexity: an Ornstein-Uhlenbeck process with spatially correlated noise, a modified stochastic Allen-Cahn equation, and the 2D Navier-Stokes equations.
View Article and Find Full Text PDFQual Life Res
January 2025
Occupational Medicine Department, University Hospital Sahloul, Sousse, Tunisia.
Background: Since the COVID-19 pandemic, health care workers (HCWs) faced an enormous physical and mental burden, sometimes altering their quality of life due mainly to persistent challenges stemming from their frontline position.
Aims: Todetermine the prevalence of post-COVID-19 syndrome, and its impact on the Health-Related Quality of Life (HRQoL) among HCWs.
Methods: This is an exhaustive cross-sectional study with analytical scope, conducted among all HCWs of the University Hospital Sahloul of Sousse, Tunisia, who have contracted COVID-19 between September 2020 and 30 March 2021 (N=529 cases).
Pain Ther
January 2025
Department of Trauma and Orthopaedic Surgery, Faculty of Medicine and Psychology, University La Sapienza, 00185, Rome, Italy.
Introduction: Elbow ailments are common, but conventional treatment modalities have shortcomings, offering only interim pain relief rather than targeting the underlying pathophysiology. The last two decades have seen a marked increase in the use of autologous peripheral blood-derived orthobiologics (APBOs), such as platelet-rich plasma (PRP), to manage elbow disorders. Platelet-rich plasma (PRP) is the most widely used APBO, but its efficacy remains debatable.
View Article and Find Full Text PDFJ Nephrol
January 2025
Division of Nephrology, Department of Medicine, Centre Hospitalier de l'Université de Montréal, Montreal, QC, Canada.
Background: Climate change poses a significant risk to kidney health, and countries with lower national wealth are more vulnerable. Yet, citizens from lower-income countries demonstrate less concern for climate change than those from higher-income countries. Education is a key covariate.
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