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Related papers: Fractal and Fractional SIS model for syphilis data

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Effective sequence modeling fundamentally requires balancing the retention of unbounded history with the high-resolution detection of abrupt short-term variations common in real-world phenomena. However, existing state space models (SSMs)…

Artificial Intelligence · Computer Science 2026-05-12 Mengqi Li , Wensheng Lin , Jinshuai Yang , Lixin Li

In network-based SIS models of infectious disease transmission, infection can only occur between directly connected individuals. This constraint naturally gives rise to spatial correlations between the states of neighboring nodes, as the…

Statistical Mechanics · Physics 2026-03-18 Alexander Leibenzon , Samuel W. S. Johnson , Ruth E. Baker , Michael Assaf

The global pandemic of the 2019-nCov requires the evaluation of policy interventions to mitigate future social and economic costs of quarantine measures worldwide. We propose an epidemiological model for forecasting and policy evaluation…

Applications · Statistics 2020-10-30 Philip Nadler , Shuo Wang , Rossella Arcucci , Xian Yang , Yike Guo

This work presents a new model and estimation procedure for the illness-death survival data where the hazard functions follow accelerated failure time (AFT) models. A shared frailty variate induces positive dependence among failure times of…

Methodology · Statistics 2022-05-10 Lea Kats , Malka Gorfine

In this work we study a modified Susceptible-Infected-Susceptible (SIS) model in which the infection rate $\lambda$ decays exponentially with the number of reinfections $n$, saturating after $n=l$. We find a critical decaying rate…

Physics and Society · Physics 2012-05-14 Nuno Crokidakis , Marcio Argollo de Menezes

In this paper, we propose and analyze a new fractional order malaria model with temporary immunity. We extend the existing malaria model to include fractional derivatives. Basic reproduction number is computed using the next generation…

Dynamical Systems · Mathematics 2016-07-15 E. Okyere , F. T. Oduro , S. K. Amponsah , I. K. Dontwi , N. K. Frempong

A variety of resting state neuroimaging data tend to exhibit fractal behavior where its power spectrum follows power-law scaling. Resting state functional connectivity is significantly influenced by fractal behavior which may not directly…

Applications · Statistics 2012-08-16 Wonsang You , Sophie Achard , Jörg Stadler , Bernd Brückner , Udo Seiffert

Using the theory of Lie-Hamilton systems, formal generalized time-dependent Hamiltonian systems that enlarge a recently proposed SIS epidemic model with a variable infection rate are considered. It is shown that, independently on the…

Mathematical Physics · Physics 2023-08-10 Rutwig Campoamor-Stursberg , Eduardo Fernandez-Saiz , Francisco J. Herranz

The main aim of this study is to analyze a fractional parabolic SIR epidemic model of a reaction-diffusion, by using the nonlocal Caputo fractional time-fractional derivative and employing the $p$-Laplacian operator. The immunity is imposed…

Optimization and Control · Mathematics 2025-04-25 Achraf Zinihi , Moulay Rchid Sidi Ammi , Delfim F. M. Torres

Studies have shown that some people with underlying conditions such as cancer, heart failure, diabetes and hypertension are more likely to get COVID-19 and have worse outcomes. In this paper, a fractional-order derivative is proposed to…

Populations and Evolution · Quantitative Biology 2022-03-29 Samuel Okyere , Joseph Ackora-Prah , Ebenezer Bonyah , Mary Osei Fokuo

This paper proposes a new generalized linear model with the fractional binomial distribution. Zero-inflated Poisson/negative binomial distributions are used for count data with many zeros. To analyze the association of such a count variable…

Methodology · Statistics 2025-08-01 Jeonghwa Lee , Chloe Breece

Enhancing reproducibility and data accessibility is essential to scientific research. However, ensuring data privacy while achieving these goals is challenging, especially in the medical field, where sensitive data are often commonplace.…

Methodology · Statistics 2025-09-24 Marta Cipriani , Lorenzo Di Rocco , Maria Puopolo , Marco Alfò

Timely estimation of the current value for COVID-19 reproduction factor $R$ has become a key aim of efforts to inform management strategies. $R$ is an important metric used by policy-makers in setting mitigation levels and is also important…

Populations and Evolution · Quantitative Biology 2020-05-26 Carlo R. Contaldi

Although pandemics are often studied as if populations are well-mixed, disease transmission networks exhibit a multi-scale structure stretching from the individual all the way up to the entire globe. The COVID-19 pandemic has led to an…

Populations and Evolution · Quantitative Biology 2024-12-13 Alexander F. Siegenfeld , Asier Piñeiro Orioli , Robin Na , Blake Elias , Yaneer Bar-Yam

We present the results from the correlation analysis of two galactic redshift surveys, the extended CfA2+SSRS2 and the slice centered on $\delta=-12^{\circ}$ of Las Campanas. Furthermore, we evaluate the likelihood confidence regions for…

Astrophysics · Physics 2007-05-23 E. Palladino , L. Amendola

We introduce the Dense Basis method for Spectral Energy Distribution (SED) fitting. It accurately recovers traditional SED parameters, including M$_*$, SFR and dust attenuation, and reveals previously inaccessible information about the…

Astrophysics of Galaxies · Physics 2017-04-12 Kartheik G. Iyer , Eric Gawiser

The aim of this work is to show, based on concrete data observation, that the choice of the fractional derivative when modelling a problem is relevant for the accuracy of a method. Using the least squares fitting technique, we determine the…

Other Statistics · Statistics 2017-04-04 Ricardo Almeida

We study the dynamic evolution of COVID-19 cased by the Omicron variant via a fractional susceptible-exposedinfected-removed (SEIR) model. Preliminary data suggest that the symptoms of Omicron infection are not prominent and the…

Numerical Analysis · Mathematics 2022-07-21 Min Cai , George Em Karniadakis , Changpin Li

We consider a stochastic SIS infection model for a population partitioned into $m$ households assuming random mixing. We solve the model in the limit $m \to \infty$ by using the self-consistent field method of statistical physics. We derive…

Statistical Mechanics · Physics 2007-05-23 G. Ghoshal , L. M. Sander , I. M. Sokolov

Based on the Riemann- and Caputo definition of the fractional derivative we use the fractional extensions of the standard rotation group SO(3) to construct a higher dimensional representation of a fractional rotation group with mixed…

General Physics · Physics 2010-07-09 Richard Herrmann