1,721,076 research outputs found
Stabilized explicit peer methods with parallelism across the stages for stiff problems
No full textIn this manuscript, we propose a new family of stabilized explicit parallelizable peer methods for the solution of stiff Initial Value Problems (IVPs). These methods are derived through the employment of a class of preconditioners proposed by Bassenne et al. (2021) for the construction of a family of linearly implicit Runge-Kutta (RK) schemes.
In this paper, we combine the mentioned preconditioners with explicit two-step peer methods, obtaining a new class of linearly implicit numerical schemes that admit parallelism on the stages. Through an in-depth theoretical investigation, we set free parameters of both the preconditioners and the underlying explicit methods that allow deriving new peer schemes of order two, three and four, with good stability properties and small Local Truncation Error (LTE). Numerical experiments conducted on Partial Differential Equations (PDEs) arising from application contexts show the efficiency of the new peer methods proposed here, and highlight their competitiveness with other linearly implicit numerical schemes
Biochemical grounds for "crosslinker sensitivity": What have we learned from pharmacology?
No full textThe literature pointing to mitomycin C bioactivation, and to the toxicity mechanisms of diepoxybutane and a group of nitrogen mustards causing DNA crosslinks in Fanconi Anemia (FA) cells is reviewed. A critical analysis of this literature prompts revisiting the FA phenotype and crosslinker sensitivity in terms of an oxidative stress (OS) background, redox-related anomalies of FA (FANC) proteins, and mitochondrial dysfunction. This re-appraisal of FA basic defect might lead to innovative approaches both in elucidating FA phenotype and in prospect developments of patients' clinical management
Exploring the social innovation co-production nexus in Sofia: The case of Toplocentrala within the AGORA project
Full text linkThis paper investigates the territorial implications of social innovation and co-production of services in strategic spatial planning. It focuses on the regeneration of Toplocentrala, a socialist heritage building in Sofia that has been transformed into a regional centre for contemporary arts, within the context of the AGORA project’s strategic planning process. The research aims to enhance our understanding of the role of public action in social innovation and the need to redefine collaborative practices within institutional frameworks to promote innovation. A multi-method approach combining qualitative and quantitative data was employed, including site visits, interviews with key stakeholders, and secondary data analysis. The study highlights how strategic spatial planning processes involving social innovation and co-production of services can reshape the relationship between the state and civil society
Fanconi anemia (FA) and crosslinker sensitivity: Re-appraising the origins of FA definition
No full textThe commonly accepted definition of Fanconi anemia (FA) relying on DNA repair deficiency is submitted to a critical review starting from the early reports pointing to mitomycin C bioactivation and to the toxicity mechanisms of diepoxybutane and a group of nitrogen mustards causing DNA crosslinks in FA cells. A critical analysis of the literature prompts revisiting the FA phenotype and crosslinker sensitivity in terms of an oxidative stress (OS) background, redox-related anomalies of FA (FANC) proteins, and mitochondrial dysfunction. This re-appraisal of FA basic defect might lead to innovative approaches both in elucidating FA phenotypes and in clinical managemen
On the advantages of nonstandard finite differences discretizations for differential problems
No full textExplicit discretization schemes based on NonStandard Finite Differences (NSFD) represent a modication of Standard Finite Differences (SFD) schemes in
which the classical denominators step-sizes are usually replaced by particular denominator functions that satisfy certain properties. Sometimes, moreover, a non-local approximation of discrete terms is required. Such numerical schemes may be able to grasp some stability properties of the model analytical solution you are interested in solving, impossible to replicate using classical SFD schemes. The aim of this talk lies in investigating the advantages deriving from the use of NSFD over SFD for some important and representative models of Ordinary Differential Equations (ODEs) and Partial Differential Equations (PDEs), for which it is a-priori known the behavior of the exact solution. Finally, the possibility of extending the NSFD technique to other differential problems exhibiting positive and oscillating solution is also considered
Equation dependent numerical methods for FDEs
No full textIn this talk we describe techniques that allow to enlarge the absolute stability regions of classical explicit numerical methods for Ordinary Differential Equations (ODEs). The basic idea of these techniques consists in the modification of method coefficients, which result in depending on the Jacobian of the ODE to be solved. We then analyze the possibility to apply these methodologies to numerical methods for Fractional Differential Equations (FDEs), in order to obtain an improvement in terms of accuracy and stability properties. This is a joint work with Prof. Beatrice Paternoster and Dajana Conte
Jacobian-dependent peer methods for ordinary differential equations
No full textWe consider a class of explicit numerical methods used for solving Ordinary Differential Equations (ODEs). These methods are called peer methods. In this talk we derive the coefficients of following a different path than the classical one, using the approach that was applied on explicit two- and three-stage Runge-Kutta methods, obtaining coefficients that depend on the Jacobian of f. This technique improves the stability and accuracy properties of existing peer methods, making them useful for solving stiff ODEs. We conduct numerical experiments in order to confirm theoretical properties of these new methods
A nonstandard finite difference numerical method for an oscillatory diffusion-reaction problem
No full textDiscretization schemes based on NonStandard Finite Differences (NSFD) are a modification of Standard Finite Differences (SFD) schemes in which the classical denominators are usually replaced by particular denominator functions that satisfy certain conditions. The main objective of such schemes is to be able to grasp some stability properties of the model analytical solution we are interested to solve, which we are not able to replicate with the classical SFD schemes. We want to investigate the advantages that come from using NSFD over SFD for some diffusion-reaction Partial Differential Equations systems (PDEs) models, the solution of which exibits periodic oscillations and has the positivity property. In fact, NSFD schemes are also often used when
you apriori know that the solution is non-negative. We also look at the possibility of extending our NSFD scheme to cases of problems that also have the advection term. Another method widely used to follow the apriori known qualitative behavior of the solution is the Exponential Fitting (EF) technique. For this reason, we also investigate the link between EF-based and NSFD-based discretization schemes for PDEs
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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