Search results for " scheme"
showing 10 items of 323 documents
Filament sets and decompositions of homogeneous continua
2007
Abstract This paper applies the concepts introduced in the article: Filament sets and homogeneous continua [J.R. Prajs, K. Whittington, Filament sets and homogeneous continua, Topology Appl. 154 (8) (2007) 1581–1591, doi:10.1016/j.topol.2006.12.005 ] to decompositions of homogeneous continua. Several new or strengthened results on aposyndesis are given. Newly defined decompositions are discussed. A proposed classification scheme for homogeneous continua is shown to be mostly invariant under Jones' aposyndetic decomposition.
Stochastic Galerkin method for cloud simulation
2018
AbstractWe develop a stochastic Galerkin method for a coupled Navier-Stokes-cloud system that models dynamics of warm clouds. Our goal is to explicitly describe the evolution of uncertainties that arise due to unknown input data, such as model parameters and initial or boundary conditions. The developed stochastic Galerkin method combines the space-time approximation obtained by a suitable finite volume method with a spectral-type approximation based on the generalized polynomial chaos expansion in the stochastic space. The resulting numerical scheme yields a second-order accurate approximation in both space and time and exponential convergence in the stochastic space. Our numerical results…
The Importance of Engaging Local People in Landscape Management – Experiences from an EU Project
2018
“Bull by the Horns” -project initiated landscape management and promoted biodiversity associated with diminishing High Nature Value farmland habitats in Finland. A specific focus was on grazed semi-natural grasslands and wood-pastures which are collectively referred to as traditional rural biotopes (TRBs). Collaboration among project workers, non-farming landowners, and cattle owners reintroduced grazing to abandoned pastures, and management was financed through agri-environmental payments. Using adaptive co-management principles, the project enabled collective definition of integrated site-specific management objectives. A better understanding of contemporary challenges and opportunities t…
Improving scientific rigour in conservation evaluations and a plea deal for transparency on potential biases
2020
Abstract The delivery of rigorous and unbiased evidence on the effects of interventions lay at the heart of the scientific method. Here we examine scientific papers evaluating agri‐environment schemes, the principal instrument to mitigate farmland biodiversity declines worldwide. Despite previous warnings about rudimentary study designs in this field, we found that the majority of studies published between 2008 and 2017 still lack robust study designs to strictly evaluate intervention effects. Potential sources of bias that arise from the correlative nature are rarely mentioned, and results are still promoted by using a causal language. This lack of robust study designs likely results from …
Effects of Natura 2000 on nontarget bird and butterfly species based on citizen science data
2020
The European Union's Natura 2000 (N2000) is among the largest international networks of protected areas. One of its aims is to secure the status of a predetermined set of (targeted) bird and butterfly species. However, nontarget species may also benefit from N2000. We evaluated how the terrestrial component of this network affects the abundance of nontargeted, more common bird and butterfly species based on data from long-term volunteer-based monitoring programs in 9602 sites for birds and 2001 sites for butterflies. In almost half of the 155 bird species assessed, and particularly among woodland specialists, abundance increased (slope estimates ranged from 0.101 [SD 0.042] to 3.51 [SD 1.30…
Which traits allow weed species to persist in grass margin strips ?
2017
EASPEGESTADINRA; Sown-grass margin strips, historically established to limit pesticide drift and soil erosion, are now also promoted for enhancing floral diversity and associated ecosystem services. To better understand weed community assembly in grass margin strips, we performed floral surveys in 75 sown-grass margin strips in two regions in France and characterized each species using information from trait databases. We hypothesized that traits of dominant species would differ between newly sown-grass margin strips and older strips. Weed species were separated into functional groups based on their traits using multiple correspondence analysis and hierarchical ascendant classification. Fun…
Diffusion through thin membranes: Modeling across scales
2016
From macroscopic to microscopic scales it is demonstrated that diffusion through membranes can be modeled using specific boundary conditions across them. The membranes are here considered thin in comparison to the overall size of the system. In a macroscopic scale the membrane is introduced as a transmission boundary condition, which enables an effective modeling of systems that involve multiple scales. In a mesoscopic scale, a numerical lattice-Boltzmann scheme with a partial-bounceback condition at the membrane is proposed and analyzed. It is shown that this mesoscopic approach provides a consistent approximation of the transmission boundary condition. Furthermore, analysis of the mesosco…
Spectroscopic studies of neutron-deficient light nuclei: decay properties of 21Mg, 25Si and 26P
2003
Neutron‐deficient nuclei with Tz equals to −3/2 and −2 have been produced at the GANIL/LISE3 facility in fragmentation reactions of a 95 MeV/u 36Ar primary beam in a 12C target. For the first time, β‐delayed proton and β‐γ emission has been simultaneously observed in the decay of 21Mg, 25Si and 26P. The decay scheme of the latter is proposed and the Gamow‐Teller strength distribution in its β decay is compared to shell‐model calculations based on the USD interaction. The B(GT) values derived from the absolute measurement of the β‐branching ratios are in agreement with the quenching factor of about 60% obtained for allowed Gamow‐Teller transitions in this mass region. A precise half‐life of …
Anulación del privacy shield en las transferencias internacionales de datos : ¿presenciamos un desplazamiento fáctico de la responsabilidad?
2021
This study provides a comprehensive analysis of international transfers of personal data to third countries or international organizations due to new privacy regulation. More specifically, it analyzes the effects on this regulatory scheme of the annulment of the Privacy Shield in the transatlantic information movements between the European Union and the United States and how this implies, in fact, a transfer of responsibility to the controller
Distributed channel prediction for multi-agent systems
2017
Los sistemas multiagente (MAS) se comunican a través de una red inalámbrica para coordinar sus acciones e informar sobre el estado de su misión. La conectividad y el rendimiento del sistema pueden mejorarse mediante la predicción de la ganancia del canal. Presentamos un esquema basado en regresión de procesos gaussianos (GPR) distribuidos para predecir el canal inalámbrico en términos de la potencia recibida en el MAS. El esquema combina una máquina de comité bayesiano con un esquema de consenso medio, distribuyendo así no sólo la memoria sino también la carga computacional y de comunicación. A través de simulaciones de Monte Carlo, demostramos el rendimiento del GPR propuesto. RACHEL TEC20…