Search results for "model."
showing 10 items of 23664 documents
Modelling the effects of cropping systems on weed dynamics: the trade-off between process analysis and decision support
2022
Models are essential to synthesize knowledge on weeds and to design integrated weed-management strategies. These models must rank cropping systems as a function of weed infestation, and account for variability in effects to estimate probabilities of success or failure. Three case studies are presented: (1) an empirical static single-equation model that directly relates weed biomass to crop management, with few inputs and parameters, (2) a matrix-based multiannual model predicting a few key weed stages annually, from weed control options and a few parameters, (3) a mechanistic process-based multiannual model predicting detailed soil, crop and weed state variables daily, with an individual-ba…
The software test improvement model in practice
2005
Polarization corrections to single-particle energies studied within the energy-density-functional and quasiparticle random-phase approximation approa…
2014
Background: Models based on using perturbative polarization corrections and mean-field blocking approxima- tion give conflicting results for masses of odd nuclei. Purpose: We systematically investigate the polarization and mean-field models, implemented within self- consistent approaches that use identical interactions and model spaces, to find reasons for the conflicts between them. Methods: For density-dependent interactions and with pairing correlations included, we derive and study links between the mean-field and polarization results obtained for energies of odd nuclei. We also identify and discuss differences between the polarization-correction and full particle-vibration-coupling (PV…
Automatic Generation of User Interfaces using the Set Description Language
2004
We present a paradigm to generate automatically graphical user interfaces from a formal description of the data model following the well-known model-view-control paradigm. This paradigm provide complete separation between data model and interface description, setting the programmer free from the low-level aspects of programming interfaces, letting him take care of higher level aspects. The interface along with the data model is described by means of a formal language, the Set Description Language. We also describe the infrastructure based on this paradigm we implemented to generate graphical user interfaces for generic applications. Moreover, it can adapt the user interface of a program to …
CNO and pep solar neutrino measurements and perspectives in Borexino
2015
International audience; The detection of neutrinos emitted in the CNO reactions in the Sun is one of the ambitious goals of Borexino Phase-II. A measurement of CNO neutrinos would be a milestone in astrophysics, and would allow to solve serious issues in current solar models. A precise measurement of the rate of neutrinos from the pep reaction would allow to investigate neutrino oscillations in the MSW transition region. The pep and CNO solar neutrino physics, the measurement in Borexino Phase-I and the perspectives for the new phase are reviewed in this proceeding.
Measurement of Solar pp-neutrino flux with Borexino: results and implications
2015
International audience; Measurement of the Solar pp-neutrino flux completed the measurement of Solar neutrino fluxes from the pp-chain of reactions in Borexino experiment. The result is in agreement with the prediction of the Standard Solar Model and the MSW/LMA oscillation scenario. A comparison of the total neutrino flux from the Sun with Solar luminosity in photons provides a test of the stability of the Sun on the 10(5) years time scale, and sets a strong limit on the power production by the unknown energy sources in the Sun.
Improved measurement of $^8$B solar neutrinos with $1.5 kt·y$ of Borexino exposure
2017
We report on an improved measurement of the $^8$B solar neutrino interaction rate with the Borexino experiment at the Laboratori Nazionali del Gran Sasso. Neutrinos are detected via their elastic scattering on electrons in a large volume of liquid scintillator. The measured rate of scattered electrons above 3 MeV of energy is $0.223\substack{+0.015 \\ -0.016}\,(stat)\,\substack{+0.006 \\ -0.006}\,(syst)$ cpd/100 t, which corresponds to an observed solar neutrino flux assuming no neutrino flavor conversion of $\Phi\substack{\rm ES \\ ^8\rm B}=2.57\substack{+0.17 \\ -0.18}(stat)\substack{+0.07\\ -0.07}(syst)\times$10$^6$ cm$^{-2}\,$s$^{-1}$. This measurement exploits the active volume of the …
Modeling the Sustainable Educational Process for Pupils from Vulnerable Groups in Critical Situations: COVID-19 Context in Lithuania, Latvia, and Est…
2022
The critical situation in education caused by COVID-19 has significantly reduced the involvement of pupils from vulnerable groups, particularly those with low learning achievements. The aim of this study is to reveal the modeling of the sustainable educational process and the factors that ensure optimal learning achievements of pupils from vulnerable groups in general education schools in critical educational transformation situations. To reveal the factors ensuring the sustainability of educational processes, this study was conducted in three Baltic countries (Lithuania, Latvia, and Estonia) involving 1432 subject teachers from public education schools. The results of the study highlight t…
Primārās un sekundārās modelēšanas sistēmas dzejas tekstos: Mihaila Lotmana teorētiskās pieejas piemērošana
2016
Saskaņā ar Tartu-Maskavas semiotikas skolas idejām, dabiskā valoda veido primāro modelēšanas sistēmu, uz kuras pamata tiek konstruētas augstāka līmeņa kultūras sistēmas (sekundārās modelēšanas sistēmas). Mihails Lotmans ir pārskatījis klasisko modelēšanas teoriju, un saskaņā ar viņa piedāvāto teoriju primārās un sekundārās modelēšanas sistēmas ir relatīvas viena pret otru, un tajās jēdziens „valoda” tiek šķirts no jēdziena „semiotikas sistēma”. Esošā pētījuma mērķis ir piemērot semiotikas metodes, balstītas uz Mihaila Lotmana izveidotās struktūras, Eiropas un Āfrikas mītiski reliģiskajām modelēšanas sistēmām Nigērijas dzejnieka Kristofera Okigbo darbos. Pētījuma rezultāti rāda, ka šī strukt…
Fuel cell analytical modeling: Solving the trade-off between accuracy and complexity
2013
In this paper, a 5.5 kW Proton Exchange Membrane fuel cell is modeled. The proposed analytical model is described and the parameters identification procedure is further discussed. Simulation results of all three sub-models are compared to test the accuracy of each one. A comparison between simulation and experimental results is provided as well validating the modeling approach.