Search results for "Shape"
showing 10 items of 585 documents
Multiobjective muffler shape optimization with hybrid acoustics modelling
2010
Shape optimization of a duct system with respect to sound transmission loss is considered. The objective of optimization is to maximize the sound transmission loss at multiple frequency ranges simultaneously by adjusting the shape of a reactive muffler component. The noise reduction problem is formulated as a multiobjective optimization problem. The sound attenuation for each considered frequency is determined by a hybrid method, which requires solving Helmholtz equation numerically by finite element method. The optimization is performed using non-dominated sorting genetic algorithm, NSGA-II, which is a multi-objective genetic algorithm. The hybrid numerical method is flexible with respect …
Äänenvaimentimien mallinnuspohjainen monitavotteinen muodonoptimointi
2011
Multiobjective muffler shape optimization with hybrid acoustics modelling
2011
This paper considers the combined use of a hybrid numerical method for the modeling of acoustic mufflers and a genetic algorithm for multiobjective optimization. The hybrid numerical method provides accurate modeling of sound propagation in uniform waveguides with non-uniform obstructions. It is based on coupling a wave based modal solution in the uniform sections of the waveguide to a finite element solution in the non-uniform component. Finite element method provides flexible modeling of complicated geometries, varying material parameters, and boundary conditions, while the wave based solution leads to accurate treatment of non-reflecting boundaries and straightforward computation of the …
Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at √sNN = 2.76 TeV
2016
We report on results obtained with the event-shape engineering technique applied to Pb-Pb collisions at √sNN = 2.76 TeV. By selecting events in the same centrality interval, but with very different average flow, different initial-state conditions can be studied. We find the effect of the event-shape selection on the elliptic flow coefficient v2 to be almost independent of transverse momentum pT, which is as expected if this effect is attributable to fluctuations in the initial geometry of the system. Charged-hadron, -pion, -kaon, and -proton transverse momentum distributions are found to be harder in events with higher-than-average elliptic flow, indicating an interplay between radial and e…
Fondements et approches de modélisation 3D des environnements urbains pour la géosimulation
2015
National audience; Dans le prolongement de la théorie de la géographie virtuelle proposée par Mi¬chael Batty (1997, 2008), les Environne¬ments Géographiques Virtuels (EGVs) sont proposés comme une nouvelle génération d’outils d’analyses géographiques, d’amé¬nagements et de prospective de façon plus approfondie (Lin et al., 2012). Le déve¬loppement des EGVs répond aux trois exigences scientifiques fondamentales des sciences de l’information géographique : vi-sualisation multidimensionnelle, simulation dynamique de phénomènes géographiques et la participation collaborative pluridisci¬plinaire (Goodchild, 2009). A ce titre, les Environnements Virtuels Urbains pour la Géosimulation (EVUG) sont …
Shape evolution in even-even N≤126, Z≥82 nuclei
2010
The shape evolution in the neutron-de cient lead, polonium and radium nuclei has been investigated via in-beam and delayed y-ray and conversion electron spectroscopy. The lead isotope 180Pb is found to still exhibit prolate excited structure, related to the known intruder structures in the heavier isotopes. The production cross-section of 180Pb was only 10 nb, one of the lowest ever employed in an in-beam experiment. A candidate for an excited prolate band was found in 192Po, making it the rst polonium isotope for which both oblate and prolate rotational bands have been established. Contrary to the previous results, the current experiments indicate that the onset of deformation in the radiu…
Dożynki w Polsce. Od obrzędu do widowiska
2017
Today the traditional beliefs, customs and rites relating to the harvest time are very limited as their contemporary functions and dimension have changed. The authoress is interested in the transformation process of a harvest festival that is typical of the old rural communities. The harvest festival still crowns the labours of farming and is a form of solemn thanksgiving for harvested crops but today's celebration is not accompanied with any magical practices that would bring a good harvest next year. Ritual songs are becoming obsolete and the harvesting women, if any, no longer need any orations addressed to a landlord. The customs of baking bread and making crown-shaped wreaths have surv…
El cuerpo materno en la red: entre el orden de lo ?deseable? y el de lo real
2019
El estilo de vida fitness se realiza en, y a través de, un entramado subjetivo y de poder en el que circulan y se ensamblan dispositivos empresariales, terapéuticos, sanitarios y de espectacularización de los cuerpos, tendientes a inscribir la vida de la población en las tramas conflictivas de un capitalismo heterosexista, neoliberal e informacional. En dicho marco, la temporalidad, metamorfosis y plasticidad del cuerpo materno irrumpe como problema y objeto de intervención de tecnologías diversas orientadas a ajustar su tamaño, forma y devenir a los parámetros de la vida activa y saludable. En escenarios digitales, dicha tensión se materializa, por un lado, a través de dispositivos visuale…
Mathematical Models and their Solutions for Domains of Compex Form
2014
Promocijas darbā tiek apskatīti dažādi oriģināli modeļi un to risinājumi sarežģītas formas apgabaliem. Intensīvās tērauda rūdīšanas procesi sistēmām ar ribām tiek aprakstīti ar 3D hiperbolisko, kā arī ar klasisko siltuma vadīšanas vienādojumu. Precīzā atrisinājuma iegūšanai izmantota Grīna funkciju metode un tās vispārinājums. Modernajos datoros sastopamajām sistēmām ar dubulsieniņu un dubultribu dota stacionārā un nestacionārā siltumvadīšanas problēma 2D gadījumā. Tās risinājums tiek iegūts ar konservatīvās viduvēšanas metodi, galīgo diferenču metodi un tās modifikāciju robežnosacījumiem. Piedāvāts jauns matemātiskais modelis vītola flautai, problēmas formulējumā izmantojot 1D lineāru viļņ…
Quaternary Glaciations in the French Alps and Jura
2011
During last glacial maximum, the pre-existing relief of the Alps and the Jura Mountains controlled glacier development. The Jura massive morphology, only slightly dissected by valleys, resulted in a wide ice-sheet; and this situation contrasts with the Alps where numerous deep valleys were filled by big glaciers.