Anisotropic 2D mesh adaptation in hp-adaptive FEM

AbstractThe paper presents a grammar for anisotropic two-dimensional mesh adaptation in hp-adaptive Finite Element Method with rectangular elements. It occurs that a straightforward approach to modeling this process via grammar productions leads to potential deadlock in h-adaptation of the mesh. This fact is shown on a Petri net model of an exemplary adaptation. Therefore auxiliary productions are added to the grammar in order to ensure that any sequence of productions allowed by the grammar does not lead to a deadlock state. The fact that the enhanced grammar is deadlock-free is proven via a corresponding Petri net model. The proof has been performed by means of reachability graph construction and analysis. The paper is enhanced with numerical simulations of magnetolluric measurements where the deadlock problem occured

Petri Nets Modeling of Dead-End Refinement Problems in a 3D Anisotropic hp-Adaptive Finite Element Method

We consider two graph grammar based Petri nets models for anisotropic refinements of three dimensional hexahedral grids. The first one detects possible dead-end problems during the graph grammar based anisotropic refinements of the mesh. The second one employs an enhanced graph grammar model that is actually dead-end free. We apply the resulting algorithm to the simulation of resistivity logging measurements for estimating the location of underground oil and/or gas formations. The graph grammar based Petri net models allow to fix the self-adaptive mesh refinement algorithm and finish the adaptive computations with the required accuracy needed by the numerical solution

Petri Nets Modeling of Dead-End Refinement Problems in a 3D Anisotropic hp-Adaptive Finite Element Method

We consider two graph grammar based Petri nets models for anisotropic refinements of three dimensional hexahedral grids. The first one detects possible dead-end problems during the graph grammar based anisotropic refinements of the mesh. The second one employs an enhanced graph grammar model that is actually dead-end free. We apply the resulting algorithm to the simulation of resistivity logging measurements for estimating the location of underground oil and/or gas formations. The graph grammar based Petri net models allow to fix the self-adaptive mesh refinement algorithm and finish the adaptive computations with the required accuracy needed by the numerical solution

GRAPH GRAMMAR BASED PETRI NET CONTROLLED DIRECT SOLVER ALGORITHM

In this paper we present the Petri net setting the optimal order of elimination for directsolver working with hp refined finite finite element meshes. The computational mesh is representedby a graph, with graph vertices corresponding to finite element nodes. The directsolver algorithm is expressed as a sequence of graph grammar productions, attributing thegraph vertices. The Petri net dictates the order of graph grammar productions, representingthe execution of the solver algorithm over a graph representation of computational mesh.The presentation is concluded with numerical experiments performed for a model L-shapedomain

Graph grammar based Petri net controlled direct solver algorithm Algorytm solvera dokładnego sterowany siecią Petriego wykorzystujący gramatyki grafowe /

Tyt. z nagłówka.References. p.78-79.Dostępny również w formie drukowanej.STRESZCZENIE: W artykule przedstawiona została sieć Petriego sterująca kolejnością wykonania produkcji gramatyki grafowej reprezentującej wykonanie algorytmu solvera dokładnego na h adaptowanej siatce metody elementów skończonych. Siatka obliczeniowa przedstawiona została w postaci grafu, którego wierzchołki odpowiadają węzłom elementów skończonych. Algorytm solvera dokładnego wyrażony jest w postaci sekwencji produkcji gramatyki grafowej, atrybutujących wierzchołki grafu. Sieć Petriego określa kolejność wykonania produkcji gramatyki grafowej, reprezentujących wykonanie algorytmu solvera na grafowej reprezentacji siatki obliczeniowej. Artykuł podsumowuje eksperyment numeryczny dotyczący wykonania algorytmu solvera na problemie modelowym w kształcie litery L. SŁOWA KLUCZOWE: sieci Petriego, gramatyki grafowe, solvery dokładne. ABSTRACT: In this paper we present the Petri net setting the optimal order of elimination for direct solver working with hp refined finite finite element meshes. The computational mesh is represented by a graph, with graph vertices corresponding to finite element nodes. The direct solver algorithm is expressed as a sequence of graph grammar productions, attributing the graph vertices. The Petri net dictates the order of graph grammar productions, representing the execution of the solver algorithm over a graph representation of computational mesh. The presentation is concluded with numerical experiments performed for a model L-shape domain. KEYWORDS: Petri nets, graph grammar, direct solver

Petri nets controlled concurrent adaptive solvers for engineering problems

Promotor: Maciej Paszyński.Niepublikowana praca doktorska.Tyt. z ekranu tyt.Praca doktorska. AGH University of Science and Technology in Krakow. Faculty of Computer Science, Electronics and Telecommunications. Department of Computer Science, 2015.Zawiera bibliogr.Dostępna również w wersji drukowanej.Tryb dostępu: Internet.Adaptation algorithms, mesh adaptation and deadlock problem, graph grammar models, open problems, main scientific results, petri net models of adaptive meshes, petri net based detecting of deadlock during anisotropic adaptation of 2D rectangular meshes, mesh adaptation algorithm, graph grammar model, hierarchical Petri net model, enhanced grammar, petri net based detecting of deadlock during anisotropic adaptation of 3D hexahedral meshes, mesh adaptation algorithm, graph grammar model, hierarchical Petri net model, enhanced grammar, numerical results, 2D Example, strong formulation, weak formulation, deadlock problem, 3D Example, strong formulation, weak formulation, deadlock problem, exemaplary analysis of Petri nets modeling 2D finite element method, introduction to hp adaptive Finite Element Method, two dimensional rectangular finite element, three dimensional rectangular finite element, basic definitions of Petri nets, simple Petri net, hierarchical Petri ne

Blockchain technology as a stimulant saving food safety in a supply chain

Rozwój techniki warunkuje coraz szybszy postęp poszczególnych sektorów gospodarek, a w konsekwencji ich systemu jako całości. Agrobiznes staje przed wyzwaniem sprostania rosnącym potrzebom konsumenta w kontekście jakości żywności. Jednym ze sposobów zapewnienia wyżej wymienionej jakości, opartych o digitalizację procesów, jest technologia blockchain. Wykorzystywana w łańcuchu dostaw w niektórych krajach, takich jak np. Chiny, gdzie rzecz dotyczy importu wołowiny z Australii na rynek azjatycki, zapewnia wyższą jakość żywności i tym samym zwiększa konkurencyjność producentów zaangażowanych w tworzenie sieci. Wzrost konkurencyjności gospodarek powoduje, że dotychczasowe starania o klienta przechodzą ewolucję na każdym rynku, w tym na rynku żywności. W artykule zaprezentowano nowe, dotychczas nieznane na polskim rynku żywności, wykorzystanie technologii blockchain. Wyjaśniono pojęcie, opisano schemat działania, przywołano przykłady wykorzystania sieci na innych rynkach i obszarach życia człowieka. Opracowanie ma charakter przeglądowy, opierający się na dostępnej literaturze oraz przykładach rynkowych. Celem opracowania jest zaprezentowanie możliwości wykorzystania innowacyjnej technologii blockchain w poprawie funkcjonowania łańcuchów dostaw.The development of technique conditions faster progress of individual sectors of economies, and consequently their system as a whole. Agribusiness has a challenge of satisfying the growing needs of the consumer in the context of food quality. One of the systems of ensuring food safety based on the digitalization of processes is blockchain technology. Used in the supply chain in some countries, such as China, that imports beef from Australia to the Asian market, provides higher quality food and thus increases the competitiveness of producers involved in creating the network. The increase in the competitiveness of economies means that previous efforts for clients evolve in every market, including the food market. The article presents new, hitherto unknown on the Polish food market, the use of blockchain technology. The concept was explained, a flow chart was described, examples of using the network in other markets and other areas of human life were recalled. The study is of a review nature, based on available literature and market examples The aim of the study is to present the possibilities of using innovative blockchain technology in improving the functioning of supply chains

TRADE IN POLISH BEEF WITH MUSLIM COUNTRIES IN THE CONTEXT OF THE BAN ON RITUAL SLAUGHTER

. The purpose of this paper is to identify the changes in beef trade between Poland and selected Muslim countries in the context of the ban on ritual slaughter. The economic consequences of the ban were discussed. Data from the UN Comtrade Database and FAOSTAT were used as a basis for analyzing the importance of international trade in beef and of beef production and consumption in Poland, Turkey and Bosnia and Herzegovina in the context of the Polish Ritual Slaughter Act. This research found that the ban provided for in the Act had an adverse effect on Poland’s market position as a beef exporter to Turkey and, on the other hand, made suppliers reconsider their market behavior, as reflected by beef exports to Bosnia and Herzegovina and re-exports to Turkey. Another conclusion from this research is that the ethical motivation behind the ban on ritual slaughter failed to produce expected results