Wyszukiwarka
Filtry
wszystkich: 758
-
Katalog
- Publikacje 309 wyników po odfiltrowaniu
- Czasopisma 312 wyników po odfiltrowaniu
- Konferencje 2 wyników po odfiltrowaniu
- Osoby 123 wyników po odfiltrowaniu
- Projekty 1 wyników po odfiltrowaniu
- Kursy Online 1 wyników po odfiltrowaniu
- Wydarzenia 1 wyników po odfiltrowaniu
- Dane Badawcze 9 wyników po odfiltrowaniu
Wyniki wyszukiwania dla: applied mathematics
-
Weak Solutions within the Gradient-Incomplete Strain-Gradient Elasticity
PublikacjaIn this paper we consider existence and uniqueness of the three-dimensional static boundary-value problems in the framework of so-called gradient-incomplete strain-gradient elasticity. We call the strain-gradient elasticity model gradient-incomplete such model where the considered strain energy density depends on displacements and only on some specific partial derivatives of displacements of first- and second-order. Such models...
-
A spline-based FE approach to modelling of high frequency dynamics of 1-D structures
PublikacjaIn this paper a computational methodology leading to the development of a new class of FEs, based on the application of continuous and smooth approximation polynomials, being splines, has been presented. Application of the splines as appropriately defined piecewise elemental shape functions led the authors to the formulation of a new approach for FEM, named as spFEM, where contrary to the well-known NURBS approach, the boundaries...
-
A chemo-mechano-thermodynamical contact theory for adhesion, friction, and (de)bonding reactions
PublikacjaThis work presents a self-contained continuum formulation for coupled chemical, mechanical, and thermal contact interactions. The formulation is very general and, hence, admits arbitrary geometry, deformation, and material behavior. All model equations are derived rigorously from the balance laws of mass, momentum, energy, and entropy in the framework of irreversible thermodynamics, thus exposing all the coupling present in the...
-
The law of the Iterated Logarithm for random interval homeomorphisms
PublikacjaA proof of the law of the iterated logarithm for random homeomorphisms of the interval is given.
-
Bistability in a One-Dimensional Model of a Two-Predators-One-Prey Population Dynamics System
PublikacjaIn this paper, we study a classical two-predators-one-prey model. The classical model described by a system of three ordinary differential equations can be reduced to a one-dimensional bimodalmap. We prove that this map has at most two stable periodic orbits. Besides, we describe the bifurcation structure of the map. Finally, we describe a mechanism that leads to bistable regimes. Taking this mechanism into account, one can easily...
-
On solvability of initial boundary-value problems of micropolar elastic shells with rigid inclusions
PublikacjaThe problem of dynamics of a linear micropolar shell with a finite set of rigid inclusions is considered. The equations of motion consist of the system of partial differential equations (PDEs) describing small deformations of an elastic shell and ordinary differential equations (ODEs) describing the motions of inclusions. Few types of the contact of the shell with inclusions are considered. The weak setup of the problem is formulated...
-
A convergence result for mountain pass periodic solutions of perturbed Hamiltonian systems
PublikacjaIn this work, we study second-order Hamiltonian systems under small perturbations. We assume that the main term of the system has a mountain pass structure, but do not suppose any condition on the perturbation. We prove the existence of a periodic solution. Moreover, we show that periodic solutions of perturbed systems converge to periodic solutions of the unperturbed systems if the perturbation tends to zero. The assumption on...
-
Surface effects of network materials based on strain gradient homogenized media
PublikacjaThe asymptotic homogenization of periodic network materials modeled as beam networks is pursued in this contribution, accounting for surface effects arising from the presence of a thin coating on the surface of the structural beam elements of the network. Cauchy and second gradient effective continua are considered and enhanced by the consideration of surface effects. The asymptotic homogenization technique is here extended to...
-
Minimal surfaces and conservation laws for bidimensional structures
PublikacjaWe discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent...
-
Existence of Two Periodic Solutions to General Anisotropic Euler-Lagrange Equations
PublikacjaAbstract. This paper is concerned with the following Euler-Lagrange system d/dtLv(t,u(t), ̇u(t)) =Lx(t,u(t), ̇u(t)) for a.e.t∈[−T,T], u(−T) =u(T), Lv(−T,u(−T), ̇u(−T)) =Lv(T,u(T), ̇u(T)), where Lagrangian is given by L=F(t,x,v) +V(t,x) +〈f(t),x〉, growth conditions aredetermined by an anisotropic G-function and some geometric conditions at infinity.We consider two cases: with and without forcing termf. Using a general version...
-
Local material symmetry group for first- and second-order strain gradient fluids
PublikacjaUsing an unified approach based on the local material symmetry group introduced for general first- and second-order strain gradient elastic media, we analyze the constitutive equations of strain gradient fluids. For the strain gradient medium there exists a strain energy density dependent on first- and higher-order gradients of placement vector, whereas for fluids a strain energy depends on a current mass density and its gradients....
-
Attractors of dissipative homeomorphisms of the infinite surface homeomorphic to a punctured sphere
PublikacjaA class of dissipative orientation preserving homeomorphisms of the infinite annulus,pairs of pants, or generally any infinite surface homeomorphic to a punctured sphere isconsidered. We prove that in some isotopy classes the local behavior of such homeomor-phisms at a fixed point, namely the existence of so-called inverse saddle, impacts thetopology of the attractor — it cannot be arcwise connected
-
Elastoplastic law of Cosserat type in shell theory with drilling rotation
PublikacjaWithin the framework of six-parameter non-linear shell theory, with strain measures of the Cosserat type, we develop small-strain J2-type elastoplastic constitutive relations. The relations are obtained from the Cosserat plane stress relations assumed in each shell layer, by through-the-thickness integration employing the first-order shear theory. The formulation allows for unlimited translations and rotations. The constitutive...
-
Two almost homoclinic solutions for second-order perturbed Hamiltonian systems
PublikacjaW niniejszym artykule badamy problem istnienia rozwiązań prawie homoklinicznych (rozwiązań znikających w nieskończonościach) dla układów Hamiltonowskich drugiego rzędu (układów Newtonowskich) z zaburzeniem. Nasz wynik jest uogólnieniem twierdzenia Rabinowitza-Tanaki o istnieniu rozwiązania homoklinicznego dla układów bez zaburzenia [Math. Z. 206 (1991) 473-499]. O zaburzeniu zakładamy, że jest dostatecznie małe w przestrzeni funkcji...
-
On trees with double domination number equal to 2-domination number plus one
PublikacjaA vertex of a graph is said to dominate itself and all of its neighbors. A subset D subseteq V(G) is a 2-dominating set of G if every vertex of V(G)D is dominated by at least two vertices of D, while it is a double dominating set of G if every vertex of G is dominated by at least two vertices of D. The 2-domination (double domination, respectively) number of a graph G is the minimum cardinality of a 2-dominating (double dominating,...
-
Hat problem on odd cycles
PublikacjaThe topic is the hat problem in which each of n players is randomly fitted with a blue or red hat. Then everybody can try to guess simultaneously his own hat color by looking at the hat colors of the other players. The team wins if at least one player guesses his hat color correctly, and no one guesses his hat color wrong; otherwise the team loses. The aim is to maximize the probability of a win. In this version every player can...
-
Symmetry-Breaking Bifurcation for Free Elastic Shell of Biological Cluster, Part 2
PublikacjaWe will be concerned with a two-dimensional mathematical model for a free elastic shell of biological cluster. The cluster boundary is connected with its kernel by elastic links. The inside part is filled with compressed gas or fluid. Equilibrium forms of the shell of biological cluster may be found as solutions of a certain nonlinear functional-differential equation with several physical parameters. For each multiparameter this...
-
Convergence of rational multistep methods of of Adams-Padé type
PublikacjaRational generalizations of multistep schemes, where the linear stiff part of a given problem is treated by an A-stable rational approximation, have been proposed by several authors, but a reasonable convergence analysis for stiff problems has not been provided so far. In this paper we directly relate this approach to exponential multistep methods, a subclass of the increasingly popular class of exponential integrators. This natural,...
-
Comparison of anti-plane surface waves in strain-gradient materials and materials with surface stresses
PublikacjaHere we discuss the similarities and differences in anti-plane surface wave propagation in an elastic half-space within the framework of the theories of Gurtin–Murdoch surface elasticity and Toupin–Mindlin strain-gradient elasticity. The qualitative behaviour of the dispersion curves and the decay of the obtained solutions are quite similar. On the other hand, we show that the solutions relating to the surface elasticity model...
-
Response to David Steigmann’s discussion of our paper
PublikacjaWe respond to David Steigmann's discussion of our paper "A general theory for anisotropic Kirchhoff-Love shells with in-plane bending of embedded fibers, Math. Mech. Solids, 28(5):1274-1317" (arXiv:2101.03122). His discussion allows us to clarify two misleading statements in our original paper, and confirm that its formulation is fully consistent with the formulation of Steigmann. We also demonstrate that some of our original statements...
-
Periodic solutions of Lagrangian systems under small perturbations
PublikacjaIn this paper we prove the existence of mountain pass periodic solutions of a certain class of generalized Lagrangian systems under small perturbations. We show that the found periodic solutions converge to a periodic solution of the unperturbed system if the perturbation tends to 0. The proof requires to work in a rather unusual (mixed) Orlicz–Sobolev space setting, which bears several challenges.
-
Flow through a prosthetic mechanical aortic valve: Numerical model and experimental study
PublikacjaThis research presents a numerical model dedicated for virtual patient diagnostics in the field of synthetic valve implantation. The model operates based on computational fluid dynamics solver with implemented rigid body motion solver. Characteristic indicators related to the prosthetic valve were determined to assess the correctness of cardiac system operation after implantation. A novel approach for dynamic time discretization...
-
Maximum transportation growth in energy and solute particles in Prandtl martial across a vertical 3D-heated surface: Simulations achieved using by finite element approach
PublikacjaThe goal of this study is to determine the maximum energy and solute particles' transportation growth in a 3D-heated region of Prandtl martial through a dynamic magnetic field. The effects of this field on the properties of solvent molecules and heat conduction are studied. A correctly stated functional method and a finite element approach are comparable to a certain type of differential equations. In order demonstrate the effects...
-
A general theory for anisotropic Kirchhoff–Love shells with in-plane bending of embedded fibers
PublikacjaThis work presents a generalized Kirchhoff–Love shell theory that can explicitly capture fiber-induced anisotropy not only in stretching and out-of-plane bending, but also in in-plane bending. This setup is particularly suitable for heterogeneous and fibrous materials such as textiles, biomaterials, composites and pantographic structures. The presented theory is a direct extension of classical Kirchhoff–Love shell theory to incorporate...
-
Inverse shadowing and related measures
PublikacjaWe study various weaker forms of the inverse shadowing property for discrete dynamical systems on a smooth compact manifold. First, we introduce the so-called ergodic inverse shadowing property (Birkhoff averages of continuous functions along an exact trajectory and the approximating one are close). We demonstrate that this property implies the continuity of the set of invariant measures in the Hausdorff metric. We show that the...
-
Biomimetic torene shells
PublikacjaThe genome inside the eukaryotic cells is guarded by a unique shell structure, called the nuclear envelope (NE), made of lipid membranes. This structure has an ultra torus topology with thousands of torus-shaped holes that imparts the structure a high flexural stiffness. Inspired from this biological design, here we present a novel ‘‘torene’’ architecture to design lightweight shell structures with ultra-stiffness for engineering...
-
A note on the multiplicative AHP
PublikacjaPraca dotyczy porównań parami skończonej liczby obiektów w celu obliczeniach uporządkowania w skali liczbowej. W celu obliczenia uporządkowania stosuje się metodę logarytmicznych najmniejszych kwadratów. Pokazuje się multiplikatywne własności otrzymanego rozwiązania. Metodę ilustruje się przykładem obliczeniowym.
-
Stability analysis of two-step Runge-Kutta methods for delay differential equations
PublikacjaW pracy badana jest własność stabilności dwukrokowej metody Rungego-Kutty względem liniowego równania testowego o zespolonych współczynnikach. Udowodniono, że jeśli pewne warunki są spełnione to każda A-stabilna dwukrokowa metoda Rungego-Kutty zastosowana do równania różniczkowego z opóźnieniem jest P-stabilna.
-
Numerical integration of a coupled Korteweg-deVries system
PublikacjaMetoda numeryczna została wprowadzona do rozwiązania ogólnych układów równańKorteweg´a- de Vries´a. Zastosowana do równania Hirota-Satsuma.
-
Michał Piotr Piłat dr inż.
Osoby -
Anubhav Chaturvedi dr
Osoby -
Tomasz Swebocki Dr
OsobyTomasz SWEBOCKI urodził się 19 października 1994 roku w Gdyni, w Polsce. Studia rozpoczął na Wydziale Chemii Uniwersytetu Gdańskiego w 2016 roku. W 2019 i 2021 roku uzyskał tytuły licencjata i magistra (z wyróżnieniem), realizując prace dyplomowe w zakresie chemii analitycznej i diagnostyki. W 2024 roku ukończył studia doktoranckie w dziedzinie nauk o materiałach i mikrobiologii na Uniwersytecie w Lille, w Instytucie Elektroniki,...
-
Waldemar Stampor dr hab. inż.
Osoby -
Zuzanna Poleska-Muchlado dr inż.
Osoby -
Barbara Kościelska prof. dr hab. inż.
Osoby -
Tomasz Krolikowski dr hab. inż.
OsobyIn 1996, I have graduated from the Faculty of Marine Science of Szczecin University and obtained a master's degree - ocean engineering engineer " - Control and Ocean Engineering Measurements". In 1994 I was hired as an assistant trainee at the Institute of Computer Science Technical University of Szczecin, and after graduating in 1996, I was employed as academic and teaching at the Institute of Computer Science in the Department...
-
Julien Guthmuller prof. dr hab.
Osoby -
Agnieszka Witkowska dr hab. inż.
Osoby -
Jakub Karczewski dr hab. inż.
Osoby -
Leszek Piotrowski dr hab. inż.
Osoby -
Jarosław Rybicki prof. dr hab. inż.
Osoby -
Marcin Stanisław Łapiński dr hab. inż.
Osoby -
Three positive solutions to second-order three-point impulsive differential equations with deviating arguments
PublikacjaStosując tw. Leggetta-Williamsa, pokazano że rozpatrywany trzypunktowy problem brzegowy z impulsami ma dodatnie rozwiązania (trzy). Otrzymane twierdzenia dotyczą przypadku opóźnionego oraz wyprzedzonego. W pracy podano przykład i pokazano, że przyjęte założenia są spełnione.
-
The generalized quasilinearization for integro-differential equations of Volterra type on time scales
PublikacjaBadano równania całkowo-różniczkowe on ''time scales'' i podano warunkidostateczne na zbieżność metody kwazilinearyzacji do jego rozwiązania. Podano warunki na to, aby zbieżność ta była kwadratową.
-
Fixed points of planar homeomorphisms of the form Identity + Contraction
PublikacjaW pracy dowodzi się, przy użyciu indeksu, istnienia punktów stałych dla planarnych homeomorfizmów, których orbity spełniają pewien geometryczny warunek.
-
International Network Optimization Conference, Warsaw, Poland 2015
Publikacja -
The final answer to the complexity of a basic problem in resilient network design
Publikacja -
A remark on singular sets of vector bundle morphisms
PublikacjaIf characteristic classes for two vector bundles over the same base space do not coincide, then the bundles are not isomorphic. We give under rather common assumptions a lower bound on the topological dimension of the set of all points in the base over which a morphism between such bundles is not bijective. Moreover, we show that this set is topologically non-trivial.
-
From Pathwidth to Connected Pathwidth
PublikacjaW pracy przedstawiono dowód faktu, że spójna szerokość ścieżkowa grafu wynosi co najwyżek 2k+1, gdzie k jest jego szerokością ścieżkową. Dowód jest konstruktywny, tzn., został skonstruowany algorytm, który dla podanej na wejściu dekompozycji grafu o szerekości k zwraca dekompozycję spóją o szerekości co najwyżej 2k+1.
-
2-bondage in graphs
PublikacjaA 2-dominating set of a graph G=(V,E) is a set D of vertices of G such that every vertex of V(G)D has at least two neighbors in D. The 2-domination number of a graph G, denoted by gamma_2(G), is the minimum cardinality of a 2-dominating set of G. The 2-bondage number of G, denoted by b_2(G), is the minimum cardinality among all sets of edges E' subseteq E such that gamma_2(G-E') > gamma_2(G). If for every E' subseteq E we have...