Search results for "Boundary"
showing 10 items of 1626 documents
Errors Generated by Uncertain Data
2014
In this chapter, we study effects caused by incompletely known data. In practice, the data are never known exactly, therefore the results generated by a mathematical model also have a limited accuracy. Then, the whole subject of error analysis should be treated in a different manner, and accuracy of numerical solutions should be considered within a framework of a more complicated scheme, which includes such notions as maximal and minimal distances to the solution set and its radius.
A posteriori error estimates for time-dependent reaction-diffusion problems based on the Payne-Weinberger inequality
2015
We consider evolutionary reaction-diffusion problem with mixed Dirichlet--Robin boundary conditions. For this class of problems, we derive two-sided estimates of the distance between any function in the admissible energy space and exact solution of the problem. The estimates (majorants and minorants) are explicitly computable and do not contain unknown functions or constants. Moreover, it is proved that the estimates are equivalent to the energy norm of the deviation from the exact solution.
On elliptic equations involving the 1-Laplacian operator
2018
El objetivo de esta tesis doctoral es dar a conocer los resultados obtenidos sobre existencia, unicidad y regularidad de las soluciones de diferentes ecuaciones elípticas regidas por el operador 1-laplaciano. El primer capítulo está dedicado al estudio de la ecuación - div (Du/|Du|) + g(u) |Du| = f(x) en un subconjunto abierto y acotado U de R^N con frontera Lipschitz, con la condición de Dirichlet u=0 en la frontera, tomando una función f positiva y siendo g una función real, continua y positiva. Por un lado, obtenemos soluciones no acotadas cuando el dato f pertenece al espacio de Marcinkiewicz L^{N,\infty}(U), por lo que debemos introducir la definición apropiada para este tipo de soluci…
Optimization of trigeneration systems by Mathematical Programming: influence of plant scheme and boundary conditions
2014
The large potential for energy saving by cogeneration and trigeneration in the building sector is scarcely exploited due to a number of obstacles in making the investment attractive. The analyst often encounters difficulties in identifying optimal design and operation strategies, since a number of factors, either endogenous (i.e. related with the energy load profiles) and exogenous (i.e. related with external conditions like energy prices and support mechanisms), influence the economic viability. In this paper a decision tool is presented, that simultaneously optimizes the plant lay-out, the sizes of the main components and their operation strategy. For a specific building in the hotel sect…
Positive solutions for nonlinear Robin problems
2017
We consider a parametric Robin problem driven by the p-Laplacian with an indefinite potential and with a superlinear reaction term which does not satisfy the Ambrosetti-Rabinowitz condition. We look for positive solutions. We prove a bifurcation-type theorem describing the nonexistence, existence and multiplicity of positive solutions as the parameter varies. We also show the existence of a minimal positive solution $\tilde{u}_\lambda$ and establish the monotonicity and continuity of the map $\lambda\to \tilde{u}_\lambda$.
Praca nad własną biografią matek dzieci z niepełnosprawnością na przykładzie projektu pt. „Siła kobiet”
2021
W artykule opisany został projekt edukacyjno-socjalny pt. ,,Siła kobiet", skierowany do matek dzieci z niepełnosprawnością. Projekt miał tez charakter naukowo-badawczy, którego nadrzędnym celem było poznanie procesu uczenia się z biografii. Intencją autorki było zaprezentowanie działań realizowanych podczas projektu, które miały umożliwić jego uczestniczkom zaobserwowanie procesu uczenia się z własnej biografii w kontekście niepełnosprawności swojego dziecka. W pierwszej części artykułu zamieszczony został teoretyczno-metodologiczny opis projektu i jego metodyczne podstawy. W części analitycznej zaprezentowane zostały fragmenty transkrypcji w odniesieniu do teorii uczenia się sytuacyjnego i…
Do Online Travel Communities Matter? A Literature Review
2017
The emergence of social media has migrated consumers from peripheral stakeholders to strategic partners whose inputs are critical for successful product and service innovation. Online communities provide a platform for aggregation of consumers from diverse backgrounds; online travel communities (OTCs) have recently attracted growing interest in the information systems and tourism literature because their unofficial boundary spanning role influences consumer interest in destinations. Importantly, this literature remains largely fragmented because of conflicting findings. The present study seeks to integrate prior OTC research in order to understand the motivations and consequences (negative …
Multiple solutions for a Sturm-Liouville problem with periodic boundary conditions
2013
The main purpose of this paper is to establish the existence of multiple solutions for a Sturm-Liouville problem with periodic boundary conditions. The approach is based on variational methods and multiple critical points theorems
High-Reynolds-number turbulent cavity flow using the lattice Boltzmann method
2018
We present a boundary condition scheme for the lattice Boltzmann method that has significantly improved stability for modeling turbulent flows while maintaining excellent parallel scalability. Simulations of a three-dimensional lid-driven cavity flow are found to be stable up to the unprecedented Reynolds number $\mathrm{Re}=5\ifmmode\times\else\texttimes\fi{}{10}^{4}$ for this setup. Excellent agreement with energy balance equations, computational and experimental results are shown. We quantify rises in the production of turbulence and turbulent drag, and determine peak locations of turbulent production.
Fractional Hardy inequalities and visibility of the boundary
2013
We prove fractional order Hardy inequalities on open sets under a combined fatness and visibility condition on the boundary. We demonstrate by counterexamples that fatness conditions alone are not sufficient for such Hardy inequalities to hold. In addition, we give a short exposition of various fatness conditions related to our main result, and apply fractional Hardy inequalities in connection to the boundedness of extension operators for fractional Sobolev spaces.