48 research outputs found
Strong traces to degenerate parabolic equations
We prove existence of strong traces at for quasi-solutions to the
degenerate parabolic equations under non-degeneracy assumptions. In order to
solve the problem, we introduce a defect measure type functional and combine it
with the blow up method
On a new class of functional spaces with application to the velocity averaging
We introduce a new family of functional spaces which incorporate Bochner spaces Lp(Rm; E), with E being an appropriate Banach space, and to which we extend the H-distributions. We use the developed theory to prove a general version of the velocity averaging lemma in a heterogeneous Lp, p ā¤ 2 setting
Degenerate parabolic equations -- compactness and regularity of solutions
We introduce a new method which resolves the problem of regularity and
compactness of entropy solutions for nonlinear degenerate parabolic equations
under non-degeneracy conditions on the sphere. In particular, we address a
problem of regularity of entropy solutions to homogeneous (autonomous)
degenerate parabolic PDEs and existence of weak solutions to heterogeneous
degenerate parabolic PDEs (non-autonomous PDEs -- with flux and diffusion
explicitly depending on the space and time variables). The method of proof is
reduction of the equation to a specific kinetic formulation involving two
transport equations, one of the second and one of the first order. In the
heterogeneous situation, this enables us to use (variants of) the H-measures to
get velocity averaging lemmas and then, consequently, existence of a weak
solution. In the homogeneous case, the kinetic reformulation makes it possible
to get necessary estimates of the solution on the Littlewood-Paley dyadic
blocks of the dual space.Comment: 32 page
Control theory for nonlinear fractional dispersive systems
We consider a terminal control problem for processes governed by a nonlinear
system of fractional ODEs. In order to show existence of the control, we first
consider the linear counterpart of the system and reprove a number of classical
theorems in the fractional setting (representation of the solution through the
Gramian type matrix, Kalman's principle, equivalence of the controllability and
observability). We are then in the position to use a fixed point theorem
approach and various techniques from the fractional calculus theory to get the
desired result
Velocity averaging for diffusive transport equations with discontinuous flux
We consider a diffusive transport equation with discontinuous flux and prove
the velocity averaging result under non-degeneracy conditions. As a corollary,
we show the existence of a solution for the Cauchy problem for nonlinear
degenerate parabolic equation with discontinuous flux. In order to achieve the
results, we introduce a new variant of micro-local defect functionals which are
able to "recognise" changes of the type of the equation
Velocity averaging under minimal conditions for deterministic and stochastic kinetic equations with irregular drift
This study investigates the compactness of
velocity averages of sequences of solutions for a class of kinetic
equations. The equations are examined within both deterministic and stochastic
heterogeneous environments. The primary objective is to deduce velocity
averaging results under conditions on and the drift that are more
lenient than those stipulated in previous studies. The main outcome permits the
inclusion of highly irregular drift vectors that adhere
to a general non-degeneracy condition. Moreover, the sequence is
uniformly bounded in -- for an exponent allowed to be strictly
smaller than -- under the requirement .
Resolving the matter of strong compactness in velocity averages, considering
these assumptions, has remained an open problem for a long time. The
cornerstone of our work's progress lies in the strategic employment of the
broader concept of -distributions, moving beyond the traditional reliance on
-measures. Notably, our study represents one of the first significant uses
of -distributions in this context
OBRANA GRAÄEVINSKIH KONSTRUKCIJA OD POTRESA POSTUPKOM IZOLACIJE - BUDUÄNOST ILI UTOPIJA
Ovaj rad sažeti je prikaz postupka seizmiÄke izolacije graÄevinskih konstrukcija, argumentiran kratkim prikazom provedenih seizmiÄkih analiza. Dio je diplomskog rada studentice Senke MitroviÄ, obranjenog u listopadu 2005. godine na GraÄevinskom fakultetu Osijek. HoÄe li jednog dana ovaj naÄin zaÅ”tite graÄevinskih konstrukcija postati uobiÄajen u inženjerskoj praksi u Hrvatskoj (kao u nekim sluÄajevima danas u Japanu) ili je u pitanju samo postupak zasnovan na teoriji dinamike konstrukcija, pokazat Äe vrijeme. Osim osnova na kojima se zaÅ”tita zasniva prikazan je i kratki dio numeriÄkog postupka provedenog za armiranobetonsku okvirnu konstrukciju tlocrtne povrÅ”ine 30x18 metara i visine 18 metara
PHYSICAL ASSET MANAGEMENT IN EVERYDAY LIFE
Svrha rada je pokuÅ”ati dobiti odgovor na pitanje može li Gospodarenje imovinom imati primjenu u svakodnevnom životu. Kako bi to ispitali provedeno je istraživanje. U istraživanju su ispitanicima koriÅ”tenjem studija sluÄaja simulirane situacije u kojima moraju donositi odluke. Istraživanje je provedeno u tri grupe od 114 ispitanika. Svaka od tri grupe dobila je razliÄite studije sluÄaja, a svima je zajedniÄko da donose odluku o rjeÅ”avanjima identiÄnih problema na imovini koja je takoÄer jednaka u sve tri grupe. Analiza rezultata pokazala je velika odstupanja izmeÄu pojedinih grupa. Daljnjom analizom utvrÄeno je kako su same pretpostavke iz studija sluÄaja, koje nisu bile vezane direktno za stanje imovine, imale kljuÄan utjecaj na odstupanja. Kao kljuÄni Äimbenik identificirana je kompleksnost situacija u pojedinim grupama. Nije dobiven jednoznaÄan odgovor na temeljno pitanje, ali je odreÄeno u kojim situacijama ipak ima mjesta za primjenu Gospodarenja imovinom u svakodnevnom životu.The scope of this paper is to find answer on the question āIs Physical Asset Management applicable in everyday life? To find out the answer on this question research is conducted. In this research examinees were asked to make decisions based on data from case studies. The research has been conducted on three groups of 114 examinees. Each group received different case studies, but all the case studies have in common making decision on same problems on the same assets. Analysis showed significant deviations between groups. Deeper analysis showed that facts not directly connected with Physical Assets have key impact on those differences. Complexity of situation is identified as key contributor of deviation between groups. Unambiguous answer to basic question is not found. However, situations where Physical Asset Management is applicable are defined
Elemental composition of moss and lichen species in eastern Serbia
Instrumental neutron activation analysis is used to determine a content of 47 elements (Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Ag, Cd, Sb, I, Ba, Cs, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Tm, Yb, Lu, Hf, Ta, W, Au, Hg, Th, and U) in mosses (Homolothecium sp., Hypnum cupressiforme Hedw., and Brachythecium mildeanum (Schimp.) Schimp.) and lichen (Cladonia fimbriata (L.) Fr.) collected in three locations in Eastern Serbia over years 2006-2010. Concentrations of six elements (Zr, Nd, Gd, Tm, Yb, and Lu) in mosses in Serbia are measured for the first time. For other elements, the obtained concentrations fall within the ranges reported for mosses and lichens in Europe, but no declining trend in concentrations of V, Cd, Cr, Zn, Ni, Fe, and Cu, that has been described in the literature, can be inferred from our results. Factor analysis shows that terrigenous and industrial components are the highest contributing factors to the elemental composition and that the most polluted measurement site is in the vicinity of a copper mining and smelting complex