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1622. Bifurcation of periodic solutions to variational inequalities in $\mathbb{R}^\kappa$ based on Alexander-Yorke theorem
- Creator:
- Kučera, Milan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- bifurcation, periodic solutions, variational inequality, differential inequality, finite dimensional space, and Alexander-Yorke theorem
- Language:
- English
- Description:
- Variational inequalities \[ U(t) \in K, (\dot{U}(t)-B_\lambda U(t) - G(\lambda ,U(t)),\ Z - U(t))\ge 0\ \text{for all} \ Z\in \ K, \text{a.a.} \ t\in [0,T) \] are studied, where $K$ is a closed convex cone in $\mathbb{R}^\kappa $, $\kappa \ge 3$, $B_\lambda $ is a $\kappa \times \kappa $ matrix, $G$ is a small perturbation, $\lambda $ a real parameter. The assumptions guaranteeing a Hopf bifurcation at some $\lambda _0$ for the corresponding equation are considered and it is proved that then, in some situations, also a bifurcation of periodic solutions to our inequality occurs at some $\lambda _I \ne \lambda _0$. Bifurcating solutions are obtained by the limiting process along branches of solutions to penalty problems starting at $\lambda _0$ constructed on the basis of the Alexander-Yorke theorem as global bifurcation branches of a certain enlarged system.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1623. Bifurcations for a problem with jumping nonlinearities
- Creator:
- Kárná, Lucie and Kučera, Milan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- nonlinearizable elliptic equations, jumping nonlinearities, global bifurcation, and half-eigenvalue
- Language:
- English
- Description:
- A bifurcation problem for the equation ∆u + λu − αu+ + βu− + g(λ,u)=0 in a bounded domain in N with mixed boundary conditions, given nonnegative functions α, β ∈ L∞ and a small perturbation g is considered. The existence of a global bifurcation between two given simple eigenvalues λ(1), λ(2) of the Laplacian is proved under some assumptions about the supports of the functions α, β. These assumptions are given by the character of the eigenfunctions of the Laplacian corresponding to λ(1), λ(2).
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1624. Bifurcations for Turing instability without SO(2) symmetry
- Creator:
- Ogawa, Toshiyuki and Okuda, Takashi
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- perturbed boundary conditions, imperfect pitchfork bifurcation, and Turing instability
- Language:
- English
- Description:
- In this paper, we consider the Swift-Hohenberg equation with perturbed boundary conditions. We do not a priori know the eigenfunctions for the linearized problem since the SO(2) symmetry of the problem is broken by perturbation. We show that how the neutral stability curves change and, as a result, how the bifurcation diagrams change by the perturbation of the boundary conditions.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1625. Bifurcations in the two imaginary centers problem
- Creator:
- Chiralt, Cristina, Campos, Beatriz, and Vindel, Pura
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- bifurcation, topological configuration, and orbital structure
- Language:
- English
- Description:
- In this paper we show that, for a given value of the energy, there is a bifurcation for the two imaginary centers problem. For this value not only the configuration of the orbits changes but also a change in the topology of the phase space occurs.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1626. Bifurcations of invariant measures in discrete-time parameter dependent cocycles
- Creator:
- Maltseva, Anastasia and Reitmann, Volker
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- discrete-time parameter-dependent cocycles, Hausdorff dimension estimate, and invariant measure
- Language:
- English
- Description:
- We consider parameter-dependent cocycles generated by nonautonomous difference equations. One of them is a discrete-time cardiac conduction model. For this system with a control variable a cocycle formulation is presented. We state a theorem about upper Hausdorff dimension estimates for cocycle attractors which includes some regulating function. We also consider the existence of invariant measures for cocycle systems using some elements of Perron-Frobenius theory and discuss the bifurcation of parameter-dependent measures.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1627. Big Five Inventory 2 (BFI-2): hierarchický model s 15 subškálami
- Creator:
- Hřebíčková, Martina, Jelínek, Martin, Květon, Petr, Benkovič, Adam, Botek, Marek, Sudzina, František, Soto, Christopher J., and John, Oliver P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- pětifaktorový model, psychometrické charakteristiky, BFI-2, BFI-2-S, BFI-2-XS, Five Factor Model, and psychometric characteristics
- Language:
- Czech
- Description:
- Cíle. Cílem studie bylo odhadnout základní psychometrické charakteristiky české verze metody pro měření pěti obecných dimenzí osobnosti Big Five Inventory 2 (BFI-2) a jeho zkrácených verzí (BFI-2-S, BFI-2XS). Výzkumný soubor. BFI-2 byl předložen pro sebeposouzení 1733 respondentům (42,1 % mužů a 57,9 % žen) ve věku od 15 do 26 let s průměrným věkem 20,06 let (SD = 2,53). Hypotéza. Autoři předpokládali, že české verze inventáře budou mít srovnatelné psychometrické vlastnosti s originálními verzemi. Analýza dat. Pro odhad vnitřní konzistence škál BFI-2, BFI-2-S, BFI-2-XS a subškál BFI-2, BFI-2-S byl použit Cronbachův koeficient alfa doplněný o ordinální variantu McDonaldova koeficientu omega, test-retestová stabilita tří metod byla odhadnuta pomocí Pearsonova korelačního koeficientu. Struktura inventáře BFI-2 na úrovni položek a subškál byla odvozena z analýzy hlavních komponent s následnou rotací Varimax. Vnitřní struktura jednotlivých škál byla dále ověřována pomocí konfirmační faktorové analýzy (CFA). Schopnost škál BFI-2-S a BFI- 2-XS reprezentovat celkové skóry z nezkrácené verze BFI-2 byla zjišťována pomocí Pearsonova koeficientu korelace. Výsledky. Škály BFI-2 mají dobrou reliabilitu, která se pohybuje od 0,81 do 0,89. Reliabilita subškál je uspokojivá a pohybuje se od 0,56 do 0,83 (M = 0,74). Průměrná test-retestová stabilita BFI-2 po 6 měsících byla 0,86 pro škály a 0,80 pro subškály. Všechny položky BFI-2 dosahují faktorového náboje většího nebo rovného 0,30 na odpovídajícím faktoru. V české verzi BFI-2 se za použití CFA replikovala hierarchická struktura s 15 subškálami, stejně jako v původní verzi. Zkrácená verze BFI-2-S a BFI-2-XS rekonstruuje z 91 % a 77 % skóry škál BFI-2. Limitace. Studie neobsahuje důkazy o konvergentní validitě and Objectives. The aim of the study was estimation of basic psychometric properties of the Czech adaptation of the Big Five Inventory 2 (BFI-2) measuring five basic personality dimensions and their short and extra short versions (BFI-2-S, BFI-2XS). Subject and settings. The BFI-2 was administered to 1,733 participants (42.1% men, 57.9% women) in age range from 15 to 26 years (M = 20.06, SD = 2.53). Hypothesis. Authors expected that the Czech adaptation of the BFI-2, BFI-2-S, BFI-2XS will retain comparable psychometric properties to the original versions. Statistical analysis. Internal consistency of BFI- 2, BFI-2-S, BFI-2XS domains and BFI-2, BFI- 2-S facets was estimated using Cronbach’s alpha coefficient and ordinal McDonald’s omega coefficient. Test-retest stability of the three methods was estimated using Pearson’s correlation coefficient. The structure of the BFI-2 at the level of items was explored using Principal Component Analysis with Varimax rotation; structures of domains were confirmed using Confirmatory Factor Analyses. The ability of the BFI-2-S and BFI-2-XS scales to represent BFI-2 scores was assessed using the Pearson correlation coefficient. Results. The BFI-2 domains showed good internal consistency, ranging from 0.81 to 0.89. Internal consistency of individual facets ranged from 0.56 to 0.83 (M = 0.74). Average BFI-2 test-retest reliability estimated over a 6 month period was r = 0.86 for domains and r = 0.80 for facets. All items of the BFI-2 showed factor loadings 0.30 or higher on intended factor. The BFI-2 hierarchical structure with 15 facets was confirmed using CFA. Short versions BFI-2-S and BFI-2-XS captured 91% and 77% of the domains of the full version of BFI-2 inventory. Study limitation. Convergent validity of the instrument and the self-other agreement was not evaluated.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1628. Bílá krása
- Creator:
- Drápalová, Lenka
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1629. Biliary system architecture: experimental models and visualization techniques
- Creator:
- Sarnova, L. and Gregor, M.
- Format:
- print, bez média, and svazek
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, cholestáza, vizualizace (počítačová grafika), morfologie (biologie), cholestasis, visualization (computer graphics), morphology (biology), biliary system, mouse model, 14, and 612
- Language:
- English
- Description:
- The complex architecture of the liv er biliary network represents a structural prerequisite for the formation and secretion of bile as well as excretion of toxic substances through bile ducts. Disorders of the biliary tract affect a significant portion of the worldwide population, often leading to cholestatic liver diseases. Cholestatic liver disease is a condition that results from an impairment of bile formation or bile flow to the gallbladder and duodenum. Cholestasis leads to dramatic changes in biliary tree architecture, worsening liver disease and systemic illness. Recent studies show that the preva lence of cholestatic liver diseases is increasing. The availability of well characterized animal models, as well as development of visualization approaches constitutes a critical asset to develop novel pathogenetic concepts and new treatment strategies., L. Sarnova, M. Gregor., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
1630. Bilinear multipliers on Lorentz spaces
- Creator:
- Villaroya, Francisco
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- bilinear Hilbert transform, bilinear multipliers, and Lorentz spaces
- Language:
- English
- Description:
- We give one sufficient and two necessary conditions for boundedness between Lebesgue or Lorentz spaces of several classes of bilinear multiplier operators closely connected with the bilinear Hilbert transform.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public