The paper is focused on analysis of dynamic properties of drive system. It describes the possible ways of stability analysis and possible ways of analysis of bifurcation of steady states and possible occurrence of chaotic behavior. and Obsahuje seznam literatury
The purpose of this article is to provide an elementary introduction to the subject of chaos in the electromechanical drive systems with small MPTPRS. In this article, we explore chaotic solutions of maps and continuous time systems. These solutions are also bounded like equilibrium, periodic and quasiperiodic solutions. and POZOR! Nadpis obsahuje dvě chyby (překlepy - správně je: electromechanical (tj. vypustit chybné n) + systems (tj. vypustit druhé chybné s)
The damping or the damping forces represent certain speciality in the investigation of the internal dynamics of the transmisson systems. The special significance has this damping parameter especially in the areas of impact effects in the high-speed light aircraft and mobile transmission constructions. On the example of gear mesh in one branch of forces-flow in the presudoplanetary reducer deal the paper with some partial results of the analysis of the influence of combination damping, i.e. linear and non-linear damping, on the gear mesh dynamics.
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.
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).
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.
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.
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.
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.