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.
In this study, we focused on an analysis of biguanides effects on mitochondrial enzyme activities, mitochondrial membrane potential and membrane permeabili ty transition pore function. We used phenformin, which is more efficient than metformin, and evaluated its effect on rat liver mitochondria and isolated hepatocytes. In contrast to prev iously published data, we found that phenformin, after a 5 min pr e-incubation, dose-dependently inhibits not only mitochondrial complex I but also complex II and IV activity in isolated mitochondria. The enzymes complexes inhibition is paralleled by the decreased respiratory control index and mitochondrial membrane potent ial. Direct measurements of mitochondrial swelling revealed that phenformin increases the resistance of the permeability transition pore to Ca 2+ ions. Our data might be in agreement with the hypothesis of Schäfer (1976) that binding of biguanides to membrane phospholipids alters membrane properties in a non-specific manner and, subsequently, different enzyme activities are modified via lipid phase. However, our measurements of anisotropy of fluorescence of hydrophobic membrane probe diphenylhexatriene have not shown a measurable effect of membrane fluidity with the 1 mM concentration of phenformin that strongly inhibited complex I activity. Our data therefore suggest that biguanides could be considered as agents with high efficacy but low specifity., Z. Drahota ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy