Normal mode analysis of proteins of various sizes, ranging from 46 (crambin) up to 858 residues (dimeric citrate synthase) were performed, by using standard approaches, as well as a recently proposed method that rests on the hypothesis that low-frequency normal modes of proteins can be described as pure rigid-body motions of blocks of consecutive amino-acid residues. Such a hypothesis is strong...

Adaptive optical elements are often used to compensate for disturbances in the beam enhance image quality. If element is thin, force profile its motion may lead a significant unevenness of surface impairing A remedy falls back on overactuation with larger number actuators. However, question arises what minimal actuators given requirement is. Thus, we investigate case low-frequent reference acce...

We present an interface between a deformable body mechanics model and a rigid body mechanics model. What is novel with our approach is that the physical representation in both the models is the same, which ensures behavioral correctness and allows great flexibility. We use a massspring representation extended with the concept of volume, and thus contact and collision. All physical interaction o...

The task of evaluating correlations is central to computational structural biology. The rigid-body correlation problem seeks the rigid-body transformation (R, t), R ∈ SO(3), t ∈ ℝ3 that maximizes the correlation between a pair of input scalar-valued functions representing molecular structures. Exhaustive solutions to the rigid-body correlation problem take advantage of the fast Fourier transfor...

We systematize some results on the study of the equations of plane-parallel motion of symmetric fixed rigid bodies–pendulums located in a nonconservative force fields. The form of these equations is taken from the dynamics of real fixed rigid bodies placed in a homogeneous flow of a medium. In parallel, we study the problem of a plane-parallel motion of a free rigid body also located in a simil...

We present a systematic derivation of the extended Jefferys’ orbit for rigid ellipsoidal and V-shaped polymer molecules in linear incompressible viscous flows using a Lagrange multiplier’s method based on a constraining force argument [5]. It reproduces the well-known Jefferys’ orbit for rotating ellipsoids [12]. The method is simple and applicable to any rigid body immersed in a linear flow fi...

The paper describes time-optimal control of construction transport systems with suspended loads, for example gantry type robots. Permissible oscillations of the loads are restricted because of safety requirements while transporting, especially at the end point. A mathematical model of such systems is presented as a pendulum attached by a suspension to a rigid robot body. The time-optimal contro...

This paper investigates the linearization, using perturbation methods, of the structural deformations in the nonlinear flight dynamic response of aircraft with slender, flexible wings. The starting point is the coupling of a displacement-based geometrically nonlinear flexible-body dynamics formulation with a 3D unsteady vortex lattice method. This is followed by a linearization of the structura...

A model-reduction method for linear, parameter-varying systems based on parameter-varying balanced realizations is proposed for a body freedom flutter vehicle. A high-order linear, parameter-varying model with hundreds of states describes the coupling between the short period and first bendingmode with additional structural bending and torsion modes that couple with the rigid body dynamics. How...