that astronomical observers will probably be able to make a definite decision as to whether or not any of the existing spiral nebulae have developed from bacula or from less regular forms by substantially the same method. Till that is decided further discussion would be superfluous. It is possible that there are well developed spiral nebulae in which mutual interference has done little or nothi...

Nekhoroshev's theorem on the stability of motions in quasi-integrable Hamiltonian systems is revisited. At variance with the proofs already available in the literature, we explicitly consider the case of weakly perturbed harmonic oscillators; furthermore we prove the confinement of orbits in resonant regions, in the general case of nonisochronous systems, by using the elementary idea of energy ...

This paper presents a control strategy, which is based on sliding mode control, adaptive control, and fuzzy logic system for controlling the chaotic dynamics. We consider this control paradigm in chaotic systems where the equations of motion are not known. The proposed control strategy is robust against the external noise disturbance and system parameter variations and can be used to convert th...

Modern synchrotron light sources are pushing the limits of storage ring performance. Precise control of the electron beam orbit is critical for achieving design goals in these machines. A review of closed orbit control will be given, including an overview of the sources of orbit motion, a description of closed orbit correction and feedback algorithms, and a discussion of the pitfalls and limita...

To achieve an on-orbit service mission, the mission spacecraft must approach target first, which is based on spacecraft’s relative motion. enhance safety and reliability of missions, hovering orbit was proposed needed to be studied further. A high-precision design method for presented dynamics model in this paper. Firstly, stability analysis model, a determine initial value periodic motion expl...

A direct method called fixation is introduced for solving the general motion vision problem, arbitrary motion relative to an arbitrary environment. This method results in a linear constraint equation which explicitly expresses the rotational velocity in terms of the translational velocity. The combination of this constraint equation with the Brightness-Change Constraint Equation solves the gene...

In the early stage of turbulence study, turbulent flow was deemed fully random and disorder motions of fluid particles. Thus physical quantity describing turbulence was considered as the composition of random fluctuations in spatial and temporal field. Reynoldsう1895えdivided the turbulent field into mean field and fluctuating field and then theories and methods based on statistics for turbulence...

Using more than 30 years of lunar laser ranging (LLR) data, the lunar orbit has been modeled and fit with several millimeters precision. This fit provides comprehensive confirmation of the general relativistic equations of motion for solar system dynamics, achieving several key tests of Einstein’s tensor theory of gravity, and strongly constraining presence of any additional long range interact...

A growing number of dynamical situations involve the coupling of particles or singularities with physical waves. In principle these situations are very far from the wave particle duality at quantum scale where the wave is probabilistic by nature. Yet some dual characteristics were observed in a system where a macroscopic droplet is guided by a pilot wave it generates. Here we investigate the be...