The origin of the knee in the energy spectrum of cosmic rays is an outstanding problem in astroparticle physics. Numerous mechanisms have been proposed to explain the structure in the all-particle spectrum. In the article basic ideas of several models are summarized, including diffusive acceleration of cosmic rays in shock fronts, acceleration via cannonballs, leakage from the Galaxy, interacti...

The supernova remnant G347.3–0.5 emits a featureless power-law in X-rays, thought to indicate shock-acceleration of electrons to high energies. We here produce a broadband spectrum of the bright NW limb of this source by combining radio observations from the Australia Telescope Compact Array (ATCA), X-ray observations from the Advanced Satellite for Cosmology and Astrophysics (ASCA), and TeV γ-...

We examine Fermi-type acceleration at relativistic shocks, and distinguish between the initial boost of the first shock crossing cycle, where the energy gain per particle can be very large, and the Fermi process proper with repeated shock crossings, in which the typical energy gain is of order unity. We calculate by means of numerical simulations the spectrum and angular distribution of particl...

We discuss some Lagrangian and presymplectic models concerning test particles in electromagnetic and gravitational fields, with the aim of describing an upper bound to the acceleration. Some models are based on the relativistic phase space and others on the bundle of the Lorentz frames. For the second case, an appropriate version of the methods of analytic mechanics, including the Noether theor...

As a simple model of a supernova explosion we study a point mass exploding into two equal point masses moving back to back at high velocity, or a superposition of such elementary explosions. We employ two calculational methods. In one method we assume an infinite acceleration for zero time and calculate the gravitational field and the distribution of emitted energy. A cutoff frequency in the po...

In this paper a multiobjective optimal design method of interior permanent magnet synchronous motor ( IPMSM) for traction applications so as to maximize average torque and to minimize torque ripple has been presented. Based on train motion equations and physical properties of train, desired specifications such as steady state speed, rated output power, acceleration time and rated speed of tract...

in this work an improved method for designing a linear vibrational absorber, excited by random vibrations is presented and analyzed. first, analytical expressions, for non-stationary white noise accelerations, are derived. the criterion is different from the conventional criteria, used for structural design under random vibration, and it is based on minimum displacement or acceleration response...

In the present study using the wavelet theory (WT) and later the nonlinear spectrum response of the acceleration (NSRA) resulted in estimating a strong earthquake record for the structure to a degree of freedom. WT was used in order to estimate the acceleration of earthquake mapping with equal sampling method (WTESM). Therefore, at first, the acceleration recorded in an earthquake using WTESM w...

SHAKE2000 and DEEPSOIL are the two most important programs to calculate the response analysis of soil layer. In order to analyze the similarities and differences between them, and to guide the improvement of the method and program of seismic response analysis of soil layer, 25 KiK net seismic records from 9 stations were selected as the research objects in this paper, from the aspects of surfac...