This paper proposes a blockcipher mode of operation, HCTR, which is a length-preserving encryption mode. HCTR turns an n-bit blockcipher into a tweakable blockcipher that supports arbitrary variable input length which is no less than n bits. The tweak length of HCTR is fixed and can be zero. We prove that HCTR is a strong tweakable pseudorandom permutation ( sprp), when the underlying blockciph...

For an integer m ≥ 2, let GR = GR(m,m + 2) ⊂ RP , N = m(m + 3)/2, be the Plücker embedding of the Grassmanian of msubspaces in Rm+2 . We consider a central projection of GR into a projective space RP of the same dimension as GR . The topological degree of this projection can be properly defined, although GR may be non-orientable. We find that this degree is 0 for even m , and ±u((m+ 1)/2) for o...

We demonstrate that the corotation resonance affects only some non– axisymmetric g–mode oscillations of thin accretion disks, since it is located within their capture zones. Using a more general (weaker radial WKB approximation) formulation of the governing equations, such g–modes, treated as perfect fluid perturbations, are shown to formally diverge at the position of the corotation resonance....

the goal of this research is the derivation of method for evaluation of efficiency improvement potential for district heating systems with focus on variable speed centrifugal pump. the effectiveness of the usage of the proportional pressure control is compared with the constant pressure control. this is why, energy calculation analyses have been realized for variable speed centrifugal pumps, an...

The modular multilevel converter (MMC) has been widely adopted in different applications, such as high-voltage direct current (HVDC), electric drives and static synchronous compensators. Despite the application, MMC realization requires a high number of power electronic components, sensors, communication cables. This paper proposes sliding-mode observer for capacitor voltages MMC, using measure...

The ‘Alfvén Paradox’ is that as resistivity decreases, the discrete eigenmodes do not converge to the generalized eigenmodes of the ideal Alfvén continuum. To resolve the paradox, the -pseudospectrum of the RMHD operator is considered. It is proven that for any , the pseudospectrum contains the Alfvén continuum for sufficiently small resistivity. Formal − pseudoeigenmodes are constructed using ...