The spontaneous dimerization of the frustrated spin-1 2 antiferromagnetic chains is studied by a microscopic approach based on a proper set of composite operators (i.e., pseudo-spin operators). Two approximation schemes are developed. Firstly, a spin-wave approximation is made by a Dyson-Maléev-like boson transformation. The ground-state properties and the triplet excitation spectra are obtaine...

At the fluid/porous-medium interface the pseudo-Rayleigh (pR) and pseudo-Stoneley (pSt) waves exist. The relation with the corresponding poles in the slowness plane is not unambiguous, depending on the choice of branch cuts. For a point-force excitation, the far-field Green's functions are computed using vertical branch cuts (method I) implying that the pR- and pSt-poles obey the radiation cond...

the present paper investigates the potential application of graphene sheets with attached nanoparticles as resonant sensors by introducing a nonlocal shear deformation plate model. to take into account an elastic connection between the nanoplate and the attached nanoparticle, the nanoparticle is considered as a mass-spring system. then, a combination of pseudo-spectral and integral quadrature m...

PROCESSING MULTIPLE IMAGE LINES IN REAL-TIME ACOUSTIC IMAGING Jian Shen Emad S. Ebbini Department of Electrical Engineering and Computer Science The University of Michigan, Ann Arbor, MI 48109, USA Tel : (313) 764-4121 Fax : (313) 936-1905 e-mail : [email protected], [email protected] ABSTRACT We present a new method for designing a transversal lter bank for parallel processing echo data i...

The wind deflection of overhead contact lines (OCLs) challenges the stable and safe operation electrified railways. steady causes static line, while fluctuating leads to OCL buffeting. This paper performs a response spectrum analysis caused by combined effects winds. Considering initial configuration OCL, an absolute nodal coordinate formulation method is employed model OCL. A spatial field inc...

Frequency-response measurements at high frequencies have been shown to provide a valuable design tool in various fields of electronics. These measurements are often challenging when using most commercially available measurement tools due to their relatively low maximum sampling frequency and long measurement time. This effectively prevents frequency-response-based low-cost applications where fa...

Pseudo-random single photon counting (PRSPC) is a new time-resolved optical measurement method which combines the spread spectrum time-resolved method with single photon counting. A pseudo-random bit sequence is used to modulate a continuous wave laser diode, while single photon counting is used to build up the optical signal in response to the modulated excitation. Periodic cross-correlation i...