26,208 research outputs found
Explorations in Economic Research, Volume 2, number 3 (Regional Stock Exchanges in a Central Market System)
Quantum walks with encrypted data
In the setting of networked computation, data security can be a significant
concern. Here we consider the problem of allowing a server to remotely
manipulate client supplied data, in such a way that both the information
obtained by the client about the server's operation and the information
obtained by the server about the client's data are significantly limited. We
present a protocol for achieving such functionality in two closely related
models of restricted quantum computation -- the Boson sampling and quantum walk
models. Due to the limited technological requirements of the Boson scattering
model, small scale implementations of this technique are feasible with
present-day technology.Comment: 4 pages, 2 figure
Structural reliability analysis of laminated CMC components
For laminated ceramic matrix composite (CMC) materials to realize their full potential in aerospace applications, design methods and protocols are a necessity. The time independent failure response of these materials is focussed on and a reliability analysis is presented associated with the initiation of matrix cracking. A public domain computer algorithm is highlighted that was coupled with the laminate analysis of a finite element code and which serves as a design aid to analyze structural components made from laminated CMC materials. Issues relevant to the effect of the size of the component are discussed, and a parameter estimation procedure is presented. The estimation procedure allows three parameters to be calculated from a failure population that has an underlying Weibull distribution
The mode 3 crack problem in bonded materials with a nonhomogeneous interfacial zone
The mode 3 crack problem for two bonded homogeneous half planes was considered. The interfacial zone was modelled by a nonhomogeneous strip in such a way that the shear modulus is a continuous function throughout the composite medium and has discontinuous derivatives along the boundaries of the interfacial zone. The problem was formulated for cracks perpendicular to the nominal interface and was solved for various crack locations in and around the interfacial region. The asymptotic stress field near the tip of a crack terminating at an interface was examined and it was shown that, unlike the corresponding stress field in piecewise homogeneous materials, in this case the stresses have the standard square root singularity and their angular variation was identical to that of a crack in a homogeneous medium. With application to the subcritical crack growth process in mind, the results given include mostly the stress intensity factors for some typical crack geometries and various material combinations
The crack problem in bonded nonhomogeneous materials
The plane elasticity problem for two bonded half planes containing a crack perpendicular to the interface was considered. The effect of very steep variations in the material properties near the diffusion plane on the singular behavior of the stresses and stress intensity factors were studied. The two materials were thus, assumed to have the shear moduli mu(o) and mu(o) exp (Beta x), x=0 being the diffusion plane. Of particular interest was the examination of the nature of stress singularity near a crack tip terminating at the interface where the shear modulus has a discontinuous derivative. The results show that, unlike the crack problem in piecewise homogeneous materials for which the singularity is of the form r/alpha, 0 less than alpha less than 1, in this problem the stresses have a standard square-root singularity regardless of the location of the crack tip. The nonhomogeneity constant Beta has, however, considerable influence on the stress intensity factors
Maximum size binary matroids with no AG(3,2)-minor are graphic
We prove that the maximum size of a simple binary matroid of rank
with no AG(3,2)-minor is and characterise those matroids
achieving this bound. When , the graphic matroid is the
unique matroid meeting the bound, but there are a handful of smaller examples.
In addition, we determine the size function for non-regular simple binary
matroids with no AG(3,2)-minor and characterise the matroids of maximum size
for each rank
Coexistence of pressure-induced structural phases in bulk black phosphorus: a combined x-ray diffraction and Raman study up to 18 GPa
We report a study of the structural phase transitions induced by pressure in
bulk black phosphorus by using both synchrotron x-ray diffraction for pressures
up to 12.2 GPa and Raman spectroscopy up to 18.2 GPa. Very recently black
phosphorus attracted large attention because of the unique properties of
fewlayers samples (phosphorene), but some basic questions are still open in the
case of the bulk system. As concerning the presence of a Raman spectrum above
10 GPa, which should not be observed in an elemental simple cubic system, we
propose a new explanation by attributing a key role to the non-hydrostatic
conditions occurring in Raman experiments. Finally, a combined analysis of
Raman and XRD data allowed us to obtain quantitative information on presence
and extent of coexistences between different structural phases from ~5 up to
~15 GPa. This information can have an important role in theoretical studies on
pressure-induced structural and electronic phase transitions in black
phosphorus
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