A new quantum deformation, which we call null-plane, of the (3+1) Poincaré algebra is obtained. The algebraic properties of the classical null-plane description are generalized to this quantum deformation. In particular, the classical isotopy subalgebra of the null-plane is deformed into a Hopf subalgebra, and deformed spin operators having classical commutation rules can be defined. Quantum Ha...

Twinning on the plane is a common mode of plastic deformation for hexagonal-close-packed metals. Here we report, by monitoring the deformation of submicron-sized single-crystal magnesium compressed normal to its prismatic plane with transmission electron microscopy, the reorientation of the parent lattice to a 'twin' lattice, producing an orientational relationship akin to that of the conventio...

Composite steel/concrete beams may buckle in hogging bending regions. As the top flange of I-beam in that arrangement is restricted from any translational deformation and twist, the web will distort during buckling presenting a phenomenon often described as restricted distortional buckling. There are limited studies available in the literature of restricted distortional buckling of composite st...

The main purpose of this paper is to show that ideas of deformation theory can be applied to “infinite dimensional geometry”. We develop the deformation theory of Brody curves. Brody curve is a kind of holomorphic map from the complex plane to the projective space. Since the complex plane is not compact, the parameter space of the deformation can be infinite dimensional. As an application we pr...

We describe an elastic matching procedure between plane curves based on computing a minimal deformation cost between the curves. The design of the deformation cost is based on a geodesic distance defined on an infinite dimensional group acting on the curves. The geodesic paths also provide an optimal deformation process, which allows interpolation between any plane curves. q 1999 Elsevier Scien...

Considering economical reasons and attempting to reduce carbon foot print of concrete structures, there is increasing tendency toward use of high strength reinforcement in seismically active regions. ACI 318-19, Iranian steel rebars standard INSO 3132 and next edition of Iranian national building allow the use of high strength rebars in elements of ductile force resisting systems. Therefore it ...

the scope of this research is to investigate the effect of geometrical and physical input parameters in crustal viscoelastic deformation models. to do this analysis viscoelastic model of wang et al., 2006 is used. the increasing quality of data on time-dependent deformation of the earth's surface can be used to extract more details on the spatial and temporal development of earthquake-rela...

When a plane undergoes a deformation that can be represented by a planar linear vector eld, the projected vector eld on the image plane of an optical device is at most quadratic. This 2D motion eld has one singular point, with eigenvalues identical to those of the singular point describing the deformation. As a consequence, the nature of the singular point of the deformation is a projective inv...

The quantum deformation of the group of motions of the plane and its Pontryagin dual are described in details. It is shown that the Pontryagin dual is a quantum deformation of the group of transformations of the plane generated by translations and dilations. An explicite expression for the unitary bicharacter describing the Pontryagin duality is found. The Heisenberg commutation relations are w...