in the first part of this paper, some theorems are given for a riemannian manifold with semi-symmetric metric connection. in the second part of it, some special vector fields, for example, torse-forming vector fields, recurrent vector fields and concurrent vector fields are examined in this manifold. we obtain some properties of this manifold having the vectors mentioned above.

The present investigation deals with the propagation of waves in a micropolar transversely isotropic layer. Secular equations for symmetric and skew-symmetric modes of wave propagation in completely separate terms are derived. The amplitudes of displacements and microrotation were also obtained. Finally, the numerical solution was carried out for aluminium epoxy material and the dispersion curv...

The elasticity difference tensor, used in [1] to describe elasticity properties of a continuous medium filling a space-time, is here analysed from the point of view of the space-time connection. Principal directions associated with this tensor are compared with eigendirections of the material metric. Examples concerning spherically symmetric and axially symmetric space-times are then presented.

Using reversible Hadamard difference sets, we construct symmetric Bush-type Hadamard matrices of order 4m4 for all odd integers m.

We give a space-efficient, one-pass algorithm for approximating the L1 difference Pi jai bij between two functions, when the function values ai and bi are given as data streams, and their order is chosen by an adversary. Our main technical innovation is a method of constructing families fVjg of limited-independence random variables that are range-summable, by which we mean that Pc 1 j=0 Vj(s) i...

The first infinite families of symmetric designswere obtained fromfinite projective geometries, Hadamardmatrices, and difference sets. In this paper we describe two general methods of constructing symmetric designs that give rise to the parameters of all other known infinite families of symmetric designs. The method of global decomposition produces an incidence matrix of a symmetric design as a...

Recently, we have used the symmetric bracket of vector fields, and developed the notion of the symmetric derivation. Using this machinery, we have defined the concept of symmetric curvature. This concept is natural and is related to the notions divergence and Laplacian of vector fields. This concept is also related to the derivations on the algebra of symmetric forms which has been discu...

It is commonly understood that the retrieval of a complex-valued object from its diffraction pattern using a support constraint is a difficult problem, the more so if the support is symmetric. In this Letter we show that, for just such a symmetric support, use of an iterative algorithm in which the basic iteration is specified by a difference map converges routinely. All that is required is suf...

Abstract: We consider the compound decision problem of estimating a vector of n parameters, known up to a permutation, corresponding to n independent observations, and discuss the difference between two symmetric classes of estimators. The first and larger class is restricted to the set of all permutation invariant estimators. The second class is restricted further to simple symmetric procedure...

We report the first IR characterization of a single C-D bond within a protein, methyl-d1 Met80 of horse heart cytochrome c. A comparison was made to methyl-d1/d3 methionine as well as methyl-d3 Met80. We found that for methyl-d1 and the asymmetric stretches of methyl-d3, line widths/line shapes are dominated by inhomogeneous broadening, whereas the symmetric stretch of methyl-d3 has a significa...