The present study is an attempt toward evaluating the performance of portfolios and asset selectionusing cross-efficiency evaluation. Cross-efficiency evaluation is an effective way of ranking decisionmaking units (DMUs) in data envelopment analysis (DEA). Conventional DEA models assume nonnegativevalues for inputs and outputs. However, we know that unlike return and skewness, varianceis the on...

the matrix functions appear in several applications in engineering and sciences. the computation of these functions almost involved complicated theory. thus, improving the concept theoretically seems unavoidable to obtain some new relations and algorithms for evaluating these functions. the aim of this paper is proposing some new reciprocal for the function of block anti diagonal matrices. more...

In this paper, we propose and analyze an efficient matrix method based on Bell polynomials for numerically solving nonlinear Fredholm- Volterra integral equations. For this aim, first we calculate operational matrix of integration and product based on Bell polynomials. By using these matrices, nonlinear Fredholm-Volterra integral equations reduce to the system of nonlinear algebraic equations w...

Thymol, an important and advantageous component of many essential oils, has been applied as an antimicrobial agent in animals. To increase the duration of action of this compound in ruminants, it was decided here to prepare a controlled release carrier for thymol. Hydroxy propyl methyl cellulose (HPMC) and ethyl cellulose (EC) were used as the matrix polymer here. Mixtures of thymol with eight ...

In this paper, the numerical technique based on hybrid Bernoulli and Block-Pulse functions has been developed to approximate the solution of system of linear Volterra integral equations. System of Volterra integral equations arose in many physical problems such as elastodynamic, quasi-static visco-elasticity and magneto-electro-elastic dynamic problems. These functions are formed by the hybridi...

Effective elastic properties for carbon nanotube reinforced composites are obtained through a variety of micromechanics techniques. An embedded carbon nanotube  in  a  polymer  matrix  and  its surrounding  interphase  is  replaced with an equivalent fiber for  predicting  the  mechanical  properties of  the  carbon  nanotube/polymer composite. The effects of an interphase layer between the nan...

In this paper, we solve unconstrained optimization problem using a free line search steepest descent method. First, we propose a double parameter scaled quasi Newton formula for calculating an approximation of the Hessian matrix. The approximation obtained from this formula is a positive definite matrix that is satisfied in the standard secant relation. We also show that the largest eigen value...

in this article, a numerical method based on  improvement of block-pulse functions (ibpfs) is discussed for solving the system of linear volterra and fredholm integral equations. by using ibpfs and their operational matrix of integration, such systems can be reduced to a linear system of algebraic equations. an efficient error estimation and associated theorems for the proposed method are also ...

Effective elastic properties for carbon nanotube reinforced composites are obtained through a variety of micromechanics techniques. An embedded carbon nanotube  in  a  polymer  matrix  and  its surrounding  interphase  is  replaced with an equivalent fiber for  predicting  the  mechanical  properties of  the  carbon  nanotube/polymer composite. The effects of an interphase layer between the nan...

Thymol, an important and advantageous component of many essential oils, has been applied as an antimicrobial agent in animals. To increase the duration of action of this compound in ruminants, it was decided here to prepare a controlled release carrier for thymol. Hydroxy propyl methyl cellulose (HPMC) and ethyl cellulose (EC) were used as the matrix polymer here. Mixtures of thymol with eight ...