The present article presents a method for assessing the radial stiffness of nitinol stents. An idealized stent model was created, and its radial stiffness was calculated by means of finite element modeling. The calculations were validated against experimental measurements. The variation of radial stiffness with geometrical dimensions was calculated, and the effect of increasing radial stiffness...

In DEA, we have two measures of technical efficiency with different characteristics: radial and non-radial. In this paper we compile them into a composite model called “epsilon-based measure (EBM).” For this purpose we introduce two parameters which connect radial and non-radial models. These two parameters are obtained from the newly defined affinity index between inputs or outputs along with ...

One of the major problems in Data Envelopment Analysis (DEA) is to determine the projection of inefficient Decision Making Units (DMUs) into the efficient frontier. In conventional DEA models, inputs and outputs of inefficient DMUs alter arbitrarily for reaching to the efficient frontier. Nevertheless, sometimes the ability of DMUs is defined and restricted. Moreover, there are situations in th...

We study the effect of non-radial motions on the mass function, the velocity dispersion function (hereafter VDF) and on the shape of clusters of galaxies using the model introduced in Del Popolo & Gambera (1998a,b; 1999). The mass function of clusters, obtained using the quoted model, is compared with the statistical data by Bahcall & Cen (1992a,b) and Girardi et al. (1998), while the VDF is co...

Context. Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect non-radial modes probing the internal structure of these stars? Aims. We investigate under what physical circumstances non-radial modes could be observable in red giants; what would be their amplitudes, lifetimes and heights in the power ...

In this paper we analyze a free–boundary model for free–standing fibers made from smectic layers of kinked (bent–core) liquid crystal molecules. In [1] a radial model was proposed to explain how fibers form (assuming radially symmetric configurations) based on the distinctive packing and ferroelectric properties of bent–core molecules. We develop this model further to include smectic energy ter...

Context. Solar-like oscillations have been observed in numerous red giants from ground and from space. An important question arises: could we expect to detect non-radial modes probing the internal structure of these stars? Aims. We investigate under what physical circumstances non-radial modes could be observable in red giants; what would be their amplitudes, lifetimes and heights in the power ...

one of the major problems in data envelopment analysis (dea) is to determine the projection of inefficient decision making units (dmus) into the efficient frontier. in conventional dea models, inputs and outputs of inefficient dmus alter arbitrarily for reaching to the efficient frontier. nevertheless, sometimes the ability of dmus is defined and restricted. moreover, there are situations in th...

in this paper we propose a simple non-parametric model for multiple crite-ria supplier selection problem. the proposed model does not generate a zeroweight for a certain criterion and ranks the suppliers without solving the modeln times (one linear programming (lp) for each supplier) and therefore allowsthe manager to get faster results. the methodology is illustrated using anexample.

for non-darcy flow in submerged porous media a one- dimensional mathematical model has been developed. rockfill detention dams are one of these porous media that comprised of relatively homogenous coarse rockfill which can be used to reduce flood discharge and hydrograph peak. in this research the focus was on the rockfill detention dams in submerged condition. the existence of overtopping rock...