the degree set of a graph is the set of its degrees. kapoor et al. [degree sets for graphs, fund. math. 95 (1977) 189-194] proved that for every set of positive integers, there exists a graph of diameter at most two and radius one with that degree set. furthermore, the minimum order of such a graph is determined. a graph is 2-self- centered if its radius and diameter are two. in this paper for ...

in the present work, the effects of changing punch and the die radius on several process parameters involved in deep drawing of aisi 304 steel have been studied. deep drawing process of a cylindrical cup was simulated and analysed by numerical modeling. the results were compared with those of obtained from a serie of experimental cupping tests. the comparison shows that: maximum drawing force d...

designing a power splitter with five ports has been shown in this article. in order to prevent the direct coupling between waveguides, a t-shaped structure with an appropriate distance has been used. the coupling between the parallel photonic crystal waveguides is based on multimode interference, while selecting the output efficiency is performed by setting the refractive coefficients and radiu...

the efficient detection of charged biomolecules by biosensor with appropriate semiconducting nanomaterials and with optimum device geometry has caught tremendous research interest in the present decade. here, the performance of various label-free electronic biosensors to detect bio-molecules is investigated by simulation technique. silicon nanowire sensor, nanosphere sensor and double gate fiel...

Cooperative arms are two or more arms in series which assume the structure of a parallel robot on account of gripping an intermediary object, and are commonly used in accurate assembly industries, coaxialization, movement of object, etc. Gripping an intermediary object is one of the complicated subjects in analysis of cooperative arms, whose analysis is mostly dependent upon the manner the obje...

in this paper, effects of the structural parameters on the optical characteristics of an add-drop filter, consisting of two straight waveguides and a micro-ring resonator (mrr), have been investigated. in this research, effects of mrr radius, the width of mrr and waveguide and the gap between mrr and waveguide, on free spectral range (fsr) and coupling coefficient have been studied. it is found...

By means of lattice-Boltzmann simulations the drag force on a sphere of radius R approaching a superhydrophobic striped wall has been investigated as a function of arbitrary separation h. Superhydrophobic (perfect-slip vs. no-slip) stripes are characterized by a texture period L and a fraction of the gas area ϕ. For very large values of h/R, we recover the macroscopic formulae for a sphere movi...

Tactile dots and bars serve as tactile landmarks so that people with visual impairment can use same consumer products as those used by sighted people. However, reliable age-related data on the appropriate sizes and the shapes was not necessarily available. The purpose of this study is to evaluate influences of edge radius of curvature of tactile dots and bars on their discriminability in younge...