the object of this paper is to establish a summability factor theorem for summabilitya, , k  1 k  where a is the lower triangular matrix with non-negative entries satisfying certain conditions.

we obtain sufficient conditions for the series σanλn to be absolutely summable of order k by atriangular matrix.

the ever severe dynamic competitive environment has led to increasing complexity of strategic decision making in giant organizations. strategy formulation is one of basic processes in achieving long range goals. since, in ordinary methods considering all factors and their significance in accomplishing individual goals are almost impossible. here, a new approach based on clustering method is pro...

speciated samples of pm2.5 were collected at the hamshire and orange sites in golden triangle of texas by us epa (environmental protection agency) from july of 2003 to august of 2005. a total of 269 samples for the hamshire site and 293 samples for the orange site with 52 species were measured; however, 22 species were excluded because of too many below-detectionlimit data. among the 22 species...

let $p(lambda)$ be an $n$-square complex matrix polynomial, and $1 leq k leq n$ be a positive integer. in this paper, some algebraic and geometrical properties of the $k$-numerical range of $p(lambda)$ are investigated. in particular, the relationship between the $k$-numerical range of $p(lambda)$ and the $k$-numerical range of its companion linearization is stated. moreover, the $k$-numerical ...

introduction as a tumor grows, the demand for oxygen and nutrients increases and it grows further if acquires the ability to induce angiogenesis. in this study, we aimed to present a two-dimensional continuous mathematical model for avascular tumor growth, coupled with a discrete model of angiogenesis. materials and methods in the avascular growth model, tumor is considered as a single mass, wh...

carbon nanotube (cnt) is considered as a new generation of material possessing superior mechanical, thermal and electrical properties. the applications of cnt, especially in composite materials, i.e. carbon nanotube reinforced polymer have received great attention and interest in recent years. to characterize the influence of cnt on the stress intensity factor of nanocomposites, three fracture ...