Roman dominating function} on a digraph $D$ with vertex set $V(D)$ is a labeling$fcolon V(D)to {0, 1, 2}$such that every vertex with label $0$ has an in-neighbor with label $2$. A set ${f_1,f_2,ldots,f_d}$ ofRoman dominating functions on $D$ with the property that $sum_{i=1}^d f_i(v)le 2$ for each $vin V(D)$,is called a {em Roman dominating family} (of functions) on $D$....

Domination-type parameters are difficult to manage in Cartesian product graphs and there is usually no general relationship between the parameter both factors graph. This situation of domination number, Roman number or 2-domination among others. Contrary what happens with remains unknown cylinders, that is, a cycle path this paper, we will compute cylinders small cycles. We develop two algorith...

I n the first century of Roman domination silver jewelry in the Balkan region is very numerous, and local production of these decorations lasted until the middle of the 3rd century. In that production an important role played the autochthonous component. Gold jewelry from this region is of East-Mediterranean origin, and some shapes of ornaments and use of the techinques of filigree and granulat...