one of the most important information in urban forestry is acquaintance of urban landscape’s area or proportion. nowadays, in several countries variable methods are used to achieve this aim. since there is not any complete method to study urban forest’s status in iran, it is impossible to exert authentic management for these resources. hence, in this research, sampling methods and ikonos satell...

There are many long-standing conjectures related with some labellings of trees. It is important to connect labellings that are related with conjectures. We find some connections between known labellings of simple graphs.

A Roman dominating function (RDF) on a graph $G = (V, E)$ is a labeling $f : V rightarrow {0, 1, 2}$ suchthat every vertex with label $0$ has a neighbor with label $2$. The weight of $f$ is the value $f(V) = Sigma_{vin V} f(v)$The Roman domination number, $gamma_R(G)$, of $G$ is theminimum weight of an RDF on $G$.An RDF of minimum weight is called a $gamma_R$-function.A graph G is said to be $g...

Abstract: Let G=(V,E) be a graph and let f:V(G)→{0,1,2} be a function‎. ‎A vertex v is protected with respect to f‎, ‎if f(v)>0 or f(v)=0 and v is adjacent to a vertex of positive weight‎. ‎The function f is a co-Roman dominating function‎, ‎abbreviated CRDF if‎: ‎(i) every vertex in V is protected‎, ‎and (ii) each u∈V with positive weight has a neighbor v∈V with f(v)=0 such that the func...

poplar trees are becoming extremely important as fast growing species due to the increasing need for wood and decreasing productivity of some lands in iran. the present study aimed to find the effect of canopy of poplar clones as one of the most important effective factors on soil properties compared to the distances inter-row trees. five poplar clones and species included: populus euramericana...

This paper studies a fundamental algorithmic problem related to the design of demand-aware networks: networks whose topologies adjust toward traffic patterns they serve, in an online manner. The goal is strike tradeoff between benefits such adjustments (shorter routes) and their costs (reconfigurations). In particular, we consider designing self-adjusting tree network which serves single-source...

there are many long-standing conjectures related with some labellings of trees. it is important to connect labellings that are related with conjectures. we find some connections between known labellings of simple graphs.