Trees influence the amount of solar UV radiation that reaches pedestrians. A three-dimensional model was developed to predict the ultraviolet-B (UV-B) irradiance fields in open-tree canopies where the spacing between trees is equal to or greater than the width of individual tree crowns. The model predicted the relative irradiance (fraction of above-canopy irradiance) under both sunlit and shade...

Dena Biosphere Reserve located in Iran and is a 550 Biosphere Reserve in the worlds. This research was investigated in the two protected and non-protected areas, in a Dena Biosphere Reserve, Kohkeloye va Boyrahmad province, and central zagros forest, southwest of Iran. Inventory methods designed by systemetic-randomaiz method by use the rectangular plots that were 15×30 meters in the 100×100 m ...

Dena Biosphere Reserve located in Iran and is a 550 Biosphere Reserve in the worlds. This research was investigated in the two protected and non-protected areas, in a Dena Biosphere Reserve, Kohkeloye va Boyrahmad province, and central zagros forest, southwest of Iran. Inventory methods designed by systemetic-randomaiz method by use the rectangular plots that were 15×30 meters in the 100×100 m ...

The connected vertex cover problem is a variant of the vertex cover problem, in which a vertex cover is additional required to induce a connected subgraph in a given connected graph. The problem is known to be NP-hard and to be at least as hard to approximate as the vertex cover problem is. While several 2-approximation NC algorithms are known for vertex cover, whether unweighted or weighted, n...

We introduce and test a new method to detect annual forest cover loss from time series estimates of percent tree cover. Our approach is founded on two realistic assumptions: (1) land cover disturbances are rare events over large geographic areas that occur within a short time frame; and (2) spatially discrete land cover disturbances are continuous processes over time. Applying statistically rig...

On-Line Analytical Processing (OLAP) has become a crucial element of decision support systems. Since historical, summarized and consolidated data is used in OLAP, the concept of data cube is often used to provide multidimensional views for such information. Among range-aggregates that are typical operations over the data cube, we in this paper focus on efficient processing of range-MAX and rang...

Dena Biosphere Reserve located in Iran and is a 550 Biosphere Reserve in the worlds. This research was investigated in the two protected and non-protected areas, in a Dena Biosphere Reserve, Kohkeloye va Boyrahmad province, and central zagros forest, southwest of Iran. Inventory methods designed by systemetic-randomaiz method by use the rectangular plots that were 15×30 meters in the 100×100 m ...