this paper aims to assess the quality and accuracy aster dems and the arcgis alogorthms used for hydrologic analyses. to this end, first the plan of drainage networks in the region was extracted from aerial photographs and high resolution satellite images and was set as the real ground. in the next step, using the hydrology tool in arcgis software, raster networks of the region for the whole ca...

Nowadays, the internet and social networks become more popular than ever. People in all ages use the internet and communicate by that. One of the most terrible events in our daily life is to disconnect from the internet and lose the connections. It may also influence on the economics; so the sustainability in this area is necessary. Internet service provider companies are the executors of selli...

Nowadays, the internet and social networks become more popular than ever. People in all ages use the internet and communicate by that. One of the most terrible events in our daily life is to disconnect from the internet and lose the connections. It may also influence on the economics; so the sustainability in this area is necessary. Internet service provider companies are the executors of selli...

Low-phosphorus (P) stress as a key factor limiting plant growth and production is common in most agricultural soils. Most of the soil-applied phosphate will be rapidly immobilized and most of annually applied phosphate fertilizers are fixed in the soil in organic forms by adsorption, sedimentation and transformation. However, excess P application may lead to contamination of water sources by en...

the conventional method towards deriving schedule for a fleet of ships to minimize cost alone has the short-coming of not addressing the problem of operation revenue losses associated with delays during maintenance at ships dockyards. in this paper, a preventive maintenance schedule for a fleet of ships that incorporates op-portunity cost is presented. the idea is to assign a penalty cost to al...