plants polluted with pb produced by automobiles along the roads and highways have extensively been reported all over the world. it is the most important source of pollution in the environment. this research was carried out to determine the polluting degree of plants along the highways such as: rasht-anzaly, kelachay-ramsar, tehran-karaj, and isfahan-tehran. at each arbitrary point, a transect 1...

Landscape patterns are closely related to ecological processes. Different spatial scales and research methods may lead to different results. Therefore, it is crucial to choose suitable research methods when studying different landscape patterns and ecological processes. In the present study, the methods of source-sink landscape theory were applied to the interactions between urban landscape cha...

Transportation networks and governments are both hierarchically organized. In some states state government finances most of the highways, while in other states similar roads are financed locally. Larger governments attain scale economies. However they also tend to be more bureaucratic and have higher operating costs, all else equal, due to problems such as span of control. This study relates hi...

The objective of the Interconnecting Highways problem is to construct roads of minimum total length to interconnect n given highways under the constraint that the roads can intersect each highway only at one point in a designated interval which is a line segment. We present a polynomial time approximation scheme for this problem by applying Arora’s framework in [2]. For every fixed c > 1 and gi...

Automatic extraction of roads is a present research topic. Many applications like topographic mapping, navigation applications, or image registration could profit from such algorithms. This paper is concerned with automatic road extraction from synthetic aperture radar (SAR) imagery. An approach originally developed for the extraction of roads in rural areas from optical imagery with a ground p...

We examine the link between highways and urban development by employing both hedonic analysis and multiple sales techniques to study the impact of the construction of toll roads in Orange County, California, on house prices. Urban economic theory predicts that if highways improve accessibility, that accessibility premium will be reflected in higher land prices. Our empirical analyses of house s...

We exploit historical data on planned highways, railroads, and exploration routes as sources of exogenous variation in order to estimate the effect of interstate highways on regional innovation: a 10% increase in a region’s stock of highways causes a 1.7% increase in regional patenting over a five-year period. In terms of the mechanism, we report evidence that roads facilitate local knowledge f...

whereas in other states similar roads are financed locally. Larger governments attain scale economies. However, they also tend to be more bureaucratic and have higher operating costs, all else being equal, because of problems such as span of control. A study was done to relate highway expenditures with the share of expenditure by state governments to determine how governments should allocate ex...