Method and apparatus for contour mapping using synthetic aperture radar

By using two SAR antennas spaced a known distance, B, and oriented at substantially the same look angle to illuminate the same target area, pixel data from the two antennas may be compared in phase to determine a difference delta phi from which a slant angle theta is determined for each pixel point from an equation Delta phi = (2 pi B/lambda)sin(theta - alpha), where lambda is the radar wavelength and alpha is the roll angle of the aircraft. The height, h, of each pixel point from the aircraft is determined from the equation h = R cos theta, and from the known altitude, a, of the aircraft above sea level, the altitude (elevation), a', of each point is determined from the difference a - h. This elevation data may be displayed with the SAR image by, for example, quantizing the elevation at increments of 100 feet starting at sea level, and color coding pixels of the same quantized elevation. The distance, d, of each pixel from the ground track of the aircraft used for the display may be determined more accurately from the equation d = R sin theta

Natural Gas and Inequality in Bolivia after Nationalization

The high oil prices and the sharp increases in royalties mean that the natural gas boom in Bolivia has become very important for the economy. This paper uses a Computable General Equilibrium (CGE) model to assess the impacts of this boom on key macroeconomic variables as well as the distribution of incomes in the society. From a macroeconomic perspective, the natural gas boom is a blessing, adding around 1 percentage point to GDP growth rates for at least a decade, and sharply increasing government revenues available for public spending and investment. However, the poorest segments of the population (rural small-holders and urban informals) suffer actual reductions in their real incomes, compared to the counterfactual scenario without the gas boom. This means that the natural gas boom not only causes an increase in inequality but also an increase in poverty. The paper finishes with some policy recommendations on how to counteract the negative side effects of the natural gas boom.Natural Gas, Inequality, CGE model, Bolivia

Number of walks and degree powers in a graph

This note deals with the relationship between the total number of $k$-walks in a graph, and the sum of the $k$-th powers of its vertex degrees. In particular, it is shown that the the number of all $k$-walks is upper bounded by the sum of the $k$-th powers of the degrees

Stable Determination of the Electromagnetic Coefficients by Boundary Measurements

The goal of this paper is to prove a stable determination of the coefficients for the time-harmonic Maxwell equations, in a Lipschitz domain, by boundary measurements

Assessing `not in my backyard' environmental policies: Is carbon leakage worse than we thought?

In the last few decades, high-income and high-productivity countries have pushed their agenda towards environmentally friendly policies. The carbon leakage hypothesis predicts that these policies will increase the emissions in unregulated countries, which happen to be low-income and low-productivity nations. Using a panel at the country level, we show that, because of the productivity differential, heterogeneous regulations have increased net global emissions. These results are a call for international coordination and cooperation in order to achieve a sustainable global economy