While 4-round constructions of zero-knowledge arguments are known based on the existence of one-way functions, constuctions of resettably-sound zero-knowledge arguments require either stronger assumptions (the existence of a fully-homomorphic encryption scheme), or more communication rounds. We close this gap by demonstrating a 4round resettably-sound zero-knowledge argument for NP based on the...

This paper uses contingent behavior and contingent pricing analyses to explore the proper valuation of time and transport costs within the context of recreation demand. The contingent behavior analysis poses hypothetical increases in access fees, travel time, and travel distance and considers recreation demand responses. As a useful complement, the contingent pricing analysis poses hypothetical...

A robust and efficient algorithm for trimming both local and global self-intersections in offset curves and surfaces is presented. Our scheme is based on the derivation of a rational distance map between the original curve or surface and its offset. By solving a bivariate polynomial equation for an offset curve or a system of three polynomial equations for an offset surface, all local and globa...

[1] Diurnal cycles in snow-fed streams provide a useful technique for measuring the time it takes water to travel from the top of the snowpack, where snowmelt typically peaks in the afternoon, to the river gauge, where the daily maximum flows may arrive many hours later. Hourly stage measurements in nested subbasins (6–775 km) of the Tuolumne River in Yosemite National Park illustrate travel ti...

In a recent technical article in First Break, Gausland (2004) made the case that the result of stacking is not limited to the often quoted factor of reduction in noise where n is the fold of a CMP-gather. Through his figures and illustrations, Gausland showed that stacking also acts as a frequency and wavenumber filter. Although the intentions of the article were not to, as Gausland put it, ‘gi...

Traditional transmission travel-time tomography hinges on ray tracing techniques. We propose a PDE-based Eulerian approach to travel-time tomography so that we can avoid the cumbersome ray-tracing. We start from the eikonal equation, define a mismatching functional and derive the gradient of the nonlinear functional by an adjoint state method. The resulting forward and adjoint problems can be e...

The analytical Green’s functions for the equations of zero-offset and non-zero offset migration were previously derived for a homogeneous velocity model and the far-field approximation. These approximations restricted their practical application to field data. I now derive the analytical migration Green’s functions for an inhomogeneous medium using a stationary phase approximation. These Green’...

Stem thermocouple hygrometers were subjected to transient and stable thermal gradients while in contact with reference solutions of NaCl. Both dew point and psychrometric voltages were directly related to zero offset voltages, the latter reflecting the size of the thermal gradient. Although slopes were affected by absolute temperature, they were not affected by water potential. One hygrometer r...