In this work we discuss variants of a PDE based level set method. Traditionally interfaces are represented by the zero level set of continuous level set functions. We instead use piecewise constant level set functions, and let interfaces be represented by discontinuities. Some of the properties of the standard level set function are preserved in the proposed method. Using the methods for interf...

To organize information, librarians create structures. These structures grow from a logic that goes back at least as far as Aristotle. It is the basis of classification as we practice it, and thesauri and subject headings have developed from it. Feminist critiques of logic suggest that logic is gendered in nature. This article will explore how these critiques play out in contemporary standards ...

We consider a hierarchy of notions of largeness for subsets of Z (such as thick sets, syndetic sets, IP-sets, etc., as well as some new classes) and study them in conjunction with recurrence in topological dynamics and ergodic theory. We use topological dynamics and topological algebra in βZ to establish the connections between various notions of largeness and apply the obtained results to the ...

in this paper, the concept of countably near ps-compactness inl-topological spaces is introduced, where l is a completely distributive latticewith an order-reversing involution. countably near ps-compactness is definedfor arbitrary l-subsets and some of its fundamental properties are studied.

This paper is concerned with the use of the sampled-data H∞ servo controller with generalized hold for the track-following control of hard disk drives (HDDs). Conventional input multi-rate control normally utilizes a fast zero order hold that is uniformly time-divided piecewise constant function. However, there is no need to assume such an uniformity in hold duration. Elimination of this assump...

In a series of recent papers on nonparametric regression, D. Donoho and I. Johnstone developed wavelet shrinkage methods for recovering unknown piecewise-smooth deterministic signals from noisy data. Wavelet shrinkage based on the Bayesian approach involves specifying a prior distribution on the wavelet coeecients, which is usually assumed to have a distribution with zero mean. There is no a pr...

Some useful features of microstrip patch antennas are low profile, low weight and easy fabrication. However this type of antenna suffers from having a low gain, caused by propagation surface waves. In this paper, a new near zero refractive index metamaterial (MTM) unit cell is designed and fabricated as a superstrate over a Rectangular Microstrip Patch Antennas (RMPA). In order to obtain a maxi...

Curvature continuous surfaces can be generated by tracing the zero set of a trivariate box spline of degree four. This box spline is deened by seven directions that form a regular partition of space into tetrahedra so that an eecient approximate evaluation is obtained via subdivision and piecewise linear approximation. There is a natural representation of hierarchical data by perturbation at va...