A low cross-polarization slot array antenna in the narrow wall of ridge waveguide is presented. A non-angled slot which is created in the narrow wall of the ridge waveguide is considered to be used as radiating resonant slot. The normalized resistance and normalized reactance curves are presented for design purposes. A six element slot array waveguide antenna with ridges on its narrow wall is t...

This paper presents a novel implementation of an electromagnetically coupled patch antenna using air gap filled substrates to achieve the maximum bandwidth. We also propose an efficient modeling technique using the FDTD method which can substantially reduce the simulation cost for modeling the structure. The simulated results have been compared with measurement to show the broadband behavio...

Period 08/15/98-11/30/00, Title Active Seismic Imaging of Axial Volcano, PI's William Menke & Maya Tolstoy. The region of Axial Volcano, Juan de Fuca Ridge region provides an excellent opportunity to study the interplay between active "hot spot" and "mid-ocean ridge" magmatic systems. Important questions include how the two magma systems are fed; their magma and heat budgets; the degree of inte...

Database management systems are continuously being extended with support for new types of data and more advanced querying capabilities. In large part because of this, query optimization has remained a very active area of research throughout the past two decades. At the same time, current commercial optimizers are hard to modify, to incorporate desired changes in, e.g., query algebras, transform...

In this paper, we propose a new compact quasi-fractal shaped microstrip antenna that consists of a hexagonal patch as the main radiator and a complementary stacked patch as the parasitic element. The overall surface of the proposed quasi-fractal patch is about 55% lower than the conventional hexagonal patch. Using of stacked technique, the gain reduction of compression technique is almost compe...

Introduction: Io, the innermost of the Galilean satellites, is the most volcanically active body in our solar system. While its volcanic eruptions can be studied directly, our knowledge of the underlying magmatic processes rests wholly on indirect inferences. Here we combine constraints from magma ascent and crustal density models to gain insight into the plumbing system underlying the Promethe...

Controller Area Network (CAN) is a digital communications bus used by the automotive industry for invehicle networks. Research from the Real-Time Systems Group at the University of York introduced techniques that enable CAN to operate under high loads (approx. 80% utilisation) while ensuring that all messages meet their deadlines. The research led directly to the development of commercial produ...

Volcano observatories provide near real-time information and, ultimately, forecasts about volcano activity. For this reason, multiple physical and chemical parameters are continuously monitored. Here, we present a new method to efficiently estimate the location and evolution of magmatic sources based on a stream of real-time surface deformation data, such as High-Rate GPS, and a free-geometry m...

Volcanic eruptions cause significant loss of lives and property around the world each year. Their importance is highlighted by the sheer number of volcanoes for which eruptive activity is probable. These volcanoes are classified as in a state of unrest. The Global Volcano Project maintained by the Smithsonian Institution estimates that approximately 600 volcanoes, many proximal to major urban a...