Lake Merced results have established the lake as a viable paleoseismic site on the northern San Francisco peninsula. The lake records ~ 2300 years of event beds, 17 in total. Prior to that the lake was open to the ocean and contains marine shells consistent with an estuarine environment. The...
A versatile computational technique for improved time domain modeling of electromagnetic radiative systems is demonstrated. Two computational methods are combined: the finite-difference time domain (FDTD) method, a full-wave electromagnetic field solver, and the Kirchhoff surface integral formulation, a spatial transformation technique. The combined FDTD/Kirchhoff technique is shown to increase accuracy...
This work is concerned with the modeling and analysis of lossy planar dielectric
optical waveguides. Loss mechanisms which affect propagation characteristics are
reviewed, and various representations of the propagation constant in the lossy case
are defined. Waveguide structures which are susceptable to absorption and/or to
leakage loss, in particular silicon-based...
In cellular telephones, RF power amplifiers consume a significant part of the total phone current. Reducing the average PA current will extend battery life. In GSM systems the handset is commanded by the base station to transmit at power levels lower than full power much of the time. A Doherty...
Plastic packaging is a cost-effective solution for housing RF and microwave integrated circuits in low cost communication devices. While enabling low cost packaging of integrated circuits, plastic packages including the circuit ground patch (paddle) inside the package can have a significant parasitic effect on circuit performance. The purpose of this...
Contemporary circuit design involves significant computer-based simulation, calling for a balance between circuit model accuracy and simulation run time. Traditionally, circuit modelers concentrated on producing either (1) physically-based models, where each element in the model correlates to a physically meaningful aspect of the device being modeled or (2) mathematically-based "macromodels,"...
This study tested the utility of a variable mixing efficiency formulation proposed by Mashayek, et al. (2017) for use in oceanographic models other than the modern, pre-industrial ocean. This formulation is used to calculate diapycnal (vertical) mixing due to unresolved subgrid-scale processes. Results from Last Glacial Maximum (LGM) simulations for...
We present a new nitrogen isotope model incorporated into the three-dimensional ocean component of a global Earth System Climate Model designed for millennial timescale simulations. The model includes prognostic tracers for the stable nitrogen isotopes, ¹⁴N and ¹⁵N, in the nitrate (NO₃ˉ), phytoplankton, zooplankton, and detritus variables of the marine...