Electric Fields of an H-Plane Tapered Iris

Microwave electric fields of an X -band H -plane tapered iris are calculated and plotted using the moment method for the first time. The moment method results are compared with previously obtained experimental measurements and numerical results based on an equivalent circuit approach, giving confirmation that the tapered iris is both a reciprocal and asymmetrical network. The moment method results now reveal that the asymmetry stems from the asymmetry in the phase of the input and output voltage reflection coefficients, their magnitudes being equal

Competition, Innovation and Racing for Priority at the U.S. Patent and Trademark Office

The U.S. Patent and Trademark Office resolves patent priority disputes in patent interference cases. Using a random sample of cases declared between 1988 and 1994, we establish a connection between patent interferences and patent races, and then use the data to consider some key issues in dynamic competition and innovation. We look at the incidence and distribution of patent races by technology, evidence for strategic delay of innovation by incumbent firms, and evidence that patent races moderate incentives to delay. Our results have implications for patent policy in general and for evaluating the U.S. “first to invent†patent priority rule.Patent race, Patent interference, US Board of Patent Appeals and Interferences, Patent litigation; Innovation; Research and development

Electromagnetic Field Plot of an Inductive Window by the Moment Method

A moment method is used to plot the electromagnetic field of an inductive window in a TE10 -mode rectangular waveguide. Green\u27s dyadic functions are derived based on Tai\u27s approach, which is a modified form of Hansen\u27s vector wave functions. Based on the computed electric fields, the S matrix and the equivalent aperture reactance of the waveguide window are calculated. This calculation agrees with the previously published closed-form results of Marcuvitz

An approximation scheme for an Eikonal Equation with discontinuous coefficient

We consider the stationary Hamilton-Jacobi equation where the dynamics can vanish at some points, the cost function is strictly positive and is allowed to be discontinuous. More precisely, we consider special class of discontinuities for which the notion of viscosity solution is well-suited. We propose a semi-Lagrangian scheme for the numerical approximation of the viscosity solution in the sense of Ishii and we study its properties. We also prove an a-priori error estimate for the scheme in an integral norm. The last section contains some applications to control and image processing problems

Nuclear Force from Monte Carlo Simulations of Lattice Quantum Chromodynamics

The nuclear force acting between protons and neutrons is studied in the Monte Carlo simulations of the fundamental theory of the strong interaction, the quantum chromodynamics defined on the hypercubic space-time lattice. After a brief summary of the empirical nucleon-nucleon (NN) potentials which can fit the NN scattering experiments in high precision, we outline the basic formulation to derive the potential between the extended objects such as the nucleons composed of quarks. The equal-time Bethe-Salpeter amplitude is a key ingredient for defining the NN potential on the lattice. We show the results of the numerical simulations on a $32^4$ lattice with the lattice spacing $a \simeq 0.137$fm (lattice volume (4.4 fm)$^4$) in the quenched approximation. The calculation was carried out using the massively parallel computer Blue Gene/L at KEK. We found that the calculated NN potential at low energy has basic features expected from the empirical NN potentials; attraction at long and medium distances and the repulsive core at short distance. Various future directions along this line of research are also summarized.Comment: 13 pages, 4 figures, version accepted for publication in "Computational Science & Discovery" (IOP

Continuous dependence results for Non-linear Neumann type boundary value problems

We obtain estimates on the continuous dependence on the coefficient for second order non-linear degenerate Neumann type boundary value problems. Our results extend previous work of Cockburn et.al., Jakobsen-Karlsen, and Gripenberg to problems with more general boundary conditions and domains. A new feature here is that we account for the dependence on the boundary conditions. As one application of our continuous dependence results, we derive for the first time the rate of convergence for the vanishing viscosity method for such problems. We also derive new explicit continuous dependence on the coefficients results for problems involving Bellman-Isaacs equations and certain quasilinear equation

Ultralow mode-volume photonic crystal nanobeam cavities for high efficiency coupling to individual carbon nanotube emitters

We report on high efficency coupling of individual air-suspended carbon nanotubes to silicon photonic crystal nanobeam cavities. Photoluminescence images of dielectric- and air-mode cavities reflect their distinctly different mode profiles and show that fields in the air are important for coupling. We find that the air-mode cavities couple more efficiently, and estimated spontaneous emission coupling factors reach a value as high as 0.85. Our results demonstrate advantages of ultralow mode-volumes in air-mode cavities for coupling to low-dimensional nanoscale emitters.Comment: 4 pages, 4 figure