Development of a 200 W CW High Efficiency Traveling Wave Tube at 12 GHz

The design, development, and test results are reported for an experimental PPM focused, traveling-wave tube that produces 235 watts of CW RF power over 85 MHz centered at 12.080 GHz. The tube uses a coupled cavity RF circuit with a velocity taper for greater than 30 percent basic efficiency. Overall efficiency of 51 percent is achieved by means of a nine stage depressed collector designed at NASA Lewis Research Center. This collector is cooled by direct radiation to deep space

The Warburg Dance Movement Library-The WADAMO Library: A Validation Study

The Warburg Dance Movement Library is a validated set of 234 video clips of dance movements for empirical research in the fields of cognitive science and neuroscience of action perception, affect perception and neuroaesthetics. The library contains two categories of video clips of dance movement sequences. Of each pair, one version of the movement sequence is emotionally expressive (Clip a), while the other version of the same sequence (Clip b) is not expressive but as technically correct as the expressive version (Clip a). We sought to complement previous dance video stimuli libraries. Facial information, colour and music have been removed, and each clip has been faded in and out. We equalised stimulus length (6 seconds, 8 counts in dance theory), the dancers’ clothing and video background and included both male and female dancers, and we controlled for technical correctness of movement execution. The Warburg Dance Movement Library contains both contemporary and ballet movements. Two online surveys (N = 160) confirmed the classification into the two categories of expressivity. Four additional online surveys (N = 80) provided beauty and liking ratings for each clip. A correlation matrix illustrates all variables of this norming study (technical correctness, expressivity, beauty, liking, luminance, motion energy)

VLSI design of the tiny RISC microprocessor

This report describes the Tiny RISC microprocessor designed at UC Irvine. Tiny RISC is a 16-bit microprocessor and has a RISC-style architecture. The chip was fabricated by MOSIS [1] in a 2μm n-well CMOS technology. The processor has a cycle time of 70 ns

En route position and time control of aircraft using Kalman filtering of radio aid data

Fixed-time-of-arrival (FTA) guidance and navigation is investigated as a possible technique capable of operation within much more stringent en route separation standards and offering significant advantages in safety, higher traffic densities, and improved scheduling reliability, both en route and in the terminal areas. This study investigated the application of FTA guidance previously used in spacecraft guidance. These FTA guidance techniques have been modified and are employed to compute the velocity corrections necessary to return an aircraft to a specified great-circle reference path in order to exercise en route time and position control throughout the entire flight. The necessary position and velocity estimates to accomplish this task are provided by Kalman filtering of data from Loran-C, VORTAC/TACAN, Doppler radar, radio or barometric altitude,and altitude rate. The guidance and navigation system was evaluated using a digital simulation of the cruise phase of supersonic and subsonic flights between San Francisco and New York City, and between New York City and London

On Self-Organized Criticality and Synchronization in Lattice Models of Coupled Dynamical Systems

Lattice models of coupled dynamical systems lead to a variety of complex behaviors. Between the individual motion of independent units and the collective behavior of members of a population evolving synchronously, there exist more complicated attractors. In some cases, these states are identified with self-organized critical phenomena. In other situations, with clusterization or phase-locking. The conditions leading to such different behaviors in models of integrate-and-fire oscillators and stick-slip processes are reviewed.Comment: 41 pages. Plain LaTeX. Style included in main file. To appear as an invited review in Int. J. Modern Physics B. Needs eps

Ultraviolet downconverting phosphor for use with silicon CCD imagers

The properties and application of a UV downconverting phosphor (coronene) to silicon charge coupled devices are discussed. Measurements of the absorption spectrum have been extended to below 1000 A, and preliminary results indicate the existence of useful response to at least 584 A. The average conversion efficiency of coronene was measured to be ~20% at 2537 A. Imagery at 3650 A using a backside illuminated 800 X 800 CCD coated with coronene is presented

What controls the large-scale magnetic fields of M dwarfs?

Observations of active M dwarfs show a broad variety of large-scale magnetic fields encompassing dipole-dominated and multipolar geometries. We detail the analogy between some anelastic dynamo simulations and spectropolarimetric observations of 23 M stars. In numerical models, the relative contribution of inertia and Coriolis force in the global force balance -estimated by the so-called local Rossby number- is known to have a strong impact on the magnetic field geometry. We discuss the relevance of this parameter in setting the large-scale magnetic field of M dwarfs.Comment: 4 pages, 3 figures, conference proceeding, IAUS 302 'Magnetic Fields Throughout the Stellar Evolution', (26-30 Aug 2013, Biarritz, France

What controls the magnetic geometry of M dwarfs?

Context: observations of rapidly rotating M dwarfs show a broad variety of large-scale magnetic fields encompassing dipole-dominated and multipolar geometries. In dynamo models, the relative importance of inertia in the force balance -- quantified by the local Rossby number -- is known to have a strong impact on the magnetic field geometry. Aims: we aim to assess the relevance of the local Rossby number in controlling the large-scale magnetic field geometry of M dwarfs. Methods: we explore the similarities between anelastic dynamo models in spherical shells and observations of active M-dwarfs, focusing on field geometries derived from spectropolarimetric studies. To do so, we construct observation-based quantities aimed to reflect the diagnostic parameters employed in numerical models. Results: the transition between dipole-dominated and multipolar large-scale fields in early to mid M dwarfs is tentatively attributed to a Rossby number threshold. We interpret late M dwarfs magnetism to result from a dynamo bistability occurring at low Rossby number. By analogy with numerical models, we expect different amplitudes of differential rotation on the two dynamo branches.Comment: 4 pages, 4 figures, accepted for publication in A&