Integrated control-structure design

A new approach for the design and control of flexible space structures is described. The approach integrates the structure and controller design processes thereby providing extra opportunities for avoiding some of the disastrous effects of control-structures interaction and for discovering new, unexpected avenues of future structural design. A control formulation based on Boyd's implementation of Youla parameterization is employed. Control design parameters are coupled with structural design variables to produce a set of integrated-design variables which are selected through optimization-based methodology. A performance index reflecting spacecraft mission goals and constraints is formulated and optimized with respect to the integrated design variables. Initial studies have been concerned with achieving mission requirements with a lighter, more flexible space structure. Details of the formulation of the integrated-design approach are presented and results are given from a study involving the integrated redesign of a flexible geostationary platform

The geometry of quantum learning

Concept learning provides a natural framework in which to place the problems solved by the quantum algorithms of Bernstein-Vazirani and Grover. By combining the tools used in these algorithms--quantum fast transforms and amplitude amplification--with a novel (in this context) tool--a solution method for geometrical optimization problems--we derive a general technique for quantum concept learning. We name this technique "Amplified Impatient Learning" and apply it to construct quantum algorithms solving two new problems: BATTLESHIP and MAJORITY, more efficiently than is possible classically.Comment: 20 pages, plain TeX with amssym.tex, related work at http://www.math.uga.edu/~hunziker/ and http://math.ucsd.edu/~dmeyer

Archaeological Testing at Goliad State Park, Goliad County, Texas

In December 1996, the Center for Archaeological Research (CAR) of The University of Texas at San Antonio entered into a contract with the Texas Parks and Wildlife Department to conduct archaeological investigations at Mission Espiritu Santo in Goliad State Park. On December 17, 1996, a seven-member field crew from CAR excavated 32 shovel tests along the proposed trench for replacement of existing park water and electrical lines between the mission compound and the camping area. Artifacts recovered from the shovel tests include Spanish colonial ceramics, glass, metal, stone tools and debitage, and a large quantity of animal bone. Most of the artifacts were recovered from the shovel test pits near the mission wall. Any new trenching in this area would disturb possible intact Colonial deposits. Very few artifacts were recovered from the remainder of the proposed trench line

On the Born-Oppenheimer approximation of diatomic molecular resonances

We give a new reduction of a general diatomic molecular Hamiltonian, without modifying it near the collision set of nuclei. The resulting effective Hamiltonian is the sum of a smooth semiclassical pseudodifferential operator (the semiclassical parameter being the inverse of the square-root of the nuclear mass), and a semibounded operator localised in the elliptic region corresponding to the nuclear collision set. We also study its behaviour on exponential weights, and give several applications where molecular resonances appear and can be well located.Comment: 22 page

Wavelength conversion at 10 Gb/s by four-wave mixing over a 30-nm interval

We show that the use of a long semiconductor optical amplifier increases the error-free conversion interval of a four-wave mixing (FWM)-based wavelength converter. 30-nm wavelength down-conversion and 15-nm up-conversion have been obtained at 10 Gb/s. This result is a significant improvement over the previous best performance of a FWM-based wavelength converter and suggests that the full erbium-doped fiber amplifier bandwidth can be covered with FWM wavelength converters

30-nm wavelength conversion at 10 Gbit/s by four-wave mixing in a semiconductor optical amplifier

Four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is currently the only available strictly transparent wavelength-conversion technique, which is not penalized by phase matching. The span of the conversion is limited primarily by conversion efficiency and signal-to-noise (SNR) issues, both of which are expected to improve with the use of longer SOAs. In this paper, we demonstrate significantly enhanced performance of long converters in a system experiment at 10 Gbit/s. The experiment shows for the first time, to our knowledge, that FWM wavelength down-conversions can span the full gain bandwidth of erbium-doped fiber amplifiers

Elatine lorentziana Hunz.

Sierra Grande (Falda E): La Gurisa, hacia el N de Ruta Nº 20, entre La Ollada y Pampa del MataderopublishedVersio

Cuscuta platyloba Progel var. pampeana Hunz.

Ruta Nacional Nº 3: Ea. Santa María., Pedro Luro, inmediaciones del Río ColoradopublishedVersio

Chenopodium quinoa var. lutescens Hunz.

Granja KcairapublishedVersio

Agrostis ambatoensis Asteg.

Sierra de Ambato (Falda E, subiendo desde El Rodeo), cerca de la Cumbre del Cerro ManchadopublishedVersio