Development of a prototype plastic space erectable satellite Quarterly report, Dec. 1965 - Feb. 1966

Plastic space erectable satellit

Reverse engineering of CAD models via clustering and approximate implicitization

In applications like computer aided design, geometric models are often represented numerically as polynomial splines or NURBS, even when they originate from primitive geometry. For purposes such as redesign and isogeometric analysis, it is of interest to extract information about the underlying geometry through reverse engineering. In this work we develop a novel method to determine these primitive shapes by combining clustering analysis with approximate implicitization. The proposed method is automatic and can recover algebraic hypersurfaces of any degree in any dimension. In exact arithmetic, the algorithm returns exact results. All the required parameters, such as the implicit degree of the patches and the number of clusters of the model, are inferred using numerical approaches in order to obtain an algorithm that requires as little manual input as possible. The effectiveness, efficiency and robustness of the method are shown both in a theoretical analysis and in numerical examples implemented in Python

Development of a prototype plastic space erectable satellite Quarterly report, Jun. - Aug. 1966

Copper plated high-density polyethylene film evaluation for space erectable satellite desig

Empirical Studies Applied to Software Process Models

Working Group Report: ICSE'99 Workshop on Empirical Studies of Software Development and Evolutio

Development of a prototype plastic space erectable satellite Quarterly report, Mar. - May 1966

Mechanical and tensile properties of polyethylene films for prototype plastic space erectable structure

The emergence of an educational tool industry: Opportunities and challenges for innovation in education

The paper addresses two issues. One concerns the general conditions and procedures involved in the emergence of a tool industry. Tool industries emerge and evolve as a collection of capital goods and tool inventors and manufacturers. One of our goals is to use some of the works on historical cases to build a heuristic framework concerning the main conditions for the emergence and development of tool industries. The other issue is more factual and involves the question whether a tool industry is today emerging in the area of education. The paper describes the emergence of a population of firms specialised in developing and commercialising educational tools and instructional technologies and discuss whether this trend can be seen as part of the solution to the innovation deficit and cost disease problems in this sector? (C) 2014 Elsevier B.V. All rights reserved

Towards an optimum design of wave energy converter arrays through an integrated approach of life cycle performance and operational capacity

Premio ETSI al mejor artículo científico del trimestre. 3a ed. Junio 2018 -Artículo subido a idUS con permiso de su primer autor (López-Ruiz, Alejandro), que proporciona las versiones preprint y postprint.Over the last few decades, several efforts have been made to develop an alternative and sustainable energy source from wind waves. To achieve financial sustainability of this technology, most of the research has focused on analyzing facilities composed of several wave energy converters (WECs) arrays instead of isolated ones. Although the interaction between devices and its implications on the performance of the facilities have been studied previously, these works considered only certain combinations of sea states, limiting the applicability of the results. This work applies a new methodology based on statistical methods to assess the performance of different WEC array distributions during their entire life-cycle in an efficient way, using downscaling techniques and advanced numerical modeling to propagate the wave climate. The results obtained during the hindcasting life-cycle are used to analyze the maintenance and operation capabilities of the different alternatives of arrays defined for the WEC facility. The interactions between devices and their efficiency considering the associated impact are also quantified. The assessment of these efficiencies during the complete life-cycle of the devices is highly valuable tool for promoters and coastal managers to evaluate different WEC array alternatives. The entire process was applied to a hypothetical array location in the Gulf of Cádiz (southwestern Spain), where three different array distributions were defined. The results show that the distance between WECs is a key parameter that controls the potential energy production, the efficiency of the facility and the interactions between several devices.Ministerio de Economía y Competitividad BES-2013-062617Universidad de Sevill

Towards an optimum design of wave energy converter arrays through an integrated approach of life cycle performance and operational capacity

Premio ETSI al mejor artículo científico del trimestre. 3a ed. Junio 2018 -Artículo subido a idUS con permiso de su primer autor (López-Ruiz, Alejandro), que proporciona las versiones preprint y postprint.Over the last few decades, several efforts have been made to develop an alternative and sustainable energy source from wind waves. To achieve financial sustainability of this technology, most of the research has focused on analyzing facilities composed of several wave energy converters (WECs) arrays instead of isolated ones. Although the interaction between devices and its implications on the performance of the facilities have been studied previously, these works considered only certain combinations of sea states, limiting the applicability of the results. This work applies a new methodology based on statistical methods to assess the performance of different WEC array distributions during their entire life-cycle in an efficient way, using downscaling techniques and advanced numerical modeling to propagate the wave climate. The results obtained during the hindcasting life-cycle are used to analyze the maintenance and operation capabilities of the different alternatives of arrays defined for the WEC facility. The interactions between devices and their efficiency considering the associated impact are also quantified. The assessment of these efficiencies during the complete life-cycle of the devices is highly valuable tool for promoters and coastal managers to evaluate different WEC array alternatives. The entire process was applied to a hypothetical array location in the Gulf of Cádiz (southwestern Spain), where three different array distributions were defined. The results show that the distance between WECs is a key parameter that controls the potential energy production, the efficiency of the facility and the interactions between several devices.Ministerio de Economía y Competitividad BES-2013-062617Universidad de Sevill

Contribución al conocimiento de Tegenaria domestica (Clerck, 1757) (Araneae: Agelenidae) en la Patagonia Austral

Se revisa y analiza la presencia de la araña Tegenaria domestica en la Patagonia austral. Se entregan nuevos registros para las provincias de Santa Cruz y Tierra del Fuego en Argentina y se confirma su presencia en la región de Magallanes en Chile. Se discute la significancia de los registros históricos y los nuevos aquí entregados. Se proveen ilustraciones para identificar correctamente esta especie.The presence of the spider Tegenaria domestica in southern Patagonia is revised and analyzed. New records are provided from Santa Cruz and Tierra del Fuego Province Argentina, and its presence is confirmed in Magallanes Region, Chile. The significance of the historical records and the new ones is discussed. Illustrations are provided to correctly identify the species.Fil: Faúndez, Eduardo I.. Universidad de Magallanes; ChileFil: Carvajal, Mariom A.. Universidad de Magallanes; ChileFil: Asplanato, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Austral de Investigaciones Científicas; ArgentinaFil: Raffo, Flavia. Parque Nacional Los Glaciares; ArgentinaFil: Vargas, Catalina J.. Universidad de Magallanes; Chil

A Comprehensive Overview of the Temperature-Dependent Modeling of the High-Power GaN HEMT Technology Using mm-Wave Scattering Parameter Measurements (Invited Paper)

The gallium-nitride (GaN) high electron-mobility transistor (HEMT) technology has emerged as an attractive candidate for high-frequency, high-power, and high-temperature applications due to the unique physical characteristics of the GaN material. Over the years, much effort has been spent on measurement-based modeling since accurate models are essential for allowing the use of this advanced transistor technology at its best. The present analysis is focused on the modeling of the scattering (S-) parameter measurements for a 0.25 μm GaN HEMT on silicon carbide (SiC) substrate at extreme operating conditions: a large gate width (i.e., the transistor is based on an interdigitated layout consisting of ten fingers, each with a length of 150 μm, resulting in a total gate periphery of 1.5 mm), a high ambient temperature (i.e., from 35 °C up to 200 °C with a step of 55 °C), a high dissipated power (i.e., 5.1 W at 35 °C), and a high frequency in the millimeter-wave range (i.e., from 200 MHz up to 65 GHz with a step of 200 MHz). Three different modeling approaches are investigated: the equivalent-circuit model, artificial neural networks (ANNs), and gated recurrent units (GRUs). As is shown, each modeling approach has its pros and cons that need to be considered, depending on the target performance and their specifications. This implies that an appropriate selection of the transistor modeling approach should be based on discerning and prioritizing the key features that are indeed the most important for a given application