Global design of analog cells using statistical optimization techniques

We present a methodology for automated sizing of analog cells using statistical optimization in a simulation based approach. This methodology enables us to design complex analog cells from scratch within reasonable CPU time. Three different specification types are covered: strong constraints on the electrical performance of the cells, weak constraints on this performance, and design objectives. A mathematical cost function is proposed and a bunch of heuristics is given to increase accuracy and reduce CPU time to minimize the cost function. A technique is also presented to yield designs with reduced variability in the performance parameters, under random variations of the transistor technological parameters. Several CMOS analog cells with complexity levels up to 48 transistors are designed for illustration. Measurements from fabricated prototypes demonstrate the suitability of the proposed methodology

Reconstruction of drought episodes for central Spain from rogation ceremonies recorded at the Toledo Cathedral from 1506 to 1900: A methodological approach

Rogation (ceremonies to ask God for rain: pro-pluvia, or to stop raining: pro-serenitate) analysis is an effective method to derive information about climate extremes from documentary data. Weighted annual sum by levels has been a widespread technique to analyze such data but this analysis is liable to be biased to spring values as these ceremonies are strongly related to farming activities. The analysis of the length of propluvia periods (the time span during which rogations are carried out in relation to a drought event) and the combination of annual and seasonal information offers a more objective criterion for the analysis of the drought periods and an increase in the resolution of the study. Analysis by the pro-pluvia periods method of the rogation series from the Toledo (central Spain) Cathedral Chapter allows a good characterization of the droughts during the 1506–1900 period. Two drought maxima appear during the 1600–1675 and 1711–1775 periods, characterized by rogations during almost all the year, with a middle stage (1676–1710) when droughts were less frequent and their length shortened. Sea level pressure patterns for the instrumental and documentary periods show that droughts were mostly related to a north-eastern position of the Azores High that displaced the Atlantic lowpressure systems towards a northern position. There is a weak relation with the North Atlantic Oscillation but this fact is related to the local character of the series that increases the weight of the local factors. Comparison of rainfall/drought records around Spain and theWestern Mediterranean reveals the heterogeneity of their distribution in time and space as well as stresses the need of more and longer reconstructions. Better knowledge of drought variability would help to improve regional models of climate extremes and the understanding of the atmospheric patterns related to their development

IMPLEMENTACIÓN DE SERVICIOS IPV6 EN LA UNIVERSIDAD AUTÓNOMA DE GUERRERO, MÉXICO

Al día de hoy, la comunicación en Internet es posible gracias a la suite de protocolos TCP/IP que tiene como base el Protocolo de Internet IPv4. Pero también, es una realidad que el direccionamiento público de IP está agotándose vertiginosamente y que el desempeño de muchas aplicaciones de extremo a extremo necesita de direccionamiento real para un mejor desempeño. Ésta es una de las razones principales por las cuales hace más de diez años se iniciara con las pruebas de un nuevo protocolo de red que pudiera responder a necesidades de comunicación inimaginables, pero que dado el crecimiento exponencial de Internet IPv6 pasará a ser el protocolo de comunicaciones estándar.En la Universidad Autónoma de Guerrero (UAGro), a principios de 2012 se inició el proyecto para la implementación de servicios de Internet soportados en un ambiente de comunicaciones dual mediante IPv4 e IPv6. El objetivo de este proceso es promover el uso y aplicación del protocolo de nueva generación en las instituciones educativas con la finalidad de obligar a los proveedores de comunicaciones a soportar IPv6 como protocolo nativo de manera que los tiempos de transición sean reducidos y se puedan explotar con mayor eficiencia muchas de las aplicaciones de extremo a extremo que hoy operan mediante procesos que sobrecargan las tareas de los equipos de enrutamiento

Evolución de eventos climáticos extremos (inundaciones y sequías) para la zona central de la Península Ibérica desde el siglo XVI a partir del registro de rogativas e inundaciones históricas.

En este trabajo se presenta la evolución desde 1500 a 1900 de dos tipos de eventos climáticos extremos característicos de la Península Ibérica, las inundaciones y las sequías. Este estudio se ha llevado a cabo en la meseta sur de la Península. Aprovechando la continuidad del registro documental desde el s. XVI hasta nuestros días para la zona de estudio, hemos utilizado registros de rogativas e inundaciones históricas del rio Tajo, acaecidas en Aranjuez, Toledo y Talavera. En los cuatro siglos estudiados, parece que los periodos en los que hay una alta frecuencia de sequías también existe una alta frecuencia de inundaciones, aunque estos eventos raramente coinciden en un mismo año. En función de la frecuencia y la intensidad de los eventos, se han distinguido seis periods, dos con una alta frecuencia de eventos (1557-1623), (1717-1798), uno con frencuencia media (1624-1716), dos con frecuencias bajas (1500-1556) y (1798-1850), debido probablemente a un aumento de la presión antrópica sobre los cauces y una disminución en la frecuencia de rogativas por motivos sociopolíticos

Proceso de exportación de emulsiones para la elaboración de jugos hacia la república de Argentina

Administrador (a) de EmpresasPregrad

CMOS Architectures and circuits for high-speed decision-making from image flows

We present architectures, CMOS circuits and CMOS chips to process image flows at very high speed. This is achieved by exploiting bio-inspiration and performing processing tasks in parallel manner and concurrently with image acquisition. A vision system is presented which makes decisions within sub-msec range. This is very well suited for defense and security applications requiring segmentation and tracking of rapidly moving objects

A CMOS 0.8 μm fully differential current mode buffer for HF SI circuits

El pdf del artículo es la versión post-print.We present a high-frequency fully-differential current-mode buffer to interface off-chip currents with no significant degradation of the frequency response, and to measure current-mode ICs using standard equipment. It has been fabricated in a 0.8μm double-poly double-metal CMOS technology and features more than 37MHz bandwidth. In order to show its functionality, this unit has been incorporated to the front end of a Switched-Current Band-Pass ΣΔ modulator featuring 9 bit dynamic range at 10MHz clock frequency for a 30kHz signal bandwidth centered at 2.5MHz.Peer reviewe

Twelve years of daily weather descriptions in North America in the eighteenth century (Mexico City, 1775-86)

© 2019 American Meteorological Society. The authors are very grateful to Ana Gavilán and César Paradinas for their help with the transcription of the FZO weather diary. Carlos Ordóñez reviewed the language. This work was supported by the research projects IMDROFLOOD financed by the Water Works 2014 cofunded call of the European Commission and INDECIS, which is part of ERA4CS, an ERA-NET initiated by JPI Climate by the European Union (Grant 690462). Marina Peña-Gallardo was granted by the Spanish Ministry of Economy and Competitiveness (MINECO), and Ahmed El Kenawy was supported by a postdoctoral Juan de la Cierva contract by the Spanish Ministry of Economy and Competitiveness (MINECO). F. Domínguez-Castro, M. C. Gallego, J. M. Vaquero, R. García Herrera, M. Peña-Gallardo, A. El Kenawy, and S. M. Vicente-SerranoDepto. de Física de la Tierra y AstrofísicaFac. de Ciencias FísicasTRUEUnión Europea. H2020Ministerio de Economía y Competitividad (MINECO)JPI Climate by the European Unionpu

Aurorae observed by Giuseppe Toaldo in Padua (1766–1797)

Se presenta un registro de las observaciones de auroras hechas por Giuseppe Toaldo y su asistente Vincenzo Chiminello en Padua, Italia, en la segunda mitad del siglo XVIII. Las fuentes históricas consultadas incluyen los manuscritos originales que contienen los registros meteorológicos realizados por esos dos observadores. Se construye un pequeño catálogo con las 148 observaciones aurorales. Las características de estas observaciones son analizadas. La principal característica de este conjunto de datos es que el número anual de observaciones aurorales presenta un pico intenso alrededor de 1779 y una disminución abrupta alrededor de 1790.A record is presented of the auroral observations made by Giuseppe Toaldo and his assistant Vincenzo Chiminello in Padua, Italy, in the second half of the 18th century. The historical sources consulted include the original manuscripts containing the meteorological records made by those two observers. A small catalogue is constructed with the 148 auroral observations. The characteristics of these observations are analysed. The main feature of this data set is that the annual number of auroral observations presents an intense peak at around 1779 and an abrupt decline at around 1790.• Ministerio de Ciencia e Innovación. Proyectos AYA2008-04864/AYA y AYA2014-57556-P • Junta de Extremadura. Ayuda para Grupos de Investigación GR15137 • Universidad de las Fuerzas Armadas of Ecuador (ESPE). Proyecto 2015-PIC-014 • Gobierno de Ecuador. Secretaría de Educación Superior, Ciencia, Tecnología e Innovación. Proyecto PROMETEO, para Fernando Domínguez CastropeerReviewe