116 research outputs found

    Efficient functional built-in test for RF systems using two-tone response envelope analysis

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    Trabajo presentado al AFRICON celebrado en Nairobi del 23 al 25 de septiembre de 2009.This paper presents a novel and low-cost methodology that can be used for testing RF blocks embedded in complex SoCs. It is based on the detection and spectral analysis of the two-tone response envelope of the block under test. The main non-linearity specifications of the block under test can be easily extracted from the envelope signal. The analytical basis of the proposed methodology is demonstrated, and a proposal for its implementation as a built-in test core is discussed. Finally, practical simulation examples show the feasibility of the approach.This work has been partially supported by the Spanish Ministry of Innovation through project TEST (TEC2007-68072/MIC) and CATRENE's project TOETS.Peer Reviewe

    Improving the accuracy of RF alternate test using multi-VDD conditions: application to envelope-based test of LNAs

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    Trabajo presentado al "20 Asina Test Symposium" celebrado en Nueva Delhi (India) del 20 al 23 de Noviembre del 2011.-- Reprinted from (relevant publication info). This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of the products or services of CSIC Spanish National Research Council, Digital.CSIC. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.This work demonstrates that multi-VDD conditions may be used to improve the accuracy of machine learning mod- els, significantly decreasing the prediction error. The proposed technique has been successfully applied to a previous alternate test strategy for LNAs based on response envelope detection. A prototype has been developed to show its feasibility. The prototype consists of a low-power 2.4GHz LNA and a simple envelope detector, integrated in a 90nm CMOS technology. Post- layout simulation results are provided to verify the functionality of the approach. Copyright © 2011 IEEE.This work has been partially funded by a CSIC JAE-Doc contract (cofinanced by FSE), a Spanish MAE-AECID grant and projects: SR2 - Short Range Radio (Catrene European project 2A105SR2 and Avanza I+D Spanish project TSI-020400-2010-55, cofinanced with FEDER program), Auto-calibración y auto-test en circuitos analógicos, mixtos y de radio frecuencia (Andalusian Government project P09-TIC-5386, cofinanced with FEDER program), and Catrene project TOETS (CT 302).Peer reviewe

    Optimizing algorithms for thresholding segmentation applied to weed detection on UAV remote images.

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    En este trabajo se ha buscado la implementación de una alternativa al método de Otsu (1979) desarrollada por Hui-Fuang Ng (2006), el cual maximiza la diferencia entre varianzas espectrales y realiza una búsqueda multiumbral. En el estudio se emplearon imágenes procedentes de vehículos aéreos no tripulados (UAVs) tomadas en cultivos de maíz y girasol. Con una única ejecución del algoritmo en un entorno de análisis orientado a objetos, se discriminan aquellos objetos correspondientes a la fracción vegetal del suelo desnudo y se estima un umbral diferenciador entre cultivo y malas hierbas que contribuya a un subsiguiente proceso de clasificación. La técnica de Hui-Fuang detectó un mayor porcentaje de vegetación en todos los casos estudiados, oscilando el incremento entre un 3% y un 20%.This works aimed to implement an alternative to Otsu’s method (1979) developed by Hui- Fuang Ng (2006), which maximizes the difference between spectral variances and performs a multithreshold seeking. Unmanned aerial images taken in maize and sunflower crops were used in the research. In a single algorithm execution applied to an Object Based Image Analysis environment, the objects corresponding to both the vegetation fraction and bare soil are discriminated and a threshold to separate crop from weeds was also estimated, making easier a subsequent classification process. Fui-Huang’s technique provides a higher percentage of vegetation detection in all the cases, with an improvement which ranges from 3% to 20%

    Engineering biocatalysts for the anaerobic recycling of toxic aromatic hydrocarbons

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    En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.-- 3 pages.Azoarcus sp. CIB is a denitrifying betaproteobacterium that uses different aromatic compounds, including toxic hydrocarbons such as toluene and m-xylene, as sole carbon sources, and is susceptible of genetic manipulation. To acquire a global view of all the genetic determinants involved in the anaerobic catabolism of aromatic compounds in strain CIB, and to accelerate and complete our understanding about this anaerobic catabolism, we have performed a genomic survey in the recently sequenced genome of this strain. This information paves the way for a pathway engineering approach within the field of anaerobic degradation of aromatics.Peer reviewe

    Guidelines for the efficient design of sinewave generators for analog/mixed-signal BIST

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    6 páginas, 12 figuras, 1 tabla.-- Congreso celenrado en La Grande Motte (Francia) del 7 al 9 de Junio del 2010.This paper presents a design methodology for the implementation of efficient and accurate sinewave generators suitable for analog and mixed-signal BIST applications. The design guidelines are based on an analytical discussion that contemplates the main non-idealities of the generator. A full design example is presented to illustrate the proposed methodology.This work has been funded in part by the Spanish Government through a JAE-DOC contract, and projects TEST (TEC2007-68072/MIC), SR2 (TSI-020400-2008-71/MEDEA + 2A105), TOETS (CATRENE CT302) and by the Junta de Andalucia through project ACATEX (P09-TIC-5386).Peer reviewe

    A multiscale material model for metallic powder compaction during hot isostatic pressing

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    The prediction of the distortions during Near-Net-Shape Hot Isostatic Pressing (NNS-HIP) is an intrinsic multiscale problem where the local interactions among particles determine the macroscopic distortions taking place during the sintering and densification of a component. In this work, a multiscale approach is proposed to solve this problem. In particular, a viscoplastic constitutive model capable of predicting macroscopic contractions during a HIP process with high accuracy has been developed, implemented and validated. The macroscopic model incorporates the mechanical behaviour predicted at the meso-scale by means of multiple-particle finite element models (MP-FEM) of an agglomerate of powder particles. The model is validated through the prediction of distortions during HIP of a full scale industrial case. It is concluded that adding the microscopic information of the HIP process to simulate the contractions at the macroscopic level results in a considerable improvement of the accuracy of the predictions

    Digital image correlation after focused ion beam micro-slit drilling: A new technique for measuring residual stresses in hardmetal components at local scale

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    A new method has been developed for measuring residual stresses at the surface of hardmetal components with higher spatial resolution than standard X-ray diffraction methods. It is based on measuring the surface displacements produced when stresses are partially released by machining a thin slit perpendicularly to the tested surface. Slit machining is carried out by focused ion beam (FIB). Measurement of the displacement fields around the FIB slit are performed by applying an advanced digital image correlation algorithm based on Fourier analysis with sub-pixel resolution. This method compares SEM images of the same area of the hardmetal surface before and after slitting. The method has been successfully applied to as-ground and femto-laser textured surfaces showing good correlation with the standard sin2 ψ XRD technique. It is concluded that texturing induced by laser pulses in the femtoseconds regime is not perfectly adiabatic, since residual stresses are reduced by 15

    Adaptación paramétrica de un sistema borroso mediante el filtro de Kalman extendido

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    La fase de modelado es fundamental tanto e n el proceso de análisis de un sistema dinámico como en el de diseño de un sistema de control. Esta fase es aún más crítica si se realiza en línea y l a única información que se posee del sistema proviene de datos de entrada-salida del mismo. En este trabajo se presenta un algoritmo para la adaptación paramétrica de un sistema borroso basado en el filtro de Kalman extendido, el cual permite obtener modelos precisos sin renunciar a la eficiencia computacional que caracteriza al filtro de Kalman, y que permite su aplicación en línea con el proceso

    Probing the Inhibitor versus Chaperone Properties of sp2-Iminosugars towards Human β-Glucocerebrosidase: A Picomolar Chaperone for Gaucher Disease

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    A series of sp2-iminosugar glycomimetics differing in the reducing or nonreducing character, the configurational pattern (d-gluco or l-ido), the architecture of the glycone skeleton, and the nature of the nonglycone substituent has been synthesized and assayed for their inhibition properties towards commercial glycosidases. On the basis of their affinity and selectivity towards GH1 β-glucosidases, reducing and nonreducing bicyclic derivatives having a hydroxylation profile of structural complementarity with d-glucose and incorporating an N′-octyl-isourea or -isothiourea segment were selected for further evaluation of their inhibitory/chaperoning potential against human glucocerebrosidase (GCase). The 1-deoxynojirimycin (DNJ)-related nonreducing conjugates behaved as stronger GCase inhibitors than the reducing counterparts and exhibited potent chaperoning capabilities in Gaucher fibroblasts hosting the neuronopathic G188S/G183W mutation, the isothiourea derivative being indeed one of the most efficient chaperone candidates reported up to date (70% activity enhancement at 20 pM). At their optimal concentration, the four selected compounds promoted mutant GCase activity enhancements over 3-fold; yet, the inhibitor/chaperoning balance became unfavorable at much lower concentration for nonreducing as compared to reducing derivatives.España Ministerio de Economía y Competitividad (contract numbers CTQ2015-64425-C2-1-R and SAF2016-76083-R)Junta de Andalucía contract number FQM2012-146

    Probing the Inhibitor versus Chaperone Properties of sp2-Iminosugars towards Human -Glucocerebrosidase: A Picomolar Chaperone for Gaucher Disease

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    A series of sp2-iminosugar glycomimetics differing in the reducing or nonreducing character, the configurational pattern (d-gluco or l-ido), the architecture of the glycone skeleton, and the nature of the nonglycone substituent has been synthesized and assayed for their inhibition properties towards commercial glycosidases. On the basis of their affinity and selectivity towards GH1 β-glucosidases, reducing and nonreducing bicyclic derivatives having a hydroxylation profile of structural complementarity with d-glucose and incorporating an N′-octyl-isourea or -isothiourea segment were selected for further evaluation of their inhibitory/chaperoning potential against human glucocerebrosidase (GCase). The 1-deoxynojirimycin (DNJ)-related nonreducing conjugates behaved as stronger GCase inhibitors than the reducing counterparts and exhibited potent chaperoning capabilities in Gaucher fibroblasts hosting the neuronopathic G188S/G183W mutation, the isothiourea derivative being indeed one of the most efficient chaperone candidates reported up to date (70% activity enhancement at 20 pM). At their optimal concentration, the four selected compounds promoted mutant GCase activity enhancements over 3-fold; yet, the inhibitor/chaperoning balance became unfavorable at much lower concentration for nonreducing as compared to reducing derivatives.Ministerio de Economía y Competitividad CTQ2015-64425-C2-1-R , SAF2016-76083-RJunta de Andalucía FQM2012-1467Japan Society for the Promotion of Science JSPS KAKENHI 17K1005
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