358 resultados para Álvarez Condarco, Josefa


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This paper is concerned with the derivation of new estimators and performance bounds for the problem of timing estimation of (linearly) digitally modulated signals. The conditional maximum likelihood (CML) method is adopted, in contrast to the classical low-SNR unconditional ML (UML) formulationthat is systematically applied in the literature for the derivationof non-data-aided (NDA) timing-error-detectors (TEDs). A new CML TED is derived and proved to be self-noise free, in contrast to the conventional low-SNR-UML TED. In addition, the paper provides a derivation of the conditional Cramér–Rao Bound (CRB ), which is higher (less optimistic) than the modified CRB (MCRB)[which is only reached by decision-directed (DD) methods]. It is shown that the CRB is a lower bound on the asymptotic statisticalaccuracy of the set of consistent estimators that are quadratic with respect to the received signal. Although the obtained boundis not general, it applies to most NDA synchronizers proposed in the literature. A closed-form expression of the conditional CRBis obtained, and numerical results confirm that the CML TED attains the new bound for moderate to high Eg/No.

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A general criterion for the design of adaptive systemsin digital communications called the statistical reference criterionis proposed. The criterion is based on imposition of the probabilitydensity function of the signal of interest at the outputof the adaptive system, with its application to the scenario ofhighly powerful interferers being the main focus of this paper.The knowledge of the pdf of the wanted signal is used as adiscriminator between signals so that interferers with differingdistributions are rejected by the algorithm. Its performance isstudied over a range of scenarios. Equations for gradient-basedcoefficient updates are derived, and the relationship with otherexisting algorithms like the minimum variance and the Wienercriterion are examined.

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A comparative performance analysis of four geolocation methods in terms of their theoretical root mean square positioning errors is provided. Comparison is established in two different ways: strict and average. In the strict type, methods are examined for a particular geometric configuration of base stations(BSs) with respect to mobile position, which determines a givennoise profile affecting the respective time-of-arrival (TOA) or timedifference-of-arrival (TDOA) estimates. In the average type, methodsare evaluated in terms of the expected covariance matrix ofthe position error over an ensemble of random geometries, so thatcomparison is geometry independent. Exact semianalytical equationsand associated lower bounds (depending solely on the noiseprofile) are obtained for the average covariance matrix of the positionerror in terms of the so-called information matrix specific toeach geolocation method. Statistical channel models inferred fromfield trials are used to define realistic prior probabilities for therandom geometries. A final evaluation provides extensive resultsrelating the expected position error to channel model parametersand the number of base stations.

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The imperial cult area of Tarraco was built in the 1st century AD in the highest part of the city and presided over the seat of the Concilium Prouinciae Hispaniae Citerioris. It was a temenos with a similar layout to that of the Forum Pacis and architectural decoration imitating that of the Forum Augustum in Rome, where the use of marble was a fundamental part of the architectural and sculptural decorative programme. An extensive assemblage of marble was recovered during the excavations carried out under the Tarragona Cathedral Master Plan. It reflects the use of imperial quarries in the decorative programme and has been analyzed at the Unitat d’Estudis Arqueomètrics (ICAC) facilities. This assemblage reflects the wide panorama of marmora imported and used in the decoration of the temenos. Local varieties of marmora have been identified in Tarraco, plus a series of foreign marmora from quarries all over the Roman Empire (Greece, Turkey, Egypt and North Africa). All this shows the involvement of the imperial power in the monumental architecture of the capital of the prouincia Hispania Citerior.

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[spa]En este trabajo se describe la experiencia de innovación docente desarrollada en la ULD a lo largo de los 10 años de existencia. Se comentan algunos de los indicadores del sistema de gestión de la calidad así como su evolución y los resultados más representativos obtenidos en su alimentación. El objetivo de este proyecto es introducir aspectos de la gestión de la calidad, seguridad, salud y medio ambiente en la formación de los estudiantes para que los apliquen a lo largo del desarrollo de las prácticas. De esta forma, podrán adquirir una formación transversal adicional que difícilmente le será transmitida a través de las diferentes asignaturas de la licenciatura y que mejorará sus competencias y facilitará su acceso al ámbito laboral. También se pretende contribuir en la mejora del funcionamiento y las infraestructuras de los laboratorios de prácticas de la facultad. [eng] In the following work it is summarized the innovative experience carried out by the ULD besides showing the results obtained from the different indicators that allow to evaluate the efficiency of the quality management system. The aim is to improve the management of the practical teaching by introducing aspects of quality management, safety, health and environment in the formation of the students. In such a way, they would be able to acquire a transverse additional formation that difficultly would be transmitted across the different subjects of the degree and that would improve their competitions when acceding to the working world.

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En este trabajo se analiza sumariamcnte el cpistolario entre Jalier Cortes v Pedro de Palol, constituido por 146 cartas que se conservan en la sede del Instituto Catalán dc Arqueología Clásica. Casi todas hacen referencia a la i'iìla romana de la Olmeda.

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Objective: We propose and validate a computer aided system to measure three different mandibular indexes: cortical width, panoramic mandibular index and, mandibular alveolar bone resorption index. Study Design: Repeatability and reproducibility of the measurements are analyzed and compared to the manual estimation of the same indexes. Results: The proposed computerized system exhibits superior repeatability and reproducibility rates compared to standard manual methods. Moreover, the time required to perform the measurements using the proposed method is negligible compared to perform the measurements manually. Conclusions: We have proposed a very user friendly computerized method to measure three different morphometric mandibular indexes. From the results we can conclude that the system provides a practical manner to perform these measurements. It does not require an expert examiner and does not take more than 16 seconds per analysis. Thus, it may be suitable to diagnose osteoporosis using dental panoramic radiographs.

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The first total synthesis of Aeruginazole A, prepared via a convergent strategy that involved both solid-phase peptide synthesis and solution phase chemistry and that enabled conservation of the stereochemistry of the intermediates, is reported.

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The synthesis of various polycyclic systems containing a C3aNi bond between a hexahydropyrrolo[2,3-b]indole and an indole tryptophan is described here. A series of experiments were performed to determine the best combination of five orthogonal protecting groups and the best reaction conditions for formation of said bond, which is a common feature among many recently discovered marine natural products.

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Purpose: To describe (1) the clinical profiles and the patterns of use of long-acting injectable (LAI) antipsychotics in patients with schizophrenia at risk of nonadherence with oral antipsychotics, and in those who started treatment with LAI antipsychotics, (2) health care resource utilization and associated costs. Patients and methods: A total of 597 outpatients with schizophrenia at risk of nonadherence, according to the psychiatrist's clinical judgment, were recruited at 59 centers in a noninterventional prospective observational study of 1-year follow-up when their treatment was modified. In a post hoc analysis, the profiles of patients starting LAI or continuing with oral antipsychotics were described, and descriptive analyses of treatments, health resource utilization, and direct costs were performed in those who started an LAI antipsychotic. Results: Therapy modifications involved the antipsychotic medications in 84.8% of patients, mostly because of insufficient efficacy of prior regimen. Ninety-two (15.4%) patients started an LAI antipsychotic at recruitment. Of these, only 13 (14.1%) were prescribed with first-generation antipsychotics. During 1 year, 16.3% of patients who started and 14.9% of patients who did not start an LAI antipsychotic at recruitment relapsed, contrasting with the 20.9% who had been hospitalized only within the prior 6 months. After 1 year, 74.3% of patients who started an LAI antipsychotic continued concomitant treatment with oral antipsychotics. The mean (median) total direct health care cost per patient per month during the study year among the patients starting any LAI antipsychotic at baseline was 1,407 ( 897.7). Medication costs (including oral and LAI antipsychotics and concomitant medication) represented almost 44%, whereas nonmedication costs accounted for more than 55% of the mean total direct health care costs. Conclusion: LAI antipsychotics were infrequently prescribed in spite of a psychiatrist-perceived risk of nonadherence to oral antipsychotics. Mean medication costs were lower than nonmedication costs.

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La técnica de rejilla es un instrumento de evaluación de las dimensiones y estructura del significado personal que se deriva de la teoría de los constructos personales. Tanto en la versión original de G. A. Kelly (1955) como en sus continuas actualizaciones, esta técnica pretende captar la forma en que una persona da sentido a su experiencia en sus propios términos. No se trata, por tanto, de un test convencional, sino de una forma de entrevista estructurada orientada a explicitar y analizar los constructos con los que la persona organiza su mundo. De la entrevista se genera una matriz de datos que se somete a varios análisis para revelar su estructura implícita. El programa RECORD ofrece los resultados de una forma clara y proporciona además una serie de gráficos de fácil interpretación. Todo ello permite dibujar la estructura del mapa cognitivo del sujeto desde su propia semántica, culminando así, con rigor metodológico, una vieja aspiración fenomenológica. Se trata de un instrumento muy 'flexible que puede adaptarse a diversas áreas de aplicación: evaluación individual, grupal, familiar y de pareja, intervención psicoeducativa, asesoramiento vocacional, investigación de mercados, asesoramiento empresarial, investigación terapéutica, estudio de la estructura cognitiva de la personalidad, etc.

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La técnica de rejilla es un instrumento de evaluación de las dimensiones y estructura del significado personal que se deriva de la teoría de los constructos personales. Tanto en la versión original de G. A. Kelly (1955) como en sus continuas actualizaciones, esta técnica pretende captar la forma en que una persona da sentido a su experiencia en sus propios términos. No se trata, por tanto, de un test convencional, sino de una forma de entrevista estructurada orientada a explicitar y analizar los constructos con los que la persona organiza su mundo. De la entrevista se genera una matriz de datos que se somete a varios análisis para revelar su estructura implícita. El programa RECORD ofrece los resultados de una forma clara y proporciona además una serie de gráficos de fácil interpretación. Todo ello permite dibujar la estructura del mapa cognitivo del sujeto desde su propia semántica, culminando así, con rigor metodológico, una vieja aspiración fenomenológica. Se trata de un instrumento muy 'flexible que puede adaptarse a diversas áreas de aplicación: evaluación individual, grupal, familiar y de pareja, intervención psicoeducativa, asesoramiento vocacional, investigación de mercados, asesoramiento empresarial, investigación terapéutica, estudio de la estructura cognitiva de la personalidad, etc.

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This review covers recent literature on the lamellarins, a family of marine natural products, and related analogs, encompassing synthetic strategies for total synthesis, structure-activity relationships (SAR), and studies on mechanisms of biological action, namely in the context of antitumor activity. It reviews work published from January 2008 to December 2010.