Augmentations and Rulings of Legendrian Links

For any Legendrian knot in R^3 with the standard contact structure, we show that the existence of an augmentation to any field of the Chekanov-Eliashberg differential graded algebra over Z[t,t^{-1}] is equivalent to the existence of a normal ruling of the front diagram, generalizing results of Fuchs, Ishkhanov, and Sabloff. We also show that any even graded augmentation must send t to -1.

We extend the definition of a normal ruling from J^1(S^1) given by Lavrov and Rutherford to a normal ruling for Legendrian links in #^k(S^1\times S^2). We then show that for Legendrian links in J^1(S^1) and #^k(S^1\times S^2), the existence of an augmentation to any field of the Chekanov-Eliashberg differential graded algebra over Z[t,t^{-1}] is equivalent to the existence of a normal ruling of the front diagram. For Legendrian knots, we also show that any even graded augmentation must send t to -1. We use the correspondence to give nonvanishing results for the symplectic homology of certain Weinstein 4-manifolds.

Temperature-dependent gap edge in strong-coupling superconductors determined using the Eliashberg-Nambu formalism

Using the theory of Eliashberg and Nambu for strong-coupling superconductors, we have calculated the gap function for a model superconductor and a selection of real superconductors includong the elements Al, Sn, Tl, Nb, In, Pb and Hg and one alloy, Bi2Tl. We have determined thetemperature-dependent gap edge in each and found that in materials with weak electron-phonon ($\lambda 1.20$), not only is the gap edge double valued but it also departs significantly from the BCS form and develops a shoulderlike structure which may, in some cases, denote a gap edge exceeding the $T = 0$ value. These computational results support the insights obtained by Leavens in an analytic consideration of the general problem. Both the shoulder and double value arise from a common origin seated in the form of the gap function in strong coupled materials at finite temperatures. From the calculated gap function, we can determine the densities of states in the materials and the form of the tunneling current-voltage characteristics for junctions with these materials as electroddes. By way of illustration, results are shown for the contrasting cases of Sn ($\lambda=0.74$) and Hg ($\lambad=1.63$). The reported results are distinct in several ways from BCS predictions and provide an incentive determinative experimental studies with techniques such as tunneling and far infrared absorption.

O acervo paleoictiológico do Aptiano-Albiano da Formação Santana (Bacia do Araripe), existente nas coleções do Museu de Paleontologia e Estratigrafia Paulo Milton Barbosa Landim, DGA-IGCE UNESP Rio Claro

Pós-graduação em Geologia Regional - IGCE

Diseño de un plan estratégico de comercialización para la competitividad de los agronegocios frutícolas inscritos en la Dirección general de agronegocios (DGA). Caso ilustrativo.

Los cambios estructurales experimentados en los últimos años (apertura económica, liberalización y privatización de los mercados sectoriales, las reformas legales en la tenencia de la tierra) y la globalización de las actividades económicas han tenido un fuerte impacto en la agricultura de la región, dando lugar a nuevas oportunidades, pero también planteando grandes desafíos a los agentes productivos y en particular a la agricultura de América Latina. Si bien estos cambios han definido un marco más favorable a las inversiones y al desarrollo de agronegocios en el sector agroalimentario, también han acelerado el proceso de diferenciación de la estructura productiva de dicho sector. Las reformas económicas de los años ochenta y noventa con sus programas de ajuste destinados a corregir los grandes desequilibrios, junto con la apertura comercial y la globalización de las actividades económicas dieron lugar a grandes cambios tanto en las políticas macro como en las sectoriales de la región. Por lo que la creación de los "Agronegocios" significó incentivar distintos eslabones que componen la cadena productiva de cada producto en cuestión, es decir, desde la provisión de insumos y servicios, la producción primaria, el manejo postcosecha e industrialización de los productos agropecuarios, hasta los mercados terminales y su conexión con los canales de comercialización y distribución existentes. Por lo que los agronegocios se han convertido en "motores" de la economía en el siglo XXI, representando un 50% del comercio global, por lo que se le ha considerado como un conductor del desarrollo económico, mismos que estimulan a su vez a otras actividades relacionadas. Pese a este trabajo de parte de las instituciones comprometidas con la expansión de los agronegocios, estos todavía necesitan un mayor impulso y apoyo técnico para poder penetrar los mercados potenciales del extranjero. La recolección de la información de datos se llevó a cabo a través de en muestras, entrevistas y observación directa, los cuales finalmente se analizaron para determinar las fortalezas y oportunidades así como también las debilidades y amenazas de los agronegocios fruticultores inscritos en la DGA. De acuerdo al diagnóstico realizado se terminaron las principales causas que inciden en la demanda de sus frutas tanto frescas como deshidratadas, por su características orgánicas. También se pudo determinar que los agronegociantes cuenta con precios accesibles, lo cual les permite ser competitivos, no obstante, estos no tienen un método determinado para calcularlos que le permitan evaluar la rentabilidad de sus operaciones. En función de los resultados de la investigación se diseñó un plan estratégico de mercadotecnia en el que se propone desarrollar estrategias a largo plazo que conlleven al posicionamiento y ventajas competitivas y diferenciales de sus frutas que comercializan. Los planes a corto plazo y a largo plazo finalmente ese establecen de forma tal que se puedan implementar, evaluar y controlar de forma efectiva para el logro de los objetivos previstos por la asociación de los agronegocios fruticultores.

Dynamic optimization of migration topology in internet-based distributed genetic algorithms

Distributed Genetic Algorithms (DGAs) designed for the Internet have to take its high communication cost into consideration. For island model GAs, the migration topology has a major impact on DGA performance. This paper describes and evaluates an adaptive migration topology optimizer that keeps the communication load low while maintaining high solution quality. Experiments on benchmark problems show that the optimized topology outperforms static or random topologies of the same degree of connectivity. The applicability of the method on real-world problems is demonstrated on a hard optimization problem in VLSI design.

Superconductivity in the nonadiabatic limit

Isotope-shift exponent (cu) and the pressure coefficient of superconducting transition temperature (beta) have been studied in the nonadiabatic limit. We have considered the effect of nonadiabaticity in both within and beyond the Migdal-Eliashberg formalism. It reveals from our study that the pressure coefficient of superconducting transition is high for the low-T-c region and low for the high-T-c region and the minimum value of alpha is obtained where the transition temperature is maximum. Lowest value of isotope-shift exponent is obtained for small momentum exchange between the electrons and the bosonic field. Qualitative variation of beta with temperature is consistent with the experimental results of the hole doped superconductors for small momentum exchange.

Application of artificial intelligence for the assessment of the status of power transformers

The Dissolved Gas Analysis (DGA) a non destructive test procedure, has been in vogue for a long time now, for assessing the status of power and related transformers in service. An early indication of likely internal faults that may exist in Transformers has been seen to be revealed, to a reasonable degree of accuracy by the DGA. The data acquisition and subsequent analysis needs an expert in the concerned area to accurately assess the condition of the equipment. Since the presence of the expert is not always guaranteed, it is incumbent on the part of the power utilities to requisition a well planned and reliable artificial expert system to replace, at least in part, an expert. This paper presents the application of Ordered Ant Mner (OAM) classifier for the prediction of involved fault. Secondly, the paper also attempts to estimate the remaining life of the power transformer as an extension to the elapsed life estimation method suggested in the literature.

Expected Performance of the ATLAS Experiment - Detector, Trigger and Physics

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN.

Weak-coupling superconductivity in a strongly correlated iron pnictide

Iron-based superconductors have been found to exhibit an intimate interplay of orbital, spin, and lattice degrees of freedom, dramatically affecting their low-energy electronic properties, including superconductivity. Albeit the precise pairing mechanism remains unidentified, several candidate interactions have been suggested to mediate the superconducting pairing, both in the orbital and in the spin channel. Here, we employ optical spectroscopy (OS), angle-resolved photoemission spectroscopy (ARPES), ab initio band-structure, and Eliashberg calculations to show that nearly optimally doped NaFe0.978Co0.022As exhibits some of the strongest orbitally selective electronic correlations in the family of iron pnictides. Unexpectedly, we find that the mass enhancement of itinerant charge carriers in the strongly correlated band is dramatically reduced near the Gamma point and attribute this effect to orbital mixing induced by pronounced spin-orbit coupling. Embracing the true band structure allows us to describe all low-energy electronic properties obtained in our experiments with remarkable consistency and demonstrate that superconductivity in this material is rather weak and mediated by spin fluctuations.

Adaptación de treinta y cinco fabaceas forrajeras en sabanas con suelos vérticos y vertisoles León, Nicaragua 1985-1987

Se estudió la adaptación de fabáceas a suelos veticos y vertésoles en sabanas de crescentia alata hbk. Se establecieron dos experimentos en terreno de jícaro, s.a., km152 telica san isidro, los zarzales, león. El diseño usado fue bloques completos al azar, con 3 replica y accesiones como tratamiento. Se sembró en hileras, con parcela útil de 1 m2. Los factores evaluados fueron: germinación, cobertura, altura de plantas, daños por plagas y enfermedades, nodulacion, floración y cuando fue posible biomasa (Mv y Ms) El ensayo (1985-1986) se realizó con 10 accesiones, mejoradas y nativas, en parcelas experimentales de 3.75m2 adicionalmente se observaron 2 réplicas con siembra al voleo y sin control de male3zas; una y la otra sin rotulación de suelo. El ensayo (1987) constaba con 25 accesiones introducidas del CIAT a través del programa forrajero, DGA, madrina, con parcela experimentales de 12.5m2. El género centrosema presento excelente adaptación de especies: c.brasilianum (3 accesiones), c.pubescens (mejorada y nativa) y c.macrocaroum (1 accesión). Sobresalieron las especies dolichos 1ab-1ab, pueraria phaseoloides (ambas introducidas) y calopogonium galantoides (nativa). También están: macroptilium atropurpureum (cv. Siratro nativa), aeschynomene americana: sufrutice resistente a enfermedades y anegamiento, pero con biomasa lignificada y desmodium glabrum de buen porte y biomasa apetecible. En el transcurso experimental se observó que el suelo anegado propicia enfermedades fungosas en accesiones trepadoras; soporte mecánico disminuye ataques. Siembra al voleo en suelos rotulados y sin control de malezas es factible para establecer fabáceas de “primera”.

Learning Temporal Contexts and Priming-Preparation Modes for Pattern Recognition

The system presented here is based on neurophysiological and electrophysiological data. It computes three types of increasingly integrated temporal and probability contexts, in a bottom-up mode. To each of these contexts corresponds an increasingly specific top-down priming effect on lower processing stages, mostly pattern recognition and discrimination. Contextual learning of time intervals, events' temporal order or sequential dependencies and events' prior probability results from the delivery of large stimuli sequences. This learning gives rise to emergent properties which closely match the experimental data.

An Integrated Neural Network-Event-Related Potentials Model of Temporal and Probability Context Effects on Event Categorization

We present a neural network that adapts and integrates several preexisting or new modules to categorize events in short term memory (STM), encode temporal order in working memory, evaluate timing and probability context in medium and long term memory. The model shows how processed contextual information modulates event recognition and categorization, focal attention and incentive motivation. The model is based on a compendium of Event Related Potentials (ERPs) and behavioral results either collected by the authors or compiled from the classical ERP literature. Its hallmark is, at the functional level, the interplay of memory registers endowed with widely different dynamical ranges, and at the structural level, the attempt to relate the different modules to known anatomical structures.

Previsão de avarias em transformadores de potência através da análise de ensaios físico-químicos

Os Transformadores de potência são máquinas de elevada importância ao nível dos Sistemas Elétricos de Energia (SEE) uma vez que são estas máquinas que possibilitam a interligação dos diferentes níveis de tensão da rede e a transmissão de energia elétrica em Corrente Alternada (CA). Geralmente, estas máquinas são de grandes dimensões e de elevado nível de complexidade construtiva. Caracterizam-se por possuírem períodos de vida útil bastante elevados (vinte a trinta anos) e preços elevados, o que conduz a um nível de exigência de fiabilidade muito elevada, uma vez que não e viável a existência de muitos equipamentos de reserva nos SEE. Com o objetivo de tentar maximizar o período de vida útil dos transformadores de potência e a sua fiabilidade, tenta-se, cada vez mais, implementar conceitos de manutenção preventiva a este tipo de máquinas. No entanto, a gestão da sua vida útil e extremamente complexa na medida em que, estas máquinas têm vários componentes cruciais e suscetiveis de originar falhas e, quase todos eles, encontram-se no interior de uma cuba. Desta forma, não e possível obter uma imagem do seu estado, em tempo real, sem colocar o transformador fora de serviço, algo que acarreta custos elevados. Por este motivo, desenvolveu-se uma técnica que permite obter uma indicação do estado do transformador, em tempo real, sem o retirar de serviço, colhendo amostras do óleo isolante e procedendo a sua análise físico-química e Analise Gases Dissolvidos (DGA). As análises aos óleos isolantes tem vindo a adquirir uma preponderância muito elevada no diagnóstico de falhas e na analise do estado de conservação destes equipamentos tendo-se desenvolvido regras para interpretação dos parâmetros dos óleos com carácter normativo. Considerando o conhecimento relativo a interpretação dos ensaios físico-químicos e DGA ao oleol, e possível desenvolver ferramentas capazes de otimizar essas mesmas interpretações e aplicar esse conhecimento no sentido de prever a sua evolução, assim como o surgimento de possíveis falhas em transformadores, para assim otimizar os processos de manutenção. Neste campo as Redes Neuronais Artificiais (RNAs) têm um papel fundamental

Reflexos ultramarinos na heráldica da nobreza de Portugal

RODRIGUES, Miguel Jasmins (coord.),

Nuestra Se??ora del Carmen y San Jos?? : un lugar para todos

Participante en la convocatoria: Premios de buenas pr??cticas en materia de convivencia, Gobierno de Arag??n 2009-10