Going Further with Point Pair Features

Point Pair Features is a widely used method to detect 3D objects in point clouds, however they are prone to fail in presence of sensor noise and background clutter. We introduce novel sampling and voting schemes that significantly reduces the influence of clutter and sensor noise. Our experiments show that with our improvements, PPFs become competitive against state-of-the-art methods as it outperforms them on several objects from challenging benchmarks, at a low computational cost.Comment: Corrected post-print of manuscript accepted to the European Conference on Computer Vision (ECCV) 2016; https://link.springer.com/chapter/10.1007/978-3-319-46487-9_5

Modelagem da hidrografia em planos de manejo e critérios para definição de árvores em APP pelo Modeflora.

Novas tecnologias, sendo advindas do geoprocessamento e do sensoriamento remoto, vêm sendo desenvolvidas a fim de auxiliar no processo de delimitação das APPs e demarcação das árvores. No entanto, faltam estudos para investigar e comprovar sua eficácia. Não há registro de trabalhos, publicados no Brasil, que utilizem diferentes metodologias na definição de APPs para avaliá-las. O presente trabalho teve como objetivo propor uma metodologia precisa para o mapeamento de áreas de preservação permanente e definição de árvores protegidas e exploráveis na região de influência das APPs, comprovando a sua aplicabilidade nos PMFS.bitstream/CPAF-AC-2010/23132/1/circtec-n50.pd

Dinosaurs and other vertebrates from the Papo-Seco Formation (Lower Cretaceous) of southern Portugal

New vertebrate remains reported from the Papo-Seco Formation (Lower Barremian, Lower Cretaceous) of Areias do Mastro, in Cabo Espichel, SW Portugal, south of Lisbon. The marine, lagoonal, and estuarine limestones, marls, sands and gravels have yielded remains of dinosaurs and other reptiles since the 19th century. Recent paleontological prospecting produced several vertebrate remains, including turtle shell fragments, crocodilian teeth, fish and pterosaurs. Research identified both bones and teeth of fish, crocodiles, dinosaurs Baryonyx and iguanodontian, as well as a ctenochasmatoid pterosaur, and a possible ornithocheirid pterosaur. These new disclosures are an important contribution to the knowledge of vertebrate diversity from the Portuguese Cretaceous. Faunal species combination proven to be similar to other faunal associations of Barremian formations in the Iberian Peninsula.Se presentan nuevos restos fósiles de vertebrados de la formación Papo-Seco (Barremiense inferior, Cretácico Inferior), en el yacimiento de Areias do Mastro, SW de Portugal, al sur de Lisboa. En las margas, arenas, areniscas y calizas de origen marino y estuarino de esta formación localizada en el Cabo Espichel, y ya desde el siglo XIX, se han encontrado restos de dinosaurios y otros reptiles. Recientemente, nuestra prospección sacó a la luz varios restos fósiles de vertebrados, entre los que se incluyen fragmentos de caparazón de tortuga, dientes de cocodrilo, de peces actinopterigios y de pterosaurio (ctenocasmatoideo y posiblemente ornitoqueiroideo), así como algunos huesos y dientes de dinosaurios. Hemos identificado restos de Baryonyx y de ornitópodos iguanodontios. Su descubrimiento representa una importante contribución al conocimiento de la diversidad de vertebrados existentes en el Cretácico portugués. La combinación de las especies muestra ser similar a otras asociaciones de la fauna de las formaciones Barremienses en la Península Ibérica

The Portuguese Polytechnicians of the ‘long nineteenth century’: technical expertise, military aspirations, and political disenchantment. A preliminary study

This article focuses on the career paths of students who completed the preparatory course addressed to future military officers and engineers offered by the Lisbon Polytechnic School. We show that, after completing their studies, the Lisbon polytechnicians held positions in the public service and carried out the policies of State modernization launched by the Liberals in the period known as the Regeneration (Regeneração: 1851 coup-d’état to 1868). The graduates became in this way part of the Portuguese “technoscientific aristocracy.” Yet, despite its key role in preparing this technoscientific bureaucracy, the Lisbon Polytechnic School did not turn into the alma mater of the Portuguese political elite, which continued to be the University of Coimbra. In effect, an overall study of the career paths of former students of the Lisbon Polytechnic points to a relatively low level of political formal engagement

Duración y calidad de la analgesia postoperatoria después del bloqueo del plexo braquial para cirugía del hombro: ropivacaína 0,5% frente a ropivacaína 0,5% con clonidina

Resumen OBJETIVOS: Algunos estudios han demostrado que la duración de los bloqueos nerviosos realizados con anestésicos locales puede ser prolongada con clonidina. En este estudio evaluamos la duración y la calidad de la analgesia proporcionada por el bloqueo del plexo braquial por vía interescalénica para cirugía del hombro, comparando la ropivacaína 0,5% con la ropivacaína 0,5% asociada a clonidina. PACIENTES Y MÉTODOS: Treinta pacientes fueron distribuidos en dos grupos en un estudio doble ciego. Grupo A - bloqueo realizado con ropivacaína 0,5%, 40 ml, y grupo B - ropivacaína 0,5%, 40 ml con clonidina (40 μg). Se procedió a la anestesia general con la administración de propofol e introducción de la mascarilla laríngea, siendo los pacientes mantenidos en ventilación espontánea con propofol en perfusión continua. Después de la estimulación nerviosa del plexo braquial fue administrado el (los) fármaco(s) seleccionado(s). El paciente fue instruido para recordar la hora de la reversión del bloqueo motor y sensitivo, y la analgesia postoperatoria fue evaluada a través de la escala visual analógica (EVA) a las 2, 4, 6, 8 y 24 horas. RESULTADOS: El tiempo medio de reversión del bloqueo sensitivo y motor y la evaluación del grado de dolor (EVA 0-10) a las 4, 6, 8 y 24 horas, no mostró diferencias estadísticamente significativas. CONCLUSIONES: La asociación de 40 μg de clonidina a 200 mg de ropivacaína 0,5% no prolonga el bloqueo sensitivo y motor y no mejora la calidad de la analgesia en el postoperatorio inmediato

Uso do processo oxidativo avançado na degradação de mistura de resíduos orgânicos coloridos provenientes de análises espectrofotométricas.

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Statistical models of mixtures with a biaxial nematic phase

We consider a simple Maier-Saupe statistical model with the inclusion of disorder degrees of freedom to mimic the phase diagram of a mixture of rod-like and disc-like molecules. A quenched distribution of shapes leads to the existence of a stable biaxial nematic phase, in qualitative agreement with experimental findings for some ternary lyotropic liquid mixtures. An annealed distribution, however, which is more adequate to liquid mixtures, precludes the stability of this biaxial phase. We then use a two-temperature formalism, and assume a separation of relaxation times, to show that a partial degree of annealing is already sufficient to stabilize a biaxial nematic structure.Comment: 11 pages, 2 figure

Transformations of Heun's equation and its integral relations

We find transformations of variables which preserve the form of the equation for the kernels of integral relations among solutions of the Heun equation. These transformations lead to new kernels for the Heun equation, given by single hypergeometric functions (Lambe-Ward-type kernels) and by products of two hypergeometric functions (Erd\'elyi-type). Such kernels, by a limiting process, also afford new kernels for the confluent Heun equation.Comment: This version was published in J. Phys. A: Math. Theor. 44 (2011) 07520