1,828 research outputs found

    One Decade of Glacier Mass Changes on the Tibetan Plateau Derived from Multisensoral Remote Sensing Data

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    The Tibetan Plateau (TP) with an average altitude of 4,500 meters above sea level is characterized by many glaciers and ice caps. Glaciers are a natural indicator for climate variability in this high mountain environment where meteorological stations are rare or non-existent. In addition, the melt water released from the Tibetan glaciers is feeding the headwaters of the major Asian river systems and contributes to the rising levels of endorheic lakes on the plateau. As many people directly rely on the glacier melt water a continuous glacier monitoring program is necessary in this region. In situ measurements of glaciers are important, but are spatial limited due to large logistical efforts, physical constrains and high costs. Remote sensing techniques can overcome this gap and are suitable to complement in situ measurements on a larger scale. In the last decade several remote sensing studies dealt with areal changes of glaciers on the TP. However, glacier area changes only provide a delayed signal to a changing climate and the amount of melt water released from the glaciers cannot be quantified. Therefore it is important to measure the glacier mass balance. In order to estimate glacier mass balances and their spatial differences on the TP, several remote sensing techniques and sensors were synthesized in this thesis. In a first study data from the Ice Cloud and Elevation Satellite (ICESat) mission were employed. ICESat was in orbit between 2003 and 2009 and carried a laser altimeter which recorded highly accurate surface elevation measurements. As in mid-latitudes these measurements are rather sparse glaciers on the TP were grouped into eight climatological homogeneous sub-regions in order to perform a statistical sound analysis of glacier elevation changes. To assess surface elevation changes of a single mountain glacier from ICESat data, an adequate spatial sampling of ICESat measurements need to be present. This is the case for the Grosser Aletschgletscher, located in the Swiss Alps which served as a test site in this thesis. In another study data from the current TanDEM-X satellite mission and from the Shuttle Radar Topography Mission (SRTM) conducted in February 2000 were employed to calculate glacier elevation changes. In a co-authored study, these estimates could be compared with glacier elevation changes obtained from the current French Pléiades satellite mission. In order to calculate glacier mass balances, the derived elevation changes were combined with assumptions about glacier area and ice density in all studies. In this thesis contrasting patterns of glacier mass changes were found on the TP. With an ICESat derived estimate of -15.6±10.1 Gt/a between 2003 and 2009 the average glacier mass balance on the TP was clearly negative. However, some glaciers in the central and north-western part of the TP showed a neutral mass balance or a slightly positive anomaly which was also confirmed by data from the current TanDEM-X satellite mission. A possible explanation of this anomaly in mass balance could be a compensation of the temperature driven glacier melt due to an increase in precipitation

    Modelamento e simulação de impacto balístico em sistema cerâmica-metal

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    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Ciência e Engenharia de MateriaisNovos sistemas de proteção balística vêm sendo recentemente criados com base em materiais de alta tecnologia. Um dos objetivos da indústria do ramo é desenvolver sistemas defensivos mais leves, porém mais fortes, que possibilitem ao portador, veicular ou humano, uma maior mobilidade com um maior nível de segurança. Este trabalho, baseado no trabalho original de Al-Qureshi et al [1], estuda matematicamente o comportamento de uma proteção contra um impacto de projétil. O modelo empregado inclui um sistema de proteção em camadas de cerâmica e metal, e ainda descreve o comportamento do projétil e as propriedades de absorção de impacto do sistema. A literatura ainda mostra que a taxa de erosão e desaceleração do projétil são altamente dependentes dos parâmetros geométricos e estruturais do material da proteção. O fenômeno de impacto e penetração é descrito em diferentes estágios, apresentando características particulares entre tais. As equações apresentadas demonstram diferentes propriedades do sistema ao longo dos estágios. Este trabalho ainda apresenta uma simulação matemática realizada sobre o modelo desenvolvido e aprimorado em busca de propriedades otimizadas do material para estudos futuros. Dentre as propriedades investigadas citam-se a espessura das placas utilizadas, o perfil de deformação do material metálico, a densidade da cerâmica, dentre outras características relevantes para o fenômeno. A rotina computacional possibilitou a aplicação de diferentes parâmetros nas equações propostas. Como resultado, gráficos e superfícies foram geradas, o que possibilitou uma análise mais profunda do modelo e um maior entendimento do processo de fratura em materiais por impacto de alta velocidade. Estudos futuros utilizarão estes resultados e desenvolvimentos para a produção de uma proteção balística que será utilizada para um experimento prático

    Refeudalisierung der Ökonomie : Zum Strukturwandel kapitalistischer Wirtschaft

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    Der Finanzmarktkapitalismus der Gegenwart lässt sich nur unzureichend als ideologische Ausgeburt des Neoliberalismus begreifen. Auch stellt die Ökonomie der schnellen Gewinne und hohen Verluste nicht einfach einen Verfall rationaler Erwerbsprinzipien dar. Derselbe gesellschaftliche Prozess, der die wirtschaftlichen Institutionen zur Struktur eines Finanzmarktkapitalismus modernisierte, hat vielmehr zugleich soziale Formen der Verteilung von Einkommen, Anerkennung und Macht etabliert, die ursprünglich vormoderne Muster der sozialen Ordnung aktualisieren. Mit Rekurs auf den analytischen Topos der „Refeudalisierung“, den Jürgen Habermas einst in seiner Studie über den Strukturwandel der Öffentlichkeit ausgearbeitet hat, wird die refeudalisierte Ökonomie der Gegenwart als eine Paradoxie kapitalistischer Modernisierung untersucht, deren Entstehungs- und Wirkungsmechanismen in vielfältiger Weise formale Ähnlichkeiten mit den institutionellen Transformationen moderner Öffentlichkeiten aufweisen.The rise of financial-market-based capitalism cannot be adequately explained by attributing it to prevailing neoliberal ideology alone. Similarly, the economics of fast money and big losses is not merely a sign of deteriorating economic rationality. Instead, this article argues that the societal process that transformed the economic institutions towards a financial-based model of capitalism also brought back social patterns of distributing wealth, income and power typical of the pre-modern era, albeit in an updated form. Referring to the analytical concept of “refeudalization” introduced by Jürgen Habermas in his inquiry on the Structural Transformation of the Public Sphere, the author examines the current refeudalization of the economic sphere as a paradoxical process of capitalist modernization that is often similar to the institutional transformation of the modern public sphere

    AVALIAÇÃO DE DESEMPENHO NO INSTITUTO FEDERAL DE SANTA CATARINA

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    As empresas estão sendo obrigadas a se repensarem de forma integrada, redefinindo sua estrutura e por consequência os perfis de competências necessárias dos profissionais que nelas atuam. Atualmente há necessidade de uma visão mais estratégica da área de Recursos Humanos, buscando vincular o desempenho humano aos resultados organizacionais. O plano nacional de desenvolvimento de pessoal focou nos recursos humanos como meio de desenvolvimento dos servidores e destacou as discussões sobre a gestão de competências, definindo novas diretrizes referentes à adequação das competências do servidor aos objetivos da instituição. Este estudo procurou verificar como ocorre a avaliação de desempenho no Instituto Federal de Santa Catarina, vinculando-o ao modelo de gestão por competências. Foram realizadas entrevistas no primeiro semestre de 2012 e analisados documentos da instituição. Esta pesquisa possui uma abordagem qualitativa, descritiva, através de estudo de caso. Foi observado que a instituição possui obrigação legal de implantação da gestão por competências e adota o modelo de avaliação de desempenho como ferramenta para tal, porém a prática de retroalimentação da gestão de competências não está institucionalizada na organização, existindo resistência dos servidores no processo de avaliação de desempenho

    The Broad-Band Spectrum and Infrared Variability of the Magnetar AXP 1E1048.1-5937

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    We present photometry of the Anomalous X-ray pulsar 1E1048.1-5937 in the infrared and optical, taken at Magellan and the VLT. The object is detected in the I, J and Ks bands under excellent conditions. We find that the source has varied greatly in its infrared brightness and present these new magnitudes. No correlation is found between the infrared flux and spin-down rate, but the infrared flux and X-ray flux may be anti-correlated. Assuming nominal reddening values, the resultant spectral energy distribution is found to be inconsistent with the only other AXP SED available (for 4U0142+61). We consider the effect of the uncertainty in the reddening to the source on its SED. We find that although both the X-ray and infrared fluxes have varied greatly for this source, the most recent flux ratio is remarkably consistent with what is is found for other AXPs. Finally, we discuss the implications of our findings in the context of the magnetar model.Comment: 21 pages, 5 eps figures. Submitted to Ap

    Near-infrared Circular Polarization Images of NGC 6334-V

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    We present results from deep imaging linear and circular polarimetry of the massive star-forming region NGC 6334-V. These observations show high degrees of circular polarization (CP), as much as 22% in the Ks band, in the infrared nebula associated with the outflow. The CP has an asymmetric positive/negative pattern and is very extended (~80'' or 0.65 pc). Both the high CP and its extended size are larger than those seen in the Orion CP region. Three-dimensional Monte Carlo light-scattering models are used to show that the high CP may be produced by scattering from the infrared nebula followed by dichroic extinction by an optically thick foreground cloud containing aligned dust grains. Our results show not only the magnetic field orientation of around young stellar objects, but also the structure of circumstellar matter such as outflow regions and their parent molecular cloud along the line of sight. The detection of the large and extended CP in this source and the Orion nebula may imply the CP origin of the biological homochirality on EarthPeer reviewe

    Evaluation of an efficient etack-RLE clustering concept for dynamically adaptive grids

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    This is the author accepted manuscript. The final version is available from the Society for Industrial and Applied Mathematics via the DOI in this record.Abstract. One approach to tackle the challenge of efficient implementations for parallel PDE simulations on dynamically changing grids is the usage of space-filling curves (SFC). While SFC algorithms possess advantageous properties such as low memory requirements and close-to-optimal partitioning approaches with linear complexity, they require efficient communication strategies for keeping and utilizing the connectivity information, in particular for dynamically changing grids. Our approach is to use a sparse communication graph to store the connectivity information and to transfer data block-wise. This permits efficient generation of multiple partitions per memory context (denoted by clustering) which - in combination with a run-length encoding (RLE) - directly leads to elegant solutions for shared, distributed and hybrid parallelization and allows cluster-based optimizations. While previous work focused on specific aspects, we present in this paper an overall compact summary of the stack-RLE clustering approach completed by aspects on the vertex-based communication that ease up understanding the approach. The central contribution of this work is the proof of suitability of the stack-RLE clustering approach for an efficient realization of different, relevant building blocks of Scientific Computing methodology and real-life CSE applications: We show 95% strong scalability for small-scale scalability benchmarks on 512 cores and weak scalability of over 90% on 8192 cores for finite-volume solvers and changing grid structure in every time step; optimizations of simulation data backends by writer tasks; comparisons of analytical benchmarks to analyze the adaptivity criteria; and a Tsunami simulation as a representative real-world showcase of a wave propagation for our approach which reduces the overall workload by 95% for parallel fully-adaptive mesh refinement and, based on a comparison with SFC-ordered regular grid cells, reduces the computation time by a factor of 7.6 with improved results and a factor of 62.2 with results of similar accuracy of buoy station dataThis work was partly supported by the German Research Foundation (DFG) as part of the Transregional Collaborative Research Centre “Invasive Computing” (SFB/TR 89)

    FINANCIAMENTO DE PROJETOS E CONVÊNIOS NA EDUCAÇÃO SUPERIOR: UM RETORNO SOCIAL

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    Este trabalho teve como objetivo geral: analisar de que forma os financiamentos de projetos e convênios firmados contribuem para o desenvolvimento das pesquisas na UDESC. Para alcançar este objetivo fez-se um estudo de caso das fontes de financiamento dos projetos e convênios realizados pela Universidade do Estado de Santa Catarina – UDESC no período 2010-2011. Dentre os resultados alcançados pode-se destacar que: no período a UDESC firmou 35 convênios para obtenção de financiamento de seus projetos, sendo a maioria com a SESu/MEC; 64% dos recursos financeiros obtidos pela UDESC por meio de convênios financeiros são oriundos da CAPES e da FINEP, o que demonstra que há uma concentração do montante de recursos em apenas dois órgãos de fomento; a UDESC é bastante dependente dos recursos do governo estadual para a manutenção das suas atividades; todos os convênios impactaram na dimensão sociocultural seja da própria comunidade acadêmica, seja da sociedade, a dimensão econômica foi impactada por quatro dos 10 convênios firmados entre a UDESC e entidades externas, e as dimensões ambiental e política foram impactadas por apenas um projeto
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