1,835 research outputs found

    Cal Poly Heliodon

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    The purpose of the Heliodon project is to provide professors with a means to educate students about the movement of the sun and how that movement varies with location on earth and throughout the year

    Competitive market for multiple firms and economic crisis

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    The origin of economic crises is a key problem for economics. We present a model of long-run competitive markets to show that the multiplicity of behaviors in an economic system, over a long time scale, emerge as statistical regularities (perfectly competitive markets obey Bose-Einstein statistics and purely monopolistic-competitive markets obey Boltzmann statistics) and that how interaction among firms influences the evolutionary of competitive markets. It has been widely accepted that perfect competition is most efficient. Our study shows that the perfectly competitive system, as an extreme case of competitive markets, is most efficient but not stable, and gives rise to economic crises as society reaches full employment. In the economic crisis revealed by our model, many firms condense (collapse) into the lowest supply level (zero supply, namely bankruptcy status), in analogy to Bose-Einstein condensation. This curious phenomenon arises because perfect competition (homogeneous competitions) equals symmetric (indistinguishable) investment direction, a fact abhorred by nature. Therefore, we urge the promotion of monopolistic competition (heterogeneous competitions) rather than perfect competition. To provide early warning of economic crises, we introduce a resolving index of investment, which approaches zero in the run-up to an economic crisis. On the other hand, our model discloses, as a profound conclusion, that the technological level for a long-run social or economic system is proportional to the freedom (disorder) of this system; in other words, technology equals the entropy of system. As an application of this new concept, we give a possible answer to the Needham question: "Why was it that despite the immense achievements of traditional China it had been in Europe and not in China that the scientific and industrial revolutions occurred?"Comment: 17 pages; 3 figure

    Much Easier Said Than Done: Falsifying the Causal Relevance of Linear Decoding Methods

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    Linear classifier probes are frequently utilized to better understand how neural networks function. Researchers have approached the problem of determining unit importance in neural networks by probing their learned, internal representations. Linear classifier probes identify highly selective units as the most important for network function. Whether or not a network actually relies on high selectivity units can be tested by removing them from the network using ablation. Surprisingly, when highly selective units are ablated they only produce small performance deficits, and even then only in some cases. In spite of the absence of ablation effects for selective neurons, linear decoding methods can be effectively used to interpret network function, leaving their effectiveness a mystery. To falsify the exclusive role of selectivity in network function and resolve this contradiction, we systematically ablate groups of units in subregions of activation space. Here, we find a weak relationship between neurons identified by probes and those identified by ablation. More specifically, we find that an interaction between selectivity and the average activity of the unit better predicts ablation performance deficits for groups of units in AlexNet, VGG16, MobileNetV2, and ResNet101. Linear decoders are likely somewhat effective because they overlap with those units that are causally important for network function. Interpretability methods could be improved by focusing on causally important units.Comment: 6 pages, 3 figures, to be published in I Can't Believe It's Note Better Workshop at NeurIPS 202

    An overt chemical protective garment reduces thermal strain compared with a covert garment in warm-wet but not hot-dry environments

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    © 2017 The Authors. Published by Frontiers Media. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3389/fphys.2017.00913© 2017 Maley, Costello, Borg, Bach, Hunt and Stewart. Objectives: A commercial chemical, biological, radiological and nuclear (CBRN) protective covert garment has recently been developed with the aim of reducing thermal strain. A covert CBRN protective layer can be worn under other clothing, with equipment added for full chemical protection when needed. However, it is unknown whether the covert garment offers any alleviation to thermal strain during work compared with a traditional overt ensemble. Therefore, the aim of this study was to compare thermal strain and work tolerance times during work in an overt and covert ensemble offering the same level of CBRN protection. Methods: Eleven male participants wore an overt (OVERT) or covert (COVERT) CBRN ensemble and walked (4 km·h-1, 1% grade) for a maximum of 120 min in either a wet bulb globe temperature [WBGT] of 21, 30, or 37°C (Neutral, WarmWet and HotDry, respectively). The trials were ceased if the participants' gastrointestinal temperature reached 39°C, heart rate reached 90% of maximum, walking time reached 120 min or due to self-termination. Results: All participants completed 120 min of walking in Neutral. Work tolerance time was greater in OVERT compared with COVERT in WarmWet (P 0.05). Conclusion: Those dressed in OVERT experienced lower thermal strain and longer work tolerance times compared with COVERT in a warm-wet environment. However, COVERT may be an optimal choice in a hot-dry environment. These findings have practical implications for those making decisions on the choice of CBRN ensemble to be used during work.This project is financially supported by the Australian Government, managed by the National Security Science and Technology Centre within the Defence Science and Technology Organization, and the US Government through the Technical Support Working Group within the Combating Terrorism Technical Support Office.Published versio

    Land Cover Data for the Mississippi-Alabama Barrier Islands, 2010-2011

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    Land cover on the Mississippi–Alabama barrier islands was surveyed in 2010–2011 as part of continuing research on island geomorphic and vegetation dynamics following the 2005 impact of Hurricane Katrina. Results of the survey include sub-meter GPS location, a listing of dominant vegetation species and field photographs recorded at 375 sampling locations distributed among Cat, West Ship, East Ship, Horn, Sand, Petit Bois and Dauphin Islands. The survey was conducted in a period of intensive remote sensing data acquisition over the northern Gulf of Mexico by federal, state and commercial organizations in response to the 2010 Macondo Well (Deepwater Horizon) oil spill. The data are useful in providing ground reference information for thematic classification of remotely-sensed imagery, and a record of land cover which may be used in future research

    Increased cytotoxicity of oxidized flame soot

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    AbstractCombustion–generated particles released into the atmosphere undergo reactions with oxidants, which can change the particles’ physiochemical characteristics. In this work, we compare the physical and chemical properties and cellular response of particles fresh from a flame with those oxidized by ozone and nitrogen dioxide. The reaction with ozone and nitrogen dioxide does not significantly modify the physical characteristics of the particles (primary particle size, fractal dimension, and surface area). However, oxidation affects the chemical characteristics of the particles, creating more oxygen and nitrogen containing functional groups, and increases their hydrophilicity. In addition, oxidized soot generates more reactive oxygen species, as measured by the dithiothreitol (DTT) assay. Furthermore, oxidized soot is 1.5 – 2 times more toxic than soot that was not reacted with ozone, but the inflammatory response, measured by interleukin–8 (IL–8) secretion, is unchanged. These results imply that combustion–generated particles released into the atmosphere will have an increased toxicity on or after high ozone days

    DA NÃO INCIDÊNCIA DE ISS SOBRE ATIVIDADES-MEIO NA INDÚSTRIA DO ARROZ: UMA ANÁLISE NORMATIVISTA E INSTITUCIONAL

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    O presente artigo tem por objeto a análise da tributação das atividades-meio na indústria do arroz pelo imposto sobre serviços de qualquer natureza (ISS). O estudo foi realizado sob as perspectivas normativista e institucional. Em primeiro lugar, examinaram-se a Constituição Federal, a legislação, a literatura especializada e a jurisprudência dos Tribunais sobre o assunto. Posteriormente, avaliou-se os efeitos institucionais promovidos pela possibilidade de tributação pelo ISS das referidas atividades na agroindústria orizícola, que restou materializada por autuações fiscais municipais e discutida em processos judiciais perante a Justiça Estadual do Rio Grande do Sul

    ACORDOS DE CONFIDENCIALIDADE (NDA) EM STARTUPS

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    O presente artigo contempla análise jurídica sobre os acordos de confidencialidade firmados no âmbito das startups, mediante o exame dos seus aspectos normativos e pragmáticos. O estudo abrange, de um lado, o quadro das regras positivas vigentes com relevância para a matéria e a jurisprudência dos tribunais pátrios a respeito das principais questões envolvendo contratos de confidencialidade. De outro lado, versam-se, simultaneamente, sobre as repercussões práticas, as consequências, para o mercado e os agentes envolvidos nestas relações, tais como empreendedores, investidores, funcionários e parceiros comerciais
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