6,252 research outputs found

    A NURBS-based solid modeling to enhance rapid prototyping in the restoration of decorative elements

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    In this research, we describe a computer-aided approach to improve the reconstruction method of decorum in architectural surfaces and sculpture. The effects of withdrawal caused by catalysis of mold in silicone was evaluated and simulated by a NURBS-based solid modelling. A tolerance analysis model was developed to predict manufacturing precision levels. In particular, differential increment along three dimensions was performed considering different volume distributions. The methodology was validated by experimental data obtained during the coffered ceiling restoration of Teatro Massimo Vittorio Emanuele in Palermo. The proposed methodology allowed the reconstruction of decorations or fragments of decoration with high accuracy

    Nanopore Sequencing Technology and Tools for Genome Assembly: Computational Analysis of the Current State, Bottlenecks and Future Directions

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    Nanopore sequencing technology has the potential to render other sequencing technologies obsolete with its ability to generate long reads and provide portability. However, high error rates of the technology pose a challenge while generating accurate genome assemblies. The tools used for nanopore sequence analysis are of critical importance as they should overcome the high error rates of the technology. Our goal in this work is to comprehensively analyze current publicly available tools for nanopore sequence analysis to understand their advantages, disadvantages, and performance bottlenecks. It is important to understand where the current tools do not perform well to develop better tools. To this end, we 1) analyze the multiple steps and the associated tools in the genome assembly pipeline using nanopore sequence data, and 2) provide guidelines for determining the appropriate tools for each step. We analyze various combinations of different tools and expose the tradeoffs between accuracy, performance, memory usage and scalability. We conclude that our observations can guide researchers and practitioners in making conscious and effective choices for each step of the genome assembly pipeline using nanopore sequence data. Also, with the help of bottlenecks we have found, developers can improve the current tools or build new ones that are both accurate and fast, in order to overcome the high error rates of the nanopore sequencing technology.Comment: To appear in Briefings in Bioinformatics (BIB), 201

    An Improved Method of Documenting Activity Patterns of Post-Emergence Polar Bears (Ursus maritimus) in Northern Alaska

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    Throughout their circumpolar range, pregnant female polar bears (Ursus maritimus) create snow dens in which they give birth to altricial cubs. Because polar bear neonates are born in such an undeveloped state, their survival requires a long, undisturbed period of in-den development. To mitigate human impacts on denning bears, it is necessary to understand the chronology of denning, the behaviors of denning bears, and their sensitivity to human activities. Since 2002, we have studied the den emergence behaviors of polar bears in northern Alaska; however, we moved from using on-site observers (2002 – 03) to using autonomous video systems (2005 – 08). Here we compare the duration, activity budgets, and behaviors of polar bears to see whether observation methods affected their activities. Camera systems recorded nearly 10 times the data per den recorded by human observers (526 h/den and 57 h/den respectively). We found no difference between the two study periods in emergence dates, duration at den sites, abandonment dates, or activity budgets for polar bears. We observed a 16-fold reduction in the number of bear-human interactions when using cameras instead of human observers. There was, however, a marked increase in the intensity of response when using cameras (125 m) as compared to observers in blinds (400 m). An understanding of these activity patterns can be used to manage human activities near dens so as to minimize disturbance.À l’échelle de leur aire de répartition circumpolaire, les ourses polaires (Ursus maritimus) en gestation se créent une tanière de neige pour donner naissance à leurs oursons à développement tardif. Puisque les nouveau-nés de l’ourse polaire naissent dans un état si peu développé, leur survie nécessite une longue période de développement non perturbé en tanière. Afin d’atténuer les incidences de l’être humain sur les ours en tanière, il est nécessaire de comprendre la chronologie de la mise bas, les comportements des ours en tanière et leur sensibilité à l’activité humaine. À partir de 2002, nous avons étudié les comportements de sortie des tanières des ours polaires du nord de l’Alaska, tout d’abord au moyen d’observations faites sur place (en 2002 et 2003) et ensuite, au moyen de caméras vidéo autonomes (de 2005 à 2008). Ici, nous comparons la durée, la répartition des activités et les comportements des ours polaires afin de déterminer si les méthodes d’observation ont influencé leurs activités. Les caméras ont enregistré près de dix fois plus de données par tanière que les observateurs humains (526 h/tanière et 57 h/tanière respectivement). Nous n’avons trouvé aucune différence entre les deux périodes à l’étude en ce qui a trait aux dates de sortie, aux durées de séjour en tanière, aux dates d’abandon ou à la répartition des activités des ours polaires. Lorsque nous avons utilisé des caméras par opposition à des observateurs, nous avons dénoté 16 fois moins d’interactions entre les ours et l’être humain. Cependant, nous avons remarqué une augmentation accrue sur le plan de l’intensité de la réponse lorsque nous nous sommes servis de caméras (125 m) comparativement aux observateurs dissimulés (400 m). La compréhension de ces modèles d’activités peut servir à gérer l’activité humaine à proximité des tanières afin de minimiser les perturbations

    Temperature and precipitation seasonal forecasts over the Mediterranean region: added value compared to simple forecasting methods

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    This study considers a set of state-of-the-art seasonal forecasting systems (ECMWF, MF, UKMO, CMCC, DWD and the corresponding multi-model ensemble) and quantifies their added value (if any) in predicting seasonal and monthly temperature and precipitation anomalies over the Mediterranean region compared to a simple forecasting method based on the ERA5 climatology (CTRL) or the persistence of the ERA5 anomaly (PERS). This analysis considers two starting dates, May 1st and November 1st and the forecasts at lead times up to 6 months for each year in the period 1993–2014. Both deterministic and probabilistic metrics are employed to derive comprehensive information on the forecast quality in terms of association, reliability/resolution, discrimination, accuracy and sharpness. We find that temperature anomalies are better reproduced than precipitation anomalies with varying spatial patterns across different forecast systems. The Multi-Model Ensemble (MME) shows the best agreement in terms of anomaly correlation with ERA5 precipitation, while PERS provides the best results in terms of anomaly correlation with ERA5 temperature. Individual forecast systems and MME outperform CTRL in terms of accuracy of tercile-based forecasts up to lead time 5 months and in terms of discrimination up to lead time 2 months. All seasonal forecast systems also outperform elementary forecasts based on persistence in terms of accuracy and sharpness

    Convenio tripartito entre la Universidad, la Dirección Penal Juvenil y la Secretaría de recursos hídricos en salta experiencias en transferencia y producción de tecnología.

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    Se presentan las tareas realizadas que condujeron a la concreción de un convenio entre tres partes institucionales de la Provincia de Salta. El objetivo principal fue la transferencia y producción de tecnología sencilla para la cocción solar y de cocinas a leña optimizadas, con jóvenes alojados en dispositivos dependientes de la Dirección General de Justicia Penal Juvenil, a fin de satisfacer necesidades de personas originarias de la margen salteña del río Pilcomayo.Fil: Passamai, Victor Jose. Consejo Nacional de Invest.cientif.y Tecnicas. Centro Cientifico Tecnol.conicet - Salta. Instituto de Invest.en Energia No Convencional; Argentina;Fil: Fernández, S.. Ministerio de Infraestructura y Vivienda Serv.pub.. Secretaria de Obras Publicas. Subsecretaria de Recursos Hidricos; Salta; Argentina;Fil: Cali, S.. Ministerio de Infraestructura y Vivienda Serv.pub.. Secretaria de Obras Publicas. Subsecretaria de Recursos Hidricos; Salta; Argentina;Fil: Agüero, M.. Dirección Penal Juvenil. Salta; Argentina;Fil: Teruel, F.. Dirección Penal Juvenil. Salta; Argentina

    The role of citizen science in science perception, meaning, and environmental values: An evaluation of the Living Snow Project

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    Citizen science programs provide a means for outdoor enthusiasts to combine their recreational pursuits with engagement in science. This research evaluated the role of citizen science in peoples’ perceptions of science, meaningfulness of their outdoor experiences, and environmental attitudes, identity, and connection. The Living Snow Project (LSP), a community-enabled (citizen science) program, engages the outdoor recreation community in research characterizing alpine snow microbiomes through volunteer sample collections in alpine environments. Citizen scientists (N=41) volunteering with LSP participated in this study at two time points before and after the 2019 snow sampling season. At both time points, participants completed five well-established measures to assess environmental attitudes, values, identity, and connection to nature. In addition, we collected demographic and LSP participation information (Time 1), as well as their citizen science experience and perceptions of science (Time 2). The results indicated that citizen scientists (1) reported their recreational experiences were more meaningful as a result of their engagement in citizen science; (2) had more positive perceptions of science and interest in participating in science; and (3) displayed high levels of environmental concern, connectedness to nature, and pro-environmental values and identity as evidenced by near ceiling levels across the five measures

    An android architecture for bio-inspired honest signalling in Human-Humanoid Interaction

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    This paper outlines an augmented robotic architecture to study the conditions of successful Human-Humanoid Interaction (HHI). The architecture is designed as a testable model generator for interaction centred on the ability to emit, display and detect honest signals. First we overview the biological theory in which the concept of honest signals has been put forward in order to assess its explanatory power. We reconstruct the application of the concept of honest signalling in accounting for interaction in strategic contexts and in laying bare the foundation for an automated social metrics. We describe the modules of the architecture, which is intended to implement the concept of honest signalling in connection with a refinement provided by delivering the sense of co-presence in a shared environment. Finally, an analysis of Honest Signals, in term of body postures, exhibited by participants during the preliminary experiment with the Geminoid Hi-1 is provided

    Low-temperature exsolution of Ni-Ru bimetallic nanoparticles from A-site deficient double perovskites

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    Exsolution of stable metallic nanoparticles for use as efficient electrocatalysts has been of increasing interest for a range of energy technologies. Typically, exsolved nanoparticles show higher thermal and coarsening stability compared to conventionally deposited catalysts. Here, A-site deficient double perovskite oxides, La2-xNiRuO6-δ (x = 0.1 and 0.15), are designed and subjected to low-temperature reduction leading to exsolution. The reduced double perovskite materials are shown to exsolve nanoparticles of 2–6 nm diameter during the reduction in the low-temperature range of 350–450 °C. The nanoparticle sizes are found to increase after reduction at the higher temperature (450 °C), suggesting diffusion-limited particle growth. Interestingly, both nickel and ruthenium are co-exsolved during the reduction process. The formation of bimetallic nanoparticles at such low temperatures is rare. From the in situ impedance spectroscopy measurements of the double perovskite electrode layers, the onset of the exsolution process is found to be within the first few minutes of the reduction reaction. In addition, the area-specific resistance of the electrode layers is found to decrease by 90% from 291 to 29 Ω cm2, suggesting encouraging prospects for these low-temperature rapidly exsolved Ni/Ru alloy nanoparticles in a range of catalytic applications
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