986 resultados para Simulated robots


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Saltwater intrusion and inundation can affect soil microbial activity, which regulates the carbon (C) balance in mangroves and helps to determine if these coastal forests can keep pace with sea level rise (SLR). This study evaluated the effects of increased salinity (+15 ppt), increased inundation (−8 cm), and their combination, on soil organic C loss from a mangrove peat soil (Everglades, Florida, USA) under simulated tides. Soil respiration (CO2 flux), methane (CH4) flux, dissolved organic carbon (DOC) production, and porewater nutrient concentrations were quantified. Soil respiration was the major pathway of soil organic C loss (94–98%) and was approximately 90% higher in the control water level than the inundated treatment under elevated salinity. Respiration rate increased with water temperature, but depended upon salinity and tidal range. CH4 flux was minimal, while porewater DOC increased with a concomitant, significant decline in soil bulk density under increased inundation. Porewater ammonium increased (73%) with inundation and soluble reactive phosphorus increased (32%) with salinity. Overall, the decline in soil organic C mineralization from combined saltwater intrusion and prolonged inundation was not significant, but results suggest SLR could increase this soil’s susceptibility to peat collapse and accelerate nutrient and DOC export to adjacent Florida Bay.

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Hydrology drives the carbon balance of wetlands by controlling the uptake and release of CO2 and CH4. Longer dry periods in between heavier precipitation events predicted for the Everglades region, may alter the stability of large carbon pools in this wetland's ecosystems. To determine the effects of drought on CO2 fluxes and CH4 emissions, we simulated changes in hydroperiod with three scenarios that differed in the onset rate of drought (gradual, intermediate, and rapid transition into drought) on 18 freshwater wetland monoliths collected from an Everglades short-hydroperiod marsh. Simulated drought, regardless of the onset rate, resulted in higher net CO2 losses net ecosystem exchange (NEE) over the 22-week manipulation. Drought caused extensive vegetation dieback, increased ecosystem respiration (Reco), and reduced carbon uptake gross ecosystem exchange (GEE). Photosynthetic potential measured by reflective indices (photochemical reflectance index, water index, normalized phaeophytinization index, and the normalized difference vegetation index) indicated that water stress limited GEE and inhibited Reco. As a result of drought-induced dieback, NEE did not offset methane production during periods of inundation. The average ratio of net CH4 to NEE over the study period was 0.06, surpassing the 100-year greenhouse warming compensation point for CH4 (0.04). Drought-induced diebacks of sawgrass (C3) led to the establishment of the invasive species torpedograss (C4) when water was resupplied. These changes in the structure and function indicate that freshwater marsh ecosystems can become a net source of CO2 and CH4 to the atmosphere, even following an extended drought. Future changes in precipitation patterns and drought occurrence/duration can change the carbon storage capacity of freshwater marshes from sinks to sources of carbon to the atmosphere. Therefore, climate change will impact the carbon storage capacity of freshwater marshes by influencing water availability and the potential for positive feedbacks on radiative forcing.

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Contrary to prevailing opinions, Neill Blomkamp’s recent feature film Chappie is not a movie about robots or artificial intelligence. It is not Robocop. It is not Short Circuit. It is also not District 9 or Elysium. Chappie is a movie about humanity’s dialectically creative and destructive potential. It is a movie about how it is that humans come to behave how they do through their social and material circumstances, as well as the barbaric results when the two are mixed under the thoroughly undemocratic conditions of neoliberal capitalism.

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The purpose of this study was to examine the attitudes college students have toward those with physical disabilities and what personality characteristics they attribute to physical appearance. One-hundred-one introductory psychology students at FIU were randomly assigned to one of three groups: control--no disability group, a group that viewed five slides of peers with disabilities, and a group that viewed the disability slides and heard their voices. All subjects rated the individuals' perceived personality. A one-way ANOVA revealed that those in the visual and audio disability group rated those with disabilities significantly higher in friendliness, attractiveness, and assertiveness than those who rated the individuals without disabilities. Those in the visual and audio disability group rated them higher in self-esteem than those in the visual only disability group. Since voice can have such positive effects on first impression, an occupational therapist can work on improving communication skills of those with disabilities.

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The objective in this work is to build a rapid and automated numerical design method that makes optimal design of robots possible. In this work, two classes of optimal robot design problems were specifically addressed: (1) When the objective is to optimize a pre-designed robot, and (2) when the goal is to design an optimal robot from scratch. In the first case, to reach the optimum design some of the critical dimensions or specific measures to optimize (design parameters) are varied within an established range. Then the stress is calculated as a function of the design parameter(s), the design parameter(s) that optimizes a pre-determined performance index provides the optimum design. In the second case, this work focuses on the development of an automated procedure for the optimal design of robotic systems. For this purpose, Pro/Engineer© and MatLab© software packages are integrated to draw the robot parts, optimize them, and then re-draw the optimal system parts.

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A Totally Enclosed Motor Propelled Survival Craft (TEMPSC) is currently the primary mode of escape during a maritime and offshore emergency situation. Although lifeboats have evolved from their original design, the interior comfort and habitability of the craft has remained virtually unchanged and is not considered during the certification process. Ambient carbon dioxide (CO₂) accumulation within TEMPSC is one factor, along with many others that may cause serious health implications for TEMPSC occupants. Previous research has shown that with the hatches closed and the participants at rest, an international 8-hour exposure limit of 4800ppm may be reached in as little as 15 minutes. This study uses simulation as a testing methodology to determine if vessel motions in various sea-states impact the time to reach this same CO₂ exposure limit because of physical exertions of the participants to maintain stability within their seats.

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Este proyecto consiste en el desarrollo de un sistema para simular misiones de rescate usando equipos de robots donde cada robot tiene sus propios objetivos y debe coordinarse con el resto de sus compañeros para realizar con existo la misión de rescate en escenarios dinámicos. El escenario se caracteriza por contener: - Agentes Robot: son las entidades del sistema encargado de tareas relacionadas con el rescate, como por ejemplo, explorar el terreno o rescatar a una víctima. Se organizan de forma jerárquica, esto es, hay un jefe encargado de asignar tareas a los demás robots, que serán subordinados. - Víctimas: son los objetivos a rescatar en la misión. Tienen una identificación, una localización y una esperanza de vida. -Obstáculos: delimitan una zona por la que el robot no puede pasar. Simulan la existencia de paredes, rocas, árboles…, es decir, cualquier tipo de estructura existente en un escenario real. - Zona segura: marca un punto del mapa adonde los robots moverán a las víctimas en el rescate. Representa lo que en un rescate real sería un campamento u hospital. El sistema permite: - Crear y gestionar escenarios de simulación - Definir equipos de robots con diferentes miembros, diferentes objetivos y comportamientos. - Definir modelos organizativos en los equipos y estrategias de coordinación. - Realizar los objetivos individuales y de grupo para salvar a las víctimas llevándolas al sitio seguro esquivando los obstáculos. - Realizar experimentos de simulación: probar distintas configuraciones de equipo con un número variable de robots, varias víctimas en lugares diferentes y escenarios independientes. Se ha partido del proyecto ROSACE(Robots et Systèmes AutoCommunicants Embarqués / Robots y sistemas embebidos autocomunicantes), que está construido sobre la herramienta ICARO, que es una Infraestructura Ligera de Componentes Software Java basada en Agentes y Recursos y Organizaciones para el desarrollo de aplicaciones distribuidas. El punto de partida ya implementaba una versión preliminar del proyecto capaz de organizar objetivos entre los robots y que consigan ir a la localización objetivo. El presente proyecto utiliza el patrón arquitectónico de ROSACE y parte de su infraestructura pero desarrolla un sistema original con nuevas herramientas para definir y gestionar escenarios, disponer de un modelo más realista del comportamiento de los robots y controlar el proceso de simulación para incluir posibles fallos de los robots y para el estudio individual y colectivo de los miembros de los equipos.

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© 2016 John Wiley & Sons Ltd.

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Acknowledgements Anna Nowakowska is supported by an ESRC doctoral studentship. A James S McDonnell scholar award to Amelia R. Hunt also provided financial support. We are grateful to Edvinas Pilipavicius and Juraj Sikra for data collection. We also wish to thank W. Joseph MacInnes for help with programming the experiment and Paul Hibbard for help with filtering the faces.

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Acknowledgements. This work was mainly funded by the EU FP7 CARBONES project (contracts FP7-SPACE-2009-1-242316), with also a small contribution from GEOCARBON project (ENV.2011.4.1.1-1-283080). This work used eddy covariance data acquired by the FLUXNET community and in particular by the following networks: AmeriFlux (U.S. Department of Energy, Biological and Environmental Research, Terrestrial Carbon Program; DE-FG02-04ER63917 and DE-FG02-04ER63911), AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarboItaly, CarboMont, ChinaFlux, Fluxnet-Canada (supported by CFCAS, NSERC, BIOCAP, Environment Canada, and NRCan), GreenGrass, KoFlux, LBA, NECC, OzFlux, TCOS-Siberia, USCCC. We acknowledge the financial support to the eddy covariance data harmonization provided by CarboEuropeIP, FAO-GTOS-TCO, iLEAPS, Max Planck Institute for Biogeochemistry, National Science Foundation, University of Tuscia, Université Laval and Environment Canada and US Department of Energy and the database development and technical support from Berkeley Water Center, Lawrence Berkeley National Laboratory, Microsoft Research eScience, Oak Ridge National Laboratory, University of California-Berkeley, University of Virginia. Philippe Ciais acknowledges support from the European Research Council through Synergy grant ERC-2013-SyG-610028 “IMBALANCE-P”. The authors wish to thank M. Jung for providing access to the GPP MTE data, which were downloaded from the GEOCARBON data portal (https://www.bgc-jena.mpg.de/geodb/projects/Data.php). The authors are also grateful to computing support and resources provided at LSCE and to the overall ORCHIDEE project that coordinate the development of the code (http://labex.ipsl.fr/orchidee/index.php/about-the-team).

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The recently proposed global monsoon hypothesis interprets monsoon systems as part of one global-scale atmospheric overturning circulation, implying a connection between the regional monsoon systems and an in-phase behaviour of all northern hemispheric monsoons on annual timescales (Trenberth et al., 2000). Whether this concept can be applied to past climates and variability on longer timescales is still under debate, because the monsoon systems exhibit different regional characteristics such as different seasonality (i.e. onset, peak, and withdrawal). To investigate the interconnection of different monsoon systems during the pre-industrial Holocene, five transient global climate model simulations have been analysed with respect to the rainfall trend and variability in different sub-domains of the Afro-Asian monsoon region. Our analysis suggests that on millennial timescales with varying orbital forcing, the monsoons do not behave as a tightly connected global system. According to the models, the Indian and North African monsoons are coupled, showing similar rainfall trend and moderate correlation in rainfall variability in all models. The East Asian monsoon changes independently during the Holocene. The dissimilarities in the seasonality of the monsoon sub-systems lead to a stronger response of the North African and Indian monsoon systems to the Holocene insolation forcing than of the East Asian monsoon and affect the seasonal distribution of Holocene rainfall variations. Within the Indian and North African monsoon domain, precipitation solely changes during the summer months, showing a decreasing Holocene precipitation trend. In the East Asian monsoon region, the precipitation signal is determined by an increasing precipitation trend during spring and a decreasing precipitation change during summer, partly balancing each other. A synthesis of reconstructions and the model results do not reveal an impact of the different seasonality on the timing of the Holocene rainfall optimum in the different sub-monsoon systems. They rather indicate locally inhomogeneous rainfall changes and show, that single palaeo-records should not be used to characterise the rainfall change and monsoon evolution for entire monsoon sub-systems.

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Grazing mollusks are used as a food resource worldwide, and limpets are harvested commercially for both local consumption and export in several countries. This study describes a field experiment to assess the effects of simulated human exploitation of limpets Patella vulgata on their population ecology in terms of protandry (age-related sex change from male to female), growth, recruitment, migration, and density regulation. Limpet populations at two locations in southwest England were artificially exploited by systematic removal of the largest individuals for 18 months in plots assigned to three treatments at each site: no (control), low, and high exploitation. The shell size at sex change (L50: the size at which there is a 50:50 sex ratio) decreased in response to the exploitation treatments, as did the mean shell size of sexual stages. Size-dependent sex change was indicated by L50 occurring at smaller sizes in treatments than controls, suggesting an earlier switch to females. Mean shell size of P. vulgata neuters changed little under different levels of exploitation, while males and females both decreased markedly in size with exploitation. No differences were detected in the relative abundances of sexual stages, indicating some compensation for the removal of the bigger individuals via recruitment and sex change as no migratory patterns were detected between treatments. At the end of the experiment, 0–15 mm recruits were more abundant at one of the locations but no differences were detected between treatments. We conclude that sex change in P. vulgata can be induced at smaller sizes by reductions in density of the largest individuals reducing interage class competition. Knowledge of sex-change adaptation in exploited limpet populations should underpin strategies to counteract population decline and improve rocky shore conservation and resource management.

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Grazing mollusks are used as a food resource worldwide, and limpets are harvested commercially for both local consumption and export in several countries. This study describes a field experiment to assess the effects of simulated human exploitation of limpets Patella vulgata on their population ecology in terms of protandry (age-related sex change from male to female), growth, recruitment, migration, and density regulation. Limpet populations at two locations in southwest England were artificially exploited by systematic removal of the largest individuals for 18 months in plots assigned to three treatments at each site: no (control), low, and high exploitation. The shell size at sex change (L50: the size at which there is a 50:50 sex ratio) decreased in response to the exploitation treatments, as did the mean shell size of sexual stages. Size-dependent sex change was indicated by L50 occurring at smaller sizes in treatments than controls, suggesting an earlier switch to females. Mean shell size of P. vulgata neuters changed little under different levels of exploitation, while males and females both decreased markedly in size with exploitation. No differences were detected in the relative abundances of sexual stages, indicating some compensation for the removal of the bigger individuals via recruitment and sex change as no migratory patterns were detected between treatments. At the end of the experiment, 0–15 mm recruits were more abundant at one of the locations but no differences were detected between treatments. We conclude that sex change in P. vulgata can be induced at smaller sizes by reductions in density of the largest individuals reducing interage class competition. Knowledge of sex-change adaptation in exploited limpet populations should underpin strategies to counteract population decline and improve rocky shore conservation and resource management.