60 research outputs found

    Collaborative design in virtual environments

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    How can architects and engineers work together in the digital world? The article "Collaborative Design in Virtual Environments" provides an answer. The authors describe how the use of virtual reality (VR) and augmented reality (AR) is becoming increasingly important in the architecture industry and what opportunities this opens up. In particular, the article focuses on collaboration in virtual spaces and collaborative modeling of 3D objects. The authors also present a software tool that enables collaborative 3D modeling in virtual environments. The aim of the "Industry 4.0 in Teaching" project is to promote collaboration and joint learning and to prepare students for the requirements of the digital working world. (Editor)Wie können Architekten und Ingenieure in der digitalen Welt zusammenarbeiten? Eine Antwort darauf liefert der Artikel "Collaborative Design in Virtual Environments". Die Autoren beschreiben, wie die Anwendung von Virtual Reality (VR) und Augmented Reality (AR) in der Architekturbranche immer wichtiger wird und welche Möglichkeiten sich daraus ergeben. Insbesondere die Zusammenarbeit in virtuellen Räumen und die gemeinsame Modellierung von 3D-Objekten stehen im Fokus des Artikels. Die Autoren stellen außerdem ein Software-Tool vor, das die kollaborative 3D-Modellierung in virtuellen Umgebungen ermöglicht. Das Ziel des Projekts "Industry 4.0 in Teaching" ist es, die Zusammenarbeit und das gemeinsame Lernen zu fördern und die Studierenden auf die Anforderungen der digitalen Arbeitswelt vorzubereiten. (Herausgeber

    Statistical upscaling of ecosystem CO2 fluxes across the terrestrial tundra and boreal domain: Regional patterns and uncertainties

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    The regional variability in tundra and boreal carbon dioxide (CO2) fluxes can be high, complicating efforts to quantify sink-source patterns across the entire region. Statistical models are increasingly used to predict (i.e., upscale) CO2 fluxes across large spatial domains, but the reliability of different modeling techniques, each with different specifications and assumptions, has not been assessed in detail. Here, we compile eddy covariance and chamber measurements of annual and growing season CO2 fluxes of gross primary productivity (GPP), ecosystem respiration (ER), and net ecosystem exchange (NEE) during 1990-2015 from 148 terrestrial high-latitude (i.e., tundra and boreal) sites to analyze the spatial patterns and drivers of CO2 fluxes and test the accuracy and uncertainty of different statistical models. CO2 fluxes were upscaled at relatively high spatial resolution (1 km(2)) across the high-latitude region using five commonly used statistical models and their ensemble, that is, the median of all five models, using climatic, vegetation, and soil predictors. We found the performance of machine learning and ensemble predictions to outperform traditional regression methods. We also found the predictive performance of NEE-focused models to be low, relative to models predicting GPP and ER. Our data compilation and ensemble predictions showed that CO2 sink strength was larger in the boreal biome (observed and predicted average annual NEE -46 and -29 g C m(-2) yr(-1), respectively) compared to tundra (average annual NEE +10 and -2 g C m(-2) yr(-1)). This pattern was associated with large spatial variability, reflecting local heterogeneity in soil organic carbon stocks, climate, and vegetation productivity. The terrestrial ecosystem CO2 budget, estimated using the annual NEE ensemble prediction, suggests the high-latitude region was on average an annual CO2 sink during 1990-2015, although uncertainty remains high

    The ABCflux database : Arctic-boreal CO2 flux observations and ancillary information aggregated to monthly time steps across terrestrial ecosystems

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    Past efforts to synthesize and quantify the magnitude and change in carbon dioxide (CO2) fluxes in terrestrial ecosystems across the rapidly warming Arctic-boreal zone (ABZ) have provided valuable information but were limited in their geographical and temporal coverage. Furthermore, these efforts have been based on data aggregated over varying time periods, often with only minimal site ancillary data, thus limiting their potential to be used in large-scale carbon budget assessments. To bridge these gaps, we developed a standardized monthly database of Arctic-boreal CO2 fluxes (ABCflux) that aggregates in situ measurements of terrestrial net ecosystem CO2 exchange and its derived partitioned component fluxes: gross primary productivity and ecosystem respiration. The data span from 1989 to 2020 with over 70 supporting variables that describe key site conditions (e.g., vegetation and disturbance type), micrometeorological and environmental measurements (e.g., air and soil temperatures), and flux measurement techniques. Here, we describe these variables, the spatial and temporal distribution of observations, the main strengths and limitations of the database, and the potential research opportunities it enables. In total, ABCflux includes 244 sites and 6309 monthly observations; 136 sites and 2217 monthly observations represent tundra, and 108 sites and 4092 observations represent the boreal biome. The database includes fluxes estimated with chamber (19 % of the monthly observations), snow diffusion (3 %) and eddy covariance (78 %) techniques. The largest number of observations were collected during the climatological summer (June-August; 32 %), and fewer observations were available for autumn (September-October; 25 %), winter (December-February; 18 %), and spring (March-May; 25 %). ABCflux can be used in a wide array of empirical, remote sensing and modeling studies to improve understanding of the regional and temporal variability in CO2 fluxes and to better estimate the terrestrial ABZ CO2 budget. ABCflux is openly and freely available online (Virkkala et al., 2021b, https://doi.org/10.3334/ORNLDAAC/1934).Peer reviewe

    Modeled microbial dynamics explain the apparent temperature sensitivity of wetland methane emissions

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    Methane emissions from natural wetlands tend to increase with temperature and therefore may lead to a positive feedback under future climate change. However, their temperature response includes confounding factors and appears to differ on different time scales. Observed methane emissions depend strongly on temperature on a seasonal basis, but if the annual mean emissions are compared between sites, there is only a small temperature effect. We hypothesize that microbial dynamics are a major driver of the seasonal cycle and that they can explain this apparent discrepancy. We introduce a relatively simple model of methanogenic growth and dormancy into a wetland methane scheme that is used in an Earth system model. We show that this addition is sufficient to reproduce the observed seasonal dynamics of methane emissions in fully saturated wetland sites, at the same time as reproducing the annual mean emissions. We find that a more complex scheme used in recent Earth system models does not add predictive power. The sites used span a range of climatic conditions, with the majority in high latitudes. The difference in apparent temperature sensitivity seasonally versus spatially cannot be recreated by the non‐microbial schemes tested. We therefore conclude that microbial dynamics are a strong candidate to be driving the seasonal cycle of wetland methane emissions. We quantify longer‐term temperature sensitivity using this scheme and show that it gives approximately a 12% increase in emissions per degree of warming globally. This is in addition to any hydrological changes, which could also impact future methane emissions

    Wirtschaftlichkeitsbewertung einer prozessmodularen E-Motorenfertigung

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    Die Elektrifizierung des Antriebstrangs von Kraftfahrzeugen steht im Fokus zahlreicher Vorhaben. Nach der erfolgreichen Produktion elektrifizierter Antriebe im Prototypen- bzw. Kleinserienbereich steht die Industrie unter anderem vor der Herausforderung, diese wirtschaftlich in die Massenfertigung zu überführen. Der vorliegende Beitrag stellt eine Bewertungsmethodik vor, mit deren Hilfe Investitionsentscheidungen in verschiedenen Produktionsbereichen zuverlässig unterstützt werden können. An dem Modul “Herstellung Welle” des Elektromotors wird das Vorgehen exemplarisch vorgestellt

    Indemnifying irresponsibility: how international investment law undermines responsible business conduct

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    Societal norms, legal rules, and market forces work together to shape the behavior of businesses. Those three forces (normative, legal, and market) must work in harmony to encourage and support responsible business conduct. This chapter demonstrates how one aspect of the legal framework - international investment law - can undermine the normative, legal, and market incentives for businesses to adopt more responsible practices. It argues that in disputes between investors and host governments, arbitral tribunals have disregarded businesses’ failures to identify and address actual and potential risks and harms generated by their activities, and indemnified investors for losses incurred as a result of their own misconduct. It then provides two key recommendations. First, it suggests a reorientation of international investment law so that it is supportive of responsible business conduct. And second, it suggests that businesses’ use of investment law to bring claims against states should be considered when assessing whether and to what extent businesses are complying with standards of responsible business conduct
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