2,970 research outputs found

    Tragfähige Zukunftsbilder für den Biolandbau ausgehend von seinen Wurzeln und Werten (Workshop)

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    Heute sind die unterschiedlichsten Akteure im Biosektor aktiv. Auch ihre (oft unbewussten) Antriebe und Wertorientierungen im Biolandbau sind sehr unterschiedlich.. Dies führt zu Spannungen. Für viele Menschen im Biolandbau verliert ihre Lebensform an Lebensqualität, weil sie mit der Anpassung an äussere Ansprüche ihre eigentlichen Werte und ihren inneren Kompass verlieren. Dies führt zu einer Sinn- und Zukunftskrise in der biologischen Landwirtschaft Hier sind tragfähige und glaubwürdige Zukunftsperspektiven und Umsetzungswege gefragt. Ziel des Workshops mit ForscherInnen und BeraterInnen ist erstens, die eigene innerliche Basis zu reflektieren und die eigenen Wertkonflikte vorzubringen. Zweitens wollen wir nach tragfähigen Zukunftsbildern schauen. Um innere Bilder von der Landwirtschaft sowie ihre individuelle Bewertung bei den Workshop-TeilnehmerInnen zu aktivieren, werden symbolkräftige visuelle Bilder hierzu präsentiert. Durch eine Rückkoppelung von positiven Zukunftsbildern zu den Wegen (Backcasting-Methode) können Strategieansätze für die Weiterentwicklung des Biolandbaus sichtbar werden

    Oscillation modes of dc microdischarges with parallel-plate geometry

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    Two different oscillation modes in microdischarge with parallel-plate geometry has been observed: relaxation oscillations with frequency range between 1.23 and 2.1 kHz and free-running oscillations with 7 kHz frequency. The oscillation modes are induced by increasing power supply voltage or discharge current. For a given power supply voltage, there is a spontaneous transition from one to other oscillation mode and vice versa. Before the transition from relaxation to free-running oscillations, the spontaneous increase of oscillation frequency of relaxation oscillations form 1.3 kHz to 2.1 kHz is measured. Fourier Transform Spectra of relaxation oscillations reveal chaotic behaviour of microdischarge. Volt-Ampere characteristics associated with relaxation oscillations describes periodical transition between low current, diffuse discharge and normal glow. However, free-running oscillations appear in subnormal glow only.Comment: Submitted to: New Journal of Physic

    The state of SQL-on-Hadoop in the cloud

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    Managed Hadoop in the cloud, especially SQL-on-Hadoop, has been gaining attention recently. On Platform-as-a-Service (PaaS), analytical services like Hive and Spark come preconfigured for general-purpose and ready to use. Thus, giving companies a quick entry and on-demand deployment of ready SQL-like solutions for their big data needs. This study evaluates cloud services from an end-user perspective, comparing providers including: Microsoft Azure, Amazon Web Services, Google Cloud, and Rackspace. The study focuses on performance, readiness, scalability, and cost-effectiveness of the different solutions at entry/test level clusters sizes. Results are based on over 15,000 Hive queries derived from the industry standard TPC-H benchmark. The study is framed within the ALOJA research project, which features an open source benchmarking and analysis platform that has been recently extended to support SQL-on-Hadoop engines. The ALOJA Project aims to lower the total cost of ownership (TCO) of big data deployments and study their performance characteristics for optimization. The study benchmarks cloud providers across a diverse range instance types, and uses input data scales from 1GB to 1TB, in order to survey the popular entry-level PaaS SQL-on-Hadoop solutions, thereby establishing a common results-base upon which subsequent research can be carried out by the project. Initial results already show the main performance trends to both hardware and software configuration, pricing, similarities and architectural differences of the evaluated PaaS solutions. Whereas some providers focus on decoupling storage and computing resources while offering network-based elastic storage, others choose to keep the local processing model from Hadoop for high performance, but reducing flexibility. Results also show the importance of application-level tuning and how keeping up-to-date hardware and software stacks can influence performance even more than replicating the on-premises model in the cloud.This work is partially supported by the Microsoft Azure for Research program, the European Research Council (ERC) under the EUs Horizon 2020 programme (GA 639595), the Spanish Ministry of Education (TIN2015-65316-P), and the Generalitat de Catalunya (2014-SGR-1051).Peer ReviewedPostprint (author's final draft

    Strong C+ emission in galaxies at z~1-2: Evidence for cold flow accretion powered star formation in the early Universe

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    We have recently detected the [CII] 157.7 micron line in eight star forming galaxies at redshifts 1 to 2 using the redshift(z) Early Universe Spectrometer (ZEUS). Our sample targets star formation dominant sources detected in PAH emission. This represents a significant addition to [CII] observations during the epoch of peak star formation. We have augmented this survey with observations of the [OI] 63 micron line and far infrared photometry from the PACS and SPIRE Herschel instruments as well as Spitzer IRS spectra from the literature showing PAH features. Our sources exhibit above average gas heating efficiency, many with both [OI]/FIR and [CII]/FIR ~1% or more. The relatively strong [CII] emission is consistent with our sources being dominated by star formation powered PDRs, extending to kpc scales. We suggest that the star formation mode in these systems follows a Schmidt-Kennicutt law similar to local systems, but at a much higher rate due to molecular gas surface densities 10 to 100 times that of local star forming systems. The source of the high molecular gas surface densities may be the infall of neutral gas from the cosmic web. In addition to the high [CII]/FIR values, we also find high [CII]/PAH ratios and, in at least one source, a cool dust temperature. This source, SWIRE 4-5, bears a resemblance in these diagnostics to shocked regions of Stephan's Quintet, suggesting that another mode of [CII] excitation in addition to normal photoelectric heating may be contributing to the observed [CII] line.Comment: Accepted for publication in Astrophysical Journal. To appear in December 20, 2014, V797 - 2 issu

    Requirements for the use of impact-based forecasts and warnings by road maintenance services in Germany

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    Impact-based forecasts and warnings (IBFs) are seen as important drivers for adequate anticipation and assessment of potential threats to public safety as they give a better understanding of the weather event's impacts. To prepare for impacts of weather events and prevent weather-related accidents, road maintenance services are actively using weather information in their daily work routine. This paper looks into the requirements that road maintenance services have for IBFs and how weather forecasts are used at the moment. The study is part of an interdisciplinary research project and follows a qualitative social science research approach. Findings show that the following factors are general user requirements: relevance of information, recognition of spatial and temporal requests, acceptability, comprehensibility, and technical demands. These are also applicable to IBFs with the extension to provide a benefit for road maintenance services in situations that rarely occur and where no embodied knowledge in the organization is existent
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