173 research outputs found

    Designing a Smart City Internet of Things Platform with Microservice Architecture

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    The Internet of Things (IoT) is being adopted in different application domains and is recognized as one of the key enablers of the Smart City vision. Despite the standard-ization efforts and wide adoption of Web standards and cloud computing technologies, however, building large-scale Smart City IoT platforms in practice remains challenging. The dynamically changing IoT environment requires these systems to be able to scale and evolve over time adopting new technologies and requirements. In response to the similar challenges in building large-scale distributed applications and platforms on the Web, microservice architecture style has emerged and gained a lot of popularity in the industry in recent years. In this work, we share our early experience of applying the microservice architecture style to design a Smart City IoT platform. Our experience suggests significant benefits provided by this architectural style compared to the more generic Service-Oriented Architecture (SOA) approaches, as well as highlights some of the challenges it introduces

    Neue Marktkonzentration? Eine Analyse der Open-Access-Kosten in Deutschland

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    Jahn N, Tullney M. Neue Marktkonzentration? Eine Analyse der Open-Access-Kosten in Deutschland. Forschung & Lehre. 2016;23(10):886-887

    A study of institutional spending on open access publication fees in Germany

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    Jahn N, Tullney M. A study of institutional spending on open access publication fees in Germany. PeerJ. 2016;4: e2323.Publication fees as a revenue source for open access publishing hold a prominent place on the agendas of researchers, policy makers, and academic publishers. This study contributes to the evolving empirical basis for funding these charges and examines how much German universities and research organisations spent on open access publication fees. Using self-reported cost data from the Open APC initiative, the analysis focused on the amount that was being spent on publication fees, and compared these expenditure with data from related Austrian (FWF) and UK (Wellcome Trust, Jisc) initiatives, in terms of both size and the proportion of articles being published in fully and hybrid open access journals. We also investigated how thoroughly self-reported articles were indexed in Crossref, a DOI minting agency for scholarly literature, and analysed how the institutional spending was distributed across publishers and journal titles. According to self-reported data from 30 German universities and research organisations between 2005 and 2015, expenditures on open access publication fees increased over the years in Germany and amounted to € 9,627,537 for 7,417 open access journal articles. The average payment was € 1,298, and the median was € 1,231. A total of 94% of the total article volume included in the study was supported in accordance with the price cap of € 2,000, a limit imposed by the Deutsche Forschungsgemeinschaft (DFG) as part of its funding activities for open access funding at German universities. Expenditures varied considerably at the institutional level. There were also differences in how much the institutions spent per journal and publisher. These differences reflect, at least in part, the varying pricing schemes in place including discounted publication fees. With an indexing coverage of 99%, Crossref thoroughly indexed the open access journals articles included in the study. A comparison with the related openly available cost data from Austria and the UK revealed that German universities and research organisations primarily funded articles in fully open access journals. By contrast, articles in hybrid journal accounted for the largest share of spending according to the Austrian and UK data. Fees paid for hybrid journals were on average more expensive than those paid for fully open access journals

    Surface Based Modelling of Ground Motion Areas in Lower Saxony

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    Systematic investigations have shown subsidence in almost 30% of the land area in Lower Saxony. It is essential to model these variations of the Earth surface especially to update the spatial reference system. Since the geodetic observations result in discrete points, it is necessary to mathematically model these measurements to have a continues surface. This enables the user to do predictions at any position. This is challenging especially because these types of measurements usually result in non-uniformly distributed data. There are different approaches to deal with this problem, here the stochastic method of Kriging and the deterministic method of Multilevel B-Splines are implemented to model ground motion. This paper investigates the ground motion of specific areas in Lower Saxony through the cooperation of Landesamt fĂĽr Geoinformation und Landesvermessung Niedersachsen (LGLN) and Geodetic Institute of Hannover. For this investigation, a time series of measurements from leveling, Global Navigation Satellite System (GNSS) observations and height changes that are acquired by Persistent Scatterer Interferometry (PSI) technique are taken into consideration. Evaluation of the results show not only good performance and promising results from both the approaches, but also compatibility between the approximated surface from both of them

    Design and Implementation of a Multi-Standard Event-Driven Energy Management System For Smart Buildings

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    This paper presents the design and implementation of a multi-standard energy management system, which leverages heterogeneous devices to convert existing buildings into Smart Buildings. Its main purpose is to increase the energy efficiency of buildings providing user awareness to promote green behaviors. The proposed solution has been designed to enable interoperability across different standards and protocols in order to develop applications with which end users can interact with the system. Finally, a web portal and a smartphone application to give feedback and to view environmental information are presented

    High yield recombinant penicillin G amidase production and export into the growth medium using Bacillus megaterium

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    BACKGROUND: During the last years B. megaterium was continuously developed as production host for the secretion of proteins into the growth medium. Here, recombinant production and export of B. megaterium ATCC14945 penicillin G amidase (PGA) which is used in the reverse synthesis of β-lactam antibiotics were systematically improved. RESULTS: For this purpose, the PGA leader peptide was replaced by the B. megaterium LipA counterpart. A production strain deficient in the extracellular protease NprM and in xylose utilization to prevent gene inducer deprivation was constructed and employed. A buffered mineral medium containing calcium ions and defined amino acid supplements for optimal PGA production was developed in microscale cultivations and scaled up to a 2 Liter bioreactor. Productivities of up to 40 mg PGA per L growth medium were reached. CONCLUSION: The combination of genetic and medium optimization led to an overall 7-fold improvement of PGA production and export in B. megaterium. The exclusion of certain amino acids from the minimal medium led for the first time to higher volumetric PGA activities than obtained for complex medium cultivations

    Proteome analysis of a recombinant Bacillus megaterium strain during heterologous production of a glucosyltransferase

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    A recombinant B. megaterium strain was used for the heterologous production of a glucosyltransferase (dextransucrase). To better understand the physiological and metabolic responses of the host cell to cultivation and induction conditions, proteomic analysis was carried out by combined use of two-dimensional gel electrophoresis and mass spectrometry (2-DE/MS) for protein separation and identification. 2-DE method was optimized for the separation of intracellular proteins. Since the genome of B. megaterium is not yet available, peptide sequencing using peptide fragment information obtained from nanoelectrospray ionization quadrupole-time-of-flight tandem mass spectrometry (ESI-QqTOF MS/MS) was applied for protein identification. 167 protein spots were identified as 149 individual proteins, including most enzymes involved in the central carbon metabolic pathways and many enzymes related to amino acid synthesis and protein synthesis. Based on the results a 2-DE reference map and a corresponding protein database were constructed for further proteomic approaches on B. megaterium. For the first time it became possible to perform comparative proteomic analysis on B. megaterium in a batch culture grown on glucose with xylose induction for dextrasucrase production. No significant differences were observed in the expression changes of enzymes of the glycolysis and TCA cycle, indicating that dextransucrase production, which amounted to only 2 % of the entire protein production, did not impose notable metabolic or energetic burdens on the central carbon metabolic pathway of the cells. However, a short-term up-regulation of aspartate aminotransferase, an enzyme closely related to dextransucrase production, in the induced culture demonstrated the feasibility to use 2-DE method for monitoring dextransucrase production. It was also observed that under the cultivation conditions used in this study B. megaterium tended to channel acetyl-CoA into pathways of polyhydroxybutyrate production. No expression increases were found with cytosolic chaperones such as GroEL and DnaK during dextransucrase production and secretion, whereas a strong up-regulation of the oligopeptide-binding protein OppA was observed in correlation with an increased secretion of dextransucrase into the culture medium

    Event-Driven User-Centric Middleware for Energy Efficient Buildings and Public Spaces

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    In this work, the design of an event-driven user-centric middleware for monitoring and managing energy consumption in public buildings and spaces is presented. The main purpose is to increase the energy efficiency, reducing consumption, in buildings and public spaces. To achieve this, the proposed service-oriented middleware has been designed to be event based, also exploiting the user behaviours patterns of the people who live and work into the building. Furthermore, it allows an easy integration of heterogeneous technologies in order to enable a hardware independent interoperability between them. Moreover, a Heating Ventilation and Air Conditioning (HVAC) control strategy has been developed and the whole infrastructure has been deployed in a real-world case study consisting of a historical building. Finally the results will be presented and discusse

    V605 Aquilae: a born again star, a nova or both?

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    V605 Aquilae is today widely assumed to have been the result of a final helium shell flash occurring on a single post-asymptotic giant branch star. The fact that the outbursting star is in the middle of an old planetary nebula and that the ejecta associated with the outburst is hydrogen deficient supports this diagnosis. However, the material ejected during that outburst is also extremely neon rich, suggesting that it derives from an oxygen-neon-magnesium star, as is the case in the so-called neon novae. We have therefore attempted to construct a scenario that explains all the observations of the nebula and its central star, including the ejecta abundances. We find two scenarios that have the potential to explain the observations, although neither is a perfect match. The first scenario invokes the merger of a main sequence star and a massive oxygen-neon-magnesium white dwarf. The second invokes an oxygen-neon-magnesium classical nova that takes place shortly after a final helium shell flash. The main drawback of the first scenario is the inability to determine whether the ejecta would have the observed composition and whether a merger could result in the observed hydrogen-deficient stellar abundances observed in the star today. The second scenario is based on better understood physics, but, through a population synthesis technique, we determine that its frequency of occurrence should be very low and possibly lower than what is implied by the number of observed systems. While we could not envisage a scenario that naturally explains this object, this is the second final flash star which, upon closer scrutiny, is found to have hydrogen-deficient ejecta with abnormally high neon abundances. These findings are in stark contrast with the predictions of the final helium shell flash and beg for an alternative explanation.Comment: 8 pages, 1 figures, 2 tables, accepted for MNRAS. Better title and minor corrections compared to previous versio
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