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Sharpening the Educational Toolset - Promoting Professional Development of University Lecturers
(2016)
WiFi-based Long Distance (WiLD) networks have emerged as a promising alternative approach for Internet in rural areas. However, the MAC layer, which is based on the IEEE802.11 standard, comprises contiguous stations in a cell and is spatially restricted to a few hundred meters at most. In this work, we summarize efforts by different researchers to use IEEE802.11 over long-distances. In addition, we introduce WiLDToken, our solution to optimizing the throughput and fairness and reducing the delay on WiLD links. Compared to previous alternative MAC layers protocols for WiLD, our focus is on optimizing a single link in a multi-radio multi-channel mesh. We implement our protocol in the ns-3 network simulator and show thatWiLDToken is superior to an adapted version of the Distributed Coordination Function (DCF) for different link distances. We find that the throughput on a single link is close to the physical data-rate without a major decrease over longer distances.
WiFi-based Long Distance (WiLD) networks have emerged as a promising alternative technology approach for providing Internet in rural areas. An important factor in network planning of these wireless networks is estimating the path loss. In this work, we present various propagation models we found suitable for point-to-point (P2P) operation in the WiFi frequency bands. We conducted outdoor experiments with commercial offthe- shelf (COTS) hardware in our testbed made of 7 different long-distance links ranging from 450 m to 10.3 km and a mobile measurement station. We found that for short links with omni-directional antennas ground-reflection is a measurable phenomenon. For longer links, we show that either FSPL or the Longley-Rice model provides accurate results for certain links. We conclude that a good site survey is needed to exclude influences not included in the propagation models.
Nachhaltiges Innovationsmanagement in KMU: Eine empirische Untersuchung zu Living Labs as a Service
(2016)
Die neue europäische Umweltstrategie der Integrierten Produktpolitik fordert von produzierenden kleinen und mittleren Unternehmen (KMU) eine eigenverantwortliche und produktbezogene Nachhaltigkeitsstrategie. Obgleich die Gestaltung von IKT-Services in nachhaltigkeitsrelevanten Bereichen ein großes Marktpotential verspricht, birgt das Innovationsmanagement für KMU einige Risiken. Um diese Herausforderungen zu adressieren motiviert diese Arbeit Living Labs, als Innovationsinfrastruktur, um den spezifischen Bedarfen von KMU für ein nachhaltiges Innovationsmanagement gerecht zu werden. Auf der Basis von 15 semi-strukturierten Interviews mit 7 KMU, die IKT-Lösungen in den Bereichen Wohnen und Mobilität entwickeln, wurden Herausforderungen sowie etablierte Strategien für ein nachhaltiges Innovationsmanagement erhoben sowie Potenziale und mögliche Risiken von Living Labs exploriert. Die Studie zeigt KMU spezifische Bedarfe auf, die eine Anpassung des Living Lab Ansatzes als Service-Dienstleistungen erforderlich machen.
The analysis of Δ9-tetrahydrocannabinol (THC) and its metabolites 11-hydroxy-Δ9-tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH) from blood serum is a routine task in forensic toxicology laboratories. For examination of consumption habits, the concentration of the phase I metabolite THC-COOH is used. Recommendations for interpretation of analysis values in medical-psychological assessments (regranting of driver’s licenses, Germany) include threshold values for the free, unconjugated THC-COOH. Using a fully automated two-step liquid-liquid extraction, THC, 11-OH-THC, and free, unconjugated THC-COOH were extracted from blood serum, silylated with N-methyl-N-(trimethylsilyl) trifluoroacetamide (MSTFA), and analyzed by GC/MS. The automation was carried out by an x-y-z sample robot equipped with modules for shaking, centrifugation, and solvent evaporation. This method was based on a previously developed manual sample preparation method. Validation guidelines of the Society of Toxicological and Forensic Chemistry (GTFCh) were fulfilled for both methods, at which the focus of this article is the automated one. Limits of detection and quantification for THC were 0.3 and 0.6 μg/L, for 11-OH-THC were 0.1 and 0.8 μg/L, and for THC-COOH were 0.3 and 1.1 μg/L, when extracting only 0.5 mL of blood serum. Therefore, the required limit of quantification for THC of 1 μg/L in driving under the influence of cannabis cases in Germany (and other countries) can be reached and the method can be employed in that context. Real and external control samples were analyzed, and a round robin test was passed successfully. To date, the method is employed in the Institute of Legal Medicine in Giessen, Germany, in daily routine. Automation helps in avoiding errors during sample preparation and reduces the workload of the laboratory personnel. Due to its flexibility, the analysis system can be employed for other liquid-liquid extractions as well. To the best of our knowledge, this is the first publication on a comprehensively automated classical liquid-liquid extraction workflow in the field of forensic toxicological analysis.
Die Ergebnisqualität medizinischer Rehabilitationsleistungen wird häufig über „Patient Reported Outcomes“ (PROs) gemessen. Die Bedeutung von PROs für die Nutzenbeurteilung von therapeutischen Interventionen wird häufig unterschätzt (Brettschneider et al., 2011; Calvert et al., 2013). Es wird untersucht, inwieweit sich PROs in „harten“ Endpunkten wie z. B. Beitragszahlungen der Versicherten in die Sozialversicherung widerspiegeln.