The Impact of Dynamic Two-Sided Platform Pricing on Fairness Perception in the Sharing Economy

From an economic perspective, dynamic pricing seems to be the profit maximizing pricing strategy for consumer-to-consumer (C2C) sharing platforms because it allows balancing supply and demand over time. Based on distributive justice and equity theory we investigate how two characteristics of dynamic pricing, namely -˜fee changes over time’ and -˜fee differences across consumer groups’, influence fairness perception and intention to share of consumers. Using a laboratory experiment, we find that fee differences between lenders and borrowers is the dominant source of negative fairness perception, which in turn results in a lower intention to share, especially for the consumer group that is charged with a higher fee. Consequently, C2C sharing platforms have to be aware of this negative effect from fairness perception when they implement a dynamic two-sided platform pricing strategy to maximize profits

FPGA based microserver for high performance real-time computing in Adaptive Optics

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E-ELT M4 adaptive unit final design and construction: a progress report

The E-ELT M4 adaptive unit is a fundamental part of the E-ELT: it provides the facility level adaptive optics correction that compensates the wavefront distortion induced by atmospheric turbulence and partially corrects the structural deformations caused by wind. The unit is based on the contactless, voice-coil technology already successfully deployed on several large adaptive mirrors, like the LBT, Magellan and VLT adaptive secondary mirrors. It features a 2.4m diameter flat mirror, controlled by 5316 actuators and divided in six segments. The reference structure is monolithic and the cophasing between the segments is guaranteed by the contactless embedded metrology. The mirror correction commands are usually transferred as modal amplitudes, that are checked by the M4 controller through a smart real-time algorithm that is capable to handle saturation effects. A large hexapod provides the fine positioning of the unit, while a rotational mechanism allows switching between the two Nasmyth foci. The unit has entered the final design and construction phase in July 2015, after an advanced preliminary design. The final design review is planned for fall 2017; thereafter, the unit will enter the construction and test phase. Acceptance in Europe after full optical calibration is planned for 2022, while the delivery to Cerro Armazones will occur in 2023. Even if the fundamental concept has remained unchanged with respect to the other contactless large deformable mirrors, the specific requirements of the E-ELT unit posed new design challenges that required very peculiar solutions. Therefore, a significant part of the design phase has been focused on the validation of the new aspects, based on analysis, numerical simulations and experimental tests. Several experimental tests have been executed on the Demonstration Prototype, which is the 222 actuators prototype developed in the frame of the advanced preliminary design. We present the main project phases, the current design status and the most relevant results achieved by the validation tests

From Dawn to Dusk – Mimicking Natural Daylight Exposure Improves Circadian Rhythm Entrainment in Patients with Severe Brain Injury

Study Objectives: While light therapy has proven effective in re-entraining circadian rhythms, the potential of such an intervention has not been evaluated systematically in post-comatose patients with disorders of consciousness (DOC), who often have strongly altered circadian rhythms. Methods: We recorded skin temperature over 7–8 days in patients with DOC in each of two conditions: habitual light (HL), and dynamic daylight (DDL) condition. While patients were in a room with usual clinic lighting in the HL condition, they were in an otherwise comparable room with biodynamic lighting (i.e. higher illuminance and dynamic changes in spectral characteristics during the day) in the DDL condition. To detect rhythmicity in the patients’ temperature data, we computed Lomb-Scargle periodograms and analysed normalized power, and peak period. Furthermore, we computed interdaily stability and intradaily variability, which provide information about rhythm entrainment and fragmentation. Results: We analysed data from 17 patients with DOC (i.e. unresponsive wakefulness syndrome [n=15] and minimally conscious state [n=2]). The period length of the patients’ temperature rhythms was closer to 24h in the DDL as compared to the HL condition (median deviation from 24h: HL=3.62h, DDL=0.52h). Specifically, in 11/17 (65%) patients the period length was closer to 24h in the DDL condition. Furthermore, the patients’ rhythm was more pronounced, more stable, and less variable in the DDL condition. Conclusions: Our results indicate that DDL stimulation entrains and stabilizes circadian rhythms. This highlights the importance of adequate room lighting as an adjunct therapeutic approach for improving circadian rhythms in severely brain-injured patients

Does the Heart Fall Asleep?—Diurnal Variations in Heart Rate Variability in Patients with Disorders of Consciousness

The current study investigated heart rate (HR) and heart rate variability (HRV) across day and night in patients with disorders of consciousness (DOC). We recorded 24-h electrocardiography in 26 patients with DOC (i.e., unresponsive wakefulness syndrome (UWS; n = 16) and (exit) minimally conscious state ((E)MCS; n = 10)). To examine diurnal variations, HR and HRV indices in the time, frequency, and entropy domains were computed for periods of clear day- (forenoon: 8 a.m.–2 p.m.; afternoon: 2 p.m.–8 p.m.) and nighttime (11 p.m.–5 a.m.). The results indicate that patients’ interbeat intervals (IBIs) were larger during the night than during the day, indicating HR slowing. The patients in UWS showed larger IBIs compared to the patients in (E)MCS, and the patients with non-traumatic brain injury showed lower HRV entropy than the patients with traumatic brain injury. Additionally, higher HRV entropy was associated with higher EEG entropy during the night. Thus, cardiac activity varies with a diurnal pattern in patients with DOC and can differentiate between patients’ diagnoses and etiologies. Moreover, the interaction of heart and brain appears to follow a diurnal rhythm. Thus, HR and HRV seem to mirror the integrity of brain functioning and, consequently, might serve as supplementary measures for improving the validity of assessments in patients with DOC

BMC Medicine / Actigraphy in brain-injured patients A valid measurement for assessing circadian rhythms?

Background Actigraphy has received increasing attention in classifying rest-activity cycles. However, in patients with disorders of consciousness (DOC), actigraphy data may be considerably confounded by passive movements, such as nursing activities and therapies. Consequently, this study verified whether circadian rhythmicity is (still) visible in actigraphy data from patients with DOC after correcting for passive movements. Methods Wrist actigraphy was recorded over 78 consecutive days in patients with DOC (diagnosed with unresponsive wakefulness syndrome [UWS; n = 19] and [exit] minimally conscious state [MCS/EMCS; n = 11]). The presence and actions of clinical and research staff as well as visitors were indicated using a tablet in the patients room. Following removal and interpolation of passive movements, non-parametric rank-based tests were computed to identify differences between circadian parameters of uncorrected and corrected actigraphy data. Results Uncorrected actigraphy data overestimated the interdaily stability and intradaily variability of patients activity and underestimated the deviation from a circadian 24-h rhythm. Only 5/30 (17%) patients deviated more than 1 h from 24 h in the uncorrected data, whereas this was the case for 17/30 (57%) patients in the corrected data. When contrasting diagnoses based on the corrected dataset, stronger circadian rhythms and higher activity levels were observed in MCS/EMCS as compared to UWS patients. Day-to-night differences in activity were evident for both patient groups. Conclusion Our findings indicate that uncorrected actigraphy data overestimates the circadian rhythmicity of patients activity, as nursing activities, therapies, and visits by relatives follow a circadian pattern itself. Therefore, we suggest correcting actigraphy data from patients with reduced mobility.(VLID)510059

The deformable secondary mirror of VLT: final electro-mechanical and optical acceptance test results

The Deformable Secondary Mirror (DSM) for the VLT ended the stand-alone electro-mechanical and optical acceptance process, entering the test phase as part of the Adaptive Optics Facility (AOF) at the ESO Headquarter (Garching). The VLT-DSM currently represents the most advanced already-built large-format deformable mirror with its 1170 voice-coil actuators and its internal metrology based on co-located capacitive sensors to control the shape of the 1.12m-diameter 2mm-thick convex shell. The present paper reports the final results of the electro-mechanical and optical characterization of the DSM executed in a collaborative effort by the DSM manufacturing companies (Microgate s.r.l. and A.D.S. International s.r.l.), INAF-Osservatorio Astrofisico di Arcetri and ESO. The electro-mechanical acceptance tests have been performed in the company premises and their main purpose was the dynamical characterization of the internal control loop response and the calibration of the system data that are needed for its optimization. The optical acceptance tests have been performed at ESO (Garching) using the ASSIST optical test facility. The main purpose of the tests are the characterization of the optical shell flattening residuals, the corresponding calibration of flattening commands, the optical calibration of the capacitive sensors and the optical calibration of the mirror influence functions

StroMiS - Studie zur technisch-wirtschaftlichen Analyse der Stromerzeugung aus Mikrokraftwerken in Serienfertigung

Anlagen zur Erzeugung von elektrischem Strom folgten bisher dem Paradigma der Verfahrenstechnik: Je größer, desto wirtschaftlicher (Efficiency of Size). So wuchs die Leistungen von Wind-, Kern- und fossilen Kraftwerken in den letzten Jahren kontinuierlich an. Mit deren Größe steigen jedoch die Bau- und Inbetriebnahmezei-ten sowie das Betriebsrisiko und die Akzeptanz der Bevölkerung sinkt. Gleichzeitig entsteht mit dem immensen Produktionsvolumen von Photovoltaik-Zellen zur Stromerzeugung eine starke wirtschaftliche Konkurrenz für die etablierten Technologien. Hier wirkt das Gesetz der Produktionstechnik: Je größer die Stückzahl, desto günstiger werden die Produkte (Economies of Scale). Die Studie zur technisch-wirtschaftlichen Analyse von Kleinkraftwerken, die in Serie produziert, dezentral betrieben und in intelligenten Netzen verbunden werden, zeigt grundsätzlich auf, dass die folgenden Effekte im Wettbewerb zu den bisher verfolgten Größenvorteilen beim Wirkungsgrad den massiven Einsatz von Kleinkraftwerken wettbewerbsfähig machen können: • Die enormen Kostendegressionen bei steigenden Stückzahlen kleinerer Anlagen überkompensieren den Verlust der positiven Effekte durch Größe, ohne die erhöhten Risiken in Kauf nehmen zu müssen. • Signifikant größere Produktionsvolumina ermöglichen den Wechsel zu Technologien mit deutlich besseren Leistungswerten und niedrigeren Kos-ten. • Akzeptanz, Energieautonomie sowie Umweltverträglichkeit können mit kleineren Anlagen deutlich besser erzielt werden. • Durch die um Größenordnungen reduzierten Einmalaufwendungen wird die Stromerzeugung demokratisiert und nahezu jeder Stromkonsument kann die Vorteile zur Energiekostensenkung, zur Erhöhung der Energieautonomie und zur Erhöhung der Umweltfreundlichkeit eigenverantwortlich nutzen. Damit sinken umgekehrt die zentral bei den Energieversorgern erforderlichen Investitionen für die Stromerzeugung und den Stromtransport

E-ELT M4 Unit updated design and prototype results

We present the current design of the E-ELT M4 deformable mirror consolidated at the conclusion of the Preliminary Design activity. The most prominent features of this system are the SiC Reference Body now mounted to the positioner by a whiffle-tree and cell structure, actuators bricks, capacitive sensors layout and new cooling concept. All this allowed achieving the challenging stability requirements demanded to the M4U, as proved by analysis and test results measured on the Demonstration Prototype, which has been updated to implement the current design. The final design and construction contract is now on-going: Final Design Review is planned on mid 2017 and delivery to site by late 2022