57 research outputs found
Securing Personal Items in Public Space: Stories of Attacks and Threats
While we put great effort in protecting digital devices and data, there is a lack of research on usable techniques to secure personal items that we carry in public space. To better understand situations where ubiquitous technologies could help secure personal items, we conducted an online survey (N=101) in which we collected real-world stories from users reporting on personal items, either at risk of, or actually being lost, damaged or stolen. We found that the majority of cases occurred in (semi-)public spaces during afternoon and evening times, when users left their items. From these results, we derived a model of incidents involving personal items in public space as well as a set of properties to describe situations where personal items may be at risk. We discuss reoccurring properties of the scenarios, potential multimedia-based protection mechanisms for securing personal items in public space as well as future research suggestions
BF/M-Spiegel : Journal des Betriebswirtschaftlichen Forschungszentrums für Fragen der mittelständischen Wirtschaft e. V. an der Universität Bayreuth, Heft 3, 2014
BF/M-Spiegel : Journal des Betriebswirtschaftlichen Forschungszentrums für Fragen der mittelständischen Wirtschaft e. V. an der Universität Bayreuth, 2015, Heft 1
Geometry-Informed Neural Operator for Large-Scale 3D PDEs
We propose the geometry-informed neural operator (GINO), a highly efficient
approach to learning the solution operator of large-scale partial differential
equations with varying geometries. GINO uses a signed distance function and
point-cloud representations of the input shape and neural operators based on
graph and Fourier architectures to learn the solution operator. The graph
neural operator handles irregular grids and transforms them into and from
regular latent grids on which Fourier neural operator can be efficiently
applied. GINO is discretization-convergent, meaning the trained model can be
applied to arbitrary discretization of the continuous domain and it converges
to the continuum operator as the discretization is refined. To empirically
validate the performance of our method on large-scale simulation, we generate
the industry-standard aerodynamics dataset of 3D vehicle geometries with
Reynolds numbers as high as five million. For this large-scale 3D fluid
simulation, numerical methods are expensive to compute surface pressure. We
successfully trained GINO to predict the pressure on car surfaces using only
five hundred data points. The cost-accuracy experiments show a
speed-up compared to optimized GPU-based computational fluid dynamics (CFD)
simulators on computing the drag coefficient. When tested on new combinations
of geometries and boundary conditions (inlet velocities), GINO obtains a
one-fourth reduction in error rate compared to deep neural network approaches
Real-time monitoring of beta-d-glucuronidase activity in sediment laden streams: A comparison of prototypes
AbstractDetection of enzymatic activities has been proposed as a rapid surrogate for the culture-based microbiological pollution monitoring of water resources. This paper presents the results of tests on four fully automated prototype instruments for the on-site monitoring of beta-d-glucuronidase (GLUC) activity. The tests were performed on sediment-laden stream water in the Hydrological Open Air Laboratory (HOAL) during the period of March 2014 to March 2015. The dominant source of faecal pollution in the stream was swine manure applied to the fields within the catchment. The experiments indicated that instrument pairs with the same construction design yielded highly consistent results (R2 = 0.96 and R2 = 0.94), whereas the results between different designs were less consistent (R2 = 0.71). Correlations between the GLUC activity measured on-site and culture-based Escherichia coli analyses over the entire study period yielded R2 = 0.52 and R2 = 0.47 for the two designs, respectively. The correlations tended to be higher at the event scale. The GLUC activity was less correlated with suspended sediment concentrations than with E. coli, which is interpreted in terms of indicator applicability and the time since manure application. The study shows that this rapid assay can yield consistent results over a long period of on-site operation in technically challenging habitats. Although the use of GLUC activity as a proxy for culture-based assays could not be proven for the observed habitat, the study results suggest that this biochemical indicator has high potential for implementation in early warning systems
In situ guided tissue regeneration in musculoskeletal diseases and aging: Implementing pathology into tailored tissue engineering strategies
In situ guided tissue regeneration, also addressed as in situ tissue engineering or endogenous regeneration, has a great potential for population-wide “minimal invasive” applications. During the last two decades, tissue engineering has been developed with remarkable in vitro and preclinical success but still the number of applications in clinical routine is extremely small. Moreover, the vision of population-wide applications of ex vivo tissue engineered constructs based on cells, growth and differentiation factors and scaffolds, must probably be deemed unrealistic for economic and regulation-related issues. Hence, the progress made in this respect will be mostly applicable to a fraction of post-traumatic or post-surgery situations such as big tissue defects due to tumor manifestation. Minimally invasive procedures would probably qualify for a broader application and ideally would only require off the shelf standardized products without cells. Such products should mimic the microenvironment of regenerating tissues and make use of the endogenous tissue regeneration capacities. Functionally, the chemotaxis of regenerative cells, their amplification as a transient amplifying pool and their concerted differentiation and remodeling should be addressed. This is especially important because the main target populations for such applications are the elderly and diseased. The quality of regenerative cells is impaired in such organisms and high levels of inhibitors also interfere with regeneration and healing. In metabolic bone diseases like osteoporosis, it is already known that antagonists for inhibitors such as activin and sclerostin enhance bone formation. Implementing such strategies into applications for in situ guided tissue regeneration should greatly enhance the efficacy of tailored procedures in the future
The GRAVITY+ Project: Towards All-sky, Faint-Science, High-Contrast Near-Infrared Interferometry at the VLTI
The GRAVITY instrument has been revolutionary for near-infrared
interferometry by pushing sensitivity and precision to previously unknown
limits. With the upgrade of GRAVITY and the Very Large Telescope Interferometer
(VLTI) in GRAVITY+, these limits will be pushed even further, with vastly
improved sky coverage, as well as faint-science and high-contrast capabilities.
This upgrade includes the implementation of wide-field off-axis
fringe-tracking, new adaptive optics systems on all Unit Telescopes, and laser
guide stars in an upgraded facility. GRAVITY+ will open up the sky to the
measurement of black hole masses across cosmic time in hundreds of active
galactic nuclei, use the faint stars in the Galactic centre to probe General
Relativity, and enable the characterisation of dozens of young exoplanets to
study their formation, bearing the promise of another scientific revolution to
come at the VLTI.Comment: Published in the ESO Messenge
Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020
We show the distribution of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three genomic nomenclature systems to all sequence data from the World Health Organization European Region available until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation, compare the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2
Shareholder Activism by Hedge Funds. Empirical Study for Germany
Shareholder-Aktivismus durch Hedge Fonds liegt vor, wenn Hedge Fonds durch Kommunikation mit dem Management oder Druck auf das Management versuchen, auf die Strategie eines Unternehmens einzuwirken. Das Auftreten von Aktivismus wird durch Interessenkonflikte zwischen Anteilseignern und Management ausgelöst, welche durch die Trennung von Eigentum und Kontrolle entstehen. Die Bedeutung und der Einfluss von Hedge Fonds-Aktivismus hat seit 2005 in Deutschland stark zugenommen und hält trotz der Turbulenzen am Finanzmarkt weiter an. Die bisherigen Arbeiten zum Hedge Fonds-Aktivismus bezogen sich hauptsächlich auf die USA. Das dortige Corporate Governance-Umfeld unterscheidet sich insbesondere bezüglich der Eigentümerstruktur deutlich vom Deutschen Corporate Governance- Umfeld, welches beispielhaft für andere kontinentaleuropäische Länder ist. Unter anderem wurde vermutet, dass sich das Vorhandensein von Familiengroßaktionären negativ auf den Erfolg von Hedge Fonds-Aktivismus auswirkt. Zur Eingrenzung des Untersuchungsgebietes wurde zunächst ein ausführlicher Literaturüberblick zum Hedge Fonds-Aktivismus gegeben. Es folgte eine Eventstudie mit 133 deutschen Hedge Fonds-Events, die zwischen Januar 2000 und April 2008 stattfanden. Die Auswirkungen des Hedge Fonds-Aktivismus wurden sowohl kurz- als auch langfristig empirisch untersucht. Zur Treiberanalyse wurde auf Multiple Regressionen zurückgegriffen. Es konnten kurzfristige abnormale Renditen gemessen werden, die nicht langfristig Bestand hatten. Zudem wurden die Annahmen zum Einfluss von Familiengroßaktionären bestätigt. Und es wurde gemessen, dass Hedge Fonds-Aktivismus insbesondere bei einem angestrebten Verkauf von Unternehmensteilen erfolgreich ist. Die Arbeit liefert einen Beitrag zur Literatur, indem Sie die Untersuchungen zum Hedge Fonds-Aktivismus auf ein Land mit konzentriertem Anteilsbesitz ausweitet.Shareholder activism by hedge funds occurs, if hedge funds try to influence the strategy of a corporation by communicating with the management or putting pressure on it. The appearance of hedge fund activism is caused by a conflict of interest between management and shareholders, which originate from the separation of ownership and control. Since 2005, the importance and the influence of hedge fund activism in Germany grew steadily and still prevail despite the turbulence on the financial markets. Until now, the research for shareholder activism by hedge funds mainly refers to the USA. The corporate governance system in the USA differs especially concerning the ownership structure from the German system, which is exemplary for other continental European countries. I hypothesize amongst other things that the existence of a major family shareholder with a blocking minority has a negative influence on the success of hedge fund activism. To define the scope of the study I conducted a detailed literature review about hedge fund activism. The event study has 133 German hedge fund events, which took place between January 2000 and April 2008. I measured the impact of hedge fund activism short-term and long-term. To detect the underlying drivers of the success of hedge fund activism I used multiple regressions. I found that hedge fund activism shows significant positive abnormal returns shortterm, which do not hold long-term. Furthermore, the assumptions concerning the influence of major family shareholders were supported. Moreover, it could be measured that hedge fund activism is especially successful if it tries to force the company to sell assets. The study contributes to the literature as it analyzes hedge fund activism in a country with a concentrated ownership structure
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