1,004 research outputs found
A Model-Based Framework for Simplified Collaboration of Legal and Software Experts in Data Protection Assessments
The protection of personal data has become an increasingly important issue. Legal norms focused on data protection, such as the GDPR, provide legally binding requirements for systems that process personal data. Article 25 of the GDPR refers to the obligation to Data Protection by Design and Default. This can be achieved by conducting DPLA of the system in the early stages of development and implementing data protection concepts where necessary. This ties in with Article 35, which refers to an obligation to conduct DPLA before the actual processing of data. To aid in conducting continuous DPLA during the design time of software systems, we propose a model-based collaboration framework. This framework not only aids in providing consistent views of the software system for legal experts and software architects but also simplifies communication between both parties. We discuss the overall goals and benefits of such a framework and go into detail about the processes that interact as part of the framework. We also try to align legal concepts with the processes and describe the continuous iterative development using the collaboration framework
Prediction of spiralling in BTA deep-Āhole drilling - estimating the system's eigenfrequencies
One serious problem in deepĀhole drilling is the formation of a dynamic disturbance called spiralling which causes holes with several lobes. Since such lobes are a severe impairment of the bore hole quality the formaĀtion of spiralling has to be prevented. Gessesse et al. [2] explain spiralling by the coincidence of bending modes and multiples of the rotation frequency. They derive this from an elaborate finite elements model of the process. In online measurements we detected slowly changing frequency patterns simĀilar to those calculated by Gessesse et al. We therefore propose a method
to estimate the parameters determining the change of frequencies over time from spectrogram data. This significantly simplifies the explanation of spiĀralling for practical applications compared to finite elements models which have to be correctly modified for each machine and tool assembly. It turns out that this simpler model achieves to explain the observed frequency patĀterns quite well.
We use this for estimating the variation of the frequencies as good as posĀsible. This opens up the opportunity to prevent spiralling by e.g. changing the rotary frequency
Measurement of the branching ratio for beta-delayed alpha decay of 16N
While the 12C(a,g)16O reaction plays a central role in nuclear astrophysics,
the cross section at energies relevant to hydrostatic helium burning is too
small to be directly measured in the laboratory. The beta-delayed alpha
spectrum of 16N can be used to constrain the extrapolation of the E1 component
of the S-factor; however, with this approach the resulting S-factor becomes
strongly correlated with the assumed beta-alpha branching ratio. We have
remeasured the beta-alpha branching ratio by implanting 16N ions in a segmented
Si detector and counting the number of beta-alpha decays relative to the number
of implantations. Our result, 1.49(5)e-5, represents a 24% increase compared to
the accepted value and implies an increase of 14% in the extrapolated S-factor
Amniotic-Fluid Stem Cells: Growth Dynamics and Differentiation Potential after a CD-117-Based Selection Procedure
Amniotic fluid (AF) has become an interesting source of fetal stem cells. However, AF contains heterogeneous and multiple, partially differentiated cell types. After isolation from the amniotic fluid, cells were characterized regarding their morphology and growth dynamics. They were sorted by magnetic associated cell sorting using the surface marker CD 117. In order to show stem cell characteristics such as pluripotency and to evaluate a possible therapeutic application of these cells, AF fluid-derived stem cells were differentiated along the adipogenic, osteogenic, and chondrogenic as well as the neuronal lineage under hypoxic conditions. Our findings reveal that magnetic associated cell sorting (MACS) does not markedly influence growth characteristics as demonstrated by the generation doubling time. There was, however, an effect regarding an altered adipogenic, osteogenic, and chondrogenic differentiation capacity in the selected cell fraction. In contrast, in the unselected cell population neuronal differentiation is enhanced
Modelling and understanding of chatter
Recent analysis in chatter modelling of BTA deepĀhole drilling consisted in phenomenological modelisation of relationships between the obĀ
served time series and appearance of chatter during the process. Using the newly developed MEWMA control chart [4, 5], it has even been possible to predict the occurence of chatter about 30 to 50 mm in advance (i.e. up to
one minute before the chatter starts).
Unfortunately, no relationships between the machine and model paramĀeters have been detected. Therefore, in this paper a physical model of the
boring bar is taken into account. Simulation studies of the regenerative proĀcess are performed. These simulated time series show the same characteristics as the data recorded during the drilling process and thus support the validity of our model. By running such simulations, we intend to find strategies for
chatter prevention in future work
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