131 research outputs found
Zertifizierbarer Entwicklungsprozess für komplexe Informationsverarbeitungssysteme in der Wägetechnik
The dissertation is about principles, methods and techniques during the
systematic development of embedded systems in the domain of measurement
techniques. The considered domain contains fields of application with
challenging and specific requirements of the information processing system.
E.g. the dynamic weighing systems need solutions with very high resolution
and lowest achievable measurement uncertainty in order to perform
high-speed-measurements in a mechanically disturbed environment. In
particular, the abilities for official calibration and metrologic
reliability are considered. The complex and high-performance functions are
required to guarantee measurement results. FPGA-based systems are used for
the implementation of these functions.The especially designed certifiable
development process (ZEfIRA) provides a procedural method for the
development of complex embedded systems. The metrologic reliability, the
legal requirements like calibratability, the validation and the
verification are included as a general criteria in the entire development
process. ZEfIRA is based on the 3W-model and is designed in an evolutionary
manner. This process starts with the analysis of a predecessor system
followed by the model-based development of a prototype, which leads into an
optimized and application-specific product solution.The study emphasizes
the influence of challenging requirements on the measurement system. It
will be presented, how these can be integrated into the modelling level
during the design and the implementation on a FPGA-based target platform.
The stages of the functional and technical design of the system are
analysed, whereas the realization of the partitions “FPGA logic” and “FPGA
softcore solutions” are discussed in detail.Based on the preliminary design
of the information processing in an electromagnetic force compensation
(EMC) scale, the applicability of the process ZEfIRA and its developed
methods and principles are proved. On the one hand, the optimal
system-specific algorithms of signal processing, control and safety and on
the other hand whose technical implementation are essential. This was
realized with different performance parameters. In addition, the prototype
allows the possible comprehensive analysis for embedding system. In the
conclusion, the performance of ZEfIRA based on the prototype development is
evaluated.Die Dissertation befasst sich mit Prinzipien, Methoden und Techniken der
systematischen Entwicklung von komplexen Eingebetteten Systemen. Die
betrachtete Domäne besitzt Anwendungsbereiche mit anspruchsvollen und
besonderen Anforderungen an die Informationsverarbeitung. In der
dynamischen Wägetechnik sind z.B. Lösungen mit sehr hohen Auflösungen und
kleiner Messunsicherheit bei schnellen Messungen in einem mechanisch
gestörten Umfeld notwendig. Die Anforderungen an die Eichfähigkeit und die
Metrologische Sicherheit sind Besonderheiten. Es werden komplexe und
hochleistungsfähige Funktionen zur Erzeugung der Messergebnisse verlangt.
In der Arbeit werden dafür vorwiegend FPGA-basierte Eingebettete Systeme
verwendet. Der entworfene zertifizierbare Prozess (ZEfIRA) bietet eine
Vorgehensweise für die Entwicklung von Eingebetteten Systemen. Die
Metrologische Sicherheit, die Eichfähigkeit, die Validier- und der
Verifizierbarkeit werden als Kriterien im gesamten Entwurfsprozess
berücksichtigt. ZEfIRA basiert auf einem 3W-Modell und ist evolutionär
angelegt. Innerhalb des Prozesses werden die Analyse eines eventuellen
Vorläufersystems sowie die modellbasierte prototypische Entwicklung bis hin
zu einer produzierbaren Lösung (Produkt) durchgeführt. Die Arbeit
verdeutlicht den großen Einfluss der spezifischen Anforderungen an das
Messsystem. Es wird gezeigt, wie diese bereits zu der Entwurfszeit auf
Modellebene und im Weiteren bei der Implementierung in einer FPGA-basierten
Zielplattform berücksichtigt werden. Es werden verschiedene Schritte des
funktionalen und technischen Systementwurfs untersucht und ausführlich die
Realisierungspartitionen „FPGA-Logik“ und „FPGA-Softcore-Lösungen“
betrachtet. Als Beispiel zum Nachweis der Anwendbarkeit des Prozesses
ZEfIRA dient die prototypische Entwicklung des
Informationsverarbeitungssystems einer elektromagnetischen
Kraftkompensationswaage (EMKW). Ausschlaggebend sind die optimal an das
Gesamtsystem angepassten Signalverarbeitungs-, Regelungs- und
Sicherheitsalgorithmen und deren technische Umsetzung. Dieses wurde mit
verschiedenen Leistungsparametern, wie z.B. Latenz,
Verarbeitungskomplexität und Genauigkeit realisiert. Ergänzend ermöglicht
der Prototyp umfassende Analysemöglichkeiten für das Messsystem. Die
abschließende Wertung ist eine Abschätzung der Leistungsfähigkeit von
ZEfIRA auf Basis dieser prototypischen Entwicklung
Self-Generation in the Context of Inquiry-Based Learning
Self-generation of knowledge can activate deeper cognitive processing and improve long-term retention compared to the passive reception of information. It plays a distinctive role within the concept of inquiry-based learning, which is an activity-oriented, student-centered collaborative learning approach in which students become actively involved in knowledge construction by following an idealized hypothetico-deductive method. This approach allows students to not only acquire content knowledge, but also an understanding of investigative procedures/inquiry skills – in particular the control-of-variables strategy (CVS). From the perspective of cognitive load theory, generating answers and solutions during inquiry-based learning is inefficient as it imposes an intrinsic and extraneous load on learners. Previous research on self-generation of content knowledge in inquiry-based learning has demonstrated that (1) a high cognitive load impairs retention of the generated information, (2) feedback is a fundamental requirement for self-generation of complex content knowledge, (3) self-generation success is key to long-term retention, and (4) generating and rereading place different demands on learners. However, there is still no research on the self-generation of scientific reasoning skills (procedural knowledge) and no knowledge of interaction between the (long-term) retention of these skills with prior knowledge, feedback and self-generation success. That is why this experiment was conducted. The focus of this research is to analyze the distinctive role of self-generation of scientific reasoning skills within the concept of inquiry-based learning and to identify the influence of prior knowledge and self-generation success on short-term and long-term retention. For this purpose, an experiment involving 133 6th and 7th graders was conducted. An inquiry activity that included the self-generation of scientific reasoning skills was compared to an inquiry task that had students simply read information about the experimental design. We used both an immediate and a delayed test to examine which treatment better developed a deeper understanding of CVS and an ability to apply this knowledge to novel problems (transfer). Direct instruction was clearly superior to self-generation in facilitating students’ acquisition of CVS immediately after the inquiry task. However, after a period of 1 week had elapsed, both treatment conditions turned out to be equally effective. A generation effect was only found among students with high self-generation success after a 1-week delay
Non-invasive transmission electron microscopy of vacancy defects in graphene produced by ion irradiation
Irradiation with high-energy ions has been widely suggested as a tool to
engineer properties of graphene. Experiments show that it indeed has a strong
effect on its transport, magnetic and mechanical characteristics. However, to
use ion irradiation as an engineering tool requires understanding of the type
and detailed characteristics of the produced defects which is still lacking, as
the use of high-resolution transmission electron microscopy (HRTEM) - the only
technique allowing direct imaging of atomic-scale defects - often modifies or
even creates defects during imaging, thus making it impossible to determine the
intrinsic atomic structure. Here we show that encapsulating the studied
graphene sample between two other (protective) graphene sheets allows
non-invasive HRTEM imaging and reliable identification of atomic-scale defects.
Using this simple technique, we demonstrate that proton irradiation of graphene
produces reconstructed monovacancies, which explains the profound effect that
such defects have on magnetic and transport properties. This finding resolves
the existing uncertainty with regard to the effect of ion irradiation on the
electronic structure of graphene.Comment: 18 pages, 6 figures and Supplementary Information (4 supplementary
figures
The tomato receptor CuRe1 senses a cell wall protein to identify Cuscuta as a pathogen
Parasitic plants of the genus Cuscuta penetrate shoots of host plants with haustoria and build a connection to the host vasculature to exhaust water, solutes and carbohydrates. Such infections usually stay unrecognized by the host and lead to harmful host plant damage. Here, we show a molecular mechanism of how plants can sense parasitic Cuscuta. We isolated an 11 kDa protein of the parasite cell wall and identified it as a glycine-rich protein (GRP). This GRP, as well as its minimal peptide epitope Crip21, serve as a pathogen-associated molecular pattern and specifically bind and activate a membrane-bound immune receptor of tomato, the Cuscuta Receptor 1 (CuRe1), leading to defense responses in resistant hosts. These findings provide the initial steps to understand the resistance mechanisms against parasitic plants and further offer great potential for protecting crops by engineering resistance against parasitic plants
Proton and Li-Ion Permeation through Graphene with Eight-Atom-Ring Defects
Defect-free graphene is impermeable to gases and liquids but highly permeable
to thermal protons. Atomic-scale defects such as vacancies, grain boundaries
and Stone-Wales defects are predicted to enhance graphene's proton permeability
and may even allow small ions through, whereas larger species such as gas
molecules should remain blocked. These expectations have so far remained
untested in experiment. Here we show that atomically thin carbon films with a
high density of atomic-scale defects continue blocking all molecular transport,
but their proton permeability becomes ~1,000 times higher than that of
defect-free graphene. Lithium ions can also permeate through such disordered
graphene. The enhanced proton and ion permeability is attributed to a high
density of 8-carbon-atom rings. The latter pose approximately twice lower
energy barriers for incoming protons compared to the 6-atom rings of graphene
and a relatively low barrier of ~0.6 eV for Li ions. Our findings suggest that
disordered graphene could be of interest as membranes and protective barriers
in various Li-ion and hydrogen technologies
Recommendations for optimal interdisciplinary management and healthcare settings for patients with rare neurological diseases
BackgroundIn 2017, the German Academy for Rare Neurological Diseases (Deutsche Akademie fur Seltene Neurologische Erkrankungen;DASNE) was founded to pave the way for an optimized personalized management of patients with rare neurological diseases (RND) in all age groups. Since then a dynamic national network for rare neurological disorders has been established comprising renowned experts in neurology, pediatric neurology, (neuro-) genetics and neuroradiology. DASNE has successfully implemented case presentations and multidisciplinary discussions both at yearly symposia and monthly virtual case conferences, as well as further educational activities covering a broad spectrum of interdisciplinary expertise associated with RND. Here, we present recommendation statements for optimized personalized management of patients with RND, which have been developed and reviewed in a structured Delphi process by a group of experts.MethodsAn interdisciplinary group of 37 RND experts comprising DASNE experts, patient representatives, as well as healthcare professionals and managers was involved in the Delphi process. First, an online collection was performed of topics considered relevant for optimal patient care by the expert group. Second, a two-step Delphi process was carried out to rank the importance of the selected topics. Small interdisciplinary working groups then drafted recommendations. In two consensus meetings and one online review round these recommendations were finally consented.Results38 statements were consented and grouped into 11 topics: health care structure, core neurological expertise and core mission, interdisciplinary team composition, diagnostics, continuous care and therapy development, case conferences, exchange / cooperation between Centers for Rare Diseases and other healthcare partners, patient advocacy group, databases, translation and health policy.ConclusionsThis German interdisciplinary Delphi expert panel developed consented recommendations for optimal care of patients with RND in a structured Delphi process. These represent a basis for further developments and adjustments in the health care system to improve care for patients with RND and their families
Serotonin limits generation of chromaffin cells during adrenal organ development
Adrenal glands are the major organs releasing catecholamines and regulating our stress response. The mechanisms balancing generation of adrenergic chromaffin cells and protecting against neuroblastoma tumors are still enigmatic. Here we revealed that serotonin (5HT) controls the numbers of chromaffin cells by acting upon their immediate progenitor "bridge" cells via 5-hydroxytryptamine receptor 3A (HTR3A), and the aggressive HTR3Ahigh human neuroblastoma cell lines reduce proliferation in response to HTR3A-specific agonists. In embryos (in vivo), the physiological increase of 5HT caused a prolongation of the cell cycle in "bridge" progenitors leading to a smaller chromaffin population and changing the balance of hormones and behavioral patterns in adulthood. These behavioral effects and smaller adrenals were mirrored in the progeny of pregnant female mice subjected to experimental stress, suggesting a maternal-fetal link that controls developmental adaptations. Finally, these results corresponded to a size-distribution of adrenals found in wild rodents with different coping strategies
The state of the Martian climate
60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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