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Comparison of modified Woo’s solar phase scintillation model with ESA’s BepiColombo superior solar conjunction measurement data for X-band and Ka-band
Get PDFSolar phase scintillation is of major interest in deep space mission operations for designing a communications system capable of transmitting signals when the path is close to the Sun, but also for improving the navigation under these conditions. The basis of this work is Woo’s solar phase scintillation theory which reported a useful model for the spectral power density of phase scintillations of a signal traveling through a medium close to the Sun. In this paper, Woo’s solar phase scintillation formula is used for the simulation of the spectral density of phase fluctuations induced by the Sun on coherent signals (uplink and downlink carriers are coherently related by a fractional ratio implemented by the spacecraft’s transponder), for the two downlink frequency bands supported by the ESA deep space mission BepiColombo. In particular, the model has been compared to measurement data collected at low Sun Earth Probe (SEP) angles during the superior solar conjunction campaign in March 2021 (in its cruise phase to Mercury). The comparison shows a good match between the phase noise spectral densities of the modified formula and measurement data, therefore, confirming that the formula can be used for the planning and verification of the future near Sun measurements
An evaluation and comparison of AutoML solutions: Azure AutoML and EvalML
Get PDFAutomated machine learning (AutoML) supports the development of machine learning systems by automating tasks that traditionally require manual, time-consuming labor and extensive expertise in the field.
This paper presents two AutoML systems, one open-source (EvalML) and one commercial solution (Azure AutoML), and evaluates their range of functionality as well as practical usability.
The results show that commercial tools provide better usability for beginners, while open-source alternatives tend to stand out with greater configurability
Philosophy and plurality: Providing a classification and clarification of interdisciplinarity
Get PDFStudies in Science, Society and
Sustainabilit
Multiple comparison procedures for discrete uniform and homogeneous tests
Get PDFDiscrete uniform and homogeneous p-values often arise in applications with multiple testing. For example, this occurs in genome wide association studies whenever
a non-parametric one-sample (or two-sample) test is
applied throughout the gene loci. In this paper, we considermultiple comparison procedures for such scenarios
based on several existing estimators for the proportion
of true null hypotheses, 0, which take the discreteness
of the p-values into account. The theoretical guarantees
of the several approaches with respect to the estimation of 0 and the false discovery rate control are reviewed. The performance of the discrete procedures is investigated through intensive Monte Carlo simulations considering both independent and dependent p-values. The methods are applied to three real data sets for illustration
purposes too. Since the particular estimator of
0 used to compute the q-values may influence its performance, relative advantages and disadvantages of the reviewed procedures are discussed. Practical recommendations are given
Rezension „Virtual und Augmented Reality (VR/AR) – Grundlagen und Methoden der Virtuellen und Augmentierten Realität“
Get PDFMarket availability and testing of centralized protection and control systems
Get PDFThe constant evolution of power systems and their protection and control systems has brought the need to investigate different concepts that could help improve the implementation and testing of protection and control systems during the complete lifecycle of electrical substations. Centralized protection and control system is a concept that has been under study for many years already but has gained more force lately, thanks to the evolution of computing technology and the more substantial influence of the standard IEC61850 in electrical substations.
This thesis has studied the centralized protection and control systems starting with the development of a market availably. The result shows that even though the general concept between the available systems is the same, the specific architecture depends on the technology used to implement the centralized concept. The result also shows that the two technologies leading the market availability are the SASensor from Locamation and the SSC600 from ABB. The technologies virtualization and Synaptec’s Refase system are also investigated in this thesis.
Protection and control test methodologies do also depend on the technology to be tested. Therefore, this thesis shows an overall protection and control testing lifecycle analysis of a centralized protection and control system. The architecture of the reference system used for the testing lifecycle evaluation has similarities to a decentralized digital substation architecture. Using that kind of architecture allows fully IEC61850 based protection and control testing, as the results have shown it. Therefore, knowledge, tools, and procedures developed for decentralized digital substations also apply to the centralized concept.
The last part of this work presents a practical application example that uses the SSC600 as a protection and control central unit. The device configuration is based on a power system example designed for the thesis. The IEC61850 system engineering of the system and test procedures are part of the results of the practical part
Sickness presenteeism explained by balancing perceived positive and negative effects
Get PDFWithin the ever-growing body of research on sickness presenteeism, studies of perceived consequences are scarce and equally rare are joint considerations of beneficial and harmful effects. This study examined how experienced and expected consequences of the behavior are related to presenteeism. Positive and negative effects were considered simultaneously and comprehensively. This approach allowed us to capture the trade-off process of individuals in deciding to work or call in sick when ill. In a cross-sectional online survey, 591 working adults in Germany rated a thoroughly developed pool of specific experienced or potential consequences of working while sick and gave an overall judgment of effects. The results show that perceptions of effects are consistent with behavior. Individuals who exhibit presenteeism do so primarily because of work-related effects such as the completion of one’s work tasks and the meeting of deadlines. Few specific effects stand out and can largely explain attendance behavior and the overall assessment of effects. The findings are consistent with the assumptions of the health belief model and the expectancy value theory of work motivation and they relate to the health-performance framework. They demonstrated that benefits and costs of the behavior are simultaneously weighed in the decision to engage in presenteeism or not
Approaching transglutaminase from Streptomyces bacteria over three decades
Get PDFTransglutaminases are protein cross‐linking and protein‐modifying enzymes that have attracted considerable interest due to their causal involvement in various diseases and versatility in industrial applications. In particular, microbial transglutaminases (MTG) from Streptomyces bacteria have managed in recent years to evolve from simple food additives to specialized enzymes for the site‐directed modification of therapeutic proteins. The review summarizes relevant studies from the beginning dealing with the occurrence, production, structure, catalysis, and substrate molecules of MTG enzymes. It also addresses biotechnological procedures with MTG from S. mobaraensis (SmMTG) as the most prominent representative in focus. Reassessment of the available data revealed unexpected insights into catalysis of SmMTG and other transglutaminases, suggesting selection of glutamine donor proteins by subsites at the front vestibule and the existence of distinct lysine pockets. Flexibility of the SmMTG‐accessible glutamine donor substrate regions seems to be more important than the glutamine environment. Nevertheless, residues in close vicinity to glutamines also determine interaction with the SmMTG subsites. The apparent lack of subsites for lysine donor proteins suggests self‐assembly of the substrate proteins prior to enzymatic cross‐linking. The study of natural substrate proteins, especially their mutual interaction, is proposed to further illuminate catalysis of SmMTG. To this end, structure and function of the characterized substrate proteins from S. mobaraensis are discussed in conclusion
NFDI4Memory. Consortium for the historically oriented humanities. Proposal for the National Research Data Infrastructure (NFDI)
Get PDFProposal for the consortium for the for the historically oriented humanities in the German national research data infrastructure (Nationale Forschungsdateninfrastruktur, “NFDI”). The application contains the scope and objectives, the composition and governance of the consotrium as well as the research data management strategy and the originally proposed work programme. NFDI4Memory aims to establish systematic, sustainable links between research, memory institutions and infrastructures; to integrate historical source criticism into data management; to build a network of the historically oriented research communities; to shape the knowledge order for the digital future of the past; to advance the analog / digital interface of historical source material and data; to generate standards for historical research data and sustainability; and to contribute to education and citizen participation
Visual analytics for technology and innovation management
Get PDFThe awareness of emerging trends is essential for strategic decision making because technological trends can affect a firm’s competitiveness and market position. The rise of artificial intelligence methods allows gathering new insights and may support these decision-making processes. However, it is essential to keep the human in the loop of these complex analytical tasks, which, often lack an appropriate interaction design. Including special interactive designs for technology and innovation management is therefore essential for successfully analyzing emerging trends and using this information for strategic decision making. A combination of information visualization, trend mining and interaction design can support human users to explore, detect, and identify such trends. This paper enhances and extends a previously published first approach for integrating, enriching, mining, analyzing, identifying, and visualizing emerging trends for technology and innovation management. We introduce a novel interaction design by investigating the main ideas from technology and innovation management and enable a more appropriate interaction approach for technology foresight and innovation detection