Technische Universität Dresden: Qucosa
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Flexibilisation of Intra-port Container Transport with Time Slot Bookings
No full textTruck appointment systems are a well-studied approach to reduce queues in front of container terminals and on their yard. Traditional systems are lacking in flexibility and tend to favour the terminal operators over other partners in the maritime supply chain. To enable a better fit of appointment systems to ports and to increase their flexibility, a systematic analysis of different parameters and strategies and their interdependencies is executed. The results show that longer time slots benefit terminal operators as well as trucking companies. Furthermore, the so-called flexibility options show some promise to increase efficiency with little extra effort. As there are many interdependencies, the parameters and strategies need to be chosen with care for every container terminal
Automatic Model Generation for Resource Management in Less-Than-Truckload Terminals
No full textTo address significant challenges in the Less-Than-Truckload (LTL) sector, involved companies must modify their existing terminals and enhance management of available resources. Simulation has proven to be a suitable problemsolving technique for such use cases. However, due to financial barriers, small and medium-sized enterprises (SMEs) in particular are often unable to benefit from this methodology. Therefore, in this paper, an automatically generated simulation model for LTL terminals is developed that can be used without specific simulation knowledge and fits the needs of SMEs. The focus is on evaluating resource management by developing a user interface to set relevant parameters for this scope. Simulation models are automatically generated based on data inputs, and relevant key performance indicators are determined to evaluate resource management. Experiments with five different layout variants of an LTL terminal are performed using varying resources to demonstrate the scope of functions, and possible evaluation scenarios are presented
Einsatz von Digitalen Zwillingen für die operative Steuerung von innerbetrieblichen Transportsystemen
No full textThis paper presents the architecture and functionality of a simulation-based Digital Twin designed to support decision-making in the control of internal transport systems. The developed Digital Twin leverages a wide range of data from operational information systems to predict future system loads. Specific methods for forecasting transport orders have been developed. An integrated simulation framework enables analysis of potential control decisions, such as resource allocation or the timing of order releases. The simulation results are used for multi-criteria evaluation of the available options for preventive action, thus, providing users with concrete recommendations to support their operational decision-making processes
Private Content Discovery for P2P Data Networks
No full textThe volume of data that needs to be stored and transferred is increasing. Centralized solutions, i. e., cloud providers offer scalable storage solutions, making data availability and control dependent on a single logical entity. A self-scalable, distributed, and content-centric alternative for data exchange are peer-to-peer (P2P) data networks. P2P data networks can allow users to regain control over their data.
The content-centric approach enables users to directly request the content from the network via mostly pseudonymous identifier. Unfortunately, a query reveals interest in specific content and the source of a query can be linked to a user. The combination of source and content of a query reveals the interest of a user, enabling profiling. Furthermore, performance improvements and fail-safe mechanisms spread interests widely through the network.
In this thesis, we design and explore different protocols using privacy-enhancing mechanisms. The goal of the privacy enhancement is to improve content discovery privacy with an adjustable overhead in P2P data networks. Specifically, we focus on source and query privacy mechanisms, providing different privacy guarantees. Source privacy aims to obfuscate the source of a query. With network-level methods, we increase the number of possible sources of a query, obfuscating the source, improving source privacy. The modifications to the content discovery process aim to provide plausible deniability up to relationship anonymity for messages. The second focus, query privacy, aims to hide the item of a request. By adding probabilistic data structures and cryptographic protocols to the content discovery process, we obfuscate the item of interest in a query, increasing query privacy. Specifically, we increase the anonymity set of a query from one item to a range of items, increasing the anonymity set ideally to all existing items in the network. Private set intersection reduces the privacy impediments of the content providers. We apply, explain, and evaluate our protocols in the context of a prime example of the current P2P data networks: the InterPlanetary File System (IPFS).
The protocols are evaluated using code experiments with a simulated network, analyzing the overhead’s impact on performance. We analyze the protocols in the context of the public IPFS network by using passive measurements to evaluate the protocols’ real-world feasibility. Each proposed protocol improves the privacy of content discovery, by reducing the overall information leak, effectively limiting large-scale attacks. A combination of the underlying mechanisms with additional mechanisms like cover traffic can provide strong protection
Mikromechanische Charakterisierung von humanem Wurzeldentin und bovinem Dentin mittels Mikroindentation
No full textZiel: In einer In-vitro-Studie sollten mittels Mikroindentation humanes Wurzeldentin und bovines Dentin hinsichtlich ihrer mechanischen Eigenschaften erstmalig systematisch untersucht und verglichen werden. Die Verläufe dieser Eigenschaften sollten von zervikal (bzw. koronal) nach apikal sowie von pulpanah nach pulpafern beurteilt werden.
Methodik: 34 humane erste Unterkiefermolaren und 34 bovine zentrale Inzisivi wurden untersucht. Die distale Wurzel der Molaren wurde in ein zervikales, mediales und apikales Segment und die Inzisivi in ein koronales, zervikales, mediales und apikales Segment geteilt. Die Mikroindentation der Dentinquerschnitte wurde mithilfe des Härteprüfgerätes Fischerscope H 100 C durchgeführt. Es erfolgte eine linienhafte Messung in bukko-lingualer und mesio-distaler Richtung je Dentinquerschnitt bei der die Martenshärte , die Eindringhärte IT, der Eindringmodul IT und das Eindringkriechen IT bestimmt und die Vickershärte ermittelt wurden. Vier humane und vier bovine Zähne wurden flächenhaft untersucht und die Ergebnisse mittels Konturendiagrammen dargestellt.
Ergebnisse: Durchschnittlich ist humanes Wurzeldentin 0,6/30/30 = 486 ± 7,70 MPa SE (95% KI 471 bis 501 MPa) härter als bovines Wurzeldentin 0,6/30/30 = 459 ± 7,58 MPa SE (95% KI 444 bis 474 MPa). Der Eindringmodul IT/(1−s2) 0,6/30/30 des humanen Wurzeldentins beträgt durchschnittlich 15,6 ± 0,204 GPa SE (95% KI 15,2 bis 16,0 GPa) und des bovinen Wurzeldentins 15,5 ± 0,192 GPa SE (95% KI 15,1 bis 15,8 GPa). Die Werte der Martenshärte und des Eindringmoduls des bovinen zervikalen, medialen und apikalen Wurzeldentins zeigen keinen statistischen Unterschied zu den Werten des humanen medialen Wurzeldentins. Koronales bovines Dentin besitzt eine durchschnittliche Martenshärte 0,6/30/30 = 490 ± 6,90 MPa SE (95% KI 476 bis 503 MPa) und einen Eindringmodul IT/(1 − s2) 0,6/30/30= 16,0 ± 0,184 GPa SE (95% KI 15,6 bis 16,4 GPa). Die Verläufe der mechanischen Eigenschaften von zervikal bzw. koronal nach apikal und von pulpanah nach pulpafern beider Gruppen sind ähnlich. Das weibliche bovine Dentin ist statistisch signifikant härter als das männliche. Das humane Wurzeldentin zeigt dahingehend keine Signifikanz.
Schlussfolgerung: Das bovine zervikale, mediale und apikale Wurzeldentin sind hinsichtlich ihrer mechanischen Eigenschaften ein geeigneter Ersatz für humanes mediales Wurzeldentin. Das koronale bovine Dentin ist für humanes mediales und zervikales Wurzeldentin ein adäquater Ersatz. Das Dentin weiblicher Rinder sollte bevorzugt als Ersatz für humanes Dentin eingesetzt werden. Ein standardisiertes Analyseverfahren zur Bestimmung mechanischer Eigenschaften von Zahnhartsubstanzen, insbesondere des Dentins, konnte etabliert werden. Die Martenshärte sollte als Standardhärteparameter eingeführt werden
Democratic health in the corona pandemic: The corona pandemic as a trigger or amplifier of democratic erosion or autocratization?
No full textCOVID-19 constituted an unprecedented “transboundary mega crisis” (Boin et al. 2020) that referred to all spheres of the states and societies. Originated in China and then spreading rapidly throughout the world it was probably the first truly global crisis generating an external shock for every country (Wurster 2021). On the political level, governments were confronted with a huge effort of crisis management domestically as well as in terms of regional and global coordination. On the economic level severe impacts on the overall production and thus on the well-being of economies stood at risk, provoking large-scale attempts of economic containment (Hörisch et al. 2022). While the public health systems were especially challenged, also on the societal level, enormous social cohesion and solidarity were needed and thus invoked by governments in order to tackle the crisis
vPIF-1 is an insulin-like antiferroptotic viral peptide
No full textIridoviridae, such as the lymphocystis disease virus-1 (LCDV-1) and other viruses, encode viral insulin–like peptides (VILPs) which are capable of triggering insulin receptors (IRs) and insulin-like growth factor receptors. The homology of VILPs includes highly conserved disulfide bridges. However, the binding affinities to IRs were reported to be 200- to 500-fold less effective compared to the endogenous ligands. We therefore speculated that these peptides also have noninsulin functions. Here, we report that the LCDV-1 VILP can function as a potent and highly specific inhibitor of ferroptosis. Induction of cell death by the ferroptosis inducers erastin, RSL3, FIN56, and FINO2 and nonferroptotic necrosis produced by the thioredoxin-reductase inhibitor ferroptocide were potently prevented by LCDV-1, while human insulin had no effect. Fas-induced apoptosis, necroptosis, mitotane-induced cell death and growth hormone–releasing hormone antagonist–induced necrosis were unaffected, suggesting the specificity to ferroptosis inhibition by the LCDV-1 VILP. Mechanistically, we identified the viral C-peptide to be required for inhibition of lipid peroxidation and ferroptosis inhibition, while the human C-peptide exhibited no antiferroptotic properties. In addition, the deletion of the viral C-peptide abolishes radical trapping activity in cell-free systems. We conclude that iridoviridae, through the expression of insulin-like viral peptides, are capable of preventing ferroptosis. In analogy to the viral mitochondrial inhibitor of apoptosis and the viral inhibitor of RIP activation (vIRA) that prevents necroptosis, we rename the LCDV-1 VILP a viral peptide inhibitor of ferroptosis-1. Finally, our findings indicate that ferroptosis may function as a viral defense mechanism in lower organisms
RED-SP-CoDel: Random early detection with static priority scheduling and controlled delay AQM in programmable data planes
No full textEmerging network application paradigms, such as the Tactile Internet, re-emphasize the need for different Quality of Service (QoS) levels. Due to the large packet buffers in the underlying network data plane, Active Queue Management (AQM) is generally required to curtail packet latencies for flows requiring high QoS levels. At the same time, programmable data planes, such as P4, enable packet processing at line-speed, albeit with limited packet processing functionalities. However, the existing AQM mechanisms that support QoS differentiation are too complex to readily run on P4, while the existing AQM mechanisms that run on P4 do generally not support effective QoS differentiation. We address this gap by developing to the best of our knowledge the first AQM mechanism that supports effective QoS differentiation while running on P4. Specifically, we propose SP-CoDel, which combines the well-known Controlled Delay (CoDel) AQM mechanism with Static Priority (SP) scheduling for QoS differentiation. Also, we propose RED-SP-CoDel, which adds a RED AQM component to SP-CoDel so as to make the AQM with priorities essentially parameterless. As a community resource contribution, we substantially extend the existing P4Simulator to the novel fused P4-NS3 Simulator so as to enable the evaluation of packet processing mechanisms through the combined functionalities of P4 device emulation and NS3 packet simulation. Evaluations conducted with the P4 reference switch model in the P4-NS3 Simulator indicate that SP-CoDel and RED-SP-CoDel provide high QoS to high-priority data streams, i.e., significantly reduce latency and packet loss compared to CoDel, while effectively mitigating bufferbloat
Toward reliable model-based soil moisture estimates for forest managers
No full textThe study presents a daily water balance model with a focus on quantifying drought intensity and duration in different forest stands within the Level II monitoring sites in Saxony. The model requires climatic data input and various site and stand parameters, which mostly have physical meaning and can be measured. We estimated the van Genuchten soil parameters of the model by different pedotransfer functions. Water stress is assumed to occur when the relative extractable soil water (REW) or the ratio of real transpiration and potential transpiration or pressure head drops below a certain threshold. The model was not calibrated to test the robustness of physically based parameters but was validated with available soil moisture measurements at forest climate stations (grass vegetation) and inventory locations in various vegetation and climatic conditions with Kling-Gupta efficiencies > 0.5 at most of the sites. The model captures the dynamics of soil water depletion and recharge in a study period well. Day-to-day estimates of water balance components allow us to calculate the duration and intensity of drought events and derive stress indices. A dendro-ecological application is presented: a retrospective analysis of the effects of drought on radial tree growth. Some limitations and potential of applications of the model are discussed
Prophylactic Administration of Mesenchymal Stromal Cells Does Not Prevent Arrested Lung Development in Extremely Premature-Born Non-Human Primates
No full textPremature birth is a leading cause of childhood morbidity and mortality and often followed by an arrest of postnatal lung development called bronchopulmonary dysplasia. Therapies using exogenous mesenchymal stromal cells (MSC) have proven highly efficacious in term-born rodent models of this disease, but effects of MSC in actual premature-born lungs are largely unknown. Here, we investigated thirteen non-human primates (baboons; Papio spp.) that were born at the limit of viability and given a single, intravenous dose of ten million human umbilical cord tissue-derived MSC per kilogram or placebo immediately after birth. Following two weeks of human-equivalent neonatal intensive care including mechanical ventilation, lung function testing and echocardiographic studies, lung tissues were analyzed using unbiased stereology. We noted that therapy with MSC was feasible, safe and without signs of engraftment when administered as controlled infusion over 15 minutes, but linked to adverse events when given faster. Administration of cells was associated with improved cardiovascular stability, but neither benefited lung structure, nor lung function after two weeks of extrauterine life. We concluded that a single, intravenous administration of MSC had no short- to mid-term lung-protective effects in extremely premature-born baboons, sharply contrasting data from term-born rodent models of arrested postnatal lung development and urging for investigations on the mechanisms of cell-based therapies for diseases of prematurity in actual premature organisms