Deep Reinforcement Learning zur Steigerung von Energieeffizienz und Pünktlichkeit von Straßenbahnen

Eine Steigerung von Energieeffizienz und Pünktlichkeit resultiert in einer erhöhten Wirtschaftlichkeit und Leistungsfähigkeit des Bahnsystems. Diese Leistungsindikatoren können im Vollbahnbereich aufgrund der abgetrennten Bahnkörper und vorhandener Zugsicherungssysteme mit höheren Automatisierungsgraden verbessert werden. Straßenbahnen teilen sich die Trasse mit dem motorisierten Individualverkehr, Radfahrern und Fußgängern. Aus diesen Gründen sind Automatisierungsmöglichkeiten begrenzt und durch das Fahren auf Sicht sind die Fahrer von der sicheren Fahrzeugführung vereinnahmt. Fahrzeitreserven sind dagegen durch das Fahrgast- und Verkehrsaufkommen variabel. Konventionelle Optimierungsverfahren können für einzelne Szenarien Fahrprofile ermitteln, welche den Energiebedarf bei einer pünktlichen Fahrweise minimieren. Bei betrieblichen Abweichungen sind diese Fahrprofile jedoch nicht mehr optimal. Aufgrund der variablen Fahrzeiten und Haltedauern bietet sich der Einsatz von Künstlicher Intelligenz (KI) an, welche die Muster über den Tag erlernen und darauf die Fahrprofile anpassen kann. Diese Dissertation untersucht, wie die Energieeffizienz und Pünktlichkeit von Straßenbahnen durch den Einsatz von KI gesteigert werden können. Zum Training der KI wird eine validierte Umgebung aus Messdaten aus dem regulären Fahrgastbetrieb aufgebaut. Der rechenzeitintensive Trainingsprozess wird durch ein datengetriebenes Energiebedarfsmodell beschleunigt. Auf zwei Szenarien wird die KI zu je drei Verkehrszeiten trainiert. Die ermittelten Fahrprofile werden mit denen von Fahrern aus dem regulären Fahrgastbetrieb sowie mit einem durch Dynamic Programming ermittelten theo-retischen Optimum verglichen. Zur Untersuchung der Generalisierungsfähig-keiten der KI wird diese in einem ersten Schritt ohne weiteres Training auf bekannten Szenarien zu unbekannten Haltedauern getestet und mit den Fahrern verglichen. Im zweiten Schritt wird eine Umleitungsfahrt auf einer für die KI unbekannten Strecke simuliert. Die berechneten Fahrprofile werden ebenfalls wieder mit Fahrern aus dem regulären Fahrgastbetrieb verglichen. Anhand der Ergebnisse werden abschließend potentielle Ein-satzmöglichkeiten der KI als Fahrerassistenzsystem diskutiert

Design Methodology for the Electrification of Urban Bus Lines with Battery Electric Buses

Electrically powered buses reduce CO$_{2}$ and noise emissions in urban areas and thus promote the trend towards more livable cities. Upon this reason, more and more cities are introducing their first electrified lines as pilot projects. However, no standardized technology has yet emerged, which is why statements on interactions between vehicle, operation and infrastructure in public transport are proving to be difficult to make. In order to be able to make statistically significant statements in this respect, a simulation model was developed that depicts the three subsystems vehicle, operation and infrastructure. On the basis of measurement data from the PRIMOVE research project in Mannheim, in which an urban bus line is operated with two electrically powered buses, the simulation model was validated and a data basis was laid for further investigations. As a result, simulation studies with more than 700 simulated operating days could be carried out, the results of which represent the input for the following statistical analysis. Based on this analysis, the interactions described above will be demonstrated in the design of the main technical parameters, the battery lifespan and the energy demand of electrical bus lines. Through the findings of these simulations, an optimized version of the already electrified bus line in Mannheim will then be presented. Finally, a novel design methodology for electrification based on a multi-objective optimization is introduced. All parameters of the system are variable in order to apply the presented methodology to other projects and thus underline the general validity of the work

Steigerung der Leistungsdichte und des Wirkungsgrades von Straßenbahnantrieben durch den Einsatz hochdrehender Maschinen = Increasing the power density and efficiency of light rail vehicle drives through the use of high-speed machines

Der Einsatz einer hochdrehenden Antriebsmaschine in einem Straßenbahnfahrzeug ermöglicht die Steigerung des Wirkungsgrades und der Leistungsdichte. Aus einem Referenzsystem werden die Anforderungen an den hochdrehenden Motor abgeleitet. Das Referenzsystem bildet ein Bestandsstraßenbahnfahrzeug ab, welches in Zürich eingesetzt wird. Mittels einer systematischen Technologieauswahl werden verschiedene Antriebskonzepte hinsichtlich ihrer Eignung für die Anwendung verglichen. Dabei werden verschiedene Maschinenkonzepte, Konstruktionslösungen sowie Kühlkonzepte betrachtet. Ausgewählt wird eine Asynchronmaschine mit einer Maximaldrehzahl von 20.000 min–1 und einer S1-Dauerleistung von 75 kW. Die Asynchronmaschine ist als Innenläufermaschine mit Flüssigkeitskühlung ausgeführt, basierend auf dem Anforderungskatalog. Anschließend wird ein Vergleich mit dem Referenzantrieb durchgeführt und zum Schluss ein Prototyp gefertigt

Tcf15 Primes Pluripotent Cells for Differentiation

SummaryThe events that prime pluripotent cells for differentiation are not well understood. Inhibitor of DNA binding/differentiation (Id) proteins, which are inhibitors of basic helix-loop-helix (bHLH) transcription factor activity, contribute to pluripotency by blocking sequential transitions toward differentiation. Using yeast-two-hybrid screens, we have identified Id-regulated transcription factors that are expressed in embryonic stem cells (ESCs). One of these, Tcf15, is also expressed in the embryonic day 4.5 embryo and is specifically associated with a novel subpopulation of primed ESCs. An Id-resistant form of Tcf15 rapidly downregulates Nanog and accelerates somatic lineage commitment. We propose that because Tcf15 can be held in an inactive state through Id activity, it may prime pluripotent cells for entry to somatic lineages upon downregulation of Id. We also find that Tcf15 expression is dependent on fibroblast growth factor (FGF) signaling, providing an explanation for how FGF can prime for differentiation without driving cells out of the pluripotent state

Effects of Aging on Endotoxin Tolerance Induced by Lipopolysaccharides Derived from Porphyromonas gingivalis and Escherichia coli

Background: Periodontitis is a bacterially induced chronic inflammatory disease. Exposure of the host to periodontal pathogens and their virulence factors induces a state of hyporesponsiveness to subsequent stimulations, termed endotoxin tolerance. Aging has a profound effect on immune response to bacteria challenge. The aim of this study was to explore the effects of aging on endotoxin tolerance induced by Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS) and Escherichia coli (E. coli) LPS in murine peritoneal macrophages. Methodology/Principal Findings: We studied the cytokine production (TNF-aand IL-10) and Toll-like receptor 2, 4 (TLR2, 4) gene and protein expressions in peritoneal macrophages from young (2-month-old) and middle-aged (12-month-old) ICR mice following single or repeated P. gingivalis LPS or E. coli LPS stimulation. Pretreatment of peritoneal macrophages with P. gingivalis LPS or E. coli LPS resulted in a reduction in TNF-a production and an increase in IL-10 production upon secondary stimulation (p,0.05), and the markedly lower levels of TNF-a and higher levels of IL-10 were observed in macrophages from young mice compared with those from middle-aged mice (p,0.05). In addition, LPS restimulations also led to the significantly lower expression levels of TLR2, 4 mRNA and protein in macrophages from young mice (p,0.05). Conclusions/Significance: Repeated LPS stimulations triggered endotoxin tolerance in peritoneal macrophages and the ability to develop tolerance in young mice was more excellent. The impaired ability to develop endotoxin tolerance resulte

Canagliflozin and Cardiovascular and Renal Outcomes in Type 2 Diabetes Mellitus and Chronic Kidney Disease in Primary and Secondary Cardiovascular Prevention Groups

Background: Canagliflozin reduces the risk of kidney failure in patients with type 2 diabetes mellitus and chronic kidney disease, but effects on specific cardiovascular outcomes are uncertain, as are effects in people without previous cardiovascular disease (primary prevention). Methods: In CREDENCE (Canagliflozin and Renal Events in Diabetes With Established Nephropathy Clinical Evaluation), 4401 participants with type 2 diabetes mellitus and chronic kidney disease were randomly assigned to canagliflozin or placebo on a background of optimized standard of care. Results: Primary prevention participants (n=2181, 49.6%) were younger (61 versus 65 years), were more often female (37% versus 31%), and had shorter duration of diabetes mellitus (15 years versus 16 years) compared with secondary prevention participants (n=2220, 50.4%). Canagliflozin reduced the risk of major cardiovascular events overall (hazard ratio [HR], 0.80 [95% CI, 0.67-0.95]; P=0.01), with consistent reductions in both the primary (HR, 0.68 [95% CI, 0.49-0.94]) and secondary (HR, 0.85 [95% CI, 0.69-1.06]) prevention groups (P for interaction=0.25). Effects were also similar for the components of the composite including cardiovascular death (HR, 0.78 [95% CI, 0.61-1.00]), nonfatal myocardial infarction (HR, 0.81 [95% CI, 0.59-1.10]), and nonfatal stroke (HR, 0.80 [95% CI, 0.56-1.15]). The risk of the primary composite renal outcome and the composite of cardiovascular death or hospitalization for heart failure were also consistently reduced in both the primary and secondary prevention groups (P for interaction >0.5 for each outcome). Conclusions: Canagliflozin significantly reduced major cardiovascular events and kidney failure in patients with type 2 diabetes mellitus and chronic kidney disease, including in participants who did not have previous cardiovascular disease

Geographic Differences in Genetic Susceptibility to IgA Nephropathy: GWAS Replication Study and Geospatial Risk Analysis

Peer reviewe

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Law for Engineers: "Student-Activating E-Learning 2.0"

Dieser Beitrag zeichnet die etwa zehnjährige, organische Entwicklung einer universitären Großlehrveranstaltung an der Technischen Universität Wien (A) zum modernen E-Learning-Kurs nach. Die beschriebene Vorlesung mit Übung „Daten- und Informatikrecht“ wendet sich an Technikstudierende und wird von 350-500 Personen pro Semester besucht. Für diese Lehrveranstaltung wurde ein Modell „Aktivierender Lehre“ entwickelt, das auf die persönliche und fachliche Involvierung eines möglichst großen Teils der Gesamtgruppe ausgerichtet ist. Ab 1998 wurden begleitende Materialien auf Webseiten für geschlossene Nutzergruppen bereitgestellt; hinzu kam in der Folge ein Weblog. Über eine lokale Insellösung auf der Basis des Open-Source-Produkts Moodle führte der Weg zum nunmehr umfassenden, multimedialen Online-Kurs in TUWEL, einer für die Technische Universität Wien adaptierten und zentral durch das E-Learning-Zentrum gehosteten Moodle-Lösung. Im Laufe mehrerer Jahre konnte ein fachbezogenes Anreizsystem (Bonuspunktesystem) generiert werden, dessen Umsetzung im Online-Kurs im Detail beschrieben wird. Der Beitrag skizziert sowohl die methodisch-didaktischen Ansätze als auch die konkreten Realisierungsschritte. Es wird auf Aspekte der E-Learning-Logistik für universitäre Großlehrveranstaltungen (Lehrveranstaltungsordnung) ebenso eingegangen wie auf die Notwendigkeit begleitender Qualitätssicherung (Plagiatsdetektor). Etliche offene Fragen zum „E-Learning 2.0“ runden die Darstellung ab. (Autor)This report describes in detail the development of a modern e-learning course for a mass-lecture at Vienna University of Technology (Austria), which has taken place step by step during the last ten years. The lecture in question focuses on data and information law for engineers; it is combined with exercises the students have to pass in addition. There are about 350-500 students passing this lecture with exercises per semester. From the very beginning it was an important goal to activate and thus actively involve as many participants as possible. From 1998 on, course materials have first been provided online on a website that could be accessed by participants only; soon a weblog was added. In a further step the online content was presented on the basis of a local Moodle-system and has now grown to a multimedia online course in TUWEL, a Moodle-system which has been customized for Vienna University of Technology and is hosted by the E-Learning Center. Over the years, an incentive system for the participants has been implemented in the online course. The report deals with aspects of e-learning-logistics as well as with questions of quality management (detection of plagiarism) and, finally, tries to put some open questions relating to e-learning 2.0. (Author