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Nach dem Scheitern des Privacy Shield hofft der Datenschutzberater Alexander Golland, dass die europäischen Behörden bald konkrete Maßnahmen für den Datentransfer in Drittländer vorschlagen. Auch kleine Unternehmen müssten die Herausforderung bewältigen – sonst wäre das Urteil nur Wasser auf die Mühlen jener, die ohnehin über den Datenschutz schimpfen.
Das „Recht auf Vergessenwerden“ unter Geltung der DSGVO: Anwendungsbereich und Rechtmäßigkeit
(2019)
Das „Recht auf Vergessenwerden“ unter Geltung der DSGVO: Rechtmäßigkeit der Anzeige sensibler Daten
(2019)
Aufsicht und Rechtsdurchsetzung bei unzulässigem Einsatz von Cookies & Co. unter Geltung des TTDSG
(2022)
Booster stations can fulfill a varying pressure demand with high energy-efficiency, because individual pumps can be deactivated at smaller loads. Although this is a seemingly simple approach, it is not easy to decide precisely when to activate or deactivate pumps. Contemporary activation controls derive the switching points from the current volume flow through the system. However, it is not measured directly for various reasons. Instead, the controller estimates the flow based on other system properties. This causes further uncertainty for the switching decision. In this paper, we present a method to find a robust, yet energy-efficient activation strategy.
Cheap does not imply cost-effective -- this is rule number one of zeitgeisty system design. The initial investment accounts only for a small portion of the lifecycle costs of a technical system. In fluid systems, about ninety percent of the total costs are caused by other factors like power consumption and maintenance. With modern optimization methods, it is already possible to plan an optimal technical system considering multiple objectives. In this paper, we focus on an often neglected contribution to the lifecycle costs: downtime costs due to spontaneous failures. Consequently, availability becomes an issue.
In times of planned obsolescence the demand for sustainability keeps growing. Ideally, a technical system is highly reliable, without failures and down times due to fast wear of single components. At the same time, maintenance should preferably be limited to pre-defined time intervals. Dispersion of load between multiple components can increase a system’s reliability and thus its availability inbetween maintenance points. However, this also results in higher investment costs and additional efforts due to higher complexity. Given a specific load profile and resulting wear of components, it is often unclear which system structure is the optimal one. Technical Operations Research (TOR) finds an optimal structure balancing availability and effort. We present our approach by designing a hydrostatic transmission system.
The conference center darmstadtium in Darmstadt is a prominent example of energy efficient buildings. Its heating system consists of different source and consumer circuits connected by a Zortström reservoir. Our goal was to reduce the energy costs of the system as much as possible. Therefore, we analyzed its supply circuits. The first step towards optimization is a complete examination of the system: 1) Compilation of an object list for the system, 2) collection of the characteristic curves of the components, and 3) measurement of the load profiles of the heat and volume-flow demand. Instead of modifying the system manually and testing the solution by simulation, the second step was the creation of a global optimization program. The objective was to minimize the total energy costs for one year. We compare two different topologies and show opportunities for significant savings.
Verfügbarkeit und Nachhaltigkeit sind wichtige Anforderungen bei der Planung langlebiger technischer Systeme. Meist werden bei Lebensdaueroptimierungen lediglich einzelne Komponenten vordefinierter Systeme untersucht. Ob eine optimale Lebensdauer eine gänzlich andere Systemvariante bedingt, wird nur selten hinterfragt. Technical Operations Research (TOR) erlaubt es, aus Obermengen technischer Systeme automatisiert die lebensdaueroptimale Systemstruktur auszuwählen. Der Artikel zeigt dies am Beispiel eines hydrostatischen Getriebes.
Gearboxes are mechanical transmission systems that provide speed and torque conversions from a rotating power source. Being a central element of the drive train, they are relevant for the efficiency and durability of motor vehicles. In this work, we present a new approach for gearbox design: Modeling the design problem as a mixed-integer nonlinear program (MINLP) allows us to create gearbox designs from scratch for arbitrary requirements and—given enough time—to compute provably globally optimal designs for a given objective. We show how different degrees of freedom influence the runtime and present an exemplary solution.
Resilience as a concept has found its way into different disciplines to describe the ability of an individual or system to withstand and adapt to changes in its environment. In this paper, we provide an overview of the concept in different communities and extend it to the area of mechanical engineering. Furthermore, we present metrics to measure resilience in technical systems and illustrate them by applying them to load-carrying structures. By giving application examples from the Collaborative Research Centre (CRC) 805, we show how the concept of resilience can be used to control uncertainty during different stages of product life.
The understanding that optimized components do not automatically lead to energy-efficient systems sets the attention from the single component on the entire technical system. At TU Darmstadt, a new field of research named Technical Operations Research (TOR) has its origin. It combines mathematical and technical know-how for the optimal design of technical systems. We illustrate our optimization approach in a case study for the design of a ventilation system with the ambition to minimize the energy consumption for a temporal distribution of diverse load demands. By combining scaling laws with our optimization methods we find the optimal combination of fans and show the advantage of the use of multiple fans.
Energy-efficient components do not automatically lead to energy-efficient systems. Technical Operations Research (TOR) shifts the focus from the single component to the system as a whole and finds its optimal topology and operating strategy simultaneously. In previous works, we provided a preselected construction kit of suitable components for the algorithm. This approach may give rise to a combinatorial explosion if the preselection cannot be cut down to a reasonable number by human intuition. To reduce the number of discrete decisions, we integrate laws derived from similarity theory into the optimization model. Since the physical characteristics of a production series are similar, it can be described by affinity and scaling laws. Making use of these laws, our construction kit can be modeled more efficiently: Instead of a preselection of components, it now encompasses whole model ranges. This allows us to significantly increase the number of possible set-ups in our model. In this paper, we present how to embed this new formulation into a mixed-integer program and assess the run time via benchmarks. We present our approach on the example of a ventilation system design problem.
Planning the layout and operation of a technical system is a common task
for an engineer. Typically, the workflow is divided into consecutive stages: First,
the engineer designs the layout of the system, with the help of his experience or of
heuristic methods. Secondly, he finds a control strategy which is often optimized
by simulation. This usually results in a good operating of an unquestioned sys-
tem topology. In contrast, we apply Operations Research (OR) methods to find a
cost-optimal solution for both stages simultaneously via mixed integer program-
ming (MILP). Technical Operations Research (TOR) allows one to find a provable
global optimal solution within the model formulation. However, the modeling error
due to the abstraction of physical reality remains unknown. We address this ubiq-
uitous problem of OR methods by comparing our computational results with mea-
surements in a test rig. For a practical test case we compute a topology and control
strategy via MILP and verify that the objectives are met up to a deviation of 8.7%.
A new method for improved autoclave loading within the restrictive framework of helicopter manufacturing is proposed. It is derived from experimental and numerical studies of the curing process and aims at optimizing tooling positions in the autoclave for fast and homogeneous heat-up. The mold positioning is based on two sets of information. The thermal properties of the molds, which can be determined via semi-empirical thermal simulation. The second information is a previously determined distribution of heat transfer coefficients inside the autoclave. Finally, an experimental proof of concept is performed to show a cycle time reduction of up to 31% using the proposed methodology.
Inmitten des Stuttgarter Kessels findet sich Deutschlands einziger zoologisch-botanischer Garten wieder – die Wilhelma. Umrahmt von einer denkmalgeschützten Parkanlage des 19. Jahrhunderts mit maurischen Gebäuden lässt sie Bildung mit Freizeit verschmelzen. Das neue Erscheinungsbild positioniert die schwäbische Einrichtung sowohl als Ort des Zusammenkommens als auch der Erholung und Wissensvermittlung. Bereits vor dem Betreten der Wilhelma soll ihre besondere Charakteristik aufgezeigt und entscheidend von ähnlichen Institutionen distanziert werden. Das grundlegende Gestaltungskonzept rückt die Symbiose aus Zoologie, Botanik und Historie in den Vordergrund. Inspiriert von der maurischen Architektur basiert die Gesamtgestaltung auf feinen geometrischen Formen. Diese bieten Orientierung, unterstreichen die Vielfältigkeit der Wilhelma und vereinen sich darüber hinaus im Logo miteinander.
Wir alle haben schon einmal von ihnen gehört. Die einen kennen sie aus dem Geschichtsunterricht, die anderen haben sie vielleicht auch schon mal bewusst oder unbewusst auf der Straße gesehen. Einige sind es sogar selbst. Die Rede ist von jüdischen Menschen in Deutschland.
In unserer Bundesrepublik wird die jüdische Bevölkerung unausweichlich mit dem Gedanken des Holocausts verbunden. Jüdinnen und Juden wird somit eine Identität zugesprochen, mit der sie nichts zu tun haben. Es findet eine Stigmatisierung statt. Dabei sind jüdische Menschen heutzutage so divers wie noch nie. Das Printmedium »Ich sehe was, was Du nicht siehst« beleuchtet diese selten wahrgenommene Diversität und zeigt durch spannende Interviews eine jüdische Welt, die außerhalb der NS-Verbrechen liegt. Darüber hinaus findet man Informationen zu verschiedenen jüdischen Bräuchen, historischen Ereignissen und interessanten Infografiken.
Müll ist immer und überall vorhanden – auch wenn wir ihn nicht sehen. Gerade unsichtbarer Müll birgt für den Menschen und seine Umwelt erhebliche Gefahren, die durch seine Unsichtbarkeit irrelevant erscheinen. Die Publikation mit dem Titel mikromakro deckt durch verschiedene Artikel, Interviews und Texte die Gefahren auf, die durch den unsichtbaren Müll entstehen.
Ziel war es, eine Bookazine-Reihe zu konzipieren, die in sechs Ausgaben das Thema des unsichtbaren Mülls beleuchtet. Die erste Ausgabe zum Thema Kunststoff wurde exemplarisch gestaltet.
Zusätzlich zum redaktionellen Teil untermauern Infografiken die Texte faktisch und Fotoserien emotional.
Da unsichtbarer Müll auf zwei Ebenen zu finden ist – der Makro- (groß) und Mikroebene (klein) – wurde die Publikation inhaltlich zweigeteilt, sodass sich das Layout und die Fotoserien vom Mikro- und Makroteil unterscheiden.
Der Archäologische Park Xanten (APX) gilt als Deutschlands einziger archäologischer Freiluftpark. Er zeichnet sich im Verbund mit dem Römermuseum durch seine Lage auf dem historischen Grund einer römischen Metropole und seine kontinuierliche Forschungsaktivität aus und bietet so ein einzigartiges Umfeld von kultureller Relevanz. Ziel dieses Projektes war es, ein neues Erscheinungsbild zu entwickeln, welches klar die Thematik des Parks in den Medien erkennbar macht. Das Corporate Design dient dazu, die Inhalte des Verbundes in einem einheitlichen System medienübergreifend zu präsentieren. Das Design unterstützt den APX in seiner Funktion als Begegnungs- und Bildungsstätte. Aufgrund dessen ist es im Hinblick auf das Ziel relevant, das Interesse an Kulturgeschichte und Forschung zu wecken.
Die Allianz Chronischer Seltener Erkrankungen (ACHSE) ist das einzige krankheitsübergreifende Netzwerk von und für Menschen mit einer seltenen Erkrankung in Deutschland. Insgesamt sind 4 Millionen Menschen in Deutschland von einer der rund 8.000 seltenen Krankheiten betroffen.
Durch die Seltenheit der verschiedenen Krankheiten ist es oft schwer, Experten zu finden, die richtige Versorgung sicherzustellen oder Studien durchzuführen. Betroffene fühlen sich oft nicht wahrgenommen und alleine gelassen. Die ACHSE dient als unabhängige Schnittstelle und Knotenpunkt zwischen Betroffenen, Regierung, Politik und Wirtschaft. Gemeinsam bündeln sich hier 130 Patientenorganisationen unter einem Dach, um die Betroffenen in den Fokus zu rücken. Ziel der Bachelorarbeit ist die Entwicklung eines Erscheinungsbildes sowie einer Kampagne, die das Thema mehr ins Bewusstsein der Öffentlichkeit bringt und informiert.
Seit dem Zeitpunkt seiner Gründung im Jahr 1909 lautet der Auftrag des Kölner Museums für Ostasiatische Kunst, der europäischen Gesellschaft die Kunst Ostasiens nahezubringen, für ein besseres Verständnis und die Wertschätzung seiner Kultur zu sorgen und somit auch Rassismus und kolonialistischem Denken entgegenzuwirken – ein Anliegen, welches noch heute von unveränderter Relevanz und Dringlichkeit ist.
Im Zentrum des neuen Erscheinungsbildes steht der gestürzte Buchstabe K und die somit entstehende Kombination von horizontaler und vertikaler, traditionell ostasiatischer Leserichtung deutet auf visueller Ebene ein Zusammenspiel zwischen den Kulturen an. Die Farbgebung des neuen Erscheinungsbildes greift die ruhige Atmosphäre des Museums auf und sorgt in Kombination mit einem streng gegliederten Raster für klare Struktur und Orientierung.
Transmission: Ein animiertes Musikvideo illustriert die Liebe
und Verbindung zum Genre Techno
(2021)
Techno ist seit seiner Entstehung mehr als ein Musik-Genre. Es ist ein Lebensgefühl und eine Bewegung. Techno-Partys dienen vielen Menschen als Ventil, um die Sorgen des Alltags für eine Nacht vergessen zu können. „Transmission“ porträtiert anhand der Protagonistin die persönliche Beziehung zum Genre Techno. Das Musikvideo soll die Zuschauenden visuell anregen und mitreißen. Es bietet ihnen die Möglichkeit, sich selbst wieder erkennen zu können und soll Außenstehenden einen Einblick in die Techno-Szene ermöglichen. Mithilfe des Rotoskopie-Verfahrens konnte ein realistischer Animationsstil erreicht werden, welcher durch eine unrealistische Farbgebung der Charaktere gebrochen wird. Der Schwerpunkt der Bachelorarbeit liegt in der kreativ-gestalterischen Ausarbeitung. Die Musikvideo „Transmission“ vermittelt das „Lebensgefühl Techno“ visuell anregend und nachvollziehbar.
Die Nachfrage nach flexiblen Arbeitsmodellen und damit Remote Work steigt und wird zunehmend zum Kriterium bei der Jobauswahl. Trotz der vielen Vorteile gibt es in der „Remote-Arbeitswelt“ aber immer noch einige Herausforderungen. Remote Arbeitende haben eine andere, teils nachteilige Erfahrung gegenüber Kollegen vor Ort.
Um dafür eine nutzerzentrierte Lösung zu finden, lag der Fokus bei dieser Arbeit auf den Auswirkungen und Bedürfnissen des arbeitenden Menschen. Basierend hierauf wurde ein Dienstleistungsservice konzipiert. Dieser unterstützt Unternehmen, Selbstständige und Mitarbeitende durch passende Angebote und Dienstleistungen in den Bereichen Ausstattung, Technik, Gesundheit, Corporate Benefits u.Ä. Dies ermöglicht auch Arbeitgebenden Aufgaben auszulagern und die Attraktivität und Konkurrenzfähigkeit auf dem Arbeitsmarkt zu steigern. Das wird zukünftig im „war for digitals talents“ immer wichtiger werden.
Zwei sind eine Gemeinschaft: Illustrative Neuinterpretation des Romans "Eine Insel" von T. Pratchett
(2021)
Das Projekt „Zwei sind eine Gemeinschaft“ befasst sich mit der Entwicklung einer gebundenen Fassung der Graphic Novel als Adaption des Kinderromans „Eine Insel“ von Terry Pratchett. Diese soll den Betrachtenden ermöglichen, mittels ansprechenden Illustrationen tiefer in die fantasievolle Welt der Geschichte einzutauchen, dem Alltag zu entfliehen und so die Begeisterung zum Medium Buch wieder aufleben zu lassen. Durch die Verbindung von Techniken des Grafikdesigns und der klassischen Illustration verbindet der Stil sowohl die moderne, ausdrucksstarke und sehr grafische Bildsprache mit der Eigenschaft, kreativen Interpretationsspielraum zu lassen und tiefe Emotionen zu erzeugen. Die besondere Innovation des Projekts zeigt sich durch das Konzept des illustrativen Baukastensystems, welches ermöglicht, die einzelnen Illustrationen effizient und intuitiv zu gestalten.
Die Kunst des Theaters ist alt. Gegenwärtig zählt sie allerdings immer noch zu den wichtigsten Trägern des künstlerischen Kulturguts. Doch die Welt in der wir leben hat sich in den letzten Jahren deutlich verändert. Sie ist komplexer geworden. Die Anzahl der losen Informationen, die in unsere Wahrnehmungsbereiche hineinragen, hat sich explosionsartig erhöht. Ein großer Anteil dieser Veränderung ist auf die Digitalisierung verschiedener Lebensbereiche zurückzuführen. Die Werkzeuge, welche im Zuge der Digitalisierung kreiert wurden, werden von den meisten heute selbstverständlich genutzt. Doch was bedeutet diese neue Entwicklung für das Theater und wie sollte es auf diese Veränderungen reagieren? Als gestalterische Antwort entstand ein neues Erscheinungsbild, welches crossmedial sowohl die analogen Säulen des Theaters, als auch die neuen digitalen Formen des Alltags auffangen und kommunizieren kann.
Eine Kampagne, die darauf ausgerichtet ist, die Bevölkerung auf sozialer Ebene aufzurufen, Impf-Skeptiker aufzuklären und von Impfungen zu überzeugen. Anhand von offiziellen Statistiken, die optisch ansprechend aufbereitet wurden, werden die Menschen über Krankheiten und dazu gehörige Risiken informiert. Des Weiteren wird der Impferfolg grafisch dokumentiert und leicht verständlich präsentiert, ohne Fakten auszulassen.
Durch eine Serie Plakate verschiedener Formate werden die Betrachter animiert, die Homepage impfen.info aufzusuchen und das reichhaltige Informationsangebot zu nutzen.
Mithilfe einer amüsanten Postkartenreihe wird die Verbreitung von Krankheitserregern simuliert und postalisch in die Haushalte der Impfgegner- und Skeptiker gebracht, um zu verdeutlichen, wie rasant Viren sich verbreiten und wie wichtig es ist, sich und seine Lieben zu schützen.
Was ist „Männlichkeit“ und was verstehen junge Erwachsene unter diesem Begriff? Das Ziel des Projektes war 18 bis 30 jährige Jungen und Männer des biologisch männlichen Geschlechts zu befragen, was ihre Definition von Männlichkeit sei. Diese Arbeit hatte die Intention den Befragten einen sicheren Raum zu geben, damit sie ihre ehrlichen Antworten äußern und ihre wahren Gesichter zeigen können. Die dabei entstandenen Fotografien sollen die Persönlichkeiten und die seelische Verfassung der abgebildeten Personen widerspiegeln. Es handelt sich um eine soziologische Bestandsaufnahme der „Männlichkeiten“ der heutigen Jugend und der heranwachsenden Erwachsenen im 21. Jahrhundert.
Niemand kann der täglichen Erfahrung mit Haaren entfliehen. Ob es nun der eigene Blick in den Spiegel ist, die Begegnung mit anderen Menschen, oder die mit Testimonials gespeiste Werbung für diverse Haarprodukte. Haare gehören zum Alltag. Aber was steckt hinter dem Haar, wenn es denn einmal von uns und unserer Person getrennt wird und nur noch als körperloses Büschel erkennbar ist? Zum Beispiel in Form von Echthaarextensions. Wer bedient freiwillig und unfreiwillig durch die eigene Haarpracht die millionenschwere Echthaarindustrie? Wer profitiert von der haarigen Ware und wer sind die Käufer, die den globalen Handel vorantreiben? Das jährlich erscheinende Bookazine TRICHOTOMY geht diesen Fragestellungen auf den Grund. Investigative Artikel enthüllen die Produktion und Ökonomie der vorwiegend anonymisierten Echthaarindustrie und porträtieren die Menschen und Schicksale 'hinter den Haaren'.
Die Zeit befindet sich im ständigen Wandel. Mit ihr verbindet man Zukunft, Vergangenheit und Gegenwart. Letzteres prägt das jetzige Dasein. Der Zeitwandel ist ein Prozess, über den wir uns meist erst nach Jahren bewusstwerden. Besonders, wenn man das Dorf, in welchem man aufgewachsen ist, näher betrachtet, fällt einem auf, was sich im Laufe der Jahre architektonisch oder infrastrukturell verändert hat. So stellt sich die Frage, wie das Dorf im letzten Jahrhundert ausgesehen hat. Wie sah es vor, während und nach den beiden Weltkriegen aus? Wie war das Dorfleben in der Zwischenkriegszeit? Was hat sich im letzten Jahrhundert verändert? Diese Arbeit zeigt den Wandel der Zeit, kombiniert aus Vergangenheit und Gegenwart. Damalige Aufnahmeorte wurden erneut aufgesucht, die Fotos aus der gleichen Position wurden neu abgelichtet und miteinander kombiniert.
Wie real ist unsere Realität? Wie »wirklich« ist das, was wir wahrnehmen und wie »wahr« kann die »Wahrheit« eigentlich sein? Medial vermittelte Informationen spielen für den Prozess der Meinungsbildung eine entscheidende Rolle. In der Wanderausstellung real:ly? geht es um einen Perspektivwechsel. Am Beispiel der »Atomwaffentests auf den Marshallinseln« wird das medial erzeugte Bild amerikanischer Berichterstattung persönlichen Geschichten der Marshaller*innen gegenübergestellt: Technologischer Fortschritt, das Wettrüsten mit der UdSSR und die Macht über die Atombombe treffen auf Erzählungen über Zwangsumsiedlung, Krankheit, Ausbeutung und Abhängigkeit. real:ly? soll daran erinnern, die andere Seite der Medaille zu bedenken und eine andere Perspektive einzunehmen, bevor man seine Meinung bildet. Denn alles, was wir zu wissen glauben, ist nur ein kleiner Teil der ganzen Geschichte.
Let´s change fashion!: Eine Image-Kampagne der Fair Wear Foundation
für faire und nachhaltige Mode.
(2021)
Fast Fashion-Ketten beherrschen die Modewelt. Doch einige Unternehmen, Siegel und Stiftungen versuchen die Textilindustrie neu umzugestalten. Um die Modeindustrie nachhaltig zu verändern, müssen allerdings auch den Kunden die schlechten Arbeitsbedingungen und die negativen Einflüsse der Textilbranche auf die Umwelt bewusst werden.
Das konkrete Ziel der erstellten Kampagne ist es, modebewusste Menschen davon zu überzeugen Fast Fashion hinter sich zu lassen. Es soll also ein Umdenken bei den Konsumenten stattfinden. Die Fair Wear Foundation und ihre Mitglieder vertreten die Vision, dass Mode auch fair und nachhaltig sein kann. Genau diese Vision soll mit der Kampagne vermittelt und an die Konsumenten weitergetragen werden.
Welchen Einfluss haben Erinnerungen auf unser Bewusstsein und wie definieren sie uns als Individuum? Erinnerungen gehen verloren — sei es durch einfaches Vergessen, traumatische Erlebnisse oder Krankheit. Aber wie sehr wirkt sich das Vergessen auf unsere Persönlichkeit aus? Wenn wichtige Erlebnisse aus unserer Erinnerung verschwinden, bleiben wir dann noch wir selbst?
Für die gestalterische Auseinandersetzung mit diesen Fragen wurde das Medium Film gewählt. Der Film führt uns auf eine Reise durch die Erinnerungs- und Gedankenwelt einer Person, die ihre Erinnerung verloren hat. Mit der Hilfe des Psychologen Dr. Daniel Rose soll ein Memory-Backup durchgeführt werden, um die verlorenen Erinnerungen wiederherzustellen. Dabei sollen ihre Erinnerungen neu aufgesetzt werden, um ihr altes Bewusstsein zurückzugewinnen. Stück für Stück werden die verlorenen Erinnerungen in verschiedenen Bewusstseinsphasen zusammengesetzt und mit ihnen löst sich das Rätsel ihres Verschwindens.
In den letzten 1.5 Jahren haben wir sehr deutlich gemerkt, dass es den Klimawandel wirklich gibt - ein Virus, welches unsere gesamte Welt auf links dreht, Überschwemmungskatastrophen, extreme Temperaturschwankungen, etc. Es ist also Zeit etwas zu verändern, es ist Zeit aktiv hinzusehen und zu handeln - bewusst zu leben, bewusst zu konsumieren. Das Thema Ernährung wird zwar immer wichtiger für einige von uns, jedoch reicht mir die Aufmerksamkeit bisher nicht. Es sind nicht nur Lebensmittel, welche nach dem Aufenthalt im Supermarkt in unserem Kühlschrank und anschließend in unserem Bauch landen. Mit diesen Lebensmitteln gehen außerdem folgende Aspekte einher: der Klimawandel, unsere Gesundheit, die Ausbeutung von Tieren, Menschen und Natur. Also wie sieht eigentlich der Enstehungsprozess hinter all diesen (meist) verpackten Lebensmitteln aus? Einen Teil dieser Prozesse habe ich mir im Rahmen meiner Bachelorarbeit angeschaut. Ich habe ausschließlich Bio-Höfe besucht, um mir ein eigenes Bild von "alternativer Landwirtschaft" zu machen. Die Arbeit ermöglicht Interessierten einen neutralen Einblick hinter die Kulisse unserer Lebensmittel und schafft eine Anregung für einen bewussteren Konsum.
Für die Herstellung von metallischen Bauteilen wird in der heutigen Zeit eine Vielzahl von Verfahren auf dem Markt angeboten. Dabei stehen die additiven im Wettbewerb zu den konventionellen Verfahren. Die erreichbaren Oberflächenqualitäten der additiven sind nicht mit denen spanender Verfahren vergleichbar. Für diesen Beitrag wurde analysiert, ob sich ein mittels Selektivem Laserschmelzen (SLM) additiv hergestellter Edelstahl hinsichtlich seiner Oberflächenqualität nach der Zerspanung von einem umgeformten konventionell hergestellten Edelstahl gleicher Sorte unterscheidet.
Die Studie erörtert anhand eines Fallbeispiels aus der Mathematik für Ingenieur*innen, wie didaktische Gestaltungsprinzipien für Soziale Präsenz, Kollaboration und das Lösen von praxisnahen Problemen mit mathematischem Denken in einer Online-Umgebung aussehen können. Hierfür zieht der
Beitrag den forschungsmethodologischen Rahmen Design-Based Research (DBR) hinzu und berichtet über Zwischenergebnisse. DBR wird an dieser Stelle als eine systematische Herangehensweise an kurzfristige Lehrveränderungen und als Chance auf dem Weg zu einer neuen Hochschullehre nach der COVID-19-Pandemie dargestellt, die theoretische und empirische Erkenntnisse mit Praxisverknüpfung und -relevanz vereint.
Anyone who has always wanted to understand the hieroglyphs on Sheldon's blackboard in the TV series The Big Bang Theory or who wanted to know exactly what the fate of Schrödinger's cat is all about will find a short, descriptive introduction to the world of quantum mechanics in this essential. The text particularly focuses on the mathematical description in the Hilbert space. The content goes beyond popular scientific presentations, but is nevertheless suitable for readers without special prior knowledge thanks to the clear examples.
For typical cases of non-isolated lightning protection systems (LPS) the impulse currents are investigated which may flow through a human body directly touching a structural part of the LPS. Based on a basic LPS model with conventional down-conductors especially the cases of external and internal steel columns and metal façades are considered and compared. Numerical simulations of the line quantities voltages and currents in the time domain are performed with an equivalent circuit of the entire LPS.
As a result it can be stated that by increasing the number of conventional down-conductors and external steel columns the threat for a human being can indeed be reduced, but not down to an acceptable limit. In case of internal steel columns used as natural down-conductors the threat can be reduced sufficiently, depending on the low-resistive connection of the steel columns to the lightning equipotential bonding or the earth termination system, resp. If a metal façade is used the threat for human beings touching is usually very low, if the façade is sufficiently interconnected and multiply connected to the lightning equipotential bonding or the earth termination system, resp.
Modern industry and multi-discipline projects require highly trained individuals with resilient science and engineering back-grounds. Graduates must be able to agilely apply excellent theoretical knowledge in their subject matter as well as essential practical “hands-on” knowledge of diverse working processes to solve complex problems. To meet these demands, university education follows the concept of Constructive Alignment and thus increasingly adopts the teaching of necessary practical skills to the actual industry requirements and assessment routines. However, a systematic approach to coherently align these three central teaching demands is strangely absent from current university curricula. We demonstrate the feasibility of implementing practical assessments in a regular theory-based examination, thus defining the term “blended assessment”. We assessed a course for natural science and engineering students pursuing a career in biomedical engineering, and evaluated the benefit of blended assessment exams for students and lecturers. Our controlled study assessed the physiological background of electrocardiograms (ECGs), the practical measurement of ECG curves, and their interpretation of basic pathologic alterations. To study on long time effects, students have been assessed on the topic twice with a time lag of 6 months. Our findings suggest a significant improvement in student gain with respect to practical skills and theoretical knowledge. The results of the reassessments support these outcomes. From the lecturers ́ point of view, blended assessment complements practical training courses while keeping organizational effort manageable. We consider blended assessment a viable tool for providing an improved student gain, industry-ready education format that should be evaluated and established further to prepare university graduates optimally for their future careers.
Dynamic retinal vessel analysis (DVA) provides a non-invasive way to assess microvascular function in patients and potentially to improve predictions of individual cardiovascular (CV) risk. The aim of our study was to use untargeted machine learning on DVA in order to improve CV mortality prediction and identify corresponding response alterations.
Delayed cerebral ischemia (DCI) is a common complication after aneurysmal subarachnoid hemorrhage (aSAH) and can lead to infarction and poor clinical outcome. The underlying mechanisms are still incompletely understood, but animal models indicate that vasoactive metabolites and inflammatory cytokines produced within the subarachnoid space may progressively impair and partially invert neurovascular coupling (NVC) in the brain. Because cerebral and retinal microvasculature are governed by comparable regulatory mechanisms and may be connected by perivascular pathways, retinal vascular changes are increasingly recognized as a potential surrogate for altered NVC in the brain. Here, we used non-invasive retinal vessel analysis (RVA) to assess microvascular function in aSAH patients at different times after the ictus.
Purpose Vascular risk factors and ocular perfusion are heatedly discussed in the pathogenesis of glaucoma. The retinal vessel analyzer (RVA, IMEDOS Systems, Germany) allows noninvasive measurement of retinal vessel regulation. Significant differences especially in the veins between healthy subjects and patients suffering from glaucoma were previously reported. In this pilot-study we investigated if localized vascular regulation is altered in glaucoma patients with altitudinal visual field defect asymmetry. Methods 15 eyes of 12 glaucoma patients with advanced altitudinal visual field defect asymmetry were included. The mean defect was calculated for each hemisphere separately (-20.99 ± 10.49 pro- found hemispheric visual field defect vs -7.36 ± 3.97 dB less profound hemisphere). After pupil dilation, RVA measurements of retinal arteries and veins were conducted using the standard protocol. The superior and inferior retinal vessel reactivity were measured consecutively in each eye. Results Significant differences were recorded in venous vessel constriction after flicker light stimulation and overall amplitude of the reaction (p \ 0.04 and p \ 0.02 respectively) in-between the hemispheres spheres. Vessel reaction was higher in the hemisphere corresponding to the more advanced visual field defect. Arterial diameters reacted similarly, failing to reach statistical significance. Conclusion Localized retinal vessel regulation is significantly altered in glaucoma patients with asymmetri altitudinal visual field defects. Veins supplying the hemisphere concordant to a less profound visual field defect show diminished diameter changes. Vascular dysregulation might be particularly important in early glaucoma stages prior to a significant visual field defect.
The term ocular rigidity is widely used in clinical ophthalmology. Generally it is assumed as a resistance of the whole eyeball to mechanical deformation and relates to biomechanical properties of the eye and its tissues. Basic principles and formulas for clinical tonometry, tonography and pulsatile ocular blood flow measurements are based on the concept of ocular rigidity. There is evidence for altered ocular rigidity in aging, in several eye diseases and after eye surgery. Unfortunately, there is no consensual view on ocular rigidity: it used to make a quite different sense for different people but still the same name. Foremost there is no clear consent between biomechanical engineers and ophthalmologists on the concept. Moreover ocular rigidity is occasionally characterized using various parameters with their different physical dimensions. In contrast to engineering approach, clinical approach to ocular rigidity claims to characterize the total mechanical response of the eyeball to its deformation without any detailed considerations on eye morphology or material properties of its tissues. Further to the previous chapter this section aims to describe clinical approach to ocular rigidity from the perspective of an engineer in an attempt to straighten out this concept, to show its advantages, disadvantages and various applications.
Pure analytical or experimental methods can only find a control strategy for technical systems with a fixed setup. In former contributions we presented an approach that simultaneously finds the optimal topology and the optimal open-loop control of a system via Mixed Integer Linear Programming (MILP). In order to extend this approach by a closed-loop control we present a Mixed Integer Program for a time discretized tank level control. This model is the basis for an extension by combinatorial decisions and thus for the variation of the network topology. Furthermore, one is able to appraise feasible solutions using the global optimality gap.
Nach Stand von Wissenschaft und Technik werden Komponenten hinsichtlich ihrer Eigenschaften, wie Lebensdauer oder Energieeffizienz, optimiert. Allerdings können selbst hervorragende Komponenten zu ineffizienten oder instabilen Systemen führen, wenn ihr Zusammenspiel nur unzureichend berücksichtigt wird. Eine Systembetrachtung schafft ein größeres Optimierungspotential - dem erhöhten Potential steht jedoch auch ein erhöhter Komplexitätsgrad gegenüber. Die vorliegende Arbeit ist im Rahmen des Sonderforschungsbereichs 805 entstanden, dessen Ziel die Beherrschung von Unsicherheit in Systemen des Maschinenbaus ist. Die Arbeit zeigt anhand eines realen Systems aus dem Bereich der Hydraulik, wie Unsicherheit in der Entwicklungsphase beherrscht werden kann. Hierbei ist neu, dass die durch den späteren Betrieb zu erwartende Systemdegradation eines jeden möglichen Systemvorschlags antizipiert werden kann. Dadurch können Betriebs- und Wartungskosten vorausgesagt und minimiert werden und durch eine optimale Betriebs- und Wartungsstrategie die Verfügbarkeit des Systems garantiert werden. Wesentliche Fragen bei der optimalen Auslegung des betrachteten hydrostatischen Getriebes sind dessen physikalische Modellierung, die Darstellung des Optimierungsproblems als gemischt-ganzzahliges lineares Programm, und dessen algorithmische Behandlung zur Lösungsfindung. Hierzu werden Heuristiken zum schnelleren Auffinden sinnvoller Systemtopologien vorgestellt und mittels mathematischer Dekomposition eine Bewertung des dynamischen Verschleiß- und Wartungsverlaufs möglicher Systemvorschläge vorgenommen. Die Arbeit stellt die Optimierung technischer Systeme an der Schnittstelle von Mathematik, Informatik und Ingenieurwesen sowohl gründlich als auch anschaulich und nachvollziehbar dar.
Finding a good system topology with more than a handful of components is a
highly non-trivial task. The system needs to be able to fulfil all expected load cases, but at the
same time the components should interact in an energy-efficient way. An example for a system
design problem is the layout of the drinking water supply of a residential building. It may be
reasonable to choose a design of spatially distributed pumps which are connected by pipes in at
least two dimensions. This leads to a large variety of possible system topologies. To solve such
problems in a reasonable time frame, the nonlinear technical characteristics must be modelled
as simple as possible, while still achieving a sufficiently good representation of reality. The
aim of this paper is to compare the speed and reliability of a selection of leading mathematical
programming solvers on a set of varying model formulations. This gives us empirical evidence
on what combinations of model formulations and solver packages are the means of choice with the current state of the art.
The UN sets the goal to ensure access to water and sanitation for all people by 2030. To address this goal, we present a multidisciplinary approach for designing water supply networks for slums in large cities by applying mathematical optimization. The problem is modeled as a mixed-integer linear problem (MILP) aiming to find a network describing the optimal supply infrastructure. To illustrate the approach, we apply it on a small slum cluster in Dhaka, Bangladesh.
Dieses Lehrbuch vermittelt die Grundlagen der Wärmeübertragung sowie den Umgang mit EXCEL-VBA von der Erstellung von Makros bis zu benutzerdefinierten Funktionen. Es legt damit eine Basis für die schnelle und professionelle Durchführung von Berechnungen und Simulationen. Die angeleitete Erstellung von Berechnungsmodulen mit EXCEL und VBA aus allen wichtigen Bereichen der Wärmeübertragung bildet den inhaltlichen Schwerpunkt. Dazu zählen die stationäre Wärmeleitung und der stationäre Wärmedurchgang, die instationäre Wärmeleitung, der Wärmeübergang bei freier und erzwungener Konvektion sowie die Wärmestrahlung und der Wärmeübergang beim Kondensieren und Sieden. Soweit sinnvoll und möglich werden die Stoffwertekorrelationen und die Berechnungsvorschriften aus dem VDI-Wärmeatlas verwendet. Für ausgewählte Anwendungen werden zudem komplexere Auslegungen und Simulationen von Prozessen der Wärmeübertragung sowie von Wärmeübertragern erstellt. Die Zielgruppen: Studierende in Bachelor- und Masterstudiengängen, Praktiker im Engineering
The energy-efficiency of technical systems can be improved by a systematic design approach. Technical Operations Research (TOR) employs methods known from Operations Research to find a global optimal layout and operation strategy of technical systems. We show the practical usage of this approach by the systematic design of a decentralized water supply system for skyscrapers. All possible network options and operation strategies are modeled by a Mixed-Integer Nonlinear Program. We present the optimal system found by our approach and highlight the energy savings compared to a conventional system design.
The overall energy efficiency of ventilation systems can be improved by considering not only single components, but by considering as well the interplay between every part of the system. With the help of the method "TOR" ("Technical Operations Research"), which was developed at the Chair of Fluid Systems at TU Darmstadt, it is possible to improve the energy efficiency of the whole system by considering all possible design choices programmatically. We show the ability of this systematic design approach with a ventilation system for buildings as a use case example.
Based on a Mixed-Integer Nonlinear Program (MINLP) we model the ventilation system. We use binary variables to model the selection of different pipe diameters. Multiple fans are model with the help of scaling laws. The whole system is represented by a graph, where the edges represent the pipes and fans and the nodes represents the source of air for cooling and the sinks, that have to be cooled. At the beginning, the human designer chooses a construction kit of different suitable fans and pipes of different diameters and different load cases. These boundary conditions define a variety of different possible system topologies. It is not possible to consider all topologies by hand. With the help of state of the art solvers, on the other side, it is possible to solve this MINLP.
Next to this, we also consider the effects of malfunctions in different components. Therefore, we show a first approach to measure the resilience of the shown example use case. Further, we compare the conventional approach with designs that are more resilient. These more resilient designs are derived by extending the before mentioned model with further constraints, that consider explicitly the resilience of the overall system. We show that it is possible to design resilient systems with this method already in the early design stage and compare the energy efficiency and resilience of these different system designs.
Highly competitive markets paired with tremendous production volumes demand particularly cost efficient products. The usage of common parts and modules across product families can potentially reduce production costs. Yet, increasing commonality typically results in overdesign of individual products. Multi domain virtual prototyping enables designers to evaluate costs and technical feasibility of different single product designs at reasonable computational effort in early design phases. However, savings by platform commonality are hard to quantify and require detailed knowledge of e.g. the production process and the supply chain. Therefore, we present and evaluate a multi-objective metamodel-based optimization algorithm which enables designers to explore the trade-off between high commonality and cost optimal design of single products.
To increase pressure to supply all floors of high buildings with water, booster stations, normally consisting of several parallel pumps in the basement, are used. In this work, we demonstrate the potential of a decentralized pump topology regarding energy savings in water supply systems of skyscrapers. We present an approach, based on Mixed-Integer Nonlinear Programming, that allows to choose an optimal network topology and optimal pumps from a predefined construction kit comprising different pump types. Using domain-specific scaling laws and Latin Hypercube Sampling, we generate different input sets of pump types and compare their impact on the efficiency and cost of the total system design. As a realistic application example, we consider a hotel building with 325 rooms, 12 floors and up to four pressure zones.
Given industrial applications, the costs for the operation and maintenance of a pump system typically far exceed its purchase price. For finding an optimal pump configuration which minimizes not only investment, but life-cycle costs, methods like Technical Operations Research which is based on Mixed-Integer Programming can be applied. However, during the planning phase, the designer is often faced with uncertain input data, e.g. future load demands can only be estimated. In this work, we deal with this uncertainty by developing a chance-constrained two-stage (CCTS) stochastic program. The design and operation of a booster station working under uncertain load demand are optimized to minimize total cost including purchase price, operation cost incurred by energy consumption and penalty cost resulting from water shortage. We find optimized system layouts using a sample average approximation (SAA) algorithm, and analyze the results for different risk levels of water shortage. By adjusting the risk level, the costs and performance range of the system can be balanced, and thus the
system’s resilience can be engineered
On obligations in the development process of resilient systems with algorithmic design methods
(2018)
Advanced computational methods are needed both for the design of large systems and to compute high accuracy solutions. Such methods are efficient in computation, but the validation of results is very complex, and highly skilled auditors are needed to verify them. We investigate legal questions concerning obligations in the development phase, especially for technical systems developed using advanced methods. In particular, we consider methods of resilient and robust optimization. With these techniques, high performance solutions can be found, despite a high variety of input parameters. However, given the novelty of these methods, it is uncertain whether legal obligations are being met. The aim of this paper is to discuss if and how the choice of a specific computational method affects the developer’s product liability. The review of legal obligations in this paper is based on German law and focuses on the requirements that must be met during the design and development process.
The paper industry is the industry with the third highest energy consumption in the European Union. Using recycled paper instead of fresh fibers for papermaking is less energy consuming and saves resources. However, adhesive contaminants in recycled paper are particularly problematic since they reduce the quality of the resulting paper-product. To remove as many contaminants and at the same time obtain as many valuable fibres as possible, fine screening systems, consisting of multiple interconnected pressure screens, are used. Choosing the best configuration is a non-trivial task: The screens can be interconnected in several ways, and suitable screen designs as well as operational parameters have to be selected. Additionally, one has to face conflicting objectives. In this paper, we present an approach for the multi-criteria optimization of pressure screen systems based on Mixed-Integer Nonlinear Programming. We specifically focus on a clear representation of the trade-off between different objectives.
Nahezu 100.000 denkbare Strukturen kann ein Getriebe bei gleicher Funktion aufweisen - je nach Ganganzahl und gefordertem Freiheitsgrad. Mit dem traditionellen Ansatz bei der Entwicklung, einzelne vielversprechende Systemkonfigurationen manuell zu identifizieren und zu vergleichen, können leicht innovative und vor allem kostenminimale Lösungen übersehen werden. Im Rahmen eines Forschungsprojekts hat die TU Darmstadt spezielle Optimierungsmethoden angewendet, um auch bei großen Lösungsräumen zielsicher ein für die individuellen Zielstellungen optimales Layout zu finden.
Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.
Water suppliers are faced with the great challenge of achieving high-quality and, at the same time, low-cost water supply. In practice, the focus is set on the most beneficial maintenance measures and/or capacity adaptations of existing water distribution systems (WDS). Since climatic and demographic influences will pose further challenges in the future, the resilience enhancement of WDS, i.e. the enhancement of their capability to withstand and recover from disturbances, has been in particular focus recently. To assess the resilience of WDS, metrics based on graph theory have been proposed. In this study, a promising approach is applied to assess the resilience of the WDS for a district in a major German City. The conducted analysis provides insight into the process of actively influencing the
resilience of WDS
The development of resilient technical systems is a challenging task, as the system should adapt automatically to unknown disturbances and component failures. To evaluate different approaches for deriving resilient technical system designs, we developed a modular test rig that is based on a pumping system. On the basis of this example
system, we present metrics to quantify resilience and an algorithmic approach to improve resilience. This approach enables the pumping system to automatically react on unknown disturbances and to reduce the impact of component failures. In this case, the system is able to automatically adapt its topology by activating additional valves. This enables the system to still reach a minimum performance, even in case of failures. Furthermore, timedependent disturbances are evaluated continuously, deviations from the original state are automatically detected and anticipated in the future. This allows to reduce the impact of future disturbances and leads to a more resilient
system behaviour.
The transition within transportation towards battery electric vehicles can lead to a more sustainable future. To account for the development goal ‘climate action’ stated by the United Nations, it is mandatory, within the conceptual design phase, to derive energy-efficient system designs. One barrier is the uncertainty of the driving behaviour within the usage phase. This uncertainty is often addressed by using a stochastic synthesis process to derive representative driving cycles and by using cycle-based optimization. To deal with this uncertainty, a new approach based on a stochastic optimization program is presented. This leads to an optimization model that is solved with an exact solver. It is compared to a system design approach based on driving cycles and a genetic algorithm solver. Both approaches are applied to find efficient electric powertrains with fixed-speed and multi-speed transmissions. Hence, the similarities, differences and respective advantages of each optimization procedure are discussed.
The course Physics for Electrical Engineering is part of the curriculum of the bachelor program Electrical Engineering at University of Applied Science Aachen.
Before covid-19 the course was conducted in a rather traditional way with all parts (lecture, exercise and lab) face-to-face. This teaching approach changed fundamentally within a week when the covid-19 limitations forced all courses to distance learning. All parts of the course were transformed to pure distance learning including synchronous and asynchronous parts for the lecture, live online-sessions for the exercises and self-paced labs at home. Using these methods, the course was able to impart the required knowledge and competencies. Taking the teacher’s observations of the student’s learning behaviour and engagement, the formal and informal feedback of the students and the results of the exams into account, the new methods are evaluated with respect to effectiveness, sustainability and suitability for competence transfer. Based on this analysis strong and weak points of the concept and countermeasures to solve the weak points were identified. The analysis further leads to a sustainable teaching approach combining synchronous and asynchronous parts with self-paced learning times that can be used in a very flexible manner for different learning scenarios, pure online, hybrid (mixture of online and presence times) and pure presence teaching.
Adapting augmented reality systems to the users’ needs using gamification and error solving methods
(2021)
Animations of virtual items in AR support systems are typically predefined and lack interactions with dynamic physical environments. AR applications rarely consider users’ preferences and do not provide customized spontaneous support under unknown situations. This research focuses on developing adaptive, error-tolerant AR systems based on directed acyclic graphs and error resolving strategies. Using this approach, users will have more freedom of choice during AR supported work, which leads to more efficient workflows. Error correction methods based on CAD models and predefined process data create individual support possibilities. The framework is implemented in the Industry 4.0 model factory at FH Aachen.
Around 60% of the paper worldwide is made from recovered paper. Especially adhesive contaminants, so called stickies, reduce paper quality. To remove stickies but at the same time keep as many valuable fibers as possible, multi-stage screening systems with several interconnected pressure screens are used. When planning such systems, suitable screens have to be selected and their interconnection as well as operational parameters have to be defined considering multiple conflicting objectives. In this contribution, we present a Mixed-Integer Nonlinear Program to optimize system layout, component selection and operation to find a suitable trade-off between output quality and yield.
In product development, numerous design decisions have to be made. Multi-domain virtual prototyping provides a variety of tools to assess technical feasibility of design options, however often requires substantial computational effort for just a single evaluation. A special challenge is therefore the optimal design of product families, which consist of a group of products derived from a common platform. Finding an optimal platform configuration (stating what is shared and what is individually designed for each product) and an optimal design of all products simultaneously leads to a mixed-integer nonlinear black-box optimization model. We present an optimization approach based on metamodels and a metaheuristic. To increase computational efficiency and solution quality, we compare different types of Gaussian process regression metamodels adapted from the domain of machine learning, and combine them with a genetic algorithm. We illustrate our approach on the example of a product family of electrical drives, and investigate the trade-off between solution quality and computational overhead.
Inhaltsverzeichnis
1. Die ordentliche Kündigung chronisch Kranker im Anwendungsbereich des
KSchG
– Nora Trümpener 3-56
2. Die Legitimationswirkung der Gesellschafterliste -
Erfolg trotz Grenzen?
– Jan Peters 57-112
3. Marktmanipulation – Arten, Abgrenzung und gesetzliche Handhabe
– Manuel Herzel 113-170
4. Die Zulässigkeit der Verdachtskündigung im Arbeitsverhältnis
– Alina Vollmann 171-248
5. Praxisorientierter Arbeitgeberleitfaden zur rechtssicheren Einführung von
Homeoffice im Arbeitsverhältnis
– Gina Breuer 249-304
In order to maximize the possible travel distance of battery electric vehicles with one battery charge, it is mandatory to adjust all components of the powertrain carefully to each other. While current vehicle designs mostly simplify the powertrain rigorously and use an electric motor in combination with a gearbox with only one fixed transmission ratio, the use of multi-gear systems has great potential. First, a multi-speed system is able to improve the overall energy efficiency. Secondly, it is able to reduce the maximum momentum and therefore to reduce the maximum current provided by the traction battery, which results in a longer battery lifetime. In this paper, we present a systematic way to generate multi-gear gearbox designs that—combined with a certain electric motor—lead to the most efficient fulfillment of predefined load scenarios and are at the same time robust to uncertainties in the load. Therefore, we model the electric motor and the gearbox within a Mixed-Integer Nonlinear Program, and optimize the efficiency of the mechanical parts of the powertrain. By combining this mathematical optimization program with an unsupervised machine learning algorithm, we are able to derive global-optimal gearbox designs for practically relevant momentum and speed requirements.
The chemical industry is one of the most important industrial sectors in Germany in terms of manufacturing revenue. While thermodynamic boundary conditions often restrict the scope for reducing the energy consumption of core processes, secondary processes such as cooling offer scope for energy optimisation. In this contribution, we therefore model and optimise an existing cooling system. The technical boundary conditions of the model are provided by the operators, the German chemical company BASF SE. In order to systematically evaluate different degrees of freedom in topology and operation, we formulate and solve a Mixed-Integer Nonlinear Program (MINLP), and compare our optimisation results with the existing system.
Component failures within water supply systems can lead to significant performance losses. One way to address these losses is the explicit anticipation of failures within the design process. We consider a water supply system for high-rise buildings, where pump failures are the most likely failure scenarios. We explicitly consider these failures within an early design stage which leads to a more resilient system, i.e., a system which is able to operate under a predefined number of arbitrary pump failures. We use a mathematical optimization approach to compute such a resilient design. This is based on a multi-stage model for topology optimization, which can be described by a system of nonlinear inequalities and integrality constraints. Such a model has to be both computationally tractable and to represent the real-world system accurately. We therefore validate the algorithmic solutions using experiments on a scaled test rig for high-rise buildings. The test rig allows for an arbitrary connection of pumps to reproduce scaled versions of booster station designs for high-rise buildings. We experimentally verify the applicability of the presented optimization model and that the proposed resilience properties are also fulfilled in real systems.
This chapter describes three general strategies to master uncertainty in technical systems: robustness, flexibility and resilience. It builds on the previous chapters about methods to analyse and identify uncertainty and may rely on the availability of technologies for particular systems, such as active components. Robustness aims for the design of technical systems that are insensitive to anticipated uncertainties. Flexibility increases the ability of a system to work under different situations. Resilience extends this characteristic by requiring a given minimal functional performance, even after disturbances or failure of system components, and it may incorporate recovery. The three strategies are described and discussed in turn. Moreover, they are demonstrated on specific technical systems.
Algorithmic design and resilience assessment of energy efficient high-rise water supply systems
(2018)
High-rise water supply systems provide water flow and suitable pressure in all levels of tall buildings. To design such state-of-the-art systems, the consideration of energy efficiency and the anticipation of component failures are mandatory. In this paper, we use Mixed-Integer Nonlinear Programming to compute an optimal placement of pipes and pumps, as well as an optimal control strategy.Moreover, we consider the resilience of the system to pump failures. A resilient system is able to fulfill a predefined minimum functionality even though components fail or are restricted in their normal usage. We present models to measure and optimize the resilience. To demonstrate our approach, we design and analyze an optimal resilient decentralized water supply system inspired by a real-life hotel building.
Successful optimization requires an appropriate model of the system under consideration. When selecting a suitable level of detail, one has to consider solution quality as well as the computational and implementation effort. In this paper, we present a MINLP for a pumping system for the drinking water supply of high-rise buildings. We investigate the influence of the granularity of the underlying physical models on the solution quality. Therefore, we model the system with a varying level of detail regarding the friction losses, and conduct an experimental validation of our model on a modular test rig. Furthermore, we investigate the computational effort and show that it can be reduced by the integration of domain-specific knowledge.
The application of mathematical optimization methods for water supply system design and operation provides the capacity to increase the energy efficiency and to lower the investment costs considerably. We present a system approach for the optimal design and operation of pumping systems in real-world high-rise buildings that is based on the usage of mixed-integer nonlinear and mixed-integer linear modeling approaches. In addition, we consider different booster station topologies, i.e. parallel and series-parallel central booster stations as well as decentral booster stations. To confirm the validity of the underlying optimization models with real-world system behavior, we additionally present validation results based on experiments conducted on a modularly constructed pumping test rig. Within the models we consider layout and control decisions for different load scenarios, leading to a Deterministic Equivalent of a two-stage stochastic optimization program. We use a piecewise linearization as well as a piecewise relaxation of the pumps’ characteristics to derive mixed-integer linear models. Besides the solution with off-the-shelf solvers, we present a problem specific exact solving algorithm to improve the computation time. Focusing on the efficient exploration of the solution space, we divide the problem into smaller subproblems, which partly can be cut off in the solution process. Furthermore, we discuss the performance and applicability of the solution approaches for real buildings and analyze the technical aspects of the solutions from an engineer’s point of view, keeping in mind the economically important trade-off between investment and operation costs.
The recently discovered first hyperbolic objects passing through the Solar System, 1I/’Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.
Water distribution systems are an essential supply infrastructure for cities. Given that climatic and demographic influences will pose further challenges for these infrastructures in the future, the resilience of water supply systems, i.e. their ability to withstand and recover from disruptions, has recently become a subject of research. To assess the resilience of a WDS, different graph-theoretical approaches exist. Next to general metrics characterizing the network topology, also hydraulic and technical restrictions have to be taken into account. In this work, the resilience of an exemplary water distribution network of a major German city is assessed, and a Mixed-Integer Program is presented which allows to assess the impact of capacity adaptations on its resilience.
Geochemical characterisation of hypersaline waters is difficult as high concentrations of salts hinder the analysis of constituents at low concentrations, such as trace metals, and the collection of samples for trace metal analysis in natural waters can be easily contaminated. This is particularly the case if samples are collected by non-conventional techniques such as those required for aquatic subglacial environments. In this paper we present the first analysis of a subglacial brine from Taylor Valley, (~ 78°S), Antarctica for the trace metals: Ba, Co, Mo, Rb, Sr, V, and U. Samples were collected englacially using an electrothermal melting probe called the IceMole. This probe uses differential heating of a copper head as well as the probe’s sidewalls and an ice screw at the melting head to move through glacier ice. Detailed blanks, meltwater, and subglacial brine samples were collected to evaluate the impact of the IceMole and the borehole pump, the melting and collection process, filtration, and storage on the geochemistry of the samples collected by this device. Comparisons between melt water profiles through the glacier ice and blank analysis, with published studies on ice geochemistry, suggest the potential for minor contributions of some species Rb, As, Co, Mn, Ni, NH4+, and NO2−+NO3− from the IceMole. The ability to conduct detailed chemical analyses of subglacial fluids collected with melting probes is critical for the future exploration of the hundreds of deep subglacial lakes in Antarctica.
To maximize the travel distances of battery electric vehicles such as cars or buses for a given amount of stored energy, their powertrains are optimized energetically. One key part within optimization models for electric powertrains is the efficiency map of the electric motor. The underlying function is usually highly nonlinear and nonconvex and leads to major challenges within a global optimization process. To enable faster solution times, one possibility is the usage of piecewise linearization techniques to approximate the nonlinear efficiency map with linear constraints. Therefore, we evaluate the influence of different piecewise linearization modeling techniques on the overall solution process and compare the solution time and accuracy for methods with and without explicitly used binary variables.
Inhaltsverzeichnis
1. Die Haftung des GmbH-Geschäftsführers in der Insolvenz - Grundsätze
und Modifikationen infolge der Covid-19 Pandemie
– Franziska Tings 3-61
2. Disquotale Gewinnausschüttung in der Organschaft – Die Neuregelung des
§ 14 Abs. 2 KStG und die Auslegung durch die Finanzverwaltung
– Julian Lehner 62-149
3. Auswirkungen des Mauracher Entwurfs auf die Gesellschaft bürgerlichen
Rechts – Neuerfindung oder bloße Korrektur des
Personengesellschaftsrechts?
– Elena Hoß 150-209
4. Befristung von Arbeitsverhältnissen - Rechtliche Rahmenbedingungen und
arbeitsmarktpolitische Chancen und Risiken
– Franziska Gotzens 210-270
5. Die Rolle der psychischen Gesundheit am Arbeitsplatz Entwicklung
exemplarischer Handlungsempfehlungen für den ganzheitlichen Umgang
mit psychischen Belastungen im Homeoffice
– Marie-Sophie Creutz 271-346
6. Tokenisierung von illiquiden Vermögenswerten – Wie Blockchain die
Immobilienwirtschaft verändern kann
– Nils Christ 347-404
Concentrating Solar Power
(2021)
The focus of this chapter is the production of power and the use of the heat produced from concentrated solar thermal power (CSP) systems.
The chapter starts with the general theoretical principles of concentrating systems including the description of the concentration ratio, the energy and mass balance. The power conversion systems is the main part where solar-only operation and the increase in operational hours.
Solar-only operation include the use of steam turbines, gas turbines, organic Rankine cycles and solar dishes. The operational hours can be increased with hybridization and with storage.
Another important topic is the cogeneration where solar cooling, desalination and of heat usage is described.
Many examples of commercial CSP power plants as well as research facilities from the past as well as current installed and in operation are described in detail.
The chapter closes with economic and environmental aspects and with the future potential of the development of CSP around the world.