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Water security is a major concern for water-scarce cities that face dynamic water challenges due to limited water supply, climate change and increasing water demand. Framing urban water security is challenging due to the complexity and uncertainties of the definitions and assessment frameworks concerning urban water security. Several studies have assessed water security by granting priority indicators equal weight without considering or adapting to the local conditions. This study develops a new urban water security assessment framework with application to the water-scarce city
of Madaba, Jordan. The study applies the new assessment framework on the study area and measures urban water security using the integrated urban water security index (IUWSI) and the analytic hierarchy process (AHP) as a decision management tool to prioritise and distinguish indicators that affect the four dimensions of urban water security: drinking water, ecosystems, climate change and water-related hazards, and socioeconomic aspects (DECS). The integrated urban water security index (IUWSI) highlights the state of water security and intervention strategies in Madaba. The study reveals that urban water security in Madaba is satisfactory to meet basic needs, with shortcomings in some aspects of the DECS. However, Madaba faces poor security in terms of managing climate- and water-related risks. The IUWSI framework assists with a rational and evidence-based decision-making process, which is important for enhancing water resources management in water-scarce cities.
The paper presents results of the modelling of heat transfer at film boiling of a liquid in a porous medium on a vertical heated wall bordering with the porous medium. Such processes are observed at cooling of high-temperature surfaces of heat pipes, microstructural radiators etc. Heating conditions at the wall were the constant wall temperature or heat flux. The outer boundary of the vapor film was in contact with moving or stationary liquid inside the porous medium. An analytical solution was obtained for the problem of fluid flow and heat transfer using the porous medium model in the Darcy–Brinkman and Darcy–Brinkman–Forchheimer approximation. It was shown that heat transfer at film boiling in a porous medium was less intensive than in the absence of a porous medium (free fluid flow) and further decreased with the decreasing permeability of the porous medium. Significant differences were observed in frames of both models: 20% for small Darcy numbers at Da < 2 for the Darcy–Brinkman model, and 80% for the Darcy–Brinkman–Forchheimer model. In the Darcy–Brinkman model, depending on the interaction conditions at the vapor–liquid interface (no mechanical interaction or stationary fluid), a sharp decrease in heat transfer was observed for the Darcy numbers lower than five. The analytical predictions of heat transfer coefficients qualitatively agreed with the data of Cheng and Verma (Int J Heat Mass Transf 24:1151–1160, 1981) though demonstrated lower values of heat transfer coefficients for the conditions of the constant wall temperature and constant wall heat flux.
This investigation attempts to understand the eco‐hydrology of, and accordingly suggest an option to manage floodwater for agriculture in, the understudied and data‐sparse ephemeral Baraka River Basin within the hyper‐arid region of Sudan. Reference is made to the major feature of the basin, that is, the Toker Delta spate irrigation scheme. A point‐to‐pixel comparison of gridded and ground‐based data sets is performed to enhance the estimates of rainfall. Analysis of remotely sensed land use/cover data is performed. The results show a significant reduction of the grassland and barren areas explained by a significant expansion of the cropland and open shrubland (invasive mesquite trees) areas in the delta. The cotton sown area is highly dependent on the flooded area and the discharge volume in the delta. However, the area of this major crop has declined since the early 1990s in favour of cultivation of more profitable food crops. Expansion of mesquite in the delta is problematic, taking hold under increased floodwater, and can only be manged by clearance to provide crop cultivation area. There is a great potential for floodwater harvesting during the rainfall season (June to September). A total seasonal runoff volume of around 4.6 and 10.8 billion cubic metres is estimated at 90 and 50% probabilities of exceedance (reliabilities), respectively. Rather than leaving the runoff generated from rainfall events to pass to the Red Sea or be consumed by mesquite trees, a location for runoff harvesting structure in a highly suitable area is proposed. Such a structure will support any policy shifts towards planning and managing the basin water resources for use in irrigating the agricultural scheme.
One-step preparation of bilayered films from kraft lignin and cellulose acetate to mimic tree bark
(2020)
This contribution presents the development of a dry-cast method for the one-step preparation of bio-based films from wood polymers that mimic the bilayered structure of tree bark, the natural protective layer of the tree. In a simplified view, natural bark can be considered as the superposition of an external homogeneous and non-porous layer (outer bark) and a porous substructure layer (inner bark). This work is a first step for the future development of bio-based biomimetic wood coatings. The film had a bark-like appearance and its total density, bulk density and porosity were similar to values measured in natural bark. Furthermore, the structural characteristics of the studied film, namely specific surface area (BET) and pore size distribution, as well as the performance of the water adsorption ability were investigated and discussed.
We consider a risk model in discrete time with dividends and capital injections. The goal is to maximise the value of a dividend strategy. We show that the optimal strategy is of barrier type. That is, all capital above a certain threshold is paid as dividend. A second problem adds tax to the dividends but an injection leads to an exemption from tax. We show that the value function fulfils a Bellman equation. As a special case, we consider the case of premia of size one. In this case we show that the optimal strategy is a two barrier strategy. That is, there is a barrier if a next dividend of size one can be paid without tax and a barrier if the next dividend of size one will be taxed. In both models, we illustrate the findings by de Finetti’s example.
Energiesprong (niederländisch für Energiesprung) ist ein innovatives Konzept für die energetische Sanierung von Wohngebäuden, das schnelle Umsetzung, Kostenreduktion, Nachhaltigkeit und Mieterfreundlichkeit verspricht. Energiesprong setzt auf industrielle Vorfertigung von Fassaden- und Dachelementen (serielle Sanierung) und den Einsatz von regenerativen Energien, um den sogenannten NetZero-Standard (entspricht dem Nullenergiehaus) zu erreichen. Ziel ist es, eine für alle Beteiligten attraktive Sanierung zu ermöglichen. Dies wird unter anderem über erheblich verkürzte Montagezeiten und warmmietenneutrale Refinanzierung angestrebt. Die dafür erforderlichen Kostensenkungen werden beim seriellen Sanieren durch die Automatisierung in der Produktion und Skaleneffekte in der Massenfertigung erreicht.
Im Rahmen dieser Arbeit soll das Konzept Energiesprong hinsichtlich der Anwendung auf Mehrfamilienhäuser betrachtet und kritisch hinterfragt werden. Dazu werden zuvorderst die politischen und praktischen Gründe umrissen, die die Notwendigkeit und das Potenzial von innovativen Ansätzen darstellen. Im zweiten Kapitel wird das Energiesprong-Konzept detailliert erläutert; neben den Innovationen im Plan und Bauverfahren werden die Besonderheiten der Gebäudehülle, der Anlagentechnik und des Energiekonzepts beschrieben. Darüber hinaus werden wirtschaftliche Aspekte und die Rolle der verschiedenen Akteure umrissen. Aus der Beschreibung gehen eine Vielzahl an Vorteilen hervor, die Energiesprong gegenüber konventionellen Sanierungsverfahren verspricht. Anschließend werden einige Punkte dieser zentralen Versprechen diskutiert und eine Grundlage für die Entwicklung von Kriterien zukünftiger Evaluationen entwickelt.
Das vorliegende Paper beschreibt die im Rahmen von Industrie 4.0 als Einkauf 4.0 be-zeichnete Digitalisierung der Einkaufsfunktion. Neben einer grundlegenden Einführung zu Industrie 4.0 und den Haupttreiber stellt das Paper die Auswirkungen der Digitalisie-rung auf den Einkauf vor.
Es werden generell die Möglichkeiten, Einkaufsfunktionen zu digitalisieren, eine Aus-wahl an Studien zu Kosteneinsparungen und der aktuelle Stand der Umsetzung bei Un-ternehmen dargestellt sowie die Erkenntnisse zum Einsatz von Digitalisierung im Ein-kauf zusammengefasst.
Das Praxis Paper basiert auf der Bachelorarbeit von Johannes Blechmann, die von No-vember 2019 bis Februar 2020 von Prof. Dr. Monika Engelen (TH Köln) und Sven Düs-ter (VOSS Automotive GmbH) betreut wurde.
Die Nutzung von Gamification zur Verbesserung der User Experience - Marktanalyse & Designfaktoren
(2020)
User Experience beschreibt die Wahrnehmungen und Reaktionen Benutzender zu einem System. Es umfasst die Gedanken und Emotionen, die Benutzende vor, während und nach der Nutzung eines Systems erfahren. In einer Zeit in der es zahlreiche digitale Systeme und Alternativen auf dem Markt zur Verfügung stehen, können sich voranging Systeme mit einer guten User Experience durchsetzen. Demnach kann User Experience als messbarer Erfolgsfaktor gesehen werden und dieses Verständnis darüber ist erforderlich für das Treffen von Designentscheidungen. Ziel dieser Arbeit ist es Aspekte aus Gamification, die zu einer Verbesserung der User Experience eines Systems beitragen, zu identifizieren und darzustellen. Bei Gamification handelt es sich um einen Gestaltungsprozess, der auf den Erfahrungen und Techniken des Game Designs basiert und die Gefühle und Motivationen von Menschen anspricht. Zur Ermittlung dieser Faktoren wurden mittels Literatur von, unter anderem, Huizinga und Chou relevante Aspekte spielerischen Verhaltens und grundlegende menschliche Motivationen betrachtet. Diese Erkenntnisse wurden zur Analyse der auf, dem Markt befindlichen, Systeme KptnCook und TooGoodToGo angewandt um relevante Design Faktoren zu ermitteln und darzustellen. Es wurde festgestellt, dass User Experience ein dreidimensionales Konstrukt bestehend aus den Faktoren ease-of-use, joy-of-use und purpose-of-use darstellt. Durch die Einbringung von Aspekten aus Gamification in ein System kann dieses gezielt auf die Vermittlung der Faktoren joy-of-use und purpose-of-use gestaltet und optimiert werden. Auf dieser Grundlage ist es empfehlenswert Gamification bei der Gestaltung von Systemen zu beachten um menschlichen Motivationen zur Nutzung eines Systems anzusprechen. Durch die Gestaltung mit Gamification können Benutzererlebnisse angefertigt werden, die unterhaltsam sind und Benutzende zu einer langfristigen Verwendung des Systems motivieren.
Pelleted biomass has a low, uniform moisture content and can be handled and stored cheaply and safely. Pellets can be made of industrial waste, food waste, agricultural residues, energy crops, and virgin lumber. Despite their many desirable attributes, they cannot compete with fossil fuel sources because the process of densifying the biomass and the price of the raw materials make pellet production costly.
Leaves collected from street sweeping are generally discarded in landfills, but they can potentially be valorized as a biofuel if they are pelleted. However, the lignin content in leaves is not high enough to ensure the physical stability of the pellets, so they break easily during storage and transportation. In this study, the use of eucalyptus kraft lignin as an additive in tree-leaf pellet production was studied. Results showed that when 2% lignin is added the abrasion resistance can be increased to an acceptable value. Pellets with added lignin fulfilled all requirements of European standards for certification except for ash content. However, as the raw material has no cost, this method can add value or contribute to financing continued sweeping and is an example of a circular economy scenario.
How Digital Strategy and Management Games Can Facilitate the Practice of Dynamic Decision-Making
(2020)
This paper examines how digital strategy and management games that have been initially designed for entertainment can facilitate the practice of dynamic decision-making. Based on a comparative qualitative analysis of 17 games—organized into categories derived from a conceptual model of decision-making design—this article illustrates two ways in which these games may be useful in supporting the learning of dynamic decision-making in educational practice:
(1) Players must take over the role of a decider and solve situations in which players must pursue different conflicting goals by making a continuous series of decisions on a variety of actions and measures; (2) three of the features of the games are considered to structure players’ practice of decision-making and foster processes of learning through the curation of possible decisions, the offering of lucid feedback and the modification of time. This article also highlights the games’ shortcomings, from an educational perspective, as players’ decisions are restricted by the numbers of choices they can make within the game, and certain choices are rewarded more than others. An educational application of the games must, therefore, entail a critical reflection of players’ limited choices inside a necessarily biased system.
Das vorliegende Praxis Paper ist in zwei Bereiche aufgeteilt. Zunächst wird der Prozess zur Veröffentlichung eines Buchs über Amazon dargestellt, während im zweiten Teil Erkenntnisse über die allgemeinen Grundlagen des erfolgreichen Verkaufs auf Amazon zusammengefasst werden. Es basiert auf der Bachelorarbeit von Herrn Christian Dam-bach, die von Juli 2020 bis Oktober 2020 von Prof. Dr. Monika Engelen betreut wurde.
Nach der Darstellung des Veröffentlichungsprozesses werden im weiteren Verlauf die Möglichkeiten der Suchmaschinenoptimierung auf der Produktseite gezeigt und die Suchmaschinenwerbung über Amazon Marketing Services (AMS) vorgestellt. Neben dem Controlling des Verkaufsverlaufs und des Kampagnenverlaufs, wird zunächst die Einrichtung einer Werbeanzeige erläutert und anschließend die verschiedenen Möglich-keiten der Optimierung dargestellt. Daraus werden dann allgemeine Erfolgsfaktoren für den Verkauf auf Amazon abgeleitet, die, über das Fallbeispiel hinaus, auf jegliche ange-botenen Produkte anwendbar sind.
Die Komplexität der Cybergefahr und die sich entwickelnde Natur des Risikos bringen vielfältige Herausforderungen bei der Gestaltung von Versicherungs-produkten, beim Underwriting, beim Risikomanagement und bei der Kumul-kontrolle mit sich - sowohl für Erst- als auch Rückversicherungsgesellschaften. Eine korrekte Cyberrisikobewertung ist daher unabdingbar und der richtige Ansatz muss stets weiterentwickelt werden. Insbesondere die Vielfältigkeit eines Cyberevents ist hierbei zu berücksichtigen.
In der Cyberversicherung liefert die Vergangenheit keine zuverlässigen Indizien für die Wahrscheinlichkeit eines Schadens; Risiken müssen mit aufwändigen Modellrechnungen simuliert werden. Für die Bewertung von Cyberrisiken könnte die künstliche Intelligenz (KI) von Vorteil sein, um Muster und Wahrscheinlichkeiten im Bereich des Risikotransfers einfacher und effizienter zu analysieren. Einen alternativen Lösungsansatz könnten parametrische Rückversicherungslösungen als Ergänzung zur klassischen Versicherung liefern. So kann eine parametrische Cyberdeckung mit einem definierten Trigger (z.B. mit Hilfe der DSGVO als Trigger) als Auslöser für Schadenzahlungen angeboten werden.
Für eine ausreichende Versicherbarkeit von kleinen und mittelständischen Unternehmen, als auch für größere Industrielösungen könnte eine Risk Pooling Facility geschaffen werden, in welcher sich der traditionelle Rückversiche-rungsmarkt zusammen mit den Insurance Linked Securities Markt die Schadenbelastung teilen. Durch Unterstützung der künstlichen Intelligenz und durch parametrische Trigger (z.B. durch die DSGVO) könnten Schadenverläufe effizienter und zielgerichteter erfolgen.
Durch parametrische Cyberdeckungen könnten Transparenzprobleme bei der Schadenabwicklung verhindert und aufwendige Prüfungen der Rückversicherer reduziert werden. Zudem könnte mit Hilfe einer möglichen KI-Strategie die Bewertungen von Cyberrisiken vereinfacht und effizienter gestaltet werden. Parametrische Cyberlösungen können auch für alternatives Kapital interessant sein, denn auch im NatCat-Bereich sind Vehikel mit solchen Trigger-Lösungen verbreitet.
This bachelor thesis addresses the issue of how school resilience can be measured and assessed quantitatively. Schools as social infrastructures have a significant value for society. Yet, on a global scale, they, and therefore the respective community as well, are continuously endangered by a variety of threats such as natural disasters or violence and mental abuse affecting students, parents and school staff. However, these threats differ greatly depending on climatic and geographical conditions as well as on the socio-cultural context of the corresponding community. To strengthen school resilience against potential threats and to ensure education continuity despite the occurrence of these disruptions, a methodology is developed to measure and assess school resilience in conjunction with its specific circumstances. Initially, qualitative and quantitative (composite) indicators are identified and categorised with the help of a Systematic Literature Review and Mayring's Qualitative Content Analysis. These are subsequently developed into a Comprehensive Index for School Resilience (CISR). Building on this, a pre-existing assessment methodology, which uses Likert-Scales arranged in questionnaires to assign quantitative values to the composite indicators, is adapted to operationalise the CISR and by an exemplary application at Europaschule Troisdorf, the methodology is adapted to the socio-cultural conditions in Germany using an expert’s operational and contextual knowledge. The results obtained show that the methodologies and techniques described in current international research can, after an appropriate adaptation, successfully be applied to schools in Germany as well. Nevertheless, by identifying research limitations and errors as well as potential improvements, it is evident that further research and development is needed to provide stakeholders with a decision-making tool to strengthen the resilience of schools in the future, such as an exhaustive supplement to the CISR or the integration of more precise quantification methodologies and techniques.
With Google’s Flutter framework continuing to grow in popularity for companies and developers alike, the need for an understanding of how to utilize the framework in a large-scale context has become more relevant than ever. The purpose of this thesis is to document the crucial steps most development teams using Flutter in a large-scale application will face. Additionally, a fully documented, large-scale reference application was generated so that other developers may use it as an aid when creating their own Flutter projects on a similar scale. Multiple steps were taken to ensure that optimal solutions were chosen for each aspect of the development process. For each of those aspects, a wide range of possible solutions were explored, compared and analysed. Finally, one of the possible solutions was chosen based on a wide range of scientific papers and community-generated sources. Additionally, an interview with an expert in the field was conducted to further validate those decisions. After the application was fully implemented, ten crucial aspects of the development process were identified. Those ten aspects are now explained in detail in this thesis. Ultimately, the knowledge provided by this thesis can act as a map for peers using Flutter in a large-scale context and help them overcome the crossroads they will most likely come to face.
At the case study of the city of Cologne and the neighbouring Rhein‐Erft‐Kreis (a county), selected resilience aspects of critical infrastructure (CI) and cascading effects are analysed concerning major river floods. Using a Geographic Information System, the applicability of the approach is demonstrated using open source software and data, augmented by manual entries. This study demonstrates the feasibility and limitations of analysing lifeline features of interest for disaster risk and emergency management such as roads, bridges and electricity supply. By highlighting interdependencies of emergency services with CI such as roads, cascading effects of interconnected paths are shown. The findings indicate that in an extreme event flood scenario over 2,000 km of roads and eight bridges will be exposed to floods in the area of the rivers Rhine and Erft. This places huge demands on disaster and emergency management institutions and people affected and limits their resiliency.
The Enhancement of standard dense phase carbon dioxide (DPCD) pasteurization by additional mechanical effects wasassessed in this work. These effects were induced during pasteurization by the sudden depressurization in a narrow mini-tube. The high flow velocities, moderate pressures (40–80 bar) and low temperatures (25–45°C) lead to intense degasifica-tion and shear stress. The inactivation of the test microorganismEscherichia coliDH5a(E. coliDH5a) was determinedbefore and after depressurization in the minitube, representing entirely chemical DPCD via dissolved CO2and total inacti-vation comprising the effects of dissolved CO2and mechanical effects, respectively. Compared to conventional DPCDpasteurization, which is mostly attributed to chemical effects, the additional mechanical effects increased the inactivationefficiency considerably.
This article explores the relationship between digital transformation and disaster risk.Vulnerability studies aim at differentiating impacts and losses by using fine-grained information fromdemographic, social, and personal characteristics of humans. With ongoing digital development,these characteristics will transform and result in new traits, which need to be identified andintegrated. Digital transformations will produce new social groups, partly human, semi-human,or non-human—some of which already exist, and some which can be foreseen by extrapolating fromrecent developments in the field of brain wearables, robotics, and software engineering. Thoughinvolved in the process of digital transformation, many researchers and practitioners in the field ofDisaster Risk Reduction or Climate Change Adaptation are not yet aware of the repercussions fordisaster and vulnerability assessments. Emerging vulnerabilities are due to a growing dependency ondigital services and tools in the case of a severe emergency or crisis. This article depicts the differentimplications for future theoretical frameworks when identifying novel semi-human groups and theirvulnerabilities to disaster risks. Findings include assumed changes within common indicators of socialvulnerability, new indicators, a typology of humans, and human interrelations with digital extensionsand two different perspectives on these groups and their dependencies with critical infrastructure.
This paper introduces CAAI, a novel cognitive architecture for artificial intelligence in cyber-physical production systems. The goal of the architecture is to reduce the implementation effort for the usage of artificial intelligence algorithms. The core of the CAAI is a cognitive module that processes the user’s declarative goals, selects suitable models and algorithms, and creates a configuration for the execution of a processing pipeline on a big data platform. Constant observation and evaluation against performance criteria assess the performance of pipelines for many and different use cases. Based on these evaluations, the pipelines are automatically adapted if necessary. The modular design with well-defined interfaces enables the reusability and extensibility of pipeline components. A big data platform implements this modular design supported by technologies such as Docker, Kubernetes, and Kafka for virtualization and orchestration of the individual components and their communication. The implementation of the architecture is evaluated using a real-world use case. The prototypic implementation is accessible on GitHub and contains a demonstration.
In this paper we describe traffic sign recognition with neural networks in the frequency domain. Traffic signs exist in all countries to regulate the traffic of vehicles and pedestrians. Each country has its own set of traffic signs that are more or less similar. They consist of a set of abstract forms, symbols, numbers and letters, which are combined into different signs. Automatic traffic sign recognition is important for driver assistance systems and for autonomous driving. Traffic sign recognition is a subtype of image recognition. The traffic signs are usually recorded by a camera and must be recognized in real time, i.e. assigned to a class. We use neural networks for traffic sign recognition. The special feature of our method is that the traffic sign recognition does not take place in the spatial domain but in the frequency domain. This has advantages because it is possible to significantly reduce the number of neurons and thus the computing effort of the neural network compared to a conventional neural network.