Die 10 zuletzt veröffentlichten Dokumente
More and more often, spoken information must and should be available in written form. For this purpose, various transcription programs try to support the user with various conveniences when transcribing the source material. A variety of online services go one step further and provide a ready-to-use, automatically generated transcription for a fee. Since the fees can be very expensive for the individual user and the online services may not always be used for privacy reasons, the goal of this work is to implement an open offline alternative. This alternative should be an open source editor based on the open speech-to-text-engine DeepSpeech and should on one hand provide the user with an offline transcription and on the other hand support him in correcting it. To achieve this goal, first the traditional speech recognition and eventually DeepSpeech will be described. This is followed by the conception and implementation of the editor. Since this project is explicitly intended to be an open source project, the last part will take a closer look at the release.
The main scope of this work is to develop nano-carbon-based mixed matrix celluloseacetate membranes (MMMs) for the potential use in both gas and liquid separation processes. Forthis purpose, a variety of mixed matrix membranes, consisting of cellulose acetate (CA) polymerand carbon nanotubes as additive material were prepared, characterized, and tested. Multi-walledcarbon nanotubes (MWCNTs) were used as filler material and diacetone alcohol (DAA) as solvent.The first main objective towards highly efficient composite membranes was the proper preparationof agglomerate-free MWCNTs dispersions. Rotor-stator system (RS) and ultrasonic sonotrode (USS)were used to achieve the nanofillers’ dispersion. In addition, the first results of the application of thethree-roll mill (TRM) technology in the filler dispersion achieved were promising. The filler material,MWCNTs, was characterized by scanning electron microscopy (SEM) and liquid nitrogen (LN2)adsorption-desorption isotherms at 77 K. The derivatives CA-based mixed matrix membranes werecharacterized by tensile strength and water contact angle measurements, impedance spectroscopy,gas permeability/selectivity measurements, and water permeability tests. The studied membranesprovide remarkable water permeation properties, 12–109 L/m2/h/bar, and also good separationfactors of carbon dioxide and helium separations. Specifically, a separation factor of 87 for 10%He/N2feed concentration and a selectivity value of 55.4 for 10% CO2/CH4feed concentrationwere achieved.
The use of nematic liquid crystal (LC) mixtures for microwave frequency applicationspresents a fundamental drawback: many of these mixtures have not been properly characterizedat these frequencies, and researchers do not have an a priori clear idea of which behavior they canexpect. This work is focused on developing a new procedure for the extraction of the main parametersof a nematic liquid crystal: dielectric permittivity and loss tangent at 11 GHz under differentpolarization voltages; splay elastic constantK11, which allows calculation of the threshold voltage(Vth); and rotational viscosityγ11, which allows calculating the response time of any arbitrary device.These properties will be calculated by using a resonator-based method, which is implementedwith a new topology of substrate integrated transmission line. The LC molecules should be rotated(polarized) by applying an electric field in order to extract the characteristic parameters; thus,the transmission line needs to have two conductors and low electric losses in order to preserve theintegrity of the measurements. This method was applied to a well-known liquid crystal mixture(GT3-23002 from MERCK) obtaining the permittivity and loss tangent versus bias voltage curves,the splay elastic constant, and the rotational viscosity of the mixture. The results validate the viabilityof the proposed method.
Mental illnesses in adolescence and young adulthood are steadily increasing. Thus,mental disorders represent an individual and societal challenge and an enormous health economicburden, creating an urgent need for research and action. Mental health problems are omnipresent inthe life of young people and the internet is the first resource, which helps them to understand theirsituation. Young people with migration background often have more difficulties accessing health careservices. Digital technologies offer an ideal opportunity for a low-threshold platform that addressesthe needs of young people. The current project “GeKo:mental” aims to design a multilingual websitefor Cologne-based adolescents and young adults that will enable them to obtain comprehensiveinformation about mental illness and health, treatment options and first contact points. To designthis website, this study aims to find out what kind of health information is needed and how itshould best be presented. Nine focus group discussions with adolescents and young adults withand without migration background (N = 68) were conducted; the focus group discussions took placeat schools, in an association for social youth work and in an cultural association, which is linkedto a mosque in Cologne, Germany. A qualitative content analysis was conducted on the gatheredmaterial. The participants reported concrete challenges and needs. The results will form the basis forthe development and design of a website.
Hydrogen is nowadays in focus as an energy carrier that is locally emission free. Especiallyin combination with fuel-cells, hydrogen offers the possibility of a CO2neutral mobility, providedthat the hydrogen is produced with renewable energy. Structural parts of automotive componentsare often made of steel, but unfortunately they may show degradation of the mechanical propertieswhen in contact with hydrogen. Under certain service conditions, hydrogen uptake into the appliedmaterial can occur. To ensure a safe operation of automotive components, it is therefore necessary toinvestigate the time, temperature and pressure dependent hydrogen uptake of certain steels, e.g., todeduct suitable testing concepts that also consider a long term service application. To investigate thematerial dependent hydrogen uptake, a tubular autoclave was set-up. The underlying paper describesthe set-up of this autoclave that can be pressurised up to 20 MPa at room temperature and can beheated up to a temperature of 250◦C, due to an externally applied heating sleeve. The second focusof the paper is the investigation of the pressure dependent hydrogen solubility of the martensiticstainless steel 1.4418. The autoclave offers a very fast insertion and exertion of samples and thereforehas significant advantages compared to commonly larger autoclaves. Results of hydrogen chargingexperiments are presented, that were conducted on the Nickel-martensitic stainless steel 1.4418.Cylindrical samples 3 mm in diameter and 10 mm in length were hydrogen charged within theautoclave and subsequently measured using thermal desorption spectroscopy (TDS). The resultsshow how hydrogen sorption curves can be effectively collected to investigate its dependence ontime, temperature and hydrogen pressure, thus enabling, e.g., the deduction of hydrogen diffusioncoefficients and hydrogen pre-charging concepts for material testing.
Bridging Gaps in Minimum Humanitarian Standards and Shelter Planning by Critical Infrastructures
(2021)
Current agendas such as the Sendai Framework for Disaster Risk Reduction or the Sustain-able Development Goals are demanding more integration of disaster risk management into otherthematic fields and relevant sectors. However, certain thematic fields such as shelter planning andcritical infrastructure have not been integrated yet. This article provides an analysis of minimumhumanitarian standards contained in the well-known Sphere handbook. Gaps are identified forseveral critical infrastructure services. Moreover, guidance on how to derive infrastructure or lifelineneeds has been found missing. This article analyses the missing service supply and infrastructureidentification items and procedures. The main innovation is a more integrative perspective on infras-tructure that can improve existing minimum humanitarian standards. It can guide the provision ofinfrastructure services to various types for different hazard scenarios, hence make humanitarian aidand shelter planning more sustainable in terms of avoiding infrastructure or lifeline shortages.
Ghana suffers from frequent power outages, which can be compensated by off-grid energysolutions. Photovoltaic-hybrid systems become more and more important for rural electrificationdue to their potential to offer a clean and cost-effective energy supply. However, uncertainties relatedto the prediction of electrical loads and solar irradiance result in inefficient system control and canlead to an unstable electricity supply, which is vital for the high reliability required for applicationswithin the health sector. Model predictive control (MPC) algorithms present a viable option to tacklethose uncertainties compared to rule-based methods, but strongly rely on the quality of the forecasts.This study tests and evaluates (a) a seasonal autoregressive integrated moving average (SARIMA)algorithm, (b) an incremental linear regression (ILR) algorithm, (c) a long short-term memory (LSTM)model, and (d) a customized statistical approach for electrical load forecasting on real load data of aGhanaian health facility, considering initially limited knowledge of load and pattern changes throughthe implementation of incremental learning. The correlation of the electrical load with exogenousvariables was determined to map out possible enhancements within the algorithms. Results showthat all algorithms show high accuracies with a median normalized root mean square error (nRMSE)<0.1 and differing robustness towards load-shifting events, gradients, and noise. While the SARIMAalgorithm and the linear regression model show extreme error outliers of nRMSE >1, methods viathe LSTM model and the customized statistical approaches perform better with a median nRMSE of0.061 and stable error distribution with a maximum nRMSE of <0.255. The conclusion of this study isa favoring towards the LSTM model and the statistical approach, with regard to MPC applicationswithin photovoltaic-hybrid system solutions in the Ghanaian health sector.
The majority of Niger ’s population faces a widespread lack of access to electricity. Althoughthe country lies in the Sahara belt, exploitation of solar energy is so far minimal. Due to ongoing fossilfuel exploration in the country, this fuel might dominate the future electricity supply. Today, Nigerimports the most of its electricity from Nigeria. There is a need to expand electricity generation andsupply infrastructures in Niger. When doing so, it is important to choose a proper set of electricitygeneration resource/technology that fulfils sustainability criteria. Thus, the objective of this work isto analyze a methodology in order to assess different energy technologies for Niger. A multi-criteriadecision approach was selected to assess the most accessible energy system for the country. Forthis purpose, indicators were developed and weighted for ranking electricity generation options.Altogether 40 indicators are selected under six dimensions (availability, risk, technology, economics,environment and social) to assess eight different alternatives, considering the aggregated results andcorresponding scores under each dimension. A merit list of technology and resources for electricitygeneration presented in this work could support the stakeholders in their decision-making for furtherprojects implementation in the country.
Das Ziel dieser Bachelorarbeit besteht in der Konzeption und Umsetzung eines CSS-Frameworks auf der Basis von Disneys zwölf Prinzipien der Animation. Dazu wird die folgende Forschungsfrage gestellt: Welche Relevanz haben Disneys zwölf Prinzipien der Animation im Kontext von UI-Animationen und wie lassen sie sich auf Elemente im Bereich Web umsetzen? Um diese Forschungsfrage zu beantworten, wurden die Prinzipien analysiert und in einem UI/UX-Kontext betrachtet. Dabei wurden potenzielle Einsatzmöglichkeiten für die Verwendung der Prinzipien und deren mögliche Auswirkungen auf die User Experience beschrieben. Um zu demonstrieren, wie eine Umsetzung der Prinzipien für gängigeElemente im Web aussehen könnte, wurde die Konzeption und Implementierung eines CSS-Frameworks durchgeführt. Dabei konnte festgestellt werden, welche Prinzipien für UI-Animationen geeignet oder ungeeignet sind und wie diese mithilfe von CSS und JavaScript implementiert werden köonnen. Schlagwörter: Animation, User Experience, Design, Web Development
Die Kölner Forschungsstelle Rückversicherung analysiert die aktuellen Entwicklungen des Rückversicherungsmarktes und begleitet diese gegebenenfalls durch Forschungsprojekte.
Dabei verbindet die Forschungsstelle RV ihre Forschungsaktivitäten mit der Rückversicherungspraxis. Das Jahr 2020 war vor allem durch die weltweite Pandemie Covid-19 geprägt. Es ergaben sich sowohl allgemein als auch speziell für die (Rück-) Versicherungswirtschaft zahlreiche substanzielle Herausforderungen. Natürlich war auch die Kölner Forschungsstelle Rückversicherung durch die vielen Veranstaltungsausfälle beziehungsweise deren behelfsmäßige Durchführung in Online-Formaten in dem Austausch sowie dem bidirektionalem Wissenstransfer mit der Praxis stark beeinträchtigt. Insbesondere der Ausfall des 17. Kölner Rückversicherungs-Symposiums hat uns sehr geschmerzt. Die 13. Jahrestagung des Förderkreises Rückversicherung war in dem gewählten Online-Format durchaus geglückt- aber natürlich möchten wieder so bald wie möglich zu der traditionellen Veranstaltungsform im Clostermannshof zurückkehren. Ein voller Erfolg war mit 178 Teilnehmern dagegen die von der Forschungsstelle RV ausgerichtete Webinar-Reihe zu
der EIOPA Initiative bzgl. der Risk Mitigation Techniques, die die Effekte von Rückversicherung unter Solvency II verändern könnte.
In der Kölner Forschungsstelle Rückversicherung sind derzeit zwölf Mitarbeiter*innen beschäftigt. Sämtliche Personal-, Sach- und Reisekosten der Forschungsstelle
RV werden vollständig aus Drittmitteln des Förderkreises Rückversicherung finanziert.
Die Forschungsarbeit sowie die Kommunikation und Kooperation zwischen den Mitarbeiter*innen der Forschungsstelle RV war durch die besonderen Umstände kaum eingeschränkt. Da die meisten Mitarbeiter*innen ohnehin nicht in Köln leben und arbeiten, war für diese das Remote- und Online-Arbeiten bereits vor den Corona-
Zeiten die Regel. Auch für die weiteren Mitarbeiter*innen gelang der Übergang ins Home Office (nahezu) reibungslos.
Wie in jedem Jahr gilt unser Dank dem Förderkreis Rückversicherung, der Hochschulleitung und -verwaltung sowie dem Institut für Versicherungswesen für die Unterstützung unserer Forschungsarbeit.