Die 10 zuletzt veröffentlichten Dokumente
A test tool for Langton's ant-based algorithms is created. Among other things, it can create test files for the NIST-Statistical-Test-Suite. The test tool is used to investigate the invertibility, ring formation and randomness of 7 created models which are extensions of Langton’s ant. The models are examined to possibly use them as pseudo-random generator (PRG) or block cipher. All models use memories which are based on tori. This property is central, because this is how rings are formed in the first place and in addition the behavior of all models at the physical boundaries of the memory is clearly defined in this way. The different models have special properties which are also investigated. These include variable color sets, discrete convolution, multidimensionality, and the use of multiple ants, which are arranged fractal hierarchically and influence each other. The extensions convolution, multidimensional scalable and multidimensional scalable fractal ant colony are presented here for the first time. It is shown that well-chosen color sets and high-dimensional tori are particularly well suited as a basis for Langton's ant based PRGs. In addition, it is shown that a block cipher can be generated on this basis.
The Cologne Research Centre for Reinsurance analyses the latest developments in the reinsurance market and, where appropriate, monitors these through research projects. In the process, the Research Centre for Reinsurance links its research activities with practices in the reinsurance sector. The year 2020 was dominated by the global COVID-19 pandemic. There were numerous substantial challenges that arose not just in general but also for the (re-)insurance industry in particular. Naturally, interaction and practical, bidirectional knowledge transfer at the Cologne Research Centre for Reinsurance was also hard-hit by the many event cancellations and their makeshift relocation to online formats. We particularly regretted the cancellation of the 17th Cologne Reinsurance Symposium. The 13th Annual Meeting of the Sponsoring Group Reinsurance was quite a success in the chosen online format – but of course we would like to return to the traditional event format at Clostermannshof as soon as possible. A complete success, on the other hand, with 178 participants, was the webinar series hosted by the Research Centre for Reinsurance on the European Insurance and Occupational Pensions Authority (EIOPA) initiative on risk mitigation techniques that could alter the effects of reinsurance under Solvency II.
There are twelve people currently employed at the Cologne Research Centre for Reinsurance. All of the personnel, material and travel costs for the Research Centre for Reinsurance are fully financed by third-party funds provided by the Sponsoring Group Reinsurance. The special circumstances were scarcely an impediment to the research, communication and cooperation among the employees of the Research Centre for Reinsurance. As most employees do not live and work in Cologne, anyway, working from home and online had been the rule for them even before the coronavirus crisis hit. The transition to a setting working from home was (nearly) a smooth one for the other employees as well. As every year, we would like to express our appreciation to the Sponsoring Group Reinsurance, the University leadership and administration, and the Institute of Insurance Studies for their support of our research work.
Diese Veröffentlichung basiert auf einem Vortrag an dem Forschungsinstitut für Privatversicherungsrecht (Leitung Univ.-Prof. Dr. Michael Gruber) der Universität Salzburg am 7. Januar 2020. Zunächst erfolgte ein kurzer Überblick über die – aus juristischer Sicht vielleicht interessanten – Rückversicherungsaspekte von Solvency II. Anschließend wurden die Organisation und Durchführung von Schiedsgerichtsverfahren in der Rückversicherung erläutert sowie deren Vereinbarung in Rückversicherungsverträgen. Als ein fiktives Beispiel für Gerichts- und Schiedsgerichtsverfahren wurde die fehlende Vereinbarung des für die Rückversicherungsvertragsbeziehung geltenden Rechts gewählt. An dieser Fragestellung wurden die unterschiedlichen Vorgehensweisen eines Gerichts beziehungsweise eines Schiedsgerichtsverfahrens diskutiert. Insbesondere wären in den beiden Verfahren diametral entgegengesetzte Entscheidungen zu erwarten. Im Hauptteil des Vortrags wurden dann die Hurricane-Ereignisse Harvey, Irma und Maria („HIM“) in 2017 adressiert: Verlauf, Schäden, jeweilige Besonderheiten, unterschiedliche Kommunikation gegenüber Öffentlichkeit und Investoren durch einzelne Rückversicherer, Auswirkungen auf die Dividendenpolitik und vieles andere mehr. Danach wurde anhand der Schadenereignisse in den Folgejahren und der uneinheitlichen Renewals seit 2017 in Erst- und Rückversicherung sowie Retrozession die These plausibilisiert,dass der Rückversicherungszyklus spätestens seit HIM ausgesetzt ist. Zur Abrundung wurden die – ebenfalls uneinheitlichen – jeweiligen Entwicklungen von traditionaler Rückversicherung und dem Alternative Risk Transfer durch Insurance Linked Securities gegenübergestellt. Die Volatilität der Rückversicherungsmärkte wird die Akteure sicherlich auch weiterhin in Atem halten – und dem Beobachter die Möglichkeit zu Analyse und Kommentierung.
Die UN-Behindertenrechtskonvention (UN-BRK) und das gerade in der Umsetzung begriffene Bundesteilhabegesetz (BTHG) als Inklusions- und Teilhabestärkungs-Gesetz fordern eine individuelle und selbstbestimmte Lebensführung sowie die volle Teilhabe am Leben in der Gemeinschaft für psychisch-erkrankte Menschen. Gleichzeitig zeigen Ergebnisse aus Forschung und Wissenschaft, dass die Inklusion und Teilhabemöglichkeiten von schwer psychisch erkrankten Menschen noch weit hinter den gesteckten Zielen und Forderungen zurückliegen. Einen großen Anteil daran haben anhaltende Selbst- und Fremd-Stigmatisierungsprozesse, denen die Sozialpsychiatrie mit verschiedenen Ansätzen und Konzepten zu begegnen versucht. Da digitale Medien und Internetkommunikation heute einen wesentlichen Beitrag zur gesellschaftliche Teilhabe leisten und als Medien und Orte zur Informationsbeschaffung- und gabe, zu Begegnung und Kommunikation eine wichtige soziale Funktion erfüllen, sollte auch Soziale Arbeit die Nutzung digitaler Medien u.a. durch (Selbst-)Bildungskonzepte fördern, unterstützen und für die Anliegen ihrer Zielgruppen fruchtbar machen. Im Mittelpunkt der vorliegenden Arbeit steht daher die Entwicklung einer Projektkonzeption, die anhand einer konkreten Einrichtungssituation der Sozialpsychiatrie entworfen wird. Es handelt sich um ein Podcast-Projekt, das von Menschen mit einer psychischen Erkrankung geplant, durchgeführt und reflektiert wird.
Diese Arbeit soll eine Brücke schlagen zwischen dem Recht auf Teilhabe, dem Auftrag Sozialer Arbeit in Bezug auf die soziale Existenz des Menschen, den Folgen psychischer Erkrankungen und den Möglichkeiten digitaler Medien. Der Podcast als Beispiel eines modernen Kommunikationsformats im Internet dient dabei als das verbindende Medium.
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.