Network-Induced Oscillatory Behavior in Material Flow Networks

Network theory is rapidly changing our understanding of complex systems, but the relevance of topological features for the dynamic behavior of metabolic networks, food webs, production systems, information networks, or cascade failures of power grids remains to be explored. Based on a simple model of supply networks, we offer an interpretation of instabilities and oscillations observed in biological, ecological, economic, and engineering systems. We find that most supply networks display damped oscillations, even when their units - and linear chains of these units - behave in a non-oscillatory way. Moreover, networks of damped oscillators tend to produce growing oscillations. This surprising behavior offers, for example, a new interpretation of business cycles and of oscillating or pulsating processes. The network structure of material flows itself turns out to be a source of instability, and cyclical variations are an inherent feature of decentralized adjustments.Comment: For related work see http://www.helbing.or

Verbesserung von Cloud Sicherheit mithilfe von vertrauenswürdiger Ausführung

The increasing popularity of cloud computing also leads to a growing demand for security guarantees in cloud settings. Cloud customers want to be able to execute sensitive data processing in clouds only if a certain level of security can be guaranteed to them despite the unlimited power of the cloud provider over her infrastructure. However, security models for cloud computing mostly require the customers to trust the provider, its infrastructure and software stack completely. While this may be viable to some, it is by far not to all customers, and in turn reduces the speed of cloud adoption. In this thesis, the applicability of trusted execution technology to increase security in a cloud scenario is elaborated, as these technologies are recently becoming widespread available even in commodity hardware. However, applications should not naively be ported completely for usage of trusted execution technology as this would affect the resulting performance and security negatively. Instead they should be carefully crafted with specific characteristics of the used trusted execution technology in mind. Therefore, this thesis first comprises the discussion of various security goals of cloud-based applications and an overview of cloud security. Furthermore, it is investigated how the ARM TrustZone technology can be used to increase security of a cloud platform for generic applications. Next, securing standalone applications using trusted execution is described at the example of Intel SGX, focussing on relevant metrics that influence security as well as performance of such an application. Also based on Intel SGX, in this thesis a design of a trusted serverless cloud platform is proposed, reflecting the latest evolution of cloud-based applications.Die steigende Popularität von Cloud Computing führt zu immer mehr Nachfrage und auch strengeren Anforderungen an die Sicherheit in der Cloud. Nur wenn trotz der technischen Möglichkeiten eines Cloud Anbieters über seine eigene Infrastruktur ein entsprechendes Maß an Sicherheit garantiert werden kann, können Cloud Kunden sensible Daten einer Cloud Umgebung anvertrauen und diese dort verarbeiten. Das vorherrschende Paradigma bezüglich Sicherheit erfordert aktuell jedoch zumeist, dass der Kunde dem Cloud Provider, dessen Infrastruktur sowie den damit verbundenen Softwarekomponenten komplett vertraut. Während diese Vorgehensweise für manche Anwendungsfälle einen gangbaren Weg darstellen mag, ist dies bei Weitem nicht für alle Cloud Kunden eine Option, was nicht zuletzt auch die Annahme von Cloud Angeboten durch potentielle Kunden verlangsamt. In dieser Dissertation wird nun die Anwendbarkeit verschiedener Technologien für vertrauenswürdige Ausführung zur Verbesserung der Sicherheit in der Cloud untersucht, da solche Technologien in letzter Zeit auch in preiswerteren Hardwarekomponenten immer verbreiteter und verfügbarer werden. Es ist jedoch keine triviale Aufgabe existierende Anwendungen zur portieren, sodass diese von solch gearteten Technologien profitieren können, insbesondere wenn neben Sicherheit auch Effizienz und Performanz der Anwendung berücksichtigt werden soll. Stattdessen müssen Anwendungen sorgfältig unter verschiedenen spezifischen Gesichtspunkten der jeweiligen Technologie umgestaltet werden. Aus diesem Grund umfasst diese Dissertation zunächst eine Diskussion verschiedener Sicherheitsziele für Cloud-basierte Anwendungen und eine Übersicht über die Thematik "Cloud Sicherheit". Zunächst wird dann das Potential der ARM TrustZone Technologie zur Absicherung einer Cloud Plattform für generische Anwendungen untersucht. Anschließend wird beschrieben wie eigenständige und bestehende Anwendungen mittels vertrauenswürdiger Ausführung am Beispiel Intel SGX abgesichert werden können. Dabei wurde der Fokus auf relevante Metriken gesetzt, die die Sicherheit und Performanz einer solchen Anwendung beeinflussen. Zuletzt wird, ebenfalls basierend auf Intel SGX, eine vertrauenswürdige "Serverless" Cloud Plattform vorgestellt und damit auf aktuelle Trends für Cloud Plattformen eingegangen

On the growth performance of two competing species in an Andean pasture of southern Ecuador - monitoring and simulations

The megadiverse tropical mountain forests in the southeastern Andes of Ecuador, including their biodiversity and ecosystem services, are severely threatened due to climate warming and the clearing of forests to produce pasture land. The common local practice of recurrent burning for pasture rejuvenation has proven to be non-sustainable, since it enables bracken fern to invade pastures, causing farmers to abandon heavily infested pastures and instead clear new tracts of natural forest. No quantitative information on the growth potential of pasture grass and bracken fern under current and future environmental conditions has yet been available for the Andes of Ecuador. The scientific basis required to understand bracken invasion has yet to be established. This scientific basis would enable the development of sustainable pasture management strategies. Such strategies would, in turn, help protect the remnants of natural forest. Consequently, the present work aims at investigating the growth potential of two competing species under current and future climate conditions. Outcomes provide new knowledge and methodological developments concerning pasture invasion by bracken fern in southern Ecuador. The method entails the development of a new model, the Southern Bracken Competition Model (SoBraCoMo), realistically parameterized and validated. The model code is based on existing Soil Vegetation Atmosphere Transfer (SVAT) and vegetation dynamic models to calculate the potential growth of two main competitors, the southern bracken fern (Pteridium arachnoideum) and the pasture grass (Setaria sphacelata). Extensive field measurements and proper meteorological forcing delivered new site and species-specific parameters for realistic productivity simulations of both species. An experimental site was established to observe pasture and bracken fern development under the practice of recurrent burning, and to provide atmospheric data for a realistic forcing of the developed model. A novel balloon-borne monitoring system was developed to detect species cover and provided new insights into post-fire canopy recovery. The main results demonstrate that, under current environmental conditions, Setaria has a slightly higher competitive growth potential under undisturbed conditions (no grazing, trampling, or light competition). Furthermore, this growth advantage of Setaria should most likely increase due to global warming. Because field observations show bracken infestation, however, other factors than those investigated should be responsible for the bracken fern’s current success. The most likely cause of bracken success to be investigated in the future is cattle browsing; although browsing continuously removes aboveground biomass, this disruption of the upper soil does not affect deep roots and rhizomes of bracken plants. The newly developed SoBraCoMo can now provide an excellent basis to implement new mechanisms like browsing for future simulations

Cooking System

The invention refers to a cooking system, preferably cooking hob, more preferably induction hob

Localizing and prioritizing roof greening opportunities for urban heat island mitigation: insights from the city of Krefeld, Germany

Context: Climate change may increase the frequency, intensity, and occurrence of urban heat islands (UHI) in cities worldwide, often with harmful impacts on citizens. Strategic planning and implementation of multifunctional green roofs promises to help mitigating UHI effects, but cities often lack up-to-date scientific understanding of best-suited locations. Objectives: The aim of this paper is to develop and apply a socio-ecological approach to explore and prioritize present and prospective opportunity spaces for roof greening based on remote sensing data to mitigate UHI effects. Methods: The city of Krefeld, Germany, serves as a case study. The research design consists of three steps, applied to the conditions of 2019 and a 2030 scenario: (i) Examining residents’ vulnerability to heat, (ii) Assessing existing green roofs and potentials for greening, and (iii) Prioritizing opportunity spaces for roof greening to reduce UHI effects. Results: Findings showed that the area of high vulnerability due to combined high heat exposures and densities of sensitive residents in Krefeld accounts for almost 300 hectares in 2019 and may triple until 2030. More than 90% of evaluated horizontal roofs have no vegetation cover. Highest priority for roof greening is attributed to 59 ha and 113 ha of roofs in 2019 and 2030, respectively. Conclusions: The findings can inform strategic roof greening efforts for climate adaptation, e.g. for the extension of cadasters, and facilitate communication to increase understandings, public and policy support, and implementation

Do You Know Your Terms? - A Procedure Model for Terminology Management

Due to the extensive development und use of information technology, a lot of companies gained access to vast internal and external information sources. Yet nonetheless, efficiency when dealing with information and trying to find the right content is not on an appropriate level. Managing terms and classifying information has a long tradition in Knowledge Management, namely by the usage of glossaries and taxonomies as two instruments of Terminology Management. But even with today’s portals, search engines and auto-classifiers, it does not work without human interaction and high costs. Therefore, we propose a procedure model for Terminology Management to build up and maintain glossaries and taxonomies. To discover the evidence of our approach three action research cases have been analysed. The first focuses on the introduction of a glossary for a Swiss insurance company whereas the second case illustrates the initial activities and results for setting up a corporate taxonomy at an international professional services firm. Based on the learnings we developed a prototype (third case) which combines glossary and taxonomy for document classification and retrieval. We conclude that only a well suited trade-off between centralized and decentralized Terminology Management activities will be sustainable

Identification of subpopulations with characteristics of mesenchymal progenitor cells from human osteoarthritic cartilage using triple staining for cell surface markers

We first identified and isolated cellular subpopulations with characteristics of mesenchymal progenitor cells (MPCs) in osteoarthritic cartilage using fluorescence-activated cell sorting (FACS). Cells from osteoarthritic cartilage were enzymatically isolated and analyzed directly or after culture expansion over several passages by FACS using various combinations of surface markers that have been identified on human MPCs (CD9, CD44, CD54, CD90, CD166). Culture expanded cells combined and the subpopulation derived from initially sorted CD9(+), CD90(+), CD166(+ )cells were tested for their osteogenic, adipogenic and chondrogenic potential using established differentiation protocols. The differentiation was analyzed by immunohistochemistry and by RT-PCR for the expression of lineage related marker genes. Using FACS analysis we found that various triple combinations of CD9, CD44, CD54, CD90 and CD166 positive cells within osteoarthritic cartilage account for 2–12% of the total population. After adhesion and cultivation their relative amount was markedly higher, with levels between 24% and 48%. Culture expanded cells combined and the initially sorted CD9/CD90/CD166 triple positive subpopulation had multipotency for chondrogenic, osteogenic and adipogenic differentiation. In conclusion, human osteoarthritic cartilage contains cells with characteristics of MPCs. Their relative enrichment during in vitro cultivation and the ability of cell sorting to obtain more homogeneous populations offer interesting perspectives for future studies on the activation of regenerative processes within osteoarthritic joints

Kiel und die Hanse: Zur Hansegeschichtsschreibung am Historischen Seminar der Christian-Albrechts-Universität

Hansegeschichtsschreibung hat in Kiel Tradition. Seit knapp 170 Jahren und damit bereits vor der Einrichtung des Historischen Seminars an der Christian-Albrechts-Universität zu Kiel im Jahr 1872 setzen sich Historikerinnen und Historiker vor Ort mit dem Sujet Hanse auseinander. Dabei lässt sich die ganze Breite an unterschiedlichen, je nach Zeitgeist durchaus variierenden Forschungsperspektiven und -fragen, die in diesem Zeitraum an die Hanse herangetragen wurden, auch in Kiel wiederfinden: Die seinerzeit vorherrschende militär- und politikgeschichtliche Ausrichtung der kaiserzeitlichen Hansehistoriographie, lässt sich in Kiel genauso prominent beobachten, wie ihre folgenschwere, damals gleichwohl als innovativ auftretende völkisch-nationalistische Pervertierung in der Zwischenkriegszeit und im Nationalsozialismus. Aber auch mit Blick auf die internationale und methodenübergreifende Neuausrichtung der Hanseforschung nach dem Ende des Zweiten Weltkrieges und dem Fall des Eisernen Vorhangs spielte der Kieler Standort eine zentrale Rolle. Als wohl namhafteste Vertreter dieses Forschungsfeldes, die zugleich als Professoren zumindest einstweilen an der Kieler Förde ihre Wirkstätte gefunden hatten, lassen sich Ernst Robert Daenell, Friedrich Hermann Rörig und etwa Rolf Hammel-Kiesow benennen – sie alle haben die wissenschaftliche Erforschung der Hanse bis heute nachhaltig geprägt. Ziel des Aufsatzes ist es nun, die Hansegeschichtsschreibung in Kiel, ihre Ausgangspunkte und Fortentwicklung, bis in die Gegenwart zu analysieren und schließlich in die je eigenen Forschungsdiskurse einzubetten.Writing Hanseatic history has a long tradition in Kiel. Historians have been dealing with the subject of the Hanseatic League for almost 170 years, and thus already before the establishment of the History Department at Kiel University in 1872. The whole range of different research perspectives and questions posed on the Hanseatic League during this timeframe – varying according to the respective Zeitgeist – can also be found in Kiel: The predominant military and political-historical orientation of the Hanseatic historiography during the Kaiserzeit can be observed in Kiel just as prominently as its momentous völkisch-nationalist perversion during the interwar period and National Socialism, which, nevertheless, appeared innovative at the time. But beyond that Kiel also played a central role in the international and multi-methodological reorientation of Hanseatic research after the end of the Second World War and the fall of the Iron Curtain. Ernst Robert Daenell, Friedrich Hermann Rörig and Rolf Hammel-Kiesow can be named as the most renowned representatives of this field of research, who at the same time found their place of work as professors, at least temporarily, at the Kieler Förde – they all have had a lasting influence on the scientific study of the Hanseatic League up to the present day. The essay aims to analyse the Hanseatic Historiography in Kiel, its starting points and further development, and finally to embed it in its own research discourses

Ausarbeitung der Monographie „Herba Anserinae“ sowie Ergänzungen zu den Monographien „Flos Croci“ und „Herba Herniariae“ für das Österreichische Arzneibuch (ÖAB)

Argentina anserina wird seit jeher mit sehr guten Erfolgen in der Volksmedizin, hauptsächlich bei gastrointestinalen Beschwerden und Dysmenorrhoe, verwendet. Dies geht aus zahlreichen Quellen und der VOLKDMED- Datenbank hervor. In der Expertenrunde des Österreichischen Arzneibuchs wurde die Aufnahme von Gänse-fingerkraut (Herba Anserinae) in das Österreichische Arzneibuch (ÖAB) beschlossen. Die Erstellung einer Monographie für Herba Anserinae war das vorherrschende Ziel der vorliegenden Diplomarbeit. Weiters sollte eine Ergänzung der Monographie von Crocus sativus, erstellt werden. Wobei eine Charakterisierung der gängigen Verfäl-schung von Flos Croci durch Carthamus tinctorius durchgeführt werden sollte. Darüber hinaus war eine Ergänzung der Monographie von Herba Herniariae das Ziel. Hierbei sollte ein spezifisches DC – System für Herba Herniariae erstellt werden. Die bei dieser Arbeit verwendeten Methoden zur Prüfung auf Identität, Reinheit und Gehalt, sowie die Reagenzien entsprachen aus Gründen der Anpassung allesamt den Vorschriften des Europäischen Arzneibuches. Zur Erstellung von geeigneten Grenzwerten für die neue ÖAB – Monographie dien-ten die in dieser Arbeit experimentell ermittelten Werte.Since time immemorial Argentina anserina is used in folk medicine as a drug against gastrointestinal disorders and dysmenorrhoea. This arises from numerous sources and the VOLKSMED – Database. For this purpose the commission of experts have come to the decision to include this herbal drug in the ÖAB. The outcome of this was the main theme of the diploma thesis in fact the creation of a new monography from Herba Anserinae for the ÖAB. Furthermore Carthamus tinctorius, which is a common adulteration of the very ex-pensive drug Crocus sativus, was reviewed and a validation rule as an addition for the new ÖAB – monography from Flos Croci was composed. In addition the goal of this paper was the development of a suitable DC – System which proofs the identity of Herba herniariae and completes the ÖAB – monography which is in process. The methods which were used to proof the identity, pureness and content as well as the reagents where taken from the European Pharmacopoeia so that a harmonisati-on of both pharmacopoeias is possible. To create capable maximum rates for the new monography the experimental data were taken from this paper