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- DFG Forschungsgruppe 2757 / Lokale Selbstregelungen im Kontext schwacher Staatlichkeit in Antike und Moderne (LoSAM) (6)
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Government support for green technologies and renewable energy in particular has become an integral cornerstone of economic policy for most industrialized economies. Due to competitive price determination and supposedly higher efficiency, auctions have in recent years widely succeeded feed-in-tariffs as the primary support instrument (del Rio & Linares, 2014; REN21, 2021). However, literature still struggles to produce causal evidence to validate mostly descriptive findings for efficiency gains. Yet, this evidence is needed as a foundation to provide robust recommendations to policy makers (Grashof et al., 2020). By utilizing a difference-in-differences approach, this paper provides such evidence for a German photovoltaic (PV) auctioning program which came into effect in 2015. Results for this natural experiment confirm that cost-effectiveness improved significantly while previous literature shows that capacity expansion remained high. Results additionally show that falling prices for PV panels were the primary driver of cost reductions and wages also exert high influence on support price. Input cost development therefore indeed strongly influences support level which was the aim with introducing competitive auctions. Interest rate development cannot be linked to support level development, most probably due to the low interest environment in considered period.
Sprachsensibilität als Unterrichtsmerkmal erweist sich als lohnend für alle Schüler*innen, unabhängig von Migrationshintergrund und (sonderpädagogischen) Förderbedarf. Diese Handreichung versteht sich als eine praktische Annäherung an den Schnittbereich von Mehrsprachigkeit und dem Förderschwerpunkt emotionale und soziale Entwicklung. Zum einen sollen die Bezüge und Gemeinsamkeiten der beiden betreffenden Bereiche geklärt werden (Teil I), zum anderen bieten zahlreiche Methoden, Ideen zur Umsetzung und Materialien bereits praxisgeeignete Vorschläge zum Umgang mit sprachlicher Heterogenität (Teil II). Der vorliegende, zweite Teil stellt demnach die Materialsammlung dar und baut auf dem ersten Teil direkt auf. Entstehungshintergründe und die wissenschaftliche Legitimation zu Inhalt und Aufbau können demnach in diesem nachgelesen werden. Die zahlreichen Methoden, Umsetzungsideen und Materialien sind als schon praxisgeeignete Vorschläge zum Umgang mit sprachlicher Heterogenität zu verstehen. Es dient für alle pädagogischen Fachkräfte als Inspiration und kann als Grundlage für die eigene Arbeit mit Kindern und Jugendlichen verwendet werden.
Sprachsensibilität als Unterrichtsmerkmal erweist sich als lohnend für alle Schüler*innen, unabhängig von Migrationshintergrund und (sonderpädagogischen) Förderbedarf. Diese Handreichung versteht sich als eine theoretische Annäherung an den Schnittbereich von Mehrsprachigkeit und dem Förderschwerpunkt emotionale und soziale Entwicklung. Zum einen sollen die Bezüge und Gemeinsamkeiten der beiden betreffenden Bereiche geklärt werden (Teil I), zum anderen bieten zahlreiche Methoden, Ideen zur Umsetzung und Materialien bereits praxisgeeignete Vorschläge zum Umgang mit sprachlicher Heterogenität (Teil II). Der vorliegende, erste Teil stellt die theoretische Fundierung dar.
International trade is highly imbalanced both in terms of values and in terms of embodied carbon emissions. We show that the persistent current value trade imbalance patterns contribute to a higher level of global emissions compared to a world of balanced international trade. Specifically, we build a Ricardian quantitative trade model including sectoral input-output linkages, trade imbalances, fossil fuel extraction, and carbon emissions from fossil fuel combustion and use this framework to simulate counterfactual changes to countries' trade balances. For individual countries, the emission effects of removing their trade imbalances depend on the carbon intensities of their production and consumption patterns, as well as on their fossil resource abundance. Eliminating the Russian trade surplus and the US trade deficit would lead to the largest environmental benefits in terms of lower global emissions. Globally, the simultaneous removal of all trade imbalances would lower world carbon emissions by 0.9 percent or 295 million tons of carbon dioxide.
In network research, reproducibility of experiments is not always easy to achieve. Infrastructures are cumbersome to set up or are not available due to vendor-specific devices. Emulators try to overcome those issues to a given extent and are available in different service models. Unfortunately, the usability of emulators requires time-consuming efforts and a deep understanding of their functionality. At first, we analyze to which extent currently available open-source emulators support network configurations and how user-friendly they are. With these insights, we describe, how an ease-to-use emulator is implemented and may run as a Network Emulator as a Service (NEaaS). Therefore, virtualization plays a major role in order to deploy a NEaaS based on Kathará.
Service orchestration requires enormous attention and is a struggle nowadays. Of course, virtualization provides a base level of abstraction for services to be deployable on a lot of infrastructures. With container virtualization, the trend to migrate applications to a micro-services level in order to be executable in Fog and Edge Computing environments increases manageability and maintenance efforts rapidly. Similarly, network virtualization adds effort to calibrate IP flows for Software-Defined Networks and eventually route it by means of Network Function Virtualization. Nevertheless, there are concepts like MAPE-K to support micro-service distribution in next-generation cloud and network environments. We want to explore, how a service distribution can be improved by adopting machine learning concepts for infrastructure or service changes. Therefore, we show how federated machine learning is integrated into a cloud-to-fog-continuum without burdening single nodes.
In recent years, satellite communication has been expanding its field of application in the world of computer networks. This paper aims to provide an overview of how a typical scenario involving 5G Non-Terrestrial Networks (NTNs) for vehicle to everything (V2X) applications is characterized. In particular, a first implementation of a system that integrates them together will be described. Such a framework will later be used to evaluate the performance of applications such as Vehicle Monitoring (VM), Remote Driving (RD), Voice Over IP (VoIP), and others. Different configuration scenarios such as Low Earth Orbit and Geostationary Orbit will be considered.
The introduction of new types of frequency spectrum in 6G technology facilitates the convergence of conventional mobile communications and radar functions. Thus, the mobile network itself becomes a versatile sensor system. This enables mobile network operators to offer a sensing service in addition to conventional data and telephony services. The potential benefits are expected to accrue to various stakeholders, including individuals, the environment, and society in general. The paper discusses technological development, possible integration, and use cases, as well as future development areas.
In this work, we describe the network from data collection to data processing and storage as a system based on different layers. We outline the different layers and highlight major tasks and dependencies with regard to energy consumption and energy efficiency. With this view, we can outwork challenges and questions a future system architect must answer to provide a more sustainable, green, resource friendly, and energy efficient application or system. Therefore, all system layers must be considered individually but also altogether for future IoT solutions. This requires, in particular, novel sustainability metrics in addition to current Quality of Service and Quality of Experience metrics to provide a high power, user satisfying, and sustainable network.
How to Model and Predict the Scalability of a Hardware-In-The-Loop Test Bench for Data Re-Injection?
(2023)
This paper describes a novel application of an empirical network calculus model based on measurements of a hardware-in-the-loop (HIL) test system. The aim is to predict the performance of a HIL test bench for open-loop re-injection in the context of scalability. HIL test benches are distributed computer systems including software, hardware, and networking devices. They are used to validate complex technical systems, but have not yet been system under study themselves. Our approach is to use measurements from the HIL system to create an empirical model for arrival and service curves. We predict the performance and design the previously unknown parameters of the HIL simulator with network calculus (NC), namely the buffer sizes and the minimum needed pre-buffer time for the playback buffer. We furthermore show, that it is possible to estimate the CPU load from arrival and service-curves based on the utilization theorem, and hence estimate the scalability of the HIL system in the context of the number of sensor streams.
Cooperative, connected and automated mobility (CCAM) systems depend on a reliable communication to provide their service and more crucially to ensure the safety of users. One way to ensure the reliability of a data transmission is to use multiple transmission technologies in combination with redundant flows. In this paper, we describe a system requiring multipath communication in the context of CCAM. To this end, we introduce a data plane-based scheduler that uses replication and integration modules to provide redundant and transparent multipath communication. We provide an analytical model for the full replication module of the system and give an overview of how and where the data-plane scheduler components can be realized.
Cooperative, connected and automated mobility (CCAM) systems depend on a reliable communication to provide their service and more crucially to ensure the safety of users. One way to ensure the reliability of a data transmission is to use multiple transmission technologies in combination with redundant flows. In this paper, we describe a system requiring multipath communication in the context of CCAM. To this end, we introduce a data plane-based scheduler that uses replication and integration modules to provide redundant and transparent multipath communication. We provide an analytical model for the full replication module of the system and give an overview of how and where the data-plane scheduler components can be realized.
This paper gives an overview of our recent activities in the field of satellite communication networks, including an introduction to geostationary satellite systems and Low Earth Orbit megaconstellations. To mitigate the high latencies of geostationary satellite networks, TCP-splitting Performance Enhancing Proxies are deployed. However, these cannot be applied in the case of encrypted transport headers as it is the case for VPNs or QUIC. We summarize performance evaluation results from multiple measurement campaigns. In a recently concluded project, multipath communication was used to combine the advantages of very heterogeneous communication paths: low data rate, low latency (e.g., DSL light) and high data rate, high latency (e.g., geostationary satellite).
The first step towards aerial planetary exploration has been made. Ingenuity shows extremely promising results, and new missions are already underway. Rotorcraft are capable of flight. This capability could be utilized to support the last stages of Entry, Descent, and Landing. Thus, mass and complexity could be scaled down.
Autorotation is one method of descent. It describes unpowered descent and landing, typically performed by helicopters in case of an engine failure. MAPLE is suggested to test these procedures and understand autorotation on other planets. In this series of experiments, the Ingenuity helicopter is utilized. Ingenuity would autorotate a ”mid-air-landing” before continuing with normal flight. Ultimately, the collected data shall help to understand autorotation on Mars and its utilization for interplanetary exploration.
Lightning has fascinated humanity since the beginning of our existence. Different types of lightning like sprites and blue jets were discovered, and many more are theorized. However, it is very likely that these phenomena are not exclusive to our home planet. Venus’s dense and active atmosphere is a place where lightning is to be expected. Missions like Venera, Pioneer, and Galileo have carried instruments to measure electromagnetic activity. These measurements have indeed delivered results. However, these results are not clear. They could be explained by other effects like cosmic rays, plasma noise, or spacecraft noise. Furthermore, these lightning seem different from those we know from our home planet. In order to tackle these issues, a different approach to measurement is proposed. When multiple devices in different spacecraft or locations can measure the same atmospheric discharge, most other explanations become increasingly less likely. Thus, the suggested instrument and method of VELEX incorporates multiple spacecraft. With this approach, the question about the existence of lightning on Venus could be settled.
Um zu beweisen, daß Senecas Tragödien nicht aufführbar seien, hat Kugelmeier auf ihre zahlreichen Unstimmigkeiten und Widersprüche hingewiesen. Zum Beispiel begehe Phaedra Selbstmord über dem Leichnam des Hippolytus, als dieser noch gar nicht vorhanden ist. Für Kugelmeier werden diese Unstimmigkeiten allerdings, wenn der Text nur vorgelesen wird, infolge der „inneren Vergegenwärtigung“ nicht ernsthaft wahrgenommen. Die vorliegende Arbeit möchte genau das Gegenteil zeigen: Berücksichtigung dessen, was auf einer Bühne dargestellt werden kann und eindringliches Studium von Senecas Texten erweisen, daß die Tragödien aufführbar sind und nach Absicht Senecas auch für Aufführungen konzipiert wurden. In einer wohldurchdachten Aufführung verschwinden die von Kugelmeier behaupteten Schwierigkeiten.
Time-to-Live (TTL) caches decouple the occupancy of objects in cache through object-specific validity timers. Stateof- the art techniques provide exact methods for the calculation of object-specific hit probabilities given entire cache hierarchies with random inter-cache network delays. The system hit probability is a provider-centric metric as it relates to the origin offload, i.e., the decrease in the number of requests that are served by the content origin server. In this paper we consider a user-centric metric, i.e., the response time, which is shown to be structurally different from the system hit probability. Equipped with the state-of-theart exact modeling technique using Markov-arrival processes we derive expressions for the expected object response time and pave a way for its optimization under network delays.
Utilizing multiple access technologies such as 5G, 4G, and Wi-Fi within a coherent framework is currently standardized by 3GPP within 5G ATSSS. Indeed, distributing packets over multiple networks can lead to increased robustness, resiliency and capacity. A key part of such a framework is the multi-access proxy, which transparently distributes packets over multiple paths. As the proxy needs to serve thousands of customers, scalability and performance are crucial for operator deployments. In this paper, we leverage recent advancements in data plane programming, implement a multi-access proxy based on the MP-DCCP tunneling approach in P4 and hardware accelerate it by deploying the pipeline on a smartNIC. This is challenging due to the complex scheduling and congestion control operations involved. We present our pipeline and data structures design for congestion control and packet scheduling state management. Initial measurements in our testbed show that packet latency is in the range of 25 μs demonstrating the feasibility of our approach.
Die vorliegende Arbeit gibt einen Überblick über die bisher noch kaum evaluierte Wirkung arbeitsmarktzentrierter Integrationsmaßnahmen auf die Arbeitsmarkintegration von Geflüchteten in Deutschland. Dazu wird, mit theoretischer Fundierung durch neoklassische (Humankapital- und Signaling-Theorie) sowie institutionelle (Akteurzentrierter Institutionalismus) Ansätze, eine Sekundärdatenanalyse auf Basis der ersten drei Befragungswellen der IAB-BAMF-SOEP-Befragung von Geflüchteten durchgeführt. Methodische Grundlage der Untersuchung stellt eine Fixed-Effects-Logit-Regression dar, mit welcher durch die Kontrolle unbeobachteter Heterogenität präzise Within-Schätzungen kausaler Zusammenhänge ermöglicht werden. Die Arbeit zeigt, dass sowohl die Wahrnehmung des arbeitsmarktzentrierten Beratungsangebots (Arbeitsmarktberatung der BA) als auch die Teilnahme an dem berufsbezogenen Sprachförderkurs (ESF-BAMF-Kurs) eine kausal positive Wirkung auf die Arbeitsmarktintegration aufweist. Ebenso geht aus den Analysen hervor, dass es die Wirkungsevaluation praxisorientierter Integrationsmaßnahmen (PerF, PerjuF, PerF-W und KompAS) aufgrund einer bis dato unzureichenden Datenlage zu vertagen gilt. Dennoch konnten somit in der Bundesrepublik Deutschland zwei hochwirksame arbeitsmarktzentrierte Maßnahmen identifiziert werden, mit welchen den Geflüchteten eine solide Integrationsbasis für den Arbeitsmarkt und damit auch für die Aufnahmegesellschaft bereitgestellt wird. Ein verstärkter Einsatz der Maß-nahmen sowie eine gezielte Förderung erscheinen insbesondere im Hinblick auf die mannigfaltigen Vorteile gelungener Integration anstrebenswert.
Civil society organizations only started to be considered a sector in the 1970s in the United States. Amitai Etzioni pioneered the use of the expression third sector, which became common in academic and political literature. However, in the United States, the non-profit sector concept gradually became more robust and was spread internationally based on the studies conducted by Lester Salomon and associated researchers.
The theory built on the concept of the non-profit sector is strongly related to the North American cultural context, marked by the tradition of philanthropy and volunteerism, but with little importance given to associative and cooperative organizations.
The non-profit sector is implicitly or explicitly conceived as part of the private sphere. In contrast, theoretical currents such as liberal communitarianism, the theories of cooperation, common goods, social capital, European social economy, and the Latin American solidarity economy highlight the primacy of cooperation in solving collective problems. These theories underpin the associative approach of the third sector and link it to the community, not to the market.
This paper argues that the associative approach is more appropriate for international studies on the third sector and the relevance of self-organization. The third sector, i.e., the set of organizations created and maintained by civil society, is the inheritor of the millennial associative tradition, including both entities whose values are compatible with the common good and those with particularistic values, authoritarian and contrary to human rights. The third sector is not entirely virtuous, but it is a vital sector for solving great human problems.