193 research outputs found

    Service composition based on SIP peer-to-peer networks

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    Today the telecommunication market is faced with the situation that customers are requesting for new telecommunication services, especially value added services. The concept of Next Generation Networks (NGN) seems to be a solution for this, so this concept finds its way into the telecommunication area. These customer expectations have emerged in the context of NGN and the associated migration of the telecommunication networks from traditional circuit-switched towards packet-switched networks. One fundamental aspect of the NGN concept is to outsource the intelligence of services from the switching plane onto separated Service Delivery Platforms using SIP (Session Initiation Protocol) to provide the required signalling functionality. Caused by this migration process towards NGN SIP has appeared as the major signalling protocol for IP (Internet Protocol) based NGN. This will lead in contrast to ISDN (Integrated Services Digital Network) and IN (Intelligent Network) to significantly lower dependences among the network and services and enables to implement new services much easier and faster. In addition, further concepts from the IT (Information Technology) namely SOA (Service-Oriented Architecture) have largely influenced the telecommunication sector forced by amalgamation of IT and telecommunications. The benefit of applying SOA in telecommunication services is the acceleration of service creation and delivery. Main features of the SOA are that services are reusable, discoverable combinable and independently accessible from any location. Integration of those features offers a broader flexibility and efficiency for varying demands on services. This thesis proposes a novel framework for service provisioning and composition in SIP-based peer-to-peer networks applying the principles of SOA. One key contribution of the framework is the approach to enable the provisioning and composition of services which is performed by applying SIP. Based on this, the framework provides a flexible and fast way to request the creation for composite services. Furthermore the framework enables to request and combine multimodal value-added services, which means that they are no longer limited regarding media types such as audio, video and text. The proposed framework has been validated by a prototype implementation

    Explaining and promoting participation in demand response programs: The role of rational and moral motivations among German energy consumers

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    Demand response programs aim to increase flexibility in electricity consumption. Yet, their success hinges on a sufficient level of consumer participation, which makes it important to understand the factors that motivate participation. Though it is often assumed that consumers participate in demand response programs for the potential financial benefits, these programs can also generate collective environmental benefits, such as an increase in the share of renewable energy. Consequently, we studied potential motivations that underlie individuals’ participation in demand response programs (indicated by their acceptance, interest, and intention to participate). By examining the role of specific beliefs about costs and benefits and the role of general personal motivations (i.e., financial, environmental, and innovation-seeking) for individuals’ participation in quota schemes (a novel type of incentive-based demand response), we found that both financial and environmental beliefs underlie participation. Moreover, compared to a personal financial motivation, a personal environmental motivation (and, to a lesser extent, an innovation-seeking motivation) was both more strongly related to participation and better able to explain favorable beliefs about participation. Furthermore, we experimentally manipulated different benefits and modes of participation (through frame manipulation) and found that emphasizing the environmental benefits of participation leads to stronger acceptance and interest in participating among those strongly motivated by the environment. Conversely, this tailoring effect does not exist among those strongly financially motivated when the financial benefits are emphasized. Additionally, participation was generally higher when participation was described as voluntary compared to mandatory. We discuss the theoretical and practical implications arising from these findings

    A Behavioral Science Perspective on Consumers’ Engagement With Demand Response Programs

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    Residential electricity demand response programs can play a substantial role in facilitating a sustainable energy transition, but it is important to examine the consumer behaviors necessary to harness this potential. We outline three behavioral dimensions relevant for effective demand response, namely investment, participation, and actual response. We discuss the factors that underpin them as well as possible behavioral interventions to promote demand response behaviors

    Consumer preferences for the design of a demand response quota scheme – Results of a choice experiment in Germany

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    Demand response (DR) programs are increasingly discussed as policy options to facilitate an efficient energy transition. More recently, quota schemes, a novel type of incentive-based DR program that aims to restrict electricity consumption of some household appliances at certain times, have received considerable attention as a tool for preventing local grid congestion. However, little is known about the preferences of household consumers regarding the design of DR programs in general and quota schemes in particular. We examined the preferences of 1034 German consumers using data from a choice experiment. Our model results show that respondents’ choices for quota scheme designs are mainly driven by the time period during which consumption is constrained, followed by the financial compensation. That said, the order of importance reverses if consumers are free to choose whether to participate or not, while the frequency and duration of DR measures remain unimportant. This shift in preferences suggests that preferences for certain DR programs may not necessarily translate into willingness to participate. Sociodemographic characteristics explain these preferences only to a limited extent, with female and older persons and persons currently purchasing green electricity showing a slightly higher willingness to participate. We discuss policy implications arising from these findings

    The limited potential of regional electricity marketing – Results from two discrete choice experiments in Germany

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    The German energy transition has led to a strong expansion of renewable energies in recent years. As a result, the German population is increasingly coming into contact with generation facilities. To increase local acceptance for new installations and to create new sales channels for energy suppliers, the legislature has established the “System for Guarantees of Regional Origin” in 2019, which allows the marketing of electricity from subsidized facilities as “electricity generated in the region”. However, regional electricity comes with additional costs on the procurement and sales side of energy suppliers, and it is unclear whether and to what extent consumers are willing to pay a premium for electricity generated regionally. This study investigates the willingness to pay (WTP) of residential customers based on two samples of 838 and 59 respondents, respectively. Our model results show that, on average, WTP for regional electricity generation is positive, especially among female, younger and better-educated customers, although differences in WTP between these sociodemographic characteristics are small. Factors that are more relevant are the current type of electricity tariff, differentiated into non-green and green, with the latter having a positive influence, but also the tariff switching behavior of the past, which is a proxy for price sensitivity. Although WTP is positive, it is severely limited, and only pertains to a subgroup of electricity customers. Hence, it is not surprising that our simulation shows that including a regional green electricity tariff in an energy supplier\u27s portfolio is likely to lead to product cannibalization, meaning that mainly green electricity customers will choose this tariff. From an energy supplier\u27s perspective, these results raise the question of whether offering a regional electricity tariff is economically viable. Future research could further investigate what underlying factors drive preferences for regionally generated electricity and how it can contribute to local acceptance

    Abnormal Cortical Network Activation in Human Amnesia: A High-resolution Evoked Potential Study

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    Little is known about how human amnesia affects the activation of cortical networks during memory processing. In this study, we recorded high-density evoked potentials in 12 healthy control subjects and 11 amnesic patients with various types of brain damage affecting the medial temporal lobes, diencephalic structures, or both. Subjects performed a continuous recognition task composed of meaningful designs. Using whole-scalp spatiotemporal mapping techniques, we found that, during the first 200ms following picture presentation, map configuration of amnesics and controls were indistinguishable. Beyond this period, processing significantly differed. Between 200 and 350ms, amnesic patients expressed different topographical maps than controls in response to new and repeated pictures. From 350 to 550ms, healthy subjects showed modulation of the same maps in response to new and repeated items. In amnesics, by contrast, presentation of repeated items induced different maps, indicating distinct cortical processing of new and old information. The study indicates that cortical mechanisms underlying memory formation and re-activation in amnesia fundamentally differ from normal memory processin

    Molybdenum-isotope signals and cerium anomalies in Palaeoproterozoic manganese ore survive high-grade metamorphism

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    Abstract Molybdenum (Mo) and its isotopes have been used to retrieve palaeoenvironmental information on the ocean–atmosphere system through geological time. Their application has so far been restricted to rocks least affected by severe metamorphism and deformation, which may erase or alter palaeoenvironmental signals. Environmental Mo-isotope signatures can be retrieved if the more manganese (Mn)-enriched rocks are isotopically depleted and the maximum range of ή98Mo values is close to the ~2.7‰ Mo-isotope fractionation known from Mo sorption onto Mn oxides at low temperature. Here, we show that the Morro da Mina Mn-ore deposit in Minas Gerais, Brazil, contains Mn-silicate–carbonate ore and associated graphitic schist that likely preserve ή98Mo of Palaeoproterozoic seawater, despite a metamorphic overprint of at least 600 °C. The extent of Mo-isotope fractionation between the Mn-silicate–carbonate ore and the graphitic schist is similar to modern Mn-oxide precipitates and seawater. Differences in ή98Mo signals are broadly reflected in cerium (Ce) anomalies, which suggest an oxic–anoxic-stratified Palaeoproterozoic ocean

    Stereoselective synthesis of trans-fused iridoid lactones and their identification in the parasitoid wasp Alloxysta victrix, Part II: iridomyrmecins

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    Abstract Following our earlier approach to the synthesis of dihydronepetalactones, all eight stereoisomers of trans-fused iridomyrmecins were synthesized starting from the enantiomers of limonene. Combined gas chromatography and mass spectrometry including enantioselective gas chromatography revealed that volatiles released by the endohyperparasitoid wasp Alloxysta victrix contain (4S,4aR,7S,7aR)-iridomyrmecin of 95-97% ee and stereochemically pure (4S,4aS,7R,7aS)-iridomyrmecin as a minor component. 125

    RegionalitÀt aus Sicht von Energieversorgungsunternehmen: Eine qualitative Inhaltsanalyse zu Regionalstrom in Deutschland

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    Anfang 2019 wurde beim Umweltbundesamt das Regionalnachweisregister ins Leben gerufen, mit dessen Hilfe Energieversorger die RegionalitĂ€t einer Stromlieferung gegenĂŒber ihren Kunden ausweisen können. Doch auch ohne Regionalnachweisregister wird teilweise mit der RegionalitĂ€t von Stromtarifen geworben. Dies wirft die Frage auf, wie Regionalstrom aus Sicht von Energieversorgern ökonomisch zu bewerten ist. Im Rahmen dieser Arbeit wurden Experteninterviews mit 17 Vertretern von Energieversorgungsunter-nehmen durchgefĂŒhrt. Es zeigt sich, dass viele Energieversorger dem Trend folgen, Regionalstrom anzu-bieten. Insbesondere sind laut Experten das Unternehmensimage kommunaler Energieversorger und die Produktaussagen von Regionalstrom stimmig. Dennoch sehen fast alle Interviewpartner Regionalstrom in seiner heutigen Form als Nischenprodukt, das es mit hoher Wahrscheinlichkeit auch bleiben wird. Die aktuelle Regulatorik, im Rahmen derer Regionalstrom als Premiumprodukt mit einem Aufpreis ggĂŒ. nicht regionalem Strom vertrieben wird, macht das Produkt fĂŒr viele Kunden unattraktiv

    RegionalitÀt aus Sicht von Energieversorgungs- und Direktvermarktungsunternehmen: Eine qualitative Inhaltsanalyse zu Regionalstrom in Deutschland

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    Anfang 2019 wurde beim Umweltbundesamt das Regionalnachweisregister ins Leben gerufen, mit dessen Hilfe Energieversorgungsunternehmen die RegionalitĂ€t einer Stromlieferung gegenüber ihren Kunden ausweisen können. Doch auch ohne Regionalnachweisregister wird teilweise mit der RegionalitĂ€t von Stromtarifen geworben. Dies wirft die Frage auf, wie Regionalstrom aus Sicht von Energieversorgungsunternehmen ökonomisch zu bewerten ist. Daran anschließend stellt sich die Frage, ob und inwieweit eine regionale Vermarktung von Erzeugung aus Erneuerbare Energien Anlagen für Anlagenbetreiber bzw. Direktvermarktungsunternehmen neue Erlösmöglichkeiten eröffnet. Im Rahmen dieser Arbeit wurden Experteninterviews mit 17 Vertretern von Energieversorgungsunternehmen (Stichprobe 1) und sechs Vertretern von Direktvermarktungsunternehmen (Stichprobe 2) durchgeführt. Es zeigt sich, dass viele Energieversorgungsunternehmen dem Trend folgen, Regionalstrom anzubieten. Insbesondere sind laut Experten das Unternehmensimage kommunaler Energieversorger und die Produktaussagen von Regionalstrom stimmig. Dennoch sehen fast alle Interviewpartner Regionalstrom in seiner heutigen Form als Nischenprodukt, das es mit hoher Wahrscheinlichkeit bleiben wird. Die aktuelle Regulatorik geht mit finanziellen Nachteilen für Anlagenbetreiber bzw. Direktvermarktungsunternehmen und Energieversorgungsunternehmen einher was dazu führt, dass Regionalstrom an Endkunden als Premiumprodukt mit einem Aufpreis ggü. nicht regionalem Strom vertrieben wird. Dies, in Kombination mit weiteren Hürden auf der Vertriebsseite (z.B. geringes Involvement), mache das Produkt für viele Kunden unattraktiv
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