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Willingness-to-pay for alternative fuel vehicle characteristics : a stated choice study for Germany
(2016)
In the light of European energy efficiency and clean air regulations, as well as an ambitious electric mobility goal of the German government, we examine consumer preferences for alternative fuel vehicles (AFVs) based on a Germany-wide discrete choice experiment among 711 potential car buyers. We estimate consumers’ willingness to-pay and compensating variation (CV) for improvements in vehicle attributes, also taking taste differences in the population into account by applying a latent class model with 6 distinct consumer segments. Our results indicate that about 1/3 of the consumers are oriented towards at least one AFV option, with almost half of them being AFV-affine, showing a high probability of choosing AFVs despite their current shortcomings. Our results suggest that German car buyers’ willingness-to-pay for improvements of the various vehicle attributes varies considerably across consumer groups and that the vehicle features have to meet some minimum requirements for considering AFVs. The CV values show that decision-makers in the administration and industry should focus on the most promising consumer group of ‘AFV aficionados’ and their needs. It also shows that some vehicle attribute improvements could increase the demand for AFVs cost-effectively, and that consumers would accept surcharges for some vehicle attributes at a level which could enable their private provision and economic operation (e.g. fast-charging infrastructure). Improvement of other attributes will need governmental subsidies to compensate for insufficient consumer valuation (e.g. battery capacity).
Today the optimization of metal forming processes is done using advanced simulation tools in a virtual process, e.g. FEM-studies. The modification of the free parameters represents the different variants to be analysed. So experienced engineers may derive useful proposals in an acceptable time if good initial proposals are available. As soon as the number of free parameters growths or the total process takes long times and uses different succeeding forming steps it might be quite difficult to find promising initial ideas. In metal forming another problem has to be considered. The optimization using a series of local improvements, often called a gradient approach may find a local optimum, but this could be far away from a satisfactory solution. Therefore non-deterministic approaches, e.g. Bionic Optimization have to be used. These approaches like Evolutionary Optimization or Particle Swarm Optimization are capable to cover a large range of high dimensional optimization spaces and discover many local optima. So the chance to include the global optimum increases when using such non-deterministic methods. Unfortunately these bionic methods require large numbers of studies of different variants of the process to be optimized. The number of studies tends to increase exponentially with the number of free parameters of the forming process. As the time for one single study might be not too small as well, the total time demand will be inacceptable, taking weeks to months even if high performance computing will be used. Therefore the optimization process needs to be accelerated. Among the many ideas to reduce the time and computer power requirement Meta- and Hybrid Optimization seem to produce the most efficient results. Hybrid Optimization often consists of global searches of promising regions within the parameter space. As soon as the studies indicate that there could be a local optimum, a deterministic study tries to identify this local region. If it shows better performance than other optima found until now, it is preserved for a more detailed analysis. If it performs worse than other optima the region is excluded from further search. Meta-Optimization is often understood as the derivation of Response Surfaces of the functions of free parameters. Once there are enough studies performed, the optimization is done using the Response Surfaces as representatives e.g. for the goal and the restrictions of the optimization problem. Having found regions where interesting solutions are to be expected, the studies available up to now are used to define the Response Surfaces. In many cases low degree polynomials are used, defining their coefficients by least square methods. Both proposals Hybrid Optimization and Meta-Optimization, sometimes used in combination often help to reduce the total optimization processes by large numbers of variants to be studied. In consequence they are highly recommended when dealing with time consuming optimization studies.
Die vorliegende Erfindung betrifft ein Verfahren zur Regelung einer Totzeit in einem Synchronwandler (100), in welchem ein zyklisches Schalten eines Steuerschalters (2) und eines Synchronschalters (3) erfolgen, wobei der Steuerschalter (2) mittels eines ersten Schaltsignals (S1) und der Synchronschalter (3) mittels eines zweiten Schaltsignals (S2) geschaltet werden. Das Verfahren umfasst ein Erfassen und Vorhalten eines Spannungswertes, welcher eine Spannung (VSW) über den Synchronschalter (3) zu einem bestimmten Zeitpunkt beschreibt, und ein Anpassen des ersten und/oder zweiten Schaltsignals (S1, S2) für einen folgenden Zyklus basierend auf dem vorgehaltenen Spannungswert.
Die Alterungsbeständigkeit von geschirmten Kabeln und Kontaktpaaren gewinnt angesichts des zunehmenden Einsatzes elektronischer softwarebasierter Steuerungen in Transportmitteln an Relevanz. Elektro- und Hybridantriebe sowie die Implementierung von Fahrassistenzsystemen bis hin zu autonom fahrenden Fahrzeugen führen zu komplexen Kabelbäumen mit einer großen Zahl von geschirmten Kabeln und Steckverbindern.
Um die Stabilität von Kontaktsystemen hinsichtlich ihrer Stabilität zu prüfen, werden Hochspannungskabel unterschiedlicher Hersteller und Dimensionierung für den Einsatz in Hybridfahrzeugen untersucht. Diese wurden mit Modellsteckern versehen, die die Schimung kontaktierten und hinreichend gewährleisteten.
Impedanz und Schirmwirkungsdämpfung wurden an thermisch belasteten Kabeln und Kontaktpaaren vergleichend zu Neuteilen untersucht. Der Einfluss der in Anlehnung an die LV 214 induzierten thermischen Alterung auf das frequenzabhängige Übertragungsprofil sowie den Gesamtstreuverlust wurde messtechnisch ermittelt. Zusätzlich wurden die Alterungseffekte an den Leitungsmaterialien mittels moderner bildgebender Analytik dokumentiert.
Instead of waiting for and constantly adapting to details of political interventions, utilities need to focus on their environment from a holistic perspective. The unique position of the company - be it a local utility, a bigger player, or an international utility specializing in specitic segments - has to be the basis of goals and strategies. But without consistent translation of these goals and strategies into processes, structures, and company culture, a strategy remains pure theory. Companies need to engage in a continuing learning process. This means being willing to pass on strategies, to slow down or speed up, to work from a different angle etc.
Virtual prototyping of integrated mixed-signal smart sensor systems requires high-performance co-simulation of analog frontend circuitry with complex digital controller hardware and embedded real-time software. We use SystemC/TLM 2.0 in conjunction with a cycle-count accurate temporal decoupling approach (TD) to simulate digital components and firmware code execution at high speed while preserving clock-cycle accuracy and, thus, real-time behavior at time quantum boundaries. Optimal time quanta ensuring real-time capability can be calculated and set automatically during simulation if the simulation engine has access to exact timing information about upcoming inter-process communication events. These methods fail in the case of non-deterministic, asynchronous events, resulting in potentially invalid simulation results. In this paper, we propose an extension to the case of asynchronous events generated by blackbox sources from which a priori event timing information is not available, such as coupled analog simulators or hardware in the loop. Additional event processing latency or rollback effort caused by temporal decoupling is minimized by calculating optimal time quanta dynamically in a SystemC model using a linear prediction scheme. We analyze the theoretical performance of the presented predictive temporal decoupling approach (PTD) by deriving a cost model that expresses the expected simulation effort in terms of key parameters such as time quantum size and CPU time per simulation cycle. For an exemplary smart-sensor system model, we show that quasi-periodic events that trigger activities in TD processes are handled accurately after the predictor has settled.
Optimization-based analog layout automation does not yet find evident acceptance in the industry due to the complexity of the design problem. This paper presents a Self-organized Wiring and Arrangement of Responsive Modules (SWARM), able to consider crucial design constraints both implicitly and explicitly. The flexibility of algorithmic methods and the expert knowledge captured in PCells combine into a flow of supervised module interaction. This novel approach targets the creation of constraint-compliant layout blocks which fit into a specified zone. Provoking a synergetic self-organization, even optimal layout solutions can emerge from the interaction. Various examples depict the power of that new concept and the potential for future developments.
Despite 30 years of Electronic Design Automation, analog IC layouts are still handcrafted in a laborious fashion today due to the complex challenge of considering all relevant design constraints. This paper presents Self-organized Wiring and Arrangement of Responsive Modules (SWARM), a novel approach addressing the problem with a multi-agent system: autonomous layout modules interact with each other to evoke the emergence of overall compact arrangements that fit within a given layout zone. SWARM´s unique advantage over conventional optimization-based and procedural approaches is its ability to consider crucial design constraints both explicitly and implicitly. Several given examples show that by inducing a synergistic flow of self-organization, remarkable layout results can emerge from SWARM’s decentralized decision-making model.
The deterioration of the shielding performance of electromagnetic interference finger stock gaskets in a corrosive environment is investigated. The visualization of the real contact area shows a drastic reduction of the engaged active contact region between fingers and their mating surfaces in presence of corrosives residues. In fact, additional openings occur besides the “Tlike” holes due to the porous nature of gaskets. This leads to a strong degradation of the shielding effectiveness. Modified Bethe’s theory is used to estimate the equivalent circuit parameters while the shielding effectiveness in terms of ratio between two transfer functions is obtained upon applying the filter theory. Quantitative measurements carried out for different gasket types show a good agreement with calculated results, demonstrating thus the validity of the approach.
Die zunehmende erneuerbare Stromerzeugung erfordert Anstrengungen, um den damit verbundenen Angebotsschwankungen und der zusätzlichen Netzbelastung entgegen zu wirken. Eine dezentrale und am Bedarf orientierte Stromerzeugung mittels Kraft-Wärme-Kopplung (KWK) kann hier einen wesentlichen Beitrag leisten, um eine sichere und konstante Stromversorgung zu gewährleisten und die Netze zu entlasten. Zu diesem Zweck ist jedoch ein Steuerungssystem erforderlich, das die KWK-Anlagen in die Lage versetzt, sowohl die Deckung des Wärmebedarfs im Objekt aufrecht zu erhalten, als auch die elektrische Energie genau zu den Zeiten zu erzeugen, in denen sie benötigt wird. Die Entkopplung von Stromerzeugung und Deckung des Wärmebedarfs kann dabei über den standardmäßig vorhandenen Wärmespeicher erfolgen. Dieser stellt damit das zentrale Element der Gesamtanlage dar, für die das Steuerungssystem zur Eigenstromoptimierung im Rahmen des Forschungsvorhabens entwickelt und erprobt wurde.