Expressiveness and Robustness of First-Price Position Auctions

Since economic mechanisms are often applied to very different instances of the same problem, it is desirable to identify mechanisms that work well in a wide range of circumstances. We pursue this goal for a position auction setting and specifically seek mechanisms that guarantee good outcomes under both complete and incomplete information. A variant of the generalized first-price mechanism with multi-dimensional bids turns out to be the only standard mechanism able to achieve this goal, even when types are one-dimensional. The fact that expressiveness beyond the type space is both necessary and sufficient for this kind of robustness provides an interesting counterpoint to previous work on position auctions that has highlighted the benefits of simplicity. From a technical perspective our results are interesting because they establish equilibrium existence for a multi-dimensional bid space, where standard techniques break down. The structure of the equilibrium bids moreover provides an intuitive explanation for why first-price payments may be able to support equilibria in a wider range of circumstances than second-price payments

10 Years of Object-Oriented Analysis on H1

Over a decade ago, the H1 Collaboration decided to embrace the object-oriented paradigm and completely redesign its data analysis model and data storage format. The event data model, based on the RooT framework, consists of three layers - tracks and calorimeter clusters, identified particles and finally event summary data - with a singleton class providing unified access. This original solution was then augmented with a fourth layer containing user-defined objects. This contribution will summarise the history of the solutions used, from modifications to the original design, to the evolution of the high-level end-user analysis object framework which is used by H1 today. Several important issues are addressed - the portability of expert knowledge to increase the efficiency of data analysis, the flexibility of the framework to incorporate new analyses, the performance and ease of use, and lessons learned for future projects.Comment: 14th International Workshop on Advanced Computing and Analysis Techniques in Physics Researc

Beitrag zum Vorkommen und Ausbreitung des Trauer-Rosenkäfers Oxythyrea funesta (Poda, 1761) (Coleoptera, Scarabaeidae) in Deutschland:: ein Citizen-Science-Projekt

Der auffällig gezeichnete Trauerrosenkäfer Oxythyrea funesta konnte sich in den letzten 30 Jahren in Mitteleuropa rasant ausbreiten und eignet sich auch deshalb als Modell für Citizen-Science-Projekte. Bei „kerbtier.de“ wurde 2019 ein Kartierungsprojekt gestartet, um die Art durch Fotos der Nutzer gezielt zu melden und die Ausbreitung in Deutschland besser zu dokumentieren. Es wurden insgesamt 1.345 Anfragen von 309 Nutzern ausgewertet. Unsere Ergebnisse bestätigen, dass Oxythyrea funesta mittlerweile aus allen Regionen Deutschlands nachgewiesen ist und in der südlichen Hälfte Deutschlands eine weit verbreitete und häufige Art ist. In Norddeutschland liegt ihr aktueller Verbreitungsschwerpunkt in und um die Städte Hannover, Bremen und Hamburg. Generell scheint die Art vom Klimawandel zu profitieren, sowie durch das Vorhandensein von ausreichend Blütenpflanzen und Komposthaufen in urbanen Gebieten, wo die Art überwiegend dokumentiert wurde. Die Eignung von Citizen-Science-Projekten in der Biodiversitätsforschung wird diskutiert.The characteristic white-spotted rose beetle Oxythyrea funesta has spread rapidly in Central Europe over the past 30 years and is therefore a suitable model for Citizen Science projects. A project to document the dispersal of O. funesta in Germany was started on “kerbtier.de” in 2019 to record the species through photos uploaded by the users. 1,345 inquiries from 309 users were evaluated. Our results show that O. funesta is currently present in all regions of Germany and became a widespread and common species in the southern half of Germany. In Northern Germany, its current distribution is focused in and around the cities of Hanover, Bremen and Hamburg. In general, the species appears to benefit from climate change, as well as from the presence of sufficient flowering plants and compost heaps in urban areas where the species has been mainly documented. The suitability of Citizen-Science-projects in biodiversity research is discussed

Fast urban inundation simulation with RIM2D for flood risk assessment and forecasting

IntroductionUrban pluvial flooding is a growing concern worldwide as consequence of rising urban population and climate change induced increases in heavy rainfall. Easy-to-implement and fast simulation tools are needed to cope with this challenge.MethodsThis study describes the development of the parsimonious, GPU-accelerated hydraulic model RIM2D for urban pluvial flood simulations. This is achieved by considering the built-up urban area as flow obstacles, and by introducing capacity-based approaches to consider urban drainage by infiltration on pervious surfaces and sewer drainage from roofs and sealed surfaces. The model performance was analyzed by simulating 8 heavy rainfall events in a test area in the city of Dresden, Germany. For these events detailed discharge measurements of sewer discharge are available, providing a unique dataset for evaluating the sewer drainage simulation, which is of high importance for realistic pluvial inundation simulations in urban areas.Results and discussionWe show that the model simulates the temporal dynamics of the sewer discharge and the sewer volume within acceptable ranges. Moreover, the erratic variation of the simulated to measured sewer discharge suggests that the deviations from the measurements are caused by the precipitation input rather than the model simplifications. We conclude that RIM2D is a valid tool for urban inundation simulation. Its short simulation runtimes allow probabilistic flood risk assessments and operational flood forecasts

Polarized parton distributions from charged-current deep-inelastic scattering and future neutrino factories

We discuss the determination of polarized parton distributions from charged-current deep-inelastic scattering experiments. We summarize the next-to-leading order treatment of charged-current polarized structure functions, their relation to polarized parton distributions and scale dependence, and discuss their description by means of a next-to-leading order evolution code. We discuss current theoretical expectations and positivity constraints on the unmeasured C-odd combinations Delta q-Delta qbar of polarized quark distributions, and their determination in charged-current deep-inelastic scattering experiments. We give estimates of the expected errors on charged-current structure functions at a future neutrino factory, and perform a study of the accuracy in the determination of polarized parton distributions that would be possible at such a facility. We show that these measurements have the potential to distinguish between different theoretical scenarios for the proton spin structure.Comment: 35 pages, 13 figures, plain TeX with harvmac; Final version, to be published in Nucl. Phys. B. Typo in eq 2.13 corrected and two references adde