Shifted Landau levels in curved graphene sheets

We study the Landau levels in curved graphene sheets by measuring the discrete energy spectrum in the presence of a magnetic field. We observe that in rippled graphene sheets, the Landau energy levels satisfy the same square root dependence on the energy quantum number as in flat sheets, $E_n \sim \sqrt{n}$. Though, we find that the Landau levels in curved sheets are shifted towards lower energies by an amount proportional to the average spatial deformation of the sheet. Our findings are relevant for the quantum Hall effect in curved graphene sheets, which is directly related to Landau quantization. For the purpose of this study, we develop a new numerical method, based on the quantum lattice Boltzmann method, to solve the Dirac equation on curved manifolds, describing the low-energetic states in strained graphene sheets

The market-s reaction on (alternative) M&A announcements in the automotive industry - an event study approach

The automotive industry is currently experiencing the biggest transformation in its history. Pressure from technological disruption, the emergence of new competitors and changing consumer demands require established OEMs to revise and innovate their business models. This work project takes an external perspective to investigate the influence of (alternative) M&A announcements on the automotive OEM’s equity value. It is proposed to be examined by means of an event study to shed light on the shareholders’ evaluation of external innovation. Overall, this work project provides insights for the OEM’s management and investors on how the market reacts to (alternative) deal-making in the automotive industry

Open Set Logo Detection and Retrieval

Current logo retrieval research focuses on closed set scenarios. We argue that the logo domain is too large for this strategy and requires an open set approach. To foster research in this direction, a large-scale logo dataset, called Logos in the Wild, is collected and released to the public. A typical open set logo retrieval application is, for example, assessing the effectiveness of advertisement in sports event broadcasts. Given a query sample in shape of a logo image, the task is to find all further occurrences of this logo in a set of images or videos. Currently, common logo retrieval approaches are unsuitable for this task because of their closed world assumption. Thus, an open set logo retrieval method is proposed in this work which allows searching for previously unseen logos by a single query sample. A two stage concept with separate logo detection and comparison is proposed where both modules are based on task specific CNNs. If trained with the Logos in the Wild data, significant performance improvements are observed, especially compared with state-of-the-art closed set approaches.Comment: accepted at VISAPP 201

Noninvasive brain stimulation techniques can modulate cognitive processing

Recent methods that allow a noninvasive modulation of brain activity are able to modulate human cognitive behavior. Among these methods are transcranial electric stimulation and transcranial magnetic stimulation that both come in multiple variants. A property of both types of brain stimulation is that they modulate brain activity and in turn modulate cognitive behavior. Here, we describe the methods with their assumed neural mechanisms for readers from the economic and social sciences and little prior knowledge of these techniques. Our emphasis is on available protocols and experimental parameters to choose from when designing a study. We also review a selection of recent studies that have successfully applied them in the respective field. We provide short pointers to limitations that need to be considered and refer to the relevant papers where appropriate

Confining massless Dirac particles in two-dimensional curved space

Dirac particles have been notoriously difficult to confine. Implementing a curved space Dirac equation solver based on the quantum Lattice Boltzmann method, we show that curvature in a 2-D space can confine a portion of a charged, mass-less Dirac fermion wave-packet. This is equivalent to a finite probability of confining the Dirac fermion within a curved space region. We propose a general power law expression for the probability of confinement with respect to average spatial curvature for the studied geometry.Comment: 10 pages 8 figure

Genetic variability of Chilean and Peruvian surfclams (Donax marincovichi and Donax obesulus)

Exposed intertidal sandy beaches are commonly dominated by surf clams of the genus Donax. In Peru and Chile these bivalves play an important role for artisanal fisheries. Beside that, little is known about the taxonomy, biology, and the clams susceptibility to climatically induced changes. The taxonomic status of the two Donax species Donax marincovichi and Donax obesulus, distributed along the Peruvian coastline, is controversially discussed. As morphometric comparisons reveal no significant differences we possibly deal with a single rather than with two species. Furthermore, our knowledge on larval dispersal allowing gene flow among populations is scarce. Therefore, both putative Donax species were sampled at ten beaches along the coastline from northern Chile to northern Peru. Partial cytochrome oxidase I sequences were analysed in order to estimate the genetic distances between both putative species and to estimate the intraspecific gene flow along the coastline. Region specific patterns and the dependence on recruitment of local stocks are discussed

Getting better or getting worse? Consumer responses to decreasing, constant, and ascending multi-dimensional price profiles

This research investigates consumer preferences for different multi-dimensional price profiles. Drawing on research on price affect, we investigate whether consumers prefer descending monthly installments (e.g., 40, 30, 20, 10) over constant (e.g., 25, 25, 25, 25), or ascending ones (e.g., 10, 20, 30, 40). Results of a field experiment with a sample of 1,628 German car buyers corroborate the hypothesized profile effect. In the experiment, participants were asked to evaluate different finance offers for a new car that all had the same present value but differed in terms of how the installments unfolded over time. Consistent with the hypotheses, decreasing monthly installments are evaluated more favorably than constant installments, which, in turn are evaluated more favorably than ascending installments. Furthermore, the results provide evidence for the underlying process by showing that the impact of different MDP profiles is mediated by positive affect. Finally, it was hypothesized that consumers' individual differences (i.e., debt aversion, financial expectations, and product category knowledge) would exert a moderating influence on evaluations of different price profiles; these hypotheses, however, were only partially confirmed. Theoretical and managerial implications are discusse