Ownership versus shared economy : implications on german car manufacturers

In times of financial uncertainty, sustainable demands, and resource scarcity, consumers tend to share rather than own items. Digitalization has played its part, start-ups have evolved, and consumers become suppliers. In 2008, the first app entered a mobile device, and a company called Uber was founded only one year later. It has ever since transformed business, markets, and processes in one of the largest industries in the world – the automotive sector. Despite the rapid development of digitalization and tech giants dominating markets, there isn't an ideal solution for traditional German carmakers to defend their turf. Those implications create uncertainties for incumbents of the automotive industry. Therefore, two research questions animate this thesis: What is the impact of the shared economy on the automotive industry? What is the impact of digitalization on the automotive industry? This requires a precise understanding of the reason behind changing consumer preferences and the actual development and impact of digitalization in the automotive industry. In today's business world, industries are emerging, and new competitors are joining the stage frequently. The theoretical research exhausts vast literature and recent news to understand changing consumer preferences and the impact of digitalization on the automotive industry. Through qualitative data collection, the academic findings are supported by practical insights, gained through eight interviews. That combined approach of literature and qualitative data concluded that the car has to become pre-dominantly a service rather than the actual hardware in the future. Carmakers have to move towards becoming software companies to stay competitive with tech giants entering the field.Em tempos de incerteza financeira, demandas sustentáveis e escassez de recursos, os consumidores tendem a compartilhar em vez de possuir itens. A digitalização tem desempenhado o seu papel, as start-ups têm evoluído, e os consumidores se tornam fornecedores. Apesar do rápido desenvolvimento da digitalização e dos gigantes tecnológicos dominando os mercados, não existe uma solução ideal para as montadoras alemãs tradicionais defenderem seu território. Essas implicações criam incertezas para os operadores históricos da indústria automotiva. Portanto, duas questões de pesquisa animam esta tese: Qual é o impacto da economia compartilhada na indústria automotiva? Qual o impacto da digitalização na indústria automobilística? Isso requer um entendimento preciso da razão por trás da mudança das preferências dos consumidores e do desenvolvimento e impacto real da digitalização na indústria automotiva. No mundo dos negócios de hoje, as indústrias estão emergindo e novos concorrentes estão se juntando ao palco com freqüência. As pesquisas teóricas esgotam literatura e notícias recentes para entender as mudanças nas preferências dos consumidores e o impacto da digitalização na indústria automotiva. Através da coleta de dados qualitativos, os resultados acadêmicos são apoiados por perspectivas práticos, obtidos através de oito entrevistas. Essa abordagem combinada de literatura e dados qualitativos concluiu que o carro tem que se tornar um serviço pré-dominante e não o hardware real no futuro. Os fabricantes de automóveis têm que se tornar empresas de software para se manterem competitivos com os gigantes da tecnologia que entram no campo

Optical Properties of TMDC Monolayers and Their Heterostructures

Recently, the 2D semiconductors represented by transition-metal dichalcogenides (TMDCs) received strong attention owing to a number of important features. These include the large exciton binding energies relevant for room-temperature applications, the valley pseudo-spin degree of freedom and polarization sensitivity, and the overall strong light-matter interactions at the monolayer limit which motivate their use for optoelectronics. Furthermore, van-der-Waals stacking of different 2D crystals results in out-of-plane heterostructures, which can, in addition to the inherited properties of the individual layered constituents, even exhibit tailored properties caused by the strong influence of the environment and hybridization of atomic orbitals. Accordingly, a mixture of unique and novel properties can arise. Ultimately, in contrast to conventional semiconductor heterostructure growth, there is no direct need for lattice matching or a fixed orientation during assembly. Nonetheless, the relative orientation between different or similar 2D lattices may indeed be important for the composed stack’s features. Thus, the vast number of possible combinations of 2D-materials with each other, as well as with substrates and with conventional semiconductors or molecular materials, offer huge opportunities for engineering and tailoring the material stack properties to meet the demand of a specific application. To do that effectively and systematically, several questions need to be addressed, to the answering of which the following studies contribute with important insights focusing on the optical properties of semiconductor monolayers and van-der-Waals stacks. In this work, four central chapters discuss excitonic signatures in different TMDC 2D structures, shedding light on the role of the environment and stacking configuration, as well as on the quasi-particle energy-momentum dispersion, valley polarization as well as light-matter interactions. Firstly, the influence of the surroundings on the fundamental properties of 2D-semiconductor monolayers, such as the energetics, the exciton–phonon coupling, exciton–exciton annihilation and exciton diffusion, is addressed based on time-integrated and time-resolved photoluminescence spectroscopy. Thereby, the important role of hexagonal BN as substrate or capping layer and as encapsulant is discussed. Following that, a better understanding of high-symmetry alignments for bilayers is gained employing epitaxially grown tungsten-disulfide samples with two distinct and deterministically obtained configurations. While formerly only the symmetry of the stack itself was considered, the study presented here shows that also the symmetry of the surrounding has to be considered as it can lift the degeneracy between the layers. Thereby, the out-of-plane symmetry break renders homobilayers in fact heterojunctions. Moreover, the aspect of spin–valley and spin–layer locking has been discussed for the natural and artificial bilayer type, with eyes towards valleytronic applications. In contrast to high-symmetry stacks, investigations on arbitrarily stacked heterostructures are at the starting point for explorations on the impact of moiré patterns and interlayer hybridization. Here, a preliminary study on a tungsten-based heterostructure exhibits pronounced spectral features attributed to such interlayer effects, besides the occurrence of conventional intra- and interlayer excitons. Next, regarding linewidth improved encapsulated monolayers, a unique access to the excitonic energy–momentum dispersion is demonstrated with the help of angle-resolved spectrospopy. The analysis of Fourier-space-resolved emission and reflection spectra hereby facilitate the ongoing discussion of dispersion relations in 2D semiconductors. The so far unrivalled optical measurements show novel experimental evidence of meV strong excitonic dispersion within the light cone in support of theories discussed in the literature. Furthermore, Fourier-space spectroscopy delivers a tool to identify the radiative patterns of bright and partially dark excitonic states and provided evidence for the phonon-sidebands in agreement with the prediction in the literature. Finally, improvements of the light–matter interactions and of the emission behavior towards optoelectronic applications are crucial, taking further into account challenges in the integration of van-der-Waals materials in established silicon-, III/V semiconductors- or fiber-based technology. Therefore, a nanostructured photonic substrate landscape for lateral confinement of optical fields and vertical enhancement of coupling of light into and out of 2D-materials is investigated as a prototype structure for possible nanophotonic applications

On the difficulty of feature-based attentional modulations in visual object recognition: A modeling study.

Numerous psychophysical experiments have shown an important role for attentional modulations in vision. Behaviorally, allocation of attention can improve performance in object detection and recognition tasks. At the neural level, attention increases firing rates of neurons in visual cortex whose preferred stimulus is currently attended to. However, it is not yet known how these two phenomena are linked, i.e., how the visual system could be "tuned" in a task-dependent fashion to improve task performance. To answer this question, we performed simulations with the HMAX model of object recognition in cortex [45]. We modulated firing rates of model neurons in accordance with experimental results about effects of feature-based attention on single neurons and measured changes in the model's performance in a variety of object recognition tasks. It turned out that recognition performance could only be improved under very limited circumstances and that attentional influences on the process of object recognition per se tend to display a lack of specificity or raise false alarm rates. These observations lead us to postulate a new role for the observed attention-related neural response modulations

A Detailed Look at Scale and Translation Invariance in a Hierarchical Neural Model of Visual Object Recognition

The HMAX model has recently been proposed by Riesenhuber & Poggio as a hierarchical model of position- and size-invariant object recognition in visual cortex. It has also turned out to model successfully a number of other properties of the ventral visual stream (the visual pathway thought to be crucial for object recognition in cortex), and particularly of (view-tuned) neurons in macaque inferotemporal cortex, the brain area at the top of the ventral stream. The original modeling study only used ``paperclip'' stimuli, as in the corresponding physiology experiment, and did not explore systematically how model units' invariance properties depended on model parameters. In this study, we aimed at a deeper understanding of the inner workings of HMAX and its performance for various parameter settings and ``natural'' stimulus classes. We examined HMAX responses for different stimulus sizes and positions systematically and found a dependence of model units' responses on stimulus position for which a quantitative description is offered. Interestingly, we find that scale invariance properties of hierarchical neural models are not independent of stimulus class, as opposed to translation invariance, even though both are affine transformations within the image plane

Vacuum Induced Ground-State Instabilities

We use the hydrogen atom's bound state electron as a probe and investigate the consequences inflicted by time-resolved vacuum effects. Explicitly, we derive a closed form for the time-dependent modification of the Maxwell equations emanating from vacuum fluctuations in quantum electrodynamics. As a consequence, we find a non-vanishing probability that the corresponding hydrogen ground state can be excited through interactions with fermionic currents that are entailed in the vacuum state.Comment: 11 pages, 2 figure

Mitochondrial protein import

Transport of nuclear-encoded precursor proteins into mitochondria includes proteolytic cleavage of aminoterminal targeting sequences in the mitochondrial matrix. We have isolated the processing activity from Neurospora crassa. The final preparation (enriched ca. 10,000-fold over cell extracts) consists of two proteins, the matrix processing peptidase (MPP, 57 kd) and a processing enhancing protein (PEP, 52 kd). The two components were isolated as monomers. PEP is about 15-fold more abundant in mitochondria than MPP. It is partly associated with the inner membrane, while MPP is soluble in the matrix. MPP alone has a low processing activity whereas PEP alone has no apparent activity. Upon recombining both, full processing activity is restored. Our data indicate that MPP contains the catalytic site and that PEP has an enhancing function. The mitochondrial processing enzyme appears to represent a new type of “signal peptidase,” different from the bacterial leader peptidase and the signal peptidase of the endoplasmic reticulum

Ackerwildkrautschutz in Luxemburg durch Schutzäcker, Feldflorareservate und Ökologische Landwirtschaft

Arable plants are becoming increasingly rare in today's cultural landscape and belong to the most endangered plant species in Luxemburg. Their main threat is the intensification of agriculture, where high usage of pesticides and fertilizer, better seed cleaning methods and the abandonment of marginal yield sites all negatively affect arable plant communities. Another factor is the loss of (potential) habitat due to the expansion of settlements and subsequent loss of agricultural lands. The dire situation calls for urgent action. Within the framework of the bachelor thesis of the first author, a concept for the protection of arable plants in Luxembourg was developed. The following article describes and discusses the four most promising applied approaches to arable plant conservation identified in the course of this work, namely organic farming, two types of “conservation fields” (“Schutzacker” and “Feldflorareservat”) and pesticide-free field margins