Bücher der Reihe BestMasters

Shared value not only offers a new concept to face the current business environmental dynamics but it also responds to macro-economic challenges.

The literature on business model innovation mainly regards large enterprises and is not tailored to SME characteristics. Oana Buliga takes an exploratory look at whether SMEs use strategies which are mainly designed for large enterprises for innovating their business models.

Andre Roehm investigates the dynamic properties of two-state lasing quantum dot lasers, with a focus on ground state quenching. Additionally, the turn-on dynamics and modulation response curves of two-state lasing devices are presented.

Michael Schenk evaluates new technologies and methods, such as cryogenic read-out electronics and a UV laser system, developed to optimise the performance of large liquid argon time projection chambers (LArTPC). Amongst others, the author studies the uniformity of the electric field produced by a Greinacher high-voltage generator operating at cryogenic temperatures, measures the linear energy transfer (LET) of muons and the longitudinal diffusion coefficient of electrons in liquid argon. The results are obtained by analysing events induced by cosmic-ray muons and UV laser beams. The studies are carried out with ARGONTUBE, a prototype LArTPC in operation at the University of Bern, Switzerland, designed to investigate the feasibility of drift distances of up to five metres for electrons in liquid argon.

Currently, a new potential paragon of fundraising and financing, in particular crowd funding (CF) attracts a lot of attention. Scientific discourse on CF is still nascent, since existing studies and papers focus on the potential of CF and its basic principles.

Increasingly, luxury brands join forces with the arts today. Regardless of their growing practical relevance for the creation of contemporary luxury brands though, the varied forms of Luxury Brand-Art Collaborations (LBACs) have remained largely unexplored to date.

The Author shows that modelling the uncertain cash flow dynamics of an investment project deserves careful attention in real options valuation. The valuation results suggest that stochastic process choice can have substantial implications for valuation results and optimal investment rules.

Model-based recursive partitioning (MOB) provides a powerful synthesis between machine-learning inspired recursive partitioning methods and regression models. Hanna Birke extends this approach by allowing in addition for measurement error in covariates, as frequently occurring in biometric (or econometric) studies, for instance, when measuring blood pressure or caloric intake per day. After an introduction into the background, the extended methodology is developed in detail for the Cox model and the Weibull model, carefully implemented in R, and investigated in a comprehensive simulation study.

The master thesis of Kevin Berk develops a stochastic model for the electricity demand of small and medium-sized companies that is flexible enough so that it can be used for various business sectors. The model incorporates the grid load as an exogenous factor and seasonalities on a daily, weekly and yearly basis. It is demonstrated how the model can be used e.g. for estimating the risk of retail contracts. The uncertainty of electricity demand is an important risk factor for customers as well as for utilities and retailers. As a consequence, forecasting electricity load and its risk is now an integral component of the risk management for all market participants.

Various psychographic traits that most directly influence consumers' private label attitudes are the focal point of Stefanie Weiss' investigation. The hypothesized relationships between consumers' private label attitude and various psychographic traits are tested on a sample of German and Austrian consumers using an online questionnaire.

In his Master project Sven Herrmann for the first time carried out fundamental investigations into the development of polyoxometalate based ionic liquids (POM-ILs). The POM-ILs were obtained by charge balancing inorganic polyoxometalate (POM) anions with sterically demanding tetraalkylammonium or tetraalkylphosphonium cations. By functionalization of lacunary Keggin clusters with 3d-transition metals and charge balancing with tetraalkylammonium cations of differing chain length, a model system for the correlation of the molecular structure with macroscopic materials properties was obtained. In a systematic approach the syntheses via self-aggregation is presented. Analytic methods comprise UV-Vis, FTIR, NMR, EPR and Mobauer spectroscopy. For determination of the materials properties TGA and DSC were carried out and rheological studies shed light onto the flow characteristics of the highly viscous materials.

This book covers relevant topics of social media in the area of research institutes. Daniel Hurrle and Julia Postatny follow the research question of how social media can empower the communication of such institutes by using the example of the Berlin-Brandenburg Academy of Sciences and Humanities.

Florian Auinger highlights the core weaknesses and sources of criticism regarding the VIX Index as an indicator for the future development of financial market volatility.

Jochen Szangolies contributes a novel way of dealing with the problem of the experimental testability of the Kochen-Specker theorem posed by realistic, that is, noisy, measurements. Such noise spoils perfect compatibility between successive measurements, which however is a necessary requirement to test the notion of contextuality in usual approaches. To overcome this difficulty, a new, extended notion of contextuality that reduces to Kochen-Specker contextuality in the limit of perfect measurement implementations is proposed by the author, together with a scheme to test this notion experimentally. Furthermore, the behaviour of these tests under realistic noise conditions is investigated.

Sandra Haschke presents a strategy to enhance the Fe2O3 electrode performance by controlled nanostructuring of the catalyst surface, based on anodized aluminum oxide coated by means of atomic layer deposition. Furthermore, she investigates the influence of underlying conductive layers and post-deposition annealing on the electrode performance and the associated changes in morphology and chemical composition. Exploiting all effects combined delivers an increase in steady-state water oxidation throughput by a factor of 2.5 with respect to planar electrodes.

Paul M. Geffert analyses the interplay of noise and time delay in non-excitable nonlinear systems and the modulation of stochastic effects. In particular, the author studies coherence resonance, which is a constructive effect of noise that occurs in nonlinear systems, and demonstrates that it can be modulated by time-delayed feedback. Analytical methods for the investigation of stochastic delay differential equations are developed. Noise or random perturbations and time delay are two phenomena which arise in many fields of physics, chemistry, or biology, just to mention a few examples. The investigated model is a generic Hopf normal form so that these methods and results can be transferred to many different areas of science.

Tamara Bernadette Aigner designed a set of biocompatible and biodegradable poly(organophosphazenes). In order to tailor their biological and chemical properties, she further modified these macromolecules by adding functional moieties via thiol-ene chemistry. The author used the same photochemistry for crosslinking to obtain a mechanically stable network. She further altered the degradation rate of the matrix as well as the mechanical properties by adding blending agents and created a porous matrix, which is necessary for cell invasion and communication, by a newly developed photocrosslinking particulate-leaching method. Thus, a modular hybrid system was established which is able to adapt to different microenvironments based upon tissue type.

Karl Striegler investigates novel materials for photocatalytic hydrogen evolution from water. Graphitic Carbon Nitrides are an interesting class of materials with a structure close to graphite. For overcoming certain limitations, the author used different approaches to functionalize the basic material. He deposited nanoparticles to enhance the catalytic activity and used copolymerization as well as sensitizing to increase the amount of harvested light.

Sebastian Uhlig presents the first experimental investigation of self-organized surface structures (LIPSS) generated by ablation from different (semiconductor and metallic) targets with an ultrafast white-light continuum (WLC) spreading in wavelength from 400-750 nm. The main goal is to study the possibility of LIPSS formation upon irradiation with an incoherent and polychromatic light source (e.g. the WLC) in order to discriminate between the two debated formation scenarios. The generation of a suitable WLC in terms of sufficient white-light pulse energy, broad spectral bandwidth, and low spatial coherence for the LIPSS generation, as well as the characterization of this WLC are additional important objectives of this work.

Melanie Weichselbaumer presents the synthesis of the monomers as well as the electropolymerization on Pt-electrodes. The electrolysis experiments were carried out for 40 hours and the products were analysed by gas chromatography and ionic chromatography. Pyridine-functionalized and Rhenium bipyridine-functionalized Polythiophenes can be used as heterogeneous catalysts for CO2-reduction.

Richard Moser shows how to use and upgrade toy bricks for the construction of a lightweight, low-cost and easy to reproduce tensile testing setup. Tailored for the characterization of elastomers and stretchable electrodes, the setup is capable of performing stress-strain studies along with resistance-strain measurements. Based on the underlying theory of material deformation and rubber elasticity, the author applies the setup to mechanically characterize polydimethylsiloxane (PDMS) with different grades of stiffness. The versatility of the device is highlighted with the electromechanical characterization of stretchable thin film metal electrodes on PDMS. Applications of the author's setup range from using it as an educational tool in practical physics and engineering courses over being showcase in scientific exhibitions to its utilization as an inexpensive and reliable laboratory tool.

Michael Lepper presents a detailed room temperature scanning tunneling microscopy study of Nickel-tetraphenyltetrabenzoporphyrin on Cu(111), a prototype system for the fabrication of functional molecular architectures. The peculiar adsorption behavior, in particular the observation of three different coexisting supramolecular arrangements and the identification of two different intramolecular conformations within one arrangement, yield valuable insights into the specific molecular interactions and the self-assembly process in general.

In this book Simona Roccioletti reviews several valuable studies about risk measures and their properties; The main contribution of the work is the application of "Test 1" and "Test 2" developed by Acerbi and Szekely (2014) on different models and for five global market indexes.

This thesis uses neoclassical growth models toevaluate what effect the limited availability of nonrenewable resources has onthe economy's (world's) growth potential. After a thorough analysis of the models it isconcluded that the ultimate solution to long-term economic growth is a backstoptechnology.

By drawing up a model of the internal communication system of Bangladeshi ready-made garment factories, Helene Blumer identifies the existence and intensity of its communication flows.

Leonid Ryvkin gives a motivated and self-sustainedintroduction to n-plectic geometry with a special focus on symmetries. Therelevant algebraic structures from scratch are developed. The author generalizesknown symplectic notions, notably observables and symmetries, to the n-plecticcase, culminating in solving the existence question for co-moment maps forgeneral pre-n-plectic manifolds. Finally partial results scattered along theliterature are derived from our general result.

Manuel Kroiss examines the differentiation of hematopoietic stem cells using machine learning methods. This work is based on experiments focusing on the lineage choice of CMPs, the progenitors of HSCs, which either become MEP or GMP cells. The author presents a novel approach to distinguish MEP from GMP cells using machine learning on morphology features extracted from bright field images. He tests the performance of different models and focuses on Recurrent Neural Networks with the latest advances from the field of deep learning. Two different improvements to recurrent networks were tested: Long Short Term Memory (LSTM) cells that are able to remember information over long periods of time, and dropout regularization to prevent overfitting. With his method, Manuel Kroiss considerably outperforms standard machine learning methods without time information like Random Forests and Support Vector Machines.

Carolin Loos introduces two novel approaches for theanalysis of single-cell data. Both approaches can be used to study cellularheterogeneity and therefore advance a holistic understanding of biologicalprocesses. The first method, ODE constrained mixture modeling, enables theidentification of subpopulation structures and sources of variability in single-cellsnapshot data. The second method estimates parameters of single-cell time-lapsedata using approximate Bayesian computation and is able to exploit the temporalcross-correlation of the data as well as lineage information. 

Daniel Halwidl presents the development of an effusive molecular beam apparatus, which allows the dosing of gases, liquids, and solids in ultra-high vacuum. The apparatus is designed to adsorb precise and reproducible doses to a defined area on metal oxide samples, which is required in Temperature Programmed Desorption and other surface chemistry experiments. The design and the construction of the apparatus is described. The properties of the molecular beam are experimentally confirmed. The beam profile has a core diameter of 3.5 mm and a standard core pressure of 4 x 10-8 mbar, while the background pressure is 4 orders of magnitude lower. 

In experiments on aprototypical combustor, Richard Steinert identifies new insights on the impactof noise on the phenomenon known as thermoacoustic instability. The phenomenonis a concerning issue which creates a technical limit on the efficiency andenvironmental impact of fossil fuels combustion in industrial combustors. Itposes a threat to the structural integrity of practical systems such as gasturbine combustors and rocket engines. The experiments demonstrate thatthermoacoustic systems feature an interesting noise-induced behaviour known ascoherence resonance - a coherent response of dynamical systems close to theirstability boundary that is induced by stochastic excitation. The work containedin this publication is an example illustrating the importance of fundamentalconsiderations in solving perplexing engineering issues.