Modelling Critical Success Factors of International Joint Ventures in Real Estate Development: Perspective of a Capital Investor

The aim of this dissertation, undertaken between 2012 and 2017, is to contribute towards the improvement of international joint venture (“IJV”) management in real estate development projects by analysing performance and factors, critical for the success of real estate IJVs. The assumption is that a real estate capital investor acts as the international partner of the IJV-construct, while local developers, operators and/or real estate professionals represent the local partner. The thesis focuses on the perspective of the real estate capital investor as a key actor in an IJV. The thesis adopts a systems approach in identifying and discussing the critical success factors of IJVs in the literature review, followed by the development of an integrated, theory-based framework that offers a theoretical conceptualisation of the research problem and key research questions. The methodology and research design were compiled using quantitative (questionnaire survey) and qualitative (focus group and semi-structured interviews) approaches. Data were collected from international capital providers investing as IJV-partners in real estate development using a mixed method approach, the thesis proposes and elaborates on a performance model for IJVs in real estate development, with an aim to ensure empirically valid performance measurement. The focus was to identify and justify determinants and their relationships. The empirical investigation in the thesis supports the notion that the investment process and the selection of the partner are particularly important for a project’s success in real estate development IJVs. In addition, aspects related to the structural and organisational dimension are relevant to the overall IJV performance. Moreover, the model has shown significant relationships between the (1) structural, organisational and investment dimensions on the one hand, and the (2) external, organisational and investment dimensions, on the other hand, for the overall success in the formation-stage. With respect to the post-formation stage, relationships between (1) partner and organisational dimension, (2) partner and investment dimension and (3) investment and organisational dimensions have been proven relevant to improve IJV performance in the context of real estate development IJVs

Supersymmetry breaking and weakly vs. strongly coupled string theory

In the context of the field theory limit of superstrings, we consider an almost realistic model of supersymmetry breaking by gaugino condensation which includes, through nonperturbative corrections to the K\"ahler potential, dilaton stabilization at a value compatible with a weak coupling regime. Invariance under modular transformations is ensured through a Green-Schwarz term and string threshold corrections, which lead to moduli stabilization at the self-dual point. We are thus in a position to discuss several issues of physical relevance: gravitino, dilaton and moduli masses, axion, soft supersymmetry breaking parameters and gauge coupling unification.Comment: LATEX, 15 page

Out Of This World Supersymmetry Breaking

We show that in a general hidden sector model, supersymmetry breaking necessarily generates at one-loop a scalar and gaugino mass as a consequence of the super-Weyl anomaly. We study a scenario in which this contribution dominates. We consider the Standard Model particles to be localized on a (3+1)-dimensional subspace or ``3-brane'' of a higher dimensional spacetime, while supersymmetry breaking occurs off the 3-brane, either in the bulk or on another 3-brane. At least one extra dimension is assumed to be compactified roughly one to two orders of magnitude below the four-dimensional Planck scale. This framework is phenomenologically very attractive; it introduces new possibilities for solving the supersymmetric flavor problem, the gaugino mass problem, the supersymmetric CP problem, and the mu-problem. Furthermore, the compactification scale can be consistent with a unification of gauge and gravitational couplings. We demonstrate these claims in a four-dimensional effective theory below the compactification scale that incorporates the relevant features of the underlying higher dimensional theory and the contribution of the super-Weyl anomaly. Naturalness constraints follow not only from symmetries but also from the higher dimensional origins of the theory. We also introduce additional bulk contributions to the MSSM soft masses. This scenario is very predictive: the gaugino masses, squark masses, and $A$ terms are given in terms of MSSM renormalization group functions.Comment: 42 pages, LateX, references added, corrections added as Eqs. (43, 53

Tools for Brain-Computer Interaction: A General Concept for a Hybrid BCI

The aim of this work is to present the development of a hybrid Brain-Computer Interface (hBCI) which combines existing input devices with a BCI. Thereby, the BCI should be available if the user wishes to extend the types of inputs available to an assistive technology system, but the user can also choose not to use the BCI at all; the BCI is active in the background. The hBCI might decide on the one hand which input channel(s) offer the most reliable signal(s) and switch between input channels to improve information transfer rate, usability, or other factors, or on the other hand fuse various input channels. One major goal therefore is to bring the BCI technology to a level where it can be used in a maximum number of scenarios in a simple way. To achieve this, it is of great importance that the hBCI is able to operate reliably for long periods, recognizing and adapting to changes as it does so. This goal is only possible if many different subsystems in the hBCI can work together. Since one research institute alone cannot provide such different functionality, collaboration between institutes is necessary. To allow for such a collaboration, a new concept and common software framework is introduced. It consists of four interfaces connecting the classical BCI modules: signal acquisition, preprocessing, feature extraction, classification, and the application. But it provides also the concept of fusion and shared control. In a proof of concept, the functionality of the proposed system was demonstrated

Solving the Hierarchy Problem without Supersymmetry or Extra Dimensions: An Alternative Approach

In this paper, we propose a possible new approach towards solving the gauge hierarchy problem without supersymmetry and without extra spacetime dimensions. This approach relies on the finiteness of string theory and the conjectured stability of certain non-supersymmetric string vacua. One crucial ingredient in this approach is the idea of ``misaligned supersymmetry'', which explains how string theories may be finite even without exhibiting spacetime supersymmetry. This approach towards solving the gauge hierarchy problem is therefore complementary to recent proposals involving both large and small extra spacetime dimensions. This approach may also give a new perspective towards simultaneously solving the cosmological constant problem.Comment: 33 pages, LaTeX, 3 figure

Data from the German TwinLife Study: Genetic and Social Origins of Educational Predictors, Processes, and Outcomes

The major aim of the German TwinLife study is the investigation of gene-environment interplay driving educational and other inequalities across developmental trajectories from childhood to early adulthood. TwinLife encompasses an 8-year longitudinal, cross-sequential extended twin family design with data from same-sex twins of four age cohorts (5, 11, 17, and 23 years) and their parents, as well as their non-twin siblings, partners, and children, if available, altogether containing N = 4,096 families. As such, TwinLife includes unique and openly accessible data that allows, but is not limited to, genetically informative and environmentally sensitive research on sources of inequalities regarding educational attainment, school achievement, and skill development

String Theory and the Path to Unification: A Review of Recent Developments

This is a pedagogical review article surveying the various approaches towards understanding gauge coupling unification within string theory. As is well known, one of the major problems confronting string phenomenology has been an apparent discrepancy between the scale of gauge coupling unification predicted within string theory, and the unification scale expected within the framework of the Minimal Supersymmetric Standard Model (MSSM). In this article, I provide an overview of the different approaches that have been taken in recent years towards reconciling these two scales, and outline some of the major recent developments in each. These approaches include 1) string GUT models; 2) higher affine levels and non-standard hypercharge normalizations; 3) heavy string threshold corrections; 4) light supersymmetric thresholds; 5) effects from intermediate-scale gauge and matter structure beyond the MSSM; 6) strings without supersymmetry; and 7) strings at strong coupling.Comment: 104 pages, LaTeX, 21 figures, 3 tables. Substantially expanded and updated, with new material and references added. Final version to appear in Physics Report