Open Access

Does the presentation of travel experience affect personal prestige of tourists? Prestige enhancement has been considered a motive for travel by tourism researchers for decades. Yet, the question whether representation of travel experience actually leads to personal prestige enhancement has been widely neglected so far. The study of prestige benefits of travel is a necessary endeavour to develop suitable methodological approaches toward the concept, in order to close critical knowledge gaps and enhance scientific understanding. The present thesis lays out the rationale and results of three research projects which shed light onto the relationship between touristic self-presentation and its effects on personal prestige evaluations of the social environment. The empirical studies conducted in the frame of this dissertation conclude in the following main findings: Leisure travel is a useful means for people to self-express in a positive way, and material representations of travel are frequently displayed to others. Tourists make use of travel experience to self-present in a positive way by uploading photos on social media, collecting and displaying souvenirs, wearing jewellery and clothing from their last trip, or talking about their trips to others. They express positive self-messages about personal character traits, affiliation to social in-groups and proof of having travelled somewhere. The findings ascertain the utility of travel representations for positive self-expression, showing that travel experience is an effective vehicle for conspicuous consumption and self-expression as an antecedent for personal prestige enhancement. Personal prestige is an element of social relations, and holds capacity to affect perceptions of social inclusion and social distinction, so it has to be conceptualised as a multidimensional construct. In a tourism context, personal prestige is reliably measurable along the four dimensions of hedonism, social inclusion, social distinction and prosperity. The herein developed Personal Prestige Inventory (PPI) is a valid, reliable and parsimonious measurement tool which substantially enhances methodological approaches toward empirical research into personal prestige. The way in which people represent travel experience to others measurably affects how their personal prestige is evaluated by social others. Empirical evidence of a series of experimental studies provides support for the assumption that representation of travel experience has an effect on the social evaluation of tourists’ personal prestige. Experimental variance suggests small to moderate effects on personal prestige depending on the amount of leisure information given about a person, participation in tourism, and the destination and type of travel represented. This evidence is reasonable basis to conclude that whether and how people travel, and whether and how they share travel experience with others, does measurably affect social other’s evaluation of their personal prestige. By providing qualitative evidence for positive self-presentation through leisure travel, and the subsequent development and experimental application of the Personal Prestige Inventory (PPI) in a tourism context, the present dissertation enhances scientific understanding of personal prestige in the context of leisure travel and provides useful methodological advancements for further research into the topic.

Many dynamics are reshaping the global macroeconomics and finance. This cumulative dissertation empirically examines the impacts of two major global dynamics, the disaster risks and the China’s rise, on the global economy. Chapter 1 introduces the motivation and summarizes the dissertation. Chapter 2 investigates how geopolitical risks affect financial stress in the whole financial system and its sub-sectors (banking, stock, foreign exchange, bond) of major emerging economies. Chapter 3 shows how different disaster risks (financial, geopolitical, natural-technological) can explain the returns and risk premiums of stock and housing in advanced economies between 1870 and 2015. Chapter 4 examines how the rise of China is contributing to higher economic growth in emerging economies, especially after the Global financial crisis of 2007-2008. Chapter 5 illustrates how a close trade and investment relation with China has helped African countries to reduce poverty and to improve their income distribution.

Human activities have become a major driver of global change, so that global society and economy are facing consequences such as climate change, increasing scarcity of resources, environmental pollution and degradation as well as disturbances of ecosystem functioning and services.In order to meet these main challenges in an appropriate way, adequate starting points and solutions must be pursued at all levels to shift the current socio-economic pathway from an unsustainable to a safe operating and thus sustainable development within the planetary boundaries. One of the application concepts in industrial contexts is Industrial Symbiosis (IS), which deals with the set-up of advanced circular/cascading systems, in which the energy and material flows are prolonged for multiple material and energetic (re-)utilization within industrial systems in order to increase resource productivity and efficiency, while reducing environmental impacts. The overarching goal of the research project was to identify and develop approaches to enable the evolution of Industrial Symbiosis (IS) in Industrial Parks (IPs). Industrial Symbiosis (IS) is a collaborative cross-sectoral approach to connect the resource supply and demand of various industries in order to optimize the resource use through exchange of materials, energy, water and human resources across different companies, while generating ecological, technical, social and economic benefits. Many Information Communication Technology (ICT) tools have been developed to facilitate IS, but they predominantly focus on the as-is analysis of the IS system, and do not consider the development of a common desired target vision or corresponding possible future scenarios as well as conceivable transformation paths from the actual to the defined (sustainability) target state. This gap shall be addressed in this work, presenting the software requirements engineering results for a holistic IT-supported IS tool covering system analysis, transformation simulation and goal-setting. This study also aims to present the conceptual IT-supported IS tool and its corresponding prototype, developed for the identification of IS opportunities in IPs. This IS tool serves as an IS facilitating platform, providing transparency among market players and proposing potential cooperation partners according to selectable criteria (e.g. geographical radius, material properties, material quality, purchase quantity, delivery period). Therefore a quantitative indicator system was compiled and recurring patterns were identified to utilize this knowledge in the comprehensive IT-supported IS tool. So this IS tool builds the technology-enabled environment for the processes of first screening of IS possibilities and initiation for further complex business-driven negotiations and agreements for long-term IS business relationships.

Urban areas are prone to climate change impacts. Simultaneously the world’s population increasingly resides in cities. In this light, there is a growing need to equip urban decision makers with evidence-based climate information tailored to their specific context, to adequately adapt to and prepare for future climate change. To construct climate information high-resolution regional climate models and their projections are pivotal, to provide a better understanding of the unique urban climate and its evolution under climate change. There is a need to move beyond commonly investigated variables, such as temperature and precipitation, to cover a wider breath of possible climate impacts. In this light, the research presented in this thesis is centered around enhancing the understanding about regional-to-local climate change in Berlin and its surroundings, with a focus on humidity. More specifically, following a regional climate modelling and data analysis approach, this research aims to understand the potential of regional climate models, and the possible added value of convection-permitting simulations, to support the development of high-quality climate information for urban regions, to support knowledge-based decision-making. The first part of the thesis investigates what can already be understood with available regional climate model simulations about future climate change in Berlin and its surroundings, particularly with respect to humidity and related variables. Ten EURO-CORDEX model combinations are analyzed, for the RCP8.5 emission scenario during the time period 1970 ̶ 2100, for the Berlin region. The results are the first to show an urban-rural humidity contrast under a changing climate, simulated by the EURO-CORDEX ensemble, of around 6 % relative humidity, and a robust enlarging urban drying effect, of approximately 2 ̶ 4 % relative humidity, in Berlin compared to its surroundings throughout the 21st century. The second part explores how crossing spatial scales from 12.5 km to 3 km model grid size affects unprecedented humidity extremes and related variables under future climate conditions for Berlin and its surroundings. Based on the unique HAPPI regional climate model dataset, two unprecedented humidity extremes are identified happening under 1.5 °C and 2 °C global mean warming, respectively SH>0.02 kg/kg and RH<30 %. Employing a double-nesting approach, specifically designed for this study, the two humidity extremes are downscaled to the 12.5 km grid resolution with the regional climate model REMO, and thereafter to the 3 km with the convection-permitting model version of REMO (REMO NH). The findings indicate that the convection-permitting scale mitigates the SH>0.02 kg/kg moist extreme and intensifies the RH<30 % dry extreme. The multi-variate process analysis shows that the more profound urban drying effect on the convection-permitting resolution is mainly due to better resolving the physical processes related to the land surface scheme and land-atmosphere interactions on the 3 km compared to the 12.5 km grid resolution. The results demonstrate the added value of the convection-permitting resolution to simulate future humidity extremes in the urban-rural context. The third part of the research investigates the added value of convection-permitting models to simulate humidity related meteorological conditions driving specific climate change impacts, for the Berlin region. Three novel humidity related impact cases are defined for this research: influenza spread and survival; ragweed pollen dispersion; and in-door mold growth. Simulations by the regional climate model REMO are analyzed for the near future (2041 ̶ 2050) under emission scenario RCP8.5, on the 12.5 km and 3 km grid resolution. The findings show that the change signal reverses on the convection-permitting resolution for the impact cases pollen, and mold (positive and negative). For influenza, the convection-permitting resolution intensifies the decrease of influenza days under climate change. Longer periods of consecutive influenza and mold days are projected under near-term climate change. The results show the potential of convection-permitting simulations to generate improved information about climate change impacts in urban regions to support decision makers. Generally, all results show an urban drying effect in Berlin compared to its surroundings for relative and specific humidity under climate change, respectively for the urban-rural contrast throughout the 21st century, for the downscaled future extreme conditions, and for the three humidity related impact cases. Added value for the convection-permitting resolution is found to simulate humidity extremes and the meteorological conditions driving the three impacts cases. The research makes novel contributions that advance science, through demonstrating the potential of regional climate models, and especially the added value of convection-permitting models, to understand urban rural humidity contrasts under climate change, supporting the development of knowledge-based climate information for urban regions.

The worldwide decline of plant and insect species during the last decades has far-reaching consequences for the functionality of ecosystems and their inherent processes. Pollination as one of them is an indispensable ecosystem service for human wellbeing. More than 85% of the worldwide flowering-plant species depend to some degree on pollination by insects (pollinators). Similarly, many pollinators depend on the flowers of the plants, as they need nectar and pollen as food resources for themselves and their offspring. However, an increasing number of pollinator and plant species are threatened by multiple, interacting, and sometimes synergistic causes (habitat loss, fragmentation, diseases, parasites, pesticides, monocultures) that are becoming a growing threat to ecosystem functioning. Given the loss of plant species diversity, it is increasingly difficult for pollinators to find food throughout the year. Therefore, this study analyses the influence of plant diversity on pollinators. The study was conducted in the course of the Jena Experiment, which is a long-term biodiversity experiment (since 2002) with 60 plant species, common to Central European Arrhenatherum grasslands. With a plant diversity gradient of 1, 2, 4, 8, 16, and 60 plant species per plot, time-series data resulted from a wide range of ecosystem processes, ranging from productivity, decomposition, C-storage, and N-storage to herbivory, and pollination. These were studied to investigate the mechanisms underlying the relationships between biodiversity and ecosystem processes. Chapter 2 studies the spatio-temporal distribution of pollinators on flowers along an experimental plant diversity gradient. For this purpose, the pollinators were divided into four different functional groups, i.e. honeybees, bumblebees, solitary bees and hoverflies. In particular, the spatial pollinator behaviour was examined, that is, in which flowering height the flowers were visited within the plant community. In order to study the temporal component, pollinator visits were observed over the course of the day and the season. As a result, an unprecedented high resolution of plant-pollinator interactions was found. For the first time it was possible to demonstrate that the different pollinator functional groups can complementarily use different spatio-temporal niches which was most pronounced in species-rich plant mixtures,. This leads to the conclusion that species-rich plant mixtures provide sufficient resources that can be used by generalists, such as honeybees and bumblebees, as well as other pollinator functional groups, such as hoverflies and solitary bees. Chapters 3 and 4 continues on the chemical composition of flower nectar (nectar) of various plant species. Nectar is used as food resource for adult pollinators, but is also largely used as a supply for their offspring, making it the most important pollinator reward. The chemical composition of the nectar was analysed for the two most important macronutrients, carbohydrates (C) and amino acids (AA), using high performance liquid chromatography (HPLC). Subsequently, their contents were analysed in terms of concentration, proportional content and the ratio of carbohydrates to amino acids (C:AA). In Chapter 3, the nectar of 34 plant species from the grasslands of the Jena Experiment was compared. In doing so, similarities and/or differences of the nectar compositions were investigated with respect to the most important macronutrients carbohydrates and amino acids between the individual species but also between the most representative plant families. This should lead to a better understanding about how plant diversity influences consuming pollinators and which factors, e.g. phylogenetics, morphology or ecology, can lead to different nectar compositions. We could show that each plant species differs in terms of carbohydrate content, amino acid content and C:AA-ratio. In addition, there were clear differences between the four representative plant families Apiaceae, Asteraceae, Fabaceae and Lamiaceae regarding the proportions of essential amino acids. The proportions of the individual sugars and the C:AA-ratios also differed greatly between the four plant families. Therefore, it can be assumed that these nectar contents are family-specific. The need for differences in carbohydrate content are probably due to the different morphology of the flowers, as plants with open flowers and exposed nectar, as in Apiaceae and Asteraceae, can protect their nectar from evaporation if the nectar has a higher osmolality, which can be achieved by a higher hexose (fructose and glucose) content. Thus, the nectar can remain dilute for a longer time and consequently remain consumable for pollinators, which in turn can contribute to the pollination of plants. Fabaceae and Lamiaceae showed different results. Here the nectar was probably protected from evaporation by closed flowers, which explains the high proportion of sucrose, leading to a lower osmolality that would enhance evaporation for exposed nectar. The metabolic pathways controlling the family-specific C:AA-ratios are yet to be explored. In conclusion, it can be suggested that this study contributes to elucidating the morphological and phylogenetic characteristics that control each plant species’ nectar composition. In Chapter 4, nectar was investigated in the context of diversity effects on the example of the plant species Field Scabious, Knautia arvensis. It was analysed to what extent the nectar quality (nutrient content) differs between plant individuals of one species. The underlying factors causing these differences in nectar composition have never been studied before. In order to investigate these coherences, plant communities in the Jena Experiment of different plant species richness levels containing the target plant species K. arvensis were used. In particular, we examined whether the nectar of K. arvensis is influenced by other neighbouring plant species, e.g. through competition for pollinators. The carbohydrate and amino acid content in nectar varied both between individuals of K. arvensis and between the different plant species richness levels. However, there were significant non-linear differences in the proportions of certain essential and phagostimulatory amino acids, which were produced proportionally more in the nectar of K. arvensis plants in species-rich plant communities, while histidine, one of the generally inhibiting amino acids tended to be less present. Our findings therefore suggest that the nectar of K. arvensis is more palatable when the plants grow in species-rich plant communities. Overall, these studies indicate how fragile plant-pollinator interactions are but also how important plant species-rich grasslands are to support plant-pollinator interactions. Increased plant species diversity is essential to ensure the availability of flowering resources throughout the year. Pollinators, such as honeybees, bumblebees, solitary bees, and hoverflies can use the niches in time and in vertical space complementarily. However, in plant species-poor grasslands there may be more niche overlaps, which is probably due to a reduced availability of resources. This points to the need to include different plant species belonging to different plant families, whose nectar may have evolved in response to morphological flower traits and metabolic pathways. Therefore plant species diversity can supply pollinators with nectar differing in carbohydrate and amino acid content and thus differing in quality. Also C-AA ratios have proven to be a useful measurement to reveal differences between plant species. In addition, C:AA ratios were not differing in nectar of K. arvensis individuals growing in different plant species richness levels, although their nectar seemed to be more attractive in mixtures with 16 plant species, likely due to higher content of essential and phagostimulatory amino acids than in plant species-poor mixtures. Thus further research investigating diversified farming systems, including pollinator-friendly practices to reveal the attractiveness of different plant species. More diversified field margins and grasslands, for the maintenance of pollinator services for sustainable provision of crop pollination.

Rangelands are the most widespread land-use systems in drylands, where they often represent the only sustainable form of land-use due to the limited water availability. The intensity of the land-use of such rangeland ecosystems in drylands depends to a large extent on the climatic variability in time and space, as on the one hand it influences the growth of biomass and therefore the grazing intensity, but on the other hand it can also destroy entire herds through extreme climatic events. Rangeland systems are seriously threatened by climate change, because climate change will alternate the availability of water in time and space. This is dangerous in that we have not yet fully understood how grazing affects vegetation under different climatic conditions. Inadequate rangeland management can quickly lead to serious degradation of the grazing grounds. This dissertation therefore deals with the question which role climatic variability plays for the effects of grazing on vegetation in dry rangelands. The relatively intact steppes in central Mongolia were chosen as a model system. They are characterised by low precipitation and high climatic variability in the south (100 mm annual precipitation), and comparatively high precipitation and low climatic variability in the north (250 mm). The effects of grazing on vegetation on 15 grazing transects were investigated along the climatic gradient. The central elements were the plant species and their abundances on 10 m x 10 m areas, for which functional characteristics such as height, affiliation of functional groups or leaf nutrients were recorded. The main hypothesis of this dissertation is that grazing has a greater impact on vegetation communities with increasing rainfall. To test this hypothesis, three studies were carried out. In a first study, we found that the vegetation communities in the dry area differ strongly along the climatic gradient, while the plant communities in the wetter area differ more strongly along the grazing gradient. The results of the second study suggested that this difference can be explained by a functional environmental filter that becomes weaker from south to north as the niche spectrum increases. The third study has shown that this is likely a function of the higher availability of resources, which at the same time leads to higher grazing pressure, therewith stressing the vegetation especially in years with droughts. In summary, I conclude that the climate gradient also represents an environmental filter that filters species for certain characteristics, thus having a significant influence on the vegetation. Climatic variability influences the effect of grazing on vegetation, which is particularly problematic where the grazing intensity is high and the species are less adapted to strong climatic fluctuations. Future scenarios predict increasing productivity and therefore increasing livestock density. This may lead to an increase in floristic and functional diversity across the climate gradient, but also to increasing grazing effects and therefore threads for overgrazing. Increasing climatic variability is likely to intensify this thread, especially in the moister regions, whereas the dry rangelands are likely to be more resilient due to the adaptation of the plants to non-equilibrium dynamics. The fate of Mongolia’s rangeland systems therefore clearly lies in the hand of the rangeland managers. The sustainable use of Mongolia’s vast steppe ecosystems might depend on a flexible livestock management system which balances the grazing intensity with the available resources, while still considering climatic variability as a key for the management decisions. A potential link-up for future studies might arise from the shortcomings of the studies presented. This dissertation suggests that long-term observations are necessary to better understand the effects of climatic variability. In addition, grazing gradients must be selected more carefully in the future in order to be able to ensure better comparability, and functional analyses should have a stronger relationship to forage quality. With these points in mind, a comparative study of several rangeland ecosystems on a global level must be the ultimate goal. This could be an important step for the sustainable use of drylands in the context of global climate and land use change.

Corporate Social Responsibility (CSR) has been established in recent years as an essential component of the economic system, demanded and promoted by a wide variety of stakeholder groups. The present dissertation shows that organizations face major communicative challenges with regard to CSR. CSR is not only determined by organizations themselves, but rather arises in the interplay with economic and social discourses. It is assumed that boundarys of organizational action are under constant change, so that CSR actors inevitably initiate constitutive communication processes. The resulting polyphony requires an understanding of the underlying communication processes. Hence, the performative character of CSR communication is taken up by this dissertation and thus the constitution of both the communicating actors and their relationships in the network is illustrated. The presented scientific papers are united by the overarching assumption that communication does not accompany and describe organizational action, but unfolds its own power.

The doctoral dissertation deals with the problems of the diagnosis of rolling bearings using recurrence analysis. The main topic is the influence of radial internal clearance on the change of dynamics in a self-aligning double-row ball bearing with a tapered bore, in which the axial preload can control this parameter in a wide range. The dissertation began with an analysis of the state of knowledge, where the works related to the analyzes of the impact of radial clearance on the dynamics of rolling bearings have been cited so far. In the next part of the dissertation, the thesis was formulated and activities related to its proving were defined. The theoretical part was supplemented with the basics related to vibroacoustic diagnostics of rolling bearings and presented methods that can be used for their diagnostics. The research on proving the thesis was started with the preparation of a mathematical model in which a change in the damping coefficient in the field of radial clearance was adopted, a difference in the clearance value for a given row of balls was proposed, and the influence of shape errors and radial shaft endplay on the dynamics of the tested bearing was taken into account. During the dynamics tests, the radial clearance was adopted as a bifurcation parameter, and on the basis of the bifurcation diagram, it was possible to indicate the characteristic areas of bearing operation due to the radial internal clearance. In order to verify the model, experimental tests were carried out with a series of bearings in which the radial clearance was changed in a wide range possible to be physically realized. Recurrence analysis was used for both the dynamic response obtained from model and experimental studies. Owing to the comparative analysis of the dynamic response, recurrence quantificators were selected that are most susceptible to changes in radial clearance to bearing dynamics. Moreover, as a result of the research, it was possible to select a narrow range of radial clearance, ensuring the smoothest operation of the tested bearing.

Extracting meaningful representations of data is a fundamental problem in machine learning. Those representations can be viewed from two different perspectives. First, there is the representation of data in terms of the number of data points. Representative subsets that compactly summarize the data without superfluous redundancies help to reduce the data size. Those subsets allow for scaling existing learning algorithms up without approximating their solution. Second, there is the representation of every individual data point in terms of its dimensions. Often, not all dimensions carry meaningful information for the learning task, or the information is implicitly embedded in a low-dimensional subspace. A change of representation can also simplify important learning tasks such as density estimation and data generation. This thesis deals with the aforementioned views on data representation and contributes to them. We first focus on computing representative subsets for a matrix factorization technique called archetypal analysis and the setting of optimal experimental design. For these problems, we motivate and investigate the usability of the data boundary as a representative subset. We also present novel methods to efficiently compute the data boundary, even in kernel-induced feature spaces. Based on the coreset principle, we derive another representative subset for archetypal analysis, which provides additional theoretical guarantees on the approximation error. Empirical results confirm that all compact representations of data derived in this thesis perform significantly better than uniform subsets of data. In the second part of the thesis, we are concerned with efficient data representations for density estimation. We analyze spatio-temporal problems, which arise, for example, in sports analytics, and demonstrate how to learn (contextual) probabilistic movement models of objects using trajectory data. Furthermore, we highlight issues of interpolating data in normalizing flows, a technique that changes the representation of data to follow a specific distribution. We show how to solve this issue and obtain more natural transitions on the example of image data.

Increased international compliance with human rights and democracy standards is a core issue for both human rights and democratizing actors as well as for victims of human rights abuse. International human rights organizations (IHROs) are expected to make positive contributions to this end, even though they possess low levels of authority. This authority has been renegotiated multiple times in various reform processes. An oversimplified expectation would have us assume that democracies would want to strengthen IHROs, and that autocracies would seek to weaken them. As the United Nations Human Rights Council (UNHRC) was reformed in 2006, 2007, 2010, and 2011, some autocracies strived to abolish parts of the UNHRC. Other autocracies aimed “merely” to weaken them. Democracies displayed an even larger variance. Indonesia and India predominantly favored weakening the UNHRC, whereas Ghana and Spain supported exclusively strengthening of the organization. Additionally, some attitudes towards the UNHRC changed from one year to the next. Autocracies diverge not only in their stances towards the UNHRC, but also across their domestic and international dimensions. Nigeria allows different levels of participation by societal actors than, say, Belarus. Cuba does not have the same domestic institutions as Russia. Iran enters international negotiations from a different position than Thailand. Democracies vary on the domestic and international dimensions as well. The Czech Republic is not the US, and Costa Rica is different from South Africa. The question that drives my research is how we can explain the broad variety of state preferences for strengthening or weakening IHROs. Previous research has mostly concentrated on democracies, leaving autocracies understudied. It also treated countries as black boxes. To account for such shortcomings, first, I systematically test the relationship between the UNHRC and its authoritarian and democratic members by means of inferential statistics. Second, I analyze a bottom-up process inherent to New Liberalism. It scrutinizes the role of domestic societal actors, domestic institutions, as well as pressures on the international stage. The results reveal that societal actors, along with the interplay of wealth and regime type in the international realm, figure as the most important predictors of delegation preferences voiced by autocracies and democracies during the reform of the monitoring bureaucracy Special Procedures of the UNHRC. Societal actors play a more important role in democracies than in autocracies. Institutionalized domestic oversight mechanisms help societal actors to conduct effective lobbying at the domestic level. Oversight mechanisms are more important than the rule of law and electoral institutions. Regarding international coalition building, authoritarian regimes turn out to be better organized than democracies. I conclude that supporters of strong IHROs shall 1. empower domestic societal actors; 2. disrupt cohesive delegation preferences of authoritarian regimes; and 3. invest in independent domestic oversight mechanisms.