4242 research outputs found
Sort by
Essays on the Role of Content in Digital Marketing Communications
Full text linkIn Essay I, the author develops and validates a 4-dimensional second-order measurement model including 17 items to assess consumer perceived firm-generated content value in social media. In addition, the author calculates a multi-group model, revealing that marketers should particularly pay attention to emphasize informative content on Twitter, entertaining content on Instagram, and empathic content on Facebook. Essay II includes a field experiment on Facebook. The author investigates key characteristics of Digital Content Marketing in comparison to Digital Advertising. Moreover, the author demonstrates that perceived content value significantly translates through a positive attitude toward the content into purchase intention and content post interaction intention (i.e., intentions to like, share, and comment). Essay III constitutes a systematic literature review. The author offers a synoptic framework on the impact of digital content dimensions on firm-related consequences that have been examined in the leading marketing journals during the years 2000-2019
H-ROV-LARS: Entwicklung eines Aussetz- und Bergesystems mit integrierter, neuartiger Kommunikation und Ortung für das Hybrid-ROV (LARS), Schlussbericht.
Full text linkGlobal climate and Indonesian Throughflow during the Middle Miocene Climate Transition : a modeling approach
No full textThe current study focuses on the Middle Miocene Climate Transition (MMCT), a main global cooling step during the Cenozoic (66-0 Ma). This transition, likely triggered by changes in the Earth's orbital configuration and a decrease in atmospheric CO2 concentration, entailed major expansion of the Antarctic ice sheet, cooling of the surface and deep ocean, and global eustatic sea level fall during the interval 15-13 Ma. A central aim of this study is to assess, by means of the global coupled model Community Climate System Model version 3 (CCSM3), the ocean response to atmospheric CO2 dropdown and Antarctic ice sheet expansion during the MMCT. In particular, it is investigated whether the combined effects of the CO2 decrease and Antarctic ice sheet expansion could explain the cooling of surface and deep waters across the MMCT inferred from proxy data, the separate effects of these two forcings on surface and deep water temperatures, and the mechanisms these forcings were triggering that explain their modeled effects on ocean temperatures. Ocean gateways are relatively narrow channels of water separating two main ocean basins. Changes in the bathymetry of ocean gateways alter the water properties of the basins they connect and this can have regional to global scale climate effects. An example of ocean gateway is the Indonesian gateway, the tropical passage connecting the Pacific and Indian oceans, which has a significant influence on the climatic states of those oceans. The origin of the West Pacific Warm Pool, for example, the most extensive warm surface water mass on Earth, has been suggested to be linked to narrowing of the Indonesian gateway. A further aim of this study is that of modeling the characteristics of the Indonesian Throughflow during the MMCT by means of CCSM3, providing estimates of volume transport, analyzing the vertical structure of the waterflow, the direction of waterpaths, the relative contributions of North and South Pacific water to the Indonesian Throughflow, the control mechanisms of its seasonal variability, and examining whether a similar structure to the present-day West Pacific Warm Pool existed during the MMCT in the Indonesian Throughflow area. The model boundary conditions employed in our experiments include Middle Miocene global vegetation, topography, and bathymetry - comprising a geographic reconstruction of Southeast Asia for 15 Ma - as well as Antarctic ice sheet configurations, sea levels, and atmospheric CO2 concentrations characterizing the periods before (Middle Miocene Climatic Optimum) and after the transition (Middle Miocene Glaciation)
Robust Capacitated Vehicle Routing Problem with Uncertain Demands
Full text linkThis thesis addresses the Static and Stochastic Capacitated Vehicle Routing Problem with Stochastic Demands (SSCVRPSD). In this problem, an initial a priori route plan is designed. During plan execution, corrective actions are applied as each demand is revealed, if the real total demand of a route exceeds the vehicle capacity. The goal is to calculate a robust a-priori route plan that will only undergo small changes when the true demands are revealed during its implementation. For that, we propose a mathematical formulation based on a Mean Absolute Deviation (MAD) objective function. This objective function combines two conflicting objectives, minimization of the expected planned transportation cost (optimality) and minimization of the mean absolute deviation of the second-stage transportation cost (robustness). In the MAD model, the variability term is multiplied by a parameter of decision-maker's choice A , used to obtain a spectrum of route plans that can be more or less robust. In this manner, the proposed formulation delivers flexibility to the decision-maker to define desired safety levels and allows to trade off cost minimization and protection
The response of CO2 emissions to the business cycle: New evidence for the U.S.
Full text linkThis paper investigates the response of CO2 emissions to the business cycle for the U.S. on a monthly basis between 1973-2015. Using a rolling-regression approach, we find that the emissions elasticity with respect to GDP is not constant over time, irrespective which filtering method, such as the Hodrick-Prescott, the Baxter-King, the Christiano-Fitzgerald or the Butterworth filter has been employed. In order to check whether or not emissions react differently during normal and recession times, next, we employ a Markov-switching approach. We find, first, that emissions are significantly more elastic during recessions, than in normal times. Second, depending on the filtering method, we also obtain parameter estimates of the emissions elasticity above one in recession times and below one in normal times. Thus, environmental policy instruments not turning out to be sub-optimal should account for this asymmetric response of emissions due to changes in GDP
Influence of Coulomb interaction and spatial inhomogeneities on two-dimensional materials
Full text linkNowadays a large variety of two-dimensional (2d) materials ranging from (functionalized) graphene, graphene analogues like hexagonal boron nitride to metallic, semiconducting or superconducting transition metal dichalcogenides are studied theoretically and experimentally. Their remarkable material features, resulting from the unique two-dimensional physics, as well as flexibility in tuning of their properties made them interesting for various applications. For example regarding electronic devices novel kinds of heterostructures were created with the possibility for on demand tailoring through the stacking of different layered materials. Coulomb interaction effects play a major role in characterizing 2d materials. Due to the low dimensionality of the systems, the interaction effects are enhanced and highly sensitive to external screening. In this thesis we make use of these peculiar interaction effects to create lateral heterojunctions within otherwise homogeneous monolayers through the external manipulation of the Coulomb interaction. Therefore we study the band gap modulation in semiconducting transition metal dichalcogenides placed on laterally structured substrates and show spatially sharp band gap transitions on the order of a few unit cells. Contrary to other kinds of heterostructures, the proposed mechanism is non-invasive leaving the active material of the heterojunction untouched. With respect to optical properties we study the response of the exciton to tuning of the Coulomb interaction and find that the lowest energy excited state is nearly unaffected by dielectric environments. However, higher energy excitations can be strongly manipulated. For the construction of optimal tailor-made devices a comprehensive understanding of the underlying Coulomb interaction effects is necessary. However, interaction effects are often not well understood and can be difficult to describe. To this end we utilize models based on ab-initio calculations which include the main features of the investigated materials and suitable descriptions of the screening effects. To find optimal candidates for these kind of heterostructures we compare the effect of external dielectric environments on different semiconducting transition metal dichalcogenides. All materials under investigation show the same relative changes in the band gap for increasing dielectric screening rendering this class of materials equally suitable for further applications. Not only the dielectric but also the chemical environment, e.g. different gaseous atmospheres, can alter the material properties of a 2d material. Finally we investigate the influence of O2 adsorption on (doped) monolayer MoS2 as a promising candidate for sensing applications
Fast Robot Learning using Prospection and Experimental Knowledge : A Cognitive Approach with Narrative-Enabled Episodic Memories and Symbolic Knowledge
Full text linkHumans employ data-efficient learning mechanisms to obtain new skills and to improve the existing ones. Robots have already replaced humans in terms of labor in performing repetitive and dangerous tasks in structured environments like factories. On the other hand, developing completely autonomous robotic systems for unstructured environments, like a household, is still a challenge for roboticists due to the infeasibility of programming every possible case and today's data-hungry machine learning approaches. In order to assist humans in such environments, I believe that robots should be able to gain and improve skills using human-like learning mechanisms regularly. For this purpose, I present a cognition-enabled fast learning framework in this dissertation which makes use of symbolic knowledge, episodic memories, and cloud robotics services along with a cutting-edge deep imitation learning methodology in order to reduce the dependency on big experiment data. Using this framework, robots can (1) imitate tasks demonstrated by a human demonstrator in virtual-reality, (2) adapt the actions of itself and others to new conditions, and (3) prospect which task parameters lead to the desired goal. To validate these abilities, I have provided some experimental results. These experiments were conducted with four different service robots in various kitchen environments. The human demonstrations were recorded inside a game-with-a-purpose using virtual-reality equipment. Such a setup enables roboticists to crowdsource their training data by eliminating the requirement of being in the same environment with the robot
Microbial processes and element cycling from micro- to meso-scale : from single cells and aggregates to the whole water column perspective.
Full text linkMarine microorganisms are important drivers of the C-, N- and S- cycles on earth. They can adapt to various substrates and, thus, inhabit extreme environments, such as sub- and anoxic or even sulfidic waters or micro-zones within sinking particles. The latter still represent a major black box in microbial ecology due to their fragile nature, which makes them inaccessible for detailed micro-scale observations. Moreover, sinking particles and their complex communities represent a biogeochemical link between small- and large-scale processes because they are shaped by a wide variety of physical and biological processes ranging from the micro- to meso-scale. In this thesis, cutting-edge methodologies were applied to investigate microbial processes of free-living and particle-associated organisms at the micro-scale, and to build strategies to integrate these processes into a broader understanding of microbial dynamics at oceanographic scales of relevance to the global ocean
Glory to Trumpland! Critically Playing Border Games
No full textThis project examines the critical play of a variety of games about immigrant and refugee experience. These border games take place within fictional or actual borderlands and follow characters either in transit or trapped in detainment centers between nations. Spanning a range of genres, each deals differently with the major problem posed by their content - how to create a sensitive procedural rhetoric around migration. Drawing from Flanagan's conceptualization of critical play and Mukherjee's work on the ambivalence of postcolonial playing back, I explore the possibilities of critically playing border games and the extent to which each game's design (dis)allows for certain forms of play and protest. I focus on three paired case studies, Escape from Woomera (2003) and Smuggle Truck (2012); Papers, Please (2013) and Liberty Belle's Immigration Nation (2014); and Bury Me, My Love (2017) and The Waiting Game (2018). By considering both the design of these border games and the metagaming practices that have developed around them, I show how postcolonial misplay of fictional games draw more effective critical attention to injustice than the most well-intentioned and serious educational gam
The role of discourses in a transformation of social practices towards sustainability : the case of meat eating related practices
Full text linkSocial practice theories help challenge the often hidden paradigms, worldviews and values at the basis of many unsustainable practices. However, practice theoretical research can also struggle to provide useful results for policymaking. Connected to social practices, discourses and their boundaries define what is seen as possible, what the range of issues and their solutions are. By exploring the connections between practices and discourses - where paradigms, worldviews and values are represented through cognitive frames a this thesis develops, firstly, a conceptual approach to help enable purposive change in unsustainable social practices. This is done in an interdisciplinary manner integrating different literatures. Secondly, the thesis takes the current meat system as a central theme. Radical transformation towards new meatways is arguably necessary, yet complex psychological, ideological and power related mechanisms currently inhibit change. Discourses are explored for answers