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Understanding the Regional Variation in Charging Behaviour across Germany
No full textAs Germany advances towards widespread electric vehicle (EV) adoption, understanding regional disparities in charging patterns is critical for optimising infrastructure, policy design, and grid stability. This study examines regional differences in EV charging behaviour across Germany, analysing factors such as urbanisation levels, grid capacity, socio-economic conditions, and renewable energy integration. Using the data from EV driver survey conducted in Germany, we identify variations in charging frequency, duration, and preferred time slots between urban and rural areas. The study also explores the impact of socio-economic factors, including income levels and vehicle ownership patterns, on charging behaviour. Higher-income regions tend to have a greater share of private home charging, whereas lower-income urban areas depend more on public infrastructure. Furthermore, regional differences in transportation habits, such as the use of EVs for long-distance commuting versus short urban trips, influence the timing and intensity of charging demand. Policy implications include the need for tailored infrastructure investments, dynamic pricing models, and incentives to promote off-peak and renewable-based charging in different regions. The study contributes to the broader discourse on electrifying the transportation sector by providing perceptions into how localised factors shape EV charging behaviours, aiding stakeholders in designing region-specific strategies for an efficient and equitable transition to electric mobility in Germany
Road User Detection with Automotive Polarimetric Radars
No full textWith the availability of the first automotive polarimetric 77Ghz radars that are small enough to be integrated in cars, a new information dimension given by measuring the polarization of received electromagnetic waves and knowing the polarization of transmitted waves can be exploited for automotive applications. In this thesis, the benefits of polarimetric information for road user classification and detection in the automotive context are investigated. For this purpose, a variation of real-world traffic scenarios has been recorded and annotated to form a large dataset that allows the evaluation of the potential of polarimetric radars. A general impression of how different road users appear to polarimetric radars is obtained by measuring and analyzing their polarimetric signatures. The signatures show that, especially for cars and bicycles, the scattering behavior changes depending on the aspect angle under which they are observed, potentially allowing for better classification and orientation estimation of these objects. Using sparse radar point clouds in which each point has additional polarimetric information, a classical random forest classifier is applied with hand-crafted features computed on clusters of radar points. The classification performance with additional polarimetric features is significantly improved compared to the performance without the availability of polarimetric features. In the next step, a machine learning model is used to learn features directly on the polarimetric radar point clouds. Again, it is observed that the scattering information measured with polarimetric radars improves the class and instance segmentation performance compared to when only conventional radar information is available. An additional importance analysis shows that the polarimetric information is more valuable than the RCS. Sparse radar point clouds are extracted from denser underlying data that contains more information, so potentially valuable data can be lost in the radar point cloud generation step. Therefore, a machine learning model using this layer of data, also referred to as a 'radar data cube', is presented and evaluated for improving road user detection. The model predicts oriented bounding boxes with class labels. Experiments with the model show that the raw data layer enriched with polarimetric scattering data provides significantly better detection and orientation results than without this data
Target classification using polarimetric scattering properties of volume scattering measured with weather radars
No full textDie Luftfeuchtigkeit in der Troposphäre stellt sich in Form verschiedener Arten von Teilchen dar, welche auch Hydrometeore genannt werden. Mithilfe der Messungen eines Mikrowellenradars ist es nun möglich diese Hydrometeore zu charakterisieren. Die Analyse der aufgenommenen Datensätze liefert dabei einen wichtigen Anteil der vorliegenden Arbeit. Einen weiteren Grundstein bildet die Simulation der Streuung der vom Wetterradar empfangenen elektromagnetischen Welle. Damit liegt ein zusätzliches Verfahren vor, um die Eigenschaften der Partikel näher zu untersuchen. Die Klassifikation der Teilchen ergibt sich daraufhin durch die Kombination der Analyse der gemessenen Radardaten mit den simulierten Werten aus der Streutheorie. Ein Vergleich unterschiedlicher Klassifikationsmethoden mit ihren spezifischen Vor- und Nachteilen führt letztendlich zu einem Klassifikationsschema, welches besonders für den Übergang von Schneeflocken zu Regentropfen ausgelegt ist.:1 Introduction
2 Polarimetric Fundamentals of Electromagnetic Waves and Weather Radars
3 Theory of Scattering Simulations for Hydrometeors
4 Simulation Results for Hydrometeor Scattering
5 Hydrometeor Classification based on Radar Measurements
6 Conclusions and Outloo
Surface Enhancement of Macro-PBF-LB/M Components via Plasma Electrolytic Polishing
No full textThis study investigates surface enhancement of components fabricated using a macro powder bed
fusion with laser beam (macro-PBF-LB/M) process. Stainless steel 1.4301 was used with coarse
powder particles (0.2–1 mm), 1 mm layer thickness, and a 4 kW laser to produce a 25 × 25 × 50
mm³ test specimen. While macro-PBF-LB/M offers high deposition rates comparable to directed
energy deposition (DED), it results in poor surface quality, necessitating extensive post-processing.
Plasma electrolytic polishing (PEP) was applied as a non-mechanical post-processing method to
improve surface topography. In the PEP setup, the component acts as the anode in an electrically
conductive electrolyte, where high current density generates a vapor–plasma envelope responsible
for material smoothing. The effectiveness of PEP in reducing surface roughness and modifying
topographical features is assessed. Results demonstrate PEP’s potential as an effective finishing
technique for macro-PBF-LB/M components, enabling higher throughput additive manufacturing
while meeting surface quality requirements for engineering applications
Influence of Plasma-electrolytic Polishing (PeP) on Spark-eroded Surfaces
No full textDepending on the surface pretreatment, the results of plasma electrolytic polishing (PeP) vary
considerably. Investigations of copper and steel samples cut using Wire-Electro-Discharge
Machining (WEDM) demonstrate that the results differ from each other and differ from grinding
surfaces. In the case of eroded surfaces, the factors such as pulse energy, micro cracking, and heat-
affected zone (HAZ) play a crucial role. The sample surfaces examined show the changes in the
surfaces after PeP and which surface substructures cannot be influenced. Similar influences were
observed in narrow deep channels [1]
Das Phänomen Reibwert – Exemplarische Betrachtung der Paarung Polyoxymethylen (POM) gegen ultrahochmolekulares Polyethylen (UHMWPE)
No full textDer Reibwert einer Materialpaarung ist ein wesentlicher Bestandteil zur Auslegung von Maschinen und Anlagen. Im Bereich der Fördertechnik betrifft das u. a. die Kettenförderer. Hier ist der Reibwert zwischen der Kette und den Stütz- bzw. Führungselementen sowohl für die benötigte Antriebsleistung als auch für die Belastung der Kette entscheidend. Ein fälschlicherweise zu gering angesetzter Reibwert kann deshalb zu ungeplant hohem Energieverbrauch sowie verstärktem Verschleiß und Funktionsstörungen bis hin zum Bruch der Kette und Ausfall der Anlage führen. Umgekehrt ist durch gezieltes Verringern des Reibwertes ein energieeffizienter und langlebiger Transportvorgang möglich. Die erwähnten Kettenförderer werden häufig mit Kunststoffketten aus Polyoxymethylen (POM) ausgerüstet, welche typischerweise mit Gleitelementen aus Polyethylen (PE), oft ultrahochmolekularem UHMWPE, abgestützt und geführt werden. Hierbei ergibt sich bei der Dimensionierung folglich die Frage nach dem exakten Reibwert zwischen diesen beiden Werkstoffen. Im Beitrag wird anhand von theoretischen und experimentellen Untersuchungen dargestellt, dass diese Frage unmöglich eindeutig beantwortet werden kann, da der Reibwert in erheblichem Maß von den zugrundeliegenden Randbedingungen abhängig ist. Wie die Testergebnisse zeigen, muss das tribologische Verhalten von dauerbelasteten Bauteilen in Langzeitversuchen unter möglichst anwendungsnahen Bedingungen untersucht werden
Detection of sensorimotor perturbations in grasping and walking
No full textLiving in a dynamic environment requires continuous adjustments of our actions to interact efficiently with our dynamic world. However, learning how to adjust motor actions is inherently complex and relies on multiple sources of information, initiating various processes of a gradual improvement of motor actions. One such process on a sensory based level is called sensorimotor adaptation, a form of sensorimotor learning. Some of these adjustments can occur automatically, without being detected by the actor, others however are consciously initiated as the actor becomes aware of the need to correct their action. Thus, identifying the underlying properties and mechanisms making people aware of sensorimotor differences between informational inputs – that is, perturbation detection – and therefore making sensorimotor adaptation explicit is the core of this thesis. Having outlined the latest findings on potential properties and suitable measurements of perturbation detection, I present a first study examining the impact of two candidate factors in the detection of motor perturbations – on the one hand, the magnitude of a perturbation (i.e., physical mismatch between two stimuli) and on the other hand, the size of the perceived sensory error signal. Using grasping, a well-studied motor action with respect to sensorimotor adaptation, I developed an experimental setup allowing participants to grasp real-world cuboids while manipulating these two perturbation properties. Results highlighted the importance of the sensory error signal on perturbation detection, suggesting that adaptation impedes the perturbation detection in grasping. To improve the generalizability of the reported properties, mismatch and error signal, on detectability of perturbations, the next step was to examine other real-world actions like walking that engage different effectors, thus providing different error feedback to adapt to. Since the current literature is lacking precise threshold estimates in walking and barely discusses the differences in increasing versus decreasing speed perturbations, I first focused on filling this gap in study 2. This would be a necessary foundation for replicating the effects found in grasping of sensory error signals on perturbation detection also in walking. Using adaptive psychophysical methods, customized to a naturalistic walking environment, I report precise and reliable measurements for just-noticeable differences of increased- and deceased-speed split-belt perturbations. Comparing variability of these threshold estimates emphasizes the importance of considering individual differences for measuring perturbation detection while walking. Enhancing the understanding of perturbation detection across different modalities and actions also revealed some methodological difficulties that are further addressed in study 3. Psychophysical discrimination tasks have been reported to change the attention towards perturbations, which in turn changes the error signal as it enables cognitive adjustments. To overcome this problem, I added confidence estimation to the discrimination task in the grasping experiment and included pupillometry as a potential physiological no-report measure of perturbation detection. I found similar results compared to study 1, underlining the importance of the sensory error signal on perturbation detection while considering the special role of uncertainty. Moreover, pupil parameters responded to experimental manipulations as well as the grasping error, providing a promising methodological approach for a measurement of perturbation detection without relying on participant’s direct report. Finally, I discuss the implication of these results embedded in the wider context of sensorimotor adaptation and perturbation detection. I present perspectives on how these findings contribute to open questions of perception and action as well as future directions on how these could further be implemented in a more applied framework.:Bibliographische Beschreibung 1
Abstract 2
Acknowledgements 4
1 General introduction 7
1.1 Development of action improvement 8
1.1.1 Adjustments to sensory errors 9
1.1.2 Sensorimotor adaptation to perturbations 10
1.1.3 Sensory errors in computational models of adaptation 14
1.1.4 Implicit and explicit adaptation processes 17
1.1.5 Including awareness in models of adaptation 20
1.2 Detecting perturbations 22
1.2.1 Making a perturbation detectable 22
1.2.2 Constraints in changing perturbation properties 24
1.2.3 Dissociating mismatch and error signal 25
1.3 Measuring perturbation detection 25
1.3.1 Report-based measures of perturbation detection 26
1.3.2 No-report measures of perturbation detection 27
1.4 Summary and overall goal 29
2. Perturbation detection in grasping based on sensory mismatch and error signal 30
2.1 Size-perturbations in grasping 30
2.2 Study 1: Sensorimotor adaptation impedes perturbation detection in grasping 32
2.2.1 Abstract 32
2.2.2 Introduction 33
2.2.3 Methods 35
2.2.4 Results 42
2.2.5 Discussion 50
2.3 Contributions in a wider perspective I 52
3. Detecting perturbations in different actions 54
3.1 Sensorimotor perturbations in walking 54
3.1.1 Perceiving information in grasping and walking 54
3.1.2 Gait parameters and treadmill walking 55
3.1.3 Detecting split-belt speed perturbations 57
3.1.4 Manipulating gait speed – the QUEST procedure 59
3.2 Study 2: Perceiving inter-leg speed differences while walking on a split-belt treadmill 60
3.2.1 Abstract 60
3.2.2 Introduction 61
3.2.3 Methods 63
3.2.4 Results 68
3.2.5 Discussion 72
3.3 Perception thresholds in grasping and walking 76
3.4 Contributions in a wider perspective II 77
4. Pupillometry as a no-report marker for perturbation detection 78
4.1 Limitations of psychophysical measures in the context of perturbation detection 78
4.2 Pupil diameter in sensorimotor adaptation tasks 79
4.3 Combining psychophysics and pupillometry 81
4.4 Study 3: “Can Pupillometry Reveal Perturbation Detection in Sensorimotor Adaptation during Grasping?' 82
4.4.1 Abstract 82
4.4.2 Introduction 83
4.4.3 Methods 88
4.4.4 Results 96
4.4.5 Discussion 105
4.4.6 Appendix 109
4.5 Contributions in a wider perspective III 112
5. General Discussion 113
5.1 Detecting and reporting perturbations 114
5.1.1 Is reporting just the plain response of a detected perturbation? 114
5.1.2 Perception of sensory errors in real-world behavior 116
5.1.3 Dealing with uncertainty 117
5.1.4 Properties of perturbation detection 119
5.2 Future perspectives 120
5.2.1 Implications on perturbation procedures 120
5.2.2 Pupillometry and properties of perturbation detection in walking 121
5.2.3 Importance of the sensory error signal 123
5.2.4 Contributions on naturalistic actions and applications 124
5.3 Conclusion 126
6. References 128
Publication list 15
Tour de Tech: Iterating Toward a VR CAVE Test Environment for Investigating Cyclists Intentions
No full textThis paper introduces an innovative VR CAVE test environment designed to investigate cyclists' intentions in virtual scenarios. While intention prediction is the long-term application, this study focuses on the technical feasibility and user perception of the system. The evaluation reveals that the system already delivers an engaging and enjoyable virtual cycling experience, supported by the use of a real bicycle and head tracking. Results indicate that additional sensory stimuli significantly enhance the realism and Ecological Validity of the environment, although perceived control and overall presence still require improvement. To address the identified technical bottlenecks, planned hard-and software are discussed. These developments will enable systematic, reproducible, and safe investigations of cyclists' behavior and intention. This data will help improve trajectory planning in autonomous vehicles and advance the mobility transition
How Consistently We Behave as Pedestrians or as Drivers: Do Traffic Accidents or Driving Experience Influence Our Behavior?
No full textThe current study aims to investigate the relationship between the reported pedestrian and driver behavior as well as whether this behavior differs regarding certain traffic related factors. A total number of 295 drivers (168 male and 127 female) with a mean age of 31.58 years completed the demographic information form, Pedestrian Behavior Scale, Driver Behavior Questionnaire and Positive Driver Behavior Scale. The results show that aberrant pedestrian behavior is positively related to aberrant driver behavior and positive pedestrian behavior is positively related to positive driver behavior. In addition, it is found that individuals with accident experience report to violate rules as both driver and pedestrian and to perform more aggressively as pedestrians compared to those without accident experience. Finally, drivers who drove daily reported less violation of rules as pedestrians and performed fewer lapses than either drivers who drove less or those who never drove. As for driver errors, they reported making less errors than either drivers who drove less or those who never drove. The results and the limitations of this study are discussed
The role of playfulness during the idea generation process in the early stage of innovation in organizations
No full textPlay is training for the unexpected”.
This statement by Mark Beckoff sums up not only the potential of play for humanity, but also its high value for every aspect of life. From an anthropological explanatory model based on the principles of Johan Huizinga's 'Homo Ludens', play was and is not only a necessity for the development of our modern civilization, but also an innate, primal human trait. With this in mind and knowing that play can provide an appropriate skill set to face the unexpected, a return to our playful abilities could be helpful in meeting the challenges of our dynamic and volatile times. Play allows us to immerse ourselves in the unknown while at the same time getting closer to the essential core of what it means to be human. When this state of total immersion and flow is achieved, the mindset for creating and crafting new ways, solutions or ideas for challenges of any kind becomes more tangible.
To deal with challenges and complexities, organizations and companies have relied on the skills of their members or employees to foster innovation. For this reason, organizations and companies have postulated groups and teams to facilitate and manage innovation processes. An integral part of the process of fostering innovation in organizations or companies is always the generation of ideas through creativity workshops. In creativity workshops, a heterogeneous group of people is brought together under the guidance of a facilitator. The facilitator's task is to use different types of creativity methods that best suit the goals of the workshop. As a facilitator, it is crucial to find the right balance between stimulating creativity through guided creativity methods on the one hand and maintaining an environment of independent free thinking and creative spontaneity without guidelines on the other. Today, as the paradigm shift of the free market towards an ecological and sustainable economy increases the demand to accelerate the output of new technologies and innovative solutions, organizations need to find new effective ways to enrich their idea generation processes. Although various methods with playful attributes such as serious games or gamification frameworks are common, the coherent use of play, playfulness or creativity methods with playful elements in the context of idea generation in organizations still needs to be improved or fully developed.
This cumulative dissertation examines the role of playfulness in idea generation in the early stages of innovation. By opening up the understanding of the concept of play in the first paper, a general theoretical basis and definition of what play can offer as a means of creative idea generation is manifested for the dissertation. Huizinga's model of Homo Ludens suggests that every act of play is meaningful. It is in this spirit of meaningful endeavor that engagement and motivation with the subject under discussion will arise according to the principles of Homo Ludens. As a result of my comparative literature research in the first paper, I suggested that the use of actual playful elements would be beneficial to the generation of new ideas.
In order to test whether or not the use of playful elements in idea generation is indeed helpful, the second paper was designed to compare, in a quasi-experimental setting, three creativity methods with playful interventions in terms of their impact on creative output and the workshop experience for participants. In particular, the research looked at the playful interventions of drama intervention, toolkit-based modelling, and gaming. We used the methods independently in several real-world creativity workshops. To create types of outcomes, we assessed the quantity and quality of ideas developed with each method, and also the workshop experience of participants in an exploratory study. It turned out that there was no significant difference between the methods, but compared to traditional workshops, playful interventions outperformed traditional workshops in terms of quantity and quality of creative output. In addition, the workshop experience was a source of inspiration for participants in their day-to-day collaboration. Data collection for the second and third papers in this thesis was conducted with and in a case organization in the automotive sector in Germany. After investigating the influence of playfulness or playful elements in the sense of Homo Ludens, we shifted the focus from the influence of playful creativity methods to the influence of personality traits with the practitioners of such playful creativity methods, the facilitators. In the third and final paper we asked what influence the personality of the facilitator has on creativity workshops. We identified distinctive facilitator personalities for the quasi-experimental case study. The quasi-experimental case study was therefore designed to identify distinctive facilitator personality traits. We selected three facilitators who were asked to facilitate identically designed workshops, and we created personality profiles using the NEO-FFI Big Five personality model. The quantity and quality of ideas generated, the participants' experience of the workshop and the conduct of participatory observations were assessed as creative outcomes. The study found that a facilitator who is extroverted, empathetic, has deep methodological knowledge and extensive experience in facilitating creativity workshops is particularly advantageous. Finally, the findings suggest that the facilitator's personality may influence the outcomes of creativity workshops in terms of creative output and workshop experience.
With regard to all three papers, this dissertation achieves a number of results and contributes to a broader understanding of how creative ideas can be achieved through playfulness in organizations. Based on the contributions of the first paper, the concept of play was introduced and re-conceptualized for the context of idea generation. The next paper highlighted three different types of playful interventions that can be used as a scientifically validated guide for organizations. The final paper explored the role of the facilitator persona in the implementation of playful creativity methods. The results can be considered valuable as they assessed personality traits that are beneficial for effective facilitation of playful interventions in creativity workshops.
The coherence of all the research efforts during this dissertation provides a general and specific understanding of the question of the role of playfulness in the idea generation process from a methodological and practical perspective.:Abstract 2
Résumé 4
Zusammenfassung 9
Acknowledgement 11
1. Introduction and motivation 14
2. Structure 17
3. Publications 25
3.1 Ideate Hard, Play Harder - The importance of play and its contribution to idea generation workshops 27
Introduction 27
Play harder – the power of play for humankind 29
Homo Ludens reconsidered 30
Where the magic happens – The Magic Circle and the State of Flow 31
Why so serious? – Seriousness ≠ Play? 33
Happiness as a motive for play 34
A short history of … Serious Games 35
A short history of … Gamification 37
Ideate hard – The role of idea generation workshops in business 38
Ideate hard, Play harder – Discussion and Conclusion 39
Bibliography 41
3.2 The impact of playful interventions for idea generation processes: a case study of an automotive producer 44
1 Introduction 45
2 Theoretical background 46
3 Research Process 50
4 Findings 53
5 Discussion 55
6 Conclusions 59
References 60
3.3 The role of workshop facilitator personas: A case study of creativity workshops at an automotive producer 65
1. Introduction 65
2. Theoretical background 67
3.Research Process 71
4.Findings 76
5. Discussion 80
6. Conclusions 84
References 86
Appendix 94
4. Conclusion 97
References 10