One of the central goals of design is the creation of experiences that are rated favorably in the intended application context. User expectations play an integral role in tactile product quality and tactile plausibility judgments alike. In the vibrotactile authoring process for virtual environments, vibra-tion is created to match the user’s expectations of the presented situational context. Currently, inefficient trial and error approaches attempt to match expectations implicitly. A more efficient, model-driven procedure based explicitly on tactile user expectations would thus be beneficial for author-ing vibrations. In everyday life, we are frequently exposed to various whole-body vibrations. Depending on their temporal and spectral proper-ties we intuitively associate specific perceptual properties such as “tin-gling”. This suggests a systematic relationship between physical parame-ters and perceptual properties. To communicate with potential users about such elicited or expected tactile properties, a standardized design language is proposed. It contains a set of sensory tactile perceptual attributes, which are sufficient to characterize the perceptual space of vibration encountered in everyday life. This design language enables the assessment of quantita-tive tactile perceptual specifications by laypersons that are elicited in situational contexts such as auditory-visual-tactile vehicle scenes. Howev-er, such specifications can also be assessed by providing only verbal de-scriptions of the content of these scenes. Quasi identical ratings observed for both presentation modes suggest that tactile user expectations can be quantified even before any vibration is presented. Such expected perceptu-al specifications are the prerequisite for a subsequent translation into phys-ical vibration parameters. Plausibility can be understood as a similarity judgment between elicited features and expected features. Thus, plausible vibration can be synthesized by maximizing the similarity of the elicited perceptual properties to the expected perceptual properties. Based on the observed relationships between vibration parameters and sensory tactile perceptual attributes, a 1-nearest-neighbor model and a regression model were built. The plausibility of the vibrations synthesized by these models in the context of virtual auditory-visual-tactile vehicle scenes was validat-ed in a perceptual study. The results demonstrated that the perceptual spec-ifications obtained with the design language are sufficient to synthesize vibrations, which are perceived as equally plausible as recorded vibrations in a given situational context. Overall, the demonstrated design method can be a new, more efficient tool for designers authoring vibrations for virtual environments or creating tactile feedback. The method enables further automation of the design process and thus potential time and cost reductions.:Preface III Abstract V Zusammenfassung VII List of Abbreviations XV 1 Introduction 1 1.1 General Introduction 1 1.1 Objectives of the Thesis 4 1.2 Structure of the Thesis 4 2. Tactile Perception in Real and Virtual Environments 7 2.1 Tactile Perception as a Multilayered Process 7 2.1.1 Physical Layer 8 2.1.2 Mechanoreceptor Layer 9 2.1.3 Sensory Layer 19 2.1.4 Affective Layer 26 2.2 Perception of Virtual Environments 29 2.2.1 The Place Illusion 29 2.2.2 The Plausibility Illusion 31 2.3 Approaches for the Authoring of Vibrations 38 2.3.1 Approaches on the Physical Layer 38 2.3.2 Approaches on the Mechanoreceptor Layer 40 2.3.3 Approaches on the Sensory Layer 40 2.3.4 Approaches on the Affective Layer 43 2.4 Summary 43 3. Research Concept 47 3.1 Research Questions 47 3.1.1 Foundations of the Research Concept 47 3.1.2 Research Concept 49 3.2 Limitations 50 4. Development of the Experimental Setup 53 4.1 Hardware 53 4.1.1 Optical Reproduction System 53 4.1.2 Acoustical Reproduction System 54 4.1.3 Whole-Body Vibration Reproduction System 56 4.2 Software 64 4.2.1 Combination of Reproduction Systems for Unimodal and Multimodal Presentation 64 4.2.2 Conducting Perceptual Studies 65 5. Assessment of a Sensory Tactile Design Language for Characterizing Vibration 67 5.1.1 Design Language Requirements 67 5.1.2 Method to Assess the Design Language 69 5.1.3 Goals of this Chapter 70 5.2 Tactile Stimuli 72 5.2.1 Generalization into Excitation Patterns 72 5.2.2 Definition of Parameter Values of the Excitation Patterns 75 5.2.3 Generation of the Stimuli 85 5.2.4 Summary 86 5.3 Assessment of the most relevant Sensory Tactile Perceptual Attributes 86 5.3.1 Experimental Design 87 5.3.2 Participants 88 5.3.3 Results 88 5.3.4 Aggregation and Prioritization 89 5.3.5 Summary 91 5.4 Identification of the Attributes forming the Design Language 92 5.4.1 Experimental Design 93 5.4.2 Participants 95 5.4.3 Results 95 5.4.4 Selecting the Elements of the Sensory Tactile Design Language 106 5.4.5 Summary 109 5.5 Summary and Discussion 109 5.5.1 Summary 109 5.5.2 Discussion 111 6. Quantification of Expected Properties with the Sensory Tactile Design Language 115 6.1 Multimodal Stimuli 116 6.1.1 Selection of the Scenes 116 6.1.2 Recording of the Scenes 117 6.1.3 Recorded Stimuli 119 6.2 Qualitative Communication in the Presence of Vibration 123 6.2.1 Experimental Design 123 6.2.2 Participants 124 6.2.3 Results 124 6.2.4 Summary 126 6.3 Quantitative Communication in the Presence of Vibration 126 6.3.1 Experimental Design 127 6.3.2 Participants 127 6.3.3 Results 127 6.3.4 Summary 129 6.4 Quantitative Communication in the Absence of Vibration 129 6.4.1 Experimental Design 130 6.4.2 Participants 132 6.4.3 Results 132 6.4.4 Summary 134 6.5 Summary and Discussion 135 7. Synthesis Models for the Translation of Sensory Tactile Properties into Vibration 137 7.1 Formalization of the Tactile Plausibility Illusion for Models 139 7.1.1 Formalization of Plausibility 139 7.1.2 Model Boundaries 143 7.2 Investigation of the Influence of Vibration Level on Attribute Ratings 144 7.2.1 Stimuli 145 7.2.2 Experimental Design 145 7.2.3 Participants 146 7.2.4 Results 146 7.2.5 Summary 148 7.3 Comparison of Modulated Vibration to Successive Impulse-like Vibration 148 7.3.1 Stimuli 149 7.3.2 Experimental Design 151 7.3.3 Participants 151 7.3.4 Results 151 7.3.5 Summary 153 7.4 Synthesis Based on the Discrete Estimates of a k-Nearest-Neighbor Classifier 153 7.4.1 Definition of the K-Nearest-Neighbor Classifier 154 7.4.2 Analysis Model 155 7.4.3 Synthesis Model 156 7.4.4 Interpolation of acceleration level for the vibration attribute profile pairs 158 7.4.5 Implementation of the Synthesis 159 7.4.6 Advantages and Disadvantages 164 7.5 Synthesis Based on the Quasi-Continuous Estimates of Regression Models 166 7.5.1 Overall Model Structure 168 7.5.2 Classification of the Excitation Pattern with a Support Vector Machine 171 7.5.3 General Approach to the Regression Models of each Excitation Pattern 178 7.5.4 Synthesis for the Impulse-like Excitation Pattern 181 7.5.5 Synthesis for the Bandlimited White Gaussian Noise Excitation Pattern 187 7.5.6 Synthesis for the Amplitude Modulated Sinusoidal Excitation Pattern 193 7.5.7 Synthesis for the Sinusoidal Excitation Pattern 199 7.5.8 Implementation of the Synthesis 205 7.5.9 Advantages and Disadvantages of the Approach 208 7.6 Validation of the Synthesis Models 210 7.6.1 Stimuli 212 7.6.2 Experimental Design 212 7.6.3 Participants 214 7.6.4 Results 214 7.6.5 Summary 219 7.7 Summary and Discussion 219 7.7.1 Summary 219 7.7.2 Discussion 222 8. General Discussion and Outlook 227 Acknowledgment 237 References 237 / Eines der zentralen Ziele des Designs von Produkten oder virtuellen Um-gebungen ist die Schaffung von Erfahrungen, die im beabsichtigten An-wendungskontext die Erwartungen der Benutzer erfüllen. Gegenwärtig versucht man im vibrotaktilen Authoring-Prozess mit ineffizienten Trial-and-Error-Verfahren, die Erwartungen an den dargestellten, virtuellen Situationskontext implizit zu erfüllen. Ein effizienteres, modellgetriebenes Verfahren, das explizit auf den taktilen Benutzererwartungen basiert, wäre daher von Vorteil. Im Alltag sind wir häufig verschiedenen Ganzkörper-schwingungen ausgesetzt. Abhängig von ihren zeitlichen und spektralen Eigenschaften assoziieren wir intuitiv bestimmte Wahrnehmungsmerkmale wie z.B. “kribbeln”. Dies legt eine systematische Beziehung zwischen physikalischen Parametern und Wahrnehmungsmerkmalen nahe. Um mit potentiellen Nutzern über hervorgerufene oder erwartete taktile Eigen-schaften zu kommunizieren, wird eine standardisierte Designsprache vor-geschlagen. Sie enthält eine Menge von sensorisch-taktilen Wahrneh-mungsmerkmalen, die hinreichend den Wahrnehmungsraum der im Alltag auftretenden Vibrationen charakterisieren. Diese Entwurfssprache ermög-licht die quantitative Beurteilung taktiler Wahrnehmungsmerkmale, die in Situationskontexten wie z.B. auditiv-visuell-taktilen Fahrzeugszenen her-vorgerufen werden. Solche Wahrnehmungsspezifikationen können jedoch auch bewertet werden, indem der Inhalt dieser Szenen verbal beschrieben wird. Quasi identische Bewertungen für beide Präsentationsmodi deuten darauf hin, dass die taktilen Benutzererwartungen quantifiziert werden können, noch bevor eine Vibration präsentiert wird. Die erwarteten Wahr-nehmungsspezifikationen sind die Voraussetzung für eine anschließende Übersetzung in physikalische Schwingungsparameter. Plausible Vibratio-nen können synthetisiert werden, indem die erwarteten Wahrnehmungs-merkmale hervorgerufen werden. Auf der Grundlage der beobachteten Beziehungen zwischen Schwingungs¬parametern und sensorisch-taktilen Wahrnehmungsmerkmalen wurden ein 1-Nearest-Neighbor-Modell und ein Regressionsmodell erstellt. Die Plausibilität der von diesen Modellen synthetisierten Schwingungen im Kontext virtueller, auditorisch-visuell-taktiler Fahrzeugszenen wurde in einer Wahrnehmungsstudie validiert. Die Ergebnisse zeigten, dass die mit der Designsprache gewonnenen Wahr-nehmungsspezifikationen ausreichen, um Schwingungen zu synthetisieren, die in einem gegebenen Situationskontext als ebenso plausibel empfunden werden wie aufgezeichnete Schwingungen. Die demonstrierte Entwurfsme-thode stellt ein neues, effizienteres Werkzeug für Designer dar, die Schwingungen für virtuelle Umgebungen erstellen oder taktiles Feedback für Produkte erzeugen.:Preface III Abstract V Zusammenfassung VII List of Abbreviations XV 1 Introduction 1 1.1 General Introduction 1 1.1 Objectives of the Thesis 4 1.2 Structure of the Thesis 4 2. Tactile Perception in Real and Virtual Environments 7 2.1 Tactile Perception as a Multilayered Process 7 2.1.1 Physical Layer 8 2.1.2 Mechanoreceptor Layer 9 2.1.3 Sensory Layer 19 2.1.4 Affective Layer 26 2.2 Perception of Virtual Environments 29 2.2.1 The Place Illusion 29 2.2.2 The Plausibility Illusion 31 2.3 Approaches for the Authoring of Vibrations 38 2.3.1 Approaches on the Physical Layer 38 2.3.2 Approaches on the Mechanoreceptor Layer 40 2.3.3 Approaches on the Sensory Layer 40 2.3.4 Approaches on the Affective Layer 43 2.4 Summary 43 3. Research Concept 47 3.1 Research Questions 47 3.1.1 Foundations of the Research Concept 47 3.1.2 Research Concept 49 3.2 Limitations 50 4. Development of the Experimental Setup 53 4.1 Hardware 53 4.1.1 Optical Reproduction System 53 4.1.2 Acoustical Reproduction System 54 4.1.3 Whole-Body Vibration Reproduction System 56 4.2 Software 64 4.2.1 Combination of Reproduction Systems for Unimodal and Multimodal Presentation 64 4.2.2 Conducting Perceptual Studies 65 5. Assessment of a Sensory Tactile Design Language for Characterizing Vibration 67 5.1.1 Design Language Requirements 67 5.1.2 Method to Assess the Design Language 69 5.1.3 Goals of this Chapter 70 5.2 Tactile Stimuli 72 5.2.1 Generalization into Excitation Patterns 72 5.2.2 Definition of Parameter Values of the Excitation Patterns 75 5.2.3 Generation of the Stimuli 85 5.2.4 Summary 86 5.3 Assessment of the most relevant Sensory Tactile Perceptual Attributes 86 5.3.1 Experimental Design 87 5.3.2 Participants 88 5.3.3 Results 88 5.3.4 Aggregation and Prioritization 89 5.3.5 Summary 91 5.4 Identification of the Attributes forming the Design Language 92 5.4.1 Experimental Design 93 5.4.2 Participants 95 5.4.3 Results 95 5.4.4 Selecting the Elements of the Sensory Tactile Design Language 106 5.4.5 Summary 109 5.5 Summary and Discussion 109 5.5.1 Summary 109 5.5.2 Discussion 111 6. Quantification of Expected Properties with the Sensory Tactile Design Language 115 6.1 Multimodal Stimuli 116 6.1.1 Selection of the Scenes 116 6.1.2 Recording of the Scenes 117 6.1.3 Recorded Stimuli 119 6.2 Qualitative Communication in the Presence of Vibration 123 6.2.1 Experimental Design 123 6.2.2 Participants 124 6.2.3 Results 124 6.2.4 Summary 126 6.3 Quantitative Communication in the Presence of Vibration 126 6.3.1 Experimental Design 127 6.3.2 Participants 127 6.3.3 Results 127 6.3.4 Summary 129 6.4 Quantitative Communication in the Absence of Vibration 129 6.4.1 Experimental Design 130 6.4.2 Participants 132 6.4.3 Results 132 6.4.4 Summary 134 6.5 Summary and Discussion 135 7. Synthesis Models for the Translation of Sensory Tactile Properties into Vibration 137 7.1 Formalization of the Tactile Plausibility Illusion for Models 139 7.1.1 Formalization of Plausibility 139 7.1.2 Model Boundaries 143 7.2 Investigation of the Influence of Vibration Level on Attribute Ratings 144 7.2.1 Stimuli 145 7.2.2 Experimental Design 145 7.2.3 Participants 146 7.2.4 Results 146 7.2.5 Summary 148 7.3 Comparison of Modulated Vibration to Successive Impulse-like Vibration 148 7.3.1 Stimuli 149 7.3.2 Experimental Design 151 7.3.3 Participants 151 7.3.4 Results 151 7.3.5 Summary 153 7.4 Synthesis Based on the Discrete Estimates of a k-Nearest-Neighbor Classifier 153 7.4.1 Definition of the K-Nearest-Neighbor Classifier 154 7.4.2 Analysis Model 155 7.4.3 Synthesis Model 156 7.4.4 Interpolation of acceleration level for the vibration attribute profile pairs 158 7.4.5 Implementation of the Synthesis 159 7.4.6 Advantages and Disadvantages 164 7.5 Synthesis Based on the Quasi-Continuous Estimates of Regression Models 166 7.5.1 Overall Model Structure 168 7.5.2 Classification of the Excitation Pattern with a Support Vector Machine 171 7.5.3 General Approach to the Regression Models of each Excitation Pattern 178 7.5.4 Synthesis for the Impulse-like Excitation Pattern 181 7.5.5 Synthesis for the Bandlimited White Gaussian Noise Excitation Pattern 187 7.5.6 Synthesis for the Amplitude Modulated Sinusoidal Excitation Pattern 193 7.5.7 Synthesis for the Sinusoidal Excitation Pattern 199 7.5.8 Implementation of the Synthesis 205 7.5.9 Advantages and Disadvantages of the Approach 208 7.6 Validation of the Synthesis Models 210 7.6.1 Stimuli 212 7.6.2 Experimental Design 212 7.6.3 Participants 214 7.6.4 Results 214 7.6.5 Summary 219 7.7 Summary and Discussion 219 7.7.1 Summary 219 7.7.2 Discussion 222 8. General Discussion and Outlook 227 Acknowledgment 237 References 237

How do we design for connection? How might we introduce quirkiness, personal expression and a little bit of magic to our unified, unemotional black screens? Working with design systems can have perks, but something gets lost when we systemise how we communicate. I argue to open up rigid design systems and loosen their rules to elicit something new that’s cute, weird, and so unique: it becomes magical. To make an empathic connection with people in their context. I apply research through design and user-centred methods to gain insights while prototyping along the way to test and tweak communication features. The result is "Expressive Signals," a repository of design explorations promoting personalised digital communication. The intention is to challenge the status quo and enhance expression and thrilling unexpectedness while connecting. They are five design examples playing with the following features; showing presence in digital conversations, how speech bubbles can match their content, how emojis can be personalised, creating a digital repository of cherished messages and ensuring that our messages get read in the right context. Expressive Signals allow users to cut through the noise and generate strong signals to enhance expression in digital systems. The focus is on combining, tweaking, and exploring new digital communication elements to enhance expression and connect on a deeper level. They utilise micro-interactions, haptics and tools with purposefully loose constraints to invite to be broken, to elicit what we don’t expect. Expressive signals promote play, joy, and other aspects of life that have been neglected in favour of utility or pragmatism in digital communication spaces. I am asking: can a system ever make space for the thrilling and unexpected? Design bursts with self-expression. I intend to design for precisely that. This passion project dwells on my interest in language, communication, storytelling and every nerdy cognitive science bit around it. It explores how to combine and tweak new features to enhance expression, ultimately aiming to design for self-expression and unexpected magic.

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This paper is an explorative interaction design study focusing on the development of a wearable device for enhanced learning of bodily skills. It uses a variation of technology scouting and matchmaking to explore possible technologies related to assistive technology for learning. Semi-structured interviews were conducted with people in the concerned fields and analysis of the interviews resulted in insights that could inform the development of the design. Research findings suggest that a wearable learning system that leverages AI to guide and assist learning of bodily skills through a haptic interface could be possible with current technology. The paper proposes a schematic diagram of the system, UX goals and evaluates user attitudes towards such a system. Overall, this design study could serve as a resource for future development of AI-assisted education for activities involving bodily movement.

A bilateral teleoperation system makes it possible for a human operator to interact with a remote environment and receive feedback from their actions. In this work, two different teleoperation architectures are studied, one well-established approach called position-force, and another approach called Model-Mediated Teleoperation (MMT). Position-force generates force feedback by measuring forces and sending them over the network, subject to network delay, while MMT generates nondelayed force feedback through a local environment model. The two architectures are compared in terms of transparency (quality of force feedback) and state consistency (equivalence of positions) under different network conditions. Up to 150 ms constant delay in Round Trip Time (RTT) is added. Both architectures are implemented as relatively simple versions of themselves. The case (teleoperation task) under consideration is pushing a cuboid object on a planar surface in a single direction. The MMT architecture is also studied in further detail, in terms of model complexity. Two versions of an MMT model are investigated, one simpler model that has a linear representation of energy loss and one less simple model that has a non-linear representation of energy loss. The purpose is to see what implications there are of increasing or decreasing model complexity. The results indicate that position-force has better performance in terms of both transparency and state consistency than both MMT models for all investigated network conditions. The simple version of MMT (linear model) performs better than the non-linear model, in terms of transparency and state consistency of cuboid positions, for all network conditions except the largest added delay. In terms of state consistency for the device positions, the non-linear model only performs better than the linear model with no added delay. / En distansstyrt system med tvåsidig kommunikation gör det möjligt för en mänsklig operatör att interragera med en avlägsen miljö och få återkoppling. I detta arbete studeras två olika arkitekturer för dessa typer av system. Ett väletablerat tillvägagångssätt som kallas position-force, och ett annat som kallas Model-Mediated Teleoperation (MMT). Position-force genererar kraftåterkoppling genom att mäta krafter och skicka dem över nätverket, utsatt för nätverksfördröjningar, medan MMT genererar en icke-fördröjd kraftåterkoppling från en lokalt modellerad miljö. De två arkitekturerna jämförs med avseende på ”transparency” (kvalitén på kraftåterkopplingen) och ”state consistency” (matchning av positioner) under olika nätverksförhållanden. De studerade förhållandena innefattar upp till 150 ms konstant fördröjning i tur och returtid. Båda arkitekturer implementeras som förhållandevis enkla versioner av sig själva. Det studerade fallet (operatörens uppgift) innefattar puttande på ett rätblock på en plan yta i en enkel riktning. MMT arkitekturen studeras även i vidare detalj med avseende på komplexitet hos den lokala modellen. Två versioner av MMT modellen undersöks, en enklare model som har en linjär representation av energiförlust, och en mer avancerad model som har en icke-linjär representation av energiförlust. Avsikten bakom detta är undersöka vilka implikationer som finns när komplexiteten hos modellen höjs eller sänks. Resultaten indikerar att position-force presterar bättre än MMT med avseende på både transparency och state consistency för alla undersökta nätverksfördröjningar. Den linjära MMT modellen presterar bättre än den icke-linjära modellen, med avseende på transparency och state consistency i rätblockspositioner, för alla nätverksförhållnaden utom den största pålagda fördröjningen. Vidare presterar den icke-linjära modellen bättre än den linjära modellen, med avseende på state consistency för styrande/styrd apparat, endast då ingen nätverksfördröjning läggs på.

On-the-job injuries that occur even after implementing safety interventions highlight the need for identifying the limitations in them and for making future safety interventions and technological advances more effective. One possible reason for this lower-than-expected-safety returns is the latent side-effect of safety interventions, known as risk compensation. This dissertation aimed to provide empirical evidence and theoretical considerations of risk compensation effect in the construction industry. Accordingly, a multi-sensor immersive mixed-reality environment consists of a virtual projection of the environment and passive haptics of a roof was developed to study risk compensation among residential roofers. Simulating height, environmental factors (wind and sound), passive haptic, and virtual falls stimulated sufficient Sense of Presence to trigger subjects' behavioral changes while installing shingles on a 27-degree sloped roof under three levels of safety interventions (i.e., with no fall-safety intervention, with an injury-reducing fall-safety intervention—i.e., fall-arrest system—and with an injury-preventing fall-safety intervention— i.e., a fall-arrest system and a guardrail). The baseline demographic, psychographic, and cognitive measures combined with real-time tracking and wearable sensors provided an opportunity to track the worker's motions, localize his/her position, obtain real-time musculoskeletal data, and monitor the his/her behavioral and physiological responses. The collected data is then translated into information about the risk perception and risk-taking behavior of the worker. The results yielded unequivocal evidence of risk compensation—the lower perceived risk associated with the situation (lower levels of stress) and the false sense of security among roofers when they were provided with safety interventions apparently encouraged them to be less cautious by leaning over the edge, stepping closer to the roof edge, spending more time exposing themselves to fall risk, over-relying on the safety equipment through different facing directions and choices of posture stability. As a result, they also experienced more near-misses (close calls). This behavioral adaptation was more pronounced when they were provided with an injury-preventing safety intervention (e.g., guardrail). The findings also suggested that the productivity and safety benefits of safety interventions can be negated due to risk compensation, which identifies vital information for the construction-safety community to consider during the design and implementation of more effective safety interventions and technological advances. Roofers with high risk tolerance and sensation seekers were identified as high-risk groups who are more likely to be involved in risk-compensatory behaviors; various behavioral interventions are suggested in this dissertation to counteract excessive risk-taking and to reduce risk compensation. The findings of this study shed light on the question of why injury rates have remained at worrisome levels despite advances in protective measures and interventions. In the long-term, a better understanding of risk compensation will translate into fundamental knowledge about how the construction industry should approach and maintain controls after safety interventions. / Doctor of Philosophy / While researchers have dispensed considerable efforts to reduce the risk of occupational injuries by implementing safety interventions, the large number of safety incidents occurring each year in the construction industry. It is hypothesized that the latent effect of safety interventions, known as risk compensation, might be a possible reason why many of the safety interventions and technological advances have not fully achieved their safety objectives. This dissertation aimed to empirically examine the changes in workers' productivity, risk perception, risk-taking behaviors as a function of different safety interventions in place. To study this within a risk-free setting, an immersive mixed-reality environment simulating roofing task was developed. Then, the reactionary behavioral responses of participants were monitored using real-time tracking sensors and qualitative sources of data while they were completing a roofing task under three counterbalanced levels of safety interventions (i.e., with no fall-safety intervention, with an injury-reducing fall-safety intervention—i.e., fall-arrest system—and with an injury-preventing fall-safety intervention— i.e., a fall-arrest system and a guardrail). The findings indicated that the reduced perceived risk and the desire for increased productivity may skew risk analysis and strongly bias workers toward presuming invulnerability when safety interventions are in place. According to risk compensation theory, workers' risk tolerance and perceptions of risk influence their risk-taking behavior—as the perceived risk associated with the situation decreases, individuals take more risks to achieve a level of risk they can comfortably tolerate. Therefore, the workers might become less cautious by leaning over the edge, stepping closer to the roof edge, spending more time exposing themselves to fall risk, over-relying on the safety equipment through different facing directions and choices of posture stability. This result does not necessarily imply the safety innovations are completely ineffective, but rather demonstrates dangers users face when they misperceive the effectiveness of a safety intervention. Furthermore, roofers with high risk tolerance and a high sensation-seeking disposition were identified as high-risk groups who are more likely to be involved in risk-compensatory behaviors. This research represented a substantive departure from the status quo by proposing novel pathways for proactive incident prevention due to risk compensation in the construction industry. The contribution of this study is especially significant because a better understanding of risk compensation will translate into fundamental knowledge about how the construction industry should approach and maintain controls after safety interventions.

This dissertation presents research in the development and use of a multi-modal visual and haptic virtual model in higher education. The model, named Chemical Force Feedback (CFF), represents molecular recognition through the example of protein-ligand docking, and enables students to simultaneously see and feel representations of the protein and ligand molecules and their force interactions. The research efforts have been divided between educational research aspects and development of haptic feedback techniques. The CFF model was evaluated in situ through multiple data-collections in a university course on molecular interactions. To isolate possible influences of haptics on learning, half of the students ran CFF with haptics, and the others used the equipment with force feedback disabled. Pre- and post-tests showed a significant learning gain for all students. A particular influence of haptics was found on students reasoning, discovered through an open-ended written probe where students' responses contained elaborate descriptions of the molecular recognition process. Students' interactions with the system were analyzed using customized information visualization tools. Analysis revealed differences between the groups, for example, in their use of visual representations on offer, and in how they moved the ligand molecule. Differences in representational and interactive behaviours showed relationships with aspects of the learning outcomes. The CFF model was improved in an iterative evaluation and development process. A focus was placed on force model design, where one significant challenge was in conveying information from data with large force differences, ranging from very weak interactions to extreme forces generated when atoms collide. Therefore, a History Dependent Transfer Function (HDTF) was designed which adapts the translation of forces derived from the data to output forces according to the properties of the recently derived forces. Evaluation revealed that the HDTF improves the ability to haptically detect features in volumetric data with large force ranges. To further enable force models with high fidelity, an investigation was conducted to determine the perceptual Just Noticeable Difference (JND) in force for detection of interfaces between features in volumetric data. Results showed that JNDs vary depending on the magnitude of the forces in the volume and depending on where in the workspace the data is presented.

This project focuses on the design and modeling of a two degree-of-freedom dissipative passive haptic display. Haptic displays are man-machine interfaces that transmit forces to the human operator. A dissipative passive haptic display is one that may only remove energy from the system using actuators such as brakes and dampers, thus ensuring the safety of the human operator. These devices may be used to implement virtual constraints such as desired paths and obstacles. Traditional friction brakes have previously been used as dissipative and coupling elements in a two degree-of-freedom parallel manipulator, resulting in undesired effects such as vibration, stiction, and slow response times. Alternatively, the new robot is actuated by rheological brakes, which feature fast response times and smooth application of torque. This approach aims to improve upon the accuracy and feel of the previous design. A commercial magnetorheological (MR) fluid brake was selected and put through an extensive series of tests. The data was used to develop a model that characterizes MR fluid behavior in low speed braking applications. A parallel five bar linkage was designed and built that has separate configurations corresponding to 3-brake and 4-brake operation. The length of each arm was chosen by means of a geometrical optimization that weighs the size and area of the workspace and actuator effects. A simulation was then developed by incorporating the brake model into the equations of motion of the robot. Next, two forms of path following velocity control were devised and tested in simulation. Finally, the accuracy, workload, and smoothness of both controllers and both configurations were examined in preliminary tests with human operators.

Neben der äußeren Formgebung und den guten Fahreigenschaften eines Kraftfahrzeugs kommt dem Innenraum eine immer größer werdende Bedeutung für die Schaffung einer positiven Emotionalität zu. Der Innenraum ist der Bereich, in dem der Kunde den engsten Kontakt mit dem Auto hat. Hier bewältigt er seine Fahraufgabe, hier „lebt“ er während der Fahrzeugnutzung. Die unterschiedliche Gewichtung der Anforderungen für die Gestaltung des Fahrzeuginnenraums bei den verschiedenen Automobilherstellern führte zu Beginn der 1990er-Jahre dazu, dass die Stellteile trotz einer steigenden Anzahl von Funktionen tendenziell abnahmen. Dies wurde durch die Einführung von sogenannten multifunktionalen Stellteilen ermöglicht. Eine intern durchgeführte Analyse von Anordnungskonzepten für Bedienelemente im PKW-Innenraum [Anguelov, 2002] bestätigte die folgenden zwei Erkenntnisse: Erstens findet eine Funktionsgruppierung der Stellteile und damit auch eine räumliche Gruppierung im Innenraum statt, zweitens sind die am häufigsten betätigten Stellteile der Taster und der Drehschalter. Weiterhin zeigte diese Analyse, dass häufig und herstellerunabhängig für sicherheits- und fahrspezifische Funktionen Taster und/oder Drehschalter verwendet werden – Start-Stopp- Taster, Taster für die Warnblinkanlage, Notruftaster, Taster für das elektronische Stabilitätsprogramm (ESP), Lichtdrehschalter etc. Der Kunde interessiert sich nicht dafür, was sich hinter dem einzelnen Bedienelement verbirgt, solange es seine Funktion erfüllt. Außerdem erwartet der Kunde hinsichtlich des Interieurs, dass der erste optische Eindruck durch die bei der Betätigung der Bedienelemente wahrnehmbare Haptik und das dabei auftretende Geräusch bestätigt wird. Kann diese Erwartungshaltung aufgrund des Schaltergeräusches nicht bestätigt werden, so verliert selbst ein ergonomisch hervorragender und mit einer ansprechenden Optik versehener Schalter jedwede Kundenakzeptanz. Die Steigerung der haptischen und akustischen Wertigkeit im Innenraum erweist sich daher als ein wesentlicher Beitrag zur Wertanmutung des gesamten Fahrzeugs. Kundengruppen mit spezifischen Eigenschaften und Motiven zu identifizieren und zu beschreiben. Psychologen arbeiten stetig an der Verbesserung der existierenden Kundentypologien, wobei Merkmale wie z. B. der Fahrstil und die technische Affinität berücksichtigt werden. Ohne ein solides Wissen über die speziellen Wünsche und Erwartungen der Kunden bezüglich der haptischen und akustischen Gestaltung der Bedienelemente ist der Automobilhersteller oft zu weit vom Kunden entfernt und entwickelt Produkte, welche die erwartete und erhoffte Kundenakzeptanz verfehlen. Aber nicht nur die Automobilhersteller, sondern auch die entsprechenden Zulieferer entdecken zunehmend die Wichtigkeit der Wertanmutung, wie folgende Zitate belegen: „Die Wertanmutung wird zu einem der wichtigsten Kriterien beim Kauf“ [Pressemappe Fa. Faurecia, Oktober 2004]; „Wertigkeit und Emotion sind entscheidende Elemente im Fahrzeuginnenraum. Denn die empfundene Wertanmutung ist bedeutend für die Kaufentscheidung des Kunden“ [Internetpublikation, Fa. Bayern Innovativ GmbH, Innovationskongress November 2006]. Trotz der weitverbreiteten Verwendung des Kunstwortes „Wertanmutung“ liegen seine genaue Bedeutung und Herkunft noch immer im Dunkeln, da es eine klare und eindeutige Definition des Begriffes in der deutschen Sprache bis heute nicht gibt. Aus den im Duden beschriebenen Bedeutungen der Begriffe „anmuten“1 und „zumuten“2 ließe sich jedoch ableiten, dass dieses Begriffspaar für eine Subjekt-Objekt- Beziehung steht bzw. auf eine solche übertragen werden kann. Demzufolge fühlt sich ein Subjekt „angemutet“ als Reaktion auf die „Zumutung“ eines Gegenstandes. Darüber hinaus suggeriert der Begriff „Anmutung“ ein gefühlsmäßiges, meist unbewusstes Eindruckerlebnis.

Games in general and computer games in particular have now become a mainstream activity for young people in the industrialized nations. Sadly, people’s interaction with computer artifacts and games are mainly still limited to the visual and auditive modalities. This constrains the richness of our interaction with those artifacts, it constrains the possibilities of using those artifacts to communicate and build relations with others, and it excludes some people from using them at all. This thesis answers the questions of whether it’s possible to use haptics as a single modality for conveying information in computer games, if it’s possible to translate the standard interfaces of existing computer games into haptic interfaces, and if it can be accomplished with the technology used in the gamepads of current generation game consoles. It also contains a theoretical foundation for using haptics in game design and a new design method for analyzing the requirements of computer game interface modalities. A computer game prototype called Sightlence was developed in order to answer these questions. The prototype was developed in four iterative cycles of design, development, and evaluative play sessions. Four groups of people participated in the play sessions: graduate students, and teachers, specializing in games; people who are deafblind; people from the general population; and pupils from a national special needs school in Sweden for children with deafness or impaired hearing combined with severe learning disabilities, or congenital deafblindness. The prototypes were tested with usability techniques for measuring performance and learnability. The usability tests showed that Sightlence can be successfully learned by people from the general population while the pupils with cognitive development disorders from the special needs school would need additional support in the game in order to learn to handle the increased abstraction caused by the haptic interface. The thesis ends with discussion of the designed and developed artifact Sightlence. The discussion touches on the design process, the usability testing, and possible future research and development relevant for making haptics a fruitful tool and medium for designers and people.