MCI Dissertationen

https://dl.gi.de/handle/20.500.12116/42243

In diesem Bereich sammeln wir (Verweise auf) Dissertationen zu MCI-Themen. Ausser dem Kriterium, dass die Dissertation erfolgreich abgeschlossen worden sein soll, gibt es keine weiteren Kriterien für die Aufnahme in dieses Verzeichnis (also keine Mindestnote wie summa oder magna). Wenn eine Arbeit in Bereich Mensch-Computer-Interaktion fällt und Sie die Arbeit wert finden, hier aufgenommen zu werden, dann bitte einfach formlos an michael.koch@unibw.de melden.

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Dissertation
Interaktive und dynamische Visualisierung für die chirurgische Ausbildung und Interventionsplanung
(2008) Bade, Ragnar
Computerunterstützte Interventionsplanung für chirurgische Eingriffe kann die Qualität, Quantität und auch Machbarkeit komplizierter Eingriffe verbessern. Computerunterstützung erfolgt dabei bei der Bildaufnahme mit modernen CT- und MRT-Geräten, der Analyse und Extraktion von Informationen aus den aufgenommenen Bilddaten, der angemessenen Visua- lisierung und Präsentation dieser Daten sowie bei der Therapieentscheidungsfindung, zum Beispiel durch Abschätzung und Simulation von zu erwartenden Therapieergebnissen. Herausforderungen für die Computerunterstützung stellen unter anderem die Reduktion von Artefakten aus Bildaufnahme und Bildanalyse sowie die standardisierte dynamische Visua- lisierung patientenspezifischer Bilddaten dar. Im Rahmen dieser Arbeit werden Techniken zur Extraktion von qualitativ hochwertigen Oberflächenmodellen für die Visualisierung der durch Bildanalyse gewonnenen dreidimensionalen Patientenanatomie untersucht sowie Techniken zur standardisierten dynamischen Präsentation und effizienten interaktiven Exploration der dreidimensionalen Daten analysiert. Darauf aufbauend werden zwei effiziente Verfahren für die aufgabenangepasste Extraktion von Oberflächenmodellen aus Bildanalyseergebnissen entwickelt. Weiterhin werden Interaktionstechniken zur effizienten Exploration der dreidimensionalen Patientenanatomie evaluiert und es wird ein skriptbasiertes Verfahren zur Unterstützung der interaktiven Exploration und zur Erzeugung standardisierter dynamischer Visualisierungen vorgestellt. Abschließend werden alle erarbeiteten Methoden, Techniken und Erkenntnisse in der Konzeption und Entwicklung eines Lernsystems für die chirurgische Interventionsplanung in der Leberchirurgie zusammengeführt.
Dissertation
Szenariobasierte Konzeption, Entwicklung und Evaluierung chirurgischer Trainingssysteme
(2011) Mönch, Jeanette
Die klassische medizinische Aus- und Weiterbildung wird zunehmend durch den Einsatz computergestützter Ausbildungs- und Trainingssysteme ergänzt. Im chirurgischen Bereich dienen sie beispielsweise zur Vermittlung anatomischer Grundlagen sowie zum Training von Therapieentscheidungen und deren Durchführung. Eigene Erfahrungen bei der Entwicklung chirurgischer Trainingssysteme wurden während der Konzeption und Umsetzung des LIVERSURGERYTRAINERS und des SPINESURGERY-TRAINERS gesammelt. Die Konzeption und Entwicklung beider Systeme wird in dieser Arbeit beschrieben. Dabei wird vor allem auf die didaktische Konzeption und die szenariobasierte Vorgehensweise eingegangen. Ziel dieser Arbeit war der Entwurf von Empfehlungen für die Konzeption, Entwicklung und Evaluierung chirurgischer Lernsysteme. Die Empfehlungen vereinen eigene Erfahrungen bei der Entwicklung dieser Systeme sowie existierende Leit- und Richtlinien. Diese sind auf die speziellen Anforderungen der chirurgischen Lernsysteme und ihrer Anwender zugeschnitten. Sie sollen anderen Entwicklern als Unterstützung für die Auswahl geeigneter Methoden zur Konzeption und Entwicklung chirurgischer Ausbildungs- oder Trainingssysteme und deren Nutzung dienen. Der Schwerpunkt liegt auf dem Einsatz des szenariobasierten Designs, dem Einsatz didaktischer Konzepte und Modelle sowie dem fallbasierten Lernen.
Dissertation
Risks and potentials of graphical and gesture-based authentication for touchscreen mobile devices: balancing usability and security through user-centered analysis and design
(2016) Zezschwitz, Emanuel von
While a few years ago, mobile phones were mainly used for making phone calls and texting short messages, the functionality of mobile devices has massively grown. We are surfing the web, sending emails and we are checking our bank accounts on the go. As a consequence, these internet-enabled devices store a lot of potentially sensitive data and require enhanced protection. We argue that authentication often represents the only countermeasure to protect mobile devices from unwanted access. Knowledge-based concepts (e.g., PIN) are the most used authentication schemes on mobile devices. They serve as the main protection barrier for many users and represent the fallback solution whenever alternative mechanisms fail (e.g., fingerprint recognition). This thesis focuses on the risks and potentials of gesture-based authentication concepts that particularly exploit the touch feature of mobile devices. The contribution of our work is threefold. Firstly, the problem space of mobile authentication is explored. Secondly, the design space is systematically evaluated utilizing interactive prototypes. Finally, we provide generalized insights into the impact of specific design factors and present recommendations for the design and the evaluation of graphical gesture-based authentication mechanisms. The problem space exploration is based on four research projects that reveal important real-world issues of gesture-based authentication on mobile devices. The first part focuses on authentication behavior in the wild and shows that the mobile context makes great demands on the usability of authentication concepts. The second part explores usability features of established concepts and indicates that gesture-based approaches have several benefits in the mobile context. The third part focuses on observability and presents a prediction model for the vulnerability of a given grid-based gesture. Finally, the fourth part investigates the predictability of user-selected gesture-based secrets. The design space exploration is based on a design-oriented research approach and presents several practical solutions to existing real-world problems. The novel authentication mechanisms are implemented into working prototypes and evaluated in the lab and the field. In the first part, we discuss smudge attacks and present alternative authentication concepts that are significantly more secure against such attacks. The second part focuses on observation attacks. We illustrate how relative touch gestures can support eyes-free authentication and how they can be utilized to make traditional PIN-entry secure against observation attacks. The third part addresses the problem of predictable gesture choice and presents two concepts which nudge users to select a more diverse set of gestures. Finally, the results of the basic research and the design-oriented applied research are combined to discuss the interconnection of design space and problem space. We contribute by outlining crucial requirements for mobile authentication mechanisms and present empirically proven objectives for future designs. In addition, we illustrate a systematic goal-oriented development process and provide recommendations for the evaluation of authentication on mobile devices.
Dissertation
Zugänglichkeit virtueller Klassenzimmer für Blinde
(2016) Köhlmann, Wiebke
Die vorliegende Arbeit untersucht die Zugänglichkeit virtueller Klassenzimmer für blinde Nutzende, um eine möglichst gleichberechtigte Teilhabe an synchronen, kollaborativen Lernszenarien zu ermöglichen. Im Rahmen einer Produktanalyse werden dazu virtuelle Klassenzimmer auf ihre Zugänglichkeit und bestehende Barrieren untersucht und Richtlinien für die zugängliche Gestaltung von virtuellen Klassenzimmern definiert. Anschliessend wird ein alternatives Benutzungskonzept zur Darstellung und Bedienung virtueller Klassenzimmer auf einem zweidimensionalen taktilen Braille-Display entwickelt, um eine möglichst gleichberechtigte Teilhabe blinder Lernender an synchronen Lehrveranstaltungen zu ermöglichen. Nach einer ersten Evaluation mit blinden Probanden erfolgt die prototypische Umsetzung des Benutzungskonzepts für ein Open-Source-Klassenzimmer. Die abschliessende Evaluation der prototypischen Umsetzung zeigt die Verbesserung der Zugänglichkeit von virtuellen Klassenzimmern für blinde Lernende unter Verwendung eines taktilen Flächendisplays und bestätigt die Wirksamkeit der im Rahmen dieser Arbeit entwickelten Konzepte.
Dissertation
The tool space: designing indirect touch input techniques for personal muti-surface computing devices
(2017) Palleis, Henri
Visions of futuristic desktop computer work spaces have often incorporated large interactive surfaces that either integrate into or replace the prevailing desk setup with displays, keyboard and mouse. Such visions often connote the distinct characteristics of direct touch interaction, e.g. by transforming the desktop into a large touch screen that allows interacting with content using one’s bare hands. However, the role of interactive surfaces for desktop computing may not be restricted to enabling direct interaction. Especially for prolonged interaction times, the separation of visual focus and manual input has proven to be ergonomic and is usually supported by vertical monitors and separate – hence indirect – input devices placed on the horizontal desktop. If we want to maintain this ergonomically matured style of computing with the introduction of interactive desktop displays, the following question arises: How can and should this novel input and output modality affect prevailing interaction techniques. While touch input devices have been used for decades in desktop computing as track pads or graphic tablets, the dynamic rendering of content and increasing physical dimensions of novel interactive surfaces open up new design opportunities for direct, indirect and hybrid touch input techniques. Informed design decisions require a careful consideration of the relationship between input sensing, visual display and applied interaction styles. Previous work in the context of desktop computing has focused on understanding the dual-surface setup as a holistic unit that supports direct touch input and allows the seamless transfer of objects across horizontal and vertical surfaces. In contrast, this thesis assumes separate spaces for input (horizontal input space) and output (vertical display space) and contributes to the understanding of how interactive surfaces can enrich indirect input for complex tasks, such as 3D modeling or audio editing. The contribution of this thesis is threefold: First, we present a set of case studies on user interface design for dual-surface computer workspaces. These case studies cover several application areas such as gaming, music production and analysis or collaborative visual layout and comprise formative evaluations. On the one hand, these case studies highlight the conflict that arises when the direct touch interaction paradigm is applied to dual-surface workspaces. On the other hand, they indicate how the deliberate avoidance of established input devices (i.e. mouse and keyboard) leads to novel design ideas for indirect touch-based input. Second, we introduce our concept of the tool space as an interaction model for dual-surface workspaces, which is derived from a theoretical argument and the previous case studies. The tool space dynamically renders task-specific input areas that enable spatial command activation and increase input bandwidth through leveraging multi-touch and two-handed input. We further present evaluations of two concept implementations in the domains 3D modeling and audio editing which demonstrate the high degrees of control, precision and sense of directness that can be achieved with our tools. Third, we present experimental results that inform the design of the tool space input areas. In particular, we contribute a set of design recommendations regarding the understanding of two-handed indirect multi-touch input and the impact of input area form factors on spatial cognition and navigation performance.
Dissertation
CommunityMirrors: Interaktive Großbildschirme als ubiquitäre Natural User Interfaces für Kooperationssysteme
(2018) Ott, Florian
Steigende Komplexität informatisierter Geschäftsprozesse sowie zunehmende Durchdringung unseres Alltags mit Smartphones und Tablets für den allgegenwärtigen Zugriff auf Internetdienste und Kooperationssysteme haben zur fast vollständigen Digitalisierung unserer Wissensgesellschaft beigetragen. Neben ihren vielen Vorteilen für die individuelle Informationsversorgung fördern ubiquitäre Benutzerschnittstellen jedoch die bildschirmbasierte Separation sozialer Akteure und damit digitale Vereinsamung. Interaktive Großbildschirme können in diesem Spannungsfeld aufgrund ihrer physischen Ausmaße und der daraus resultierenden gleichzeitigen „geteilten“ Nutzbarkeit durch mehrere Personen einen Betrag zur Resozialisierung der Wissensarbeit leisten, z. B. beim kommunikativen gemeinsamen Stöbern in Informationsräumen oder dem kooperativen Erarbeiten von Inhalten. Auch für die periphere Informationsversorgung im Vorübergehen bieten sie großes Potenzial, jedoch wird dies bisher primär von passiven Advertising Displays im öffentlichen Raum für die Anzeige von Werbung genutzt. Im Unternehmenskontext fehlen Displays, die Informationen aus kollaborativen Wissensprozessen an halb-öffentlichen Orten, wie Kaffee-Ecken, neben dem Aufzug oder vor frequentierten Gruppenräumen, interaktiv sichtbar, greifbar und gemeinsam erlebbar machen. Eine wesentliche Ursache der fehlenden Nutzung ist die soziotechnischen Komplexität der erforderlichen halb-öffentlichen synchron-kolozierten Mehrbenutzerinteraktion mit einem Großbildschirm. Für eine längerfristig nutzenstiftende Anwendungsentwicklung ist nicht ausreichend klar, welche konkreten Potenziale der Systemeinsatz für die Verbesserung der Informationsversorgung in kollaborativen Wissensprozessen bieten kann und wie der halb-öffentliche Interaktionskontext dafür gestaltet werden muss. Wichtige Erkenntnisse hierzu sind über verschiedene Forschungsbereiche gestreut und verwenden z. T. gänzlich unterschiedliche Terminologien, wodurch der Praxistransfer erschwert wird. Hier setzt die vorliegende Forschungsarbeit an und stellt sich die Frage, welche soziotechnischen Gestaltungsparameter beim Einsatz interaktiver Großbildschirme als halb-öffentliche ubiquitäre Natural User Interfaces in kollaborativen Wissensprozessen existieren und wie diese sowie ihre potenziellen Auswirkungen auf die Wissensarbeit in einem interdisziplinär verständlichen konzeptionellen Systemmodell beschrieben werden können. Zur Komplexitätsreduktion beschäftigt sich die Arbeit zunächst mit der argumentativ-deduktiven Aufarbeitung der zentralen Komponenten des soziotechnischen Systems kollaborativer Wissensprozesse und halb-öffentlicher interaktiver Großbildschirme aus Makro- und Mikroperspektive in Form terminologischer Definitionen sowie grafischer Visualisierungen. Auf Basis mehrerer explorativer Technology Probes mit einem dafür implementierten technischen Framework untersucht die Arbeit anschließend in realen Einsatzszenarien die Gestaltungsparameter und Nutzungspotenziale des Systemeinsatzes und dokumentiert diese in einem interdisziplinär verständlichen soziotechnischen Interaktionskontextmodell.
Dissertation
Supporting users in password authentication with persuasive design
(2018) Seitz, Tobias
Activities like text-editing, watching movies, or managing personal finances are all accomplished with web-based solutions nowadays. The providers need to ensure security and privacy of user data. To that end, passwords are still the most common authentication method on the web. They are inexpensive and easy to implement. Users are largely accustomed to this kind of authentication but passwords represent a considerable nuisance, because they are tedious to create, remember, and maintain. In many cases, usability issues turn into security problems, because users try to work around the challenges and create easily predictable credentials. Often, they reuse their passwords for many purposes, which aggravates the risk of identity theft. There have been numerous attempts to remove the root of the problem and replace passwords, e.g., through biometrics. However, no other authentication strategy can fully replace them, so passwords will probably stay a go-to authentication method for the foreseeable future. Researchers and practitioners have thus aimed to improve users' situation in various ways. There are two main lines of research on helping users create both usable and secure passwords. On the one hand, password policies have a notable impact on password practices, because they enforce certain characteristics. However, enforcement reduces users' autonomy and often causes frustration if the requirements are poorly communicated or overly complex. On the other hand, user-centered designs have been proposed: Assistance and persuasion are typically more user-friendly but their influence is often limited. In this thesis, we explore potential reasons for the inefficacy of certain persuasion strategies. From the gained knowledge, we derive novel persuasive design elements to support users in password authentication. The exploration of contextual factors in password practices is based on four projects that reveal both psychological aspects and real-world constraints. Here, we investigate how mental models of password strength and password managers can provide important pointers towards the design of persuasive interventions. Moreover, the associations between personality traits and password practices are evaluated in three user studies. A meticulous audit of real-world password policies shows the constraints for selection and reuse practices. Based on the review of context factors, we then extend the design space of persuasive password support with three projects. We first depict the explicit and implicit user needs in password support. Second, we craft and evaluate a choice architecture that illustrates how a phenomenon from marketing psychology can provide new insights into the design of nudging strategies. Third, we tried to empower users to create memorable passwords with emojis. The results show the challenges and potentials of emoji-passwords on different platforms. Finally, the thesis presents a framework for the persuasive design of password support. It aims to structure the required activities during the entire process. This enables researchers and practitioners to craft novel systems that go beyond traditional paradigms, which is illustrated by a design exercise.
Dissertation
Designing communication technologies based on physiological sensing
(2018) Hassib, Mariam
The human body, that marvelous chamber of secrets, reveals myriads of information about its owner’s physical, psychological, emotional and cognitive state. In the last century, scientists in the medical field achieved huge leaps in identifying, collecting and analysing of signals generated inside the human brain and body.The advancement in the technology of sensing and collecting those physiological signals has finally matured enough; making the mysterious human body a more attainable source of information to regular non-trained users. Research in the field of Human Computer Interaction has always looked for new ways to interface between humans and machines.With the help of physiological sensing, a new channel of information originating inside the human body becomes available. The opportunities this new channel provides are limitless. In this thesis we take this opportunity to look at our own bodies as a source of information, to better understand ourselves, and others. In a world where partners and friends are in long-distance relationships, meeting rooms are distributed over cities, and working teams are remote, efficient communication mediated over a distance becomes crucial. We see our bodies as a direct interface for communication: our heartbeats reveal how excited we are, our brain reveals how focused we are, and our skin reveals how stressed we are. How can we use this information to create an implicit communication channel between people? Can we increase empathy, connectedness, and awareness, if we include the body as a source of information in our communication systems? What are the ethical and social implications of this type of novel sensing and sharing of information? These are some of the questions this thesis is concerned with. The field of Computer Mediated Communication (CMC) has a long rich history. In this work, we extend on the means of mediating communication to include the body at the source, and the sink, of a communication system. Through a user-centred design process, we first start with a requirements gathering stage in which we investigate the expectations of users towards implicit physiological sensing and sharing of information. We build on top of existing CMC concepts to include bio-signals of the human body within communication.We chart our view of an extensive design space that includes implicit sensing opportunities and dimensions that consider new trends in communication including the distribution and remoteness of users. Through a set of research probes, ordered by one dimension of our extended design space, namely the number of senders and receivers, we explore how signals from the human body can be collected, visualized, and communicated. Starting with self-reflection as a form of communication, we look into how the revealing of information about one’s own body to oneself can enhance their understanding and interaction with systems in different contexts. Using electroencephalography signals from the frontal lobe of the brain, we build a system that aims to aid information workers in understanding how their attention varies during different tasks, and aids in scheduling and increased awareness. In a second research probe, we investigate the effect of revealing affective valence information collected through heart rate and electroencephalography to car drivers and its impact on driving performance. Looking at one-to-one personal communication, comprising the bigger part of our 21st century relationships, we develop two probes which use intimate information collected from the human body to enhance empathy, awareness and connectedness. We explore ways to visualize and communicate heart rate in online chat scenarios and how users deal with such an intimate yet ambiguous source of information. In another probe we introduce the idea of, not only implicitly sensing emotions as an input from one sender, but also using an actuating component at the output side of the communication channel. We explain and develop our concept of embodied emotion actuation using electroencephalography on one side and electrical muscle stimulation on the receiver’s side to enhance the connection between communicating partners. Communication in the large, with multiple senders and receivers who may be distributed or collocated over time and place, is the subject of our final set of research probes. Here we explored the area of audience sensing using physiological sensors to provide feedback to presenters or stakeholders. In two probes we investigated the use of electroencephalography to collect feedback from multiple audiences, in collocated, or distributed scenarios. In one probe, presenters can view real-time or post-hoc feedback to their presented material to evaluate and enhance it. In the second probe, visitors in a museum can implicitly rate their interest in exhibits which can be used by museum curators for better understanding of their audience. Finally, throughout our developed and evaluated research probes we reflect back on the design space presented in the beginning. We derive implications and recommendations for design as well as a conceptual architecture for physiologically augmented communication. We dedicate a discussion to the ethical and social implications of implicit physiological communication derived through our field and lab evaluations of our developed probes.We conclude with a vision of computer mediated communication for the next 20 years and discuss opportunities of future work.
Dissertation
Extending head-up displays: exploring the potential of large & 3D automotive windshield displays
(2018) Häuslschmid, Renate
Drivers consume an increasing amount of information while driving. The information is accessed on the in-car displays but also on personal devices such as the smartphone. Head-up displays are designed for a safe uptake of additional visual information while driving but their benefits are limited by the small display space. This motivates academia and industry to advance the head-up to the so-called windshield display. A windshield display will provide an extended display space, which largely or entirely covers the driver’s visual field through the windshield, as well as 3D and depth perception. Technologically, they are not yet feasible, but, thanks to steady advancements they will become available in the future. Extending a small 2D to a large 3D space requires a rethinking of the entire user interface. The windshield display opens up new opportunities for the type and amount of information, as well as for the way it is presented – ranging up to full augmented reality but it also raises concerns about a distracted driver. The core question of this thesis is whether such an extension is reasonable and desirable – meaning if there are convincing arguments and use cases which justify the potential risk of distraction. This thesis presents our research about the risks and benefits of the transition from a head-up to a windshield display. Thus, we explore the potentials and examine the safety risks and benefits as well as the drivers’ satisfaction of various display aspects. We developed a design space that shows how the new size and depth possibilities create new, or interrelate with existing, design factors. New design opportunities arise and suggest a redesign of existing functionality but also the integration of new content. We researched the information content that could be displayed on a windshield display and asked drivers what content they need and personally desire. We thereby obtained an extensive list of use cases and applications. We approached the question of where such content should be displayed, given the large 3D space. To enable the design of safe interfaces, we first examined the driver’s visual perception across the windshield and identified locations that promote information recognition, particularly in the new peripheral area. Simultaneously, we examined the different ways of placing and stabilizing the content. We compared the traditional screen-fixed with world-fixed (augmented reality) and head-stabilized placement methods in terms of user satisfaction, understandability and safety. The gained knowledge about the locations that support information uptake and about the best ways of placing content was merged into a layout concept that subdivides the driver’s view into several information areas. We also incorporated the drivers’ preferences into this design process and compared their personalized layouts with our vision-based layout concept. We assessed the safety of both layout versions and present a revised concept. We close this thesis by reflecting on other trends that may interrelate with the windshield display, namely autonomous driving and augmented reality consumer devices. We look at recent advancements in realizing windshield displays and endeavor a prediction of future developments in this area.
Dissertation
Interactive advertising displays: audience behavior around interactive advertising columns, life-size screens and banner displays
(2018) Beyer, Gilbert
Interactive public displays are the latest development in the field of out-of-home advertising. Throughout history characteristic shapes for billboards evolved such as flat rectangular displays, long displays or cylindrical advertising columns. This work presents novel interactive display designs that are based on these historical role models and allow passers-by to interact with them in a natural, touchless manner. It further pursues a vision where interactive public displays become more active themselves and actively influence passer-by behavior in order to increase their effectiveness, better attract attention and improve public interaction in front of them. First, to overcome the challenge that passers-by often do not expect public displays to be interactive and thus pay no attention to them, this work presents a solution called unaware initial interaction that surprises passers-by and communicates interactivity by giving visual feedback to their initial movements. To be effective, the visual feedback has to be designed considering the specific display shapes, their requirements to contents and the typical approaching trajectories. Second, to overcome the challenge that larger groups of passers-by often crowd together in front of wide public displays or do not take optimal positions for interaction, this work presents a solution to subtly and actively guide users by dynamic and interactive visual cues on the screen in order to better distribute them. To explore these concepts and following an initial analysis of the out-of-home domain and of typical display qualities, interactive counterparts to the classical display shapes are designed such as interactive advertising columns, long banner displays and life-size screens. Then interactive contents and visual feedbacks are designed which implement the presented interactivity concepts, and audience behavior around them is analyzed in several long-term field studies in public space. Finally the observed passer-by and user behavior and the effectiveness of the display and content designs are discussed and takeaways given that are useful for practitioners and researchers in the field of public interaction with out-of-home displays.

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