With the ever increasing amount of digital information, information workers desire more screen real estate to process their daily desktop work. Thanks to the quick advance in display technology, big screens are increasingly affordable and have been gradually adopted in desktop computing environments. A large wall-size high resolution display, a recent emerging class of display which possesses a huge visualization surface, could potentially benefit information processing work. In this dissertation we investigate such a large display as the primary working space for information processing work. We firstly conducted a longitudinal diary study and three control experiments investigating effects of a large display on information processing work. The longitudinal diary study investigates large display use in a personal desktop computing context by comparing it with single- and dual-monitor. The three controlled experiments further investigate the effects of two factors determining resolution of a display—physical size and pixel-density on users’ performance and behaviors. The diary study reveals the distinct behavior patterns of large display users in partitioning screen space and managing windows, while the control experiments deeply reveal the effects of the physical size and pixel density of a display on different information processing tasks. Aside from studying a continuous large display, we also articulate how interior bezels within a tiled-monitor large display affect users’ performance and behaviors in basic visual search and action tasks via a series of controlled experiments. Based on the understanding of large display effects and users’ behavior patterns, we then design new interaction techniques to address a big challenge of working on a large display: managing overflowing windows. We design and implement a large display oriented window management system prototype: WallTop. It includes a set of interaction techniques that provide greater flexibility for managing windows. Usability tests show that users can quickly and easily learn the new techniques and apply them to realistic window management tasks with increased efficiency on a large display.

With the ever increasing amount of digital information, information workers desire more screen real estate to process their daily desktop work. Thanks to the quick advance in display technology, big screens are increasingly affordable and have been gradually adopted in desktop computing environments. A large wall-size high resolution display, a recent emerging class of display which possesses a huge visualization surface, could potentially benefit information processing work. In this dissertation we investigate such a large display as the primary working space for information processing work. We firstly conducted a longitudinal diary study and three control experiments investigating effects of a large display on information processing work. The longitudinal diary study investigates large display use in a personal desktop computing context by comparing it with single- and dual-monitor. The three controlled experiments further investigate the effects of two factors determining resolution of a display—physical size and pixel-density on users’ performance and behaviors. The diary study reveals the distinct behavior patterns of large display users in partitioning screen space and managing windows, while the control experiments deeply reveal the effects of the physical size and pixel density of a display on different information processing tasks. Aside from studying a continuous large display, we also articulate how interior bezels within a tiled-monitor large display affect users’ performance and behaviors in basic visual search and action tasks via a series of controlled experiments. Based on the understanding of large display effects and users’ behavior patterns, we then design new interaction techniques to address a big challenge of working on a large display: managing overflowing windows. We design and implement a large display oriented window management system prototype: WallTop. It includes a set of interaction techniques that provide greater flexibility for managing windows. Usability tests show that users can quickly and easily learn the new techniques and apply them to realistic window management tasks with increased efficiency on a large display.

After introducing the concept of multiple monitors, which is a computer system with a physically partitioned but virtually contiguous display space (a single computer with many monitors attached), we discuss open Human-Computer Interaction multiple-monitor research areas including window management. We argue to conduct a high-level study of window management practices and a low-level study specifically comparing single-monitor and multiple-monitor window management practices. When combined with other field work on multiple monitors, the studies suggest that there is an increasingly crucial distinction between input focus (where the active window is) and user focus (where the user is actually looking on-screen) since multiple monitors encourage users to display reference information in non-active windows to aid interaction in the active window. To further explore this distinction we constructed three tools: Snip; Snap; and Mudibo. We deployed Snip and Snap in a field study, finding that participants used Snip in many of the ways that we expected though Snap did not appear to be as useful. Results from our follow-up laboratory-based study indicated that Snip can provide multiple-monitor users with dramatic time savings for referencing the snipped windows as compared to regular, overlapping windows. A laboratory-based study of Mudibo, a dialog box placement interface, provided further motivation of the tool and uncovered key interface improvements necessary to make Mudibo suitable for everyday multiple-monitor screen interaction. The findings support the original conclusion about the initial field work, namely that understanding the potentially larger gap between input focus and user focus necessitates appropriately targeted user interface development and evaluation.

abstract: With the growth of IT products and sophisticated software in various operating systems, I observe that security risks in systems are skyrocketing constantly. Consequently, Security Assessment is now considered as one of primary security mechanisms to measure assurance of systems since systems that are not compliant with security requirements may lead adversaries to access critical information by circumventing security practices. In order to ensure security, considerable efforts have been spent to develop security regulations by facilitating security best-practices. Applying shared security standards to the system is critical to understand vulnerabilities and prevent well-known threats from exploiting vulnerabilities. However, many end users tend to change configurations of their systems without paying attention to the security. Hence, it is not straightforward to protect systems from being changed by unconscious users in a timely manner. Detecting the installation of harmful applications is not sufficient since attackers may exploit risky software as well as commonly used software. In addition, checking the assurance of security configurations periodically is disadvantageous in terms of time and cost due to zero-day attacks and the timing attacks that can leverage the window between each security checks. Therefore, event-driven monitoring approach is critical to continuously assess security of a target system without ignoring a particular window between security checks and lessen the burden of exhausted task to inspect the entire configurations in the system. Furthermore, the system should be able to generate a vulnerability report for any change initiated by a user if such changes refer to the requirements in the standards and turn out to be vulnerable. Assessing various systems in distributed environments also requires to consistently applying standards to each environment. Such a uniformed consistent assessment is important because the way of assessment approach for detecting security vulnerabilities may vary across applications and operating systems. In this thesis, I introduce an automated event-driven security assessment framework to overcome and accommodate the aforementioned issues. I also discuss the implementation details that are based on the commercial-off-the-self technologies and testbed being established to evaluate approach. Besides, I describe evaluation results that demonstrate the effectiveness and practicality of the approaches. / Dissertation/Thesis / M.S. Computer Science 2014

Il est admis depuis quelque temps déjà qu’une interaction, pour être utile et efficace, doit être pensée “en contexte”. Cependant ce contexte reste une notion floue regroupant de nombreux concepts la rendant difficile à exploiter lors de la conception de techniques d’interaction. La présente thèse se concentre sur la partie spatiale du Contexte dans le cadre des environnements de bureau et de la gestion des fenêtres.Nous avons tout d’abord conçu et implémenté un ensemble de techniques d’interaction regroupées sous l’ap- pellation PowerTools. Ces interactions ont comme particularité de conserver la disposition des éléments à l’écran et de garder l’interaction localisée autour du point d’attention de l’utilisateur. Deux de ces techniques, DeskPop et StackLeafing s’intéressent plus particulièrement à la navigation entre les fenêtres (et le bureau) pendant une interaction de glisser-déposer. DeskPop permet de révéler et d’interagir avec l’espace du bureau sans pour autant déplacer ou cacher les fenêtres. StackLeafing elle, propose d’utiliser le non-chevauchement des fenêtres pour les regrouper en couches et ainsi pouvoir parcourir l’ensemble des fenêtres plus rapidement que par la simple inspec- tion individuelle. TimeShift pour sa part propose une méthode de déclenchement des historiques de copier-coller et glisser-déposer permettant de conserver l’interaction autour du point d’attention de l’utilisateur. La conception des PowerTools nous a conduit à effectuer trois études plus théoriques portant sur le contexte spatial et qui ont donné lieu à des expériences utilisateurs en laboratoire.La première de ces études considère l’acquisition de cibles surgissantes ou animées où nous faisons varier le délai d’apparition et d’animation. Il s’avère que l’animation ou l’apparition soudaine d’une cible reste très proche au niveau des performances du pointage classique (cible statique toujours affichée) pour des délais d’apparition ou d’animation très court (en dessous de 200 ms). Cependant, le cas non statique conduit à plus d’erreurs et, dès que le délai dépasse 200 ms, on observe des différences de performance avec le cas statique. Ces résultats montrent que des techniques telles que StackLeafing et DeskPop qui conservent les cibles potentielles statiques et visibles possèdent un avantage par rapport aux techniques classiques.La seconde étude porte sur la profondeur en gestion des fenêtres. Elle a pour but de déterminer si l’application d’un effet graphique sur les fenêtres peut aider les utilisateurs à mieux percevoir la profondeur de couches de fenêtres comme utilisé dans la technique StackLeafing. Cette étude compare trois effets, appelés indices visuels de profondeur : ombres, flou, et luminosité. Ces indices sont appliqués à des scènes composées de fenêtres disposées en couches (ensemble de fenêtres ne se recouvrant pas), les indices de flou et de luminosité étant appliqués de manière plus forte pour les couches plus profondes. Les sujets devaient alors déterminer le nombre total de couches de la scène. L’expérience montre que l’indice le plus efficace est la luminosité.Enfin, la conception de TimeShift à également porté à notre attention la difficulté d’intégrer de nouvelles tech- niques d’interaction dans un environnement existant. Dans le cas de l’implémentation des historiques de copier- ou-déplacer, nous avons utilisé des interactions “temporisées”. Pour généraliser ces interactions temporelles, nous proposons que l’utilisateur communique avec le système par la reproduction de motifs rythmiques. Nous avons défini un vocabulaire propice à l’interaction homme-machine puis nous avons mené des expériences utilisateurs pour évaluer les capacités de reproduction et de mémorisation d’association de rythmes à des commandes. Les ex- périences montrent que le type d’interaction rythmique que nous proposons est effectivement adapté à l’Interaction Homme-Machine.La proposition de départ de cette thèse était de modifier le moins possible la disposition des éléments affichés et de conserver l’interaction autour du point d’attention de l’utilisateur afin de conserver le contexte et la mémoire spatiale de ce dernier. Nous avons tout d’abord conçu et intégré un ensemble de techniques dans un environnement réel. Puis, nous avons élaboré et mené des expériences en laboratoire afin de mieux comprendre les implications des choix de conception. / It is already well known that for an interaction to be useful, it must be thought “in context”. Unfortunately, this Context remains quite a blurry notion encompassing a lot of different concepts, making it hard to use when designing new interaction techniques. This thesis focus on the spatial part of this context in the field of window management and desktop usage.First, we designed and implemented a set of interaction techniques we called PowerTools. These interactions have the particularity of keeping the position and size of on-screen objects and to keep interaction around the user’s focus of attention. Two of these techniques, DeskPop and StackLeafing more precisely focus on the navigation between windows (and desktop) while using a drag-and-drop interaction. DeskPop allow to uncover and interact with the desktop’s content without requiring to hide or move opened windows. StackLeafing’s purpose is to use the non overlapping of windows to group them in layers, thus allowing to search through them by group instead of individually. On the other hand, TimeShift offer a triggering technique for copy-and-paste histories whose particularity is to keep the interaction around the user’s point of interest.The desing of these PowerTools brought us to conduct three more theorical studies on the spatial context which in turn led to controlled user experiments.The first of these studies looked at the the acquisition of popping and animated targets where we made the delay of apprarition or animation vary. It turns out that the cases where the target is animated or pops are really close to the traditionnal static case in term of pointing performance for small delays (under 200 ms). However, the non static cases lead to more pointing errors and once the delay goes above the 200 ms limit, we observe a drop in performance compared to the static case. These results show that techniques akind to StackLeafing and DeskPop that keep the potential target visible and static have an advantage over classic techniques.The second study looked at the depth dimension in window management. Its purpose was to see if applying some graphical effect on windows could help users better perceive the depth windows layers like the ones used in the StackLeafing technique. This study compared three depth visual cues: shadows, blur and luminance. These cues were used in scenes composed of windows group into layers (set of windows that does not everlap). The blur and luminance cues were applied more strongly on “distant” windows than on closer ones. Participants had then to guess the number of layers in the scene. This sudy shows that the luminance cue is a clear winner.Finally, the desing of TimeShift also brought our attention on the difficulty to integrate a new interaction tech- nique into an existing system. In the case of copy-and-paste histories conception, we used “timed” interactions. In order to generalise this temporal interactions we propose to use rhythmic patterns as a mean to communicate with interactive systems. We defined a vocabulary suited for human-computer interaction. We then evaluated through user studies the capacity for non experts to reproduce and memorise the association of such patterns and commands. These studies indeed show that the type of rhythmic patterns we defined are usable in the context of human-computer-interaction.the starting point of this thesis was to keep the on-screen elements static and to keep the interaction around the user’s locus of attention in order to preserve the user’s memory and spatial context. First, we integrated a set of techniques insite a real environment. Then, in order to better understand conception choices, we designed and ran controlled experiments.

We propose the concept of spatial analytic interfaces (SAIs) as a tool for performing in-situ, everyday analytic tasks. Mobile computing is now ubiquitous and provides access to information at nearly any time or place. However, current mobile interfaces do not easily enable the type of sophisticated analytic tasks that are now well-supported by desktop computers. Conversely, desktop computers, with large available screen space to view multiple data visualizations, are not always available at the ideal time and place for a particular task. Spatial user interfaces, leveraging state-of-the-art miniature and wearable technologies, can potentially provide intuitive computer interfaces to deal with the complexity needed to support everyday analytic tasks. These interfaces can be implemented with versatile form factors that provide mobility for doing such taskwork in-situ, that is, at the ideal time and place. We explore the design of spatial analytic interfaces for in-situ analytic tasks, that leverage the benefits of an upcoming generation of light-weight, see-through, head-worn displays. We propose how such a platform can meet the five primary design requirements for personal visual analytics: mobility, integration, interpretation, multiple views and interactivity. We begin with a design framework for spatial analytic interfaces based on a survey of existing designs of spatial user interfaces. We then explore how to best meet these requirements through a series of design concepts, user studies and prototype implementations. Our result is a holistic exploration of the spatial analytic concept on a head-worn display platform. / October 2016