Published Article / This paper explores the manipulation of Van der Waals' forces by geometrical parameters in a micro-material handling system. It was observed that the flat-flat interactive surfaces exerted the highest intensity of Van der Waals' forces followed by cone-flat, cylinder-flat, sphere-flat and sphere-sphere interactive surfaces, respectively. A conical micro-gripper proved to be versatile in manipulating the Van der Waals' forces efficiently in a 'picking up' and 'releasing' mechanism of micro-work parts. It was deduced that the pick-up position should be rough and spherical, and the placement position should be smooth and flat for an effective 'pick-and-place' cycle to be realised.

In this dissertation, I investigate interactive visual history for collaborative exploratory data analysis (EDA). In particular, I examine use of analysis history for improving the awareness of the dimension space coverage 1 2 3 to better support data exploration. Commonly, interactive history tools facilitate data analysis by capturing and representing information about the analysis process. These tools can support a wide range of use-cases from simple undo and redo to complete reconstructions of the visualization pipeline. In the con- text of exploratory collaborative Visual Analytics (VA), history tools are commonly used for reviewing and reusing past states/actions and do not efficiently support other use-cases such as understanding the past analysis from the angle of dimension space coverage. How- ever, such knowledge is essential for exploratory analysis which requires constant formulation of new questions about data. To carry out exploration, an analyst needs to understand “what has been done” versus “what is remaining” to explore. Lack of such insight can result in premature fixation on certain questions, compromising the coverage of the data set and breadth of exploration [80]. In addition, exploration of large data sets sometimes requires collaboration between a group of analysts who might be in different time/location settings. In this case, in addition to personal analysis history, each team member needs to understand what aspects of the problem his or her collaborators have explored. Such scenarios are common in domains such as science and business [34] where analysts explore large multi-dimensional data sets in search of relationships, patterns and trends. Currently, analysts typically rely on memory and/or externalization to keep track of investigated versus uninvestigated aspects of the problem. Although analysis history 4 mechanisms have the potential to assist analyst(s) with this problem, most common visual representations of history are geared towards reviewing & reusing the visualization pipeline or visualization states. I started this research with an observational user study to gain a better understanding of analysts’ history needs in the context of collaborative exploratory VA. This study showed that understanding the coverage of dimension space by using linear history 5 was cumbersome and inefficient. To address this problem, I investigated how alternate visual representations of analysis history could support this use-case. First, I designed and evaluated Footprint-I, a visual history tool that represented analysis from the angle of dimension space coverage (i.e. history of investigation of data dimensions; specifically, this approach revealed which dimensions had been previously investigated and in which combinations). I performed a user study that evaluated participants’ ability to recall the scope of past analysis using my proposed design versus a linear representation of analysis history. I measured participants’ task duration and accuracy in answering questions about a past exploratory VA session. Findings of this study showed that participants with access to dimension space coverage information were both faster and more accurate in understanding dimension space coverage information. Next, I studied the effects of providing coverage information on collaboration. To investigate this question, I designed and implemented Footprint-II, the next version of Footprint-I. In this version, I redesigned the representation of dimension space coverage to be more usable and scalable. I conducted a user study that measured the effects of presenting history from the angle of dimension space coverage on task coordination (tacit breakdown of a common task between collaborators). I asked each participant to assume the role of a business data analyst and continue a exploratory analysis work which was started by a collaborator. The results of this study showed that providing dimension space coverage information helped participants to focus on dimensions that were not investigated in the initial analysis, hence improving tacit task coordination. Finally, I investigated the effects of providing live dimension space coverage information on VA outcomes. To this end, I designed and implemented a standalone prototype VA tool with a visual history module. I used scented widgets [76] to incorporate real-time dimension space coverage information into the GUI widgets. Results of a user study showed that providing live dimension space coverage information increased the number of top-level findings. Moreover, it expanded the breadth of exploration (without compromising the depth) and helped analysts to formulate and ask more questions about their data. / Graduate / 0984 / ali.sarvghad@gmail.com

Em computação ubíqua, existe a ideia de tornar o computador onipresente, \"invisível\", de modo a aproximar computadores e humanos. Com o avanço das tecnologias de hardware e de software, torna-se interessante investigar possibilidades inovadoras de interação com os computadores. Neste trabalho, exploramos novas formas de interação inspiradas nos atos de desenhar, agarrar e gesticular. Para testá-las, desenvolvemos novos algoritmos baseados em câmeras RGBD para detecção, classificação e rastreamento de objetos, o que permite a concepção de uma instalação interativa que utilize equipamentos portáteis e de baixo custo. Para avaliar as formas de interação propostas, desenvolvemos a Superfície Mágica, um sistema que transforma uma superfície comum (como uma parede ou uma mesa) num espaço interativo multi-toque. A Superfície Mágica identifica toques de dedos de mãos, de canetas coloridas e de um apagador, oferecendo também suporte a uma varinha mágica para interação 3D. A Superfície Mágica suporta a execução de aplicativos, permitindo que uma superfície comum se transforme numa área interativa para desenho, num explorador de mapas, num simulador 3D para navegação em ambientes virtuais, entre outras possibilidades. As áreas de aplicação do sistema vão desde a educação até a arte interativa e o entretenimento. A instalação do protótipo envolve: um sensor Microsoft Kinect, um projetor de vídeo e um computador pessoal. / Ubiquitous computing is a concept where computing is thought to be omnipresent, effectively \"invisible\", so that humans and computers are brought together in a seamless way. The progress of hardware and software technologies make it compelling to investigate innovative possibilities of interaction with computers. In this work, we explore novel ways of interaction that are inspired by the acts of drawing, grasping and gesturing. In order to test them, we have developed new RGBD camera-based algorithms for object detection, classification and tracking. This allows the conception of an interactive installation that uses portable and low cost equipment. In order to evaluate the proposed ways of interaction, we have developed the Magic Surface, a system that transforms a regular surface (such as a wall or a tabletop) into a multitouch interactive space. The Magic Surface detects touch of hand fingers, colored pens and eraser. It also supports the usage of a magic wand for 3D interaction. The Magic Surface can run applications, allowing the transformation of a regular surface into an interactive drawing area, a map explorer, a 3D simulator for navigation in virtual environments, among other possibilities. Areas of application range from education to interactive art and entertainment. The setup of our prototype includes: a Microsoft Kinect sensor, a video projector and a personal computer.

Em computação ubíqua, existe a ideia de tornar o computador onipresente, \"invisível\", de modo a aproximar computadores e humanos. Com o avanço das tecnologias de hardware e de software, torna-se interessante investigar possibilidades inovadoras de interação com os computadores. Neste trabalho, exploramos novas formas de interação inspiradas nos atos de desenhar, agarrar e gesticular. Para testá-las, desenvolvemos novos algoritmos baseados em câmeras RGBD para detecção, classificação e rastreamento de objetos, o que permite a concepção de uma instalação interativa que utilize equipamentos portáteis e de baixo custo. Para avaliar as formas de interação propostas, desenvolvemos a Superfície Mágica, um sistema que transforma uma superfície comum (como uma parede ou uma mesa) num espaço interativo multi-toque. A Superfície Mágica identifica toques de dedos de mãos, de canetas coloridas e de um apagador, oferecendo também suporte a uma varinha mágica para interação 3D. A Superfície Mágica suporta a execução de aplicativos, permitindo que uma superfície comum se transforme numa área interativa para desenho, num explorador de mapas, num simulador 3D para navegação em ambientes virtuais, entre outras possibilidades. As áreas de aplicação do sistema vão desde a educação até a arte interativa e o entretenimento. A instalação do protótipo envolve: um sensor Microsoft Kinect, um projetor de vídeo e um computador pessoal. / Ubiquitous computing is a concept where computing is thought to be omnipresent, effectively \"invisible\", so that humans and computers are brought together in a seamless way. The progress of hardware and software technologies make it compelling to investigate innovative possibilities of interaction with computers. In this work, we explore novel ways of interaction that are inspired by the acts of drawing, grasping and gesturing. In order to test them, we have developed new RGBD camera-based algorithms for object detection, classification and tracking. This allows the conception of an interactive installation that uses portable and low cost equipment. In order to evaluate the proposed ways of interaction, we have developed the Magic Surface, a system that transforms a regular surface (such as a wall or a tabletop) into a multitouch interactive space. The Magic Surface detects touch of hand fingers, colored pens and eraser. It also supports the usage of a magic wand for 3D interaction. The Magic Surface can run applications, allowing the transformation of a regular surface into an interactive drawing area, a map explorer, a 3D simulator for navigation in virtual environments, among other possibilities. Areas of application range from education to interactive art and entertainment. The setup of our prototype includes: a Microsoft Kinect sensor, a video projector and a personal computer.

In this work, I present empirically validated techniques to realize gesture and touch interaction using a novel near touch tracking system. This study focuses on identifying the intended center of action for grab and release gestures close to an interactive surface. Results of this experiment inform a linear model that can approximate the intended location of grab and release actions with an accuracy of R^2 = 0.95 for horizontal position and R^2 = 0.84 for vertical position. I also present an approach for distinguishing which hand was used to perform the interaction. These empirical model data and near touch tracking system contributions provide new opportunities for natural and intuitive hand interactions with computing surfaces. / Graduate