Deng Jiangwen. / "April 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 156-170). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

In comparison with other methods assuming that multi-contacts between tool and object are point or line based contacts, our body-based haptic interaction model involves the intrinsic contacts with different tool/object materials acquired from the real world for the realistic haptic simulation. Our studies in interactive haptic deformations is to marry the merits of traditional deformable modeling techniques in computer graphics with force-enabled deformations guided by real-world physics laws, simulating the realistic tangible sensation of interactive haptic manipulation with user-specified constraints in touch-enabled virtual environments. The multi-resolution rendering framework developed in our system unifies the graphics/haptics rendering processes based on the construction of hierarchical imposter representations of surface and volumetric models, and the optimal haptic-scene performance at run time is employed to meet both the visual and haptic perceptual qualities. The proposed work is extensible to support users perceptually experience the virtual objects with different materials through the tangible interfaces in the augmented virtual worlds. In general, haptic perception and manipulation can be further constructed uniformly in the multi-resolution rendering framework. The future work includes investigating multiple force evaluation methods and haptic contact models and in addition integrating them into the unified haptic-scene framework, for the rich and dexterous experiences in large, touch-enable virtual environments. / The body-based haptic interaction model is proposed and developed for simulating the contacted forces between the haptic tools and interacting object, based on Hertz's theory establishing the intrinsic stress distribution related to real material properties. In comparison with the common force evaluation models, the proposed body-based haptic interaction model involves the intrinsic contacts with different tool/object materials acquired from the real world for the realistic haptics simulation. For adding the haptic sensations with touch-enabled soft objects, the thesis first studies multiple force-reflecting deformable objects in volume sculpting, then soft object deformation of Loop subdivision surfaces, and further the soft object freeform deformation through mass-spring Bezier volume lattice. The constrained haptic deformations based on the metaballs are experimented to effectively control the interactive force distribution within the influence range, making the deformable simulation of objects easy to control and manipulate. Lastly, the unified multi-resolution rendering framework of touch-enabled virtual environments is proposed and developed, with level-of-detail imposter representations of both graphics and haptics perceptions. The hierarchical graphics/haptics imposter descriptions of hybrid models (e.g. surfaces/volumes) within the virtual environment are constructed in advance, to maximize the optimal performance of the rendering processes during the interactive haptic-scene navigation and explorations. / This thesis dissertation is mainly devoted to investigate the realistic haptics techniques in touch-enabled virtual environments. It has three major parts: the body-based haptic interaction model to simulate the realistic, physical tool-object interactions based on Hertz's contact theory and applications; the realization of interactive haptic manipulation of deformable objects with volume/surface representations, and further development of constrained haptic deformations based on the metaballs; the integration of multi-resolution rendering framework with level-of-detail impostor representations of graphics and haptics objects, to support the optimal rendering performance during the interactive navigation of touch-enabled virtual environments. / Virtual Reality (VR) applications strive to simulate real or imaginary scenes with which users can interact and perceive the effects of their actions in real time. Adding haptic information such as vibration, tactile array, force feedback simulation enhances the sense of presence in virtual environments. Realistic haptic modeling & rendering is the core component in feeling and manipulating virtual objects within the virtual environments. Haptics interfaces present new challenges in data processing analysis, physical modeling, interactive visualization and tangible simulations, especially in the situation where it is crucial for the operators to touch, grasp and manipulate rigid/soft objects in the virtual worlds. / Chen Hui. / "April 2006." / Adviser: Hanqiu Sun. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6498. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (p. 177-185). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

Learning and memory abilities decline with age; however collaborative learning with a familiar partner has been found to improve older adults’ performance on memory tasks and reduce these age-related differences. However it is unclear whether collaborating with a familiar partner is more beneficial to learning compared with collaborating with a stranger. Similarly, it is unclear whether older adults collaborate similarly with human and computer partners. The aim of this PhD thesis is to understand the role of collaborator identity on collaborative learning, and to investigate whether collaborative learning is as efficient and accurate with a range of learning partners. While collaborative learning is a socially-based memory task, the relationships between collaborative learning and social cognition have not yet been explored. The secondary aim of this thesis is to use experimental collaborative learning paradigms alongside standardised and experimental measures of social cognition to explore whether social cognition accounts for a significant amount of variance in collaborative learning performance with different partners. Two studies compare younger and older adults’ learning with familiar and unfamiliar partners on different collaborative learning paradigms. Two subsequent studies compare older adults’ learning on computerised versions of the collaborative learning tasks with partners they perceive to be humans or computers based on recordings of natural human or synthetic speech respectively. In all studies, measures of social cognition were used to assess whether social abilities affect learning outcomes with different partner types. When comparing older and younger adults’ results, familiarity had no effect on learning or immediate or delayed recall performance. Older adults initially took longer to complete the learning trials but performed with similar efficiency as younger adults by the final trials. Younger and older adults recalled collaboratively learned information with comparable accuracy after a delay of one hour, however after one week, older adults recalled the route less accurately than younger adults. Social cognition was not related to collaborative learning with familiar partners, but was related with unfamiliar partners, suggesting that those who are better able to take the perspective of another person may benefit during interactive learning. Social cognition was related to collaborative learning with perceived human partners but not perceived computer partners. This thesis offers a new perspective on the interplay between social and cognitive function in collaborative learning with different learning partners, and explores the differences between younger and older adults when learning collaboratively. The findings are discussed in relation to cognitive, social, and technological theories. On the whole, collaborative learning can result in older adults learning with similar speed and accuracy to younger adults; while familiarity does not improve learning outcomes, perceived human-ness does.

Current human-aware navigation approaches use a predominantly metric representation of the interaction which makes them susceptible to changes in the environment. In order to accomplish reliable navigation in ever-changing human populated environments, the presented work aims to abstract from the underlying metric representation by using Qualitative Spatial Relations (QSR), namely the Qualitative Trajectory Calculus (QTC), for Human-Robot Spatial Interaction (HRSI). So far, this form of representing HRSI has been used to analyse different types of interactions online. This work extends this representation to be able to classify the interaction type online using incrementally updated QTC state chains, create a belief about the state of the world, and transform this high-level descriptor into low-level movement commands. By using QSRs the system becomes invariant to change in the environment, which is essential for any form of long-term deployment of a robot, but most importantly also allows the transfer of knowledge between similar encounters in different environments to facilitate interaction learning. To create a robust qualitative representation of the interaction, the essence of the movement of the human in relation to the robot and vice-versa is encoded in two new variants of QTC especially designed for HRSI and evaluated in several user studies. To enable interaction learning and facilitate reasoning, they are employed in a probabilistic framework using Hidden Markov Models (HMMs) for online classiffication and evaluation of their appropriateness for the task of human-aware navigation. In order to create a system for an autonomous robot, a perception pipeline for the detection and tracking of humans in the vicinity of the robot is described which serves as an enabling technology to create incrementally updated QTC state chains in real-time using the robot's sensors. Using this framework, the abstraction and generalisability of the QTC based framework is tested by using data from a different study for the classiffication of automatically generated state chains which shows the benefits of using such a highlevel description language. The detriment of using qualitative states to encode interaction is the severe loss of information that would be necessary to generate behaviour from it. To overcome this issue, so-called Velocity Costmaps are introduced which restrict the sampling space of a reactive local planner to only allow the generation of trajectories that correspond to the desired QTC state. This results in a exible and agile behaviour I generation that is able to produce inherently safe paths. In order to classify the current interaction type online and predict the current state for action selection, the HMMs are evolved into a particle filter especially designed to work with QSRs of any kind. This online belief generation is the basis for a exible action selection process that is based on data acquired using Learning from Demonstration (LfD) to encode human judgement into the used model. Thereby, the generated behaviour is not only sociable but also legible and ensures a high experienced comfort as shown in the experiments conducted. LfD itself is a rather underused approach when it comes to human-aware navigation but is facilitated by the qualitative model and allows exploitation of expert knowledge for model generation. Hence, the presented work bridges the gap between the speed and exibility of a sampling based reactive approach by using the particle filter and fast action selection, and the legibility of deliberative planners by using high-level information based on expert knowledge about the unfolding of an interaction.

Yim-Pan Chui. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 126-132). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgments --- p.v / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Introduction to Collaborative Virtual Environments --- p.1 / Chapter 1.2 --- Barriers to Resource Management and Optimization --- p.3 / Chapter 1.3 --- Thesis Contributions --- p.5 / Chapter 1.4 --- Application of this Research Work --- p.6 / Chapter 1.5 --- Thesis Organization --- p.6 / Chapter 2 --- Resource Optimization - Intelligent Server Partitioning --- p.9 / Chapter 2.1 --- Introduction --- p.9 / Chapter 2.2 --- Server Partitioning --- p.13 / Chapter 2.2.1 --- Related Works --- p.15 / Chapter 2.2.2 --- Global Optimization Approaches --- p.17 / Chapter 2.3 --- Hybrid Genetic Algorithm Paradigm --- p.17 / Chapter 2.3.1 --- Drawbacks of traditional GA --- p.18 / Chapter 2.3.2 --- Problem Modeling --- p.19 / Chapter 2.3.3 --- Discussion --- p.24 / Chapter 2.4 --- Results --- p.25 / Chapter 2.5 --- Concluding Remarks --- p.28 / Chapter 3 --- Dynamic State Management - Dead Reckoning of Attitude --- p.32 / Chapter 3.1 --- Introduction to Dynamic State Management --- p.32 / Chapter 3.2 --- The Dead Reckoning Approach --- p.35 / Chapter 3.3 --- Attitude Dead Reckoning by Quaternion --- p.37 / Chapter 3.3.1 --- Modeling of the Paradigm --- p.38 / Chapter 3.3.2 --- Prediction Step --- p.39 / Chapter 3.3.3 --- Convergence Step --- p.40 / Chapter 3.3.4 --- Overall Algorithm --- p.46 / Chapter 3.4 --- Results --- p.47 / Chapter 3.5 --- Conclusion --- p.51 / Chapter 4 --- Polynomial Attitude Extrapolation --- p.52 / Chapter 4.1 --- Introduction --- p.52 / Chapter 4.2 --- Related Works on Kalman Filtering --- p.53 / Chapter 4.3 --- Historical Propagation of Quaternion --- p.54 / Chapter 4.3.1 --- Cumulative Extrapolation --- p.54 / Chapter 4.3.2 --- Method I. Vandemonde Approach --- p.55 / Chapter 4.3.3 --- Method II. Lagrangian Approach --- p.58 / Chapter 4.4 --- History-Based Attitude Management --- p.60 / Chapter 4.4.1 --- Multi-order Prediction --- p.60 / Chapter 4.4.2 --- Adaptive Attitude Convergence --- p.63 / Chapter 4.4.3 --- Overall Algorithm --- p.67 / Chapter 4.5 --- Results --- p.69 / Chapter 4.6 --- Conclusion --- p.77 / Chapter 5 --- Forward Difference Approach on State Estimation --- p.78 / Chapter 5.1 --- Introduction --- p.78 / Chapter 5.2 --- Positional Forward Differencing --- p.79 / Chapter 5.3 --- Forward Difference on Quaternion Space --- p.80 / Chapter 5.3.1 --- Attitude Forward Differencing --- p.83 / Chapter 5.3.2 --- Trajectory Blending --- p.84 / Chapter 5.4 --- State Estimation --- p.86 / Chapter 5.5 --- Computational Efficiency --- p.87 / Chapter 5.6 --- Results --- p.88 / Chapter 5.7 --- Conclusion --- p.96 / Chapter 6 --- Predictive Multibody Kinematics --- p.98 / Chapter 6.1 --- Introduction --- p.98 / Chapter 6.2 --- Dynamic Management of Multibody System --- p.100 / Chapter 6.2.1 --- Multibody Representation --- p.100 / Chapter 6.2.2 --- Paradigm Overview --- p.101 / Chapter 6.3 --- Motion Estimation by Joint Extrapolation --- p.102 / Chapter 6.3.1 --- Individual Joint Extrapolation --- p.102 / Chapter 6.3.2 --- Forward Propagation of Joint State --- p.104 / Chapter 6.3.3 --- Pose Correction --- p.107 / Chapter 6.4 --- Limitations on Predictive Articulated State Management --- p.108 / Chapter 6.5 --- Implementation and Results --- p.109 / Chapter 6.6 --- Conclusion --- p.112 / Chapter 7 --- Complete System Architecture --- p.113 / Chapter 7.1 --- Server Cluster Model --- p.113 / Chapter 7.1.1 --- Peer-Server Systems --- p.114 / Chapter 7.1.2 --- Server Hierarchies --- p.114 / Chapter 7.2 --- Multi-Level Resource Management --- p.115 / Chapter 7.3 --- Aggregation of State Updates --- p.116 / Chapter 7.4 --- Implementation Issues --- p.117 / Chapter 7.4.1 --- Medical Visualization --- p.117 / Chapter 7.4.2 --- Virtual Walkthrough Application --- p.118 / Chapter 7.5 --- Conclusion --- p.119 / Chapter 8 --- Conclusions and Future directions --- p.121 / Chapter 8.1 --- Conclusion --- p.121 / Chapter 8.2 --- Future Research Directions --- p.122 / Chapter A --- Quaternion Basis --- p.124 / Chapter A.1 --- Basic Quaternion Mathematics --- p.124 / Chapter A.2 --- The Exponential and Logarithmic Maps --- p.125 / Bibliography --- p.126

A dissertation submitted to the Faculty of Arts, University of the Witwatersrand, Johannesburg, for the Degree of Master of Arts. / Increasingly complex technology in modern times has changed the nature of many work activities. Mechanisation and automation have served to emphasise the importance of mental workload to productivity, physicaI and mental health. The study uses a simulated routine office stocktaking task to compare subjective experiences of mental workload between traditional pen and paper methods and the more recently developed computer techniques. An analysis is also made of assessments of difficulty by subjects free to adopt a working method of their choice (ie. in a flexible environment) and subjects whohave no freedom of working method (ie. a rigid externally imposed working strategy). Also included is an analysis of the cognitive strategies adopted during task performance and across the different t.reatmerrt conditions. Research findings are of particular relevance to the design of jobs in the modern office environment where human-computer interaction is becoming increasingly prevalent, the effective design of man-machine systems, and to the general field of workload research. / AC2018

abstract: An old proverb claims that “two heads are better than one”. Crowdsourcing research and practice have taken this to heart, attempting to show that thousands of heads can be even better. This is not limited to leveraging a crowd’s knowledge, but also their creativity—the ability to generate something not only useful, but also novel. In practice, there are initiatives such as Free and Open Source Software communities developing innovative software. In research, the field of crowdsourced creativity, which attempts to design scalable support mechanisms, is blooming. However, both contexts still present many opportunities for advancement. In this dissertation, I seek to advance both the knowledge of limitations in current technologies used in practice as well as the mechanisms that can be used for large-scale support. The overall research question I explore is: “How can we support large-scale creative collaboration in distributed online communities?” I first advance existing support techniques by evaluating the impact of active support in brainstorming performance. Furthermore, I leverage existing theoretical models of individual idea generation as well as recommender system techniques to design CrowdMuse, a novel adaptive large-scale idea generation system. CrowdMuse models users in order to adapt itself to each individual. I evaluate the system’s efficacy through two large-scale studies. I also advance knowledge of current large-scale practices by examining common communication channels under the lens of Creativity Support Tools, yielding a list of creativity bottlenecks brought about by the affordances of these channels. Finally, I connect both ends of this dissertation by deploying CrowdMuse in an Open Source online community for two weeks. I evaluate their usage of the system as well as its perceived benefits and issues compared to traditional communication tools. This dissertation makes the following contributions to the field of large-scale creativity: 1) the design and evaluation of a first-of-its-kind adaptive brainstorming system; 2) the evaluation of the effects of active inspirations compared to simple idea exposure; 3) the development and application of a set of creativity support design heuristics to uncover creativity bottlenecks; and 4) an exploration of large-scale brainstorming systems’ usefulness to online communities. / Dissertation/Thesis / Doctoral Dissertation Computer Science 2019

We explore user interactions with concrete physical visualizations—physicalizations—of personal experiential data. We conducted three user studies involving physicalizations of data gathered while trail running—a sport in which participants are largely more focused on the experience than the exercise itself. In two qualitative studies, we asked trail runners to give us a GPS path from a "significant run" and then prepared a 3D physicalization featuring the path overlaid as a raised line on the corresponding real-world terrain. In the first, physicalizations had a significant impact in helping participants recall memories of their experiences, and participants shared many stories. In a follow-up study, we found that participants told frequent stories when interacting with physicalizations and very few with paper topographic maps. In a third, quantitative study, we found that participants could identify features of a path in mountainous terrain with greater speed and accuracy on a 3D physicalization than on a paper map. We theorize that these physicalizations allow for a reduced cognitive load as compared to 2D topographic maps, leaving mental faculties free to recall stored memories.

Prior research has indicated that laypeople construct mental representations of physical symptoms in order to attempt to understand illness (e.g., Leventhal, Safer, Panagis, 1983; Leventhal & Contrada, 1987; Lau, Bernard, & Hartman, 1989). These "illness representations" are influenced by prior experience with and prior knowledge about illness as well as efforts to seek additional information through social channels or media. More and more, the internet is a prominent source of health information, especially for older adults (aged 50 year and up). Yet, few studies have systematically examined how older adults search for health information online. Similarly, recent trends in healthcare such as health consumerism assume that patients will be more empowered if they have access to more information. However, little has been done to investigate whether patients, in fact, feel more empowered after acquiring online health information. The current study examined the online health information seeking of older adults (N = 79) in order to determine the cognitive and diagnostic processes that older adults use to acquire information. Older adults read a vignette which depicted one of two common illnesses and then were asked to "think-aloud" while they attempted to diagnose the illness. Older adults then diagnosed the illness using either a traditional search engine (Google) or popular self-diagnosis tool (WebMD Symptom Checker), and answered questions about illness representations, cognitive effort, web interactivity, and feelings of empowerment after the search. Quantitative results showed inconsistent change in illness representations. Plausible reasons for a lack of findings are discussed. Participants who used WebMD perceived greater cognitive effort while using the computer program than those who used Google, and participants who were inaccurate in their diagnosis perceived greater cognitive effort of diagnosing than those who were accurate. Accuracy was unrelated to perceived interactivity, age, or search method. Participants 50-64 years old found a new version of WebMD to be less interactive than Google. In contrast, participants 65 years or older perceived no difference in interactivity depending upon search method. In terms of empowerment, participants who used Google perceived greater choice than WebMD. There were no differences in feelings of competence depending upon search method. Qualitative results showed that participants spent the majority of time navigating the computer and processing health information. Most participants diagnosed the illness by eliminating diseases whose symptoms did not match the symptoms of the illness vignette. Participants tended to visit commercial health websites such as Everyday Health and begin their information search by typing a vignette symptom into the search bar. Participants who were 65 years or older were less confident about their diagnosis than 50-64 year old participants. Finally, participants who used Google to diagnose were more likely to comment about the credibility of the information found when compared to those who used WebMD. The current study found no change in illness representations after an online information search. However, this produces questions as to the amount of time in which the layperson constructs his/her illness representation. In addition, few differences in interactivity, accuracy, or empowerment were found between an online health information search conducted with a search engine as compared to a self-diagnosis tool. However, individual differences suggest that different age cohorts may prefer information to be presented in different ways which could influence web design. Further studies in human-computer interaction and health cognition may be able to answer the questions that arose.

Intresset för chattbotar är idag mycket stort och de används i många olika områden. Det finns många tillvägagångssätt för att implementera chattbotar, ett av dessa sätt är med verktyget Hubot. Detta arbete undersöker hur effektiv en chattbot utvecklad med Hubot är med avseende på användbarhet och responstid. Användbarheten bedömdes med hjälp av System Usablity Scale (SUS) med 8 testpersoner. Resultatet visade att chattboten hade en relativt låg användbarhet (64,38 poäng enligt SUS), men mycket snabba responstider. Detta indikerade att Hubot inte är en effektiv chattbotlösning i detta arbetes kontext