TIME BALANCING OF COMPUTER GAMES USING ADAPTIVE TIME-VARIANT MINIGAMES

Game designers spend a great deal of time developing balanced game experiences. However, differences in player ability, hardware capacity (e.g. network connections) or real-world elements (as in mixed-reality games), make it difficult to balance games for different players in different conditions. In this research, adaptive time-variant minigames have been introduced as a method of addressing the challenges in time balancing as a part of balancing players of games. These minigames were parameterized to allow both a guaranteed minimum play time (the minimum time to complete a minigames to address the fixed temporal constraints) and dynamic adaptability (the ability of adapting the game during the game play to address temporal variations caused by individual differences). Three time adaptation algorithms have been introduced in this research and the interaction between adaptive algorithm, game mechanic, and game difficulty were analyzed in controlled experiments. The studies showed that there are significant effects and interactions for all three factors, confirming the initial hypothesis that these processes were important and linked to each other. Furthermore, the studies revealed that finer temporal granularity leads to less-perceptible adaptation and smaller deviations in game completion times. The results also provided evidence that adaptation mechanisms allow accurate prediction of play time. The designed minigames were valuable in helping to balance temporal asymmetries in a real mixed-reality game. It was also found that these adaptation algorithms did not interrupt the overall play experience

Balance ninja: towards the design of digital vertigo games via galvanic vestibular stimulation

Vertigo – the momentary disruption of the stability of perception – is an intriguing game element that underlies many unique play experiences, such as spinning in circles as children to rock climbing as adults, yet vertigo is relatively unexplored when it comes to digital play. In this paper we explore the potential of Galvanic Vestibular Stimulation (GVS) as a game design tool for digital vertigo games. We detail the design and evaluation of a novel two player GVS game, Balance Ninja. From study observations and analysis of Balance Ninja (N=20), we present three design themes and six design strategies that can be used to aid game designers of future digital vertigo games. With this work we aim to highlight that vertigo can be a valuable digital game element that helps to expand the range of games we play

A dynamic difficulty adjustment model for dysphonia therapy games

CMUP-ERI/TIC/0033/2014Studies on childhood dysphonia have revealed considerable rates for voice disorders in 4 – 12 year-old children. The sustained vowel exercise is widely used as a technique in the vocal (re)education process. However this exercise can become tedious after a short practice. Here, we propose a novel dynamic difficulty adjustment model to be used in a serious game with the sustained vowel exercise to motivate children on practicing this exercise often. The model automatically adapts the difficulty of the challenges in response to the child’s performance. The model is not exclusive to this game and can be used in other games for dysphonia treatment. In order to measure the child’s performance, the model uses parameters that are relevant to the therapy treatment. The proposed model is based on the flow model in order to balance the difficulty of the challenges with the child’s skills.publishersversionpublishe

Towards Balancing Fun and Exertion in Exergames: Exploring the Impact of Movement-Based Controller Devices, Exercise Concepts, Game Adaptivity and Player Modes on Player Experience and Training Intensity in Different Exergame Settings

Physical inactivity remains one of the biggest societal challenges of the 21st century. The gaming industry and the fitness sector have responded to this alarming fact by introducing game-based or gamified training scenarios and thus established the promising trend of exergaming. Exergames – games controlled by active (whole) body movements – have been extolled as potential attractive and effective training tools. However, the majority of the exergames do not meet the required intensity or effectiveness, nor do they induce the intended training adherence or long-term motivation. One reason for this is that the evaluated exergames were often not co-designed with the user group to meet their specific needs and preferences, nor were they co-designed with an interdisciplinary expert team of game designers (to ensure a good gaming experience) and sports scientists (for a great training experience). Accordingly, the research results from studies with these exergames are rather limited. To fully exploit the potential of these innovative movement tools and to establish them as attractive and effective training approach, it is necessary to understand and explore both the underlying interdisciplinary theories and concepts as well as possible design approaches and their impact on the game and training experience. This dissertation aims to contribute to a better understanding of well-balanced exergame design. It explores and evaluates how different movement-based control devices, exercise concepts, game adaptations, and player modes influence the attractiveness and effectiveness of exergames. The work provides theoretical and practical contributions to the problem area of effective and attractive exergames. For this purpose, a research and development (R&D) approach with iterative phases was followed. As preliminary work for the contributions of this dissertation, exergames were approached from a theoretical perspective. Underlying multidisciplinary theories and concepts of exergames from relevant fields were analyzed and a generic framework was built, which structured the findings based on three interdependent dimensions: the player, the game controller, and the virtual game scenario. Some commercially available exergames were explored to verify the theory-based assumption that the interposition of technology brings specific transformations in the coupling of perception and action that do not occur in real sports situations. Among other things, the comparative pilot study showed that two different controllers (one gesture-based and one haptic device), which allowed for different physical input, were likely to induce diverse gameplay experiences (e.g., higher feeling of flow and self-location when playing with the haptic device) with differently skilled players. However, certain design-specific differences in the two exergame conditions meant that these results could only be interpreted as a first trend. To overcome the limitations of this preliminary study approach (e.g., unequal game design of the commercial exergames and very sports-specific movement concept), Plunder Planet, an adaptive exergame environment, was iteratively designed with and for children and allowed for a single- and cooperative multiplayer experience with two different controller devices. The user-centered design was further informed by insights from the growing body of related R&D work in the field of exergames. The first study presented in this dissertation compared the subjectively experienced attractiveness and effectiveness of Plunder Planet when played with different motion-based controllers. Besides a generally great acceptance of the exergame, it was found that the haptic full-body motion controller provided physical guidance and a more cognitively and coordinatively challenging workout, which was more highly rated by experienced gamers with fewer athletic skills. The gesture-based Kinect sensor felt more natural, allowed more freedom of movement, and provided a rather physically intense but cognitively less challenging workout, which was more highly rated by athletic players with less gameplay experience. Furthermore, experiments were made with an exploratory adaptive algorithm that enabled the cognitive and the physical challenge of the exergame to be manually adapted in real-time based on the player’s fitness and gaming skills. The first and the second study also compared an adaptive with a non-adaptive single player version of Plunder Planet. It could be shown that the (well-balanced) adaptive version of the exergame was better valued than the non-adaptive version with regard to the experienced and measured attractiveness (motivation, game flow, spatial presence experience, balance of cognitive and physical challenge) and effectiveness (heart rate, physical exertion, balance of cognitive and physical challenge) by differently skilled players. Finally, and contrary to the findings from related work, the results of the third study proved that the specifically designed controller technology could be used as an “enabler”, “supporter” and “shaper” of bodily interplay in social exergaming. Based on these promising findings, the goal became to further explore the effectiveness of exergames, refine the adaptive game difficulty algorithm, and explore further attractiveness- and motivation-boosting design approaches. Therefore, the ExerCube, a physically immersive and adaptive fitness game setting, was developed. It was iteratively designed with and for adults and allowed for cooperatively and competitive exergame experiences. With its physically immersive game setup, the ExerCube combines a mixed version of the advantages of both previously tested controllers. A coordinatively and cognitively challenging functional workout protocol with scalable intensity (moderate to high) was developed and the subjective experience of the ExerCube training was compared with a conventional functional training with a personal trainer. The fourth study showed that the game-based training gave signs of reaching a similar intensity to the personal training, but was more highly rated for flow, motivation, and enjoyment. Based on this exploratory comparison of the ExerCube with a personal trainer session, valuable avenues for further design could be identified. Among other things, it could be proved that the player’s focus during the ExerCube session was more on the game than on the own body. Players experienced stronger physical exertion and social pressure with the personal trainer and a stronger cognitive exertion and involvement with the ExerCube. Furthermore, a refined version of the previously tested adaptive game difficulty algorithm was implemented and automated for the first time for purpose of this study. Again it was shown that the adaptive version had benefits with regard to subjectively experienced attractiveness (motivation, game flow, balance of cognitive and physical challenge) and effectiveness (physical exertion, balance of cognitive and physical challenge) compared to the non-adaptive version. In order to further enhance the gaming experience, experiments were also conducted with sound designs and an adaptive audio design with adaptive background music and sound feedback was implemented. It was found to be a promising and beneficial add-on for a user-centered attractive exergame design. To inform the design of a multiplayer version of the ExerCube, different social play mechanics were explored in the fifth study. This resulted in differently balanced experiences of fun, and in physical as well as cognitive exertion. As the preliminary comparative evaluation of the subjectively experienced effectiveness and attractiveness of an ExerCube session and a personal trainer session could prove the general feasibility of the concept and revealed the first indications of the intensity of the ExerCube’s training concept, the objectively measured effectiveness of a single ExerCube session with a functional high-intensity interval training (fHIIT) with a personal trainer was compared in a final sixth study, and after another design iteration. Again, the subjectively experienced attractiveness of both conditions was assessed. It could be shown that the ExerCube is a feasible training device for training at fHIIT-level. While physical exertion was slightly lower than in the conventional fHIIT condition, the ExerCube condition’s average heart rate values reached the fHIIT threshold and also yielded significantly better results for flow, enjoyment, and motivation. The ExerCube training also resulted in a subjectively experienced higher cognitive load (dual-domain training). To sum up, it can be stated that this dissertation provides valuable and fundamental research contributions to the promising field of exergames as attractive and effective training tools. Furthermore, important contributions to design questions in this field could be developed. Since this field is still relatively unexplored, the work presented creates a sound basis for future R&D work in this area

A Controls-Oriented Approach For Modeling Professional Drivers During Ultra-High Performance Maneuvers

In the study of vehicle dynamics and controls, modeling ultra-high performance maneuvers (i.e., minimum-time vehicle maneuvering) is a fascinating problem that explores the boundaries of capabilities for a human controlling a machine. Professional human drivers are still considered the benchmark for controlling a vehicle during these limit handling maneuvers. Different drivers possess unique driving styles, i.e. preferences and tendencies in their local decisions and corresponding inputs to the vehicle. These differences in the driving style among professional drivers or sets of drivers are duly considered in the vehicle development process for component selection and system tuning to push the limits of achievable lap times. This work aims to provide a mathematical framework for modeling driving styles of professional drivers that can then be embedded in the vehicle design and development process. This research is conducted in three separate phases. The first part of this work introduces a cascaded optimization structure that is capable of modeling driving style. Model Predictive Control (MPC) provides a natural framework for modeling the human decision process. In this work, the inner loop of the cascaded structure uses an MPC receding horizon control strategy which is tasked with finding the optimal control inputs (steering, brake, throttle, etc.) over each horizon while minimizing a local cost function. Therein, we extend the typical fixed-cost function to be a blended cost capable of optimizing different objectives. Then, an outer loop finds the objective weights used in each MPC control horizon. It is shown that by varying the driver\u27s objective between key horizons, some of the sub-optimality inherent to the MPC process can be alleviated. In the second phase of this work, we explore existing onboard measurements of professional drivers to compare different driving styles. We outline a novel racing line reconstruction technique rooted in optimal control theory to reconstruct the driving lines for different drivers from a limited set of measurements. It is demonstrated that different drivers can achieve nearly identical lap times while adopting different racing lines. In the final phase of this work, we use our racing line technique and our cascaded optimization framework to fit computable models for different drivers. For this, the outer loop of the cascaded optimization finds the set of objective weights used in each local MPC horizon that best matches simulation to onboard measurements. These driver models will then be used to optimize vehicle design parameters to suit each driving style. It will be shown that different driving styles will yield different parameters that optimize the driver/vehicle system

Coping in High-Risk Snow-Sports: A Qualitative Exploration of Alpine Racing and Freestyle Athletes’ Experiences

This study examines how semi-elite student snow-sport athletes utilise process and trait coping strategies to combat risk-taking, potential loss and trauma, and other stressors integral to their sport participation. Factors influencing coping strategy preference are also explored. Semi-structured interviews were used to explore ten participants’ experiences; the narratives were analysed using thematic analysis. Five master themes emerged from the analysis: Challenges to Overcome; Taking Action; Changing Perspectives; Staying in Control; and Underlying Influences. The findings highlight how participants’ develop and utilise preferred coping strategies, although the unpredictable nature of snow-sports can result in situation-specific process coping. Findings are discussed in relation to the differences between racing and freestyle disciplines