How Fast Can We Play Tetris Greedily With Rectangular Pieces?

Consider a variant of Tetris played on a board of width $w$ and infinite height, where the pieces are axis-aligned rectangles of arbitrary integer dimensions, the pieces can only be moved before letting them drop, and a row does not disappear once it is full. Suppose we want to follow a greedy strategy: let each rectangle fall where it will end up the lowest given the current state of the board. To do so, we want a data structure which can always suggest a greedy move. In other words, we want a data structure which maintains a set of $O(n)$ rectangles, supports queries which return where to drop the rectangle, and updates which insert a rectangle dropped at a certain position and return the height of the highest point in the updated set of rectangles. We show via a reduction to the Multiphase problem [P\u{a}tra\c{s}cu, 2010] that on a board of width $w=\Theta(n)$, if the OMv conjecture [Henzinger et al., 2015] is true, then both operations cannot be supported in time $O(n^{1/2-\epsilon})$ simultaneously. The reduction also implies polynomial bounds from the 3-SUM conjecture and the APSP conjecture. On the other hand, we show that there is a data structure supporting both operations in $O(n^{1/2}\log^{3/2}n)$ time on boards of width $n^{O(1)}$, matching the lower bound up to a $n^{o(1)}$ factor.Comment: Correction of typos and other minor correction

Fatigue-Focused Manufacturing Optimization for Welded Structures

Welded structures have an inherent vulnerability of fatigue failure at joint locations due to change in geometry and material properties. The U.S. Army, in an effort to to increase overall readiness, has taken interest in understanding fatigue behavior and failure prevention specific to their ground combat vehicles. Fatigue testing of armor-grade joints was conducted in order to understand the material behavior, and this work incorporates the information developed from these tests with structural load cases to create a proactive assembly plan. By acknowledging the higher stress regions from typical (i.e., high frequency) loading scenarios and avoiding weld placement in these areas, reduced vehicle vulnerability can be achieved. Current fatigue life optimization research centers around topographical analysis of structural components, primarily focusing on shape and weight with fatigue limits. These optimizations rarely, if ever, consider the manufacturability and cost of the component or structure. This work develops optimization algorithms, tailored to meet manufacturing limitations, with the primary objective of minimizing weld stress exposure and a secondary consideration of cost. The final algorithm takes direction from bin-packing optimizations by filling in a representative vehicle side panel with a set of designated plate sizes, and evaluating the stress exposure and cost based on the weld placements and weld types. The stress exposure is determined by the position of the weld and scaled by the weld type. The cost of the assembly considers the overall length of welds and wasted material. The panel assembly designs are then ranked by these evaluations. Results provide a comprehensive, feasible assembly plan that extends the fatigue life of a structure.PHDNaval Architecture & Marine EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/169604/1/mayhoodc_1.pd

Generation and Analysis of Content for Physics-Based Video Games

The development of artificial intelligence (AI) techniques that can assist with the creation and analysis of digital content is a broad and challenging task for researchers. This topic has been most prevalent in the field of game AI research, where games are used as a testbed for solving more complex real-world problems. One of the major issues with prior AI-assisted content creation methods for games has been a lack of direct comparability to real-world environments, particularly those with realistic physical properties to consider. Creating content for such environments typically requires physics-based reasoning, which imposes many additional complications and restrictions that must be considered. Addressing and developing methods that can deal with these physical constraints, even if they are only within simulated game environments, is an important and challenging task for AI techniques that intend to be used in real-world situations. The research presented in this thesis describes several approaches to creating and analysing levels for the physics-based puzzle game Angry Birds, which features a realistic 2D environment. This research was multidisciplinary in nature and covers a wide variety of different AI fields, leading to this thesis being presented as a compilation of published work. The central part of this thesis consists of procedurally generating levels for physics-based games similar to those in Angry Birds. This predominantly involves creating and placing stable structures made up of many smaller blocks, as well as other level elements. Multiple approaches are presented, including both fully autonomous and human-AI collaborative methodologies. In addition, several analyses of Angry Birds levels were carried out using current state-of-the-art agents. A hyper-agent was developed that uses machine learning to estimate the performance of each agent in a portfolio for an unknown level, allowing it to select the one most likely to succeed. Agent performance on levels that contain deceptive or creative properties was also investigated, allowing determination of the current strengths and weaknesses of different AI techniques. The observed variability in performance across levels for different AI techniques led to the development of an adaptive level generation system, allowing for the dynamic creation of increasingly challenging levels over time based on agent performance analysis. An additional study also investigated the theoretical complexity of Angry Birds levels from a computational perspective. While this research is predominately applied to video games with physics-based simulated environments, the challenges and problems solved by the proposed methods also have significant real-world potential and applications

Development and user experience evaluation of language learning mobile applications

https://www.ester.ee/record=b5258014*es

An “other” experience of videogames: analyzing the connections between videogames and the lived experience of chronic pain

In this dissertation I argue for the connections between the lived experience of chronic pain and videogames, exploring what interacts with and influences them. To answer this, I draw on cripistemology as I engage in autoethnography, close-reading and close-gameplay, restorying, mixed methods design, formal interviews, surveys, and inductive coding. I further argue for pushing back against the unhelpful binaries that define the “human” and a false idea of “universal” experience or ability, instead pointing to the intersectionality that better reflects the biopolitics of disability, including both debility and capacity. I engage with these methods in three specific projects that consider additional sub-questions to further tease out why videogames disability, chronic pain, game design, lived experience, human centered design, embodiment in video games have impacted me so deeply and how this ties to my identity as a disabled woman. I further offer this dissertation to highlight the growing research of lived experience and disability in the field of game studies, providing empirical data that offers a foundational look of how I as a member of the chronic pain community think and feel about videogames, as well as how a small portion of the chronic pain community discusses videogames and the range of experiences this encompasses. In doing so, I unpack and argue on the relationship that exists between chronic pain and videogames, and further articulate why this matters. In Chapter 1 I provide necessary history and information regarding my research to better articulate the findings as presented in the following chapters. In Chapter 2, I analyze my connection to Animal Crossing: New Leaf (AC:NL) (Nintendo EAD, 2012) and explore opportunities about genre and mechanics as reflections of my own daily lived experience with chronic pain, especially including my experience in a 2014 pain rehabilitation program. Through this process, I define the “slice of life” genre and argue that AC:NL is exemplary of its markers. In Chapter 3 I provide a deep reading and analysis of Nintendo’s GameCube release Chibi-Robo! (Skip Ltd. et al., 2005) to “restory” the titular main character to have chronic pain like my own. Through the lens of debility and capacitation machines, I map these ideas onto the biopsychosocial model to organize a thorough analysis of his restoried identity. In modding the game’s narrative to reflect a lived experience of chronic pain like my own, I interweave fanfiction with deep reading and deep gameplay to unpack what representation I am looking for in videogames both narratively and mechanically. In this I further argue how this practice can be used to inform future game design. Finally, in Chapter 4, I interview members of the chronic pain community to understand their perspective on the connections between their lived experience with chronic pain and videogames, as well as how additional factors of their identity impact those experiences. For this I engage in a mixed methods design to conduct a survey and formal interviews to offer foundational work on how the chronic pain community interacts with videogames. I offer this project to intersect current research in chronic pain and videogames (and its related technology) that focuses on games as tools for “curing” pain, and argue the importance of considering what embodiment people with chronic pain already have in videogames instead. Ultimately, I argue for the necessity to complicate current design practices in human centered design (HCD) and game design. To do so, I highlight the lived experience of Othered identities to combat misguided notions of “universal” intent. In this, I analyze the inherent connections between videogames and disability, in this case chronic pain, through embodiment and lived experience. I center in on how my experience of chronic pain has impacted the way in which I engage and think about with videogames, and further, how my experiences align with that of the chronic pain community

The major and the minor on political aesthetics in the control society

This thesis examines the crucial diagnostic and productive roles that the concepts of minor and major practice, two interrelated modes of cultural production set out by Gilles Deleuze and Félix Guattari in Kafka: toward a Minor Literature (1975), have to play in the present era of ubiquitous digital technology and informatics that Deleuze himself has influentially described as the control society. In first establishing the conditions of majority and majority, Deleuze and Guattari’s historical focus in Kafka is the early twentieth century period of Franz Kafka’s writing, a period which, for Deleuze, marks the start of a transition between two types of society – the disciplinary society described by Michel Foucault in Discipline and Punish and the control society that is set apart by its distribution, indifferent technical processes and the replacement of the individual with the dividual in social and political thought. Because of their unique conceptual location, at the transition between societies, the concepts of majority and minority present an essential framework for understanding the impact of ubiquitous digital technology and informatics on cultural production in the twentieth century and beyond. In order to determine the conditions of contemporary major and minor practice across the transition from disciplinary to control societies, the thesis is comprised of two interconnecting threads corresponding to majority and minority respectively. Drawing on the theoretical work of Deleuze and Guattari, Friedrich Kittler and Fredric Jameson alongside pioneering figures in the historical development of computation and informatics (Alan Turing, Claude Shannon and others), material observation on the technical function of digital machines, and the close examination of emblematic cultural forms, I determine the specific conditions of majority that emerge through the development of the contemporary control era. Alongside this delineation of the conditions of majority I examine the prospective tactics, corresponding to the characteristics of minority set out by Deleuze and Guattari in Kafka, which emerge as a contemporary counter-practice within the control-era. This is carried out through the close observation of key examples of cultural production in the fields of literature, film, video, television and the videogame that manifest prospective tactics for a control-era minor practice within the overarching technical characteristics of the control-era major. Through an examination of these interrelated threads the thesis presents a framework for both addressing the significant political and cultural changes that ubiquitous computation effects in constituting the contemporary control society and determining the ways in which these changes can be addressed and countered through cultural production

Virtual Reality Games for Motor Rehabilitation

This paper presents a fuzzy logic based method to track user satisfaction without the need for devices to monitor users physiological conditions. User satisfaction is the key to any product’s acceptance; computer applications and video games provide a unique opportunity to provide a tailored environment for each user to better suit their needs. We have implemented a non-adaptive fuzzy logic model of emotion, based on the emotional component of the Fuzzy Logic Adaptive Model of Emotion (FLAME) proposed by El-Nasr, to estimate player emotion in UnrealTournament 2004. In this paper we describe the implementation of this system and present the results of one of several play tests. Our research contradicts the current literature that suggests physiological measurements are needed. We show that it is possible to use a software only method to estimate user emotion

Digitally Interactive Works and Video Games: A Philosophical Exploration

This dissertation explores the philosophy of digitally interactive works and video games. There are two central questions to this thesis, namely, what is distinctive about computer art, and more specifically, what is distinctive about the interactivity that these kinds of works afford? The latter question is a response to the former, but, as I will articulate in the chapters that follow, this distinctive type of interactivity is not restricted to works that are comprised of digital media. As it turns out, games (especially video games) are paradigmatic examples and so both analytic aesthetics and game theory are relevant to a discussion of interactivity. In what follows, I address topics that pertain to interactivity such as art categories, prescriptions, appreciation, and ontology. This thesis will show that interactive works consist of unique displays and prescriptions and are, therefore, a distinctive category of art. I conclude that interactive works do not belong in a performance ontology, that the prescriptions of interactive art bear player engagement, and, importantly, the distinctive features of digitally interactive works hinge on an algorithmic ontology