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

Directed Emergent Drama

A fully interactive drama, where the player interacts with intelligent Non- Player Characters (NPCs), can revolutionise entertainment, gaming, education, and therapy. Creating such a genuinely interactive drama that is entertaining and gives players a sense of coherency as active participants in the unfolding drama has seen a substantial research effort. Authors have the power to shape dramatised stories for theatre or television at will. Conversely, the authors' ability to shape interactive drama is limited because the drama emerges from players' and NPCs actions during game-play, which significantly limits authoring control. A coherent drama has a recognisable dramatic structure. One philosophy is to use planning algorithms and narrative structures to reduce required authoring. However, planning algorithms are intractable for the large state-spaces intrinsic to interactive dramas, and they have not reduced the authoring problem sufficiently. A more straightforward and computationally feasible method is emergent interactive drama from players' and NPCs' actions. The main difficulty with this approach is maintaining a drama structure and theme, such as a mystery theme or a training scenario, that the player experiences while interacting with the game world. Therefore, it is necessary to impose some form of structure to guide or direct the unfolding drama. The solution introduced in this thesis is to distribute the computation among autonomous actors that are guided by goals and drama structures which a centralised autonomous director agent distributes among the actors, which comprises the following four main elements: a) autonomous rational actor agents that know they are acting and can negotiate dialogues between them to remain realistic while simultaneously progressing the drama, without the player knowing, b) Bayesian network to model the actors reasoning, including beliefs about other actors' mental states c) an autonomous director agent uses "schemas", conceptual structures based on motifs, to guide the actors

‘IMPLICIT CREATION’ – NON-PROGRAMMER CONCEPTUAL MODELS FOR AUTHORING IN INTERACTIVE DIGITAL STORYTELLING

Interactive Digital Storytelling (IDS) constitutes a research field that emerged from several areas of art, creation and computer science. It inquires technologies and possible artefacts that allow ‘highly-interactive’ experiences of digital worlds with compelling stories. However, the situation for story creators approaching ‘highly-interactive’ storytelling is complex. There is a gap between the available technology, which requires programming and prior knowledge in Artificial Intelligence, and established models of storytelling, which are too linear to have the potential to be highly interactive. This thesis reports on research that lays the ground for bridging this gap, leading to novel creation philosophies in future work. A design research process has been pursued, which centred on the suggestion of conceptual models, explaining a) process structures of interdisciplinary development, b) interactive story structures including the user of the interactive story system, and c) the positioning of human authors within semi-automated creative processes. By means of ‘implicit creation’, storytelling and modelling of simulated worlds are reconciled. The conceptual models are informed by exhaustive literature review in established neighbouring disciplines. These are a) creative principles in different storytelling domains, such as screenwriting, video game writing, role playing and improvisational theatre, b) narratological studies of story grammars and structures, and c) principles of designing interactive systems, in the areas of basic HCI design and models, discourse analysis in conversational systems, as well as game- and simulation design. In a case study of artefact building, the initial models have been put into practice, evaluated and extended. These artefacts are a) a conceived authoring tool (‘Scenejo’) for the creation of digital conversational stories, and b) the development of a serious game (‘The Killer Phrase Game’) as an application development. The study demonstrates how starting out from linear storytelling, iterative steps of ‘implicit creation’ can lead to more variability and interactivity in the designed interactive story. In the concrete case, the steps included abstraction of dialogues into conditional actions, and creating a dynamic world model of the conversation. This process and artefact can be used as a model illustrating non-programmer approaches to ‘implicit creation’ in a learning process. Research demonstrates that the field of Interactive Digital Storytelling still has to be further advanced until general creative principles can be fully established, which is a long-term endeavour, dependent upon environmental factors. It also requires further technological developments. The gap is not yet closed, but it can be better explained. The research results build groundwork for education of prospective authors. Concluding the thesis, IDS-specific creative principles have been proposed for evaluation in future work

First steps in the study of cyber-psycho-cognitive operations

Dissertação (mestrado)—Universidade de Brasília, Instituto de Relações Internacionais, Programa de Pós-Graduação em Relações Internacionais, 2019.O presente trabalho é uma análise dos mecanismos informáticos e tecno-comunicacionais envolvidos na articulação de mundos da vida orientados estrategicamente para estimular, prever ou minar o desenvolvimento das condições psico-cognitivas adequadas para a construção e sustento da legitimidade racional de uma autoridade ou ação política. A aplicação de instrumentos “arqueológicos” Foucauldianos ao estudo das narrativas políticas que engendraram e surgiram de “Russiagate” permitiu situar a teoria num contexto histórico e validar a premissa da convergência e incorporação de tendências de agendamento comuns e de práticas típicas de operações psicológicas tradicionais. Contudo, os efeitos tanto da disponibilidade comercial das TICs com capacidade de “deep learning”, quanto da estruturação baseada em conhecimento permitida pela ubiquidade e centralidade econômica dessas tecnologias, tornam o conjunto de mecanismos analisados num fenômeno que merece uma conceptualização e marco investigativo únicos. A obra é uma contribuição a esse empreendimento.This is an analysis of the ICT-based mechanisms involved in the articulation of lifeworlds that are strategically oriented to foster, prevent or undermine the development of psycho-cognitive conditions adequate for the construction or sustainability of an authority’s or a political action’s rational legitimacy. While grounding theory to a historical context, the application of Foucauldian “archeological” instruments to the study of the political narratives giving birth and springing from “Russiagate” also served to validate the premised convergence and incorporation of common agenda-setting trends and practices typical of traditional psychological operations. However, the effects of both the commercial availability of deep-learning ICTs and the cognition-based structuration afforded by their ubiquity and economic centrality set this “dispositif” apart, thereby deserving a unique conceptualization and research framework. This study is a contribution to such endeavor

Air Force Institute of Technology Research Report 2018

This Research Report presents the FY18 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs). Interested individuals may discuss ideas for new research collaborations, potential CRADAs, or research proposals with individual faculty using the contact information in this document

Digital life stories: Semi-automatic (auto)biographies within lifelog collections

Our life stories enable us to reflect upon and share our personal histories. Through emerging digital technologies the possibility of collecting life experiences digitally is increasingly feasible; consequently so is the potential to create a digital counterpart to our personal narratives. In this work, lifelogging tools are used to collect digital artifacts continuously and passively throughout our day. These include images, documents, emails and webpages accessed; texts messages and mobile activity. This range of data when brought together is known as a lifelog. Given the complexity, volume and multimodal nature of such collections, it is clear that there are significant challenges to be addressed in order to achieve coherent and meaningful digital narratives of our events from our life histories. This work investigates the construction of personal digital narratives from lifelog collections. It examines the underlying questions, issues and challenges relating to construction of personal digital narratives from lifelogs. Fundamentally, it addresses how to organize and transform data sampled from an individual’s day-to-day activities into a coherent narrative account. This enquiry is enabled by three 20-month long-term lifelogs collected by participants and produces a narrative system which enables the semi-automatic construction of digital stories from lifelog content. Inspired by probative studies conducted into current practices of curation, from which a set of fundamental requirements are established, this solution employs a 2-dimensional spatial framework for storytelling. It delivers integrated support for the structuring of lifelog content and its distillation into storyform through information retrieval approaches. We describe and contribute flexible algorithmic approaches to achieve both. Finally, this research inquiry yields qualitative and quantitative insights into such digital narratives and their generation, composition and construction. The opportunities for such personal narrative accounts to enable recollection, reminiscence and reflection with the collection owners are established and its benefit in sharing past personal experience experiences is outlined. Finally, in a novel investigation with motivated third parties we demonstrate the opportunities such narrative accounts may have beyond the scope of the collection owner in: personal, societal and cultural explorations, artistic endeavours and as a generational heirloom