The Cost of Perfection for Matchings in Graphs

Perfect matchings and maximum weight matchings are two fundamental combinatorial structures. We consider the ratio between the maximum weight of a perfect matching and the maximum weight of a general matching. Motivated by the computer graphics application in triangle meshes, where we seek to convert a triangulation into a quadrangulation by merging pairs of adjacent triangles, we focus mainly on bridgeless cubic graphs. First, we characterize graphs that attain the extreme ratios. Second, we present a lower bound for all bridgeless cubic graphs. Third, we present upper bounds for subclasses of bridgeless cubic graphs, most of which are shown to be tight. Additionally, we present tight bounds for the class of regular bipartite graphs

Dynamic Procedural Music Generation from NPC Attributes

Procedural content generation for video games (PCGG) has seen a steep increase in the past decade, aiming to foster emergent gameplay as well as to address the challenge of producing large amounts of engaging content quickly. Most work in PCGG has been focused on generating art and assets such as levels, textures, and models, or on narrative design to generate storylines and progression paths. Given the difficulty of generating harmonically pleasing and interesting music, procedural music generation for games (PMGG) has not seen as much attention during this time. Music in video games is essential for establishing developers\u27 intended mood and environment. Given the deficit of PMGG content, this paper aims to address the demand for high-quality PMGG. This paper describes the system developed to solve this problem, which generates thematic music for non-player characters (NPCs) based on developer-defined attributes in real time and responds to the dynamic relationship between the player and target NPC. The system was evaluated by means of user study: participants confront four NPC bosses each with their own uniquely generated dynamic track based on their varying attributes in relation to the player\u27s. The survey gathered information on the perceived quality, dynamism, and helpfulness to gameplay of the generated music. Results showed that the generated music was generally pleasing and harmonious, and that while players could not detect the details of how, they were able to detect a general relationship between themselves and the NPCs as reflected by the music

Adapting models of visual aesthetics for personalized content creation

This paper introduces a search-based approach to personalized content generation with respect to visual aesthetics. The approach is based on a two-step adaptation procedure where (1) the evaluation function that characterizes the content is adjusted to match the visual aesthetics of users and (2) the content itself is optimized based on the personalized evaluation function. To test the efficacy of the approach we design fitness functions based on universal properties of visual perception, inspired by psychological and neurobiological research. Using these visual properties we generate aesthetically pleasing 2D game spaceships via neuroevolutionary constrained optimization and evaluate the impact of the designed visual properties on the generated spaceships. The offline generated spaceships are used as the initial population of an interactive evolution experiment in which players are asked to choose spaceships according to their visual taste: the impact of the various visual properties is adjusted based on player preferences and new content is generated online based on the updated computational model of visual aesthetics of the player. Results are presented which show the potential of the approach in generating content which is based on subjective criteria of visual aesthetics.Thanks to all the participants of the interactive evolution experiement. The research was supported, in part, by the FP7 ICT project SIREN (project no: 258453) and by the Danish Research Agency, Ministry of Science, Technology and Innovation project AGameComIn; project number: 274- 09-0083.peer-reviewe

Towards hermeticist grammars of music : a proposal for systems of composition based on the principles of the hermetic tradition, with musical demonstrations

PhD Thesis, Multimedia items accompanying this thesis to be consulted at Robinson LibraryThis thesis is a composer's manual on how to select and appropriately use musical materials in accordance with some of the parameters of the Hermetic Tradition. It puts to the reader's consideration a few proposals for Hermeticist grammars of musical composition. 'Grammar' here is used in the sense of a set of rules which govern the construction of musical discourse. Musical grammars thus comprise rules pertaining to the construction and selection of both 'lineal' musical materials such as pitch rows, rhythms, motifs and timbres, as well as of simultaneous events such as harmonic or contrapuntal textures. The adjective 'Hermeticist', derived from the noun Hermeticism, refers to a form of traditional Western urban, learned and humanist occultism. This occultism is distinct from folk, popular, or religious/devotional forms of magic, which also occur in the West as well as in other cultures and societies. It is also distinct from other Western occult movements that are either revivalist in their inspiration (such as Wicca or neopagan religions) or related to the 'pop culture' of the last quarter of the twentieth century, such as the movements of New Age and Chaos Magick. The first part of the thesis, the textual component, briefly examines the historical encounters between Hermeticism and music theory, very few of which have produced sounding pieces of music, while most of them have happened exclusively at the theoretical, philosophical or mystical-speculative levels. In the second part, the portfolio of musical compositions, I demonstrate the application of the proposed methods through pieces of music I have composed using the historical, theoretical and technical background presented at length in part 1. I further comment on these musical results through annotations and description of precompositional work, context research and composition processes used in each individual piece

Sistema de animação multi-resolução

As malhas multi-resolução são cada vez mais utilizadas em computação gráfica, pois permitem ter várias resoluções de um mesmo modelo. Devido ao desenvolvimento de tecnologias para aquisição de dados 3D, como por exemplo, os scanners 3D e devido ao detalhe com que estes dispositivos conseguem criar as representações geométricas dos modelos 3D, é necessário muitas vezes recorrer a algoritmos de simplificação de malhas. O trabalho desenvolvido nesta dissertação, teve como objectivo testar a viabilidade da aplicação de um esquema multi-resolução para malhas aplicado a um sistema de animação, ou seja, consoante a distância da malha ao observador, esta vai sendo simplificada ou refinada. Assim, quando a malha se afasta do observador é aplicado um algoritmo de simplificação de modo a gerar uma representação com menos detalhe, de modo inverso quando a malha se aproxima é gerada uma malha com mais detalhe através de um algoritmo de refinamento. Tal como na vida real, o detalhe que uma pessoa tem dos objectos depende da distância a que está deles, pois se o objecto estiver muito longe os seus pormenores não são todos perceptíveis, enquanto que se o objecto estiver perto do utilizador os pormenores já são perceptíveis

Non-Standard Sound Synthesis with Dynamic Models

Full version unavailable due to 3rd party copyright restrictions.This Thesis proposes three main objectives: (i) to provide the concept of a new generalized non-standard synthesis model that would provide the framework for incorporating other non-standard synthesis approaches; (ii) to explore dynamic sound modeling through the application of new non-standard synthesis techniques and procedures; and (iii) to experiment with dynamic sound synthesis for the creation of novel sound objects. In order to achieve these objectives, this Thesis introduces a new paradigm for non-standard synthesis that is based in the algorithmic assemblage of minute wave segments to form sound waveforms. This paradigm is called Extended Waveform Segment Synthesis (EWSS) and incorporates a hierarchy of algorithmic models for the generation of microsound structures. The concepts of EWSS are illustrated with the development and presentation of a novel non-standard synthesis system, the Dynamic Waveform Segment Synthesis (DWSS). DWSS features and combines a variety of algorithmic models for direct synthesis generation: list generation and permutation, tendency masks, trigonometric functions, stochastic functions, chaotic functions and grammars. The core mechanism of DWSS is based in an extended application of Cellular Automata. The potential of the synthetic capabilities of DWSS is explored in a series of Case Studies where a number of sound object were generated revealing (i) the capabilities of the system to generate sound morphologies belonging to other non-standard synthesis approaches and, (ii) the capabilities of the system of generating novel sound objects with dynamic morphologies. The introduction of EWSS and DWSS is preceded by an extensive and critical overview on the concepts of microsound synthesis, algorithmic composition, the two cultures of computer music, the heretical approach in composition, non- standard synthesis and sonic emergence along with the thorough examination of algorithmic models and their application in sound synthesis and electroacoustic composition. This Thesis also proposes (i) a new definition for “algorithmic composition”, (ii) the term “totalistic algorithmic composition”, and (iii) four discrete aspects of non-standard synthesis

Machine learning and its applications in reliability analysis systems

In this thesis, we are interested in exploring some aspects of Machine Learning (ML) and its application in the Reliability Analysis systems (RAs). We begin by investigating some ML paradigms and their- techniques, go on to discuss the possible applications of ML in improving RAs performance, and lastly give guidelines of the architecture of learning RAs. Our survey of ML covers both levels of Neural Network learning and Symbolic learning. In symbolic process learning, five types of learning and their applications are discussed: rote learning, learning from instruction, learning from analogy, learning from examples, and learning from observation and discovery. The Reliability Analysis systems (RAs) presented in this thesis are mainly designed for maintaining plant safety supported by two functions: risk analysis function, i.e., failure mode effect analysis (FMEA) ; and diagnosis function, i.e., real-time fault location (RTFL). Three approaches have been discussed in creating the RAs. According to the result of our survey, we suggest currently the best design of RAs is to embed model-based RAs, i.e., MORA (as software) in a neural network based computer system (as hardware). However, there are still some improvement which can be made through the applications of Machine Learning. By implanting the 'learning element', the MORA will become learning MORA (La MORA) system, a learning Reliability Analysis system with the power of automatic knowledge acquisition and inconsistency checking, and more. To conclude our thesis, we propose an architecture of La MORA