I detta arbete utförs en jämförelse av exekveringstid för tolkning och rendering av Lindenmayersystem (L-system), utfört av samma algoritm på CPU’n (eng. central processingunit) och GPU’n (eng. graphics processing unit). Undersökningen fokuserar på exekveringstid och dess utveckling vid olika typer av L-system, längder samt upplösning. Algoritmen implementerades i spelmotorn Unity både på CPU’n via C# och på GPU’n medhjälp av beräknings-shaders. Experimenten bestod av två L-system. Ett med förgreningaroch ett utan. Båda L-systemen testades med olika upplösningar och längder, varpå exekveringstid avlästes. Experimentens resultat påvisar stor fördel hos CPU-lösningen gällande exekveringstid. Bristen på GPU-anpassad kod, exempelvis kod utan förgreningar och med bra minneshantering, leder till att GPU’n presterar sämre. Arbetet avslutas med förslag på vidareforskning. Förslagen innefattar utökad testning på olika hårdvara, en mer kontrollerad testmiljö samt implementering av algoritmen i faktisk spelproduktion.

This thesis details the results and conclusions of a project conducted at the game studio FromSoftware in Tokyo, Japan during the autumn of 2008. The aim ofthe project was the design and implementation of a system able to generate 3D graphical representations of road networks.

傳統的裝飾紋路，如獸面紋和雲紋，是經過工匠藝術家將其對於自然的變化與鳥獸的形態加以抽象化，藉由這些精妙的花紋傳遞豐富的訊息，形成具有象徵意義的紋路。本論文針對傳統中國雲紋進行分析，發現其保有高度的自我相似性，以此特性為基礎，我們發現到L-system也常被運用於此類特性紋路之創建，本論文以此語法為基礎撰寫生長規則，配合parametric L-system參數化的特性，不但可以讓雲紋達到很好的多樣性，同時配合非相片寫實電腦繪圖技術強化風格效果，讓我們的結果更忠於傳統雲紋，更進一步透過具時間序列的向量場資訊影響L-system之成長，產生具東方風格之動態雲紋。 / Traditional decorative patterns, such as animal mask and cloud patterns, are the art heritage from the abstraction of the changing nature and the shape of animals. These decorative patterns are not only exquisite art, but also meaningful symbolic patterns. In this thesis, we analysis the traditional Chinese cloud patterns, and find out the structure of self-similarity in cloud pattern. In this thesis, we design the growth rules base on the grammar of L-system and the parameterization of parametric L-system. We also combine the stylized line drawing to achieve a good variety of cloud patterns, and our results are faithful to the traditional art. Furthermore, we can generate the dynamic oriental cloud patterns with a time-varying vector field to affect the growth rule.

TITLE: LEGO Mindstorms: Didactic utilization in mathematics with a focus on fractals ABSTRACT: The objective of this thesis is to determine whether the teaching of fractal geometry supported by computer and robotic LEGO Mindstorms NXT has its place in the education of primary and secondary schools pupils in the Czech Republic. The theoretical part focuses on key topics and personalities closely connected to fractal geometry problematics. It provides a brief historical overview of the fractal geometry development, its potential use in teaching mathematics (with reference to Turkish curriculum documents), and a description of LEGO Mindstorms NXT which can well serve as a manual for teachers and pupils. The practical part contains instructions for building a robotic turtle as well as a proposal of teaching block aimed to support pupils' algorithmic and geometric thinking including key competencies. Quantitative comparison of the results taken from Turkish studies and evaluation of the project by the author and pupils are a part of the experiment as well. KEYWORDS: LEGO Mindstorms NXT, fractal, programming, Logo, learning by doing, turtle, Papert, L-system, microworlds

This work deals with evolutionary design of 3D structures. The work brings the summary of the previous works in this area and brings autor's suggested solution of evolutionary design of 3D structures. This paper seeks to the ability of easy fitness function definition in the systems for evolutionary design of structures. The author tries to make one of the first steps to the future systems for evolution design of any universal structures in contrast with the evolution systems for design of a concrete type of structure. The result of this work is the basic system for evolutionary design of 3D structures with the ability of external fitness function definition via the XML file. This paper offers also the  simple advices and observations for the potential future work in this area.

I den här uppsatsen presenteras ett nytt sätt att procedurellt generera pseudo-oändligadungeons som kan traverseras i tre dimensioner. För att hålla genereringen koherent bådeunder och mellan spelsessioner utgår genereringen från ett ”seed”. Ett seed garanterar sammainnehåll på samma plats varje gång miljön genereras. Med en metod som är baserad iL-system genererar vi här en maze dungeon med tvådimensionell grammatikexpansion ochvi undersöker sedan hur duglig den är. Vi försöker få svaret på hur avancerade L-system somkrävs för att nå en nivå av variation som känns tillräcklig för en miljö av pseudo-oändligkaraktär. Variationstestet samlar data från ett urval områden i den färdiggenererade dungeonen.Resultaten visar på att den utvecklade metoden i det här projektet fungerar väl förändamålet. / In this paper we present a novel way of procedurally generating pseudo infinite dungeonsthat can be traversed in three dimensions. To ensure consistent generation both duringand between playing sessions the generation is ”seeded”. Seeded generation guarantees thesame content in the same place every time the environment is generated. Using a methodbased in L-systems we generate a maze dungeon with two dimensional grammar expansionand explore its viability. We try to find the needed complexity of the L-system to achievea level of variation that feels adequate for an environment of pseudo infinite character.The variation tests collect data from sample areas in the generated dungeons. The resultsindicate that the method used in this project works well for the intended purpose.

L'azote est une ressource importante pour la croissance des plantes, et pour les pathogènes des cultures. L'objectif de cette thèse est de proposer une modélisation mécaniste des dynamiques d'azote dans une plante de blé en post-floraison. Pour cela, une approche structure-fonction a été mise en oeuvre. Des expérimentations ont permis de caractériser les dynamiques spatio-temporelles d'azote dans la tige feuillée. La masse d'azote surfacique des limbes et des gaines diminuait avec la distance depuis le sommet du couvert, mais elle était homogène le long d'un limbe ou d'une gaine. Les dynamiques temporelles étaient identiques pour les gaines et les limbes suggérant que ces deux entités répondent de la même manière à la lumière interceptée et à l'état azoté de la plante. De plus, les dynamiques étaient synchrones pour tous les phytomères et identiques à un facteur d'échelle près. En période d'absence d'absorption d'azote racinaire, ces dynamiques suivaient une cinétique d'ordre un. Ces résultats ont permis de développer un modèle structure-fonction des dynamiques d'azote au sein de la structure botanique d'une tige feuillée. Les principales hypothèses de ce modèle sont: (i) la teneur en azote d'un limbe est déterminée par le turnover des protéines de l'appareil photosynthétique; (ii) les différentes entités de la tige feuillée partagent un pool commun d'azote mobile. Ce modèle a été validé sur une gamme contrastée de conditions environnementales avec un jeu unique de six paramètres. Les relations azote-éclairement sont une propriété émergente des processus décrits à l'échelle locale. Ce travail ouvre des perspectives pour simuler la régulation des dynamiques d'azote dans des modèles individus-centrés de peuplements végétaux.

This work focuses on application of rewriting systems in the context of biology-inspired development of structures in evolutionary algorithms. As a part of this work, a method has been proposed for design of general structures that uses the aforementioned principle. This document includes an introduction into the theory of sorting networks and their design, the problem of which is later shown to be solvable using the proposed method. In addition, the theoretical background of evolutionary algorithms and rewriting systems is discussed. In the field of rewriting systems, an extension to the class of IL-systems has been created for use in the proposed method. The proposed method has been successfuly applied in the design of growing sorting networks. The results produced by the proposed method significantly outperform the results of the currently best-known comparable method.

The thesis was focused on creation of a coniferous tree by nondestructive method allowing description of structure of adult spruce trees. After processing provided data we created a model of L-system which creates a tree branch. Thereafter, a Python script generated parameters which were required for the creation of the model of the tree in graphical software Blender. Model of coniferous tree was sucesfully generated. Its memory requirements are high but for our purposes this is not an essential problem.

This master thesis describes deterministic context-free L-systems and its context in procedural modeling, especially in fractal geometry, deals with rewriting technique and its usage for modeling structures similar to plants. Further it describes more complex types of L-systems, especially their context and parametric variations, and shows usage of L-systems in computer graphics and describes its usage for procedural modeling of architecture. At the end of this thesis there are described some other possibilities of usage procedural modeling with L-systems and introduced some extensions of rewriting rules, which will be subject of future research.