Three-dimensional (3D) enveloping grasps for dexterous robotic hands possess several advantages over other types of grasps. However, their innate characteristics such as the several degrees of freedom of the dexterous hand, complexity of analyzing the 3D geometry of the object to be grasped or detecting the 3D contact points between the object and the hand make planning them automatically a very challenging problem. This thesis describes a new method for kinematic 3D enveloping grasp planning for a three-fingered dexterous hand. The required inputs are the geometric models of the object and hand; and the kinematic model of the hand. The outputs are the position and orientation of the palm and the angular joint positions of the fingers. The method introduces a new way of processing the 3D object. Instead of considering the object as a whole, a series of 2D slices (vertical and horizontal) of the object are used to define its geometry. This method is considerably simpler than other methods of object modeling and its parameters can be easily setup. A new idea for grading the object's 3D grasp search domain is proposed. The grading system analyzes the curvature pattern and thickness of the object and grades object regions according to their suitability for grasping. The proposed method is capable of eliminating most of the ungraspable areas of the object from the grasp search domain at the early stages of the search. This improves the overall efficiency of the search for a grasp. In modeling a dexterous hand a new method is proposed to model the fingers. In this model each finger is modeled by three articulated line segments, representing the top, centre and bottom of the finger. This model has significant benefits that it is efficient and does not need the exact coordinate of the 3D contact point between the finger and the object to analyze the feasibility of the grasp. The new grasp planning method was implemented by writing a 4300 line MATLAB program. The program has been run successfully with several 3D objects. These results are documented. / Thesis / Master of Applied Science (MASc)

This project is about a 3D graphics system for engineers and architects. Its goal is twofold: to provide tools for drawing 3D models, and to create a database support system where data related to these models would be stored (at present the first part has been implemented). Costs, materials, calculations of loads, stresses, and other important factors will be available to the user during the whole design process. The system will therefore allow for drawing realistic projects, not just conceptual visual models. The drawing tools provided by the system include a few drawing techniques and viewing functions. The system’s drawing routines operate on sets of points, lines, or components so that they are very fast and efficient. This approach to the method of drawing along with the description of the system are given in the following write-up. / Thesis / Master of Science (MS)

No / PANIVE (PC-based Architecture Networked Interactive Virtual Environments) is an extensible architecture in which various networked virtual environment applications can be realized. This chapter describes our efforts in realizing applications in the area of “3D virtual community building”, in which people can virtually meet each other, speak to each other, interact with each other, etc. in a virtual equivalent of conventional social communities. The overall architecture will be discussed briefly. Some attention will be given to the realization of the audio component in the system (speech input and 3D sound output) that supports intuitive interaction among the participants in a shared virtual environment. The main part of the chapter discusses and illustrates some demonstrative example applications that highlight the potential for realizing 3D networked virtual communities in the architecture.

This thesis is aimed toward developing a method to simulate ion thruster discharge chambers in a full three dimensional environment and to study the effect of discharge chamber size on ion thruster performance. The study focuses solely on ring-cusped thrusters that make use of Xenon for propellant and discharge cathode assembly for mean of propellant ionization. Commercial software is used in both the setup and analysis phases. Numerical simulation is handled by 3D Particle-In-Cell Monte-Carlo-Collision method. Simulation results are analyzed and compared with other works. It is concluded that the simulation methodology is validated and can be used to simulate different cases. Therefore, different simulation cases of varying chamber sizes are done and the results are used to develop a performance curve. This plot suggests that the most efficient case is the 30 cm thruster. The result further validates the simulation process since the operating parameters used for all of the cases are taken from a 30 cm thruster experiment. One of the obvious applications for such a simulation process is to determine a set of the most efficient operating parameters for a certain size thruster before actual fabrication and laboratory testing. / Master of Science

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L'intégration 3DVLSI, également connue sous le nom d'intégration monolithique ou séquentielle, est présentée et évaluée dans cette thèse comme une alternative à la réduction du nœud technologique des circuits logiques CMOS. L’avantage principal de cette technologie par rapport à l'intégration parallèle 3D, déjà existante, est l'alignement précis entre les niveaux, ce qui permet des contacts 3D réduits et plus proches. Un autre avantage, extrêmement favorable à l’approche 3DVLSI, est l’amélioration du placement et du routage par rapport aux circuits planaires, notamment parce qu’elle permet des interconnexions plus courtes et qu’elle offre a un degré de liberté supplémentaire dans la direction Z pour la conception. Par exemple, les fils les plus longs dans les circuits planaires peuvent ainsi être réduits grâce aux contacts 3DCO, en diminuant les éléments parasites d'interconnexion. Il est ainsi possible d’augmenter la vitesse du circuit et de réduire la puissance électrique. Dans ce contexte, la thèse a été divisée en deux parties. La première partie traite de l’évaluation de la Consommation, des Performances et de la Surface (CPS) et donne des recommandations pour la conception des circuits 3D. La deuxième partie traite la variabilité des circuits 3D en utilisant un modèle statistique unifié, et en proposant une approche pour la variabilité des circuits multi-niveaux. / 3DVLSI integration, also known as monolithic or sequential integration is presented and evaluated in this thesis as a potential contender to continue the scaling for CMOS logic circuits. The main advantage of this technology compared to the already existing 3D parallel integration is its high alignment among tiers, enabling small size and pitch with the inter-tier contacts (3DCO). Another great 3DVLSI feature is its improved capability to place and route circuits, compared to the planar approach: the interconnections can be shorter as the design has an additional degree of freedom in the Z direction. For instance, long wires in planar circuits can cut thanks to 3DCO contacts, lowering the interconnection parasitic elements and speeding up the circuit as well as reducing the power. In this framework, the thesis has been divided into two parts: the first part is dedicated to the evaluation of Performance, Power and Area (PPA) of 3D circuits and gives design guidelines. The second part treats the variability in 3D circuits by using a 3D unified statistical model and propose an approach for the multi-tier variability.

This master's thesis deals with the possibilities of using open source 3D game engine Java Monkey Engine (jME) in developing applications for the Android platform. It includes theoretical knowledge for the jMonkey Engine architecture and the Android platform. In the following section, the thesis describes used techniques and external libraries in solving issues of interaction between jME and Android platform and of working with objects in the 3D scene and their way of implementation.

Das Verständnis über visuelle Aufmerksamkeitsprozesse ist nicht nur für die Kognitionsforschung von großem Interesse. Auch in alltäglichen Bereichen des Lebens stellt sich die Frage, wie wir unsere Umwelt in unterschiedlichen Situationen visuell wahrnehmen. Entsprechende Untersuchungen können in realen Szenarien und aufgrund neuer innovativer 3D-Verfahren auch in Umgebungen der virtuellen Realität (VR) durchgeführt werden. Zur Erforschung von Aufmerksamkeitsprozessen wird unter anderem die Methode der Blickbewegungsmessung (Eyetracking) angewandt, da das Sehen für uns Menschen die wichtigste Sinnesmodalität darstellt. Herkömmliche Blickbewegungsmessungen beziehen sich allerdings überwiegend auf zweidimensionale Messebenen, wie Bildschirm, Leinwand oder Szenevideo. Die vorliegende Arbeit stellt eine Methode vor, mit der dreidimensionale Blickorte und Blickbewegungen sowohl in einer realen als auch in einer stereoskopisch projizierten VR-Umgebung anhand moderner Eyetracking-Technologien bestimmt werden können. Dafür wurde zunächst in Studie I geprüft, ob die Blickbewegungsmessung durch die für eine stereoskopische Bildtrennung notwendigen 3D-Brillen hindurch möglich ist und inwieweit durch diesen Versuchsaufbau die Qualität der erhobenen Eyetracking-Daten beeinflusst wird. Im nächsten Schritt wurde zur Berechnung dreidimensionaler Blickorte das Anforderungsprofil an einen universellen Algorithmus erstellt und mit einem vektorbasierten Ansatz umgesetzt. Die Besonderheit hierbei besteht in der Berechnung der Blickvektoren anhand der Augen- bzw. Foveaposition und binokularen Eyetracking-Daten. Wie genau dreidimensionale Blickorte anhand dieses Algorithmus berechnet werden können, wurde nachfolgend in realer (Studie II) als auch stereoskopisch projizierter VR-Umgebung (Studie III) untersucht. Anschließend erfolgte die Bestimmung dreidimensionaler Blickbewegungen aus den berechneten 3D-Blickorten. Dazu wurde ein ellipsoider Fixationserkennungsalgorithmus konzipiert und implementiert. Für die dispersionsbasierte Blickbewegungserkennung waren sowohl ein zeitlicher als auch örtlicher Parameter für die Identifikation einer Fixation erforderlich. Da es noch keinerlei Erkenntnisse im dreidimensionalen Bereich gab, wurden die in Studie II und III ermittelten 3D-Blickorte der ellipsoiden Fixationserkennung übergeben und die daraus berechneten Fixationsparameter analysiert. Die entwickelte Methode der räumlichen Blickbewegungsmessung eröffnet die Möglichkeit, bislang in zwei Dimensionen untersuchte Blickmuster nunmehr räumlich zu bestimmen und grundlegende Zusammenhänge zwischen Blickbewegungen und kognitiven Prozessen dreidimensional sowohl in einer realen als auch virtuellen Umgebung zu analysieren.

Syfte: Att utreda hur digitala 3D-modeller bör anpassas inför utskrift i en 3D-skrivare samt undersöka hur en sådan modell kan användas i byggprocessens olika skeden. Metod: En fallstudie genomförs med en befintlig digital 3D-modell som utgångspunkt där intervjuer och action research används som datainsamlingsmetoder. Empirin jämförs och analyseras med det teoretiska ramverket som tagits fram genom litteraturstudier. Resultat: En fysisk 3D-modell skulle kunna användas i flera skeden i byggprocessen, huvudsakligen i idéskedet, produktionsskedet och genomgående processen som ett kommunikationsverktyg och vid reklam/försäljning/presentation för ökad förstående. Inför utskrift bör alla byggnadsdelar vara solida, detaljer bör raderas beroende på skala och komponenter bör bestå av samma material. Konsekvenser: Då intervjuerna utförs med personer med varierande kunskap och erfarenhet är det viktigt att beakta det faktum att förslag på användningsområden eventuellt inte är genomförbara i praktiken då dessa är önskemål. Trots detta kan användning av fysiska 3D-modeller rekommenderas i flera av byggprocessens skeden för ökad förståelse och bättre kommunikation, vilket även styrks av det teoretiska ramverket. Gällande anpassningar av en digital modell krävs en digital 3D-model som utgångspunkt och viss vana av 3D-projektering. Begränsningar: Då denna studie är en fallstudie utförd på ett specifikt fall, kan kunskap och rekommendationer inte generaliseras statistiskt på andra typer av byggnader. Dock kan resultatet i denna studie implementeras på liknande projekt om små justeringar tillämpas. På grund av det faktum att studien är kvalitativ med ett begränsat antal respondenter finns möjlighet till ett annat resultat om utförandet skett med andra förutsättningar. Nyckelord: BIM-modell, fysisk byggnadsmodell, 3D-modell, 3D-skrivare, 3D- utskrift / Purpose: To investigate how digital 3D models should be adapted to enable 3D printing for use in the construction process in its various stages. Method: A case study is conducted with an existing digital 3D-model where interviews and action research is used as a data collection method. The empirical data are compared and analyzed with the theoretical framework developed through literature studies. Findings: A physical 3D model can be used at several stages in the construction process, mainly in idea development stages, the production stage and throughout the process as a communication tool and for advertising/sales/presentation for increased understanding. Prior to printing, all parts of the building should be solid, details should be erased depending on the scale used and components should consist of the same material. Implications: Based on interviews with people with varying knowledge and experience within the subject, it is important to take into consideration the fact that the proposals on the fields of use may not be enforceable in reality since they are requests. Despite this, the use of physical 3D models can be recommended in several construction phases of the process for greater understanding and better communication, which is corroborated by the theoretical framework. Adaptions of a digital model require a digital 3D model as a prerequisite and a certain experience of 3D design. Limitations: Since this study is a case study conducted in a specific case, knowledge and recommendations cannot be generalized statistically to other types of buildings. However, with small adjustments, this study can be implemented in similar projects. Due to the fact that the study is qualitative with a limited number of interviewees, there is a possibility of a different result if the execution occurred with other conditions. Keywords: BIM model, physical building model, 3D model, 3D printer, 3D printing