Dissertations / Theses on the topic '3D-format'

<p>Kunderna i en webbshop kan ibland uppleva den sortens inköp som diffusa och osäkra. Osäkerheten beror på att man inte kan testa, känna eller se produkten i verkligheten. Produkterna i webbshopar presenteras ofta i 2D-format i form av ett foto och visas då i en vinkel. Genom att tillföra webbshopen nya egenskaper som att kunna undersöka varorna och titta på dem från olika håll, kan kundernas osäkerhet minskas.</p><p>Valet av produkt föll i det här arbetet på möbler på grund av att de utgör en varugrupp som anses som svåra att handla via nätet.</p><p>Frågeställningen har varit om 3D-format, i motsats till 2D-format, kan leda till att kunderna lättare kan avgöra ett inköpsbeslut i en webbshop genom att känslan för hur möblerna ser ut ökas? Uppfattningen om möblerna har i det här fallet ökats genom en interaktiv 3D-prototyp. Med hjälp av prototypen kan möblerna undersökas genom att vrida, förstora, öppna, stänga och ändra utföranden på dem. På detta sätt får kunderna ut mer information om möblernas utseende, storlek och funktion än från en traditionell webbshop i 2D. Prototypen, som är tänkt att användas i samband med en webbutik, skapades för att ett användartest skulle kunna utföras. Testet gick ut på att undersöka frågeställningen.</p><p>Resultatet av undersökningen visar att drygt hälften av testdeltagarna ansåg att de fått så pass mycket information från prototypen, att de kunde avgöra om de ville köpa produkten eller inte. Resultatet visade även att det hade betydelse om man inte handlat via nätet förut. Det har lett till att man, trots upplevelsen av positiva egenskaper hos verktyget (i vissa fall), inte kände sig bekväm med den sortens inköp. Dessa personer kunde även urskilja färre egenskaper hos båda presentationerna än vad de vana Internethandlarna kunde. Största orsaken till de osäkra testdeltagarnas tvekan var att de ville se möblerna i verkligheten.</p><p>Slutsatsen blev ändå att produktpresentation genom interaktiv 3D upplevs som mer intressant och underhållande än en 2D-presentation. Det konstaterades också att majoriteten var positiv till att möbler presenterades i 3D även om det inte var det mest ultimata sättet.</p>

Syftet med uppsatsen har varit att undersöka 3D-formatet som attraktion inom filmmediet och dess förändring över tid samt dess möjliga framtid. Inom detta undersöktes också hur det nya 3D-formatet (som i uppsatsen kallas det digitala 3D-formatet) har påverkats av tekniska och ekonomiska omständigheter. 3D-formatet har under uppsatsen jämförts med ljudet och färgens utveckling mot standard för att se ifall 3D-formatet följer en liknande riktning och själv håller på att gå över till en standard. Grunden i uppsatsen har legat på teorin av Tom Gunnings cinema of attraction och utifrån den teorin har analysen fokuserat på hur filmer från olika tidsperioder har används sig av 3D-formatet. Analysen har också granskat filmernas genrertillhörighet och dess användning av slogans. Resultatet var i korthet att 3D-formatet fortfarande är en attraktion men att den inte längre följer Gunnings teori. Numera är 3D-formatet invävt i narrationen genom att kameran och skådespelarnas agerande följer med i 3D-formatets rörelse. Innovationen pausar därför inte längre berättelsen för att visa sin attraktion. 3D-formatet följer både ljudet och färgens utveckling till vis del. Färgen är den innovationsom 3D-formatet mest påminner om. Precis som färgen, som använde sig av färg för att skilja mellan verklighet och dröm, har 3D-formatet även tagit del av detta berättargrepp. Möjligheten finns att 3D-formatets spridning ut i andra medier, precis som färgens spridning till televisionen, kan hjälpa 3D-formatet i dess väg att bli en standard inom filmmediet. Dockär 3D-formatet fortfarande låst i sin visuella attraktion och används mer för att visuellt underhålla än för att visuellt berätta. Det är både tekniska och ekonomiska omständigheter som samarbetat för att få 3D-formatet att återkomma i ett digitalt format. Ingen av dem kunde enskilt få fram innovationen. Vikten ligger på de tekniska omständigheterna i och med digitaliseringen som sker hos biograferna, men digitaliseringen i sig styrs både av tekniska och ekonomiska val och 3D-formatet är främst en ekonomisk hjälp för biograferna att göra digitaliseringen. 3D-formatet är därmed mer en ekonomisk hjälp än en teknisk utbyggnad av filmmediet.

Skin is an organ with a complex structure which plays a crucial role in thebody’s defence against external threats and in maintaining major homeostatic functions. The need for in vitro models that mimic the in vivo milieu is therefore high and relevant with various applications including, among others, penetration, absorption, and toxicity studies. In this context, the choice of the biomaterial that will provide a 3D scaffold to the cultured cells is defining the model’s success. The FN-4RepCT silk is here suggested as a potent biomaterial for skin tissue engineering applications. This recombinantly produced spider silk protein (FN-4RepCT), which can self-assemble into fibrils, creates a robust and elastic matrice with high bioactivity, due to its functionalization with the fibronectin derived RGD-containing peptide. Hence it overcomes the drawbacks of other available biomaterials either synthetic or based on animal derived proteins. Additionally, the FN-4RepCT silk protein can be cast in various 3D formats, two of which are utilized within this project. We herein present a bilayered skin tissue equivalent supported by the FN-4RepCT silk. This is constructed by the combination of a foam format, integrated with dermal fibroblasts and endothelial cells, and a membrane format supporting epidermal keratinocytes. As a result, a vascularized dermal layer that contains ECM components (Collagen I, Collagen III, and Elastin) is constructed and attached to an epidermal layer of differentiated keratinocytes.The protocol presented in this project offers a successful method of evenly integrating cells in the FN-4RepCT silk scaffold, while preserving their ability to resume some of their major in vivo functions like proliferation, ECM secretion, construction of vascular networks, and differentiation. The obtained results were evaluated with immunofluorescence stainings of various markers of interest and further analysed, when necessary, with image processing tools. The results that ensued from the herein presented protocol strongly suggest that the FN-4RepCT silk is a promising biomaterial for skin tissue engineering applications.

The main aim of the thesis is the reconstruction of three-dimensional surface from a~set of two-dimensional images. For the implementation of this application the programming language Java and its extension, that allows work with three-dimensional models, were chosen. First, viewing of three-dimensional models of two different file formats was necessary to allow. To create the three-dimensional models, the Marching Cubes algorithm was used. This algorithm is decribed theoretically in the text, description of the implementation and correction of deficiencies follows. Finally, the implementation of the inversion procedure of reconstruction of the three-dimensional surface, which is the extraction of two-dimensional images from the three-dimensional model, is described.

The overall goal of this research work is to enhance the capabilities of large-format, polymer material extrusion, additive manufacturing (AM) systems. Specifically, the aims of this research are to (1) Construct, and develop a robust workflow for, a large-format, robotic, AM system; (2) Develop an algorithm for determining and relaying proper rotation commands for 5 degree of freedom (DoF) multi-axis deposition; and (3) Create a method for printing a removable support material in large-format AM. The development and systems-integration of a large-format, pellet-fed, polymer, material extrusion (ME), AM system that leverages an industrial robotic arm is presented. The robotic arm is used instead of the conventional gantry motion stage due to its multi-axis printing ability, ease of tool changes for multi-material deposition and/or subtraction, and relatively small machine footprint. A novel workflow is presented as a method to control the robotic arm for layer-wise fabrication of parts, and several machine modifications and workflow enhancements are presented to extend the multi-axis manufacturing capabilities of the robot. This workflow utilizes existing AM slicers to simplify the motion path planning for the robotic arm, as well as allowing the workflow to not be restricted to a single robotic deposition system. To enable multi-axis deposition, a method for generating tool orientations and resulting deposition toolpaths from a geometry's STL file was developed for 5-DoF conformal printing and validated via simulation using several different multi-DOF robotic arm platforms. Furthermore, this research proposes a novel method of depositing a secondary sacrificial support material was created for large-format AM to enable the fabrication of complex geometries with overhanging features. This method employs a simple tool change to deposit a secondary, water-soluble polymer at the interfaces between the part and supporting structures. In addition, a means to separate support material into smaller sections to extend the range of geometries able to be manufactured via large-format AM is presented. The resultant method was used to manufacture a geometry that would traditionally be considered unprintable on conventional large-format AM systems.<br>Master of Science<br>Additive manufacturing (AM), also known as 3D printing, is a method of manufacturing objects in a layer-by-layer technique. Large-format AM is typically defined as an AM system that can create an object larger than 1 m3. There are only a few manufacturers in the world of these systems, and all currently are built on gantry-based motion stages that only allow movement of the printer in three principal axes (X, Y, Z). The primary goal of this thesis is to construct a large-format AM system that uses a robotic arm to enable printing in any direction or orientation. The use of an industrial robotic arm enables printing in multiple planes, which can be used to print structures without support structures, print onto curved surfaces, and to purt with curved layers which produces a smoother external part surface. The design of the large-format AM system was validated through successful printing of objects as large as 1.0x0.5x1.2 m, simultaneous printing of a sacrificial support material to enable overhanging features, and through completing multi-axis printing. To enable multi-axis printing, an algorithm was developed to determine the proper toolpath location and relative orientation to the part surface. Using a part's STL file as input, the algorithm identifies the normal vector at each movement command, which is then used to calculate the required tool orientation. The tool orientations are then assembled with the movement commands to complete the multi-axis toolpath for the robot to perform. Finally, this research presents a method of using a second printing tool to deposit a secondary, water-soluble material to act as supporting structures for overhanging and bridging part features. While typical 3D printers can generally print sacrificial material for supporting overhangs, large-format printers produce layers up to 25 mm wide, rendering any support material impossible to remove without post-process machining. This limits the range of geometries able to be printed to just those with no steep overhangs, or those where the support material is easily reachable by a tool for removal. The solution presented in this work enables the large scale AM processes to create complex geometries.

Cette étude porte sur trois problématiques reliées à l’utilisation du son multicanal 3D dans le contexte des applications Audio Professionnelles. Le système SIRIUS est présenté. Il s’agit d’une technique de transport du son multicanal qui répond aux contraintes de Fiabilité, Synchronisation et Latence des applications professionnelles et garantie un compromis entre ces différents aspects. Le système peut fonctionner sur les infrastructures LAN classiques et coexister avec d’autres types de trafic réseau. Il est aussi basé sur une couche protocolaire n’utilisant que des protocoles standards, ce qui lui procure un certain niveau d’interopérabilité avec des technologies équivalentes. La seconde contribution est la méthodologie AQUA. Il s’agit d’une nouvelle approche pour l’évaluation de la qualité du son multicanal qui propose des outils efficaces pour l’analyse subjective et objective de la qualité. La partie subjective consiste en un nouveau protocol pour les tests d’écoute qui combine l’analyse de l’information perceptive et spatiale. La précision de la localisation est évaluée grâce au suivi des gestes des auditeurs. Notre méthode, basée sur l’utilisation de la Kinect, permet d’obtenir cette information d’une façon rapide et précise. Le protocole utilise notamment l’analyse EEG pour étudier les biais psychologiques et filtrer efficacement les sujets. La partie objective repose sur un moteur binaural qui convertit le flux multicanal en un flux stereo binaural plus simple à analyser et qui préserve l’information spatiale. Le signal audio résultant est analysé par un modèle perceptif et un modèle spatial qui permettent d’estimer une représentation interne équivalente. Les variables la constituant alimentent ensuite un Réseau de Neurones Artificiel qui permet d’obtenir une note objective de qualité. Parallèlement, le modèle psychologique simule le comportement humain en ajustant la note en fonction des notes précédentes. Les performances obtenues montrent que le système peut être utilisé pour prédire la qualité perceptive et spatiale du son multicanal avec un grand niveau de précision et de réalisme. Le dernier axe d’étude porte sur l’optimisation de la qualité d’écoute dans les systèmes audio surround. Etant donné leur problème de Sweet Spot, et la complexité des systèmes suggérant de l’élargir, on propose une technique basée sur le suivi de la position réelle des auditeurs. Le suivi est réalisé d’une façon non-intrusive par l’analyse d’images thermiques. Les canaux audio initiaux sont considérés comme des sources virtuelles et sont re-mixés par VBAP pour simuler leur déplacement vers l’auditeur. Les performances obtenues montrent un suivi efficace et une amélioration de l’expérience d’écoute<br>In this work, three complementary topics regarding the use of multichannel spatial audio in professional applications have b e en studied. SIRIUS, is an audio transport mechanism designed to convey multiple professional-grade audio channels over a regular LAN while maintaining their synchronization. The system reliability is guaranteed by using a FEC mechanism and a selective redundancy, without introducing any important network overload. The system also offers a low latency that meet the professional applications requirements and can operate on the existing infrastructures and coexist with other IT traffic. The system relies on standard protocols and offers a high level of interoperability with equivalent technologies. The overall performances satisfy Pro Audio requirements. The second contribution is AQUA, a comprehensive framework for multichannel audio quality assessment that provides efficient tools for both subjective and objective quality evaluation. The subjective part consists of a new design of reliable listening tests for multichannel sound that analyze both perceptual and spatial information. Audio localization accuracy is reliably evaluated using our gesture-based protocol build around the Kinect. Additionally, this protocol relies on EEG signals analysis for psychological biases monitoring and efficient subjects screening. The objective method uses a binaural model to down-mix the multichannel audio signal into a 2-channels binaural mix that maintains the spatial cues and provides a simple and scalable analysis. The binaural stream is processed by a perceptual and spatial models that calculate relevant cues. Their combination is equivalent to the internal representation and allows the cognitive model to estimate an objective quality grade. In parallel, the psychological model simulate the human behavior by adjusting the output grades according to the previous ones (i.e., the experience effect). The overall performance shows that AQUA model can accurately predict the perceptual and spatial quality of a multichannel audio in a very realistic manner. The third focus of the study is to optimize the listening experience in surround sound systems (OPTIMUS). Considering the sweet spot issue in these systems and the complexity of its widening, we introduce a tracking technique that virtually moves the sweet spot location to the actual position of listener(s). Our approach is non-intrusive and uses thermal imaging for listeners identification and tracking. The original channels are considered as virtual sources and remixed using the VBAP technique. Accordingly, the audio system virtually follows the listener actual position. For home-cinema application, the kinect can be used for the tracking part and the audio adjustment can be done using HRTFs and cross-talk cancellation filters. The system shows an improvement of the localization accuracy and the quality of the listening experience

Les technologies nomades (smartphones, tablettes, . . . ) étant actuellement très répandues,nous avons souhaité, dans le cadre de cette thèse, les utiliser comme vecteur pour proposer au grand public des outils de spatialisation sonore. La taille et le nombre de transducteurs utilisés pour la captation et la restitution sonore spatialisée sont à ce jour la limitation principale pour une utilisation nomade. Dans une première étape, la captation d’un opéra pour une restitution sur des tablettes tactiles nous a permis d’évaluer les technologies audio 3D disponibles aujourd’hui. Les résultats de cette évaluation ont révélé que l’utilisation des quatre capteurs du microphone Soundfield donne de bons résultats à condition d’effectuer un décodage binaural adapté pour une restitution sur casque. Selon une approche inspirée des méthodes de localisation de source et le concept de format « objet », un prototype de prise de son 3D léger et compact a été développé. Le dispositif microphonique proposé se compose de trois capsules microphoniques cardioïdes. A partir des signaux microphoniques, un algorithme de post-traitement spatial est capable, d’une part, de déterminer la direction des sources et, d’autre part, d’extraire un signal sonore représentatif de la scène spatiale. Ces deux informations permettent ainsi de caractérisercomplètement la scène sonore 3D en fournissant un encodage spatial offrant le double avantage d’une compression de l’information audio et d’une flexibilité pour le choix du système de reproduction. En effet, la scène sonore ainsi encodée peut être restituée en utilisant un décodage adapté sur n’importe quel type de dispositif.Plusieurs méthodes de localisation et différentes configurations microphoniques (géométrie et directivité) ont été étudiées.Dans une seconde étape, l’algorithme d’extraction de l’information spatiale a été modifié pour prendre en compte les caractéristiques réelles in situ des microphones.Des méthodes pour compléter la chaîne acoustique sont proposées permettant la restitution binaurale ainsi que sur tout autre dispositif de restitution. Elles proposent l’utilisation de capteurs de localisation présents sur les terminaux mobiles afin d’exploiter les capacités qu’ils offrent aujourd’hui<br>Mobile technologies (such as smartphones and tablets) are now common devices of the consumer market. In this PhD we want to use those technologies as the way to introduce tools of sound spatialization into the mass market. Today the size and the number of traducers used to pick-up and to render a spatial sound scene are the main factors which limit the portability of those devices. As a first step, a listening test, based on a spatial audio recording of an opera, let us to evaluate the 3D audio technologies available today for headphone rendering. The results of this test show that, using the appropriate binaural decoding, it is possible to achieve a good binaural rendering using only the four sensors of the Soundfield microphone.Then, the steps of the development of a 3D sound pick-up system are described. Several configurations are evaluated and compared. The device, composed of 3 cardioid microphones, was developed following an approach inspired by the sound source localization and by the concept of the "object format encoding". Using the microphone signals and an adapted post-processing it is possible to determine the directions of the sources and to extract a sound signal which is representative of the sound scene. In this way, it is possible to completely describe the sound scene and to compress the audio information.This method offer the advantage of being cross platform compatible. In fact, the sound scene encoded with this method can be rendered over any reproduction system.A second method to extract the spatial information is proposed. It uses the real in situ characteristics of the microphone array to perform the sound scene analysis.Some propositions are made to complement the 3D audio chain allowing to render the result of the sound scene encoding over a binaural system or any king of speaker array using all capabilities of the mobile devices

This thesis deals with library for recording video in the background of 3D application. A library is designed to work under the Microsoft Windows and Linux operation systems.  It records image and also sound. Image recording is supported in OpenGL, Direct3D9, Direct3D10 and Direct3D11. To reduce video data size, library supports image compression using MJPG codec. Audio is recorded by WaveForm audio, Windows Core Audio or ALSA. Recorded sound is for whole operation system. A library is able to record up to two audio streams to accommodate possible microphone input. It can mix audio data together if needed. Output data are then written into AVI file. It is possible to write own text information as overlay that is rendered as part of application screen output.

The challenge of interoperability is to retain model integrity when different software applications exchange and interpret model data. Transferring CAD data between heterogeneous CAD systems is a challenge because of differences in feature representation. A study by the National Institute for Standards and Technology (NIST) performed in 1999 made a conservative estimate that inadequate interoperability in the automotive industry costs them $1 billion per year. One critical part of eliminating the high costs due to poor interoperability is a neutral format between heterogeneous CAD systems. An effective neutral CAD format should include a current-state data store, be associative, include the union of CAD features across an arbitrary number of CAD systems, maintain design history, maintain referential integrity, and support multi-user collaboration. This research has focused on extending an existing synchronous collaborative CAD software tool to allow for a neutral, current-state data store. This has been accomplished by creating a Neutral Parametric Canonical Form (NPCF) which defines the neutral data structure for many basic CAD features to enable translation between heterogeneous CAD systems. The initial architecture developed begins to define a new standard for storing CAD features neutrally. The NPCF's for many features have been implemented in a multi-user interoperability program and work between NX and CATIA CAD systems. The 2D point, 2D line, 2D arc, 2D circle, 2D spline, 3D point, extrude, and revolve NPCF's will be specifically defined. Complex models have successfully been modeled and exchanged in real time and have validated the NPCF approach. Multiple users can be in the same part at the same time in different CAD systems and create and update models in real time.

L’objectif de cette thèse est de proposer un Alphabet Structural (AS) permettant une caractérisation fine et précise des structures tridimensionnelles (3D) des protéines, à l’aide des chaînes de Markov cachées (HMM) qui permettent de prendre en compte la logique issue de l’enchaînement des fragments structuraux en intégrant l’augmentation des conformations 3D des structures protéiques désormais disponibles dans la banque de données de la Protein Data Bank (PDB). Nous proposons dans cette thèse un nouvel alphabet, améliorant l’alphabet structural HMM-SA27,appelé SAFlex (Structural Alphabet Flexibility), dans le but de prendre en compte l’incertitude des données (données manquantes dans les fichiers PDB) et la redondance des structures protéiques. Le nouvel alphabet structural SAFlex obtenu propose donc un nouveau modèle d’encodage rigoureux et robuste. Cet encodage permet de prendre en compte l’incertitude des données en proposant trois options d’encodages : le Maximum a posteriori (MAP), la distribution marginale a posteriori (POST)et le nombre effectif de lettres à chaque position donnée (NEFF). SAFlex fournit également un encodage consensus à partir de différentes réplications (chaînes multiples, monomères et homomères) d’une même protéine. Il permet ainsi la détection de la variabilité structurale entre celles-ci. Les avancées méthodologiques ainsi que l’obtention de l’alphabet SAFlex constituent les contributions principales de ce travail de thèse. Nous présentons aussi le nouveau parser de la PDB (SAFlex-PDB) et nous démontrons que notre parser a un intérêt aussi bien sur le plan qualitatif (détection de diverses erreurs)que quantitatif (rapidité et parallélisation) en le comparant avec deux autres parsers très connus dans le domaine (Biopython et BioJava). Nous proposons également à la communauté scientifique un site web mettant en ligne ce nouvel alphabet structural SAFlex. Ce site web représente la contribution concrète de cette thèse alors que le parser SAFlex-PDB représente une contribution importante pour le fonctionnement du site web proposé. Cette caractérisation précise des conformations 3D et la prise en compte de la redondance des informations 3D disponibles, fournies par SAFlex, a en effet un impact très important pour la modélisation de la conformation et de la variabilité des structures 3D, des boucles protéiques et des régions d’interface avec différents partenaires, impliqués dans la fonction des protéines<br>The purpose of this PhD is to provide a Structural Alphabet (SA) for more accurate characterization of protein three-dimensional (3D) structures as well as integrating the increasing protein 3D structure information currently available in the Protein Data Bank (PDB). The SA also takes into consideration the logic behind the structural fragments sequence by using the hidden Markov Model (HMM). In this PhD, we describe a new structural alphabet, improving the existing HMM-SA27 structural alphabet, called SAFlex (Structural Alphabet Flexibility), in order to take into account the uncertainty of data (missing data in PDB files) and the redundancy of protein structures. The new SAFlex structural alphabet obtained therefore offers a new, rigorous and robust encoding model. This encoding takes into account the encoding uncertainty by providing three encoding options: the maximum a posteriori (MAP), the marginal posterior distribution (POST), and the effective number of letters at each given position (NEFF). SAFlex also provides and builds a consensus encoding from different replicates (multiple chains, monomers and several homomers) of a single protein. It thus allows the detection of structural variability between different chains. The methodological advances and the achievement of the SAFlex alphabet are the main contributions of this PhD. We also present the new PDB parser(SAFlex-PDB) and we demonstrate that our parser is therefore interesting both qualitative (detection of various errors) and quantitative terms (program optimization and parallelization) by comparing it with two other parsers well-known in the area of Bioinformatics (Biopython and BioJava). The SAFlex structural alphabet is being made available to the scientific community by providing a website. The SAFlex web server represents the concrete contribution of this PhD while the SAFlex-PDB parser represents an important contribution to the proper function of the proposed website. Here, we describe the functions and the interfaces of the SAFlex web server. The SAFlex can be used in various fashions for a protein tertiary structure of a given PDB format file; it can be used for encoding the 3D structure, identifying and predicting missing data. Hence, it is the only alphabet able to encode and predict the missing data in a 3D protein structure to date. Finally, these improvements; are promising to explore increasing protein redundancy data and obtain useful quantification of their flexibility

This thesis focuses on applying one of the rapidly growing non-deterministic optimization algorithms, the ant colony algorithm, for simulating automatic hose/pipe routing with several conflicting objectives. Within the thesis, methods have been developed and applied to single objective hose routing, multi-objective hose routing and multi-hose routing. The use of simulation and optimization in engineering design has been widely applied in all fields of engineering as the computational capabilities of computers has increased and improved. As a result of this, the application of non-deterministic optimization techniques such as genetic algorithms, simulated annealing algorithms, ant colony algorithms, etc. has increased dramatically resulting in vast improvements in the design process. Initially, two versions of ant colony algorithms have been developed based on, respectively, a random network and a grid network for a single objective (minimizing the length of the hoses) and avoiding obstacles in the CAD model. While applying ant colony algorithms for the simulation of hose routing, two modifications have been proposed for reducing the size of the search space and avoiding the stagnation problem. Hose routing problems often consist of several conflicting or trade-off objectives. In classical approaches, in many cases, multiple objectives are aggregated into one single objective function and optimization is then treated as a single-objective optimization problem. In this thesis two versions of ant colony algorithms are presented for multihose routing with two conflicting objectives: minimizing the total length of the hoses and maximizing the total shared length (bundle length). In this case the two objectives are aggregated into a single objective. The current state-of-the-art approach for handling multi-objective design problems is to employ the concept of Pareto optimality. Within this thesis a new Pareto-based general purpose ant colony algorithm (PSACO) is proposed and applied to a multi-objective hose routing problem that consists of the following objectives: total length of the hoses between the start and the end locations, number of bends, and angles of bends. The proposed method is capable of handling any number of objectives and uses a single pheromone matrix for all the objectives. The domination concept is used for updating the pheromone matrix. Among the currently available multi-objective ant colony optimization (MOACO) algorithms, P-ACO generates very good solutions in the central part of the Pareto front and hence the proposed algorithm is compared with P-ACO. A new term is added to the random proportional rule of both of the algorithms (PSACO and P-ACO) to attract ants towards edges that make angles close to the pre-specified angles of bends. A refinement algorithm is also suggested for searching an acceptable solution after the completion of searching the entire search space. For all of the simulations, the STL format (tessellated format) for the obstacles is used in the algorithm instead of the original shapes of the obstacles. This STL format is passed to the C++ library RAPID for collision detection. As a result of using this format, the algorithms can handle freeform obstacles and the algorithms are not restricted to a particular software package.

3D printing applications have achieved increased success as an additive manufacturing (AM) process. Micro-structure of mechanical/biological materials present design challenges owing to the resolution of 3D printers and material properties/composition. Biological materials are complex in structure and composition. Efforts have been made by 3D printer manufacturers to provide materials with varying physical, mechanical and chemical properties, to handle simple to complex applications. As 3D printing is finding more medical applications, we expect future uses in areas such as hip replacement - where smoothness of the femoral head is important to reduce friction that can cause a lot of pain to a patient. The issue of print resolution plays a vital role due to staircase effect. In some practical applications where 3D printing is intended to produce replacement parts with joints with movable parts, low resolution printing results in fused joints when the joint clearance is intended to be very small. Various 3D printers are capable of print resolutions of up to 600dpi (dots per inch) as quoted in their datasheets. Although the above quoted level of detail can satisfy the micro-structure needs of a large set of biological/mechanical models under investigation, it is important to include the ability of a 3D slicing application to check that the printer can properly produce the feature with the smallest detail in a model. A way to perform this check would be the physical measurement of printed parts and comparison to expected results. Our work includes a method for using ray casting to detect features in the 3D CAD models whose sizes are below the minimum allowed by the printer resolution. The resolution validation method is tested using a few simple and complex 3D models. Our proposed method serves two purposes: (a) to assist CAD model designers in developing models whose printability is assured. This is achieved by warning or preventing the designer when they are about to perform shape operations that will lead to regions/features with sizes lower than that of the printer resolution; (b) to validate slicing outputs before generation of G-Codes to identify regions/features with sizes lower than the printer resolution.

Useless things. I normally use trash things like pattern in painting still life. My father suffers from obsessive compulsive disorder – accumulation of things. In addition to painting, I also work with objects themselves. My interest also closely related to how the concepts of the subject, object and artifact are appliing in contemporary art. There are the tradition of imitation fact, principle of ready-made, the issue of technical reproducibility and virtual reality of things in history of art. As a central theme of my thesis, I selected the part of bodywork Tatra 613, which carries all the testimony about ,,useless and hopeless "situation in which it is located. It is also an object monumental and visually very aesthetic. Yet it is not my intention to settle for the principle of redy-made. Asked about artwork as intermediaries art and its seemingly useless producing and reproducing, I want to try to create another such usless situation. That's why I make a cardboard copy (1: 1) of this object. I also make video with motive 3D copy of the same object. I like to create some voltage between that useless object and valuable art practice. I think, it does not just mean such futility when these objects will be viewed as an art.

碩士<br>國立成功大學<br>資訊工程學系碩博士班<br>95<br>Transmitting digital media over networks has become very convenient and popular in recent years. Therefore, information hiding in multimedia has drawn a lot of attention and has become an important research issue. A message is hidden in digital media such as images, videos, audios, documents or 3D polygon models in an imperceptible manner. This is done so as not to impede host media use, while information hiding can be helpful for various interesting applications such as covert communications and watermarking for ownership authentication and content protection. A single information hiding scheme cannot be suitable for all of these applications due to their incompatible goals. In this thesis, we concentrate on information hiding, or “steganography”, on 3D polygon models for covert communications. How to exploit the geometric characteristics of 3D models to provide high-capacity data hiding is the main task in this thesis. In this thesis, we hide messages in both spatial domain and representation domain. In representation domain, an ultrahigh-capacity distortion-free information hiding algorithm for 3D polygon models is presented. We propose a novel embedding approach to embed messages in the representation domain of 3D polygon model using the proposed rearrangement approach in distortion-free manner. In contrast to the general data hiding schemes which embed messages by slightly modifying the appearance of the cover media, the proposed approach does not hide messages in the vertex coordinates/normals of cover model, therefore, will not change the appearance of the cover model, i.e., distortion-free. Furthermore, the proposed approach can hide very high capacity (above 9 bits/per vertex) in the representation domain. Experimental results show that the cover and stego models are still identical as the volume of embedding messages is up to 20 bits/per vertex. In the spatial domain, a very high-capacity, information-hiding algorithm based on a novel multi-layered embedding scheme for 3D polygon models is presented. The proposed approach can hide 3(|V|-3)n_layers bits on a polygon model ( |V| represents the number of vertices and n_layers represents the number of hiding layers); while the upper-bounded distortion can be limited to I (I represents the width of a partitioning interval). Experimental results show that the proposed approach can provide much higher hiding capacity than other state-of-the-art approaches, while obeying the low distortion and security basic requirements for steganography.