Understanding 3D objects and being able to interact with them in the physical world are essential for building intelligent computer vision systems. It has tremendous potentials for various applications ranging from augmented reality, 3D printing to robotics. It might seem simple for human to look and make sense of the visual world, it is however a complicated process for machines to accomplish similar tasks. Generally, the system is involved with a series of processes: identify and segment a target object, estimate its 3D shape and predict its pose in an open scene where the target objects may have not been seen before. Although considerable research works have been proposed to tackle these problems, they remain very challenging due to a few key issues: 1) most methods rely solely on color images for interpreting the 3D property of an object; 2) large labeled color images are expensive to get for tasks like pose estimation, limiting the ability to train powerful prediction models; 3) training data for the target object is typically required for 3D shape estimation and pose prediction, making these methods hard to scale and generalize to unseen objects. Recently, several technological changes have created interesting opportunities for solving these fundamental vision problems. Low-cost depth sensors become widely available that provides an additional sensory input as a depth map which is very useful for extracting 3D information of the object and scene. On the other hand, with the ease of 3D object scanning with depth sensors and open access to large scale 3D model database like 3D warehouse and ShapeNet, it is possible to leverage such data to build powerful learning models. Third, machine learning algorithm like deep learning has become powerful that it starts to surpass state-of-the-art or even human performance on challenging tasks like object recognition. It is now feasible to learn rich information from large datasets in a single model. The objective of this thesis is to leverage such emerging tools and data to solve the above mentioned challenging problems for understanding 3D objects with a new perspective by designing machine learning algorithms utilizing RGB-D data. Instead of solely depending on color images, we combine both color and depth images to achieve significantly higher performance for object segmentation. We use large collection of 3D object models to provide high quality training data and retrieve visually similar 3D CAD models from low-quality captured depth images which enables knowledge transfer from database objects to target object in an observed scene. By using content-based 3D shape retrieval, we also significantly improve pose estimation via similar proxy models without the need to create the exact 3D model as a reference.

In this thesis, we investigate how the optical and electronic properties of graphene may be modified in proximity to various other materials. We present several examples of how modification in this way can help make graphene better suited for specific device applications. We develop a method of up-scaling the fabrication of FeCl3-intercalated few-layer graphene from micron-sized flakes to macroscopic films so that it may be used as a transparent electrode in flexible light-emitting devices. We also find that photo-responsive junctions can be arbitrarily written into FeCl3-intercalated few-layer graphene by means of optical lithography. These junctions produce photocurrent signals that are directly proportional to incident optical power over an extended range compared to other graphene photodetectors. Through theoretical analysis of these junctions, we conclude that the enhanced cooling of hot carriers with lattice phonons is responsible for this behaviour. Finally, we trial rubrene single crystals as the light-absorbing layer in a graphene phototransistor. We find that rubrene single crystal-graphene interfaces exhibit enhanced charge transfer efficiencies under illumination with extremely weak light signals. Through a comparative study with similar devices, we conclude that the wide variation in sensitivity amongst graphene phototransistors is largely due to extraneous factors relating to device geometry and measurement conditions.

The topics of Grounding and Metaphysical Explanation have been at the forefront of research and debate within metaphysics for the last decade. Grounding is commonly taken to be a relation of non-causal dependence. In this thesis I address the pertinent question as to what sorts of entities are related in instances of grounding. There has so far been little enquiry into this issue, and it therefore requires urgent attention. I argue here that the entities involved in grounding are facts, where facts are true Fregean propositions. True Fregean propositions are abstract entities composed of senses, and are individuated according the senses which they involve. I proceed by setting out some desiderata which the entities involved in grounding will fulfil. Firstly, they will be individuated sufficiently finely as to provide instances of grounding to back all putative cases of non-causal explanation. Secondly, they will ensure that there is unity between instances of grounding and instances of causation. Finally, they will be mind- independent. I survey different types of entity and show that true Fregean propositions are best-equipped to fulfil these desiderata. We therefore have reason to believe that grounding relates facts, so understood. The conclusion of this thesis therefore makes it incumbent upon us to extend our ontology to include true Fregean propositions.

Cao Liangliang. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 64-69). / Abstracts in English and Chinese. / Chapter 1 --- Introduction and Related Work --- p.1 / Chapter 1.1 --- Reconstruction from Single Line Drawings and the Applications --- p.1 / Chapter 1.2 --- Optimization-based Reconstruction --- p.2 / Chapter 1.3 --- Other Reconstruction Methods --- p.2 / Chapter 1.3.1 --- Line Labeling and Algebraic Methods --- p.2 / Chapter 1.3.2 --- CAD Reconstruction --- p.3 / Chapter 1.3.3 --- Modelling from Images --- p.3 / Chapter 1.4 --- Finding Faces of Line Drawings --- p.4 / Chapter 1.5 --- Generalized Cylinder --- p.4 / Chapter 1.6 --- Research Problems and Our Contribution --- p.5 / Chapter 1.6.1 --- A New Criteria --- p.5 / Chapter 1.6.2 --- Recover Objects from Line Drawings without Hidden Lines --- p.6 / Chapter 1.6.3 --- Reconstruction of Curved Objects --- p.6 / Chapter 1.6.4 --- Planar Limbs Assumption and the Derived Models --- p.6 / Chapter 2 --- A New Criteria for Reconstruction --- p.8 / Chapter 2.1 --- Introduction --- p.8 / Chapter 2.2 --- Human Visual Perception and the Symmetry Measure --- p.10 / Chapter 2.3 --- Reconstruction Based on Symmetry and Planarity --- p.11 / Chapter 2.3.1 --- Finding Faces --- p.11 / Chapter 2.3.2 --- Constraint of Planarity --- p.11 / Chapter 2.3.3 --- Objective Function --- p.12 / Chapter 2.3.4 --- Reconstruction Algorithm --- p.13 / Chapter 2.4 --- Experimental Results --- p.13 / Chapter 2.5 --- Summary --- p.18 / Chapter 3 --- Line Drawings without Hidden Lines: Inference and Reconstruction --- p.19 / Chapter 3.1 --- Introduction --- p.19 / Chapter 3.2 --- Terminology --- p.20 / Chapter 3.3 --- Theoretical Inference of the Hidden Topological Structure --- p.21 / Chapter 3.3.1 --- Assumptions --- p.21 / Chapter 3.3.2 --- Finding the Degrees and Ranks --- p.22 / Chapter 3.3.3 --- Constraints for the Inference --- p.23 / Chapter 3.4 --- An Algorithm to Recover the Hidden Topological Structure --- p.25 / Chapter 3.4.1 --- Outline of the Algorithm --- p.26 / Chapter 3.4.2 --- Constructing the Initial Hidden Structure --- p.26 / Chapter 3.4.3 --- Reducing Initial Hidden Structure --- p.27 / Chapter 3.4.4 --- Selecting the Most Plausible Structure --- p.28 / Chapter 3.5 --- Reconstruction of 3D Objects --- p.29 / Chapter 3.6 --- Experimental Results --- p.32 / Chapter 3.7 --- Summary --- p.32 / Chapter 4 --- Curved Objects Reconstruction from 2D Line Drawings --- p.35 / Chapter 4.1 --- Introduction --- p.35 / Chapter 4.2 --- Related Work --- p.36 / Chapter 4.2.1 --- Face Identification --- p.36 / Chapter 4.2.2 --- 3D Reconstruction of planar objects --- p.37 / Chapter 4.3 --- Reconstruction of Curved Objects --- p.37 / Chapter 4.3.1 --- Transformation of Line Drawings --- p.37 / Chapter 4.3.2 --- Finding 3D Bezier Curves --- p.39 / Chapter 4.3.3 --- Bezier Surface Patches and Boundaries --- p.40 / Chapter 4.3.4 --- Generating Bezier Surface Patches --- p.41 / Chapter 4.4 --- Results --- p.43 / Chapter 4.5 --- Summary --- p.45 / Chapter 5 --- Planar Limbs and Degen Generalized Cylinders --- p.47 / Chapter 5.1 --- Introduction --- p.47 / Chapter 5.2 --- Planar Limbs and View Directions --- p.49 / Chapter 5.3 --- DGCs in Homogeneous Coordinates --- p.53 / Chapter 5.3.1 --- Homogeneous Coordinates --- p.53 / Chapter 5.3.2 --- Degen Surfaces --- p.54 / Chapter 5.3.3 --- DGCs --- p.54 / Chapter 5.4 --- Properties of DGCs --- p.56 / Chapter 5.5 --- Potential Applications --- p.59 / Chapter 5.5.1 --- Recovery of DGC Descriptions --- p.59 / Chapter 5.5.2 --- Deformable DGCs --- p.60 / Chapter 5.6 --- Summary --- p.61 / Chapter 6 --- Conclusion and Future Work --- p.62 / Bibliography --- p.64

Deng Jiangwen. / "April 2002." / Thesis (Ph.D.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (p. 156-170). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web. / Abstracts in English and Chinese.

In recent years, the actuator disc approach which employs the Reynolds-Averaged Navier-Stokes (RANS) solvers has been extensively applied in wind and tidal energy field to estimate the wake of a horizontal axis turbine. This method is simpler to administer and requires moderate computational resources in modelling a tidal turbines rotor. Nonetheless, the use of actuator disc approximation in predicting the performance of tidal devices has been limited to studies involving an extremely small disc (e.g. rotor diameter of 0.1 meter). The drawback of a small scale actuator disc model is the overestimation of essential parameters such as the mesh density and the resolution of the vertical layers, making them impractical to be replicated in a regional scale model. Hence, this study aims to explore the methodology on implementation of the Three- Dimensional (3D) actuator disc-RANS model in an ocean scale simulation. Additionally, this study also aspires to examine the sensitivity of the applied momentum source term and its validity in representing full-size tidal devices. Nonetheless, before the effectiveness of an actuator disc in a regional model can be tested, tidal flow models for the area of interest needed to be set up first. This was essential for two reasons: (a) to ensure accurate hydrodynamic flow conditions at the deployment site were replicated, (b) to give confidence in the outputs produced by the regional scale actuator disc simulations, since in-situ turbine measurement data from a real deployment site were difficult to source. This research was undertaken in two stages; in the first stage, a numerical model which can simulate the tidal flow conditions of the deployment sites was constructed, and, in the second stage, the actuator disc method which is capable of modelling an array of real scale-sized tidal turbines rotors has been implemented. In the first stage, tidal flow simulations of the Pentland Firth and Orkney Waters (PFOW) were conducted using two distinct open-source software - Telemac3D, which is a finite element based numerical model, and Delft3D, which is a finite difference based model. Detailed methodologies in developing a 3D tidal flow model for the PFOW using both numerical models were presented, where their functionality, as well as limitations were explored. In the calibration and validation processes, both models demonstrated excellent comparison against the measured data. However, Telemac3D was selected for further modelling of the actuator disc considering the model's capability to perform parallel computing, together with its flexibility to combine both structured and unstructured mesh. In the second stage, to examine the actuator disc's accuracy in modelling a full size tidal device, the momentum source term was initially applied in an idealised channel study, where the presence of a 20-meter diameter turbine was simulated for both single and array configurations. The following parameters were investigated: (i) size of the unstructured mesh utilised in the computational domain, (ii) variation in disc's thickness, (iii) resolution of the imposed structured grid to represent turbine's enclosure, (iv) variation in the vertical layers, and (v) influence of hydrostatic and non-hydrostatic formulations on the models' outputs. It is to be noted that the turbine's support structures have not been included in the modelling. The predicted velocities and computed turbulence intensities from the models were compared against laboratory measurement data sourced from literature, where excellent agreement between the model outputs and the data from literature was observed. In essence, these studies highlighted the efficiency and robustness of the applied momentum source term in replicating the wake profiles and turbulence characteristics downstream of the disc, hence providing credence in implementing the actuator disc method for a regional scale application. Subsequently, the validated actuator disc method was applied to the Inner Sound region of the Pentland Firth to simulate arrays of up to 32 tidal turbine rotors. The wake development, flow interactions with the rotor arrays, and flow recovery at the Inner Sound region have been successfully mapped. Also, this study highlighted the importance of employing optimal numerical margins, specifically for the structured grid and horizontal planes, as both parameters were relevant in defining the disc's swept area. As published materials on the implementation of actuator disc approach within a regional scale model is still scarce, it was aspired that this work could provide some evidence, guidance and examples of suggested best practice in effort to fill the research gap in modelling tidal turbine arrays using the actuator disc approach.

Orientador: Oscar Ferreira de Lima / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-09-24T18:27:35Z (GMT). No. of bitstreams: 1 Siqueira_EzequielCosta_M.pdf: 11787391 bytes, checksum: 424aa203ebfa572c02c0b2875dde771f (MD5) Previous issue date: 2006 / Resumo: O interesse em sistemas de multicamadas supercondutoras/ferromagnéticas deve-se a algumas questões importantes relacionadas com a supressão da temperatura crítica, à coexistência da supercondutividade e ferromagnetismo e às transições dimensionais da matéria de vórtices. Neste trabalho foram estudados filmes multicamadas preparados por magnetron sputtering, com fórmula geral Ni(x)[Nb(y)/Ni(x)]n, onde x e y são espessuras fixas (4 º A até 20 º A e 87 º A até 250 º A) e n é o número de bicamadas de Ni/Nb. Os filmes foram caracterizados por difração de raios X em baixo e alto ângulo e por medidas de momento magnético como função da temperatura (T) e campo (H), para orientações perpendicular e paralela às camadas. Os resultados das medidas de raios X em baixo ângulo indicaram uma boa estrutura de multicamadas tendo a espessura das bicamadas ficado dentro de 5% dos valores nominais. As medidas em alto ângulo revelaram a texturização das camadas de Ni e Nb nas direções (111) e (110), respectivamente. Este estudo foi concentrado nas transições dimensionais do acoplamento supercondutor e suas implicações sobre a matéria de vórtices. Medidas de magnetização feitas na amostra Ni(20 º A)[Nb(250 º A)/Ni(20 º A)]9 indicaram uma transição 3D-2D do sistema de vórtices, como revelado pelo comportamento do campo crítico H c2 ?? (T) paralelo às camadas. Consistentemente, foi identificada uma possível linha de desacoplamento dos vórtices associada com a transição das linhas de vórtices de Abrikosov em vórtices panquecas, para a orientação de H perpendicular às camadas. Um linha de irreversibilidade foi determinada e sugere diferentes regimes da matéria de vórtices, onde a função exercida pelas camadas ferromagnéticas de Ni pode ser relevante. Todas as amostras estudadas mostraram instabilidades no momento magnético medido, devido à forte interação entre as contribuições supercondutora, das camadas de Nb, e ferromagnética, das camadas de Ni. As amostras com espessuras de Ni menores mostraram um comportamento paramagnético evidenciandoeos efeitos de tamanho finito sobre o magnetismo das camadas de Ni. A temperatura crítica supercondutora nestas amostras (4 K < Tc< 6 K) foi reduzida em relação ao valor apresentado por uma amostra volumétrica de Nb ( Tc= 9,2 K). Em conclusão, todos os efeitos observados neste trabalho mostram uma relação muito próxima com os efeitos de tamanho finito das camadas de Ni e Nb, e com a competição entre supercondutividade e ferromagnetismo / Abstract: The interest in multilayered superconductor/ferromagnetic structures originates from some important questions related to the critical temperature suppression, the coexistence of superconductivity and magnetism, and dimensional transitions of the vortex matter. In this work we have studied multilayered films prepared by magnetron sputtering, with general formula Ni(x)[Nb(y)/Ni(x)]n, where x and y are fixed thicknesses (4 º A to 20 º A and 87 º A to 250 º A), and n is the number of bi-layers of Ni/Nb. The films were characterized by high and low angle X-ray diffraction and by measurements of the magnetic moment as a function of temperature (T) and magnetic field (H), for perpendicular and parallel orientations with respect to the layers. The results of low angle diffraction indicate a good multilayer structure having bi-layer thicknesses within 5% of the nominal values. The high angle results indicate that Ni and Nb layers are textured in (111) and (110) directions. In this study we have concentrated on the dimensional transitions of the superconducting phase and their effects on the vortex matter. Magnetization measurements made in the Ni(20 º A)[Nb(250 º A)/Ni(20 º A) ]9 sample indicated a 3D-2D crossover of the vortex system, as revealed by the parallel upper critical field behavior. Consistently, it was identified a possible decoupling line associated with transition of Abrikosov vortex lines into vortex pancakes, for H perpendicular to the layers. An irreversibility line was determined and it suggests different regimes of the vortex matter, where the role played by the Ni ferromagnetic layers might be relevant. All the samples studied show magnetic moment instabilities, due to the strong interplay between the superconducting Nb layers and the magnetic Ni layers. The samples with more thinner Ni layers showed a paramagnetic behavior in the normal state, revealing a finite size effect on the magnetic properties of the Ni layers. The superconducting critical temperature in those samples (4 K < Tc < 6 K) was reduced in relation to its bulk value (Tc= 9,2 K). In conclusion, all the effects observed in this work have shown a close relation with finite size effects of the Ni and Nb layers, and with the interplay between superconductivity and magnetism / Mestrado / Supercondutividade / Mestre em Física

Orientador: Eduardo Miranda / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-10-31T13:24:18Z (GMT). No. of bitstreams: 1 HoyosNeto_JoseAbel_D.pdf: 1434769 bytes, checksum: 70acbb99e5c8d9636d4209b0919b56ca (MD5) Previous issue date: 2005 / Resumo: O propósito desse trabalho é estudar o papel da desordem em sistemas de spins fortemente interagentes de baixa dimensionalidade. Do ponto de vista teórico, cadeias de spin são extremamente atrativas por apresentarem uma nova física de baixas energias que vem da competição entre o ordenamento magnético e as .utuações quânticas. A introdução de desordem, onipresente no contexto experimental, é um elemento que pode desestabilizar as fases puras dando origem a uma nova física. Essa é a motivação principal do estudo de seu papel. Neste trabalho nós estudamos 4 sistemas de spins antiferromagnéticos desordenados:(i ) as escadas de spins-1/2 dos tipos 2 pernas e zig-zag, (ii ) as cadeias isotrópicas de spins SU(N), (iii ) a cadeia anisotrópica de spins SU(4), e (iv ) revisitamos a cadeia de spins-1/2. O estudo destes sistemas foi realizado aplicando generalizações da técnica do grupo de renormalização no espaço real para desordem forte. No caso do primeiro sistema, nós mostramos que as escadas de spins sempre renormalizam em cadeias de spins muito bem conhecidas. A escada de 2 pernas renormaliza para uma cadeia de spins-1/2 dimerizada antiferromagnética desordenada e, portanto, possui duas fases. Para dimerização forte ou equivalentemente desordem fraca, o sistema se encontra na fase de Haldane onde há um "gap" e a desordem é irrelevante. Para dimerização fraca ou equivalentemente desordem forte, o "gap" de Haldane se fecha e o sistema se encontra numa fase de Griffiths onde as quantidades termodinâmicas são controladas por um expoente não universal denominado expoente dinâmico z . Em contraste, a escada zig-zag renormaliza ou para uma cadeia de spins-1/2 antiferromagnética desordenada ou para uma cadeia de spins com acoplamentos ferro e antiferromagnéticos desordenada. Se a desordem e a frustração são suficientemente fracas, a escada renormaliza para a primeira cadeia, caso contrário esta pertence à mesma classe de universalidade da segunda. Além disso, relacionamos o expoente dinâmico da cadeia de spins com acoplamentos ferro e antiferromagnéticos com a distribuição de ponto fixo desses acoplamentos. Finalmente, através de argumentos simples, consideramos dizimações de acoplamentos correlacionados. Nesse caso, torna-se bem claro que a frustração é responsável pelo surgimento de acoplamentos ferromagnéticos que põem a escada na bacia de atração do ponto fixo das cadeias com acoplamentos ferro e antiferromagnéticos. Com relação à cadeia SU(N), desenvolvemos uma generalização do método do grupo de renormalização para desordem forte para uma cadeia isotrópica antiferromagnética de spins que pertencem à representações irredutíveis totalmente anti-simétricas do grupo SU(N), com N maior ou igual a 2. Conseguimos resolver as equações de fluxo analiticamente e descobrimos que essas cadeias pertencem a uma nova classe de universalidade cujos pontos fixos são de desordem infinita e, por tal motivo, nossos resultados se tornam assintoticamente exatos. Próximo a esses pontos fixos, os expoentes característicos são universais, i. e., independentes da desordem inicial da cadeia, e dependem somente do posto N do grupo de simetria. Devido às similaridades entre as regras de aglomeração de spins quando da dizimação de uma cadeia de spins com acoplamentos ferro e antiferromagnéticos e da dizimação da cadeia isotrópica de spins SU(N) no limite N ® µ , fomos capazes de calcular analiticamente, através de expansões de 1/N , a função correlação da primeira cadeia.Com relação à cadeia de spins SU(4), modificamos a generalização do método de grupo de renormalização para levar em conta a anisotropia dos acoplamentos. Conseguimos determinar o diagrama de fases através de cálculos analíticos e numéricos. Todos os pontos fixos encontrados são universais e de desordem infinita, entretanto, os expoentes característicos dependem de uma maneira não trivial da anisotropia do sistema. Por fim, revisitamos a cadeia de spins-1/2 antiferromagnética. Calculamos a amplitude da função de correlação média e a relacionamos com a amplitude da entropia de emaranhamento da mesma. Além disso, argumentamos em favor da universalidade dessas amplitudes / Abstract: The purpose of this thesis is the study of the role of quenched disorder in low-dimensional strongly interacting quantum spin systems. From the theoretical point of view, spin chains are extremely attractive due to their unconventional behavior that originates in the competition between magnetic ordering and quantum fluctuations. The introduction of disorder, ubiquitous in experimental realizations, is an element that can destabilize the clean phases giving rise to new physical behavior. That is the main motivation of this study. In this thesis, we study 4 random antiferromagnetic spin systems: (i ) the spin-1/2 two-leg and zigzag ladders, (ii ) the isotropic SU(N) spin chains, (iii ) the anisotropic SU(4) spin chain, and (iv ) we also revisit the spin-1/2 chain. For such a task, we use generalizations of the strong disorder real-space renormalization group method. Concerning the first systems, we show that the ladders are always renormalized to well-known spin chains. The two-leg ladder is renormalized to a random dimerized antiferromagnetic spin-1/2 chain, hence exhibiting two phases. For strong dimerization or equivalently weak disorder the system is in the gapful Haldane phase where disorder is irrelevant. Otherwise, the Haldane gap closes and the system is driven into a nonuniversal Griffiths phase, where the thermodynamical quantities are controled by the dynamical exponent z. In contrast, the zigzag ladder is renormalized either to a random antiferromagnetic spin-1/2 chain or to a random spin chain with both ferro- and antiferromagnetic couplings. If the randomness and frustration are sufficiently weak, the ladder is renormalized to the former chain, but otherwise it belongs to the same universality class of the latter one. In addition, we related the dynamical exponent of the ferro- and aniferromagnetic spin chain with its fixed point coupling constant distributions. Moreover, through simple qualitative arguments, we determined the phase diagram of the zigzag ladder with correlated disorder. That calculation clearly showed that frustration is responsible for the appearance of ferromagnetic couplings, which place the system in the basin of attraction of the fixed point of the ferro- and antiferromagnetic spin chains. With respect to theSU(N) spin chain, we developed a generalization of the strong-disorder renormalization group method to the case of an antiferromagnetic isotropic spin chain whose spins belong to the totally antisymmetric irreducible representations of the SU(N) group, with N greater than or equal to 2. We solved the flow equations analytically and found that such chains belong to a new universality class whose fixed point distributions are characterized by infinite disorder, rendering our results asymptotically exact. The characteristic exponents of these fixed points are universal, i. e., independent of the bare disorder, and depend only on the symmetry group rank. Due to the similarities of the spin clustering rules between the ferro- and antiferromagnetic spin chain and the isotropic SU(N) spin chain in the limit of N ® µ, we were able to analytically calcu- late, through a 1/N expansion, the mean correlation function of the former chain. In the case of the SU(4) spin chain, we modified the generalization of the renormalization group method to take into account the coupling anisotropy. We determined the phase diagram through analytical and numerical calculations. All fixed points found are universal and of infinite-randomness type. However, the characteristic exponents depend in a nontrivial fashion on the anisotropy. Finally, we revisited the antiferromagnetic spin-1/2 chain. We calculated the amplitude of the mean correlation function and related it with the amplitude of the entanglement entropy of the chain. In addition, we gave arguments in favor of the universality of these amplitudes / Doutorado / Física da Matéria Condensada / Doutor em Ciências

by Fung Wai Keung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 146-151). / Acknowledgements --- p.viii / Abstract --- p.1 / Chapter 1 --- Overview --- p.3 / Chapter 1.1 --- Tactile Sensing in Human and Robot --- p.4 / Chapter 1.1.1 --- Human Hands and Robotic Hands --- p.4 / Chapter 1.1.2 --- Mechanoreceptors in skin and Tactile Sensor Arrays --- p.7 / Chapter 1.2 --- Motivation --- p.12 / Chapter 1.3 --- Objectives --- p.13 / Chapter 1.4 --- Related Work --- p.14 / Chapter 1.4.1 --- Using Vision Alone --- p.15 / Chapter 1.4.2 --- Integration of Vision and Touch --- p.15 / Chapter 1.4.3 --- Using Touch Sensing Alone --- p.17 / Chapter 1.4.3.1 --- Ronald S. Fearing's Work --- p.18 / Chapter 1.4.3.2 --- Peter K. Allen's Work --- p.22 / Chapter 1.5 --- Outline --- p.26 / Chapter 2 --- Geometric Models --- p.27 / Chapter 2.1 --- Introduction --- p.27 / Chapter 2.2 --- Superquadrics --- p.27 / Chapter 2.2.1 --- 2D Superquadrics --- p.27 / Chapter 2.2.2 --- 3D Superquadrics --- p.29 / Chapter 2.3 --- Model Recovery of Superquadric Models --- p.31 / Chapter 2.3.1 --- Problem Formulation --- p.31 / Chapter 2.3.2 --- Least Squares Optimization --- p.33 / Chapter 2.4 --- Free-Form Deformations --- p.34 / Chapter 2.4.1 --- Bernstein Basis --- p.36 / Chapter 2.4.2 --- B-Spline Basis --- p.38 / Chapter 2.5 --- Other Geometric Models --- p.41 / Chapter 2.5.1 --- Generalized Cylinders --- p.41 / Chapter 2.5.2 --- Hyperquadrics --- p.42 / Chapter 2.5.3 --- Polyhedral Models --- p.44 / Chapter 2.5.4 --- Function Representation --- p.45 / Chapter 3 --- Sensing Strategy --- p.54 / Chapter 3.1 --- Introduction --- p.54 / Chapter 3.2 --- Sensing Algorithm --- p.55 / Chapter 3.2.1 --- Assumption of objects --- p.55 / Chapter 3.2.2 --- Haptic Exploration Procedures --- p.56 / Chapter 3.3 --- Contour Tracing --- p.58 / Chapter 3.4 --- Tactile Sensor Data Preprocessing --- p.59 / Chapter 3.4.1 --- Data Transformation and Sensor Calibration --- p.60 / Chapter 3.4.2 --- Noise Filtering --- p.61 / Chapter 3.5 --- Curvature Determination --- p.64 / Chapter 3.6 --- Step Size Determination --- p.73 / Chapter 4 --- 3D Shape Reconstruction --- p.80 / Chapter 4.1 --- Introduction --- p.80 / Chapter 4.2 --- Correspondence Problem --- p.81 / Chapter 4.2.1 --- Affine Invariance Property of B-splines --- p.84 / Chapter 4.2.2 --- Point Inversion Problem --- p.87 / Chapter 4.3 --- Parameter Triple Interpolation --- p.91 / Chapter 4.4 --- 3D Object Shape Reconstruction --- p.94 / Chapter 4.4.1 --- Heuristic Approach --- p.94 / Chapter 4.4.2 --- Closed Contour Recovery --- p.97 / Chapter 4.4.3 --- Control Lattice Recovery --- p.102 / Chapter 5 --- Implementation --- p.105 / Chapter 5.1 --- Introduction --- p.105 / Chapter 5.2 --- Implementation Tool - MATLAB --- p.105 / Chapter 5.2.1 --- Optimization Toolbox --- p.107 / Chapter 5.2.2 --- Splines Toolbox --- p.108 / Chapter 5.3 --- Geometric Model Implementation --- p.109 / Chapter 5.3.1 --- FFD Examples --- p.111 / Chapter 5.4 --- Shape Reconstruction Implementation --- p.112 / Chapter 5.5 --- 3D Model Reconstruction Examples --- p.120 / Chapter 5.5.1 --- Example 1 --- p.120 / Chapter 5.5.2 --- Example 2 --- p.121 / Chapter 6 --- Conclusion --- p.128 / Chapter 6.1 --- Future Work --- p.129 / Appendix --- p.133 / Bibliography --- p.146

Cheung Man-Tai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2001. / Includes bibliographical references (leaves 81-84). / Abstracts in English and Chinese. / List of Figures --- p.vi / List of Tables --- p.viii / Chapter Chapter 1. --- Introduction --- p.1 / Chapter 1.1. --- Background --- p.1 / Chapter 1.1.1. --- Parallax --- p.2 / Chapter 1.2. --- Literature Review --- p.3 / Chapter 1.3. --- Research Objective --- p.6 / Chapter 1.4. --- Organization of Thesis --- p.6 / Chapter Chapter 2. --- The 3-Image Algorithm --- p.1 / Chapter 2.1. --- Projective Reconstruction --- p.10 / Chapter 2.2. --- Epipolar Geometry and Fundamental Matrix --- p.11 / Chapter 2.3. --- Determine the Projective Mapping --- p.12 / Chapter 2.3.1. --- Conditions for Initial Matches --- p.13 / Chapter 2.3.2. --- Obtaining the Feature Correspondence --- p.17 / Chapter 2.4. --- Registering Pixel Element --- p.21 / Chapter 2.4.1. --- Single Homography Approach --- p.22 / Chapter 2.4.2. --- Multiple Homography Approach --- p.23 / Chapter 2.4.3. --- Triangular Patches Clustering --- p.24 / Chapter 2.4.3.1. --- Delaunay Triangulation --- p.25 / Chapter 2.5. --- Mosaic Construction --- p.29 / Chapter Chapter 3. --- The n-Image Algorithm --- p.31 / Chapter Chapter 4. --- The Uneven-Sampling-Rate n-Image Algorithm --- p.34 / Chapter 4.1. --- Varying the Reference-Target Images Separation --- p.35 / Chapter 4.2. --- Varying the Target-Intermediate Images Separation --- p.38 / Chapter Chapter 5. --- Experiments --- p.43 / Chapter 5.1. --- Experimental Setup --- p.43 / Chapter 5.1.1. --- Measuring the Performance --- p.43 / Chapter 5.2. --- Experiments on the 3-Image Algorithm --- p.44 / Chapter 5.2.1. --- Planar Scene --- p.44 / Chapter 5.2.2. --- Comparison between a Global Parametric Transformation and the 3-Image Algorithm --- p.46 / Chapter 5.2.3. --- Generic Scene --- p.49 / Chapter 5.2.4. --- The Triangular Patches Clustering against the Multiple Homography Approach --- p.52 / Chapter 5.3. --- Experiments on the n-Image Algorithm --- p.56 / Chapter 5.3.1. --- Initial Experiment on the n-Image Algorithm --- p.56 / Chapter 5.3.2. --- Another Experiment on the n-Image Algorithm --- p.58 / Chapter 5.3.3. --- the n-Image Algorithm over a Longer Image Stream --- p.61 / Chapter 5.4. --- Experiments on the Uneven-Sampling-Rate n-Image Algorithm --- p.65 / Chapter 5.4.1. --- Varying Reference-Target Images Separation --- p.65 / Chapter 5.4.2. --- Varying Target-Intermediate Images Separation --- p.69 / Chapter 5.4.3. --- Comparing the Uneven-Sampling-Rate n-Image Algorithm and Global Transformation Method --- p.73 / Chapter Chapter 6. --- Conclusion and Discussion --- p.76 / Bibliography --- p.81