An Approach to the Procedural Generation of Worn Metal Surfaces

Motivated by the phenomenon that wear and tear tends to happen more near sharp cornersof a surface, this thesis presents a method for procedurally generating photorealistic metal surfacesbased upon evaluating curvature values. The thesis describes the development of eight metal shadersthat are used to replace the manual texture painting typically used in production. The approach isdemonstrated by applying these metal shaders to a robotic dog model from a short film involvinglive action and CG elements. Frames from a short animation of the robotic dog are presented, anda discussion of the strengths and weaknesses of this methodology

Incompressible Limit of Compressible Ideal MHD Flows inside a Perfectly Conducting Wall

We prove the incompressible limit of compressible ideal magnetohydrodynamic (MHD) flows in a reference domain where the magnetic field is tangential to the boundary. Unlike the case of transversal magnetic fields, the linearized problem of our case is not well-posed in standard Sobolev space $H^m~(m\geq 2)$, while the incompressible problem is still well-posed in $H^m$. The key observation to overcome the difficulty is a hidden structure contributed by Lorentz force in the vorticity analysis, which reveals that one should trade one normal derivative for two tangential derivatives together with a gain of Mach number weight $\varepsilon^2$. Thus, the energy functional should be defined by using the anisotropic Sobolev space $H_*^{2m}$. The weights of Mach number should be carefully chosen according to the number of tangential derivatives, such that the energy estimates are uniform in Mach number. Besides, part of the proof is parallel to the study of compressible water waves, so our result opens the possibility to study the incompressible limit of free-boundary problems in ideal MHD such as current-vortex sheets.Comment: 28 page

Empirical study on flow experience in China tourism e-commerce market

Purpose: While tourism e-commerce develops rapidly in China, these channels are truly new to both web providers and web consumers, understanding the nature of these media attaches greater importance. This study investigates the mediation effects of flow experience on the relationship between motivation and behavior intention in tourism e-commerce. Design/methodology/approach: Based on the technology acceptance model, an empirical study is designed to test this relationship. We estimated the measurement model with 13 manifest indicators and 4 latent constructs by CFA to assess the reliability and validity of the construct measures, then tested hypotheses by OLS regression and a formal three-step mediation procedure. Findings: Overall, the results reveal that trust is incorporated in motivation and play it’s role together with other motivations; telepresence and concentration are confirmed in flow experience, and both partially mediated the relationship. Research limitations/implications: This study demonstrates that to improve consumers’ usage adoption, marketers should pay much attention to not only consumers’ motivation but also the areas such as flow experiencePeer Reviewe

Piecewise Linear Patch Reconstruction for Segmentation and Description of Non-smooth Image Structures

In this paper, we propose a unified energy minimization model for the segmentation of non-smooth image structures. The energy of piecewise linear patch reconstruction is considered as an objective measure of the quality of the segmentation of non-smooth structures. The segmentation is achieved by minimizing the single energy without any separate process of feature extraction. We also prove that the error of segmentation is bounded by the proposed energy functional, meaning that minimizing the proposed energy leads to reducing the error of segmentation. As a by-product, our method produces a dictionary of optimized orthonormal descriptors for each segmented region. The unique feature of our method is that it achieves the simultaneous segmentation and description for non-smooth image structures under the same optimization framework. The experiments validate our theoretical claims and show the clear superior performance of our methods over other related methods for segmentation of various image textures. We show that our model can be coupled with the piecewise smooth model to handle both smooth and non-smooth structures, and we demonstrate that the proposed model is capable of coping with multiple different regions through the one-against-all strategy