Computational modeling of part relations of shapes is a challenging problem that has been addressed by many researchers since sixties. The most important source of the difficulty is the continuous nature of shapes, which makes the expression of shape very difficult in terms of discrete parts. When discrete parts are combined, they fuse and yield new parts, i.e. parts emerge. There is a number of methods that support emergent part detection. However all of these methods are based on strong assumptions in terms of what constitute a part. There is a need for a generic solution that treats a shape independently of any restriction resulting from analytical, geometrical, or logical abstractions. To this end, we have developed two novel strategies, which can be used both separately and jointly. Both strategies are relatable to the algebraic formalization of shape grammars (by Stiny). In the course of this thesis work, we have introduced a novel data structure called Over-Complete Graph to address the problem of part embedding in the existence of discrete registration marks / and we have developed a novel and robust method for the automatic selection of registration marks. Both developments are certainly useful for other visual problems. On the application side, we have tested our techniques on puzzling Seljuk patterns (from Kayseri) to demonstrate how the developed techniques give way to computational creativity. Apart from the techniques we have developed, the most important contribution of our work is that shapes are treated as perceived wholes rather than composed, as compellingly demonstrated by Seljuk pattern experiments.

Advanced composites are extremely strong, rigid, and light, even when compared with advanced metals. Advanced composites are replacing high-tech metals as the material of choice for aerospace engineering. However, the processes used to manufacture advanced composites generally lose some of the properties of the materials by their process limitations. One process that keeps the theoretically awesome qualities of the composite materials in tact is filament winding. Filament wound parts are used as rocket shells, bicycle frame tubes, drive shafts, pressure vessels, etc. Filament winding is an automated process and makes reliable parts to close tolerances. If a straight tube were to be made by all the existing composites manufacturing processes, filament wound tubes would be significantly better than any other. However, filament winding is generally limited to making straight tubes. A new process based on filament winding is proposed; one that can wind complex shapes of the same high quality as conventional filament winding. This process has achieved this by winding continuous, uncut, and aligned fibers. This process is called Lotus Filament Winding.

Two ways of drawing cubes on dot paper connect students to life outside their classroom.

<strong>Objective:</strong> This study was designed to inform the development of a web tool to simplify access to and analysis of available evidence for youth tobacco control. This tool will support planning, evaluation and research related to youth tobacco control. Primary objectives were to examine useful functions and characteristics of potential end-users. <br /> <strong>Methods:</strong> A pilot-tested, web-based questionnaire was administered to potential end-users (N=43). A purposeful sample of participants was selected to represent individuals working in youth tobacco control from research, health, and education sectors in Western, Central, and Eastern Regions of Canada. Data were analyzed using frequency calculations and cross-tabulations by sector. Results guided the creation of a prototype. Interviews were conducted with a subset of participants (N=6) to validate the prototype and identify further functions. Data were analyzed using content analysis. <br /> <strong>Results:</strong> Useful functions of the prototype identified varied slightly across sectors. Research participants felt that access to raw data was a useful function. Health sector practitioners were interested in accessing data and creating summary reports of data. Educators were mostly interested in obtaining summary information from data, through reports. Further, health and research participants felt the information resources function was redundant. This research has provided important insights that will guide the development of a functional web tool. <br /> <strong>Implications:</strong> This tool can enable users to identify effective interventions, track the progress of school or health regions relative to benchmarks, and identify high risk schools or communities to target intervention efforts. This tool is an innovative way to maximize the use of available resources to link research, policy, and practice.

Detta kandidatarbete handlar om hur ett främmande objekt kan påverka en betraktares uppfattning av en karaktärs förhållande till gott och ont. Kandidatarbetet utforskar ämnen som stereotyper, former, fördomar och intryck. Olika metoder används i framtagandet av karaktärerna, där bland annat former används för att förstärka uppfattningen av karaktärens ställning till gott och ont. Karaktärerna skapades i två versioner, en utan det främmande objektet och en med. En enkät skickades ut och deltagare fick poängsätta karaktärer för att sedan motivera sina val med kommentarer. Resultatet visade att ett främmande objekt har möjlighet att påverka betraktaren, där betraktarens relation till objektet har en avgörande roll i hur karaktären vinklas åt gott eller ont. / This thesis describes how a foreign object can affect an observer's perception of a character's relation to good and evil. The thesis explores topics like stereotypes, forms, prejudices and impressions. Various methods are used in the development of the characters, which include shapes that are used to enhance the perception of the character's position between good and evil. The characters were created ​​in two versions, one without the foreign object and one with the foreign object. A survey was created and the participants had to score the characters and then justify their choice with comments. The results showed that a foreign object is able to influence the viewer, where the viewer's relationship to the object has a crucial role in how the character is angled towards good or evil.

In packaging industries, the demand for usage of Low Density Poly Ethylene foil is of profound interest. In the past, research was carried out on finite and infinite plates with varying crack lengths but having constant crack width. In this thesis, a detailed analysis on crack initiation is carried out on finite plates by varying width of the hole. The hole shapes for stress analysis include circle, ellipse and rectangular notch. Initially, maximum stress is found out using Linear Elastic Fracture Mechanics (LEFM) theory and compared with Finite element method (FEM) results. Secondly using Elastic Plastic Fracture Mechanics theory (EPFM), critical stress and geometric function are evaluated theoretically by Modified Strip Yield Model (MSYM) and numerically by ABAQUS. Finally, a tensile test is conducted to validate the theoretical and numerical results.  By varying the width of the hole, a study on the parameters like critical stress, geometric function is presented. A conclusion is drawn that the effect of hole width should be considered when calculating fracture parameters.

Este trabalho apresenta resultados de uma análise teórico-experimental sobre a resistência à compressão de perfis I soldados de aço, formados por chapas cortadas a maçarico. A construção metálica no Brasil utiliza os perfis I soldados formados por chapas cortadas a maçarico em virtude da pouca disponibilidade no mercado dos perfis laminados. Os perfis soldados brasileiros apresentam dimensões (altura, largura de mesa e espessura) diferentes das encontradas nos perfis laminados e soldados, fabricados em outros países. Apresentam-se os principais parâmetros envolvidos na formulação das curvas de resistência à compressão para perfis soldados de pequenas dimensões, tais como: tensões residuais, imperfeições geométricas iniciais e seus efeitos no cálculo da resistência à compressão dos perfis soldados compostos por chapas cortadas a maçarico. Os perfis ensaiados são das séries PS 200x25, PS 225x29 e CS 150x25, sendo que foram obtidos resultados experimentais da força normal crítica e das imperfeições geométricas iniciais para três modelos de cada série com quatro índices de esbeltez diferente. / This work presents results of theoretical and experimental analysis about the compressive strength of steel welded I-shapes manufactured from flame-cut plates. Steel construction in brazil uses these welded I-shapes because of the limited availabilily of hot-rolled shapes in the market. The brazilian welded shapes have dimensions (height, flange width and thickness) that differ from steel welded shapes manufactured in other countries. It presents the main parameters in the formulation of the compressive strength curves for welded shapes of small dimensions as: residual stresses, geometrical initial crookedness and their effects in the evaluation of the compressive strength of the welded shapes manufactured from flame-cut plates. The tested shapes are of PS 200x25, PS 225x29 and CS 150x25 series. Test results were obtained for the critical axial load and the geometrical initial crookedness to three models with four different slenderness ratio in each serie.

Leaf primordia initiation takes place at the flanks of SAM and then passes through common developmental stages. Very different final leaf shapes and sizes result from varying the timing and further patterning events within these developmental stages. Similar final leaf shapes may also result from very distinct early events. Begonia section Gireoudia is a recently radiated group of species with highly divergent leaf forms. I have used a classical genetic approach and candidate gene approach to explain the evolution of leaf form in this genus. These results suggest that convergent evolution of peltate leaves may be through changes at different loci. Key developmental regulators KNOX and ARP genes are reported to be involved in the evolution of leaf form in different species. I have shown that in at least one species ARP is linked to the evolution of peltate leaf form. In a second species there is no link between STM-like KNOX genes and leaf dissection. Estimates of the rate of evolution of ARP CDS showed that different domains of the genes are under different selection pressures. Myb domain2 of ARP genes is under positive selection and variable between two copies of ARP genes in Begonia. Results of complementation tests with Begonia ARP genes in Arabidopsis show that ARPs from Begonia are functionally equivalent to Arabidopsis AS1 genes and one of the two ARP genes in Begonia may be a dominant negative. Expression analysis based on insitu hybridization in compound, peltate and simple leaved Begonias is described. There is no variation in expression patterns between peltate, non peltate or compound leaved Begonia species for BARP1 and KNB1 genes.

First of all, the PDE form of the classical level set function phi is parameterized with an analytical form of Radial Basis Function (RBF), which is real-valued and continuously differentiable. Such that the upwind scheme, extension velocity and reinitialization algorithms in solving the discrete Hamilton-Jacobi equation can be waived in the numerical process, the whole framework is transformed into a standard mathematical programming problem in which the linear objective function can be directly optimized by a gradient algorithm - shape sensitivity. The minimization of the mean compliance is studied and presented to demonstrate the advantages of the parametrical method. / Parametrization substantially reduces the complexity of the original discrete PDE level set method. However, the result shows that the high number of RBF knots leads to dense coefficient matrices. Thus, it induces numerical instabilities, slow convergence and less accuracy in the process. Consequently, we then study the distribution of knots density for faster computation. By updating the movement of the knot, the knot moves towards the position where the change is directly determined by the shape sensitivity. In such case, we may use lesser number of knots to describe the properties of the system while the smoothness of the implicit function is satisfied. The sensitivity study is evaluated carefully and discussed in detail. Results show a significant improvement in the computational speed and stability. / The study found significant improvement obtained in the structural optimization with the parametric level set method, both the stability and efficiency were given as the benefits of using the method of the parametrization. / Traditional structural optimization approaches can be referred to as sizing optimization, since their design variables are the proportions of the structure or material. A major restriction in the sizing problem is that the shape and the topology of the structure are fixed a priori. Undoubtedly, changes in shape (e.g., curved boundary) and topology (e.g., holes in a member) could produce more significant improvement in dynamic performance than modifications in size alone. A recent development of shape and topology optimization based on the implicit moving boundaries with the use of the renowned level set method is regarded as one of the most sophisticated methods in handling the change of the structural topology. In this thesis, we study the parametrization of the classical level set method for the structural optimization and the associated computational methodology. / Usually, a large-scale model will lead to bulk coefficient matrices in the RBF optimization and the linear function normally require O (N3) flops and O (N2) memory while processing. It is becoming impractical to solve as N goes over 10,000. In fact, the dense system equation matrix frequently leads to the numerical instabilities and the failure of the optimization. Finally, we introduce the method of Partition of Unity (POU) to deal with this problem. POU is often used in 3D reconstruction of implicit surfaces from scattered point sets. It breaks the global domain into smaller overlapping subdomains such that the implicit functions can be more efficiently interpolated. Meanwhile, the global solution is obtained by blending all the local solutions with a set of weighting functions. The algorithm of POU is presented here, and we analyze and discuss the numerical results accordingly. / Ho, Hon Shan. / Adviser: Michael Y. Wang. / Source: Dissertation Abstracts International, Volume: 73-03, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 106-119). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

隨著互聯網上3D模型的大量增加，產生了開發3D模型搜索引擎的需求。本論文提出了一個基於草圖和3D模型的3D模型搜索引擎。 / 對於使用3D模型作檢索條件的搜索系統，我們提出了兩種新的3D模型描述子，分別叫做Sphere Image 描述子和Bag-of-View-Words (BoVW)描述子。Sphere Image描述子是由一系列投影圖的特徵組成。我們將每一個視角看到的圖形都當作是一個"像素"，把視角的位置看作像素點的位置，把所看到的圖形的特徵值看作是像素值。我們同時也提出了一種基於概率圖的3D模型匹配算法，並開發了一個3D模型檢索系統來檢測我們的算法。BoVW描述子通過3D模型投影圖出現的次數來描述3D模型。我們用一種自適應的聚類算法，對3D模型的所有投影圖進行分類，然後用一個多層次的柱狀圖來描述一個3D模型。我們同時提出一種新的金字塔匹配算法來比較3D模型。我們使用SHREC和普林斯頓的3D模型庫來檢驗我們的系統，實驗結果證明我們的系統在檢索效率和精度上都優與現今的3D模型檢索系統。 / 對於使用草圖作檢索條件的3D模型搜索系統，我們提出Bigger ExposureOpportunity Views (BEOV) 描述子來表示3D模型，同時提出Shape-Ring描述子來表示草圖。BEOV描述子是由一些特徵圖組成，這些圖的特點是更容易被人們看到。Shape-Ring描述子保留了圖形的輪廓和內部特徵。我們使用SHREC2012草圖數據庫來檢驗我們的系統，實驗結果證明我們的系統在精度和計算複雜度上都優與現今的3D模型檢索系統。 / The large number of 3D models on the Internet encourages us to develop 3D model search engines. In this dissertation, we present a 3D model retrieval system using both the 3D model query and the sketch query. / For 3D model query based retrieval system, we propose two new 3D model descriptors, named the Sphere Image and the Bag-of-View-Words (BoVW) descriptor. The Sphere Image is defined as a collection of view features. A viewpoint of a 3D model is regarded as a "pixel": (1) The position of the viewpoint is denoted as the coordinate of the "pixel". (2) The feature descriptor of the projected view is denoted as the value of the "pixel". We also propose a probabilistic graphical model for 3D model matching, and develop a 3D model retrieval system to test our approach. The BoVW descriptor describes a 3D model by measuring the occurrences of its projected views. An adaptive clustering method is applied to reduce the redundancy of the projected views of each 3D model. A 3D model is represented by a multi-resolution histogram, which is combined by several BoVW descriptors at different levels. The codebook is obtained by unsupervised learning. We also propose a new pyramid matching method for 3D model comparison. We have conducted experiments based on the SHape REtrieval Contest (SHREC) 2012 Generic 3D model benchmark and the Princeton Shape Benchmark (PSB). Experimental results indicate that our system outperforms some state-of-the-art 3D model retrieval systems with respect to the retrieval precision and the computational cost. / For sketch query based retrieval system, we propose a Bigger Exposure Opportunity Views (BEOV) descriptor and a Shape-Ring descriptor, for representing the 3D model candidates and the sketch query, respectively. The BEOV descriptor represents a 3D model by several characteristic views, which have more chances to be exposed to people. The Shape-Ring descriptor preserves the features of the contour and the inside detail of the sketch query and the BEOV. Experiments have been conducted based on the SHape REtrieval Contest (SHREC) 2012 and SHREC 2013 sketch track data sets. Our approach outperforms the existing 3D model retrieval methods in terms of the retrieval precision and the computational cost. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Ding, Ke. / Thesis (Ph.D.) Chinese University of Hong Kong, 2014. / Includes bibliographical references (leaves 107-120). / Abstracts also in Chinese.