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Registering a Non-Rigid Multi-Sensor Ensemble of ImagesKim, Hwa Young January 2009 (has links)
Image registration is the task of aligning two or more images into the same reference frame to compare or distinguish the images. The majority of registration methods deal with registering only two images at a time. Recently, a clustering method that concurrently registers more than two multi-sensor images was proposed, dubbed ensemble clustering. In this thesis, we apply the ensemble clustering method to deformable registration scenario for the first time. Non-rigid deformation is implemented by a FFD model based on B-splines. A regularization term is added to the cost function of the method to limit the topology and degree of the allowable deformations. However, the increased degrees of freedom in the transformations caused the Newton-type optimization process to become ill-conditioned. This made the registration process unstable. We solved this problem by using the matrix approximation afforded by the singular value decomposition (SVD). Experiments showed that the method is successfully applied to non-rigid multi-sensor ensembles and overall yields better registration results than methods that register only 2 images at a time. In addition, we parallelized the ensemble clustering method to accelerate the performance of the method. The parallelization was implemented on GPUs using CUDA (Compute Unified Device Architecture) programming model. The GPU implementation greatly reduced the running time of the method.
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Chemical Synthesis and Ionic Conductivity of Water-Soluble Articulated Rigid-Rod Polyelectrolytes Derivatized with Sulfonated Ionomer PendantsDu, Yue-Lin 15 February 2005 (has links)
Articulated rigid-rod polymers asPBI were synthesized via polycondensation reaction. Using 2-sulfoterephthalic acid and 5-sulfoisophthalic acid in different ratios for copolycondensation reaction making the fully conjugated rigid-rod backbone became articulated. Both rigid-rod and articulated rigid-rod were further derivatized using alkane sulfonated pendants and became water-soluble rigid-rod and articulated rigid-rod polyelectrolytes.
Lithium salt doped cast films of the polyelectrolytes showed a root-temperature DC conductivity parallel to film surface (
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Generation of Globoidal Cam Surfaces with Conical RollersLin, Sheng-yang 07 February 2006 (has links)
This thesis presents a geometry design method to generate the surfaces of the globoidal cam with the conical roller follower. Based on the trace of the rigid body and the theory of differential geometry, the conjugate surfaces can be the offset surfaces of the ruled surface.
With different roller¡¦s axial height, its radius and the meshing vector also be changed. For this reason, the contact points on the outward roller are hard to find. To overcome this problem, we propose the triangular graph with meshing angle, it can present the vector quantity caused from the motion angle. We replace it into the procedures of the rigid body transformation method to derive the cam surfaces with the conical roller follower. Furthermore, two models with modified sine and constant velocity motion curves are generated and analyzed.
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The synthesis and analysis of water soluble rigid-rod polyelectrolyteKuo, Chien-Hung 01 August 2000 (has links)
Development of opto-electronic polymers has been focused on conjugated rigid-rod polymers which assume a para-catenated backbone yielding a rod-like configuration. As a consequence of their rigidity, the rod-like molecules display superior mechanical properties, thermo-oxidative stability and solvent resistance. The later two characters cause difficulties in processing these high-performance rigid-rod polymers. This in terms limits their applications in critical technologies, such as conducting polymers, nonlinear optics, and solid polyelectrolytes.
In this study, chemical derivatives of the rigid-rod polymers were synthesized using pendants of propane-sulfonated ionomers to (1) enhance the solubility of the rigid-rod polymers, and (2) generate a solid polyelectrolyte suitable for energy storage. Extensive synthesis efforts were focused on generating monomers and polymers of propane-sulfonated poly(p-phenylene-benzobisimidazole), PBI, making it a water soluble electrolyte. Various analysis techniques were applied to ascertain the chemical structure and the purity of the monomers and of the polymers. The polymer molecular weight was also determined using viscometry. An intrinsic viscosity of 4.9 dL/g was achieved for the 2-sulfo-PBI and of 0.58 dL/g for the propane-sulfonated PBI with Na+ ionomer pendants
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Aspect Ratio Modulations of Fully Conjugated Rod-like Polymer Electrolyte for Enhanced Three-dimensionally Isotropic Ionic ConductivityWang, Jia-Huei 02 October 2009 (has links)
This study utilized polycondensation reaction to synthesize fully conjugated rod-like polymer dihydroxy-PBI. Chemical derivatizations were applied to attach pendants of propane sulfonic coil for dihydroxy-PBI-PS and to attach aromatic phenylene ring with Li ionic moiety for dihydroxy-PBI-AS. The attachment of pendants for dihydroxy-PBI-PS was 42.27 % and for dihydroxy-PBI-AS was only for 0.04 % causing by stereo hindrance of this molecule. These polymers seemed to have good thermal stability. Dihydroxy-PBI started to show degradation at 467.8 oC and retained 60.5 wt. % at 800 oC. Derivatized dihydroxy- PBI-PS and dihydroxy-PBI-AS lost their pendants at 295.3 oC and 314.4 oC, respectively.
Dihydroxy-PBI was cast into thin film. Upon doping with lithium salt of LiClO at 2.02 wt. %, dihydroxy-PBI cast film showed the highest room-temperature dc conductivity parallel to the film (£m¡ü) of 1.71 x 10-4 S/cm and perpendicular to the film (£m¡æ) of 1.49 x 10-5 S/cm. For dihydroxy-PBI-PS cast film, the highest conductivity was at 0.49 wt. % of LiClO4 with £m¡ü of 1.05 x 10-3 S/cm and £m¡æ of 1.05 x 10-4 S/cm. For dihydroxy-PBI-AS cast film, the highest conductivity was at 2.02 wt. % of LiClO4 with £m¡ü of 1.32 x 10-3 S/cm and £m¡æ of 2.26 x 10-5 S/cm.
From scanning electron microscopy and wide-angle x-ray scattering, it was learned that cast films of dihydroxy-PBI and dihydroxy-PBI-AS had anisotropic layered structure parallel to the film, and that of dihydroxy-PBI-PS showed less of this anisotropy.
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Rotating dynamics of pendula systems for energy harvesting from ambient vibrationsNajdecka, Anna January 2013 (has links)
This thesis has been motivated by the idea of harvesting the energy from ambient vibrations via nonlinear dynamics of the parametric pendulum. It aims to cover those aspects of the pendulum dynamics, which are relevant for energy extraction purposes and have not been addressed in previous studies. A simple system like parametric pendulum can experience variety of responses. One of them is rotary motion, which is characterised by significantly higher kinetic energy than oscillations and thus has a potential of delivering more energy, when subjected to the parametric excitation. Initially, a preliminary study on the dynamics of parametric pendulum has been conducted. This involved comparison of oscillatory and rotary responses with a view to application in energy harvesting, numerical continuation of rotary solutions and developing a control method for initiating and maintaining the desired response. As a next step, different forcing configurations have been considered, including pendulum excited along a tilted axis and a combined excitation, where pendulum additionally performs rocking action. The influence of the forcing arrangement on the lower limit of stability of rotary motion has been examined. The vibrations which can be observed in the environment are rarely perfectly harmonic. To provide more realistic results, the response of the pendulum under noisy excitation has been studied. Different types of noise have been considered and their influence on the pendulum rotation examined. One of the major energy sources, which could be utilised are the oscillating ocean surfaces. Therefore, a stochastic model of the sea wave has been constructed and the response of the pendulum system studied under parametric excitation by a wave profile. Finally, taking into account the imbalanced forces which rotating pendulum exerts on the supporting base, the model has been extended to a system of two pendulums. Synchronization in such a system was studied. The influence of the synchronization mode on the rotation of the pendulums and on the stability of supporting structure was considered. All of the numerical results presented in this thesis have been verified experimentally to ensure good correspondence.
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Stability of Generic Equilibria of the 2n Dimensional Free Rigid Body Using the Energy-Casimir MethodSpiegler, Adam January 2006 (has links)
The rigid body has been one of the most noteworthy applications of Newtonian mechanics. Applying the principles of classical mechanics to the rigid body is by no means routine. The equations of motion, though discovered two hundred and fifty years ago by Euler, have remained quite elusive since their introduction. Understanding the rigid body has required the applications of concepts from integrable systems, algebraic geometry, Lie groups, representation theory, and symplectic geometry to name a few. Moreover, several important developments in these fields have in fact originated with the study of the rigid body and subsequently have grown into general theories with much wider applications.In this work, we study the stability of equilibria of non-degenerate orbits of the generalized rigid body. The energy-Casimir method introduced by V.I. Arnold in 1966 allows us to prove stability of certain non-degenerate equilibria of systems on Lie groups. Applied to the three dimensional rigid body, it recovers the classical Euler stability theorem [12]: rotations around the longest and shortest principal moments of inertia are stable equilibria. This method has not been applied to the analysis of rigid body dynamics beyond dimension n = 3. Furthermore, no conditions for the stability of equilibria are known at all beyond n = 4, in which case the conditions are not of the elegant longest/shortest type [10].Utilizing the rich geometric structures of the symmetry group G = SO(2n), we obtain stability results for generic equilibria of the even dimensional free rigid body. After obtaining a general expression for the generic equilibria, we apply the energy-Casimir method and find that indeed the classical longest/shortest conditions on the entries of the inertia matrix are suffcient to prove stability of generic equilibria for the generalized rigid body in even dimensions.
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Plieninių kabamųjų tiltų su standžiais lynais įtempių ir deformacijų būvis / Stress and deformation state of suspension steel bridges with rigid cablesGrigorjeva, Tatjana 02 April 2007 (has links)
Suspension bridges possess a number of advantages, allowing overlapping average and large spans. The basic disadvantage of suspension bridges can be considered their increased deformability, particularly under the action of non-symmetrical and local loads. Deformability depends, in general, on the kinematical character of displacements of a flexible suspension cable. Required rigidity of suspension bridges is achieved, by increasing the height, and consequently the weight of a stiffening girder, by diagonal suspenders or two-cable or combined prestressed systems. Reduction of kinematical displacements of the main cable can also be achieved by a reduction of the sag-to-span ratio, but the smaller the sag of a cable, the greater are the cable thrust forces and the required cross-sectional areas of the cables. One of the ways of suspension systems stabilization is giving certain bending stiffness to the suspension cables. Such structural solution with success is used in suspension roofs. With the aim to increase the stability of suspension bridges the author proposes to use the finite bending stiffness cables. The cables can be made of standard steel profiles or have composite sections. Conventionally, they are called as “rigid cables”. To verify this solution, the investigation on behavior of suspension bridges with rigid cables under loading has to be undertaken.
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Plieninių kabamųjų tiltų su standžiais lynais įtempių ir deformacijų būvis / Stress And Deformation State Of Suspension Steel Bridges With Rigid CablesGrigorjeva, Tatjana 02 April 2007 (has links)
Suspension bridges possess a number of advantages, allowing overlapping average and large spans. The basic disadvantage of suspension bridges can be considered their increased deformability, particularly under the action of non-symmetrical and local loads. Deformability depends, in general, on the kinematical character of displacements of a flexible suspension cable. Required rigidity of suspension bridges is achieved, by increasing the height, and consequently the weight of a stiffening girder, by diagonal suspenders or two-cable or combined prestressed systems. Reduction of kinematical displacements of the main cable can also be achieved by a reduction of the sag-to-span ratio, but the smaller the sag of a cable, the greater are the cable thrust forces and the required cross-sectional areas of the cables. One of the ways of suspension systems stabilization is giving certain bending stiffness to the suspension cables. Such structural solution with success is used in suspension roofs. With the aim to increase the stability of suspension bridges the author proposes to use the finite bending stiffness cables. The cables can be made of standard steel profiles or have composite sections. Conventionally, they are called as “rigid cables”. To verify this solution, the investigation on behavior of suspension bridges with rigid cables under loading has to be undertaken.
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Analytical models for calculating the response of temporary soil-filled walls subjected to blast loadingScherbatiuk, Kevin Daniel 13 January 2010 (has links)
The aims of the thesis were to study the response of temporary soil-filled walls both experimentally and numerically, and to develop an efficient and accurate analytical model to predict 2-D planar response from blast loading which could be used to efficiently calculate a pressure-impulse (P-I) curve. An explicit finite element (FE) formulation was constructed using LS-Dyna software, and two analytical models were also derived and presented: a Rigid-Body Rotation model as a preliminary model, and the Rigid-Body Hybrid model as the proposed model of this thesis. Seven full-scale experiments which consisted of blast loading simple free-standing soil-filled Hesco Bastion (HB) walls are presented.
Apart from comparison of an experimental result where the soil-fill in the wall possessed sizable cohesion, the response of the Rigid-Body Hybrid model was in very good agreement with the experiments overall (within 10 %). A soil sensitivity study was conducted and overall very good agreement was reached between the Rigid-Body Hybrid model in comparison with the FE model in its ability to capture differences in displacement-time histories from differences in soil parameters. Comparison with the FE model for different height-to-width ratios of walls showed that the Rigid-Body Hybrid model was within 10 % for all rotation angles and predictions of critical overturning impulse for height-to-width ratios of walls . P-I curves were developed using the analytical and FE models for the three different wall configurations studied in the experiments. The results demonstrated that the proposed Rigid-Body Hybrid model is useful for calculating a P-I curve for a HB wall efficiently and yielded very accurate results (within 5 % for the impulse asymptotes).
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