12,052 research outputs found
Free-form deformation of solid models in CSR.
Lai Chi-fai.Thesis (M.Phil.)--Chinese University of Hong Kong, 2000.Includes bibliographical references (leaves 98-99).Abstracts in English and Chinese.Chapter 1. --- INTRODUCTION --- p.7Chapter 1.1 --- Motivations and objectives --- p.7Chapter 1.2 --- Thesis Organization --- p.10Chapter 2. --- related works --- p.11Chapter 2.1 --- Deformation Techniques --- p.11Chapter 2.1.1 --- Deformation techniques requiring a deformation tool --- p.11Chapter 2.1.2 --- Directly specified deformation techniques --- p.14Chapter 2.1.3 --- Comparison on Different Deformation Technique --- p.15Chapter 2.2 --- Application of Deformation --- p.16Chapter 2.2.1 --- Deforming superquadrics --- p.16Chapter 2.2.2 --- Volume wraping --- p.16Chapter 2.2.3 --- Deforming linear object --- p.17Chapter 2.2.4 --- FFD for animation synthesis --- p.17Chapter 2.2.5 --- Using FFD on feature-based Surface --- p.18Chapter 2.2.6 --- NURBS-BASED Free-Form Deformation (NFFD) --- p.18Chapter 2.3 --- Algebraic Patch Techniques --- p.20Chapter 2.3.1 --- Dahmen's scheme --- p.20Chapter 2.3.2 --- Lodha and Warren's technique --- p.20Chapter 2.3.3 --- Guo's method --- p.21Chapter 3. --- BACKGROUND THEORIES --- p.22Chapter 3.1 --- Algebraic Patches --- p.22Chapter 3.1.1 --- Bernstein-Bezier representation of a single patch --- p.22Chapter 3.1.2 --- Constructing free-form objects --- p.29Chapter 3.1.2.1 --- Bounding volumes for quadric patches --- p.29Chapter 3.1.2.2 --- Filling two-sided gaps --- p.31Chapter 3.2 --- Constructive Shell Representation --- p.35Chapter 3.2.1 --- Properties of quadric patches and its construction tetrahedron and trunctets --- p.38Chapter 3.3 --- Free-Form Deformation --- p.40Chapter 3.3.1 --- Formulating free-form deformation --- p.40Chapter 4. --- FREE-FORM DEFORMATION OF CSR SOLID MODELS --- p.43Chapter 4.1 --- Determination of Lattice Structure --- p.43Chapter 4.2 --- "Relation between weights, normals and shape of a trunctet" --- p.46Chapter 4.3 --- Applying FFD on CSR solid models --- p.49Chapter 4.3.1 --- Deforming normal at vertices --- p.52Chapter 4.3.2 --- Using vertices' neighborhoods --- p.54Chapter 4.4 --- Free-Form Deformation of CSR objects by Surface Fitting --- p.57Chapter 4.4.1 --- Deforming a single surface patch --- p.57Chapter 4.4.1.1 --- Locating surface points --- p.59Chapter 4.4.1.2 --- Conversion between barycentric and Cartesian coordinates --- p.61Chapter 4.4.1.3 --- Evaluating the deformed surface patch --- p.62Chapter 4.4.1.4 --- Saddle shape trunctet --- p.64Chapter 4.4.1.5 --- Using double tetrahedrons --- p.66Chapter 4.4.1.6 --- Surface subdivision --- p.69Chapter 4.4.2 --- Deforming Entire Solid Model --- p.72Chapter 4.4.3 --- Comparison on different approaches --- p.75Chapter 4.5 --- Conversion of CSG solid Models into CSR --- p.76Chapter 4.5.1 --- Converting halfspaces into CSR objects --- p.77Chapter 5. --- IMPLEMENTATION AND RESULTS --- p.82Chapter 5.1 --- Implementation --- p.82Chapter 5.2 --- Experimental Results --- p.84Chapter 6. --- CONCLUSION AND SUGGESTIONS FOR FURTHER WORK --- p.93Chapter 6.1 --- Conclusion --- p.93Chapter 6.2 --- Suggestions for further work --- p.9
Algebraic constructive quantum field theory: Integrable models and deformation techniques
Several related operator-algebraic constructions for quantum field theory
models on Minkowski spacetime are reviewed. The common theme of these
constructions is that of a Borchers triple, capturing the structure of
observables localized in a Rindler wedge. After reviewing the abstract setting,
we discuss in this framework i) the construction of free field theories from
standard pairs, ii) the inverse scattering construction of integrable QFT
models on two-dimensional Minkowski space, and iii) the warped convolution
deformation of QFT models in arbitrary dimension, inspired from non-commutative
Minkowski space.Comment: Review article, 57 pages, 3 figure
Final State Interactions in Hypernuclear Decay
We present an update of the One-Meson-Exchange (OME) results for the weak
decay of s- and p-shell hypernuclei (Ref. Phys. Rev. C {\bf 56}, 339 (1997)),
paying special attention to the role played by final state interactions between
the emitted nucleons. The present study also corrects for a mistake in the
inclusion of the and exchange mechanisms, which substantially
increases the ratio of neutron-induced to proton-induced transitions,
. With the most up-to-date model ingredients, we find that
the OME approach is able to describe very satisfactorily most of the measured
observables, including the ratio .Comment: 20 pages, 2 eps figure
NS5-branes on an ellipsis and novel marginal deformations with parafermions
We consider NS5-branes distributed along the circumference of an ellipsis and
explicitly construct the corresponding gravitational background. This provides
a continuous line of deformations between the limiting cases, considered
before, in which the ellipsis degenerates into a circle or into a bar. We show
that a slight deformation of the background corresponding to a circle
distribution into an ellipsoidal one is described by a novel non-factorizable
marginal perturbation of bilinears of dressed parafermions. The latter are
naturally defined for the circle case since, as it was shown in the past, the
background corresponds to an orbifold of the exact conformal field theory coset
model SU(2)/U(1) times SL(2,R)/U(1). We explore the possibility to define
parafermionic objects at generic points of the ellipsoidal families of
backgrounds away from the circle point. We also discuss a new limiting case in
which the ellipsis degenerates into two infinitely stretched parallel bars and
show that the background is related to the Eguchi-Hanson metric, via T-duality.Comment: 24 page
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