Search results for "Lift"

Spline-Based Wavelet Transforms

2018

The Lifting Scheme introduced in (Sweldens, Appl. Comput. Harmon. Anal. 3(2), 186–200 (1996) and Sweldens, SIAM J. Math. Anal. 29(2), 511–546 (1997).) [3, 4] is a method that constructs bi-orthogonal wavelet transforms of signals and provides their efficient implementation. The main feature of the lifting scheme is that all the constructions are derived directly in the spatial domain and therefore can be custom designed to more general and irregular settings such as non-uniformly spaced data samples and bounded intervals. In this chapter, we outline the lifting scheme and describe how to use the local quasi-interpolating splines, introduced in Chap. 6, for the construction of wavelet transf…

Biorthogonal Wavelet Transforms Originating from Splines

2015

This chapter describes how to design families of biorthogonal wavelet transforms of signals and respective biorthogonal Wavelet bases in the signal space using spline-based prediction filters. Although the designed Wavelets originate from splines, they are not splines themselves. The design and implementation of the biorthogonal Wavelet transforms is done using the Lifting scheme. Most of the filters participating in the expansion of signals over the presented bases have infinite impulse responses and are implemented by recursive filtering whose computational cost is competitive with the FIR filtering cost. Properties of the designed Wavelets, such as symmetry, flat spectra, good time domai…

MULTIRESOLUTION ANALYSIS FOR IRREGULAR MESHES WITH APPEARANCE ATTRIBUTES

2004

We present a new multiresolution analysis framework based on the lifting scheme for irregular meshes with attributes. We introduce a surface prediction opera- tor to compute the detail coefficients for the geometry and the attributes of the model. Attribute analysis gives appearance information to complete the geomet- rical analysis of the model.We present an application to adaptive visualization and some experimental results to show the efficiency of our framework.

Multiresolution Analysis for Meshes with Appearance Attributes

2005

International audience; We present a new multiresolution analysis framework for irregular meshes with attributes based on the lifting scheme. We introduce a surface prediction operator to compute the detail coefficients for the geometry and the attributes of the model. Attribute analysis gives appearance information to complete the geometrical analysis of the model. A set of experimental results are given to show the efficiency of our framework. We present two applications to adaptive visual-ization and denoising.

Some morfologiacal effects related to a non uniform uplifting of crustal blocks in Northern Sicily (central Mediterranean)

2010

FACELIFT FOR A NEW PORT AREA IMAGE: THE CASE OF PALERMO

2012

The renewal of the urban look (Urban Facelift), starting from the harbor zones, could play a crucial role for the development of the whole city. This study will analyze the case of Palermo port area, considered as the “face” of the city. Sicily is indeed an island, therefore, because of its natural and infrastructural features, the sea is still the privileged connection with the world. For this reason, the urban renovation in the city of Palermo has begun just with its coast area. The tested methodology will combine the Urban Faces with the present state evaluation criteria by involving different stakeholders. After that, the Urban Faces will be associated with possible and suitable future …

Active heave compensation of floating wind turbine installation using a catamaran construction vessel

2021

Abstract The application of floating wind turbines is limited by the high cost that increases with the water depth. Offshore installation and maintenance continue to consume a high percentage of the project budget. To improve the installation efficiency of the floating offshore wind turbine, a novel concept is proposed by the SFI MOVE project. Several wind turbine superstructure components are preassembled onshore and carried to the installation site by a catamaran construction vessel. Each assembly can then be installed using only one lift, and the concept is less sensitive to weather conditions. In this paper, a control algorithm of the proposed hydraulic active heave compensator system i…

Discrete and differential homotopy in circular restricted three-body control

2010

The planar circular restricted three-body problem is considered. The control enters linearly in the equation of motion to model the thrust of the third body. The minimum time optimal control problem has two scalar parameters: The ratio of the primaries masses which embeds the two-body problem into the three-body one, and the upper bound on the control norm. Regular extremals of the maximum principle are computed by shooting thanks to continuations with respect to both parameters. Discrete and dierential homotopy are compared in connection with second order sucient conditions in optimal control. Homotopy with respect to control bound gives evidence of various topological structures of extr…

A Study on Patch-Based Progressive Coding Schemes of Semi-Regular 3D Meshes for Local Wavelet Compression and View-Dependent Transmission

2010

International audience; This paper firstly introduces a wavelet-based segmentation for three-dimensional (3D) Semi-Regular (SR) meshes, as a pre-processing step, in a region-independent progressive coding algorithm. The proposed segmentation process aims at producing homogeneous regions with respect to their frequency amplitudes on the mesh surface, in other words: patches with different degrees of roughness. We have then studied the behavior of the wavelets, obtained during the independent coding of each region, especially close to the patch boundaries. The main contribution of this paper consists in considering three different possible wavelet decompositions, close to the region borders, …

Trīsdimensiju koniskā stara datortomogrāfijas attēla kvalitātes kritēriju izvērtējums pie augšžokļa dobuma pamatnes paaugstināšanas

2017

Bakalaura darba tēma ir „Trīsdimensiju koniskā stara datortomogrāfijas attēla kvalitātes kritēriju izvērtējums pie augšžokļa dobuma pamatnes paaugstināšanas”. Darba mērķis ir izvērtēt trīsdimensiju koniskā stara datortomogrāfijas izmeklējumu attēlu kvalitātes kritērijus pirms un pēc augšžokļa dobuma pamatnes paaugstināšanas, kā arī apzināt biežākos ierobežojumus radiogrāfera praksē veicot KSDT izmeklējumus augšžokļa dobumam. Darba pirmo daļu veido literatūras apskats un apkopojums; otro daļu veido pētījums, kurā analizēta radioloģisko izmeklējumu attēlu kvalitātes atbilstība izstrādātajiem attēlu kvalitātes kritērijiem, kas balstās uz literatūras analīzes un pētījuma rezultātiem. Pētījuma r…