Search results for "Fractal"
showing 10 items of 329 documents
A three-dimensional fractal approach of urban morphology, fomalisation and application
1999
International audience
Tangents to fractal curves and surfaces
2010
International audience; The aim of our work is to specify and develop a geometric modeler, based on the formalism of iterated function systems with the following objectives: access to a new universe of original, various, aesthetic shapes, modeling of conventional shapes (smooth surfaces, solids) and unconventional shapes (rough surfaces, porous solids) by defining and controlling the relief (surface state) and lacunarity (size and distribution of holes). In this context we intend to develop differential calculus tools for fractal curves and surfaces defined by IFS. Using local fractional derivatives, we show that, even if most fractal curves are nowhere differentiable, they admit a left and…
Persistence in complex systems
2022
Persistence is an important characteristic of many complex systems in nature, related to how long the system remains at a certain state before changing to a different one. The study of complex systems' persistence involves different definitions and uses different techniques, depending on whether short-term or long-term persistence is considered. In this paper we discuss the most important definitions, concepts, methods, literature and latest results on persistence in complex systems. Firstly, the most used definitions of persistence in short-term and long-term cases are presented. The most relevant methods to characterize persistence are then discussed in both cases. A complete literature r…
Adverse reactions to the injection of face and neck aesthetic filling materials: a systematic review
2022
Adverse reactions, caused during the inflammation and healing process, or even later, can be induced by the injection of dermal filler and can present a variety of clinical and histological characteristics. In this study we aimed to review the adverse reactions associated with the injection of aesthetic filling materials in the face and neck. The review was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. Studies published that mentioned adverse reactions in patients with aesthetic filling materials in the face or neck were included. Risk of bias was assessed using the Joanna Briggs Institute appraisal tool. After a 2-step selection pro…
The effects of image compression on quantitative measurements of digital panoramic radiographs
2012
WOS: 000314401800026
Characterizing Cavities in Model Inclusion Fullerenes: A Comparative Study
2001
Abstract: The fullerene-82 cavity is selected as a model system in order to test several methods for characterizing inclusion molecules. The methods are based on different technical foundations such as a square and triangular tessellation of the molecular surface, spherical tessellation of the molecular surface, numerical integration of the atomic volumes and surfaces, triangular tessellation of the molecular surface, and cubic lattice approach to the molecular volume. Accurate measures of the molecular volume and surface area have been performed with the pseudorandom Monte Carlo (MCVS) and uniform Monte Carlo (UMCVS) methods. These calculations serve as a reference for the rest of the meth…
Preference for Fractal-Scaling Properties Across Synthetic Noise Images and Artworks
2018
A large number of studies support the notion that synthetic images within a certain intermediate fractal-scaling range possess an intrinsic esthetic value. Interestingly, the fractal-scaling properties that define this intermediate range have also been found to characterize a vast collection of representational, abstract, and graphic art. While some have argued that these statistic properties only serve to maximize the visibility of the artworks’ spatial structure, others argue that they are intrinsically tied to the artworks’ esthetic appeal. In this study, we bring together these two threads of research and make a direct comparison between visual preference for varying fractal-scaling cha…
On the fractal morphology of urban borders: Belgian cities versus toy cities
2013
International audience
The fractal morphology of settlements and transportation networks
1993
International audience
Using fractal dimensions for characterizing intra-urban diversity : the example of Brussels
2003
International audience; The objective of this paper is to compare fractal-based parameters calculated by different fractal methods for urban built-up areas and to link the observed spatial variations to variables commonly used in urban geography, urban economics, or land-use planning. Computations are performed on Brussels, Belgium. Two fractal methods (correlation and dilation) are systematically applied for evaluating the fractal dimension of built-up surfaces; correlation is used to evaluate the fractal dimension of the borders (lines). Analyses show that while fractal dimension is ideal for distinguishing the morphology of Brussels, each estimation technique leads to slightly different …