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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Fractal Analysis of the Gravitational Waves as a Unique Ultra-Wideband Process
摘要： The results of the fractal analysis of the gravitational waves generated by a binary black hole merger and registered first on September 14, 2015 at 09:50:45 UTC by two detectors of the Laser Interferometer Gravitational-Wave Observatory (United States) are considered. Being a unique ultra-wideband natural process, the gravitational waves were appeared to be fractal one too. Their fractal structure is described by the set of numerical characteristics based on estimation of different fractal dimensions. The results obtained are widely discussed.
关键词： ultra-wideband process,gravitational wave,fractal analysis
更新于2025-09-23 15:22:29
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Topographic characterization of zirconia-based ceramics by atomic force microscopy: A case study on different laser irradiations
摘要： The purpose of the present study is to evaluate the effects of different laser irradiations including Nd-YAG (neodymium-doped yttrium aluminum garnet laser; Nd:Y3Al5O12), Er-YAG (erbium-doped yttrium aluminum garnet laser, erbium YAG laser), and Carbon dioxide (CO2) infrared lasers on surface topography of zirconia-based ceramics samples which were prepared by copy milling technique. Three dimensional (3D) atomic force microscopy (AFM) images were applied to investigate surface properties by extracting information via MountainsMap? Premium software which divides the surface into peaks and pits and through watershed segmentation algorithm. This method made motif analysis possible by detecting surface dimensions, curvature, volume, perimeters, shape, structure, etc.
关键词： Atomic force microscopy,Laser irradiation,Stereometric analysis,Fractal analysis
更新于2025-09-23 15:21:01
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[IEEE 2018 IEEE Workshop on Complexity in Engineering (COMPENG) - Florence, Italy (2018.10.10-2018.10.12)] 2018 IEEE Workshop on Complexity in Engineering (COMPENG) - Fractal-Radiomics as Complexity Analysis of CT and MRI Cancer Images
摘要： Cancer is the second leading cause of death globally. Early diagnosis can allow intervention to reduce mortality but due to cancer complex structure and spatial heterogeneity among different tumors and within each lesion, it is difficult to differentiate it from healthy tissue using conventional imaging techniques. Quantification of its complexity can be a prognostic tool for fighting this disease. In recent years, clinical imaging allows this quantification thanks to Radiomics, which extracts features from images. In this study, Fractal Dimension (FD) and Lacunarity (L) in computed tomography (CT) and magnetic resonance (MR) images for different kinds of cancer were examined using box counting method. Our aim is to highlight the potentiality of features based on fractal analysis, in order to obtain new indicators able to detect tumor spatial complexity and heterogeneity. The results indicated that both FD and L show problems linked to the lack of connection between complexity estimated with Radiomics and the underlying biological model.
关键词： cancer heterogeneity,lacunarity,complexity,fractal analysis,cancer,Radiomics
更新于2025-09-23 15:21:01
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Charged Particle Oscillations in Transient Plasmas Generated by Nanosecond Laser Ablation on Mg Target
摘要： The dynamics of a transient plasma generated by laser ablation on a Mg target was investigated by means of the Langmuir probe method and fractal analysis. The empirical data showcased the presence of an oscillatory behavior at short expansion times (<1 μs) characterized by two oscillation frequencies and a classical behavior for longer evolution times. Space- and time-resolved analysis was implemented in order to determine main plasma parameters like the electron temperature, plasma potential, or charged particle density. In the motion fractal paradigm, a theoretical model was built for the description of laser-produced plasma dynamics expressed through fractal-type equations. The calibration of such dynamics was performed through a fractal-type tunneling effect for physical systems with spontaneous symmetry breaking. This allows both the self-structuring of laser-produced plasma in two structures based on its separation on different oscillation modes and the determination of some characteristics involved in the self-structuring process. The mutual conditionings between the two structures are given as joint invariant functions on the action of two isomorph groups of SL(2R) type through the Stoler-type transformation, explicitly given through amplitude self-modulation.
关键词： laser ablation,joint invariant functions,Langmuir probe,fractal analysis,charged particle oscillations,Lie groups
更新于2025-09-19 17:13:59
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Lorenz Type Behaviors in the Dynamics of Laser Produced Plasma
摘要： An innovative theoretical model is developed on the backbone of a classical Lorenz system. A mathematical representation of a differential Lorenz system is transposed into a fractal space and reduced to an integral form. In such a conjecture, the Lorenz variables will operate simultaneously on two manifolds, generating two transformation groups, one corresponding to the space coordinates transformation and another one to the scale resolution transformation. Since these groups are isomorphs various types isometries become functional. The Lorenz system was further adapted to describe the dynamics of ejected particles as a result of laser matter interaction in a fractal paradigm. The simulations were focused on the dynamics of charged particles, and showcase the presence of current oscillations, a heterogenous velocity distribution and multi-structuring at different interaction scales. The theoretical predictions were compared with the experimental data acquired with noninvasive diagnostic techniques. The experimental data confirm the multi-structure scenario and the oscillatory behavior predicted by the mathematical model.
关键词： plasma structuring,fractal analysis,laser produced plasmas,ionic oscillations,Lorenz system
更新于2025-09-16 10:30:52
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Particle distribution in transient plasmas generated by ns-laser ablation on ternary metallic alloys
摘要： Understanding the fundamental mechanisms behind industrial laser-based technologies represents one the cornerstones of the development and tailoring of new materials. With the thin-film deposition using laser ablation being one of the most important techniques for obtaining complex materials with controllable stoichiometry, there is a high request for both experimental and theoretical studies towards understanding the behavior of multi-component alloys under high-power laser irradiation. Here we investigate the laser ablation process on two ternary metallic alloys (Cu–Mn–Al and Fe–Mn–Si) by means of space-and time-resolved optical emission spectroscopy and fast camera imaging with the focus being on the spatial distribution of each composing element. Information regarding the kinetic and thermal energy of the ejected particles is extracted and discussed in the framework of an inner structuring of the laser-produced plasmas based on a mass and energy distribution. The hypothesis is then verified by implementing a fractal analysis to the multi-component plasmas. The theoretical fractal approach offers results in good agreement with the experimental data gives important insight in the inner dynamics of complex laser-produced plasmas.
关键词： Ternary metallic alloys,Optical emission spectroscopy,Fractal analysis,Fast camera imaging,Laser ablation
更新于2025-09-12 10:27:22