Fractal assessment of capacitating spermatozoa in video sequences

En este trabajo se proponen metodologías y herramientas robustas para en análisis no supervisado de la fertilidad de muestras de semen a partir de secuencias de video. El método consiste en determinar la proporción de espermatozoides hiperactivados a partir de un análisis de sus trayectorias respectivas utilizando descriptores fractales. Para ello se desarrollo un algoritmo para el seguimiento automático de las trayectorias de los espermatozoides en la muestra. Se propone la aplicación de dos descriptores fractales para el análisis de estas trayectorias: la dimensión box counting, y un nuevo método de regresión, al que denominamos dimensión fractal de la dependencia temporal, que establece una relación entre la longitud de la trayectoria respecto de la resolución temporal de la secuencia de video.This work is aimed to develop tools for the robust, unsupervised assessment of fertility of sperm samples using video sequences, by means of an estimation of the proportion of hyperactivated spermatozoa in the sample. For this purpose, we developed a software tool for trajectory tracking in standard video takes of sperm samples. We discuss the steps of the tracking procedure and present some results. Then, we study two fractal characterizations for spermatozoa trajectories, the well known box counting dimension, and a new regression, which we call time dependency fractal dimension, which establishes a relationship between the length of the trajectory and the frame rate of the tracking.Workshop de Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI

Evidence of diffusive fractal aggregation of TiO2 nanoparticles by femtosecond laser ablation at ambient conditions

The specific mechanisms which leads to the formation of fractal nanostructures by pulsed laser deposition remain elusive despite intense research efforts, motivated mainly by the technological interest in obtaining tailored nanostructures with simple and scalable production methods. Here we focus on fractal nanostructures of titanium dioxide, $TiO_2$, a strategic material for many applications, obtained by femtosecond laser ablation at ambient conditions. We model the fractal formation through extensive Monte Carlo simulations based on a set of minimal assumptions: irreversible sticking and size independent diffusion. Our model is able to reproduce the fractal dimensions and the area distributions of the nanostructures obtained in the experiments for different densities of the ablated material. The comparison of theory and experiment show that such fractal aggregates are formed after landing of the ablated material on the substrate surface by a diffusive mechanism. Finally we discuss the role of the thermal conductivity of the substrate and the laser fluence on the properties of the fractal nanostructures. Our results represent an advancement towards controlling the production of fractal nanostructures by pulsed laser deposition.Comment: 21 page

Fractal assessment of capacitating spermatozoa in video sequences

En este trabajo se proponen metodologías y herramientas robustas para en análisis no supervisado de la fertilidad de muestras de semen a partir de secuencias de video. El método consiste en determinar la proporción de espermatozoides hiperactivados a partir de un análisis de sus trayectorias respectivas utilizando descriptores fractales. Para ello se desarrollo un algoritmo para el seguimiento automático de las trayectorias de los espermatozoides en la muestra. Se propone la aplicación de dos descriptores fractales para el análisis de estas trayectorias: la dimensión box counting, y un nuevo método de regresión, al que denominamos dimensión fractal de la dependencia temporal, que establece una relación entre la longitud de la trayectoria respecto de la resolución temporal de la secuencia de video.This work is aimed to develop tools for the robust, unsupervised assessment of fertility of sperm samples using video sequences, by means of an estimation of the proportion of hyperactivated spermatozoa in the sample. For this purpose, we developed a software tool for trajectory tracking in standard video takes of sperm samples. We discuss the steps of the tracking procedure and present some results. Then, we study two fractal characterizations for spermatozoa trajectories, the well known box counting dimension, and a new regression, which we call time dependency fractal dimension, which establishes a relationship between the length of the trajectory and the frame rate of the tracking.Workshop de Computación Gráfica, Imágenes y Visualización (WCGIV)Red de Universidades con Carreras en Informática (RedUNCI

Application of Fractal Analysis While Designing of Family of Spacecraft for Needs of Space Industry

This paper deals with methods of fractal analysis, which allow creation of a line of spacecraft from different classes as addition to classical methods for needs of space industry. It is shown that the fractal analysis that widens opportunities of classical methods can become a base for solution of the modern problems of space technologies. Besides, the results of fractal analysis in this chapter are practically valued recommendations for designing of the line, algorithms of control over equipment to measure microaccelerations and of majority control over measuring data. It clearly demonstrates potential and applicability of methods of fractal analysis in practice

Fractal assessment analysis of China's air-HSR network integration

High-speed rail (HSR) has emerged as a significant mode for intercity transport in several countries, particularly China, setting an environment that may promote integration between air and HSR networks. To better measure the current level of integration of China's air-HSR intermodal network and identify implementation issues, this paper establishes a novel assessment framework that considers three primary areas: service capability, network connectivity and transfer potential. The framework is based on a comprehensive literature review of network measurement and assessment methodologies. Then, fractal theory is used to establish an assessment model that associates the fractal dimension to the level of intermodal integration, which can serve as an important complement to traditional weighting methods. The model and framework are applied to the 10 cities in China with the potential for air-HSR integration. The results show that international hub airports, together with their closest HSR station, do not necessarily perform at a higher integration level than regional hubs. The paper also proposes policy and practical recommendations to enhance air-HSR network integration levels from service supply, network coordination and transfer design perspectives

MEASURING ARCHITECTURE: QUESTIONING THE APPLICATION OF NON-LINEAR MATHEMATICS IN THE ANALYSIS OF HISTORIC BUILDINGS

In the late 1970s the mathematician Benoit Mandelbrot argued that natural systems frequently possess characteristic geometric or visual complexity over multiple scales of observation. This proposition suggests that systems which have evolved over time may exhibit certain local visual qualities that also possess deep structural resonance. In mathematics this observation lead to the formulation of fractal geometry and was central to the rise of the sciences of non-linearity and complexity. During the 1990s a number of researchers developed this concept in relation to architectural design and urban planning and more recently architectural scholars have suggested that such approaches might be used in the analysis of historic buildings. At the heart of this approach, in both its theoretical and computational forms, is a set of processes initially developed by Carl Bovill for analyzing buildings. However, the assumptions implicit in Bovill’s method (itself an extrapolation of an approach proposed by Mandelbrot) have never been adequately questioned. The present paper returns to the origins of Bovill’s analytical method to reconsider his original investigation of key works of 20th century architecture and the way in which Bovill frames images for analysis. The aim of this analysis is to question several assumptions present in Bovill’s method about the way in which computer technology is used to understand the visual qualities of historic buildings

New opportunities of computer assessment of knowledge based on fractal modeling

[EN] In this article the urgent problem of control systems modeling of professional competences and mathematical knowledge assessment of students is discussed. Pedagogical expediency in management of students` cognitive activity by using of new informational technologies instruments in monitoring and assessment of knowledge is proved. The possibility of fractal methods application in perfecting of the system of computer monitoring of mathematical knowledge of students as a part of the adaptive training systems is considered and realized. The design of the technology of computer monitoring of students` knowledge on the basis of fractal methods includes the following stages: development of cross-disciplinary fractal and organized base of key mathematical concepts; the creation of the expansible bank of educational and cognitive and research tasks, which is coordinated with fractal structure of the conceptual framework; the development of the program module, which is focused on individual estimation of quality of students` educational cognitive activity in two characteristics — depth of knowledge based on the Hurst exponent and the size of synergetic effect of educational cognitive activity. The software realization of technology of the computerized control of training in mathematical disciplines quality as a part of the adaptive training system is enabled in the programming language C#. The experience of implementation and operation of the controlling systems realized in the adaptive training systems based on the fractal model operation showed reliability of their work and allowed to increase the quality of educational process management and its effectiveness in general. Using of fractal techniques in computer assessment of mathematical knowledge of students makes it possible to increase the accuracy and speed of evaluation of the students` knowledge.Work was carried out with the support of RNF, the project № 16-18-10304.Dvoryatkina, S.; Smirnov, E.; Lopukhin, A. (2017). New opportunities of computer assessment of knowledge based on fractal modeling. En Proceedings of the 3rd International Conference on Higher Education Advances. Editorial Universitat Politècnica de València. 854-864. https://doi.org/10.4995/HEAD17.2017.544585486

Pavement Friction Estimation Based on the Heinrich/Klüppel Model

Tire-pavement interaction is a critical analysis for conducting friction measurements and safety evaluation on highway pavements. Substantial field studies and research efforts indicate pavement friction can be predicted with tire/texture-related models (e.g. empirical or analytical models); however, developing a reliable friction prediction model for network level pavement survey still remains a challenge. In this paper Heinrich/Klüppel friction prediction model is utilized to estimate friction on Asphalt Concrete (AC) pavements. High resolution texture data are acquired from Ames high-speed profiling system, and subsequently pavement friction data are collected on the same sections with Dynatest 6875 Highway friction tester. Findings from the study indicate a good agreement between the predicted and measured Friction Numbers (FNs). It is concluded that Heinrich/Klüppel friction theory can be used as a promising surrogate for pavement safety evaluation. This study would be beneficial for complementing the existing safety evaluation methods used in highway safety program