Fractional bioheat equation

In this work we develop a new mathematical model for the Pennes’ bioheat equation assuming a fractional time derivative of single order. A numerical method for the solu- tion of such equations is proposed, and, the suitability of the new model for modelling real physical problems is studied and discussed

Global vs. local nonlinear optimization techniques for human-like movement of an anthropomorphic robot

In this paper a comparison between using global and local optimization techniques for solving the problem of generating human-like arm and hand movements for an anthropomorphic dual arm robot is made. Although the objective function involved in each optimization problem is convex, there is no evidence that the admissible regions of these problems are convex sets. For the sequence of movements for which the numerical tests were done there were no significant differences between the optimal solutions obtained using the global and the local techniques. This suggests that the optimal solution obtained using the local solver is indeed a global solution.

Nonlinear optimization for human-like synchronous movements of a dual arm-hand robotic system

In previous work we have presented a model capable of generating human-like movements for a dual arm-hand robot involved in human-robot cooperative tasks. However, the focus was on the generation of reach-to-grasp and reach-to-regrasp bimanual movements and no synchrony in timing was taken into account. In this paper we extend the previous model in order to accomplish bimanual manipulation tasks by synchronously moving both arms and hands of an anthropomorphic robotic system. Specifically, the new extended model has been designed for two different tasks with different degrees of difficulty. Numerical results were obtained by the implementation of the IPOPT solver embedded in our MATLAB simulator.

Towards human-like bimanual movements in anthropomorphic robots: a nonlinear optimization approach

Previously we have presented a model for generating human-like arm and hand movements on an unimanual anthropomorphic robot involved in human-robot collaboration tasks. The present paper aims to extend our model in order to address the generation of human-like bimanual movement sequences which are challenged by scenarios cluttered with obstacles. Movement planning involves large scale nonlinear constrained optimization problems which are solved using the IPOPT solver. Simulation studies show that the model generates feasible and realistic hand trajectories for action sequences involving the two hands. The computational costs involved in the planning allow for real-time human robot-interaction. A qualitative analysis reveals that the movements of the robot exhibit basic characteristics of human movements.

Testing Nelder-Mead based repulsion algorithms for multiple roots of nonlinear systems via a two-level factorial design of experiments

This paper addresses the challenging task of computing multiple roots of a system of nonlinear equations. A repulsion algorithm that invokes the Nelder-Mead (N-M) local search method and uses a penalty-type merit function based on the error function, known as 'erf', is presented. In the N-M algorithm context, different strategies are proposed to enhance the quality of the solutions and improve the overall efficiency. The main goal of this paper is to use a two-level factorial design of experiments to analyze the statistical significance of the observed differences in selected performance criteria produced when testing different strategies in the N-M based repulsion algorithm. The main goal of this paper is to use a two-level factorial design of experiments to analyze the statistical significance of the observed differences in selected performance criteria produced when testing different strategies in the N-M based repulsion algorithm.

Nonlinear behavior of gelatin networks reveals a hierarchical structure

We investigate the strain hardening behavior of various gelatin networks-namely physical gelatin gel, chemically cross-linked gelatin gel, and a hybrid gel made of a combination of the former two-under large shear deformations using the pre-stress, strain ramp, and large amplitude oscillations shear protocols. Further, the internal structures of physical gelatin gels and chemically cross-linked gelatin gels were characterized by small angle neutron scattering (SANS) to enable their internal structures to be correlated with their nonlinear rheology. The Kratky plots of SANS data demonstrate the presence of small cross-linked aggregates within the chemically cross-linked network whereas, in the physical gelatin gels, a relatively homogeneous structure is observed. Through model fitting to the scattering data, we were able to obtain structural parameters, such as the correlation length (ξ), the cross-sectional polymer chain radius (Rc) and the fractal dimension (df) of the gel networks. The fractal dimension df obtained from the SANS data of the physical and chemically cross-linked gels is 1.31 and 1.53, respectively. These values are in excellent agreement with the ones obtained from a generalized nonlinear elastic theory that has been used to fit the stress-strain curves. The chemical cross-linking that generates coils and aggregates hinders the free stretching of the triple helix bundles in the physical gels.

Factores Críticos del Desarrollo Local y Regional Integrado zona serrana y Norte de la Provincia de Córdoba-. Validación causal estadística de Modelos de Ecuaciones Estructurales. Identificación de problemas normativos de las OSC.Critical Factors of Local and Regional Development in north of the Province of Córdoba. Causal validation with Structural Equation Modeling. Legal regulations of civil society.

En la investigación anterior -en la zona pampeana de la Provincia de Córdoba- se demostró teórica y empíricamente, que el desarrollo de la Sociedad Civil muchas veces libradas a su suerte y con limitaciones legales apoyan decididamente el desarrollo local, sin embargo han logrado solo parcialmente sus objetivos, por lo que es necesario comenzar un camino de fortalecimiento en los nuevos roles que deben asumir. Los gobiernos locales, a la vez, intentan trabajosamente con contados éxitos detener el procesos de descapitalización social -financiera y humana- de sus comunidades locales y regionales, peregrinando con escaso éxito a los centros concentrados del poder político y económico, para procurar los recursos financieros y humanos necesarios que no alcanzan a reponer los que se fugan desde hace décadas de sus localidades. Las empresas, con ciclos recurrentes de crecimiento y decrecimiento vinculados a los mercados en que colocan sus productos, también se debaten en la búsqueda de los escasos recursos, financieros y humanos, que les permitan consolidar un desarrollo a mediano y largo plazo. El desarrollo alcanzado en Sistemas de información, instrumentos de relevamiento, análisis y elaboración de propuestas para el Desarrollo Local, nos permite avanzar en: 1. La confirmación empírica de las hipótesis iniciales - factores exógenos y endógenos - en la zona Norte y Serrana de la provincia 2. La validación científica -mediante el Análisis de ecuaciones estructurales. de tales supuestos, para el conjunto de las poblaciones analizadas en ambas etapas. 3. La identificación de los problemas normativos que afectan el desarrollo de las Organizaciones de la Sociedad Civil (OSC). METODOLOGÍA Respecto la validación empírica en la zona norte y serrana 1. Selección de las 4 localidades a relevar de acuerdo a las categorías definidas 2. Elaboración de acuerdos con autoridades e instituciones locales. 3. Relevamiento cualitativo con líderes locales y fuentes de datos secundarias. 4. Adaptación de instrumentos de relevamiento a las realidades locales y estudios previos 5. Relevamiento cuantitativo de campo, capacitación de encuestadores y supervisores. 6. Procesamiento y elaboración de informes finales locales. Respecto de la construcción de modelos de desarrollo 1. Desarrollar las dimensiones especificas y las variables (items) de cada factor crítico. 2. Revisar el instrumento con expertos de cada una de las dimensiones. 3. Validar a nivel exploratorio por medio de un Análisis de Componentes Principales 4. Someter a los expertos la evaluación de una serie de localidades que representan cada uno. Respecto de la identificación de las normas legales que afectan a la Sociedad Civil 1.Relevamiento documental de normas 2. Relevamiento con líderes de instituciones de la Sociedad Civil 3. Análisis de las normas vigentes 4. Elaboración de Informes Finales y Transferencia a líderes e instituciones

Nonlinear analysis and control of PEM fuel cells

Magdeburg, Univ., Fak. für Elektrotechnik und Informationstechnik, Diss., 2010

Approximations of the Fisher information for the construction of efficient experimental designs in nonlinear mixed effects models

Magdeburg, Univ., Fak. für Mathematik, Diss., 2012

equivalence of almost bent and almost perfect nonlinear functions and their generalizations

Vectorial Boolean function, almost bent, almost perfect nonlinear, affine equivalence, CCZ-equivalence

An Equation for the Prediction of Oxygen Consumption in a Brazilian Population

Background: The equations predicting maximal oxygen uptake (VO2max or peak) presently in use in cardiopulmonary exercise testing (CPET) softwares in Brazil have not been adequately validated. These equations are very important for the diagnostic capacity of this method. Objective: Build and validate a Brazilian Equation (BE) for prediction of VO2peak in comparison to the equation cited by Jones (JE) and the Wasserman algorithm (WA). Methods: Treadmill evaluation was performed on 3119 individuals with CPET (breath by breath). The construction group (CG) of the equation consisted of 2495 healthy participants. The other 624 individuals were allocated to the external validation group (EVG). At the BE (derived from a multivariate regression model), age, gender, body mass index (BMI) and physical activity level were considered. The same equation was also tested in the EVG. Dispersion graphs and Bland-Altman analyses were built. Results: In the CG, the mean age was 42.6 years, 51.5% were male, the average BMI was 27.2, and the physical activity distribution level was: 51.3% sedentary, 44.4% active and 4.3% athletes. An optimal correlation between the BE and the CPET measured VO2peak was observed (0.807). On the other hand, difference came up between the average VO2peak expected by the JE and WA and the CPET measured VO2peak, as well as the one gotten from the BE (p = 0.001). Conclusion: BE presents VO2peak values close to those directly measured by CPET, while Jones and Wasserman differ significantly from the real VO2peak.

Theory and application of nonlinear wave propagation phenomena in combined reaction/separation processes

Reaction separation processes, reactive distillation, chromatographic reactor, equilibrium theory, nonlinear waves, process control, observer design, asymptoticaly exact input/output-linearization

Sparse nonlinear discriminants

Kernel-Functions, Machine Learning, Least Squares, Speech Recognition, Classification, Regression

Analysis of the potential of nonlinear solvent gradients in preparative chromatography

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2010

Nonlinear frequency response analysis for the diagnosis of polymer electrolyte membrane fuel cells

Magdeburg, Univ., Fak. für Verfahrens- und Systemtechnik, Diss., 2012