Differential equation Research Papers - Academia.edu (original) (raw)

RIASSUNTO L'eccessivo sfruttamento degli acquiferi carsici del Salento ha prodotto, da tempo, l'insorgere del fenomeno della salsificazione delle acque di falda. L'uso di acque salmastre per l'irriga-zione delle... more

RIASSUNTO L'eccessivo sfruttamento degli acquiferi carsici del Salento ha prodotto, da tempo, l'insorgere del fenomeno della salsificazione delle acque di falda. L'uso di acque salmastre per l'irriga-zione delle colture può determinare, nel lungo termine, la perdita del ...

A method is proposed for deriving dynamical equations for systems with both rigid and flexible components. During the derivation, each flexible component of the system is represented by a ``surrogate element'''' which... more

A method is proposed for deriving dynamical equations for systems with both rigid and flexible components. During the derivation, each flexible component of the system is represented by a ``surrogate element'''' which captures the response characteristics of that component and is easy to mathematically manipulate. The derivation proceeds essentially as if each surrogate element were a rigid body. Application of an extended form of Lagrange''s equation yields a set of simultaneous differential equations which can then be transformed to be the exact, partial differential equations for the original flexible system. This method''s use facilitates equation generation either by an analyst or through application of software-based symbolic manipulation.

There are two common types of solution methods for solving simple integrals: using integration constants or using limits of integration. We use the resources framework to model student solution methods. Preliminary results indicate both... more

There are two common types of solution methods for solving simple integrals: using integration constants or using limits of integration. We use the resources framework to model student solution methods. Preliminary results indicate both problematic and meaningful intersections of physical meaning and mathematical formalism when solving linked integrals.

We introduce a differential equation for star formation in galaxies that incorporates negative feedback with a delay. When the feedback is instantaneous, solutions approach a self-limiting equilibrium state. When there is a delay, even... more

We introduce a differential equation for star formation in galaxies that incorporates negative feedback with a delay. When the feedback is instantaneous, solutions approach a self-limiting equilibrium state. When there is a delay, even though the feedback is negative, the solutions can exhibit cyclic and episodic solutions. We find that periodic or episodic star formation only occurs when two conditions

Solution algebras can be associated to any connection over a smooth affine variety. It turns out that he spectrum of a solution algebra is an algebraic fiber space over the base variety, with quasi-homogeneous fiber. We discuss the... more

Solution algebras can be associated to any connection over a smooth affine variety. It turns out that he spectrum of a solution algebra is an algebraic fiber space over the base variety, with quasi-homogeneous fiber. We discuss the relevance of this result to Transcendental Number Theory.

The use of dynamical system techniques, optimization methods and statistical algorithms to estimate the characteristics of brain electrical activity are explored. A system approach for characterizing EEG (electroencephalogram) signals,... more

The use of dynamical system techniques, optimization methods and statistical algorithms to estimate the characteristics of brain electrical activity are explored. A system approach for characterizing EEG (electroencephalogram) signals, based on nonlinear estimation of dynamical characteristics and modeling the evolution of dynamical processes over time is applied. The dynamical characteristics can be used to better visualize the “state vector” of epileptic EEG signals and for the purpose of pattern recognition. An optimization method for reconstructing parameter spaces of dynamical systems is applied to systems with one or more hidden variables, and can be used to reconstruct maps or differential equations of the brain dynamics. The methods are illustrated by using numerically generated data and EEG data from epileptic patients.

The paper presents a dynamic model considering the human upper limb as a mechanic system with 6 degrees of freedom where the segments are moved by their own weight forces. The bones were modeled in Solid Works, the model of the upper limb... more

The paper presents a dynamic model considering the human upper limb as a mechanic system with 6 degrees of freedom where the segments are moved by their own weight forces. The bones were modeled in Solid Works, the model of the upper limb obtained being very close as form to the real one. Based on this model, the calculus of

sail:lab, as an interdisciplinary project of mathematicians and sport scientists, uses the physical description of sailing to develop an E-Learning component, which can be integrated in Blended Learning scenarios in both departments. By... more

sail:lab, as an interdisciplinary project of mathematicians and sport scientists, uses the physical description of sailing to develop an E-Learning component, which can be integrated in Blended Learning scenarios in both departments. By calculating the forces and moments due to wind and current which take effect at sail, hull, rudder, and fin, the movement of a jolly-boat is visualized. An