Data perturbation is a data security technique that adds 'noise' to databases to allow individual record confidentiality. This technique allows users to ascertain key summary information about the data while preventing a security breach. Four bias types have been proposed which assess the effectiveness of such a technique. However, these biases deal with simple aggregate concepts (averages, etc...

Time-dependent perturbation theory is formulated in a systematic way. The focus is shifted from the wavefunction to the unitary transformation that evolves the wavefunction from one slice of time to another. Perturbation theory is formulated in terms of a systematic iterative expansion of the unitary transformation in terms of the perturbing hamiltonian, expressed in the interaction representat...

the current paper focuses on some analytical techniques to solve the non-linear duffing oscillator with large nonlinearity. four different methods have been applied for solution of the equation of motion; the variational iteration method, he’s parameter expanding method, parameterized perturbation method, and the homotopy perturbation method. the results reveal that approximation obtained by th...

In this paper the stability of the Korteweg-de Vries (KdV) equation is investigated. It is shown analytically and numerically that small perturbations of solutions of the KdV-equation introduce effects of dispersion, hence the perturbation propagates with a different velocity then the unperturbed solution. This effect is investigated analytically by formulating a differential equation for pertu...

Spindle speed variation has been shown to be an effective method for chatter control. In this paper, a single-degree-of-freedom regenerative type chatter equation is treated using perturbation methods. Rather than using the time coordinate, the angle of revolution is taken as the independent coordinate for maintaining a constant delay in the equations. The spindle speed is taken to be harmonica...

The motivation of Privacy Preserving Data Mining (PPDM) is to obtain valid data mining results without access to the original sensitive information. The different privacy preserving technique on Perturbation based PPDM approach introduces random perturbation to individual values to preserve privacy before data are published. This proposed work is based on perturbation based privacy preserving d...

OBJECTIVE The operatic singing technique is frequently used in classical music. Several acoustical parameters of this specific technique have been studied but how these parameters combine remains unclear. This study aims to further characterize the Western operatic singing technique by observing the effects of melody and technique on acoustical and musical parameters of the singing voice. MET...

During inflation quantum effects from massless, minimally coupled scalars and gravitons can be strengthened so much that perturbation theory breaks down. To follow the subsequent evolution one must employ a nonperturbative resummation. Starobinskĭı has developed such a technique for simple scalar theories. I discuss recent progress in applying this technique to more complicated models.

in this paper, an intelligent control strategy based on combination of the “flatness based control technique” and the “perturbation and observation (p&o;) mppt algorithm” is developed and investigated to control a hybrid electric energy source (heps). this ehps is composed of a fuel cell system (fc) and a solar panel (sp), as the main source and a supercapacitor bank (sc), as the auxiliary sour...

The monotone iterative technique is applied to a class of nonlinear first order integro-differential equations in Banach spaces. First a linear system with a “small” nonlinear perturbation is solved using Banach’s Contraction Principle and the technique of Green’s function. Then based upon a comparison result, the existence of minimal and maximal solutions is proved.