Nonlinear dynamics underpin a vast array of physical phenomena ranging from interfacial motion to jamming transitions. In many cases, insight into the nonlinear behavior can be gleaned through exploration of higher order harmonics. Here, a method using band excitation scanning probe microscopy (SPM) to investigate higher order harmonics of the electromechanical response, with nanometer scale sp...

In music, harmony refers to a pleasant combination of sounds. In mathematics, a harmonic function is a sine function obtained by projecting a circular motion on a diameter, and harmonic analysis is the theory of the development of periodic functions into harmonic components, or the theory of similar developments. The occurrence of the same word in musical and mathematical contexts is neither a ...

We study the effects of the confining conditions on the occurrence of stochastic resonance (SR) in continuous bistable systems. We model such systems by means of double-well potentials that diverge like |x| for |x| → ∞. For super-harmonic (hard) potentials with q > 2 the SR peak sharpens with increasing q, whereas for sub-harmonic (soft) potentials, q < 2, it gets suppressed. PACS. 05.40.-a Flu...

Several techniques have been developed in an effort to estimate mechanical properties of tissues. These techniques typically estimate static or harmonic motion resulting from an externally or internally applied mechanical stimulus. In this paper, we discuss the advantages of utilizing a new technique that performs radiofrequency (RF) signal tracking to estimate the localized oscillatory motion ...

Let A be the set of all points of the plane C, visited by 2-dimensional Brownian motion before time 1. With probability 1, all points of A are “twist points” except a set of harmonic measure zero. “Twist points” may be continuously approached in C \ A only along a special spiral. Although negligible in the sense of harmonic measure, various classes of “cone points” are dense in A, with probabil...

The action for the D = 10 type II Dirichlet super–p–branes, which has been obtained recently, is reconstructed in a more geometrical form involving Lorentz harmonic variables. This new (Lorentz harmonic) formulation possesses κ–symmetry in an irreducible form and is used as a basis for applying a generalized action principle that provides the superfield equations of motion and clarifies the geo...

OBJECTIVE To examine the influence of second harmonic imaging during dobutamine echocardiography on regional endocardial visibility, interobserver agreement in the interpretation of wall motion abnormalities, and diagnostic accuracy in patients with reduced image quality. DESIGN Blinded comparison. SETTING Tertiary care centre. PATIENTS 103 consecutive patients with suspected coronary art...

the harmonic index h(g) , of a graph g is defined as the sum of weights 2/(deg(u)+deg(v)) of all edges in e(g), where deg (u) denotes the degree of a vertex u in v(g). in this paper we define the harmonic polynomial of g. we present explicit formula for the values of harmonic polynomial for several families of specific graphs and we find the lower and upper bound for harmonic index in caterpill...

this paper presents a new control methodology for active power filters that provide an adaptive online harmonic estimation with partial and selective harmonic reduction schemes, which has been implemented within an integrated controller. the proposed approach is to provide partial and selective reduction of those individual harmonics which exceed the recommended levels as set by regulatory bodi...

Typically, MR-elastography (MRE) encodes the propagation of monochromatic acoustic waves in the MR-phase images via sinusoidal gradients characterized by a detection frequency equal to the frequency of the mechanical vibration. Therefore, the echo time of a conventional MRE sequence is typically longer than the vibration period which is critical for heart tissue exhibiting a short T(2). Thus, f...