This mostly expository paper shows how weak convergence methods provide simple, elegant proofs of (i) the stabilization of an inverted pendulum under fast vertical oscillations, (ii) the existence of particle traps induced by rapidly varying electric fields and (iii) the adiabatic invariance of ∫ Γ p dx for slowing varying planar Hamiltonian dynamics. Under an appropriate, but very restrictive,...

This work seeks to improve dynamic accuracy of viewpoint tracking for Augmented Reality. Using an inverted pendulum to model the head, dynamic orientation sensing in a vertical plane is achieved using only a dual axis accelerometer. A unique solution is presented as conventional approaches to solve the model equations fail to produce stable results due to ill conditioning. Accuracy is limited b...

The effect of correlated data errors on matched-field geoacoustic inversion for vertical array data is examined. The correlated errors stem from the inability to model the inhomogeneities in the environment resulting in an additional error term beyond ambient noise. Simulated data with these correlated errors are generated and then inverted with or without using the proper covariance matrix. Re...

We set out in this study to analyze the impact of vertical integration on the innovative performance of a firm and to explore the interaction between vertical integration and different modes of external knowledge sourcing. Our empirical results reveal an initial increase in the effect of vertical integration on innovative performance up to a certain level of integration, although this is subseq...

In this paper, we present Fuzzy Neural Network (FNN) structure and the back-propagation process, which tunes the weighting factors of FNN such that its output can follow the desired signal. Then they are applied to design an FNN controller to let the pole of an inverted pendulum be as vertical as possible. Simulation results show that the proposed approach produces better responses than the fuz...

The phenomenon of dynamic stabilization of the inverted pendulum whose pivot is forced to oscillate with a high frequency in vertical direction is revisited. A simple physically meaningful explanation of the phenomenon is presented, followed by the derivation of an approximate quantitative criterion of stability. A computer program simulating the physical system is developed, which aids the ana...

A human walker vaults up and over each stance limb like an inverted pendulum. This similarity suggests that the vertical motion of a walker's center of mass reduces metabolic cost by providing a mechanism for pendulum-like mechanical energy exchange. Alternatively, some researchers have hypothesized that minimizing vertical movements of the center of mass during walking minimizes the metabolic ...

Stephenson (1908a, b) showed that it is possible to stabilize a single rigid pendulum in its inverted, or upside-down, equilibrium position by subjecting the pivot to small vertical oscillations of suitably high frequency. He confirmed his theoretical predictions by a practical demonstration of the phenomenon. While this is a well-known curiosity of classical mechanics it does not seem to be ge...

We examine two prevailing, yet surprisingly contradictory, theories of human walking. The six determinants of gait are kinematic features of gait proposed to minimize the energetic cost of locomotion by reducing the vertical displacement of the body center of mass (COM). The inverted pendulum analogy proposes that it is beneficial for the stance leg to behave like a pendulum, prescribing a more...

In a previous article, White et al 1 concluded that the horizontal breast reduction technique yields superior breast scars. The authors claimed that theirs was the first prospective study to evaluate breast reduction scars. However, other published studies, both prospective and retrospective , have compared vertical and inverted-T scars, finding that patients prefer a vertical scar. One study, ...