A simple qualitative physical explanation is suggested for the phenomenon of dynamic stabilization of the inverted rigid planar pendulum whose pivot is constrained to oscillate with a high frequency in the vertical direction. A quantitative theory based on the suggested approach is developed. A computer program simulating the physical system supports the analytical investigation. The simulation...

Oscillations in quantum phase about a mean value of π, observed across micropores connecting two 3He−B baths, are explained in a Ginzburg-Landau phenomenology. The dynamics arises from the Josephson phase relation,the interbath continuity equation, and helium boundary conditions. The pores are shown to act as Josephson tunnel junctions, and the dynamic variables are the inter bath phase differe...

This paper presents travel time geoacoustic inversion of broadband data collected on a vertical line array at short range of 230 m during the Shallow Water 2006 experiments. A ray-tracing method combined with a hybrid optimization algorithm that utilizes differential evolution and downhill simplex was used for the inversion of sediment properties. The ocean sound speed profile and geometric par...

This paper considers how competition can affect aggregate innovative activity through its effects on firms’ decision whether or not to vertically integrate. A moderate increase in competition enhances innovation incentives, too much competition discourages innovative effort. These effects generates an inverted-U relationship between competition and innovation and between competition and the inc...

This is the rst of two papers on the zero-viscosity limit for the incompressible Navier-Stokes equations in a half-space. In this paper we prove short time existence theorems for the Euler and Prandtl equations with analytic initial data in either two or three spatial dimensions. The main technical tool in this analysis is the abstract Cauchy-Kowalewski theorem. For the Euler equations, the pro...

Like many others before him, Nicholas Wade, in a recent publication in this journal, did not provide the correct title of Adolf Fick's dissertation, approved by the University at Marburg, Germany, in 1851, and Wade also wrongly attributed now famous illusion figures, meant to illustrate the so-called horizontal-vertical illusion (the +, the L, and the inverted T), to this author. After having c...

Ultraviolet laser irradiation of a lithium niobate +z polar surface enables the production of ridge waveguides. Ultraviolet laser induced inhibition of poling is used to define an inverted domain pattern which transforms into a ridge structure by differential etching in Hydrofluoric acid. The laser irradiation step also induces a refractive index change that provides the vertical confinement wi...

The excellent locomotion ability of geckos on various rough and/or inclined substrates has attracted scientists' attention for centuries. However, the moving ability of gecko-mimicking robots on various inclined surfaces still lags far behind that of geckos, mainly because our understanding of how geckos govern their locomotion is still very poor. To reveal the fundamental mechanism of gecko lo...

inverted papillomas of the nose and paranasal sinuses are uncommon neoplasms, characterized by their tendency to occur and by their association with malignancy. in the past decade there has been a trend toward the use of endoscopic surgical techniques in the management of these tumors. this article presents the results of a prospective study of24 patients with inverted papilloma resected by the...