Based on a simple observation that a classical second order differential equation may be decomposed into a set of two first order equations, we introduce a Hamiltonian framework to quantize the damped systems. In particular, we analyze the system of a linear damped harmonic oscillator and demonstrate that the time evolution of the Schrödinger equation is unambiguously determined. * This work is...

We analyze a simple stochastic model to describe motor molecules which cooperate in large groups and present a physical mechanism which can lead to oscillatory motion if the motors are elastically coupled to their environment. Beyond a critical fuel concentration, the non-moving state of the system becomes unstable with respect to a mode with angular frequency ω. We present a perturbative descr...

Results for the light meson mass spectrum from a Bethe-Salpeter approach are presented. The results obtained in the standard framework are Poincaré covariant and compare favourably with lattice results. Using a more sophisticated scheme, the pseudoscalar, vector and 1++ (a1/ f1) axialvector charge eigenstate masses are unaltered whereas the 1+− (b1/h1) axialvector meson mass is raised. The Beth...

BACKGROUND While age is a common confounder, its impact on health-related quality of life (HRQoL) after total hip replacement is uncertain. This could be due to improper statistical modeling of age in previous studies, such as treating age as a linear variable or by using age categories. We hypothesized that there is a non-linear association between age and HRQoL. METHODS We selected a nation...

It is well-known that the Macfarlane-Biedenharn q-oscillator and its generalization has no Hopf structure, whereas the Hong Yan q-oscillator can be endowed with a Hopf structure. In this letter, we demonstrate that it is possible to construct a general q-oscillator algebra which includes the Macfarlane-Biedenharn oscillator algebra and the Hong Yan oscillator algebra as special cases. E-mail ad...

PURPOSE To describe spherical equivalent (sph eq) refractive errors in preschool members of a Native American tribe with a high prevalence of astigmatism. METHODS Cycloplegic autorefraction measurements were obtained for 819 three- and four-year-old Tohono O'odham children, with follow-up measurements in 146 after 4 to 8 years. RESULTS Mean sph eq was significantly more hyperopic in the ast...

where ω = vk and k± = k x̂ ± kΓ ŷ. Slepian also noted that if v < c, then cos(kΓy) = cosh(kΓ′y) where Γ′ = iΓ = √ 1− v2/c2, and the waveform (1) again propagates with speed v. The vector potential (1), together with scalar potential V = 0, satisfy the conditions for the Coulomb, Gibbs, Lorenz and velocity gauges. See, for example, [2]. For completeness, the electric field is E = iωA ≡ E+ + E− wh...