Ecosystems are linked to neighbouring ecosystems not only by dispersal, but also by the movement of subsidy. Such subsidy couplings between ecosystems have important landscape-scale implications because perturbations in one ecosystem may affect community structure and functioning in neighbouring ecosystems via increased/decreased subsidies. Here, we combine a general theoretical approach based ...

Abstract: This paper presents a new algorithm for the closed-loop H∞ control of a class of singularly perturbed nonlinear systems with an exogenous disturbance, using the successive Galerkin approximation (SGA). The singularly perturbed nonlinear system is decomposed into two subsystems of a slow-time scale and a fast-time scale in the spirit of the general theory of singular perturbation. Two ...

Structure formation within the Lemâıtre-Tolman model is investigated in a general manner. We seek models such that the initial density perturbation within a homogeneous background has a smaller mass than the structure into which it will develop, and the perturbation then accretes more mass during evolution. This is a generalisation of the approach taken by Bonnor in 1956. It is proved that any ...

The adiabatic criterion, widely used in astronomical dynamics, is based on the harmonic oscillator. It asserts that the change in action under a slowly varying perturbation is exponentially small. Recent mathematical results precisely deene the conditions for invariance show that this model does not apply in general. In particular, a slowly varying perturbation may cause signiicant evolution st...

The effect of the Coriolis force on a moving system can be described as a holonomy with respect to a particular connection known as the Cartan–Hannay–Berry connection. The resulting geometric phase is called the Hannay–Berry phase, and it provides direct information about the imposed motion on the system. This approach assumes that the imposed motion is adiabatic. In this paper we describe the ...

We evaluate renormalization factors of the domain-wall fermion system with various improved gauge actions at one loop level. The renormalization factors are calculated for quark wave function, quark mass, bilinear quark operators, threeand four-quark operators in MS scheme with the dimensional reduction(DRED) as well as the naive dimensional regularization(NDR). We also present detailed results...

In this paper, a novel H? control method in two time scales is proposed for active suspension systems. Two are considered based on the natural scale separation existing systems, i.e. sprung mass part corresponding to fast dynamics and unsprung slow dynamics. Singular perturbation theory used establish dual model design controller. Compared with commonly controller, time-sharing dynamic characte...

The time-dependent Schrödinger equation for two quite general types of perturbation has been solved by introducing the Laplace transforms to eliminate the time variable. The resulting time-independent differential equation can then be solved by the perturbation method, the variation method, the variation-perturbation method, and other methods.

The parametric resonance of the axial vibrations of a cantilever pipe conveying harmonically perturbed two-phase flow is investigated using the method of multiple scale perturbation. The nonlinear coupled and uncoupled planar dynamics of the pipe are examined for a scenario when the axial vibration is parametrically excited by the pulsating frequencies of the two phases conveyed by the pipe. Aw...