A method of physical parameter system identification (SI) is proposed here for threedimensional (3D) building structures with in-plane rigid floors in which the stiffness and damping coefficients of each structural frame in the 3D building structure are identified from the measured floor horizontal accelerations. A batch processing least-squares estimation method for many discrete time domain m...

Diskoseismic c-modes in accretion discs have been invoked to explain low-frequency variabilities observed in black-hole X-ray binaries. These modes are trapped in the inner-most region of the disc and have frequencies much lower than the rotation frequency at the disc inner radius. We show that because the trapped waves can tunnel through the evanescent barrier to the corotational wave zone, th...

The study is concerned with the mathematical modelling and parameter identification of nonlinear motion control systems. The control systems under review are the axis motion control systems for a 3-axis CNC machine tool. The modelling process commences with lumped parameter methods applied to each element and then to each axis in turn. Comparing the dynamic performance of the simulated axis dri...

We investigate the scalar field perturbations of the 4+1-dimensional Schwarzschild black hole immersed in a Gödel Universe, described by the Gimon-Hashimoto solution. This may model the influence of the possible rotation of the Universe upon the radiative processes near a black hole. In the regime when the scale parameter j of the Gödel background is small, the oscillation frequency is linearly...

Brownian motion in a periodic potential driven by an ac (oscillatory) force is investigated for the full range of damping constant from the overdamped limit to the underdamped limit. The path (functional) integral approach is advanced to produce formulas for the probability distribution function and for the current of the Brownian particle in response to an ac driving force. The negative fricti...

The damping sensitivity analysis of interconnected power system low frequency oscillation is studied. The function of sensitivity analysis is implemented in the Small Signal Stability Analysis Package (SSAP). The paper mainly analyzes the sensitivities of oscillation modes with respect to the parameters of power system stabilizer (PSS) in the excitation systems of generators for a physical larg...

Most studies of Coherent Synchrotron Radiation (CSR) have only considered the radiation from independent dipole magnets. However, in the damping rings of future linear colliders, a large fraction of the radiation power will be emitted in damping wigglers. In this paper, the longitudinal wakefield and impedance due to CSR in a wiggler are derived in the limit of a large wiggler parameter K. Afte...

It is shown that the Mel'nikov-Meshkov formalism for bridging the very low damping (VLD) and intermediate-to-high damping (IHD) Kramers escape rates as a function of the dissipation parameter for mechanical particles may be extended to the rotational Brownian motion of magnetic dipole moments of single-domain ferromagnetic particles in nonaxially symmetric potentials of the magnetocrystalline a...

Malaysians were reported to have the most number of Facebook friends, spend more time on Facebook and might be addicted to Facebook as well. This paper explored Facebook usage pattern, motivations and psycho logical/behavioural factors affecting the users. A focus group study was first conducted to explo re motives to use Facebook and symptoms related to excessive Facebook usage. The themes eme...