An adaptive feedforward controller design for tracking repeatable runout (RRO) in bit patterned media recording (BMPR) is proposed for single stage hard disk drives (HDD). The technique is based on modified filtered-x least mean squares (MFXLMS) algorithm with deterministic periodic input, and a novel variable step size that boosts both the convergence rate and the steady state error. Comprehen...

The purpose of this research is to determine the empirical model for surface roughness in a turning process. This process is performed in the final assembly department at a manufacturing company which supplies fluid dynamic bearing (FDB) spindle motors for hard disk drives (HDDs). The workpieces used were the sleeves of FDB motors made of ferritic stainless steel, grade AISI 12L14. A 2 factoria...

A systematic approach using factorial analysis was conducted on the C4-C6 finite element model to analyse the influence of six spinal components (cortical shell, vertebral body, posterior elements, endplate, disc annulus and disc nucleus) on the internal stresses and external biomechanical responses under compression, anterior and posterior shear. Results indicated that the material properties ...

Tensile strength is an important control parameter for the design and stability analysis in rock engineering. In order to reveal influence of elastic modulus on tensile test results, Brazilian splitting tests were carried out specimens with different strengths, such as mudstone, white sandstone, green red marble. Longitudinal transverse strains monitored analyze maximum contact angle peak load ...

We discover a pronounced dependence of the strength of the soft X-ray orbital modulation and the spectral hardness in Cyg X-1 in the hard state on its superorbital phase. We find our results can be well modelled as a combination of two effects: the precession of the accretion disc (which appears to cause the superorbital flux modulation) and the orbital-phase dependent X-ray absorption in an ac...

We discover a pronounced dependence of the strength of the soft X-ray orbital modulation in Cyg X-1 in the hard state on its superorbital phase. We find our results can be well modelled as orbital-phase dependent X-ray absorption in an accretion bulge, located at the accretion disc edge close to the companion but displaced from the line connecting the stars by about 25◦ and in the case when the...

Recently, result diversification has attracted a lot of attention as a means to improve the quality of results retrieved by user queries. In this paper, we propose a new, intuitive definition of diversity called DisC diversity. A DisC diverse subset of a query result contains objects such that each object in the result is represented by a similar object in the diverse subset and the objects in ...

The 1998 outburst of the bright Galactic black hole binary system XTE J1550 − 564 was used to constrain the accretion disc structure in the strongly Comptonized very high state spectra. These data show that the disc emission is not easily compatible with the constant area L ∝ T 4 behaviour seen during the thermal-dominated high/soft state and weakly Comptonized very high state. Even after corre...

Some novel interlacing properties of the zeros for the Bessel and spherical Bessel functions are first presented and then applied to prove an interesting uniqueness result in inverse acoustic obstacle scattering. It is shown that in the resonance region, the shape of a sound-soft/sound-hard ball in R3 or a soundsoft/sound-hard disc in R2 is uniquely determined by a single far-field datum measur...

We consider the directed Hausdorff distance between point sets in the 9 plane, where one or both point sets consist of imprecise points. An imprecise point is 10 modelled by a disc given by its centre and a radius. The actual position of an imprecise 11 point may be anywhere within its disc. Due to the direction of the Hausdorff Distance 12 and whether its tight upper or lower bound is computed...