A control system is proposed for a low Earth orbit gravity gradient stabilised microsatellite using Z wheel. The microsatellite is 3-axis stabilized using a yaw reaction wheel, with dual redundant 3-axis magnetorquers. Two vector magnetometers and four dual sun sensors are carried in order to determine the full attitude. The attitude was estimated using an Euler angles (small libration version)...

Keywords: Toeplitz matrices Spectral factorization Paraunitary filters Filter design In this work we present the explicit expression of all rectangular Toeplitz matrices B, C which verify the equation BB H + CC H = al for some a > 0. This matrix equation arises in some signal processing problems. For instance, it appears when designing the even and odd components of paraunitary filters, which a...

In this paper, a current-mode Kerwin-Huelsman-Newcomb (KHN) filter structure employing four z-copy current follower transconductance amplifiers (ZC-CFTAs) and two grounded capacitors is proposed. The circuit structure has one low-impedance current input and three high-impedance current outputs and enables realizing lowpass, bandpass and highpass current responses simultaneously. The bandstop an...

Digital filters are commonly used as an essential element of everyday electronics such as radios, cell phones, and stereo receivers. Digital filters may be more expensive than an equivalent analog filter due to their increased complexity, but they may lead to many designs which are impractical or impossible as analog filters. Basically there are two types of digital filters, which are FIR (Fini...

We look at the design of oversampled filter banks and the resulting framelets. The undecimated wavelet transform is known for its shift invariant properties and has applications in areas such as denoising [7]. The framelets we will design, will have improved shift invariant properties over decimated wavelet transform. Shift invariance has applications in many areas particularly denoising [6], [...

For a given pair of s-dimensional real Laurent polynomials (~a(z),~b(z)), which has a certain type of symmetry and satisfies the dual condition~b(z) T ~a(z) = 1, an s× s Laurent polynomial matrix A(z) (together with its inverse A−1(z)) is called a symmetric Laurent polynomial matrix extension of the dual pair (~a(z),~b(z)) if A(z) has similar symmetry, the inverse A−1(Z) also is a Laurent polyn...

The past decade has seen impressive progress in the detection of $z>7$ galaxies with Hubble Space Telescope, however little is known about their properties. James Webb Telescope will revolutionise high-$z$ field by providing NIR (i.e., rest-frame optical) data unprecedented depth and spatial resolution. Measuring galaxy quantities such as resolved stellar ages or gas metallicity gradients tradi...

To effectively capture singularities in high-dimensional data and functions, multivariate compactly supported tight framelets, having directionality and derived from refinable box splines, are of particular interest in both theory and applications. The d-dimensional Haar refinable function χ[0,1]d is a simple example of refinable box splines. For every dimension d ∈ N, in this paper we construc...

an air filter is a significant element of any mechanical ventilation system. however, the importance and performance evaluation of air filters have not been well publicized and related scientific reports are scarce. in this study, a transportable, off-line, air filter-testing unit (the unit) was designed and utilized to simulate the filter housing of a mechanical ventilation system. the unit wa...

Perfect reconstruction oversampled filter banks are equivalent to a particular class of frames in `(Z). These frames are the subject of this paper. First, necessary and sufficient conditions on a filter bank for implementing a frame or a tight frame expansion are established, as well as a necessary and sufficient condition for perfect reconstruction using FIR filters after an FIR analysis. Comp...