In this paper, an acoustic echo canceller (AEC) based on an M-channel infinite-impulse response (IIR) cosine-modulated filter bank (CMFB) with near-perfect reconstruction (PR) property is proposed. The use of a 2-channel lossless lattice section with 1 st order allpass filter in the design of the prototype filter that is common to both the analysis and the synthesis filter banks permits the fil...

We present the three main mathematical constructs used to represent the attitude of a rigid body in threedimensional space. These are (1) the rotation matrix, (2) a triple of Euler angles, and (3) the unit quaternion. To these we add a fourth, the rotation vector, which has many of the benefits of both Euler angles and quaternions, but neither the singularities of the former, nor the quadratic ...

OFDM is a broadband wireless technology which supports data rates in excess of 100 Mbps. In addition to this, OFDM has some limitations as it requires strict frequency synchronization and low peak to average power ratio. So considering DFT-OFDMA, which performance in terms of PAPR, is equivalent to SC-FDMA. This paper represents the suitability of using OFDMA in the up-link for high-data-rate s...

DNA bending in 86 complexes with sequence-specific proteins has been examined using normal vector plots, matrices of normal vector angles between all base pairs in the helix, and one-digit roll/slide/twist tables. FREEHELIX, a new program especially designed to analyze severely bent and kinked duplexes, generates the foregoing quantities plus local roll, tilt, twist, slide, shift and rise param...

duce acoustic images of the~seafloor on-line with a Sea Beam multibeam echo-sounder. This ystem uses a stand alone interface between the Sea Beam system and a grey-scale line-scan recorder. The interface is built around a Motorola 68000 microprocessor and has digitizing capabilities. I t digitizes the detected echo signals from each of the 16 preformed beams inside the Sea Beam echo process...

This work studies the practicality of using finite-time Lyapunov exponents (FTLEs) to detect the inception of parametric resonance for vessels operating in irregular longitudinal seas. Parametrically excited roll motion is modelled as a single degree-of-freedom system, with nonlinear damping and restoring terms. FTLEs are numerically calculated at every integration time step. Using this numeric...

A series of parallel striations observed on thermal satellite images over flat terrain in arid West Africa is identified as helical roll vortices in the Atmospheric Boundary Layer (ABL). This is because their length and spacing conforms to the dimensions expected for such roll structures according to climatic conditions at the time of the image. Knowledge of helical roll vortices is usually der...

We report experiments on turbulent Rayleigh-Bénard convection of air in a cylindrical large-scale facility with a diameter of 7 meters and Rayleigh numbers up to Ra approximately 10(12). The facility is used to explore the structure of the large-scale circulation for continuously varying aspect ratios between Gamma approximately 1 and Gamma approximately 10. Using autocorrelation functions deri...

We report on the manufacture of a first batch of approximately 2,000 Gas Electron Multipliers (GEMs) using 3M’s fully automated roll to roll flexible circuit production line. This process allows low-cost, reproducible fabrication of a high volume of GEMs of dimensions up to 30×30 cm. First tests indicate that the resulting GEMs have optimal properties as radiation detectors. Production techniqu...