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Non-linear stabilisation and control of a PVTOL vehicle has received much attention in the literature for the low speed case, where aerodynamic effects can be neglected. In this paper, a non-linear control design is presented for a three degree of freedom "Hovering Rocket" with aerodynamic effects included, such that the controller remains functional at(More)
In order to detect faces in pictures presenting difficult real-world conditions such as dark background or backlighting, we propose a new method which is robust to varying illuminations and which automatically adapts itself to these lighting changes. The proposed face detection technique is based on an efficient AdaBoost super-classifier and relies on(More)
In a 1967 publication, D. P. Gaver studied a probabilistic model of a multiprogramming computer system. His results have been utilized recently by a number of authors. However, we have observed that Gaver's results contain inconsistencies. These inconsistencies are discussed in detail and a correction suggested and verified through an independent derivation.
A probabilistic model of a multiprogramming system is exercised in order to determine the conditions under which the dynamic repacking of main memory is beneficial. An expression is derived for the maximum interference that a repacking process may introduce before the original performance of the system is degraded. Alternative approaches to repacking are(More)
New code design methods and Viterbi detector architectures are presented for high-rate trelliscoded partialresponse (TCPR) systems. The methods, which extend the matched-spectral-null (MSN) coding technique, use novel code constraints and time-varying detector trellis structures to reduce path memory requirements by as much as a factor of two, relative to(More)
The classical (Bancilhon-Spyratos) correspondence between view update translations and views with a constant complement reappears more generally as the correspondence between update strategies and meet complements in the order based setting of S. Hegner. We show that these two theories of database view updatability are linked by the notion of “lens” which(More)
In this paper, we propose a high performance, Lyapunov based control design for symmetric VTOL vehicles to track trajectories at which aerodynamic effects are significant. We consider the case where an accurate model of aerodynamic forces may be obtained either analytically or empirically. A Lyapunov based control strategy is proposed. To avoid lengthy and(More)
The class of systems know as VTOL vehicles encapsulates a wide variety of real world systems of interest including helicopters, jets and unmanned aerial vehicles. These VTOL vehicles exhibit heavily nonlinear dynamics. Consequently, nonlinear control techniques are required to achieve global stabilisation. Often, VTOL vehicles are stabilised using nonlinear(More)
Modulation codes with d>0 are essential in optical recording to enable useful densities, since the minimum mark size achievable is limited by the diffraction-limited spot size. The EFMPLus modulation code is a coding scheme adopted for the digital video disk (DVD). This is a run-length limited code with constraints d=2 and k=10. It is appropriate to exploit(More)