In this paper we investigate the relationship between classes of tree-to-tree-series (for short: t-ts) and o-tree-to-tree-series (for short: o-t-ts) transformations computed by restricted deterministic bottom-up weighted tree transducers (for short: deterministic bu-w-tt). Essentially, deterministic bu-w-tt are deterministic bottom-up tree series transducers [EFV02, FV03, ful, FGV04], but the former are de ned over monoids whereas the latter are de ned over semirings and only use the multiplicative monoid thereof. In particular, the common restrictions of non-deletion, linearity, totality, and homomorphism [Eng75] can equivalently be de ned for deterministic bu-w-tt. Using well-known results of classical tree transducer theory (cf., e.g., [Eng75, Fül91]) and also new results on deterministic bu-w-tt, we order classes of t-ts and o-t-ts transformations computed by restricted deterministic bu-w-tt by set inclusion. More precisely, for every commutative monoid we completely specify the inclusion relation of the classes of t-ts and o-t-ts transformations for all sensible combinations of restrictions by means of inclusion diagrams.

Transition of natural convection flow on a heated flat plate and inside a heated channel is studied numerically. Three different RANS based turbulent k-ε models namely standard, RNG and Realizable with an enhanced wall function are employed in the simulations. Additionally, a Large Eddy Simulation (LES) technique is also applied to particularly investigate the flow field and transition in a heated plate facing upward. Numerous published papers presented the typical characteristic behaviour of natural convection flow inside a channel, however, none of these provided information about the transition behaviour of flow inside a channel, and importantly, how the transition is affected by the merging of two growing boundary layers which occur inside a channel. Therefore, taking the above important things into consideration, the aim of the study is to carry out in-depth investigations of the transition of the free convection flow inside a channel with an effect of its width, angular orientation and several important thermal and boundary conditions. Moreover, the transition phenomena of the free convection flow developing in a heated channel facing both downward and upward are thoroughly investigated in the thesis. Numerically predicted results are compared with available experimental data in the published literatures. Fluid properties are assumed to be constant except for the density which changes with temperature and gives rise to the buoyancy forces and is treated by using the Boussinesq approach. Air with a Prandtl number of 0.7 is used as a test fluid in all the simulations. In the RANS based models, the results show that the Realizable model with an enhanced wall function predicts numerical results well compared to the experiment than those obtained by the other two models (standard and RNG), therefore this model was selected to perform all the other RANS based numerical simulations in this work. The results particularly indicate that the inclination of the channel has major effects on the transition stage. As the inclination angle is increased, the transition stage moves further downstream of the channel. However, the predicted local heat flux, reached its minimum further upstream of the channel, does not agree with that of the velocity and turbulent kinetic energy in a small channel width. Natural convection from an isothermal plate is conducted by using a Large Eddy Simulation method. The results show that with an increase in the angle the peak of the thermal and velocity boundary layers move from the near outlet of the plate for the vertical case to the middle of the plate when θ = -70°. So the thermal and boundary layers become fatter which causes an early transition.

ITC/USA 2006 Conference Proceedings / The Forty-Second Annual International Telemetering Conference and Technical Exhibition / October 23-26, 2006 / Town and Country Resort & Convention Center, San Diego, California / DataProbeCLASSIC is the new PC-based version of the classic tool for telemetry data analysis and visualization. DataProbe was the brainchild of the Unites States Navy and its contractors. At a time when computer terminals were expensive and graphical visualization of data was cutting edge, this software product was specifically designed to process time-series data in an efficient manner. The primary strength of DataProbe is the capability to read specific data items for specific time slices from very large data files rather than reading the entire data file into memory. The efficiency and versatility of the product was quickly noted, and it gained widespread use within the testing community. This paper presents a brief history of the legacy product and discusses the features and strengths of new implementation.

In order to optimise the Resonance Enhanced Drilling (RED) performance in different rock formations, it is important to understand both the influence of the system parameters on the drilling dynamics, and other measures that are involved in the drilling operation. This work studies the dynamic behaviour of the drilling system. It also investigates the influence of various system parameters on the drilling module dynamics in order to identify in real-time the formation being drilled from the dynamical responses of the drilling assembly. It also aims to optimise the selection of the operating parameters for a drilled formation, resulting in an improvement in the Rate Of Penetration (ROP). A nonlinear time series analysis approach has been used to infer the changes in the system parameters from subtle changes in the system dynamics. Using the acceleration time-series as a measurement of simulated and experimental impact oscillators representing a model for drilling conditions with intermittent impacts, the systems attractors were reconstructed and characterised. It is shown that the stiffness correlates well with the topology of the reconstructed attractor. Nonimpacting trajectories formed an approximate plane within the three dimensional reconstructed phase-space. Contact with the constraint caused a systematic deviation from the linear subspace, the inclination of which, measured by statistics of the tangent vector, can be used to infer the stiffness. Based on the developed framework it is now possible to classify stiffness of the impacted material from a single variable in a simple way and in real-time. An experimental impact drilling rig was designed, built and used to study the influence of the system parameters on the high-frequency impact drilling. The newly designed rig is a smaller and simpler apparatus. It is designed to mimic the actual RED apparatus in terms of providing controlled axial vibration into a conventional rotary drilling whilst avoiding complications that might arise from including all RED rig elements. An instrumentation and sensing system was also developed to measure motions and forces resulting from the dynamic interactions between the drill-bit and the rock formations.

No description available.

published_or_final_version / Statistics / Doctoral / Doctor of Philosophy

published_or_final_version / abstract / Statistics and Actuarial Science / Master / Master of Philosophy

published_or_final_version / Statistics and Actuarial Science / Doctoral / Doctor of Philosophy

published_or_final_version / Statistics and Actuarial Science / Master / Master of Philosophy

No description available.