Emulation is the practice of simulating one computer system on another. There are many methods of implementing an emulator. They exist on a performance continuum from simple interpretation to dynamic binary translation extended with various optimizations. Optimizations are diverse, including just in time compilation, large translation units, shadow stack, register mapping and many more. The goal of this thesis is to develop a high performance, portable emulator for the ARM v4 architecture without requiring substantial code analysis. This thesis describes the implementation of a dynamic binary translator translating to an intermediate language targeting a virtual machine. Targeting a virtual machine ensures that the emulator is portable. Optimizations implemented include forming large translation units and branch straightening in hot regions. The particular combination of translating to intermediate form for a virtual machine, and creating large translation units from hot regions does not seem to appear in the literature. The performance of the described dynamic binary translator exceeds the performance of an interpreter on the same platform by an order of magnitude. Code analysis was only used to straighten branches in hot regions. While many popular dynamic binary translation optimizations are not readily applicable when using a virtual machine target, the performance achieved shows that using virtual machine as translation target is viable method of implementing dynamic binary translator. / Graduate

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This research focuses on the dynamic seat comfort in aircrafts specifically during takeoff, landing and cruise through turbulence flight conditions. The experiments are performed using a multi axis shaker table in the Automotive Centre of Excellence (ACE) at the University of Ontario Institute of Technology subjected to sample takeoff, landing and cruise vibration recordings obtained onboard of an actual flight. The input vibrations introduced to the aircraft seats during actual flight conditions and during the experiments in the ACE are compared and it is concluded that the given flight conditions were successfully replicated for the interest of this thesis. The experiments are conducted with two different aircraft seats, economy class and business class. Furthermore, to investigate the importance of seat cushion characteristics in addition to economy and business class seat cushions, three laboratory made cushions were included in the investigation as well. Moreover, the effect of passenger weight is also discussed by conducting the experiments with 1 and 2 identical dummies. It is concluded that static seat properties play a significant role in the comfort perception level as well as flight conditions. Among the three flight condition, landing appeared to be the most uncomfortable case comparing to takeoff and cruise. In addition to experimental work, a numerical study to simulate the flight conditions is undertaken with the initial work of CAD modelling. The simulated responses of the seat is partially matching with experimental results due to unknown parameters of the cushion and the connections of the aircraft seat that cannot be created in the CAD model due to unknown manufacturing processes.

Dynamic mechanism design is an important area of multiagent systems, and commonly used in resource allocation where the resources are time related or the agents exist dynamically. We focus on a multiagent model within which the agents stay, and the resources arrive and depart. The resources are interpreted as work or jobs and are called tasks. The allocation outcome space has a special restriction that every agent can only work on one resource at a time, because every agent has a finite computational capability in reality. We propose a dynamic mechanism and analyze its incentive properties; we show that the mechanism is incentive compatible. Empirically, our dynamic mechanism performs well and is able to achieve high economic efficiency, even outperforming standard approaches if the agents are concerned about future tasks. We also introduce a static mechanism under the setting of a restricted outcome space; it is proved that the static mechanism is incentive compatible, and its computational complexity is much less than that of the standard VCG mechanism.

With the increasing developments of exploiting oil and natural gas in deep water and harnessing renewable (wave and wind) energy in the sea, mooring lines and risers are widely deployed to position the related floating structures. Subject to environmental loads, a mooring line or riser connected to floating structure, moves up and down, back and forth, and sometimes from the left to the right. In computation of the dynamics of a mooring line or riser, it is often modeled as a flexible slender rod. While the bending moment of a chain or a rope is neglected, that of a riser is considered and specified by characteristics of the riser. Existing numerical codes for simulating the dynamics of a slender rod, such as CABLE3D, allow for the vertical support force and longitudinal (along the direction of the rod) friction from soils of the seabed while the transverse (in the direction transverse to the slender rod) friction between the rod and the seabed soils is not considered. In this study, we extend the current version of CABLE3D to allow for the transverse friction applied on the portion of a slender rod contacting the seabed soil, which is time-varying when it is moving. The friction between a slender rod and the seabed soil is computed based upon a Coulomb model originally developed for the simulation of the friction in all dry contact mechanical systems. In applying the Coulomb model, the transverse friction depends on the transverse displacement and/or velocity of a slender rod contacting the seabed. In addition, vertical bottom support of the seabed soil is calculated based on the shear stress of the seabed soil. The simulations of the dynamics of a few typical mooring lines are made given their motions at their fairleads and the results are compared with the corresponding results obtained using Orcaflex, a commercial code, and the existing version of CABLE3D.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 197-202). / Also available by subscription via World Wide Web / xi, 202 leaves, bound ill. 29 cm

The purpose of this research was to quantify feedstock supply risk over the lifetime of an agricultural residue-based (straw and chaff) biorefinery and to determine the range of delivered prices. The Peace River region of Alberta was used as a case study for analysis, with a geographic information system utilized for data analysis. Inter-year availability of crop residues was highly variable over the 20 year period under study, which created significant differences in the delivered price of feedstock between minimum, average, and maximum availability scenarios. At the four primary study sites (Fahler, Grimshaw, Peace River, and Sexsmith), the range was from double the average availability for the maximum scenario to zero biomass available for the minimum scenario. Biomass availability is a function of grain yield, the biomass to grain ratio, the cropping frequency, and residue retention rate used to ensure future crop productivity. Using minimum, average, and maximum supply scenarios, delivered price was determined using the dynamic (time-dependent) Integrated Biomass Supply Analysis and Logistics (IBSAL) simulation model. Five biorefinery capacities, ranging from 50,000 to 500,000 tonnes of feedstock per year, were analyzed. Since no biomass was available to model in true minimum years, a simulated minimum of half the average availability was used. Delivered cost, including harvest and transportation, for the 50,000 t plant ranged from $24.01 t-1 for the maximum availability scenario at the Sexsmith site to $42.63 t-1 for the simulated minimum scenario at the Fahler site. The range for the 500,000 t plant at the Sexsmith site was $41.78 for the maximum availability and $70.98 for the simulated minimum availability. As no biomass is available (and hence the true cost is unknown) in some years, storage strategies must be implemented and alternate feedstock sources identified to supply biorefineries in low-yield years. Since feedstock cost is a large component of total operating cost of a biorefinery, feedstock supply variability and delivered cost inconsistency should be primary decision criteria for any future biorefinery projects.