Detector arrays are required for many applications in health and defense. Whether searching for contraband or controlling radioactive spread after an event, a "passive" data collection strategy is a key component. This can take the form of portal monitors attached to a fixed location or a movable array, attached to a vehicle or person, which searches for abnormalities in the radiation background. The main goal of this project was to create software that would allow the digiBASE-E to be used to create arrays of gamma detection instruments and gather data over a long span of time. To take full advantage of the digiBASE-E, the software focused on the list mode capabilities of these devices. List mode attaches a timestamp to each detection event. Every particle detected can be traced to a particular point in time, and the full history of the device?s detection over the acquisition period can be reconstructed. The list mode ability of the digiBASE-E is a powerful tool for producing arrays of detectors, as a more familiar spectrum can be generated for any arbitrary section of time, even after-the-fact. The software package, called "CraneWow", was field tested at the Port of Tacoma in August of 2011. Perl scripts included as part of the package were used to partially analyze the data collected, allowing for verification of the proof-of-concept's success. The software was written in C/C++, with supplemental scripts written in Perl to facilitate processing of the data once collected. Additionally, a user manual and programming guide were written to allow easy use and maintenance of the software.

La société moderne avancée révèle une diversité de communautés sociales, particulièrement en milieu urbain. Chaque communauté urbaine représente un microcosme et participe à une sous-culture spécifique. Valérie Fournier, chercheuse en sciences sociale à Genève, nomme ces communautés urbaines: les nouvelles tribus urbaines. Les bars sont souvent le lieu de rencontre de ces tribus urbaines. Ce mémoire consiste à une analyse empirique d'un bar reconnu à Montréal, les Foufounes Électriques. Ce bar particulier a ouvert ses portes en 1983, sa sous-culture a donc évolué depuis toutes ces années. Le concept de sous-culture est un concept dynamique qui bouge et se tranforme dans le temps. Nous nous sommes donc penché sur les transformations qu'a subies l'univers des Foufounes Électriques. En faisant parler différents niveaux d'acteurs sociaux endogènes et exogènes, nous retraçons l'historique du bar et révèlons les transformations de sa sous-culture. Puis nous tentons d'interpréter cette transformation que nous qualifions d'un passage d'un statut underground à statut overground. Nous croyons que ce passage s'effectue par le phénomène de la mode. Nous explorons aussi dans ce mémoire, les ambiguïtés que révèlent le passage de statut underground à overground d'une sous-culture urbaine. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Les Foufounes électriques, Sous-culture, Underground, Overground, Changement culturel.

Dowel bars in jointed plain concrete pavement (JPCP) have the important function of transferring wheel loads from one slab to the other, hence ensuring that the deflections on each side of the joint are kept almost equal. As well, the dowels should not impede the concrete pavement movements due to environmental effects (temperature and moisture). Dowel bar misalignment, attributed to deficient construction practice, is a major cause of joint distress or faulting by inhibiting the free movement of the slab at the joint. To prevent these issues, tolerance guidelines on misalignment levels are implemented by transportation agencies. Review of previous studies indicate that many researchers analysed the effects of dowel bar misalignment on pavement behaviour using a pull-out test, that is a forcebased opening of the joint. These approaches neglect that joints movements in the field are strain-governed by non-linear temperature and shrinkage actions, leading to combined axial movements and curling of the slab. In this study, the fundamental dowel bar behaviour under shrinkage and thermal loading was determined through detailed 3D finite element modelling (3D-FEM). To that end, models of dowel jointed concrete slabs were developed and subjected to realistic non-linear profiles of shrinkage and thermal strains. Studies were carried out on a single-bar model, taking into account bar-concrete friction and plastic concrete behaviour. The parameters that were investigated included different configurations and levels of bar misalignment and different friction coefficients between the steel and the concrete, simulating the use of bond-breakers. To interpret the results from the numerical analysis, criteria for concrete damage were developed and used in parallel with measures of joint load transfer efficiency; these were obtained by examining the response of the slab under a Falling Weight Deflectometer (FWD) drop at the joint. The results were verified by comparing the outputs of a model consisting of one half of a slab to published data. The analysis of the models revealead that none of the models showed signs of significant damage after the application of shrinkage and two thermal cycles. Analyses with up to ten thermal cycles did not indicate progressive accumulation of damage, suggesting that for the chosen parameters there is no the concrete around the dowel bar will not fail. Models with bars placed higher in the slab and bars with angular misalignment exhibited more damage than the non-misaligned models without reaching the damage criteria used in this study. The models did not exhibit the amount of damage reported in the studies on dowel bar misalignment having used pull-out tests. It was found that no significant difference existed between uncoated and coated dowel bars models results with regards to concrete damage at the joint. However, a high coefficient of friction between the dowel and the concrete, simulating dowel bar corrosion, proved to be the most detrimental to joint integrity. All of the models performed very well with respect to joint load transfer efficiency, suggesting that the plastic strains in the concrete around the dowel did not have a significant impact on joint performance for the realistic range of parameters investigated.

In this work, three aluminum sheet alloys, AA5754, AA5182 and AA6111, which are prime candidates for replacing mild steel in automobile structures, are tested in tension at quasi-static and high strain rates. <br /><br /> In order to characterize the constitutive response of AA5754, AA5182 and AA6111 at high strain rates, tensile experiments were carried out at strain rates between 600 s^-1 and 1500 s^-1, and at temperatures between ambient and 300°C, using a tensile split Hopkinson bar (TSHB) apparatus. As part of this research, the apparatus was modified in order to provide an improved means of gripping the sheet specimens. Quasi-static experiments also were conducted using an Instron machine. <br /><br /> The experimental data was fit to the Johnson-Cook and Zerilli-Armstrong constitutive models for all three alloys. The resulting fits were evaluated by numerically simulating the tensile experiments conducted using a finite element approach.

Dowel bars in jointed plain concrete pavement (JPCP) have the important function of transferring wheel loads from one slab to the other, hence ensuring that the deflections on each side of the joint are kept almost equal. As well, the dowels should not impede the concrete pavement movements due to environmental effects (temperature and moisture). Dowel bar misalignment, attributed to deficient construction practice, is a major cause of joint distress or faulting by inhibiting the free movement of the slab at the joint. To prevent these issues, tolerance guidelines on misalignment levels are implemented by transportation agencies. Review of previous studies indicate that many researchers analysed the effects of dowel bar misalignment on pavement behaviour using a pull-out test, that is a forcebased opening of the joint. These approaches neglect that joints movements in the field are strain-governed by non-linear temperature and shrinkage actions, leading to combined axial movements and curling of the slab. In this study, the fundamental dowel bar behaviour under shrinkage and thermal loading was determined through detailed 3D finite element modelling (3D-FEM). To that end, models of dowel jointed concrete slabs were developed and subjected to realistic non-linear profiles of shrinkage and thermal strains. Studies were carried out on a single-bar model, taking into account bar-concrete friction and plastic concrete behaviour. The parameters that were investigated included different configurations and levels of bar misalignment and different friction coefficients between the steel and the concrete, simulating the use of bond-breakers. To interpret the results from the numerical analysis, criteria for concrete damage were developed and used in parallel with measures of joint load transfer efficiency; these were obtained by examining the response of the slab under a Falling Weight Deflectometer (FWD) drop at the joint. The results were verified by comparing the outputs of a model consisting of one half of a slab to published data. The analysis of the models revealead that none of the models showed signs of significant damage after the application of shrinkage and two thermal cycles. Analyses with up to ten thermal cycles did not indicate progressive accumulation of damage, suggesting that for the chosen parameters there is no the concrete around the dowel bar will not fail. Models with bars placed higher in the slab and bars with angular misalignment exhibited more damage than the non-misaligned models without reaching the damage criteria used in this study. The models did not exhibit the amount of damage reported in the studies on dowel bar misalignment having used pull-out tests. It was found that no significant difference existed between uncoated and coated dowel bars models results with regards to concrete damage at the joint. However, a high coefficient of friction between the dowel and the concrete, simulating dowel bar corrosion, proved to be the most detrimental to joint integrity. All of the models performed very well with respect to joint load transfer efficiency, suggesting that the plastic strains in the concrete around the dowel did not have a significant impact on joint performance for the realistic range of parameters investigated.

The primary barrier to the production of better machined parts is machine tool error. Present day applications are requiring closer machine part tolerances. The errors in dimensional part accuracy derive from the machine, in this case, a vertical two axis CNC lathe. A two axis vertical lathe can be utilized to produce a variety of parts ranging from cylindrical features to spherical features. A vertical lathe requires a spindle to rotate the work at speeds reaching 3000rpm, while simultaneously requiring the machine tool to be positioned in such a manner to remove material and produce an accurate part. For this to be possible, the machine tool must be precisely controlled in order to produce the correct contours on the part. There are many sources of errors to be considered in the two axis vertical lathe. Each axis of importance contains six degrees of freedom. The machine has linear displacement, angular, spindle thermal drift, straightness, parallelism, orthogonal, machine tool offset and roundness error. These error components must be measured in order to determine the resultant error. The characterization of the machine addresses thermal behavior and geometric errors. This thesis presents the approach of determining the machine tool errors and using these errors to transform the actual tool path closer to the nominal tool path via compensation schemes. One of these schemes uses a laser interferometer in conjunction with a homogenous transformation matrix to construct the compensated path for a circular arc, facing and turning. The other scheme uses a ball bar system to directly construct the compensated tool path for a circular arc. Test parts were created to verify the improvement of the part accuracy using the compensated tool paths.

This dissertation consists of three parts. In the

Cognate mechanisms have been often used in design of linkages. Improper positions of fixed link or transmission angle could be improved effectively. Cognate mechanisms of planar linkages have been developed well, but the research on the spherical cognate is still wild open. There are just only spherical supplement mechanisms that have been presented by Soni(1967) until today. The aim of this thesis is to investigate the existence of spherical four-bar linkages cognate mechanisms. The geometry and properties of planar cognate mechanisms are discussed and a simulation program is written for the planar cognate mechanism. Then, the characteristics of spherical mechanisms are considered and the spherical cognate simulation program is built by using the result of planar cognate as a reference. Three examples are given to demonstrate the existence of pseudo-cognates for spherical mechanisms.

Linkage mechanisms have been investigated for ages. The characteristics of planar four-bar linkages, though most fundamental of all, have laid the theoretical foundation of research and advancement of other linkages. Most papers have focused only on the standard crank-driven, torque-input four-bars, leaving the coupler-driven, force-input types comparatively less studied. Transmission performance is an important issue of mechanism design. In this thesis, an index that couples the coupler curve and the transmissivity of mechanical advantage for the coupler-driven, force-input four-bar is proposed. The new index, called the CCTMA, is used when its shape, length, curvature, and symmetry are inspected. A WS curve and a WS angle are also defined to facilitate the use and understanding of the CCTMA. A straightforward procedure is also presented for designing coupler-driven, force-input four-bar linkages. The idea of the CCTMA is introduced into the design process to exclude input coupler points what have unsatisfactory transmission properties. This procedure is also valid for improving existing coupler-driven, force-input four-bar mechanisms.

Peer-to-peer (p2p) approaches are an increasingly effective way to deploy services. Popular examples include BitTorrent, Skype, and KaZaA. These approaches are attractive because they can be highly fault-tolerant, scalable, adaptive, and less expensive than a more centralized solution. Cooperation lies at the heart of these strengths. Yet, in settings where working together is crucial, a natural question is: "What if users stop cooperating?" After all, cooperative services are typically deployed over multiple administrative domains, and thus vulnerable to Byzantine failures and users who may act selfishly. This dissertation explores how to construct p2p systems to tolerate Byzantine participants while also incentivizing selfish participants to contribute resources. We describe how to balance obedience against choice in building a robust p2p live streaming system. Imposing obedience is desirable as it leaves little room for peers to attack or cheat the system. However, providing choice is also attractive as it allows us to engineer flexible and efficient solutions. We first focus on obedience by using Nash equilibria to drive the design of BAR Gossip, the first gossip protocol that is resilient to Byzantine and selfish nodes. BAR Gossip relies on verifiable pseudo-random partner selection to eliminate non-determinism, which can be used to game the system, while maintaining the robustness and rapid convergence of traditional gossip. A novel fair enough exchange primitive entices cooperation among selfish peers on short timescales, thereby avoiding the need for distributed reputation schemes. We next focus on tempering obedience with choice by using approximate equilibria to guide the construction of a novel p2p live streaming system. These equilibria allow us to design incentives to limit selfish behavior rigorously, yet provide sufficient flexibility to build practical systems. We show the advantages of using an [element of]-Nash equilibrium, instead of an exact Nash, to design and implement FlightPath, our live streaming system that uses bandwidth efficiently, absorbs flash crowds, adapts to sudden peer departures, handles churn, and tolerates malicious activity. / text