<p>The rolling isolation system (RIS) studied in this dissertation functions on the principle of a rolling pendulum; an isolated object rests on a steel frame that is supported at its corners by ball-bearings that roll between shallow steel bowls, dynamically decoupling the floor motion from the response of the object. The primary focus of this dissertation is to develop predictive models that can capture experimentally-observed phenomena and to advance the state-of-the-art by proposing new isolation technologies to surmount current performance limitations. To wit, a double RIS increases the system's displacement capacity, and semi-active and passive damped RISs suppress the system's displacement response.</p><p>This dissertation illustrates the performance of various high-performance isolation strategies using experimentally-validated predictive models. Effective modeling of RISs is complicated by the nonholonomic and chaotic nature of these systems which to date has not received much attention. Motivated by this observation, the first part of this dissertation addresses the high-fidelity modeling of a single, undamped RIS, and later this theory is augmented to account for the double (or stacked) configuration and the supplemental damping via rubber-coated bowl surfaces. The system's potential energy function (i.e. conical bowl shape) and energy dissipation model are calibrated to free-response experiments. Forced-response experiments successfully validate the models by comparing measured and predicted peak displacement and acceleration responses over a range of operating conditions.</p><p>Following the experimental analyses, numerical simulations demonstrate the potential benefits of the proposed technologies. This dissertation presents a method to optimize damping force trajectories subject to constraints imposed by the physical implementation of a particular controllable damper. Potential improvements in terms of acceleration response are shown to be achievable with the semi-active RIS. Finally, extensive time-history analyses establish how the undamped and damped RISs perform when located inside biaxial, hysteretic, multi-story structures under recorded earthquake ground motions. General design recommendations, supported by critical-disturbance spectra and peak-response distributions, are prescribed so as to ensure the uninterrupted operation of vital equipment.</p> / Dissertation

Previous studies have demonstrated that observers may ignore highly salient feature singletons during a conjunction search task through focusing the attentional window (Belopolsky, Zwaan, Theeuwes, & Kramer, 2007), or by the suppression of bottom-up information (Treisman & Sato, 1990). In the current study, observers’ eye movements were monitored while performing a search task in which a feature singleton was present and corresponded with the target at a chance level. With practice, observers were less likely to make an initial saccade toward the singleton item, but initial saccades directed at the target were likely throughout. Results demonstrate that, in an effort to ignore the singleton, observers were more likely to suppress bottom-up information than adjust the size of the attentional window.

Age-related inhibitory effects were investigated during spatial memory performance. In Experiment 1, 15 young (M = 20 years) and 16 old adults (M = 70 years) completed two spatial tasks (i.e., Block Suppression Test, Corsi Block Tapping Test) that differed in need for inhibitory processing. Accuracy differences within each task revealed age-related differences in spatial working memory and between task differences revealed that older adults had difficulty ignoring irrelevant items. Experiment 2 (10 young, 10 old adults) examined whether the distractibility of irrelevant items in the inhibition task (i.e. BST) accounted for the age-related inhibitory effects. Findings were largely consistent with the initial experiment indicating that inhibitory function was affected by adult aging.

Cognitive bias and thought suppression are two maladaptive patterns of thinking that have been associated with borderline personality disorder (BPD). Negative cognitive biases related to BPD include thoughts that they are bad, powerless, or vulnerable and that the world is dangerous. Thought suppression is a maladaptive emotion regulation strategy where unwanted thoughts are intentionally pushed out of one’s consciousness. However, previous research has connected thought suppression and cognitive biases to BPD only via self-report measures. The present study examined whether a laboratory task meant to measure cognitive bias and thought suppression (Scrambled Sentences Test) would predict BPD features over and above self report measures of cognitive bias and thought suppression. A sample of 153 undergraduates completed self-report measures of BPD features, thought suppression, and negative cognitive biases, as well as the Scrambled Sentences Test (SST). Results showed that while the SST was a good predictor of cognitive biases, it did not predict thought suppression when self report measures were included. Recognizing the importance of negative cognitive bias in BPD may be useful in continued treatment development. Further research into other ways of measuring thought suppression and cognitive biases in the lab may be warranted.

Reduced tillage and living mulches are alternative management strategies that can improve soil quality by minimizing disturbance and building soil organic matter. Weed suppression by these two practices alone is often insufficient to avoid crop yield losses, but their performance in an integrated system is not well understood. This project investigated the production of bell pepper (Capsicum annuum L.) and dry bean (Phaseolus vulgaris L.) in conventional tillage and strip tillage with a living mulch of teff (Eragrostis tef Zucc.) and Korean lespedeza (Kummerowia stipulacea Maxim.). Yields of pepper and bean were generally higher under conventional tillage without living mulch. Weed biomass was not influenced by tillage, and was adequately suppressed by teff in a year when conditions for teff growth were favorable. Mowing appeared to suppress weed growth but not living mulch growth. Soil nitrate and ammonium concentration was generally higher under conventional tillage without living mulch. Delaying living mulch seeding by 15 days after crop establishment generally did not affect weed suppression or crop yield. Soil aggregate stability was not consistently affected by tillage or living mulch. Increased mowing frequency, living mulch planting delay, or distance between the crop row and the living mulch may be necessary to achieve acceptable yields with living mulches.

La radio astronomie étudie les sources cosmiques au travers de leur rayonnement dans le domaine radio. Les astronomes, utilisateurs passifs du spectre électromagnétique, ont à faire face à une pollution radio de plus en plus importante. Cette thèse s'intéresse particulièrement aux interférences radio d'origine humaine (RFI), et comment les observations radio astronomiques peuvent être réalisées en bandes de fréquences non-protégées. Les approches classiques consistent à contrôler les paramètres statistiques d'une observation. Une fois détectées, les données polluées sont retirées avant post-traitement. En plus d'autres avantages techniques par rapport aux radiotélescopes paraboliques classiques, les réseaux d'antennes offrent une information spatiale lors d'une observation astronomique. La diversité spatiale entre source cosmique d'intérêt (SCOI) et RFI peut être exploitée pour développer des traitements spatiaux d'interférences. Après la formulation d'un module de données multidimensionnel, une technique de soustraction de sous espace RFI est introduite. Cette technique consiste à soustraire la contribution des RFI aux données d'une observation. La projection orthogonale a déjà été considérée auparavant. Cependant, l'orthogonalité requise entre CSOI et RFI pour retrouver une source d'intérêt non biaisée ne peut vraisemblablement pas être satisfaite. Une approche basée sur une projection oblique est introduite afin de pallier à cette condition. Les techniques de projections sont comparées aux techniques classiques de beamforming en termes de réjection de l'interférence et de récupération de la source d'intérêt. Le sous-espace RFI est inconnu de manière générale et se doit d'être estimé. Plusieurs techniques permettant cette estimation, basées sur des propriétés statistiques des RFI et sources cosmiques, sont également présentées et comparées. Les différentes techniques ont été appliquées à des données astronomiques délivrées par le radio télescope Européen LOFAR. Enfin, une implémentation d'un algorithme de traitement spatial d'interférences sur le démonstrateur EMBRACE est présenté.

Cette thèse est une contribution à l'amélioration des observations pour les radiotélescopes à réseaux phasés en présence d'interférences. L'originalité de cette thèse repose sur l'utilisation de la séparation spatiale entre les sources cosmiques et les brouilleurs issus des télécommunications en se basant sur la cyclostationnarité de ces derniers. Cette thèse s'inscrit dans le cadre du projet européen SKADS pour l'amélioration des techniques de suppression d'interférences en radioastronomie pour les futurs instruments d'observations.Nous avons proposé trois techniques de traitement d'interférences : la détection,l'estimation et la soustraction, et le filtrage spatial. Les performances des techniques proposées ont été évaluées à travers des simulations sur des données synthétiqueset/ou réelles, et comparées aux techniques existantes.

This degree project is divided into two subprojects. Both of the projects are executed for Fogmaker, a company that specialises in designing and installing fire suppression systems in engine compartments. These projects are executed according to product development methods. The first subproject described in this report is about designing a handle for the transportation of a 35kg weighing fire extinguisher. The handle functions as a safety seal and as a grip that makes it easier and safer to lift the fire extinguisher. A casted zinc T-handle is the best solution based on cost and AHP (Analytic Hierarchy Process) analysis. An FMECA (Failure Mode Effect and Criticality Analysis) and a FEM (Finite Element Method) study have been performed to verify the design. A zinc prototype of the safety handle has been manufactured and is ready for testing. It is expected that 10.000 handles will be produced every year once this prototype is approved by Fogmaker. The second subproject concerns a connection hub placed on a pressurized bottle. In order to make the fire suppression system more reliable this component needs to be redesigned. An external company with the required expertise in hydraulic systems will develop the connection hub in cooperation with Fogmaker, based on the conceptual designs described in this report. An FMECA of the new connection hub concept proves this redesign increases the safety of the system. The overlying subject of both of these projects is the safety of the fire suppression system. Thanks to the accomplishment of both project, the system has become safer and more reliable.

The pathogen Campylobacter fetus (CF) is classified into two subspecies, Campylobacter fetus subspecies fetus (CFF) and Campylobacter fetus subspecies venerealis (CFV). Even though CFF and CFV are genetically closely related, they exhibit differences in their host adaptation; CFF inhabits the gastrointestinal tract of both humans and several animal species, while classical CFV is specific to the bovine genital tract and is of particular concern with respect to international bovine trade regulation. Traditionally, differentiation between the two subspecies has been achieved using a limited number of biochemical tests but more rapid and definitive genetic methods of discrimination are desired. A recent study suggested that the presence of a genomic island only in CFV could discriminate between the two sub- species but this hypothesis could not be confirmed on a collection of isolates originating in Canada. To identify alternative gene targets that would support accurate subspecies discrimination, this study has applied several approaches including suppression subtractive hybridization and whole genome sequencing supplemented with optical mapping. A subtractive hybridization screen, using a well-characterized CFV isolate recovered during routine screening of bulls in an Artificial Insemination center in western Canada and that lacked much of the genomic island and a typical Canadian CFF isolate, yielded 50 clones; characterization of these clones by hybridization screening against selected CF isolates and by nucleotide sequence BLAST analysis identified three potentially CFV-specific clones that contained inserts originating from a second genomic island. Further screening using a larger CF sample set found that only Clone #35 was truly CFV-specific. Optical maps (NcoI digest) of the Canadian CFF and CFV isolates used for the subtractive hybridization showed that certain regions of these genomes were quite distinct from those of two reference strains. Whole genome sequencing of these two isolates identified two target genes (PICFV5_ORF548 and CFF_Feature #3) that appear to be selectively retained in the two subspecies. Screening of a collection of CF isolates by PCRs targeting these three loci (SSH_Clone #35, PICFV5_ORF548 and CFF_Feature #3) supported their use for subspecies discrimination. This work demonstrates the complex genomic diversity associated with these CF subtypes and the challenge posed by their discrimination using limited genetic loci.

Charmed hadron production has been studied in 225 pb^-1 of data collected with the ZEUS detector in the HERA-II runnning period. Studies were made in the D* → D⁰π → Kππ decay channel to determine the potential for the microvertex detector to improve charm signals. Integrated cross sections were measured for the decays D⁰ → K⁰_sπ⁺ π⁻, D^± → K⁰_s π^±, D^±_s → K⁰s K^± and Lambda^±_c → Lambda⁰π^± in the kinematic region 5< Q² < 1000 GeV², 0.02 < y < 0.7, 1.5 < pT(D,Lambda_c) < 20.0 GeV, -1.6 < pseudorapidity(D, Lambda_c) < 1.6. The D⁰ cross section was additionally measured down to pT(D⁰) > 1.0 GeV. Differential cross sections as a function of Q², x, pT(D) and pseudorapidity(D) were measured for the D⁰, D^±, and D_s^± channels. The measurements were compared to next-to-leading order (NLO) QCD calculations, and good agreement found for all variables in all channels over the measured kinematic region. The strangeness-suppression factor, gamma_s = D_s^±/(D^± + D⁰), was measured and found to be in good agreement with values previously measured at HERA and elsewhere, and with the DJANGOH and RAPGAP Monte Carlo. The ratio of charmed baryons to mesons, Lambda_c^±/(D^± + D⁰), was measured and also found to be in good agreement with Monte Carlo.