Thesis (M.S.)--University of Michigan, 1992.

Cette thèse s'inscrit dans le cadre de l'étude de la stabilisation de modules d'un futur collisionneur linéaire, CLIC (Compact Linear Collider). Afin d'assurer le fonctionnement et la collision des particules dans ce futur grand instrument de physique, il faut garantir l'alignement de modules guidant des faisceaux de dimensions nanométriques. Les travaux développés ont pour support expérimental deux dispositifs : un dispositif de micropositionnement, avec une résolution inférieur au 1µm, où les perturbations peuvent être simulées et un prototype de nanostabilisation active pour charges importantes (>50kg @300Hz), avec une résolution validée expérimentalement inférieur à 0,15 nm, permettant de démontrer la faisabilité du contrôle de la stabilisation subnanométrique en s'intéressant particulièrement au rejet des mouvements du sol. Les problématiques traitées lors de ces travaux portent sur la méthodologie de conception de tels systèmes, ce qui inclue la conception électromécanique et l'instrumentation, ; la mise en œuvre et la modélisation du comportement des prototypes ,; le contrôle avec notamment les aspects de non linéarité des actionneurs. Les performances obtenues de ces différents travaux et validées expérimentalement incluent notamment les points suivants: La bande passante de fonctionnement pour du micro-positionnement à l'aide d'actionneurs piézoélectriques a été augmentée grâce à la compensation d'hystérésis : Rejet de perturbation issue du support jusqu'à 100 Hz et positionnement jusqu'à 190 Hz. Il a été démontré la faisabilité du contrôle à l'aide de capteurs sismiques. L'isolation active réalisée présente une atténuation des nano-mouvement du sol dans une bande passante comprise entre 12 et 100Hz. Expérimentalement, cela conduit à une réduction des mouvements du sol de 0,6nm [rms] à 0,25nm [rms] à 50Hz et de 3,7nm [rms] à 0,9nm [rms] à 20Hz. / This thesis takes place in the framework of a general study about the stabilization of the mechanical modules of a future linear collider, CLIC (Compact Linear Collider). In order to guarantee the good operation and the particle collision, the nanometer sized beams need to be stabilized. The proposed approach was developed on two mock-ups: one dedicated to micropositioning with disturbances generation capabilities, and an active isolation system operating heavy load (up to 50kg at 300Hz) at the nanometer scale with an experimentally validated resolution of 0.15 nm. This work studies the electromechanical design and the instrumentation, the implementation of the two set-ups and their modeling,; the control scheme that takes into account the nonlinearities of the actuators. The experimental achievements include the increase of the bandwidth for piezoelectric micro-positioning thanks to an inverse hysteresis operator: the perturbation rejection is efficient until 100 Hz and the tracking control until 190 Hz. A control scheme using seismic sensors is developed to attenuate ground motion and to isolate a platform in a 12 Hz to 100 Hz frequency range. The experimental displacement is reduced from 0.6 nm to 0.25 nm at 50 Hz and from 3.7 to 0.9 at 20 Hz.

SAMMANFATTNING   Bakgrund: Med dagens epidemiologiska förändringar ökar behovet av isoleringsvård för att förhindra spridningen av vårdrelaterade infektioner samt skydda patienter vid infektionskänslighet. Tidigare forskning visar att isolering kan upplevas psykiskt påfrestande. Ett flertal studier har fokuserat på ämnet och därför är det viktigt med en litteraturöversikt för att sammanställa denna forskning. För att kunna säkerställa en god omvårdnad krävs det att sjuksköterskor har god kunskap och förståelse om hur patienter upplever isoleringen. Genom denna litteraturöversikt kan medvetenheten hos sjuksköterskorna öka. Syfte: Syftet med denna litteraturöversikt var att utforska patienters upplevelser av att vara isolerade inom somatisk vård. Metod: En litteraturöversikt genomfördes för att analysera och sammanställa tidigare data från empiriska kvalitativa studier. Resultat: Resultatsanalysen resulterade i fyra kategorier: Positiva upplevelser av isolering, Negativa upplevelser av isolering, Vårdmiljöns betydelse och Vårdpersonalens betydelse. Slutsats: Resultatet i denna litteraturöversikt visar att upplevelsen av att vårdas isolerat varierade bland patienterna. Sjuksköterskan bör arbeta utifrån utgångspunkten att varje människa är unik och anpassa omvårdnaden individuellt för varje patient. Detta för att förebygga och minska lindande hos patienten. / ABSTRACT   Background: With today's epidemiological changes, the need for isolation care increases to prevent the spread of health-related infections and protect patients from infection susceptibility. Previous research shows that isolation can be experienced psychologically stressful. A number of studies have focused on the subject and therefore it is important to have a literature review to compile this research. In order to ensure good nursing care, nurses need good knowledge and understanding of how patients experience isolation. Through this literature review, the awareness of nurses can increase. Purpose: The purpose of this literature review was to explore patients' experiences of being isolated in somatic care. Method: A literature review was conducted to analyze and compile previous data from empirical qualitative studies. Results: The results analysis resulted in four categories: Positive experiences of isolation, Negative experiences of isolation, The importance of the health care environment and the importance of the care staff. Conclusion: The results of this literature review show that the experience of being cared for was varied among patients. The nurse should work on the basis that every person is unique and adjusts the care individually for each patient. This is to prevent and reduce unwinding of the patient.

Le sujet principal de la thèse est la mesure de la section efficace de production du boson de Higgs se décomposant en deux bosons Z dans l'état final à quatre leptons (H → ZZ * → 4l, l = e, μ), en utilisant 36.1 fb-1 de données collectées en 2015 et 2016 par l'expérience ATLAS au Grand Collisionneur de Hadrons (LHC) au CERN. La section efficace inclusive dans la chaîne de décomposition H → ZZ * → 4l est mesurée à 3.62 ±0.53 (stat) ± 0.25 (syst) fb, en accord avec la prédiction du Modèle Standard, de 2.91 ± 0.13 fb. Plusieurs sections efficaces fiducielles différentielles sont mesurées en fonction d'observables sensibles aux modes de production et de décomposition du boson de Higgs, incluant les variables cinématiques des jets produits avec le boson de Higgs. Les données et les prédictions du Modèle Standard sont en bon accord. Les sections efficaces extraites sont aussi utilisées pour contraindre des interactions anormales du boson de Higgs avec des particules du Modèle Standard.La deuxième partie de la thèse concerne l'isolation des muons. Les variables sont construites à partir des informations du tracker (isolation de trace) et des calorimètres (isolation calorimétrique). Elles mesurent l'activité ambiante autour de la trajectoire de la particule dans les détecteurs et constituent un outil puissant pour rejeter le bruit de fond. Avec les données collectées par ATLAS en 2015 et 2016,les distributions des variables sont comparées entre données et simulation. Des points de fonctionnement correspondant à des ensembles de coupures sur ces variables sont alors définis. En utilisant la décomposition du boson Z en deux muons, les efficacités du signal sont mesurées. Des facteurs d'échelle correspondant aux ratios entre données et simulation sont alors calculés. Le bon accord conduit à des facteurs d'échelle proches de l'unité. / The main subject of the thesis is the measurement of the production cross section of the Higgs boson decaying to two Z bosons in the four-lepton final state (H →ZZ * → 4l, l = e, μ), using 36.1 fb- 1 of data recorded during 2015 and 2016 with the ATLAS experiment installed at the Large Hadron Collider (LHC) at CERN. The inclusive fiducial cross section in the H → ZZ * → 4l decay channel is measured to be 3.62 ± 0.53 (stat) ± 0.25 (syst) fb,in agreement with the Standard Model prediction of 2.91 ± 0.13 fb. Several differential fiducial cross sections are measured for observables sensitive to the Higgs-boson production and decay, including kinematic distributions of the jets produced together with the Higgs boson. Good agreement is found between the data and the predictions of the Standard Model. The extracted cross-section distributions are also used to constrain anomalous Higgs-boson interactions with Standard-Model particles.The second part of the thesis is dedicated to the muon isolation. Isolation variables, based on information from the tracker (track-based isolation) and the calorimeters (calorimeter-based isolation) measure the ambient activity surrounding a particle in the detectors and are a powerful tool to reject background objects. Using36.1 fb-1 of data recorded by ATLAS in 2015 and2016, the variable distributions are compared with simulation. Working points are then defined as sets of cuts applied to the isolation variables. Using theZ boson decays to a pair of muons, the signal efficiency of the working points is calculated. Scale factors are then derived as ratio of efficiencies measured in data over simulation. The good agreement leads to scale factors close to one.

No description available.

Le cloud computing est un modèle informatique donnant accès à un grand nombre de ressources de calcul et de stockage. Trois types de cloud existent, le cloud public, le cloud privé et le cloud hybride. Afin de proposer une solution cloud hybride, nous utilisons le protocole TRILL qui permet d'optimiser l'utilisation des ressources réseau d'une infrastructure. Cependant, TRILL ne permet pas d'interconnecter des data centers sans perdre l'indépendance de leur plan de contrôle. Pour modifier ce comportement, lequel implique la création d'un unique domaine de broadcast s'étendant sur tout le réseau, nous proposons, comme première contribution, une solution (MLTP) qui permet d'interconnecter des réseaux TRILL tout en les maintenant indépendants. Un autre élément manquant de TRILL est l'isolation des flux réseau. Notre seconde contribution consiste donc à trouver et implémenter une solution d'isolation des flux au sein de MLTP. Ce nouveau protocole (MLTP+VNT), permet d'avoir une solution de cloud hybride, mais elle possède deux désavantages. Le premier est la gestion des pannes. Certains éléments de MLTP+VNT, les Border RBridges (BRB), contiennent des informations nécessaires au routage inter-data center et lorsqu'ils tombent en panne, ces informations sont perdues. Pour éviter cela, nous avons, dans notre troisième contribution, modifié MLTP+VNT pour synchroniser les BRBs. Le second est l'obligation de n'utiliser que des réseaux MLTP+VNT pour réaliser un cloud hybride. Pour lever cette restriction, nous avons, dans notre quatrième contribution, conçu une passerelle entre un réseau TRILL, pour le cloud public, et un réseau OpenFlow, pour le cloud privé. / Cloud computing uses infrastructure with a lot of computing and storage resources. There are three types of cloud: Public cloud, Private cloud, and Hybrid cloud. In order to provide a hybrid cloud solution, we used as a base the TRILL protocol which optimizes the use of the data center infrastructure. However, TRILL cannot interconnect data centers as doing so will merge the data centers networks and each data center will lose its independence. Our first contribution is to change this behavior and we develop MLTP which allows to interconnect TRILL or MLTP network without merging them. Another functionality missing from TRILL is network isolation. To fill this lack, in our second proposal we add to MLTP a solution called VNT and we then have a new protocol called MLTP+VNT. In this protocol, each user traffic is isolated from one another. Therefore, MLTP+VNT allows to have a hybrid cloud environment. Nevertheless, it has two shortcomings. The first one is its “single” point of failure. As a matter of fact, MLTP+VNT uses a new type of nodes called Border RBridges which contains inter-data centers routing information. If a Border RBridge fails, then the information it contained is lost. In order to prevent this loss, we implement a method to synchronize the Border RBridges in our third contribution. The second shortcoming is the obligation to use MLTP+VNT in each network to form the hybrid cloud. To lift this limitation, we design and develop, in our fourth contribution, a bridge between a MLTP+VNT network and an OpenFlow network. This way, our solution allows to create a hybrid cloud environment with the MLTP+VNT solution in the public cloud and OpenFlow in the public cloud.

Cette thèse est motivée par diverses questions qui se posent quant à l’utilisation de l’isolation sismique dans l’industrie nucléaire. À la différence de la grande majorité des travaux antérieurs sur l’isolation sismique en générale et l’isolation mixte en particulier, qui portent principalement leur intérêt sur la réponse de la structure isolée (déplacements relatifs, accélérations maximales des étages, etc.), une grande partie de ce travail est consacrée au comportement des équipements, par le biais de l’étude des spectres de plancher. L’objectif principal est de diminuer la déformation des isolateurs sans amplification de la réponse des modes supérieurs, qui peut apparaître sous certaines conditions et qui peut être une source de sollicitation des équipements. Pour ce faire, des alternatives aux appuis parasismiques couramment utilisés sont explorées. Il s’agit des combinaisons d’un appui à faible amortissement avec un élément de Maxwell (isolateur de relaxation) ou avec un amortisseur hydraulique semi-actif (système d’isolation mixte). L’élément de Maxwell se comportant comme un amortisseur à basse fréquence et un ressort de faible rigidité à haute fréquence permet de satisfaire l’objectif souhaité. En ce qui concerne les systèmes d’isolation mixtes, trois techniques de contrôle semi-actif sont proposées. Afin d’améliorer la performance du contrôle, une attention particulière a été donné à la prise en compte de l’excitation sismique et des caractéristiques de l’amortisseur lors de la conception du contrôleur est focalisée. Les analyses numériques confirment l'efficacité de ces systèmes. En vue de l’utilisation de ces méthodes pour de structures réelles, certains aspects pratiques comme, par exemple, l’observation du système, les effets de la réduction du modèle utilisé par le contrôleur ou du temps de retard sur la performance du contrôle, ainsi que le contrôle d’un ensemble de plusieurs dispositifs semi-actifs redondant, sont, également, abordés. / This thesis is motivated by various questions that arise regarding the use of base isolation in the nuclear industry. Unlike the majority of previous work on base isolation in general and mixed isolation in particular, which focus mainly on the response of the isolated structure (interstorey drifts, maximum accelerations of floors, etc.), this work focuses on the behavior of equipment, through the study of floor response spectra. The main objective is to reduce the deformation of the isolators without amplification of the response of the higher modes, which may appear under certain conditions and which can be a source of equipment solicitation. To this end, alternatives to the commonly used base isolators are explored. These are combinations of a low damping rubber bearing with a Maxwell element (relaxation isolator) or a semi-active hydraulic damper (mixed base isolation system).Maxwell element behaves like a damper in low frequency and as a low stiffness spring in high frequency. Hence it meets the above objectives. . Regarding isolation systems, three semi-active control techniques are proposed. In order to improve the performance of the control, the seismic excitation and the characteristics of the damper are taken into account in the design of the controller. Numerical analyzes confirm the effectiveness of these systems. Having in mind implementation of these methods to real structures, some practical aspects such as, observation of the system, effects of model reduction, considered by the controller, or time delay on the control performance, as well as the control of a set of redundant semi-active devices, are also studied.

Bakgrund: Isolering kan leda till psykosociala biverkningar och negativa känsloupplevelser, vilket tidigare forskning har uppmärksammat. Utifrån de identifierade omvårdnadsproblemen designades en litteraturstudie för ytterligare undersökande av patienters upplevelser vid isoleringsvård.    Syfte: Syftet var att undersöka patienters upplevelser av isolering i samband med allmänfarlig sjukdom på sjukhus.    Metod: Allmän litteraturöversikt med deskriptiv design.    Resultat: I patienternas upplevelser identifierades fem olika teman: stigmatisering, känslor, miljö, socialt liv och vård. I resultatet framkom det att patienter i isolering har många negativa upplevelser relaterat till vården och miljön i isoleringen. Även det sociala livet och känslolivet påverkas och många upplever stigmatisering. Förutom de negativa upplevelserna framkom även vissa positiva upplevelser, främst relaterat till relationen med vårdpersonal samt fördelarna med det utökade privatlivet ett eget rum innebar.    Slutsats: Syftet med studien var att undersöka patienters upplevelser av isoleringsvård. I resultatet framkom det flera negativa och positiva upplevelser som till stor del stämde överens med tidigare forskning inom området. Studien gav en fördjupad förståelse för patienters situation under isoleringsvård. Denna ökade medvetenhet och kunskap behövs för att vårdpersonal genom riktade omvårdnadsåtgärder ska kunna förbättra omvårdnaden av isolerade patienter i framtiden. / Background: Isolation can lead to a variety of psychosocial problems and negative emotional experiences, which previous studies have shown. Based on the identified nursing problems, a literature study was designed to further explore patients experiences in source isolation.    Aim: The aim was to investigate patients experiences of being isolated with a disease dangerous to public health in a hospital setting.    Method: A general literature review with descriptive design.    Result: The patients experiences were identified and categorized into 5 themes: stigma, feelings, enviornment, social life and care. The results showed that patients in isolation have a lot of negative experiences related to care and the environment in the isolation ward. The social life and feelings of the patients were also affected, and many reported that they experienced stigmatization. Aside from the negative experiences there were also some positive ones, mainly related to the relationship between the patients and the hospital staff and the extended privacy of having your own room in the ward.    Conclusion: The aim was to investigate patients experiences of source isolation. This study shows both negative and positive experiences among patients in source isolation, which mainly aligned with already existing studies. The result of this study gave a better understanding of patients experiences in source isolation. This knowledge and awereness is needed by healthcare workers to be able to improve the care of patients in isolation with targeted nursing care measures.

During strong ground motions, structures equipped with base isolation systems have been shown to have their seismic demand significantly reduced, mitigating adverse effects such as damage and loss of life. More recently, the fiber-reinforced elastomeric isolator (FREI) has been investigated as a relatively new type of isolator for the base isolation of structures. Constructed from alternating layers of elastomer and carbon-fiber cloth, FREI can be produced in large pads that can be cut to any desired size and shape when required. In bridges, FREI can to be used in an unbonded application (U-FREI) by placing them between the bridge deck and the piers. Experimental and numerical investigations have shown U-FREI as a viable option for the isolation of bridges. However, experimental studies have been limited to room temperature testing. In North America, climates vary drastically across the continent. Northern climates, such as those existent in Canada, are capable of reaching extremely low temperatures. Thus, base isolated bridges in these regions require isolation systems that perform adequately at cold temperatures. The studies presented in this dissertation have been completed in order to investigate the effects that low temperatures have on U-FREI used in bridge structures. An experimental program was conducted that evaluated the behaviour of U-FREI. It was found that U-FREI performed adequately under lateral displacements expected during a seismic event, and provided acceptable response under vertical and rotational testing that is typical of normal bridge operation. Using these results, a numerical model for U-FREI was then updated to account for the effects of low temperature. The model was combined with a bridge model to evaluate the seismic response of a bridge structure isolated with U-FREI subjected to low temperatures. A substantial reduction in seismic demand was achieved, even under the most severe conditions tested. / Thesis / Master of Applied Science (MASc)

Yes / Many governments including Malaysia imposed movement restrictions as public health measure to minimize COVID-19 (coronavirus) risks. Due to prolonged isolation, poorer physical and mental health is expected in the general population. Our aims were to examine (1) the mediating role of perceived social isolation (SI) and fear of social isolation (FSI) on the relationship between gratitude and anxiety, and (2) to explore the moderating role of age, education and socioeconomic status (SES) on the mediation model. A total of 427 participants currently living in Malaysia (Mage = 37.90, SD = 16.51, 313 females) completed a survey on isolation, gratitude and anxiety during a period of national lockdown. Results showed that that those with higher gratitude reported having less SI and FSI and less anxiety (Model 1). In Model 2 with age as moderator, young adults (YA) and middle-aged adults (MA) who had higher gratitude experienced lower SI and in turn had lowered anxiety, but such mediating role of SI was not observed among older adults (OA). As for FSI, MA who had higher gratitude had lower FSI and also lower anxiety but this relationship was not observed in YA or OA. We also examined the role of education and SES as moderators in the parallel mediation analysis. Results showed that the indirect association of gratitude with anxiety via FI and FSI was moderated by both education and SES. Specifically, among those with low education levels (regardless of SES), those with higher gratitude had lower SI and FSI which in turn reduced anxiety. This relationship is similar for those with medium level of education and from low and middle level of SES as well. Our findings highlight the importance of having some coping mechanism e.g., gratitude and social connection during the pandemic to have higher wellbeing and quality of life, especially for MA sample and people from low education and SES background. / This work was supported by Newton Fund Institutional Links grant ID: 331745333, under Newton-Ungku Omar Fund partnership to MHY. The grant is funded by the UK Department for Business, Energy and Industrial Strategy and Malaysian Industry-Government Group for High Technology (MIGHT) and delivered by the British Council. For further information, please visit www.newtonfund.ac.uk . The Newton Fund played no role in the planning and conceptualization of the manuscript, did not participate in the writing of the manuscript, and played no role in the decision to submit the manuscript.