Au cours de cette thèse une technique d'imagerie ultrasonore nommée "Supersonic Shear Imaging (SSI)", capable de quantifier en temps réel l'élasticité de cisaillement des tissus, a été utilisée pour la caractérisation des tissus biologiques. Des études cliniques et précliniques ont été réalisées pour évaluer le potentiel de la technique pour suivre les changements de propriétés élastiques dus au développement de cancer ou encore aux traitements thérapeutiques. Une étude clinique a été réalisée sur 23 patientes présentant des lésions du sein ayant subi un traitement de chimiothérapie à l'Institut Curie. Le but de cette étude était d'utiliser pour la première fois l'élastographie 3D pour estimer le volume et l'élasticité globale de tumeurs en cours de traitement par chimiothérapie. Les volumes tumoraux estimés sur les images échographiques ont été comparés aux estimations d'imagerie par résonnance magnétique (IRM) et ont montré une bonne corrélation. Les résultats de l'étude ont montré que la 3D-SWE permet de suivre la réaction tumorale à la chimiothérapie en offrant des mesures précises d'élasticité tumorale en trois dimensions tout au long de l'étude. La technique SSI a été utilisée pour la surveillance des tissus cancéreux dans le cadre de deux études précliniques, réalisées chez des souris nues. L'une des études, menée en collaboration avec l'Hôpital Européen Georges-Pompidou (HEGP), vise à comprendre la rigidité pathologie sous-jacente. L'imagerie a été utilisée pour surveiller la croissance et la réaction à la chimiothérapie de carcinomes humains implantés sur des souris. Les résultats ont montré que pour ce modèle particulier de tumeur, le volume tumoral et l'élasticité de la tumeur étaient très bien corrélées. Les analyses histo-pathologiques ont révélé que l'élasticité de la tumeur est également très bien corrélée avec la nécrose tumorale et la fibrose. La deuxième étude préclinique, réalisée en collaboration avec la Faculté de Pharmacie de l'Université Paris Descartes V, a permis d'évaluer la faisabilité d'utiliser l'imagerie d'élasticité pour suivre un traitement anti-vasculaire sur un type particulier de carcinome du côlon humain implanté chez des souris. Les résultats ne montrent pas de tendance claire de variation de l'élasticité associée au traitement. Afin d'étudier de nouveaux paramètres mécaniques supplémentaires qui permettent une meilleure caractérisation des tissus, une méthode combinant des compressions quasi-statiques axiales et la technique SSI a été mise au point pour mesurer la non-linéarité de cisaillement des tissus. Les premières cartes connues de non-linéarité 2D ont été calculées sur des fantômes imitant les tissus et des échantillons ex vivo de foie de boeuf avec une bonne précision.

This Paper analyzes the factors influencing the labor force participation of low-income adults on public housing assistance. A quasi-experiment is designed to fulfill the purpose of measuring the magnitudes of certain attributes of given individuals, e.g. the age in influencing employment status while controlling other factors such as other personal attributes and living environments. A number of logistic regressions are performed to assist the empirical analysis. Two final models are presented while statistical results are diagnosed to ensure the reliability of findings. Based on the unique data provided by AHA (the Atlanta Housing Authority), over 70 variables are analyzed to determine their significance on influencing individuals¡¯ future employment status. Finally, we find five the most significant predictors to be the individual¡¯s current employment status, age, and income, whether one resides in a mixed-income community in comparison to living in a housing project, and whether one uses housing vouchers in comparison to living in a housing project. The individual¡¯s immediate living environment is found to play an extremely important role in shaping his/her future employment status. The results demonstrate that living in the mixed-income community as opposed to living in conventional public housing projects can boost one¡¯s odds of being employed in the future by 170% while using housing vouchers as opposed to living in traditional public housing can increase one¡¯s odds of being employed by 90%. Both statistics are significant even at the 0.001 level. Hence, our findings strongly support the view that environment matters and distressed public housing projects should be revitalized, which has been a controversial topic over years. This study introduces an innovative index system-that consists of the Family Development Index (FDI), the Neighborhood Development Index (NDI), and the Quality of Life Index (QLI)-developed by Dr. Boston to show the development of low-income adults¡¯ socio-economic status and living environments induced by the revitalization of public housing projects in Atlanta over the period of 1995-2001. Based on this innovative index system, this paper tentatively proposes a reasonable approach to separate the self-selective effect from the environmental effect in influencing the labor force participation, which has long been reckoned as a complex task in social science research. We create the Self-distinguishing Index (SDI) based on a similar mechanism by which Dr. Boston created the FDI and NDI and combine it with the FDI to generate the Self-selective Index (SSI). We also modify the NDI to serve our purpose of measuring the environmental changes at the personal level. By this method, we successfully detach the self-selective effect from the environmental effect in determining the individual¡¯s future employment status. Those two effects are found to be significant at the 0.001 level and the 0.01 level respectively. A side-finding that individuals belonging to the treatment group have significantly better odds of being employed in the future is shown as well.

<p>The focus of this study is on potential problems resulting from construction on expansive soils in Kibaha region, Tanzania. For the fact that most of the affected structures are founded on expansive soils, a clear understanding of the soil behaviour and their interaction with structures, specifically as they relate to shallow foundations, has been of more interest to the study in order to evaluate properly the source of the problem.</p><p>The geotechnical behaviour of expansive clay soils is investigated by looking into the geomorphologic, geological and climatic conditions and mineralogical composition of the soils in the study area. The geotechnical results are linked with the performance of the foundation as well as structures.</p><p>Two sites, representative of known problem-areas in Kibaha were selected for geotechnical tests. Geotechnical site investigation consisted of open trial pits, profile description and the collection of both disturbed and undisturbed samples.</p><p>The collected samples were submitted to soil laboratories at KTH and DIT for mineralogical composition tests, natural water content, density, Atterberg limits and swell tests (free swell and swelling pressure). The results of this investigation indicate that soil in Kibaha contains clay (31%), have high liquid limit (59%) and plastic limit (37%) which indicate high potential swell.</p><p>Since swell potential and swell pressure are key properties of expansive soils, the swell parameters were measured by free swell tests and one-dimensional oedometer swell tests respectively. The free swell ranged from 100% to 150% and the swell pressure was in the region of 45 kPa.</p><p>The properties of expansive soils were confirmed by the x-ray diffraction test which showed the presence of montmorillonite in the soil. It is from this fact that the source of the problem is in the expansive soils coupled with poor building materials.</p><p>Physical conditions of the surveyed properties in the area confirmed the hypothesis of building damages due to poor building materials triggered by expansive soils. In support of the obtained data, the actual behaviour of the foundations is supplemented with prototypes of strip foundations whose performances are to be monitored over a long period. Finally, suggested are the ways forward to solve the problem of foundation on expansive soil.</p>

The Swedish compulsory education system is not seen as high quality according to the (OECD, 2015). Instead eyes are turning towards Finland and Singapore for best practice. Sweden's results are falling in international assessments such as PISA and TIMMS (Skolverket, 2016a/2016b), despite high expenditure per capita and several education reforms lately, such as a new curriculum and new teacher training education. The Swedish Schools Inspectorate scrutinizes schools with the objective to ensure a good education in a safe environment and to sustain nationwide equity. The authority therefore has a decisive role in judging the quality of schools in Sweden. The objective of this thesis is to study the criticism of Swedish Schools Inspectorate towards schools that have received a penalty for not abiding the law. The data consists of six school inspection reports seen as a case. Qualitative analysis is used building on discourse analysis theory. The findings of the research are that discipline and value-based issues are two of the areas discussed most in the criticism of the Swedish Schools Inspectorate. The inspectors also seem to look for discrepancies between documents and school staff. Different groups have the power to express themselves on various issues, such as special educators in student health. The pupils are also given a strong voice and space to define their school in the reports.

The prototypes vibration test carried out for obtaining reliable information concerning machine’s dynamic properties in development process. Analysis results should be able to correlate with FE model to determine if some underlying assumptions (material properties &amp; boundary conditions) were correct. EMA used for extracting structure modal parameter under laboratory condition. However, EMA can generally not provide all required information concerning machine dynamic property. To simulate vibration in operating, it commonly requires the model based on dynamic properties of the machine under operating. Thus, vibration tests need carried out under operational condition. OMA is a useful tool for extracting information concerning dynamic properties of operating machine. This report concerns vibration test of part of mining machine under operating condition. Modal parameters extracted by two kinds of OMA methods. Results from OMA was compared with corresponding EMA results, illustrates reader the advantages of OMA.

No description available.

The current study examined specific aspects of human factors involved in driving a vehicle with a modified Drive-by-Wire (DBW) control system. A DBW system is an electro-mechanical system which controls the primary operations of a vehicle such as steering, acceleration, and braking using a controller such as a joystick. Designing a human interface system for a DBW system involves three main phases in the human factors design process namely user centric/ergonomic design conception, building a prototype and validating the prototype based on human factor considerations. The main objective and focus of this research is to conceptualize a more ergonomic DBW control interface based on human participant evaluations completed in a virtual reality driving simulator equipped with DBW controls. A secondary consideration is the gathering of data for the preparation of a future driver training course. The driving characteristics of 30 participants consisting of 3 different groups, ages 18-64, ages 65+,and people with disabilities were evaluated while driving with three different controllers: a joystick, a reduced effort steering wheel plus gas-brake lever combination (GB), and conventional vehicle controls (no Drive-by-Wire or NDBW), which included foot pedals and a steering wheel. The participants were required to drive through different scenarios such as mountain, city, and highway roads, in order to obtain user capabilities related to the steering, accelerating, braking, and compliance with traffic rules. To examine the steering lane data obtained from the simulator, percent error in lane deviation was calculated and presented against time. The results indicated that the joystick was the most difficult to drive on a straight road. The GB controller was easier to control on straight path maneuvers than the joystick, but it had an over-steering tendency at curves while the joystick was better at curves. To examine group differences of different variables, a one-way analysis of variance (ANOVA) was performed. Results showed that lane position variation, reaction time to brake, reaction distance and stopping distance had significance among variables such as maximum vehicle speed, improper space cushions, and missed turn signals, etc. Understanding the above characteristics can largely help in the development of a DBW interface system that heavily weighs human factors.

Virtual simulators have proven to be extremely effective tools for training individuals for tasks that might otherwise be cost-prohibitive, dangerous, or impractical. One advantage of using a virtual simulator is that it provides a safe environment for emergency scenarios. For many years the United States military and NASA have used simulators, including those affixed with drive-by-wire (DBW) controls, effectively and efficiently to train subjects in a variety of ways. A DBW system utilizes electrical circuits to actuate servo motors from a given input signal to achieve a desired output. In DBW systems the output is not directly mechanically connected to a control surface (steering, acceleration, deceleration, etc.); usually, the input controller is linked by electrical wires to a localized servo motor where direct control can be given. This project is aimed at developing a novel simulator for a future training program using DBW systems that caters specifically to individuals who currently use or will be using for the first time vehicle modifications in order to drive and maintain their independence. Many of these individuals use one or a combination of powered steering, acceleration, braking, or secondary DBW controls to drive. The simulator integrates a virtual training environment and advanced electronic vehicle interface technology (AEVIT) DBW controls (4-way joystick, gas-brake lever/small zero-effort steering wheel). In a 30 participant study of three groups (able-bodied individuals, elderly individuals, and individuals with disability), it was found that training with a DBW joystick steering system will require more instruction and simulator practice time than a gas-brake lever/small steering wheel combination (GB/S) to obtain a similar level of competency. Drivers using the joystick completed predetermined driving courses in longer times, at slower speeds, with more errors than the other DBW system. On average, the reaction time to a stopping signal was fastest with the gas-brake lever at 0.54 seconds. Reaction times for the standard vehicle controls and the joystick were 0.741 and 0.677 seconds respectively. It was noted that reaction times using DBW controls were shorter overall. When driving in traffic, drivers committed 4.9, 5.1, and 8.3 driving infractions per minute using standard vehicle controls (No Drive by Wire, (NDBW)), the gas/brake and steering system, and joystick system respectively. Most drivers felt that the GB/S system was easier to learn, easier to operate, safer, and more reliable than the joystick system.

The purpose of this study was to explore the evolution science content used during college students' negotiation of biology-based socioscientific issues (SSI) and examine how it related to students' conceptual understanding and acceptance of biological evolution. Specific research questions were, (1a) what specific evolutionary science content do college students evoke during SSI negotiation, (1b) what is the depth of the evolutionary science content reflected in college students' SSI negotiation, and (2) what is the nature of the interaction between evolution understanding and evolution acceptance as they relate to depth of use of evolution content during SSI negotiation? The Socioscientific Issues Questionnaire (SSI-Q) was developed using inductive data analysis to examine science content use and to develop a rubric for measuring depth of evolutionary science content use during SSI negotiation. Sixty upper level undergraduate biology and non-biology majors completed the SSI-Q and also the Conceptual Inventory of Natural Selection (CINS: Anderson, Fisher, & Norman, 2002) to measure evolution understanding and the Measure of Acceptance of the Theory of Evolution (MATE: Rutledge & Warden, 1999) to measure evolution acceptance. A multiple regression analysis tested for interaction effects between the predictor variables, evolution understanding and evolution acceptance. Results indicate that college students primarily use science concepts related to evolution to negotiate biology-based SSI: variation in a population, inheritance of traits, differential success, and change through time. The hypothesis that the extent of one's acceptance of evolution is a mitigating factor in how evolution content is evoked during SSI negotiation was supported by the data. This was seen in that evolution was the predominant science content used by participants for each of the three SSI scenarios used in this study and used consistently throughout the three SSI scenarios. In addition to its potential to assess aspects of argumentation, a modification of the SSI-Q could be used for further study about students' misconceptions about evolution or scientific literacy, if it is defined as one's tendency to utilize science content during a decision-making process within an SSI context.

The focus of this study is on potential problems resulting from construction on expansive soils in Kibaha region, Tanzania. For the fact that most of the affected structures are founded on expansive soils, a clear understanding of the soil behaviour and their interaction with structures, specifically as they relate to shallow foundations, has been of more interest to the study in order to evaluate properly the source of the problem. The geotechnical behaviour of expansive clay soils is investigated by looking into the geomorphologic, geological and climatic conditions and mineralogical composition of the soils in the study area. The geotechnical results are linked with the performance of the foundation as well as structures. Two sites, representative of known problem-areas in Kibaha were selected for geotechnical tests. Geotechnical site investigation consisted of open trial pits, profile description and the collection of both disturbed and undisturbed samples. The collected samples were submitted to soil laboratories at KTH and DIT for mineralogical composition tests, natural water content, density, Atterberg limits and swell tests (free swell and swelling pressure). The results of this investigation indicate that soil in Kibaha contains clay (31%), have high liquid limit (59%) and plastic limit (37%) which indicate high potential swell. Since swell potential and swell pressure are key properties of expansive soils, the swell parameters were measured by free swell tests and one-dimensional oedometer swell tests respectively. The free swell ranged from 100% to 150% and the swell pressure was in the region of 45 kPa. The properties of expansive soils were confirmed by the x-ray diffraction test which showed the presence of montmorillonite in the soil. It is from this fact that the source of the problem is in the expansive soils coupled with poor building materials. Physical conditions of the surveyed properties in the area confirmed the hypothesis of building damages due to poor building materials triggered by expansive soils. In support of the obtained data, the actual behaviour of the foundations is supplemented with prototypes of strip foundations whose performances are to be monitored over a long period. Finally, suggested are the ways forward to solve the problem of foundation on expansive soil. / QC 20101118