The purpose of this retrospective study was to examine the predictive value of quantitative MRI disc displacement for changes of TMD signs and symptoms in a pre-orthodontic adolescent patient sample. The sample consisted of fifty-five adolescent patients who had baseline temporomandibular joint MRI and longitudinal clinical records of TMD signs and symptoms. Thirty-eight were females and seventeen were males. The mean age was 12.9 ±1.6 years (range 7.4-16.6). Our analysis revealed that MRI right disc displacement has significant association with changes of ipsilateral joint locking. However, predictive value of disc displacement for changes of joint locking could not be analyzed due to small sample size. Nevertheless, MRI right disc displacement can distinguish subjects with persistent ipsilateral clicking from those who were persistently free of clicking from T1 to T2. These findings indicate that clinical assessment of right joint clicking is consistent with MRI determination of disc displacement.

Shallow foundations are extensively used to support structures of all sizes and derive their support from near surface soils. Thus, they are typically embedded up to a few meters into the soil profile. Designers of shallow foundations are required to meet two limit states: overall failure of the soil beneath the foundation (bearing capacity) and excessive settlement. Existing bearing capacity design methods use an assumed shearing plane within the soil and perfectly plastic soil behavior to estimate the ultimate resistance available. The immediate settlement of a shallow foundation is typically approximated using an elasticity-based method that does not account for actual, nonlinear soil behavior. A load test database was developed from footing load tests reported in the literature to assess the accuracy and uncertainty in existing design methodologies for calculating bearing capacity and immediate settlement. The assessment of uncertainty in bearing capacity and immediate settlement was accomplished through the application of a hyperbolic bearing pressure-displacement model, and the adaptation of the Duncan-Chang soil constitutive model to footing displacements. The prediction of bearing capacity using the general bearing capacity formula was compared to the bearing capacity extrapolated from the load test database using a hyperbolic bearing pressure-displacement model. On average the general bearing capacity formula under-predicts the bearing capacity and exhibits a significant amount of variability. The comparison was used to develop resistance statistics that were implemented to produce resistance factors for an LRFD based design approach using AASHTO load statistics. The Duncan-Chang model was adapted to predict bearing pressure displacement curves for footings in the load test database and used to estimate governing soil parameters. Bearing pressure-displacement curves fitted to the observed curves were used to back calculate soil stiffness. The soil stiffness was used with an elasticity-based displacement prediction method to evaluate the accuracy of the method. Finally, the back-calculated modulus from the fitted Duncan-Chang model was used to assess the accuracy and uncertainty associated with the elasticity-based K-factor, a correlation based stiffness parameter. In general the comparisons indicate that the current design procedures over-predict the bearing pressure associated with a given displacement and exhibit a significant amount of uncertainty. / Graduation date: 2012

Soils, like several other materials, exhibit strong time-dependent behaviour which can be evidenced in terms of creep or strain-rate effects. The degree of this rheological behaviour varies with the type of soil, its structure, and with the stress history. This effect is exacerbated in pile load testing where the procedure duration tends to be shortened under increasing time pressures. The modelling needed to interpret the results therefore becomes more and more complex, including soil viscosity, wave radiation into the soil and other significant phenomena. The objective of the research reported herein is to refine the rheological parameters characterizing the influence of the loading rate within the framework of a relevant pile/soil interaction model fed with dynamic measurements acquired during pile Dynamic Load Tests (DLTs). The final goal is to predict and simulate the quasi-static pile load settlement curve. The pile/soil interaction system is described by a non-linear mass/spring/dashpot system supposed to represent the pile and the soil, with constitutive relationships existing within and between them. These relationships account for the static and the dynamic or rheologic behaviour. A back-analysis process based on a matching procedure between measured and computed quantities allows one to characterize the pile/soil interaction in terms of constitutive and rheologic parameters based on the dynamic measurements. After optimisation of the matching procedure, the parameters obtained are used to simulate the “static” load-settlement curve. The matching procedure is based on an automatic and stochastic parameter perturbation analysis. Since the parameters influence the system response with a relative weight, they are sorted in order to optimise all the parameters by successively retrieving the most influential ones and working on the remaining ones. The back-analysis performed on real dynamic measurements in this research leads to an improved pile/soil interaction model. The slippage between pile and soil along the pile shaft must be explicitly taken into account. This refinement increases the number of degrees of freedom needed to describe the pile/soil system but brings deeper insight into the behaviour of an interfacing zone of limited thickness surrounding the pile shaft.

A new dynamic model is presented for piezoelectric tube actuators commonly used in high-precision instruments. The model captures coupling between motions in all three axes such as bending motion due to a supposedly pure extension of the actuator. Both hysteresis and creep phenomena are included in the overall actuator model permitting modeling nonlinear sensitivity in the voltage to displacement response. Experimental data on hysteresis and creep are presented to support the modeling. Experiments and model predictions show that due to coupling a voltage Vz corresponding to vertical displacement will produce lateral displacement that acts as a disturbance to the main lateral response. The resonance frequency for the lateral dynamics is inherently lower than that of the longitudinal dynamics. Therefore, Vz is expected to contain frequencies that may excite the lateral resonance. Accordingly, this out of bandwidth disturbance will not be well compensated for either in open or closed loop control of the actuator. In order to preserve performance in open loop actuator control and stability and performance in closed loop control, a large reduction in the bandwidth of vertical motion would be required to avoid exciting the first bending mode. / Singapore-MIT Alliance (SMA)

Concerns the situation of indigenous people in Argentina. / UN Job no.: G0511710 E. Material type: NGO written statements. Issued under agenda item 15, agenda document E/CN.4/2005/1.

The refugee problem is a canker in contemporary human affairs without the ‘limboness’ that protractedness adds to it. Yet many refugee situations, especially in Africa, become forgotten emergencies as women assume new roles both at the family and community level, whilst children are born and bred in camps which were meant to be temporary in the first place. This study explores the life situation of Liberian Refugee Women and Children at the Gomoa Budumburam Refugee Settlement in Ghana. It examines the livelihood means they employ as a means of coping, emphasisng their security and educational concerns. It touches on the challenges faced by the camp children or the youth a they strive to deal with their situation and assign meaning to their lives. Actor-oriented theories help conceptualise ways in which the refugees display agency in mediating the structures that enable them and/or constrain them in their protracted displacement. In view of the need to find solutions to the refugee problem, the three proposed solutions are examined in the light of the reasons informing refugees’ choice of one solution over the other. The concepts of Space and Place help analyse the realities of the solutions available vis-à-vis the preferred choice of the refugees. Highlighting the importance of hearing refugees’ voice on problems and solutions they consider viable in their situation, a qualitative methodological approach is employed. This is complemented by observations, focus group discussions, informal conversations as well as secondary data sources. The analysis relates the data collected to the outlined objectives, research questions and theories. It brings to the fore the resourcefulness displayed by the refugees as they employ various strategies to cope on a short and long term basis. The study has also revealed the refugees’ ideas about “home” as where one makes it, rather than a nostalgic country of origin to which one must return for life to be complete. (S) GBV has been highlighted as an area needing more attention than that accorded it presently if the causes of women’s vulnerabilities are to be addressed in a wholesome way. Suggestions have been made based on refugees’ recommendation as well as that of the organizations in place and the researcher’s.

Essay 1: Hurst and Lusardi (2004) use higher-order polynomials in wealth in estimating the relationship with entrepreneurship. They find evidence conflicting with the existence of extensive liquidity constraints in the United States. In this paper, their approach is replicated on Swedish data. A positive relationship between wealth and entrepreneurship is found, which supports the liquidity constraints hypothesis. Alternative methods attempting to handle the endogeneity problem and distinguish between absolute decreasing risk aversion and liquidity constraints give further support to the hypothesis. The paper suggests that there exist liquidity constraints in Sweden, which are possibly more extensive than in the United States. Essay 2: Displacement is expected to decrease the reservation wage of self-employment by decreasing earnings in paid employment and increasing the probability of unemployment. This paper examines whether displacement increases the probability of self-employment using propensity score matching on Swedish register-based data. The data include all individuals displaced due to plant closures in 1987 and 1988, and a random sample of 200,000 employed individuals. The results suggest that displacement almost doubles the probability of entering self-employment the year after displacement. A sub-sample analysis indicates that individuals with a potentially worse position on the labor market react more strongly to displacement in terms of entering self-employment. Essay 3: A large literature has studied the effect of displacement on labor market outcomes in general, but no one has evaluated how the displaced succeed as self-employed. This paper studies how the survival of the business is affected by displacement in connection to entry, using a discrete-time proportional hazard model on a matched sample of displaced and non-displaced individuals. The main result of the paper is that, as a consequence of previous displacement, the probability of switching from self-employment to paid employment decreases and the probability of switching to unemployment is unaffected.

During certain seasons, rural and peripheral locations with significant numbers of second homes become the destination for major traffic and commodity flows. The outcome of this seasonal flow can be somewhat problematic and cause conflicts. One of the most controversial issues of conflict is whether the demand for second homes has a displacement effect on permanent residents. It has been argued that, especially in attractive destinations, the demand for second homes has caused an involuntary out-migration of permanent residents. More affluent second home buyers can outbid the competition from permanent residents. Hence, permanent residents must buy dwellings elsewhere, or must leave due to rising living costs through increased property taxes in the area. This thesis aims to study the issue of second home induced displacement in attractive second home locations in Sweden. This is justified because it is unknown to what extent second homes have contributed to the problems in these areas. The thesis consists of four empirical studies presented in four separate papers. The studies derive from two different data sources. The first three papers are based on official register data, whereas the fourth paper is based on data collected from a questionnaire survey. The first paper is aimed at finding possible locations of second home induced displacement in Sweden. Results show that areas with a positive population development, proximity to the sea and with long traditions of tourism seem to attract second home owners. The Stockholm archipelago has been deemed to be the most attractive second home region in Sweden and a place that may possibly harbour second home induced displacement. The second paper tests the displacement theory in a regional context in the Stockholm archipelago. Results show that the number of second homes has decreased in favour of permanent homes. Further, the permanent homes’ share of the total property values in the area is increasing. Hence, permanent homes have strengthened their position, implying that dwellings used for permanent purposes have a higher impact on price inflation for dwellings than second homes do. The Stockholm archipelago is in a state of repopulation rather than second home induced displacement. Paper three examines in- and out-migration and dwelling development in three case study islands in the Stockholm archipelago. Results show that these islands have the preconditions for displacement. However, results also show that individuals leave the islands for reasons associated with major events in life such as studies and job opportunities, not displacement. The final paper deals with second home related out-migration from the island of Sandö, one of the single most attractive destinations in Sweden. Results show that the out-migrants left the island on a voluntary basis and did not perceive themselves as being displaced. They state that their life improved after they left Sandö and they are, in general, not willing to return. The paper concludes that people move from the rural periphery to urban areas in order to find a better future and this move is not associated with a forced displacement. In conclusion, this thesis has shown that second home tourism is not a widespread problem or the main cause of depopulation in attractive second home destinations in Sweden. As for many other countries throughout the world, the preconditions for a displacement situation are present in many locations. However, other causes such as job opportunities and educational possibilities are more important in explaining the negative population development. Second home owners are described as an external threat to the traditional way of life and serve as convenient scapegoats, compared to less tangible and underlying causes, which are far more difficult to address.

During recent years there has been a great focus on the climate changes within the media. More or less every day more newspaper articles are presented about the global warming issue and the effect on us human race. Climate models predict higher temperatures and more rain in the northern part of Europe. It is also predicted that the weather will become more extreme e.g. it will rain a lot during longer periods than has been the norm. If these predictions are correct, the amount of water that is going to be transported away in streams and rivers will increase and so also will the subsoil water level. The latter increases the risk for landslides in areas with fine grained soils. An early warning system that is able to alert people before a landslide take place would be of great interest. The purpose of this work is to develop a complete real-time displacement monitoring system based on observations from several GPS-receivers that could be used as an early warning system. Due to the complex correlation structure of the traditionally used double differences, an alternative method based on undifferenced observations is used. Theoretically this approach shows some advantages and simplifies the correlative structure of observables compared to the double differenced method. A complete model for the undifferenced approach is presented in this thesis including its software implementation. A displacement detection system includes not only the positioning algorithms, but also methods to detect if any displacement occurs. There are many methods available to discriminate displacements, which are used in the traditional control of manufacturing processes. Several of these methods are compared in this thesis, such as the Shewhart chart, different Weighted Moving Average (WMA) charts and the CUmulative SUMmation (CUSUM). Practical tests show that it is possible to detect an abrupt shift on sub centimetre level at the same epoch as the shift occurs. Smaller shifts are also detectable with the applied approach but with a slightly longer detection time. / QC 20100624

In previous studies on suction box dewatering, three mechanisms were identified that determine the dry content of a web, viz. web compression, displacement of water by air and rewetting. In the present work, the relative importance of the three mechanisms was investigated through direct measurement of the web deformation, the dry content changes during and after the suction pulse, the air flow through the fibre network and the saturation of the web after the suction pulse. Suction pressure, suction time and rewetting time were varied. The experiments were done with chemical and mechanical pulp webs of various grammages. It was found that a large web deformation took place during the suction pulse, particularly at its beginning. Compression dewatering was found to be the most dominant dewatering mechanism. Displacement dewatering started after most of the web compression had occurred. Its contribution to the increase in dry content was most pronounced for higher suction pressures, longer suction times and for chemical pulp webs. A surprisingly large expansion of the web was observed immediately after the suction pulse. This expansion was the effect of rewetting. This rewetting strongly reduced the dry content of the web if the web had not been immediately separated from the forming fabric at the end of the suction pulse. Under the conditions studied, the decrease in dry content amounted to the order of 3 to 6 %. Rewetting was smaller for longer suction times and higher suction pressures. A considerable air flow through the web occurred under these conditions. This air flow apparently moved water from the forming fabric into the suction box, thus making less water available for rewetting. Rewetting for mechanical pulp webs was more pronounced and took place faster than for chemical pulps. The use of a membrane on top of the web during suction box dewatering proved to be advantageous for reducing the air flow through the web. However, under the conditions investigated, the dry content could not be improved. Although the web compression was increased when using a membrane, especially at a higher suction pressure, rewetting after the suction pulse had an even larger negative impact on the dry content, which, as a result, was lower. / QC 20100924