Direct model reference adaptive control of a flexible robotic manipulator

Quick, precise control of a flexible manipulator in a space environment is essential for future Space Station repair and satellite servicing. Numerous control algorithms have proven successful in controlling rigid manipulators wih colocated sensors and actuators; however, few have been tested on a flexible manipulator with noncolocated sensors and actuators. In this thesis, a model reference adaptive control (MRAC) scheme based on command generator tracker theory is designed for a flexible manipulator. Quicker, more precise tracking results are expected over nonadaptive control laws for this MRAC approach. Equations of motion in modal coordinates are derived for a single-link, flexible manipulator with an actuator at the pinned-end and a sensor at the free end. An MRAC is designed with the objective of controlling the torquing actuator so that the tip position follows a trajectory that is prescribed by the reference model. An appealing feature of this direct MRAC law is that it allows the reference model to have fewer states than the plant itself. Direct adaptive control also adjusts the controller parameters directly with knowledge of only the plant output and input signals

Improving health outcomes for girls : reflections on the impact on body issue of a girl\u27s only health and physical education intervention

Background: The issues surrounding girls' lack of participation in physical activity are many and varied, but\ud generally relate to the broader social context of adolescent health in which the social relations of gender play a significant part in a lack of engagement with sports; with a lack of physical skills and confidence for\ud equitable participation; friendship considerations; body image issues and a concern about bullying and\ud harassment.\ud \ud Objectives: This paper reports on data collected as part of a larger project researching the impact of a non-traditional physical education and health intervention designed to build girls connectedness to each other,\ud their school and their community by engaging them in a girls' only negotiated physical activity program that\ud was supported by a targeted health education curricula.\ud \ud Underlying values and principles: Grade 8 girls in the State of Victoria, Australia have the lowest school\ud connectedness data than any other cohort. Using youth participation principles and underpinned by strong\ud educational guidelines an integrated health and physical education program was developed by a high school\ud in Australia in an attempt to improve connectedness. It facilitated the exploration of a number of different\ud lifestyle physical activities such as bellying dance, self-defense and yoga, to engage the girls with alternative\ud physical activities that were potentially available in their community as well as discussion and activities on\ud sexuality, body image and mental health.\ud \ud Knowledge base/ Evidence base: Whilst evaluation of girls' only physical activity programs are not new,\ud research into the impact of an integrated school-based health and physical education curricula are and have\ud implications for future school based approaches.\ud \ud Context of intervention/project/work: The project initially focused on adolescent girls at a small 7-12\ud Secondary College in an isolated community approximately 200 kilometres from the Capital city of Victoria. A\ud grant was awarded to a consortium of local/regional agencies to implement and extend the program over\ud three years. Overwhelmingly the program was conducted by regional and local agencies in conjunction with\ud the local secondary school. It is a partnerships model built on the notion of increasing participation and\ud access for young women whilst building a sustainable program run in partnership with the school and local\ud agencies and services. In 2009 the program was also run in a metropolitan secondary school that had a\ud similar socia-economic background. This paper draws on data from both schools.\ud \ud Methods: This paper reports on qualitative date collected on young women's perceptions of the program, its\ud contribution to their health and wellbeing and the impact of the program on understandings of health related\ud issues of relevance to young women. The data is drawn from focus group data collected from two high\ud schools in the state of Victoria, Australia in 2007, 2008 and 2009. Sixty five girls' in grade 7, 8, 9 and 10\ud participated in the pre and post program interviews.\ud \ud Results and Conclusions: We argue that whilst the data indicates that a girls only program can have a\ud pOSitive impact on aspect of connectedness such as relationships with their peers, reducing bullying\ud behaviour, the data raises some important questions around the adequacy of school-based health education,\ud and the sustainability of approaches designed to be delivered by outside agencies rather than classroom\ud teachers. We argue that whilst single sex health and physical education programs may be necessary for girls\ud to participate and engage fully, the current approach has little impact on traditional notions of gender and\ud body issues.\ud \ud Disclosure of Interest: Centre for Educational Futures and Innovation, Grant Research Support. Victorian Health Promotion Foundation, Grant Research Support

Predicting the movements of permanently installed electrodes on an active landslide using time-lapse geoelectrical resistivity data only

If electrodes move during geoelectrical resistivity monitoring and their new positions are not incorporated in the inversion, then the resulting tomographic images exhibit artefacts that can obscure genuine time-lapse resistivity changes in the subsurface. The effects of electrode movements on time-lapse resistivity tomography are investigated using a simple analytical model and real data. The correspondence between the model and the data is sufficiently good to be able to predict the effects of electrode movements with reasonable accuracy. For the linear electrode arrays and 2D inversions under consideration, the data are much more sensitive to longitudinal than transverse or vertical movements. Consequently the model can be used to invert the longitudinal offsets of the electrodes from their known baseline positions using only the time-lapse ratios of the apparent resistivity data. The example datasets are taken from a permanently installed electrode array on an active lobe of a landslide. Using two sets with different levels of noise and subsurface resistivity changes, it is found that the electrode positions can be recovered to an accuracy of 4 % of the baseline electrode spacing. This is sufficient to correct the artefacts in the resistivity images, and provides for the possibility of monitoring the movement of the landslide and its internal hydraulic processes simultaneously using electrical resistivity tomography only

Non-invasive characterisation of road subgrade with towed-array capacitive resistivity imaging

A towed-array Capacitive Resistivity Imaging (CRI) system has been used in a controlled experiment to acquire multi-channel high-resolution ERT data on an asphalt road. Results from a CRI survey on a purpose-built trial road are discussed and compared to corresponding GPR profile data. It is demonstrated that CRI is particularly effective for the assessment of road subgrade condition. The technique is found to be sensitive to variations in moisture content and porosity in the subgrade layer, which can be used to distinguish areas of structural weakness in roadbeds. We conclude that CRI can be a valuable tool in pavement engineering as it provides complementary information to existing non-destructive testing techniques

Hydrogeological classification of superficial clays: apparent resistivity measurements from the Garboldisham, Norfolk pilot study area

Three types of apparent resistivity measurements have been undertaken at the Garboldisham pilot study area in Norfolk in support of the superficial clays programme. Resistivity soundings have established the intrinsic resistivities for the strata encountered. Cover sand (possibly mixed with glacial sand) ofresistivities 100 - 200 ohm.m overlies till ofresistivities 22 - 32 ohm.m which lies directly on chalk of resistivities 65 - 85 ohm.m. At the sounding sites, depth to chalk is in the range 11 - 15 m. Azimuthal apparent resistivity measurements were made in an attempt to identify fracture sets within the till and to establish the degree of fracturing between measurement sites. These fracture sets will have an important influence on the hydrogeological regime. At only two of the five sites investigated was a fracture trend recognised and this had an orientation of 210-225 degrees. There was an indication of a change in the intensity of fracturing between the two sites. The results indicate that there is either a lack of fracturing with a consistent trend within the till or that there is an insufficient resistivity contrast between the conductive till and the fractures. Detailed dipole-dipole apparent resistivity measurements undertaken with the BGS RESCAN system were able to map the thickness ofcover sand over a suspected sand channel. The sand body has a north - south orientation with a variable depth to the till surface. Maximum depths are up to two metres. The effectiveness of the resistivity technique for mapping sand lying on till has been demonstrated in this study

Controlled biomineralization of magnetite (Fe₃O₄) by <i>Magnetospirillum gryphiswaldense</i>

Results from a study of the chemical composition and micro-structural characteristics of bacterial magnetosomes extracted from the magnetotactic bacterial strain Magnetospirillum gryphiswaldense are presented here. Using high-resolution transmission electron microscopy combined with selected-area electron diffraction and energy dispersive X-ray microanalysis, biogenic magnetite particles isolated from mature cultures were analysed for variations in crystallinity and particle size, as well as chain character and length. The analysed crystals showed a narrow size range (∼14-67 nm) with an average diameter of 46±6.8 nm, cuboctahedral morphologies and typical Gamma type crystal size distributions. The magnetite particles exhibited a high chemical purity (exclusively Fe3O4) and the majority fall within the single-magnetic-domain range

Preventative tele-health supported services for early stage chronic obstructive pulmonary disease: a protocol for a pragmatic randomized controlled trial pilot

Background Chronic Obstructive Pulmonary Disease (COPD) is a prevalent debilitating long term condition. It is the second most common cause of emergency admission to hospital in the UK and remains one of the most costly conditions to treat through acute care. Tele-health monitoring offers potential to reduce the rates of re-hospitalisation and emergency department visits and improve quality of life for people with COPD. However, the current evidence base to support technology adoption and implementation is limited and the resource implications for implementing tele-health in practice can be very high. This trial will employ tele-health monitoring in a preventative capacity for patients diagnosed with early stage COPD following discharge from hospital to determine whether it reduces their need for additional health service support or hospital admission and improves their quality of life. Methods/Design We describe a pilot study for a two arm, one site randomized controlled trial (RCT) to determine the effect of tele-health monitoring on self-management, quality of life and patient satisfaction. Sixty patients who have been discharged from one acute trust with a primary diagnosis of COPD and who have agreed to receive community clinical support following discharge from acute care will be randomly assigned to one of two groups: (a) Tele-health supported Community COPD Service; or (b) Usual Care. The tele-health supported service involves the patient receiving two home visits with a specialist COPD clinician (nurse or physiotherapist) then participating in daily tele-monitoring over an eight week period. Usual care consists of six home visits to the patient by specialist COPD clinicians again over eight successive weeks. Health status and quality of life data for all participants will be measured at baseline, on discharge from the service and at six months post discharge from the service. Discussion The tele-health service under study is a complex service delivered through a collaboration between local authority and health care partners. The implementation of this service demanded significant changes to established working patterns and has been a challenging process requiring considerable planning - a challenge that many providers are likely to face in the future. Trial registration Current Controlled Trials ISRCTN6885601

Measles vaccination and antibody response in autism spectrum disorder

OBJECTIVE: To test the hypothesis that measles vaccination was involved in the pathogenesis of autism spectrum disorders (ASD) as evidenced by signs of a persistent measles infection or abnormally persistent immune response shown by circulating measles virus or raised antibody titres in children with ASD who had been vaccinated against measles, mumps and rubella (MMR) compared with controls. DESIGN: Case-control study, community based. METHODS: A community sample of vaccinated children aged 10-12 years in the UK with ASD (n = 98) and two control groups of similar age, one with special educational needs but no ASD (n = 52) and one typically developing group (n = 90), were tested for measles virus and antibody response to measles in the serum. RESULTS: No difference was found between cases and controls for measles antibody response. There was no dose-response relationship between autism symptoms and antibody concentrations. Measles virus nucleic acid was amplified by reverse transcriptase-PCR in peripheral blood mononuclear cells from one patient with autism and two typically developing children. There was no evidence of a differential response to measles virus or the measles component of the MMR in children with ASD, with or without regression, and controls who had either one or two doses of MMR. Only one child from the control group had clinical symptoms of possible enterocolitis. CONCLUSION: No association between measles vaccination and ASD was shown