172 research outputs found

    Structural Health Monitoring from the Window Seat of a Passenger Airplane

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    Recent advances in computer vision and graphics have shown that regular, monocular cameras and video (e.g. cell phone cameras and Digital SLRs) can be used to identify the resonant frequencies of structures, and even image visually subtle operational deflection shapes. This paper is offered as a teaser for that work, focusing specifically on an example that may be of interest to people in the structural health monitoring (SHM) community. The discussion is high-level, and presented in an intentionally casual tone (much of the paper presents an anecdote-about recovering the operational deflection shape of an airplane wing using a cell phone and a dish sponge-using the first person). Our hope is to make this text as accessible and painless to read as possible, with hopes of introducing readers from different engineering disciplines to our related work in computer vision and graphics

    Shapecollage: Occlusion-Aware, Example-Based Shape Interpretation

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    This paper presents an example-based method to interpret a 3D shape from a single image depicting that shape. A major difficulty in applying an example-based approach to shape interpretation is the combinatorial explosion of shape possibilities that occur at occluding contours. Our key technical contribution is a new shape patch representation and corresponding pairwise compatibility terms that allow for flexible matching of overlapping patches, avoiding the combinatorial explosion by allowing patches to explain only the parts of the image they best fit. We infer the best set of localized shape patches over a graph of keypoints at multiple scales to produce a discontinuous shape representation we term a shape collage. To reconstruct a smooth result, we fit a surface to the collage using the predicted confidence of each shape patch. We demonstrate the method on shapes depicted in line drawing, diffuse and glossy shading, and textured styles.National Science Foundation (U.S.) (Grant 1111415)United States. Office of Naval Research (Grant N00014-09-1-1051)National Institutes of Health (U.S.) (Grant R01-EY019262

    Preliminary hydrogeological modeling and optimal monitoring network design for a contaminated abandoned mine site area: application of developed monitoring network design software

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    In abandoned mine sites, i.e., mine sites where mining operations have ended, wide spread contaminations are often evident, but the potential sources and pathways of contamination especially through the subsurface, are difficult to identify due to inadequate and sparse geochemical measurements available. Therefore, it is essential to design and implement a planned monitoring net-work to obtain essential information required for establishing the potential contamination source locations, i.e., waste dumps, tailing dams, pits and possible pathways through the subsurface, and to design a remediation strategy for rehabilitation. This study presents an illustrative application of modeling the flow and transport processes and monitoring network design in a study area hydrogeologically resembling an abandoned mine site in Queensland, Australia. In this preliminary study, the contaminant transport process modeled does not incorporate the reactive geochemistry of the contaminants. The transport process is modeled considering a generic conservative contaminant for the illustrative purpose of showing the potential application of an optimal monitoring design methodology. This study aims to design optimal monitoring network to: 1) minimize the contaminant solute mass estimation error; 2) locate the plume boundary; 3) select the monitoring locations with (potentially) high concentrations. A linked simulation optimization based methodology is utilized for optimal monitoring network design. The methodology is applied utilizing a recently developed software package CARE-GWMND, developed at James Cook University for optimal monitoring network design. Given the complexity of the groundwater systems and the sparsity of pollutant concentration observation data from the field, this software is capable of simulating the groundwater flow and solute transport with spatial interpolation of data from a sparse set of available data, and it utilizes the optimization algorithm to determine optimum locations for implementing monitoring wells

    Management of traumatic events: influence of emotion-centered coping strategies on the occurrence of dissociation and post-traumatic stress disorder

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    Our aim was to assess the influence of the coping strategies employed for the management of traumatic events on the occurrence of dissociation and traumatic disorders. We carried out a 1-year retrospective study of the cognitive management of a traumatic event in 18 subjects involved in the same road vehicle accident. The diagnosis of post-traumatic stress disorder (PTSD) was made for 33.3% of the participants. The participants with a PTSD diagnosis 1 year after the event used emotion-centered strategies during the event more often than did those with no PTSD, P < 0.02. In the year after the traumatic event, our results show a strong link between the intensity of PTSD and the severity of the post-traumatic symptoms like dissociation (P = 0.032) and the use of emotion-centered strategies (P = 0.004). Moreover, the participants who presented Peritraumatic Dissociative Experiences Questionnaire scores above 15 made greater use of emotion-centered coping strategies than did those who did not show dissociation, P < 0.04. Our results confirm that the cognitive management of traumatic events may play an essential role in the development of a state of post-traumatic stress in the aftermath of a violent event

    Search for composite and exotic fermions at LEP 2

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    A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

    Search for lightest neutralino and stau pair production in light gravitino scenarios with stau NLSP

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    Promptly decaying lightest neutralinos and long-lived staus are searched for in the context of light gravitino scenarios. It is assumed that the stau is the next to lightest supersymmetric particle (NLSP) and that the lightest neutralino is the next to NLSP (NNLSP). Data collected with the Delphi detector at centre-of-mass energies from 161 to 183 \GeV are analysed. No evidence of the production of these particles is found. Hence, lower mass limits for both kinds of particles are set at 95% C.L.. The mass of gaugino-like neutralinos is found to be greater than 71.5 GeV/c^2. In the search for long-lived stau, masses less than 70.0 to 77.5 \GeVcc are excluded for gravitino masses from 10 to 150 \eVcc . Combining this search with the searches for stable heavy leptons and Minimal Supersymmetric Standard Model staus a lower limit of 68.5 \GeVcc may be set for the stau mas

    Post Genome-Wide Association Studies of Novel Genes Associated with Type 2 Diabetes Show Gene-Gene Interaction and High Predictive Value

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    Recently, several Genome Wide Association (GWA) studies in populations of European descent have identified and validated novel single nucleotide polymorphisms (SNPs), highly associated with type 2 diabetes (T2D). Our aims were to validate these markers in other European and non-European populations, then to assess their combined effect in a large French study comparing T2D and normal glucose tolerant (NGT) individuals. rs7903146 SNP, were combined (8.68-fold for the 14% of French individuals carrying 18 to 30 risk alleles with an allelic OR of 1.24). With an area under the ROC curve of 0.86, only 15 novel loci were necessary to discriminate French individuals susceptible to develop T2D. strongly associate with T2D in French individuals, and mostly in populations of Central European descent but not in Moroccan subjects. Genes expressed in the pancreas interact together and their combined effect dramatically increases the risk for T2D, opening avenues for the development of genetic prediction tests

    Genome-Wide Search Reveals the Existence of a Limited Number of Thyroid Hormone Receptor Alpha Target Genes in Cerebellar Neurons

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    Thyroid hormone (T3) has a major influence on cerebellum post-natal development. The major phenotypic landmark of exposure to low levels of T3 during development (hypothyroidism) in the cerebellum is the retarded inward migration of the most numerous cell type, granular neurons. In order to identify the direct genetic regulation exerted by T3 on cerebellar neurons and their precursors, we used microarray RNA hybridization to perform a time course analysis of T3 induced gene expression in primary cultures of cerebellar neuronal cell. These experiments suggest that we identified a small set of genes which are directly regulated, both in vivo and in vitro, during cerebellum post-natal development. These modest changes suggest that T3 does not acts directly on granular neurons and mainly indirectly influences the cellular interactions taking place during development
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