3 research outputs found

    3D automatic target recognition for missile platforms

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    The quest for military Automatic Target Recognition (ATR) procedures arises from the demand to reduce collateral damage and fratricide. Although missiles with two-dimensional ATR capabilities do exist, the potential of future Light Detection and Ranging (LIDAR) missiles with three-dimensional (3D) ATR abilities shall significantly improve the missile’s effectiveness in complex battlefields. This is because 3D ATR can encode the target’s underlying structure and thus reinforce target recognition. However, the current military grade 3D ATR or military applied computer vision algorithms used for object recognition do not pose optimum solutions in the context of an ATR capable LIDAR based missile, primarily due to the computational and memory (in terms of storage) constraints that missiles impose. Therefore, this research initially introduces a 3D descriptor taxonomy for the Local and the Global descriptor domain, capable of realising the processing cost of each potential option. Through these taxonomies, the optimum missile oriented descriptor per domain is identified that will further pinpoint the research route for this thesis. In terms of 3D descriptors that are suitable for missiles, the contribution of this thesis is a 3D Global based descriptor and four 3D Local based descriptors namely the SURF Projection recognition (SPR), the Histogram of Distances (HoD), the processing efficient variant (HoD-S) and the binary variant B-HoD. These are challenged against current state-of-the-art 3D descriptors on standard commercial datasets, as well as on highly credible simulated air-to-ground missile engagement scenarios that consider various platform parameters and nuisances including simulated scale change and atmospheric disturbances. The results obtained over the different datasets showed an outstanding computational improvement, on average x19 times faster than state-of-the-art techniques in the literature, while maintaining or even improving on some occasions the detection rate to a minimum of 90% and over of correct classified targets

    2014 Update of the Alzheimer's Disease Neuroimaging Initiative: A review of papers published since its inception

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    The Alzheimer's Disease Neuroimaging Initiative (ADNI) is an ongoing, longitudinal, multicenter study designed to develop clinical, imaging, genetic, and biochemical biomarkers for the early detection and tracking of Alzheimer's disease (AD). The initial study, ADNI-1, enrolled 400 subjects with early mild cognitive impairment (MCI), 200 with early AD, and 200 cognitively normal elderly controls. ADNI-1 was extended by a 2-year Grand Opportunities grant in 2009 and by a competitive renewal, ADNI-2, which enrolled an additional 550 participants and will run until 2015. This article reviews all papers published since the inception of the initiative and summarizes the results to the end of 2013. The major accomplishments of ADNI have been as follows: (1) the development of standardized methods for clinical tests, magnetic resonance imaging (MRI), positron emission tomography (PET), and cerebrospinal fluid (CSF) biomarkers in a multicenter setting; (2) elucidation of the patterns and rates of change of imaging and CSF biomarker measurements in control subjects, MCI patients, and AD patients. CSF biomarkers are largely consistent with disease trajectories predicted by β-amyloid cascade (Hardy, J Alzheimer's Dis 2006;9(Suppl 3):151-3) and tau-mediated neurodegeneration hypotheses for AD, whereas brain atrophy and hypometabolism levels show predicted patterns but exhibit differing rates of change depending on region and disease severity; (3) the assessment of alternative methods of diagnostic categorization. Currently, the best classifiers select and combine optimum features from multiple modalities, including MRI, [(18)F]-fluorodeoxyglucose-PET, amyloid PET, CSF biomarkers, and clinical tests; (4) the development of blood biomarkers for AD as potentially noninvasive and low-cost alternatives to CSF biomarkers for AD diagnosis and the assessment of α-syn as an additional biomarker; (5) the development of methods for the early detection of AD. CSF biomarkers, β-amyloid 42 and tau, as well as amyloid PET may reflect the earliest steps in AD pathology in mildly symptomatic or even nonsymptomatic subjects and are leading candidates for the detection of AD in its preclinical stages; (6) the improvement of clinical trial efficiency through the identification of subjects most likely to undergo imminent future clinical decline and the use of more sensitive outcome measures to reduce sample sizes. Multimodal methods incorporating APOE status and longitudinal MRI proved most highly predictive of future decline. Refinements of clinical tests used as outcome measures such as clinical dementia rating-sum of boxes further reduced sample sizes; (7) the pioneering of genome-wide association studies that leverage quantitative imaging and biomarker phenotypes, including longitudinal data, to confirm recently identified loci, CR1, CLU, and PICALM and to identify novel AD risk loci; (8) worldwide impact through the establishment of ADNI-like programs in Japan, Australia, Argentina, Taiwan, China, Korea, Europe, and Italy; (9) understanding the biology and pathobiology of normal aging, MCI, and AD through integration of ADNI biomarker and clinical data to stimulate research that will resolve controversies about competing hypotheses on the etiopathogenesis of AD, thereby advancing efforts to find disease-modifying drugs for AD; and (10) the establishment of infrastructure to allow sharing of all raw and processed data without embargo to interested scientific investigators throughout the world
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