2,128 research outputs found

    Over time RF fitting for Jitter Free 3D Vertebra Reconstruction from Video Fluoroscopy

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    Over the past decades, there has been an increasing interest in spine kinematics. Various approaches have been proposed on how to observe and analyse spine kinematics from a computer vision perspective. Amongst all, emphasis has been given to both the shape of the individual vertebrae as well as the overall spine curvature as a means of providing accurate and valid spinal condition diagnosis. Traditional invasive methods cannot accurately delineate the intersegmental motion of the spine vertebrae. On the contrary, capturing and measuring spinal motion via the non-invasive fluoroscopy has been a popular technique choice because of its low incurred patient radiation exposure nature. In general, image-based and other reconstruction methods target individual frames and focus on static spine instances. However, even the ones analysing sequences yield in unstable and jittery animations of the reconstructed spine. In this report, we address this issue using a novel approach to robustly reconstruct and rigidly derive a shape with no inter-frame variations. This is to produce animations that are jitter free across our sequence based on fluoroscopy video. Our main contributions are 1) retaining the shape of the solid vertebrae across the frame range, 2) helping towards a more accurate image segmentation even when there's a limited training set. We show our pipeline's success by reconstructing and comparing 3D animations of the lumbar spine from a corresponding fluoroscopic video

    Ultra-Low-Power Superconductor Logic

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    We have developed a new superconducting digital technology, Reciprocal Quantum Logic, that uses AC power carried on a transmission line, which also serves as a clock. Using simple experiments we have demonstrated zero static power dissipation, thermally limited dynamic power dissipation, high clock stability, high operating margins and low BER. These features indicate that the technology is scalable to far more complex circuits at a significant level of integration. On the system level, Reciprocal Quantum Logic combines the high speed and low-power signal levels of Single-Flux- Quantum signals with the design methodology of CMOS, including low static power dissipation, low latency combinational logic, and efficient device count.Comment: 7 pages, 5 figure

    Starting currents of modes in cylindrical cavities with mode-converting corrugations for second-harmonic gyrotrons

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    A self-consistent system of equations (known as single-mode gyrotron equations) is extended to describe the beam-wave interaction in a cylindrical gyrotron cavity with mode-converting longitudinal corrugations, which produce coupling of azimuthal basis modes. The system of equations is applied to investigate the effect of corrugations on starting currents of the cavity modes. For these modes, eigenvalues, ohmic losses, field structure, and beam-wave coupling coefficients are investigated with respect to the corrugation parameters. It is shown that properly sized mode-converting corrugations are capable of improving the selectivity properties of cylindrical cavities for second-harmonic gyrotrons

    Optic atrophy, necrotizing anterior scleritis and keratitis presenting in association with Streptococcal Toxic Shock Syndrome: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>We report a case of optic atrophy, necrotizing anterior scleritis and keratitis presenting in a patient with Streptococcal Toxic Shock Syndrome.</p> <p>Case presentation</p> <p>A 43-year-old woman developed streptococcal toxic shock syndrome secondary to septic arthritis of her right ankle. Streptococcus pyogenes (b-haemolyticus Group A) was isolated from blood cultures and joint aspirate. She was referred for ophthalmology review as her right eye became injected and the pupil had become unresponsive to light whilst she was in the Intensive Therapy Unit (ITU). The iris appeared atrophic and was mid-dilated with no direct or consensual response to light. Three zones of sub-epithelial opacification where noted in the cornea. There where extensive posterior synechiae. Indirect ophthalmoscopy showed a pale right disc. The vision was reduced to hand movements (HM). A diagnosis of optic atrophy was made secondary to post-streptococcal uveitis. She subsequently developed a necrotizing anterior scleritis.</p> <p>Conclusion</p> <p>This case illustrates a previously unreported association of optic atrophy, necrotizing anterior scleritis and keratitis in a patient with post-streptococcal uveitis. This patient had developed Streptococcal Toxic Shock Syndrome secondary to septic arthritis. We recommend increased awareness of the potential risks of these patients developing severe ocular involvement.</p

    Cycle-Consistent Adversarial Networks and Fast Adaptive Bi-Dimensional Empirical Mode Decomposition for Style Transfer

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    Recently, research endeavors have shown the potentiality of Cycle-Consistent Adversarial Networks (CycleGAN) in style transfer. In Cycle-Consistent Adversarial Networks, the consistency loss is introduced to measure the difference between the original images and the reconstructed in both directions, forward and backward. In this work, the combination of Cycle-Consistent Adversarial Networks with Fast and Adaptive Bidimensional Empirical Mode Decomposition (FABEMD) is proposed to perform style transfer on images. In the proposed approach the cycle-consistency loss is modified to include the differences between the extracted Intrinsic Mode Functions (BIMFs) images. Instead of an estimation of pixel-to-pixel difference between the produced and input images, the FABEMD is applied and the extracted BIMFs are involved in the computation of the total cycle loss. This method enriches the computation of the total loss in a content-to-content and style-to-style comparison by connecting the spatial information to the frequency components. The experimental results reveal that the proposed method is efficient and produces qualitative results comparable to state-of-the-art methods

    A grid-based infrastructure for distributed retrieval

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    In large-scale distributed retrieval, challenges of latency, heterogeneity, and dynamicity emphasise the importance of infrastructural support in reducing the development costs of state-of-the-art solutions. We present a service-based infrastructure for distributed retrieval which blends middleware facilities and a design framework to ā€˜liftā€™ the resource sharing approach and the computational services of a European Grid platform into the domain of e-Science applications. In this paper, we give an overview of the DILIGENT Search Framework and illustrate its exploitation in the ļ¬eld of Earth Science

    Relationship between internal accuracy and load-bearing capacity of minimally invasive lithium disilicate occlusal veneers

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    Purpose: To test whether internal accuracy affects the load-bearing capacity of 0.5-mm-thick occlusal veneers made out of milled or heat-pressed lithium disilicate (LS2). Materials and methods: Extracted human molars (N = 80) were divided into four groups (n = 20 each) depending on the bonding substrate (enamel [E] or dentin [D]) and the fabrication method (milling [CAD] or heat pressing [PRE]) for the occlusal LS2 veneers: (1) E-CAD, (2) D-CAD, (3) E-PRE, or (4) D-PRE. After restoration fabrication, the abutment teeth and the corresponding restorations were scanned and superimposed in order to measure the marginal and internal accuracy. After adhesive cementation, the specimens were thermomechanically aged and thereafter loaded until fracture. The load-bearing capacities (Fmax) were measured. Fmax and the marginal and internal accuracy between the groups were compared using Kruskal-Wallis test (P < .05) and pairwise group comparisons. In addition, the relationship between Fmax and the internal accuracy was analyzed using Spearman rank correlation. Results: Median Fmax values (and first and third quartiles) per group were as follows: 1,495 N (Q1: 932; Q3: 2'318) for E-CAD; 1,575 N (Q1: 1,314; Q3: 1,668) for E-PRE; 1,856 N (Q1: 1,555; Q3: 2,013) for D-CAD; and 1,877 N (Q1: 1,566; Q3: 2,131) for D-PRE. No statistical difference was found between the groups (P = .0981). Overall, the internal accuracy in the areas of the cusp (P < .0007) and fossa (P < .0001) showed significant differences. While no significant differences were detected in the marginal area (P = .3518), a significant correlation with a negative linear relationship was found between the 3D internal accuracy and the Fmax values (P = .0007). Conclusion: An increase in the internal accuracy raised the load-bearing capacity of minimally invasive LS2 occlusal veneers. In general, the restorations bonded to dentin in the occlusal regions showed a better accuracy compared to those bonded to enamel
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