558 research outputs found

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    Gerard Manley Hopkins - a poet who opened up many poetic vistas for Scotland

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    Acute Angle Repositioning in Mobile C-Arm Using Image Processing and Deep Learning

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    During surgery, medical practitioners rely on the mobile C-Arm medical x-ray system (C-Arm) and its fluoroscopic functions to not only perform the surgery but also validate the outcome. Currently, technicians reposition the C-Arm arbitrarily through estimation and guesswork. In cases when the positioning and repositioning of the C-Arm are critical for surgical assessment, uncertainties in the angular position of the C-Arm components hinder surgical performance. This thesis proposes an integrated approach to automatically reposition C-Arms during critically acute movements in orthopedic surgery. Robot vision and control with deep learning are used to determine the necessary angles of rotation for desired C-Arm repositioning. More specifically, a convolutional neural network is trained to detect and classify internal bodily structures. Image generation using the fast Fourier transform and Monte Carlo simulation is included to improve the robustness of the training progression of the neural network. Matching control points between a reference x-ray image and a test x-ray image allows for the determination of the projective transformation relating the images. From the projective transformation matrix, the tilt and orbital angles of rotation of the C-Arm are calculated. Key results indicate that the proposed method is successful in repositioning mobile C-Arms to a desired position within 8.9% error for the tilt and 3.5% error for the orbit. As a result, the guesswork entailed in fine C-Arm repositioning is replaced by a better, more refined method. Ultimately, confidence in C-Arm positioning and repositioning is reinforced, and surgical performance with the C-Arm is improved

    Examining Analogue Film's Viability as A Preservation Method for Film Archives

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    The purpose of this project is to examine film stock’s viability as a method of preservation for film archives in the current climate of later-stage practice transition. It seeks to identify the impact of the film stock production decrease upon archival practice and assess and compare analogue and digital practice. It also seeks to determine the viability of a film stock production increase, and in turn film stock’s viability, and propose potential future uses for film stock outside the archival sector. The methods used include conceptual and historical analyses of literature in the field, and a selective critical literature review of 4 film stock producers’ and 33 European and American film archives’ websites, supported by a film archive curator interview. The analyses of literature support that there is viable infrastructure and practice supporting film stock as a preservation method in film archives when compared to digital preservation. However, the selective critical literature review shows that due to the production decrease and corresponding costs, film stock is not a viable active preservation method. The research shows that film archives are currently in transition to digital practice without defined terminology, affordable digital infrastructure or practice, or an equivalent digital preservation method to rival film stock’s abilities, creating a risk of information loss. The research shows a need for either a longer transition period between film stock and digital media, which is unviable, or the development of archive-specific digital preservation technology

    Numerical methods for coupled reconstruction and registration in digital breast tomosynthesis.

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    Digital Breast Tomosynthesis (DBT) provides an insight into the fine details of normal fibroglandular tissues and abnormal lesions by reconstructing a pseudo-3D image of the breast. In this respect, DBT overcomes a major limitation of conventional X-ray mam- mography by reducing the confounding effects caused by the superposition of breast tissue. In a breast cancer screening or diagnostic context, a radiologist is interested in detecting change, which might be indicative of malignant disease. To help automate this task image registration is required to establish spatial correspondence between time points. Typically, images, such as MRI or CT, are first reconstructed and then registered. This approach can be effective if reconstructing using a complete set of data. However, for ill-posed, limited-angle problems such as DBT, estimating the deformation is com- plicated by the significant artefacts associated with the reconstruction, leading to severe inaccuracies in the registration. This paper presents a mathematical framework, which couples the two tasks and jointly estimates both image intensities and the parameters of a transformation. Under this framework, we compare an iterative method and a simultaneous method, both of which tackle the problem of comparing DBT data by combining reconstruction of a pair of temporal volumes with their registration. We evaluate our methods using various computational digital phantoms, uncom- pressed breast MR images, and in-vivo DBT simulations. Firstly, we compare both iter- ative and simultaneous methods to the conventional, sequential method using an affine transformation model. We show that jointly estimating image intensities and parametric transformations gives superior results with respect to reconstruction fidelity and regis- tration accuracy. Also, we incorporate a non-rigid B-spline transformation model into our simultaneous method. The results demonstrate a visually plausible recovery of the deformation with preservation of the reconstruction fidelity

    Opening CALASYS to All Members

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    Since the Chinese American Librarians Association’s Academic Resources and Repository System (CALASYS, https://ir.cala-web.org/) was initiated in 2013, its collections have grown gradually by way of the Committee’s curation and entries with occasional help from LIS students. In order to resolve the bottleneck problems, promote CALASYS and expand its content, the 2020-2021 CALASYS Committee has strongly pursued the idea of opening CALASYS to all of the CALA members. The Committee began to implement the author self-contribution plug-in in the CALASYS’ Omeka platform in 2020. This poster will focus on the implementation of the self-contribution plug-in. It will cover the main steps and tasks of the implementation, including making metadata contribution templates, selecting copyright options, establishing contributor verification, testing workflow and developing end-user guide and back-end management documentations. It will also address the Committee’s work on creating training materials on workflow and metadata and plans on providing training sessions online to the CALA community. It will include the CALASYS’ history, its main features, collections, and usage statistics as well. By opening CALASYS to all members, it is hoped that it will better achieve the CALA’s strategic plan of 2020-2025, “Make CALA’s impact on local, state, national, and international levels.” Meanwhile, the bottleneck problems will be resolved and CALASYS will continue to grow at a faster pace in a more inclusive direction. The accompanying video is also available at: https://youtu.be/q9g4SXsnuO0

    INR-LDDMM: Fluid-based Medical Image Registration Integrating Implicit Neural Representation and Large Deformation Diffeomorphic Metric Mapping

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    We propose a fluid-based registration framework of medical images based on implicit neural representation. By integrating implicit neural representation and Large Deformable Diffeomorphic Metric Mapping (LDDMM), we employ a Multilayer Perceptron (MLP) as a velocity generator while optimizing velocity and image similarity. Moreover, we adopt a coarse-to-fine approach to address the challenge of deformable-based registration methods dropping into local optimal solutions, thus aiding the management of significant deformations in medical image registration. Our algorithm has been validated on a paired CT-CBCT dataset of 50 patients,taking the Dice coefficient of transferred annotations as an evaluation metric. Compared to existing methods, our approach achieves the state-of-the-art performance

    The experience of the religious through silent moving image and the silence of Bill Viola’s Passions

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    Com a descoberta do cinema no fim do século 19, novas formas de representar e de exprimir o Religioso nasceram. A indústria cinematográfica percebeu rapidamente que o filme tinha o poder de atrair novas audiências e transformou a mensagem religiosa explícita num discurso teológico implícito no cinema de ficção. Hoje, o conceito de “cinema” tem que ser repensado e alargado, tal como a noção de “Transcendental” porque a forte impressão de realidade da imagem fílmica pode mergulhar o espectador numa verdadeira experiência religiosa.With the creation of the moving image at the end of the 19th Century a new way of representing and expressing the Religious was born. The cinema industry rapidly understood that film has a powerful way to attract new audiences and transformed the explicit religious message into an implicit theological discourse of the fictional film. Today, the concept of “cinema” needs to be rethought and expanded, as well as the notion of “Transcendental” since the strong reality effect of the film image can allow a true religious experience for the spectator
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