3,415 research outputs found

    Augmented Reality

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    Augmented Reality (AR) is a natural development from virtual reality (VR), which was developed several decades earlier. AR complements VR in many ways. Due to the advantages of the user being able to see both the real and virtual objects simultaneously, AR is far more intuitive, but it's not completely detached from human factors and other restrictions. AR doesn't consume as much time and effort in the applications because it's not required to construct the entire virtual scene and the environment. In this book, several new and emerging application areas of AR are presented and divided into three sections. The first section contains applications in outdoor and mobile AR, such as construction, restoration, security and surveillance. The second section deals with AR in medical, biological, and human bodies. The third and final section contains a number of new and useful applications in daily living and learning

    Is the Thoracolumbar Injury Severity Score (TLISS) still a good base for the education of residents in Orthopaedics and Traumatology?

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    ABSTRACT Introduction. Thoracolumbar spinal injuries indicated for surgical intervention specify the necessity of intervention within 24 hours. The traumatologists working in a structure without a Spinal Unit must be able to evaluate such injury and set indications for surgical treatment, that is, nonoperative treatment. The purpose of this study is to evaluate if Thoracolumbar Injury Severity Score (TLISS) is still a good base for the classification of thoracolumbar spinal injuries and to give a correct indication for nonoperative, that is, surgical treatment. Patients and Methods. Six Orthopaedics and Traumatology residents from Siena (Italy), five Orthopaedics and Traumatology residents from the Clinical Centre of Banja Luka (Bosnia and Herzegovina) and five Orthopaedics and Traumatology residents from the Alta Val d’Elsa Hospital, Siena (Italy) were presented 24 clinical cases from professional literature where the following data were indicated: patient’s age, neurological conditions, description of the injury, mechanism of the injury and radiological findings (RTG, MR). The abovementioned 24 patients were chosen from the literature based on the injuries mostly seen by an orthopaedist with a lack of experience in the problems of spinal column trauma (low energy trauma, with partial or without neurological impairments, with the TLISS score of 4). The residents from the three groups had to classify all patients according to the TLISS score and to define the most appropriate method of treatment-conservative or surgical, and after that, all classifications, as well as the therapeutic decisions, were compared. The statistical methods used in this study include: statistical significance, reliability (P<0.05), the validity of the decision, the percentage of accuracy and Cohen’s kappa coefficient. The best results in evaluation of the mechanism of the injury were demonstrated by the group of doctors from the Orthopaedic Hospital with an accuracy of 78.8% (P<0.05) and with an average correlation (K = 0.598). The best description of the injury was presented by the doctors from Siena with 87% accuracy (P<0.05) and with correlation (K=0.749). The doctors from Siena responded best at evaluating the neurological status with 97.6% accuracy (P<0.05) and with correlation (K=0.936). The assessment of the injury of the PCL residents from Siena was 64.7% accurate (P<0.05) with correlation (K=0.426). The total TLISS score was best calculated by the residents of Siena with 82% accuracy (P<0.05) and correlation (K=0.718). The most appropriate therapeutic decision was made by the residents from Siena with 80.3% accuracy (P<0.05) and with correlation (K =0.707). Conclusion. Currently, the Denis classification and the AO classification are the most widely used classification algorithms for the fractures of thoracolumbar spine but some defects have also been identified in both of them. The value of TLISS evaluation is by the three groups of residents in presented 24 patients from the professional literature. Significant differences in accuracy were found in defining a real damage of the spinal cord at the level of the cauda equina. The evaluation of the integrity of the posterior longitudinal ligament by the radiography is of low accuracy

    Adaptive threshold optimisation for colour-based lip segmentation in automatic lip-reading systems

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    A thesis submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in ful lment of the requirements for the degree of Doctor of Philosophy. Johannesburg, September 2016Having survived the ordeal of a laryngectomy, the patient must come to terms with the resulting loss of speech. With recent advances in portable computing power, automatic lip-reading (ALR) may become a viable approach to voice restoration. This thesis addresses the image processing aspect of ALR, and focuses three contributions to colour-based lip segmentation. The rst contribution concerns the colour transform to enhance the contrast between the lips and skin. This thesis presents the most comprehensive study to date by measuring the overlap between lip and skin histograms for 33 di erent colour transforms. The hue component of HSV obtains the lowest overlap of 6:15%, and results show that selecting the correct transform can increase the segmentation accuracy by up to three times. The second contribution is the development of a new lip segmentation algorithm that utilises the best colour transforms from the comparative study. The algorithm is tested on 895 images and achieves percentage overlap (OL) of 92:23% and segmentation error (SE) of 7:39 %. The third contribution focuses on the impact of the histogram threshold on the segmentation accuracy, and introduces a novel technique called Adaptive Threshold Optimisation (ATO) to select a better threshold value. The rst stage of ATO incorporates -SVR to train the lip shape model. ATO then uses feedback of shape information to validate and optimise the threshold. After applying ATO, the SE decreases from 7:65% to 6:50%, corresponding to an absolute improvement of 1:15 pp or relative improvement of 15:1%. While this thesis concerns lip segmentation in particular, ATO is a threshold selection technique that can be used in various segmentation applications.MT201

    Implications of changing winter fjord ice melanges for Greenland outlet glacier dynamics

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    Recent studies have demonstrated rapid change along the margin of the Greenland Ice Sheet (GIS) over the last decade. In particular, increases in glacier velocities coincident with terminus retreat for many of Greenland\u27s outlet glaciers have effectively increased the amount of ice discharged. Much of this calved ice passes through elaborate fjord systems en route to the ocean. This study utilizes remote sensing observations to investigate the changing conditions in several of Greenland\u27s pro-glacial fjords and changes along glacier termini. The findings indicate that changes in the mix of calved ice and water in pro-glacial fjords have implications for the location of the calving front and for glacier speed and thickness in the near-terminus region on seasonal to interannual time scales. The ability of the fjord ice to influence terminus dynamics and glacier stability has implications for predicting ice loss over much longer time scales

    Segmentation in dermatological hyperspectral images: dedicated methods

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    Background: Segmentation of hyperspectral medical images is one of many image segmentation methods which require profiling. This profiling involves either the adjustment of existing, known image segmentation methods or a proposal of new dedicated methods of hyperspectral image segmentation. Taking into consideration the size of analysed data, the time of analysis is of major importance. Therefore, the authors proposed three new dedicated methods of hyperspectral image segmentation with special reference to the time of analysis. Methods: The segmentation methods presented in this paper were tested and profiled to the images acquired from different hyperspectral cameras including SOC710 Hyperspectral Imaging System, Specim sCMOS-50-V10E. Correct functioning of the method was tested for over 10,000 2D images constituting the sequence of over 700 registrations of the areas of the left and right hand and the forearm. Results: As a result, three new methods of hyperspectral image segmentation have been proposed: fast analysis of emissivity curves (SKE), 3D segmentation (S3D) and hierarchical segmentation (SH). They have the following features: are fully automatic; allow for implementation of fast segmentation methods; are profiled to hyperspectral image segmentation; use emissivity curves in the model form, can be applied in any type of objects not necessarily biological ones, are faster (SKE-2.3 ms, S3D-1949 ms, SH-844 ms for the computer with Intel® Core i7 4960X CPU 3.6 GHz) and more accurate (SKE-accuracy 79 %, S3D-90 %, SH-92 %) in comparison with typical methods known from the literature. Conclusions: Profiling and/or proposing new methods of hyperspectral image segmentation is an indispensable element of developing software. This ensures speed, repeatability and low sensitivity of the algorithm to changing parameters
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