234 research outputs found

    Heuristic standards for universal design in the face of technological diversity.

    Get PDF
    CENTRAL PRINCIPLE Important technologies require validated standards for the design heuristics that are used to design and evaluate them, but not necessarily identical heuristics for every technology. BACKGROUND Heuristic standards provide a valuable toolkit with which to evaluate the accessibility of modern information society technologies (IST). But can we apply the same heuristic, generic standards to all types of technological platforms, in the face of their growing diversity e.g. websites, social websites, blogs, virtual reality applications, ambient intelligence etc (Adams, 2007)? Or would it be wiser to expect that different technologies might require different, if overlapping, standards? Can we really expect to design the interface of a modern cell phone on the same basis as for a table computer? Most impartial observers would probably say “no”. How can we introduce a systematic and thorough approach to the diverse technologies that are seen or predicted to be seen? Work in our laboratory has explored two useful questions. First, how to computer literate users perceive the different technologies? Second, how can different heuristic standards be developed where needed

    The potential of the BCI for accessible and smart e-learning

    Get PDF
    The brain computer interface (BCI) should be the accessibility solution “par excellence” for interactive and e-learning systems. There is a substantial tradition of research on the human electro encephalogram (EEG) and on BCI systems that are based, inter alia, on EEG measurement. We have not yet seen a viable BCI for e-learning. For many users for a BCI based interface is their first choice for good quality interaction, such as those with major psychomotor or cognitive impairments. However, there are many more for whom the BCI would be an attractive option given an acceptable learning overhead, including less severe disabilities and safety critical conditions where cognitive overload or limited responses are likely. Recent progress has been modest as there are many technical and accessibility problems to overcome. We present these issues and report a survey of fifty papers to capture the state-of-the-art in BCI and the implications for e-learning

    An enhanced deep learning architecture for classification of Tuberculosis types from CT lung images

    Get PDF
    In this work, an enhanced ResNet deep learning network, depth-ResNet, has been developed to classify the five types of Tuberculosis (TB) lung CT images. Depth-ResNet takes 3D CT images as a whole and processes the volumatic blocks along depth directions. It builds on the ResNet-50 model to obtain 2D features on each frame and injects depth information at each process block. As a result, the averaged accuracy for classification is 71.60% for depth-ResNet and 68.59% for ResNet. The datasets are collected from the ImageCLEF 2018 competition with 1008 training data in total, where the top reported accuracy was 42.27%

    Optical flow estimation via steered-L1 norm

    Get PDF
    Global variational methods for estimating optical flow are among the best performing methods due to the subpixel accuracy and the ‘fill-in’ effect they provide. The fill-in effect allows optical flow displacements to be estimated even in low and untextured areas of the image. The estimation of such displacements are induced by the smoothness term. The L1 norm provides a robust regularisation term for the optical flow energy function with a very good performance for edge-preserving. However this norm suffers from several issues, among these is the isotropic nature of this norm which reduces the fill-in effect and eventually the accuracy of estimation in areas near motion boundaries. In this paper we propose an enhancement to the L1 norm that improves the fill-in effect for this smoothness term. In order to do this we analyse the structure tensor matrix and use its eigenvectors to steer the smoothness term into components that are ‘orthogonal to’ and ‘aligned with’ image structures. This is done in primal-dual formulation. Results show a reduced end-point error and improved accuracy compared to the conventional L1 norm

    A review of hough transform and line segment detection approaches

    Get PDF
    In a wide range of image processing and computer vision problems, line segment detection is one of the most critical challenges. For more than three decades researchers have contributed to build more robust and accurate algorithms with faster performance. In this paper we review the main approaches and in particular the Hough transform and its extensions, which are among the most well-known techniques for the detection of straight lines in a digital image. This paper is based on extensive practical research and is organised into two main parts. In the first part, the HT and its major research directions and limitations are discussed. In the second part of the paper, state-of-the-art line segmentation techniques are reviewed and categorized into three main groups with fundamentally distinctive characteristics. Their relative advantages and disadvantages are compared and summarised in a table

    Introducing mobile home agents into the distributed authentication protocol to achieve location privacy in mobile IPv6

    Get PDF
    Mobile IPv6 will be the basis for the fourth generation 4G networks which will completely revolutionize the way telecommunication devices operate. This paradigm shift will occur due to the sole use of packed switching networks. Mobile IPv6 utilizes binding updates as a route optimization to reduced triangle routing between the mobile node, the home agent and the correspondent node, allowing direct communication between the mobile node and the correspondent. However, direct communication between the nodes produces a range of security vulnerabilities, which the home agent avoided. This paper attempts to provide the advantages of using the home agent as an intermediary whilst reducing the latency of triangle routing. This can be achieved with the proposed use of a mobile home agent which essentially follows the mobile node as it moves between points of attachment providing location privacy and pseudo-direct communication, which can be incorporated into the distributed authentication protocol or be used as a stand alone solution

    The angiogenic factor platelet-derived endothelial cell growth factor/thymidine phosphorylase is up-regulated in breast cancer epithelium and endothelium.

    Get PDF
    Tumour angiogenesis is a complex multistep process regulated by a number of angiogenic factors. One such factor, platelet-derived endothelial cell growth factor has recently been shown to be thymidine phosphorylase (TP). TP catalyses the reversible phosphorylation of thymidine to deoxyribose-1-phosphate and thymine. Although known to be generally elevated in tumours, the expression of this enzyme in breast carcinomas is unknown. Therefore, we used ribonuclease protection assays and immunohistochemistry to examine the expression of TP in 240 primary breast carcinomas. Nuclear and/or cytoplasmic TP expression was observed in the neoplastic tumour epithelium in 53% of tumours. Immunoreactivity was also often present in the stromal, inflammatory and endothelial cell elements. Although endothelial cell staining was usually focal, immunoreactivity was observed in 61% of tumours and was prominent at the tumour periphery, an area where tumour angiogenesis is most active. Tumour cell TP expression was significantly inversely correlated with grade (P = 0.05) and size (P = 0.003) but no association was observed with other tumour variables. These findings suggest that TP is important for remodelling the existing vasculature early in tumour development, consistent with its chemotactic non-mitogenic properties, and that additional angiogenic factors are more important for other angiogenic processes like endothelial cell proliferation. Relapse-free survival was higher in node-positive patients with elevated TP (P = 0.05) but not in other patient groups. This might be due to the potentiation of chemotherapeutic agents like methotrexate by TP. Therefore, this enzyme might be a prediction marker for response to chemotherapy

    Robotic Therapy for Phantom Limb Pain in Upper Limb Amputees

    Get PDF
    The system described in this paper combines virtual reality with haptic feedback to increase the level of immersion and invoke the sense of agency in patients with phantom limb pain with the aim of reducing perceived pain. This paper presents three case studies of an on-going clinical study. The initial results suggest an increased sense of embodiment of the virtual limb promotes a decrease in perceived levels of pain. The results strengthen the view that the cortical map does not fully “disappear” yet lays dormant

    Onchocerca parasites and Wolbachia endosymbionts: evaluation of a spectrum of antibiotic types for activity against Onchocerca gutturosa in vitro

    Get PDF
    BACKGROUND: The filarial parasites of major importance in humans contain the symbiotic bacterium Wolbachia and recent studies have shown that targeting of these bacteria with antibiotics results in a reduction in worm viability, development, embryogenesis, and survival. Doxycycline has been effective in human trials, but there is a need to develop drugs that can be given for shorter periods and to pregnant women and children. The World Health Organisation-approved assay to screen for anti-filarial activity in vitro uses male Onchocerca gutturosa, with effects being determined by worm motility and viability as measured by reduction of MTT to MTT formazan. Here we have used this system to screen antibiotics for anti-filarial activity. In addition we have determined the contribution of Wolbachia depletion to the MTT reduction assay. METHODS: Adult male O. gutturosa were cultured on a monkey kidney cell (LLCMK 2) feeder layer in 24-well plates with antibiotics and antibiotic combinations (6 to 10 worms per group). The macrofilaricide CGP 6140 (Amocarzine) was used as a positive control. Worm viability was assessed by two methods, (i) motility levels and (ii) MTT/formazan colorimetry. Worm motility was scored on a scale of 0 (immotile) to 10 (maximum) every 5 days up to 40 days. On day 40 worm viability was evaluated by MTT/formazan colorimetry, and results were expressed as a mean percentage reduction compared with untreated control values at day 40. To determine the contribution of Wolbachia to the MTT assay, the MTT formazan formation of an insect cell-line (C6/36) with or without insect Wolbachia infection and treated or untreated with tetracycline was compared. RESULTS: Antibiotics with known anti-Wolbachia activity were efficacious in this system. Rifampicin (5 × 10(-5)M) was the most effective anti-mycobacterial agent; clofazimine (1.25 × 10(-5)M and 3.13 × 10(-6)M) produced a gradual reduction in motility and by 40 days had reduced worm viability. The other anti-mycobacterial drugs tested had limited or no activity. Doxycycline (5 × 10(-5)M) was filaricidal, but minocycline was more effective and at a lower concentration (5 × 10(-5)M and 1.25 × 10(-5)M). Inactive compounds included erythromycin, oxytetracycline, trimethoprim and sulphamethoxazole. The MTT assay on the insect cell-line showed that Wolbachia made a significant contribution to the metabolic activity within the cells, which could be reduced when they were exposed to tetracycline. CONCLUSION: The O. gutturosa adult male screen for anti-filarial drug activity is also valid for the screening of antibiotics for anti-Wolbachia activity. In agreement with previous findings, rifampicin and doxycycline were effective; however, the most active antibiotic was minocycline. Wolbachia contributed to the formation of MTT formazan in the MTT assay of viability and is therefore not exclusively a measure of worm viability and indicates that Wolbachia contributes directly to the metabolic activity of the nematode
    • 

    corecore