1,157 research outputs found

    Texture Classification using Fractal Geometry for the Diagnosis of Skin Cancers

    Get PDF
    We present an approach to object detection and recognition in a digital image using a classification method that is based on the application of a set of features that include fractal parameters such as the Lacunarity and Fractal Dimension. The principal issues associated with object recognition are presented and a self-learning procedure for designing a decision making engine using fuzzy logic and membership function theory considered. The methods discussed, and the ‘system’ developed, have a range of applications in ‘machine vision’ and in this publication, we focus on the development and implementation of a skin cancer screening system that can be used in a general practice by non-experts to ‘filter’ normal from abnormal cases so that in the latter case, a patient can be referred to a specialist. The paper provides an overview of the system design and includes a link from which interested readers can download and use a demonstration version of the system developed to date

    Object Detection and Texture Classification with Applications to the Diagnosis of Skin Cancer

    Get PDF
    We present an approach to object detection and recognition in a digital image using a classification method that is based on the application of a set of features that include fractal parameters such as the Lacunarity and Fractal Dimension. The principal issues associated with object recognition are presented and a self-learning procedure for designing a decision making engine using fuzzy logic and membership function theory considered. The methods discussed, and the ‘system’ developed, have a range of applications in ‘machine vision’ and in this publication, we focus on the development and implementation of a skin cancer screening system that can be used in a general practice by non-experts to ‘filter’ normal from abnormal cases so that in the latter case, a patient can be referred to a specialist. The paper provides an overview of the system design and includes a link from which interested readers can download and use a demonstration version of the system developed to dat

    Stegacryption of DICOM Metadata

    Get PDF
    Digital Imaging and Communications in Medicine (DICOM) files are an international data standard for storing, distributing and processing medical images of all types. DICOM files include a header file containing Metadata on details which may include information on the patient. This often inhibits the free distribution of DICOM files due to issues relating to the confidentiality of data on identifiable living people, thereby limiting the potential for other radiologists to provide a diagnosis, for example, through distribution of the data over the Internet. This problem is a current limiting condition with regard to the development of Tele-medical imaging. Thus in this paper we consider a method of encrypting and embedding (or Stegacrypting) DICOM Metadata into the DICOM image, thereby providing a solution to a problem that currently inhibits the distribution of medical images using a file type that is an established international standard. The proposed method removes or ‘anonymises’ the private data, encrypt it and then embeds it into the DICOM image in an imperceptible way. The specific algorithm developed retains the private data attached to a DICOM image even when the image is converted into a standard image file format. Keywords — Coding and Encryption, Information Hiding, Medica

    Analysis of heating rates and forces on bodies subject to rocket exhaust plume impingement

    Get PDF
    Computer programs and engineering methods for calculating heating rates and forces in jet plume impingement problem

    Enhanced conformational space sampling improves the prediction of chemical shifts in proteins.

    Get PDF
    A biased-potential molecular dynamics simulation method, accelerated molecular dynamics (AMD), was combined with the chemical shift prediction algorithm SHIFTX to calculate (1)H(N), (15)N, (13)Calpha, (13)Cbeta, and (13)C' chemical shifts of the ankyrin repeat protein IkappaBalpha (residues 67-206), the primary inhibitor of nuclear factor kappa-B (NF-kappaB). Free-energy-weighted molecular ensembles were generated over a range of acceleration levels, affording systematic enhancement of the conformational space sampling of the protein. We have found that the predicted chemical shifts, particularly for the (15)N, (13)Calpha, and (13)Cbeta nuclei, improve substantially with enhanced conformational space sampling up to an optimal acceleration level. Significant improvement in the predicted chemical shift data coincides with those regions of the protein that exhibit backbone dynamics on longer time scales. Interestingly, the optimal acceleration level for reproduction of the chemical shift data has previously been shown to best reproduce the experimental residual dipolar coupling (RDC) data for this system, as both chemical shift data and RDCs report on an ensemble and time average in the millisecond range

    Re-negotiating Ideologies of Bilingualism on the Margins of Education

    Get PDF
    This article reports on an ethnographic study carried out in three interrelated sites: two contrasting secondary schools and a Youth-Club (the principal focus of this article), in an area of southwest Wales. This article highlights the incongruence between the language at home and the language of the school and posits that the relationship between language use at school and in the wider community needs to be problematised and questioned far more than has been done thus far. This study questions whether school-based ideologies and school-based practices are re-negotiated or contested on the margins of education and whether this re-negotiation and contestation plays an important role in whether a young person chooses to use Welsh or English outside of school. It will be argued that recreational spaces, even though loosely connected to schools as institutions, function as more open spaces where institutional ideologies are actively reworked and renegotiated, either through choosing to use English or by mixing and blending different aspects of linguistic resources, or by re-negotiating and questioning which version of Welshness is more valuable, ‘the removed and authentic’ (as seen at the Welsh school) or the ‘new and hybrid’ as seen at the Youth-Club

    The effects of a 12-Month, small changes group intervention on weight loss and menopausal symptoms in overweight women

    Get PDF
    To better understand how psychological principles related to goal-setting and motivation can be applied to the problem of obesity and menopausal symptoms, we examined the effectiveness of a Small Changes Intervention (SCI) program on forty-five overweight (BMI = 33.67 ± 7.03) women (mean age = 50.14 ± 12.16). Grounded in task motivation theory (cf. Locke & Latham, 2002), our SCI group therapy approach instituted small and maintainable steps in nutrition and physical activity to promote weight loss and a reduction in menopausal symptoms. Body weight, Body Mass Index (BMI), and scores on the Greene Climacteric Scale were assessed at Baseline (pre-intervention), 3-month post-treatment, 6-month follow-up, and 12-month follow-up. By the end of the 12-month study, 20 women were still participating and had lost, on average, 6.4% of their body weight, and had experienced a significant reduction in BMI, (BMI = 30.9 ± 6.13), providing further support for the SCI approach as an effective weight loss intervention method. Cross-sectional correlational analyses found expected associations between obesity and menopausal symptoms at the follow-up assessments. These relationships were especially strong by the last assessment period. Most importantly, menopausal symptoms decreased over the duration of the intervention. Taken together, these results suggest that the longitudinal impact of SCI on weight and BMI can have a positive impact on menopausal symptoms. These findings underscore the importance of applying wellresearched social psychological principles in goal setting to the problem of obesity and menopausal symptoms. Furthermore, the results obtained from the SCI approach suggest that that while obese individuals may experience increased symptoms of menopause, the process of losing excess body weight through achievement of small, achievable goals has the potential to improve menopausal symptoms

    Fractal Graphene Patch Antennas and the THz Communications Revolution

    Get PDF
    Fractal antennas have and are continuing to receive attention in regard to the futureof wireless communications. This is because of their wide- and multi-band capabilities, theopportunity of fractal geometries to drive multiple resonances, and, the ability to make smallerand lighter antennas with fewer components and radiative elements with higher gains. Smallscale (i.e. on the micro- and nano-scale) and ultra high frequency (in the Terahertz or THz range)fractal antennas composed of Graphene have the potential to enhance wireless communicationsat a data rate that is unprecedented, i.e.∼1012bits per second. A Fractal Graphene antennais a high-frequency tuneable antenna for radio communications in the THz spectrum, enablingunique applications such as wireless nano-networks. This is because (mono-layer) Grapheneis a one-atom-thick two-dimensional allotrope of Carbon with the highest known electricalconductivity that is currently unavailable in any other material, including metals such as Goldand Silver. Thus, combining the properties of Graphene with the self-affine characteristics ofa fractal at the micro- and nano-scale, provides the potential to revolutionise communications,at least in the near field (the order of a few metres) for low power systems. In this paper, weconsider the basic physics and some of the principle mathematical models associated with thedevelopment of this new disruptive technology in order to provide a guide to those engagedin current and future research, a fractal Graphene antenna being an example of an advancedmaterial for demanding applications. This includes some example simulations on the THz fieldpatterns generated by a fractal patch antenna composed of Graphene whose conductivity istaken to scale with the inverse of the frequency according to a ‘Drude’ model. The approachto generating THz sources using Graphene is also explored based on Infrared laser pumping toinduce a THz photo-current

    Fractal Graphene Patch Antennas and the THz Communications Revolution

    Get PDF
    Fractal antennas have and are continuing to receive attention in regard to the futureof wireless communications. This is because of their wide- and multi-band capabilities, theopportunity of fractal geometries to drive multiple resonances, and, the ability to make smallerand lighter antennas with fewer components and radiative elements with higher gains. Smallscale (i.e. on the micro- and nano-scale) and ultra high frequency (in the Terahertz or THz range)fractal antennas composed of Graphene have the potential to enhance wireless communicationsat a data rate that is unprecedented, i.e.∼1012bits per second. A Fractal Graphene antennais a high-frequency tuneable antenna for radio communications in the THz spectrum, enablingunique applications such as wireless nano-networks. This is because (mono-layer) Grapheneis a one-atom-thick two-dimensional allotrope of Carbon with the highest known electricalconductivity that is currently unavailable in any other material, including metals such as Goldand Silver. Thus, combining the properties of Graphene with the self-affine characteristics ofa fractal at the micro- and nano-scale, provides the potential to revolutionise communications,at least in the near field (the order of a few metres) for low power systems. In this paper, weconsider the basic physics and some of the principle mathematical models associated with thedevelopment of this new disruptive technology in order to provide a guide to those engagedin current and future research, a fractal Graphene antenna being an example of an advancedmaterial for demanding applications. This includes some example simulations on the THz fieldpatterns generated by a fractal patch antenna composed of Graphene whose conductivity istaken to scale with the inverse of the frequency according to a ‘Drude’ model. The approachto generating THz sources using Graphene is also explored based on Infrared laser pumping toinduce a THz photo-current

    Spiders have rich pigmentary and structural colour palettes

    Get PDF
    Elucidating the mechanisms of colour production in organisms is important for understanding how selection acts upon a variety of behaviours. Spiders provide many spectacular examples of colours used in courtship, predation, defence and thermoregulation, but are thought to lack many types of pigments common in other animals. Ommochromes, bilins and eumelanin have been identified in spiders, but not carotenoids or melanosomes. Here, we combined optical microscopy, refractive index matching, confocal Raman microspectroscopy and electron microscopy to investigate the basis of several types of colourful patches in spiders. We obtained four major results. First, we show that spiders use carotenoids to produce yellow, suggesting that such colours may be used for condition-dependent courtship signalling. Second, we established the Raman signature spectrum for ommochromes, facilitating the identification of ommochromes in a variety of organisms in the future. Third, we describe a potential new pigmentary-structural colour interaction that is unusual because of the use of long wavelength structural colour in combination with a slightly shorter wavelength pigment in the production of red. Finally, we present the first evidence for the presence of melanosomes in arthropods, using both scanning and transmission electron microscopy, overturning the assumption that melanosomes are a synapomorphy of vertebrates. Our research shows that spiders have a much richer colour production palette than previously thought, and this has implications for colour diversification and function in spiders and other arthropods
    corecore