1,033 research outputs found

    Iris Image Recognition using Optimized Kohonen Self Organizing Neural Network

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    The pursuit to develop an effective people management system has widened over the years to manage the enormous increase in population. Any management system includes identification, verification and recognition stages. Iris recognition has become notable biometrics to support the management system due to its versatility and non-invasive approach. These systems help to identify the individual with the texture information distributed around the iris region. Many classification algorithms are available to help in iris recognition. But those are very sophisticated and require heavy computation. In this paper, an improved Kohonen self-organizing neural network (KSONN) is used to boost the performance of existing KSONN. This improvement is brought by the introduction of optimization technique into the learning phase of the KSONN. The proposed method shows improved accuracy of the recognition. Moreover, it also reduces the iterations required to train the network. From the experimental results, it is observed that the proposed method achieves a maximum accuracy of 98% in 85 iterations

    Skeletal muscle and kidney crosstalk in chronic kidney disease

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    The functioning of complex organisms requires a constant and delicate balance of processes both between and within cells, tissues, and organ systems. There is growing appreciation for the role of signalling crosstalk connecting different organ systems of the body, even from tissues traditionally classified as “inert” in terms of their capacity to produce chemical signals that can act on other organ systems. Many of these secreted molecules have been shown to contribute to, or exacerbate, a variety of functions and diseases in other organ systems, even if the two organs are not functionally linked. For example, there is a strong association with skeletal muscle atrophy and dysfunction in patients with chronic kidney disease (CKD). Identification of molecules produced and secreted by skeletal muscle has existed for some time, and there is emerging evidence that skeletal muscle may directly affect kidney function. Conversely, factors produced and secreted by the kidneys in various models of CKD have been shown to contribute to reduced muscle functionality. This review will focus on crosstalk in both directions between skeletal muscle and the kidneys. The emphasis will be on direct interaction between these organs using examples of secreted factors that are produced by the muscle or kidneys (including activin A, myostatin, microRNA’s, irisin and mitsugumin 53),often under pathophysiological conditions. Our understanding of how the kidneys and skeletal muscle interact with each other is key to elucidating the pathophysiology processes that drive health and disease

    Sensitivities of the absorptive partitioning model of secondary organic aerosol formation to the inclusion of water

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    The predicted distribution of semi-volatile organic components between the gaseous and condensed phase as a function of ambient relative humidity and the specific form of the partitioning model used has been investigated. A mole fraction based model, modified so as not to use molar mass in the calculation, was found to predict identical RH dependence of component partitioning to that predicted by the conventional mass-based partitioning model which uses a molar mass averaged according to the number of moles in the condensed phase. A recently reported third version of the partitioning model using individual component molar masses was shown to give significantly different results to the other two models. Further sensitivities to an assumed pre-existing particulate loading and to parameterised organic component non-ideality are explored and shown to contribute significantly to the variation in predicted secondary organic particulate loading

    Granular Elasticity without the Coulomb Condition

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    An self-contained elastic theory is derived which accounts both for mechanical yield and shear-induced volume dilatancy. Its two essential ingredients are thermodynamic instability and the dependence of the elastic moduli on compression.Comment: 4pages, 2 figure

    The CRI v2.2 reduced degradation scheme for isoprene

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    The reduced representation of isoprene degradation in the Common Representative Intermediates (CRI) mechanism has been systematically updated, using the Master Chemical Mechanism (MCM v3.3.1) as a reference benchmark, with the updated mechanism being released as CRI v2.2. The complete isoprene degradation mechanism in CRI v2.2 consists of 186 reactions of 56 closed shell and free radical species, this being an order of magnitude reduction in size compared with MCM v3.3.1. The chemistry initiated by reaction with OH radicals, NO3 radicals and ozone (O3) is treated. An overview of the updates is provided, within the context of reported kinetic and mechanistic information. The revisions mainly relate to the OH-initiated chemistry, which tends to dominate under atmospheric conditions, although these include updates to the chemistry of products that are also generated from the O3- and NO3-initiated oxidation. The revisions have impacts in a number of key areas, including recycling of HOx and NOx. The performance of the CRI v2.2 isoprene mechanism has been compared with those of the preceding version (CRI v2.1) and the reference MCM v3.3.1 over a range of relevant conditions, using a box model of the tropical forested boundary layer. In addition, tests are carried out to ensure that the performance of MCM v3.3.1 remains robust to more recently reported information. CRI v2.2 has also been implemented into the STOCHEM chemistry-transport model, with a customized close-variant of CRI v2.2 implemented into the EMEP MSC-W chemistry-transport model. The results of these studies are presented and used to illustrate the global-scale impacts of the mechanistic updates on HOx radical concentrations

    Are they ‘worth their weight in gold’? Sport for older adults: benefits and barriers of their participation for sporting organisations

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    The ageing global population has led to an increased focus on health for older adults. However, older adults have not been a specific priority for some sporting organisations (SOs). Thus, there is an emerging opportunity for this age group to be considered within international sport policy. The aim of this study was to understand the benefits and barriers that SOs encounter when engaging older adults. Eight focus group interviews (n = 49) were held with representatives of Australian national sporting organisations (NSOs), and older adults who were either sport club or non-sport club members. The socioecological model domains, interpersonal, organisational and policy, were used as a framework for thematic analysis, and organisational capacity building concepts were utilised to explain the findings. Common perceived benefits included interpersonal benefits (intergenerational opportunities and role models) and organisational benefits (volunteering, financial contributions and maximised facility usage) for engaging older adults. Common perceived barriers included interpersonal barriers (competing priorities and perceived societal expectations), organisational barriers (lack of appropriate playing opportunities, lack of facility access and lack of club capacity) and policy barriers (strategic organisational focus on children and elite sport and risk management). Whilst participation in sport is not common for older adults, their involvement can be invaluable for sport clubs. It is not anticipated that any policy focus on older adults will significantly increase active participation for this age group. However, any increase in older adults’ sport participation either through actively playing, supporting family and friends and/or volunteering will contribute to the positive health of individuals, sport clubs and the community.Peer reviewedFinal Accepted Versio

    Dilatancy, Jamming, and the Physics of Granulation

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    Granulation is a process whereby a dense colloidal suspension is converted into pasty granules (surrounded by air) by application of shear. Central to the stability of the granules is the capillary force arising from the interfacial tension between solvent and air. This force appears capable of maintaining a solvent granule in a jammed solid state, under conditions where the same amount of solvent and colloid could also exist as a flowable droplet. We argue that in the early stages of granulation the physics of dilatancy, which requires that a powder expand on shearing, is converted by capillary forces into the physics of arrest. Using a schematic model of colloidal arrest under stress, we speculate upon various jamming and granulation scenarios. Some preliminary experimental results on aspects of granulation in hard-sphere colloidal suspensions are also reported.Comment: Original article intended for J Phys Cond Mat special issue on Granular Materials (M Nicodemi, Ed.

    Variance Analysis of Wind and Natural Gas Generation under Different Market Structures: Some Observations

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    Does large scale penetration of renewable generation such as wind and solar power pose economic and operational burdens on the electricity system? A number of studies have pointed to the potential benefits of renewable generation as a hedge against the volatility and potential escalation of fossil fuel prices. Research also suggests that the lack of correlation of renewable energy costs with fossil fuel prices means that adding large amounts of wind or solar generation may also reduce the volatility of system-wide electricity costs. Such variance reduction of system costs may be of significant value to consumers due to risk aversion. The analysis in this report recognizes that the potential value of risk mitigation associated with wind generation and natural gas generation may depend on whether one considers the consumer's perspective or the investor's perspective and whether the market is regulated or deregulated. We analyze the risk and return trade-offs for wind and natural gas generation for deregulated markets based on hourly prices and load over a 10-year period using historical data in the PJM Interconnection (PJM) from 1999 to 2008. Similar analysis is then simulated and evaluated for regulated markets under certain assumptions

    A Comparison of Two Ovine Lumbar Intervertebral Disc Injury Models for the Evaluation and Development of Novel Regenerative Therapies

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    © The Author(s) 2018. Study Design: Large animal research. Objective: Lumbar discectomy is the most commonly performed spinal surgical procedure. We investigated 2 large animal models of lumbar discectomy in order to study the regenerative capacity of mesenchymal stem cells following disc injury. Methods: Twelve adult ewes underwent baseline 3-T magnetic resonance imaging (MRI) followed by lumbar intervertebral disc injury by either drill bit (n = 6) or annulotomy and partial nucleotomy (APN) (n = 6). Necropsies were performed 6 months later. Lumbar spines underwent 3-T and 9.4-T MRI prior to histological, morphological and biochemical analysis. Results: Drill bit-injured (DBI) and APN-injured discs demonstrated increased Pfirrmann grades relative to uninjured controls (P <.005), with no difference between the 2 models. Disc height index loss was greater in the APN group compared with the DBI group (P <.005). Gross morphology injury scores were higher in APN than DBI discs (P <.05) and both were higher than controls (P <.005). Proteoglycan was reduced in the discs of both injury models relative to controls (P <.005), but lower in the APN group (P <.05). Total collagen of the APN group disc regions was higher than DBI and control discs (P <.05). Histology revealed more matrix degeneration, vascular infiltration, and granulation in the APN model. Conclusion: Although both models produced disc degeneration, the APN model better replicated the pathobiology of human discs postdiscectomy. We therefore concluded that the APN model was a more appropriate model for the investigation of the regenerative capacity of mesenchymal stem cells administered postdiscectomy

    ARK: Autonomous mobile robot in an industrial environment

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    This paper describes research on the ARK (Autonomous Mobile Robot in a Known Environment) project. The technical objective of the project is to build a robot that can navigate in a complex industrial environment using maps with permanent structures. The environment is not altered in any way by adding easily identifiable beacons and the robot relies on naturally occurring objects to use as visual landmarks for navigation. The robot is equipped with various sensors that can detect unmapped obstacles, landmarks and objects. In this paper we describe the robot's industrial environment, it's architecture, a novel combined range and vision sensor and our recent results in controlling the robot in the real-time detection of objects using their color and in the processing of the robot's range and vision sensor data for navigation
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