43 research outputs found

    TEXTURE CLASSIFICATION USING WEIGHTED PROBABILISTIC NEURAL NETWORKS

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    Texture classification is basically the problem of classifying pixels in an image according to their textural cues. This is different from conventional image segmentation as the texture is characterized using both the gray value for a given pixel and gray-level pattern in the neighborhood surrounding the pixel. In this project, the novel temporal updating approach is developed for weighted probabilistic neural network (WPNN) classifiers that can be used to classify the textures. This is done by utilizing the temporal contextual information and adjusting the WPNN to adapt to such changes. Whenever a new set of images arrives, an initial classification is first performed using the WPNN updated to the last frame while at the same time, a prediction using PNN is also based on the classification results of previous frame. The result of both the PNN and WPNN are then compared. Compared to the PNN, WPNN includes weighting factors between pattern layers and summation layer of the PNN. Performance of this approach is compared with model based and feature based methods in terms of signal to noise ratio and classification rate

    A Methodology for Secured Routing and Intrusion Detection in Wireless Mesh Networks

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    Abstract:-The basic aspect of evolution of wireless mesh networks is its characteristic of dynamically self organising, self configured nodes in the network that establish a mesh connectivity with lower mobility mesh routers, low power consumption of nodes that has put this technology into the emerging trends of the day to day networking applications. In general, throughput and security are two vast areas of research. Here we propose the methodology of handling both the security aspect and efficient routing. Initially the main aspect of an efficient communication is through exchange of information that shouldn’t avail ease of access by unauthenticated parties, therefore security issues have to be concentrated. Here we discuss various aspects optimal path selection for efficient routing considering the relevant routing metrics that proportionately affects the throughput. Finally several intrusion detection mechanisms are followed and basic approaches of their prevention for the black hole and grey hole attacks. All these aspects can be visualised by the network simulator tools like ns2, ns3, nctuns etc. DOI: 10.17762/ijritcc2321-8169.15072

    Prevalence and cause of gestational diabetes mellitus in a tertiary care center in Kolar district: a population based study

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    Background: Gestational diabetes mellitus (GDM) is carbohydrate intolerance at the onset of pregnancy which induces pathological short term or long term outcomes for both mother and baby. The aim of the present study was to know the prevalence of GDM in pregnant women who were attending the antenatal care (ANC) center at a tertiary care hospital in Kolar, Karnataka, India.Methods: This prospective study was conducted in Department of Obstetrics and Gynecology, Sri Devaraj Urs Medical College, a constituent of Sri Devaraj Urs Academy of Higher Education and Research, Kolar, Karnataka, India. The duration of the study was two months. In this study, 108 pregnant women above 24 weeks of gestation were screened for GDM by oral glucose tolerance test. Fasting 2 milli liter blood was collected and were given 75 grams of glucose in 200 milli liters of water and asked to drink within 5 minutes. Again 2 milli liters venous blood was collected after 1 hour and 2 hours from all participants. Plasma sample was used for the estimation of glucose by glucose oxidase and peroxidase (GOD-POD) method.Results: Out of 108, 12 women (11.1%) were diagnosed with GDM. The prevalence rate was higher in the age group of 26-30 years (41.6%).  Among 12 diabetic women, five (47.2%) exercised regularly and seven (58.3%) did not doing exercise. Out of 12 GDM subjects, eight of them had family history of diabetes in first degree relatives; among which one was hypertensive and five were suffering from thyroid problems.Conclusions: In the present study, the prevalence of GDM was found to be 11.1%. Prevalence of GDM might be influenced by increasing age, pre pregnancy weight, family history of diabetes, past history of pregnancy complications, status of literacy and exercise

    Influence of iron nanopowder addition on the densification of chromium-prealloyed water-atomised powder metallurgy steel admixed with nickel

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    High sintered density is desired for heavy-duty applications and there are different ways through which the sintered density can be improved. In the current study, nanopowder is blended to the conventionally used micrometre-sized water-atomised steel powder to evaluate its impact on sintering. Both the powder variants, without and with nanopowder, were subjected to thermogravimetry analysis, and uniaxially compacted to the same green density of 7.15 g/cc or 90% relative density and sintered at 1250\ub0C in pure hydrogen. A comparative analysis was performed with respect to the microstructural evolution between the micro and micro/nano bimodal powder compacts. JMatPro and electron backscattered diffraction was used to understand the microstructural evolution. An attempt was made to understand the improved linear shrinkage in the micro/nano bimodal powder compact using a combination of microstructure analysis and chemical analysis

    Metallurgical investigation of cracked Al–5.5Zn–2.5Mg–1.5Cu aluminium alloy valve

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    AbstractThe high strength aluminium alloy Al–5.5Zn–2.5Mg–1.5Cu (AA7075) is being widely used in realisation of aerospace components. A component ‘fill and vent valve’ used in liquid propulsion system was fabricated from AA 7075 forgings in T7352 temper condition, and subsequently undergone various functional tests, four years back. Recently, during dye penetrant test after proof pressure test at 525bar, a valve indicated presence of a crack. Detailed metallurgical investigation indicated that failure was caused by stress corrosion cracking

    Differential Deposition for Surface Figure Corrections in Grazing Incidence X-Ray Optics

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    Differential deposition corrects the low- and mid- spatial-frequency deviations in the axial figure of Wolter-type grazing incidence X-ray optics. Figure deviations is one of the major contributors to the achievable angular resolution. Minimizing figure errors can significantly improve the imaging quality of X-ray optics. Material of varying thickness is selectively deposited, using DC magnetron sputtering, along the length of optic to minimize figure deviations. Custom vacuum chambers are built that can incorporate full-shell and segmented Xray optics. Metrology data of preliminary corrections on a single meridian of full-shell x-ray optics show an improvement of mid-spatial frequencies from 6.7 to 1.8 arc secs HPD. Efforts are in progress to correct a full-shell and segmented optics and to verify angular-resolution improvement with X-ray testing

    Full-Shell X-Ray Optics Development at NASA Marshall Space Flight Center

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    NASAs Marshall Space Flight Center (MSFC) maintains an active research program toward the development of high-resolution, lightweight, grazing-incidence x-ray optics to serve the needs of future x-ray astronomy missions such as Lynx. MSFC development efforts include both direct fabrication (diamond turning and deterministic computer-controlled polishing) of mirror shells and replication of mirror shells (from figured, polished mandrels). Both techniques produce full-circumference monolithic (primary + secondary) shells that share the advantages of inherent stability, ease of assembly, and low production cost. However, to achieve high-angular resolution, MSFC is exploring significant technology advances needed to control sources of figure error including fabrication- and coating-induced stresses and mounting-induced distortions

    Lynx X-Ray Observatory: An Overview

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    Lynx, one of the four strategic mission concepts under study for the 2020 Astrophysics Decadal Survey, provides leaps in capability over previous and planned x-ray missions and provides synergistic observations in the 2030s to a multitude of space- and ground-based observatories across all wavelengths. Lynx provides orders of magnitude improvement in sensitivity, on-axis subarcsecond imaging with arcsecond angular resolution over a large field of view, and high-resolution spectroscopy for point-like and extended sources in the 0.2- to 10-keV range. The Lynx architecture enables a broad range of unique and compelling science to be carried out mainly through a General Observer Program. This program is envisioned to include detecting the very first seed black holes, revealing the high-energy drivers of galaxy formation and evolution, and characterizing the mechanisms that govern stellar evolution and stellar ecosystems. The Lynx optics and science instruments are carefully designed to optimize the science capability and, when combined, form an exciting architecture that utilizes relatively mature technologies for a cost that is compatible with the projected NASA Astrophysics budget

    X-Ray Optics at NASA Marshall Space Flight Center

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    NASA's Marshall Space Flight Center (MSFC) engages in research, development, design, fabrication, coating, assembly, and testing of grazing-incidence optics (primarily) for x-ray telescope systems. Over the past two decades, MSFC has refined processes for electroformed-nickel replication of grazing-incidence optics, in order to produce high-strength, thin-walled, full-cylinder x-ray mirrors. In recent years, MSFC has used this technology to fabricate numerous x-ray mirror assemblies for several flight (balloon, rocket, and satellite) programs. Additionally, MSFC has demonstrated the suitability of this technology for ground-based laboratory applications-namely, x-ray microscopes and cold-neutron microscopes and concentrators. This mature technology enables the production, at moderately low cost, of reasonably lightweight x-ray telescopes with good (15-30 arcsecond) angular resolution. However, achieving arcsecond imaging for a lightweight x-ray telescope likely requires development of other technologies. Accordingly, MSFC is conducting a multi-faceted research program toward enabling cost-effective production of lightweight high-resolution x-ray mirror assemblies. Relevant research topics currently under investigation include differential deposition for post-fabrication figure correction, in-situ monitoring and control of coating stress, and direct fabrication of thin-walled full-cylinder grazing-incidence mirrors
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