1,114 research outputs found

    Achieving Information Security by multi-Modal Iris-Retina Biometric Approach Using Improved Mask R-CNN

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    The need for reliable user recognition (identification/authentication) techniques has grown in response to heightened security concerns and accelerated advances in networking, communication, and mobility. Biometrics, defined as the science of recognizing an individual based on his or her physical or behavioral characteristics, is gaining recognition as a method for determining an individual\u27s identity. Various commercial, civilian, and forensic applications now use biometric systems to establish identity. The purpose of this paper is to design an efficient multimodal biometric system based on iris and retinal features to assure accurate human recognition and improve the accuracy of recognition using deep learning techniques. Deep learning models were tested using retinographies and iris images acquired from the MESSIDOR and CASIA-IrisV1 databases for the same person. The Iris region was segmented from the image using the custom Mask R-CNN method, and the unique blood vessels were segmented from retinal images of the same person using principal curvature. Then, in order to aid precise recognition, they optimally extract significant information from the segmented images of the iris and retina. The suggested model attained 98% accuracy, 98.1% recall, and 98.1% precision. It has been discovered that using a custom Mask R-CNN approach on Iris-Retina images improves efficiency and accuracy in person recognition

    Petrophysical Modelling For the Bahariya Formation, Egypt

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    AbstractLithologic laminations have great consequences on the Bahariya sandstone, which are distinguished by the calculated reservoir statistical parameters. The non-laminated Bahariya studied samples have the lowest mean bulk density and specific internal surface values, while they have the highest mean porosity, permeability and Spor values. On the other hand, the laminated samples exhibit high values. The non-laminated Bahariya samples have the lowest mean permeability anisotropy, due to its relative pore-framework homogeneity. Contrary, the laminated Bahariya samples have the highest mean permeability anisotropy. By the same behaviour, the non-laminated Bahariya samples have the highest mean electrical resistivity value, due to the lack of conductive minerals, while the laminated Bahariya samples have the highest mean electrical resistivity.The non-laminated Bahariya samples show the lowest mean magnetic susceptibility value, while the laminated samples reveal high values. Sonic wave velocities (Vp and Vs) are statistically treated, while the velocity anisotropy is calculated for all samples. Laminated samples display higher velocity in comparable to the non-laminated ones. Thin sections and SEM-micrographs were made for some selected samples in order to recognize the Bahariya sandstone forming minerals. Glauconite, micas, zircon, rutile and pyrite minerals are composing the laminas in the laminated samples, while some glauconitic sandstone are predominant in the non-laminated ones.A number of linear regression models were performed among some measured petrophysical parameters, in order to differentiate between the laminated and the non-laminated sandstones, and to obtain reliable relationships permitting reservoir characterization

    Modelling of cardiac hemodynamics: A case study

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    AbstractObservations made on patients under cardiac catheterization are used to develop validated models for the heart cavities and the main blood vessels, treating them as compartments of the cardiac system. The algorithm utilizes realistic nonlinear formulations and the least squares techniques for optimal parameter estimation. A comprehensive investigation made for modelling of the hemodynamics of one of the compartments is reported as a case study. The modelling procedure is broad-based in character, and may be used advantageously as an aid in the diagnosis of heart diseases

    System Identification and Seismic Performance Evaluation of Earth Dams

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    A system identification technique is developed to provide dynamic properties of earth dams from their seismic records. The technique is utilized to assess the capabilities and limitation of analytical models in terms of dynamic nonlinear constitutive relationships as well as damping. The technique is based on the least square method using Gaussian hypothesis. Earth dams are modeled as a three-dimensional nonhomogeneous visco-elasto-plastic soil structure. The forward problem is solved using a Galerkin-Ritz formulation in which the solution is expanded using basis function, which is selected to be the eigenmodes. The spatial variation of the excitation is considered by using global shape functions defined on the boundary domain to interpolate the input motion on the dam boundaries using recorded motion at discrete locations. The constitutive model is used to accommodate the nonlinear path dependent behavior of the dam material as well as coupling between different constituent of the soil mixture. The model is implemented using Druker-Prager multi-yield surface model and linear Kelvin-Voigt model. Application to instrumented dams, in recent earthquake, showed significant match between the recorded response and the optimal estimated response

    Structure of the Deformed 7075 Aircraft Al - Alloy with Material Analysis Using Diffraction (MAUD)

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    This work aims to study the effect of plastic deformation on the 7075 Al - alloy using Material Analyses Using Diffraction (MAUD). Plastic deformation produces dislocation defects. Using a hydraulic press, samples were deformed up to 25%. The XRD was measured for each degree of deformation. The MAUD program was used to analyze the data, and mathematical methods were deployed to understand the various behaviors observed. The lattice parameter, crystallite size, average internal stress, micro-strain, and dislocation density of the 7075Al-alloy were calculated. As the deformation degree increased, there was a progressive decline in the crystallite size as an increase in the micro-strain and dislocation density. The flow stress changes from 5.8 to 49 MPa and the stored dislocation energy varies from 2.62 to 185 kPa

    Experimental and computational investigation of energy ball wind turbine aerodynamic performance

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    The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was supported by the British University in Egypt and the Center for Renewable Energy. Author contributions E.E. prepared this manuscript. This study was carried out under the supervision of N.E., A.A.A.F., and T.A.E.-S. All authors carried out data analysis, discussed the results, and contributed to writing the paper.Peer reviewedPublisher PD

    Dexmedetomidine as an adjuvant to bupivacaine in ultrasound fascia iliaca compartment block in proximal end femur surgeries

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    Background: Fracture neck femur is a common cause of hospital admission among the elderly population. Many patients admitted with fracture femur have long-standing cardiac, hepatic or renal problems. This makes a challenge to balance adequate analgesia with side effects of opioids. Fascia iliaca compartment block (FICB) is one of the peripheral nerve block techniques. It became widely used in providing postoperative analgesia for patient with fracture neck femur either in emergency department or in the operating room.Objective: To evaluate the efficacy of addition of dexmedetomidine to bupivacaine on the duration and quality of postoperative analgesia in ultrasound guided fascia iliaca compartment block in proximal end femur surgeries.Patients and methods: Sixty patients with American Society of Anesthesiologists (ASA) physical status I - II of both sexes aged from 20-60 years scheduled for proximal end femur surgeries. They were randomly assigned to one of two equal groups (n=30 each), using closed envelope technique: Bupivacaine group (B group), and Bupivacaine + dexmedetomidine (BD group). Result: Our study demonstrated prolongation of postoperative analgesia in bupivacaine-dexmedetomidine group (BD) compared to bupivacaine group (B). It showed statistically significant reduction in cumulative pethidine doses and prolongation in the time till first rescue analgesic is required in the BD group in comparison with the B group in the first 24 hours. Hemodynamic changes and incidence of side effects, were statistically insignificant among the two groups. Conclusion: Addition of dexmedetomidine, as an adjuvant to the local anesthetic bupivacaine, in ultrasound fascia iliaca compartment block provides prolongation of the duration of postoperative analgesia with less opioid consumption without remarkable side effects
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