232 research outputs found

    Mathematics Yearbook 2021

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    The Deakin University Mathematics Yearbook publishes student reports and articles in all areas of mathematics with an aim of promoting interest and engagement in mathematics and celebrating student achievements. The 2021 edition includes 7 coursework articles, where students have extended upon submissions in their mathematics units, as well as 4 articles based on student research projects conducted throughout 2020 and 2021

    Development of a model for smart card based access control in multi-user, multi-resource, multi-level access systems

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    The primary focus of this research is an examination of the issues involved in the granting of access in an environment characterised by multiple users, multiple resources and multiple levels of access permission. Increasing levels of complexity in automotive systems provides opportunities for improving the integration and efficiency of the services provided to the operator. The vehicle lease / hire environment provided a basis for evaluating conditional access to distributed, mobile assets where the principal medium for operating in this environment is the Smart Card. The application of Smart Cards to existing vehicle management systems requires control of access to motor vehicles, control of vehicle operating parameters and secure storage of operating information. The issues addressed include examination of the characteristics of the operating environment, development of a model and design, simulation and evaluation of a multiple application Smart Card. The functions provided by the card include identification and authentication, secure hash and encryption functions which may be applied, in general, to a wide range of access problems. Evaluation of the algorithms implemented indicate that the Smart Card design may be provably secure under single use conditions and conditionally secure under multiple use conditions. The simulation of the card design provided data to support further research and shows the design is practical and able to be implemented on current Smart Card types

    Internet Protocol version 6 and the future of home networking

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    Home networking will be more of a necessity in the future than it is today. The homes of the future will make our lives easier in many ways. As microprocessors become less expensive and require less power they will be implanted into many of the common household items used everyday. Appliances and components will evolve into smart devices that communicate with each other. Connecting these devices will become more important as devices incorporate new technologies. It will be necessary to build a network that can handle the needs of this type of computing environment. The home networks of the future will require many of the same features that can be found in today\u27s corporate networks. However, there will be four issues that will determine the level of success of implementing home networks. The first issue is the increase in volume of the devices accessing and utilizing the Internet. Security will be a high priority for homeowners, since the data that accumulates and circulates in and out of the home is sensitive and personal. The third critical issue is ease of use, because the average homeowner does not have the skills necessary to configure and maintain networks. The last issue that will be important in the home is the increased need for bandwidth and the ability to accommodate all types of data traffic. There is no doubt that the Internet Protocol will be important in future home networks. Some proponents of IP say IP over everything The trend has been finding new ways of making IP the answer to all types of voice and data communications. Initially the Internet Protocol was designed for a specific application. Over time, IPv4 has been able to successfully adapt to the changing needs and demands of the Internet. At one point in the early 90\u27s, it was feared that IPv4 would not be able to meet the future needs. As a result, The Internet Engineering Task Force (IETF) developed a next generation Internet Protocol, referred to as Internet Protocol version 6. In the meantime, new fixes to old IPv4 problems have been temporarily halted. The implementation of IPv6 has been extremely slow since the imminent danger of declining address space has been temporarily addressed. IP version 6 has many new features built into the protocol that will streamline and enhance many aspects of the network, but these features alone may not be enough to cause the displacement of the massive infrastructure of IPv4. Will IPv6 be better at handling the demands of the home networks of the future, or will the additions and updates for IPv4 be sufficient? What are some of the resolutions that are being developed or are already implemented for the key issues in home networks- the increasing number of devices, security, ease of use and data flow

    NASA Tech Briefs, November/December 1987

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    Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences

    Real-time signal detection and classification algorithms for body-centered systems

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    El principal motivo por el cual los sistemas de comunicación en el entrono corporal se desean con el objetivo de poder obtener y procesar señales biométricas para monitorizar e incluso tratar una condición médica sea ésta causada por una enfermedad o el rendimiento de un atleta. Dado que la base de estos sistemas está en la sensorización y el procesado, los algoritmos de procesado de señal son una parte fundamental de los mismos. Esta tesis se centra en los algoritmos de tratamiento de señales en tiempo real que se utilizan tanto para monitorizar los parámetros como para obtener la información que resulta relevante de las señales obtenidas. En la primera parte se introduce los tipos de señales y sensores en los sistemas en el entrono corporal. A continuación se desarrollan dos aplicaciones concretas de los sistemas en el entorno corporal así como los algoritmos que en las mismas se utilizan. La primera aplicación es el control de glucosa en sangre en pacientes con diabetes. En esta parte se desarrolla un método de detección mediante clasificación de patronones de medidas erróneas obtenidas con el monitor contínuo comercial "Minimed CGMS". La segunda aplicacióin consiste en la monitorizacióni de señales neuronales. Descubrimientos recientes en este campo han demostrado enormes posibilidades terapéuticas (por ejemplo, pacientes con parálisis total que son capaces de comunicarse con el entrono gracias a la monitorizacióin e interpretación de señales provenientes de sus neuronas) y también de entretenimiento. En este trabajo, se han desarrollado algoritmos de detección, clasificación y compresión de impulsos neuronales y dichos algoritmos han sido evaluados junto con técnicas de transmisión inalámbricas que posibiliten una monitorización sin cables. Por último, se dedica un capítulo a la transmisión inalámbrica de señales en los sistemas en el entorno corporal. En esta parte se estudia las condiciones del canal que presenta el entorno corporal para la transmisión de sTraver Sebastiá, L. (2012). Real-time signal detection and classification algorithms for body-centered systems [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/16188Palanci

    Fourth NASA Goddard Conference on Mass Storage Systems and Technologies

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    This report contains copies of all those technical papers received in time for publication just prior to the Fourth Goddard Conference on Mass Storage and Technologies, held March 28-30, 1995, at the University of Maryland, University College Conference Center, in College Park, Maryland. This series of conferences continues to serve as a unique medium for the exchange of information on topics relating to the ingestion and management of substantial amounts of data and the attendant problems involved. This year's discussion topics include new storage technology, stability of recorded media, performance studies, storage system solutions, the National Information infrastructure (Infobahn), the future for storage technology, and lessons learned from various projects. There also will be an update on the IEEE Mass Storage System Reference Model Version 5, on which the final vote was taken in July 1994

    Eight-Channel Head Array and Control System for Parallel Transmit/Receive Magnetic Resonance Imaging

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    Interest in magnetic resonance imaging (MRI) at high fields strengths (3 Tesla and above) is driven by the associated improvements in signal-to-noise ratio and spectral resolution. In practice, however, technical challenges prevent these benefits from being straightforwardly realized. High fields are associated with an increase in frequency and a decrease in the radiofrequency (RF) wavelength. The shortened wavelength causes potential inhomogeneity in the transmit field of the RF coil, resulting in non-uniform excitations. Susceptibility effects are also more pronounced at high field strengths, and can cause local distortions in the field and create areas of signal dropout. Parallel transmit is one method in development to address these challenges at high fields. Parallel transmit involves using multiple independently driven channels with RF pulses varying in amplitude, phase, and pulse envelope to create desired transmit excitations. Parallel transmit has been implemented to create homogenous transmit patterns and compensate for magnetic susceptibility effects, but despite its proven usefulness, the technology has yet to receive widespread adoption. Few parallel transmit systems exist and little work has been done in the pre-clinical realm. Studies demonstrating the clinical benefits of parallel transmit constitute a gap in the current body of work. This works presents an approach to a parallel transmit array and control system that can be easily and safely integrated on a clinical whole-body scanner. The transmit array was designed for use with ultra-low output impedance amplifiers and demonstrates an array design with a simplified decoupling network augmented by amplifier decoupling in both transmit and receive. The control system was programmed in LabVIEW using off-the-shelf hardware to manage pulse playback, correct transmit chain non-linearities, monitor on-coil waveforms, and drive the transmit hardware. The transmit array was shown with well-isolated patterns, and parallel transmit capability was demonstrated. This work progressed the translation of experimental parallel transmit technology to pre-clinical use

    Free vibration of symmetric angly-plane layered truncated conical shells under classical theory

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    Truncated conical shell finds wide ranging of engineering applications. They are used in space crafts, robots, shelters, domes, tanks, nozzles and in machinery devices. Thus, the study of their vibrational characteristics has long been of interest for the designers. The use of the lamination for the structures leads to design with the maximum reliability and minimum weight. Moreover, the study of free vibration of laminated conical shells has been treated by a number of researchers. Irie et al. (1982) studied free vibration of conical shells with variable thickness using Rayleigh-Ritz method of solution. Wu and Wu (2000) provided 3D elasticity solutions for the free vibration analysis of laminated conical shells by an asymptotic approach. Wu and Lee (2001) studied the natural frequencies of laminated conical shells with variable stiffness using the differential quadrature method under first-order shear deformation theory (FSDT). Tripathi et al. (2007) studied the free vibration of composite conical shells with random material properties of the finite element method. Civalek (2007) used the Discrete Singular Convolution (DSC) to investigate the frequency response of orthotropic conical and cylindrical shells. Sofiyez et al. (2009) studied the vibrations of orthotropic non-homogeneous conical shells with free boundary conditions. Ghasemi et al. (2012) presented their study of free vibration of composite conical shells which was investigated under various boundary conditions using the solution of beam function and Galerkin method. Viswanathan et al. (2007, 2011) studied free vibration of laminated cross-ply plates, including shear deformation, symmetric angle-ply laminated cylindrical shells of variable thickness with shear deformation theory using the spline collocation method. In the present work, free vibration of symmetric angle-ply laminated truncated conical shells is analyzed and displacement functions are approximated using cubic and quantic spline and collocation procedure is applied to obtain a set of field equations. The field equations along with the equations of boundary conditions yield a system of homogeneous simultaneous algebraic equations on the assumed spline coefficients which resulting to the generalized eigenvalue problem. This eigenvalue problem is solved using eigensolution technique to get as many eigenfrequencies as required. The effect of circumferential mode number, length ratio, cone angle, ply angles and number of layers under two boundary conditions on the frequency parameter is studied for three- and five- layered conical shells consisting of two types of layered materials
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