326 research outputs found

    Primary total hip arthroplasty: Staying out of trouble intraoperatively

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    Total hip Arthroplasty is one of the most successful and commonly performed procedures in Orthopaedic Surgery. Meticulous preoperative planning allows to surgeon anticipate potential problems to reduce postoperative complications and optimize patient outcomes. Currently, the posterior approach is the most common approach utilized in the United States. In order to prevent errors in stem version, especially with cementless fixation, the entry point should be posterior, and the initial entry point should be aligned in the correct anteversion as this will determine the ultimate version of the stem. Preoperative evaluation should asses for true and apparent lengths. For successful osseointegration of cementless components, bone ingrowth occurs when there is less than 40 μm of motion between the implant and bone. Certain socket conformations such as elliptical versus hemispherical are more prone to generate fractures at the time of impaction

    Knowledge Maps for Intelligent Questioning Systems in Engineering Education

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    The development of a hierarchical knowledge map with an intelligent questioning system to improve the educational process in engineering courses is discussed. Knowledge map represents the architecture of the entire curriculum and each course as an interconnection of modules. The knowledge system provides the necessary framework to allow a questioning system to select appropriate questions. It will also give immediate feedback and assistance to the student for improving the delays with classical assessment

    An Instrument for Assessing Knowledge Gain in a First Course in Circuit Theory

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    Although there has been considerable research on the development and use of assessment instruments to measure the effectiveness of various pedagogical approaches to teaching introductory physics classes (Hestenes et al. 1, Hestenes et al 2, Hake 3, Saul et al. 4) and other science courses (for example, see Vosniadou 5), there is relatively little similar work that has been done to develop assessment instruments for the first circuit theory course that is taught in electrical and computer engineering. Given the large numbers of students nationwide who take such a course, the challenge this course presents to beginning engineering students, and the introduction of new approaches to teach this material, an instrument similar to those available for physics is needed to identify student misconceptions at the beginning of the class and to measure the normalized learning gain at the end of the class (Hake 3). These gains and other metrics can then be used to compare the effect of different teaching methods. In addition, this same instrument or portions of it can be offered at later times in the curriculum to measure retention and reinforcement from other courses. This concept-based testing approach is useful to examine the overall effectiveness of the circuit component of a curriculum and could thus be used as part of the continuous self-improvement process required under the ABET 2000 rules

    Hyperfine structure of the ground state muonic He-3 atom

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    On the basis of the perturbation theory in the fine structure constant α\alpha and the ratio of the electron to muon masses we calculate one-loop vacuum polarization and electron vertex corrections and the nuclear structure corrections to the hyperfine splitting of the ground state of muonic helium atom (μ e 23He)(\mu\ e \ ^3_2He). We obtain total result for the ground state hyperfine splitting Δνhfs=4166.471\Delta \nu^{hfs}=4166.471 MHz which improves the previous calculation of Lakdawala and Mohr due to the account of new corrections of orders α5\alpha^5 and α6\alpha^6. The remaining difference between our theoretical result and experimental value of the hyperfine splitting lies in the range of theoretical and experimental errors and requires the subsequent investigation of higher order corrections.Comment: Talk on poster section of XXIV spectroscopy congress, 28 February-5 March 2010, Moscow-Troitsk, Russia, 21 pages, LaTeX, 8 figure

    Radiation Testing of Electronics for the CMS Endcap Muon System

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    The electronics used in the data readout and triggering system for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) particle accelerator at CERN are exposed to high radiation levels. This radiation can cause permanent damage to the electronic circuitry, as well as temporary effects such as data corruption induced by Single Event Upsets. Once the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will have five times higher instantaneous luminosity than LHC, allowing for detection of rare physics processes, new particles and interactions. Tests have been performed to determine the effects of radiation on the electronic components to be used for the Endcap Muon electronics project currently being designed for installation in the CMS experiment in 2013. During these tests the digital components on the test boards were operating with active data readout while being irradiated with 55 MeV protons. In reactor tests, components were exposed to 30 years equivalent levels of neutron radiation expected at the HL-LHC. The highest total ionizing dose (TID) for the muon system is expected at the inner-most portion of the CMS detector, with 8900 rad over ten years. Our results show that Commercial Off-The-Shelf (COTS) components selected for the new electronics will operate reliably in the CMS radiation environment

    The Computational Complexity of Symbolic Dynamics at the Onset of Chaos

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    In a variety of studies of dynamical systems, the edge of order and chaos has been singled out as a region of complexity. It was suggested by Wolfram, on the basis of qualitative behaviour of cellular automata, that the computational basis for modelling this region is the Universal Turing Machine. In this paper, following a suggestion of Crutchfield, we try to show that the Turing machine model may often be too powerful as a computational model to describe the boundary of order and chaos. In particular we study the region of the first accumulation of period doubling in unimodal and bimodal maps of the interval, from the point of view of language theory. We show that in relation to the ``extended'' Chomsky hierarchy, the relevant computational model in the unimodal case is the nested stack automaton or the related indexed languages, while the bimodal case is modeled by the linear bounded automaton or the related context-sensitive languages.Comment: 1 reference corrected, 1 reference added, minor changes in body of manuscrip

    An A3P approach towards Image Privacy on Social Sites

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    Usage of social media’s has been considerably increasing in today’s world which enables the user to share their personal information like images with other users. This improved technology leads to privacy desecration where the users can share large number of images across the network. To provide security for the information, we put forward this paper consisting Adaptive Privacy Policy Prediction (A3P) framework to help users create security measures for their images. The role of images and its metadata are studied as a measure of user’s privacy preferences. The Framework defines the best privacy policy for the uploaded images. It includes an Image classification framework for association of images with similar policies and a policy prediction technique to automatically generate a privacy policy for user-uploaded images

    Hyperfine Structure of S-States in Muonic Helium Ion

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    Corrections of orders alpha^5 and alpha^6 are calculated in the hyperfine splittings of 1S and 2S - energy levels in the ion of muonic helium. The electron vacuum polarization effects, the nuclear structure corrections and recoil corrections are taken into account. The obtained numerical values of the hyperfine splittings -1334.56 meV (1S state), -166.62 meV (2S state) can be considered as a reliable estimate for the comparison with the future experimental data. The hyperfine splitting interval Delta_{12}=(8 Delta E^{hfs}(2S)- Delta E^{hfs}(1S)) = 1.64 meV can be used for the check of quantum electrodynamics.Comment: 14 pages, 5 figure

    Laboratory biomarkers associated with COVID-19 severity and management

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    The heterogeneous disease course of COVID-19 is unpredictable, ranging from mild self-limiting symptoms to cytokine storms, acute respiratory distress syndrome (ARDS), multi-organ failure and death. Identification of high-risk cases will enable appropriate intervention and escalation. This study investigates the routine laboratory tests and cytokines implicated in COVID-19 for their potential application as biomarkers of disease severity, respiratory failure and need of higher-level care. From analysis of 203 samples, CRP, IL-6, IL-10 and LDH were most strongly correlated with the WHO ordinal scale of illness severity, the fraction of inspired oxygen delivery, radiological evidence of ARDS and level of respiratory support (p ≤ 0.001). IL-6 levels of ≥3.27 pg/ml provide a sensitivity of 0.87 and specificity of 0.64 for a requirement of ventilation, and a CRP of ≥37 mg/l of 0.91 and 0.66. Reliable stratification of high-risk cases has significant implications on patient triage, resource management and potentially the initiation of novel therapies in severe patients

    Radiation testing of electronics for the CMS endcap muon system

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    The electronics used in the data readout and triggering system for the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) particle accelerator at CERN are exposed to high radiation levels. This radiation can cause permanent damage to the electronic circuitry, as well as temporary effects such as data corruption induced by Single Event Upsets. Once the High Luminosity LHC (HL-LHC) accelerator upgrades are completed it will have five times higher instantaneous luminosity than LHC, allowing for detection of rare physics processes, new particles and interactions. Tests have been performed to determine the effects of radiation on the electronic components to be used for the Endcap Muon electronics project currently being designed for installation in the CMS experiment in 2013. During these tests the digital components on the test boards were operating with active data readout while being irradiated with 55 MeV protons. In reactor tests, components were exposed to 30 years equivalent levels of neutron radiation expected at the HL-LHC. The highest total ionizing dose (TID) for the muon system is expected at the innermost portion of the CMS detector, with 8900 rad over 10 years. Our results show that Commercial Off-The-Shelf (COTS) components selected for the new electronics will operate reliably in the CMS radiation environment.Physic
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