553 research outputs found
Asian Women's Perceived Impact of Leadership Characteristics and Skills on their UIUC Campus Life
Poster Presentation for EUI Spring 2017 Student Conference, concerning Asian women's perceived impact of leadership skills and characteristics on their UIUC campus life.Ope
WristSketcher: Creating Dynamic Sketches in AR with a Sensing Wristband
Restricted by the limited interaction area of native AR glasses (e.g., touch
bars), it is challenging to create sketches in AR glasses. Recent works have
attempted to use mobile devices (e.g., tablets) or mid-air bare-hand gestures
to expand the interactive spaces and can work as the 2D/3D sketching input
interfaces for AR glasses. Between them, mobile devices allow for accurate
sketching but are often heavy to carry, while sketching with bare hands is
zero-burden but can be inaccurate due to arm instability. In addition, mid-air
bare-hand sketching can easily lead to social misunderstandings and its
prolonged use can cause arm fatigue. As a new attempt, in this work, we present
WristSketcher, a new AR system based on a flexible sensing wristband for
creating 2D dynamic sketches, featuring an almost zero-burden authoring model
for accurate and comfortable sketch creation in real-world scenarios.
Specifically, we have streamlined the interaction space from the mid-air to the
surface of a lightweight sensing wristband, and implemented AR sketching and
associated interaction commands by developing a gesture recognition method
based on the sensing pressure points on the wristband. The set of interactive
gestures used by our WristSketcher is determined by a heuristic study on user
preferences. Moreover, we endow our WristSketcher with the ability of animation
creation, allowing it to create dynamic and expressive sketches. Experimental
results demonstrate that our WristSketcher i) faithfully recognizes users'
gesture interactions with a high accuracy of 96.0%; ii) achieves higher
sketching accuracy than Freehand sketching; iii) achieves high user
satisfaction in ease of use, usability and functionality; and iv) shows
innovation potentials in art creation, memory aids, and entertainment
applications
Composite metamaterials with dual-band magnetic resonances in the terahertz frequency regime
Composite metamaterials(CMMs) combining a subwavelength metallic hole array
(i.e. one-layer fishnet structure) and an array of split-ring resonators(SRRs)
on the same board are fabricated with gold films on silicon wafer. Transmission
measurements of the CMMs in the terahertz range have been performed. Dual-band
magnetic resonances, namely, a LC resonance at 4.40 THz and an additional
magnetic resonance at 8.64 THz originating from the antiparallel current in
wire pairs in the CMMs are observed when the electrical field polarization of
the incident light is parallel to the gap of the component SRR. The numerical
simulations agree well with the experimental results and further clarify the
nature of the dual-band magnetic resonances.Comment: 4 figures, 14 page
Analyzing the formation of normal and abnormal O waves in thoracic impedance graph using the impedance change components for aorta, blood vessels in lung and ventricles
Background: Many measurements of thoracic impedance graph show that the small C wave and big O wave appear often for patients with cardiac insufficiency, and the O/C ratio is bigger. And for the normal body, especially a younger one, the bigger O wave may also appear. But since the amplitude of the C wave of a normal body is bigger, the O/C ratio is smaller. The aim of the present paper is to investigate the formation mechanism of the normal and abnormal O waves in thoracic impedance graph. Methods and Results: The thoracic mixed impedance changes are measured with 6 leads consisting of 15 electrodes. The impedance change components for the aorta (AO), blood vessel in left lung (PL), blood vessel in right lung (PR), left ventricle (LV) and right ventricle (RV) are separated from thoracic mixed impedance changes by means of establishing and solving the thoracic impedance equations. The amplitudes of the O and C waves of various impedance change components are measured for 50 normal healthy adults and 34 patients with cardiac insufficiency. The formation mechanism of normal and abnormal O waves in thoracic impedance graph is analyzed using the superposition of the O waves of the above impedance change components. Detection subjects are 50 healthy adults and 34 hospital patients with cardiac insufficiency. (1) Thoracic impedance graph: The O/C ratios of the normal group are significantly smaller than that of the abnormal group, p < 0.001. The O wave of first lead (E1-E1’) is significantly bigger than that of leads 4 and 5 (E4-E4’ and E5-E5’) in the normal group, p < 0.001. (2) The impedance change component: The O waves of the AO, PL, and PR are significantly smaller than that of the LV and RV in the normal group, p < 0.001. The O wave and O/C of the AO, PL and PR of normal group are significantly smaller than that of the abnormal group, p < 0.001. Conclusions: The O wave of the thoracic impedance graph is formed due to the superposition of the O waves of the impedance change components for the aorta, blood vessels in lung and ventricles
Signal-independent RFF Identification for LTE Mobile Devices via Ensemble Deep Learning
Radio frequency fingerprint (RFF)-based wireless device authentication is an emerging technique to prevent potential spoofing attacks in wireless communications. The random access preamble of the physical random access channel (PRACH) in Long Term Evolution (LTE) systems is the first message sent from a user equipment (UE). However, PRACH preambles change under different evolved Node B (eNB), which will affect the RFF extraction. In this paper, a signal-independent RFF extraction method is first proposed to extract varying LTE PRACH preambles under different LTE eNBs. Residual transient segment (RTS) features from the varying PRACH preambles are extracted for RFF identification. A convolutional neural network (CNN) based ensemble deep learning scheme is proposed to integrate benefits from different RFF features. An experimental system under real operator LTE eNB is designed to capture and identify real UE signals. Experimental results show that the classification accuracy of five UEs can reach more than 95% under the same eNB and 85% under different eNBs. Furthermore, longtime evaluations show that the UE RTS feature is robust over time
Genomic characterization of tigecycline-resistant Escherichia coli and Klebsiella pneumoniae isolates from hospital sewage
IntroductionThe tigecycline-resistant Enterobacterales have emerged as a great public concern, and the mobile tet(X) variants and tmexCD-toprJ efflux pump are mainly responsible for the spread of tigecycline resistance. Hospital sewage is considered as an important reservoir of antimicrobial resistance, while tigecycline resistance in this niche is under-researched.MethodsIn this study, five Escherichia coli and six Klebsiella pneumoniae strains were selected from a collection of tigecycline-resistant Enterobacterales for further investigation by antimicrobial susceptibility testing, conjugation, whole-genome sequencing, and bioinformatics analysis.ResultsAll five E. coli strains harbored tet(X4), which was located on different plasmids, including a novel IncC/IncFIA(HI1)/IncHI1A/IncHI1B(R27) hybrid structure. In addition, tet(X4)-bearing plasmids were able to transfer by conjugation and be stabilized in the recipient in the absence of antibiotics. tmexCD1-toprJ1 was identified in two K. pneumoniae (LZSFT39 and LZSRT3) and it was carried by a novel multidrug-resistance transposon, designated Tn7368, on a novel IncR/IncU hybrid plasmid. In addition, we found that two K. pneumoniae (LZSFZT3 and LZSRT3) showed overexpression of efflux genes acrB and oqxB, respectively, which was most likely to be caused by mutations in ramR and oqxR.DiscussionIn conclusion, the findings in this study expand our knowledge of the genetic elements that carry tigecycline resistance genes, which establishes a baseline for investigating the structure diversity and evolutionary trajectories of human, animal, and environmental tigecycline resistomes
Mechanical Properties of MJ-Class Toroidal Magnet Wound by Composite HTS Conductor
An MJ-class superconducting magnetic energy storage (SMES) system has a wide range of potential applications in electric power systems. The composite high-temperature superconducting HTS conductor, which has the advantages of carrying large critical currents and withstanding high magnetic fields, is suitable for winding an MJ-class magnet coil. However, the Lorentz force of an HTS wire is so large that its induced mechanical stresses should be examined to ensure that the magnet is in good condition. By means of the equivalent material properties method and the sequential coupling method, this paper studies the mechanical properties of a three MJ toroidal SMES magnet wound by a composite HTS conductor. Based on the electromagnetic-structural coupling analysis, the Von-Mises stress, the radial stress, and the hoop stress of a magnet coil are calculated and employed to validate the stability of the MJ-class toroidal SMES magnet
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