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Background: The challenges that viral pneumonia poses to the global public health system remain daunting. In this study, an analysis of publications on viral pneumonia over the past two decades was conducted. Through this work, we hope to provide inspiration for future research on viral pneumonia. Methods: We extracted all of the English publications relevant to viral pneumonia published during 1999-2019 from Web of Science. GraphPad Prism, CiteSpace, and VOSviewer were used to collect and analyze the publication trends in related fields. Results: We identified 2,006 publications with 62,155 citations as of February 16, 2021. The United States accounted for the largest number of publications (34.2%), with the highest number of citations (27,616) and the highest h-index (78). China ranked second in the number of publications. Ctr Dis Control & Prevent proved to be the center of research cooperation. Clinical Infectious Diseases included the most papers published relating to the topic of viral pneumonia. Chan KH published the most papers in this field (25), while an article from Fouchier RAM presented the highest citation frequency (1,275). Conclusions: According to the bibliometric analysis database and related software results, the United States dominates the field of viral pneumonia research. The key term extracted by VOSviewer has shifted to “Diagnosis and management”, indicating a new trend for viral pneumonia research.

The effect of mass loading is an important phenomenon for the calibration of back-to-back accelerometers. When a transfer standard back-to-back accelerometer that has been calibrated for a given mass load is used to calibrate an accelerometer whose mass is different, an error is introduced. For this reason, accelerometer manufactures may supply correction curves for the mass loading effect or specify a maximum sensitivity change due to mass loads. These data, however, often have limited applicability. In this paper, the effect of mass loading on the shock sensitivity of some transfer standard accelerometers is presented. The shock-shaped excitation varied in amplitude from 5000 m/s2 to 10000 m/s2, for different mass loads from 37 g to 200 g. It has been found that the shock sensitivity of the accelerometers investigated decreases linearly as the load mass increases at a rate of about 0.007 %/g. This rate of decrease in shock sensitivity is almost constant for different shock accelerations., 27th International Congress on Sound and Vibration, ICSV 2021, July 11-16, 2021, Virtual, Online

Proceedings of the ICA 2019 and EAA Euroregio : 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019 : 9-13 September 2019, Aachen, Germany / proceedings editor: Martin Ochmann, Michael Vorländer, Janina Fels 23rd International Congress on Acoustics, integrating 4th EAA Euroregio 2019, ICA 2019, Aachen, Germany, 9 Sep 2019 - 13 Sep 2019; Aachen (2019)., Published by Aachen

25th International Congress on Sound and Vibration, July 8-12, 2018, Hiroshima, Japan

Most primary accelerometer calibrations, or absolute calibrations, are currently performed using laser interferometry under the guideline of the international standard (ISO 16063-11, 1999). Due to rocking motion of vibration shakers, however, the measured accelerometer sensitivities at different laser incidence points can vary for up to a few percent. For the accurate determination of rocking motion on the effect of calibration results, a dual-beam laser interferometer was developed at National Research Council Canada. This paper describes the method and apparatus for simultaneous measurements of displacement amplitudes and its distribution along a straight line using a dual-beam laser interferometer. The interferometer directs two beams that are incident at distinct points on a moving surface. A separation distance between the two sensing spots on the moving surface is provided. In the present setup, the separation distance is adjustable along a straight line. This feature allows the interferometer to measure the displacement distribution along a line. To reduce the measurement uncertainty a model-based estimation is used to accurately determine the displacement amplitudes from the current outputs of photo diodes. This paper also presents the measurement results showing the difference of displacement amplitudes due to rocking motion. The system may also be used for direct quantitative study of moving surface deformation during vibration., ICSV 21: 21st International Congress on Sound and Vibration, July 13-17, 2014, Beijing, China

Most primary shock calibrations, or absolute shock calibrations, are currently performed using laser interferometry under the guideline of the international standard (ISO 16063-13, 2001). The laser interferometric method measures the displacement of a moving anvil with a shock accelerometer mounted on. To achieve high accuracy in the measurement of acceleration it requires a straight motion of the accelerometer with desired shock pulse duration and shape. Unfortunately, shock generators usually present high levels of unwanted motions, such as rotation, transverse motion, and pitch motion. The presence of unsymmetric forces on the anvil causes these motions. To reduce the effect of these motions, measurements may be performed at multiple incidence points equally spaced along the border of the accelerometer on the mounting surface or on the top surface of the accelerometer and the corresponding average is then estimated. Obviously, this method is very time consuming. Alternatively, supporting structures can be added to the anvil in such a way that few or no unsymmetric forces cause rotation and deviations from rectilinear motion. To obtain the best results, the supporting structure should be optimized for a specific type of accelerometer with its dummy mass if any. For this purpose, a real-time anvil motion monitoring system was developed at National Research Council Canada. This paper describes the detail of the system and presents the measurement results under different operating conditions. Static air bearing measurements were performed using the system to study the radial stiffness and pitch stiffness of the anvil. Dynamic air bearing measurements were also performed using the system to ensure that the resonance frequencies of the anvil are at least 10/T, where T is the pulse duration., The 22nd International Congress on Sound and Vibration, 12-16 July 2015, Florence, Italy, Series: Proceedings of the ... International Congress on Sound and Vibration (ICSV 22)

Most primary accelerometer calibrations, or absolute calibrations, are currently performed using laser interferometry under the guideline of the international standard (ISO 16063-11, 1999). The laser interferometric method measures the displacement amplitude of a moving surface with an accelerometer mounted. To achieve high accuracy in the measurement of acceleration it requires a poston-like and distortion-free vibration of the accelerometer at calibration frequencies and amplitudes. Unfortunately, vibration shakers usually present hgih levels of rocking motion. Rocking motions is an unwanted phenomenon exhibited by vibration shaker. It is usually manifested in oscillatory back and forth, side to side, or rotatory movements. It causes the measurements of accelerometer sensitivity deviating from each other for up to a few percent. To reduce the effect of rocking motion, measurements may be performed at multiple incidence points equally spaced along the border of the accelerometer on the mounting surface and the corresponding average is then estimated. Recently, mechanical filters have been used to decouple the rocking motion from vibration shaker to acceleromteter. to obtain the best results, the filter should be optimized for a specific type of reference accelerometer. For this purpose, a real-time rocking motion monitoring system was developed at the National Research Council Canada. This paper describes the improvements of the system since it was developed and reported and presents the measurement results of rocking motion for different conditions., 20th International Congress on Sound & Vibration (ICSV20), July 7-11, 2013, Bangkok, Thailand

19th International Congress on Sound and Vibration (ICSV19), 8-12 July 2012, Vilnius, Lithuania

Accelerometer cables should be securely fastened to stationary components with clamp, tape, or other adhesive means to minimize relative cable motion (cable whip). Cable motion can introduce self noise, especially in high-impedance signal paths (for example, from piezoelectric accelerometer output to charge amplifier input). This self-generated noise is referred to as the triboelectric effect. Although the low-noise treatment of cable is a solution to minimizing this effect it is still necessary to limit the motion of cables to further reduce noise. When an accelerometer cable is fastened to non-moving structure it introduces cable strain near the electrical connector of the accelerometer that pushes or pulls the accelerometer while it is in movement. Such a push or pull contributes to the accelerometer rocking motion that is a main source of measurement uncertainty. In practice, leaving enough slack to allow free movement of the accelerometer while securing the cable may reduce the cable strain in trade with cable motion limitation. This paper presents the development of a laser position sensing system to study this trade-off. Dummy accelerometers are fabricated that integrate mirrors and electrical connector. The dummy accelerometers have the same mechanical dimensions of commercial accelerometers and are made of solid steel to eliminate the rocking motion due to accelerometer housing. A laser beam is incident on one of the mirrors of the dummy accelerometer. The reflected laser beam is received by a lateral effect position sensitive detector (PSD) to monitor any motion that deviates from the axial motion due to the rocking motion. A twochannel waveform recorder is used to capture the PSD output signals. The waveform recorder, which is equipped with a computer interface, is capable of analog-to-digital conversion, storage of the PSD output signals and display of laser beam deviations in real time. With this system the adjustment of cable fastening can be done in real time. An example is given in this paper that shows the accelerometer rocking motion for different cable fastening conditions. The system can also be used to study the rocking motion of a vibration shaker while performing calibration for different mass loads and air bearing flow rates. Copyright © (2011) by the International Institute of Acoustics & Vibration., 18th International Congress on Sound and Vibration 2011, ICSV 2011, 10 July 2011 through 14 July 2011, Rio de Janeiro

Acoustics Week in Canada, 13-15 October 2010, Victoria, British Columbia

Accelerometers are designed to measure vibration in one precisely defined principal axis, usually perpendicular to the mounting surface. Ideally, there should be no response to accelerations in the other directions. In practice, the accelerometer does produce a charge or voltage when it is vibrated in the axis at 90° to the principal axis of measurement. The resulting output is indistinguishable from the response to the acceleration in the principal axis. This leads to an increased measurement uncertainty if these transverse accelerations exist during the calibration of the accelerometer. For this reason, the international standard ISO 16063-11 specifies limits for the transverse motion of vibration shakers. This paper presents the development of a laser interferometric system, which is designed to measure the transverse motion of an air-bearing calibration-grade shaker for various loads. The use of a mounting fixture with integrated plane mirror reflectors allows the transverse motion to be measured during the calibration itself. The system is capable of simultaneously measuring transverse motions along two axes. The measured transverse motion of a low-frequency accelerometer mounted on a long-stroke shaker is presented for frequencies in the range from 2 Hz to 40 Hz., 16th International Congress on Sound and Vibration (ICSV16), 5-9 July 2009, Krakow, Poland

A sound calibrator contains a stable sound source that can be coupled to the microphone of a measuring instrument. This allows the calibration of an entire measurement system prior to a measurement. The calibration of the measurement system is so important that many noise regulations specify the requirement of calibration. The sound calibrator itself needs to be calibrated routinely traceable to national standards. The International Standard IEC 60942:2003, Electroacoustics - Sound calibrators, specifies performance requirements for the sound pressure level generated by a sound calibrator, especially the short-term level fluctuation of sound pressure. The aim of this paper is to evaluate several methods proposed for the measurement of fluctuation in the sound pressure level generated by the sound calibrator. Specifically, this paper focuses on the sound level meter method, the analyzer method (using either a FFT analyzer or a set of 1/n octave band filters), and the time capture method. The analysis is emphasized on the key points for implementing IEC 60942:2003. The time capture method implemented at National Research Council Canada has a measurement uncertainty of 0.016 dB, which is better than the maximum permitted expanded uncertainty of measurement for short-term level fluctuation specified in IEC 60942:2003., 37th International Congress and Exposition on Noise Control Engineering, 26-29 October 2008, Shanghai, China

The final results of Sistema Interamericano de Metrologia (SIM) interlaboratory comparison on microphone calibration SIM.AUV.A-K1 in the frequency range from 125 Hz to 8000 Hz are presented. Initially the comparison involved NORAMET countries: USA, Canada and Mexico. Later, the comparison was extended to include Argentina and Brazil, resulting in a SIM.AUV.A-K1 microphone interlaboratory comparison. The national metrology institutes (NMIs) of the five American countries that participated were the Institute for National Measurement Standards (INMS–Canada), National Institute of Standards and Technology (NIST–USA), Centro Nacional de Metrología (CENAM–Mexico), Instituto Nacional de Metrologia, Normalização e Qualidade Industrial (INMETRO–Brazil) and Instituto Nacional de Tecnología Industrial (INTI–Argentina). The INMS, Canada was the pilot laboratory that provided the data for this report. The final results were presented, discussed and agreed upon by all participants during a meeting held in INMETRO in October 2000. The maximum RMS deviation for the two LS1P laboratory standard microphones measured by the above participants is 0.037 dB. Fil: Wong, George. Institute for National Measurement Standards; Canadá Fil: Wu, Lixue. Institute for National Measurement Standards; Canadá