Load Spectrum Compilation Based on Nonparametric Statistical Extrapolation

2013 ◽  
Vol 694-697 ◽  
pp. 271-277 ◽  
Author(s):  
Zhi Qiang Xu ◽  
Hong Jian Wang ◽  
Ming Yao Yao
Keyword(s):  
Kernel Function ◽  
Time History ◽  
Critical Issue ◽  
Extrapolation Method ◽  
Load History ◽  
Load Spectrum ◽  
Load Characteristics ◽  
Nonparametric Statistical ◽  
Function Shape

Considering the special load characteristics of the wheel loader, thispaper focus on compiling the load spectrum of the transmission of the wheelloader using the nonparametric statistical extrapolation method (NSEM). In thisprocess, the determination of the kernel function shape is the critical issue,which has been discussed in detail. Before extrapolating the sample loadspectrum, the signal denoising of the field-tested time-history load signals isperformed. After that, the sample load cycles are obtained using the rainflowcounting method and the corresponding kernel function shape is determined. Thenthe NSEM of rainflow matrix is proposed, by which the whole-life load spectrumis estimated. The proposed extrapolation method can well realize the estimationof the load cycles that do not appear in sample load cycles but may exist inthe whole-life load history.

Tensorial Deformation Measures for Flexible Joints

2010 ◽  
Vol 6 (3) ◽  
Author(s):  
Olivier A. Bauchau ◽  
Leihong Li ◽  
Pierangelo Masarati ◽  
Marco Morandini
Keyword(s):  
Finite Deformation ◽  
Nonlinear Behavior ◽  
Critical Issue ◽  
Finite Deformations ◽  
Flexible Joints ◽  
Elastic Bodies ◽  
Infinitesimal Deformations ◽  
Stiffness Characteristics ◽  
Definition Of

Flexible joints, sometimes called bushing elements or force elements, are found in all multibody dynamics codes. In their simplest form, flexible joints simply consist of sets of three linear and three torsional springs placed between two nodes of a multibody system. For infinitesimal deformations, the selection of the lumped spring constants is an easy task, which can be based on a numerical simulation of the joint or on experimental measurements. If the joint undergoes finite deformations, the identification of its stiffness characteristics is not so simple, especially if the joint itself is a complex system. When finite deformations occur, the definition of deformation measures becomes a critical issue. Indeed, for finite deformation, the observed nonlinear behavior of materials is partly due to material characteristics and partly due to kinematics. This paper focuses on the determination of the proper finite deformation measures for elastic bodies of finite dimension. In contrast, classical strain measures, such as the Green–Lagrange or Almansi strains, among many others, characterize finite deformations of infinitesimal elements of a body. It is argued that proper finite deformation measures must be of a tensorial nature, i.e., must present specific invariance characteristics. This requirement is satisfied if and only if the deformation measures are parallel to the eigenvector of the motion tensor.

Determination of carbapenemase genes in clinical isolates using Cepheid Xpert Carba-R

2021 ◽  
pp. 16-19
Author(s):  
N. I. Gabrielyan ◽  
V. G. Kormilitsyna ◽  
V. K. Zaletaeva ◽  
A. V. Krotevich ◽  
I. A. Miloserdov ◽  
...  
Keyword(s):  
Targeted Therapy ◽  
Infection Control ◽  
Resistance Genes ◽  
Carbapenem Resistance ◽  
Critical Issue ◽  
Sensitivity Study ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Carbapenem Resistant

Detection of carbapenem resistance genes is a critical issue for hospitals due to possible recommendations for infection control and targeted therapy. The Cepheid Xpert instrument, a Carba-R test for the detection and differentiation of five common carbapenemase genes, was tested from September 2020 to February 2021. As part of the approbation, 20 tests were provided. This review presents the results of the approbation of a relatively regular sensitivity study on Siemens WalkAway‑96 plus. Cepheid Xpert Carba-R analysis has been shown to be an accurate and fast tool for detecting colonization by carbapenem-resistant gram-negative bacteria, which can help limit the spread of these organisms in hospitals.

Experimental studies of load characteristics of bogie frames for 350 km/h EMUs

2011 ◽  
Vol 226 (2) ◽  
pp. 216-227 ◽  
Author(s):  
Z Ren ◽  
S Sun ◽  
Q Li ◽  
Z Liu
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Lateral Force ◽  
Load Spectrum ◽  
Dynamic Stresses ◽  
Dynamic Coefficients ◽  
Sample Data ◽  
Load Characteristics ◽  
Amplitude Level ◽  
Track Irregularities

In this paper,methods to measure the axle spring load, trailing arm seat lateral force and dynamic stresses of powered and non-powered bogies of a 350 km/h electrical-multi-unit (EMU) are presented. The dynamic amplitude and Hilbert transform of the sample data are used to investigate the characteristics of the forces and the stresses for the EMU running on typical sections including high-speed division, turnout zone, curves, and depot entrance. The load spectrum is then introduced to survey the amplitude level and the number of occurrence of the loads and stresses. Dynamic coefficients of the loads are compared with the recommended values in the Code UIC615-4. The effects of track irregularities and vibrations of gear boxes and motors on the loads and stresses are investigated and the measured loads are classified into six types according to effects of forces on the bogie's movement. The characteristics of the measured loads are useful to establish load conditions for laboratory tests of bogie’s fatigue assessment.

scholarly journals Tracking patchy pulsating aurora through all-sky images

2017 ◽  
Vol 35 (4) ◽  
pp. 777-784 ◽  
Author(s):  
Eric Grono ◽  
Eric Donovan ◽  
Kyle R. Murphy
Keyword(s):  
Time History ◽  
Image Data ◽  
Auroral Oval ◽  
Automatic Identification ◽  
Inner Magnetosphere ◽  
Wide Range ◽  
History Of ◽  
Initial Results ◽  
Automatic Technique

Abstract. Pulsating aurora is frequently observed in the evening and morning sector auroral oval. While the precipitating electrons span a wide range of energies, there is increasing evidence that the shape of pulsating auroral patches is controlled by structures in near-equatorial cold plasma; these patches appear to move with convection, for example. Given the tremendous and rapidly increasing amount of auroral image data from which the velocity of these patches can be inferred, it is timely to develop and implement techniques for the automatic identification of pulsating auroral patch events in these data and for the automatic determination of the velocity of individual patches from that data. As a first step towards this, we have implemented an automatic technique for determining patch velocities from sequences of images from the Time History of Events and Macroscale Interactions during Substorms (THEMIS) all-sky imager (ASI) and applied it to many pulsating aurora events. Here we demonstrate the use of this technique and present the initial results, including a comparison between ewograms (east–west keograms) and time series of patch position as determined by the algorithm. We discuss the implications of this technique for remote sensing convection in the inner magnetosphere.

scholarly journals Abundance variations of tracers and their effects on our determination of molecular cloud structure

1991 ◽  
Vol 147 ◽  
pp. 177-181
Author(s):  
Paul F. Goldsmith
Keyword(s):  
Molecular Cloud ◽  
Molecular Clouds ◽  
Column Density ◽  
Critical Issue ◽  
Structure Stability ◽  
Molecular Gas ◽  
Cloud Structure ◽  
Molecular Tracer ◽  
Short Presentation

Our understanding of the molecular phase of the interstellar medium is critically dependent on use of various lines from different molecular species to trace this dense material. As our knowledge of molecular clouds becomes more refined, and we pursue in detail issues of molecular cloud structure, stability, and how star formation depends on and affects the molecular gas, it is appropriate to examine the basis by which we determine the morphology of clouds, their density, and other key parameters. This is obviously a major undertaking, well beyond the scope of the short presentation at this conference, so I will concentrate on one very basic, but critical issue, which is that of abundance variations of tracers of density and molecular column density which are widely used to delineate the denser portions of all types of molecular clouds. In this summary, I will first highlight some of the apparent indications of significant variations of abundance within individual clouds, as a way of indicating some potential dangers and the importance of the molecular tracer selected. I will also briefly suggest how such variations may be themselves important diagnostics of cloud structure and evolution.

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