scholarly journals CALIBRATION AND STABILITY ANALYSIS OF THE VLP-16 LASER SCANNER

2016 ◽  
Vol XL-3/W4 ◽  
pp. 55-60 ◽  
Author(s):  
C. L. Glennie ◽  
A. Kusari ◽  
A. Facchin
Keyword(s):  
Stability Analysis ◽  
Point Cloud ◽  
Temporal Stability ◽  
Laser Scanner ◽  
Effect Of Temperature ◽  
Geometric Calibration ◽  
Long Term Stability ◽  
The Individual

We report on a calibration and stability analysis of the Velodyne VLP-16 LiDAR scanner. The sensor is evaluated for long-term stability, geometric calibration and the effect of temperature variations. To generalize the results, three separate VLP-16 sensors were examined. The results and conclusions from the analysis of each of the individual sensors was similar. We found that the VLP-16 showed a consistent level of performance, in terms of range bias and noise level over the tested temperature range from 0–40 °C. A geometric calibration was able to marginally improve the accuracy of the VLP-16 point cloud (by approximately 20%) for a single collection, however the temporal stability of the geometric calibration negated this accuracy improvement. Overall, it was found that there is some long-term walk in the ranging observations from individual lasers within the VLP-16, which likely causes the instability in the determination of geometric calibration parameters. However, despite this range walk, the point cloud delivered from the VLP-16 sensors tested showed an accuracy level within the manufacturer specifications of 3 cm RMSE, with an overall estimated RMSE of range residuals between 22 mm and 27 mm.

scholarly journals CALIBRATION AND STABILITY ANALYSIS OF THE VLP-16 LASER SCANNER

2016 ◽  
Vol XL-3/W4 ◽  
pp. 55-60 ◽  
Author(s):  
C. L. Glennie ◽  
A. Kusari ◽  
A. Facchin
Keyword(s):  
Stability Analysis ◽  
Point Cloud ◽  
Temporal Stability ◽  
Laser Scanner ◽  
Effect Of Temperature ◽  
Geometric Calibration ◽  
Long Term Stability ◽  
The Individual

We report on a calibration and stability analysis of the Velodyne VLP-16 LiDAR scanner. The sensor is evaluated for long-term stability, geometric calibration and the effect of temperature variations. To generalize the results, three separate VLP-16 sensors were examined. The results and conclusions from the analysis of each of the individual sensors was similar. We found that the VLP-16 showed a consistent level of performance, in terms of range bias and noise level over the tested temperature range from 0–40 °C. A geometric calibration was able to marginally improve the accuracy of the VLP-16 point cloud (by approximately 20%) for a single collection, however the temporal stability of the geometric calibration negated this accuracy improvement. Overall, it was found that there is some long-term walk in the ranging observations from individual lasers within the VLP-16, which likely causes the instability in the determination of geometric calibration parameters. However, despite this range walk, the point cloud delivered from the VLP-16 sensors tested showed an accuracy level within the manufacturer specifications of 3 cm RMSE, with an overall estimated RMSE of range residuals between 22 mm and 27 mm.

scholarly journals Using MoS2/Fe3O4 as Ion-Electron Transduction Layer to Manufacture All-Solid-State Ion-Selective Electrode for Determination of Serum Potassium

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 155
Author(s):  
Yan Su ◽  
Ting Liu ◽  
Caiqiao Song ◽  
Aiqiao Fan ◽  
Nan Zhu ◽  
...  
Keyword(s):  
High Performance ◽  
Accurate Determination ◽  
Water Layer ◽  
Ion Selective Electrode ◽  
Potential Response ◽  
Selective Electrode ◽  
Response Measurement ◽  
Long Term Stability

As an essential electrolyte for the human body, the potassium ion (K+) plays many physiological roles in living cells, so the rapid and accurate determination of serum K+ is of great significance. In this work, we developed a solid-contact ion-selective electrode (SC-ISE) using MoS2/Fe3O4 composites as the ion-to-electron transducer to determine serum K+. The potential response measurement of MoS2/Fe3O4/K+-ISE shows a Nernst response by a slope of 55.2 ± 0.1 mV/decade and a low detection limit of 6.3 × 10−6 M. The proposed electrode exhibits outstanding resistance to the interference of O2, CO2, light, and water layer formation. Remarkably, it also presents a high performance in potential reproducibility and long-term stability.

scholarly journals Visualizing the Bohr effect in hemoglobin: neutron structure of equine cyanomethemoglobin in the R state and comparison with human deoxyhemoglobin in the T state

2016 ◽  
Vol 72 (7) ◽  
pp. 892-903 ◽  
Author(s):  
Steven Dajnowicz ◽  
Sean Seaver ◽  
B. Leif Hanson ◽  
S. Zoë Fisher ◽  
Paul Langan ◽  
...  
Keyword(s):  
Structural Changes ◽  
Accurate Determination ◽  
Bohr Effect ◽  
Salt Bridges ◽  
Histidine Residues ◽  
Regions Of Stability ◽  
The Individual ◽  
T State

Neutron crystallography provides direct visual evidence of the atomic positions of deuterium-exchanged H atoms, enabling the accurate determination of the protonation/deuteration state of hydrated biomolecules. Comparison of two neutron structures of hemoglobins, human deoxyhemoglobin (T state) and equine cyanomethemoglobin (R state), offers a direct observation of histidine residues that are likely to contribute to the Bohr effect. Previous studies have shown that the T-state N-terminal and C-terminal salt bridges appear to have a partial instead of a primary overall contribution. Four conserved histidine residues [αHis72(EF1), αHis103(G10), αHis89(FG1), αHis112(G19) and βHis97(FG4)] can become protonated/deuterated from the R to the T state, while two histidine residues [αHis20(B1) and βHis117(G19)] can lose a proton/deuteron. αHis103(G10), located in the α1:β1dimer interface, appears to be a Bohr group that undergoes structural changes: in the R state it is singly protonated/deuterated and hydrogen-bonded through a water network to βAsn108(G10) and in the T state it is doubly protonated/deuterated with the network uncoupled. The very long-term H/D exchange of the amide protons identifies regions that are accessible to exchange as well as regions that are impermeable to exchange. The liganded relaxed state (R state) has comparable levels of exchange (17.1% non-exchanged) compared with the deoxy tense state (T state; 11.8% non-exchanged). Interestingly, the regions of non-exchanged protons shift from the tetramer interfaces in the T-state interface (α1:β2and α2:β1) to the cores of the individual monomers and to the dimer interfaces (α1:β1and α2:β2) in the R state. The comparison of regions of stability in the two states allows a visualization of the conservation of fold energy necessary for ligand binding and release.

Determination of Long-Term Stability and Quality of HT-PEM MEAs

2018 ◽  
Vol 86 (13) ◽  
pp. 301-314
Author(s):  
Maren Rastedt ◽  
Julian Büsselmann ◽  
Tomas Klicpera ◽  
Karsten Reinwald ◽  
Nadine Pilinski ◽  
...  
Keyword(s):  
Term Stability ◽  
Long Term Stability

scholarly journals Long-term stability analysis and its relationship with the steel structure of gauge blocks from several manufacturers

2021 ◽  
Vol 1193 (1) ◽  
pp. 012077
Author(s):  
A Mínguez ◽  
J Moreno ◽  
J De Vicente
Keyword(s):  
Stability Analysis ◽  
Statistical Method ◽  
Dimensional Stability ◽  
Steel Structure ◽  
Metallographic Analysis ◽  
Measuring Instruments ◽  
Dimensional Metrology ◽  
Long Term Stability ◽  
History Of

Abstract Gauge blocks are one of the most widespread measurement standards (etalons) in dimensional metrology laboratories. Among all its properties, it is worth highlighting the importance of dimensional stability. This property allows to classify these measuring instruments in quality grades. Although the gauge blocks should be dimensionally stable, it can be observed that there is a drift that can be observed when the calibration history is revised. In this document, authors present a statistical method for the estimation of the dimensional stability of gauge blocks using the calibration history of samples from the main manufacturers. In addition, all the samples have been subjected to metallographic analysis to evaluate the structure.

LONG-TERM STABILITY ANALYSIS OF ACOUSTIC ABSORBING BOUNDARY CONDITIONS

2013 ◽  
Vol 23 (11) ◽  
pp. 2129-2154 ◽  
Author(s):  
HÉLÈNE BARUCQ ◽  
JULIEN DIAZ ◽  
VÉRONIQUE DUPRAT
Keyword(s):  
Stability Analysis ◽  
Boundary Conditions ◽  
Absorbing Boundary Conditions ◽  
Computational Domain ◽  
Acoustic Wave Equation ◽  
Absorbing Boundary ◽  
Term Stability ◽  
Long Term Stability ◽  
The Stability

This work deals with the stability analysis of a one-parameter family of Absorbing Boundary Conditions (ABC) that have been derived for the acoustic wave equation. We tackle the problem of long-term stability of the wave field both at the continuous and the numerical levels. We first define a function of energy and show that it is decreasing in time. Its discrete form is also decreasing under a Courant–Friedrichs–Lewy (CFL) condition that does not depend on the ABC. Moreover, the decay rate of the continuous energy can be determined: it is exponential if the computational domain is star-shaped and this property can be illustrated numerically.

Sign in / Sign up

Export Citation Format

Share Document