scholarly journals Determination of the area of exponential attraction in one-dimensional finite-time systems using meshless collocation

2018 ◽  
Vol 23 (4) ◽  
pp. 1835-1850
Author(s):  
Peter Giesl ◽  
◽  
James McMichen
Keyword(s):  
Finite Time ◽  
One Dimensional ◽  
Meshless Collocation ◽  
Time Systems

scholarly journals Determination of positive realizations with reduced numbers of delays or without delays for discrete-time linear systems

2012 ◽  
Vol 22 (4) ◽  
pp. 451-465 ◽  
Author(s):  
Tadeusz Kaczorek
Keyword(s):  
Transfer Function ◽  
Linear Systems ◽  
Discrete Time ◽  
Sufficient Conditions ◽  
Diagram Method ◽  
State Variable ◽  
Discrete Time Systems ◽  
Time Systems ◽  
Time Linear

A new modified state variable diagram method is proposed for determination of positive realizations with reduced numbers of delays and without delays of linear discrete-time systems for a given transfer function. Sufficient conditions for the existence of the positive realizations of given proper transfer function are established. It is shown that there exists a positive realization with reduced numbers of delays if there exists a positive realization without delays but with greater dimension. The proposed methods are demonstrated on a numerical example.

scholarly journals Finite-time estimation algorithms for LPV discrete-time systems with application to output feedback stabilization

Automatica ◽  
2021 ◽  
Vol 125 ◽  
pp. 109436
Author(s):  
Khadidja Chaib-Draa ◽  
Ali Zemouche ◽  
Fazia Bedouhene ◽  
Rajesh Rajamani ◽  
Yan Wang ◽  
...  
Keyword(s):  
Discrete Time ◽  
Output Feedback ◽  
Finite Time ◽  
Time Estimation ◽  
Feedback Stabilization ◽  
Estimation Algorithms ◽  
Output Feedback Stabilization ◽  
Discrete Time Systems ◽  
Time Systems

Improved thin-layer chromatographic determination of phospholipids in gastric aspirate from newborns, for assessment of lung maturity.

1988 ◽  
Vol 34 (4) ◽  
pp. 736-738 ◽  
Author(s):  
D Serrano de la Cruz ◽  
E Santillana ◽  
A Mingo ◽  
G Fuenmayor ◽  
A Pantoja ◽  
...  
Keyword(s):  
Thin Layer ◽  
Fetal Lung ◽  
Chromatographic Determination ◽  
Solvent Mixture ◽  
Gastric Aspirate ◽  
One Dimensional ◽  
Acetic Acid Water ◽  
Chromatographic Resolution ◽  
Lung Maturity

Abstract This one-dimensional thin-layer chromatographic method is used for assay of phospholipids in the gastric aspirate of newborns. The solvent mixture (chloroform/hexane/methanol/glacial acetic acid/water, 12/7/4/3/0.3 by vol) completely resolves lecithin, sphingomyelin, phosphatidylinositol, phosphatidylserine, phosphatidylethanolamine, and phosphatidylglycerol. The method is simple, precise, inexpensive, and rapid (chromatographic development takes less than 25 min) and gives high chromatographic resolution. We used this method to determine the lecithin/sphingomyelin densitometric ratio (L/S ratio) and the phosphatidylglycerol percentage in 200 samples of gastric aspirate and found an L/S ratio of 2.5 to be a satisfactory cutoff value for distinguishing fetal lung maturity and immaturity. We confirmed that the presence of phosphatidylglycerol excluded the possibility of respiratory distress.

Formalism for the determination of intermediate stress gradients using X-ray diffraction

2009 ◽  
Vol 42 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Thomas Gnäupel-Herold
Keyword(s):  
Lattice Strain ◽  
Narrow Line ◽  
X Ray Diffraction ◽  
Beam Spot ◽  
Strain Measurements ◽  
One Dimensional ◽  
X Ray ◽  
Stress Gradients ◽  
Shaped Beam

A method is outlined that allows the determination of one-dimensional stress gradients at length scales greater than 0.2 mm. By using standard four-circle X-ray diffractometer equipment and simple aperture components, length resolutions down to 0.05 mm in one direction can be achieved through constant orientation of a narrow, line-shaped beam spot. Angle calculations are given for the adjustment of goniometer angles, and for the effective azimuth and tilt of the scattering vector for general angle settings in a four-circle goniometer. The latter is necessary for the computation of stresses from lattice strain measurements.

Experimental determination of spectral densities in quasi-one-dimensional electron systems

1998 ◽  
Vol 249-251 ◽  
pp. 175-179
Author(s):  
B. Kardynal ◽  
C.H.W. Barnes ◽  
E.H. Linfield ◽  
D.A. Ritchie ◽  
J.T. Nicholls ◽  
...  
Keyword(s):  
Experimental Determination ◽  
Electron Systems ◽  
Dimensional Electron ◽  
Spectral Densities ◽  
One Dimensional

Determination of soil water hydraulic parameters from infiltration data

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yan Gao ◽  
Kai Chang ◽  
Xuguang Xing ◽  
Jiaping Liang ◽  
Nian He ◽  
...  
Keyword(s):  
Soil Water ◽  
Water Retention ◽  
Test Method ◽  
Water Retention Curve ◽  
Absorption Method ◽  
Retention Curve ◽  
Content Type ◽  
One Dimensional ◽  
Water Diffusivity

PurposeTraditional laboratory measurements of soil water diffusivity (D) and soil water retention curve (SWRC) are always time-consuming and labor-intensive. Therefore, this paper aims to present a simple and robust test method for determining D and SWRC without reducing accuracy.Design/methodology/approachIn this study, a D model of unsaturated soil was established based on Gardner–Russo model and then a combination of Gardner–Russo model with one-dimensional horizontal absorption method to obtain n and a parameters of Gardner–Russo model. One-dimensional horizontal absorption experiments on loam, silt loam and sandy clay loam were conducted to obtain the relationships between measured infiltration rate and cumulative infiltration with wetting front distance. Based on the obtained relationships, the measured infiltration data from the one-dimensional horizontal absorption tests were used to calculate n and a parameters and further constructing D and SWRC.FindingsBoth the calculated D and SWRC inversed from the infiltration data were in good agreement with the measured ones that obtained from the traditional horizontal absorption method and the centrifuge method, respectively. Error analysis indicated that only the infiltration data are enough to reliably synchronously determine D and SWRC.Originality/valueA simple and robust method is proposed for synchronous determination of soil water diffusivity and water retention curve.

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