Critical Assessment of the Least Square Error Method Used in Derivation of Morison’s Force Coefficients

1994 ◽  
Vol 116 (1) ◽  
pp. 1-6 ◽  
Author(s):  
G. Najafian ◽  
R. Burrows
Keyword(s):  
Critical Assessment ◽  
Least Square ◽  
New Method ◽  
Statistical Moments ◽  
Circular Cylinders ◽  
Wave Forces ◽  
Lower Intensity ◽  
Maximum Correlation ◽  
Error Method

The least square error (LSE) method is frequently used in determination of Morison’s coefficients from the analysis of measured wave forces on circular cylinders. It will be proved in this paper that Morison’s coefficients determined from the LSE method always lead to predicted forces which have smaller variances (2nd-order statistical moments) than those of the measured forces. In other words, it is proved that predicted forces from this method are of lower intensity compared to the measured forces, and hence can be unconservative. A new method, termed the maximum correlation (MC) method, has been introduced. This method has all the advantages of the LSE method, but leads to predicted forces whose variances are equal to those of the measured forces.

scholarly journals Determination of the Sediment Carrying Capacity Based on Perturbed Theory

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Zhi-hui Ni ◽  
Qiang Zeng ◽  
Wu Li-chun
Keyword(s):  
Carrying Capacity ◽  
Influencing Factor ◽  
Least Square Method ◽  
Least Square ◽  
New Method ◽  
Linear Regression Method ◽  
Average Flow Velocity ◽  
New Formula ◽  
Sediment Carrying Capacity

According to the previous studies of sediment carrying capacity, a new method of sediment carrying capacity on perturbed theory was proposed. By taking into account the average water depth, average flow velocity, settling velocity, and other influencing factors and introducing the median grain size as one main influencing factor in deriving the new formula, we established a new sediment carrying capacity formula. The coefficients were determined by the principle of dimensional analysis, multiple linear regression method, and the least square method. After that, the new formula was verified through measuring data of natural rivers and flume tests and comparing the verified results calculated by Cao Formula, Zhang Formula, Li Formula, Engelung-Hansen Formula, Ackers-White Formula, and Yang Formula. According to the compared results, it can be seen that the new method is of high accuracy. It could be a useful reference for the determination of sediment carrying capacity.

scholarly journals A NEW METHOD FOR THE DETERMINATION OF TOXIC DYE USING FTIR SPECTROSCOPY

2010 ◽  
Vol 9 (2) ◽  
pp. 27-38 ◽  
Author(s):  
Mohammad Elwathig Saeed Mirghani ◽  
Nassereldeen A. Kabbashi ◽  
Isam Y. Qudsieh ◽  
Faiz A. Elfaki
Keyword(s):  
Ftir Spectroscopy ◽  
Partial Least Square ◽  
Least Square ◽  
New Method ◽  
Calibration Model ◽  
Chemical Methods ◽  
Toxic Dyes ◽  
Wet Chemical ◽  
The Difference

A new method was developed to determine toxic dyes content in textileand other products using Fourier Transform Infrared (FTIR) spectroscopy withAttenuated Total Reflectance (ATR) element and KBr transmission cell. Thewavelengths used were selected using pure dyes and dye mixtures. Transmittance valuesfrom the wavelengths regions 3500 – 2650 and 1675 – 1500 cm-1 and partial least square(PLS) regression method were used to derive FTIR spectroscopic calibration model fordyes containing –N=N– in their structure. The coefficient of determinations (R2) for themodels were computed by comparing the results obtained from FTIR spectroscopyagainst the actual values of the dyes concentrations. R2 were 0.9321 and 0.9819 for twosamples of toxic dyes respectively. The standard errors (SE) of calibrations were 1.84and 1.36 respectively. The calibration model was cross validated within the same set ofsamples and the standard deviation (SD) of the difference for repeatability and accuracyof the FTIR method were determined. With its speed and ease of data manipulation,FTIR spectroscopy is a useful alternative method to wet chemical methods for rapid androutine detection of azo dyes as toxic dyes in such products for quality control.

Hydrodynamic Forces on Linear and Multi-Dimensional Arrays of Circular Cylinders

2014 ◽  
Vol 567 ◽  
pp. 259-264
Author(s):  
A.A. Sebastian ◽  
V. John Kurian ◽  
A.M. Al-Yacouby ◽  
M.S. Liew ◽  
V.G. Idichandy
Keyword(s):  
Circular Cylinders ◽  
Wave Forces ◽  
Tank Model ◽  
Line Spacing ◽  
Time Periods ◽  
The Waves ◽  
Random Nature ◽  
Four Cylinders ◽  
Accurate Wave

In this paper, major focus is given for determining the accurate wave forces recorded on circular cylinders present in different array configurations. Investigation is made to establish any trend in variation of these forces, when the wave time periods, location of the cylinders in the array and the spacing between cylinders are varied. Wave tank model tests were conducted in regular waves. Tandem cylinder configurations involving a maximum of four cylinders were considered for the present study. In addition to this, two linear arrays of four cylinders each, were installed side by side in the waves and the forces on each of the cylinders were determined. The spacing between the cylinders in this two dimensional array was varied and the trend in the variation of forces are presented. Change of transverse spacing between the cylinders was found to have more effect on the forces on cylinders, than the change in in-line spacing. The wave forces acting on singly existing cylinders were found to be less than that acting on individual cylinders present in the different array configurations considered. The variation of force coefficients with respect to the time periods was found to be of random nature. Morison equation is made use in the determination of these coefficients.

Least-square refinement of structure parameters from CBED integrated intensities: application to determination of temperature factors in Y BA2CU3O7

1992 ◽  
Vol 50 (2) ◽  
pp. 1456-1457
Author(s):  
Kjersti Gjønnes ◽  
Jon Gjønnes
Keyword(s):  
Least Square ◽  
Measured Intensity ◽  
Structure Information ◽  
Accurate Temperature ◽  
Least Square Fit ◽  
Case Application ◽  
Integrated Intensities ◽  
Temperature Factors ◽  
Narrow Bands

Electron diffraction intensities can be obtained at large scattering angles (sinθ/λ ≥ 2.0), and thus structure information can be collected in regions of reciprocal space that are not accessable with other diffraction methods. LACBED intensities in this range can be utilized for determination of accurate temperature factors or for refinement of coordinates. Such high index reflections can usually be treated kinematically or as a pertubed two-beam case. Application to Y Ba2Cu3O7 shows that a least square refinememt based on integrated intensities can determine temperature factors or coordinates.LACBED patterns taken in the (00l) systematic row show an easily recognisable pattern of narrow bands from reflections in the range 15 < l < 40 (figure 1). Integrated intensities obtained from measured intensity profiles after subtraction of inelastic background (figure 2) were used in the least square fit for determination of temperature factors and refinement of z-coordinates for the Ba- and Cu-atoms.

A new method for the determination of nitrates

1960 ◽  
Vol 23 ◽  
pp. 227-232 ◽  
Author(s):  
P WEST ◽  
G LYLES
Keyword(s):  
New Method

A New Method for the Determination of Plasma Activators of Fibrinolysis

1977 ◽  
Vol 37 (02) ◽  
pp. 210-215 ◽  
Author(s):  
R Margalit ◽  
E Gidron ◽  
Y Shalitin
Keyword(s):  
New Method ◽  
Effective Activator

SummaryThe term “effective activator” of plasminogen is proposed, to denote the resultant of activator-antiactivator interaction, and a method for the determination of the level of these activators is described. By adding axcess plasminogen to the euglobulin fraction of plasma the influence of the level of endogenous plasminogen and of the antiplasmin is eliminated. It is shown that the level of fibrinogen has very little bearing on the results. An effective activator unit is defined as equal to 1 CTA unit of urokinase activity on a fibrinogen-plasminogen substrate.

The Plasmin Inhibitors of Plasma

1964 ◽  
Vol 12 (01) ◽  
pp. 119-125 ◽  
Author(s):  
Y Shamash ◽  
A Rimon
Keyword(s):  
Human Plasma ◽  
New Method ◽  
Normal Amount ◽  
Caseinolytic Activity ◽  
Before And After ◽  
Plasmin Inhibitors

SummaryA new method for the assay of plasmin inhibitors in human plasma is described. The method consists of determination of the caseinolytic activity of a standard plasmin solution before and after incubation with the inhibitor, with lysine added to the mixture as a stabilizer of plasmin. Using this method, it was found that plasma contains enough inhibitors to inactivate 30 caseinolytic units of plasmin, or 10 times the normal amount of plasminogen in human plasma.

AGGLUTINATION INHIBITION REACTIONS FOR THE DETERMINATION OF GONADOTROPHINS

1969 ◽  
Vol 62 (1_Suppl) ◽  
pp. S95-S112 ◽  
Author(s):  
A. H. W. M. Schuurs
Keyword(s):  
Immune System ◽  
Quantitative Determination ◽  
Haemagglutination Inhibition ◽  
Latex Agglutination ◽  
Literature Survey ◽  
New Method ◽  
Test Fluid ◽  
Main Application ◽  
Test Systems

ABSTRACT Various techniques for sensitising erythrocytes and latex particles with gonadotrophins, particularly with HCG, are described. The haemagglutination inhibition reactions are generally interpreted by means of »erythrocyte settling patterns«. By a new method of evaluating these patterns a relatively precise quantitative determination is possible. Latex agglutination inhibition reactions on slides are particularly suitable as rapid qualitative tests. In cases where the maximum attainable sensitivity of the agglutination inhibition tests is insufficient, e. g. for determining LH concentrations in urine, the hormone in the test fluid has to be concentrated or extracted. An alternative method is a modified haemagglutination inhibition test for large volumes which is applicable to unconcentrated urine. Due to non-specific inhibitions the above-mentioned tests cannot be applied to unprocessed serum. Agglutination inhibition tests with HCG are already well advanced, pregnancy diagnosis being their main application. Now that highly purified HCG is available, a satisfactory specificity for these tests can be attained. If the immune system for HCG is used for estimating LH, it has to meet additional specificity requirements. Furthermore, the measure of cross-reaction and the choice of standard merit special attention. Finally, a literature survey is given of test systems in which LH and FSH were used as antigens.

Development of a New Method for Determination of the Oil Content from Microalgae Lipid Fraction

2017 ◽  
Vol 68 (4) ◽  
pp. 671-674
Author(s):  
Ana Maria Galan ◽  
Ioan Calinescu ◽  
Elena Radu ◽  
Elena Emilia Oprescu ◽  
Gabriel Vasilievici ◽  
...  
Keyword(s):  
Sunflower Oil ◽  
Oil Content ◽  
Lipid Fraction ◽  
New Method ◽  
Ms Analysis ◽  
Qualitative Determination ◽  
Tga Analysis

The purpose of this study was to develop a method for rapid quantitative and qualitative determination of the oil from microalgae lipid fraction obtained from Nannochloris sp biomass. The lipid fraction was first refluxed with 4% KOH in MeOH (60, 90, 120 min), followed by reaction with 20% BF3 in MeOH, using different times of reflux (90,120, 150 min) for each time of reflux with 4% KOH in MeOH. The FAME samples were analyzed by GC-MS analysis. 120 min reflux with 4% KOH in MeOH, 90 min with 20% BF3 in MeOH and a ratio lipid fraction: 4% KOH in MeOH: 20% BF3 in MeOH=1:20:27, were required to obtain the higher percent of oil in the microalgae lipid fraction. The relevance of the method developed was proved by TGA analysis and by transesterification of a sunflower oil sample in the same conditions.

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