Fitting Weibull Strength Data and Applying It to Stochastic Mechanical Design

1992 ◽  
Vol 114 (1) ◽  
pp. 35-41 ◽  
Author(s):  
C. R. Mischke
Keyword(s):  
Mechanical Design ◽  
Least Square ◽  
Stochastic Methods ◽  
Coordinate Transformations ◽  
Strength Data ◽  
The Third ◽  
Tension Tests ◽  
Property Data ◽  
Simple Tension ◽  
Best Fit

This is the second paper in a series relating to stochastic methods in mechanical design. The first is entitled, “Some Property Data and Corresponding Weibull Parameters for Stochastic Mechanical Design,” and the third, “Some Stochastic Mechanical Design Applications.” When data are sparse, many investigators prefer employing coordinate transformations to rectify the data string, and a least-square regression to seek the best fit. Such an approach introduces some bias, which the method presented here is intended to reduce. With mass-produced products, extensive testing can be carried out and prototypes built and evaluated. When production is small, material testing may be limited to simple tension tests or perhaps none at all. How should a designer proceed in order to achieve a reliability goal or to assess a design to see if the goal has been realized? The purpose of this paper is to show how sparse strength data can be reduced to distributional parameters with less bias and how such information can be used when designing to a reliability goal.

Some Stochastic Mechanical Design Applications

1992 ◽  
Vol 114 (1) ◽  
pp. 42-47 ◽  
Author(s):  
C. R. Mischke
Keyword(s):  
Mechanical Design ◽  
Stochastic Methods ◽  
Strength Data ◽  
Weibull Parameters ◽  
The Third ◽  
Active Constraints ◽  
Stochastic Problems ◽  
Property Data ◽  
Machine Elements ◽  
Machinery Design

This is the third paper in a series relating to stochastic methods in mechanical design. The two previous ones were entitled, “Some Property Data and Corresponding Weibull Parameters for Stochastic Mechanical Design,” and “Fitting Weibull Strength Data and Applying it to Stochastic Mechanical Design.” They presented the groundwork for addressing stochastic problems in machinery design to a reliability goal when strength data are sparse. The purpose of this paper is to utilize procedures for estimating reliability of machine elements when yielding, fracture, or distortion are the limiting or active constraints.

Some Property Data and Corresponding Weibull Parameters for Stochastic Mechanical Design

1992 ◽  
Vol 114 (1) ◽  
pp. 29-34 ◽  
Author(s):  
C. R. Mischke
Keyword(s):  
Goodness Of Fit ◽  
Mechanical Design ◽  
Stochastic Methods ◽  
Published Data ◽  
Short Supply ◽  
Strength Data ◽  
Weibull Parameters ◽  
Property Data ◽  
Strength Distributions

This is the first paper in a series of three relating to stochastic methods in mechanical design. The others are entitled, “Fitting Weibull Strength Data and Applying it to Stochastic Mechanical Design,” and “Some Stochastic Mechanical Design Applications.” The purpose of this paper is to present some Weibull parameters of strength distributions that were deduced from published histographic data. Stochastic materials data are in short supply; yet a closer look shows a surprising amount available. However, the published data may need to be interpreted and personal tests reduced. This paper shows histographic data that was converted to three-parameter Weibull distributional fits with relevant goodness-of-fit information displayed.

Direct Assessment of Effective Renal Plasma Flow from Renoscintigraphy with a Gamma Camera and an On-Line Computer

1981 ◽  
Vol 20 (06) ◽  
pp. 274-278
Author(s):  
J. Liniecki ◽  
J. Bialobrzeski ◽  
Ewa Mlodkowska ◽  
M. J. Surma
Keyword(s):  
Count Rate ◽  
Renal Plasma Flow ◽  
Early Period ◽  
Least Square Method ◽  
Least Square ◽  
Uptake Coefficient ◽  
Positive Linear Correlation ◽  
On Line ◽  
Best Fit ◽  
Plasma Activity

A concept of a kidney uptake coefficient (UC) of 131I-o-hippurate was developed by analogy from the corresponding kidney clearance of blood plasma in the early period after injection of the hippurate. The UC for each kidney was defined as the count-rate over its ROI at a time shorter than the peak in the renoscintigraphic curve divided by the integral of the count-rate curve over the "blood"-ROI. A procedure for normalization of both curves against each other was also developed. The total kidney clearance of the hippurate was determined from the function of plasma activity concentration vs. time after a single injection; the determinations were made at 5, 10, 15, 20, 30, 45, 60, 75 and 90 min after intravenous administration of 131I-o-hippurate and the best-fit curve was obtained by means of the least-square method. When the UC was related to the absolute value of the clearance a positive linear correlation was found (r = 0.922, ρ > 0.99). Using this regression equation the clearance could be estimated in reverse from the uptake coefficient calculated solely on the basis of the renoscintigraphic curves without blood sampling. The errors of the estimate are compatible with the requirement of a fast appraisal of renal function for purposes of clinical diagknosis.

Nappes d'huile: prediction de leurs deplacements comme agent efficace d'un plan de mesure d'urgence

1979 ◽  
Vol 14 (1) ◽  
pp. 89-109
Author(s):  
B. Coupal ◽  
M. de Broissia
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Finite Elements ◽  
Mass Balance ◽  
Stochastic Method ◽  
Stochastic Methods ◽  
Deterministic Approach ◽  
First Order ◽  
The Third ◽  
Comme Agent

Abstract The movement of oil slicks on open waters has been predicted, using both deterministic and stochastic methods. The first method, named slick rose, consists in locating an area specifying the position of the slick during the first hours after the spill. The second method combines a deterministic approach for the simulation of current parameters to a stochastic method simulating the wind parameters. A Markov chain of the first order followed by a Monte Carlo approach enables the simulation of both phenomena. The third method presented in this paper describes a mass balance on the spilt oil, solved by the method of finite elements. The three methods are complementary to each other and constitute an important point for a contingency plan.

Poisson Brackets & Angular Momentum

2018 ◽  
Author(s):  
Peter Mann
Keyword(s):  
Generating Functions ◽  
First Integrals ◽  
Lagrangian Mechanics ◽  
Poisson Brackets ◽  
Coordinate Transformations ◽  
Canonical Transformations ◽  
Gauge Transformations ◽  
The Third ◽  
Point Transformations ◽  
Canonical Coordinate

This chapter discusses canonical transformations and gauge transformations and is divided into three sections. In the first section, canonical coordinate transformations are introduced to the reader through generating functions as the extension of point transformations used in Lagrangian mechanics, with the harmonic oscillator being used as an example of a canonical transformation. In the second section, gauge theory is discussed in the canonical framework and compared to the Lagrangian case. Action-angle variables, direct conditions, symplectomorphisms, holomorphic variables, integrable systems and first integrals are examined. The third section looks at infinitesimal canonical transformations resulting from functions on phase space. Ostrogradsky equations in the canonical setting are also detailed.

scholarly journals Analysis of Consumer Behavior on Buying Decision at the Online Shop, Easy Shopping Indonesia

2022 ◽  
Vol 19 (2) ◽  
pp. 97-104
Author(s):  
Dewi Indriani Jusuf
Keyword(s):  
Consumer Behavior ◽  
Social Factor ◽  
Partial Least Square ◽  
Least Square ◽  
Equation Modeling ◽  
Decision Variable ◽  
Personal Factors ◽  
Payment Method ◽  
Product Selection ◽  
The Third

Know the effect of the consumer behavior of online shop, Easy Shopping Indonesia on the consumers’ buying decision. The quantitative approach, descriptive and verified design are used. As much as 100 consumers of Essay Shopping in Bandung are selected as respondents using a purposive method. The instrument of data collection is questionnaire. The data analysis used is Structural Equation Modeling based on Partial Least Square (PLS SEM). The research results show that the consumer behavior of Easy Shopping online shop affects the consumer buying decision significantly.  The biggest effect of the consumer behavior dimension on the buying decision variable is a personal factor; the second one is a psychological factor; the third one is a social factor and the fourth one is a cultural factor. The biggest effect of the consumer behavior variable is on the dimension of payment method; then the second one is distribution selection; the third one is on brand selection; the fourth one is on buying time and the last one is on product selection. Those findings are the antecedents of the online buying decision which finally affect the changes of the buying decision from the conventional buying process into the online one. Key Words : consumer behavior, cultural factors, social factors, personal factors and psychological factors, buying decision, product selection, brand selection, distribution selection, payment method and timing.  

scholarly journals Biopolymer Drill-in Fluid Performance for Different Rheological Models using Statistical Characterisation

2019 ◽  
Vol 19 (1) ◽  
pp. 86-92
Author(s):  
M. Owusu ◽  
H. Osei
Keyword(s):  
Rheological Model ◽  
Rheological Behaviour ◽  
Primary Objective ◽  
Least Square ◽  
Model Parameters ◽  
Drilling Fluids ◽  
Cleaning Efficiency ◽  
Rheological Models ◽  
Least Square Regression ◽  
Best Fit

Appropriate selection of rheological models is important for hydraulic calculations of pressure loss prediction and hole cleaning efficiency of drilling fluids. Power law, Bingham-Plastic and Herschel-Bulkley models are the conventional fluid models used in the oilfield. However, there are other models that have been proposed in literature which are under/or not utilized in the petroleum industry. The primary objective of this paper is to recommend a rheological model that best-fits the rheological behaviour of xanthan gum-based biopolymer drill-in fluids for hydraulic evaluations. Ten rheological models were evaluated in this study. These rheological models have been posed deterministically and due to the unrealistic nature have been replaced by statistical models, by adding an error (disturbance) term and making suitable assumptions about them. Rheological model parameters were estimated by least-square regression method. Models like Sisko and modified Sisko which are not conventional models in oil industry gave a good fit. Modified Sisko model which is a four parameter rheological model was selected as the best-fit model since it produced the least residual mean square of 0.61 Ibf2/100ft4. There is 95% certainty that the true best-fit curve lies within the confidence band of this function of interest. Keywords: Biopolymer; Least-Square Regression; Residual Mean Squares; Rheologram

scholarly journals The measurements results adjustment by the Least Square Method

2021 ◽  
Vol 1 ◽  
pp. 1-8
Author(s):  
Oleksandr Samoilenko ◽  
Yurii Kuzmenko
Keyword(s):  
Reference Value ◽  
Least Square Method ◽  
Systematic Errors ◽  
Least Square ◽  
Key Comparisons ◽  
System Of Equations ◽  
The Third ◽  
Measurement Results ◽  
Free Case ◽  
Degrees Of Equivalence

The method for processing of the measurement results obtained from Comite International des Poids et Measures (CIPM) Key, Regional Metrology Organizations (RMO) or supplementary comparisons, from the proficiency testing by interlaboratory comparisons and the calibrations is proposed. It is named by authors as adjustment by least square method (LSM). Additive and multiplicative parameters for each measuring standard of every particular laboratory will be the results of this adjustment. As well as the parameters for each artifact. The parameters of the measurements standards are their additive and multiplicative degrees of equivalence from the comparison and the estimations of the systematic errors (biases) from calibrations. The parameters of the artifacts are the key comparisons reference value from the comparison and the assigned quantity values from the calibrations. The adjustment is considered as a way to solving a problem of processing the great amount of homogeneous measurements with many measuring standards at a different comparison levels (CIPM, RMO or supplementary), including connected problems. Four different cases of the adjustments are considered. The first one is a free case of adjustment. It was named so because of the fact that none of participants has any advantage except their uncertainties of measurements. The second one is a fixed case of adjustment. Measuring results of RMO and supplementary comparisons are rigidly linked to additive and multiplicative parameters of measuring standards of particular laboratories participated in CIPM key comparisons. The third one is a case of adjustment with dependent equations. This one is not so rigidly linked of the new comparisons results to previous or to some other comparisons as for fixed case. It means that the new results of comparisons are influenced by the known additive and multiplicative parameters and vice versa. The fourth one is a free case of adjustment with additional summary equations. In that case certain checking equations are added to the system of equations. So, the sum of parameters multiplied by their weights of all measurement standards for particular laboratories participated in comparisons should be equal to zero.

scholarly journals Movement Studies on a Hanging Glacier in Relation with an Ice Avalanche

1977 ◽  
Vol 19 (81) ◽  
pp. 671-672 ◽  
Author(s):  
André Flotron
Keyword(s):  
Flow Pattern ◽  
The State ◽  
Least Square ◽  
Velocity Versus ◽  
Surface Part ◽  
Different Types ◽  
Best Fit ◽  
Ice Avalanche

AbstractIn 1972 the state of a hanging glacier on the Weisshorn gave cause for alarm, as part of it seemed to be accelerating and a repetition of an earlier avalanche of ice seemed possible (see Röthlisberger, previous abstract). For this reason movement surveys were undertaken. The various surveying methods applied on the Weisshorn are outlined and the accuracy of the measurements is given. By least-square analysis different types of curves have been fitted to the data for velocity versus time. The best fit obtained so-far has been with hyperbolae. The confidence of extrapolations from such curves is discussed in relation to forecasts. By evaluating repeated photographs taken by an automatic camera from a single position, using a stereo plotter, the flow pattern has been established at the surface, part of the front, and one of the lateral faces of the ice mass. Changes with time caused by the deformation of the ice mass, the formation of crevasses and the crumbling away of the ice at the edge have been observed.

Dosimetric evaluation of tandem-based cervical high-dose-rate brachytherapy treatment planning using American Brachytherapy Society 2011 recommendations

2016 ◽  
Vol 15 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Manish K. Goyal ◽  
T. S. Kehwar ◽  
Jayanand Manjhi ◽  
Jerry L. Barker ◽  
Bret H. Heintz ◽  
...  
Keyword(s):  
Linear Regression ◽  
Dose Rate ◽  
Regression Line ◽  
High Dose Rate ◽  
Least Square ◽  
High Dose ◽  
Hdr Brachytherapy ◽  
Linear Regression Line ◽  
Significant Difference ◽  
Best Fit

AbstractPurposeThis study evaluated dosimetric parameters for cervical high-dose-rate (HDR) brachytherapy treatment using varying dose prescription methods.MethodsThis study includes 125 tandem-based cervical HDR brachytherapy treatment plans of 25 patients who received HDR brachytherapy. Delineation of high-risk clinical target volumes (HR-CTVs) and organ at risk were done on original computed tomographic images. The dose prescription point was defined as per International Commission in Radiation Units and Measurements Report Number 38 (ICRU-38), also redefined using American Brachytherapy Society (ABS) 2011 criteria. The coverage index (V100) for each HR-CTV was calculated using dose volume histogram parameters. A plot between HR-CTV and V100was plotted using the best-fit linear regression line (least-square fit analysis).ResultsMean prescribed dose to ICRU-38 Point A was 590·47±28·65 cGy, and to ABS Point A was 593·35±30·42 cGy. There was no statistically significant difference between planned ICRU-38 and calculated ABS Point A doses (p=0·23). The plot between HR-CTV and V100is well defined by the best-fit linear regression line with a correlation coefficient of 0·9519.ConclusionFor cervical HDR brachytherapy, dose prescription to an arbitrarily defined point (e.g., Point A) does not provide consistent coverage of HR-CTV. The difference in coverage between two dose prescription approaches increases with increasing CTV. Our ongoing work evaluates the dosimetric consequences of volumetric dose prescription approaches for these patients.

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