An empirical validation of the relationship between the magnitude of relative error and project size

2003 ◽  
Author(s):  
E. Stensrud ◽  
T. Foss ◽  
B. Kitchenham ◽  
I. Myrtveit
Keyword(s):  
Relative Error ◽  
Empirical Validation ◽  
Project Size ◽  
The Relationship

ANALYSIS OF THE ERROR IN DETERMINING THE EQUIVALENT SIZE OF A DEFECT BY THE STANDARDLESS METHOD DURING ULTRASONIC TESTING

2021 ◽  
pp. 50-57
Author(s):  
A. N. Kireev ◽  
M. A. Kireeva
Keyword(s):  
Relative Error ◽  
High Reliability ◽  
Ultrasonic Method ◽  
Experimental Studies ◽  
Standard Samples ◽  
Defect Identification ◽  
Identification Method ◽  
Maximum Value ◽  
Software Product ◽  
The Relationship

The article provides a review and analysis of the defect identification method for determining the size of discontinuities when diagnosing various machine parts and units by the manual ultrasonic method. This method makes it possible to determine the equivalent size of discontinuities of various types without using standard samples of an enterprise: point planar and volumetric; extended planar and volumetric. The method is based on the use of the relationship between the amplitude and time characteristics of the echo signal from the discontinuity and the backside signal in the object being diagnosed and the equivalent size of the discontinuity. The article presents the mathematical apparatus for the implementation of this method. Also presented is a software product that allows you to automate calculations when using this defect identification method. The article contains experimental studies of the method for determining the equivalent dimensions of discontinuities of various types, which have shown its high reliability. The maximum value of the relative error in determining the equivalent size of a point planar discontinuity was 2.867 %. The maximum value of the relative error in determining the equivalent size of a point volumetric discontinuity was 1.986 %. The maximum value of the relative error in determining the transverse equivalent size of an extended planar discontinuity was 0.667 %. The maximum value of the relative error in determining the transverse equivalent size of an extended volumetric discontinuity was 1.95 %.

Modeling of PVA Modified Non-Woven for Submerged Membrane Bioreactor Treating Synthetic Wastewater

2011 ◽  
Vol 356-360 ◽  
pp. 1109-1117
Author(s):  
Chun Hua Zhang ◽  
Yu Ying Dong ◽  
Feng Jie Zhang
Keyword(s):  
Wastewater Treatment ◽  
Relative Error ◽  
Membrane Bioreactor ◽  
Synthetic Wastewater ◽  
Design Parameters ◽  
Stable Operation ◽  
Fouling Resistance ◽  
Submerged Membrane Bioreactor ◽  
Operation Conditions ◽  
The Relationship

In this study, a mathematical model has been developed for the submerged membrane bioreactor (SMBR). Polyvinyl alcohol (PVA) Modified Non-woven model is immerged in MBR to be used for synthetic wastewater treatment. The results show that membrane fouling resistance is mostly cake resistance occurring during filtration. Based on the concept of specific fouling resistance and Darcy law that describes the relationship between flux and resistance during filtration driven by pressure, a module is established to explain the relationship between specific fouling resistance and time during filtration controlled by cake resistance in SMBR. The decline trend of flux can be predicted by the model. The model is used to predict the decline trend of flux during pharmaceutical wastewater treatment. Compared with experimental data, the relative error is less than 10% at t>b, the relative error is less than 5% at t>2b. It shows that the model can predict the decline trend of flux during stable operation of SMBR. But the relative error is bigger during unstable operation at initial stage (t<b). The model developed in this study would provide a useful tool in optimizing operation conditions as well as design parameters for a SMBR system.

Cognitive, experiential, and marketing factors mediate the effect of brand personality on brand equity

2017 ◽  
Vol 45 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Ying-Kai Liao ◽  
Wann-Yih Wu ◽  
Adriana A. Amaya Rivas ◽  
Teresa Lin Ju
Keyword(s):  
Brand Equity ◽  
Reference Point ◽  
Validation Studies ◽  
Brand Personality ◽  
Empirical Validation ◽  
Branding Strategies ◽  
Research Gap ◽  
The Relationship

Many researchers have investigated the effects of brand personality on brand equity; however, the antecedent factors contributing to the development of brand personality have been largely ignored. We aimed to bridge this research gap by integrating cognitive, experiential, and marketing factors as antecedents to explore the effect of brand personality on the relationship between these antecedents and brand equity. Participants were 292 cosmetics users in Taiwan, who were asked to identify the cosmetic brands they favored, then interviewed about their perception of a brand they had mentioned. Results indicated that cognitive, experiential, and marketing factors all had significant effects on brand equity, and that brand personality served as a key mediator increasing the influence of these antecedents on brand equity. Our findings offer a reference point for academics to conduct further empirical validation studies, and for professionals to develop appropriate branding strategies in the cosmetics marketplace.

scholarly journals A Wet Gas Metering System Based on the Extended-Throat Venturi Tube

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2120
Author(s):  
Haobai Xue ◽  
Peining Yu ◽  
Maomao Zhang ◽  
Haifeng Zhang ◽  
Encheng Wang ◽  
...  
Keyword(s):  
Relative Error ◽  
Theoretical Models ◽  
Venturi Tube ◽  
Iteration Algorithm ◽  
Liquid Content ◽  
Wet Gas ◽  
Error Distributions ◽  
Relative Errors ◽  
Throat Section ◽  
The Relationship

Although the use of a classical Venturi tube for wet gas metering has been extensively studied in the literature, the use of an extended-throat Venturi (ETV) tube has rarely been reported since its first proposal by J. R. Fincke in 1999. The structure of an ETV is very simple, but due to the complexity of multiphase flow, its theoretical model has not been fully established yet. Therefore, in this paper theoretical models have been developed for the convergent and throat sections of an ETV, and the gradients of front and rear differential pressures are derived analytically. Several flowrate algorithms have been proposed and compared with the existing ones. Among them, the iteration algorithm is found to be the best. A reasonable explanation is provided for its performance. The relationship between the differential pressure gradient and the flowrate relative error is also studied, such that the relative error distributions varying with ETV measured flowrates can be derived. The gas flowrate error of ETV increases with the liquid content whilst the liquid flowrate error of ETV decreases with the liquid content, and the relative errors of liquid flowrate are generally 2 to 3 times larger than that of the gas flowrate. Finally, the ETV tends to be more accurate than the classical Venturi tube. The ETV can be designed more compact under the same signal intensity due to its significantly higher velocity in the throat section.

scholarly journals Managerial Discretion: The Relationship Between Investments in R & D and Performance -Revisited: Case of Tunisian Enterprises

2021 ◽  
Vol 12 (1) ◽  
pp. 17
Author(s):  
Dorsaf Bentaleb Sfar
Keyword(s):  
Time Lapse ◽  
Managerial Discretion ◽  
Empirical Validation ◽  
Managerial Entrenchment ◽  
And Performance ◽  
The Relationship ◽  
Investment Choices ◽  
Main Relationship ◽  
Performance Equation

This article proposes a re-reading of the role of R & D investments in the performance equation when a manifestation of an opportunistic inclination on the part of managers occurs. Often, the manager and the owners express different expectations regarding investment choices in R & D. Although shareholders are looking for performance, the manager sometimes has a tendency to broaden his managerial discretion. The choice of R & D investments could thus reinforce managerial entrenchment. We will demonstrate the moderation exercised by managerial discretion on the R & D / Performance relationship.Our empirical validation will be put to examination against the Tunisian context by deploying various tests. We come to grips with the characteristics of the Tunisian context through an empirical study of 75 companies observed over a 7 -year time lapse, i.e. from 2008 to 2014. The explanatory analysis was an opportunity to highlight the existence of a moderation exercised over the main relationship dealt with.

“I buy green products for my benefits or yours”: understanding consumers' intention to purchase green products

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ying Sun ◽  
Tieshan Li ◽  
Shanyong Wang
Keyword(s):  
Consumer Behavior ◽  
Social Dilemma ◽  
Social Pressure ◽  
Price Sensitivity ◽  
Empirical Validation ◽  
Green Products ◽  
Content Type ◽  
Purchasing Intention ◽  
Green Purchasing ◽  
The Relationship

PurposeThis research aims to conduct a comprehensive conceptual model and empirical validation of the integration of negative (ego-centric) and positive (altruistic and ego-centric) drivers of green buying based on social dilemma theory and psychological egoism theory.Design/methodology/approachData were collected using a self-administered questionnaire survey and analyzed with hierarchical regression analysis.FindingsThe results indicate that moral obligations, green self-identity, environmental concern and social pressure are positively related to green purchase intention, while perceived cost of green purchasing and price sensitivity are negatively. Meanwhile, social pressure positively moderates the relationship between price sensitivity and consumers' green purchasing intention, but negatively moderates the relationship between perceived cost of green purchasing and consumers' green purchasing intention.Originality/valueFirst, this study is a comprehensive model of the concept and empirical validation of the integration of negative (ego-centric) and positive (altruistic and ego-centric) drivers of green buying. Specially, this study emphasizes the neglected importance of positive ego-centric factors of green consumer behavior. Second, this study explicitly incorporated the moderating effect of social pressure in the context of China. Since green buying is a social dilemma, the changes in this social dilemma after being affected by social pressure under the Chinese collectivist culture are also worth noting. Third, little is known about what motivates green consumption in emerging economies, and this has been hampered by a lack of cultural knowledge, conceptual richness and behavioral research that critically analyses consumer behavior.

Study on Electrical Automation with Design of the Constant-Precision Frequency Meter Based on MCU and CPLD

2013 ◽  
Vol 703 ◽  
pp. 269-272
Author(s):  
Xiao Yang ◽  
Yu Wen Zhai
Keyword(s):  
Relative Error ◽  
Frequency Measurement ◽  
Measurement Precision ◽  
Gate Time ◽  
Frequency Meter ◽  
Simulation Results ◽  
Precision Frequency ◽  
Relationship Of ◽  
The Relationship

According to the principle of constant-precision frequency measurement in the field of electrical automation, the relationship of frequency measurement precision and gate time is analyzed. And the constant-precision frequency meter based on MCU and CPLD is designed in this paper. It can keep the relative error being 0.0001% constantly when frequency measuring within the range of 0.1Hz to 1MHz. Its simulation results by MUX+PLUS is presented.

Numerical Simulation and Experimental Study on Internal Flow Characteristic in the Dynamic Fluidic Sprinkler

2020 ◽  
Vol 36 (1) ◽  
pp. 61-70
Author(s):  
Alexander Fordjour ◽  
Xingye Zhu ◽  
Shouqi Yuan ◽  
Frank Agyen Dwomoh ◽  
Zakaria Issaka
Keyword(s):  
Numerical Simulation ◽  
Velocity Distribution ◽  
Relative Error ◽  
Crop Production ◽  
Rotation Speed ◽  
Experimental Results ◽  
List Type ◽  
Operating Pressure ◽  
Perfect Correlation ◽  
The Relationship

HighlightsA detailed study of the relationship between the velocity distribution, length of tube and nozzle sizes. Rotation speed decreased approximately linearly as the length of the tube increased.Relative error was less than 4% for validated results indicating a perfect correlation between the values of numerical simulation, calculated, and experiment results. Abstract.A detailed study of the relationship between velocity distribution, length of tube and nozzle sizes was conducted using a dynamic fluidic sprinkler. Therefore, the objectives of this article were: (1) to study inner flow characteristics of dynamic fluidic sprinkler, (2) to compare numerical simulation and experimental results (3) to introduce an empirical equation of the variation trend of rotation speed for the newly designed sprinkler. A mathematical model for simulation of the inner flow distribution of the sprinkler was obtained by using computational fluid dynamics. The results were validated by numerical simulation and compared to the experimental results. The minimum average deviation between the calculated, simulation and experiment was 0.25%, whiles the maximum was 0.90%. It was found that the relative error was less than 4% results indicating a perfect correlation between the values of numerical simulation, calculated and experiment results. It was established that the rotation speed decreases approximately linearly as the length of the tube increases. The results revealed that the nozzle diameter, length of the tube, and the operating pressure had a significant influence on the rotation speed of the sprinkler. This study provides baseline information to improve water application efficiency for crop production in sprinkler irrigated fields. Keywords: Dynamic fluidic sprinkler, Inner flow, Nozzle, Numerical simulation, Water saving.

Fast Prediction Model for Closure Pressure in Hot Isostatic Pressing

2014 ◽  
Vol 887-888 ◽  
pp. 1240-1245
Author(s):  
Dong Qiao Zhang ◽  
Jian Xin Zhou ◽  
Jun Li Tang ◽  
Hong Wang
Keyword(s):  
Prediction Model ◽  
Relative Error ◽  
Hot Isostatic Pressing ◽  
Commercial Software ◽  
Isostatic Pressing ◽  
Fast Prediction ◽  
Relationship Of ◽  
The Relationship ◽  
Complex Casting ◽  
Hip Process

Simulation of hot isostatic pressing (HIP) process with complex castings was rarely referred for its time-consuming and difficulties existed in meshing by commercial software. A fast prediction model was proposed to overcome those limitations in present work. The relationship of holes size, shape, and closure pressure was established by analysing the closed hole in ZTC4 castings with simple structures based on the software. Then the fast prediction model was applied to a complex casting. A relative error of 4.09% was obtained between this model and result calculated by the software, which verified its effectiveness in predicting ZTC4 castings with complicated structures.

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