Statistical Calculations

2021 ◽  
pp. 311-351
Keyword(s):  
Surface Roughness ◽  
Piston Ring ◽  
Hypothesis Test ◽  
Probability Distributions ◽  
Measured Data ◽  
Descriptive Statistics ◽  
Theoretical Distribution ◽  
Hypothesis Tests ◽  
Oil Additives ◽  
Data Statistics

This chapter presents statistical commands and its applications to various problems of the mechanics and tribology (M&T). Descriptive statistics, data statistics tool, specialized statistical graphs, probability distributions, and hypothesis tests are discussed. The solutions of various applied problems are given. In particular, surface roughness indices are calculated by the measured data using the descriptive statistics command; the histogram generated by a runout data are matched with the theoretical distribution; capability plot generation is shown by the data for the piston ring gaps; friction torques for two different oil additives are compared using a hypothesis test.

scholarly journals Motivating factors in the adoption of better corporate governance practices by Brazilian companies

2010 ◽  
Vol 8 (1) ◽  
pp. 515-525 ◽  
Author(s):  
Oderlene Vieira de Oliveira ◽  
Lindenberg Araújo Aragão ◽  
Vera Maria Rodrigues Ponte ◽  
Marcelle Colares Oliveira ◽  
Augusto Marcos Carvalho de Sena
Keyword(s):  
Corporate Governance ◽  
Capital Market ◽  
Hypothesis Test ◽  
Probability Distributions ◽  
Analytical Techniques ◽  
Descriptive Statistics ◽  
Motivating Factors ◽  
Institutional Image ◽  
Governance Practices ◽  
Decision Making Processes

The present research aims to identify the main motivating factors leading to the adoption of better Corporate Governance practices by Brazilian companies. A set of questionnaires was applied to the members of the APIMEC. Descriptive statistics, probability distributions and hypothesis test were used as analytical techniques. Evidenced showed that among the motivating factors literature depicts as relevant, investigated analysts considered to be the most important the following: professionalization of the company; transparency and relationship with the capital market; perpetuation of the company; addition of value to shareholders; valuation of the company shares; improvement of institutional image; increase of liquidity of company shares; recovery of investors’ trust; capital opening; reduction of cost of capital; and improvements in decision-making processes.

PENGARUH AKUNTANSI PERTANGGUNGJAWABAN, KOMITMEN ORGANISASI, DAN PARTISIPASI ANGGARAN TERHADAP KINERJA MANAJERIAL

Wahana ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 50-60
Author(s):  
Wiwik Pratiwi ◽  
Andari Asri Kartika
Keyword(s):  
Organizational Commitment ◽  
Linear Regression ◽  
Hypothesis Test ◽  
Descriptive Statistics ◽  
Survey Method ◽  
Manufacturing Companies ◽  
Validity And Reliability ◽  
Managerial Performance ◽  
Regression Test ◽  
Responsibility Accounting

This study is meant to test empirically the influence of responsibility accounting, organizational commitment, and budget participation to the managerial performance on manufacturing companies in Jakarta. This research used survey method by questionnaries. The data were examined using descriptive statistics, test of validity and reliability, classic assumption test, multiple linear regression test, and hypothesis test by using SPSS versi 24.0 for windows. The results of this research showed that responsibility accounting, organizational commitment, and budget participation were effect on managerial performance partially and simultaneously. Keywords: responsibility accounting, organizational commitment, budget participation, managerial performance

PENGARUH AKUNTANSI PERTANGGUNGJAWABAN, KOMITMEN ORGANISASI, DAN PARTISIPASI ANGGARAN TERHADAP KINERJA MANAJERIAL

Wahana ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 50-60
Author(s):  
Wiwik Pratiwi ◽  
Andari Asri Kartika
Keyword(s):  
Organizational Commitment ◽  
Linear Regression ◽  
Hypothesis Test ◽  
Descriptive Statistics ◽  
Survey Method ◽  
Manufacturing Companies ◽  
Validity And Reliability ◽  
Managerial Performance ◽  
Regression Test ◽  
Responsibility Accounting

This study is meant to test empirically the influence of responsibility accounting, organizational commitment, and budget participation to the managerial performance on manufacturing companies in Jakarta. This research used survey method by questionnaries. The data were examined using descriptive statistics, test of validity and reliability, classic assumption test, multiple linear regression test, and hypothesis test by using SPSS versi 24.0 for windows. The results of this research showed that responsibility accounting, organizational commitment, and budget participation were effect on managerial performance partially and simultaneously. Keywords: responsibility accounting, organizational commitment, budget participation, managerial performance

W-Peakedness: A Simulation based Study

2015 ◽  
Vol 1 (1) ◽  
Author(s):  
Suboohi Safdar ◽  
Dr. Ejaz Ahmed
Keyword(s):  
Probability Distributions ◽  
Extensive Study ◽  
Descriptive Statistics ◽  
Target Point ◽  
Density Functions ◽  
Central Value ◽  
Distribution Shape ◽  
Simulation Based ◽  
Different Shapes ◽  
Kurtosis Coefficient

Kurtosis is a commonly used descriptive statistics. Kurtosis “Coefficient of excess” is critically reviewed in different aspects and is called as, measuring the fatness of the tails of the density functions, concentration towards the central value, scattering away from the target point or degree of peakedness of probability distribution. Kurtosis is referred to the shape of the distribution but many distributions having same kurtosis value may have different shapes while Kurtosis may exist when peak of a distribution is not in existence. Through extensive study of kurtosis on several distributions, Wu (2002) introduced a new measure called “W-Peakedness” that offers a fine capture of distribution shape to provide an intuitive measure of peakedness of the distribution which is inversely proportional to the standard deviation of the distribution. In this paper the work is extended for different others continuous probability distributions. Empirical results through simulation illustrate the proposed method to evaluate kurtosis by W-peakedness

Calibration of Mobility and Interface Trap Parameters for High Temperature TCAD Simulation of 4H-SiC VDMOSFETs

2012 ◽  
Vol 717-720 ◽  
pp. 1101-1104 ◽  
Author(s):  
M.G. Jaikumar ◽  
Shreepad Karmalkar
Keyword(s):  
Surface Roughness ◽  
Measured Data ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Material Parameters ◽  
Velocity Saturation ◽  
Physical Mechanisms ◽  
Surface Roughness Scattering ◽  
Wide Range ◽  
Tcad Simulation

4H-Silicon Carbide VDMOSFET is simulated using the Sentaurus TCAD package of Synopsys. The simulator is calibrated against measured data for a wide range of bias conditions and temperature. Material parameters of 4H-SiC are taken from literature and used in the available silicon models of the simulator. The empirical parameters are adjusted to get a good fit between the simulated curves and measured data. The simulation incorporates the bias and temperature dependence of important physical mechanisms like interface trap density, coulombic interface trap scattering, surface roughness scattering and velocity saturation.

scholarly journals ASPECTOS BIOMÉTRICOS E MORFOLÓGICOS DE FRUTOS E SEMENTES DE Schinopsis brasiliensis

Nativa ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 219
Author(s):  
Jania Claudia Camilo dos Santos ◽  
Dayane Mércia Ribeiro Silva ◽  
Renato Nunes Costa ◽  
Carlos Humberto Da Silva ◽  
Wilton Da Silva Santos ◽  
...  
Keyword(s):  
Measured Data ◽  
Descriptive Statistics ◽  
Morphological Description ◽  
Environmental Restoration ◽  
Biometric Data ◽  
Water Imbibition ◽  
Morphological Aspects ◽  
Length Width ◽  
Forest Seeds

O objetivo deste trabalho foi avaliar a biometria e morfologia de S. brasiliensis, visando identificar características que auxiliem no uso e propagação dessa espécie da Caatinga em programa de restauração ambiental. Os dados biométricos foram obtidos a partir de 1000 frutos e 1000 sementes. Foram medidos o comprimento, largura, espessura e massa de frutos e sementes. Os dados foram ajustados utilizando a estatística descritiva e teste de Shapiro-Wilk. Para a descrição morfológica dos frutos, foram relatadas observações sobre os aspectos externos e internos do pericarpo, consistência da casca, coloração, brilho, forma e deiscência. Já as descrições morfológicas externa das sementes foram feitas observações sobre consistência, coloração, textura, forma e hilo. A caracterização biométrica de frutos e sementes de S. brasiliensis, possibilitou verificar a variação existente entre as classes biométricas através de histograma de frequência. Os frutos apresentam morfologia completa, em forma de sâmara, indeiscente e monospérmico. As sementes foram caracterizadas em oblongas e reniformes, envolvidas pelo endocarpo, resultando no pirênio, sendo esta a camada que dificulta o processo de embebição de água, a qual antecede a germinação, no entanto, esta camada é capaz de promover maior longevidade as sementes.Palavras-chave: análises biométricas, características morfológicas, sementes florestais, Caatinga. BIOMETRIC AND MORPHOLOGICAL ASPECTS OF THE FRUITS AND SEEDS OF SCHINOPSIS BRASILIENSIS ABSTRACT:The objective of this work was to evaluate the biometry and morphology of S. brasiliensis, aiming to identify traits that help in the use and propagation of this Caatinga species in an environmental restoration program. Biometric data were obtained from 1000 fruits and 1000 seeds. The length, width, thickness and mass of fruits and seeds were measured. Data were adjusted using descriptive statistics and Shapiro-Wilk test. For the fruits morphological description, observations on the external and internal traits of the pericarp, peel consistency, coloration, brightness, shape and dehiscence were reported. Already the external morphological descriptions of the seeds were made on consistency, color, texture, shape and thread. The biometric characterization of fruits and seeds of S. brasiliensis made it possible to verify the variation between the biometric classes through frequency histogram. The fruits presented complete morphology, in the form of a samara, indiscriminate and monospermic. The seeds were characterized in oblong and reniform, surrounded by the endocarp, resulting in the pyrenium, which is the layer that hinders the process of water imbibition, which precedes the germination, however this layer is able to promote greater longevity of the seeds.Keywords: biometric analyzes, morphological traits, forest seeds, Caatinga. DOI:

scholarly journals Improving Transparency, Falsifiability, and Rigour by Making Hypothesis Tests Machine Readable

2020 ◽  
Author(s):  
Daniel Lakens ◽  
Lisa Marie DeBruine
Keyword(s):  
Peer Review ◽  
Hypothesis Test ◽  
Scientific Information ◽  
Real Life ◽  
R Package ◽  
Statistical Prediction ◽  
Hypothesis Tests ◽  
Research Questions ◽  
Meta Analyses ◽  
Machine Readable

Making scientific information machine-readable greatly facilitates its re-use. Many scientific articles have the goal to test a hypothesis, so making the tests of statistical predictions easier to find and access could be very beneficial. We propose an approach that can be used to make hypothesis tests machine readable. We believe there are two benefits to specifying a hypothesis test in a way that a computer can evaluate whether the statistical prediction is corroborated or not. First, hypothesis test will become more transparent, falsifiable, and rigorous. Second, scientists will benefit if information related to hypothesis tests in scientific articles is easily findable and re-usable, for example when performing meta-analyses, during peer review, and when examining meta-scientific research questions. We examine what a machine readable hypothesis test should look like, and demonstrate the feasibility of machine readable hypothesis tests in a real-life example using the fully operational prototype R package scienceverse.

Numerical Simulation of Pressure Loss and Heat Transfer Characteristics for Additively Manufactured Channels

2020 ◽  
Author(s):  
Bryan Arko ◽  
Chad Iverson ◽  
Nicholas Staudigel
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Surface Roughness ◽  
Nusselt Number ◽  
Pressure Loss ◽  
Reynolds Numbers ◽  
Measured Data ◽  
Transfer Effects ◽  
Micro Channels ◽  
Heat Transfer Effects

Abstract This body of work provides an initial study of modeling both surface roughness and heat transfer concurrently in a numerical simulation of micro-channels representative of those that might be found in a turbine cooling application. Increased use of additive manufacturing (AM) or 3D printing techniques for turbomachinery components enable the manufacture of complex features to achieve higher operational performance. Accurate modeling of flow losses and heat transfer effects are critical to designing parts which achieve optimal efficiency paired with durability. Surface finish is rougher with AM compared to more traditional manufacturing techniques; therefore enhancing the pressure loss and heat transfer effects. Proper implementation of surface roughness within the computational model and correct modeling of the near wall boundary mesh must be maintained to produce accurate results. This study focuses on the comparison of near wall mesh treatment coupled with surface roughness to determine a practice for obtaining accurate pressure loss and heat transfer within a cooling passage, as compared to measurements. Steady-state computational fluid dynamics (CFD) models consisting of a wind tunnel inlet nozzle and outlet diffuser, along with internal cooling passages represented using micro-channels, has been run for a range of Reynolds numbers and simulated roughness levels. Analysis of a baseline configuration with aerodynamically smooth walls is first compared to the measured data to verify the assumption of aerodynamically smooth walls. Surface roughness is then added to the channel walls, from published test coupon measurements, and compared to published experimental data for a range of Reynolds numbers. The metal surrounding the passages is also included as a conjugate heat transfer model providing heat addition to the fluid. Pressure loss and heat transfer is compared to the measured data as a friction factor and Nusselt number for the range of Reynolds numbers. Since surface roughness units and measurements vary, an effect of surface roughness values on pressure loss and heat transfer will also be investigated to determine the importance of using and converting to the correct units for the numerical model. This serves as a starting point for a guideline that will help when both heat transfer and surface roughness are included in a CFD model. Further study is recommended to understand the diminishing levels of increase in friction factor and Nusselt number observed as surface roughness was continually increased in the numerical simulation.

Awareness and Use of Electronic Health Information Resources in Teaching, Research and Patient Care

2018 ◽  
Vol 7 (4) ◽  
pp. 45-68
Author(s):  
Samuel Akande Bello
Keyword(s):  
Health Information ◽  
Hypothesis Test ◽  
Information Resources ◽  
Descriptive Statistics ◽  
P Value ◽  
Frequency Of Use ◽  
Electronic Health ◽  
Health Information Resources ◽  
Electronic Health Information ◽  
University Of Ibadan

The central objective of this study was to determine the level of awareness and use of Electronic Health Information Resources (EHIRs) among the Academic Physicians of College of Medicine, University of Ibadan (COMUI), Nigeria. Others were to find out the frequency of use, the purposes and barriers against the use. Two hypotheses formulated and tested. This is a total enumeration research with 265 COMUI Academic Physicians, Nigeria. Questionnaire, designed with nominal and dichotomous questions was used. Data collected was analyzed with SPSS version 20.0. Descriptive statistics was used. Test of Pearson Moment Correlation (PMC) with Independent Sample t – test at 5% p – value used. The Academic Physicians mean age was 37.75. The results obtained indicated variations: 96.0% aware and used HINARI, 94.0% aware and used PubMed/Medline, NCBI was 64.9%. Hypothesis Test between awareness and use of EHIRs signified coefficient of proportionality (r = 218, p < 05).

Analysis of Surface Roughness Transformation of Oxide Scale during Hot Steel Manufacturing

2010 ◽  
Vol 126-128 ◽  
pp. 987-992
Author(s):  
Zheng Yi Jiang ◽  
Jian Ning Tang ◽  
A. Kiet Tieu ◽  
Wei Hua Sun ◽  
Dong Bin Wei
Keyword(s):  
Surface Roughness ◽  
Oxide Scale ◽  
Measured Data ◽  
Initial Surface ◽  
Surface Asperity ◽  
Decrease Rate ◽  
Steel Manufacturing ◽  
Simulation Results ◽  
Scale Surface

In this paper, the effects of the surface asperity wavelength, reduction and lubrication (friction) on the surface roughness transformation of the oxide scale have been studied. The simulation results show that the oxide scale surface roughness decreases with an increase of the average asperity wavelength and reduction. The initial surface roughness affects the decrease rate of surface roughness when the reduction increases. The surface roughness of the oxide scale and steel is quite close when the rolling with lubrication and both of them are reduced with reduction, and the surface roughness of the oxide scale is reduced less comparing with that of without lubrication case. The calculated roughness is close to the measured data.

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