Transformation of Life-Test Data

1968 ◽  
Vol 11 (3) ◽  
pp. 475-488 ◽  
Author(s):  
Norman R. Draper ◽  
Irwin Guttman
Keyword(s):  
Exponential Distribution ◽  
Analysis Of Variance ◽  
Gamma Distribution ◽  
Test Data ◽  
Life Testing ◽  
Life Test ◽  
Constant Variance ◽  
Dependent Variables ◽  
Special Case

In a recent paper Box and Cox (1964) considered the problem of transforming dependent variables in regression and analysis of variance problems, in order to achieve the usual assumptions of Normality, constant variance and additivity of effects. Here we adopt the same approach to investigate transformations of data which allow the transformed observations to follow a Gamma distribution. A special case of this is the exponential distribution, valuable in life-testing, for which examples are given.

scholarly journals Life Prediction on a T700 Carbon Fiber Reinforced Cylinder with Limited Accelerated Life Testing Data

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Ma Xiaobing ◽  
Zhang Yongbo
Keyword(s):  
Carbon Fiber ◽  
Test Data ◽  
Life Prediction ◽  
Rupture Life ◽  
Accelerated Life Testing ◽  
Accelerated Life Test ◽  
Life Testing ◽  
Life Test ◽  
Failure Data ◽  
Accelerated Life

An accelerated life testing investigation was conducted on a composite cylinder that consists of aluminum alloy and T700 carbon fiber. The ultimate failure stress predictions of cylinders were obtained by the mixing rule and verified by the blasting static pressure method. Based on the stress prediction of cylinder under working conditions, the constant stress accelerated life test of the cylinder was designed. However, the failure data cannot be sufficiently obtained by the accelerated life test due to the time limitation. Therefore, most of the data presented to be high censored in high stress level and zero-failure data in low stress level. When using the traditional method for rupture life prediction, the results showed to be of lower confidence. In this study, the consistency of failure mechanism for carbon fiber and cylinder was analyzed firstly. According to the analysis result, the statistical test information of carbon fiber could be utilized for the accelerated model constitution. Then, rupture life prediction method for cylinder was proposed based on the accelerated life test data and carbon fiber test data. In this way, the life prediction accuracy of cylinder could be improved obviously, and the results showed that the accuracy of this method increased by 35%.

A New Cumulative Damage Model: Part 2

1978 ◽  
Vol 45 (2) ◽  
pp. 251-257 ◽  
Author(s):  
J. L. Bogdanoff ◽  
W. Krieger
Keyword(s):  
Test Data ◽  
Damage Model ◽  
Cumulative Damage ◽  
Life Testing ◽  
Life Test ◽  
Wear Life ◽  
Cumulative Damage Model

A series of illustrative examples are presented to aid in understanding the generality of the model as it applies to cumulative damage. Results from the model are used to describe and analyze some fatigue and wear life test data. Comments are made on the uses of the model. A discussion is presented on the shortcomings of current methods of life testing when prediction is involved.

Test Validation Without Measurement

2016 ◽  
Vol 32 (3) ◽  
pp. 204-214 ◽  
Author(s):  
Emilie Lacot ◽  
Mohammad H. Afzali ◽  
Stéphane Vautier
Keyword(s):  
Test Data ◽  
Test Scores ◽  
Scientific Explanation ◽  
Test Validation ◽  
Clinical Tests ◽  
Ethical Perspective ◽  
Power Of Test ◽  
Memory Accuracy ◽  
Social Uses ◽  
Special Case

Abstract. Test validation based on usual statistical analyses is paradoxical, as, from a falsificationist perspective, they do not test that test data are ordinal measurements, and, from the ethical perspective, they do not justify the use of test scores. This paper (i) proposes some basic definitions, where measurement is a special case of scientific explanation; starting from the examples of memory accuracy and suicidality as scored by two widely used clinical tests/questionnaires. Moreover, it shows (ii) how to elicit the logic of the observable test events underlying the test scores, and (iii) how the measurability of the target theoretical quantities – memory accuracy and suicidality – can and should be tested at the respondent scale as opposed to the scale of aggregates of respondents. (iv) Criterion-related validity is revisited to stress that invoking the explanative power of test data should draw attention on counterexamples instead of statistical summarization. (v) Finally, it is argued that the justification of the use of test scores in specific settings should be part of the test validation task, because, as tests specialists, psychologists are responsible for proposing their tests for social uses.

STUDY ON PHYSICAL AND SENSORICAL CHARACTERISTICS OF FLESH RESTRUCTURED WITH SAGO CATFISH JERKY

2014 ◽  
Vol 4 (2) ◽  
pp. 55-64
Author(s):  
Amir Jayani ◽  
Zulman Efendi ◽  
Devi Silsia
Keyword(s):  
Physical Properties ◽  
Water Content ◽  
Analysis Of Variance ◽  
Test Data ◽  
Organoleptic Test ◽  
Significant Difference

This study aims to gain influence the thickness and concentration variations affect the characteristics of sago binder physical properties of catfish jerky. As well as getting influence the thickness and concentration variations affect the level of binder sago joy panelists in terms of organoleptic test. Data were analyzed by analysis of variance using the Analysis Of Variance (ANOVA). If there is a significant difference followed by a further test of DMRT 5% level (physical properties). While the hedonic test performed using Kruskal Wallis analysis. Results uniformity analysis (ANOVA) showed catfish fillet thickness and concentration of sago affect the physical properties of the water content and the level of violence. Where catfish jerky using sago binder 5% and 10% significantly different. The use of sago binder 5% and 10% led to an increase in water content. Besides the addition of the binder resulted in increasing levels of violence catfish jerky. Based on the statistics found that the influence of the thickness and concentration of the binder sago aroma, flavor and color of the sixth jerky catfish were not significantly different. But the texture was significantly different.

Nine, Seven, Five, or Three: How Many Figures Do We Need for Assessing Body Image?

2005 ◽  
Vol 100 (2) ◽  
pp. 488-492 ◽  
Author(s):  
Neala Ambrosi-Randić ◽  
Alessandra Pokrajac-Bulian ◽  
Vladimir Takšić
Keyword(s):  
Body Image ◽  
Analysis Of Variance ◽  
Optimal Number ◽  
Female Students ◽  
Validity And Reliability ◽  
Main Effect ◽  
Dependent Variables ◽  
Post Hoc ◽  
Main Effects

320 Croatian female students ( M = 20.4 yr.) were recruited to examine the validity and reliability of figural scales using different numbers of stimuli (3, 5, 7, and 9) and different serial presentation (serial and nonserial order). A two-way analysis of variance (4 numbers × 2 orders of stimuli) was performed on ratings of current self-size and ideal size as dependent variables. Analysis indicated a significant main effect of number of stimuli. This, together with post hoc tests indicated that ratings were significantly different for a scale of three figures from scales of more figures, which in turn did not differ among themselves. Main effects of order of stimuli, as well as the interaction, were not significant. The results support the hypothesis that the optimal number of figures on a scale is seven plus (or minus) two.

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