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Based on the analysis of the seismic performance of 16 partially prestressed concrete(PPC) frame structures designed according to China current codes, the quantitative index of PPC frame performance levels and the reliability of a design... more
Based on the analysis of the seismic performance of 16 partially prestressed concrete(PPC) frame structures designed according to China current codes, the quantitative index of PPC frame performance levels and the reliability of a design displacement in Direct Displacement-Based Design(DDBD) had been analyzed. After three performance levels of basic integrity, life safety and collapse prevention defined, crack width, bearing capacity had been suggested as a quantitative reference index and the corresponding interstory drift ratio as a final quantitative index. At the same time, taking the interstory drift ratio corresponding to a quantitative index as resistances and corresponding to expected earthquakes as effects, a simplified method had been put forward, in which reliability can be taken into account in DDBD and associated to the reliability level of current codes. In this method, the error arose from the coefficient of variation can be avoid greatly and different requirements ca...
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This article explores the two‐interval, two‐alternative forced‐choice (2I2AFC) paradigm in signal detection theory (SDT), which can also be called the paired A‐Not A with AB and BA pairs in the sensory and consumer fields. The article... more
This article explores the two‐interval, two‐alternative forced‐choice (2I2AFC) paradigm in signal detection theory (SDT), which can also be called the paired A‐Not A with AB and BA pairs in the sensory and consumer fields. The article describes how to estimate the parameters and their variances from the psychometric function of the method. Tables and R codes were developed and are provided for the estimations. The performance of the method is evaluated. It shows that the paired A‐Not A with AB and BA pairs is more effective and powerful than the conventional A‐Not A and the A‐Not A with reminder (A‐Not AR) tests. An extension of the method, that is, the ratings of the paired A‐Not A with AB and BA pairs is also explored. A facial shine case study applying this method is provided.Practical applicationsAs one of the paired versions of sensory discrimination methods, the paired A‐Not A with AB and BA pairs has wide potential applications to detect and measure sensory difference, especi...
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Abstract This paper proposes a new type of sensory discrimination methods, i.e., paired versions of various sensory discrimination forced-choice methods, which can be regarded as modified versions of the same-different method. The new... more
Abstract This paper proposes a new type of sensory discrimination methods, i.e., paired versions of various sensory discrimination forced-choice methods, which can be regarded as modified versions of the same-different method. The new type of methods possesses the advantage of the same-different test for measuring overall sensory difference, but overcomes its weaknesses of large variations of response bias and lower testing power. An important finding is that this type of methods is closely related to the same-different area theorem and its extension. The same-different area theorem establishes an equivalence between the area under the receiver operating characteristic (ROC) curve of the same-different method and the proportion of correct responses ( P c ) in the dual-pair method. This paper re-demonstrates and extends the same-different area theorem. An analytical expression of a general psychometric function for the new type of methods is derived. Performances of the new type of methods are evaluated with testing power and sample size in both difference and similarity/equivalence tests. R codes are provided for the new type of methods for P c , Thurstonian discriminal distance δ, and variance of d′ , where d′ is an estimator of δ.
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Abstract ANOVA and multiple comparisons based on generalized linear model (GLM) with a binomial distribution are proposed to be used for testing product differences with CATA data. The methods of Cochran’s Q test and ANOVA based on a... more
Abstract ANOVA and multiple comparisons based on generalized linear model (GLM) with a binomial distribution are proposed to be used for testing product differences with CATA data. The methods of Cochran’s Q test and ANOVA based on a normal distribution for CATA data analyses have only historical significance. There is no sound reason nowadays to insist on using these methods for CATA data analyses from both a theoretical and a practical perspective.
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Abstract In a recent paper in the sensory literature, the method of “M+N” with larger M and N is proposed to be a new kind of sensory discrimination method. Fisher's exact test is used for the method for discrimination testing. The... more
Abstract In a recent paper in the sensory literature, the method of “M+N” with larger M and N is proposed to be a new kind of sensory discrimination method. Fisher's exact test is used for the method for discrimination testing. The current article focuses on sensory measurements for the method. Five indices for sensory measurements and effect-sizes are derived, estimated, and proposed. The indices include log odds ratio, R-index, Thurstonian discriminal distance δ (or d′), Cohen's Δ (or d) and Gini-index. Variances of the estimators of the indices are also produced. With the proposed indices, the method of “M+N” with larger M and N can be connected to and compared with the conventional sensory discrimination methods based on common sensory measurements. Practical Applications The method of “M+N” with larger M and N can be used for both sensory discrimination tests and measurements. The method is particularly suitable for a range of nonfatiguing discrimination tasks, e.g., visual inspection and, to a certain extent, manual inspection. With the indices proposed in this article, sensory effects can be measured for the new method. Built-in R programs are used in the article for the analysis. R codes for estimations of the indices and their variances for the method are developed and provided. Tables for two important sensory indices, R-index and d′, corresponding to the observed odds ratio are presented and used in the article.
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Demographics and psychographics are used to study the influence of different consumers on product effects in food development and testing. Demographics have a longer history and are routinely used in most research; psychographics are more... more
Demographics and psychographics are used to study the influence of different consumers on product effects in food development and testing. Demographics have a longer history and are routinely used in most research; psychographics are more recent, raising the question of whether they add to research on food products. The research presented here represents extensive exploratory data that demonstrate that both demographic measures and psychographic measures add to our understanding of consumer’s liking ratings for nutrient supplements. The results are discussed in the context of broader research on a range of food products. In addition, the research reported here was conducted in four different countries, demonstrating many country effects. Finally, tests were conducted with users of the products, lapsed users of the product, and users of other nutrient supplements (non-users), and this led to many differences in product testing. These results further suggest that age and gender are no...
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ABSTRACT The A–Not A with reminder (A–Not AR) is a relatively new method in the sensory literature. This paper derives and demonstrates the function illustrating the relationship between the area under the receiver operating... more
ABSTRACT The A–Not A with reminder (A–Not AR) is a relatively new method in the sensory literature. This paper derives and demonstrates the function illustrating the relationship between the area under the receiver operating characteristic (ROC) curve and d′ for the A–Not AR with the differencing strategy. This function shows that the area under an ROC curve for the A–Not AR is equal to the maximum proportion of correct responses in an A–Not A. This theoretic function can be used to estimate d′ and its variance from the ratings of the A–Not AR. A simulation study shows that the nonparametric estimation based on this function is close to those obtained by using the maximum likelihood estimation. The estimation of the variance of d′ based on the delta method is close to that obtained by using the bootstrap method. R codes are provided for the estimations of d′ and its variance as well as simulations. Practical ApplicationsThe A–Not AR is a variation of the conventional A–Not A method, which is used in the sensory field for discrimination testing. This method is particularly useful when it is difficult to have an adequate familiarization procedure for the test samples for panelists before a test. This approach also offers the potential for applying such a method to problems like hedonic, purchase intent, and consumer concept measures in addition to other measures in the sensory and consumer science field. This paper provides a new nonparametric method and R codes for estimating d′ and its variance from the ratings of the A–Not AR.
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ABSTRACT Psychometric functions for discrimination tests, which connect probabilities of correct response, pc, with Thurstonian discriminal distances, d′, are of theoretical and practical significance. This paper uses a computer-intensive... more
ABSTRACT Psychometric functions for discrimination tests, which connect probabilities of correct response, pc, with Thurstonian discriminal distances, d′, are of theoretical and practical significance. This paper uses a computer-intensive approach to produce simulation-derived psychometric functions for the "M+N" test, which is a generalization and can be considered as a framework of many forced-choice methods. The paper demonstrates and describes chance probabilities in different situations for the "M+N" test. The paper compares the performances of the specified and unspecified "M+N" test with the M=N test. The paper provides novel tables for pc and d′ for four specific versions of the "M+N" test: the specified "two-out-of-five" test (i.e., the "M+N" test with M=3 and N=2); the unspecified "one-out-of-four" test (i.e., the "M+N" test with M=3 and N=1); the specified and unspecified octad tests (i.e., the "M+N" test with M=N=4). The corresponding B values, for calculation of the variances of d' for the tests, are also provided. The concept and practice of pseudo-correct response, i.e., forgiveness introduced by Ennis, are discussed and generalized.
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ABSTRACT
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Bi, J. (1993). Introduction of GB 6379-86, Precision of test methods—Determination of repeatability and reproducibility for a standard test method by interlaboratory tests. In T. Shen (ed) Guide to the Basic Chinese National Standards. 80-89, China Statistics Publisher, Bejing. ISBN 7-5037-1000-4...more
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ABSTRACT
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ABSTRACT