Indirect Bias Research Articles

Accurate Estimation of Subcriticality Using Indirect Bias Estimation Method, (II)

Subcriticalities were estimated by applying the Indirect Bias Estimation Method to subcritical experiments on a light-water moderated/reflected low-enriched UO2 lattice cores. Two measurable values, prompt neutron time-decay constant and spatial-decay constant were calculated using MCNP 4A and JENDL-3.2. With these calculation errors, the biases in calculated reactivity were derived from the Indirect Bias Estimation Method. The differences between the calculated and measured spatial-decay constants were more or less at the same extent of experimental errors. These results show that the accuracy of subcriticality estimation of MCNP 4A and JENDL-3.2 ranges within the uncertainty which can be achieved by the exponential experiment. The differences between calculated and measured prompt neutron decay constants derive significant biases in calculated reactivity. The subcriticalities were estimated by using the effective multiplication factors adjusted based on these biases in calculated reactivity.

Accurate Estimation of Subcriticality Using Indirect Bias Estimation Method, (I)

To estimate subcriticality of a system, a new method, Indirect Bias Estimation Method, is proposed. Instead of comparing a calculated k eff with a “measured” one which cannot be measured directly, a bias in calculated k eff is evaluated by direct comparison between measured and calculated quantities which are measureable in subcritical experiments. With these errors of measurable quantities, accuracy of a subcriticality calculation is indirectly derived. Three estimation methods based on the source multiplication method, the pulse neutron method, and the exponential experiment method are presented. For three experimental methods, neutron count rate distribution, prompt neutron decay constant, and spatial decay constant are compared between calculation and measurement, respectively, deriving biases in calculated k eff's. With biases obtained by this procedures, namely Indirect Bias Estimation Method, subcriticality of a system can be estimated more precisely than by “measured” k eff's.

Accurate Estimation of Subcriticality Using Indirect Bias Estimation Method, (I) Theory.

Subcriticalities were estimated by applying the Indirect Bias Estimation Method to subcritical experiments on a light-water moderated/reflected low-enriched UO2 lattice cores. Two measurable values, prompt neutron time-decay constant and spatial-decay constant were calculated using MCNP 4A and JENDL-3.2. With these calculation errors, the biases in calculated reactivity were derived from the Indirect Bias Estimation Method. The differences between the calculated and measured spatial-decay constants were more or less at the same extent of experimental errors. These results show that the accuracy of subcriticality estimation of MCNP 4A and JENDL-3.2 ranges within the uncertainty which can be achieved by the exponential experiment. The differences between calculated and measured prompt neutron decay constants derive significant biases in calculated reactivity. The subcriticalities were estimated by using the effective multiplication factors adjusted based on these biases in calculated reactivity.

The Effects of Group Process on Bias in Job Evaluation.

Bias (or systematic measurement error) is a threat to the validity of job evaluation. This research assesses the effects of group process (consensus vs. traditional groups) on indirect (salary level) bias, a type of bias demonstrated in previous research (Grams & Schwab, 1985). Neither group type reduced salary level bias.

Sources of Bias in Job Evaluation: A Review and Critique of Research

This article reviews existing evidence of sex bias in job evaluation judgments and analyzes research methods that have been used to study the issue. There are three potential sources of bias in job evaluation: (1) direct bias—jobs held predominantly by females are judgmentally underevaluated relative to predominantly male jobs with the same content; (2) indirect bias—job evaluation judgments are influenced by knowledge of potentially discriminatory current wages; and (3) sex‐of‐rater bias. Results of the empirical studies reviewed provide little or no evidence of either direct bias or sex‐of‐rater bias. However, consistent support was found for indirect bias in job evaluation: Jobs perceived as high paying are typically assigned higher job evaluation points (or higher pay rates) than those perceived as low paying. Methodological issues in the study of job evaluation are also discussed, particularly the dilemma of attempting to manipulate pay level and job sex in realistic ways (for high external validity) that are also effective and believable to subjects (for high internal validity).