Designing an economic rectifying sampling plan in the presence of two markets

In this paper, an optimization model is developed for the economic design of a rectifying inspection sampling plan in the presence of two markets. A product with a normally distributed quality characteristic with unknown mean and variance is produced in the process. The quality characteristic has a lower specification limit. The aim of this paper is to maximize the profit, which consists the Taguchi loss function, under the constraints of satisfying the producer's and consumer's risk in two different markets simultaneously. Giveaway cost per unit of sold excess material is considered in the proposed model. A case study is presented to illustrate the application of proposed methodology. In addition, sensitivity analysis is performed to study the effect of model parameters on the expected profit and optimal solution. Optimal process adjustment problem and acceptance sampling plan is combined in the economical optimization model. Also, process mean and standard deviation are assumed to be unknown value, and their impact is analyzed. Finally, inspection error is considered, and its impact is investigated and analyzed.     

The Portfolio as Artifact and Actor

This article proposes a tentative framework to support empirical analysis of portfolios as pedagogical tools for formative and summative assessment in higher education. It aims to get a deeper understanding of the role of the portfolio in student learning both as a tool and as representations of this tool. To that end, we use three sets of theoretical ideas: Wartofsky's conceptualization of perception through the creation of artifacts, actor-network theory, and Wertch's notions of internalization, appropriation and mastery. This article is meant to complement current portfolio research with an original approach that addresses explicitly epistemological questions and concepts like learning and knowledge and explores possible avenues for analyzing and understanding portfolios as artifacts and tools in learning activities.     

Measuring Wellbeing in Developing Countries: The Case of Algeria

The International Wellbeing Index (IWI) has been developed as a complementary measure to already well-known economic measures, and as a tool for cross-cultural comparisons. It comprises two subscales: the Personal Wellbeing Index (PWI) and the National Wellbeing Index (NWI). The aims of this paper are two-fold. Firstly, to test the psychometric characteristics of the IWI. Secondly, to study how people of Algeria, a third world country that is yet suffering from a harsch economical and social situation, respond to questions dealing with their own lives and life in their country in general, compared to samples from more developed countries where wellbeing was previously measured. The IWI items were presented to individuals either in a questionnaire form to be self-rated or in interview sessions. The total of 1417 answers were analysed. As was expected, a very low satisfaction on both scales was found, compared to the results that were reported in countries, such as Australia or Hong Kong. Comparisons on the demographic characteristics basis show that women are significantly more satisfied than men with their personal lives, though no differences were found with regard to NWI. Eldest and youngest age groups rated the PWI significantly higher than other age groups. Education groups comparisons showed higher ratings on both subscales in favour of groups with no education and those with university levels. Marginal statistically significant differences were found with regard to the PWI in favour of the higher earning group, but no differences in the NWI. No statistically significant results were found as far as marital status, number of children, and income are concerned. The results add to the evidence of the usefulness of the scale to predict satisfaction of people with their own lives and life in their country. Its psychometric performance was proved to be very high in terms of validity, reliability and sensitivity. The results were interpreted on the light of the Homeostasis Theory and the particular situation of the Algerian society.     

Posterior Regret Γ-Minimax Estimation and Prediction with Applications on k-Records Data Under Entropy Loss Function

Robust Bayesian analysis is connected with the effect of changing a prior within a class Γ instead of being specified exactly. The multiplicity of prior leads to a collection or a range of Bayes actions. It is interesting not only to investigate the range of estimators but also to recommend the optimal procedures. In this article, we deal with posterior regret Γ-minimax (PRGM) estimation and prediction of an unknown parameter θ and a value of a random variable Y under entropy loss function. Applications for k-records such as estimation and prediction problems are discussed.     

One-way ANOVA with Unequal Variances

We consider the one-way ANOVA problem of testing the equality of several normal means when the variances are not assumed to be equal. This is a generalization of the Behrens-Fisher problem, but even in this special case there is no exact test and the actual size of any test depends on the values of the nuisance parameters. Therefore, controlling the actual size of the test is of main concern. In this article, we first consider a test using the concept of generalized p-value. Extensive simulation studies show that the actual size of this test does not exceed the nominal level, for practically all values of the nuisance parameters, but the test is not too conservative either, in the sense that the actual size of the test can be very close to the nominal level for some values of the nuisance parameters. We then use this test to propose a simple F-test, which has similar properties but avoids the computations associated with generalized p-values. Because of its simplicity, both conceptually as well as computationally, this F-test may be more useful in practice, since one-way ANOVA is widely used by practitioners who may not be familiar with the generalized p-value and its computational aspects.