Bayesian prediction for progressively censored data from the Burr model

Received: August 14, 2000; revised version: April 23, 2001     

Merging data from multiple sources: pretest and shrinkage perspectives

In this article, we have developed asymptotic theory for the simultaneous estimation of the k means of arbitrary populations under the common mean hypothesis and further assuming that corresponding population variances are unknown and unequal. The unrestricted estimator, the Graybill-Deal-type restricted estimator, the preliminary test, and the Stein-type shrinkage estimators are suggested. A large sample test statistic is also proposed as a pretest for testing the common mean hypothesis. Under the sequence of local alternatives and squared error loss, we have compared the asymptotic properties of the estimators by means of asymptotic distributional quadratic bias and risk. Comprehensive Monte-Carlo simulation experiments were conducted to study the relative risk performance of the estimators with reference to the unrestricted estimator in finite samples. Two real-data examples are also furnished to illustrate the application of the suggested estimation strategies.     

Collective and Elective Ethnicity: Caste Among Urban Muslims in India

This article explores how the significance of ethnic identity can vary within a stable population, using caste among Muslims in Hyderabad, India as a case study. While some Hyderabadi Muslims are still embedded in ethnic networks, most now experience ethnicity as elective and do not rely on a corporate caste group for their social connections. This reflects a decline in the value of caste identities, which no longer provide economic or political resources. Increasingly, Muslims seek status through education, profession, or income. Thus, most Muslims in Hyderabad experience caste membership, identity, and networks in a weakened or attenuated way.     

A Taguchi-based Kansei engineering study of mobile phones at product design stage

This article is aimed at applying Taguchi method in Kansei engineering and explores a way to integrate it into an industrial product design stage. Emotional customer needs are derived using Kansei image word pairs. The Taguchi-based approach is validated by a case study with mobile phones. Experimental work in implementing the proposed approach was able to suggest design attributes of a mobile phone that are essential to be considered at the product design stage to satisfy the customers’ expectations and hence to increase the company's sales.     

Distributionally robust maximum probability shortest path problem

In this study, we discuss and develop a distributionally robust joint chance-constrained optimization model and apply it for the shortest path problem under resource uncertainty. In sch a case, robust chance constraints are approximated by constraints that can be reformulated using convex programming. Since the issue we are discussing here is of the multi-resource type, the resource related to cost is deterministic; however, we consider a robust set for other resources where covariance and mean are known. Thus, the chance-constrained problem can be expressed in terms of a cone constraint. In addition, since our problem is joint chance-constrained optimization, we can use Bonferroni approximation to divide the problem into L separate problems in order to build convex approximations of distributionally robust joint chance constraints. Finally, numerical results are presented to illustrate the rigidity of the bounds and the value of the distributionally robust approach.

     

On the computation of the noncentral <Emphasis Type="Italic">F</Emphasis> and noncentral beta distribution

Unfortunately many of the numerous algorithms for computing the comulative distribution function (cdf) and noncentrality parameter of the noncentral F and beta distributions can produce completely incorrect results as demonstrated in the paper by examples. Existing algorithms are scrutinized and those parts that involve numerical difficulties are identified. As a result, a pseudo code is presented in which all the known numerical problems are resolved. This pseudo code can be easily implemented in programming language C or FORTRAN without understanding the complicated mathematical background. Symbolic evaluation of a finite and closed formula is proposed to compute exact cdf values. This approach makes it possible to check quickly and reliably the values returned by professional statistical packages over an extraordinarily wide parameter range without any programming knowledge. This research was motivated by the fact that a very useful table for calculating the size of detectable effects for ANOVA tables contains suspect values in the region of large noncentrality parameter values compared to the values obtained by Patnaik’s 2-moment central-F approximation. The cause is identified and the corrected form of the table for ANOVA purposes is given. The accuracy of the approximations to the noncentral-F distribution is also discussed. The authors wish to thank Mr. Richárd Király for his preliminary work. The authors are grateful to the Editor and Associate Editor of STCO and the unknown reviewers for their helpful suggestions.     

Estimation of the mean of the exponential distribution using moving extremes ranked set sampling

Moving Extremes Ranked Set Sampling (MERSS) is a useful modification of Ranked Set Sampling (RSS). Unlike RSS, MERSS allows for an increase of set size without introducing too much ranking error. The method is considered parametrically under exponential distribution. Maximum likelihood estimator (MLE), and a modified MLE are considered and their properties are studied. The method is studied under both perfect and imperfect ranking (with error in ranking). It appears that these estimators can be real competitors to the MLE using the usual simple random sampling (SRS).     

Ascertaining the effect of planned organizational change on the work environment

In a dynamic environment, organizations often are required to effect major changes in operations. The success of such changes invariably depends upon numerous factors one of which is how the change affects the work environment. Therefore, in planning organizational change it is important to consider the work environment and to objectively evaluate changes in the work environment in a timely fashion so that corrective actions may be formulated if needed. Such framing and monitoring of the organizational change facilitates successful implementation of the organizational change. This paper suggests a measure which may be used in evaluating an organization's work environment. A case is discussed.     

In Good Times but Not in Bad: The Role of Managerial Discretion in Moderating the Stakeholder Management and Financial Performance Relationship

We examine the role of managers in controlling the positive impact of stakeholder management (SM) on firm financial performance (FP) in the long term. We develop and test competing hypotheses on whether managers act as “good citizens” or engage in “self‐dealing” when allowed greater discretion. We test our assertions using dynamic panel data analysis of a sample of 806 U.S. public firms operating in 34 industries over 5 years (2005–2009). Our results indicate a nuanced influence of managerial discretion contexts on the SM‐FP relationship. We infer that given more latitude in decision making, as long as the “going is good” managers act as good citizens, but otherwise they revert to managerial self‐dealing. In light of our results, firms designing governance mechanisms to encourage managers to balance the needs of both shareholders and stakeholders must remain cognizant of contextual contingencies.     

Unemployment Insurance in Algeria: Help or Hindrance?

The issue of employment has become a crucial one in Algeria. Not only does the economy no longer offer opportunities for jobseekers; economic reforms have led to countless public-sector businesses being wound up, putting thousands of people out of work. Against this background, a system of temporary unemployment benefits has been introduced, though its effectiveness has been sharply criticized. How many of the occupations targeted by the legislation setting up the system are actually covered by Algeria's unemployment insurance system, and on what terms? What obstacles are there to the full realization of this system's objectives, and how effective is it in an economic and financial sense? The unemployment insurance system is traditionally accused of clogging up the machinery of employment and preventing a return to a competitive labour market. There are also those who believe that this system helps to foster voluntary unemployment and encourages people to spend more time on leisure pursuits. Our article considers all these views. At the end the reader will also find brief details of unemployment insurance in South Africa and Egypt.