Estimation of mean using double sampling for stratification and multivariate auxiliary information

Several estimators for estimating the mean of a principal variable are proposed based on double sampling for stratification (DSS) and multivariate auxiliary information. The general properties of the proposed estimators are studied, search for optimum estimators is made and the proposed estimators are compared with the corresponding estimators based on unstratified double sampling (USDS).     

Neuroticism,locus of control,type A behaviour pattern and occupational stress

Abstract

The aim of this study was to investigate the relationship between individual differences in personality and susceptibility to stress in the workplace. Stress in lecturers employed by a computer training organization was assessed by means of self-report and measurement of salivary cortisol output during lecturing and non-lecturing weeks. Neuroticism, Type A behaviour pattern and locus of control were measured. Self-reported stress was found to be much greater during lecturing weeks, but cortisol levels were unaffected by working conditions. There was a significant positive correlation between neuroticism and locus of control and a negative correlation between locus of control and Type A behaviour pattern that approached significance. Multiple regression was employed to explore relations between personality and stress. Subjects with lower neuroticism scores yielded a bigger increase in reported stress, in the lecturing compared with the non-lecturing week, than subjects with high neuroticism scores. Type B subjects showed a progressive decrease in cortisol over the working week while Type A counterparts showed a resurgence of cortisol towards the end of the week. Finally, Type B subjects having an internal locus of control showed a faster decline in cortisol level during the lecturing week than the other subjects. Implications of these results are discussed in terms of the importance simultaneously incorporating a variety of individual differences in personality dimensions and stress indices in research designs.     

Psychometric and Demographic Predictors of the Perceived Risk of Terrorist Threats and the Willingness to Pay for Terrorism Risk Management Programs

A 2009 national telephone survey of 924 U.S. adults assessed perceptions of terrorism and homeland security issues. Respondents rated severity of effects, level of understanding, number affected, and likelihood of four terrorist threats: poisoned water supply; explosion of a small nuclear device in a major U.S. city; an airplane attack similar to 9/11; and explosion of a bomb in a building, train, subway, or highway. Respondents rated perceived risk and willingness to pay (WTP) for dealing with each threat. Demographic, attitudinal, and party affiliation data were collected. Respondents rated bomb as highest in perceived risk but gave the highest WTP ratings to nuclear device. For both perceived risk and WTP, psychometric variables were far stronger predictors than were demographic ones. OLS regression analyses using both types of variables to predict perceived risk found only two significant demographic predictors for any threat—Democrat (a negative predictor for bomb) and white male (a significant positive predictor for airline attack). In contrast, among psychometric variables, severity, number affected, and likelihood were predictors of all four threats and level of understanding was a predictor for one. For WTP, education was a negative predictor for three threats; no other demographic variables were significant predictors for any threat. Among psychometric variables, perceived risk and number affected were positive predictors of WTP for all four threats; severity and likelihood were predictors for three; level of understanding was a significant predictor for two.     

Resource smoothing: A cost minimization approach

From the available literature, there seems to be no defined approach to resource smoothing exercise except those attempted by Weist (1967, Management Science, 13, B359-B377) and Burgess and Killebrew (1962, Journal of Industrial Engineering, 13, 76-83). The aim of the smoothing exercise is to achieve optimal resource usage by avoiding high peaks and deep valleys in the project resource profile. The general approach has always been to move some activities with floats in the high peak regions to be started at a later date, and as this is done, the valleys will be filled to smooth the resource profile subject of course to time constraint. If this approach is followed as it is, it would be difficult to determine optimality especially when many resources are involved. A cost minimization approach is envisaged in the present study with no limitation on the number of resource inputs. In a situation where the resources are assumed to have the same value, the cost assigned to each of them should be similar. The method follows the general concept but with a difference; cost of the activity in question is considered. The exercise is continued until all the floats are exhausted. The optimum result would then be the one with the minimum cost profile. From examples used for the evaluation, the results obtained are comparable to those of the above two researchers, and some with better results in the majority of cases.     

Further influence measures in factor analysis

Various influence measures are discussed for sensitivity analysis in factor analysis. The internal norm is used to characterize the vector-valued influence curves in factor analysis. Influence curves for the chi-square goodness of fit test, and the determinants of the model covariance matrix and unique variance matrix are derived. They are found to have simple formulas which are easy to be interpreted and have nice distributions for calibration. The likelihood displacement is also applied to sensitivity analysis in maximum likelihood factor analysis.     

Recurrence relations for moments of different orders of extremes from gamma distribution

Certain recurrence relations for the moments of different orders of the largest order statistic from a gamma distribution with shape parameter p are obtained. By using this it is shown that for obtaining the moment of any order of each order statistic of a sample of size n from the gamma distribution, one has to evaluate at most n-2 single integrals.     

Costs,Benefits, and Management Considerations of a Prepaid Student Dental Health Plan

Abstract

The Student Dental Health Program (SDHP) is an open panel, prepaid dental insurance plan at the University of Alabama in Birmingham. The program was developed primarily to provide optimal dental health service; however the SDHP also serves educational and research functions that are consistent with the objectives of the university. The student bodies of the Schools of Dentistry, Medicine, Nursing, and Optometry constitute the enrollee population.

Total cost rose from $18,418 in 1969–70 with 862 enrollees, to $70,930 in 1975–76 with 1,618 enrollees. During the same period the number of procedures completed increased from 2,868 to 6,796, with the average cost per procedure increasing from $6.42 to $10.44. The number of restorative services declined and preventive services increased. In 1976–77 benefits per student treated were estimated at $80 as compared to the annual fee of $48. The value of unmet needs upon entrance to the program averaged $59 per enrollee in 1974–75. By 1976–77 this figure was reduced to $26 due to implementation of an initial screening. The program is self-supporting due to a variety of cost containment measures. On balance, the program can be considered successful and beneficial to all parties concerned.     

Cost of Including Males in a University Rubella Immunization Program: A Recommendation to Change a Discriminatory Policy

Abstract

Twenty-seven University of Rochester students developed clinical manifestations of rubella during 1976–77. Twenty-five were male and had not been immunized against this disease; 18 required infirmary care costing $4,876. On the basis of data for freshman males, a cost analysis demonstrates the feasibility of changing the university policy which encourages immunization only of females to encouragement of either selective or mass immunization of all males as well. Immunization during childhood with combined MMR vaccine is least expensive and should be encouraged. In certain circumstances, selective immunization of susceptible males may be less expensive than the present selective policy, which leaves males at risk.     

Call to action: Better care,better health,and greater value in college health

ABSTRACT

It is time for action by leaders across higher education to strengthen quality improvement (QI) in college health, in pursuit of better care, better health, and increased value – goals closely linked to students' learning and success. The size and importance of the college student population; the connections between wellbeing, and therefore QI, and student success; the need for improved standards and greater accountability; and the positive contributions of QI to employee satisfaction and professionalism all warrant a widespread commitment to building greater capacity and capability for QI in college health. This report aims to inspire, motivate, and challenge college health professionals and their colleagues, campus leaders, and national entities to take both immediate and sustainable steps to bring QI to the forefront of college health practice – and, by doing so, to elevate care, health, and value of college health as a key pathway to advancing student success.