A state-of-art survey of static scheduling research involving due dates

This paper provides a guided tour of those scheduling techniques in which the performance measures bear in one way or the other on job due dates. The classification is based on scheduling objectives. Within each category the theoretical developments and computational experiences have been reviewed.     

Adolescent Gambling: Understanding the Role of Stress and Coping

The central variables of stress, coping, and gambling severity were examined along three lines of inquiry. The first addressed whether adolescents with gambling problems reported a greater number of minor or major stressful (i.e., negative) life events relative to others. The second examined whether more with gambling problems employed less-effective coping styles, such as those characterized as less task- or solution-focused, and more emotion- or avoidance-focused coping. Finally, the third question explored whether adolescents’ coping styles mediated the association between stress and gambling severity. Ranging from 11 to 20 years of age, 2,156 high-school students completed instruments assessing gambling involvement, gambling severity, stressful life events, and coping styles. Results indicated that, overall, adolescents with gambling-related problems reported more negative life events relative to social gamblers and non-gamblers. When negative life events were further separated into major and minor events, results revealed that problem gamblers reported more major negative life events but not more minor negative life events relative to others. Results indicated that adolescents with gambling-related problems used less task-focused coping, and more avoidance-focused coping. Males, but not females, who experience gambling-related problems reported using more emotion-focused coping strategies. Finally, emotion-oriented coping was found to mediate the relationship between negative life events and gambling severity. Implications and directions for future research are discussed.

IPPS Sampling Plans Excluding Adjacent Units

The concept of inclusion probability proportional to size sampling plans excluding adjacent units separated by at most a distance of m (≥ 1) units {IPPSEA plans} is introduced. IPPSEA plans ensure that the first-order inclusion probabilities of units are proportional to size measures of the units, while the second-order inclusion probabilities are zero for pairs of adjacent units separated by a distance of m units or less. IPPSEA plans have been obtained by making use of binary, proper, and unequireplicated block designs and linear programing approach. The performance of IPPSEA plans using Horvitz–Thompson estimator of population total has been compared with existing sampling plans such as simple random sampling without replacement (SRSWOR), balanced sampling plans excluding adjacent units {BSA (m) plans}, probability proportional to size with replacement, Hartley and Rao's plan (1962 Hartley , H. O. , Rao , J. N. K. ( 1962 ). Sampling with unequal probabilities and without replacement . Ann. Math. Statist. 33 : 350 – 374 .[Crossref] , [Google Scholar]), Rao et al.'s strategy (1962 Rao , J. N. K. , Hartley , H. O. , Cochran , W. G. ( 1962 ). On a simple procedure of unequal probability sampling without replacement . J. Roy. Statist. Soc. B 24 : 482 – 491 . [Google Scholar]), and Sampford's IPPS plan (1967 Sampford , M. R. ( 1967 ). On sampling without replacement with unequal probabilities of selection . Biometrika 54 ( 3 ): 499 – 513 .[Crossref], [PubMed] , [Google Scholar]) using a real life population. Unbiased estimation of Horvitz–Thompson estimator of population total is not possible in these types of plans because some of the second-order inclusion probabilities are zero. To resolve this problem, one approximate variance estimation technique has been suggested.     

Computer-Generated Change-Over Designs for Correlated Observations

Change-over designs with independently distributed errors in the model have been studied extensively in the literature. Martin and Eccleston (2001 Martin , R. J. , Eccleston , J. A. ( 2001 ). Optimal and near optimal designs for dependent observations . Statist. Applic. 3 : 101 – 116 . [Google Scholar]) gave an algorithm for the generation of efficient change-over designs when the errors are correlated. This article proposes an algorithm for the generation of efficient change-over designs for estimation of direct effects of treatments in the presence of first-order residual effects in the model and when the errors are correlated.     

Gammaization and wishartness of dependent quadratic forms

In this paper two equivalent sets of necessary and sufficient conditions are derived for dependent quadratic forms to be distributed as multivariate gamma distribution. The procedure also gives a set of necessary and sufficient conditions for principal minors of generalized quadratic forms to be jointly distributed as the joint distribution of principal minors of a Kishart matrix.     

Subset selection based on likelihood from uniform and related popupulations

Let π_i (i=1,2,…, k) be charceterized by the uniform distribution on (a_i;b_i), where exactly one of a_i and b_i is unknown. With unequal sample sizes, suppose that from the k (>=2) given populations, we wish to select a random-size subset containing the one with the smllest value of θ_i= b_i - a_i. RuleR_i selects π if a likelihood-based k-dimensional confidence region for the unknown (θ₁,… θ_k) contains at least one point having θ_i as its smallest component. A second rule, R , is derived through a likelihood ratio and turns out to be that of Barr and prabhu whenthe sample sizes are equal. Numerical comparisons are made. The results apply to the larger class of densities g ( z ; θ_i) =M(z)Q(θ_i) if a(θ_i) < z <b(θ_i). Extensions to the cases when both a_i and b_i are unknown and when θ_j isof interest are indicated. 1<=j<=k     

Structural properties and estimation in m|EK| 1 queue

In this paper we study the distribution of the number of customers served in a busy period in the framework of modified power series distribution introduced by Gupta (197U) and obtain the moments and probability generating function of this distribution. We also study the maximum likelihood estimation of the parameter θand the variance and the asymptotic bias of the MLE are also obtained. The minimum variance unbiased estimate of θ^ris investigated and an estimate of the probabilities is given.     

Direction and collinearity factors of wilks‘s a - a review

Wilks's A was factorized by Bartlett (1951) for testing the hypothesis of goodness of fit of a hypothetical discriminant function in the case of several groups. This test has applications in various areas such as Econometrics, contingency tables, growth curves, principal components analysis, design of experiments and so on. This paper gives a consolidated account of the research done in these areas on the application of factors of Wilks's A     

Type a incomplete multi-response designs

Srivastava considered the problem of designing and analysis of incomplete multi-response experiments, The main characteristics of the analysis given by her are investigated and a general class of incomplete multiresponse designs (Type A) is obtained on the basis of these investigations.