Online algorithms for maximizing weighted throughput of unit jobs with temperature constraints

We consider a temperature-aware online deadline scheduling model. The objective is to schedule a number of unit jobs, with release dates, deadlines, weights and heat contributions, to maximize the weighted throughput subject to a temperature threshold. We first give an optimally competitive randomized algorithm. Then we give a constant competitive randomized algorithm that allows a tradeoff between the maximum heat contribution of jobs and the competitiveness. Finally we consider the multiple processor case and give several tight upper and lower bounds.     

Goodness of fit tests for the multiple logistic regression model

Several test statistics are proposed for the purpose of assessing the goodness of fit of the multiple logistic regression model. The test statistics are obtained by applying a chi-square test for a contingency table in which the expected frequencies are determined using two different grouping strategies and two different sets of distributional assumptions. The null distributions of these statistics are examined by applying the theory for chi-square tests of Moore Spruill (1975) and through computer simulations. All statistics are shown to have a chi-square distribution or a distribution which can be well approximated by a chi-square. The degrees of freedom are shown to depend on the particular statistic and the distributional assumptions.

The power of each of the proposed statistics is examined for the normal, linear, and exponential alternative models using computer simulations.     

Stress,Anxiety, Resilience and Coping in Social Work Students (A Study from India)

Social work is a stressful occupation but continues to attract large numbers of students every year. This study was conducted by undergraduate students of all three cohorts at a women’s-only college in Tiruchirapalli in South India (N = 73). Standardised instruments to assess stress, anxiety, resilience and coping were administered. It was seen that anxiety and stress levels were relatively higher in the first- and third-year students while compared to those in the second year of their course, while resilience and coping was relatively low in the first-year group. Correlations were significantly positive for the stress and anxiety scores as well as the coping and resilience scores. However, it was seen that only the anxiety scores significantly predicted the manifestation of stress in the students. Implications of the findings and the limitations of the study have also been discussed.     

Matrix Theory Formalism for Event Tree Analysis: Application to Nuclear-Risk Analysis

It is pointed out that the familiar analytical device of "event tree", widely used in risk analysis, can be viewed as a transition matrix expressing the likelihood of going from "entry states" to "exit states". This point of view is shown to have numerous interesting conceptual and computational features which promise to make it a very useful addition to the arsenal of tools for risk analysis. The basic idea is explained first in terms of a simple, made-up example. The application of the idea to a very real and complicated problem, nuclear-plant risk assessment, is then outlined.     

An Alternative Approach to Dietary Exposure Assessment

The method of dietary exposure assessment currently used by the Environmental Protection Agency (EPA), the Dietary Residue Evaluation System (DRES), combines a consumption distribution derived from the United States Department of Agriculture (USDA) 1977-1978 Nationwide Food Consumption Survey (NFCS) with a single estimate of residue level. The National Academy of Sciences'¹' recommended that EPA incorporate both the distribution of residues and the distribution of consumption into their exposure assessment methodology and proposed using a Monte Carlo approach. This paper presents an alternative method, the Joint Distributional Analysis (JDA), that combines the consumption and residue distributions, without relying on random sampling or fitting theoretical distributions like the Monte Carlo method. This method permits simultaneous analysis of the entire diet, including assessing exposure from residues in different foods.     

The Rise and Fall of the Area Dental Officer

Reorganization of the NHS in 1974 sped up the process of professionalization of the leadership of the Community Dental Health Services. Since that event public dental officers have gained status through recognition of the need for specialists in community dental health. Nevertheless, by the beginning of 1982 no trainees had yet been appointed to begin the special training programme, thus far failing the efforts of those area dental officers who have striven since 1974 to raise the standards of their successors.