On concave entropies of discrete systems

A new class of entropy functions of discrete systems, the class of concave entropies, is introduced. Each concave entropy function satisfies the fundamental axioms of general entropies. The Shannon and trigonometric entropies belong to the class of concave entropies. Each of the classes of Renyi and polynomial entropies contains a subclass of concave entropies. A sufficient condition is given, under which the total entropy tends to ∞, when the number N of probability components approaches ∞.     

Stress and coping of adults and young adults in economically uncertain rural areas

This paper discusses the degree and type of stress experienced by adults and young adults, coping strategies used, and their family, financial, and community satisfaction in economically distressed rural counties. Data were analyzed from questionnaires completed by 447 adults and 118 young adults. Results indicate greater perceived stress, use of some less effective coping strategies, and less satisfaction among young adults. Both groups indicate similar numbers of stressful events and a generally positive perception of community social services.Dorothy Z. Price received her Ph.D. from Michigan State University. She is a Professor, Department of Child & Family Studies, Washington State University, Pullman, WA 99164-2010. Research interests include decision-making and consumer behavior.Lonnie J. Dunlap, M.A. is a Graduate Research Assistant, Interdisciplinary Ph.D. Program, Department of Child & Family Studies, Washington State University, Pullman, WA 99164-2010. Research interests include work and family interactions and career development.     

Emissions from Mass Burn Resource Recovery Facilities

Recent resource recovery facility stack tests have increased the available pool of data on emissions from these facilities. This has led to more accurate predictions of emissions from proposed facilities. The source, type, and rate of emissions presented are based upon a review of the literature, theoretical approaches, stack test data from existing facilities, permit levels of other facilities, and discussions with equipment manufacturers. The pollutants selected for study are those regulated by United States Environmental Protection Agency (USEPA) Prevention of Significant Deterioration (PSD) regulations and other pollutants of concern. The pollutants studied are particulate matter, sulfur dioxide, nitrogen oxides, carbon monoxide, nonmethane hydrocarbons, hydrogen sulfide, reduced sulfide, reduced sulfur compounds, total reduced sulfur, lead, mercury, beryllium, arsenic, cadmium, chromium, chromium +6, copper, manganese, nickel, vanadium, zinc, hydrogen chloride, fluorides, sulfuric acid mist, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, vinyl chloride, dioxins, furans, formaldehyde, and asbestos.     

Bayes procedures for detecting a shift in the probability of success in a series of Bernoulli trials

The determination of a stopping rule for the detection of the time of an increase in the success probability of a sequence of independent Bernoulli trials is discussed. Both success probabilities are assumed unknown. A Bayesian approach is applied; the distribution of the location of the shift in the success probability is assumed geometric and the success probabilities are assumed to have known joint prior distribution. The costs involved are penalties for late or early stoppings. The nature of the optimal dynamic programming solution is discussed and a procedure for obtaining a suboptimal stopping rule is determined. The results indicate that the detection procedure is quite effective.     

Lactational Transfer of Tetrachloroethylene in Rats

Tetrachloroethylene (PCE) is a commonly used organic solvent and a suspected human carcinogen, reportedly transferred to human breast milk following inhalation exposure. Transfer of PCE to milk may represent a threat to the nursing infant. A physiologically based pharmacokinetic (PBPK) model was developed to quantitatively assess the transfer of inhaled PCE into breast milk and the consequent exposure of the nursing infant. The model was validated in lactating rats. Lactating Sprague-Dawley female rats were exposed via inhalation to PCE at concentrations ranging from 20-1000 ppm, and then returned to their nursing, 10- to 11-day-old pups. Tetrachloroethylene concentrations in the air, blood, milk, and tissue were determined by gas chromatography and compared to model predictions. The model described the distribution of inhaled PCE in maternal blood and milk, as well as the nursed pup's gastrointestinal tract, blood, and tissue. Several computer simulations of PCE distribution kinetics in exhaled air, blood, and milk of exposed human subjects were run and compared with limited human data available from the literature. It is concluded that the PBPK model successfully described the concentration of PCE in both lactating rats and humans. Although predictions vs. observations were good, the model slightly underpredicted the peak whole pup PCE concentration and underpredicted systemic clearance of PCE from the pup.     

A characterization of probability distributions similar to the exponential

A concept of the lack-of-memory property at a given time point c > 0 is introduced. It is equivalent to the concept of the almost-lack-of-memory (ALM) property of the random variables. A representation theorem is given for the cumulative distribution function of such random variables as well as for corresponding decompositions in terms of independent random variables. It is shown that a periodic failure rate for a random variable is equivalent to the ALM property. In addition some properties of the service time of an unreliable server are observed.