On Multiprocessor System Scheduling

We show that there is a good algorithm for scheduling the average completion time of a set of unknown DAGs (i.e., data dependency relation graphs of programs) on a multiprocessor in the PRAM model (Karp and Ramachandran, 1990) (orother similar shared memory models.) Then, we show that a large class ofparallel jobs can be scheduled with near-optimal average completion time in the BSP model (Valiant, 1990a) though this is not possible for theclass of all unknown DAGs (Deng and Koutsoupias, 1993) (the same holds forother similar distributed memory models.)     

Negotiating for more than a slice of the pie

Negotiation is an important way for physician executives to manage conflict and to accomplish new projects. Because of the rapidly changing nature of the health care environment, as well as conflicts and politics within their organizations, managers need to effectively negotiate with a wide range of other parties. Managers should consider the relative importance of both the substantive and relationship outcomes of any potential negotiation. These two factors may guide the executive's selection of initial negotiation strategies.     

Graph Algorithms with Small Communication Costs

We study minimizing communication cost in parallel algorithm design, by minimizing the number of communication phases in coarse-grained parallel computers. There have been several recent papers dealing with parallel algorithms of small communication cost under different models. Most of these results are for computational geometry problems. For these problems it has been possible to decompose tasks into appropriate subproblems in a communication-efficient way. It appears to be somewhat more difficult to design parallel algorithms with small communication phases for graph theory problems. In this paper we focus on the design of deterministic algorithms with a small number of communication phases for the list ranking problem and the shortest path problem.     

Validating the Gambling Functional Assessment—Revised in a United Kingdom Sample

The gambling functional assessment-revised (GFA-R) was designed to assess whether the respondent’s gambling was maintained by positive reinforcement or escape. The present study attempted to validate the GFA-R’s psychometric properties using United Kingdom (UK) university students and to compare the results to those from a sample of American university students. Two hundred seventy four UK students completed the GFA-R, and 153 also completed the South Oaks gambling screen (SOGS). Two hundred one United States (US) university students completed both measures. A confirmatory factor analysis indicated that the original model of the GFA-R provided an excellent fit for the UK data and internal consistency was high. These outcomes were similar, if not superior, to those from the US sample. SOGS scores strongly correlated with GFA-R escape subscale scores in both samples, replicating previous results. These findings indicate that the GFA-R is a valid measure for use in the UK, which is potentially useful to both practitioners and researchers. They also suggest that the strong relationship between endorsing gambling as an escape and measures of disordered gambling may be ubiquitous.     

Validation of a Novel Air Toxic Risk Model with Air Monitoring

Three modeling systems were used to estimate human health risks from air pollution: two versions of MNRiskS (for Minnesota Risk Screening), and the USEPA National Air Toxics Assessment (NATA). MNRiskS is a unique cumulative risk modeling system used to assess risks from multiple air toxics, sources, and pathways on a local to a state‐wide scale. In addition, ambient outdoor air monitoring data were available for estimation of risks and comparison with the modeled estimates of air concentrations. Highest air concentrations and estimated risks were generally found in the Minneapolis‐St. Paul metropolitan area and lowest risks in undeveloped rural areas. Emissions from mobile and area (nonpoint) sources created greater estimated risks than emissions from point sources. Highest cancer risks were via ingestion pathway exposures to dioxins and related compounds. Diesel particles, acrolein, and formaldehyde created the highest estimated inhalation health impacts. Model‐estimated air concentrations were generally highest for NATA and lowest for the AERMOD version of MNRiskS. This validation study showed reasonable agreement between available measurements and model predictions, although results varied among pollutants, and predictions were often lower than measurements. The results increased confidence in identifying pollutants, pathways, geographic areas, sources, and receptors of potential concern, and thus provide a basis for informing pollution reduction strategies and focusing efforts on specific pollutants (diesel particles, acrolein, and formaldehyde), geographic areas (urban centers), and source categories (nonpoint sources). The results heighten concerns about risks from food chain exposures to dioxins and PAHs. Risk estimates were sensitive to variations in methodologies for treating emissions, dispersion, deposition, exposure, and toxicity.