Experiments in scientific computation on the PlayStation 3

The Sony PlayStation 3 (PS3) offers the computational power of a parallel processor at low cost, which makes it a great starter unit for development in parallel programming. To explore the capabilities of the unit, we took a simple ray tracing program and extended it to render triangulated height field data across the PS3’s 6 synergistic processing units (SPUs). We also implemented the heat averaging equation as a precursor to CFD analysis on the PS3. In our studies, we found the Cell engine in the PS3 to be a powerful machine, however great care must be taken while developing because its unique platform calls for many levels of optimization to ensure efficiency.     

Estimation and Application of a Production Function in Decision Rules for Swine Producers1

Production functions are estimated for swine based on experimental data designed for the purpose. The functions are estimated with gain as output and corn and protein supplement as inputs. The gain functions are first estimated for five trials with different starting weights. With use of dummy variables, the data are then pooled for estimation of a single overall production function. Among several algebraic forms used in estimation, a quadratic equation was selected for application. Derivation and estimation of gain isoquants are illustrated and comparison is suggested with a previous study where the isoquants are estimated directly by means of an instrumental variable approach to circumvent problems of autocorrelation. The data then are used in a production decision model which considers fluctuating prices.
Des fonctions de production porcine sont estimées à partir de données expéri-mentales developées à cette fin. La fonction de production est représentée par le gain de poids avec le maïs et les supplements de proteine jouant le rôle de variables. Les gains de poids sont dabord estimés sur cinq essais à partir de divers poids ini-tiaux. Les données sont ensuite combinées à l'aide de variables annexes afin destimer une fonction de production générale. Parmi les diverses formes algebriques employées lors de l'estimation une équation quadratique fût sélectionée comme application. L'estimation et l'obtention des isoquantes gain de poids sont présentés. Une comparaison est faite avec une étude antérieure où les isoquantes sont directement estimées à partir de variables instrumentales ce qui évite les problémes d'autocorre-lation. Les donnees servent ensuite dans un model de décision de production qui comprend des fluctuations de prix.     

Use diffusion: An extension and critique

This study demonstrates that exponential modeling applies to the diffusion of foods. By using per capita data rather than gross consumption data, we show that this exponential process is not an artifact of a simultaneous population increase. However, whereas previous researchers predict that use diffusion continues indefinitely though at decreasing rates from one time period to the next, the present study demonstrates that it can end or even reverse, as well as attenuate. The extension of reinforcement theory in psychology to “social learning” theory is rejected as an explanation of this change, and the alternative “technological substitution” model is discussed.     

The relationship of psychological and situational variables to usage of a second-order marketing system

The study of one type of second-order market, personal sales, indicated that various consumer attitudes and merchandising strategies were related to utilization of this market. Similarities and differences between this market and other second-order markets were also noted.     

Don't forget our charge nurses

In response to the nursing shortage, many health care organizations are utilizing a team approach to nursing care delivery. Although, the role of the charge nurse in these changing nursing care delivery models is a pivotal one to the effective and safe management of patient care units, many receive no leadership training. An educational program that hundreds of charge nurses have attended over the past 2 years is described. Strategies that organizations should consider when planning their own training are shared.