3,507 research outputs found

    Payload shrouds structural optimization study Final report

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    Computer programs for synthesizing structural arrangements for ring-stiffened, honeycomb sandwich, and ring-stringer stiffened methods of construction for Saturn nose fairing

    Natural Philosophy or Science in Premodern Epistemic Regimes? The Case of the Astrology of Albert the Great and Galileo Galilei

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    Scholarly attempts to analyze the history of science sometime suffer from an imprecise use of terms. In order to understand accurately how science has developed and from where it draws its roots, researchers should be careful to recognize that epistemic regimes change over time and acceptable forms of knowledge production are contingent upon the hegemonic discourse informing the epistemic regime of any given period. In order to understand the importance of this point, I apply the techniques of historical epistemology to an analysis of the place of the study of astrology in the medieval and early modern periods alongside a discussion of the “language games” of these period as well as the role of the “archeology of knowledge” in uncovering meaning in our study of the past. In sum, I argue that the term “science” should never be used when studying approaches to knowledge formation prior to the seventeenth century

    The California Red Sea Urchin, Strongylocentrotus franciscanus, Fishery: Catch, Effort, and Management Trends

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    California's red sea urchin, Strongylocentrotus franciscanus, catch peaked at 23,577 metric tons (t) in 1988. Since then, catches and CPUE have trended downward at different rates in northern and southern California, with 10,086 t landed statewide in 1995. West coast sea urchin catches and CPUE from British Columbia, Can., to Baja California, Mex., have generally declined during this period which followed a decade of rapid fishery expansion. This expansion was in response to increasing demand from Japan fueled by rising prices based largely on a more favorable export currency exchange rate. West coast stock assessment methods have been based on integrating a combination of fisheries dependent data and population surveys into models at various levels of complexity. California management policy has centered on technical measures such as size limits and seasonal closures and has been largely ineffective in stabilizing declining catches

    Apollo experience report: Command and service module electrical power distribution on subsystem

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    A review of the design philosophy and development of the Apollo command and service modules electrical power distribution subsystem, a brief history of the evolution of the total system, and some of the more significant components within the system are discussed. The electrical power distribution primarily consisted of individual control units, interconnecting units, and associated protective devices. Because each unit within the system operated more or less independently of other units, the discussion of the subsystem proceeds generally in descending order of complexity; the discussion begins with the total system, progresses to the individual units of the system, and concludes with the components within the units

    Defining adaptation in a generic multi layer model : CAM: the GRAPPLE conceptual adaptation model

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    Authoring of Adaptive Hypermedia is a difficult and time consuming task. Reference models like LAOS and AHAM separate adaptation and content in different layers. Systems like AHA! offer graphical tools based on these models to allow authors to define adaptation without knowing any adaptation language. The adaptation that can be defined using such tools is still limited. Authoring systems like MOT are more flexible, but usability of adaptation specification is low. This paper proposes a more generic model which allows the adaptation to be defined in an arbitrary number of layers, where adaptation is expressed in terms of relationships between concepts. This model allows the creation of more powerful yet easier to use graphical authoring tools. This paper presents the structure of the Conceptual Adaptation Models used in adaptive applications created within the GRAPPLE adaptive learning environment, and their representation in a graphical authoring tool

    Defining adaptation in a generic multi layer model : CAM: the GRAPPLE conceptual adaptation model

    Get PDF
    Authoring of Adaptive Hypermedia is a difficult and time consuming task. Reference models like LAOS and AHAM separate adaptation and content in different layers. Systems like AHA! offer graphical tools based on these models to allow authors to define adaptation without knowing any adaptation language. The adaptation that can be defined using such tools is still limited. Authoring systems like MOT are more flexible, but usability of adaptation specification is low. This paper proposes a more generic model which allows the adaptation to be defined in an arbitrary number of layers, where adaptation is expressed in terms of relationships between concepts. This model allows the creation of more powerful yet easier to use graphical authoring tools. This paper presents the structure of the Conceptual Adaptation Models used in adaptive applications created within the GRAPPLE adaptive learning environment, and their representation in a graphical authoring tool

    Property Law Innovation in Latin America with Recommendations

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    Screen Exposure and BMI Status in 2-11 Year Old Children

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    Objective. To measure the relationship between screen exposure and obesity in a large, urban sample of children and to examine whether the relationship is moderated by sociodemographics. Methods. We asked parents of 11 141 children visiting general pediatrics clinics if the child had a television (TV) in the bedroom and/or watched more than 2 hours of TV/computer daily. We measured children’s height and weight, then used logistic regression to determine whether screen exposure indicators predicted obesity (body mass index ≥85th percentile) and interacted with race/ethnicity, sex, age, and health care payer. Results. Having a TV in the bedroom predicted obesity risk (P = .01); however, watching TV/computer for more than 2 hours a day did not (P = 0.54). There were no interactions. Conclusions. Asking whether a child has a TV in the bedroom may be more important than asking about duration of screen exposure to predict risk for obesity

    Magnetospheric considerations for solar system ice state

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    The current lattice configuration of the water ice on the surfaces of the inner satellites of Jupiter and Saturn is likely shaped by many factors. But laboratory experiments have found that energetic proton irradiation can cause a transition in the structure of pure water ice from crystalline to amorphous. It is not known to what extent this process is competitive with other processes in solar system contexts. For example, surface regions that are rich in water ice may be too warm for this effect to be important, even if the energetic proton bombardment rate is very high. In this paper, we make predictions, based on particle flux levels and other considerations, about where in the magnetospheres of Jupiter and Saturn the ∼MeV proton irradiation mechanism should be most relevant. Our results support the conclusions of Hansen and McCord (2004), who related relative level of radiation on the three outer Galilean satellites to the amorphous ice content within the top 1 mm of surface. We argue here that if magnetospheric effects are considered more carefully, the correlation is even more compelling. Crystalline ice is by far the dominant ice state detected on the inner Saturnian satellites and, as we show here, the flux of bombarding energetic protons onto these bodies is much smaller than at the inner Jovian satellites. Therefore, the ice on the Saturnian satellites also corroborates the correlation

    Pediatricians’ Responses to Printed Clinical Reminders: Does Highlighting Prompts Improve Responsiveness?

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    Objective Physicians typically respond to roughly half of the clinical decision support prompts they receive. This study was designed to test the hypothesis that selectively highlighting prompts in yellow would improve physicians' responsiveness. Methods We conducted a randomized controlled trial using the Child Health Improvement Through Computer Automation clinical decision support system in 4 urban primary care pediatric clinics. Half of a set of electronic prompts of interest was highlighted in yellow when presented to physicians in 2 clinics. The other half of the prompts was highlighted when presented to physicians in the other 2 clinics. Analyses compared physician responsiveness to the 2 randomized sets of prompts: highlighted versus not highlighted. Additionally, several prompts deemed high priority were highlighted during the entire study period in all clinics. Physician response rates to the high-priority highlighted prompts were compared to response rates for those prompts from the year before the study period, when they were not highlighted. Results Physicians did not respond to prompts that were highlighted at higher rates than prompts that were not highlighted (62% and 61%, respectively; odds ratio 1.056, P = .259, NS). Similarly, physicians were no more likely to respond to high-priority prompts that were highlighted compared to the year before, when the prompts were not highlighted (59% and 59%, respectively, χ2 = 0.067, P = .796, NS). Conclusions Highlighting reminder prompts did not increase physicians' responsiveness. We provide possible explanations why highlighting did not improve responsiveness and offer alternative strategies to increasing physician responsiveness to prompts
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