21,378 research outputs found
Estimating the Underlying Infant Mortality Rates for Small Populations, Even Those Reporting Zero Infant Deaths: a Case Study of 66 Local Health Areas in British Columbia
FEATS - Finite element thermal stress analysis of plane or axisymmetric solids
FEATS computer code uses finite element analysis to calculate steady state temperature and thermal stress fields for either axisymmetric or plane two-dimensional bodies with boundary conditions, including specified displacements, loads, and thermal boundary conditions
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The role of education in vertebrate pest control
Lack of adequate information is emphasized as a major problem in attaining effective control of damage by vertebrate pests, and it is stressed that the problem is widespread in all elements of the public, including those directly involved, like producers and government officials, as well as those only indirectly involved, like the average citizen. A number of specific examples are cited to illustrate the problems of uninformed or inadequately informed publics
General series solution technique for bending of irregular laterally loaded flat plates
Computer program calculates the stresses and lateral deflections to a uniform thickness flat plate with a uniform pressure load. The plate to be analyzed may have several different boundary conditions. The program is written in FORTRAN 4 for use on the CDC 6600 computer
Langley experience with ADABAS/NATURAL
The use of the data base management system ADABAS and the companion software NATURAL and COM-PLETE at the Langley Research Center is evaluated. A brief overview of data base management system technology is provided as well as system upgrading, user requirements, and use of the system for administrative support
The WTP for property rights for the Giant Panda: can a charismatic species be an instrument for conservation of natural habitat?
The paper presents the results from a stated preference study to address issues concerning the potential for using flag-ship species, such as the Giant Panda, to purchase the property rights for the conservation of natural habitat. The study finds, first, that there is clear WTP for acquiring the property rights for panda habitat. The nature of this demand is found both convincing and logically coherent in that it is an increasing function of land
(at a diminishing rate). Secondly, the study decomposed the elicited values into genetic stock, animal welfare and implicit biodiversity values. The results show that the latter type of value consist of almost half of total value implying that the Panda is in fact a potential instrument for greater biodiversity conservation. Thirdly, the study shows that these implicit biodiversity values are dependent on the preservation of the flagship species itself, implying that the panda is not only a potential instrument for habitat conservation, but a necessary one. Finally, the extent to which the flagship approach can be capable of contributing to wider biodiversity conservation is discussed
Some volcanologic aspects of Columbia River basalt volcanism relevant to the extinction controversy
The Columbia River Basalt Group is the youngest and most thoroughly studied flood-basalt province known; information about it should be relevant to questions about the possible relation of flood-basalt volcanism to mass extinctions. The group has a total volume of about 174,000 cu km and covers an area of about 164,000 sq km. It was erupted between 17.5 and 6 Ma, as measured by K-Ar and Ar-40/Ar-39 dates. Early eruptions formed the Imnaha Basalt. More than 85 percent of the group was produced during a 1.5 my period between 17 and 15.5 Ma, forming the Grande Ronde and greatly subordinate Picture Gorge Basalts. Later flows formed the Wanapum Basalt, which includes the well-known Roza Member, and the Saddle Mountains Basalt. Linear vent systems for many of the flows are known and are located only in the eastern third of the Columbia Plateau. No systematic migration of vents occurred throughout the 11.5 my period of activity; this and other considerations make it unlikely that the province is related to a hot spot. Model calculations based on observations that little cooling occurred during flow of hundreds of kilometers suggest eruption and emplacement durations of a few days. Some voluminous flows occur in all formations, but most such flows apparently were erupted during Grande Ronde time. The eruption and emplacement of more than 1,000 cu km of 1100 C basaltic lava on the surface within several days doubtless had at least local meteorologic effects. Whether the effects were broader can at present only be hypothesized. Grande Ronde Basalt and Picture Gorge Basalts contain moderately common but thin sedimentary interbeds between flows, whereas earlier and later formations contain numerous, locally thick sediment accumulations. Volcaniclastic debris derived from extra-plateau sources commonly occurs in the testbeds
Response Criterion Placement Modulates the Effects of Graded Alerting Systems on Human Performance and Learning in a Target Detection Task
Human operators can perform better with the use of an automated diagnostic aid than without the use of an aid in a signal detection task. This experiment aimed to determine whether any differences existed among graded aidsâautomated diagnostic aids that use a scale of confidence levels reflecting a spectrum of probabilistic information or uncertainty when making a judgmentâthat enabled better human detection performance, and either binary or graded aid produced better learning. Participants performed a visual search framed as a medical decision making task. Stimuli were arrays of random polygons (âcellsâ) generated by distorting a prototype shape. The target was a shape more strongly distorted than the accompanying distracters. A target was present on half of the trials. Each participant performed the task with the assistance of either a binary aid, one of three graded aids, or no aid. The aidsâ sensitivities were the same (dⲠ= 2); the difference between the aids lay in the placement of their decision criteria, which determines a tradeoff between the aidâs predictive value and the frequency with which it makes a diagnosis. The graded aid with 90% reliability provided a judgment on the greatest number of trials, the graded aid with 94% reliability gave a judgment on fewer trials, and the third graded aid with 96% reliability gave a judgment on the least number of trials. The binary aid with 84% reliability gave a judgment on each trial. All aids improved human detection performance, though the graded aids trended towards improving performance more than the binary aid. The binary and graded aids did not produce significantly better or worse learning than did unaided performance. The binary and graded aids did not significantly help learning, but they certainly did not worsen human detection performance when compared to the unaided condition. These results imply that the decision boundaries of a graded alert might be fixed to encourage appropriate reliance on the aid and improve human detection performance, and indicate employing either a graded or binary automated aid may be beneficial to learning in a detection task
Life prediction and constitutive models for engine hot section anisotropic materials program
The purpose is to develop life prediction models for coated anisotropic materials used in gas temperature airfoils. Two single crystal alloys and two coatings are now being tested. These include PWA 1480; Alloy 185; overlay coating, PWA 286; and aluminide coating, PWA 273. Constitutive models are also being developed for these materials to predict the plastic and creep strain histories of the materials in the lab tests and for actual design conditions. This nonlinear material behavior is particularily important for high temperature gas turbine applications and is basic to any life prediction system
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