3,076 research outputs found
Expandable space frames
Expandable space frames having essentially infinite periodicity limited only by practical considerations, are described. Each expandable space frame comprises a plurality of hinge joint assemblies having arms that extend outwardly in predetermined symmetrically related directions from a central or vertex point. The outer ends of the arms form one part of a hinge point. The outer expandable space frame also comprises a plurality of struts. The outer ends of the struts from the other part of the hinged joint. The struts interconnect the plurality of hinge point in sychronism, the spaceframes can be expanded or collapsed. Three-dimensional as well as two-dimensional spaceframes of this general nature are described
A diminishing population whose every cohort more than replaces itself
We observe that a dynamic population model can have period fertility that is always below replacement and cohort fertility that is always above replacement. We ask whether such a paradoxical population will get larger or smaller, and show that it must become smaller. Cohort replacement does not imply population replacement, and emphasizing fertility timing and cohort fertility ignores the issue of relative cohort size. The resolution of this apparent paradox reinforces the importance of the level of period fertility in demographic analysis.Bongaarts-Feeney adjusted fertility, cohort, cohort fertility, dynamic population model, fertility, fertility timing, period fertility
Estimating multistate transition rates from population distributions
The ability to estimate transition rates (or probabilities) from population distributions has many potential applications in demography. Iterative Proportional Fitting (IPF) has been used for such estimation, but lacks a meaningful behavioral, or demographic, foundation. Here a new approach, Relative State Attractiveness (RSA), is advanced. It assumes that states become more (or less) attractive, and that rates respond accordingly. The RSA estimation procedure is developed and applied to model and actual data where the underlying rates are known. Results show that RSA provides accurate estimates under a wide range of conditions, usually yielding values similar to those produced by IPF. Both methods are then applied to U.S. data to provide new estimates of interregional migration between the years 1980 and 1990.entropy, estimation techniques, iterative proportional fitting, multistate models
Existence, Regularity, and Properties of Generalized Apparent Horizons
We prove a conjecture of Tom Ilmanen's and Hubert Bray's regarding the
existence of the outermost generalized apparent horizon in an initial data set
and that it is outer area minimizing.Comment: 16 pages, thoroughly revised, no major changes, to appear in Comm.
Math. Phy
VASCOMP 2. The V/STOL aircraft sizing and performance computer program. Volume 6: User's manual, revision 3
This report describes the use of the V/STOL Aircraft Sizing and Performance Computer Program (VASCOMP II). The program is useful in performing aircraft parametric studies in a quick and cost efficient manner. Problem formulation and data development were performed by the Boeing Vertol Company and reflects the present preliminary design technology. The computer program, written in FORTRAN IV, has a broad range of input parameters, to enable investigation of a wide variety of aircraft. User oriented features of the program include minimized input requirements, diagnostic capabilities, and various options for program flexibility
Utilization requirements. A southern California Gas Company project SAGE report: Utilization requirements
Utilization requirements are given and comparisons made of two phase III SAGE (solar assisted gas energy) installations in California: (1) a retrofit installation in an existing apartment building in El Toro, and (2) an installation in a new apartment building in Upland. Such testing in the field revealed the requirements to be met if SAGE-type installations are to become commercially practical on a widespread basis in electric and gas energy usage
Expandable space frames
Frame consists of struts connected by hinge joint assemblies. Because struts are hinged, entire frame can be collapsed during transportation and expanded at construction site. Frame has two types of hinge joint assemblies; one for three-dimensional space frame expansion and another for two-dimensional expansion
State Trends in Premiums and Deductibles, 2003-2009: How Building on the Affordable Care Act Will Help Stem the Tide of Rising Costs and Eroding Benefits
Examines 2003-09 state trends in family coverage premiums and deductibles for private employers. Looks at projected savings on premiums if the 2010 healthcare reform succeeds in slowing growth by 1 percentage point annually and weighs policy implications
Aiming Higher: Results From a State Scorecard on Health System Performance, 2009
Ranks states on thirty-eight indicators of healthcare access, prevention and treatment, avoidable hospital use and costs, equity, and healthy lives. Examines trends, including eroding adult insurance coverage, poor care coordination, and rising costs
Securing a Healthy Future: The Commonwealth Fund State Scorecard on Child Health System Performance, 2011
Ranks states on twenty indicators of healthcare access, affordability, prevention and treatment, potential for healthy lives, and health system equity for children. Examines the need for targeted initiatives and policy implications for better performance
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