27,807 research outputs found
Project Management in NASA: The system and the men
An analytical description of the NASA project management system is presented with emphasis on the human element. The NASA concept of project management, program managers, and the problems and strengths of the NASA system are discussed
Spin-other-orbit matrix elements for f sup 4 configurations
Data for spin orbit matrix elements for f to 4th power configuratio
Configuration interaction matrix elements for d sup n configurations
Configuration interaction matrix elements for weak interaction
Matrix elements of the spin-spin interactions for f sup 4 configurations
Matrix elements of spin-spin interactions for F4 electron configuration
Matrix elements of atomic interaction operators for d sup n configurations
Tabulation of matrix elements of atomic interaction operators for various configuration
Coordinate Confusion in Conformal Cosmology
A straight-forward interpretation of standard
Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies is that objects move
apart due to the expansion of space, and that sufficiently distant galaxies
must be receding at velocities exceeding the speed of light. Recently, however,
it has been suggested that a simple transformation into conformal coordinates
can remove superluminal recession velocities, and hence the concept of the
expansion of space should be abandoned. This work demonstrates that such
conformal transformations do not eliminate superluminal recession velocities
for open or flat matter-only FRLW cosmologies, and all possess superluminal
expansion. Hence, the attack on the concept of the expansion of space based on
this is poorly founded. This work concludes by emphasizing that the expansion
of space is perfectly valid in the general relativistic framework, however,
asking the question of whether space really expands is a futile exercise.Comment: 5 pages, accepted for publication in MNRAS Letter
A Pilot Study to Measure Upper Extremity H-reflexes Following Neuromuscular Electrical Stimulation Therapy after Stroke
Upper extremity (UE) hemiparesis persists after stroke, limiting hand function. Neuromuscular electrical stimulation (NMES) is an effective intervention to improve UE recovery, although the underlying mechanisms are not fully understood. Our objective was to establish a reliable protocol to measure UE agonist–antagonist forearm monosynaptic reflexes in a pilot study to determine if NMES improves wrist function after stroke. We established the between-day reliability of the H-reflex in the extensor carpi radialis longus (ECRL) and flexor carpi radialis (FCR) musculature for individuals with prior stroke (n = 18). The same-day generation of ECRL/FCR H-reflex recruitment curves was well tolerated, regardless of age or UE spasticity. The between-day reliability of the ECRL H-reflex was enhanced above FCR, similar to healthy subjects [20], with the Hmax the most reliable parameter quantified in both muscles. H-reflex and functional measures following NMES show the potential for NMES-induced increases in ECRL Hmax, but confirmation requires a larger clinical study. Our initial results support the safe, easy, and efficacious use of in-home NMES, and establish a potential method to measure UE monosynaptic reflexes after stroke
Measuring Attitudes towards Public Spending using a Multivariate Tax Summary Experiment
It is difficult to measure public views on tradeoffs between spending priorities because public understanding of existing government spending is limited and the budgetary problem is complicated. We present a new measurement strategy using UK taxpayer summaries as the baseline for a continuous treatment, multivariate choice experiment. The experiment proposes deficit neutral bundles of changes in spending and taxation, allowing us to investigate attitudes towards modifications to the existing budget. We then use a structural choice model to estimate public preferences over 13 spending categories and the taxation level, on average and as a function of respondent attributes. We find that the UK public favours paying more in tax to finance large spending increases across major budget categories; that spending preferences are multidimensional; and that younger people prefer lower levels of taxation and spending than older people. Finally, we report a pre-registered out-of-sample validation of the estimates from the experiment
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