15,100 research outputs found
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The Senior Executive Service: Background and Options for Reform
[Excerpt] The Senior Executive Service (SES) was established by the Civil Service Reform Act of 1978 (CSRA; P.L. 95-454, 92 Stat. 1111). Congress created the SES to provide a government-wide, mobile corps of managers within federal agencies. The SES, comprising mostly career appointees who are chosen through a merit staffing process, is the link between the politically appointed heads of agencies and the career civil servants within those agencies. The creators of the SES envisioned it as a cadre of high-level managers in the government who would provide leadership for agencies across administrations and ensure productivity and efficiency within the government. The CSRA incentivized good performance among senior executives by basing their compensation on their performance.
Over the three decades of the SES’s operation, various ideas and suggestions have been offered as to how it may be improved. Although a few statutory changes have been implemented since its creation, many argue that the current state of the SES calls for more comprehensive reforms. The most recent change made to the SES was a revision of its pay system enacted in 2004. Advocates for additional changes to the SES argue that further changes would improve the efficiency and the management of government programs and the government workforce. Some of the changes they call for include improvement in recruiting efforts, more opportunities for onboard training and career development of senior executives, and further changes to the current pay structure.
This report provides a history and background of the SES, examines the central features of the SES, and discusses some areas in which advocates for SES reform have called for change
Stochastic pumping of heat: Approaching the Carnot efficiency
Random noise can generate a unidirectional heat current across asymmetric
nano objects in the absence (or against) a temperature gradient. We present a
minimal model for a molecular-level stochastic heat pump that may operate
arbitrarily close to the Carnot efficiency. The model consists a fluctuating
molecular unit coupled to two solids characterized by distinct phonon spectral
properties. Heat pumping persists for a broad range of system and bath
parameters. Furthermore, by filtering the reservoirs' phonons the pump
efficiency can approach the Carnot limit
Quantum Hall Effect on the Hyperbolic Plane
In this paper, we study both the continuous model and the discrete model of
the Quantum Hall Effect (QHE) on the hyperbolic plane. The Hall conductivity is
identified as a geometric invariant associated to an imprimitivity algebra of
observables. We define a twisted analogue of the Kasparov map, which enables us
to use the pairing between -theory and cyclic cohomology theory, to identify
this geometric invariant with a topological index, thereby proving the
integrality of the Hall conductivity in this case.Comment: AMS-LaTeX, 28 page
Twisted K-theory and finite-dimensional approximation
We provide a finite-dimensional model of the twisted K-group twisted by any
degree three integral cohomology class of a CW complex. One key to the model is
Furuta's generalized vector bundle, and the other is a finite-dimensional
approximation of Fredholm operators.Comment: 26 pages, LaTeX 2e, Xypic; main theorem improve
Primary transit of the planet HD189733b at 3.6 and 5.8 microns
The hot Jupiter HD 189733b was observed during its primary transit using the
Infrared Array Camera on the Spitzer Space Telescope. The transit depths were
measured simultaneously at 3.6 and 5.8 microns. Our analysis yields values of
2.356 +- 0.019 % and 2.436 +- 0.020$ % at 3.6 and 5.8 microns respectively, for
a uniform source. We estimated the contribution of the limb-darkening and
star-spot effects on the final results. We concluded that although the limb
darkening increases by ~0.02-0.03 % the transit depths, and the differential
effects between the two IRAC bands is even smaller, 0.01 %. Furthermore, the
host star is known to be an active spotted K star with observed photometric
modulation. If we adopt an extreme model of 20 % coverage with spots 1000K
cooler of the star surface, it will make the observed transits shallower by
0.19 and 0.18 %. The difference between the two bands will be only of 0.01 %,
in the opposite direction to the limb darkening correction. If the transit
depth is affected by limb darkening and spots, the differential effects between
the 3.6 and 5.8 microns bands are very small. The differential transit depths
at 3.6 and 5.8 microns and the recent one published by Knutson et al.(2007) at
8 microns are in agreement with the presence of water vapour in the upper
atmosphere of the planet. This is the companion paper to Tinetti et al.
(2007b), where the detailed atmosphere models are presented.Comment: 6 pages, 4 figures, Astrophysical Journal 675. Accepted Nov 21,
20007, to appear on March 10, 200
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VA Accountability Act of 2015 (H.R. 1994), as Reported to the House
[Excerpt] This report describes the VA Accountability Act of 2015 (H.R. 1994) as reported to the House by the Committee on Veterans Affairs on July 23 2015 and compares it to current law where appropriate. A press account has reported that Chairman Jeff Miller may meet with all committee members to seek views of the minority before floor action. As a result of this meeting, it is possible that the final bill that will go to the House floor may have some provisions that differ from those that the Committee reported.
This report provides a section-by-section description of the act
Simulation model of a twin-tail, high performance airplane
The mathematical model and associated computer program to simulate a twin-tailed high performance fighter airplane (McDonnell Douglas F/A-18) are described. The simulation program is written in the Advanced Continuous Simulation Language. The simulation math model includes the nonlinear six degree-of-freedom rigid-body equations, an engine model, sensors, and first order actuators with rate and position limiting. A simplified form of the F/A-18 digital control laws (version 8.3.3) are implemented. The simulated control law includes only inner loop augmentation in the up and away flight mode. The aerodynamic forces and moments are calculated from a wind-tunnel-derived database using table look-ups with linear interpolation. The aerodynamic database has an angle-of-attack range of -10 to +90 and a sideslip range of -20 to +20 degrees. The effects of elastic deformation are incorporated in a quasi-static-elastic manner. Elastic degrees of freedom are not actively simulated. In the engine model, the throttle-commanded steady-state thrust level and the dynamic response characteristics of the engine are based on airflow rate as determined from a table look-up. Afterburner dynamics are switched in at a threshold based on the engine airflow and commanded thrust
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