Declining Unionization: Do Fringe Benefits Matter?

This study examines whether there is a relationship between benefits and private sector unionization in the US. In their regression analysis, the authors use FRINGE in their as an explanatory variable. The dependent variable is UNIZ, the fraction of the private, non-farm labor force that is unionized. The changing nature of compensation has affected union density. In the private sector, as fringe benefits have become a more prominent component of workers' pay, ceteris paribus, union density has declined nationwide. Over the fifty-year period 1948-1997, at least 12% of the drop in unionization can be attributed to the growing role of non-wage benefits. For the private sector in general and manufacturing in particular, the authors have established that unionization is related to the composition of pay. Yet the influence of non-wage benefits may vary across industries or even different subsectors of manufacturing. It remains to be seen whether there are similar findings for other sectors.

Spacecraft-spacecraft very long baseline interferometry. Part 1: Error modeling and observable accuracy

In Part 1 of this two-part article, an error budget is presented for Earth-based delta differential one-way range (delta DOR) measurements between two spacecraft. Such observations, made between a planetary orbiter (or lander) and another spacecraft approaching that planet, would provide a powerful target-relative angular tracking data type for approach navigation. Accuracies of better than 5 nrad should be possible for a pair of spacecraft with 8.4-GHz downlinks, incorporating 40-MHz DOR tone spacings, while accuracies approaching 1 nrad will be possible if the spacecraft incorporate 32-GHz downlinks with DOR tone spacing on the order of 250 MHz; these accuracies will be available for the last few weeks or months of planetary approach for typical Earth-Mars trajectories. Operational advantages of this data type are discussed, and ground system requirements needed to enable spacecraft-spacecraft delta DOR observations are outlined. This tracking technique could be demonstrated during the final approach phase of the Mars '94 mission, using Mars Observer as the in-orbit reference spacecraft, if the Russian spacecraft includes an 8.4-GHz downlink incorporating DOR tones. Part 2 of this article will present an analysis of predicted targeting accuracy for this scenario

Preparing School Leaders for Special Education: Old Criticisms and New Directions

In the context of accountability and high-stakes testing, professors of educational administration in Texas and across the nation are under tremendous pressure to develop innovative principal preparation programs that produce effective school leaders, especially as research methodologies emerge to disaggregate the effects of such programs. One area few programs adequately address, including more innovative programs, is special education - despite the fact that principals struggle with accountability for all students, but particularly those principals in schools and districts with limited resources and limited professional development opportunitie~ (Bays & Crocket, 2007; Wakeman, Browder, Flowers, & Ahlgrim-Delzell, 2006). Principals have long reported that their preparation programs did not prepare them with the legal and instructional knowledge in the area of special education (DiPaola & Walther-Thomas, 2003; Hirth & Valesky, 1990)

On Type IIA geometries dual to N = 2 SCFTs

We provide explicit solutions of Type IIA supergravity which are believed to be dual to N = 2 superconformal four dimensional gauge theories. These explicit solutions are based on the general ansatz for such a type of backgrounds introduced by Gaiotto and Maldacena.Comment: 23 pages, 10 figures; minor corrections, references correcte

Turbulent transport measurements with a laser Doppler velocimeter

The power spectrum of phototube current from a laser Doppler velocimeter operating in the heterodyne mode has been computed. The spectrum is obtained in terms of the space time correlation function of the fluid. The spectral width and shape predicted by the theory are in agreement with experiment. For normal operating parameters the time average spectrum contains information only for times shorter than the Lagrangian integral time scale of the turbulence. To examine the long time behavior, one must use either extremely small scattering angles, much longer wavelength radiation or a different mode of signal analysis, e.g., FM detection

On the temperature of surfaces

The concept of the temperature of a surface is introduced from the viewpoint of the physical chemistry of surfaces. The surface, near surface and microlayer regions of the interface are defined. Most methods measure the temperature of the microlayer or at best the near surface region and may err in representing the surface temperature. Methods based on capillary ripples actually measure the surface temperature since surface tension (or surface tension tensor when a monolayer has been spread or absorbed at the interface) is the main restoring force that controls their propagation. Light scattering methods are described for determining the elevation of very small amplitude capillary waves through the computation of various correlation functions from which the surface tension can be estimated. Procedures for estimating the surface temperature are described

Time-marching transonic flutter solutions including angle-of-attack effects

Transonic aeroelastic solutions based upon the transonic small perturbation potential equation were studied. Time-marching transient solutions of plunging and pitching airfoils were analyzed using a complex exponential modal identification technique, and seven alternative integration techniques for the structural equations were evaluated. The HYTRAN2 code was used to determine transonic flutter boundaries versus Mach number and angle-of-attack for NACA 64A010 and MBB A-3 airfoils. In the code, a monotone differencing method, which eliminates leading edge expansion shocks, is used to solve the potential equation. When the effect of static pitching moment upon the angle-of-attack is included, the MBB A-3 airfoil can have multiple flutter speeds at a given Mach number

The goldstone real-time connected element interferometer

Connected element interferometry (CEI) is a technique of observing a celestial radio source at two spatially separated antennas and then interfering the received signals to extract the relative phase of the signal at the two antennas. The high precision of the resulting phase delay data type can provide an accurate determination of the angular position of the radio source relative to the baseline vector between the two stations. This article describes a recently developed connected element interferometer on a 21-km baseline between two antennas at the Deep Space Network's Goldstone, California, tracking complex. Fiber-optic links are used to transmit the data to a common site for processing. The system incorporates a real-time correlator to process these data in real time. The architecture of the system is described, and observational data are presented to characterize the potential performance of such a system. The real-time processing capability offers potential advantages in terms of increased reliability and improved delivery of navigational data for time-critical operations. Angular accuracies of 50-100 nrad are achievable on this baseline