The Composition of Strike Activity in the Construction Industry

This study shows that strikes in construction have, by most measures, increased during the years since 1949, a period during which strike activity tended to decline in American industry as a whole. The authors demonstrate that this increase has resulted not from an increase in the number of wage disputes but from a growing number of jurisdictional strikes and the increasing severity of economic and union-organizing strikes. They also show that the number of strikes in construction does not vary significantly with the unemployment rate in that industry nor with the presence of wage controls, but both of those factors have a significant impact on the composition of strike activity in construction

Development and use of a linear momentum exchange device

In 1981 the Marshall Space Flight Center (MSFC) began establishing an inhouse facility for testing control concepts to be applied to Large Space Structures (LSS). The original concept called for a long flexible beam suspended from the ceiling by a low friction support system. The lower end of the beam was to be mounted to the Advanced Gimbal System (AGS). Analysis and system engineering soon showed that a more tenable design would be where the whole system was inverted, i.e., the AGS hung from the ceiling with the beam hanging down from it. While this configuration, augmented by a base excitation table (RET) was being built, an ASTROMAST obtained from the Jet Propulsion Laboratory was extended, analyzed and tested. From that basic configuration was evolved the cruciform, VCOSS and ACES configurations as shown. The addition of the cruciform added low frequency nested modes and the additional instrument package at the tip contains gyros to monitor tip motion

Between a Rock and a Hard Place: Games Coverage and its Network of Ambivalences

It's as tough a time as ever for game critics, who seem to be stuck between a rock and a hard place—an industry that acts as gatekeepers to most of the information they cover and an increasingly combative readership. Because of these tensions, an exploratory study was conducted first of the emergence of game criticism and the historical role of critics in creating the conception of gamer identity and, second, the effect of that identity on critics’ self-perception of their profession. We find that throughout the late 1980s and the end of the 20th century the game press was complicit in reinforcing the notion of the hardcore, primarily male “gamer,” while at the same time wrestling with their role as mediators between the industry and audience to which they were beholden. Through a subsequent study of articles and public meta-criticism by prominent figures in the field, we describe a network of ambivalences over the basic elements of their practice—particularly style, content, and format—as well as what motivates their daily work. In order to cope with these ambivalences, game critics, in recommending changes to their craft, rely not on the occupational ideology—or a common set of shared professional values—but instead their personal background and ancillary careers. Finally, after reviewing this network of ambivalences and its effect on games writing, we suggest critics make efforts toward establishing a common critical authority for their field, particularly as their occupation enters the mainstream

Vladivostok and beyond: SALT I and the propects for SALT II

Journal ArticleThe tortuously constricted boundaries within which the Vladivostok agreement can be considered as an advance toward the goal of arms reduction and stability remind us once again that technology unconstrained by law inexorably limits that arena within which we enjoy the capacity to control our own future

Alignment-insensitive coupling for PLC-based surface mount photonics

A flip-chip waveguide coupler with an order of magnitude greater alignment tolerance than competing approaches is presented for the first time. Experimental data for an "optical jumper" agree with simple design considerations. Application to a planar lightwave circuit-based surface mount photonics platform is outlined

G3-RAD and G3X-RAD: Modified Gaussian-3 (G3) and Gaussian-3X (G3X) procedures for radical thermochemistry

The G3-RAD, G3X-RAD, G3(MP2)-RAD, and G3X(MP2)-RAD, procedures, designed particularly for the prediction of reliable thermochemistry for free radicals, are formulated and their performance assessed using the G2/97 test set. The principal features of the RAD procedures include (a) the use of B3-LYP geometries and vibrational frequencies (in place of UHF and UMP2), including the scaling of vibrational frequencies so as to reproduce ZPVEs, (b) the use of URCCSD(T) [in place of UQCISD(T)] as the highest-level correlation procedure, and (c) the use of RMP (in place of UMP) to approximate basis-set-extension effects. G3-RAD and G3X-RAD are found to perform well overall with mean absolute deviations (MADs) from experiment of 3.96 and 3.65 kJ mol⁻¹, respectively, compared with 4.26 and 4.02 kJ mol⁻¹ for standard G3 and G3X. G3-RAD and G3X-RAD successfully predict heats of formation with MADs of 3.68 and 3.11 kJ mol⁻¹, respectively (compared with 3.93 and 3.60 kJ mol⁻¹ for standard G3 and G3X), and perform particularly well for radicals with MADs of 2.59 and 2.50 kJ mol⁻¹, respectively (compared with 3.51 and 3.18 kJ mol⁻¹ for standard G3 and G3X). The G3(MP2)-RAD and G3X(MP2)-RAD procedures give acceptable overall performance with mean absolute deviations from experiment of 5.17 and 4.92 kJ mol⁻¹, respectively, compared with 5.44 and 5.23 kJ mol⁻¹ for standard G3(MP2) and G3X(MP2). G3(MP2)-RAD and G3X(MP2)-RAD give improved performance over their standard counterparts for heats of formation (MADs=4.73 and 4.44 kJ mol⁻¹, respectively, versus 4.94 and 4.64 kJ mol⁻¹). G3(MP2)-RAD shows similar performance to G3(MP2) for radical heats of formation (MAD=5.10 versus 5.15 kJ mol⁻¹) while G3X(MP2)-RAD performs significantly better than G3X(MP2) (MAD=4.67 versus 5.19 kJ mol⁻¹).The authors gratefully acknowledge generous allocations of computing time on the Compaq Alphaserver of the National Facility of the Australian Partnership for Advanced Computing, Australian National University Supercomputer Facility, and the support of the Australian Research Council

The 8 Micron Phase Variation of the Hot Saturn HD 149026b

We monitor the star HD 149026 and its Saturn-mass planet at 8.0 micron over slightly more than half an orbit using the Infrared Array Camera (IRAC) on the Spitzer Space Telescope. We find an increase of 0.0227% +/- 0.0066% (3.4 sigma significance) in the combined planet-star flux during this interval. The minimum flux from the planet is 45% +/- 19% of the maximum planet flux, corresponding to a difference in brightness temperature of 480 +/- 140 K between the two hemispheres. We derive a new secondary eclipse depth of 0.0411% +/- 0.0076% in this band, corresponding to a dayside brightness temperature of 1440 +/- 150 K. Our new secondary eclipse depth is half that of a previous measurement (3.0 sigma difference) in this same bandpass by Harrington et al. (2007). We re-fit the Harrington et al. (2007) data and obtain a comparably good fit with a smaller eclipse depth that is consistent with our new value. In contrast to earlier claims, our new eclipse depth suggests that this planet's dayside emission spectrum is relatively cool, with an 8 micron brightness temperature that is less than the maximum planet-wide equilibrium temperature. We measure the interval between the transit and secondary eclipse and find that that the secondary eclipse occurs 20.9 +7.2 / -6.5 minutes earlier (2.9 sigma) than predicted for a circular orbit, a marginally significant result. This corresponds to e*cos(omega) = -0.0079 +0.0027 / -0.0025 where e is the planet's orbital eccentricity and omega is the argument of pericenter.Comment: 17 pages, 12 figure, accepted for publication in Ap

BOSH:Bayesian Optimization by Sampling Hierarchically

Deployments of Bayesian Optimization (BO) for functions with stochastic evaluations, such as parameter tuning via cross validation and simulation optimization, typically optimize an average of a fixed set of noisy realizations of the objective function. However, disregarding the true objective function in this manner finds a high-precision optimum of the wrong function. To solve this problem, we propose Bayesian Optimization by Sampling Hierarchically (BOSH), a novel BO routine pairing a hierarchical Gaussian process with an information-theoretic framework to generate a growing pool of realizations as the optimization progresses. We demonstrate that BOSH provides more efficient and higher-precision optimization than standard BO across synthetic benchmarks, simulation optimization, reinforcement learning and hyper-parameter tuning tasks

Propulsion simulation for magnetically suspended wind tunnel models

The feasibility of simulating propulsion-induced aerodynamic effects on scaled aircraft models in wind tunnels employing Magnetic Suspension and Balance Systems. The investigation concerned itself with techniques of generating exhaust jets of appropriate characteristics. The objectives were to: (1) define thrust and mass flow requirements of jets; (2) evaluate techniques for generating propulsive gas within volume limitations imposed by magnetically-suspended models; (3) conduct simple diagnostic experiments for techniques involving new concepts; and (4) recommend experiments for demonstration of propulsion simulation techniques. Various techniques of generating exhaust jets of appropriate characteristics were evaluated on scaled aircraft models in wind tunnels with MSBS. Four concepts of remotely-operated propulsion simulators were examined. Three conceptual designs involving innovative adaptation of convenient technologies (compressed gas cylinders, liquid, and solid propellants) were developed. The fourth innovative concept, namely, the laser-assisted thruster, which can potentially simulate both inlet and exhaust flows, was found to require very high power levels for small thrust levels