9,559 research outputs found
Nutation Damper System
The Nutation Damper System is a three function mechanism designed for the Galileo Spacecraft, a spin stabilized deep-space probe to Jupiter. By damping the movement of a large deployable science boom acting as an outboard pendulum, the nutation damper rapidly stabilizes the spacecraft from dynamic irregularities. The system includes the boom deployment device and the ultra-low friction boom hinge. This paper describes the mechanism, the degree to which friction, stiction and lost motion have been eliminated, and the unique test methods that allow its performance to be measured
Synchronization of interconnected networks: the role of connector nodes
In this Letter we identify the general rules that determine the
synchronization properties of interconnected networks. We study analytically,
numerically and experimentally how the degree of the nodes through which two
networks are connected influences the ability of the whole system to
synchronize. We show that connecting the high-degree (low-degree) nodes of each
network turns out to be the most (least) effective strategy to achieve
synchronization. We find the functional relation between synchronizability and
size for a given network-of-networks, and report the existence of the optimal
connector link weights for the different interconnection strategies. Finally,
we perform an electronic experiment with two coupled star networks and conclude
that the analytical results are indeed valid in the presence of noise and
parameter mismatches.Comment: Accepted for publication in Physical Review Letters. Main text: 5
pages, 4 figures. Supplemental material: 8 pages, 3 figure
Supersymmetric Musings on the Predictivity of Family Symmetries
We discuss the predictivity of family symmetries for the soft supersymmetry
breaking parameters in the framework of supergravity. We show that unknown
details of the messenger sector and the supersymmetry breaking hidden sector
enter into the soft parameters, making it difficult to obtain robust
predictions. We find that there are specific choices of messenger fields which
can improve the predictivity for the soft parameters.Comment: 20 pages, 5 figure
Does Culture Affect Divorce? Evidence From European Immigrants in the United States
This article explores the role of culture in determining divorce by examining country-of-origin differences in divorce rates of immigrants in the United States. Because childhood-arriving immigrants are all exposed to a common set of U.S. laws and institutions, we interpret relationships between their divorce tendencies and home-country divorce rates as evidence of the effect of culture. Our results are robust to controlling for several home-country variables, including average church attendance and gross domestic product (GDP). Moreover, specifications with country-of-origin fixed effects suggest that immigrants from countries with low divorce rates are especially less likely to be divorced if they reside among a large number of coethnics. Supplemental analyses indicate that divorce culture has a stronger impact on the divorce decisions of females than of males, pointing to a potentially gendered nature of divorce taboos
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