1,025 research outputs found
Interwar Price Level Targeting
Fackler and Parker argue that the Great Depression may have been preventable with a formalized policy rule proposed by economist Irving Fisher. Policymakers have an ongoing debate about whether formalized policy rules are better than discretionary policy decisions for economic outcomes. The authorsâ analysis suggests that in the case of the Great Depression, if Fisherâs policy rule had been adopted in 1930 the collapse of the economy would have been avoided
The Role of Functional, Social, and Mobility Dynamics in Facilitating Older African Americans Participation in Clinical Research
Purpose: Older African Americans experience disproportionately higher incidence of morbidity and mortality related to chronic and infectious diseases, yet are significantly underrepresented in clinical research compared to other racial and ethnic groups. This study aimed to understand the extent to which social support, transportation access, and physical impediments function as barriers or facilitators to clinical trial recruitment of older African Americans. Methods: Participants (N=221) were recruited from six African American churches in Atlanta and surveyed on various influences on clinical trial participation
Spanning tree methods for sampling graph partitions
In the last decade, computational approaches to graph partitioning have made
a major impact in the analysis of political redistricting, including in U.S.
courts of law. Mathematically, a districting plan can be viewed as a balanced
partition of a graph into connected subsets. Examining a large sample of valid
alternative districting plans can help us recognize gerrymandering against an
appropriate neutral baseline. One algorithm that is widely used to produce
random samples of districting plans is a Markov chain called recombination (or
ReCom), which repeatedly fuses adjacent districts, forms a spanning tree of
their union, and splits that spanning tree with a balanced cut to form new
districts. One drawback is that this chain's stationary distribution has no
known closed form when there are three or more districts. In this paper, we
modify ReCom slightly to give it a property called reversibility, resulting in
a new Markov chain, RevReCom. This new chain converges to the simple, natural
distribution that ReCom was originally designed to approximate: a plan's
stationary probability is proportional to the product of the number of spanning
trees of each district. This spanning tree score is a measure of district
"compactness" (or shape) that is also aligned with notions of community
structure from network science. After deriving the steady state formally, we
present diagnostic evidence that the convergence is efficient enough for the
method to be practically useful, giving high-quality samples for full-sized
problems within several hours. In addition to the primary application of
benchmarking of redistricting plans (i.e., describing a normal range for
statistics), this chain can also be used to validate other methods that target
the spanning tree distribution
Civic Engagement and People with Disabilities: The Role of Advocacy and Technology
Disability legislation acknowledges the right of people with disabilities to participate in political and public life on an equal basis with others, but there continue to be significant barriers in accessing all aspects of the policymaking process. Advocacy and technology are two core strategies used by the disability community to advance the rights of people with disabilities. Further understanding of how these strategies and tools empower people with disabilities to connect with government is needed. This research seeks to develop and enhance civic knowledge and practices of people with disabilities by conducting civic engagement training and evaluation and examining the role of four disability advocacy organizations. Using qualitative and quantitative data, the research explores the inclusion and participation of people with disabilities in civic society, with a focus on advocacy and technology
Network Structures and the Properties of Na-Ca-Sr-Borophosphate Glasses
Borophosphate glasses were prepared with the nominal molar compositions 16Na2O-(24-y)CaO-ySrO-xB2O3-(60-x)P2O5 (mol%), where 0â€xâ€60 and y=0, 12, and 24. Information about the compositional dependence of borate and phosphate site speciation and next nearest neighbor linkages was obtained by 11B and 31P MAS NMR and Raman spectroscopies, and by high pressure liquid chromatography (HPLC). With the initial replacement of P2O5 by B2O3, tetrahedral borate sites linked to four phosphate anions, B(ĂP)4, are created in the glass structure, and the average phosphate anion becomes smaller as bridging PĂP bonds are replaced by bridging PĂB bonds. With further increases in the B2O3 content, borate units, including B-triangles, replace phosphate units linked to the B-tetrahedra. Compositional trends for the glass transition temperature (Tg) and molar volume are explained by considering the number and types of bridging oxygens per glass former, consistent with topological models reported elsewhere
Hawking Radiation from AdS Black Holes
We investigate Hawking radiation from black holes in (d+1)-dimensional
anti-de Sitter space. We focus on s-waves, make use of the geometrical optics
approximation, and follow three approaches to analyze the radiation. First, we
compute a Bogoliubov transformation between Kruskal and asymptotic coordinates
and compare the different vacua. Second, following a method due to Kraus,
Parikh, and Wilczek, we view Hawking radiation as a tunneling process across
the horizon and compute the tunneling probablility. This approach uses an
anti-de Sitter version of a metric originally introduced by Painleve for
Schwarzschild black holes. From the tunneling probability one also finds a
leading correction to the semi-classical emission rate arising from the
backreaction to the background geometry. Finally, we consider a spherically
symmetric collapse geometry and the Bogoliubov transformation between the
initial vacuum state and the vacuum of an asymptotic observer.Comment: 13 pages, latex2e, v2: some clarifications and references adde
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