5,873 research outputs found
Volunteer Management Capacity in America's Charities and Congregations
The volunteer management capacity study was completed in 2003 under contract with the Corporation for National and Community Service. Results are based on surveys of separate samples of U.S. charities and congregations. The study concludes that prevailing low levels of management capacity have not translated into widespread concern regarding the challenges of volunteer management. While charities and congregations need help in developing their capacity to recruit and manage volunteers, these organizations are nonetheless eager and prepared to take on additional volunteers. This conclusion has already been taken as validation by the federal government that the President's Call to Service need not be postponed due to an inability of organizations to take on new volunteers
Sarasota Performing Arts Research Coalition Community Report
Presents findings from a 2002 Urban Institute survey of Sarasota residents' perceptions of and attitudes toward the performing arts
Seattle Performing Arts Research Coalition Community Report 2002
Presents findings from a 2002 Urban Institute survey of Seattle residents' perceptions of and attitudes toward the performing arts
Pittsburgh Performing Arts Research Coalition Community Report
Presents findings from a 2002 Urban Institute survey of Pittsburgh residents' perceptions of and attitudes toward the performing arts
Sarasota Performing Arts Research Coalition Community Report
Presents findings from a 2002 Urban Institute survey of Sarasota residents' perceptions of and attitudes toward the performing arts
Washington, D.C. Performing Arts Research Coalition Community Report
Presents findings from a 2002 Urban Institute survey of Washington-area residents' perceptions of and attitudes toward the performing arts
Washington, D.C. Performing Arts Research Coalition Community Report
Presents findings from a 2002 Urban Institute survey of Washington-area residents' perceptions of and attitudes toward the performing arts
Boston Performing Arts Research Coalition Community Report
Presents findings from a 2002 Urban Institute survey of Boston residents' perceptions of and attitudes toward the performing arts
Interseismic strain accumulation: Spin-up, cycle invariance, and irregular rupture sequences
Using models of infinite length strike-slip faults in an elastic layer above linear viscoelastic regions, we investigate interseismic deformation. In the models we investigate, interseismic strain accumulation on mature faults is the result of the cumulative effects of all previous ruptures and is independent of the fault loading conditions. The time for a fault to spin-up to a mature state depends on the rheologies and the fault loading conditions. After the model has spun-up, the temporal variation of shear stresses is determined by the fault slip rate and model rheologies. The change in stress during spin-up depends on the slip rate, rheologies, and fault loading conditions but is independent of the magnitude of the initial stress. Over enough cycles such that the cumulative deformation is block-like, the average mature interseismic velocities are equal to the interseismic velocities of an elastic model with the same geometry and distribution of shear moduli. In a model that has spun-up with the fault rupturing periodically, the cumulative deformation is block-like at the end of each seismic cycle, and the interseismic deformation is cycle-invariant (i.e., the same in all cycles). When the fault ruptures nonperiodically, the fault spins up to a mature state that is the same as if the fault had ruptured periodically with the mean slip rate. When the fault slip rate within each cycle varies, the interseismic deformation evolves toward the cycle-invariant deformation determined by the most recent fault slip rate. Around a fault whose slip rate has been faster (slower) than average, interseismic velocities are larger (smaller) than the cycle-invariant velocities and increase (decrease) from cycle to cycle
The effects of rheological layering on post-seismic deformation
We examine the effects of rheological layering on post-seismic deformation using models of an elastic layer over a viscoelastic layer and a viscoelastic half-space. We extend a general linear viscoelastic theory we have previously proposed to models with two layers over a half-space, although we only consider univiscous Maxwell and biviscous Burgers rheologies. In layered viscoelastic models, there are multiple mechanical timescales of post-seismic deformation; however, not all of these timescales arise as distinct phases of post-seismic relaxation observed at the surface. The surface displacements in layered models with only univiscous, Maxwell viscoelastic rheologies always exhibit one exponential-like phase of relaxation. Layered models containing biviscous rheologies may produce multiple phases of relaxation, where the distinctness of the phases depends on the geometry and the contrast in strengths between the layers. Post-seismic displacements in models with biviscous rheologies can often be described by logarithmic functions
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