9,137 research outputs found
Variational Theory and Domain Decomposition for Nonlocal Problems
In this article we present the first results on domain decomposition methods
for nonlocal operators. We present a nonlocal variational formulation for these
operators and establish the well-posedness of associated boundary value
problems, proving a nonlocal Poincar\'{e} inequality. To determine the
conditioning of the discretized operator, we prove a spectral equivalence which
leads to a mesh size independent upper bound for the condition number of the
stiffness matrix. We then introduce a nonlocal two-domain variational
formulation utilizing nonlocal transmission conditions, and prove equivalence
with the single-domain formulation. A nonlocal Schur complement is introduced.
We establish condition number bounds for the nonlocal stiffness and Schur
complement matrices. Supporting numerical experiments demonstrating the
conditioning of the nonlocal one- and two-domain problems are presented.Comment: Updated the technical part. In press in Applied Mathematics and
Computatio
Automated pilot advisory system test and evaluation at Manassas Municipal Airport
In cooperation with the Federal Aviation Administration, NASA developed an experimental automated pilot advisory system (APAS) to provide airport and air traffic advisories at high density uncontrolled airports. The APAS concept is to utilize low cost automated systems to provide the necessary information for pilots to more safely plan and execute approach and landing at uncontrolled high density airports. The system is designed to be a natural extension of the procedural visual flight rules system used at uncontrolled airports and, as an advisory system, will enhance the "see-and-be-seen" rule and an evaluation of the APAS concept was obtained from pilots who used the system at the Manassas, Virginia airport. These evaluations and the system performance are presented
HUMAN CAPITAL NEEDS OF BLACK LAND-GRANT INSTITUTIONS
Labor and Human Capital, Teaching/Communication/Extension/Profession,
Study to determine potential flight applications and human factors design guidelines for voice recognition and synthesis systems
A study was conducted to determine potential commercial aircraft flight deck applications and implementation guidelines for voice recognition and synthesis. At first, a survey of voice recognition and synthesis technology was undertaken to develop a working knowledge base. Then, numerous potential aircraft and simulator flight deck voice applications were identified and each proposed application was rated on a number of criteria in order to achieve an overall payoff rating. The potential voice recognition applications fell into five general categories: programming, interrogation, data entry, switch and mode selection, and continuous/time-critical action control. The ratings of the first three categories showed the most promise of being beneficial to flight deck operations. Possible applications of voice synthesis systems were categorized as automatic or pilot selectable and many were rated as being potentially beneficial. In addition, voice system implementation guidelines and pertinent performance criteria are proposed. Finally, the findings of this study are compared with those made in a recent NASA study of a 1995 transport concept
Delineation of major soil associations using ERTS-1 imagery
The delineation of a major soil association in the loess region of Obion County has been accomplished using ERTS-1 imagery. Channel 7 provides the clearest differentiation. The separation of other smaller soil associations in an intensive row crop agricultural area is somewhat more difficult. Soil differentiation has been accomplished visually as well as electronically using a scanning microdensitometer. Lower altitude aircraft imagery permits a more refined soil association identification and where imagery is of sufficient scale, even individual soils may be identified
Automated Pilot Advisory System
An Automated Pilot Advisory System (APAS) was developed and operationally tested to demonstrate the concept that low cost automated systems can provide air traffic and aviation weather advisory information at high density uncontrolled airports. The system was designed to enhance the see and be seen rule of flight, and pilots who used the system preferred it over the self announcement system presently used at uncontrolled airports
PROGRAM PLANNING IN FAITH-BASED DEVELOPMENT ORGANIZATIONS
There is a growing demand for scientific efficiency of faith-based development programs,
resulting in the need for well-defined program goals. This study explored the presence of a
systematic program planning process, based on the Lifelong Education Program Planning (LEPP)
Model by Peter Cookson, which can help faith-based organizations formulate program goals.
The influence of organizational structure on the systematic program planning process was also
explored. Qualitative telephone interviews were used to interview representatives from six faithbased
development organizations.
Results from this study indicate that systematic program planning does occur in faith-based
development organizations. The LEPP Model effectively models the program planning process,
but not all quadrants are used at all times. Furthermore, the organizational structure greatly
influences the program planning process. Recommendations were made to develop a common
terminology for the program planning process to increase effective communication
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