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We describe the successful design, implementation, and operation of a 12 GHz holography system installed on the Robert C. Byrd Green Bank Telescope (GBT). We have used a geostationary satellite beacon to construct high-resolution holographic images of the telescope mirror surface irregularities. These images have allowed us to infer and apply improved position offsets for the 2209 actuators which control the active surface of the primary mirror, thereby achieving a dramatic reduction in the total surface error (from 390 microns to ~240 microns, rms). We have also performed manual adjustments of the corner offsets for a few panels. The expected improvement in the radiometric aperture efficiency has been rigorously modeled and confirmed at 43 GHz and 90 GHz. The improvement in the telescope beam pattern has also been measured at 11.7 GHz with greater than 60 dB of dynamic range. Symmetric features in the beam pattern have emerged which are consistent with a repetitive pattern in the aperture due to systematic panel distortions. By computing average images for each tier of panels from the holography images, we confirm that the magnitude and direction of the panel distortions, in response to the combination of gravity and thermal gradients, are in general agreement with finite-element model predictions. The holography system is now fully integrated into the GBT control system, and by enabling the telescope staff to monitor the health of the individual actuators, it continues to be an essential tool to support high-frequency observations., Comment: Accepted for publication in PASP. Contains 28 pages with 2 tables and 9 figures (several at reduced quality). The full resolution version is available at http://wwwlocal.gb.nrao.edu/ptcs/papers/Hunter2011/gbtholo.ps.gz (34MB gzip file unpacks to 134MB postscript)

This paper describes a project for the development of instructional and assessments systems to increase user-proficiency levels for the software created by WordPerfect Corporation. The project was part of an effort by WordPerfect and the Institute for Computer Uses in Education/Evaluation to create and establish standards of proficiency in the use of WordPerfect. The project included development of two computer-administered high-stakes assessments for use in the United States and Canada, a training kit for Authorized Training Center instructors, and a student training kit for self-paced or group instruction. All of these products were developed for WordPerfect Office 4.0 software. The work-model approach, which was used to develop the performance-based documentation, is described. Work models, when developed correctly, represent the common general features of a job and the relationships between these features on which experts agree. The work models, taken together, provide a structure that describes the knowledge and performance capabilities of an experienced WordPerfect Office 4.0 system administrator, and consequently allows the construction of the tests and documentation. Three figures illustrate the development process. (Contains 7 references.) (SLD)