Embrace

A conceptual modular skate shoe system, for personalized protection and styl

Virtual prototyping as an aid for control system analysis

Virtual Prototyping provides an opportunity for control engineers to observe and evaluate their designs in a "real world" setting without the costs or risks associated with flight test. Designers Workbench is a computer aided design tool that allows a user to create, view, modify and animate three- dimensional databases. These may include instruments, avionics displays and any out-the-window applications such as runways or terrain. The dynamic behavior of specific elements can be observed by linking data to the desired element. In this way a realtime animation of the simulation can be generated. The animation provides another analysis tool for the designer, by representing data in a more intuitive environment. Data files from two separate controller simulations was used. Cockpit instrumentation was modelled and used for each animation to monitor the aircraft states. In addition, each animation had an out-the-window perspective to view the aircraft model as it flew the prescribed trajectory.http://archive.org/details/virtualprototypi1094543024U.S. Navy (USN) authorApproved for public release; distribution is unlimited

Exploring the Best Practices of Virtual Training Delivery for the Prospective Air Traffic Controllers

The recent steady growth in the volume of air traffic in the National Airspace System has increased the public’s need for continued safe and efficient air traffic control services. The Federal Aviation Administration (FAA) plans to hire more air traffic controllers (ATCs) over the next few years. This initiative will keep up with increased traffic volume and replace the large number of ATCs expected to retire in the next ten years. Along with increased hiring, the FAA will also need to provide up-to-date and cost-effective training that will enable new hires to maintain dynamic traffic flow during ongoing increases in traffic volume. Training on complex procedures, rules, and traffic patterns is a key component in the education of the perspective ATCs at the FAA Academy. Since the perspective ATCs are from a generation accustomed to learning via media-rich, computer-based interfaces to interact with instructors and peers, using online and computer-based training modalities is essential to achieving transfer of training into performance on the job. This study looked at the perceptions of students and instructors on virtual training delivery methods, and how they could be utilized to improve the current training techniques at FAA academy and Collegiate Training Initiative (CTI) Schools. To determine student’s perception of virtual training delivery, face-to-face interviews and online surveys were conducted. These results will help guide the development of new training courses to promote technology enriched self-learning environment and easy assessment of student performance to improve the current training outcomes at FAA Academy and CTI schools

Estimation of Evapotranspiration Across the Conterminous United States Using a Regression with Climate and Land-Cover Data

Evapotranspiration (ET) is an important quantity for water resource managers to know because it often represents the largest sink for precipitation (P) arriving at the land surface. In order to estimate actual ET across the conterminous United States (U.S.) in this study, a water-balance method was combined with a climate and land-cover regression equation. Precipitation and streamflow records were compiled for 838 watersheds for 1971-2000 across the U.S. to obtain long-term estimates of actual ET. A regression equation was developed that related the ratio ET⁄P to climate and land-cover variables within those watersheds. Precipitation and temperatures were used from the PRISM climate dataset, and land-cover data were used from the USGS National Land Cover Dataset. Results indicate that ET can be predicted relatively well at a watershed or county scale with readily available climate variables alone, and that land-cover data can also improve those predictions. Using the climate and land-cover data at an 800-m scale and then averaging to the county scale, maps were produced showing estimates of ET and ET⁄P for the entire conterminous U.S. Using the regression equation, such maps could also be made for more detailed state coverages, or for other areas of the world where climate and land-cover data are plentiful

Near Optimal Feedback Guidance Design and the Planar Restricted Three-Body Problem

In this paper, we present the application of the ZEM/ZEV guidance algorithm to the planar restricted three-body problem (PR3BP). The ZEM/ZEV guidance law as a feedback guidance strategy is presented and applied to the PR3BP. The fuel optimal solution to the PR3BP for a transfer from GTO to L1 in the Earth-Moon system is presented as a point for comparison, showing the near optimality of the closed-loop guidance approach. Challenges of the approach and strategies for implementation in spacecraft mission design are discussed