An input adaptive, pursuit tracking model of the human opertor

Developed and evaluated is a simple model of the input adaptive behavior of the human operator (HO) in a pursuit tracking task in which the plant controlled consists of a pure gain. If it is assumed that the HO is approximately an optimal predictor using only position and velocity information, then there is a simple method of computing the values of the model parameters in terms of the autocorrelation function of the input signal. Experimental evidence indicates that the ability of the HO to use velocity information decreases with increasing signal velocity indicating that a biased estimator of the velocity weighting should be used. A suitable approximation is derived which has rapid convergence and low variance. The model thus derived is compared to actual subject transfer functions and is found to be in close agreement. In addition to tracking random processes the model can adapt to and track deterministic signals, such as sine waves, up to approximately the frequency at which human operators begin to track precognitively

Multi-touch 3D Exploratory Analysis of Ocean Flow Models

Modern ocean flow simulations are generating increasingly complex, multi-layer 3D ocean flow models. However, most researchers are still using traditional 2D visualizations to visualize these models one slice at a time. Properly designed 3D visualization tools can be highly effective for revealing the complex, dynamic flow patterns and structures present in these models. However, the transition from visualizing ocean flow patterns in 2D to 3D presents many challenges, including occlusion and depth ambiguity. Further complications arise from the interaction methods required to navigate, explore, and interact with these 3D datasets. We present a system that employs a combination of stereoscopic rendering, to best reveal and illustrate 3D structures and patterns, and multi-touch interaction, to allow for natural and efficient navigation and manipulation within the 3D environment. Exploratory visual analysis is facilitated through the use of a highly-interactive toolset which leverages a smart particle system. Multi-touch gestures allow users to quickly position dye emitting tools within the 3D model. Finally, we illustrate the potential applications of our system through examples of real world significance

A model for the submarine depthkeeping team

The most difficult task the depthkeeping team must face occurs during periscope-depth operations during which they may be required to maintain a submarine several hundred feet long within a foot of ordered depth and within one-half degree of ordered pitch. The difficulty is compounded by the facts that wave generated forces are extremely high, depth and pitch signals are very noisy and submarine speed is such that overall dynamics are slow. A mathematical simulation of the depthkeeping team based on the optimal control models is described. A solution of the optimal team control problem with an output control restriction (limited display to each controller) is presented

High-tip-speed, low-loading transonic fan stage. Part 3: Final report

Tests were conducted on a high-tip-speed, low-loading transonic fan stage to determine the performance and inlet flow distortion tolerance of the design. The fan was designed for high efficiency at a moderate pressure ratio by designing the hub section to operate at minimum loss when the tip operates with an oblique shock. The design objective was an efficiency of 86 percent at a pressure ratio of 1.5, a specific flow (flow per unit annulus area) of 42 lb/sec-sq. ft (205.1 kgm/sec-m sq), and a tip speed of 1600 ft/sec (488.6 m/sec). During testing, a peak efficiency of 84 percent was achieved at design speed and design specific flow. At the design speed and pressure ratio, the flow was 4 percent greater than design, efficiency was 81 percent, and a stall margin of 24 percent was obtained. The stall line was improved with hub radial distortion but was reduced when the stage was tested with tip radial and circumferential flow distortions. Blade-to-blade values of static pressures were measured over the rotor blade tips

INVESTIGATION OF THE LOW-SUBSONIC STABILITY AND CONTROL CHARACTERISTICS OF A 0.34 -SCALE FREE-FLYING MODEL OF A MODIFIED HALF-CONE REENTRY VEHICLE

Low subsonic stability and control of a 0.34-scale free flying model of a half cone reentry vehicl

Hightip-speed, low-loading transonic fan stage. Part 2: Data compilation

Tests were conducted on a high-tip-speed low-loading transonic fan stage to determine the performance and inlet flow distortion tolerance of the design. Test data were recorded for overall and blade element performance with both uniform and distorted inlet flows. A tabular summary of the data and a representative selection of the computer data reduction sheets are presented

Panoramic Images for Situational Awareness in a 3D Chart-of-the-Future Display

Many early charts featured sketches of the coastline, providing a good picture of what the shore looked like from the bridge of a ship. These helped the mariner to distinguish one port from another during an approach and establish their rough position within that approach. More recent experimental 3D chart interfaces have incorporated 3D models of land topography and man-made structures to perform the same function. However, topography is typically captured from the air, by means of stereophotogrammetry or lidar and fails to present a good representation of what is seen from a vessel’s bridge. We have been conducting an investigation of ways to present photographic imagery to the mariner to better capture the utility of the early coastline sketches. Our focus has been on navigation in restricted waters, using the Piscataqua River as a test area. This is part of our “Chart-of-the-Future” project being conducted by The Data Visualization Research Lab at the UNH Center for Coastal and Ocean Mapping. Through our investigation, we have developed a new method for presenting photographic imagery to the mariner, in the form of a series of panoramic images progressing down the channel. The panoramas consist of images stitched almost seamlessly together into circular arcs, whose centers are intended to be close to the position of a vessel’s bridge during transit. When viewed from this center, there is no distortion, and distortion increases to a maximum between two panorama centers. Our preliminary trials suggest that panoramas can provide an excellent supplement to electronic navigation aids by making them visible in the context of what can be seen out the window. We believe panoramas will be especially useful both in familiarizing a mariner with an unfamiliar approach during planning, and in enhancing situational awareness at times of reduced visibility such as in fog, dusk, or nightfall

Pilot cryo tunnel: Attachments, seals, and insulation

Several different tests are described which simulated the actual configuration of a cryogenic wind tunnel operating at pressures up to 5 atmospheres (507 kPa) and temperatures from -320 F (78K) to 120 F (322K) in order to determine compatible bolting, adequate sealing, and effective insulating materials. The evaluation of flange attachments (continuous threaded studs) considered bolting based on compatible flanges, attachment materials, and prescribed bolt elongations. Various types of seals and seal configurations were studied to determine suitability and reusability under the imposed pressure and temperature loadings. The temperature profile was established for several materials used for structural supports