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The purpose of this study was to examine the relationship between Japanese, Korean, and American cultures in their ability to comprehend icons used in airline passenger safety information. The 116 subjects were outbound international airline passengers traveling from San Francisco International Airport to either Japan or Korea. The instrument used contained thirteen icons similar to those on current passenger safety briefing cards. Subjects were asked to identify the icons as accurately as possible. Answers were graded on a three point ordinal scale, and frequency data were obtained. To test for significant differences between cultures, the data were analyzed through use of the chi-square test in a two-way design. Five of the 13 icons showed significant differences in interpretation among the three cultures. Appropriate recommendations were made.

"Time duration estimates can play an intricate part of one's daily life. This study examined the time duration judgments in two paradigms, when participants were aware they were being timed (prospective) and when they were unaware they were being timed (retrospective). Furthermore, this study investigated the effect of an external stimulus, when an auditory stimulus was used, to determine the effect, if any, between both of these paradigms. To ensure the participants were engaged in a task, a simulation was used that required several tasks to be completed. To ensure the participants were engaged in the simulation, the performance of the primary was measured. For this between-subject, fully factorial experiment, 60 participants were engaged in a simulation and placed in one of the four conditions: retospective paradigm without a distraction, retrospective paradigm with an auditory distraction, prospective paradigm without a distraction, and prospective paradigm with the same auditory distraction. During the experiment, participants were required to perform one primary and three secondary tasks and at the end of the simulation produced a time duration judgment of the length of the experiment. This study examined both the accuracy of the time duration judgment and the performance of the primary task. The only significant finding for this study showed the importance of how a simple auditory distraction has the ability to distort the time perceived. Data indicated that auditory distraction increases the time duration judgments recalled after performing a task."--Leaf v.

View from elevation of Rosebud, Montana. Northern Pacific Railroad depot, Rosebud Supply Company, and other businesses and homes clearly visible. Yellowstone River in background., Vintage negative number : 390.

View of cowboys branding cattle in a chute., Vintage negative number : 10, 30.

Series of views of large group of horses in rope corral at roundup camp. Cowboys, roundup wagons, and roundup tents discernible in background., Vintage negative number : 353, no number.

View of large band of sheep grazing around patches of snow., Vintage negative number : 126C.

View of Miles City, Montana from center of Main Street. Log, frame, and board and batten buildings line street. Ox teams and wagons in foreground. Signage indicates a livery among the buildings., Vintage negative number : 15-16, no number.

View of front exterior of the school on the Fort Berthold Indian Reservation. Flag pole and flag to side., Vintage negative number : 39.

View of school children at the Mandan, Hidatsas, and Arikaras reservation, Fort Berthold. Children in uniforms pose with school teachers. Fire hydrant in foreground., Vintage negative number : 39.

View of sheep herder and dogs seated on hill above Big Dry Creek. Sheep graze by edge of creek below., Vintage negative number : (no number).

Views of cattle grazing and watering near creek., Vintage negative number : (no number).

In order to provide a means for testing noise reduction techniques in propellers and fans, a low-speed, low-turbulence, anechoic wind tunnel was designed, fabricated and evaluated at Embry-Riddle Aeronautical University. This open circuit wind tunnel was designed using several other existing wind tunnels as a guide and incorporated an open jet test section. The tunnel, which was built almost entirely out of wood and fiberglass, is powered by a 15 hp centrifugal fan. Tufts of yarn, a pitot-static tube, and a hot film anemoter were used to determine the flow characteristics in the test section of this wind tunnel. From the hot film anemometer, values of velocity, standard deviation and turbulence intensity were determined for three different velocity settings; approximately 114 ft/s, 145 ft/s, and 215 ft/s respectively. For the 215 ft/s and 114 ft/s tests, the turbulence intensity ranged from 0.42% to 0.87% within a seven inch diameter about the centerline. This seven inch diameter was mapped out to simulate a seven inch diameter propeller. For the 145 ft/s test, the turbulence intensity became more erratic, and ranged between 0.67% and 1.5%. The velocity across the test section for all three tests varied by less than 2.0%, with 90% of the points varying by less than 1.0%.

The purpose of this study was to investigate the effect of automated and passive control on air traffic controller dynamic memory. The study consisted of two experiments, each involving a realistic ATC scenario for radar approach control with a mix of arriving and departing traffic. In Experiment I, the subjects performed manual control of the traffic while, in Experiment II, the scenario was highly automated and the subjects were tasked with only monitoring the situation. The dynamic memory performance was measured by interrupting the scenario and having the subjects recall the traffic situation at the moment of simulation interruption. The accuracy of recall was compared between the manual and automated scenarios. It was anticipated that subjects exercising manual control would have superior recall ability and a “picture.” This would have significant implications on the design of automated systems for ATC and the role of the human controller within the ATC system.

The goal of this project was to develop and test a self-aspirating aerovalve pulsejet and measure its operating characteristics. An investigation of pulsejets developed by previous experimenters revealed design trends associated with the engine geometry. These trends were followed in the development of an aerovalve pulsejet engine entitled the Astra. The engine employed variable fuel injection methods, ignition location and exhaust pipe length to show that certain combinations of geometry relations and fuel injection methods were more conducive to pulse combustion. Even though the engine pulsed with forced inlet air, the Astra did not self-aspirate as did the engines on which its design was based due to insufficient mixing of fuel and air. Data regarding combustion chamber pressures and temperatures were collected to verify pulsing behavior. The project also included extensive documentation of engine design changes and experimentation to serve as a guideline for future aerovalve pulsejet developers.

The application of active noise control to reduce cabin noise in single engine, general aviation aircraft is investigated through the use of the 'filtered x' least mean square algorithm and a simple acoustic feedforward method to generate a reference signal is tested. The system is designed to utilize one reference signal and up to two feedback signals and two audio speakers. The feedforward system consists of a microphone placed in close proximity to the front windshield and isolated from the cabin noise. Cabin noise and reference signals are recorded during flight in a Cessna 172 Skyhawk, a Piper Cherokee 140 and a Piper Malibu Mirage. The recorded data is used in laboratory tests to evaluate the capability of the control system to reduce the cabin noise signal with the recorded reference signal. The reference signal was found to lack coherence with the cabin noise in most aircraft which limited the noise reductions. Alternative feedforward methods are investigated and an alternative reference signal is tested in a laboratory simulation. The results with the recorded data and the modified reference signal are detailed in each case.

The purpose of this study was to assess the opinions, beliefs, and perspectives of former air traffic controllers who were terminated from employment with the Federal Aviation Administration for participating in the Professional Air Traffic Controllers Organization (PATCO) strike of 1981. The study examines the perceptions of the former controllers to determine their feelings toward the justification for going on strike over 13 years ago. This is relevant in light of recent events including the lifting of the ban against rehiring PATCO controllers by the Clinton Administration. The data collected for this study were obtained with an opinionnaire mailed via a newsletter to former controllers who were members of the PATCO union. It was expected that a majority of the controllers would feel their actions of 1981 were justified. This feeling, however, would be mitigated by the fact that the controllers were terminated for their actions and sacrificed their careers with the decision to strike.

This study used acoustic emission (AE) signal parameters to isolate the failure mechanisms in a 0° unidirectional, fiberglass/epoxy tensile test specimen. Since several failure mechanisms were known to be present, the lack of any distinctly identifiable bands in the original amplitude distribution indicated that there was considerable overlap between the AE signals of the various failure mechanisms. In order to separate the amplitude bands associated with each mechanism, it was necessary to sort on the duration of the AE signal. Two additional plots, counts versus amplitude and hits versus counts, were used to verify that the amplitude distributions were comprised of a single predominant mechanism. A total of seven failure mechanisms were isolated from the original data set, all but two having a shape similar to that of a normal distribution.

In recent years increased public awareness has made the reduction of environmental noise pollution a top priority for the aviation industry. Utilizing current technology, this study examines the reduction of noise generated by two bladed general aviation propellers, through design. The Aircraft Noise Prediction Program - Propeller Analysis System (ANOPP-PAS) is used to predict the noise and performance characteristics for an industry typical reference propeller as well as for the final quiet and efficient design. This investigation is based on the use of a 200 hp engine rotating a 76 inch propeller. Typically, such a propeller would be rotated at 2700 rpm; however, the quiet propeller is designed to operate at 2400 rpm. This rotational velocity reduction is incorporated in order to decrease the rotational tip speed thereby preventing the formation of undesirable shocks at the tip. The reference propeller spinning at 2400 rpm achieves a 9 dB reduction in far field OASPL and a 9.6 (14 dBA) reduction in near field OASPL when compared to the reference propeller spinning at 2700 rpm. It should be noted that the values at 2700 rpm are under predicted by 3-10 dB due to a known ANOPP shortfall in shock wave noise prediction. Blade twist distribution, tip shape, airfoil design, and blade sweep were all modified and examined through parametric study to further quiet the design and maintain desirable performance characteristics. These modifications produced additional reduction of 1.1 dB (3.6 dBA) reduction in far-field OASPL. Near-field noise characteristics were reduced by 17 dB (2.3 dBA). The final quiet design is achieved with a 1% increase in performance.

The purpose of this study was to determine if the utilization of an experimental computer-based selection test battery would aid in the prediction of a candidate's performance when using an air traffic control computer-based simulation program. Each candidate completed the selection test battery, and then received air traffic control instruction using the air traffic control simulation program incorporated in the TRACON/Pro™ simulator system. The selection test battery results were correlated with the subsequent simulator scoring results.

Edge-welded metal bellows present an ongoing challenge: the prediction of an accurate cycle life. Current methods rely on physical leak detection to determine a bellow's cycle life to failure. It is known, however, that crack initiation begins many cycles before a leak path is present. Bellows manufacturers require a method for detection of fatigue cracks when they initiate but before they result in leak rates large enough to contaminate a process. Acoustic emission (AE) testing is one method which can meet this need and is a proven, reliable technique for detecting crack initiation and monitoring fatigue crack growth. Four sets of metal bellows samples were fatigue tested and AE parameter data recorded. The data sets were analyzed and the determination made that amplitude, duration, and time of occurrence were the AE data variables required for separation of the various failure mechanisms. For two of the four materials, an expanded set of tests were performed. Fourteen tests were used to train and test a back-propagation neural network for prediction of bellows cycle life. The input data consisted of a material identifier, AE parameter data consisting of the amplitude distribution (50-100 dB) of the first 250 hits, and the final cycle life. The network was structured with an input layer consisting of the identifier and amplitude data, two hidden layers for mapping failure mechanisms, and an output layer for predicting cycle life. The network required training on four samples for the Inconel 718 and five samples for the 350 stainless steel. Once trained the network was able to predict cycle life with a worst case error of-4.45 percent and 2.66 percent for the Inconel 718 and 350 stainless steel, respectively. Finally, through the use of multiple linear regression, a statistical analysis was made to develop a model capable of accurate prediction. Applying a natural log transformation to the independent variables of amplitude and energy resulted in a model capable of explaining 95 percent of the variability in cycle life prediction.

From an environmental point of view, the reduction of aircraft noise has become an important factor recently. There are two factors that make airplane noise: propeller noise and engine noise. This report puts emphasis on only the engine noise in order to begin understanding what airplane engine exhaust noise is. At first, the engine exhaust noise is comprehended using the Dobrzynski's engine noise theory. Next, a discussion about an Embry-Riddle Aeronautical University (ERAU) engine system, engine exhaust system configurations, and microphone setting standards that show the ERAU engine system exhaust noise data. Finally, an Intermittent-Combustion (IC) General Aviation (GA) aircraft engine exhaust noise prediction algorithm using FORTRAN code is compiled. The predicted noise level by this algorithm is compared with the actual airplane engine noise data. Consequently, the results from this algorithm can serve to modify the propulsion system and to design the engine noise reduction system.

The acoustic emission (AE) given off by a structure as it is stressed provides a passive means to characterize flaw growth activity in complex structures. This thesis demonstrates how the qualitative analysis of AE data can be refined to provide a quantitative tool for predicting the ultimate strength of composite tensile test specimens. From an original sample set of only six specimens, a multivariate statistical analysis was used to generate an ultimate strength prediction equation. The variables of the multivariate statistical analysis were obtained through the mathematical modeling of the specimen's AE amplitude distributions produced during proof testing. Ultimate strengths were then accurately predicted at proof stresses less than 25% of the expected failure stress for five randomly drawn tensile coupons. The results of this and previously conducted composite pressure vessel research demonstrate the ability to accurately predict ultimate strengths in composite structures using AE amplitude distribution data.

A cowboy in woolies (chaps) sits on a horse and looks at a herd of cattle, in (probably) Montana. Low hills are in the distance. The horse has a brand in the shape of an arrow.

A pack train and a team of horses with a wagon of supplies ready to head to the mines from a supply store at the Revenue Mine, Ouray County, Colorado. The ore processing facilities show across a creek.

View of the William V. Hodges residence at 1145 Pennsylvania Street in the Capitol Hill neighborhood of Denver, Colorado; features stone trim, a curved porch, arched windows, and turret with balcony.

Studio portrait (standing) of Private David Sweet, a Native American (Cheyenne) man, in uniform and riding boots. He holds a medicine bundle.

Studio portrait of a Native American (Sioux Miniconjou) man, identified as Hump, and two of his wives. Hump wears leggings and a print shirt and holds a fur and war club in his hands; a hat with his name on the band rests on his knee. One of his wives sits next to him and wears plaid blankets over clothes, a hair pipe necklace, and earrings. The other wife stands wrapped in a blanket.

The Hotel Colorado, Bath House and hot springs from the Denver and Rio Grande Railway Depot platform across railroad tracks and the Colorado River, Glenwood Springs, Garfield County, Colorado. The newly constructed hotel features a U-shape plan with twin towers and first floor arches. The stone bath house has turrets, dormers and curved porch. People stand around the pool which has a fountain and slide.

View of the Victorian Denver & Rio Grande Railroad depot, Palmer Lake, El Paso County, Colorado; shows people on benches, baggage trucks, and carts. Sign reads: "Pine Crest."

Pack mules, dogs, and men on horses, at the edge of a cliff in Ouray County, Colorado; they are flanked by a metal pipeline and road grade.

A boy on a horse leads pack mules, carrying lumber and bundles, on an Otto Mears toll road (the Million Dollar Highway), in Ouray or San Juan County, Colorado.

View of a buggy on a dirt road by a river, somewhere in Colorado. Graffiti covers rocks; legible letters read: "Wheeler Wilson Sewing Machine," and "Peeble Drug Store."

Native American Sioux pause outside of Miles City, Montana with horses and travois (tepee poles with bundles of their belongings.) Shows the main street businesses with false fronts.

A Native American (Sioux) man sits on the ground near the uncovered frame of a sweat lodge. A fire pit is in the center of the lodge, teepes are in the background.

View of a Native American (Yanktonais) camp, shows tepees among bare trees and snow.

An overhanging rock in the foreground shows stripes from many years of runoff; mesa lands are in the background in what may be Mesa Verde National Park, Colorado.

Panoramic view of Ouray (also known as Uncompaghre), Colorado in San Juan County.