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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.

Fly Far, Lift More? What Patterns Exist Within Interindividual Capacity of Flight Performance Traits in Bombus impatiens?

Shewchenko, Tera January 2017 (has links)
Locomotion is central to the survival of many animal species; however large variation in performance, for example in speed or endurance, exists between individuals within a species. Using the bumblebee species, Bombus impatiens, I studied the extent of the variation in several flight performance traits and how they are associated. I first addressed how bumblebee workers vary in foraging effort and observed that only around half of the monitored individuals underwent foraging activity. Additionally, significant variation in metabolic rate between foragers and non-foragers was uncovered. I further investigated if such variation could be associated with flight performance capacity, such as an individual’s ability to carry a load, their flight speed and distance traveled, their wing morphology and kinematics, and their flight metabolic rate. These traits are commonly measured to characterize flight capacity in insects, however the links between them have yet to be investigated. Links between morphology, wing kinematics and peak metabolic rate previously uncovered in the literature were observed in my analysis, although variation in their scaling with body mass was detected. Vertical force scaled isometrically with body mass but was not related to it when expressed in on a mass specific basis (VF m-1g-1, where m is gravitation acceleration). In regard to forward flight speed, body mass does have an affect, however it alone does not have a great degree of explanatory power and other factors such as morphology and wing kinematics are likely to play a greater part in its determination. Finally, maximum flight speed had a significant relationship with total flight time. Together, these results demonstrate that some links do exist between flight performance traits, however links are not present between all traits and certain flight performance traits should be treated as independent of each other.

Pediatric Emergencies on a US-Based Commercial Airline

Moore, Brian R., Ping, Jennifer M., Claypool, David W. 01 November 2005 (has links)
Objectives: The purpose of this investigation was to determine the incidence and character of pediatric emergencies on a US-based commercial airline and to evaluate current in-flight medical kits. Methods: In-flight consultations to a major US airline by a member of our staff are recorded in an institutional database. In this observational retrospective review, the database was queried for consultations for all passengers up to 18 years old between January 1, 1995, and December 31, 2002. Consultations were reviewed for type of emergency, use of the medical kit, and unscheduled landings. Results: Two hundred twenty-two pediatric consultations were identified, representing 1 pediatric call per 20,775 flights. The mean age of patients was 6.8 years. Fifty-three emergencies were pre-flight calls, and 169 were in-flight pediatric consultations. The most common in-flight consultations concerned infectious disease (45 calls, 27%), neurological (25 calls, 15%), and respiratory tract (22 calls, 13%) emergencies. The emergency medical kit was used for 60 emergencies. Nineteen consultations (11%) resulted in flight diversions (1/240,000 flights), most commonly because of in-flight neurological (9) and respiratory tract (5) emergencies. International flights had a higher incidence than domestic flights of consultations and diversions for pediatric emergencies. Conclusions: The most common in-flight pediatric emergencies involved infectious diseases and neurological and respiratory tract problems. Emergency medical kits should be expanded to include pediatric medications.

Dynamics and Control of Morphing Aircraft

Seigler, Thomas Michael 14 September 2005 (has links)
The following work is directed towards an evaluation of aircraft that undergo structural shape change for the purpose of optimized flight and maneuvering control authority. Dynamical equations are derived for a morphing aircraft based on two primary representations; a general non-rigid model and a multi-rigid-body. A simplified model is then proposed by considering the altering structural portions to be composed of a small number of mass particles. The equations are then extended to consider atmospheric flight representations where the longitudinal and lateral equations are derived. Two aspects of morphing control are considered. The first is a regulation problem in which it is desired to maintain stability in the presence of large changes in both aerodynamic and inertial properties. From a baseline aircraft model various wing planform designs were constructed using Datcom to determine the required aerodynamic contributions. Based on nonlinear numerical evaluations adequate stabilization control was demonstrated using a robust linear control design. In maneuvering, divergent characteristics were observed at high structural transition rates. The second aspect considered is the use of structural changes for improved flight performance. A variable span aircraft is then considered in which asymmetric wing extension is used to effect the rolling moment. An evaluation of the variable span aircraft is performed in the context of bank-to-turn guidance in which an input-output control law is implemented. / Ph. D.

Work schedule stress and wellness in female air cabin attendants

Porter, P January 1988 (has links)
Bibliography: pages 140-155. / The research investigated Work Schedule Stress experienced by female air cabin attendants (CAs) employed by South African Airways and its relationship to health variables in CAs. Specifically, it was hypothesised that Work Schedule Stress is an important stressor for CAs and is inversely related to health variables. Furthermore, the variables of Potency, Trait Anxiety, Trait Anger, and Social Support were proposed to moderate the relationship between Work Schedule Stress and the health variables. Data were collected from a sample of 108 domestic crew and 43 international crew. The data collection was conducted in two phases, via interviews and self-report inventories. The interview data were used in a qualitative study but were also content-analysed in terms of a number of dimensions; the latter were included with the quantitative data obtained from the questionnaire. The qualitative analysis, based on the grounded theory approach, formed the backbone of the research. The quantitative data were subjected to correlational analysis, supplemented by subgroup analysis to assess moderator effects. Work Schedule Stress was demonstrated to represent a major stress for CAs with consequent adverse effects on health. The results did not provide support for the moderating effects. Conclusions were drawn, recommendations made to the SAA and CAs themselves of means to enhance wellness, and suggestions for future research proposed.

A Microcomputer Implementation of a Flight Simulator Visual Display System

Campbell, Jerry Wayne 01 July 1979 (has links) (PDF)
The use of computer graphics has brought about a universal means of depicting phenomena or solving engineering problems. The combination of graphic and computer skills offers a solution to a number of technical needs. One major area that computer graphics can be used is in the field of flight simulation. The software packages necessary to project three-dimensional scenes for flight training are not very common. The purpose of this paper is to generate the programs necessary to allow the pilot to observe a three-dimensional scene from any location and angle. The report discusses some of the basic aspects of computer graphics and presents specific computer software for projecting simulated flight landings at Herndon Airport in Orlando, Florida. The three-dimensional projections are calculated and displayed on the video monitor in the form of two-dimensional scenes. The Southwest Terminal System hardware was used as the interface to the video monitor. A description of the various operating parameters for simulated flight landings is presented. Included in the discussion are various pictorial representations of simulated landing approaches at Herndon Airport. Suggestions for additional work that could be undertaken in this research area concludes the report.

Image Analysis and Improvement of a Point Light Source Visual Flight Simulator

Butrimas, Steve K. 01 January 1974 (has links) (PDF)
It has long been desired to simulate a non-preprogrammed controllable visual scene of the real world in a limited area for the purpose of training, in particular for aviation training. There presently exists a point light source projection system designed to accomplish this, however due to physical limitations, the display image, as compared to the corresponding real world scene which is being simulated, is somewhat distorted and limited. This point light source system is analyzed to determine the distortions and deviations from reality and methods are proposed to improve the display by minimizing the distortions and deviations.


Maschhoff, Robert H., Johnson, David W. 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1993 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes a data acquisition system with integral signal conditioning capability. It is a distributed bus oriented system which greatly reduces the amount of wiring and structural penetrations required in previous systems used for this purpose. The system interfaces with virtually all of the transducer types existing on operational aircraft as well as those typically used for flight testing and proofing such as the strain gauges. It outputs data in digital form to a central unit which combines this data with other aircraft operational parameters for recording on tape or telemetry to the ground. The system consists of a remote multiplexer (RMUX) which provides the formatting and central processing functions and has provision for 16 plug-in signal conditioning modules. It also has provision for up to 20 external multiplexers (EMUXes) which are designed to service a cluster of like sensors in a local area. EMUX types include bridge, thermocouple, and a highly integrated pressure scanner unit. Signal conditioning and processing functions include input transient protection, variable blocks of gain, analog pre-sample filtering, and precision bandlimiting using digital techniques . The penalty for moving the acquisition units to remote locations on the aircraft as compared to previously used cabin mounted equipment is a much more severe environment. Temperature extremes and vibration are particularly severe around the engines. Because of the planned use on operational aircraft, provisions to prevent lightning propagation to the cabin are a significant future.


Scofield, Don, Powell, Dave 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / Joint Advanced Missile Instrumentation (JAMI), a 1997 new-start multi-year Central Test and Evaluation Investment Program (CTEIP), is developing advanced telemetry system components that can be used in an integrated instrumentation package for tri-service small missile test and training applications. JAMI will provide telemetry, Time-Space-Position Information (TSPI), flight termination and end-game vector scoring in a low cost, modular package that will allow world-wide test and training- eliminating, in most cases, the need for range-specific (or multi-system) facilities. JAMI will incorporate Global Positioning System (GPS)-based technology as the TSPI and vector scoring engine, and is completing the development of a solid state programmable safe and arm device for flight safety applications. The JAMI program has progressed into Phase 2 and full-scale development of advanced GPS technologies. This paper discusses the progress of the program during the past year and the efforts planned for fiscal year 2000. Testing of GPS receivers and problems encountered in programming GPS simulator for missile flight profiles are discussed.

The application of digital flight and event data recorders to improving helicopter flight safety

Barclay, Alan Laverton January 2014 (has links)
The current state of international civilian (General Aviation) helicopter flight safety was perceived to be poor and without focus on the potential application of low-cost digital data acquisition devices to increase the quantity of flight data available for analysis, which could help identify issues leading to common incident and accident scenarios. The research project undertook a review of some of the common incident and accident scenarios, performed an analysis of the composition of the worldwide helicopter fleet and explored the interaction of operators, pilots, missions, and national aviation authorities, in order to understand and define the context for this study. Two radically different types of digital flight and event data recorders were then developed, which were considered appropriate for use in the most common small to medium sized helicopter types identified, in order to determine if reliable low-cost digital data acquisition was achievable. Also developed were software tools for extracting the recorded data sets and their processing/analysis. The proof of concept devices were flight tested, in a variety of environments by a number of helicopter operators and manufacturers in Europe and North America, in order to determine whether such simple devices actually returned useful flight data and in doing so contribute to improving flight safety by highlighting the occurrence of common issues. During the flight trials a number of real safety critical events were captured or observed, despite being flown for only a fraction of the time that would statistically elapse between incidents. Examination of the data sets revealed an abundance of information about pilot behaviour, which it will be argued substantiates the widely held belief that most accidents are caused by pilot error or negligence. It will be asserted that these results demonstrate that real improvements in training and flight safety can be achieved through the wide spread use of such proof of concept devices and their associated software tools. The international helicopter community has subsequently expressed a strong desire for such devices to become common place in small to medium sized helicopters.

A comparative study of the anatomical basis of flight in Hemiptera

Cullen, M. J. January 1971 (has links)
No description available.

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