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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.
291

Aircraft simulation and robust flight control system design

Aslin, P. P. January 1985 (has links)
No description available.
292

Qualitative simulation: A tool for global decision making

Vesanterä, Pentti Juhani, 1955- January 1988 (has links)
As a decision making aid for the human operator of a highly automated, complex system, qualitative modeling is presented as a tool to mimic the human global assessment process by learning from the system behavior. Such qualitative model is applied to reason about the behavior of a quantitatively simulated aircraft model, to determine on-line when a malfunction occurs in the quantitative model, to hypothesize about the nature of this malfunction, and to suggest a global strategy that would allow to operate (control) the quantitative aircraft under the modified flying conditions. Such an algorithm could be utilized as an addition to a conventional autopilot which would allow it to remain operational after a malfunction has taken place.
293

Noninteracting control synthesis applied to a basic automatic pilot system

Rigby, Norman Carl, 1933- January 1960 (has links)
No description available.
294

A slow neutron chopper

Cooper, Wilson Edward, 1939- January 1963 (has links)
No description available.
295

Streamline-based simulation of water injection in naturally fractured reservoirs

Al-Huthali, Ahmed 30 September 2004 (has links)
The current streamline formulation is limited to single-porosity systems and is then not suitable for application to naturally fractured reservoirs. Describing the fluid transport in naturally fractured reservoirs has been recognized as a main challenge for simulation engineers due to the complicated physics involved. In this work, we generalized the streamline-based simulation to describe the fluid transport in naturally fractured reservoirs. We implemented three types of transfer function: the conventional transfer function (CTF), the diffusion transfer function (DTF), and the empirical transfer function (ETF). We showed that these transfer functions can be implemented easily in the current single-porosity streamline codes. These transfer functions have been added as a source term to the transport equation that describes the saturation evolution along the streamlines. We solved this equation numerically for all types of transfer functions. The numerical solution of the continuity equation with DTF and ETF requires discretizing a convolution term. We derived an analytical solution to the saturation equation with ETF in terms of streamline TOF to validate the numerical solution. We obtain an excellent match between the numerical and the analytical solution. The final stage of our study was to validate our work by comparing our dual-porosity streamline simulator (DPSS) to the commercial dual-porosity simulator, ECLIPSE. The dual-porosity ECLIPSE uses the CTF to describe the interaction between the matrix-blocks and the fracture system. The dual-porosity streamline simulator with CTF showed an excellent match with the dual-porosity ECLIPSE. On the other hand, dual-porosity streamline simulation with DTF and ETF showed a lower recovery than the recovery obtained from the dual-porosity ECLIPSE and the DPSS with CTF. This difference in oil recovery is not due to our formulation, but is related to the theoretical basis on which CTF, DTF, and ETF were derived in the literature. It was beyond the scope of this study to investigate the relative accuracy of each transfer function. We demonstrate that the DPSS is computationally efficient and ideal for large-scale field application. Also, we showed that the DPSS minimizes numerical smearing and grid orientation effects compared to the dual-porosity ECLIPSE.
296

Airline crew scheduling under uncertainty

Schaefer, Andrew James 12 1900 (has links)
No description available.
297

Visual and olfactory sensory systems employed by monarch butterflies (Danaus plexippus) to locate their milkweed host plants

Garlick, Kristopher Michael 09 August 2007 (has links)
Monarch butterflies (Danaus plexippus) are well known to depend almost exclusively on milkweed (genus Asclepias) host plants for oviposition sites, as their larvae need to ingest compounds critical for adult butterfly chemical defense against predators. Many phytophagous insects make fast and accurate decisions on the quality of host plants, and whether or not to accept them as oviposition sites. We were interested in the cues that attract monarchs (males and females) to milkweed, while in flight, before contact stimulation can occur. We developed a novel flight apparatus to test monarch attraction behaviour, under a number of different experimental protocols, to both milkweed and control stimuli in order to identify the cues necessary or sufficient for monarch attraction to milkweed. Monarchs were found to be attracted to milkweed stimuli when the visual image alone of milkweed was available or when olfactory cues alone were available. Attraction behaviour was maximized when both cues were available. It was also discovered that attraction to milkweed was significantly diminished when ultraviolet reflection from milkweed leaves was prevented from being detected by monarchs in flight. / Thesis (Master, Neuroscience Studies) -- Queen's University, 2007-08-09 12:22:17.691
298

Estimation of additive and non-additive effects in traits related to growth, adult size, fecundity and flight in the cricket : Gryllus firmus

Sokolovska, Natalia January 2002 (has links)
Non-additive effects may affect the evolution of populations by lowering the heritability of the traits that they affect, thus causing inbreeding depression within populations and playing a role in the conversion of non-additive into additive variation during bottlenecks and in the evolution and maintenance of negative genetic correlations between traits (Crnokrak and Roff 1995, Wolf et al. 2000). Furthermore, dominance variance should be present to a greater degree in traits closer to fitness (Crnokrak and Roff 1995). This study uses diallel cross analyses of inbred lines of the sand cricket Gryllus firmus, to examine the sources of variation in weight at age, adult size, development time, fecundity and flight muscle weight and in particular the ratios of additive, dominance and maternal variance to total variance. We also examine the genetic relationships between the traits. / Our study also examines the presence of maternal effects in growth traits and adult size in the sand cricket Gryllus firmus using diallel cross analyses of inbred lines.
299

Development of a full potential solver for rotor aerodynamics analysis

Prichard, Devon S. 05 1900 (has links)
No description available.
300

Helicopter rotor dynamic inflow modeling for maneuvering flight

Krothapalli, Krishnamohan Rao 08 1900 (has links)
No description available.

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