Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (p. 89-95).

Thesis--Auburn University, 2009. / Abstract. Vita. Includes bibliographical references (p. 95-97).

Thesis (M.S.)--Rochester Institute of Technology, 2009. / Typescript. Includes bibliographical references (leaves 36-39).

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: visual; clutter; measurement; reduction; information; visualization; air traffic. Includes bibliographical references. (p.64-66)

Thesis (MEng)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: Increasing air traffic and urbanisation has led to a cluttered airspace, particularly near airports, where both complex terrain and multiple moving obstacles are frequent. Accurately and efficiently predicting violations in safe separation criteria for commercial aircraft, a process called conflict detection, is therefore crucial in assessing risk associated with threats of collision. Existing avoidance systems in operation such as TCAS, EGPWS and ATC exhibit shortcomings, leaving room for uncertainty and possible conflict scenarios. A single on-board system capable of minimising errors in prediction would inform conflict resolution decisions more accurately as well as support the notion of free flight, an objective of next-generation air traffic management systems. This thesis investigates the viability of a modern algorithm, probability flow, as a method of probabilistic conflict detection for commercial aircraft in airport environments. Simulation results for realistic flight scenarios are presented in comparison with a ground-truth result obtained through Monte Carlo simulation. Observations are made regarding the suitability of probability flow for real-world application. It is found that probability flow is capable of calculating a tight upper bound to the probability of conflict quickly and accurately for most conflict scenarios. However, unreasonably large overestimates on the probability of conflict are obtained when flying parallel to an obstacle conflict region. This problem could lead to a high frequency of false alerts, particularly in aborted landing scenarios and at airports operating parallel runways. It is therefore advised that further research be conducted to resolve this problem before probability flow can be reliably implemented in an airport environment. / AFRIKAANSE OPSOMMING: Toenemende lugverkeer en verstedeliking het gelei tot ‘n deurmekaar lugruim, veral naby lughawens, waar beide komplekse terrein en verskeie bewegende struikelblokke gereeld voorkom. Akkuraat en doeltreffende voorspelling van oortredings in veilige skeidingskriteria vir kommersiële vliegtuie, naamlik konflik opsporing, is dus van kardinale belang in die beoordeling van die risiko wat verband hou met dreigemente van ‘n botsing. Bestaande vermyding stelsels in werking soos TCAS, EGPWS en ATC toon tekortkominge, wat ruimte laat vir onsekerheid en moontlike konflik scenario’s. ‘n Enkele aanboordstelsel, wat in staat is om foute in voorspelling te verminder, sou konflikresolusie besluite meer akkuraat in kennis stel, asook om die idee van vrye vlug te ondersteun, ‘n doelwit van toekomstige lugverkeer beheerstelsels. Hierdie tesis ondersoek die lewensvatbaarheid van ‘n moderne algoritme, waarskynlikheidsvloei, as ‘n metode van probabilistiese konflik opsporing vir kommersiële vliegtuie in die lughawens omgewing. Simulasie resultate vir realistiese vlug scenario’s word aangebied in vergelyking met ‘n grond-waarheid resultaat wat verkry word deur middel van Monte Carlo simulasie. Waarnemings word gemaak ten opsigte van die geskiktheid van waarskynlikheidsvloei vir die werklikheid. Dit is bevind dat waarskynlikheidsvloei in staat is om die berekening van ‘n stywe bogrens tot die waarskynlikheid van konflik vinnig en akkuraat te bepaal vir die meeste konflik scenario’s. Tog is daar ‘n onredelike groot oorskatting op die waarskynlikheid van konflik wat verkry word wanneer ‘n vliegtuig parallel met ‘n hindernis konflik streek vlieg. Hierdie probleem kan lei tot ‘n hoë frekwensie van valse waarskuwings, veral in mislukte landing scenario’s en by lughawens wat van parallel aanloopbane gebruik maak. Dit word dus aanbeveel dat verdere navorsing gedoen word om die probleem op te los voordat waarskynlikheidsvloei betroubaar in ’n lughawe omgewing geïmplementeer word.

In aviation, the demand for air traffic grows at a higher rate than the capacity. As the demand is predicted to continue to grow also in the future, so is the problem of capacity shortage. If the capacity cannot match the demand, it will result in congestion and delay. There are numerous factors that limit the capacity both on airside and landside, for example the runway capacity, noise restrictions, the environment surrounding the airport etc. Actors such as airlines, ground service companies, ICAO and IATA also affect and are affected by the available capacity. When planning opening of new airports or in case of changes in the location and size of the airports, the requirement for, as well as the currently available capacity must be examined. Previous studies regarding key limiting factors to air traffic capacity, address different constraints, but lack a comprehensive view. A compilation of air traffic constraints would therefore be a valuable tool in airport planning when capacity demand changes. The aim of this thesis was to identify key limiting factors and see how they affect air traffic. This thesis analyses the importance of different limiting factors in respect to the level of significance to which previous research has acknowledged the different constraints. To compliment the literature review, professionals in airport planning were interviewed. The result from the literature review as well as the interviews showed that the major limiting factor to air traffic capacity is the runway. The runway was also the factor that was affecting as well was affected by other limiting factors. Previous literature considered wake vortex to be the second most important constraint whereas the interviewees considered stands to be the runner up limiting factor. In conclusion, this thesis showed that the runway is the most important limiting factor to air traffic capacity. The thesis also showed that different limiting factors are closely linked to each other. For an overall understanding of air traffic capacity constraints and how these constraints affect air traffic flow, it is essential to understand the interaction between the limiting factors.

Radiotelephony between air traffic controllers and pilots utilises standard phraseology as the medium of communications. Standard phraseology employs specific structure, terminology and pronunciation to ensure effectiveness and accuracy. On occasions when standard phraseology is found insufficient, plain language is used to efficiently relay vital information. By default, English is the designated language of communication between controllers and pilots of international flights. Deviations from the usage of standard phraseology and lack of language proficiency had been identified as one of the causal factors in safety occurrences. Language deficiencies, specifically of the non-native speakers of the English language, had raised much concern but there is limited information in the area. This research attempted to fill a small segment of this knowledge gap. It was focussed on the usage of standard phraseology and English language in an air traffic control environment involving English Second Language users. Audio data was sourced from routine radiotelephony recordings of ‘live’ air traffic control facilities in Malaysia to capture realistic communications between controllers and pilots in the Terminal Approach Radar, Area Radar and Aerodrome Control environments. A detailed cross sectional investigation of the radiotelephony characteristics, deficiencies and errors of transmitted messages revealed the radiotelephony performances of controllers and pilots in the environments. The recurrence of deviations from standards and occurrence of errors implied the likelihood of such deficiencies taking place. Demographic groups’ descriptions complemented the radiotelephony analyses as background information on language related training. The results were comparative to other similar studies and offered new information on English Second Language speakers in the Air Traffic Control environment.

abstract: This study examined the impact of Situation Presence Assessment Method (SPAM) administration on air traffic control (ATC) students’ task workload and performance in high-fidelity ATC simulations. ATC students performed high-fidelity en-route simulations in two conditions: baseline conditions (without SPAM questions) and SPAM conditions. The data collected show that while workload in the two conditions were not significantly different, there was a trend of higher mental workload in SPAM conditions than in baseline conditions. Performance immediately following SPAM questions was revealed to be poorer than that preceding the SPAM questions and that over the equivalent time periods in the baseline conditions. The results suggest that a "Ready" signal before a SPAM question may not be enough to eliminate the impact of SPAM administration on ATC students’ workload and performance in high-fidelity en-route simulations. / Dissertation/Thesis / Masters Thesis Technology 2016

This paper formally analyzes the role of yearly snowfall in explaining the changes in home valuations near ski resorts in the western United States. Using data on housing values for selected U.S. Census tracts, combined with detailed weather data, passenger arrival data from 10% of all commercial air traffic, and characteristics of nearby ski resorts, I find precise and consistent estimates of days of snowfall and number of available destinations by airport on housing values.

M.Sc. / This thesis investigates how intelligent agents can be used to solve airline scheduling problems. It is divided into three parts. The first states what airline scheduling consists of; the second discusses the results of a literature study; and the third consists of solutions to the problem. Airline scheduling consists of three major activities viz. market-driven flight generation, crew assignment and operational problem management. The market schedulers first create a flight set based on a forecast of passenger numbers and passenger preferences. The crew schedulers attempt to crew the flights generated by the market schedulers (subject to safety and rest regulations). The operational schedulers maintain the flights from seven days prior to the day of operation to one day after the end of the flight. Finding a global solution to this three-phase operation is the airline scheduling problem. An agent-based solution to the airline scheduling problem was the focus of this thesis. Agents encapsulate many useful artificial intelligence solution strategies. For the proposed solution to the market driven scheduling problem a distributed negotiation scheme using agents was used. A routing and an assignment agent were defined to assist the crew scheduler. Finally an operational scheduling agent was defined to solve the operational scheduling problem. The routing and assignment agents make use of FIFOqueues and genetic algorithms. The operational scheduling agent makes use of a traditional expert system combined with a learning algorithm to give it more flexibility. A prototype, developed in Java, was used to demonstrate how agents could solve the market driven scheduling problem. This distributed negotiation scheme was implemented on Sun SPARC workstations running the Solaris operating system. A prototype developed in Delphi was also developed to show how learning algorithms could be applied to the scheduling environment.