Transit agencies have the opportunity to improve the delivery of services by using data from Intelligent Transportation Systems (ITS). On-time performance is an important measure. The objective of this paper is to adjust the timetables so that the probability of on-time performance is maximized. For this purpose we analyze data distributions of travel time and also consider the general case that data distribution is unknown. Statistical procedures are presented to find scheduled time for some selected distributions. Monte Carlo simulation is introduced for the purpose of finding scheduled time when data distribution is not known. Simulation studies indicate that the on-time performance would increase using the proposed methodology. The contribution of this paper is to provide transit system a procedure to set up or update their timetables based on current ITS data and its distribution, and hence increase level of service.

No description available.

In this research, statistical models of airport delay and single flight arrival delay were developed. The models use the Airline On-Time Performance Data from the Federal Aviation Administration (FAA) and the Surface Airways Weather Data from the National Climatic Data Center (NCDC). Multivariate regression, ANOVA, neural networks and logistic regression were used to detect the pattern of airport delay, aircraft arrival delay and schedule performance. These models are then integrated in the form of a system for aircraft delay analysis and airport delay assessment. The assessment of an airport¡¯s schedule performance is discussed. The results of the research show that the daily average arrival delay at Orlando International Airport (MCO) is highly related to the departure delay at other airports. The daily average arrival delay can also be used to evaluate the delay performance at MCO. The daily average arrival delay at MCO is found to show seasonal and weekly patterns, which is related to the schedule performance. The precipitation and wind speed are also found contributors to the arrival delay. The capacity of the airport is not found to be significant. This may indicate that the capacity constraint is not an important problem at MCO. This research also investigated the delays at the flight level, including the flights with delay ¡Ý0 minute and the flights with delay ¡Ý15min, which provide the delay pattern of single arrival flights. The characteristics of single flight and their effect on flight delay are considered. The precipitation, flight distance, season, weekday, arrival time and the time spacing between two successive arriving flights are found to contribute to the arrival delay. We measure the time interval of two consecutive flights spacing and analyze its effect on the flight delay and find that for a positively delayed flight, as the time space increases, the probability of the flights being delayed will decrease. While it was possible to calculate the immediate impact of originating delays, it is not possible to calculate their impact on the cumulative delay. If a late departing aircraft has no empty space in its down line schedule, it will continue to be late. If that aircraft enters a connecting airport, it can pass its lateness on to another aircraft. In the research we also consider purifying only the arrival delay at MCO, excluding the flights with originating delay >0. The model makes it possible to identify the pattern of the aircraft arrival delay. The weather conditions are found to be the most significant factors that influence the arrival delay due to the destination airport.

International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / There are two basic approaches to developing data acquisition systems. The first is to buy or develop acquisition hardware and to then write software to input, identify, and distribute the data for processing, display, storage, and output to a network. The second is to design a system that handles some or all of these tasks in hardware instead of software. This paper describes the differences between software-driven and hardware-driven system architectures as applied to real-time data acquisition systems. In explaining the characteristics of a hardware-driven system, a high-performance real-time bus system architecture developed by L-3 will be used as an example. This architecture removes the bottlenecks and unpredictability that can plague software-driven systems when applied to complex real-time data acquisition applications. It does this by handling the input, identification, routing, and distribution of acquired data without software intervention.

O gerenciamento de projetos é amplamente utilizado por organizações em âmbito mundial. Projetos de sistemas de informação, especificamente, auxiliam tais organizações a obterem sistemas a serem utilizados em suas atividades operacionais com alinhamento estratégico junto a seus objetivos, garantindo maior eficiência, alcance de melhores resultados e perenidade de sua atuação no mercado. O gerenciamento de escopo é uma das áreas de conhecimento do gerenciamento de projetos, responsável por garantir que todos os objetivos do projeto sejam conhecidos por todos os envolvidos, declarando o que será entregue e qual será o trabalho necessário para tal. O gerenciamento de escopo demanda alto nível de relacionamento entre equipes desenvolvedoras dos projetos e os clientes solicitantes. Tais clientes possuem expectativas e limitações quanto aos projetos solicitados, sendo necessário seu acompanhamento e alinhamento com a área executora para garantir que suas necessidades sejam atendidas de acordo com seu planejamento e expectativa. Acompanhar o desempenho em diversas dimensões dos projetos é importante para garantir que o resultado final esteja adequado às necessidades originais, tanto considerando-se o produto entregue pelo projeto quanto a execução do projeto em si. Duas das características mais relevantes para os projetos são seu custo e tempo de execução. Desempenhos adequados de custo e tempo dos projetos são importantes, considerando-se que as entregas são relevantes para um determinado tempo de término e com um determinado custo para sua realização. Nesta pesquisa foi realizada a avaliação da relação de processos de planejamento do gerenciamento de escopo com desempenhos de custo e tempo de projetos de SI de uma organização brasileira de grande porte do setor financeiro. Por meio da avaliação da aderência dos processos executados na instituição estudada às práticas indicadas pela literatura, foi possível identificar o nível de aderência da instituição quanto ao gerenciamento de escopo. Esta avaliação foi então relacionada aos desempenhos de custo e tempo, identificando possíveis influências. Considerando-se ainda a amostra de projetos, os gerentes de projetos que os conduziram responderam questionários indicando problemas ocorridos relacionados ao desempenho de custo e tempo dos projetos, possibilitando a identificação de impactos provenientes do gerenciamento de escopo. Por fim, foram aplicadas entrevistas aos clientes que solicitaram os projetos selecionados à área de tecnologia da informação da organização, com o objetivo de identificar causas e comportamentos das relações identificadas anteriormente. Foi possível concluir que a organização analisada possuía baixa aderência às práticas de gerenciamento de escopo. O processo de coleta de requisitos foi identificado como o principal processo relacionado aos desempenhos dos projetos e como o processo foco de maior atenção dos gerentes de projetos e clientes, com maior conhecimento de processos do modelo de desenvolvimento de sistemas de informação do que do gerenciamento de projetos. Nos projetos analisados o planejamento do gerenciamento de escopo não foi uma variável que teve um alto grau de associação com os desempenhos de custo e tempo, podendo explicá-lo adequadamente. Por outro lado, o gerenciamento de escopomostrou ser um fator de forte influência no desempenho dos projetos, pois ensejou mudanças na organização. / Project management is widely used by organizations worldwide. Information systems projects, specifically, assist such organizations get systems to be used in its operational activities with strategic alignment to your goals, ensuring greater efficiency, better results reach and perenniality of its market performance. The scope management is one of the project managements knowledge areas, responsible for ensuring that all project objectives are known by everyone involved, declaring what will be delivered and what will be the work required to such. Scope management demands high level of relationship between developers teams of the projects and the requesting clients. Such customers possess expectations and limitations with the requested projects, being necessary monitoring and alignment with the executing area to ensure that the needs will be met according with their planning and expectation. Track the performance in several dimensions of the projects is important to ensure that the end result is suited to unique needs, both considering the delivered product, as the course of entire project. Two of the most important characteristics of the projects are cost and runtime. Suitable cost performances and time of execution in the projects are important, considering that often such characteristics of projects are directly related to the expected results. In this research was held the assess the relationship the planning processes of scope management with performances of cost and time of SI projects of a Brazilian big organization in the financial sector. Through valuation of adherence of processes executed to good practices, was possible to identify the organization\'s maturity level about the scope management. This review was then related to costs and times of the projects, identifying possible influences. Considering still the selected projects for research, project managers responsible for these projects responded questionnaires indicating occurred problems related to performances of cost and time, enabling the identification of impacts coming from the scope management. Finally, interviews were applied to customers who requested the selected projects to the organization\'s information technology area, aiming to identify causes and behaviors of previously identified relations. It was possible to conclude that the analyzed organization possessed a low level of maturity about the management scope, having low adherence to good practices presented in the literature and followed by the organization. The process of requirements gathering was identified as the main proceedings related to the performance of the projects and as the process focus of more attention from projects managers and customers, with greater knowledge of information systems development methodology processes than project management processes. In the analyzed projects, scope management\'s planning was not a variable that had a high degree of association with the cost and time performances, explaining it properly. Moreover, scope management proved to be a strong influencing factor in the performance of projects, because gave rise changes in the organization.

O gerenciamento de projetos é amplamente utilizado por organizações em âmbito mundial. Projetos de sistemas de informação, especificamente, auxiliam tais organizações a obterem sistemas a serem utilizados em suas atividades operacionais com alinhamento estratégico junto a seus objetivos, garantindo maior eficiência, alcance de melhores resultados e perenidade de sua atuação no mercado. O gerenciamento de escopo é uma das áreas de conhecimento do gerenciamento de projetos, responsável por garantir que todos os objetivos do projeto sejam conhecidos por todos os envolvidos, declarando o que será entregue e qual será o trabalho necessário para tal. O gerenciamento de escopo demanda alto nível de relacionamento entre equipes desenvolvedoras dos projetos e os clientes solicitantes. Tais clientes possuem expectativas e limitações quanto aos projetos solicitados, sendo necessário seu acompanhamento e alinhamento com a área executora para garantir que suas necessidades sejam atendidas de acordo com seu planejamento e expectativa. Acompanhar o desempenho em diversas dimensões dos projetos é importante para garantir que o resultado final esteja adequado às necessidades originais, tanto considerando-se o produto entregue pelo projeto quanto a execução do projeto em si. Duas das características mais relevantes para os projetos são seu custo e tempo de execução. Desempenhos adequados de custo e tempo dos projetos são importantes, considerando-se que as entregas são relevantes para um determinado tempo de término e com um determinado custo para sua realização. Nesta pesquisa foi realizada a avaliação da relação de processos de planejamento do gerenciamento de escopo com desempenhos de custo e tempo de projetos de SI de uma organização brasileira de grande porte do setor financeiro. Por meio da avaliação da aderência dos processos executados na instituição estudada às práticas indicadas pela literatura, foi possível identificar o nível de aderência da instituição quanto ao gerenciamento de escopo. Esta avaliação foi então relacionada aos desempenhos de custo e tempo, identificando possíveis influências. Considerando-se ainda a amostra de projetos, os gerentes de projetos que os conduziram responderam questionários indicando problemas ocorridos relacionados ao desempenho de custo e tempo dos projetos, possibilitando a identificação de impactos provenientes do gerenciamento de escopo. Por fim, foram aplicadas entrevistas aos clientes que solicitaram os projetos selecionados à área de tecnologia da informação da organização, com o objetivo de identificar causas e comportamentos das relações identificadas anteriormente. Foi possível concluir que a organização analisada possuía baixa aderência às práticas de gerenciamento de escopo. O processo de coleta de requisitos foi identificado como o principal processo relacionado aos desempenhos dos projetos e como o processo foco de maior atenção dos gerentes de projetos e clientes, com maior conhecimento de processos do modelo de desenvolvimento de sistemas de informação do que do gerenciamento de projetos. Nos projetos analisados o planejamento do gerenciamento de escopo não foi uma variável que teve um alto grau de associação com os desempenhos de custo e tempo, podendo explicá-lo adequadamente. Por outro lado, o gerenciamento de escopomostrou ser um fator de forte influência no desempenho dos projetos, pois ensejou mudanças na organização. / Project management is widely used by organizations worldwide. Information systems projects, specifically, assist such organizations get systems to be used in its operational activities with strategic alignment to your goals, ensuring greater efficiency, better results reach and perenniality of its market performance. The scope management is one of the project managements knowledge areas, responsible for ensuring that all project objectives are known by everyone involved, declaring what will be delivered and what will be the work required to such. Scope management demands high level of relationship between developers teams of the projects and the requesting clients. Such customers possess expectations and limitations with the requested projects, being necessary monitoring and alignment with the executing area to ensure that the needs will be met according with their planning and expectation. Track the performance in several dimensions of the projects is important to ensure that the end result is suited to unique needs, both considering the delivered product, as the course of entire project. Two of the most important characteristics of the projects are cost and runtime. Suitable cost performances and time of execution in the projects are important, considering that often such characteristics of projects are directly related to the expected results. In this research was held the assess the relationship the planning processes of scope management with performances of cost and time of SI projects of a Brazilian big organization in the financial sector. Through valuation of adherence of processes executed to good practices, was possible to identify the organization\'s maturity level about the scope management. This review was then related to costs and times of the projects, identifying possible influences. Considering still the selected projects for research, project managers responsible for these projects responded questionnaires indicating occurred problems related to performances of cost and time, enabling the identification of impacts coming from the scope management. Finally, interviews were applied to customers who requested the selected projects to the organization\'s information technology area, aiming to identify causes and behaviors of previously identified relations. It was possible to conclude that the analyzed organization possessed a low level of maturity about the management scope, having low adherence to good practices presented in the literature and followed by the organization. The process of requirements gathering was identified as the main proceedings related to the performance of the projects and as the process focus of more attention from projects managers and customers, with greater knowledge of information systems development methodology processes than project management processes. In the analyzed projects, scope management\'s planning was not a variable that had a high degree of association with the cost and time performances, explaining it properly. Moreover, scope management proved to be a strong influencing factor in the performance of projects, because gave rise changes in the organization.

Introduction of Doppler ultrasound techniques into the Intensive Care setting has revolutionised the way haemodynamic status is monitored in the critically ill. However, in order to increase the usefulness of these techniques, the Doppler signal and its spectrum need to be further analysed in ways to facilitate a better clinical response. Extensive processing of the Doppler spectrum on Diagnostic ultrasound machines is limited by the real time performance considerations. It was therefore proposed that the spectral information from these systems be extracted off-line and full set of analytical tools be made available to evaluate this information. This was achieved by creating an integrated and modular software tool called Spectron, which was intended as an aid in the overall management of the patients. The modular nature of Spectron was intended to ensure that new analytical tools and techniques could be easily added and tested. The software provides its users with considerable latitude in choosing various data acquisition and analysis parameters to suit various clinical situations and patient requirements. Spectron was developed under the Windows environment to provide a user friendly interface and to address a range of programming problems such as memory management and the size of the colour palettes. Spectron is able to detect the maximal velocities and compute the mean and median velocities. Relative increases in maximal velocities in cardiac blood flows after the administration of inotropic drugs have been shown in the pilot studies that were conducted. Spectron is able to help in obtaining estimates of the aortic blood flows and in other applications such measuring vascular impedance. Stenotic blood flows can be detected by using the spectral broadening index and blood flow characteristics can be studied by using various blood flow indices. Thus, this project attempted to help in patient management by providing clinicians with a range of blood flow parameters and has succeeded in meeting its objective to a large extent / Master of Engineering (Hons)

Doctor of Philosophy / Economics / Philip G. Gayle / This dissertation consists of three essays on product quality in commercial aviation. Since the mid-1990s, major airlines that serve the U.S. domestic market have increasingly found it appealing to form alliances. Amidst the recent emergence of airline alliance formation, this dissertation has sought to answer questions on the product quality implications of policies regarding cooperation among airlines in the U.S. domestic air travel industry. A challenge that empirical work faces in studying the relationship between airline alliances and product quality is to find reasonable measure(s) of product quality. The first essay sheds light on whether the route network integration that comes with an airline alliance provides sufficient extra incentive to partner carriers to improve their flight routing quality. Evidence suggests that routing quality for Delta/Continental/Northwest's--our alliance of interest--products decreases in markets where pre-alliance competition among alliance partners exists, resulting in substantial negative welfare effects for passengers. In fact, routing quality for Delta/Continental/Northwest products decreased by 0.256% below the mean routing quality of the entire sample's products. More interestingly, the codeshare effects in specific markets where the alliance firms competed prior to the alliance, are also negatively associated with routing quality of the alliance firms' products, resulting in a fall in consumer utility of $0.5 per consumer. The second essay explores the potential relationship between on-time performance and airline code-sharing. Although flight delay has always received much attention, we are unaware of any empirical research that measures the on-time performance effects of airline alliances. We empirically investigate the on-time performance effects of the largest U.S. domestic alliance that began in June 2003--an alliance between Delta Air Lines, Northwest Airlines and Continental Airlines. We find evidence that code-sharing improves alliance partners' on-time performance and that the size of the alliance effect on on-time performance depends on pre-alliance competition in a market, with the effect being larger in markets where the partners competed in prior to the alliance. Using a structural econometric model, the third essay attempts to provide an alternative explanation to a long-standing question: why are airlines late? Airlines usually claim that air travel delays are out of their control, placing the blame on adverse weather or air traffic control as the most common reasons. Despite these claims, data on causes of flight delay reveal that the share of delay caused by weather and air traffic control has been on the decline while the share of delay caused by airlines has been on the rise. This suggests that on-time performance improvement is well within the reach of carriers. We investigate why airlines have little or no incentive to improve on-time performance. We also measure the cost of delay borne by consumers in terms of how much monetary value they are willing to pay to avoid delay. We find that consumers are willing to pay $0.78 for every minute of arrival delay which after extrapolation, amounts to consumer welfare effects of $1.76 billion. Our findings suggest that airlines have little to no incentive because their markups do not increase when they improve on-time performance. In fact, the marginal increase in price resulting from on-time performance improvement is offset by an increase in marginal cost causing a zero net effect on markup.

This is a report of a professional project intended to act as an informational tool for the evaluation of a dynamic dispatch system at Embarcadero Station for the San Francisco Municipal Transportation Agency (SFMTA). Systems that operate dispatch algorithms do so in response to on-time performance and reliability. The optimization problem is documented in many transportation contexts including airline networks, bus dispatch, and freight routing. According to the research, optimizing available options and re-routing based on available options can create a more efficient system that would minimize operating costs and improving service reliability for customers. The methodology presented here uses current headway information to dynamically change dispatch assignment between J, L, and M lines. The reassignment program was applied to randomly selected weekdays in March of 2012. After analysis it was determined that the application has the potential to decrease mean operating headways by up to 3% (or approximately 15 seconds).

No description available.