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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.
41

Proposta de aplicação de sistema de inferência neuro-fuzzy para otimização de tráfego

Gobbo, Alexandre Fadel 10 2010 (has links)
It is proposed in this dissertation a traffic optimization model based on neuro-fuzzy inference systems (ANFIS) to be applied in real-time optimization, targeting the architecture of the traffic control system deployed in the city of Curitiba, considering its properties and restrictions. The model presented herein has a similar approach to the best known dynamic traffic optimization system, SCOOT, implementing hill-climbing optimization on a performance index defined as a weighted sum of the links' measures of effectiveness. However, the nature of the traffic flow sampling in Curitiba, by not distinguishing the flow tuning rates, implies the simulation model should be closer to those implemented by offline traffic simulation tools. Transyt, which is one of the most popular offline traffic simulators, was used in order to generate training data and as a reference to validate the results. Real-time optimization based on the mathematical model of Transyt cannot be applied to systems with a large number of intersections in the current state of technology, due to the high computational costs of the algorithms, unless by imposing restrictions on the search space. ANFIS was used in order to capture the knowledge of the simulator, which means to approximate Transyt's outputs. ANFIS was chosen due to its precision and low execution time. Its estimations made it possible the real-time execution of optimization algorithms for a very large number of intersections. Regarding the optimization processes, well-known methods such as EQUISAT and hill-climbing were used. A hybrid optimization method was also validated using a genetic algorithm to provide an initial state for the hill-climbing method. / Neste trabalho propõe-se um método de otimização de tráfego baseado em sistemas de inferência neuro-fuzzy (ANFIS). Esse método deve ser aplicável a um contexto de otimização em tempo real e orientado à arquitetura do sistema de controle de tráfego da cidade de Curitiba, considerando suas características e restrições. O modelo proposto apresenta similaridades com o principal sistema de otimização dinâmica de tráfego existente, denominado SCOOT, empregando o método hill-climbing sobre um índice de desempenho calculado pela ponderação das estimativas de eficiência dos links. Entretanto, a amostragem de dados de fluxo no sistema de Curitiba, por não fornecer medida das conversões em tempo real, determina que o modelo de simulação seja mais aproximado ao utilizado por ferramentas offline de otimização. Empregou-se o Transyt, uma das mais populares ferramentas de simulação e otimização offline, na geração de dados de treinamento ao ANFIS e como referência para validação dos resultados. O alto custo computacional do modelo matemático implementado no Transyt impede sua aplicação na otimização em tempo real de um grande número de cruzamentos sem que se imponha restrições no espaço de busca. Utilizou-se o ANFIS para extrair o conhecimento do simulador, ou seja, aproximar seus resultados. Optou-se pelo ANFIS por apresentar boa precisão e baixo custo computacional e assim sua utilização viabilizou a execução de algoritmos de otimização para um grande número de cruzamentos. Com relação aos processos de otimização, utilizou-se métodos consagrados como o EQUISAT e o hill-climbing, mas também foi avaliado o uso de um algoritmo genético para geração de um estado inicial ao hill-climbing, em um otimizador híbrido.
42

Proposta de aplicação de sistema de inferência neuro-fuzzy para otimização de tráfego

Gobbo, Alexandre Fadel 10 2010 (has links)
It is proposed in this dissertation a traffic optimization model based on neuro-fuzzy inference systems (ANFIS) to be applied in real-time optimization, targeting the architecture of the traffic control system deployed in the city of Curitiba, considering its properties and restrictions. The model presented herein has a similar approach to the best known dynamic traffic optimization system, SCOOT, implementing hill-climbing optimization on a performance index defined as a weighted sum of the links' measures of effectiveness. However, the nature of the traffic flow sampling in Curitiba, by not distinguishing the flow tuning rates, implies the simulation model should be closer to those implemented by offline traffic simulation tools. Transyt, which is one of the most popular offline traffic simulators, was used in order to generate training data and as a reference to validate the results. Real-time optimization based on the mathematical model of Transyt cannot be applied to systems with a large number of intersections in the current state of technology, due to the high computational costs of the algorithms, unless by imposing restrictions on the search space. ANFIS was used in order to capture the knowledge of the simulator, which means to approximate Transyt's outputs. ANFIS was chosen due to its precision and low execution time. Its estimations made it possible the real-time execution of optimization algorithms for a very large number of intersections. Regarding the optimization processes, well-known methods such as EQUISAT and hill-climbing were used. A hybrid optimization method was also validated using a genetic algorithm to provide an initial state for the hill-climbing method. / Neste trabalho propõe-se um método de otimização de tráfego baseado em sistemas de inferência neuro-fuzzy (ANFIS). Esse método deve ser aplicável a um contexto de otimização em tempo real e orientado à arquitetura do sistema de controle de tráfego da cidade de Curitiba, considerando suas características e restrições. O modelo proposto apresenta similaridades com o principal sistema de otimização dinâmica de tráfego existente, denominado SCOOT, empregando o método hill-climbing sobre um índice de desempenho calculado pela ponderação das estimativas de eficiência dos links. Entretanto, a amostragem de dados de fluxo no sistema de Curitiba, por não fornecer medida das conversões em tempo real, determina que o modelo de simulação seja mais aproximado ao utilizado por ferramentas offline de otimização. Empregou-se o Transyt, uma das mais populares ferramentas de simulação e otimização offline, na geração de dados de treinamento ao ANFIS e como referência para validação dos resultados. O alto custo computacional do modelo matemático implementado no Transyt impede sua aplicação na otimização em tempo real de um grande número de cruzamentos sem que se imponha restrições no espaço de busca. Utilizou-se o ANFIS para extrair o conhecimento do simulador, ou seja, aproximar seus resultados. Optou-se pelo ANFIS por apresentar boa precisão e baixo custo computacional e assim sua utilização viabilizou a execução de algoritmos de otimização para um grande número de cruzamentos. Com relação aos processos de otimização, utilizou-se métodos consagrados como o EQUISAT e o hill-climbing, mas também foi avaliado o uso de um algoritmo genético para geração de um estado inicial ao hill-climbing, em um otimizador híbrido.
43

Traffic generation in the north arm industrial area

Pendakur, Venkatachala Setty January 1958 (has links)
In the constantly changing pattern of our cities, it is the task of the planner to guide these changes towards desired objectives. During the period of rapid growth, the structures created in the past and the needs of the present conflict, giving rise to the various problems that the planner has to face. Perhaps one of the most dramatic, undoubtedly one of the most discussed, and surely one of the most frustrating of these conflicts has manifested itself in the problem of moving persons and goods, and of the vehicles that transport them through our cities. In one generation the motor vehicle has become as much a part of our lives as has the toothbrush. The experience of the past few years has shown us how essential and important is highway transportation to our economy. Naturally, with the fast-growing transportation service, serious problems have arisen. Streets and highways have become outmoded and unsuited for present day traffic volume and speed, congestion and delays have become serious, especially in the cities; and Metropolitan Vancouver is no exception. With the expected increase in population and automobiles in the Vancouver Metropolitan Area, the traffic is bound to increase in all directions by 1971. Traffic to and from industrial areas is a problem that the planner faces everywhere, and the traffic created by the journey to work is a main problem in our metropolitan areas. The North Arm Industrial Area is an off-centre one in Metropolitan Vancouver. It has an area of 3,018 acres, of which only 386 acres were fully developed in 1955. It offers adequate open space for industry, which has been choked elsewhere in other central areas. Thus, in future, it is bound to become one of the important centers of industrial activity in the Metropolitan area. The study presents a forecast of traffic volumes for 1971 in the North Arm Area and points out the planning implication of the predicted volumes. If fully developed by 1971, as has been assumed in the study, this area is expected to have a total traffic volume of 23,200 trips per day, out of which 19,500 trips per day are expected to be home-to-work trips made during the peak hours. As at present, the arterial system lacks proper bridges to Lulu Island and is congested during peak hours. The traffic problem in our Metropolitan area is only beginning and only bold plans, continually amended, and equally bold programs of road construction can hope to meet this problem. Alternately, the growth of traffic could be controlled by restricting the land use and diverting the industries to other areas. Peak hour traffic of journey-to-work could be, to some extent, solved by staggered working hours. Building of low rental housing for industrial workers within walking distance from their work places could also be thought of as a solution to this expected problem. However, if the planners do not act in time, the traffic in this area could strangle its own circulation and become costly to handle / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
44

Heliports : their location in the central business district.

Wieler, Verner Jacob January 1958 (has links)
The helicopter represents a revolutionary approach to flight. Its most important characteristic is its flexibilily; it climbs and descends vertically, it hovers in mid-air, and it travels at relatively slow and fast speeds. Therefore, it presents a vehicle which has great potential in operating within or directly above the physically dense central business district, carrying passenger and freight traffic. Helicopter transportation is now taking root in several large metropolitan cities, and more cities are considering the installation of such a service. It appears that the helicopter will become a strong member of the urban transportation system in the near future, and therefore steps should be taken in advance of its advent to insure a proper location of the heliport, as well as an efficient route pattern within the metropolitan city. It is felt that the helicopter will be most restricted in its operation within the central business district, and at the same time will carry its greatest payload in and out of the central business district. Therefore, the location of one or a pattern of heliports within the central business district, becomes a fundamental issue to helicopter transportation. Several studies have been undertaken which considered the heliport location in light of the technical requirements of the helicopter, and to some degree the potential traffic which the helicopter might bear. The heliport location criteria which evolved reflected this more general approach, particularly to traffic generating areas. The studies did not consider individual land uses which might directly or indirectly cause the failure of a heliport because the particular characteristics of the land uses could not support helicopter transportation. Using former studies, therefore, as a basis for further research, this study has attempted to analyze traffic generating areas as they affect helicopter transportation. In this respect, the land uses of the central business district and the traffic that such land uses create have become the focal point of the study. The study draws certain conclusions with respect to heliport locations in the central business district. First; it recognizes the overlapping effects of specific land uses and the technical limitations of the helicopter on the choice of location. Although it is felt the land use factors are essentially determining over a period of time, the technical limitations create problems which must be dealt with, with equal urgency, and in some cases might initially control location. However, in all cases, the land use factors should receive precedence in the establishment of location criteria. It is the land use criteria that will determine the long-range success of the helicopter service. Secondly; the heliport should be located in the "auto-oriented" areas of the central business district, but should be closely associated with the "walking" area of the specific types of central business district workers who may be expected to be the major users of helicopter transportation. Thirdly; the technical characteristics of the helicopter require that the heliport have an area of approximately four acres. In addition, it should have a bi-directional approach route with an obstruction profile ratio minimum of 1:8, with allowance for emergency landings outward to the critical point in the take-off pattern. The problem of noise associated with the helicopter in flight have been mentioned only in passing, this involves a detailed study of the mechanical parts of the helicopter which the author could not discuss with authority. However, the noise will have its affect on adjacent land uses to a considerable degree. The onus is on the helicopter manufacturer to attempt to reduce the noise to a compatible level. The location of a heliport on a water-front site seems particularly advantageous with respect to the lower cost of land and an obstruction-free landing and departure route. However, if the water-front location cannot satisfy the land use criteria which have been developed, and which generate the traffic potential, then such a location would prove to be inadequate. Furthermore, harbour regulations pertaining to shipping in the area may result in the negation of the values of a particular water-front location from the standpoint of the land use criteria. The study was limited in obtaining sufficient data on land use in relation to the movement of central business district workers. Such research is now underway but only to a limited degree. It is felt that the contribution of this study lies in its attempt to point out the influence of land uses on the generation of traffic, and the helicopter service developing on the basis of what traffic the specific land uses are generating. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
45

Traffic distribution and relief model based upon staggered working hours.

Taggart, James Stewart January 1968 (has links)
North American cities are becoming increasingly difficult to live in and to work in largely because they are difficult to move around in. For many cities vehicle congestion has reached a saturation level for streets and highways thus creating the problem of traffic congestion. This problem is universally understood to be the urban transportation problem. The transportation problem is largely a result of the growing concentration of population and economic activities within a small central area of land. Growth of population combined with rising incomes and increasing car ownership rates are continually increasing passenger and freight movement. With the increase of motor vehicles and vehicle usage the street system has proven inadequate to meet the increased demands for movement placed upon it. This inadequacy is particularly evident in the central urban areas during two relatively short periods of the day. These periods of peak traffic demand are a function of the journey to work. They occur twice in the typical day, the first being in the morning, the second occurring in the late afternoon. At other times during the day and night the street system, under normal conditions, is capable of handling the traffic demand. Thus there appears a need to bridge the growing gap between the demand for and supply of street facilities at peak hours. The basic approaches to the problem of bringing the demand for and supply of street facilities to a state of equilibrium are: to provide additional lanes of new or improved facilities to meet the traffic demands; to design developing areas on the basis of transportation demands and supply being in a state of equilibrium or to re-assign traffic to existing street facilities in accordance with the capacity of these facilities. The last method can be accomplished by staggering working hours. The purpose of this thesis is to demonstrate the hypothesis: that by the staggering of working hours in the central business district, the peak congestion problem can be relieved. The study demonstrates the effect of staggering hours, in quantitative terms, on a particular transportation facility, the First Narrows Bridge, Vancouver, British Columbia. The technique of staggering hours, in this study, is used to limit the volume of traffic by modifying the demand upon the system. This is accomplished by breaking the total demand into smaller demand segments, by giving each segment a different deadline. This method can in effect equate the demand with the supply over a given period of time. By this method the number of vehicles arriving at the entrance to an area of restricted capacity can be equated to the supply or capacity. By applying this method to the case study it is possible to demonstrate the effects of staggering in eliminating peak period congestion delay time due to the limited capacity of a facility. Also determinable is the extent that traffic loads need be distributed over a period of time and how much time would be needed to effect economies in the level of service. To minimize the disruption of the staggering of working hours, the C.B.D. was divided into four control areas or zones based on dominant function. The starting times of the functional zones or control areas are arranged in a work starting order so as to minimize functional disruption. It is concluded from the illustration of the case study that some relief of congestion is possible through the staggering of working hours; and that this method is one contribution to improving the ability of the individual motorist to travel more economically and possibly at a more rapid rate. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
46

Calibration of the gravity model using inter-urban truck data in B. C.

Baker, James Douglas January 1976 (has links)
This thesis concerns a survey of inter-regional or inter-urban commercial truck traffic at weigh scales in B.C. and how parts of the information collected can be used to calibrate a gravity model of the type proposed by the Federal Highways Administration (U. S. A.). The results of the calibration of both the 27 and 31 node models are compared with previous, calibration efforts In an intra-urban context. There is a relatively detailed presentation of the design and completion of this type of survey. Also, the role of the gravity model of trip distribution in the planning process is explained. A new method of determining the inter-zonal impedance is used. This impedance is based on trip cost and takes into account such things as type of terrain (level, rolling, mountainous). The results indicate that the calibration was successful. The use of the gravity model of trip distribution would appear to be an appropriate technique in the analysis of inter-urban commercial truck traffic. / Applied Science, Faculty of / Civil Engineering, Department of / Graduate
47

An approach to systems analysis and a proposed piecewise linear regression technique applied to car-following theory /

Hanken, Albert Frederik January 1965 (has links)
No description available.
48

Photogrammetric determination of traffic flow parameters /

Taylor, James I. January 1965 (has links)
No description available.
49

The multi-linear speed-density relationship and its immediate applications /

Lee, Joe January 1971 (has links)
No description available.
50

The dynamic scheduling approach to automated vehicle macroscopic control /

Rule, Ronald Gordon January 1973 (has links)
No description available.

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