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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.
91

Designing multimodal public transport networks using metaheuristics

Fletterman, Manuel 16 January 2009 (has links)
The public transport system in South Africa is in a precarious state, capturing no more than 50% of the passenger market. The three public transport modes that are currently utilized—train, bus, and minibus-taxi—are competing for market share instead of complementing one another. Furthermore, most public transport networks have not been properly redesigned over the past three decades. Improvements were initiated reactively in the past: transit stops and routes were added or removed from the network when demand fluctuated. This reactive process has diminished the confidence of commuters in the public transport networks, forcing commuters to use private transport. A proactive redesign method is needed—one that includes all the modes of public transport, and anticipates an increase in demand and rapid development in geographic areas, while ensuring good accessibility to the network. Current network design models do not include multiple modes of public transport, and are based on the geographical layout of developed cities and their particularities, which makes them unsuitable for the South African environment with its unique land use disparities. This dissertation proposes a multimodal network design model that is capable of designing real world and large scale networks for the South African metropolitan areas. The City of Tshwane Metropolitan Municipality (CTMM) transport network area was used to develop and test the model, which consists of four components. The Geographic Information System (GIS) component has a central role in storing, manipulating, and exchanging the geographic data within the model. For the GIS the appropriate input data is identified, and a design for the geo-database is proposed. The Population Generation Algorithm (PGA) component translates the demographic data into point data representing the transit demand in the study area. The Bus Stop Placement Algorithm (BSPA) component is a metaheuristic that searches for near-optimal solutions for the placement of bus stops in the study area. A novel solution approach proposed in this dissertation uses geographic data of commuters to evaluate the bus stop placement in the study area. The Multimodal Network Design Algorithm (MNDA) component also employs a metaheuristic, enabling the design of near-optimal multimodal networks. The addition of multiple modes to the Transit Network Design Problem (TNDP) is also a novel and significant contribution. The two metaheuristic components are first tested on a test network, and subjected to a comprehensive sensitivity analysis. After identifying suitable parameter values and algorithm settings, the components are applied to the entire CTMM. / Dissertation (MSc)--University of Pretoria, 2009. / Industrial and Systems Engineering / unrestricted
92

Impacto económico y social en los usuarios del Sistema de Transporte Metropolitano de Lima caso de estudio: corredor segregado de alta capacidad – COSAC I - El Metropolitano

Rodríguez Cuadros, Giulianna Victoria, Suárez Quiroz, Irene, Vilchez Castellanos, Sarita Iedayola 31 July 2018 (has links)
En el presente trabajo de investigación se analiza y estima el impacto económico y social del servicio de transporte público masivo El Metropolitano que utiliza como infraestructura el Corredor Segregado de Alta Capacidad – Cosac I. Este sistema se ha constituido como el principal medio de transporte de la ciudad de Lima por atributos como: la formalidad de su servicio, la infraestructura que ofrece, su modernidad, la rapidez, entre otros aspectos que se desarrollan en las siguientes páginas. El documento está dividido en ocho capítulos. El primero está referido a los fundamentos teóricos de la investigación, el segundo contiene una breve descripción de la realidad del transporte urbano de pasajeros y de los sistemas de transporte que existen en Lima Metropolitana, la oferta actual y en este marco, se contextualiza la problemática detectada en cuanto a la informalidad, falta de regulación, baja calidad del servicio e infraestructura para la movilidad urbana en la ciudad. El tercer capítulo desarrolla la finalidad, los objetivos, justificación y alcance de la investigación. El cuarto capítulo aborda los supuestos, la hipótesis, variables e indicadores que pretendemos comprobar. Seguidamente, en el quinto capítulo se describe la metodología utilizada para realizar esta investigación y, en el sexto capítulo se presentan los resultados obtenidos de las encuestas, así como su respectiva interpretación. Por último, en el capítulo séptimo se exponen las conclusiones de la investigación realizada y en el octavo, se plasman las recomendaciones que corresponden, que esperamos sean consideradas como aporte a la gestión pública en materia de transporte. / This document of investigation measured and analyzed the economic and social impact of mass public transport service so-called “El Metropolitano” which uses as infrastructure the High Capacity Segregated Roadway  – COSAC I. This system has been established as the main means of transport of the city of Lima by attributes such as: the formality of its service, the infrastructure it offers, modernity, speed  among other aspects  that are further developed on the next chapters. The document is divided into eight chapters. The first, is related to the theoretical foundations of the research; the second chapter contains a brief description of the reality of urban passenger transport and of the transportation systems that exist in Lima Metropolitana, the existing transport offer and within that framework, the problematic detected in terms of informality, lack of regulation and low quality of service and infrastructure for urban mobility in the city. The third chapter develops the purpose, objectives, justification and scope of investigation. The fourth chapter addresses the assumptions, hypotheses, variables and indicators that we intend to verify. Next, the fifth chapter describes the methodology used to carry out this research and, in the sixth chapter the surveys outcome are presented along with the interpretation. Finally, in the seventh chapter, the conclusions of the research carried out are presented and in the eighth, the corresponding recommendations are presented, which can be a contribution to public management in the area of ​​transportation. / Trabajo de investigación
93

An Expansion of the Current Metrorail System for an Ease Public Transportation and an Increase in Economic Activity

Pugliesi Reyes, Piero Alexander 11 March 2020 (has links)
Se nos ha encomendado la tarea de desarrollar una propuesta innovadora para agregar a la industria del sector público para este informe. Siendo nativos de un condado afectado por el tráfico como Miami Dade, decidimos abordar el desafío de aliviar la red de transporte del área proponiendo una expansión del actual sistema de Metrorail obsoleto en los tramos occidental y sur del condado. Creemos que esta expansión no solo creará puestos de trabajo en el proceso de construcción, sino que en última instancia permitirá un flujo de transporte que conducirá a una economía en auge explosivo. La ciudad está preparada para una innovación de este tipo, ya que los inmigrantes de todo el mundo y los EE. UU. Acuden a ella rápidamente transformando la ciudad día a día en un titán global. Una ciudad de tal magnitud y promesas necesita un sistema de transporte público a la altura. / We have been tasked with developing an innovative proposal to add onto the public sector industry for this report. Being natives of a traffic-stricken county such as Miami Dade, we decided to tackle the challenge of alleviating the transportation network of the area by proposing an expansion to the current outdated Metrorail system into the Western and Southern reaches of the county. We believe that this expansion will not only create jobs in the process of construction but will ultimately allow a flow of transportation that will lead to an explosively booming economy. The city is primed for such an innovation as immigrants from all over the world and the US flock into it quickly transforming the city day by day into a Global titan. A city of such magnitude and promise needs a public transportation system to match it. / Trabajo de investigación
94

Validation of a Public Transport Model / Validering av en kollektivtrafikmodell

Aho, Yousef, de Jong, Johannes January 2020 (has links)
During 2018, the Public Transport Administration (Trafikförvaltningen) in the Stockholm region spent approximately 2.2 billion SEK on new infrastructure investments related to the public transport system, many of which were based on their public transport models. The previously used method for validating these models has lacked scientific rigour, efficiency and a systematic approach, which has led to uncertainty in decision making. Furthermore, few scientific studies have been conducted to develop validation methodologies for large-scale models, such as public transport models. For these reasons, a scientific validation methodology for public transport models has been developed in this thesis. This validation methodology has been applied on the 2014 route assignment model used by Trafikförvaltningen, for the transport modes bus, commuter train and local tram. In the developed validation methodology, the selected validation metrics called MAPE, %RMSE and R^2 are used to compare link loads from a route assignment model with observed link loads from an Automatic Passenger Counting (APC) system. To obtain an overview of the performance of the route assignment model, eight different scenarios are set, based on whether the validation metrics meet acceptable thresholds or not. In the application of the developed validation methodology, the average link loads for the morning rush have been validated. To adjust the developed validation methodology to system-specific factors and to set acceptable metric thresholds, discussions with model practitioners have taken place. The validation has been performed on both lines and links, and for bus entire line number series have been validated as well. The validation results show that commuter train meets the set threshold values in a higher proportion than bus and local tram do. However, Trafikförvaltningen is recommended to further calibrate the route assignment model in order to achieve a better model performance. The developed validation methodology can be used for validation of public transport models, and can in combination with model calibration be used in an iterative process to fine-tune model parameters for optimising validation results. Finally, a number of recommendations are proposed for Trafikförvaltningen to increase the efficiency and quality of the validation process, such as synchronising model data with the observed data. / Under 2018 spenderade Trafikförvaltningen ungefär 2,2 miljarder kronor på nya infrastrukturinvesteringar för kollektivtrafiksystemet i Stockholm, varav många av dessa baserades på deras kollektivtrafikmodeller. Den tidigare metoden för att valideras dessa modeller har saknat gedigen vetenskaplig grund, effektivitet och ett systematiskt tillvägagångssätt, vilket lett till osäkerhet gällande investeringsbeslut. Dessutom har få vetenskapliga studier genomförts för att ta fram valideringsmetodologier för storskaliga modeller, såsom kollektivtrafikmodeller. Av dessa skäl har en vetenskaplig valideringsmetodologi för kollektivtrafikmodeller tagits fram i detta examensarbete. Denna valideringsmetodologi har tillämpats på Trafikförvaltningens 2014 års nätutläggningsmodell, för trafikslagen buss, pendeltåg och spårväg. I den framtagna valideringsmetodologin har de valda valideringsmåtten vid namn MAPE, %RMSE och R^2 använts för att jämföra länkbelastningar från en nätutläggningsmodell med observerade länkbelastningar från ett Automatisk Trafikanträkning-system (ATR). För att ge en översikt över modellens precision har åtta scenarios satts baserat på om valideringsmåtten godkänns eller inte enligt tröskelvärden. I tillämpningen av den framtagna valideringsmetodologin har de genomsnittliga länkbelastningarna för morgonens rusningstrafik validerats. För att justera den framtagna valideringsmetodologin efter systemspecifika faktorer och för att sätta godkända tröskelvärden för valideringsmåtten, har diskussioner med trafikanalytiker hållits. Valideringen har utförts både på linjer och länkar, och för buss har även hela linjeserier validerats. Valideringsresultaten för pendeltåg har en högre andel godkända mätningar än buss och spårväg. Trafikförvaltningen rekommenderas dock att kalibrera nätutläggningsmodellen ytterligare för att uppnå ett bättre resultat. Den framtagna valideringsmetodologin kan användas för valideringar av kollektivtrafikmodeller, och kan i kombination med modellkalibrering användas i en iterativ process för att finjustera modellparametrar och därmed optimera valideringsresultaten. Slutligen föreslås ett antal rekommendationer för Trafikförvaltningen för att öka effektiviteten och kvaliteten på valideringsprocessen, till exempel att synkronisera modelldata med observerad data.
95

Modeling, Optimization And Design Of A Solar Thermal Energy Transport System For Hybrid Cooking Application

Prasanna, U R 07 1900 (has links) (PDF)
Cooking is an integral part of each and every human being as food is one of the basic necessities for living. Commonly used sources of energy for cooking are firewood, crop residue, cow dung, kerosene, electricity, liquefied petroleum gas(LPG), biogas etc. Half of the world’s population is exposed to indoor air pollution, mainly the result of burning solid fuels for cooking and heating. Wood cut for cooking purpose contributes tothe16 million hectares(above4% of total area of India) of forest destroyed annually. The World Health Organization(WHO) reports that in 23 countries 10% of deaths are due to just two environmental risk factors: unsafe water, including poor sanitation and hygiene; and indoor air pollution due to solid fuel usage for cooking. In under-developed countries, women have to walk 2kms on average and spend significant amount of time for collecting the firewood for cooking. The cooking energy demand in rural areas of developing countries is largely met with bio-fuels such as fuel wood, charcoal, agricultural residues and dung cakes, whereas LPG or electricity is predominantly used in urban areas. India has abandon amount of solar energy in most of the regions making it most ideal place for harvesting solar energy. With almost 300 sunny days each year, one can confidently relay on this source of energy. India’s geographical location is in such a way that theoretically it receives 5x1015 kWh/ year of solar energy. Solar cooking is the simplest, safest, environmental friendly and most convenient way to cook. It is a blessing for those who cook using firewood or cow dung, who walk for miles to collect wood, who suffer from indoor air pollution. Hence solar cooking is going to play major role in solving future energy problem. Solar based cooking has never been a strong contender in the commercial market or even close to being a preferred method of cooking. They have been relegated to demonstration appliances to show case the solar based concepts. In this mode, cooking is no longer a time independent activity that can be performed at any time of day. One is forced to cook only at certain times when there is sufficient insolation. The geography of the cooking activity also shifts away from the kitchen. The kitchen is no longer the hearth of the home as the actual cooking activity shifts to the roof tops or high insolation platforms. This further adds to the inconvenience apart from being unable to cook at night or during cloudy conditions or during most of the winter days. Another issue of significant inconvenience is the general social structure in most families of the developing countries wherein the cooking activity is carried out by the senior ladies of the home. They are generally not athletic enough to be moving to and from the kitchen and the roof top to carry out the cooking exercise. As the solar cookers are enclosed spaces, interactive cooking is not possible let alone having any control on the rate of cooking. These are some of the more significant issues in the social psyche that has abundantly impeded the acceptance of solar thermal based cooking appliances. These issues and problems are in fact the motivating factors for this thesis. Based on these motivating factors, this thesis aims to propose solutions keeping the following points as the major constraints. cooking should be performed in the kitchen. one should be able to perform the cooking activity independent of the time of day or insolation. the cooking activity should be interactive the time taken for cooking should be comparable with the conventional methods in vogue. there should be a reduction in the use of conventional energy. Using the constraints and the motivating factors discussed above as the central theme, this thesis proposes a method to transfer solar thermal energy to the kitchen and act as a supplement to the conventional source of energy like the LPG or other sources that are traditionally being used in the households. The method proposed is in fact a hybrid scenario wherein the solar thermal is used to supplement the traditional source. Solar photovoltaic cells are also used to power the electronics and apparatus proposed in this thesis. This thesis addresses in detail the issues in analysis, modeling, designing and fabrication of the proposed hybrid solar cooking topology. The main goal of the proposed system is to transfer heat from sun to the cooking load that is located in the kitchen. The topology includes an additional feature for storing the energy in a buffer. The heat is first transferred from the solar thermal collector to a heat storage tank(that acts as the buffer) by circulating the heat transfer fluid at a specific flow rate that is controlled by a pump. The stored heat energy that is collected in the buffer is directed into the kitchen by circulating the heat transfer fluid into the heat exchanger, located in the kitchen. This is accomplished by controlling the flow rate using another pump. The solar thermal collector raises the temperature of the thermic fluid. The collector can be of a concentrating type in order to attain high temperatures for cooking. Concentrating collector like linear parabolic collector or parabolic dish collector is used to convert solar energy into heat energy. Absorption of energy from the incident solar insolation is optimized by varying the flow rate of circulating thermic fluid using a pump. This pump is energized from a set of photovoltaic panels(PV cell) which convert solar energy into electrical energy. The energy absorbed from the solar thermal collector is stored in a buffer tank which is thermally insulated. Whenever cooking has to be carried out, the high temperature fluid from the buffer tank is circulated through a heat exchanger that is located in the kitchen. The rate of cooking can be varied by controlling both the flow rate of fluid from the buffer tank to heat exchanger and also by controlling the amount of energy drawn from the auxiliary source. If the available stored energy is not sufficient, the auxiliary source of energy is used for cooking in order to ensure that cooking is in-dependent of time and solar insolation. In the proposed hybrid solar cooking system, the thesis addresses the issues involved in optimization of energy extracted from sun to storage tank and its subsequent transfer from the storage tank to the load. The flow rate at which maximum energy is extracted from sun depends on many parameters. Solar insolation is one of the predominant parameters that affect the optimum flow rate. Insolation at any location varies with time on a daily basis (diurnal variations) and also with day on a yearly basis(seasonal variation). This implies that the flow rate of the fluid has to be varied appropriately to maximize the energy absorbed from sun. In the proposed system, flow rate control plays a very significant role in maximizing the energy transfer from the collector to the load. The flow rate of the thermic fluid in the proposed system is very small on the order of 0.02kg/s. It is very difficult to sense such low flows without disrupting the operating point of the system. Though there are many techniques to measure very low flow rates, they invariably disrupt the system in which flow rate has to be measured. Further, the low flow sensors are far too expensive to be included in the system. A reliable, accurate and inexpensive flow measuring technique has been proposed in this thesis which is non-disruptive and uses a null-deflection technique. The proposed measuring method compensates the pressure drop across the flow meter using a compensating pump. The analysis, modeling, design and fabrication of this novel flow meter are addressed. The design and implementation of different subsystems that involves the selection and design of solar concentrating collector and tracking are explained. Finally, it is essential to know the economic viability of the proposed system that is designed and implemented. To understand the economics, the life cycle cost analysis of the proposed system is presented in this thesis. The major contributions of this thesis are: Energy transport: Major challenge in energy transport is to bring heat energy obtained from the sun to the kitchen for cooking. Energy transferred from solar insolation to the cooking load has to be optimized to maximize the overall efficiency. This can be split in to two parts,(a) optimizing efficiency of energy transferred from the collect or to the energy buffer tank,(b) optimizing efficiency of energy transferred from the buffer tank to the load. The optimization is performed by means of a maximum power point tracking(MPPT) algorithm for a specific performance index. Modeling of the cooking system: There are several domains that exist in the solar cooking system such as electrical domain, thermal domain, and hydraulic domain. The analysis of power/energy flow across all these domains presents a challenging task in developing a model of the hybrid cooking system. A bond graph modeling approach is used for developing the mathematical model of the proposed hybrid cooking system. The power/energy flow across different domains can be seamlessly integrated using the bond graph modeling approach. In this approach, the various physical variables in the multi-domain environment are uniformly de-fined as generalized power variables such as effort and flow. The fundamental principle of conservation of power/energy issued in describing the flow of power/energy across different domains and thus constructing the dynamic model of the cooking system. This model is validated through experimentation and simulation. Flow measurement: A novel method of low fluid mass flow measurement by compensating the pressure drop across the ends of measuring unit using a compensating pump has been proposed. The pressure drop due to flow is balanced by feedback control loop. This is a null-deflection type of measurement. As insertion of such a measuring unit does not affect the functioning of the systems, this is also a non-disruptive flow measurement method. This allows the measurement of very low flow rate at very low resolution. Implementation and design of such a unit are discussed. The system is modeled using bond graph technique and then simulated. The flow meter is fabricated and the model is experimentally validated. Design Toolbox: Design of hybrid cooking system involves design of multi domain systems. The design becomes much more complex if the energy source to operate the system is hybrid solar based. The energy budget has to be evaluated considering the worst case conditions for the availability of the solar energy. The design toolbox helps in assessing the user requirement and help designing the cooking system to fulfill the user requirement. A detailed toolbox is proposed to be developed that can be used in designing/selecting sub-systems like collector, concentrator, tracking system, buffer tank, heat exchanger, PV panel, batteries etc. The toolbox can also be used for performing life cycle costing.
96

Untersuchungen zu Nitrat-induzierbaren Proteinen der Plasmamembran von Chlorella saccharophila (Krüger) Nadson / Investigations on nitrate-inducible proteins in the plasma membrane of Chlorella saccharophila (Krueger) Nadson

Brechlin, Peter 30 October 2002 (has links)
No description available.
97

Návrh plánu společných zařízení ve zvolené lokalitě

ROLNÍKOVÁ, Jitka January 2019 (has links)
The diploma thesis is devoted to the elaboration of a plan of common facilities in the cadastral area Přídolí. The work focused on the methodological procedure in the implementation of ground adaptations, according to technical and metodical standards. The content of the first part is a literature review, which not only describes the field of land consolidation and its course, but also specifies the plan of common facilities together with the scope of work necessary for its elaboration. Everything important in this section is theoretically described. In the second practical part, attention is paid to the selection of the territory and the evaluation of its condition with the help of exploratory works. Further to the field research, the practical part is focused mainly on the proposal of individual proceedings concerning the protection of ZPF, elements of TSES, water management elements and ensuring access to lands. The results of surveys and draft measures are presented in both text and graphic form.
98

Pendlarnod : en knutpunkt för ett hållbart samhälle / Commuter node : a junction for a sustainable society

Trulsson, Patricia, Wahlgren, Amanda January 2019 (has links)
Examensarbetet är bland annat ett förslag med hållbara riktlinjer för hur planering av en pendlarnod kan gå till samt identifikation av generella servicefunktioner som bör finnas hos en pendlarnod. Arbetet grundas i den ökande användningen av bilen gentemot val av hållbara färdmedel i form av gång-, cykel- och kollektivtrafik. En viktig aspekt i planeringen av pendlarnoder är stadskärnornas attraktivitet samt sammankopplingen mellan landsbygd och tätort. Om bilens framkomlighet begränsas kan hållbart resande gynnas och på så sätt sammankoppla Sveriges vägnät med bättre förbindelser. Förslaget är till för att underlätta för framtida stads- och trafikplanering i Sveriges tätorter. Studien grundas på vad andra städer har gjort för att öka det hållbara resandet. Resultaten visar att genom att placera pendlarnoder i utkanten av Växjö minskas bilanvändningen i centrum och främjar istället människans hälsa och välbefinnande. Pendlarnoderna är även en förutsättning för att alla människor ska ha möjlighet att kunna ta sig till fritidsaktiviteter, arbete och studier oavsett vart de bor. Samtidigt frigörs stora ytor i centrum som kan utformas till gröna områden som uppmuntrar till en mer levande stad och fysisk aktivitet för människorna som bor i den. En pendlarnods attraktion ökar i takt med vad den kan erbjuda. Genom att erbjuda ett utbud av funktioner, tjänster och upplevelser under samma tak kan attraktionen av det hållbara resandet öka i Sveriges tätorter. / This work including a proposal with sustainable guidelines on how to plan a commuter node, as well as identification of general service functions that should be available. The work is based on the increasing use of cars against choice of sustainable transport in the form of pedestrian, bicycle and public transport. An important part of the planning of the commuter hubs is the attractiveness of the city center as well as the interconnection between countryside and urban areas. If the cars accessibility is limited, sustainable travel can benefit and thus better link Sweden’s road network with better connections. This proposal will make urban and traffic planning easier. The study is based on what other cities have done in the past to encourage sustainable travel, use of proven analytical methods and interviews with expert and potential users. The result shows that by placing commuter nodes on the edge of Växjö, car use is reduced in the center and instead promotes human health and well-being. The commuter nodes are also a prerequisite for all people to have the opportunity to access leisure activities, work and studies wherever they live. At the same time, large areas in the center are released, which can be designed into green areas that encourage a more vibrant city and physical activity for people living in it. A commuter node's attraction increases as it can offer. Being able to offer a range of functions, services and experiences is a connection between public transport and land value.
99

Zpracování průzkumných prací ve zvolené lokalitě jako podklad pro KoPÚ / Processing of survey works in the selected locality as the basis for land consolidation project

ZEZULOVÁ, Martina January 2015 (has links)
The thesis deals with the processing of exploratory work according to valid methodology in the cadastral area of Přídolí. It provides a list of all the information that is needed for further processing of land consolidation. In addition to the basic characteristics of natural and economic conditions in the area, major emphasis is put on the data acquisition and processing in the field of transport system, soil degradation, locations and state of all elements for control of soil erosion and territorial system of ecological stability, water supply conditions and landscape value. The processing of the obtained documents, field survey and territory analysis should be used to optimize the land consolidation process, especially common facilities planning.
100

Doprava a dopravní výchova jako odraz dopravní gramotnosti účastníka cestovního ruchu / Transportation and traffic ecucation as a reflection of traffic literacy of participant of tourist trade

MARKOVÁ, Pavlína January 2009 (has links)
Graduation thesis is bent on analysis traffic literacy of participants of tourist trade. According to the research only a half of the polled people have heard about a transport education first time in Kindergarten. This is a very bad result because children belong to the most risky group of traffic operations. That is why the analysis was made in Kindergarten, concretely in Kindergarten Bratrská, Dačice, to find out present status of transport education. We set up a project which should obtain an improvement of transport education.

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