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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.
1

Estudo de viabilidade do transporte marítimo de contêineres por cabotagem na costa brasileira.

Ono, Ricardo Terumichi 03 April 2001 (has links)
O presente trabalho apresenta o panorama atual do transporte marítimo de contêineres por cabotagem no Brasil. Fez-se um breve descritivo do contexto em que se situa tal segmento do transporte marítimo, avaliando as condições para a sua viabilidade e apontando os principais entraves e reformas necessárias no setor portuário. O grande potencial de crescimento encontrado no setor motivou a elaboração de uma metodologia para desenvolvimento de uma ferramenta de apoio à decisão, na qual parâmetros relativos à demanda de mercados e características da frota podem ser testados para o dimensionamento desta, bem como a programação dos navios estabelecendo rotas e escalas nos portos que configuram esse cenário. A metodologia empregada pode ser dividida em duas etapas: a primeira consiste na geração de todos os roteiros viáveis, juntamente com os parâmetros relativos a cada uma das rotas para cada classe de embarcação. A segunda etapa consiste no desenvolvimento de um modelo de programação linear, cujo objetivo é a minimização do custo total da operação de cabotagem. Os modelos foram estruturados de forma a apresentar o dimensionamento da frota por classe de embarcação, a rota para cada embarcação da frota e a freqüência de atendimento ou escala em cada porto.
2

Estudo de viabilidade do transporte marítimo de contêineres por cabotagem na costa brasileira.

Ricardo Terumichi Ono 03 April 2001 (has links)
O presente trabalho apresenta o panorama atual do transporte marítimo de contêineres por cabotagem no Brasil. Fez-se um breve descritivo do contexto em que se situa tal segmento do transporte marítimo, avaliando as condições para a sua viabilidade e apontando os principais entraves e reformas necessárias no setor portuário. O grande potencial de crescimento encontrado no setor motivou a elaboração de uma metodologia para desenvolvimento de uma ferramenta de apoio à decisão, na qual parâmetros relativos à demanda de mercados e características da frota podem ser testados para o dimensionamento desta, bem como a programação dos navios estabelecendo rotas e escalas nos portos que configuram esse cenário. A metodologia empregada pode ser dividida em duas etapas: a primeira consiste na geração de todos os roteiros viáveis, juntamente com os parâmetros relativos a cada uma das rotas para cada classe de embarcação. A segunda etapa consiste no desenvolvimento de um modelo de programação linear, cujo objetivo é a minimização do custo total da operação de cabotagem. Os modelos foram estruturados de forma a apresentar o dimensionamento da frota por classe de embarcação, a rota para cada embarcação da frota e a freqüência de atendimento ou escala em cada porto.
3

Feasibility study for electrification of Logistics centre at Stockholm Royal Seaport

Sachdewani, Rohit Kumar January 2021 (has links)
In the eastern part of Stockholm, a major urban development project is taking place. It is called Stockholm Royal Seaport and up to the year 2030 approximately 12000 new homes, 35000 workplaces and 600000 square meters of commercial areas will be added to the area. The project has been given a very ambitious environmental action program. As a part of that, the City of Stockholm has established a logistics centre in the area. The logistics centre is supposed to coordinate all transports of building material and handle the waste during the construction phase. One objective with the logistics centre is to reduce the number of transports and thereby reduction in the use of energy. The thesis-work mainly focused on developing an optimisation program for electricity supply to the logistics centre, in order to find the optimal way of managing charging and the use of electrical energy, when the logistics centre has procured a new batterypowered truck. The main objective is to minimize the purchase of power bought from the grid, for the loads at the logistics centre at Stockholm Royal Seaport. This thesis not only focused on this site in particular, but the work also resulted in creating a benchmark model that could be used for studying the electrification process for other construction sites in general. The logistics centre contains stationary battery storage, electrified distribution trucks, a PV generation system, and other electrical loads at the site. This thesis aimed at considering all the limitations and constraints for all the resources at the site and then finding an optimal method of utilising these resources in order to minimize the overall energy consumption. In this thesis, the optimal sizing of the battery for an electrified distribution truck is also performed considering the overall functional requirements of the distribution truck. Various charging strategies have been identified and simulated to understand the routines of charging the truck and their direct impact on the grid due to the purchase of energy during various hours of the day. The work resulted in optimised use of assets at the site during different hours of the day. The simulation work identified the best strategy and the use of resources at the site thus saving some amount of energy consumption at the site. This directly resulted in saving overall operational costs of the logistics centre. / I den östra delen av Stockholm pågår ett stort stadsutvecklingsprojekt. Det kallas Norra Djurgårdsstaden och fram till år 2030 kommer cirka 12000 nya bostäder, 35000 arbetsplatser och 600000 kvadratmeter kommersiella områden att läggas till området. Projektet har fått ett mycket ambitiöst miljöprogram och som en del av det har Stockholm stad inrättat ett logistikcenter i området. Logistikcentret ska samordna alla transporter av byggmaterial och hantera avfallet under byggfasen. Ett mål med logistikcentret är att minska antalet transporter och därmed minska energianvändningen. Examensarbetet fokuserade främst på att utveckla ett optimeringsprogram för elförsörjningen till bygglogistikcentret för att hitta det optimala sättet att hantera laddning och användning av elektrisk energi när logistikcentret investerar i en ny batteridriven lastbil. Huvudmålet är att minimera importen av elkraft som köps från nätet för att försörjar lasterna vid Norra Djurgårdsstadens Bygglogistikcenter. Målet är att göra en vägledande modell som kan användas för att studera elektrifieringsprocessen för byggarbetsplatser i allmänhet. Detta logistikcenter innehåller stationär batterilagring, elektrifierade distributionsbilar, ett PV -genereringssystem och andra elektriska laster på platsen. Syftet med denna avhandling var att överväga begränsningarna och resurserna på platsen och sedan hitta en optimal metod för att använda dessa resurser för att minimera den totala energiförbrukningen. I detta examensarbetet utförs också den optimala dimensioneringen av batteriet för en elektrifierad distributionsbil med beaktande av de övergripande funktionella kraven för distributionsbilen. Olika laddningsstrategier har identifierats och simulerats för att förstå rutinerna för laddning av lastbilen och dess direkta påverkan på nätet på grund av inköp av energi under olika timmar på dygnet. Arbetet resulterade i optimerad användning av tillgångar på platsen under olika timmar på dygnet. Simuleringsarbetet identifierade den bästa strategin och användningen av resurser på platsen, vilket sparar en viss energiförbrukning på platsen. Detta resulterade direkt i att spara logistikcentralens totala driftskostnader.
4

Estimating the LES demand system using Finnish household budget survey data.

Palmer, Django January 2019 (has links)
No description available.
5

Modelling of a Natural-Gas-Based Clean Energy Hub

Sharif, Abduslam January 2012 (has links)
The increasing price of fuel and energy, combined with environmental laws and regulations, have led many different energy producers to integrate renewable, clean energy sources with non-renewable ones, forming the idea of energy hubs. Energy hubs are systems of technologies where different energy forms are conditioned and transformed. These energy hubs offer many advantages compared to traditional single-energy sources, including increased reliability and security of meeting energy demand, maximizing use of energy and materials resulting in increasing the overall system efficiency. In this thesis, we consider an energy hub consisting of natural gas (NG) turbines for the main source of energy— electricity and heat— combined with two renewable energy sources—wind turbines and PV solar cells. The hub designed capacity is meant to simulate and replace the coal-fired Nanticoke Generating Station with NG-fired power plant. The generating station is integrated with renewable energy sources, including wind and solar. The hub will also include water electrolysers for hydrogen production. The hydrogen serves as an energy storage vector that can be used in transportation applications, or the hydrogen can be mixed into the NG feed stream to the gas turbines to improve their emission profile. Alkaline electrolysers’ technology is fully mature to be applied in large industrial applications. Hydrogen, as an energy carrier, is becoming more and more important in industrial and transportation sectors, so a significant part of the thesis will focus on hydrogen production and cost. In order to achieve the goal of replacing the Nanticoke Coal-fired Power Plant by introducing the energy hub concept, the study investigates the modeling of the combined system of the different technologies used in terms of the total energy produced, cost per kWh, and emissions. This modeling is done using GAMS® in order to make use of the optimization routines in the software. The system is modeled so that a minimum cost of energy is achieved taking into account technical and thermodynamic constrains. Excess energy produced during off-peak demand by wind turbines and PV solar cells is used to feed the electrolyser to produce H2 and O2. Through this method, a significant reduction in energy cost and greenhouse gas (GHG) emissions are achieved, in addition to an increased overall efficiency.
6

Modelling of a Natural-Gas-Based Clean Energy Hub

Sharif, Abduslam January 2012 (has links)
The increasing price of fuel and energy, combined with environmental laws and regulations, have led many different energy producers to integrate renewable, clean energy sources with non-renewable ones, forming the idea of energy hubs. Energy hubs are systems of technologies where different energy forms are conditioned and transformed. These energy hubs offer many advantages compared to traditional single-energy sources, including increased reliability and security of meeting energy demand, maximizing use of energy and materials resulting in increasing the overall system efficiency. In this thesis, we consider an energy hub consisting of natural gas (NG) turbines for the main source of energy— electricity and heat— combined with two renewable energy sources—wind turbines and PV solar cells. The hub designed capacity is meant to simulate and replace the coal-fired Nanticoke Generating Station with NG-fired power plant. The generating station is integrated with renewable energy sources, including wind and solar. The hub will also include water electrolysers for hydrogen production. The hydrogen serves as an energy storage vector that can be used in transportation applications, or the hydrogen can be mixed into the NG feed stream to the gas turbines to improve their emission profile. Alkaline electrolysers’ technology is fully mature to be applied in large industrial applications. Hydrogen, as an energy carrier, is becoming more and more important in industrial and transportation sectors, so a significant part of the thesis will focus on hydrogen production and cost. In order to achieve the goal of replacing the Nanticoke Coal-fired Power Plant by introducing the energy hub concept, the study investigates the modeling of the combined system of the different technologies used in terms of the total energy produced, cost per kWh, and emissions. This modeling is done using GAMS® in order to make use of the optimization routines in the software. The system is modeled so that a minimum cost of energy is achieved taking into account technical and thermodynamic constrains. Excess energy produced during off-peak demand by wind turbines and PV solar cells is used to feed the electrolyser to produce H2 and O2. Through this method, a significant reduction in energy cost and greenhouse gas (GHG) emissions are achieved, in addition to an increased overall efficiency.
7

Optimización de la Operación del Sistema Embalse Puclaro Incorporando el Objetivo de Generación Hidroeléctrica

Beyá Marshall, Ignacio Nicolás January 2010 (has links)
En la cuenca del río Elqui, región de Coquimbo, están ubicados los Embalses La Laguna y Puclaro. Recientemente en el año 2008 al embalse Puclaro se le integró la central hidroeléctrica del mismo nombre concebida como central de pasada, manteniéndose las decisiones de operación del embalse dominadas por el uso del agua para riego. El esquema de operación actual, considerado como conservador, apunta principalmente a tener los embalses, La Laguna y Puclaro, llenos al inicio de la temporada de riego. Tal esquema resulta a menudo en vertimientos desde los embalses durante la época de deshielo, con la consiguiente pérdida de energía generable. El objetivo del presente trabajo es explorar posibles mejoras de la operación actual de los sistemas de control de aguas en la cuenca del río Elqui que no solamente consideren el uso del agua en riego, sino que también la generación hidroeléctrica. Específicamente, se busca un esquema de operación que permita incrementar la generación eléctrica sin perjuicio de la producción agrícola. Se desarrolló una herramienta capaz de proponer una política y secuencia de operación que maximiza la producción eléctrica considerando las demandas de riego. Se utilizó el programa computacional de modelamiento algebraico GAMS para modelar el sistema y optimizar la operación en base a un pronóstico de caudales afluentes a la cuenca. La herramienta desarrollada utiliza dos modelos acoplados, donde el primero de ellos, denominado Modelo de Valor Futuro del Agua Embalsada entrega, mediante el método Value iteration (programación dinámica), entrega una aproximación de las funciones de valor futuro del agua embalsada. Los resultados de este primer modelo son utilizados por el segundo modelo, de Re-optimización, el que tiene el objetivo de generar una secuencia óptima de operación en el periodo de simulación, a partir de un pronóstico de caudales afluentes a la cuenca y las funciones de valor futuro. El análisis de los resultados obtenidos permite concluir que se desarrolló una herramienta de apoyo a la toma de decisiones que optimiza el recurso hídrico disponible en la cuenca y se espera que el trabajo realizado sea un aporte real al mejoramiento de la operación de los sistemas de control de aguas en la cuenca del río Elqui. Los modelos generados en este trabajo están ajustados para ser utilizados en la cuenca del río Elqui. Sin embargo, pueden ser implementados en otras cuencas que posean uno o más embalses y centrales hidroeléctricas, y que además no necesariamente tengan como objetivo principal suplir las demandas de riego.
8

Optimalizační modely rizik v produkci ryb / Optimization Risk Models in Fish Production

Franěk, Martin January 2021 (has links)
This diploma thesis deals with the risk associated with fish production. Selected risks are further taken into account. The risks are further described and addressed using the FMEA matrix. The thesis contains a mathematical model that solves the optimal population of the pond in order to maximize profits. The model includes fixed input parameters, which includes the price of hatchery material and the market price of fish. Furthermore, the model contains random input parameters that are limited by the intervals and includes the growth coefficient and the size of the population in the pond. The optimization model is based on simulated data, which are based on real data and statistically determined estimates. The used data are processed into tables in MS Excel for better visualization. GAMS software is used for software implementation of the model.
9

Vybrané optimalizační modely pro redukci rizik v letecké přepravě / Selected Optimization Models for Risk Reduction in Air Transport

Schwarz, Ondřej January 2015 (has links)
The diploma thesis deals with mathematical modeling of the situation when due to the increased risks occurring around Europe there is a need of immediate transport of Czech citizens back to the Czech Republic. The model takes into account the general level of random fluctuations in demand and transportation costs. The optimization model is then built on the ideas of stochastic programming and includes real and expert data in the field of air transportation, which are later implemented into GAMS. The results are discussed. The survey part of the diploma thesis is devoted to the possibility of applying linear and stochastic programming, the interpretation of the mathematical transportation theory. It describes the basic tools and development environment and the realization of mathematical model based on real data in GAMS. The second part of the thesis deals with a proposal of possible improvements in aviation by applying the real data into the model and by analyzing the obtained results.
10

LARGE SCALE LINEAR OPTIMIZATION FOR WIRELESS COMMUNICATION SYSTEMS

Hosny, Sameh Shawky Ibrahim 23 May 2017 (has links)
No description available.

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