• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 30
  • 14
  • 13
  • 9
  • 6
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 88
  • 23
  • 20
  • 19
  • 19
  • 19
  • 14
  • 14
  • 13
  • 12
  • 11
  • 11
  • 11
  • 11
  • 11
  • 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.
21

Simulation and Economic Analysis of a Hybrid Wind Diesel System for Remote Area Power Supply

Abdullah, Jalal 06 September 2010 (has links)
The Kingdom of Saudi Arabia has an area of 1.69 million square kilometers. It is the biggest oil producers in the world, and the electricity industry relies heavily on oil. The annually growth request for electricity is around 5%. The price of electricity will be expensive in the next 30 years and there could be a shortage of electricity supply. It is better to use alternative forms of energy to prolong the life of the oil industry in Saudi Arabia. To reduce dependence on oil, the Kingdom of Saudi Arabia is considering using alternative sources of energy including solar energy and energy wind. Since the wind speed is around 10m/s and in the summer it is full of sunshine; therefore, the renewable energy should play a more important role in future electric power supply of the Kingdom of Saudi Arabia. A hybrid system is proposed in this thesis to study the possible power supply system in the remote areas. Wind information in Dhahran is used in simulations in order to make sure that the system is reliable and appropriate to be used in the remote areas of the country. Economic analysis is also conducted to compare the cost of the hybrid system with that of a 200 km transmission line connected from existing service area.
22

A Comparison of Waterflood Management Using Arrival Time Optimization and NPV Optimization

Tao, Qing 2009 December 1900 (has links)
Waterflooding is currently the most commonly used method to improve oil recovery after primary depletion. The reservoir heterogeneity such as permeability distribution could negatively affect the performance of waterflooding. The presence of high permeability streaks could lead to an early water breakthrough at the producers and thus reduce the sweep efficiency in the field. One approach to counteract the impact of heterogeneity and to improve waterflood sweep efficiency is through optimal rate allocation to the injectors and producers. Through optimal rate control, we can manage the propagation of the flood front, delay water breakthrough at the producers and also increase the sweep and hence, the recovery efficiency. The arrival time optimization method uses a streamline-based method to calculate water arrival time sensitivities with respect to production and injection rates. It can also optimize sweep efficiency on multiple realizations to account for geological uncertainty. To extend the scope of this optimization method for more general conditions, this work utilized a finite difference simulator and streamline tracing software to conduct the optimization. Apart from sweep efficiency, another most widely used optimization method is to maximize the net present value (NPV) within a given time period. Previous efforts on optimization of waterflooding used optimal control theorem to allocate injection/production rates for fixed well configurations. The streamline-based approach gives the optimization result in a much more computationally efficient manner. In the present study, we compare the arrival time optimization and NPV optimization results to show their strengths and limitations. The NPV optimization uses a perturbation method to calculate the gradients. The comparison is conducted on a 4- spot synthetic case. Then we introduce the accelerated arrival time optimization which has an acceleration term in the objective function to speed up the oil production in the field. The proposed new approach has the advantage of considering both the sweep efficiency and net present value in the field.
23

Valuation of Governmental Guarantee in BOT Project Finance with Real Option Analysis

Jun, Jae Bum 14 January 2010 (has links)
The limitation of public funds available for infrastructure projects has induced governments to attract private entities to participate in long-term contracts for financing, constructing, and operating huge infrastructure projects through Public Private Partnerships (PPPs) to reduce debt, constrain taxation, and share financial risks and rewards between the public and private sectors. Because these projects have such complicated risk evolutions, diverse contractual forms for project members to hedge their risks are necessary. Hence, the Build-Operate-Transfer (BOT) model has been considered as a very popular type to accomplish PPPs with the characteristic of a shared-ownership. For the government to attract private sector?s participation, they have used incentive systems such as debt payment guarantee, Minimum Revenue Guarantee (MRG), or direct cash support. These incentive systems have been important critical success factors in BOT projects yet they have remained unfavorable in bidding process by failure of the traditional capital budgeting theory, Net Present Value (NPV) analysis, in evaluating the guarantee values. This is because NPV analysis can not reflect the guarantee agreements? contingent characteristic. For this reason, ?Real Option Concept? imported from ?Option Pricing Theory? in finance has been used as an effective way in estimating the guarantee value during the construction and operation of the project. However, there are still open issues in identifying, formulating, and calculating the guarantee agreements? contingency due to the complexity of option pricing theory and in considering the uncertainty of the underlying asset. Furthermore, in recent real option-related research that evaluate BOT investment projects, the volatility of rate of return in underlying asset (project value) is assumed to be just given or too simplified in its calculating process despite its significant impact on the guarantee value. The purpose of this research is to develop the binomial real option model to better evaluate the MRG value by complementing existing real option models without violating the option pricing theory. To do so, the developed model in this research is to formulate the MRG agreement as a put option, consider the uncertainty of the underlying asset, and use the more detailed level of volatility with a Monte Carlo simulation approach. To verify the applicability of the developed model, the model is applied to three different BOT project case studies, then, the results are compared with those by NPV analysis, Cheah and Liu (2006)?s real option model, and option pricing theory derived from Black-Scholes model. Finally, based upon the results and analyses, the developed real option model appears to provide a practical and theoretical framework to quantitatively evaluate the MRG agreement under the BOT scheme and help the government establish better BOT policies and help the developer make appropriate bidding strategies in its investment.
24

Įmonės investicijos: Planavimas. Analizė. Kontrolė / Investments of the company: planning, analysis, control

Baranauskienė, Ilona 01 June 2005 (has links)
In the master final work problems of real investments validity assessment are formulated, theoretical methods of assessment of investments efficiency of Lithuanian and foreign authors are analyzed and systemized, advantages and disadvantages of separate methods evaluating real investments are presented, the position of the governmental policy concerning investment issues and legal regulation of this sphere are analyzed. Planned investments of “PAJŪRIO ALKA“ JSC were analyzed using the methods of investment payback period, profitability of the total invested capital and share capital, internal rate of return, net present value and employing their modified forms. The analysis of methods confirms the author’s formulated hypothesis of the scientific research that not separate assessed indicators influence decisions made in the company concerning investments validity, but consistency of calculated indicators and their reciprocity. Furthermore, the model of assessment of investment projects inside the company based upon consistency of coordination of the main financial efficiency assessment indicators is proposed.
25

Making the Most of Wind : a Business Perspective on Subsidy Systems in France, Germany, Spain and Sweden

Barney, Andrew January 2012 (has links)
Determining which countries are the most financially attractive for businesses to build wind projects is a matter of serious discussion that lacks succinct commentary. To fill this void this paper employs an empirical study of the wind subsidy support systems used by Germany, France, Spain and Sweden. This paper is based on the premise that businesses prefer to build where they can find the highest overall remuneration for their production; recognizing also the need for stability in those payments and businesses’ strong preference for larger early returns on their investments. The paper also analyzes the results and gives recommendations on possible improvements to each country’s system and where businesses should invest.In order to reach their 20-20-20 E.U. goals (European Commission, 2010), countries are encouraging the creation of new green energy projects, and this encouragement is frequently in the form of subsidies. The subsidy types used by the countries reviewed are feed-in tariffs, premiums and a certificate quota system. Each country’s support history is detailed along with the criteria of their respective systems.The countries systems are then compared using actual income and production data for four criteria at three different production levels – 100 percent, 75 percent and 150 percent of actual – and at two different lengths of time, 7 and 20 years. The first criteria of the comparison is total income, the second for variability of payments, the third for timing of payments and the final is the stability of the system itself.The results of this research show that the German and French systems are superior at all levels for their low variability in payment prices and in making larger payments to businesses earlier. They are also generally superior at lower and actual production levels for total income amounts. However, the Spanish options are superior at high levels of production for income and have middling variability levels. The Swedish system generally has the highest levels of variability for the lowest levels of income. Only the Spanish system is considered to be unstable in its political support of subsidies. Based upon the preceding findings are given to each country to improve their relative weaknesses. Also recommendations are given to businesses based upon the quality of the locations wind resources.
26

Utilizing Managerial Cash Flow Estimates for Applied Real Options Analysis

Barton, Kelsey 01 December 2011 (has links)
Real options analysis has been recommended to identify and quantify opportunities where managerial flexibility can influence worth. However, real options models in the literature have become increasingly sophisticated, and managers have cited their reluctance to use such models due to their level of complexity and lack of transparency. Presented in this thesis is a real options model that can be easily incorporated into the current project selection methodology of a firm; the model uses managerial cash flow estimates to price real options on tangible investment opportunities in a financially consistent manner. Next, to demonstrate the application of real options analysis in practice, five real options models, including the proposed model, are applied to value a medical device project. The models all price the real option differently, due to the differences in their underlying assumptions, but they all yield the same investment conclusion: the medical device project has value.
27

Utilizing Managerial Cash Flow Estimates for Applied Real Options Analysis

Barton, Kelsey 01 December 2011 (has links)
Real options analysis has been recommended to identify and quantify opportunities where managerial flexibility can influence worth. However, real options models in the literature have become increasingly sophisticated, and managers have cited their reluctance to use such models due to their level of complexity and lack of transparency. Presented in this thesis is a real options model that can be easily incorporated into the current project selection methodology of a firm; the model uses managerial cash flow estimates to price real options on tangible investment opportunities in a financially consistent manner. Next, to demonstrate the application of real options analysis in practice, five real options models, including the proposed model, are applied to value a medical device project. The models all price the real option differently, due to the differences in their underlying assumptions, but they all yield the same investment conclusion: the medical device project has value.
28

Análise de expansão de cava com múltiplas restrições de superfície sob incerteza geológica

Kuckartz, Bruno Tomasi January 2017 (has links)
A operação e gerência de empreendimentos mineiros são tarefas normalmente difíceis e complexas. Para otimizar toda a operação, os engenheiros precisam lidar com muitos aspectos técnicos e restrições, como a modelagem geológica, estimativa de reservas, determinação da necessidade de blendagem, projeto das cavas ótimas e operacionais, custos operacionais, questões ambientais, entre outros. Nesse sentido, o posicionamento de infraestruturas de superfície é um dos pontos críticos dentro do planejamento de mina. Aproximar as estruturas da cava, com o intuito de reduzir custos operacionais, pode interferir em eventuais expansões da cava em novos e favoráveis cenários. Nesses casos, impactos no valor presente líquido (VPL) do projeto são inevitáveis e precisam ser tratados tecnicamente, avaliando um grande número de cenários alternativos para delinear uma estratégia que incremente a lucratividade do projeto. O objetivo deste estudo é avaliar, por meio de comparações de VPL entre diferentes cenários de múltiplas restrições de superfície, sob incerteza geológica, a possibilidade de mover pilhas de estéril e outras infraestruturas de suas atuais posições e/ou definir prioridades e mensurar o impacto que cada restrição representa na lucratividade do projeto. A metodologia foi aplicada a uma mina de fosfato para ilustrar como determinar a melhor alternativa em uma perspectiva de planejamento de mina de longo prazo. Utilizando o método de cavas híbridas, aplicado ao modelo de teores simulados, foi possível identificar zonas de probabilidade de ocorrência dentro da cava matemática, o que forneceu informações cruciais para auxiliar na tomada de decisão a respeito da necessidade de relocação de estruturas. / The operation and management of mining enterprises are usually difficult and complex tasks. To optimize the entire operation the engineers must deal with several technical aspects and constraints, such as orebody modelling, reserves estimation, determination of blending necessity, optimum and operational pit designs, operational costs, environmental issues, among others. In this sense, locating surface infrastructures is one of the most critical mine planning concerns. Approximating these structures to the pit, in order to reduce the operational costs, might interfere with future pit expansions in new favorable scenarios. In such cases, impacts on project’s net present value (NPV) are inevitable and must be deal technically, evaluating several alternative scenarios to delineate a strategy to maximize profitability. The aim of this study is to evaluate, through NPV comparisons considering different scenarios with multiple constraints, under geological uncertainty, the possibility of moving waste piles and infrastructure buildings from their current position and/or defining priorities to after measuring the impact that each constraint represents on the project´s profitability. The methodology will be applied to a phosphate mine, to determine the best alternative from a long-term mine planning perspective. Using the hybrid pits method, applied to a simulated grades model, allowed the identification os occurrence probability zones within mathematical pit, providing critical data to support decision making regarding infrastructure relocation.
29

Využití procesu extruze při produkci bioplynu z pšeničné slámy / Use of the extrusion process to produce biogas from wheat straw

VERNER, Dušan January 2012 (has links)
Many agricultural biogas stations process predominantly phytomass specifically grown for power engineering purposes as a primary raw material. This results in gradual increase of maize proportion in sowing sequences at the exclusion of traditional area-specific crops, which presents various potential negative effects. The aim of study is to evaluate the substitution of maize with wheat straw in the anaerobic fermentation process from the biotechnological and economic viewpoint. For this purpose, wheat straw pellets were pretreated using the high-pressure extruder in compliance with UV CZ 21314 at different runtime parameters. Cumulative methane (CH4) production in quarter-mode operation simulation, based on the extrusion pressure, cycle duration and fermentation temperature, was the main evaluation criteria. Optimal run time parameters were derived from the approximation ? extrusion pressure 1,35 MPa, reaction time 210 s, in order to achieve maximal CH4 production at mesophilic fermentation temperature (38 °C). For fermentation temperature 48 °C, optimal pressure 1,25 MPa and cycle duration 180 s were approximated. The discount rate of Net Present Value (NPV) was established as a main comparative criterion considering overall executive, legislative and technological aspects of analyzed biological effects. Based on these findings suggest, wheat straw extrusion is interesting, unconventional and profitable technology in the field of biogas production.
30

Análise de expansão de cava com múltiplas restrições de superfície sob incerteza geológica

Kuckartz, Bruno Tomasi January 2017 (has links)
A operação e gerência de empreendimentos mineiros são tarefas normalmente difíceis e complexas. Para otimizar toda a operação, os engenheiros precisam lidar com muitos aspectos técnicos e restrições, como a modelagem geológica, estimativa de reservas, determinação da necessidade de blendagem, projeto das cavas ótimas e operacionais, custos operacionais, questões ambientais, entre outros. Nesse sentido, o posicionamento de infraestruturas de superfície é um dos pontos críticos dentro do planejamento de mina. Aproximar as estruturas da cava, com o intuito de reduzir custos operacionais, pode interferir em eventuais expansões da cava em novos e favoráveis cenários. Nesses casos, impactos no valor presente líquido (VPL) do projeto são inevitáveis e precisam ser tratados tecnicamente, avaliando um grande número de cenários alternativos para delinear uma estratégia que incremente a lucratividade do projeto. O objetivo deste estudo é avaliar, por meio de comparações de VPL entre diferentes cenários de múltiplas restrições de superfície, sob incerteza geológica, a possibilidade de mover pilhas de estéril e outras infraestruturas de suas atuais posições e/ou definir prioridades e mensurar o impacto que cada restrição representa na lucratividade do projeto. A metodologia foi aplicada a uma mina de fosfato para ilustrar como determinar a melhor alternativa em uma perspectiva de planejamento de mina de longo prazo. Utilizando o método de cavas híbridas, aplicado ao modelo de teores simulados, foi possível identificar zonas de probabilidade de ocorrência dentro da cava matemática, o que forneceu informações cruciais para auxiliar na tomada de decisão a respeito da necessidade de relocação de estruturas. / The operation and management of mining enterprises are usually difficult and complex tasks. To optimize the entire operation the engineers must deal with several technical aspects and constraints, such as orebody modelling, reserves estimation, determination of blending necessity, optimum and operational pit designs, operational costs, environmental issues, among others. In this sense, locating surface infrastructures is one of the most critical mine planning concerns. Approximating these structures to the pit, in order to reduce the operational costs, might interfere with future pit expansions in new favorable scenarios. In such cases, impacts on project’s net present value (NPV) are inevitable and must be deal technically, evaluating several alternative scenarios to delineate a strategy to maximize profitability. The aim of this study is to evaluate, through NPV comparisons considering different scenarios with multiple constraints, under geological uncertainty, the possibility of moving waste piles and infrastructure buildings from their current position and/or defining priorities to after measuring the impact that each constraint represents on the project´s profitability. The methodology will be applied to a phosphate mine, to determine the best alternative from a long-term mine planning perspective. Using the hybrid pits method, applied to a simulated grades model, allowed the identification os occurrence probability zones within mathematical pit, providing critical data to support decision making regarding infrastructure relocation.

Page generated in 0.0163 seconds