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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.
11

Generation adequacy assessment of power systems with significant wind generation : a system planning and operations perspective

D'Annunzio, Claudine 03 February 2010 (has links)
One of the great challenges to increasing the use of wind generation is the need to ensure generation adequacy. In this dissertation, we address that need by investigating and assessing the planning and operational generation adequacy of power systems with significant wind generation. At the onset of this dissertation, key metrics are presented for determining a power system’s generation adequacy assessment based on loss-of-load analytical methods. With these key metrics understood, a detailed methodology is put forward on how to integrate wind plants in the assessment’s framework. Then, through the examination of a case study, we demonstrate that wind generation does contribute capacity to the system generation adequacy. Indeed, results indicates that at wind penetration levels of less than 5%, a wind plant’s reliability impact is comparable to an energy equivalent conventional unit. We then show how to quantify a wind plant’s capacity contribution by using the effective load carrying capability metric (ELCC), providing a detailed description of how to implement this metric in the context of wind generation. However, as certain computational setbacks are inherent to the metric, a novel noniterative approximation is proposed and applied to various case studies. The accuracy of the proposed approximation is evaluated in a comparative study by contrasting the resulting estimates to conventionally-computed ELCC values and the wind plant’s capacity factor. The non-iterative method is shown to yield accurate ELCC estimates with relative errors averaging around 2%. Case study findings also suggest the importance of period-specific ELCC calculations to better evaluate the variable capacity contribution of wind plants. Even when considering a well-planned system in which wind generation has been appropriately integrated in the adequacy assessment, wind plants do create significant challenges in maintaining generation adequacy on an operational level. To address these challenges, a novel operational reliability assessment tool is proposed to quantitatively evaluate the system’s operational generation adequacy given potential generator forced outages, load and wind power forecasts, and forecasting deviations. / text
12

A Study of the Relationship Between Foundational Per Pupil Investment and Student Outcomes

Mathias, Michelle Baird 16 June 2010 (has links)
The concept of return on investment for public education requires an understanding of the cumulative impact of resources employed to educate a student over time. The State of Vermont presented a unique opportunity to measure the return on investment as indicated by student outcomes. The governance structure of Vermont school districts allowed the identification of investments at the local school level, thereby enabling a match between the outcomes for 1355 students on the New Standards Reference Exam and cumulative investments over time. The longitudinal study examined the relationship between the cumulative investment made during the first eight years of school and student outcomes based upon three assessment points, in fourth, eighth and tenth grades for students within the sample. The study included an examination of the relationship between poverty, investments and student outcomes, indicated included Free or Reduced Lunch eligibility and Adjusted Gross Income. The study also examined the relationship between student performance and responses to the Opportunity to Learn Survey, assessing the student‟s perception of their school. Vermont Department of Education databases included financial investments from 1997 through 2004 and matched student outcomes on the New Standards Reference Exam in 2000, 2004, and 2006 in both English and Language Arts and Math. The results analysis indicated statistically significant relationships between student outcomes and investment which grew over time, and when the investments were more closely related to direct instruction on students, and were especially evident in math. Furthermore, there was a statistically significant relationship between levels of investment and outcomes for students within the same economic group and between students‟ responses to the Opportunity to Learn survey and investment levels. The results of this study provide legislators and policy makers with longitudinal clarification regarding the relationship between per pupil investment and student outcomes.
13

Adequacy assessment of composite generation and transmission systems incorporating wind energy conversion systems

Gao, Yi 24 March 2010
The development and utilization of wind energy for satisfying electrical demand has received considerable attention in recent years due to its tremendous environmental, social and economic benefits, together with public support and government incentives. Electric power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of wind energy facilities therefore affect power system reliability in a different manner than those of conventional systems. The reliability impact of such a highly variable energy source is an important aspect that must be assessed when the wind power penetration is significant. The focus of the research described in this thesis is on the utilization of state sampling Monte Carlo simulation in wind integrated bulk electric system reliability analysis and the application of these concepts in system planning and decision making. Load forecast uncertainty is an important factor in long range planning and system development. This thesis describes two approximate approaches developed to reduce the number of steps in a load duration curve which includes load forecast uncertainty, and to provide reasonably accurate generating and bulk system reliability index predictions. The developed approaches are illustrated by application to two composite test systems.<p> A method of generating correlated random numbers with uniform distributions and a specified correlation coefficient in the state sampling method is proposed and used to conduct adequacy assessment in generating systems and in bulk electric systems containing correlated wind farms in this thesis. The studies described show that it is possible to use the state sampling Monte Carlo simulation technique to quantitatively assess the reliability implications associated with adding wind power to a composite generation and transmission system including the effects of multiple correlated wind sites. This is an important development as it permits correlated wind farms to be incorporated in large practical system studies without requiring excessive increases in computer solution time. The procedures described in this thesis for creating monthly and seasonal wind farm models should prove useful in situations where time period models are required to incorporate scheduled maintenance of generation and transmission facilities.<p> There is growing interest in combining deterministic considerations with probabilistic assessment in order to evaluate the quantitative system risk and conduct bulk power system planning. A relatively new approach that incorporates deterministic and probabilistic considerations in a single risk assessment framework has been designated as the joint deterministic-probabilistic approach. The research work described in this thesis illustrates that the joint deterministic-probabilistic approach can be effectively used to integrate wind power in bulk electric system planning. The studies described in this thesis show that the application of the joint deterministic-probabilistic method provides more stringent results for a system with wind power than the traditional deterministic N-1 method because the joint deterministic-probabilistic technique is driven by the deterministic N-1 criterion with an added probabilistic perspective which recognizes the power output characteristics of a wind turbine generator.
14

Adequacy assessment of composite generation and transmission systems incorporating wind energy conversion systems

Gao, Yi 24 March 2010 (has links)
The development and utilization of wind energy for satisfying electrical demand has received considerable attention in recent years due to its tremendous environmental, social and economic benefits, together with public support and government incentives. Electric power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of wind energy facilities therefore affect power system reliability in a different manner than those of conventional systems. The reliability impact of such a highly variable energy source is an important aspect that must be assessed when the wind power penetration is significant. The focus of the research described in this thesis is on the utilization of state sampling Monte Carlo simulation in wind integrated bulk electric system reliability analysis and the application of these concepts in system planning and decision making. Load forecast uncertainty is an important factor in long range planning and system development. This thesis describes two approximate approaches developed to reduce the number of steps in a load duration curve which includes load forecast uncertainty, and to provide reasonably accurate generating and bulk system reliability index predictions. The developed approaches are illustrated by application to two composite test systems.<p> A method of generating correlated random numbers with uniform distributions and a specified correlation coefficient in the state sampling method is proposed and used to conduct adequacy assessment in generating systems and in bulk electric systems containing correlated wind farms in this thesis. The studies described show that it is possible to use the state sampling Monte Carlo simulation technique to quantitatively assess the reliability implications associated with adding wind power to a composite generation and transmission system including the effects of multiple correlated wind sites. This is an important development as it permits correlated wind farms to be incorporated in large practical system studies without requiring excessive increases in computer solution time. The procedures described in this thesis for creating monthly and seasonal wind farm models should prove useful in situations where time period models are required to incorporate scheduled maintenance of generation and transmission facilities.<p> There is growing interest in combining deterministic considerations with probabilistic assessment in order to evaluate the quantitative system risk and conduct bulk power system planning. A relatively new approach that incorporates deterministic and probabilistic considerations in a single risk assessment framework has been designated as the joint deterministic-probabilistic approach. The research work described in this thesis illustrates that the joint deterministic-probabilistic approach can be effectively used to integrate wind power in bulk electric system planning. The studies described in this thesis show that the application of the joint deterministic-probabilistic method provides more stringent results for a system with wind power than the traditional deterministic N-1 method because the joint deterministic-probabilistic technique is driven by the deterministic N-1 criterion with an added probabilistic perspective which recognizes the power output characteristics of a wind turbine generator.
15

Methodology on the Analysis of Shell Utilization of Hermit Crabs, Diogenes spp. in Shallow Waters

Hu, Chieh-Shen 30 August 2010 (has links)
¡@The shell utilization of two sympatric hermit carb species was studied in shallow waters of Kaohsiung and Pingtung, southern Taiwan. Principal components, canonical variates and univariate analysis was used to compare three major variables of shell resource: species, size, and shape between species and sites. The regression between crab and shell and shell adequacy index (SAI) revealed that two species shared the same resource which had shell size limitation in the field had different pattern. Shells used by Diogenes rectimanus were larger than those uesd by D. nitidimanus of same size. But the utilization pattern was the same under a shell sufficient condition in the laboratory, suggesting that there was no resource partitioning or competition between these two species. The size of shell composed a continuous morphological overlap at four different sites and shown a good consistency with crab size. This revealed the utilization of crabs in different size selected different shells and suggested a status of sufficient resource utilization. Although the shell resource were highly similar, but different composition of shell species and other factors could caused variances in shell size and shape between four sites, and caused crab size divergence among different populations.
16

A Study of Risk-Based Bank Deposit Reserve System

Chen, Yung-chieh 26 June 2012 (has links)
Our country, the same type of deposit applies the same interest rate. The reserve ratio in the world has gradually been reduced even adjusted to zero. Because of the control policy increases in bank operating costs, and impact the efficiency of resource allocationa. The competent national authorities still see the control policy as the main monetary policy. Domestic banks under this system face a very high control costs. Presently our country is still unable to adopt "zero" reserve, so this study consider existing banking supervision system to develop a "Risk-Based Deposit System" for existing national reserve system.The concept of risk stratification derives from deposit insurance, using the capital adequacy ratio, banks integrated risk rating score and the financial leverage ratio. Each Bank based on their respective level of risk to employ different deposit reserve ratio. "Risk-Based Deposit System" can make the banking sector to spontaneously reduce their own business risk in order to meet the lower deposit reserve ratio of the risk criteria. Therefore, it will help banking sector to reduce regulatory burden, and assist banks in Taiwan to follow Basel III to strengthen its competitiveness and meet the world trend.
17

Adequacy Assessment in Power Systems Using Genetic Algorithm and Dynamic Programming

Zhao, Dongbo 2010 December 1900 (has links)
In power system reliability analysis, state space pruning has been investigated to improve the efficiency of the conventional Monte Carlo Simulation (MCS). New algorithms have been proposed to prune the state space so as to make the Monte Carlo Simulation sample a residual state space with a higher density of failure states. This thesis presents a modified Genetic Algorithm (GA) as the state space pruning tool, with higher efficiency and a controllable stopping criterion as well as better parameter selection. This method is tested using the IEEE Reliability Test System (RTS 79 and MRTS), and is compared with the original GA-MCS method. The modified GA shows better efficiency than the previous methods, and it is easier to have its parameters selected. This thesis also presents a Dynamic Programming (DP) algorithm as an alternative state space pruning tool. This method is also tested with the IEEE Reliability Test System and it shows much better efficiency than using Monte Carlo Simulation alone.
18

none

Chen, Yi-Yun 25 May 2002 (has links)
none
19

Current Account Deficits, Sudden Stops, and International Reserves Accumulation

Nechi, SALEM 17 August 2009 (has links)
This dissertation addresses the causes of and policy responses to the 1990s current account crises. The first chapter explores the relative importance of external shocks as key determinants of the significant increase of foreign reserves accumulated in many emerging market economies, and provides a comprehensive framework to assess the adequacy of reserve holdings. Using the case of Mexico, I find that more than two thirds of the increase in international reserves can be replicated by a linear combination of external shocks, without an abrupt regime shift after the Tequila crisis. I also find that Mexico has historically adopted an appropriate reserves policy, with 1994 being an exception. However, under the current reserves policy, there is a positive probability of a current account crisis in the near future. In chapter Two, I investigate the optimal reserves policy. The analysis predicts an optimal level of reserves in Mexico that is considerably higher than the actual level. When I account for the possibility of a bailout by the outside world in case of a crisis, Mexico's current reserves policy is in the range of my model's predictions. The final chapter proposes a new explanation for the existence and nature of sudden stops. In my model, a sudden stop forms a necessary solution to the moral hazard problem in investment and can be rationalized as part of an optimal lending strategy in the face of asymmetric information. / Thesis (Ph.D, Economics) -- Queen's University, 2009-08-13 22:52:26.219
20

Regulation of banks under Basel frameworks / Regulation of banks under Basel frameworks

Miškovič, Branislav January 2010 (has links)
This diploma thesis provides a high-level overview of banking regulation under the general rules of the Basel agreements that are followed in almost every international bank globally. The introductory part of this paper is devoted to the fundamental purpose of regulation and explains the risks banks are exposed to. The following chapters outline the evolution of banking regulation as agreed by the Basel committee, explain the various capital adequacy frameworks, risk measurement methodologies and look into the proposed future developments in the regulatory area, including ex-post (Basel I, II) and ex-ante analysis of the practical impacts on banks. The final part of this diploma work is focused on actual real world application of the Basel II rules in a banking organization, precisely Barclays Capital, the investment banking arm of Barclays Plc. headquartered in London, UK and regulated by the Financial Services Authority (FSA).

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