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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.
331

Applying Value-at-Risk to Financial Risk Evaluation in BOT Projects

Sung, Chao-Hsien 28 May 2010 (has links)
There is a growing trend to use public-private partnerships (PPP) for infrastructure project delivery due to lack of budget and inefficiency of public sector. The most popular PPP option is a concession-based type such as build-operate-transfer (BOT). However, construction delay, costs overrun, and disastrous financial performance in the early operation phase are not rarely seen in large BOT projects. The case of Taiwan High Speed Rail (THSR) is the evidence. The problem lies in over-optimism in financial feasibility analysis and under-estimation in risk exposure evaluation. Based on information of Case Project - Kaohsiung Intercontinental Terminal (KIT), which started its Phase One Plan in 2007 at a cost of about NT$42.89 billions in land procurement, peripheral public infrastructure and construction and facilities of the terminal, I will apply traditional capital investment methodology to evaluate its financial feasibility. This is done by calculating key financial indexes from Total Investment Point of View and Equity Point of View and determine whether this project is acceptable or not by conventional criteria from three main participants¡¦ position, including government agency, financial institutions, and private investors. However, we can not realize risk exposure of Case Project from traditional methods. Therefore, ideas of Value-at-Risk (VAR) that commonly used in evaluating risk exposure of financial assets are brought in. The VAR concepts are used in four financial indexes, including self-liquidation ratio (SLR), net present value (NPV), debt coverage ratio (DCR) and times interest earned (TIE), which are regarded as critical in decision by government agency, private investors, and financial institutions. This is done by applying Monte Carlo Simulation, which involves 1,000 iterations of sampling based on parameter settings of risk factors and consideration of correlations in risk factors. Volatility of key risk factor is analyzed to further realize comprehensively risk exposure in terms of VARs of financial indexes. Evidences show that, while parameter settings of risk factors are critical to simulations results, consideration of correlations of risk factors will also diverge results from that of ignoring. In addition, sensitivity analysis in terms of volatility in key risk factors presents full-scale financial risk exposure, which is helpful in reaching final decision. Of all three participants in Case Project, while private investors face greatest risk exposure due to high financial leverage employed, financial institutions confront relatively low risk in terms of loan repayment. From government agency¡¦s view, probability of fully self-liquidated with no subsidy in Case Project is 90%.
332

A Theoretical Approach for the Determination and Mechanistic Interpretation of Radiation D10-value

Ekpanyaskun, Nont 2009 May 1900 (has links)
In the design of the food irradiation process, the knowledge of the radiation resistance of the target organism in a specific food commodity is required. The D10-value, the radiation dose needed to inactivate 90% of the microbial load in the food medium, is used to relate the amount of absorbed energy to the surviving bacterial population. Numerous experimental studies have been performed to determine the D10 values of several food-borne microorganisms irradiated under various conditions. Nevertheless, accurate predictions of D10 values of the pathogens in food products that have not been empirically examined cannot be made due to insufficient understanding of the biological response to radiation exposure. A theoretical model for the derivation of the D10-value has been proposed in this study to mechanistically assess the production of radiation-induced DNA damage by energetic electrons. The step-by-step Monte-Carlo simulation technique, which employs the detailed histories of the ionizing particles and the radiolytic species, was utilized. The effects of selected parameters including the genomic sequence, the type of DNA double strand break, the DNA damaging agents, the radical scavengers, the degree of dispersion of DNA molecules, and the number of genome equivalents were hypothetically investigated. The developed computational methodology as well as the results presented can be used as an analytical tool to evaluate the impact of ionizing radiation on cell survival.
333

A Study on the Impacts of Grid Connection Wind Power Generations

Kuo, Zhi-Yuan 01 July 2004 (has links)
Wind power generations have increased impacts on the electric utility power systems. When the wind power is placed into service in an electric system, it becomes a functioning part of the system, which may require other design changes to the system and special practices to integrate it to the system. The presence of the wind power generation units will directly affect voltage profiles along a feeder by changing the direction and magnitude of active/reactive power flows. A number of coordination issues including safety issue, protection, voltages and frequency control presently require study in order to understand technical limits to the penetration of wind power or distributed generation on a given system. The aim of this thesis is to investigate the impacts of wind generators connected to a distribution system. To take load uncertainty and wind power generation uncertainty due to wind speed variation in the analysis, Monte Carlo simulation technique is used. A number of cases are tested to assess the impacts of wind power generations in various scenarios for the studied network. Test results have shown that the when wind power generators are connected to distribution network, it would not only reduce the probability of occurrence of undervoltage but also decrease the feeder losses. The analytical models proposed in this thesis can provide the utility useful information in placing the wind power generators.
334

An Analysis on the Blade Design Parameters of Turbo Molecular Pumps

Tsai, Hong-Zhi 27 July 2000 (has links)
Turbo Molecular pumps, abbreviated as TMP, can create a high vacuum environment for some special industries, especially the semiconductor and IC industries. The turbo blade design is one of the main technologies that affect the performance of a TMP. The object of this study is to investigate what kind of blade design parameters, e.g. blade angle, blade spacing, blade chord, blade velocity, etc., will affect the performance of TMP. It is hope that an analysis methodology of these parameters can be setup in the viewpoint of pumping rate curve. The results of this study will be useful for the design of TMP.
335

A reliability assessment methodology for distribution systems with distributed generation

Duttagupta, Suchismita Sujaya 16 August 2006 (has links)
Reliability assessment is of primary importance in designing and planning distribution systems that operate in an economic manner with minimal interruption of customer loads. With the advances in renewable energy sources, Distributed Generation (DG), is forecasted to increase in distribution networks. The study of reliability evaluation of such networks is a relatively new area. This research presents a new methodology that can be used to analyze the reliability of such distribution systems and can be applied in preliminary planning studies for such systems. The method uses a sequential Monte Carlo simulation of the distribution system’s stochastic model to generate the operating behavior and combines that with a path augmenting Max flow algorithm to evaluate the load status for each state change of operation in the system. Overall system and load point reliability indices such as hourly loss of load, frequency of loss of load and expected energy unserved can be computed using this technique. On addition of DG in standby mode of operation at specific locations in the network, the reliability indices can be compared for different scenarios and strategies for placement of DG and their capacities can be determined using this methodology.
336

Medical physics calculations with MCNP: a primer

Lazarine, Alexis D 30 October 2006 (has links)
The rising desire for individualized medical physics models has sparked a transition from the use of tangible phantoms toward the employment of computational software for medical physics applications. One such computational software for radiation transport modeling is the Monte Carlo N-Particle (MCNP) radiation transport code. However, no comprehensive document has been written to introduce the use of the MCNP code for simulating medical physics applications. This document, a primer, addresses this need by leading the medical physics user through the basic use of MCNP and its particular application to the medical physics field. This primer is designed to teach by example, with the aim that each example will illustrate a practical use of particular features in MCNP that are useful in medical physics applications. These examples along with the instructions for reproducing them are the results of this thesis research. These results include simulations of: dose from Tc-99m diagnostic therapy, calculation of Medical Internal Radiation Dose (MIRD) specific absorbed fraction (SAF) values using the ORNL MIRD phantom, x-ray phototherapy effectiveness, prostate brachytherapy lifetime dose calculations, and a radiograph of the head using the Zubal head phantom. Also included are a set of appendices that include useful reference data, code syntax, and a database of input decks including the examples in the primer. The sections in conjunction with the appendices should provide a foundation of knowledge regarding the MCNP commands and their uses as well as enable users to utilize the MCNP manual effectively for situations not specifically addressed by the primer.
337

Dosimetric characterization of elongated brachytherapy sources using Monte Carlo methods

Bannon, Elizabeth 07 April 2010 (has links)
Current brachytherapy treatment planning systems are unable to accurately calculate dose distributions in the vicinity of brachytherapy sources having active lengths much greater than 5 mm. While low dose-rate ¹³⁷Cs sources are dosimetrically characterized using antiquated along-away tables with simple linear-linear interpolation errors in dose calculation exceeding 30% occur due to algorithm inadequacy. The method presented in this thesis permits dosimetric characterization of elongated brachytherapy sources with active lengths 0 < L < 10 cm for implementation on an FDA-approved clinical TPS. Low- and high-energy photon-emitting sources of Pd-103 and Ir-192, respectively, were examined.
338

Simulación Monte Carlo de la transición orden-desorden y la formación de agregados atómicos en las aleaciones modelos tridimensionales

Manrique Castillo, Erich Víctor January 2006 (has links)
No description available.
339

Numerical exact simulations of actual-size bosonic optical lattice systems /

Ma, Ping-nang. January 2009 (has links)
Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 52-54). Also available online.
340

Das Amt des Architetto del Popolo Romano : die Geschichte einer Institution unter besonderer Berücksichtigung von Carlo Rainaldi /

Kempfer, Jacqueline, January 1994 (has links)
Dissertation--Frankfurt am Main--Universität, 1994.

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