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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.
51

Mass, Composition, Source Identification and Impact Assessment for Fine and Coarse Atmospheric Particles in the Desert Southwest

Clements, Andrea 05 June 2013 (has links)
A year-long study was conducted in Pinal County, Arizona to characterize fine and coarse particulate matter as a means of furthering our understanding of ambient concentrations and composition in rural, arid environments. Detailed measurement of ambient fine and coarse mass, ion, metal, and carbon concentrations at one-in-six day resolution was conducted at three sites from February 2009 to February 2010. Detailed organic carbon speciation was collected at 5-week resolution. A series of samples representing native soil, agricultural soil, road dust, and cattle feed lot material was collected, resuspended in the laboratory, and analyzed to provide a chemical source profile for each soil type yielding insights into unique source signatures. Observations within the chemical speciation data and subsequent modeling analysis show a strong impact from local sources at the Cowtown site where mass concentrations are highest. Source apportionment results confirm the significant impact from the cattle feedlot adjacent to the site. Chemical analysis of ambient particles and local feedlot material shows the presence of chemical marker species including phosphate which is unique to this source. Fugitive dust is a significant contributor to ambient particulate matter concentrations at all monitoring locations. Seasonal observations show higher concentrations during tilling and harvesting indicating the large role agricultural sources play on particle concentrations in this area. Chemical characterization and modeling show that re-entrained road dust is a significant factor. Fine particle modeling results indicate that concentrations are influenced significantly by motor vehicles including impacts from direct emissions including brake wear and indirect emissions including resuspended road dust. A significant fraction is also associated with crustal sources while about 5 g/m3 appears to be transported into the region from beyond the air shed. Detailed analysis of the local monsoon season indicates that monsoon rains serve to clean the atmosphere resulting in a marked decrease in ambient coarse mass and resulted in a period where local coarse PM concentrations measured at all sites became more uniform. The monsoon season also featured localized high wind events which severely increased coarse PM concentrations and often caused exceedences of the PM National Ambient Air Quality Standard.
52

Mass, Composition, Source Identification and Impact Assessment for Fine and Coarse Atmospheric Particles in the Desert Southwest

Clements, Andrea 05 June 2013 (has links)
A year-long study was conducted in Pinal County, Arizona to characterize fine and coarse particulate matter as a means of furthering our understanding of ambient concentrations and composition in rural, arid environments. Detailed measurement of ambient fine and coarse mass, ion, metal, and carbon concentrations at one-in-six day resolution was conducted at three sites from February 2009 to February 2010. Detailed organic carbon speciation was collected at 5-week resolution. A series of samples representing native soil, agricultural soil, road dust, and cattle feed lot material was collected, resuspended in the laboratory, and analyzed to provide a chemical source profile for each soil type yielding insights into unique source signatures. Observations within the chemical speciation data and subsequent modeling analysis show a strong impact from local sources at the Cowtown site where mass concentrations are highest. Source apportionment results confirm the significant impact from the cattle feedlot adjacent to the site. Chemical analysis of ambient particles and local feedlot material shows the presence of chemical marker species including phosphate which is unique to this source. Fugitive dust is a significant contributor to ambient particulate matter concentrations at all monitoring locations. Seasonal observations show higher concentrations during tilling and harvesting indicating the large role agricultural sources play on particle concentrations in this area. Chemical characterization and modeling show that re-entrained road dust is a significant factor. Fine particle modeling results indicate that concentrations are influenced significantly by motor vehicles including impacts from direct emissions including brake wear and indirect emissions including resuspended road dust. A significant fraction is also associated with crustal sources while about 5 g/m3 appears to be transported into the region from beyond the air shed. Detailed analysis of the local monsoon season indicates that monsoon rains serve to clean the atmosphere resulting in a marked decrease in ambient coarse mass and resulted in a period where local coarse PM concentrations measured at all sites became more uniform. The monsoon season also featured localized high wind events which severely increased coarse PM concentrations and often caused exceedences of the PM National Ambient Air Quality Standard.
53

Functionality Based Refactoring: Improving Source Code Comprehension

Beiko, Jeffrey Lee 27 September 2007 (has links)
Thesis (Master, Computing) -- Queen's University, 2007-09-25 12:38:48.455 / Software maintenance is the lifecycle activity that consumes the greatest amount of resources. Maintenance is a difficult task because of the size of software systems. Much of the time spent on maintenance is spent trying to understand source code. Refactoring offers a way to improve source code design and quality. We present an approach to refactoring that is based on the functionality of source code. Sets of heuristics are captured as patterns of source code. Refactoring opportunities are located using these patterns, and dependencies are verified to check if the located refactorings preserve the dependencies in the source code. Our automated tool performs the functional-based refactoring opportunities detection process, verifies dependencies, and performs the refactorings that preserve dependencies. These refactorings transform the source code into a series of functional regions of code, which makes it easier for developers to locate code they are searching for. This also creates a chunked structure in the source code, which helps with bottom-up program comprehension. Thus, this process reduces the amount of time required for maintenance by reducing the amount of time spent on program comprehension. We perform case studies to demonstrate the effectiveness of our automated approach on two open source applications. / Master
54

A Probabilistic Approach for the Design of an Early Warning Source Water Monitoring Station

Mustard, Heather Patricia January 2007 (has links)
This thesis involves the design of an early warning source water monitoring station for a riverine source of drinking water. These stations provide downstream water utilities with advanced notification of contamination events so they have time in which to implement a response. Many threats facing riverine water supplies, such as accidental spills, are uncertain in nature. Therefore, designing a monitoring station for the detection of these events requires a probabilistic modelling approach. Sources of uncertainty considered in this research include the location, mass and duration of a spill event as well as the flow at the time of the spill and the water quality model parameters. Probability distributions for each of these uncertainties were defined and a Monte Carlo experiment was conducted. The design objectives include maximizing the probability of detection and maximizing the probability of having a threshold amount of warning time. These objectives are in conflict with each other because the probability of detection improves as the station moves closer to the intake and the amount of warning time increases as the station is located further upstream. Values for the competing objectives were calculated for a number of potential monitoring station locations at multiple sample intervals and the tradeoff solutions were analyzed. This methodology was applied to the Hidden Valley Intake which services the Regional Municipality of Waterloo’s Mannheim Water Treatment Plant. The Hidden Valley Intake is located in Kitchener, Ontario and withdraws up to 72 ML of water per day from the Grand River. Based on an analysis of the Monte Carlo simulation results for the case study application, it was found that locating the monitoring station near the Victoria Street Bridge, approximately 11 km upstream of the intake, represents the best tradeoff in the design objectives. Sampling at least once per hour is recommended to increase the amount of warning time. The impact of various sources of uncertainty was also explored in this thesis. It was found that the flow at the time of a spill and the spill location are the only sources of uncertainty that significantly impact the probability distributions of relevant model results.
55

A Probabilistic Approach for the Design of an Early Warning Source Water Monitoring Station

Mustard, Heather Patricia January 2007 (has links)
This thesis involves the design of an early warning source water monitoring station for a riverine source of drinking water. These stations provide downstream water utilities with advanced notification of contamination events so they have time in which to implement a response. Many threats facing riverine water supplies, such as accidental spills, are uncertain in nature. Therefore, designing a monitoring station for the detection of these events requires a probabilistic modelling approach. Sources of uncertainty considered in this research include the location, mass and duration of a spill event as well as the flow at the time of the spill and the water quality model parameters. Probability distributions for each of these uncertainties were defined and a Monte Carlo experiment was conducted. The design objectives include maximizing the probability of detection and maximizing the probability of having a threshold amount of warning time. These objectives are in conflict with each other because the probability of detection improves as the station moves closer to the intake and the amount of warning time increases as the station is located further upstream. Values for the competing objectives were calculated for a number of potential monitoring station locations at multiple sample intervals and the tradeoff solutions were analyzed. This methodology was applied to the Hidden Valley Intake which services the Regional Municipality of Waterloo’s Mannheim Water Treatment Plant. The Hidden Valley Intake is located in Kitchener, Ontario and withdraws up to 72 ML of water per day from the Grand River. Based on an analysis of the Monte Carlo simulation results for the case study application, it was found that locating the monitoring station near the Victoria Street Bridge, approximately 11 km upstream of the intake, represents the best tradeoff in the design objectives. Sampling at least once per hour is recommended to increase the amount of warning time. The impact of various sources of uncertainty was also explored in this thesis. It was found that the flow at the time of a spill and the spill location are the only sources of uncertainty that significantly impact the probability distributions of relevant model results.
56

Celebrity Endorsement : Hidden factors to success

Saouma, Joulyana, Chabo, Dimed January 2005 (has links)
<p>Abstract</p><p>The use of celebrity endorsement strategy is nowadays more frequently used by marketers in order to increase their sales and thereby extend their market shares. Many celebrities are used in various marketing campaigns and in most cases; the use of celebrities as endorsers is seen from mainly positive aspects. This made the authors curious whether the negative aspects, that also exists when using celebrities as endorsers, affects consumers in their purchasing decisions when a celebrity gets associated with negative publicity. Another cause of interest is which factors of a certain celebrity are most important and crucial in consumers’ perceptions, in the case of negative publicity.</p><p>Purpose: The purpose of this thesis is to study which factors consumers find important for a company to consider when a celebrity gets negative publicity, to maintain successful brand recognition.</p><p>Literature review: The use of previous studies within the field of celebrity endorsement clarifies many important aspects when it comes to celebrity endorsement and this chapter is elaborated from 4 different perspectives; Company, Celebrity, Brand and Consumer. Based on previous studies, the authors identified 6 crucial attributes when using celebrities as endorsers and this can also be seen as a pre-study that the research process has been based upon. Furthermore, the 6 attributes are chosen from the three first mentioned perspectives in order to be able to fulfil the purpose. Hence, this thesis is conducted from a consumer’s point of view.</p><p>Method: A quantitative method is used in this thesis since the authors want to base the results on collected data that is expressed in numbers and also to generate a general apprehension in this phenomenon. Moreover, the combinations containing the 6 attributes are used in the conjoint experiment.</p><p>Conclusions: It was proven in this study that consumers do get affected by celebrities as endorser, when the attributes from the literature review are in a combination. But, the consumers’ perception of the attributes differs in different cases. However, the main finding was that there are two crucial attributes, trustworthiness and expertise that companies should take into account when using celebrities in their advertising campaign.</p>
57

An investigation of the combustive sound source

McNeese, Andrew Reed 23 December 2010 (has links)
This thesis describes the development and testing of the Combustive Sound Source (CSS), which is a broadband underwater sound source. The CSS is being developed as a clean, safe, and cost effective replacement to underwater explosive charges, which exhibit an inherent danger to marine life and researchers using the charges. The basic operation of the CSS is as follows. A combustible mixture of gas is held below the surface of the water in a combustion chamber and ignited with an electric spark. A combustion wave propagates through the mixture and converts the fuel and oxidizer into a bubble of combustion products, which expands due to an increase in temperature, and then ultimately collapses to a smaller volume than before ignition, producing a high intensity, low frequency acoustic signal. The thesis begins by discussing the background, history, and purpose of developing the CSS. It continues by describing the current apparatus and the essential components and convenient features added to the latest mechanical design. The general operation is discussed along with a description of an experiment conducted to determine the acoustic output and robustness of the current CSS. The results of this experiment are presented in terms of the effect of volume, ignition depth, oxidizing gas, combustion chamber size, and repeatability of acoustic signatures. Discussion of apparatus robustness is presented to suggest improvements for future CSS designs. / text
58

Numerical Simulation and Laboratory Testing of Time-Frequency MUSIC Beamforming for Identifying Continuous and Impulsive Ground Targets from a Mobile Aerial Platform

Silva, Ramon Alejandro 03 October 2013 (has links)
When a microphone array is mounted on a mobile aerial platform, such as an unmanned aerial vehicle (UAV), most existing beamforming methods cannot be used to adequately identify continuous and impulsive ground. Here, numerical simulation results and laboratory experiments are presented that validate a proposed time-frequency beamforming method based on the Multiple Signal Classification (MUSIC) algorithm to detect these acoustic sources from a mobile aerial platform. In the numerical simulations three parameters were varied to test the proposed algorithm’s location estimation performance: 1) the acoustic excitation types; 2) the moving receiver’s simulated flight conditions; and 3) the number of acoustic sources. Also, a distance and angle error analysis was done to quantify the proposed algorithm’s source location estimation accuracy when considering microphone positioning uncertainty. For experimental validation, three laboratory experiments were conducted. Source location estimations were done for: a 600 Hz sine source, a banded white noise source between 700-800 Hz, and a composite source combined simultaneously with both the sine and banded white noise sources. The proposed algorithm accurately estimates the simulated monopole’s location coordinates no matter the excitation type or simulated trajectory. When considering simultaneously-excited, multiple monopoles at high altitudes, e.g. 50 m, the proposed algorithm had no error when estimating the source’s locations. Finally, a distance and angle error analysis exposed how relatively small microphone location error, e.g. 1 cm maximum error, can propagate into large averaged distance error of about 10 m in the far-field for all monopole excitation types. For all simulations, however, the averaged absolute angle error remained small, e.g. less than 4 degrees, even when considering a 5 cm maximum microphone location error. For the laboratory experiments, the sine source had averaged distance and absolute angle errors of 0.9 m and 14.07 degrees from the source’s true location, respectively. Similarly, the banded white noise source’s averaged distance and absolute angle errors were 1.9 m and 47.14 degrees; and lastly, the averaged distance and absolute angle errors of 0.78 m and 8.14 degrees resulted when both the sources were simultaneously excited.
59

Linking field-scale phosphorus export to a watershed-scale model /

Freihoefer, Adam T. January 2007 (has links) (PDF)
Thesis (M.S.)--University of Wisconsin--Stevens Point, 2007. / Includes bibliographical references (leaves 105-112).
60

Simulation and design of hybrid geothermal heat pump systems

Chiasson, Andrew D. January 2007 (has links)
Thesis (Ph.D.)--University of Wyoming, 2007. / Title from PDF title page (viewed on June 17, 2009). Includes bibliographical references (p. 167-178).

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