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Title: Using computer simulations to study relativistic heavy ion collisions
Creator: Murray, Joelle
Date: 1998
Collection: Electronic Theses & Dissertations

Title: Energy utilization modeling of animal draft power (EUMDAP) for Kenyan small-holder semi-arid agriculture
Creator: Mungai, George S. N.
Date: 1998
Collection: Electronic Theses & Dissertations

Title: Dynamic simulation of the electrorheological effect in a uniformly distributed electric field
Creator: Cristescu, Nicolae
Date: 2000
Collection: Electronic Theses & Dissertations

Title: Two-dimensional drafting template and three-dimensional computer model representing the average adult male in automotive seated postures
Creator: Bush, Neil James
Date: 1992
Collection: Electronic Theses & Dissertations

Title: Shelf life estimation of USP 10mg Prednisone calibrator tablets in relation to dissolution & new windows-based shelf life computer program
Creator: Yoon, Seungyil
Date: 2000
Collection: Electronic Theses & Dissertations

Title: Evaluation of calibration for optical see-through augmented reality systems
Creator: McGarrity, Erin Scott
Date: 2001
Collection: Electronic Theses & Dissertations

Title: Parallel discrete event simulation and its application on logic simulation
Creator: Xu, Jinsheng
Date: 2002
Collection: Electronic Theses & Dissertations

Title: Modular modeling of engineering systems using fixed input-output structure
Creator: Byam, Brooks Philip
Date: 1999
Collection: Electronic Theses & Dissertations

Title: Designing a package for pharmaceutical tablets in relation to moisture and dissolution
Creator: Yoon, Seungyil
Date: 2003
Collection: Electronic Theses & Dissertations

Title: Evaluation of the impacts of a simulated irrigation withdrawal on the habitat and populations of brook trout and benthic macroinvertebrates in Hunt Creek, Michigan
Creator: Baker, Edward Allen
Date: 1995
Collection: Electronic Theses & Dissertations

Title: On the beneficial effects of deleterious mutations
Creator: Covert, Arthur W.
Date: 2010
Collection: Electronic Theses & Dissertations

Title: Multichix, a computer model that projects receipts and expenses for egg production enterprises
Creator: Jacobs, Roger Dean
Date: 1978
Collection: Electronic Theses & Dissertations

Title: Toward a formalization of demographic transition theory
Creator: Lazer, S. Charles, 1946-
Date: 1969
Collection: Electronic Theses & Dissertations

Title: Numerical model for hemodialysis
Creator: Siefert, Andrew W.
Date: 2009
Collection: Electronic Theses & Dissertations

Title: Network-wide traffic state analysis : estimation, characterization, and evaluation
Creator: Saedi Germi, Ramin
Date: 2020
Collection: Electronic Theses & Dissertations
Description: The Network Fundamental Diagram (NFD) represents dynamics of traffic flow at the network level. It is exploited to design various network-wide traffic control and pricing strategies to improve mobility and mitigate congestion. This study presents a framework to estimate NFD and incorporates it for three specific applications in large-scale urban networks. Primarily, a resource allocation problem is formulated to find the optimal location of fixed measurement points and optimal sampling of...
Show moreThe Network Fundamental Diagram (NFD) represents dynamics of traffic flow at the network level. It is exploited to design various network-wide traffic control and pricing strategies to improve mobility and mitigate congestion. This study presents a framework to estimate NFD and incorporates it for three specific applications in large-scale urban networks. Primarily, a resource allocation problem is formulated to find the optimal location of fixed measurement points and optimal sampling of probe trajectories to estimate NFD accounting for limited resources for data collection, network traffic heterogeneity and asymmetry in OD demand in a real-world network. Using a calibrated simulation-based dynamic traffic assignment model of Chicago downtown network, a successful application of the proposed model and solution algorithm to estimate NFD is presented. The proposed model, then, is extended to take into account the stochasticity of day-to-day fluctuations of OD demand in NFD estimation.Three main applications of NFD are also shown in this research: network-wide travel time reliability estimation, network-wide emission estimation, and real-time traffic state estimation for heterogenous networks experiencing inclement weather impact. The main objective of the travel time reliability estimation application is to improve estimation of this network-wide measure of effectiveness using network partitioning. To this end, a heterogeneous large-scale network is partitioned into homogeneous regions (clusters) with well-defined NFDs using directional and non-directional partitioning approaches. To estimate the network travel time reliability, a linear relationship is estimated that relates the mean travel time with the standard deviation of travel time per unit of distance at the network level. Partitioning and travel time reliability estimation are conducted for both morning and afternoon peak periods to demonstrate the impacts of travel demand pattern variations.This study also proposes a network-level emission modeling framework via integrating NFD properties with an existing microscopic emission model. The NFDs and microscopic emission models are estimated using microscopic and mesoscopic traffic simulation tools at different scales for various traffic compositions. The major contribution is to consider heterogenous vehicle types with different emission generation rates in the network-level model. Non-linear and support vector regression models are developed using simulated trajectory data of thirteen simulated scenarios. The results show a satisfactory calibration and successful validation with acceptable deviations from underlying microscopic emission model, regardless of the simulation tool that is used to calibrate the network-level emission model.Finally, the NFD application for real-time traffic state estimation in a network experiencing inclement weather conditions is explored. To this end, the impacts of weather conditions on the NFD and travel time reliability relation are illustrated through a scenario-based analysis using traffic simulation. Then, the real-time traffic state prediction framework in the literature is adjusted to capture weather conditions as a key parameter. The extended Kalman filter algorithm is employed as an estimation engine to predict the real-time traffic state. The results highlight the importance of considering weather conditions in the traffic state prediction model.
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Title: Orientation guided texture synthesis using PatchMatch
Creator: Dutka, Rosemary L.
Date: 2013
Collection: Electronic Theses & Dissertations
Description: Texture describes the unique structural patterns that we perceive in the world. Various surface geometric details such as animal fur, plant leaves, and carpets can be thought of as texture. In computer graphics, textures stored as images are ubiquitously used to decorate boundary surfaces of objects. There are multiple approaches to acquire realistic and aesthetically pleasing textures. One of the most popular methods is a process known as texture synthesis, in which we produce seamless...
Show moreTexture describes the unique structural patterns that we perceive in the world. Various surface geometric details such as animal fur, plant leaves, and carpets can be thought of as texture. In computer graphics, textures stored as images are ubiquitously used to decorate boundary surfaces of objects. There are multiple approaches to acquire realistic and aesthetically pleasing textures. One of the most popular methods is a process known as texture synthesis, in which we produce seamless nonrepetitive textures from a small patch of texture sample.In this thesis, we present an orientation guided fast texture synthesis based on an image editing tool, PatchMatch, which is included in PhotoShop. Given an example image, our model adopts a hierarchical process to improve retention of structural texture features at multiple scales. We generalize PatchMatch by using orientation to guide the alignment of texture features, indicated by a planar direction field, in the creation of large texture patches. To demonstrate the effectiveness of our approach, we first apply our algorithm in designing new textures with two and four-way symmetry which can be extended to n-way symmetry, and then in enhancing latent fingerprints. Furthermore, our results show empirically that orientation guided PatchMatch has the advantages of providing control over the density of singularities without knowing the exact locations and reducing spurious singularities.
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Title: Regional climate response to land use and land cover change in contiguous United States
Creator: Nikolić, Jovanka
Date: 2020
Collection: Electronic Theses & Dissertations
Description: Future land use and land cover (LULC) pattern in the Contiguous United States (CONUS) is expected to be significantly different from that of the present, and as an important surface forcing for earth's climate system, the potential changes in LULC will contribute to climate change at all scales (local, regional to global). While numerous studies have examined how the earth's climate will respond to the anthropogenic increase of greenhouse gas concentrations in the earth's atmosphere, this...
Show moreFuture land use and land cover (LULC) pattern in the Contiguous United States (CONUS) is expected to be significantly different from that of the present, and as an important surface forcing for earth's climate system, the potential changes in LULC will contribute to climate change at all scales (local, regional to global). While numerous studies have examined how the earth's climate will respond to the anthropogenic increase of greenhouse gas concentrations in the earth's atmosphere, this research aims to quantify the response of several climate variables to the expected LULC change in the CONUS using simulations from a regional climate model. The research is composed of three individual studies. The first study assesses the sensitivity of simulated low-level jet (LLJ) characteristics on changes in LULC pattern. As a prominent weather and climate process responsible for transport of moisture from the Gulf of Mexico northward into central CONUS, LLJ plays an important role in the hydrological cycle and wind energy generation over the Great Plains. Therefore, it is important to quantify the potential changes in jet characteristics, such as jet speed, height and frequency, under the influence of LULC change. The second study investigates the impact of LULC change on frost indices - the dates of last spring frost and first fall frost and the length of frost free seasons. Frost is one of the major factors affecting the growth and development of plants and crop production. Future changes in LULC could make some regions more beneficial, while others more harmful to agricultural practice. Finally, the third study examines the potential impact of the changes in LULC pattern on future wind energy resources. As a zero carbon energy resource, wind energy helps limit greenhouse gasses emissions and mitigate climate change. Knowledge gained on where in the CONUS wind power class would likely to change from unsuitable or marginal to suitable, and vice versa, as a result of LULC change can be useful for future wind farm sitting and for making better informed energy policies.
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Title: On the evolution of mutation bias in digital organisms
Creator: Rupp, Matthew
Date: 2011
Collection: Electronic Theses & Dissertations
Description: Mutation is one of the primary drivers of genetic change. In this work I study mutation biases, which are sets of different genetic-state inflow probabilities. Mutation biases have the potential to change the composition of genomes over time, leading to divergent short- and long-term evolutionary outcomes. I use digital organisms, self-replicating computer programs, to explore whether or not mutation biases are capable of altering the long-term adaptive behavior of populations; whether...
Show moreMutation is one of the primary drivers of genetic change. In this work I study mutation biases, which are sets of different genetic-state inflow probabilities. Mutation biases have the potential to change the composition of genomes over time, leading to divergent short- and long-term evolutionary outcomes. I use digital organisms, self-replicating computer programs, to explore whether or not mutation biases are capable of altering the long-term adaptive behavior of populations; whether mutation biases can be competitive traits; and whether mutation biases can evolve. I find that mutation biases can alter the long-term adaptive behavior of mutation bias-obligate populations in terms of both mean fitness and complex trait evolution. I also find that mutation biases can compete against one another under a variety of conditions, meaning mutation bias can selectable over relatively-short periods of time. The competitive success of a mutation bias does not always depend upon the presence of beneficial mutations, implicating an increase in the probability of neutral mutations as a sufficient mechanism for bias selection. Finally, I demonstrate that by giving organisms a mutable mutation bias allele, populations preferentially evolve to possess specific biases over others. Overall, this work shows that mutation bias can act as a selectable trait, influencing the evolution of populations with regard to both their internal-genetic and external environments.
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Title: Reliability improvement of DFIG-based wind energy conversion systems by real time control
Creator: Elhmoud, Lina Adnan Abdullah
Date: 2015
Collection: Electronic Theses & Dissertations
Description: Reliability is the probability that a system or component will satisfactorily perform its intended function under given operating conditions. The average time of satisfactory operation of a system is called the mean time between failures (MTBF) and. the higher value of MTBF indicates higher reliability and vice versa. Nowadays, reliability is of greater concern than in the past especially for offshore wind turbines since the access to these installations in case of failures is both costly and...
Show moreReliability is the probability that a system or component will satisfactorily perform its intended function under given operating conditions. The average time of satisfactory operation of a system is called the mean time between failures (MTBF) and. the higher value of MTBF indicates higher reliability and vice versa. Nowadays, reliability is of greater concern than in the past especially for offshore wind turbines since the access to these installations in case of failures is both costly and difficult. Power semiconductor devices are often ranked as the most vulnerable components from reliability perspective in a power conversion system. The lifetime prediction of power modules based on mission profile is an important issue. Furthermore, lifetime modeling of future large wind turbines is needed in order to make reliability predictions in the early design phase. By conducting reliability prediction in the design phase a manufacture can ensure that the new wind turbines will operate within designed reliability metrics such as lifetime.This work presents reliability analysis of power electronic converters for wind energy conversion systems (WECS) based on semiconductor power losses. A real time control scheme is proposed to maximize the system's lifetime and the accumulated energy produced over the lifetime. It has been verified through the reliability model that a low-pass-filter-based control can effectively increase the MTBF and lifetime of the power modules. The fundamental cause to achieve higher MTBF lies in the reduction of the number of thermal cycles.The key element in a power conversion system is the power semiconductor device, which operates as a power switch. The improvement in power semiconductor devices is the critical driving force behind the improved performance, efficiency, reduced size and weight of power conversion systems. As the power density and switching frequency increase, thermal analysis of power electronic system becomes imperative. The analysis provides information on semiconductor device rating, reliability, and lifetime calculation. The power throughput of the state-of-the-art WECS that is equipped with maximum power point control algorithms is subjected to wind speed fluctuations, which may cause significant thermal cycling of the IGBT in power converter and in turn lead to reduction in lifetime. To address this reliability issue, a real-time control scheme based on the reliability model of the system is proposed. In this work a doubly fed induction generator is utilized as a demonstration system to prove the effectiveness of the proposed method. Average model of three-phase converter has been adopted for thermal modeling and lifetime estimation. A low-pass-filter based control law is utilized to modify the power command from conventional WECS control output. The resultant reliability performance of the system has been significantly improved as evidenced by the simulation results.
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Title: Modular model assembly from finite element models of components
Creator: Ren, Zhen
Date: 2008
Collection: Electronic Theses & Dissertations

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