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Title: LOW-DOSE CARDIAC SPECT USING POST-FILTERING, DEEP LEARNING, AND MOTION CORRECTION
Creator: Song, Chao
Date: 2019
Description: Single photon emission computed tomography (SPECT) is an important technique in use today for the detection and evaluation of coronary artery...
Show moreSingle photon emission computed tomography (SPECT) is an important technique in use today for the detection and evaluation of coronary artery diseases. The image quality in cardiac SPECT can be adversely affected by cardiac motion and respiratory motion, both of which can lead to motion blur and non-uniform heart wall. In this thesis, we mainly investigate imaging de-noising algorithms and motion correction methods for improving the image quality in cardiac SPECT on both standard dose and reduced dose.First, we investigate a spatiotemporal post-processing approach based on a non-local means (NLM) filter for suppressing the noise in cardiac-gated SPECT images. Since in recent years low-dose studies have gained increased attention in cardiac SPECT owing to its potential radiation risk, to further improve the image quality on reduced dose, we investigate a novel de-noising method for low-dose cardiac-gated SPECT by using a three dimensional residual convolutional neural network (CNN). Furthermore, to reduce the negative effect of respiratory-binned acquisitions and assess the benefit of this approach in both standard dose and reduced dose using simulated acquisitions. Inspired by the success in respiratory correction, we investigate the potential benefit of cardiac motion correction for improving the detectability of perfusion defects. Finally, to combine the benefit of above two types of motion correction, dual-gated data acquisitions are implemented, wherein the acquired list-mode data are further binned into a number of intervals within cardiac and respiratory cycle according to the electrocardiography (ECG) signal and amplitude of the respiratory motion.
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Title: Development of a Job Attitudes Composite for Measuring Employee Engagement
Creator: Vallejo, Rodney Scott
Date: 2019
Description: The measurement of employee engagement is important for researchers and practitioners given its relation to positive work outcomes and...
Show moreThe measurement of employee engagement is important for researchers and practitioners given its relation to positive work outcomes and importance to company success. Although numerous measures of employee engagement have been established, they lack depth and fall short in potentially explaining why an employee may or may not be engaged in the workplace. The current study aimed to provide an alternative way of measuring employee engagement at a finer level by utilizing job attitudes and a composite approach. Specifically, job attitudes from an employee survey instrument that were identified as antecedents to employee engagement were organized into a composite and relationships with employee engagement and employee turnover were tested. Results showed a both relationship between a composite of job attitudes and employee engagement and utility of the composite by predicting employee turnover.
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Title: IN SITU X-RAY ABSORPTION SPECTROSCOPY STUDY OF TIN-BASED GRAPHITE COMPOSITE ANODES FOR LITHIUM-ION BATTERIES
Creator: Ding, Yujia
Date: 2019
Description: Sn-based anode materials such as Sn, SnO2, Sn4P3, and SnS2 that exhibit large theoretical capacities are promising alternatives to traditional...
Show moreSn-based anode materials such as Sn, SnO2, Sn4P3, and SnS2 that exhibit large theoretical capacities are promising alternatives to traditional graphite anodes for Li-ion batteries. However, their capacities fade drastically in a few cycles due to substantial volume changes during the lithiation/delithiation process resulting in cracking and pulverization of the electrode. A graphite matrix is introduced by high-energy ball milling to obtain a graphite composite and enhance the electrochemical performance. Indeed, Sn4P3/graphite composite exhibits a reversible capacity of 651 mA h g-1 in the 100th cycle, and SnS2/graphite composite shows 591 mA h g-1 in the 50th cycle.To obtain a better understanding of the improved performance of the composite materials and the reason for the more gradual capacity fading, in situ EXAFS is used to investigate these mechanisms using in situ coin cells and in situ vacuum-sealed pouch cells. The collected EXAFS data were analyzed by modeling to extract detailed local environment changes during the lithiation/delithiation process.In the crystalline phases of Sn-based materials, the conversion reaction forming metallic Sn is partially reversible and partially irreversible, and the subsequent alloying/dealloying reaction forming LiSn alloys is reversible. Introducing the graphite matrix increases electrical conductivity and prevents aggregation of intermediate Sn clusters. The graphite matrix also plays a significant role in transforming composites into highly dispersed amorphous phases. These amorphous phases, formed in the first few cycles of Sn4P3/graphite and SnS2/graphite composites, exhibit excellent reversibility in both conversion and alloying/dealloying reactions, which is the main reason for the significant improvements in electrochemical performance. The slow growth of metallic Sn clusters and the slight reduction in amorphous phases result in gradual capacity loss over long-term cycling. Introducing the graphite matrix and creating highly dispersed composite samples are the successful strategies that can be scaled up to develop new battery materials in the future.
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Title: Multi-function multi-modality sensing and communication system: a designer's perspective
Creator: Fepeussi, Tonmo Vanessa Carine
Date: 2019
Description: The combination of sensing and communication functionalities on the same electronic device is the key to autonomous sensing applications in...
Show moreThe combination of sensing and communication functionalities on the same electronic device is the key to autonomous sensing applications in the transportation industry, including driverless vehicles and structural health monitoring (SHM) of aero-vehicles. Due to the limited availability of spectral and hardware resources, there is a need for resource sharing between sensing and communication systems. This is achieved by the efficient integration of sensing and communication functions through a unified design of both systems into smart sensors. To that end, a multi-modality approach is employed in this research to design multi-functional systems at two different bands of the frequency spectrum, namely radio and acoustic frequencies.First, a radio-frequency (RF) software-defined system capable to support radar sensing and RF communication is proposed for use in modern interconnected automotive applications such as driverless vehicles. The proposed RF radar is designed on a software-defined homodyne transceiver prototype capable of radio communication. The system is implemented in the S band over a narrow frequency bandwidth of 34 MHz between 3.550 GHz and 3.584 GHz. Experimental measurements show that the designed radar sensor can measure short-range targets with a range accuracy of less than 21 cm.An acoustic sensing and communication system is developed in parallel for use in autonomous SHM monitoring of aero-vehicles. The proposed communication system uses M-ary time-reversal pulse position modulation (M-TRPPM) as the modulation scheme for dispersion compensated wireless communication across the elastic channel. The time reversal based time division multiple access (TR-TDMA) protocol is introduced to regulate channel access by multiple sensors. Simulation and experimental validation demonstrate that the designed system, using an excitation signal generated by a PZT sensor disc at 300 kHz resonant frequency, is capable of reliable data transmission with a bit error rate (BER) approximating zero at low data rates of a few kilobits per seconds.
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Title: Kinetic and Structural Characterization of the Vibrio cholerae Flavin Transferase ApbE
Creator: Fang, Xuan
Date: 2019
Description: Cholera has long been a global concern and in the past decades traditional antibiotic treatments have failed due to the emergence of the...
Show moreCholera has long been a global concern and in the past decades traditional antibiotic treatments have failed due to the emergence of the antibiotic-resistance of its causative agent, V. cholerae. The resistance is mainly supported by a transmembrane electrochemical gradient of Na+ produced by the respiratory complex Na+-NQR coupled with an internal electron transfer pathway. The assembly and function of Na+-NQR is fulfilled by ApbE, the only known flavin transferase which covalently attaches two FMN molecules to the complex as part of its electron transport chain. Hence, ApbE is closely associated with the cause of antibiotic resistance. Because it does not have any human homologues, ApbE becomes an excellent drug target. In this work, we have investigated the physical properties of the enzyme and clarified its substrate specificity and pH dependence. For instance, our experiments indicate that divalent cations are essential for ApbE function, and that the selectivity depends largely on the size and the coordination sphere of the cation. Our data also show that ApbE regulation by pH, ADP and potassium is an important mechanism that enhances the adaptation, survival and colonization of V. cholerae in the small intestine. Moreover, pH dependence, mutagenesis, and steady-state kinetic studies have led us to identify the conserved His257 as a residue with dual roles: substrate binding and catalysis. Furthermore, bi-substrate kinetic studies have also revealed that ApbE follows a random Bi Bi mechanism. Together with structural studies, we propose a reaction mechanism where His257 functions as a base, shedding light into the understanding of the ApbE family.
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Title: DIAGNOSING AND TREATING ADHD: CLINICIAN CHARACTERISTICS, METHODS OF DIAGNOSIS, DIAGNOSTIC RATES, AND TREATMENT RECOMMENDATIONS
Creator: Haak, Christopher Luke
Date: 2019
Description: Attention-deficit/hyperactivity disorder (ADHD) is one of the top five most common referrals among all neuropsychologists (Sweet et al. 2015)...
Show moreAttention-deficit/hyperactivity disorder (ADHD) is one of the top five most common referrals among all neuropsychologists (Sweet et al. 2015) and continues to elicit public and professional concern about over-diagnosis in children (Sciutto & Eisenberg, 2007) and under-diagnosis in adults (Asheron et al., 2012; Kooji et al., 2010). In recent years, the prevalence of ADHD has increased (Polanczyk et al., 2007 & 2014, Thomas et al., 2015). It is unclear what is driving these changes though changes in criteria may be playing a role (van de Voort et al., 2014). Further, there has been little research on whether professional training, beliefs, and practice factors can influence the likelihood to diagnose ADHD. The purpose of this study was to examine the extent to which neuropsychologists’ professional characteristics, training, and beliefs about ADHD diagnosis and treatment influence their likelihood to diagnose ADHD. The study also evaluated whether there are differences in assessing and treating ADHD based upon the client population focus (child, lifespan, or adult) of neuropsychologists. Participants in this study were 106 neuropsychologists from across the United States and Canada who were recruited through neuropsychology listservs to participate in an online survey. Results indicated that population focus was associated with significant differences in approach to diagnosing and treating ADHD, with child- and lifespan-focused neuropsychologists reporting higher rates of ADHD diagnosis. Additionally, having a higher percent of clinical cases in which ADHD is a referral question and greater self-reported adherence to following full diagnostic criteria for making a diagnosis were associated with higher ADHD diagnostic rates, controlling for age, gender, ethnicity, and other professional characteristics. This study is among the first to examine specific clinician factors impacting diagnostic rates and its findings have several implications for practice and research.
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Title: Mathematics of Civil Infrastructure Network Optimization
Creator: Rumpf, Adam Andrew
Date: 2020
Description: We consider a selection of problems from civil infrastructure network design that are of great importance in modern urban planning but have,...
Show moreWe consider a selection of problems from civil infrastructure network design that are of great importance in modern urban planning but have, until relatively recently, gone largely ignored in mathematical literature. Each of these problems is approached from the perspective of network optimization-based modeling, with a major focus placed on the development of efficient solution algorithms.We begin with a study of the phenomenon of interdependent civil infrastructure networks, wherein the functionality of one network (such as a telecommunications system) requires the input of resources from another network (such as the electrical power grid). We first consider a linear relaxation of an established binary interdependence minimum-cost network flows model, including its unique modeling applications and its use as part of a randomized rounding approximation algorithm for the mixed integer model. We also develop a generalized network simplex algorithm for the efficient solution of this generalized minimum-cost network flows problem. We then move on to consider a trilevel network interdiction game for use in planning the fortification of interdependent networks subject to targeted attacks. A variety of solution algorithms are developed for both the binary and the linear interdependence models, and the linear interdependence model is used to develop an approximation algorithm for the more computationally expensive binary model.We then develop a public transit network design model which incorporates a social access objective in addition to traditional operator cost and user cost objectives. The model is meant for use in planning minor modifications to a public transit network capable of improving equity of access to important services while guaranteeing that service levels remain within a specified tolerance of their initial values. A hybrid tabu search/simulated annealing algorithm is developed to solve this model, which is then applied to a test case based on the Chicago public transit network with the objective of improving equity of primary health care access across the city.
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Title: A Risk-Based Approach in Selecting Design Natural Hazard Loads for Temporary Structures
Creator: Saleh, Eman
Date: 2020
Description: Temporary structures are systems that are used for short period applications such as in maintenance and retrofit applications or for staged...
Show moreTemporary structures are systems that are used for short period applications such as in maintenance and retrofit applications or for staged performances. Examples of its applications are tents, scaffoldings, and other facilities that have a short service life. Structures under construction and structures under serviceability conditions also fall under this category of structures; because their service time period is only limited to the duration of the construction, which is much shorter than the lifetime of the finished structure. One of the main characteristics of these types of structures is their high vulnerability to stability. Most specifications rarely cover temporary structures. Designing these structures to appropriate levels of the dead and live load does not impose an issue, in which using the same load factors as in permanent structures is considered a reasonable choice. However, an issue is raised when choosing the appropriate wind, seismic and snow load levels, where using the same exposure levels as in permanent structures may not be a desirable economic decision. Thus, for temporary structures, it makes sense to reduce the extreme event design loads proportional to the intended design life. In this manner, it is imperative to have specific rules or guidelines that would address the design aspects and reliability of these structures especially against lateral loads such as wind and earthquakes. This study aims at establishing several decision-making processes that could help contractors, designers, and erectors of temporary works to decide upon safety factors and/or return periods for environmental loads, with emphasis on the wind load. This decision-making process can be used in temporary projects (e.g., bridge erecting) to establish a design criterion based on the nature of the project. The study shows that the optimal decision-making process depends on the willingness to take advantage of wind locality characteristics (e.g., seasonality factor) in certain construction period or region, type of information available for the decision-maker (i.e., precise or imprecise), the risk associated with the constructed facility or the temporary structure itself, a potential for recourse actions, and the decision-maker’s attitude toward the trade-off between losses and gains with respect to uncertainty. The suggested decision-making process proposed is Bayesian decision process, the fuzzy decision process; (3) a two-stage stochastic programming solution; and (4) case-based decision theory. Several practical examples are presented in this thesis to show how different situations may require varying decision-making processes in order to reach the optimal decision. The design of temporary structures can be altered in response to a forecasted hurricane; thus, we propose a three-stage stochastic programming solution to decide upon their optimal wind design load. In addition, we extend the hurricane catastrophe models for application in temporary structures. This enables contractors to forecast the hurricane losses as a basis for estimating the adequate catastrophe cover such as insurance premiums and reinsurance for temporary structures. This scheme is then illustrated in an example for deciding the required temporary bracings for a steel frame under construction during the hurricane season.To prevent temporary structures from collapse, it is important to investigate the performance quality of previous projects and remove any causes for potential mishaps. This can be done by continuous monitoring of different projects and an investigation of accidents, if any, to help prevent future failures. In this study, we use an audit evidence scheme based on commonly available evidence theories used in the construction industry. In one such theory, the evidence is represented via a tree structure, in which the propagation is toward the variables that represent the project as a whole and separate work packages within a project. For simplicity, we only consider the binary case of variables i.e. whether or not a project conforms to the quality standards. The formulation of the auditing tool relates belief functions to the assertion of the quality assurance and quality control (QA/QC) measures and provides formulas for human error risk. These formulas provide plausibilities of human error in a belief-function format. An auditor may use the belief values to assess the degree of quality performance and to identify the sources of the problem in temporary work. We further illustrate the method in a practical application to evaluate the shoring/reshoring operations for estimating the construction risk in a multistory concrete structure. This evaluation may be used to decide on an appropriate time for formwork removal, shoring/reshoring schedule, casting cycles, post-tensioning sequence, and the required number of reshoring levels given the available evidence. To reduce the computational burden, we describe the shoring/reshoring system as a multi-state system (MSS) where the universal generating function (UGF) was used to estimate the reliability of the system.
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Title: Incorporating Real-Time Estimates of Physiological States in Artificial Pancreas Systems
Creator: Sevil, Mert
Date: 2020
Description: Type-1 diabetes is a chronic disease that has a negative impact on the life of a person with diabetes causing other chronic diseases, reducing...
Show moreType-1 diabetes is a chronic disease that has a negative impact on the life of a person with diabetes causing other chronic diseases, reducing the quality of life, and the possibility of causing dangerous reductions in blood glucose levels that may lead to coma or death. More than 100 million U.S. adults are now living with diabetes or pre-diabetes. Diabetes is one of the most expensive public health problems in the U.S. at $327 billion in 2017. Thus, alternative solutions or novel proposals are crucial to more effective treatments and cure. Artificial pancreas systems are one of the common treatment techniques of Type-1 Diabetes, which reduce the risk of diabetes-related complications and make diabetics' lives easier and make it convenient. Artificial pancreas systems aim to maintain blood glucose concentrations in a tighter target blood glucose range, which is a challenging problem. Several factors affect blood glucose concentrations including intensity of exercise, type of exercise, acute psychological stress and the physical state of a person with diabetes. These factors are unknown disturbances for artificial pancreas control systems. In this project, a single non-invasive wrist-worn device is used to obtain different biosignals in-real time. Biosignals are utilized with the development energy expenditure estimation model, psychological stress detection and physical state classification models. Several machine learning methods are tested and validated until the best classification and estimation accuracy is achieved for each estimate. Obtained models are incorporated with the current artificial pancreas design to improve its glycemic control performance. The controller is aware of such measurable disturbances with the proposed method, which allows for providing accurate and timely control action. Additional estimates are utilized to improve blood glucose concentration prediction model accuracy. Clinical trials are used to test and validate the proposed work. In summary, the presented work illustrates different machine learning techniques and algorithms that can enhance automated insulin delivery by a multivariable artificial pancreas system and enhance the quality of life of people with Type 1 diabetes.
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Title: Integrated Design Framework For Electric Motor Drive Systems
Creator: Salameh, Mohamad
Date: 2020
Description: This thesis aims to develop a flexible and time-efficient framework for machine design optimization that considers driving cycles,...
Show moreThis thesis aims to develop a flexible and time-efficient framework for machine design optimization that considers driving cycles, multiphysics domains and current design. The proposed development of the framework is based on the enhancement of three key aspects in the machine design process. A data mining algorithm – the X-means – is employed in the driving cycle analysis, to establish a trade-off between the optimization objectives and the computational intensity. A novel vibration surrogate model is proposed to evaluate the vibroacoustic behavior of the machine in an accurate and time-efficient way. In the identification process, the time effectiveness of the model is attained with a minimized number of finite element simulations. Furthermore, the principle of simultaneous coupled optimization is considered in the framework, where current design variables are included in the optimization environment to allow identifying design candidates with improved performance.
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Title: Scale and Scope Economies Drive Asymmetric Competition in Tech Industries
Creator: Ryali, Balajirao
Date: 2020
Description: This research is motivated by my industry experience of working with small manufacturers in the high technology industry market space and ...
Show moreThis research is motivated by my industry experience of working with small manufacturers in the high technology industry market space and large manufacturers in the telecom and healthcare industry market spaces. In these industries, small manufacturers thrive on specialization and focus on breakthrough innovation to maintain product differentiation and premium positioning and to sustain competition. In contrast, large manufacturers enjoy the benefits of economies of scale that provide cost efficiencies and use price as major differentiating factor. This research work endeavors to model asymmetric competition that emerges endogenously in industries where scale and scope economies interact to force firms to adopt specialized strategies and address the below research questions:1. How does the cost structure shaped by scope and scale economies in engineering, sales and service drive asymmetric product line choices?2. What channel coordination problems arise in this context?3. How can manufacturers redesign their operating mechanism and sales force to optimize the channel?
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Title: ANALYSIS AND OPTIMIZATION OF VIBRATION AND ACOUSTIC NOISE IN SWITCHED RELUCTANCE MACHINES
Creator: Yaman, Selin
Date: 2019
Description: One of the main drawbacks of switched reluctance machines (SRM) is the vibration and high acoustic noise compared to other electrical motors....
Show moreOne of the main drawbacks of switched reluctance machines (SRM) is the vibration and high acoustic noise compared to other electrical motors. The root cause of the high level of acoustic noise is radial forces with high harmonic content. These harmonics may trigger resonant modes in the stator and cause the machine to create high vibration and acoustic noise. To better understand the factors influencing vibration and acoustic noise in an SRM, this dissertation first develops a multi-physics model in ANSYS Workbench environment and carries out a comprehensive analysis of multiple variations in stator and rotor geometries. Based on this understanding, this dissertation identifies distinct factors affecting noise in the machine, which are affected by electromagnetic design and power electronic control. From the electromagnetic perspective, geometrical optimizations in the stator and rotor structures are evaluated to understand the impact on NVH (noise, vibration and harshness) performance. This background is used to develop a fast geometry-sensitive analytical approach to reduce acoustic noise in the machine. While optimizing the geometry for a silent machine design, different design of experiments (DoE) methods and response surface (RS) optimization methods are also compared and presented. Furthermore, material analysis is included in structural design, where high flux material effect on vibration and acoustic noise is observed. The second topic of the NVH analysis is power electronic and switching solutions. In this study, multiple basic and advanced switching techniques have been considered and optimized to reduce acoustic noise under a preset efficiency constraint. Further, a time efficient model of SRM is introduced with vibro-acoustic noise perspective by developing a computationally cost effective SRM modeling. By using this analytical time-efficient NVH model, a current shape optimization is implemented, and results are discussed. Finally, experimental validations are provided for NVH and psychoacoustics analysis for different operating conditions and current control methods.
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Title: COMMUNICATION-BASED DISTRIBUTED CONTROL IN MICROGRIDS AND NETWORKED MICROGRIDS
Creator: Zhou, Quan
Date: 2019
Description: Microgrids representing localized small-scale power systems are capable of operating as self-controlled entities, which cluster and manage...
Show moreMicrogrids representing localized small-scale power systems are capable of operating as self-controlled entities, which cluster and manage distributed energy resources (DERs) and other smart devices within a defined electrical boundary. By utilizing locally available resources, microgrids reduce their dependencies on the utility grid, which provide more reliable, resilient, and economic power services to local customers. Geographically close microgrids can be connected for forming a networked microgrid system, which provides additional operational flexibility and further enhances the system reliability and resilience by sharing available DERs.Considering variable and controllable characteristics of DERs, locally available DERs need to be appropriately coordinated and controlled to respond to changing loads. The proliferation of microgrids will make it inevitable to rely on communication systems among microgrids for realizing the coordinated control of participating DERs in networked microgrid systems. The networked microgrid system is considered as a cyber-physical system (CPS) which requires sophisticated network technologies to cope with the massive adaption of communication, computation and control devices. Conventionally, a networked system has been managed by a centralized master controller, which processes the data collected from participating DERs and sends operational set points to each participant.Compared with the centralized control strategies, distributed control is more advantageous for connecting participating DERs. The connectivity of distributed control system (i.e., meshed network) is higher than that of a centralized structure (i.e., star network), in particular when critical circumstances are encountered in which some of the network connections are lost. Also, the distributed control system enables parallel data processing and control, which speeds up the networked system response to variable DERs and loads and promote economic merits. The communication-based distributed control strategies have proven to demonstrate higher reliability, resilience, and scalability while possessing lower implementation costs as compared with centralized control strategies.We have proposed several communication-based distributed control strategies for realizing the coordinated operation of participating microgrids and DERs, which can be applied to achieve various operational objectives, including proportional active power sharing, DER plug-and-play capability, seamless microgrid islanding, and resynchronization operations, and optimal economic operations. The benefits and challenges of communication-based distributed control strategies in networked microgrid systems are discussed and addressed in our work. Extensive case studies have been conducted in this thesis to validate the effectiveness of the proposed communication-based distributed controller design.
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Title: Novel Chelating Agents for Positron Emission Tomography Imaging and Theranostic Applications
Creator: Zhang, Shuyuan
Date: 2022
Description: Positron emission tomography (PET) is a molecular imaging technology that can be used to detect various diseases including cancer. Zirconium...
Show morePositron emission tomography (PET) is a molecular imaging technology that can be used to detect various diseases including cancer. Zirconium-89 (t1/2 = 78.4 h) is one of the positron-emitting radionuclides that has been widely explored for PET imaging because its half-life matches the long biological half-life of antibody. Research efforts have been devoted to the development of chelation chemistry for 89Zr, a bone-seeking radionuclide. Deferoxamine (DFO) is the most frequently used chelator for 89Zr in both clinical and preclinical trials. DFO can rapidly sequester 89Zr to form 89Zr-DFO complex. However, DFO is not an ideal ligand for 89Zr because 89Zr-labeled DFO-antibody conjugate showed high bone uptake in mice. We wanted to develop novel small molecule donors and novel chelators for 89Zr. We discovered N-methyl-N-(pyridin-2-yl)hydroxylamine (Py-HA) and 2,6-bis(N-methylhydroxylamino)pyridine (Py-BHA) as small molecule donors for 89Zr. Based on the new small molecule donors (Py-HA and Py-BHA), we have designed and synthesized a series of novel macrocyclic chelators containing TACN (1,4,7-triazacyclononane), CYCLEN (1,4,7,10-tetraazacyclododecane), and a diaza-crown ether backbone for 89Zr-based PET imaging applications. Moreover, bifunctional chelators (BFCs) structured on TACN and diaza-18-crown-6 were synthesized for conjugation to antibody. Theranostics contains a diagnostic agent and a therapeutic drug that can be used for simultaneous therapy and imaging of diseases. Radiotheranostics includes radiometal complexes for both therapy and imaging. 177Lu is a promising radiotheranostic metal because it can emit gamma radiation for single photon emission computed tomography (SPECT) imaging and emit β radiation for radiotherapy. A radioisotope pair with complementary emission such as 64Cu/67Cu and 86Y/90Y, can be used for PET imaging and radiotherapy. In this study, we synthesized nonfunctional TACN and diaza crown ether-backboned chelators containing different donor groups for 177Lu, 64Cu/67Cu, and 86Y/90Y. Finally, two bifunctional chelators were synthesized for coupling with hydroxamic acid-based small molecule as a potential histone deacetylase (HDAC) inhibitor to generate a small molecule ligand-chelator conjugate (SMLC) for theranostic applications.
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Title: TESTING COMPUTER INTERACTION TECHNOLOGY AND METHODS WITH CHILDREN
Creator: FROEHLICH, THORSTEN
Date: 2007-07
Description: Deploying educational computer games for children in schools requires understanding of usability. Usability of computer hardware as well as...
Show moreDeploying educational computer games for children in schools requires understanding of usability. Usability of computer hardware as well as the game user interaction is a major concern of this research. The aim of this thesis is to compare the usability of mice and touchpads, as well as test graphics tablets, with third and fifth grade students. Each of these technologies' usability is measured using drag and drop, point and click, and click-only interaction by measuring time to complete tasks and error rate. For this purpose, 142 students participated in a quantitative usability test conducted in five Chicago-area elementary schools. Students played a custom-designed computer game asking them to solve mathematical problems appropriate for their level of education. The main purpose of the game was to create a realistic workload for users. The game tracked students' interactions by recording on-screen cursor movements. Statistical analysis of variance (a = 0.01) of usability showed no significant difference using point and click compared to drag and drop. There was no significant difference between using mice and touchpads. However, because students had no prior experience using graphics tablets, tablet use could not be learned within ten minutes. Finally, usability was found to increase with students' age. Further, when the movements were analyzed for patterns, statistical analysis revealed that workload had a significant influence on usability. Two patterns emerged: hovering with the cursor to find answers on screen, and evading screen areas where accidental dropping of an item could result in an incorrect answer. Although students employing these patterns require more time than reported in previous research, workload had never been considered as a significant factor before. In conclusion, schools can deploy either desktop computers commonly using mice or notebook computers commonly using touchpads because usability does not differ significantly. Workload is the important factor on usability, and thus when developing and usability testing specific games, the users' workload has to be observed. In addition, game designers should consider supporting both drag and drop and point and click. Finally, when testing games, children should be exactly the age of the target audience for accurate results.
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Title: THE FRONT VOWELS BEFORE R OF THE NORTH-CENTRAL STATES
Creator: HARTMANN, ERIKA
Date: 1981-05

Title: INCORPORATING DATABASE EDUCATION INTO THE GRADUATE TECHNICAL COMMUNICATION CURRICULUM
Creator: GEHRS, GORDON SCOTT
Date: 2008-05
Description: The purpose of this study was to identify if there existed a need for database education in technical communication programs. This was...
Show moreThe purpose of this study was to identify if there existed a need for database education in technical communication programs. This was achieved using a two part approach: Jobs data was collected from three major search engines and the results plotted showing a roughly 20% requirement for techcomm positions to have some database knowledge and skill. Then the data was further striated by which techcomm positions were expected to have which skills. The jobs data was also supported by the database skills taught in computer science education, and that of information technology. Next, twelve graduate programs were analyzed for their database educational requirements to show that the need for database skills was not being met in techcomm graduate programs. Finally course content was proposed for five new database courses: OS and Networking Basics, Introduction to Databases, Database Design, and Using Databases. A single course outline is proposed for programs wishing to implement the material more easily.
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Title: DEVELOPING INFORMATION PRODUCTS USING QUALITY MANAGEMENT
Creator: BATSON, LAURA SHEEHAN
Date: 2010-12
Description: In regards to information design, research provides high-level suggestions on how to learn and interact with customers to obtain their desired...
Show moreIn regards to information design, research provides high-level suggestions on how to learn and interact with customers to obtain their desired requirements; but specifics on an approach to eliciting and controlling measurable requirements throughout the development process are not explored. In other areas of design, such an approach already exists: Quality Management, which has successfully improved processes and provided measurements for improvement in order to decrease errors and increase productivity. This dissertation analyzes the applicability of quality management tools to the process of developing information products. The methodology involved two phases. In the initial phase, the researcher had the task of improving a company's benefits enrollment package for two groups. A Traditional Group used the currently accepted best practices in technical communication, performing a heuristic evaluation and a usability test to determine what changes to make in the existing package. This group focuses on the existing benefits enrollment package. In contrast, a Quality Management Group developed a benefits enrollment package using quality management tools, gathering quantifiable functional requirements early in the design and continuing throughout the process. The researcher prepared a revised benefits enrollment package for both groups, and the results of the studies were compared. According to the usability analysis, the Traditional Group showed considerable improvement from the original package to the redesigned package. However, the Quality Management Group showed even greater improvements in several areas, suggesting the potential viability of this method in information design. Future studies should focus on testing the effectiveness of this process on other types of information products. For the products that are successful, information designers could greatly benefit in learning how to use quality management tools to provide more precise and measurable information products.
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Title: Investigation of Novel Solid Polymer Electrolytes and Lithium Salts for Rechargeable Lithium Batteries
Creator: Zhao, Wendy
Date: 2021
Description: Lithium-ion batteries (LIBs) are extensively used in many consumer electronic products. LIBs have great potential for application in electric...
Show moreLithium-ion batteries (LIBs) are extensively used in many consumer electronic products. LIBs have great potential for application in electric vehicles by virtue of their high power density and charge cycles. Research and development in this area has been focused on all around the globe. The major challenges include high cost, safety issues of the solvent based electrolytes, and low conductivities at ambient temperature of the solid polymer electrolytes (SPEs).This dissertation describes four novel electrolyte systems and a series of low lattice energy lithium salts synthesized and characterized for applications in LIBs. First, a new SPE has been derived from oligomeric poly(ethylene oxide) (PEO)-grafted crosslinked polystyrene (XPS) microspheres containing 1-2 lithium sulfonate moieties. This SPE possesses amorphous character with a glass transition temperature (Tg) around 135 ºC, displayed a good electrochemical stability with excellent ionic conductivity in excess of 10^-4 S/cm at 25ºC, and no significant thermal decomposition until 420 ºC. Second, a hybrid composite polymer electrolyte (CPE) was constructed with a gel matrix formed through hydrogen bonding by incorporating nanoparticles of fumed silica into the nanoscale network of PEO-XPS. Fumed silica with large surface modification group like polysiloxane formed an ideal gel structure offering significant high mechanical strength above 10^4 Pa, and a good ionic conductivity at 25°C. Third, a nonvolatile x-linked gel membrane electrolyte was synthesized with amino methacrylate, to introduce hemi-labile ligands as ionic liquid, into the polymer network. This new material exhibited improved salt solubility and ionic conductivity, due to the fast ligand exchange that facilitates the lithium ion structural transport, and also displayed an excellent electrochemical stability(4.8 V vs, Li/Li+). Fourth, a self-healing and thermal reversible polymer electrolyte designed based on Diels-Alder conjugation between multi-maleimides (2M-3M) and multi-furans (2F-4F) was synthesized. The reversible x-linking was realized through Diels-Alder (DA) and Retro-DA reactions by applying heating (>130°C)/cooling (<90°C) cycles. Last, new lithium salts with star and branch structures containing 1-4 of imide or methide moieties were synthesized and evaluated in PEO electrolyte system. These salts demonstrated good ambient temperature ionic conductivity at low concentrations, and the electrochemical stabilities were equal to or better than the most commonly used lithium salt, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). Synthesis and characterization, including electrochemical properties, thermal and electrochemical stabilities, mechanical behaviors and surface morphologies of these new materials are described and discussed.
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Title: BLOCKCHAIN FOR TRANSACTIVE ENERGY MARKET WITH NETWORKED MICROGRIDS
Creator: Yan, Mingyu
Date: 2021
Description: Transactive energy, which allows and incentivizes microgrids (MGs) to trade energy with each other, is regarded as the next-generation energy...
Show moreTransactive energy, which allows and incentivizes microgrids (MGs) to trade energy with each other, is regarded as the next-generation energy management scheme to accommodate the penetration of distributed energy resources (DERs). Blockchain provides an effective and decentralized strategy, which can address the operational challenges introduced by the transactive energy market. This thesis is aimed at providing effective transactive energy markets for incentivizing MGs to trade energy and utilizing blockchain technologies to provide a secure and efficient energy trading environment for all participants.First, this thesis offers a centralized transactive market for networked MGs to transact energy through the centralized distribution system operator (DSO) while ensuring the power network limits. All MGs cooperate in this market and the cooperative behaviors are captured using the cooperative game with externalities. A two-level problem is studied to allocate the total payoff to all participating MGs. Numerical results for a 4-MG system and the IEEE 33-bus show the validity of the centralized transactive energy model. Second, this thesis proposes a two-level network-constrained peer-to-peer (P2P) transactive energy for multi-MGs, which guarantees the distribution power network security and allows MGs to trade energy with each other flexibly. At the lower level, a P2P transactive energy is employed for multi-MGs to trade energy with each other. A multi-leader multi-follower (MLMF) Stackelberg game approach is utilized to model the energy trading process among MGs. At the upper level, the DSO reconfigures the distribution network based on the P2P transactive energy trading results by applying the AC optimal power flow considering the distribution network reconfiguration. If there are any network violations, the DSO requests energy trading adjustments at the lower level for network security. Numerical results for a 4-MG system, the modified IEEE 33-bus, and the 123-bus distribution power systems show the effectiveness of the proposed transactive energy model and its solution technique. Third, this thesis adopts the blockchain for the peer-to-peer transactive energy market among MGs. A two-level integrated blockchain-power system is provided, in which all MGs and the DSO are equipped with blockchain. At the lower level, MGs trade energy with each other through the lower-level MG blockchain, while the DSO manages the network security through the upper level DSO blockchain. We illustrate how to utilize blockchain technologies, i.e., public and private keys and smart contracts, to provide an efficient and secure energy trading environment for all MGs. Last, this thesis applies the blockchain for transacting energy and carbon right for networked MGs. MGs transact energy and carbon right through the centralized DSO while ensuring the power network limits. The introduction of blockchain achieves secure and decentralized market settlements in this centralized market. Numerical results for a 4-MG system and modified IEEE 33-bus systems show the effectiveness of the proposed transactive energy and carbon market.
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