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Title: SAFETY IMPACTS OF SIGNAL TIMING OPTIMIZATION ON URBAN INTERSECTIONS WITH RED LIGHT RUNNING PHOTO ENFORCEMENT
Creator: Feng, Siyang
Date: 2015, 2015-12
Description: The traffic safety issue especially in urban areas is getting increasingly severe due to the ever-growing travel demand which closely related...
Show moreThe traffic safety issue especially in urban areas is getting increasingly severe due to the ever-growing travel demand which closely related to people’s basic necessities. As a part of the urban traffic network, the safety of the intersections in the urban area also reflects the efficiency and quality of the integrated urbanization level. Red light running at intersections has been a major safety concern in the United States. Because the red light running at intersection often results in a disproportionally higher percentage of injuries. From this point of view, the safety improvement of the urban intersections is imperative. The red light running photo enforcement has been designed to increase safety on streets by reducing the head-on, rear-end, and sideswipe crashes at intersections. Meanwhile, methods for intersection signal timing optimization in urban areas have been developed to reduce intersection delays. As a result of delay reductions, it is also important to analyze changes in vehicle crashes in order to gain a holistic understanding of traffic mobility and safety impacts. This study introduces an Empirical Bayesian (EB) before and after analysis method to evaluate the safety impacts of signal timing optimization on urban intersections with some intersections involved with red light running photo enforcement. Data on 842 signalized intersections are collected to calibrate the safety performance functions and to quantify the crash reduction effects before and after the signal timing optimization. Base on the EB method application, it is reviewed that a certain extent of safety enhancements is achieved as measured by crash type and severity level after intersection signal timing optimization and red light photo enforcement treatments.
M.S. in Civil Engineering, December 2015
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Title: THE LENGTH-TENSION CURVE OF AND LATTICE SPACING CHANGES IN SKINNED FLIGHT MUSCLE IN MANDUCA SEXTA
Creator: Shaoshuai, Chen
Date: 2016, 2016-05
Description: The synchronous indirect flight muscle (DLM1) of the Hawk moth, Manduca Sexta, has similarities to cardiac striated muscle in its...
Show moreThe synchronous indirect flight muscle (DLM1) of the Hawk moth, Manduca Sexta, has similarities to cardiac striated muscle in its physiological properties. In particular, both operate in vivo on the so-called ascending limb of the length-tension curve. The length-tension curve is a classical experiment to study the physiological properties of muscle. The length tension curve of DLM1 of Manduca sexta has previously been reported with a descending limb that is steeper than what would be expected given likely dimensions for the thick and thin filaments. Excessive rundown of the muscle preparations is a likely cause of these observations. Factors caused muscle rundown are many, such as the time allowed for the muscle to relax, the time for muscle spends contracting or the time spent on sarcomere length adjusting. Insights into the factors mentioned above were obtained by conducting a series of experiments designed to systematically explore the causes of rundown. These included Constant Sarcomere Length Experiments, Reciprocating Stretch Experiments and Back to SL 3.25 μm Experiment. Then a modified protocol for carrying out the length-tension experiment was developed based on these findings. A new length-tension curve was plotted and shows a shape closer to what might be expected theoretically. The force went to zero at about SL 5.7μm. This result is constant with other measurements of the length of the myofilaments. Finally, the lattice spacing experiment was carried out to figure out how the interfilament lattice spacing changes across the SL growing. Result shows that the lattice spacing did not change much over the plateau region of the length-tension curve (SL 2.9- 3.1) but increased substantially as SL decreases further in the ascending limb of the length tension curve.
M.S. in Biology, May 2016
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Title: INACTIVATION OF MURINE NOROVIRUS ON STRAWBERRIES USING PULSED LIGHT
Creator: Chen, Dongjie
Date: 2016, 2016-12
Description: Norovirus have become the predominant viral causes of foodborne illnesses worldwide, the foodborne happened mainly in schools and childcare...
Show moreNorovirus have become the predominant viral causes of foodborne illnesses worldwide, the foodborne happened mainly in schools and childcare facilities, strawberries were identified as the most likely vehicle according to the analytical epidemiological studies. So this study evaluated the efficacy of pulsed light (PL) treatments to inactivate murine norovirus (MNV-1), a human norovirus surrogate, inoculated onto strawberries. Two different PL treatments were evaluated - 3 Hz and 100 Hz PL treatments. PL treatments inactivated 1.5-3 log PFU/g MNV-1 on strawberry in a time-dependent manner of 30-120 s at both 3 and 100 Hz. The inactivation efficacy of PL is dependent on the pulsed frequency received with both PL treatment parameters. It can achieve 1.7 log PFU/g reduction after 120 s 3 Hz PL treatment at the distance of 8.3 cm from the quartz window, on the other hand, MNV-1 was inactivated by 3.2 log PFU/g after 120 s exposure to 100 Hz PL treatment at the distance of 8.3 cm from the quartz window. These results demonstrated that higher inactivation effect of MNV-1 on strawberry was associated with higher frequency of PL treatment. Therefore, this technology could be used to improve the microbial safety of fresh strawberries.
M.S. in Food Process Engineering, December 2016
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Title: Elastic Proteins in the Flight Muscle of Manduca Sexta
Creator: Yuan, Chen-ching
Date: 2012-05-01, 2012-05
Description: Unlike the asynchronous flight muscles of Lethocerus or Drosophila, the flight muscles (DLM1) of the Hawkmoth Manduca sexta are synchronous,...
Show moreUnlike the asynchronous flight muscles of Lethocerus or Drosophila, the flight muscles (DLM1) of the Hawkmoth Manduca sexta are synchronous, requiring a neural spike for each contraction. While the asynchronous muscles can only extend a few percent, Manduca flight muscle can reversibly extend 50% in vitro and 9% in vivo. Furthermore, the dorsal and ventral regions of the DLM1 have different power output presumably due to the temperature gradient across from the cooler dorsal to the warmer ventral subunits. Together with the observation that length-tension curves of Manduca flight muscles resemble mammalian cardiac muscle, these observations suggest that Manduca muscle might be a useful model system to study some aspects of cardiac muscle contractility. The detailed protein composition of Manduca flight muscle is not known. Here we aimed to identify proteins which might be responsible for the unique properties of Manduca muscle. We used 1% vertical SDS-agarose gel electrophoresis (VAGE) to separate the high molecular weight proteins in Manduca, Lethocerus, and Drosophila flight muscle and bovine left ventricular myocardium. The Manduca samples showed two bands around 2MDa and 1.6MDa, smaller than the two titin isoforms in bovine cardiac muscle, but larger than the largest Lethocerus proteins. Projectin and Kettin are elastic proteins found in Lethocerus and Drosophila with sequence homologies to vertebrate titin. Using western blots, the Manduca sample showed two bands cross-reacting with projectin antibodies at ~800 kDa and ~1030 kDa. Ventral (warmer) DLM1 subunits expressed higher level of both projectin isoform. The 1030 kDa projectin is the predominant expressed isoform in both dorsal and ventral subunits. Kettin antibodies cross-reacted to bands at the same position in both Lethocerus and Manduca. We also used western blots from 4-15% PAGE gels to detect a flightin –cross reacting band at around 23kDa in Lethocerus and 30 kDa in Manduca. Flightin is a thick filament associated protein that presumably helps filament assembly and stability. However, toponin I and T antibodies did not cross-react with similar molecular weight proteins from Manduca flight muscle. Thus, Manduca flight muscle has not only proteins homologous to Lethocerus projectin, kettin, flightin, but also several unknown high molecular weight proteins which might play a role in stabilizing sarcomere structure and give the muscle its unique mechanical properties.
M.S. in Biology, May 2012
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Title: Construction Management of Power Plants
Creator: Demirci, Ferhat Suleyman
Date: 2011-04-28, 2011-05
Description: Construction Management (CM), in general, has on objective of achieving greater benefits in terms of cost and time for owners of a...
Show moreConstruction Management (CM), in general, has on objective of achieving greater benefits in terms of cost and time for owners of a construction project. Professional management services are also the responsibilities of a construction manager. CM includes not only the management services but also the interdisciplinary information and data sharing. So the CM can use these presented information of a proposed project before and during power plant construction from the technical point of view. However, there is still ambiguity about the compatibility of the CM duties and responsibilities. This study determines whether there is a need for updating the duties and responsibilities of the CM for power plant construction, presents the fundamentals of power plant construction management profession, introduces CCGT (combined cycle gas turbine) power plant technologies, evaluates previous and existing datas on power plant construction regarding their usage in CM practice in terms of cost, and presents the updated duties and responsibilities of the CM. A case study is also conducted to identify the costs of a current power plant. Based on the collected information’s and case study, it is determined that the CM is highly needed in power plant industry that runs even in the recession periods. On the other hand, the management functions of the power plant industry are still deficient. This study does not include a specific chapter that defines deficiencies and solutions to those in terms of proposed duties and responsibilities. However, new approaches and practical application results are presented from the very beginning of this thesis till the end of the study.
M.S. in Electrical Engineering, May 2011
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Title: DESIGN CHALLENGES AND CONSIDERATIONS FOR WIRELESS ELECTRIC VEHICLE CHARGING
Creator: Bloom, Matthew Aaron
Date: 2012-06-05, 2012-07
Description: As plug-in hybrid vehicles (PHEVs) become more popular and common place, there has been a considerable demand for hassle-free charging, in the...
Show moreAs plug-in hybrid vehicles (PHEVs) become more popular and common place, there has been a considerable demand for hassle-free charging, in the form of wireless technologies. The goal of this research was to investigate the design challenges associated with the design of a high-efficiency, wireless, Level-2 PHEV charger. This work analyzes the challenges presented by the magnetic coupling factor, AC resistance and Q-factor, coil radius, and power electronics, as well as their impact on the overall efficiency and output power level. In this work, the design specifications were centered on the Chevy Volt, and the wireless technology used for power transfer was the WiTricity™ system. In order to regulate the load current/voltage, a “current chopper” circuit is presented, which acts as similarly to a modified boost converter. To validate the ideas presented in this thesis, a 3.3 kW charging system was designed and simulated. To accurately model the WiTricity™ system in simulation, an electromagnetic/circuit-level co-simulation was performed using MATLAB Simulink and Infolytica MagNet. Waveforms from simulation are presented and analyzed in this work. The current chopper circuit was found to accomplish both voltage regulation for resistive loads, as well as constant-current and constant-voltage mode charging for Li-ion battery applications. Because of the switching nature of the current chopper, direct efficiency calculations were not possible; however, at full load, the wall-to-load efficiency was calculated to be 80%.
M.S. in Electrical Engineering, July 2012
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Title: A TIME COURSE STUDY OF FIBRONECTIN MATRIX ASSEMBLY ON SURFACES ACTIVATED WITH CELL AND FIBRONECTIN BINDING DOMAINS
Creator: Chiang, Chun-yi
Date: 2011-07, 2011-07
Description: Fibronectin mediates cell adhesion, migration and initiates extracellular matrix assembly. Therefore, it plays critical roles on wound healing...
Show moreFibronectin mediates cell adhesion, migration and initiates extracellular matrix assembly. Therefore, it plays critical roles on wound healing processes. The purpose of the study is to elucidate the effects of the combination of two functional domains, III1-2 and III9-10 subunits, on the fibronectin matrix assembly. In the present study, NIH 3T3 cells were cultured on the functionalized polyurethane (0.5 μM III9-10 and the mixture with 0.5 μM III9-10 and 0.5 μM III1-2). Functionalization enabled the formation of the covalent linkages between the coverslip polyurethane and the recombinant proteins. Surface characterization was examined by ELISA. NIH3T3 cells were plated on the functionalized coverslips and harvested after 3, 6, 12, and 24 hours culture. Total fibronectin and extracellular matrix fibronectin which is insoluble in deoxycholic acid (DOC) were analyzed through western blotting. The quantification results showed that the mixture groups tended to have higher total fibronectin than the III9-10 alone groups at most time point (3, 6, and 12 hours). Especially obvious differences of DOC-insoluble fibronectin between the mixture group and III9-10 alone group were found in the early stage (3 hour) of the fibronectin matrix assembly. Immunostaining images also showed that fiber-like FN had been generated after three hours culture in the mixture group but FN still looked faint in III9-10 group. Longer and larger FN fibrils were identified in the mixture groups than in III9-10 groups at all time points. In conclusion, III1-2 enhances fibronectin matrix assembly when present with III9-10 through increase the rate of the formation of DOC-insoluble fibronectin in 24 hours culture.
M.S. in Biology, July 2011
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Title: Value of DER to distribution networks
Creator: Nasiri, Hiva
Date: 2019
Description: Distributed energy resources (DERs) provide various values to electric power systems. One of the challenges DER introduce is to determine what...
Show moreDistributed energy resources (DERs) provide various values to electric power systems. One of the challenges DER introduce is to determine what is the value of DER contributions to various sectors in distributed power systems. Analyzing such challenges require understanding the inherent variability of DERs and the uncertainty in hourly load. The value of DER is also a function of network conditions and its adaptability for responding to DERs and loading variations.The uncertain conditions in the planning and the operation of electric power systems make the DER valuation a complicated task which requires sophisticated analytical methods. DER valuation will be a critical issue for the power market operation as we try to determine the most economical and reliable generation portfolio to maximize social welfare. In the DER valuation, there is a stage in which the DER candidates are not located or sized properly, and the utility will provide an approximated solution in order to value DERs. In this thesis, DER valuation has been addressed initially using a stochastic analysis in order to determine a range of values. Once the range is determined, we calculate the economic viability of the values within the range. If DER can reduce the upgrade cost for delivering the load in a distribution system, then the proposed size and the location of DER will have viability. In addition, with the proposed method, a utility can decide on the cost and the methodology of mitigating contingencies by DERs and allocate that cost to the amount of DER for valuation. This is considered as the second phase of this valuation method.As the final phase of this thesis, different types of financial contracts are considered as part of valuation which can introduce additional merits to the utility operation. Recently, the concept of real options has been considered in electric power system projects. The real option analyses (ROA) concept has proven to be viable because of the variability in DERs and changes in real-time load as discussed in this dissertation. The DER valuation is highly case sensitive, and many special factors may have an effect on its value. In this thesis, the factors with the highest impact have been considered, however, there could be additional factors with lower impacts which usually depend on the utility planning and operation. The essence of such factors is further discussed as part of the future work are briefly explained at the end of the thesis.
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Title: Performance Analysis of Energy Harvesting- Non-Orthogonal Multiple Access IoT Network
Creator: Ni, Zhou
Date: 2019
Description: Internet of Things (IoT) systems in general consist of a lot of devices with massive connectivity. Those devices are usually constrained with...
Show moreInternet of Things (IoT) systems in general consist of a lot of devices with massive connectivity. Those devices are usually constrained with limited energy supply and can only operate at low power and low rate. One solution to limited energy is to use energy harvesting to provide sustainable energy. The set of technologies adopted in next-generation wireless communication systems, such as massive MIMO and Non-Orthogonal Multiple Access (NOMA), can provide solutions to increase the throughput of IoT systems. In this thesis, we investigate a cellular-based IoT system combined with energy harvesting and NOMA. We consider all base stations (BS) and IoT devices follow the Poisson Point Process (PPP) distribution in a given area. The unit time slot is divided into two phases, energy harvesting phase in downlink (DL) and data transmission phase in uplink (UL). That is, IoT devices will first harvest energy from all BS transmissions and then use the harvested energy to do the NOMA information transmission. We define an energy harvesting circle within which all IoT devices can harvest enough energy for NOMA transmission. The design objective is to maximize the total throughput in UL within the circle by varying the duration T of energy harvesting phase. In our work, we also consider the inter-cell interference in the throughput calculation. The analysis of Probability Mass Function (PMF) for IoT devices in the energy harvesting circle is also compared with simulation results. It is shown that the BS density needs to be carefully set so that the IoT devices in the energy harvesting circle receive relatively smaller interference and energy circles overlap only with small probability. Our simulations show that there exists an optimal T to achieve the maximum throughput. When the BSs are densely deployed consequently the total throughput will decrease because of the interference.
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Title: MICROSTRUCTURE EVOLUTION OF TWO KINDS OF HIGH-TEMPERATURE RESISTANCE FE-CR-NI ALLOYS
Creator: Pan, Weiqi
Date: 2019
Description: In this research, two different as-cast Fe-Cr-Ni alloys (35Cr-45Ni, 25Cr-35Ni) were aged at different times (1h, 10h, 100h, 1000h) and...
Show moreIn this research, two different as-cast Fe-Cr-Ni alloys (35Cr-45Ni, 25Cr-35Ni) were aged at different times (1h, 10h, 100h, 1000h) and temperature (700℃, 800℃, 900℃, 1000℃). These different aged alloys were studied by optical microscope, scanning electron microscope (SEM), Energy-dispersive spectroscopy (EDS), X-ray diffractometer, micro Vickers hardness tester. The aged sample showed a higher hardness than the as-cast one. The hardness also changed as time and temperature increased because diffusion result on phase transformation and precipitation. Both as-cast 35Cr-45Ni and 25Cr-35Ni have MC (NbC) and M7C3 (Cr7C3) phase transformation during aging. The long term high-temperature aging caused changes carbides and silicide phase. For both alloys during aging, MC carbides transformed to G-phase, and Cr7C3 transformed to Cr23C6.
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Title: SYNTHESIS OF HIGH PERFORMANCE SILICON ANODES AND SURFACE-MODIFIED NMC CATHODES FOR LI-ION BATTERIES
Creator: Ashuri, Maziar
Date: 2019
Description: Lithium-ion batteries (LIBs) have revolutionized the portable electronic devices and electric vehicles (EV) and because of this huge demand,...
Show moreLithium-ion batteries (LIBs) have revolutionized the portable electronic devices and electric vehicles (EV) and because of this huge demand, it is important to meet high power, high specific energy, and long cycle life. All mentioned characteristics are directly related to the choice of anode and cathode electrodes. Currently, graphite is used as anode, while lithium cobalt oxide serves as cathode dominantly. Although graphite can deliver ~ 370 mA h g-1 capacity without significant capacity decay for several cycles, however it is not enough to fulfill the requirements for many applications. Silicon with the theoretical capacity of about 10 times higher than graphite is a promising anode. However, this material suffers from huge volume expansion during cycling in addition to its intrinsic low conductivity. From the cathode viewpoint, the need for materials with less cobalt content is necessary. The resources for cobalt element is very limited while the price of cobalt increasing. Furthermore, cobalt is known as toxic element. Therefore, substitution of cobalt with other elements such as manganese and nickel is necessary. Lithium nickel manganese cobalt oxide (NMC) cathode family materials are introduced following this idea.Here in this thesis, two different approaches are introduced to harness the problems associated with silicon anodes. The first approach is the core/shell design and the second one is the silicon/graphite nanocomposite with tailored structure and engineered voids. Both of these designs can be synthesized easily without complicatedsynthesis steps and harmful chemicals. They have the potential of being commercialized and they do not need expensive equipment. The silicon anodes have been tested successfully in the half-cell coin cells.As for the cathode side, two different members of NMC family materials (NMC333 and NMC532) have been tested. To enhance their electrochemical properties and rate capabilities, a facile surface modification using phosphoric acid was employed. This technique resulted in the formation of thin lithium phosphate coating around the particle. The electrodes performed very well in half-cell configuration. It is expected by utilizing the proposed cathode and anode materials in full-cell set up, a high performance battery with fast charge ability is obtained.
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Title: Detection Of BAXΔ2 Reading Frame Shift Using A Dual Luciferase Reporter System
Creator: Beatty, Evan Alexander
Date: 2019
Description: While initial studies of the pro-apoptotic Bcl-2-associated X protein isoform Δ2 (BAXΔ2) identified the combination of an alternative splicing...
Show moreWhile initial studies of the pro-apoptotic Bcl-2-associated X protein isoform Δ2 (BAXΔ2) identified the combination of an alternative splicing event and a gene-level mutation as the prerequisites for biosynthesis in microsatellite unstable (MSI+) human colon cancer cells, no similar explanation existed to explain the presence of this protein in normal and normal adjacent tissues. To identify an alternative to the gene-level mutation in the absence of an MSI+ phenotype, we utilized a dual luciferase reporter assay designed to observe epigenetic recoding. Plasmid constructs containing the first two exons encoding BAXΔ2 were either transcribed and translated in vitro or transfected into BAX-negative human colon cancer cells. In both cases, assay of the protein products of the reporter genes demonstrate that a low level (2.82% in vitro, 4.43% in vivo) of all translational events which produce the protein product of an upstream reporter gene also produce the protein product of a downstream reporter gene. This occurs despite the two existing in different reading frames as a result of the BAX exons cloned between them. These results confirm that an epigenetic recoding event is able to salvage the BAX reading frame in cases where exon 2 has been excised, and further narrow down the potential mechanism involved to either transcriptional slippage or programmed ribosomal frameshifting.
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Title: MICROGRID COMMUNICATION: HARDWARE AND SOFTWARE TECHNOLOGIES
Creator: GONG, WENLONG
Date: 2019
Description: The Keating Nanogrid at Illinois Institute of Technology (IIT) was designed to be an islandable ac/dc hybrid nanogrid. The on-site rooftop...
Show moreThe Keating Nanogrid at Illinois Institute of Technology (IIT) was designed to be an islandable ac/dc hybrid nanogrid. The on-site rooftop solar and battery system are supporting the interconnected dc and ac subsystems. The nanogrid system at the ac bus is eventually interconnected with the IIT Microgrid. The battery storage system at Keating Nanogrid was designed to support its critical loads for about 8 hours daily. A battery management system (BMS) was employed so that it can monitor and report storage system status to the Keating Nanogrid controller for optimal decision making.The dc load including 94 fixtures controllable LED lighting system was designed to replace the original 189 fixtures ac florescent lighting system. The LEDs’ dc-dc driver was designed and built to enable the dc input provided by the rooftop solar photovoltaic system. The dc system control and communication module was designed and built to make the LED lights controllable individually by the Keating Nanogrid controller or sensor network.To enhance safety at night, 4 islandable LED streetlights were deployed on the east side of the Keating Nanogrid where grid connection was not available for lighting. The east-side streetlight is self-sustained with its own wind turbine, solar panel and battery. The real-time monitoring system was designed and built for the streetlights.The Keating Nanogrid was designed for multiple purposes including the monitoring and control of all elements via pertinent communication pathways. It exchanges the real-time information with the IIT Microgrid and together they make optimal operation decisions to enhance efficiency and reliability of the entire IIT Microgrid system.
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Title: The Impact of a Parent Education Program on Parent Expectations for Children with Autism Spectrum Disorder
Creator: James, Megan
Date: 2019
Description: The purpose of this study was to determine if parent psychoeducation about Autism Spectrum Disorder (ASD) impacts parents’ short-term and/or...
Show moreThe purpose of this study was to determine if parent psychoeducation about Autism Spectrum Disorder (ASD) impacts parents’ short-term and/or long-term expectations for their children with ASD. The impact of parent psychoeducation on parents' expectations for their children with ASD was assessed. Research has demonstrated that a parent’s engagement in their child’s therapy impacts the effectiveness of that intervention. Given the importance of parents’ engagement in therapy, it is clinically relevant to identify the variables that may influence a parent’s level of engagement. Working from the framework of Bandura’s expectation theory, the ability to assess and intervene on expectations would likely have a positive influence on parental engagement. Participants attending parent psychoeducation and parents on a waitlist for parent psychoeducation completed expectations questionnaires before and after parent psychoeducation. Results of a 2x2 (group x time) mixed factorial ANOVA did not support the hypotheses that expectations changed over time as a function of completing parent psychoeducation. These results are discussed in terms of potential adjustments to current parent psychoeducation curriculum or additional variables that may be of interest to better improve (i.e. increase) parent expectations.
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Title: DAMAGE ASSESSMENT OF CIVIL STRUCTURES AFTER NATURAL DISASTERS USING DEEP LEARNING AND SATELLITE IMAGERY
Creator: Jones, Scott F
Date: 2019
Description: Since 1980, millions of people have been harmed by natural disasters that have cost communities across the world over three trillion dollars....
Show moreSince 1980, millions of people have been harmed by natural disasters that have cost communities across the world over three trillion dollars. After a natural disaster has occurred, the creation of maps that identify the damage to buildings and infrastructure is imperative. Currently, many organizations perform this task manually, using pre- and post-disaster images and well-trained professionals to determine the degree and extent of damage. This manual task can take days to complete. I propose to do this task automatically using post-disaster satellite imagery. I use a pre-trained neural network, SegNet, and replaced its last layer with a simple damage classification scheme. This final layer of the network is re-trained using cropped segments of the satellite image of the disaster. The data were obtained from a publicly accessible source, the Copernicus EMS system. They provided three channel (RGB) reference and damage grading maps that were used to create the images of the ground truth and the damaged terrain. I then retrained the final layer of the network to identify civil structures that had been damaged. The resulting network was 85% accurate at labelling the pixels in an image of the disaster from typhoon Haiyan. The test results show that it is possible to create these maps quickly and efficiently.
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Title: ACCELERATING I/O USING DATA LABELS: A CONTENTION-AWARE, MULTI-TIERED, SCALABLE, AND DISTRIBUTED I/O PLATFORM
Creator: Kougkas, Antonios
Date: 2019
Description: Parallel file systems (PFS) have been the dominant storage solution in High-Performance Computing (HPC) for several years. However, as we move...
Show moreParallel file systems (PFS) have been the dominant storage solution in High-Performance Computing (HPC) for several years. However, as we move towards the exascale era, PFS have several limitations, such as scalability, complexity, metadata, data synchronization, and access latency, which can seriously affect storage's performance. These challenges along with the unprecedented data explosion accentuated the research conundrum known as I/O bottleneck. Moreover, the extreme computing scale, that exascale machines promise, brings forward another important limitation of the existing I/O path. Multiple large scientific applications will be accessing shared storage resources at the same time, and thus, will be competing. This phenomenon is known as cross-application I/O interference and is one of the most challenging performance degradation factors, even in today's petascale. To address some of the above issues, modern system designs have introduced a new memory and storage hierarchy, filled with novel special hardware technologies, that aims to ease, in a sense, the I/O bottleneck. However, software for management, I/O scheduling, and efficient data movement in this new complicated landscape of multi-tiered I/O infrastructure is limited at best. The added complexity of data access using buffering resources needs to be addressed and is of the utmost priority of several scientific sites and communities. This study makes steps towards I/O acceleration in HPC by proposing: a) a new subsystem for the I/O convergence between HPC and BigData storage ecosystems, b) a new subsystem equipped with several advanced I/O buffering techniques for the deep memory and storage hierarchy, and c) a new subsystem that implements several I/O scheduling algorithms to prevent the negative effects of I/O contention, and d) a new storage system that relies on a novel abstract notion of a data label that allows the I/O system to provide storage flexibility, versatility, agility, and malleability. The proposed work has been evaluated and results suggest that substantial improvements in I/O performance have been achieved.
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Title: Superior Reversible Hydrogen Storage of the LiBH4 + MgH2 System Enabled by High-Energy Ball Milling with In-Situ Aerosol Spraying
Creator: Ding, Zhao
Date: 2019
Description: The prospect of LiBH4 + MgH2 mixture has been limited by its sluggish kinetics, despite its excellent hydrogen storage capacity theoretically....
Show moreThe prospect of LiBH4 + MgH2 mixture has been limited by its sluggish kinetics, despite its excellent hydrogen storage capacity theoretically. We have designed a novel process termed as high-energy ball milling of MgH2 at ambient temperature along with aerosol spraying of LiBH4 dissolved in tetrahydrofuran (THF) solution (BMAS) to improve the thermodynamic and kinetic performance of LiBH4 + MgH2 hydrogen storage materials. Through this BMAS process, we have demonstrated that, for the first time, the reaction between LiBH4 + MgH2 can take place near ambient temperature, and the in-situ formation of LiH and MgB2 during BMAS is achieved through a new reaction pathway in which nano-LiBH4 decomposes to Li2B12H12 first and the newly formed Li2B12H12 reacts with MgH2 to form LiH and MgB2.Using the newly designed automated BMAS apparatus, we have successfully produced a BMAS mixture containing 1 mole of MgH2 + 0.5 mole of LiBH4, i.e., with 25% LiBH4 in the mixture for the stoichiometric reaction. The BMAS powder with 25% LiBH4 can release and absorb ~5.7 wt.% H2 at 265 oC, which is the highest one ever reported for the LiBH4 + MgH2 system at temperature ≤ 265 oC. It is found that the unusually high reversible hydrogen storage is accomplished through two parallel reaction pathways. One is nano-LiBH4 decomposes to form Li2B12H12 and H2 first and then Li2B12H12 reacts with MgH2 to form MgB2, LiH and H2. The other is nano-MgH2 decomposes to form Mg and H2 first and then Mg reacts with LiBH4 to form MgB2, LiH and H2. These reaction pathways become possible because of the presence of nano-LiBH4 and nano-MgH2 and their intimate mixing, enabled by the BMAS process. We have also revealed that the solid-state dehydrogenation kinetics of the BMAS powder with 25% LiBH4 at 265 oC is nucleation-and-growth controlled. The rate-limiting step for dehydrogenation via the two parallel reaction pathways has been identified through examination of the elementary reactions as the nucleation and growth of reaction products LiH and MgB2. Given the significantly improved hydrogen storage capacity for the LiBH4 + MgH2 system obtained via BMAS, investigation on increasing the LiBH4 content in the BMAS powder from 25% to 50% is performed. It is shown that Mg(BH4)2 can be produced during the BMAS process and it contributes to H2 release at temperature ≤ 265 oC. Three parallel H2 release mechanisms have been identified from the BMAS powder. These include (i) nano-LiBH4 decomposes to form Li2B12H12 and H2 first and then Li2B12H12 reacts with MgH2 to form MgB2, LiH and H2, (ii) nano-Mg(BH4)2 decomposes to form MgH2, B and H2, and (iii) nano-MgH2 decomposes to Mg and H2. Together these three mechanisms result in 4.11 wt.% H2 release in the solid state at temperature ≤ 265 oC. Furthermore, the predicted property of Fe3B in absorbing more H2 than releasing it is confirmed experimentally for the first time in this study. Varied models have been identified to describe the kinetic of solid-state dehydrogenation of the BMAS powder with 50% LiBH4 at 265 oC with increasing cycles. Additionally, the geometries of the solid particles involving with the dehydrogenation have also been estimated.
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Title: DEEP LEARNING IN ENGINEERING MECHANICS: WAVE PROPAGATION AND DYNAMICS IMPLEMENTATIONS
Creator: Finol Berrueta, David
Date: 2019
Description: With the advent of Artiﬁcial Intelligence research in the 1960s, the need for intelligent systems that are able to truly comprehend the...
Show moreWith the advent of Artiﬁcial Intelligence research in the 1960s, the need for intelligent systems that are able to truly comprehend the physical world around them became relevant. Signiﬁcant milestones in the realm of machine learning and, in particular, deep learning during the past decade have led to advanced data-driven models that are able to approximate complex functions from pure observations. When it comes to the application of physics-based scenarios, the vast majority of these models rely on statistical and optimization constructs, leaving minimal room in their development for the physics-driven frameworks that more traditional engineering and science ﬁelds have been developing for centuries. On the other hand, the more traditional engineering ﬁelds, such as mechanics, have evolved on a diﬀerent set of modeling tools that are mostly based on physics driven assumptions and equations, typically aided by statistical tools for uncertainty handling. Deep learning models can provide signiﬁcant implementation advantages in commercial systems over traditional engineering modeling tools in the current economies of scale, but they tend to lack the strong reliability their counterparts naturally allow. The work presented in this thesis is aimed at assessing the potential of deep learning tools, such as Convolutional Neural Networks and Long Short-Term Memory Networks, as data-driven models in engineering mechanics, with a major focus on vibration problems. In particular, two implementation cases are presented: a data driven surrogate model to a Phononic eigenvalue problem, and a physics-learning model in rigid-body dynamics scenario. Through the applications presented, this work that shows select deep learning architectures can appropriately approximate complex functions found in engineering mechanics from a system’s time history or state and generalize to set expectations outside training domains. In spatio-temporal systems, it is also that shown local learning windows along space and time can provide improved model reliability in their approximation and generalization performance
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Title: Toward a Comprehensive Atomistic View of Bacterial Outer Membrane Remodeling and Antimicrobial Peptide Susceptibility
Creator: Rice, Amy
Date: 2019
Description: The cell membrane is arguably one of the most important and complex features of a cell, serving to demarcate “self” from “environment” and...
Show moreThe cell membrane is arguably one of the most important and complex features of a cell, serving to demarcate “self” from “environment” and selectively controlling the flow of material in and out of the cell. Bacterial cell membranes are of additional interest since they serve as the first point of contact for antibiotic drugs or other antimicrobial agents. In this work, I use atomistic molecular dynamics simulations to study factors that alter bacterial susceptibility to antimicrobial agents and their environment, with the goal of better understanding how bacteria are able to modulate their sensitivity.First, I present results from a series of simulations of antimicrobial peptides (AMP) interacting with phospholipid bilayers to elucidate the observed interaction differences between arginine and lysine-containing AMPs. Simulations show that the extensive interaction with arginine is due in part to arginine's strong atomic charge distribution, rather than being purely an effect of the greater hydrogen bond capacity. These results highlight the role of charge and hydrogen bond strength in peptide bilayer insertion, and offer potential insights for designing more potent analogues in the future.Next, the effects of bacterial lipopolysaccharide (LPS) modifications are examined, first to understand study how three key modifications observed in S. enterica affect bilayer properties, as well as to examine the role these modifications play in AMP resistance. We hypothesize that defects at the crystalline/liquid-ordered boundary facilitate LL-37 intercalation into the outer membrane, whereas LPS modification protects against this process by having already increased crystallinity and packing efficiency. These results further improve our understanding of outer membrane chemical properties and help elucidate how outer membrane modification systems are able to alter bacterial virulence and susceptibility. Lastly, I investigate the effects of ion type and phosphate charge on four distinct LPS types. Simulations show that bilayer properties are highly influenced by the choice of cation type, ion parameterization, and phosphate group charges. Additional free energy perturbation simulations predict that the protonated LPS state should dominate at physiological pH, in contrast to the deprotonated state utilized by many LPS force fields. Overall, these results reveal inaccuracies in the existing LPS force fields and establish guidelines to better reproduce experimental LPS membrane properties.
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Title: CYBER PHYSICAL SYSTEM WITH COUPLED NETWORKS: SECURITY AND PRIVACY
Creator: Zhao, Jing
Date: 2019
Description: With the development of cyber physical systems, people and electronic devices are connected via various networks. In many scenarios, different...
Show moreWith the development of cyber physical systems, people and electronic devices are connected via various networks. In many scenarios, different networks are strongly coupled with each other, e.g. power grid is strongly coupled with the communication network in smart grid. On one hand, such coupling brings benefits such as improved efficiency and quick response to system service exceptions. However, the coupling of different networks also brings security and privacy problems. In this thesis we study two scenarios: the the secure coupling of visual connection with short range pairwise communication and privacy aware coupling of smart home with smart grid. For the first scenario, we propose SCsec, a secure screen-camera communication system, which achieves secure one-way communication. The throughput of SCsec is comparable to current screen communication systems. For the second scenario, we propose a novel randomized battery load hiding algorithm which ensures differential privacy for smart homes with smart meters.
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