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- Creator:
- Zhang, Kaihua and Collette, Matthew D.
- Description:
- This Ph.D. research focuses on two subject areas: experimental and numerical model, which serves as two essential parts of a digital twin. A digital twin contains models of real-world structures and fuses data from observations of the structures and scale experiment to pull the models into better agreement with the real world. Digital twin models have the promise of representing complex marine structures and providing enhanced lifecycle performance and risk forecasts. Experimentally verifying the updating approaches is necessary but rarely performed. Thus, the proposed work is designing an experiment and developing a numerical model updated by the experimental data. The dataset contains all the data collected in the experiment of a four-crack hexagon- shaped specimen is presented, designed to mimic many of the properties of complex degrading marine structural systems, such as crack interaction, component inter- dependence, redundant load path, and non-binary failure.
- Keyword:
- System Reliability, Dynamic Bayesian Networks, Fatigue Experiment, Crack Length Measurement, Experimental Validation, Reliability Prediction
- Citation to related publication:
- "Evaluating Crack Growth Prediction in Structural Systems with Dynamic Bayesian Networks", submitted to Computers and Structure and Zhang, K., & Collette, M. (2021). Experimental investigation of structural system capacity with multiple fatigue cracks. Marine Structures, 78, 102943. https://doi.org/10.1016/j.marstruc.2021.102943
- Discipline:
- Engineering
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- Creator:
- Robert Buckley, Grace O'Brien, and Zoe Zhou
- Description:
- The purpose of the research is to better understand and approximate the Thurston Set. This project was computational in nature and Python was used to collect our data. The data set contains encoded itineraries that can be used to compute values that are elements of the Thurston Set. A visual approximation of the Thurston Set can be found here ( https://arxiv.org/abs/1402.2008), on the first page Thurston’s own paper. The data can also be used to study the distribution of superattracting beta values within the interval (1, 2] and to explore an analogous Mandelbrot-Julia Correspondence. This research was conducted through the Lab of Geometry at Michigan under the advisement of Harrison Bray during the Fall semester of 2019. , The Python 3.x scripts in this deposit are the exact versions used to created the *.txt files that are in the zip archive. As the project continues, any expansion to the work, such as further analysis or visualization scripts, will be posted to the project's GitHub https://github.com/Tent-Maps-Team/Thurston-Set. Also, a user can reproduce our results and generate bigger datasets on machines with large amounts of memory. , and The data consists of zipper folders representing tent map itinerary orbit lengths. These orbit files can be used to create visualizations, create and explore conjectures such as refining proposed bounds on the Thurston Set and supporting an analogous Mandelbrot-Julia Correspondence. Within these zipped folders are .txt files in CSV format with the naming structure of xx_y of admissible itineraries up to the length indicated by the folder name where xx is the length of the encoded itineraries included. The txt's have a single column and each line(row) is an array representing an encoding of an itinerary. Some of the txt's have been split into multiple parts (whenever there are more than 200 MB of itinerary data) and these txt's have been numbered using the y after the underscore. As we exclude the degenerate tent map (where β = 1), we cannot have orbit length 1 or 2 and this is why the orbits start with length 3 (i.e. start with 3.zip).
- Keyword:
- Math, mathematics, tent maps, thurston, milnor, Milnor-Thurston, supperattracting, entropy, orbit, and itineraries
- Citation to related publication:
- Buckley R, O’Brien G, Zhou Z (2021). On Itineraries of Tent Maps. Forthcoming.
- Discipline:
- Other
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- Creator:
- Agnit Mukhopadhyay
- Description:
- Conducting quantitative metrics-based performance analysis of first-principles-based global magnetosphere models is an essential step in understanding their capabilities and limitations, and providing scope for improvements in order to enhance their space weather prediction capabilities for a range of solar conditions. In this study, a detailed comparison of the performance of three global magnetohydrodynamic (MHD) models in predicting the Earth’s magnetopause location and ionospheric cross polar cap potential (CPCP) has been presented. Using the Community Coordinated Modeling Center’s Run-on-Request system and extensive database on results from various magnetospheric scenarios simulated for a variety of solar wind conditions, the aforementioned model predictions have been compared for magnetopause standoff distance estimations obtained from six empirical models, and with cross polar cap potential estimations obtained from the Assimmilative Mapping of Ionospheric Electrodynamics (AMIE) Model and the Super Dual Auroral Radar Network (SuperDARN) observations. We have considered a range of events spanning different space weather activity to analyze the performance of these models. Using a fit performance metric analysis for each event, we have quantified the models’ reproducibility of magnetopause standoff distances and CPCP against empirically-predicted observations, and identified salient features that govern the performance characteristics of the modeled magnetospheric and ionospheric quantities.
- Citation to related publication:
- Mukhopadhyay, A., Jia, X., Welling, D. T., & Liemohn, M. W. (2021). Global Magnetohydrodynamic Simulations: Performance Quantification of Magnetopause Distances and Convection Potential Predictions. Frontiers in Astronomy and Space Sciences, 8. https://doi.org/10.3389/fspas.2021.637197
- Discipline:
- Engineering and Science
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- Creator:
- McCuen, Brett A.
- Description:
- These data are TLA events identified in MACCS magnetometer data throughout 2015. These events are short-timescale (< 60 s), large -amplitude (> 6 nT/s) magnetic disturbances measured at Earth's surface that are analyzed for space weather research purposes. and The events were identified in a year's worth of magnetic field data using an algorithm developed in the MATLAB platform. The algorithm dBdt_main.m can be run using the associated scripts (clean_maccs.m, simple_dbdt.m, extremes1.m, newdbdt.m) to return the events in the 2015_AllEvents.csv file. The substorm onset delays of each event are determined with the onset_delays.m script and the substorm event list 20191127-15-56-substorms.csv (both included).
- Keyword:
- space weather impacts, geomagnetically induced currents, GIC, transient induced currents, transient large amplitude, dB/dt search algorithm, and TLA
- Citation to related publication:
- Engebretson, M. J., Pilipenko, V. A., Ahmed, L. Y., Posch, J. L., Steinmetz, E. S., Moldwin, M. B., … Vorobev, A. V. (2019). Nighttime Magnetic Perturbation Events Observed in Arctic Canada: 1. Survey and Statistical Analysis. Journal of Geophysical Research: Space Physics, 124(9), 7442–7458. https://doi.org/10.1029/2019JA026794
- Discipline:
- Science
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- Creator:
- Pine, Alexandra F and Love, Brian J
- Description:
- This data is from a project concerned with dehydrating samples of saturated superabsorbent polymer using a centrifuge. The goal was to consider centrifugation as an energy efficient scheme to dehydrate SAP with the notion of reusing it. The data provided contains mass fractions of solvent removed through centrifugation with varied parameters.
- Keyword:
- Superabsorbent Polymer
- Citation to related publication:
- Pine, A., Wu, C. C., Raghavan, S., & Love, B. (2021). The efficiency of dehydrating desiccants by centrifugation: An assessment of superabsorbent polymers. Drying Technology, 0(0), 1–8. https://doi.org/10.1080/07373937.2021.1939710
- Discipline:
- Engineering
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- Creator:
- Zhang, Yan, Gao, Chuanyu, Zhang, Shaoqing, Yang, Ping, Meyers, Philip A, and Wang, Guoping
- Description:
- The study focuses on reconstructing the histories of peat deposition using n-alkane biomarkers in peat cores and associated modern plant communities from four sites around a shallow maar lake in the Changbai Mountains of northeastern China. Peat development patterns in the four sites are not concordant although the sites experienced the same paleoclimate histories. Evidently, lava flows and tephra deposits produced an uneven topography of the volcanogenic lake basin that controls the water depths at the four lake edge locations, thereby leading to differences in peat-forming plant communities and peat deposition among the four sites.
- Keyword:
- peat deposition, n-alkanes, volcanic eruptions, and Changbai Lake
- Citation to related publication:
- Zhang, Y., Gao, C., Zhang, S., Yang, P., Meyers, P. A., & Wang, G. (2020). N-Alkane-based reconstructions of peat accumulations and depositional conditions at four locations around a shallow maar lake in the Changbai Mountains, northeastern China (world) [Preprint]. Earth and Space Science Open Archive; Earth and Space Science Open Archive. https://doi.org/10.1002/essoar.10505381.1
- Discipline:
- Science
-
- Creator:
- Moldwin, Mark B. and O'Brien, Paul
- Description:
- A new empirical model of the plasmapause location has been developed using density data from the plasma wave receiver onboard the CRRES spacecraft for nearly 1000 orbits. The “plasmapause” is identified here as the innermost sharp gradient in density (change of a factor of 5 in <0.5 L). Such a sharp gradient was observed on 73% of the CRRES inbound and outbound orbits that returned data. The plasmapause location is expressed as a linear function of Kp (previous 12 hour maximum) and local time. The model gives the linear best fit location of the plasmapause as well as the standard deviations of the model parameters.
- Keyword:
- Plasmapause and Plasmasphere
- Citation to related publication:
- Moldwin, M. B., Downward, L., Rassoul, H. K., Amin, R., and Anderson, R. R. (2002), A new model of the location of the plasmapause: CRRES results, J. Geophys. Res., 107( A11), 1339, doi:10.1029/2001JA009211 and O'Brien, T. P., and Moldwin, M. B. (2003), Empirical plasmapause models from magnetic indices, Geophys. Res. Lett., 30, 4, 1152. doi:10.1029/2002GL016007
- Discipline:
- Science
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- Creator:
- Dewaraja, Yuni K and Van, Benjamin J
- Description:
- This publication contains anonymized diagnostic imaging scans of two patients. The images provided are pre-therapy scans used by clinicians for diagnosis and for selecting patients for treatment with Lu-177 DOTATATE. Multiple imaging modalities are present including diagnostic CT, MRI, and Ga68 PET, depending on the selected patient. All images are in DICOM format.
- Keyword:
- Lu-177, Lutathera, Dosimetry, Radionuclide, CT, MRI, and PET
- Discipline:
- Health Sciences
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- Creator:
- Dewaraja, Yuni K and Van, Benjamin J
- Description:
- This publication contains anonymized planar whole body images of two patients. Patient scans were taken at 4 different time points in the week following a therapeutic dose of Lu-177 DOTATATE. Both anterior and posterior views are provided. All images are in DICOM format.
- Keyword:
- Lu-177, Lutathera, Dosimetry, Radionuclide, and Planar
- Discipline:
- Health Sciences
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- Creator:
- Dewaraja, Yuni K and Van, Benjamin J
- Description:
- This publication contains anonymized SPECT/CT scans of two patients. Patient scans were taken at 4 different time points in the week following a therapeutic dose of Lu-177 DOTATATE. Both the SPECT and the co-registered CT are provided. All images are in DICOM format.
- Keyword:
- Lu-177, Dosimetry, Radionuclide, SPECT, and CT
- Discipline:
- Health Sciences