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- Creator:
- Hoffmann, Alex P.
- Description:
- Research Overview: In situ magnetic field measurements are often difficult to obtain due to the presence of stray magnetic fields generated by spacecraft electrical subsystems. The conventional solution is to implement strict magnetic cleanliness requirements and place magnetometers on a deployable boom. However, this method is not always feasible on low-cost platforms due to factors such as increased design complexity, increased cost, and volume limitations. To overcome this problem, we propose using the Quad-Mag CubeSat magnetometer with an improved Underdetermined Blind Source Separation (UBSS) noise removal algorithm. The Quad-Mag consists of four magnetometer sensors in a single CubeSat form-factor card that allows distributed measurements of stray magnetic fields. The UBSS algorithm can remove stray magnetic fields without prior knowledge of the magnitude, orientation, or number of noise sources. UBSS is a two-stage algorithm that identifies signals through cluster analysis and separates them through compressive sensing. We use UBSS with single source point (SSP) detection to improve the identification of noise signals and iteratively-weighted compressed sensing to separate noise signals from the ambient magnetic field. Using a mock CubeSat, we demonstrate in the lab that UBSS reduces four noise signals producing more than 100 nT of noise at each magnetometer to below the expected instrument resolution (near 5 nT). Additionally, we show that the integrated Quad-Mag and improved UBSS system works well for 1U, 2U, 3U, and 6U CubeSats in simulation. Our results show that the Quad-Mag and UBSS noise cancellation package enables high-fidelity magnetic field measurements from a CubeSat without a boom.
- Keyword:
- source separation, demixing, magnetometers, stray magnetic fields, noise removal, and cubesat
- Citation to related publication:
- Hoffmann, A. P., Moldwin, M. B., Strabel, B. P., & Ojeda, L. V. (2023). Enabling Boomless CubeSat Magnetic Field Measurements with the Quad-Mag Magnetometer and an Improved Underdetermined Blind Source Separation Algorithm. Journal of Geophysical Research: Space Physics, 128, e2023JA031662. https://doi-org.proxy.lib.umich.edu/10.1029/2023JA031662
- Discipline:
- Engineering
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- Creator:
- Limon, Garrett C.
- Description:
- The work guides the processing of CAM6 data for use in machine learning applications. We also provide workflow scripts for training both random forests and neural networks to emulate physic s schemes from the data, as well as analysis scripts written in both Python and NCL in order to process our results.
- Keyword:
- Machine Learning, Climate Modeling, and Physics Emulation
- Citation to related publication:
- Limon, G. C., Jablonowski, C. (2022) Probing the Skill of Random Forest Emulators for Physical Parameterizations via a Hierarchy of Simple CAM6 Configurations [Pre Print]. ESSOAr. https://10.1002/essoar.10512353.1
- Discipline:
- Engineering and Science
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SHIFDR: Sub-metered HVAC Implemented For Demand Response
User Collection- Creator:
- Lin, Austin and Mathieu, Johanna
- Description:
- The Sub-metered HVAC Implemented for Demand Response (SHIFDR) dataset is a massive dataset that captures the response of individual commercial building HVAC system components to demand response events. The dataset includes device-level power consumption during demand response events as well as during normal operation. We have organized the data into subsets, with each subset containing data from buildings in different parts of the world. Kindly refer to the README file within each subsection for specific information about how data is organized. Please reach out if you have data that you would like to share, find any mistakes in the data, or have any questions. We are always trying to improve SHIFDR.
- Discipline:
- Engineering
1Works -
- Creator:
- Kim, Wonhui, Ramanagopal, Manikandasriram Srinivasan, Barto, Charles , Yu, Ming-Yuan, Rosaen, Karl , Goumas, Nick , Vasudevan, Ram, and Johnson-Roberson, Matthew
- Description:
- PedX is a large-scale multi-modal collection of pedestrians at complex urban intersections. The dataset provides high-resolution stereo images and LiDAR data with manual 2D and automatic 3D annotations. The data was captured using two pairs of stereo cameras and four Velodyne LiDAR sensors.
- Citation to related publication:
- https://doi.org/10.48550/arXiv.1809.03605, https://github.com/umautobots/pedx, and http://pedx.io/
- Discipline:
- Engineering
-
- Creator:
- Habbal, Osama, Orabi, Mohamad , Mohanty, Pravansu, and Pannier, Christopher
- Description:
- This research introduces a novel method to produce biomimetic shapes using low cost soluble 3D printed molds. Mesenchymal stem cells in alginate matrix cell viability was studied. The alginate stem cell structure is made in a construct that is 21 mm wide, 6 mm high, with an arbor diameter of 1 mm (see Combined_Test_Channels.stl). The cells showed 64% survivability at 7 days in the 3D constructs.
- Keyword:
- 3D Printing, Additive Manufacturing, and 3D bio scaffold
- Discipline:
- Engineering
-
- Creator:
- Sun, Hu
- Description:
- Complete Global Total Electron Content Database based on the VISTA Algorithm
- Keyword:
- Total Electron Content, Matrix Completion, VISTA, Spherical Harmonics, and Spatial-Temporal Smoothing
- Discipline:
- Engineering
2Works -
- Creator:
- Billings, Gideon H and Johnson-Roberson, Matthew
- Description:
- UWslam is a dataset for underwater stereo and hybrid monocular fisheye + stereo SLAM in natural seafloor environments. The dataset includes a spiral survey of a shallow reef captured with a diver operated stereo rig and 4 hybrid image sequences captured with a deep ocean ROV in different deep ocean environments. Ground truth pose estimates for the spiral stereo trajectory were obtained by processing the image sequence through COLMAP. Ground truth pose estimates for the hybrid sequences were obtained by distributing fiducials on the seafloor before capturing an image sequence and processing the image sequences with the ROS based TagSLAM package.
- Keyword:
- SLAM, Simultaneous Localization and Mapping, Visual Reconstruction, and Underwater
- Citation to related publication:
- G. Billings, R. Camilli and M. Johnson-Roberson, "Hybrid Visual SLAM for Underwater Vehicle Manipulator Systems," in IEEE Robotics and Automation Letters, vol. 7, no. 3, pp. 6798-6805, July 2022, doi: 10.1109/LRA.2022.3176448.
- Discipline:
- Engineering
-
- Creator:
- Billings, Gideon H and Johnson-Roberson, Matthew
- Description:
- UWHandles is a dataset for 6D object pose estimation in underwater fisheye images. It provides 6D pose and 2D bounding box annotations for 3 different graspable handle objects used for ROV manipulation. The dataset consists of 28 image sequences collected in natural seafloor environments with a total of 20,427 annotated frames. and Meta repository for the dataset https://github.com/gidobot/UWHandles
- Keyword:
- Deep Learning, Pose Estimation, and Underwater Vision
- Citation to related publication:
- Billings, G., & Johnson-Roberson, M. (2020). SilhoNet-fisheye: Adaptation of a ROI based object pose estimation network to monocular fisheye images. IEEE Robotics and Automation Letters, 5(3), 4241-4248.
- Discipline:
- Engineering
-
- Creator:
- Raghani, Ravi M, Urie, Russell R, and Shea, Lonnie D
- Description:
- The IN were sampled during and after ICB and sequenced to identify gene expression signatures that correlated with sensitivity or resistance. We also analyzed gene expression at the IN prior to ICB treatment to identify markers predicting therapeutic response. Longitudinally interrogating an IN, to monitor changes associated with ICB response, presents a new opportunity to personalize care and investigate mechanisms underlying treatment resistance.
- Keyword:
- Immunotherapy resistance, Biomaterials, Metastasis, Checkpoint blockade, and Therapy monitoring
- Discipline:
- Engineering and Health Sciences
-
- Creator:
- Ponder, Brandon M., Ridley, Aaron J., Goel, Ankit, and Bernstein, Dennis S.
- Description:
- This research was completed to statistically validate that a data-model refinement technique could integrate real measurements to remove bias from physics-based models via changing the forcing parameters such as the thermal conductivity coefficients.
- Keyword:
- Thermosphere, GITM, CHAMP, GRACE, MSIS, Upper Atmosphere Modeling, and Data Assimilation
- Citation to related publication:
- Ponder, B. M., Ridley, A. J., Goel, A., & Bernstein, D. S. (2023). Improving forecasting ability of GITM using data-driven model refinement. Space Weather, 21, e2022SW003290. https://doi.org/10.1029/2022SW003290
- Discipline:
- Engineering and Science
-
- Creator:
- Szuromi, Matthew P. and Stacey, William C.
- Description:
- The data and scripts are meant to show how burster dynamics determine response to a single biphasic stimulus. The files include data which show trends in the propensity of termination for different burster types and the MATLAB scripts used to generate this data. The MATLAB scripts also allow the user to generate their own data sets for alternative bursting paths and stimulus parameter combinations. Furthermore, they allow the user to visually examine the effects of single stimuli in the voltage timeseries and in state space. How the user can access these features of the script is described in the file "ReadMe.pdf."
- Keyword:
- Epilepsy, Stimulation, Modelling, Dynamics, Seizure, and Dynamotype
- Citation to related publication:
- (PROVISIONAL) Optimization of Ictal Aborting Stimulation Using the Dynamotype Taxonomy
- Discipline:
- Health Sciences, Engineering, and Science
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- Creator:
- Eckels, Joshua D.
- Description:
- The goal of the research was to train a surrogate model for the prediction of electric field distribution for a given electrospray emitter geometry design. The surrogate is to be used in reduced-fidelity modeling of electrospray thruster arrays. The code repository is included in the README.txt file.
- Keyword:
- Electrospray design, Martinez-Sanchez hyperboloid solution, and Electrospray engineering toolkit (ESPET)
- Citation to related publication:
- J.D. Eckels, C.B. Whittaker, B.A. Jorns, A.A. Gorodetsky, B. St. Peter, R.A. Dressler, “Simulation-based surrogate methodology of electric field for electrospray emitter geometry design and uncertainty quantification”, presented at the 37th International Electric Propulsion Conference, Boston, MA USA, June19-23, 2022 Available: https://www.electricrocket.org/IEPC_2022_Papers.html
- Discipline:
- Engineering
-
- Creator:
- Minallah, Samar and Steiner, Allison L.
- Description:
- Data format: netcdf4 , Time series duration: 2016-06-01 to 2020-10-31, Temporal resolution: Daily, and Spatial resolution: The model output was regridded to a 0.05 degree rectilinear (lat/lon) grid using the conservative remapping method ("cdo remapcon" tool).
- Keyword:
- Land surface hydrology, Great Lakes, Land surface model, NOAH-MP, WRF-Hydro, and Hydrologic modeling
- Citation to related publication:
- Minallah, S. (2022). A Study on the Atmospheric, Cryospheric, and Hydrologic Processes Governing the Evolution of Regional Hydroclimates (Doctoral dissertation, University of Michigan Ann Arbor). https://dx.doi.org/10.7302/6223
- Discipline:
- Science and Engineering
-
- Creator:
- Jivani, Aniket, Sachdeva, Nishtha, Huang, Zhenguang, Chen, Yang, van der Holst, Bart, Manchester, Ward, Iong, Daniel, Chen, Hongfan, Zou, Shasha, Huan, Xun, and Toth, Gabor
- Description:
- In this work, we perform Global Sensitivity Analysis (GSA) for the background solar wind in order to quantify contributions from uncertainty of different model parameters to the variability of in-situ solar wind speed and density at 1au, both of which have a major impact on CME propagation and strength. Scripts written in the Julia language are used to build the PCE and calculate the sensitivity results. Data is available in csv, NetCDF and JLD files. A `Project.toml` file is included to activate and install all required dependencies (See README for details).
- Keyword:
- Uncertainty Quantification, Space Weather, and Global Sensitivity Analysis
- Discipline:
- Engineering
-
- Creator:
- Limon, Garrett C.
- Description:
- The data represents weekly output from three 60-year CAM6 model runs. The output includes state (.h0. files) and tendency (.h1. files) fields for three difference model configurations of increasing complexity. State fields include temperature, surface pressure, specific humidity, among others; while tendencies include temperature tendencies, specific humidity tendencies, as well as precipitation rates. Using the state variables at a given time step, machine learning techniques can be trained to predict the following tendency field, which can then be applied to the state variables to provide the state at the next physics time step of the model.
- Keyword:
- Machine Learning, Climate Modeling, and Physics Emulation
- Citation to related publication:
- Limon, G. C., Jablonowski, C. (2022) Probing the Skill of Random Forest Emulators for Physical Parameterizations via a Hierarchy of Simple CAM6 Configurations [Preprint]. ESSOAr. https://10.1002/essoar.10512353.1
- Discipline:
- Engineering and Science
-
- Creator:
- Clemett, Nathaniel M, Collette, Matthew D, and Simmons, Benjamin
- Description:
- To produce this dataset, three modes of the flywheel were tested. The first was with the flywheel off, which produced a baseline for roll without stabilization. The second mode was active stabilization with the flywheel spinning. An IMU on board took in roll in degrees. An Arduino uno used the roll angle to precess the flywheel to a degree that countered the roll. The last mode was passive stabilization with the flywheel on. Here, the precession belt was removed which allowed the flywheel to freely precess and counter the moment generated by the roll.
- Discipline:
- Engineering
-
- Creator:
- Sun, Hu, Ren, Jiaen, Chen, Yang, Zou, Shasha, Chang, Yurui, Wang, Zihan, and Coster, Anthea
- Description:
- Our research focuses on providing a fully-imputed map of the worldwide total electron content with high resolution and spatial-temporal smoothness. We fill in the missing values of the original Madrigal TEC maps via estimating the latent feature of each latitude and local time along the 2-D grid and give initial guess of the missing regions based on pre-computed spherical harmonics map. The resulting TEC map has high imputation accuracy and the ease of reproducing. All data are in HDF5 format and are easy to read using the h5py package in Python. The TEC map is grouped in folders based on years and each file contains a single-day data of 5-min cadence. Each individual TEC map is of size 181*361. and WARNING: 2023-12-01 the data file for 2019-Jan-03 has badly fitted values. Please avoid using it. All other days' files are ready to use.
- Keyword:
- Total Electron Content, Matrix Completion, VISTA, Spherical Harmonics, and Spatial-Temporal Smoothing
- Citation to related publication:
- Sun, H., Hua, Z., Ren, J., Zou, S., Sun, Y., & Chen, Y. (2022). Matrix completion methods for the total electron content video reconstruction. The Annals of Applied Statistics, 16(3), 1333-1358., Sun, H., Chen, Y., Zou, S., Ren, J., Chang, Y., Wang, Z., & Coster, A. (2023). Complete Global Total Electron Content Map Dataset based on a Video Imputation Algorithm VISTA. Scientific Data, in press., and Zou, S., Ren, J., Wang, Z., Sun, H., & Chen, Y. (2021). Impact of storm-enhanced density (SED) on ion upflow fluxes during geomagnetic storm. Frontiers in Astronomy and Space Sciences, 8, 746429.
- Discipline:
- Science and Engineering
-
- Creator:
- McSherry, Sean
- Description:
- This repository includes the analysis code and raw data for a paper titled "Nanophotonic control of thermal emission under extreme temperatures in air, " in Nature Nanotechnology (see citation). In our work, well defined structure-color effects guided the design of a nanostructure containing stratified layers of two oxides, magnesium oxide (MgO) and barium zirco-hafnate (BaZr0.5Hf0.5O3 or BZHO). The repeating layers were tuned in such a way to manipulate incident infrared wavelengths. The infrared is the spectral range in which heat (in the form of electromagnetic radiation) is emitted from objects. Therefore, the nanostructure serves as a way to alter the thermal emission spectrum of hot objects, controlling how much heat can flow. This can have significant impacts on a range of technologies, such as thermal photovoltaics (TPVs), which generate electricity from the infrared light emission of hot objects (compared to visible light emission from the sun in solar photovoltaics). We envision that our MgO/BZHO nanostructure can be paired with a thermal emitter in TPV systems to beneficially manipulate the flow of infrared light, leading to more efficient electricity production. To characterize the thermal stability of this structure, we had to characterize the thermal stability and optical performance at room temperature and at 1100 °C. This lead us to conduct several experiments using ellipsometry, TEM, EDS, and FTIR.
- Keyword:
- FTIR, Infrared, Photonic Crystal, MgO, Refractory , Ellipsometry, Spectroscopy, Superlattice, and Thermal Emission
- Citation to related publication:
- McSherry et al. Nature Nanotechnology (In Press). 2022
- Discipline:
- Engineering
-
- Creator:
- Nikolov, Denislav P, Srivastava, Siddhartha, Abeid, Bachir A, Scheven, Ulrich M, Arruda, Ellen M, Garikipati, Krishna, and Estrada, Jonathan B
- Description:
- Contemporary material characterisation techniques that leverage deformation fields and the weak form of the equilibrium equations face challenges in the numerical solution procedure of the inverse characterisation problem. As material models and descriptions differ, so too must the approaches for identifying parameters and their corresponding mechanisms. The widely-used Ogden material model can be comprised of a chosen number of terms of the same mathematical form, which presents challenges of parsimonious representation, interpretability, and stability. Robust techniques for system identification of any material model are important to assess and improve experimental design, in addition to their centrality to forward computations. Using fully 3D displacement fields acquired in silicone elastomers with our recently-developed magnetic resonance cartography (MR-u) technique on the order of ~20,000 points per sample, we leverage PDE-constrained optimisation as the basis of variational system identification of our material parameters. We incorporate the statistical F-test to maintain parsimony of representation. Using a new, local deformation decomposition locally into mixtures of biaxial and uniaxial tensile states, we evaluate experiments based on an analytical sensitivity metric, and discuss the implications for experimental design. This repository contains the acquired data and MRI processing code used in this work.
- Keyword:
- continuum mechanics, magnetic resonance, sensitivity, full-field deformations, physics inference, mechanics, mechanical engineering, and computational mechanics
- Citation to related publication:
- https://doi.org/10.48550/arXiv.2204.03122
- Discipline:
- Engineering
-
- Creator:
- Towne, Aaron, Yeh, Chi-An., Patel, Het, and Taira, Kunihiko
- Description:
- This dataset contains data from a three-dimensional large eddy simulation of Mach 0.3 flow over a NACA 0012 airfoil at Reynolds number 23,000, which features a transitional boundary layer, separation over a recirculation bubble, and a turbulent wake. The dataset contains 16,000 time-resolved snapshots of the mid-span and spanwise-averaged velocity fields. All data are stored within hdf5 files, and a Matlab script showing how the data can be read and manipulated is provided. Please see the ‘airfoilLES_README.pdf’ file for more information. We recommend using the ‘airfoilLES_example.zip’ file as an entry point to the dataset. and The dataset is part of “A database for reduced-complexity modeling of fluid flows” (see references below) and is intended to aid in the conception, training, demonstration, evaluation, and comparison of reduced-complexity models for fluid mechanics. The paper introduces the flow setup and computational methods, describes the available data, and provides an example of how these data can be used for reduced-complexity modeling. Users of these data should cite the papers listed below.
- Citation to related publication:
- Towne, A., Dawson, S., Brès, G. A., Lozano-Durán, A., Saxton-Fox, T., Parthasarthy, A., Biler, H., Jones, A. R., Yeh, C.-A., Patel, H., Taira, K. (2022). A database for reduced-complexity modeling of fluid flows. AIAA Journal 61(7): 2867-2892. and Yeh, C.-A. and Taira, K. (2019) Resolvent-analysis-based design of airfoil separation control. Journal of Fluid Mechanics, 867:572–610.
- Discipline:
- Science and Engineering