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- Creator:
- Abid, Chaima, Kessentini, Marouane, Alizadeh, Vahid, Dhaouadi, Mouna, and Kazman, Rick
- Description:
- Data about the evaluation of the refactorings impact on security.
- Discipline:
- Science
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- Creator:
- Brandt, Daniel, A., Bussy-Virat, Charles, D., and Ridley, Aaron, J.
- Description:
- The Multifaceted Optimization Algorithm (MOA) is a tool for generating corrected empirical model thermospheric densities during geomagnetic storms. It consists of a suite of Python functions that operate around the Spacecraft Orbit Characterization Kit (SpOCK), an orbital propagator developed by Charles D. Bussy-Virat, PhD, Joel Getchius, and Aaron J. Ridley, PhD at the University of Michigan, and it estimates new densities for the NRLMSISE-00 atmospheric model. MOA generates new model densities by estimating modifications to inputs to the NLRMSISE-00 model that minimize the orbit error between modeled spacecraft in SpOCK, and their actual altitudes as described in publicly-available Two-Line Element Sets (TLEs), made available online via Space-track.org. MOA consists of three sub-process: (1) The Area Optimization Algorithm (AROPT), (2) the F10.7 Optimization Algorithm (FOPT), and (3) the Ap Optimization Algorithm (APOPT). AROPT computes the contribution to the drag of the modeled spacecraft due to their varying projected area. FOPT estimates modifications to the 10.7 cm solar radio flux in NRLMSISE-00, and APOPT estimates modifications to the Earth's magnetic activity in NRLMSISE-00. MOA finds these modifications across many spacecraft, and the medians of those modifications are then applied in NLRMSISE-00 along the orbit of another satellite to generate new densities for verification. In this instance, modifications are applied along the orbits of the Swarm spacecraft and compared to Swarm GPS-derived densities.
- Keyword:
- Orbit, Satellite, Two-line Element Set, Thermosphere, and Drag
- Citation to related publication:
- Brandt, D. A., Bussy-Virat, C. D., & Ridley, A. J. (2020). A Simple Method for Correcting Empirical Model Densities During Geomagnetic Storms Using Satellite Orbit Data. Space Weather, 18(12), e2020SW002565. https://doi.org/10.1029/2020SW002565
- Discipline:
- Engineering
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- Creator:
- Baskar, Deepika and Gorodetsky, Alex
- Description:
- Studying the effect of wind on urban air mobility typically requires comprehensive fluid dynamics simulations in a realistic urban geometry. Motivated to enable wide-spread autonomous drone activity in urban centers, such studies have indeed been considered by several authors in the recent literature. However, the accessibility of these approaches to those with less fluid dynamics experience and/or without access to purpose built simulation tools has limited validation and application of the resulting path planning strategies. and The .dat files contain the flow variables for each of the 402240 points sampled from the region under study. For flow visualization purposes, the .dat files are readable using Tecplot Software.
- Keyword:
- UAM, Energy efficient path planning , CFD, and City of Boston
- Citation to related publication:
- Baskar, D., & Gorodetsky, A. (2020). A Simulated Wind-field Dataset for Testing Energy Efficient Path-Planning Algorithms for UAVs in Urban Environment. In AIAA AVIATION 2020 FORUM. American Institute of Aeronautics and Astronautics. https://doi.org/10.2514/6.2020-2920
- Discipline:
- Other and Engineering
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- Creator:
- McCuen, Brett A.
- Description:
- We present a comprehensive statistical analysis of high-frequency transient-large-amplitude (TLA) magnetic perturbation events that occurred at 12 high-latitude ground magnetometer stations throughout solar cycle 24 from 2009 to 2019. TLA signatures are defined as one or more second-timescale dB/dt interval with magnitude ≥ 6 nT/s within an hour event window. This study characterizes high-frequency TLA events based on their spatial and temporal behavior as well as relation to auroral substorms, geomagnetic storm phases and nighttime geomagnetic disturbance events events (GMD). We show that TLA events occur primarily at nighttime and solely in the high-latitude region above 60 degrees geomagnetic latitude. The largest TLA events occurred more often in the declining phase of the solar cycle when solar wind velocity was higher and ring current activity was lower, suggesting association to high-speed flows caused by coronal holes and subsequent corotating interaction regions reaching Earth. TLA perturbations often occurred preceding or within the most extreme nighttime geomagnetic disturbance (GMD) events with 5-10 minute timescales, but the TLA intervals were often even more localized than the ~300 km effective radius of GMDs: occurring at only some of the stations at which GMDs occurred. We show that TLA-related GMD events can result from dipolarization fronts in the magnetotail and fast flows toward Earth and are closely temporally associated to poleward boundary intensifications (PBI) and auroral streamers. The highly localized behavior and connection to the most extreme GMD events suggests that TLA intervals are a ground manifestation of the features within rapid and complex ionospheric structures that can drive GICs.
- Keyword:
- geomagnetic field, high frequency, space weather, transient-large-amplitude, TLA, high frequency dB/dt, dB/dt search algorithm
- Citation to related publication:
- McCuen, B. A., Moldwin, M. B., Engebretson, M. J., Weygand, J. G., Nishimura, Y. (2023). A Statistical Analysis of High-frequency Transient-Large-Amplitude Geomagnetic Disturbance. [To be submitted to] Journal of Geophysical Research: Space Physics
- Discipline:
- Science
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- Creator:
- Crisp, Dakota N., Saggio, Maria L., Scott, Jared, Stacey, William C., Nakatani, Mitsuyoshi, Gliske, Stephen V., and Lin, Jack
- Description:
- This data and scripts are meant to test and show seizure differentiation based on bifurcation theory. A zip file is included which contains real and simulated seizure waveforms, Matlab scripts, and metadata. The matlab scripts allow for visual review validation and objective feature analysis. The file “README.txt” provides more detail about each individual file within the zip file. and Data citation: Crisp, D.N., Saggio, M.L., Scott, J., Stacey, W.C., Nakatani, M., Gliske, S.F., Lin, J. (2019). Epidynamics: Navigating the map of seizure dynamics - Code & Data [Data set]. University of Michigan Deep Blue Data Repository. https://doi.org/10.7302/ejhy-5h41
- Keyword:
- Bifurcation, Epilepsy, Seizure, and Divergence
- Citation to related publication:
- Saggio, M.L., Crisp, D., Scott, J., Karoly, P.J., Kuhlmann, L., Nakatani, M., Murai, T., Dümpelmann, M., Schulze-Bonhage, A., Ikeda, A., Cook, M., Gliske, S.V., Lin, J., Bernard, C., Jirsa, V., Stacey, W., 2020. In pre-print. Epidynamics characterize and navigate the map of seizure dynamics. bioRxiv 2020.02.08.940072. https://doi.org/10.1101/2020.02.08.940072
- Discipline:
- Engineering, Science, and Health Sciences
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- Creator:
- Ding, J, Moore, TY, and Gan, Z
- Description:
- Jerboas (Jaculus jaculus) are bipedal hopping rodents that frequently transition between gaits (running, hopping, and skipping) throughout their entire speed range. It has been hypothesized that these non-cursorial bipedal gait transitions are likely to enhance their maneuverability and predator evasion ability. However, it is difficult to use the underlying dynamics of these locomotion patterns to predict gait transitions due to the large number of degrees of freedom expressed by the animals. To this end, we used empirical jerboa kinematics and dynamics to develop a unified Spring Loaded Inverted Pendulum model with defined passive swing leg motions. The simulated trajectories from the model precisely matched the experimental data. Jerboas were observed to apply different neutral swing leg angles during locomotion. By investigating the gait structure of the model with coupled and uncoupled neutral swing leg, we found two set of mechanism may explain the frequent gait transitions of jerboas.
- Keyword:
- jerboa, legged locomotion, gait transition, Legged Robots, Dynamics, Bipedal locomotion, and Non-cursorial locomotion
- Citation to related publication:
- Ding, Moore, Gan (submitted) A template model explains jerboa gait transitions across a broad range of speeds. Frontiers in Bioengineering And Biotechnology
- Discipline:
- Science and Engineering
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- Creator:
- Jones, Monica L.H.
- Description:
- This study evaluated the performance of a video-based intervention for improving the belt fit obtained by drivers. Previous laboratory studies have demonstrated that some drivers position their seat belts suboptimally. Specifically, the lap portion of the belt may be higher and farther forward relative to the pelvis than best practice, and the shoulder portion of the belt may be outboard or inboard of mid-shoulder. A video was developed to present the most important aspects of belt fit best practices, with emphasis on the lap belt. The video demonstrated how a seat belt should be routed with respect to an individual’s anatomy to ensure a proper fit. The three key belt fit concepts conveyed in the video were: 1) Lap belt low on hips, touching the thighs. 2) Shoulder belt crossing middle of collarbone. 3) Belt snug, as close to bones as possible. Additional context about the ability to achieve to good belt fit, such as opening a heavy coat or adjusting the height adjusters on the B-pillar behind the windows, were also presented.
- Keyword:
- Safety, Seatbelt Fit, Intervention, and Evaluation
- Citation to related publication:
- Jones, M.L.H., Ebert, S.M., Buckley, L., Park, J., and Reed, M.P. (2016). Evaluating an Intervention to Improve Belt Fit for Drivers. Technical Report UMTRI 2016-12. University of Michigan Transportation Research Institute, Ann Arbor, MI. , Reed, M.P., Ebert-Hamilton, S.M. and Rupp, J.D. (2012). Effects of obesity on seat belt fit. Traffic Injury Prevention, 13(4):364-372. https://doi.org/10.1080/15389588.2012.659363, Reed, M.P., Ebert, S.M. and Hallman, J.J. (2013). Effects of driver characteristics on seat belt fit. Stapp Car Crash Journal, 57:43-57. https://pubmed.ncbi.nlm.nih.gov/24435726/, and Jones, M.L.H., Ebert, S.M., and Reed, M.P. (2015). Effects of High Levels of Obesity on Driver Seat Belt Fit. Advancing Transportation Leadership and Safety Technical Report ATLAS-2015-016. University of Michigan Transportation Research Institute, Ann Arbor, MI. https://trid.trb.org/view/1427384 http://www.atlas-center.org/wp-content/uploads/2015/08/ATLAS-Final-Report-ATLAS-2016-15.pdf
- Discipline:
- Engineering
-
- Creator:
- Piette, John and Abbott, Patricia A
- Description:
- Contained within is a subset of the larger dataset collected in La Paz, Bolivia in 2014. This data contains the analytic dataset (cross-sectional/descriptive) that includs the PACIC, Morisky, PHQ8, AUDIT, and a subset of socidemographic characteristics for NCD patients in La Paz.
- Keyword:
- Global Health, Bolivia, and Non-communicable disease
- Discipline:
- Health Sciences
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- Creator:
- Lumeng, Julie C
- Description:
- Healthy full-term infants were enrolled in a longitudinal study designed to examine the development of infant eating behavior. Infant weight and length was measured, mothers completed questionnaires regarding infant eating behaviors, and infant capacity for regulation of energy intake was evaluated by comparing intake between two days: one with feedings given on demand and one with feedings offered hourly. The infant's ability to downregulate intake in response to more frequent feedings was calculated.
- Keyword:
- infant, eating, weight gain, feeding, and energy regulation
- Citation to related publication:
- Reynolds, L. A., McCaffery, H., Appugliese, D., Kaciroti, N. A., Miller, A. L., Rosenblum, K. L., ... & Lumeng, J. C. (2023). Capacity for Regulation of Energy Intake in Infancy. JAMA pediatrics, 177(6), 590-598.
- Discipline:
- Health Sciences
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- Creator:
- Lumeng, Julie C
- Description:
- Healthy full-term infants were enrolled in a longitudinal study designed to examine the development of infant eating behavior. Infant weight and length was measured, mothers completed questionnaires regarding infant eating behaviors, and infant sucking behavior was quantified using the NFANT device during a typical feeding. The predictive value of the NFANT-generated sucking metrics for infant weight gain was evaluated.
- Keyword:
- infant, eating, weight gain, and sucking
- Citation to related publication:
- Feldman, Keith, Katharine Asta, Ashley N. Gearhardt, Julie M. Sturza, Danielle Appugliese, Alison L. Miller, Katherine Rosenblum, Kai Ling Kong, Amanda K. Crandall, and Julie C. Lumeng. "Characterization of a Vigorous sucking style in early infancy and its predictive value for weight gain and eating behaviors at 12 months." Appetite (2023): 106525.
- Discipline:
- Health Sciences