Alabama Department of Commerce

This paper introduces an acoustic sensing-based speeding up and slowing down (SU-SD) algorithm for a fleet of underwater robots. Each robot transmits a series of acoustic pulses from a single transducer according to a pre-defined schedule. In a bi-static setup, all robots receive acoustic signals via a hydrophone array for navigation and coordination. Robots estimate angles of arrival from their neighbors through beam-forming techniques. Ranging is achieved by measuring the one-way travel time via the matched-filtering process. Each robot adjusts its number of transmitted pulses based on the quantization level of its measurement. This approach enables decentralized operation, with robots independently analyzing acoustic signals. Velocity adjustments are made based on variations in the number of acoustic pulses detected. Swarm cohesion is maintained through relative acoustic ranging between neighboring agents. Unlike the original SU-SD implementations that rely on global information exchange, our approach uses solely acoustic sensing for both relative localization and inter-robot spacing. Computer simulations using our developed software package, muNet-AUVSim, evaluate the algorithm with detailed vehicle dynamics and hydrodynamic damping models in ocean-like conditions. A group of five autonomous underwater vehicles (AUVs) is tested in source localization of a pollution plume under varying SUSD algorithm parameters. Results demonstrate that the swarms effectively converge on pollution sources while maintaining formation stability.

Many students struggle when they are first learning to program. Without help, these students can lose confidence and negatively assess their programming ability, which can ultimately lead to dropouts. However, detecting the exact moment of student struggle is still an open question in computing education. In this work, we conducted a think-aloud study with five high-school students to investigate the automatic detection of progressing and struggling moments using a detector algorithm (SPD). SPD classifies student trace logs into moments of struggle and progress based on their similarity to prior students' correct solutions. We explored the extent to which the SPD-identified moments of struggle aligned with expert-identified moments based on novices' verbalized thoughts and programming actions. Our analysis results suggest that SPD can catch students' struggling and progressing moments with a 72.5% F1-score, but room remains for improvement in detecting struggle. Moreover, we conducted an in-depth examination to discover why discrepancies arose between expert-identified and detector-identified struggle moments. We conclude with recommendations for future data-driven struggle detection systems.

Introduction The opioid epidemic disproportionately impacts different regions in the United States (US). Unfortunately, organ donations from drug overdose (DO) now account for a significant proportion of donors. This study seeks to understand the regional variation in donations after DO and quantify the proportion of DO deaths that go on to become organ donors in the US. Materials and Methods We analyzed data from the Organ Procurement and Transplantation Network (OPTN) as of November 10, 2017 that included deceased donors with DO as reported mechanism of death who donated at least one transplanted organ between January 1, 2000 and December 31, 2016. Only donors that had data from mechanism of death were reported. National mortality data was obtained from the National Center for Health Statistics from the Centers for Disease Control and Prevention (CDC) online mortality database. Results and Discussion Drug overdose has increased at an alarming rate; among those donors with a reported cause of death, DO accounted for 1.1% of donors in 2000 compared to 12.7% in 2016 (Figure 1). State age-adjusted mortality rates for DO in 2015 (from CDC data) correlate with OPTN regions with the highest percentage of donors from DO (Figures 2 and 3). However, high mortality rates do not correlate with the percentage of all DO deaths that become organ donors (Figure 4). Despite 28.2% of drug overdose deaths occurring in health care facilities in the US in 2015, only 1.62% become organ donors. The region with the highest percentage of deaths that become donors (2.36% Region 8 in the Midwestern US) has one of the lowest mortality rates; furthermore Region 8 had over two-fold the DO donation rate as Region 4 (1.03% in Texas/Oklahoma). A mean of 0.05 organs were transplanted for each drug overdose death in the US in 2015, a mean of 0.17 organs were transplanted for each overdose death in a medical facility. Conclusion The opioid epidemic is a serious and growing problem in the United States; perhaps the only silver lining in this tragic loss of life is the gift of organ donation. Though regions with the highest mortality from drug overdose have the largest proportion of donors, mortality rate does not correlate with the percentage of drug intoxication deaths that eventually become donors. More research is needed to understand the observed regional variation and barriers to maximizing donation after death from drug overdose.

Balloon catheter dilation (BCD) of the paranasal sinuses is increasingly described as a standalone procedure in the office for minimally invasive treatment of patients with chronic rhinosinusitis (CRS). This study evaluates CRS-related healthcare utilization before and after in-office treatment as performed by otolaryngologists within the United States in an all-comer population. Retrospective claims database analysis. The MarketScan database was queried for patients undergoing BCD (Current Procedural Terminology [CPT] 31295-31297) for CRS (International Classification of Diseases Ninth Edition [ICD-9] 473.x) since 2011 in the office (place of service: 11). Exclusion criteria included < 1 year preoperative enrollment, < 6 months postoperative history, and concurrent (± 30 days) endoscopic sinus surgery (CPT 31254-31288). A cohort of 628 patients was identified. Analyses included preoperative comorbidities and CRS-related healthcare use. Preoperative comorbidities included asthma (29.0%), polyps (11.5%), and aspirin sensitivity (9.9%). An average of 3.0 sinuses (95% confidence interval: 2.91-3.17) were dilated at index. Maxillary, frontal, and sphenoid dilations were performed in 88.9%, 74.5%, and 33.8% of cases, respectively. There were two orbital complications and seven cases of hemorrhage potentially associated with the procedure, but no postoperative cerebrospinal fluid leaks. No blood transfusion, lateral canthotomy, or canthoplasty were reported. CRS-related postoperative healthcare use declined rapidly from the immediate preoperative state. Twenty-one patients underwent revisions, with one patient undergoing two surgeries for a total of 22 reoperations (3.5%). In-office BCD is associated with low risks of complications and revisions. Whereas not significant for patients with polyps, decreases in healthcare utilization pre- to postsurgery were significant for patients without polyps.

We describe a Fourier-based method of separating bars from spirals in near-infrared images. The method takes advantage of the fact that a bar is typically a feature with a relatively fixed position angle, and uses the simple assumption that the relative Fourier amplitudes due to the bar decline with radius past a maximum in the same or a similar manner as they rose to that maximum. With such an assumption, the bar can be extrapolated into the spiral region and removed from an image, leaving just the spiral and the axisymmetric background disk light. The procedure allows us to estimate the maximum gravitational torque per unit mass per unit square of the circular speed for the bar and spiral forcing separately, parameters which quantitatively define the bar strength Q_b and the spiral strength Q_s following the recent study of Buta & Block. We outline the complete procedure here using a 2.1 micron image of NGC 6951, a prototypical SAB(rs)bc spiral. We justify our assumption on how to make the bar extrapolation using an analysis of NGC 4394, a barred spiral with only weak near-infrared spiral structure, and we justify the number of needed Fourier terms using NGC 1530, one of the most strongly-barred galaxies (bar class 7) known. We also evaluate the main uncertainties in the technique. Allowing for uncertainties in vertical scaleheight, bar extrapolation, sky subtraction, orientation parameters, and the asymmetry in the spiral arms themselves, we estimate Q_b=0.28\pm0.04 and Q_s=0.21\pm0.06 for NGC 6951. (abridged)