Multi-UAV Conflict Resolution with Graph Convolutional Reinforcement Learning

Safety is the primary concern when it comes to air traffic. In-flight safety between Unmanned Aircraft Vehicles (UAVs) is ensured through pairwise separation minima, utilizing conflict detection and resolution methods. Existing methods mainly deal with pairwise conflicts, however, due to an expected increase in traffic density, encounters with more than two UAVs are likely to happen. In this paper, we model multi-UAV conflict resolution as a multiagent reinforcement learning problem. We implement an algorithm based on graph neural networks where cooperative agents can communicate to jointly generate resolution maneuvers. The model is evaluated in scenarios with 3 and 4 present agents. Results show that agents are able to successfully solve the multi-UAV conflicts through a cooperative strategy.

An empirical investigation on the correlation between solar cell cracks and hotspots

In recent years, solar cell cracks have been a topic of interest to industry because of their impact on performance deterioration. Therefore, in this work, we investigate the correlation of four crack modes and their effects on the temperature of the solar cell, well known as hotspot. We divided the crack modes to crack free (mode 1), micro-crack (mode 2), shaded area (mode 3), and breakdown (mode 4). Using a dataset of 12 different solar cell samples, we have found that there are no hotspots detected for a solar cell affected by modes 1 or 2. However, we discovered that the solar cell is likely to have hotspots if affected by crack mode 3 or 4, with an expected increase in the temperature from 25$$^\circ $$ ∘ C to 100$$^\circ $$ ∘ C. Additionally, we have noticed that an increase in the shading ratio in solar cells can cause severe hotspots. For this reason, we observed that the worst-case scenario for a hotspot to develop is at shading ratios of 40% to 60%, with an identified increase in the cell temperature from 25$$^\circ $$ ∘ C to 105$$^\circ $$ ∘ C.

Moving Toward an Age-Friendly University: Survey Process of GSU 50+ Students

The proportion of Georgia’s population that is 60 years and older is growing rapidly. The 2010 U.S. Census Bureau predicted a growth of more than 20% of older adults by the year 2030. Georgia residents who are 62 and older are eligible to take courses at no or little cost at public state colleges. Due to the expected increase in Georgia’s aging population, access to a free university education, and the large number of currently enrolled 62+ students at Georgia State University (GSU), it is crucial that GSU become an Age-Friendly University. During Fall 2019, a survey was distributed to 1046 students aged 50 years plus; 411 completed the survey (39% response rate). This presentation describes the process involved in designing and distributing the survey. Unique aspects of the survey’s development include the cross-generational and interdisciplinary contributions of the student, faculty, affiliates, and staff from GSU’s Gerontology Institute. The goal was to learn more about GSU students 50 years and older by assessing their motivation for attending school, challenges on campus, perceptions of how the university is currently addressing their needs, factors/resources that have helped/are helping them to adjust to school, and the extent to which they experience age discrimination on campus. The long-term goal of the survey is to use this information to direct GSU in becoming an Age-Friendly University.

Regional county-level housing inventory predictions and the effects on hurricane risk

Regional hurricane risk is often assessed assuming a static housing inventory, yet a region’s housing inventory changes continually. Failing to include changes in the built environment in hurricane risk modeling can substantially underestimate expected losses. This study uses publicly available data and a long short-term memory (LSTM) neural network model to forecast the annual number of housing units for each of 1,000 individual counties in the southeastern United States over the next 20 years. When evaluated using testing data, the estimated number of housing units was almost always (97.3 % of the time), no more than one percentage point different than the observed number, predictive errors that are acceptable for most practical purposes. Comparisons suggest the LSTM outperforms ARIMA and simpler linear trend models. The housing unit projections can help facilitate a quantification of changes in future expected losses and other impacts caused by hurricanes. For example, this study finds that if a hurricane with similar characteristics as Hurricane Harvey were to impact southeast Texas in 20 years, the residential property and flood losses would be nearly US$4 billion (38 %) greater due to the expected increase of 1.3 million new housing units (41 %) in the region.

Predicting the impact of low influenza activity in 2020 on population immunity and future influenza season in the United States

BackgroundsThe influenza season of 2020-21 was remarkably low, likely due to implementation of public health preventive measures such as social distancing, mask-wearing, and school closure and due to decreased international travel. This leads to a key public health question: what will happen in the 2021-22 influenza season? To answer this, we developed a multi-season influenza model that accounted for residual immunity from prior infection.MethodWe built a multi-strain, non-age structured compartmental model that captures immunity over multiple influenza seasons. By the end of the influenza season, we sorted the population based on their experience of natural infection and/or vaccination, which determines the susceptibility to influenza infection in the following season. Because the exact parameters of transmission rates and immunity are unknown, we implemented Bayesian calibration against the observed influenza epidemics (influenza hospitalization rates from 2012 to 2020 in the US) to estimate those parameters. In forward projections, we simulated low influenza activity in 2020-21 season by lowering transmission rate by 20%. Compared to the counterfactual case, in which influenza activity remained at the normal level in 2020-21, we estimated the change in the number of hospitalizations in the following seasons with varying level of vaccine uptake and effectiveness. We measured the change in population immunity over time by varying the number of seasons with low influenza activity.ResultWith the low influenza activity in 2020-21, the model estimated 102,000 [95% CI: 57,000-152,000] additional hospitalizations in 2021-22, without change in vaccine uptake and effectiveness. The expected change in hospitalization varied depending on the level of vaccine uptake and effectiveness in the following year. Achieving 50% increase in one of two measures (1.5X vaccine uptake with 1X vaccine efficacy or 1.5X vaccine efficacy with 1X vaccine uptake) was necessary to avert the expected increase in hospitalization in the next influenza season. Otherwise, increases in both measures by 25% averted the expected increase in influenza-hospitalization. If the low influenza activity seasons continue, population immunity would remain low during those seasons, with 48% the population susceptible to influneza infection.ConclusionWe predicted a large compensatory influenza season in 2021-2 due to a light season in 2020-21. However, higher influenza vaccine uptake would reduce this projected increase in influenza.

Climate Change Adaptation Measures in the Irrigation of a Super-Intensive Olive Orchard in the South of Portugal

The south of Portugal is one of the regions that will be most affected by the impacts of climate change (CC), with an expected increase in water scarcity. Irrigated super-intensive olive orchards occupy a large area of the used agricultural surface in the Alentejo region, south of Portugal, making it necessary to adapt this crop to the effects of CC. This study assessed the impacts of CC and defined adaptation measures concerning irrigation management of the super-intensive olive orchard. To compute the crop irrigation requirement (CIR), the soil water balance model ISAREG was combined with climate data relative to the reference period 1971–2000 and to the representative concentration pathways RCP4.5 and RCP8.5 for the periods 2011–2040, 2041–2070, and 2071–2100. The growing degree-days (GDD) approach was used to estimate olive phenology for these CC scenarios. Unchanged irrigation management with an average CIR increase up to 16% in RCP4.5 and 31% in RCP8.5 is expected. By adopting higher levels of water deficit, water savings of up to 22% can be realized. The results showed that the anticipated CIR increase for the CC scenarios can be mitigated through regulated deficit irrigation strategies.

Proteins in Food Systems—Bionanomaterials, Conventional and Unconventional Sources, Functional Properties, and Development Opportunities

Recently, food companies from various European countries have observed increased interest in high-protein food and other products with specific functional properties. This review article intends to present proteins as an increasingly popular ingredient in various food products that frequently draw contemporary consumers’ attention. The study describes the role of conventional, unconventional, and alternative sources of protein in the human body. Furthermore, the study explores proteins’ nutritional value and functional properties, their use in the food industry, and the application of proteins in bionanomaterials. Due to the expected increase in demand for high-protein products, the paper also examines the health benefits and risks of consuming these products, current market trends, and consumer preferences.

Balancing String Instruction in an Instrumental Lab Setting: An Intrinsic Evaluative Case Study

There is an expected increase in the need to provide adequate string-specific training for non-string specialists in the future and for preservice music teachers to develop the requisite pedagogical content knowledge to teach a variety of instruments. A multiyear instrumental lab ensemble university course was designed to help preservice music teachers integrate knowledge and skills in various instrument- and ensemble-specific areas. The purpose of this intrinsic evaluative study was to determine the extent to which the new course was successful toward these aims. Data included interviews of students and instructors, observations of lab classes, and reflective journals of teaching faculty and two external observers. Data were coded and then analyzed using the program goal statements found in the course syllabus. Findings indicated that students considered the lab format more authentic to their teacher preparation than their previous coursework, and that performance and pedagogy skills on secondary instruments elevated more rapidly than anticipated. Recommendations include the need for more explicit connection between course readings and lab activities, and improved guidelines for course teaching assistants.

RT001 in Progressive Supranuclear Palsy—Clinical and In-Vitro Observations

Background: Progressive supranuclear palsy (PSP) is a progressive movement disorder associated with lipid peroxidation and intracerebral accumulation of tau. RT001 is a deuterium reinforced isotopologue of linoleic acid that prevents lipid peroxidation (LPO) through the kinetic isotope effect. Methods: The effects of RT001 pre-treatment on various oxidative and bioenergetic parameters were evaluated in mesenchymal stem cells (MSC) derived from patients with PSP compared to controls. In parallel, 3 patients with PSP were treated with RT001 and followed clinically. Results: MSCs derived from PSP patients had a significantly higher rate of LPO (161.8 ± 8.2% of control; p < 0.001). A 72-h incubation with RT001 restored the PSP MSCs to normal levels. Mitochondrial reactive oxygen species (ROS) overproduction in PSP-MSCs significantly decreased the level of GSH compared to control MSCs (to 56% and 47% of control; p < 0.05). Incubation with RT001 significantly increased level of GSH in PSP MSCs. The level of mitochondrial DNA in the cells was significantly lower in PSP-MSCs (67.5%), compared to control MSCs. Changes in mitochondrial membrane potential, size, and shape were also observed. Three subjects with possible or probable PSP were treated with RT001 for a mean duration of 26 months. The slope of the PSPRS changed from the historical decline of 0.91 points/month to a mean decline of 0.16 points/month (+/−0.23 SEM). The UPDRS slope changed from an expected increase of 0.95 points/month to an average increase in score of 0.28 points/month (+/−0.41 SEM). Conclusions: MSCs derived from patients with PSP have elevated basal levels of LPO, ROS, and mitochondrial dysfunction. These findings are reversed after incubation with RT001. In PSP patients, the progression of disease may be reduced by treatment with RT001.

The Recovery and Concentration of Spodumene Using Dense Media Separation

In coming years, global lithium production is expected to increase as the result of widespread electric vehicle adoption. To meet the expected increase in demand, lithium must be sourced from both brine and hard-rock deposits. Heavy liquid separation (HLS) and dense media separation (DMS) tests were conducted on the pegmatites from Hidden Lake, NWT, Canada to demonstrate the potential role of this technology in the concentration of spodumene (LiAlSi2O6) from hard-rock sources. A continuously operated DMS circuit test, conducted on +840 µm material, produced a concentrate grading 6.11% Li2O with ~50% lithium recovery. The circuit rejected 50% of the original mass to tailings, with only 8% lithium losses. Sensitivity analysis showed that minor changes (+/−0.05) in the DMS-specific gravity cut point resulted in significant changes to the mass rejected and to the concentrate grade produced; this may limit the feasibility and operability of the downstream grinding and flotation circuits. The results demonstrate the potential for DMS in the concentration of spodumene from the Hidden Lake pegmatites, and by extension, the potential for DMS in the concentration of spodumene from other hard-rock occurrences.