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Experiences with Specifications Grading in Computer Engineering: Making Class About Learning Again
No full textStudents and faculty often have differing views about the fundamental reason that students should learn the material presented in university courses. Generally speaking, faculty believe in the material\u27s innate value, while students see it as preparation for a career. Both parties agree learning the material is valuable. However, classes are not frequently constructed to reward learning. Rather, they reward chasing points and earning grades, often at the expense of actual learning. This process doubly disadvantages students, especially when college grades are uncorrelated with future success. They have insufficiently learned critical skills and knowledge while being misled about their chances of future success. By changing how we assess students, we can more explicitly tie outcomes to learning objectives, reduce faculty grading time, reduce student stress, and return a focus to learning while maintaining rigorous academic standards. This change is not just a theoretical concept but a practical step that faculty can take to improve the learning environment. One form of assessment in this vein is specifications (or specs ) grading. In specs grading, all assignments are graded pass/fail according to a rubric closely coupled to the course\u27s learning objectives. Opportunities exist for students to rework assignments, including reflecting on how they missed the mark the first time, with the reflection process cementing the learned (or relearned) material. Bundling assignments throughout the semester provides a mechanism to assign a student\u27s final grade. This paper describes the process of implementing specifications grading in a medium-sized, junior-level computer engineering course, including the difficulties, mistakes, and successes encountered. Student evaluations are presented, showing a high level of satisfaction with the grading scheme and reinforcing how a reprieve from chasing points has allowed them to focus on the course material. Grade distributions from traditional points-based grading are compared with the outcomes from specs grading to show how academic standards have not been relaxed. Recommendations for faculty members interested in experimenting with specs grading are presented
Multimodal Object Detection Using Depth and Image Data for Manufacturing Parts
No full textManufacturing requires reliable object detection methods for precise picking and handling of diverse types of manufacturing parts and components. Traditional object detection methods utilize either only 2D images from cameras or 3D data from lidars or similar 3D sensors. However, each of these sensors have weaknesses and limitations. Cameras do not have depth perception and 3D sensors typically do not carry color information. These weaknesses can undermine the reliability and robustness of industrial manufacturing systems. To address these challenges, this work proposes a multi-sensor system combining an red-green-blue (RGB) camera and a 3D point cloud sensor. The two sensors are calibrated for precise alignment of the multimodal data captured from the two hardware devices. A novel multimodal object detection method is developed to process both RGB and depth data. This object detector is based on the Faster R-CNN baseline that was originally designed to process only camera images. The results show that the multimodal model significantly outperforms the depth-only and RGB-only baselines on established object detection metrics. More specifically, the multimodal model improves mAP by 13% and raises Mean Precision by 11.8% in comparison to the RGB-only baseline. Compared to the depth-only baseline, it improves mAP by 78% and raises Mean Precision by 57%. Hence, this method facilitates more reliable and robust object detection in service to smart manufacturing applications
Exploration of Electrochemical Hydrogen Pumping with Ultralow Feed Concentration Down to 1 ppm
No full textElectrochemical H2 pumping with ultralow H2 concentrations (such as 1–10 ppm) was experimentally demonstrated for prominent current response (0.42–3.1 µA), under a low cell voltage at a high flow rate, supported by Multiphysics simulation. The findings in this work may extend the application of H2 pumping to H2 detection and other advanced electrochemical systems
Predictors of lower-limb arterial occlusion pressure across commonly used cuff widths
Get PDFWe compared predictors of lower-limb arterial occlusion pressure (AOP) across commonly used blood flow restriction (BFR) cuff widths (11, 13, 18 cm) and developed prediction equations to estimate AOP for each cuff. Participants (n = 116) underwent measurements of thigh circumference (TC), systolic (SBP) and diastolic (DBP) blood pressure, and AOP was assessed using Doppler ultrasound in a seated position. Multiple linear regression models with commonality analysis and mixed-effects models were used to identify and compare predictors of AOP between each cuff. LASSO regression with bootstrap resampling was used to develop and internally validate prediction equations. TC, SBP, DBP, age, and sex explained 60%–70% of total variance in AOP, with greater predictive power in narrower cuffs. As cuff width increased, TC uniquely accounted for less (36%, 26%, 11% for 11, 13, 18 cm, respectively) and SBP uniquely accounted for more (2%, 6%, 12% for 11, 13, 18 cm, respectively) variance. A cuff width × TC interaction indicated that limb size had greater influence on AOP with narrower cuffs. In contrast, the relationship between SBP and AOP remained stable across cuff widths. Prediction equations demonstrated good predictability and calibration, with limits of agreement ranging from ±18.4 to ±28.6 mmHg and statistical equivalence between predicted and measured AOP. Internal validation showed minimal overfitting. These findings highlight the importance of accounting for cuff width in BFR pressure prescription, with narrower cuffs requiring consideration primarily of TC, and wider cuffs requiring consideration of both TC and SBP. These cuff-specific equations may offer a practical alternative to direct AOP measurement
Durability and skid resistance of high friction surface treatments with modified epoxy resin: Experimental characterization
No full textHigh Friction Surface Treatment (HFST) has emerged as an advanced road surface maintenance material due to its excellent performance and ease of application. This study investigates the durability of High Friction Surface (HFS) materials prepared with different epoxy resin binders and explores their skid resistance based on differential polishing principles. Accelerated wear tests were conducted on HFS specimens made with three different epoxy binders to examine aggregate loss over prolonged polishing. It was observed that the HFS aggregates prepared with modified epoxy resin binders exhibited the lowest aggregate loss of 5.84 % and 10.76 %, while those prepared with unmodified epoxy resin binders showed significantly higher aggregate loss compared to the experimental group. This indicates that the modified epoxy binder system has effectively enhanced its toughness and adhesive properties. Furthermore, weather resistance was evaluated through freeze-thaw cycle tests and UV aging tests, revealing that HFS prepared with modified epoxy resin binders exhibited the smallest reduction of 14.41 % in bonding performance, whereas HFS prepared with unmodified binders nearly lost their service functionality. Lastly, dynamic friction coefficient tests were performed on the post-polishing samples to assess their skid resistance durability. The results indicated that HFS made with blended aggregates and modified epoxy resin binders is more cost-effective and provides better skid resistance. Therefore, HFS prepared with modified epoxy resins demonstrates superior durability
A state-of-the-art review of asphalt aging behavior at macro, micro, and molecular scales
No full textThis paper provides an exhaustive examination of asphalt aging behavior at macro, micro, and molecular scales, incorporating a survey of pertinent literature on diverse aging tests, SARA (Saturates, Aromatics, Resins, and Asphaltenes) analysis, alterations in asphalt properties post-aging, asphalt aging kinetics, the incorporation of modifiers to augment anti-aging attributes, and the application of microscopic analysis and molecular simulation methods in studying asphalt aging. Research shows that aging increases asphalt viscosity, softening point, complex shear modulus, and creep stiffness while reducing penetration, phase angle, ductility, and creep rate. Also, aging induces structural changes in asphalt, forming ketone and sulfoxide groups, altering surface properties, and modifying molecular size. The paper also explores inconclusive or controversial areas in this field, like ultraviolet aging settings, lab-field aging correspondence, SARA ratio shifts, asphalt-aggregate adhesion change, glass transition temperature alteration, aging kinetics, empirical aged asphalt molecular models, ReaxFF simulations, and quantum mechanics studies, offering valuable insights for further research of asphalt aging
Supporting Wildlife Restoration in Eastern States via State Wildlife Action Plans
Get PDFThe biodiversity crisis is driven by extinction at two scales: the global extinction of species and the local extirpation of populations (i.e., range contraction). Local extirpations are especially acute in the eastern United States, which has lost a substantial portion of its native mammalian fauna. Species restoration in the U.S., therefore, should be utilised more to revitalise and restore degraded systems. State wildlife agencies can elevate discussions about species restoration and facilitate internal capacity to conduct restoration projects by including locally extirpated species in State Wildlife Action Plans, which are currently under revision, and will guide state conservation programs for the next 10 years
Effects of chronic metal exposure and metamorphosis on the microbiomes of larval and adult insects and riparian spiders through the aquatic-riparian food web
Get PDFThe macroinvertebrate microbiome controls various aspects of the host\u27s physiology, from regulation of environmental contaminants to reproductive output. Aquatic insects provide critical nutritional subsidies linking aquatic and riparian food webs while simultaneously serving as a contaminant pathway for riparian insectivores in polluted ecosystems. Previous studies have characterized the transport and transfer of contaminants from aquatic to riparian ecosystems through insect metamorphosis, but both contaminant exposure and metamorphosis are energetically intensive processes that may cause host microbiomes to undergo radical transformation in structure and function, potentially affecting the host\u27s physiology. We collected arthropods from three sites within Torch Lake, a historical copper mine in the Keweenaw Peninsula, Michigan, USA, and three sites within a nearby reference lake. Our objectives were to: 1) characterize the variation in microbiome communities and predicted metagenomic functions with legacy copper mining activity across space, among host types and family-level host taxonomy, 2) characterize how insect metamorphosis alters the microbiome community, including the degree of endosymbiotic infection, and predicted metagenomic function. We field-collected organisms, extracted their DNA, and sequenced the 16S region of the rRNA gene to characterize microbiome communities, then predicted metagenomic function. Site, lake, and host taxonomy affected the host microbiome community composition. Copper exposure increased the abundance of xenobiotic and lipid metabolism pathways in the Araneidae spider microbiome. Insect metamorphosis reduced the alpha diversity, altered the community composition, and predicted metagenomic function. We observed a bioconcentration of endosymbiotic bacteria in adult insects, especially holometabolous insects. Through metamorphosis, we observed a transition in function from xenobiotic degradation pathways to carbohydrate metabolism. Overall, contaminant exposure alters the microbiome composition in aquatic insects and riparian spiders and alters the function of the microbiome across the aquatic-riparian interface. Furthermore, metamorphosis is a critical element in shaping the aquatic insect microbiome across its life history
Forecasting for ESCAPE: A Multi-Institution Hybrid Forecasting and Nowcasting Operation for Sea-Breeze Convection Supporting a Ground-Based and Airborne Field Campaign
No full textThe Experiment of Sea-Breeze Convection, Aerosols, Precipitation and Environment (ESCAPE) field project deployed two aircraft and ground-based assets in the vicinity of Houston, Texas, between 27 May and 2 July 2022, examining how meteorological conditions, dynamics, and aerosols control the initiation, early growth stage, and evolution of coastal convective clouds. To ensure that airborne- and ground-based assets were deployed appropriately, a forecasting and nowcasting team was formed. Daily forecasts guided real-time decision-making by assessing synoptic weather conditions, environmental aerosol, and a variety of atmospheric modeling data to assign a probability for meeting specific ESCAPE campaign objectives. During the research flights, a small team of forecasters provided “nowcasting” support by analyzing radar, satellite, and new model data in real time. The nowcasting team proved invaluable to the campaign operation, as sometimes changing environmental conditions affected, for example, the timing of convective initiation. In addition to the success of the forecasting and nowcasting teams, the ESCAPE campaign offered a unique “testbed” opportunity where in-person and virtual support both contributed to campaign objectives. The forecasting and nowcasting teams were each composed of new and experienced forecasters alike, where new forecasters were given invaluable experience that would otherwise be difficult to attain. Both teams received training on forecast models, map analysis, Hybrid Single-Particle Lagrangian Integrated Trajectory model (HYSPLIT), and thermodynamic sounding analysis before the beginning of the campaign. In this article, the ESCAPE forecasting and nowcasting teams reflect on these experiences, providing potentially useful advice for future field campaigns requiring forecasting and nowcasting support in a hybrid virtual/in-person framework
Accelerated dermal wound healing in diabetic mice by a H2O2-generating catechol-functionalized gelatin microgel
No full textPhysically crosslinked gelatin microgels were functionalized with a bioadhesive molecule, catechol, to study the effect of in situ generated H2O2 on full-thickness wound repair in diabetic mice. Due to the physically crosslinked nature of the microgels, they transition into a hydrogel film upon hydration. The formation of a hydrogel film was confirmed by the changes in their morphology and viscoelastic properties. Additionally, these microgels released up to 86 μM of H2O2 as a result of catechol autoxidation. The generated H2O2 completely eradicated Staphylococcus epidermidis with an initial concentration of 103 CFU mL−1. These microgels were not cytotoxic and promoted VEGF upregulation in immortalized human keratinocytes (HaCaT) in vitro. When the microgels were applied to a full-thickness dermal wound in diabetic mice, dermal wound closure was accelerated over 14 days, achieving a wound closure of 90% based on the wound area. Microgel-treated wounds also resulted in complete re-epithelialization and regeneration of new dermal tissues with morphology and structure resembling those of native tissues. These results indicate that the release of micromolar concentrations of H2O2 can accelerate wound healing in a healing-impaired animal