383 research outputs found
Improving 3d pedestrian detection for wearable sensor data with 2d human pose
Collisions and safety are important concepts when dealing with urban designs like shared spaces. As pedestrians (especially the elderly and disabled people) are more vulnerable to accidents, realising an intelligent mobility aid to avoid collisions is a direction of research that could improve safety using a wearable device. Also, with the improvements in technologies for visualisation and their capabilities to render 3D virtual content, AR devices could be used to realise virtual infrastructure and virtual traffic systems. Such devices (e.g., Hololens) scan the environment using stereo and ToF (Time-of-Flight) sensors, which in principle can be used to detect surrounding objects, including dynamic agents such as pedestrians. This can be used as basis to predict collisions. To envision an AR device as a safety aid and demonstrate its 3D object detection capability (in particular: pedestrian detection), we propose an improvement to the 3D object detection framework Frustum Pointnet with human pose and apply it on the data from an AR device. Using the data from such a device in an indoor setting, we conducted a comparative study to investigate how high level 2D human pose features in our approach could help to improve the detection performance of orientated 3D pedestrian instances over Frustum Pointnet
Traffic Control Recognition with AN Attention Mechanism Using Speed-Profile and Satellite Imagery Data
Traffic regulators at intersections act as an essential factor that influences traffic flow and, subsequently, the route choices of commuters. A digital map that provides up-to-date traffic control information is beneficial not only for facilitating the commuters’ trips, but also for energy-saving and environmental protection. In this paper, instead of using expensive surveying methods, we propose an automatic way based on a Conditional Variational Autoencoder (CVAE) to recognize traffic regulators, i. e., arm rules at intersections, by leveraging the GPS data collected from vehicles and the satellite imagery retrieved from digital maps, i. e., Google Maps. We apply a Long Short-Term Memory to extract the motion dynamics over a GPS sequence traversed through the intersection. Simultaneously, we build a Convolutional Neural Network (CNN) to extract the grid-based local imagery information associated with each step of the GPS positions. Moreover, a self-attention mechanism is adopted to extract the spatial and temporal features over both the GPS and grid sequences. The extracted temporal and spatial features are then combined for detecting the traffic arm rules. To analyze the performance of our method, we tested it on a GPS dataset collected by driving vehicles in Hannover, a medium-sized German city. Compared to a Random Forest model and an Encoder-Decoder model, our proposed model achieved better results with both accuracy and F1-score of 0.90 for the three-class (arm rules of uncontrolled, traffic light, and priority sign) task. We also carried out ablation studies to further investigate the effectiveness of the GPS input branch, the image input branch, and the self-attention mechanism in our model
Kinetic study on the removal of iron from gold mine tailings by citric acid
Abstract: The Gold mining generates large volumes of tailings, with consequent disposal and environmental problems. Iron tends to react with sulphur to form pyrite and pyrrhotite which then react with rain water forming acid rain. The study focuses on the removal of iron (Fe) from Gold Mine tailings; Fe was leached using citric acid as a leaching reagent. Three parameters which have an effect on the removal of Fe from the gold mine tailings, namely; temperature (25 ÂşC and 50 ÂşC), reagent concentration (0.25 M, 0.5 M, 0.75 M and 1 M) and solid loading ratio (20 %, 30 % and 40 %) were investigated. It was found that the recovery of Fe from gold mine tailings increased with increasing temperature and reagent concentration, but decreased with increasing solid loading ratio. The optimum conditions for the recovery of Fe from gold mine tailings was found to be at a temperature of 50 ÂşC, reagent concentration of 1 M and solid loading of 20 %. Three linear kinetic models were investigated and Prout- Tompkins kinetic model was the best fit yielding linear graphs with the highest R2 values
Removal of manganese from solution using polyamide membrane
Abstract: The work demonstrates the performance of polyamide membrane in the removal of manganese ions from single salt aqueous solution simulating real acid mine drainage. The membrane was tested using a dead-end filtration cell with manganese sulphate was used to prepare a feed solution. The membrane flux and metal rejection was evaluated. Effect of operating parameters such as pH, initial feed concentration and pressure on membrane performance was investigated. The pressure was varied between 10 and 15 bar and it was observed that increasing the pressure increases the membrane flux. Acidic pH conditions contributed to the removal of the contaminate as Mn2+ ions are freely at low pH. The percentage rejection was found to be 63.5 to 77.6 % as concentration is increased from 290 ppm to 321 ppm for a feed solution. The membrane showed satisfactory results in removing metal ions from solution
Practices in scholarly publishing : making sense of rejection
Abstract: In South Africa, criticisms of peer review often hinge on allegations of racism, anti-African attitudes, and viewpoint discrimination. This article discusses the issue of peer-review, and examines these allegations in terms of claims of Western conceptual gatekeeping. Cautions are offered on allegations of exceptionalism, as are some strategies on dealing with the process of peer review
Describing an online co-development process of VAWG prevention intervention activities with young high school learners, in Eastern Cape Province, South Africa
This is the author accepted manuscript. The final version is available from SAGE Publications via the DOI in this record. Evidence suggests that co-developed participatory interventions to prevent violence against women and girls (VAWG) may support behavior change. Yet, adolescents are often excluded from intervention development. Moreover, there remains a gap in understanding if intervention co-development can occur online. Our study explored the feasibility of undertaking an online co-development process for a participatory VAWG prevention intervention. We worked with a small group of high school learners (18–19 years), from the Eastern Cape Province, South Africa. We collected session notes and audio recorded sessions. Adolescents enjoyed the level of autonomy and their depth of involvement in the process. They were eager to be involved, and they appreciated being “heard.” Adolescents found it easy to build rapport online amongst each other, and with the facilitator. There were also challenges, the main one being young people’s, and facilitator’s, histories of didactic communication. Understanding the strengths and limitations of online co-development processes is crucial, to strengthen them.Nelson Mandela UniversitySouth African National Research FoundationSouth African Medical Research CouncilUniversity of Exete
A second polymorph of chlorido(hydroxyÂdiphenylÂphosphane)gold(I)
The title complex, [AuCl{(C6H5)2P(OH)-ÎşP}] or [AuCl(C12H11OP)], contains two independent molÂecules in the asymmetric unit and is a polymorph of a previously reported structure [Hollatz et al. (1999 â–¶) J. Chem. Soc. Dalton Trans. pp. 111–114]. The crystal structure exhibits interÂmolecular Auâ‹ŻAu interÂactions with alternate distances of 3.0112 (3) Å and 3.0375 (2) Å. The Cl—Au—P bond angle varies between different molÂecular units, depending on the degree of influence of the intraÂmolecular the O—Hâ‹ŻCl hydrogen bond; the angle thus varies between negligible distortion from linearity at 179.23 (3)° and more significant distortion at 170.39 (4)°, which differs from the previously reported polymorph in which both these angles are approximately 170°. The Au—Cl [2.3366 (9) and 2.3131 (10)Ă…] and Au—P [2.2304 (10) and 2.2254 (10) Å] bond lengths vary slightly between the two independent molÂecules but overall, the bond lengths are in good agreement with those in the previously reported polymorph
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