3D-UGCN: A Unified Graph Convolutional Network for Robust 3D Human Pose Estimation from Monocular RGB Images

Human pose estimation remains a multifaceted challenge in computer vision, pivotal across diverse domains such as behavior recognition, human-computer interaction, and pedestrian tracking. This paper proposes an improved method based on the spatial-temporal graph convolution net-work (UGCN) to address the issue of missing human posture skeleton sequences in single-view videos. We present the improved UGCN, which allows the network to process 3D human pose data and improves the 3D human pose skeleton sequence, thereby resolving the occlusion issue.Proceedings of IEEE AICON202

Anthropogenic Impacts on Air Pollution - From Primary Marine Emissions to Secondary Organic Aerosol Formation

Anthropogenic air pollution consists of primary and secondary pollutants resulted from human activities. It is related to different environmental and health issues such as climate change, visibility and respiratory diseases.The maritime transport is an important source of anthropogenic primary air pollution. Natural gas (NG) vessels have become more widely used due to the more stringent emission regulations; however, emission data from NG maritime operations is still limited. This thesis conducted a comprehensive analysis on the air quality, health effects and climate change impacts of switching from diesel to NG. Results showed that PM2.5, NOx, CO2 were reduced by about 93%, 92% and 18%, respectively. However, HCHO and CH4 increased several-fold. A health risk assessment showed the diesel plume increased long-term health risk and the NG plume increased short-term health risk. A global warming potential (GWP) analysis was performed and revealed that the average NG exhaust GWP was increased by 38%. Mitigation strategies for further reducing pollutants from NG exhaust are discussed and showed potential for reducing short-term health and climate impacts.Anthropogenic secondary organic aerosol (SOA) is formed from the oxidation of volatile organic compounds (VOCs) such as aromatics and is critically impacted by NOx. Global transport models use the SOA parameters from the two major chemical pathways, RO2+NO and RO2+HO2 and the branching ratio of RO2+NO pathway (β), to predict SOA formation. This thesis attempted to improve the model prediction by experimentally investigating the SOA formation from those pathways with a novel approach of maintaining β constant throughout chamber experiments. At low-NOx conditions, multiple SOA yield curves were observed. The yield increased with HO2/RO¬2, indicating the contribution of RO2+RO2 pathway. The GEOS-Chem model showed that for the regions with high aromatic emissions but lower HO2/RO¬2, aromatic SOA was overestimated by up to 100%. At high-NOx conditions, SOA parameters were developed when controlling β at one during the chamber experiments to simulate the RO2+NO pathway without significant contribution from the other pathways. The global surface β was modelled using GEOS-Chem and four β scenarios were observed. SOA formation was investigated when simulating the daytime β profiles for those scenarios

Secondary Organic and Inorganic Aerosol Formation from a GDI Vehicle under Different Driving Conditions

This study investigated the primary emissions and secondary aerosol formation from a gasoline direct injection (GDI) passenger car when operated over different legislative and real-world driving cycles on a chassis dynamometer. Diluted vehicle exhaust was photooxidized in a 30 m3 environmental chamber. Results showed elevated gaseous and particulate emissions for the cold-start cycles and higher secondary organic aerosol (SOA) formation, suggesting that cold-start condition will generate higher concentrations of SOA precursors. Total secondary aerosol mass exceeded primary PM emissions and was dominated by inorganic aerosol (ammonium and nitrate) for all driving cycles. Further chamber experiments in high temperature conditions verified that more ammonium nitrate nucleates to form new particles, forming a secondary peak in particle size distribution instead of condensing to black carbon particles. The results of this study revealed that the absorption of radiation by black carbon particles can lead to changes in secondary ammonium nitrate formation. Our work indicates the potential formation of new ammonium nitrate particles during low temperature conditions favored by the tailpipe ammonia and nitrogen oxide emissions from gasoline vehicles

Surface Reconstruction for Interactive Modeling of Freeform Solids by Virtual Sculpting

This paper presents a new method for surface reconstruction from dexel data for virtual sculpting. This is part of our research efforts to develop a dexel model based sculpting system with the capability of interactive solid modeling with haptics interface. Dexel data are converted to a series of planar contours in parallel slices (i.e. cross sections). Then triangular meshes are created by connecting the contour points in adjacent slices. Examples are given to demonstrate the ability of the described method to convert from dexel data to triangular meshes for the viewing of a sculpted model in different directions

Freeform Modelling Using Sweep Differential Equation with Haptic Interface

This paper presents the development of a virtual sculpting system and addresses the issues of interactive freeform solid modelling with haptic interface. A virtual reality (VR) approach is taken to make the developed system more intuitive and interactive. The virtual sculpting method is based on the metaphor of carving a primitive or imported solid model into a 3D freeform object. The geometric modelling is based on the sweep differential equation method to compute the boundary of the tool swept volume. The ray-casting method is used to perform Boolean operations to simulate the sculpting process. A new method of surface reconstruction from dexel data is presented. The PHANToM™ manipulator is used to provide the position and orientation data of the sculpting tool and also to provide haptic sensation to the user hand during the sculpting. An accuracy analysis is performed to determine the limitations on the sculpted geometric details

Carbon Dot Functionalized Papers for the Selective Detection of 2,4,6-Trinitrophenol in Aqueous Solutions

The development of probes for the testing of the carcinogenic pollutant 2,4,6-trinitrophenol (TNP) is of great importance for environmental protection and human health. In this paper, a new rapid and sensitive fluorescence detection method based on carbon dots (CDs) was designed for the detection of TNP. The CDs were synthesized by simple pyrolysis using citric acid as raw material and characterized by various advanced techniques. The addition of TNP caused a significant turn off in the fluorescence of the CDs. The fluorescence quench intensity and TNP concentration exhibited a good linear correlation in the range of 0–80 μM with a minimum detection limit of 0.48 μM and a related coefficient of 0.994. The analytical method was applied to the determination of trace TNP in river water and tap water with recoveries in the range of 98%–110% and relative standard deviations less than 5%. Importantly, carbon dots functionalized papers (CDFPs) were prepared using the synthesized CDs and successfully applied to the determination of TNP in aqueous solutions, demonstrating the promising application of the method