UniFolding: Towards Sample-efficient, Scalable, and Generalizable Robotic Garment Folding

This paper explores the development of UniFolding, a sample-efficient, scalable, and generalizable robotic system for unfolding and folding various garments. UniFolding employs the proposed UFONet neural network to integrate unfolding and folding decisions into a single policy model that is adaptable to different garment types and states. The design of UniFolding is based on a garment's partial point cloud, which aids in generalization and reduces sensitivity to variations in texture and shape. The training pipeline prioritizes low-cost, sample-efficient data collection. Training data is collected via a human-centric process with offline and online stages. The offline stage involves human unfolding and folding actions via Virtual Reality, while the online stage utilizes human-in-the-loop learning to fine-tune the model in a real-world setting. The system is tested on two garment types: long-sleeve and short-sleeve shirts. Performance is evaluated on 20 shirts with significant variations in textures, shapes, and materials. More experiments and videos can be found in the supplementary materials and on the website: https://unifolding.robotflow.aiComment: CoRL 202

Experimental study of dynamic characteristics of an ultra-large jacket offshore wind turbine under wind and wave loads using aero-hydro-structural elastic similarities

Owing to the difficulties in the scaled rotor-nacelle assembly (RNA) and support structure design, and alleviation of small scaling effects, the limited dynamic model tests are conducted for the jacket offshore wind turbines (OWTs), which are extensively constructed in the offshore wind farms located in the depth of 40–50 m. To address this limitation, an integrated test method based on aero-hydro-structural elastic similarities is proposed in this study. It comprises a performance-scaled RNA model and a scaled support structure model. A redesigned blade model is adopted in the scaled RNA model to ensure the similarities of aerodynamic thrust loads without modifications of the scaled test winds. Moreover, auxiliary scaled drivetrain and blade pitch control are designed to simulate the operational states of a practical OWT. The scaled model of the OWT support structure is fabricated based on the joint hydro-structural elastic similarity, and the small scaling effects are mitigated by introducing sectional bending stiffness similarities. Subsequently, the dynamic model tests of an ultra-large jacket OWT under wind-only, wave-only, and combined wind and wave conditions are carried out. The accuracy of the fabricated OWT test model is validated based on the recorded responses, and the influence of the dominant frequencies on the dynamic responses of the OWT model is quantitatively evaluated using the wavelet packet-based energy analysis method. Further, the coupling mechanisms of the scaled OWT model under typical wind and wave loads are investigated, and the interactions between the environmental loads and OWT motions are proved

Experimental Study of Ultra-Large Jacket Offshore Wind Turbine under Different Operational States Based on Joint Aero-Hydro-Structural Elastic Similarities

The jacket substructure is generalized for offshore wind farms in the southeastern offshore regions of China. The dynamic characteristics and coupling mechanisms of jacket offshore wind turbines (OWTs) have been extensively investigated using numerical simulation tools. However, limited dynamic model tests have been designed and performed for such types of OWTs. Therefore, the coupling mechanisms of jacket OWTs that are determined using numerical methods require further validation based on experimental tests. Accordingly, an integrated scaled jacket OWT physical test model is designed in this study. It consists of a scaled rotor nacelle assembly (RNA) and support structure model. For the scaled RNA model, a redesigned blade model is adopted to ensure the similarity of the aerodynamic thrust loads without modifying the scaled test winds. Auxiliary scaled drivetrain and blade pitch control system models are designed to simulate the operational states of a practical OWT. The scaled model of the OWT support structure is fabricated on the basis of the joint hydro-structural elastic similarities. A sensor arrangement involving a three-component load cell and acceleration sensors is used to record the OWT thrust loads and model motions, respectively. Then, dynamic model tests under typical scaled wind fields are implemented. Furthermore, the coupling mechanisms of the OWT model under various test winds are investigated using the wavelet packet method, and the influences of inflow winds, operational states, and mechanical strategies are introduced

Assessment of the Sustainable Utilization Level of Water Resources in the Wuhan Metropolitan Area Based on a Three-Dimensional Water Ecological Footprint Model

The shortage and overexploitation of water resources restrict the sustainable development of metropolitan areas. To evaluate the sustainable utilization level of water resources, we identified the occupancy of natural capital stock and the consumption of natural capital flow by water resources consumption and analyzed the factors influencing water resources consumption in metropolitan area development. We took the Wuhan Metropolitan Area in China from 2010 to 2019 as the research object and introduced footprint depth and size, the water ecological footprint (WEF) model was expanded into the three-dimensional WEF model. Based on this model, an evaluation system for the sustainable utilization level of water resources was constructed with five indices—water ecological deficit, water ecological surplus, water ecological pressure, WEF depth, and WEF size. Finally, the driving factors of WEF change were analyzed using the Logarithmic Mean Divisia Index. The evaluation of the sustainable utilization level of water resources showed that the Wuhan Metropolitan Area as a whole experienced water ecological surplus from 2010 to 2019, but there were different degrees of water ecological deficit in its inner urban areas, and the most serious cumulative deficit was 5.02 ha/cap in Ezhou. In 2011 and 2019, the sustainable utilization level of water resources in the metropolitan area reached a relatively unsustainable state. Xianning was the urban area with the most sustainable utilization level of water resources. During the study period, the metropolitan area did not occupy the natural capital stock of water resources, and the natural capital flow of water resources in the inner urban areas could meet the demand of the current consumption of the region in 2010 and 2016. The analysis of the driving factors of WEF change showed that economic development effect and population pressure effect had a positive driving effect on WEF change, while WEF intensity effect and water resources carrying capacity effect had the opposite effect. Finally, according to the research results, it can be seen that improving the efficiency of water resources utilization, protecting the natural capital stock of water resources, realizing differentiated regional development through the market economy and developing water policy can be helpful to improve the level of sustainable water resources utilization

Assessment of the Sustainable Utilization Level of Water Resources in the Wuhan Metropolitan Area Based on a Three-Dimensional Water Ecological Footprint Model

The shortage and overexploitation of water resources restrict the sustainable development of metropolitan areas. To evaluate the sustainable utilization level of water resources, we identified the occupancy of natural capital stock and the consumption of natural capital flow by water resources consumption and analyzed the factors influencing water resources consumption in metropolitan area development. We took the Wuhan Metropolitan Area in China from 2010 to 2019 as the research object and introduced footprint depth and size, the water ecological footprint (WEF) model was expanded into the three-dimensional WEF model. Based on this model, an evaluation system for the sustainable utilization level of water resources was constructed with five indices—water ecological deficit, water ecological surplus, water ecological pressure, WEF depth, and WEF size. Finally, the driving factors of WEF change were analyzed using the Logarithmic Mean Divisia Index. The evaluation of the sustainable utilization level of water resources showed that the Wuhan Metropolitan Area as a whole experienced water ecological surplus from 2010 to 2019, but there were different degrees of water ecological deficit in its inner urban areas, and the most serious cumulative deficit was 5.02 ha/cap in Ezhou. In 2011 and 2019, the sustainable utilization level of water resources in the metropolitan area reached a relatively unsustainable state. Xianning was the urban area with the most sustainable utilization level of water resources. During the study period, the metropolitan area did not occupy the natural capital stock of water resources, and the natural capital flow of water resources in the inner urban areas could meet the demand of the current consumption of the region in 2010 and 2016. The analysis of the driving factors of WEF change showed that economic development effect and population pressure effect had a positive driving effect on WEF change, while WEF intensity effect and water resources carrying capacity effect had the opposite effect. Finally, according to the research results, it can be seen that improving the efficiency of water resources utilization, protecting the natural capital stock of water resources, realizing differentiated regional development through the market economy and developing water policy can be helpful to improve the level of sustainable water resources utilization

DoSDefender: A Kernel-Mode TCP DoS Prevention in Software-Defined Networking

The limited computation resource of the centralized controller and communication bandwidth between the control and data planes become the bottleneck in forwarding the packets in Software-Defined Networking (SDN). Denial of Service (DoS) attacks based on Transmission Control Protocol (TCP) can exhaust the resources of the control plane and overload the infrastructure of SDN networks. To mitigate TCP DoS attacks, DoSDefender is proposed as an efficient kernel-mode TCP DoS prevention framework in the data plane for SDN. It can prevent TCP DoS attacks from entering SDN by verifying the validity of the attempts to establish a TCP connection from the source, migrating the connection, and relaying the packets between the source and the destination in kernel space. DoSDefender conforms to the de facto standard SDN protocol, the OpenFlow policy, which requires no additional devices and no modifications in the control plane. Experimental results show that DoSDefender can effectively prevent TCP DoS attacks in low computing consumption while maintaining low connection delay and high packet forwarding throughput

NEL-Like Molecule-1 (Nell1) Is Regulated by Bone Morphogenetic Protein 9 (BMP9) and Potentiates BMP9-Induced Osteogenic Differentiation at the Expense of Adipogenesis in Mesenchymal Stem Cells

Background: BMP9 induces both osteogenic and adipogenic differentiation of mesenchymal stem cells (MSCs). Nell1 is a secretory glycoprotein with osteoinductive and anti-adipogenic activities. We investigated the role of Nell1 in BMP9-induced osteogenesis and adipogenesis in MSCs. Methods: Previously characterized MSCs iMEFs were used. Overexpression of BMP9 and NELL1 or silencing of mouse Nell1 was mediated by adenoviral vectors. Early and late osteogenic and adipogenic markers were assessed by staining techniques and qPCR analysis. In vivo activity was assessed in an ectopic bone formation model of athymic mice. Results: We demonstrate that Nell1 expression was up-regulated by BMP9. Exogenous Nell1 potentiated BMP9-induced late stage osteogenic differentiation while inhibiting the early osteogenic marker. Forced Nell1 expression enhanced BMP9-induced osteogenic regulators/markers and inhibited BMP9-upregulated expression of adipogenic regulators/markers in MSCs. In vivo ectopic bone formation assay showed that exogenous Nell1 expression enhanced mineralization and maturity of BMP9-induced bone formation, while inhibiting BMP9-induced adipogenesis. Conversely, silencing Nell1 expression in BMP9-stimulated MSCs led to forming immature chondroid-like matrix. Conclusion: Our findings indicate that Nell1 can be up-regulated by BMP9, which in turn accelerates and augments BMP9-induced osteogenesis. Exogenous Nell1 may be exploited to enhance BMP9-induced bone formation while overcoming BMP9-induced adipogenesis in regenerative medicine