34 research outputs found

    Diffusion Models Without Attention

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    In recent advancements in high-fidelity image generation, Denoising Diffusion Probabilistic Models (DDPMs) have emerged as a key player. However, their application at high resolutions presents significant computational challenges. Current methods, such as patchifying, expedite processes in UNet and Transformer architectures but at the expense of representational capacity. Addressing this, we introduce the Diffusion State Space Model (DiffuSSM), an architecture that supplants attention mechanisms with a more scalable state space model backbone. This approach effectively handles higher resolutions without resorting to global compression, thus preserving detailed image representation throughout the diffusion process. Our focus on FLOP-efficient architectures in diffusion training marks a significant step forward. Comprehensive evaluations on both ImageNet and LSUN datasets at two resolutions demonstrate that DiffuSSMs are on par or even outperform existing diffusion models with attention modules in FID and Inception Score metrics while significantly reducing total FLOP usage

    The modeling and simulation of collision protection system between the driver of non-motor vehicle and car door

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    Abstract Collision between the driver of non-motor vehicle and car door often happens when the car driver or the passenger in the parking car opens the door suddenly ignoring a non-motor vehicle passing by. The collision protection system is proposed by installing an airbag in the car door. When the collision accident between the driver of non-motor vehicle and the car is unavoidable, the airbag will automatically deploy to provide head protection for the driver of non-motor vehicle. Utilizing HyperWorks and LS-DYNA, the finite element model of the collision is established to simulate the situations of installing airbag or not with the door on different opening angles (60°, 70°) and to verify the feasibility of the proposed method

    Integrated Dynamics Response Analysis for IEA 10-MW Spar Floating Offshore Wind Turbine

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    Wind energy in the deep-sea area is more abundant and the capacity of wind turbines can be made larger. Therefore, the research on deep-sea floating offshore wind turbines will be the primary strategy for wind energy exploitation in the future. The spar-type platform depends on the characteristics of a small water plane, deep draft, and good stability, which has been applied to the commercial development of deep-sea wind energy. In the next ten years, the 10-MW wind turbine will become the mainstream class installed in the floating offshore wind turbine farm. Thus, it is very necessary to conduct a comprehensive and in-depth study on the 10-MW spar type floating offshore wind turbine. The direct-drive 10-MW offshore wind turbine was proposed by the International Energy Agency (IEA) in Wind Task 37 in 2019. In this paper, a spar-type platform is designed to support the IEA 10-MW reference wind turbines, and a nonlinear aero-hydro-servo-elastic numerical model is established using the FAST tool (which is developed by the National Renewable Energy Laboratory, NREL). Then, the accuracy of the wind turbine and the sensitivity of the controller are verified, and the natural periods of the floating offshore wind turbine are obtained by free-decay tests. The natural periods of the platform in six degrees-of-freedom are found to be within the range recommended by the design standard. The measured wind and wave data of the target site close to Fujian Province of China are used to evaluate the performance of the floating offshore wind turbine under the 100-, 50-, 5-, and 2-year-return stochastic weather conditions. The results indicate that the design of the spar platform is reasonable and has excellent hydrodynamic performance

    Multiple-Responsive Dendronized Hyperbranched Polymers

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    Absorbing oxygen carrier induces phosphorus enrichment in sludge: Preparation and screening

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    Phosphorus recovery from sludge is considered a feasible approach. By combining the oxygen carrier gasification technology and microwave heating, an absorbing oxygen carrier (AOC) is used in this study to successfully induce phosphorus enrichment in sludge char. The AOC, which is based on iron and supported on SiC, has been prepared via ultrasonic impregnation. The effects of preparation conditions (particle size of SiC and loading of iron) on the phosphorus enrichment characteristics, thermal reaction performance of the AOC and sludge, and the wave absorption performance of the AOC were investigated. The results show that the AOC prepared using a SiC particle size of 36 mesh and iron loading of 10% can achieve a phosphorus enrichment of 91.30% in the sludge char when the temperature of the microwave reactor is 600 degrees C. In the thermal reaction test, AOC can effectively increase the rate and depth of sludge gasification reaction in the medium-and high-temperature reaction stages. Iron-based is loading on the SiC surface and has a good wave absorption performance (RL = -16.28 dB; effective absorption width is 3.54 GHz). Overall, this study provides a new and effective approach for utilizing sludge

    FPGA-based CCD signal acquisition and transmission system design

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    Abstract In order to facilitate the analysis and processing of optical signals, an FPGA-based CCD signal acquisition and data transmission system is designed in this work. The system uses an FPGA as the main control device, the TCD1304DG/AP chip as the optical signal detector, and the CYUSB3KIT-003 development board product by Cypress for data transmission. Verilog and Python languages are employed for modular design and on-board verification. Through the coordination of each module, the system successfully achieves CCD signal data acquisition and transmission

    Mesoporous silica-carbon composites fabricated by a universal strategy of hydrothermal carbonization: controllable synthesis and applications

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    Mesoporous silica-carbon composite materials, with homogeneous and thickness-controllable carbon coating, were synthesized by using a universal strategy of hydrothermal carbonization, and the carbon layer could be coated on the surface of ordered and disordered mesoporous silica. The electrostatic interaction between amino-modified silica and hydrothermal carbon was regarded as the main driving force for the formation of homogeneous carbon coverage on the silica surface. The obtained composites showed high graphitization degree, and controlled morphology (shape and particle size) and pore size by adjusting the species of carriers and hydrothermal conditions. The application results demonstrated that a thin carbon layer possessed high adsorption capacities for dyes, and the composite could be rapidly recovered by sedimentation (10 min) after adsorption with 30 mu m spherical silica gel as the carrier. Besides, baseline chromatographic separation of oligosaccharide isomers could be achieved on the silica-carbon column. These results indicated that the silica-carbon composites should be promising functional materials for the large-molecule-involving processes such as adsorption and chromatographic separation
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