Boosting Few-shot Action Recognition with Graph-guided Hybrid Matching

Class prototype construction and matching are core aspects of few-shot action recognition. Previous methods mainly focus on designing spatiotemporal relation modeling modules or complex temporal alignment algorithms. Despite the promising results, they ignored the value of class prototype construction and matching, leading to unsatisfactory performance in recognizing similar categories in every task. In this paper, we propose GgHM, a new framework with Graph-guided Hybrid Matching. Concretely, we learn task-oriented features by the guidance of a graph neural network during class prototype construction, optimizing the intra- and inter-class feature correlation explicitly. Next, we design a hybrid matching strategy, combining frame-level and tuple-level matching to classify videos with multivariate styles. We additionally propose a learnable dense temporal modeling module to enhance the video feature temporal representation to build a more solid foundation for the matching process. GgHM shows consistent improvements over other challenging baselines on several few-shot datasets, demonstrating the effectiveness of our method. The code will be publicly available at https://github.com/jiazheng-xing/GgHM.Comment: Accepted by ICCV202

RF self-interference cancellation using phase modulation and optical sideband filtering

A novel optical approach to implement RF self-interference cancellation for full-duplex communication using phase modulation and optical sideband filtering is proposed and demonstrated experimentally. Based on the inherent out-of-phase property between the left and right sidebands of phase-modulated signal and optical sideband filtering, the RF self-interference cancellation is achieved by tuning the delay time and amplitude in the optical domain. RF self-interference cancellation for single frequency and microwave with various bandwidth of 1MHz, 5MHz and 10 MHz is experimentally demonstrated to verify the proposed technique

Monitoring Reaction Intermediates in Plasma-Driven SO2, NO, and NO2 Remediation Chemistry Using in Situ SERS Spectroscopy

In situ surface-enhanced Raman scattering (SERS) spectroscopy is used to identify the key reaction intermediates during the plasma-based removal of NO and SO2 under dry and wet conditions on Ag nanoparticles. Density functional theory (DFT) calculations are used to confirm the experimental observations by calculating the vibrational modes of the surface-bound intermediate species. Here, we provide spectroscopic evidence that the wet plasma increases the SO2 and the NOx removal through the formation of highly reactive OH radicals, driving the reactions to H2SO4 and HNO3, respectively. We observed the formation of SO3 and SO4 species in the SO2 wet-plasma-driven remediation, while in the dry plasma, we only identified SO3 adsorbed on the Ag surface. During the removal of NO in the dry and wet plasma, both NO2 and NO3 species were observed on the Ag surface; however, the concentration of NO3 species was enhanced under wet-plasma conditions. By closing the loop between the experimental and DFT-calculated spectra, we identified not only the adsorbed species associated with each peak in the SERS spectra but also their orientation and adsorption site, providing a detailed atomistic picture of the chemical reaction pathway and surface interaction chemistry.Fil: Li, Shujin. University of Southern California; Estados UnidosFil: Zhao, Bofan. University of Southern California; Estados UnidosFil: Aguirre, Alejo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Wang, Yu. University of Southern California; Estados UnidosFil: Li, Ruoxi. University of Southern California; Estados UnidosFil: Yang, Sisi. University of Southern California; Estados UnidosFil: Aravind, Indu. University of Southern California; Estados UnidosFil: Cai, Zhi. University of Southern California; Estados UnidosFil: Chen, Ran. University of Southern California; Estados UnidosFil: Jensen, Lasse. University of Southern California; Estados UnidosFil: Cronin, Stephen B.. University of Southern California; Estados Unido

Research on large flow intelligent liquid supply system in fully mechanized working face

The liquid supply system in fully mechanized working face has the problems of insufficient liquid supply capacity, large pressure fluctuation and poor system operation stability. In order to solve the above problems, an immune particle swarm optimization fuzzy neural network PID (IPSO-FNN-PID) algorithm is proposed. The IPSO-FNN-PID controller is designed to stabilize the pressure of the liquid supply system. In the IPSO-FNN-PID algorithm, a particle swarm optimization (PSO) algorithm and an immune algorithm (IA) are introduced into a fuzzy neural network (FNN) PID controller. The immune particle swarm optimization (IPSO) algorithm is used to solve the problem that the FNN algorithm is easy to fall into local optimization. The IA is added to the PSO algorithm to improve the convergence of the PSO algorithm. Therefore, the output of the optimal PID parameters is realized. In order to verify the effectiveness of the IPSO-FNN-PID controller, traditional PID controller, Fuzzy-PID controller and FNN-PID controller are selected to compare. The simulation results show that the IPSO-FNN-PID controller has the best control effect on the emulsion pump. The rise time, peak time and regulation time of the other three controllers are longer than the IPSO-FNN-PID controller. The maximum overshoot is greater than the IPSO-FNN-PID controller. After adding the disturbance signal, the IPSO-FNN-PID controller has good adaptability and robustness, and it takes only 1.2 s to restore to a stable state. When traditional PID and Fuzzy-PID controllers are used to control the emulsion pump, the oscillation is obvious and the overshoot is large, which are 41.2% and 22.3% respectively. When the FNN-PID controller is used to control the emulsion pump, the oscillation is significantly weakened, the overshoot is reduced to 17.6%, and the adjustment time is reduced to 2.68 s. When the IPSO-FNN-PID controller is used to control the emulsion pump, there is almost no oscillation. The overshoot is only 5.22%, the adjustment time is shortened to 2.61 s. And the stability is stronger when encountering interference signals. When the disturbance signal is received, the load disturbance has little effect on the IPSO-FNN-PID controller, the convergence is rapid, and the robustness is greatly improved. The results show that the IPSO-FNN-PID controller has good anti-disturbance and disturbance compensation capability, and can meet the pressure stabilization control requirements of the liquid supply system

Enhanced photocatalytic degradation of 2-propanol over macroporous GaN/ZnO solid solution prepared by a novel sol-gel method

Macroporous GaN/ZnO solid solution photocatalyst is synthesized through a novel sol-gel method under mild conditions. The performance of as-synthesized solid solution photocatalyst is evaluated for decomposition of gaseous 2-propanol (IPA). It is found that due to enhancement in both the adsorption to gaseous IPA and the absorbance to visible light, the porous GaN/ZnO solid solution exhibits a good photocatalytic performance for IPA decomposition. Moreover, the mechanism for photocatalytic degradation IPA over porous GaN/ZnO solid solution is also investigated in comparison with those for the two end materials ZnO and GaN. The trapping effects with different scavengers prove that both the photoexcited electrons and holes affect the IPA photodegradation process, simultaneously

Analysis and Prediction of Sustainable Utilization of Water Resources in Chengde City Based on System Dynamics Model

In addition to the social economy and the rapid development of industry and agriculture, water demand is increasing and poses challenges in the over-exploitation of water resources. This research establishes a model to assess the sustainable exploitation of water resources based on system dynamics theory and STELLA software, which solves the imbalanced allocation of industrial water, agricultural water and domestic water. The model is composed of two parts: the water quantity system (including economy, population, water availability and water demand) and the water quality system (composed of the aquatic environment), which is suitable for Chengde City with a water resource shortage. The proposed model is established by data of Chengde City from 2007 to 2016 and is verified by 2017 data. Furthermore, in order to compare the water quality and water utilization of Chengde City under different development scenarios up to 2025, the sensitivity analysis of each variable (e.g., population) is carried out in this model, and thereby the water resource utilization scenarios are acquired. Specifically, four scenarios are designed and denoted: Scenario 1: keeping the status quo unchanged, Scenario 2: slowing down economic development and devoting more energy to environmental protection, Scenario 3: only focusing more on economic development and Scenario 4: aiming at steady and rapid economic growth and an eco-friendly environment. The results shows that Scenarios 2 and 3 facilitate high-effective water resource utilization compared with the current development, Scenario 1. Scenario 4 fosters the balance of water resources supply–demand in the future and preserves the water quality. This study provides an inspiring method for realizing the sustainable utilization and optimizing allocation of water resources in Chengde City

Analysis and Prediction of Sustainable Utilization of Water Resources in Chengde City Based on System Dynamics Model

In addition to the social economy and the rapid development of industry and agriculture, water demand is increasing and poses challenges in the over-exploitation of water resources. This research establishes a model to assess the sustainable exploitation of water resources based on system dynamics theory and STELLA software, which solves the imbalanced allocation of industrial water, agricultural water and domestic water. The model is composed of two parts: the water quantity system (including economy, population, water availability and water demand) and the water quality system (composed of the aquatic environment), which is suitable for Chengde City with a water resource shortage. The proposed model is established by data of Chengde City from 2007 to 2016 and is verified by 2017 data. Furthermore, in order to compare the water quality and water utilization of Chengde City under different development scenarios up to 2025, the sensitivity analysis of each variable (e.g., population) is carried out in this model, and thereby the water resource utilization scenarios are acquired. Specifically, four scenarios are designed and denoted: Scenario 1: keeping the status quo unchanged, Scenario 2: slowing down economic development and devoting more energy to environmental protection, Scenario 3: only focusing more on economic development and Scenario 4: aiming at steady and rapid economic growth and an eco-friendly environment. The results shows that Scenarios 2 and 3 facilitate high-effective water resource utilization compared with the current development, Scenario 1. Scenario 4 fosters the balance of water resources supply–demand in the future and preserves the water quality. This study provides an inspiring method for realizing the sustainable utilization and optimizing allocation of water resources in Chengde City

Significant enhancement in photocatalytic activity of (GaN)1−x(ZnO)x nanowires via solubility and crystal facet tailoring

We report on the solubility and crystal facet tailoring of the wurtzite structured (GaN)1−x(ZnO)x solid solution nanowires via a chemical vapor deposition method. With increasing the growth temperature from 900 °C to 1000 °C, the nanowire morphology is changed from zigzag to straight, and the band gap is increased from 2.70 eV to 3.26 eV, due to decreased solubility of ZnO. Photoelectrochemical and photocatalytic performances of the zigzag nanowires are significantly improved because of the narrower band gap for absorbing more solar light and the special lateral surface atomic structure favorable for the separation of photoinduced electrons and holes