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Feature extraction of motor imagery in BCI with approximate entropy

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Journal of Computational Information systems 2012年第6期8卷 2485-2491页

作者： Fang, Yonghui Chen, Minyou Zheng, Xufei Harrison, Robert F State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing University Chongqing 400044 China School of Electronic and Information Engineering Southwest University Chongqing 400715 China College of Computer Science Sichuan University Chengdu 610065 China Department of Automatic Control and Systems Engineering University of Sheffield Sheffield United Kingdom

Approximate Entropy (ApEn) is a regularity statistic that quantifies the unpredictability of fluctuations in a time series and can classify complex systems. This study, ApEn is used to extract features from motor imagery Electroencephalogram (EEC) that containing two motor imagery tasks. This method is different from the traditional way to get the character from EEC. Appropriate parameters must been chosen for different dataset. Two datasets are used in this paper. One comes from BCI Competion2003, the other from the lab of Electromagnetic theory and artincal intelligence, Chongqing University. The results show that ApEn can extract different features in left-hand and right-hand motor imagery EEC efficiently. Comparison between ApEn and Fast Fourier Transform (FFT) shows that ApEn has good capability to the two imagery tasks Brain Computer Interface. © 2012 Binary Information Press.

关键词： Electroencephalography

Exploring the Mechanism of Electron Transfer-Mediated Peroxymonosulfate Activation Over Cu-Based Catalyst for the Selective Decomposition of Bisphenol a

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SSRN 2023年

Effective degradation of aquatic contaminants heavily depends on the adsorption of peroxymonosulfate (PMS) on active sites of catalysts. However, the influence of PMS adsorption state on PMS activation has not been well-explored. In this study, catalyst of dispersed Cu atoms on nitrogen-doped carbon skeleton (Cu-NC) was highly selective and efficient in decomposing bisphenol A (BPA) by activating PMS. Surprisingly, dosing sequence of PMS and BPA had a decisive effect on activation. When PMS were added before BPA, the activity of Cu-NC/PMS system was significantly inhibited, conversely the activity of Cu-NC/PMS system was higher. And the kinetic rate was as high as 0.997 min-1, over 99.9% of BPA removed in 3 min. Accordingly, we determined the degradation process was dominated by electron transfer from BPA to Cu-NC through various experiments and characterizations. Density functional theory (DFT) simulation indicated that PMS with bridging adsorption on the Cu site had more suitable adsorption energy which induced more intensely electron transfer and destroyed electron donors (BPA) more efficiently and highly selectively. Therefore, we propose a mechanism for PMS activation based on the capture of electrons from Cu-NC. In this mechanism, the electron donor (BPA) acts as the initiating factor for PMS activation, while the adjacent Cu sites optimizes the adsorption configuration of PMS, accelerating electron transfer. These two factors synergistically achieve efficient pollutant removal. © 2023, The Authors. All rights reserved.

关键词： Adsorption

Roller-Quadrotor: A Novel Hybrid Terrestrial/Aerial Quadrotor with Unicycle-Driven and Rotor-Assisted Turning

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arXiv

arXiv 2023年

作者： Zheng, Zhi Wang, Jin Wu, Yuze Cai, Qifeng Yu, Huan Zhang, Ruibin Tu, Jie Meng, Jun Lu, Guodong Gao, Fei The State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical Engineering Zhejiang University Hangzhou310027 China Robotics Institute of Zhejiang University Hangzhou310027 China Robotics Research Center of Yuyao City Ningbo315400 China The State Key Laboratory of Industrial Control Technology Zhejiang University Hangzhou310027 China Huzhou Institute of Zhejiang University Huzhou313000 China Center for Data Mining and Systems Biology College of Electrical Engineering Zhejiang University Hangzhou310027 China

The Roller-Quadrotor is a novel quadrotor that combines the maneuverability of aerial drones with the endurance of ground vehicles. This work focuses on the design, modeling, and experimental validation of the Roller-Quadrotor. Flight capabilities are achieved through a quadrotor configuration, with four thrust-providing actuators. Additionally, rolling motion is facilitated by a unicycle-driven and rotor-assisted turning structure. By utilizing terrestrial locomotion, the vehicle can overcome rolling and turning resistance, thereby conserving energy compared to its flight mode. This innovative approach not only tackles the inherent challenges of traditional rotorcraft but also enables the vehicle to navigate through narrow gaps and overcome obstacles by taking advantage of its aerial mobility. We develop comprehensive models and controllers for the Roller-Quadrotor and validate their performance through experiments. The results demonstrate its seamless transition between aerial and terrestrial locomotion, as well as its ability to safely navigate through gaps half the size of its diameter. Moreover, the terrestrial range of the vehicle is approximately 2.8 times greater, while the operating time is about 41.2 times longer compared to its aerial capabilities. These findings underscore the feasibility and effectiveness of the proposed structure and control mechanisms for efficient navigation through challenging terrains while conserving energy. Copyright © 2023, The Authors. All rights reserved.

关键词： Antennas

Cufe2o4@Ncnts-Functionalized Ceramic Microfiltration Membrane for Antibiotic Oxidation and Fouling control Via Heterogeneous Electro-Fenton Reaction

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SSRN 2024年

作者： Zhang, Zixin Huang, Guohe Li, Yongping Yao, Yao Zhang, Peng Chen, Xiujuan Ren, Shaojie Luo, Yifei Zhang, Yuanzheng State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing100875 China State Key Joint Laboratory of Environmental Simulation and Pollution Control China-Canada Center for Energy Environment and Ecology Research UR-BNU School of Environment Beijing Normal University Beijing100875 China Environmental Systems Engineering Program University of Regina ReginaSKS4S 0A2 Canada Institute for Energy Environment and Sustainable Communities University of Regina ReginaS4S 0A2 Canada Department of Civil Engineering The University of Texas at Arlington ArlingtonTX United States Shandong Key Laboratory of Water Pollution Control and Resource Reuse School of Environmental Science and Engineering Shandong University Qingdao266237 China College of Environmental Science and Engineering North China Electric Power University Beijing102206 China

Herein, we reported an electrocatalytic ceramic microfiltration membrane functionalized with CuFe2O4 nanoparticles supported by nitrogen-doped carbon nanotubes (NCNTs). The synergistic catalysis between Fe and Cu induced a continuous ·OH generation. The active Fe(II) and Cu(I) sites decomposed the in-situ generated H2O2 into ·OH. The electron transfer from the external circuit and Cu(I) to Fe(III) drove the regeneration of Fe(II). The interfacial electron transfer from CuFe2O4 to NCNTs decreased the electron density of Fe and Cu, thus facilitating the redox cycles of Fe(III)/Fe(II) and Cu(II)/Cu(I). Furthermore, the Fe and Cu sites at the interface of CuFe2O4 and NCNTs displayed a superior ability to non-interface sites in producing ·OH. At near-neutral pH, the electrocatalytic membrane delivered excellent tetracycline removal kinetics (0.0134 min-1) and significantly alleviated the organic fouling occurring on the membrane. These findings shed new light on the development of new-generation membranes with catalytic oxidation capabilities for water treatment. © 2024, The Authors. All rights reserved.

关键词： Antibiotics

Emission Characteristics of Lead and Particulate Matter from Lead and Zinc Smelters in China

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SSRN 2024年

作者： Zhang, Jiawei Sun, Xiaohui Wu, Qingru Deng, Jianguo Li, Zhijian Wen, Minneng Xu, Liwen Gu, Yongzheng Han, Tao Feng, Lei Duan, Lei State Key Joint Laboratory of Environmental Simulation and Pollution Control School of the Environment Tsinghua University Beijing100084 China Department of Aeronautics Imperial College London South Kensington Campus LondonSW7 2AZ United Kingdom State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing100084 China Guodian Power Development Co. Ltd. Beijing100101 China CHN ENERGY New Energy Technology Research Institute Co. Ltd. Beijing102209 China

Understanding the emission characteristics of particulate matter and associated heavy metals is essential for assessing their environmental and health impacts post-emission, as well as for identifying potential control technologies for the sources. Here, a field test was conducted at two advanced smelting plants equipped with comprehensive air pollution control devices. The particles emitted from different stages of lead and zinc smelting exhibited bi-modal size distributions, with peaks observed in PM0.1-1.0 and PM2.5-10, respectively. Particulate-bound Pb was identified as the predominant Pb species in the flue gas, primarily originating from ore crushing. Consequently, over 80% of Pb was emitted in the form of coarse particles, a marked contrast to coal-fired power plants where Pb concentrated on fine particles. High efficiencies in Pb removal were achieved by dust collectors, flue gas purification systems, and acid plants with desulfurization systems, resulting in overall Pb emission factors in lead and zinc smelting were only 89.3 and 2.60 g t-1 (of metal production), respectively. Importantly, the contribution of gas-phase Pb, which accounts for approximately 16.6% of total emissions, must not be neglected in future emission monitoring and control efforts. © 2024, The Authors. All rights reserved.

关键词： Fossil fuel power plants

Reconstructing the Nanoscale Porous Structures in Coal-Based Membranes by Ultrafast High-Temperature Sintering for Solar-Driven Water Treatment

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SSRN 2023年

作者： Liu, Chih-Chin Chen, Rong Wei, Yanzhuo Huang, Yang Zhang, Zhijun Zhao, Yixin Fu, Tairan Hu, Chuxiong Huang, Xia Zang, Xining Department of Mechanical Engineering Tsinghua University Beijing100084 China Key Laboratory for Advanced Materials Processing Technology Ministry of Education Tsinghua University Beijing100084 China State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China Department of Thermal Engineering Tsinghua University Beijing100084 China School of Chemical and Environmental Engineering China University of Mining and Technology Beijing100083 China Key Laboratory for Thermal Science and Power Engineering Ministry of Education China Beijing Key Laboratory for Precise Mining of Inter grown Energy and Resources China

Lignite, a low-grade coal, accounts for over 40% of the global coal reserves. The use of lignite has been limited compared to other grades due to its low calorific value, high impurities content, and elevated volatile matter. Exploring a scalable and environment-friendly approach to upgrade lignite will offer new opportunities. In this work, Ultrafast High-Temperature Carbonization (UHC) has been developed to carbonize lignite and modify its nanoscale structure to construct a conductive porous membrane. The whole process takes only 30 s with an ultrafast heating rate exceeding 2400°C/min and a maximum temperature over 1500°C. Upon heating the pore structures in the coal membrane evolves into micro- and mesopores with a specific surface area of over 300 m2/g. The carbonized coal-based membrane provides superior performance as a solar evaporator for water treatment, due to its interconnected porous structures, hydrophilicity, and over 85% absorption of full-band visible light. Under 1 sun solar irradiation, the membrane shows over 98.2% removal rate of salts, heavy metal ions, and volatile organic compounds (VOCs). © 2023, The Authors. All rights reserved.

关键词： Metal ions

Screening of metal-modified biochars for practical phosphorus recovery

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Science of the Total Environment 2024年 956卷 177342页

作者： Li, Man Xie, Qian Xu, Fangxi Zhang, Yan Zhuang, Zechao Xu, Jiawei Xiang, Hai Li, Yongfu Cai, Yanjiang Chen, Zuliang Yu, Bing State Key Laboratory of Subtropical Silviculture Zhejiang A&F University Hangzhou311300 China Zhejiang A&F University Hangzhou311300 China Zhejiang Taizhou Ecological and Environmental Monitoring Center Taizhou318000 China Department of Chemistry Tsinghua University Beijing100084 China Jiangsu Key Laboratory of Numerical Simulation of Large Scale Complex Systems and School of Chemistry and Materials Science Nanjing Normal University Nanjing210023 China Fujian Key Laboratory of Pollution Control and Resource Reuse School of Environmental and Resource Sciences Fujian Normal University Fujian Province Fuzhou350007 China

The utilization of metal-modified biochars (MBCs) for practical phosphorus recovery has attracted significant research interest recently. However, the optimal choice of metals and modification methods for MBCs remains unclear. This study addresses this gap by comparing the phosphate adsorption capabilities of various MBCs using real municipal wastewater. The results show that zinc-modified biochar exhibits superior phosphate adsorption compared to biochars modified with calcium, magnesium, aluminum, and iron. Specifically, zinc-modified biochar prepared through metal-mediated biomass pyrolysis with alkaline soaking (ZnBC-OH) demonstrates the highest adsorption capacity, achieving 36.6 mg P/g in wastewater with a phosphate concentration of 5 mg P/L. This performance surpasses that of previously reported non-lanthanide modified biochars and is comparable to lanthanide-modified biochars. Mechanistic investigations reveal that the exceptional performance of ZnBC-OH is due to the presence of highly dispersed ZnO sites, which facilitate the formation of Zn3(PO4)2·4H2O precipitation, effectively retaining phosphate. Furthermore, a techno-economic analysis indicates that using ZnBC-OH in a fixed-bed column system can reduce phosphate levels from 6 mg L−1 to below 0.5 mg L−1 at a cost of 1.834 USD per ton of secondary treated wastewater, underscoring its promising application potential. © 2024 Elsevier B.V.

关键词： Wastewater treatment

Authentication Technology in Industrial control System Based on Identity Password

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Authentication Technology in Industrial Control System Based...

第三十九届中国控制会议

作者： Luyao Yang Wenli Shang Chunyu Chen Tianyu Wang Zhoubin Liu Shenyang Institute of Automation Chinese Academy of Sciences School of Information Science and Engineering Northeastern University University of Chinese Academy of Sciences Institute of Robotics and Intelligent Manufacturing Innovation Chinese Academy of Sciences Key Laboratory of Networked Control Systems Chinese Academy of Sciences Electric Power Research Institute State Grid Zhejiang Electric Power Co.Ltd.

Aiming at the current lack of certification capability in domestic industrial control systems, an industrial control system authentication scheme based on identity cryptography algorithm is proposed. When authenticating between control system devices, the scheme integrates the identity-based digital signature algorithm into the SSL/TLS handshake protocol to complete identity authentication between the engineering station and the trusted PLC. At the same time, when the connection is established for the first time between devices, the connection authentication is selected by the challenge/response based method. The authentication technology based on the identity cryptographic algorithm no longer requires the existence of a public key certificate. This eliminates the need to revoke, store, and issue certificates, simplifies the certification process and reduces the amount of computation required by the authentication process. At the same time, the improved handshake protocol is universal in industrial control systems. The authentication technology based on the identity and password algorithm no longer requires the existence of a public key certificate, eliminating the need for certificate revocation, storage, and issuance, simplifying authentication steps, and reducing system maintenance. Finally, by establishing a test environment, the improved handshake protocol is implemented, and the feasibility of the authentication scheme is verified and analyzed.

关键词： Industrial control security digital signature identity authentication SSL/TLS handshake protocol

Optimal Configuration of Wind-to-Ammonia with the Electric Network and Hydrogen Supply Chain: A Case Study of Inner Mongolia

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arXiv

arXiv 2020年

作者： Li, Jiarong Lin, Jin Heuser, Philipp-Matthias Heinrichs, Heidi Ursula Xiao, Jinyu Liu, Feng Robinius, Martin Song, Yonghua Stolten, Detlef IEEE IEEE Fellow IEEE Forschungszentrum Jülich GmbH Jülich52425 Germany State Key Laboratory of Control and Simulation of Power Systems and Generation Equipment Department of Electrical Engineering Tsinghua University Beijing100084 China Forschungszentrum Jülich GmbH Jülich52425 Germany Forschungszentrum Jülich GmbH Jülich52425 Germany Global Energy Interconnection Development and Cooperation Organization Beijing100031 China State Key Laboratory of Internet of Things for Smart City University of Macau Department of Electrical Engineering Tsinghua University Beijing 100084 China Taipa999078 China

Converting wind energy into ammonia (WtA) has been recognized as a promising pathway to enhance the usage of wind generation. This paper proposes a generic optimal configuration model of WtA at the network level to minimize the ammonia production cost by optimizing capacities and locations of WtA facilities including wind turbines, electrolyzers, hydrogen tanks and optimizing supply modes among regions. Specifically, the temporal fluctuation characteristics of wind resources, the operation flexibility of the ammonia synthesis reactor and the transport distances are considered. Three typical supply modes, i.e., the Local WtA, the EN (electric network)-based WtA and the HSC (hydrogen supply chain)-based WtA, combined with two energy transport modes including EN and HT (Hydrogen truck trailers) are included with the consideration of the maximal energy transport capacity of EN and transport distance per day of HT (500km). Real data of Inner Mongolia (a typical province in China with rich wind resources and existing ammonia industries) is employed to verify the effectiveness and significance of proposed model. The effect of above significant factors on optimal planning capacity of WtA facilities and optimal energy transport modes is analyzed, which provides guidelines for WtA configuration. The economic analysis shows that the average LCOA (levelized cost of ammonia) for WtA is approximately 0.57 €/kg in Inner Mongolia and comparable to that for CtA (coal-to-ammonia, 0.41 €/kg) with a reduction of 30% in capacity cost of the facilities. Copyright © 2020, The Authors. All rights reserved.

关键词： Ammonia