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2. Energy Loss Prediction in IoT Energy Services

Author

Yang, Pengwei, Abusafia, Amani, Lakhdari, Abdallah, and Bouguettaya, Athman

Subjects
Computer Science - Distributed, Parallel, and Cluster Computing, Computer Science - Machine Learning, Computer Science - Networking and Internet Architecture
Abstract

We propose a novel Energy Loss Prediction(ELP) framework that estimates the energy loss in sharing crowdsourced energy services. Crowdsourcing wireless energy services is a novel and convenient solution to enable the ubiquitous charging of nearby IoT devices. Therefore, capturing the wireless energy sharing loss is essential for the successful deployment of efficient energy service composition techniques. We propose Easeformer, a novel attention-based algorithm to predict the battery levels of IoT devices in a crowdsourced energy sharing environment. The predicted battery levels are used to estimate the energy loss. A set of experiments were conducted to demonstrate the feasibility and effectiveness of the proposed framework. We conducted extensive experiments on real wireless energy datasets to demonstrate that our framework significantly outperforms existing methods., Comment: 11 pages, 14 figures, This paper is accepted in the 2023 IEEE International Conference on Web Services (ICWS 2023)

Published
2023

3. Monitoring Efficiency of IoT Wireless Charging

Author

Yang, Pengwei, Abusafia, Amani, Lakhdari, Abdallah, and Bouguettaya, Athman

Subjects
Computer Science - Networking and Internet Architecture, Computer Science - Distributed, Parallel, and Cluster Computing, Computer Science - Machine Learning
Abstract

Crowdsourcing wireless energy is a novel and convenient solution to charge nearby IoT devices. Several applications have been proposed to enable peer-to-peer wireless energy charging. However, none of them considered the energy efficiency of the wireless transfer of energy. In this paper, we propose an energy estimation framework that predicts the actual received energy. Our framework uses two machine learning algorithms, namely XGBoost and Neural Network, to estimate the received energy. The result shows that the Neural Network model is better than XGBoost at predicting the received energy. We train and evaluate our models by collecting a real wireless energy dataset., Comment: 3 pages, 4 figures. This is an accepted demo paper and it will appear in The 21st International Conference on Pervasive Computing and Communications (PerCom 2023)

Published
2023

4. Establishment of Neural Networks Robust to Label Noise

Author

Yang, Pengwei, Teng, Chongyangzi, and Mangos, Jack George

Subjects
Computer Science - Machine Learning
Abstract

Label noise is a significant obstacle in deep learning model training. It can have a considerable impact on the performance of image classification models, particularly deep neural networks, which are especially susceptible because they have a strong propensity to memorise noisy labels. In this paper, we have examined the fundamental concept underlying related label noise approaches. A transition matrix estimator has been created, and its effectiveness against the actual transition matrix has been demonstrated. In addition, we examined the label noise robustness of two convolutional neural network classifiers with LeNet and AlexNet designs. The two FashionMINIST datasets have revealed the robustness of both models. We are not efficiently able to demonstrate the influence of the transition matrix noise correction on robustness enhancements due to our inability to correctly tune the complex convolutional neural network model due to time and computing resource constraints. There is a need for additional effort to fine-tune the neural network model and explore the precision of the estimated transition model in future research., Comment: 11 pages, 7 figures

Published
2022

5. Contaminated Images Recovery by Implementing Non-negative Matrix Factorisation

Author

Yang, Pengwei, Teng, Chongyangzi, and Mangos, Jack George

Subjects
Computer Science - Computer Vision and Pattern Recognition
Abstract

Non-negative matrix factorisation (NMF) has been extensively applied to the problem of corrupted image data. Standard NMF approach minimises Euclidean distance between data matrix and factorised approximation. The traditional NMF technique is sensitive to outliers since it utilises the squared error of each data point, despite the fact that this method has proven effective. In this study, we theoretically examine the robustness of the traditional NMF, HCNMF, and L2,1-NMF algorithms and execute sets of experiments to demonstrate the robustness on ORL and Extended YaleB datasets. Our research indicates that each algorithm requires a different number of iterations to converge. Due to the computational cost of these approaches, our final models, such as the HCNMF and L2,1-NMF model, fail to converge within the iteration parameters of this work. Nonetheless, the experimental results illustrate, to some extent, the robustness of the aforementioned techniques., Comment: 10 pages, 7 figures

Published
2022

6. Towards peer-to-peer sharing of wireless energy services

Author

Yang, Pengwei, Abusafia, Amani, Lakhdari, Abdallah, and Bouguettaya, Athman

Subjects
Computer Science - Networking and Internet Architecture, Computer Science - Distributed, Parallel, and Cluster Computing
Abstract

Crowdsourcing wireless energy services is a novel convenient alternative to charge IoT devices. We demonstrate peer-to-peer wireless energy services sharing between smartphones over a distance. Our demo leverages (1) a service-based technique to share energy services, (2) state-of-the-art power transfer technology over a distance, and (3) a mobile application to enable communication between energy providers and consumers. In addition, our application monitors the charging process between IoT devices to collect a dataset for further analysis. Moreover, in this demo, we compare the peer-to-peer energy transfer between two smartphones using different charging technologies, i.e., cable charging, reveres charging, and wireless charging over a distance. A set of preliminary experiments has been conducted on a real collected dataset to analyze and demonstrate the behavior of the current wireless and traditional charging technologies., Comment: 4 pages, 4 figures. This is an accepted demo paper and it will appear in the 20th International Conference on Service Oriented Computing (ICSOC 2022)

Published
2022

8. Development and Challenge of Flexible Operation Technology of Thermal Power Units Under New Power System

Author

WANG Fangfang, YANG Pengwei, ZHAO Guangjin, LI Qi, LIU Xiaona, and MA Shuangchen

Subjects
new power system, thermal power units, subsynchronous oscillation, linear active disturbance rejection control, impedance model, direct-driven wind turbine, weak grid, Applications of electric power, TK4001-4102, Production of electric energy or power. Powerplants. Central stations, TK1001-1841, Science
Abstract

Under the background of “dual carbon”, new energy sources have begun to be connected to the grid on a large scale. However, the randomness and volatility of new energy generation significantly impact the power grid, making it urgent to build a new power system. As the cornerstone of the power system, traditional thermal power will transform into a basic security and system regulatory power supply, providing reliable capacity, peak regulation and frequency modulation and other auxiliary services. The flexible transformation of thermal power units has become an inevitable choice. The phased objectives, difficulties, and challenges of building a new power system were analyzed, along with the problems encountered in the flexible transformation of thermal power units at the present stage. Combined with thermal power operation data, the technical ways of configuring energy storage equipment for thermal power units were analyzed. The research shows that there are several issues in building a new power system, such as power system instability, difficulties in transforming traditional thermal power, high energy consumption, and environmental pressures. The flexibility transformation of thermal power units faces challenges such as insufficient peak regulation capacity, high operation costs, slow load response, high operation energy consumption, safety concerns, etc. The integration of thermal power and energy storage will bring better economic and environmental benefits.

Published
2024
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9. Influencing factors of telangiectasia secondary to diabetic retinopathy

Author

Li Yingying, Guo Dengshan, and Yang Pengwei

Subjects
diabetic retinopathy, telangiectasia, risk factors, macular edema, hard exudates, blood glucose, Ophthalmology, RE1-994
Abstract

AIM:To investigate the influencing factors of abnormal telangiectasia secondary to diabetic retinopathy(DR).METHODS: Prospective studies. A total of 153 cases(240 eyes)with DR treated in our hospital from January 2021 to January 2023 were selected to analyze the risk factors of abnormal telangiectasia secondary to DR and its predictive efficacy.RESULTS: The patients were divided into dilated group(77 eyes of 40 cases)and non-dilated group(163 eyes of 113 cases)according to whether they had secondary abnormal telangiectasia. There were significant differences in diabetic macular edema, hard exudates grade and fasting blood glucose level between the two groups(P

Published
2024
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11. Towards Peer-to-Peer Sharing of Wireless Energy Services

Author

Yang, Pengwei, Abusafia, Amani, Lakhdari, Abdallah, Bouguettaya, Athman, Goos, Gerhard, Founding Editor, Hartmanis, Juris, Founding Editor, Bertino, Elisa, Editorial Board Member, Gao, Wen, Editorial Board Member, Steffen, Bernhard, Editorial Board Member, Yung, Moti, Editorial Board Member, Troya, Javier, editor, Mirandola, Raffaela, editor, Navarro, Elena, editor, Delgado, Andrea, editor, Segura, Sergio, editor, Ortiz, Guadalupe, editor, Pautasso, Cesare, editor, Zirpins, Christian, editor, Fernández, Pablo, editor, and Ruiz-Cortés, Antonio, editor

Published
2023
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12. Control strategy of double-stage cascaded multilevel converters energy storage system

Author

YE Han, SHENG Xiaodong, XIE Yeyuan, WEI Xing, YANG Pengwei, and REN Zheng

Subjects
cascaded multilevel converters, cascaded energy storage, state of charge (soc), load rates, balance control, double-stage cascaded energy storage system, Applications of electric power, TK4001-4102
Abstract

Energy storage technology is the key technology to building a new power system with new energy as the main body and an important guarantee to maintain the reliable and stable operation of microgrids. Existing theoretical research and projects at home and abroad are mainly concentrated on single-level cascaded energy storage systems. The power module and battery system are connected with passive devices. The structure is simple without enough control degrees of freedom. In the meantime, aiming at an unbalanced state of charge (SOC) of the battery in cascaded energy storage, the existing intra-phase SOC balance control strategy has disadvantages such as poor adaptability to different load ratesand possible over-modulation in case of extreme imbalance. Based on the double-stage cascaded energy storage system, its overall control strategy and the inter-phase and intra-phase SOC balance strategies are illustrated in this paper. An adaptive intra-phase state of charge balance strategy is proposed and its design principle of the balanced control parameters is explained in detail. The adaptability and balance effect of the cascaded energy storage system under different working conditions such as light loads and heavy loads are improved effectively. Finally, the feasibility and effectiveness of the proposed control strategy are verified by simulation, thus providing theoretical reserves and technical support for project implementation.

Published
2023
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13. Formation of bismuth nanosheets on copper foam coupled with nanobubble technology for enhanced electrocatalytic CO2 reduction.

Author

Wu, Kai, Yang, Pengwei, Fan, Shuaijun, Wu, Yifan, Ma, Jingxiang, Yang, Lijuan, Zhu, Hongtao, Ma, Xiaoying, Gao, Heli, Chen, Wentong, Jia, Jun, and Ma, Shuangchen

Abstract

The recycling of industrially emitted CO2 is an urgent environmental task. The electrochemical reduction of CO2 into valuable chemical products presents an attractive approach. However, due to the inherent high chemical stability of CO2 molecules and the complex sequence of multiple electron and proton transfer steps involved in the CO2 reduction reaction (CO2RR), current electrocatalytic systems commonly face challenges such as low CO2 conversion rates and energy utilization efficiency, limited current density, and short electrode lifespan. Herein, we adopt a simple three-step process involving in situ chemical etching, thermal oxidation, and electrochemical reduction to construct bismuth nanosheets (Bi NSs) with abundant lattice dislocations on copper foam, and introduce nanobubble technology to enhance the CO2RR process. In an H-type cell with flowing electrolyte, our Bi NSs/CF electrode achieved a remarkable formate Faradaic efficiency (FEformate) of 95.36% at a low applied potential of −1.08 V vs. RHE (reversible hydrogen electrode), along with a significant formate partial current density (Jformate) of ∼38 mA cm−2 and an energy efficiency of ∼60%. Even within a wider operating window (−0.78 to −1.18 V), the FEformate remained at a high level (>91%). Importantly, the application of nanobubble technology increased the CO2 conversion rate by nearly fivefold. Further density functional theory calculations confirmed that the Bi NSs with lattice dislocations on the Bi NSs/CF surface can effectively stabilize the *OCHO intermediate, thereby achieving high activity and selectivity for the CO2RR. This work highlights the significant roles of nanobubble technology, size-dependent catalysis, and crystal defect engineering strategies in the field of electrocatalysis, elucidating the activity sources of the developed catalyst in the electrochemical CO2 reduction process, and providing valuable insights for the design and development of high-performance electrocatalytic systems for the CO2RR and other applications. [ABSTRACT FROM AUTHOR]

Published
2024
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23. Cobalt Doping in MOF-Derived Carbon-Loaded Tin Nanomaterials for Enhanced Electrocatalytic CO2Reduction

Author

Ma, Shuangchen, Wu, Kai, Xu, Fang, Fan, Shuaijun, Yang, Pengwei, and Ma, Jingxiang

Abstract

Among many catalysts for the electrochemical reduction of CO2, bimetallic materials have been paid more attention on enhanced catalytic activity and product selectivity. Sn is considered as an optional catalyst with excellent application potential due to its high selectivity for formate, low toxicity, low cost, and abundant reserves, which has been widely studied in recent years. However, the catalytic properties of cobalt–tin bimetallic composites have not been reported. In this study, we successfully synthesized the loaded Co/Sn bimetallic carbon matrix composite using the MOF template method and systematically studied the characteristics of the composite for the electrochemical catalytic reduction of CO2. It was found that the formate Faraday efficiency (FEFormate) of the electrode with 1% Co/Sn@C catalyst coating could reach 70% with the total current density of ∼5.6 mA cm–2at a low applied potential of −0.98 V vs RHE (reversible hydrogen electrode). Studies have shown that Co element mainly in the form of alloy doped into the catalytic materials, with trace amounts of Co doping (≤1%) can effectively improve electrode conductivity properties, increase the electrochemical active site, significantly improve selectivity for formate, and enhance the hydrogen evolution reaction (HER), which leads to more Co element doping playing a negative role. Further, the electrode with carbon paper as the support has more stable electrocatalytic activity, compared to copper foil. Experiments confirmed that the desorption of active metals on the catalyst coating on the electrode surface was the critical factor leading to the decrease in catalytic performance. This brings essential implications for the deactivation of electrodes coated with metallic elements, therefore enhancing the binding ability between the active components and the catalytic surface, or uniformly dispersing the catalytically active sites should be an effective way to improve this kind of electrode life. In addition, the carbon paper-supported 1% Co/Sn@C gas diffusion electrode (GDE) coupled with an alkaline flow cell achieved a remarkable FEFormateof ∼76% and a substantial formate partial current density of ∼24 mA cm–2at an applied potential of −0.98 V vs RHE. Electrocatalytic experiments in the flow cell for 30 h demonstrated the excellent catalytic stability of the 1% Co/Sn@C GDE during long-term electrochemical activities.

Published
2024
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24. Coal-Fired Power Plants Using Ammonia for Flexibility Enhancement under Carbon Control Strategies: Status, Development, and Perspectives

Author

Ma, Shuangchen, Yu, Linzhu, Jiang, Haoxuan, Yang, Pengwei, Li, Qi, Du, Mingzhe, Ma, Jingxiang, and Zhu, Hongtao

Abstract

Within the context of carbon control strategies, the development and utilization of renewable energy emerge as indispensable pathways to addressing the energy crisis and environmental challenges. The substantial increase in the share of electricity generated from renewable sources introduces issues such as instability and intermittency, posing significant challenges to the stability of the electrical grid. Consequently, enhancing the flexibility of coal-fired power units is of paramount importance for maintaining the balance of supply and demand within the power system and managing grid fluctuations. Ammonia energy storage, as an innovative chemical storage solution, is regarded as an effective approach to augment the power system’s capability to incorporate renewable energy generation and enhance the flexibility of coal-fired power plants. This paper summarizes three carbon reduction technologies and methodologies within the framework of carbon control strategies, elucidating the advantages and value that ammonia contributes to the process of increasing power plant flexibility. It proposes a method for coupling green power with conventional thermal power through electrolytic ammonia production, tailored for power plants. Additionally, it identifies two principal applications of ammonia within power plants as a carbon-free fuel and absorbent. Finally, it anticipates the future development trends and challenges of ammonia’s role in enhancing power plant flexibility.

Published
2024
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30. Absorption Kinetics of CO2in Aqueous Ammonia with High Load and Salinity

Author

Ma, Shuangchen, Fan, Shuaijun, Chen, Liutong, Yang, Pengwei, Chen, Gongda, and Ma, Jingxiang

Abstract

In order to improve the absorption efficiency of carbon dioxide (CO2) in the process of inorganic ammonia carbon capture, it is critical to find out the factors inhibiting CO2absorption. In this work, the mass transfer flux of CO2is measured by a multi-column wetted wall reactor. The results indicated that the boundary concentration of NH3under the conditions of chemical reaction is 1.01527 kmol·m–3. The contribution of CO2concentration in the liquid film to the reaction rate is found to be less than that of NH3. The carbonization degree is only related to pH and has nothing to do with the initial concentration of NH3. The decrease of absorption efficiency is related to the H+activity coefficient rather than the change of the diffusion coefficient. A flux prediction model with high load and salinity is presented subsequently. Furthermore, the two important regulation indexes are the pH and NH4HCO3saturation.

Published
2023
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38. Influence of Delay Analysis and Research on The Thermal Power Unit’s PFC Performance

Author

Bo Lin, Yang Pengwei, Jun Li, Song Gao, and DaPeng Liao

Subjects
Computer science, Control theory, Delay analysis, Thermal power station, Unit (housing)
Abstract

Primary frequency control(PFC) of thermal power unit is an important means to ensure power supply frequency and safe and stable operation of power grid. Through the analysis and research of the PFC standard of the power grid, combined with the control structure of conventional thermal power units, it is pointed out that the delay and inertia inherent in the unit equipment have a negative impact on the PFC performance. From two directions of field dynamic test and laboratory simulation, existing problems of currently widely used control structures are clearly defined, and the technical means of reducing the influence of delay on PFC are proposed. The practical application results show that the proposed method can effectively reduce the overshoot of the PFC system and ensure that the system recovers quickly and stably.

Published
2019
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41. Melanocortin 4 Receptor Pathway Dysfunction in Obesity: Patient Stratification Aimed at MC4R Agonist Treatment

Author

Ayers, Kristin L, primary, Glicksberg, Benjamin S, primary, Garfield, Alastair S, primary, Longerich, Simonne, primary, White, Joseph A, primary, Yang, Pengwei, primary, Du, Lei, primary, Chittenden, Thomas W, primary, Gulcher, Jeffery R, primary, Roy, Sophie, primary, Fiedorek, Fred, primary, Gottesdiener, Keith, primary, Cohen, Sarah, primary, North, Kari E, primary, Schadt, Eric E, primary, Li, Shuyu D, primary, Chen, Rong, primary, and Van der Ploeg, Lex H T, primary

Published
2018
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44. Aging and neurodegeneration are associated with increased mutations in single human neurons

Author

Lodato, Michael A., primary, Rodin, Rachel E., additional, Bohrson, Craig L., additional, Coulter, Michael E., additional, Barton, Alison R., additional, Kwon, Minseok, additional, Sherman, Maxwell A., additional, Vitzthum, Carl M., additional, Luquette, Lovelace J., additional, Yandava, Chandri, additional, Yang, Pengwei, additional, Chittenden, Thomas W., additional, Hatem, Nicole E., additional, Ryu, Steven C., additional, Woodworth, Mollie B., additional, Park, Peter J., additional, and Walsh, Christopher A., additional

Published
2017
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47. Study on viscosity reduction of non-solidified rubber asphalt waterproof coating.

Author

YANG Pengwei

Abstract

In order to reduce the large amount of energy consumption and waste gas emission during the construction of nonsolidified rubber asphalt waterproof coating, the related factors affecting its viscosity were studied in order to reduce its construction temperature. Based on the rotating viscosity test method of blochfield, raw materials such as rubber powder, SBS, SBR, asphalt and oil, filler and APAO were selected as research objects, and the influence of the above raw materials on the viscosity of non-curing rubber asphalt waterproof coating was analyzed experimentally. Results show that without adding rubber powder, reduce the amount of SBS and SBR modified agents, adjust the asphalt oil ratio to 1-3, asphalt and oil of the curing rubber asphalt waterproof coating viscosity by 1340 mPa⋅s when 180 °C reduced to 990 mPa⋅s when 130 °C, make the construction temperature of waterproof coating 30 °C lower, and its extensibility and creep is better. [ABSTRACT FROM AUTHOR]

Published
2019

49. Catalytic oxidation of polymers used in oilfield by metal-1, 2-benzenediol complex

Author

Tang, Ying, Ren, Haomiao, Yang, Pengwei, Li, Hong, Qu, Chengtun, and Zhang, Jie

Abstract

To seek an efficient catalyst for Fen-ton oxidation processing to the treatment in waste fracturing fluid containing hydroxypropyl guar gum under high pH value, a series of metal-1,2-benzenediol(L) complex was prepared for catalyzing the Fen-ton oxidation. The results show that Ni(II)L complex exhibits high catalytic performance for degradation of polymer in a wide pH range from 7.0 to 13.0. The relative viscosity of hydroxypropyl guar gum can be reduced effectively to 2.3 after adding 10.0% H2O2(mass ratio to hydroxypropyl guar gum) and using 10.0% Ni(II)L (mass ratio to H2O2) as catalysts. The COD value of the treated hydroxypropyl guar gum solution can be decreased to 195 mg/L from 7880 mg/L. It is worth noting that the high catalytic efficiency of Ni(II)L can be maintained even at high pH condition of 13. Moreover, Ni(II)L shows great catalytic ability in the degradation of various polymers by H2O2. The proposed mechanism of the activation of H2O2by the complex was studied by UV spectrum.

Published
2018
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