Artificial neural network‑based FCS‑MPC for three‑level inverters

Xinliang Yang,Kun Wang,Jongseok Kim,Ki-Bum Park 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.12

Finite control set model predictive control (FCS-MPC) stands out for fast dynamics and easy inclusion of multiple nonlinear control objectives. However, for long horizontal prediction or complex topologies with multiple levels and phases, the required computation burden surges exponentially as the increases of candidate switch states during one control period. This phenomenon leads to longer sample period to guarantee enough time for traverse progress of cost function minimization. In other words, the allowed highest switching frequency is bounded considerably far from the physical limits, especially for wide-band semiconductor applications. To overcome this issue, the parallel computing characteristic of artificial neural network (ANN) motivates the idea of an ANN-based FCS-MPC imitator (ANN-MPC). In this article, ANN-MPC is implemented on a neutral point clamped (NPC) converter using a shallow neural network. The expert (FCS-MPC) is initially designed, and the basic structure, including activation function selection, training data generation, and offline training progress, and online operation of the imitator (ANN-MPC) are then discussed. After the design of the expert and imitator, a comparative analysis is conducted by field programmable gate array (FPGA) in-the-loop implementation in MATLAB/Simulink environment. The verification results of ANN-MPC show highly similarly qualified control performance and considerably reduced computation resource requirement.

Melt Superheating on the Microstructure and Mechanical Properties of Diecast Al-Mg-Si-Mn Alloy

Wenchao Yang,Xinliang Yang,Shouxun Ji 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.2

The application of aluminium alloys in automotive body structure is one of the main developments in recentyears. The increase of the mechanical properties of the ductile die-casting is one of the most critical topics forthe application. In this work, the effect of melt superheating on the morphology, size and distribution of α-Alphase and Fe-rich intermetallics, and on the mechanical properties of the Al-Mg-Si-Mn diecast alloy wasinvestigated. The results showed that the refined microstructure could be obtained through melt superheating. The volume fraction of dendritic α-Al phase and the Fe-rich intermetallic phase formed in the shotsleeve was significantly reduced, resulting in the refined microstructure. Overall, the melt superheatingcould improve the mechanical properties of the yield strength, ultimate tensile strength, and elongation ofthe diecast Al-Mg-Si-Mn alloy. And, the Fe-rich intermetallic phase formed in the shot sleeve with thecoarse compact morphology and formed in the die cavity with the fine compact particles were identifiedas the same α-Al12(Fe,Mn)3Si composition in the present experimental conditions, which was not affectedby the melt superheating.

Integrated Hierarchical Cobalt Sulfide/Nickel Selenide Hybrid Nanosheets as an Efficient Three-dimensional Electrode for Electrochemical and Photoelectrochemical Water Splitting

Hou, Yang,Qiu, Ming,Nam, Gyutae,Kim, Min Gyu,Zhang, Tao,Liu, Kejun,Zhuang, Xiaodong,Cho, Jaephil,Yuan, Chris,Feng, Xinliang American Chemical Society 2017 NANO LETTERS Vol.17 No.7

<P>Developing highly active electrocatalysts for photoelectrochemical water splitting is critical to bring solar/electrical-to-hydrogen energy conversion processes into reality. Herein, we report a three-dimensional (3D) hybrid electrocatalyst that is constructed through in situ anchoring of Co9S8 nanosheets onto the surface of Ni3Se2 nanosheets vertically aligned on an electrochemically exfoliated graphene foil. Benefiting from the synergistic effects between Ni3Se2 and Co9S8, the highly conductive graphene support, and large surface area, the novel 3D hybrid electrode delivers superior electrocatalytic activity toward water reduction in alkaline media, featuring overpotentials of -0.17 and -0.23 V to achieve current densities of 20 and 50 mA cm(-2), respectively, demonstrating an electrocatalytic performance on the top of the Ni3Se2- and Co9S8-based electrocatalysts as reported in literature. Experimental investigations and theoretical calculations confirm that the remarkable activity of the obtained material results from the unique 3D hierarchical architecture and interface reconstruction between Ni3Se2 and Co9S8 through Ni-S bonding, which leads to charge redistribution and thus lowers the energy barrier of hydrogen desorption in the water splitting process. Further integration of the 3D hybrid electrode with a macroporous silicon photocathode enables highly active and sustainable sunlight-driven water splitting in both basic media and real river water. The overall water splitting with 10 mA cm(-2) at a low voltage of 1.62 V is achieved using our hybrid as both anode and cathode catalysts, which surpasses that of the Ir/C-Pt/C couple (1.60 V) for sufficiently high overpotentials.</P>

Isovitexin Protects Mice from Methicillin- Resistant Staphylococcus aureus-Induced Pneumonia by Targeting Sortase A

( Lili Tian ),( Xinliang Wu ),( Hangqian Yu ),( Fengying Yang ),( Jian Sun ),( Tiezhong Zhou ),( Hong Jiang ) 한국미생물생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.10

The rise of methicillin-resistant Staphylococcus aureus (MRSA) has resulted in significant morbidity and mortality, and clinical treatment of MRSA infections has become extremely difficult. Sortase A (SrtA), a virulence determinant that anchors numerous virulence-related proteins to the cell wall, is a prime druggable target against S. aureus infection due to its crucial role in the pathogenicity of S. aureus. Here, we demonstrate that isovitexin, an active ingredient derived from a variety of traditional Chinese medicines, can reversibly inhibit SrtA activity in vitro with a low dose (IC₅₀=24.72 μg/ml). Fluorescence quenching and molecular simulations proved the interaction between isovitexin and SrtA. Subsequent point mutation experiments further confirmed that the critical amino acid positions for SrtA binding to isovitexin were Ala-92, Ile-182, and Trp-197. In addition, isovitexin treatment dramatically reduced S. aureus invasion of A549 cells. This study shows that treatment with isovitexin could alleviate pathological injury and prolong the life span of mice in an S. aureus pneumonia model. According to our research, isovitexin represents a promising lead molecule for the creation of anti-S. aureus medicines or adjuncts.

Three-Month Follow-Up Study of Survivors of Coronavirus Disease 2019 after Discharge

Liang Limei,Yang Bohan,Jiang Nanchuan,Fu Wei,He Xinliang,Zhou Yaya,Ma Wan-Li,Wang Xiaorong 대한의학회 2020 Journal of Korean medical science Vol.35 No.47

Background: Most patients including health care workers (HCWs) survived the coronavirus disease 2019 (COVID-19), however, knowledge about the sequelae of COVID-19 after discharge remains limited. Methods: A prospectively observational 3-month follow-up study evaluated symptoms, dynamic changes of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) IgG and IgM, lung function, and high resolution computed tomography (HRCT) of survivors of COVID-19 after discharge at Wuhan Union Hospital, China. Results: Seventy-six survivors (55 females) with a mean age of 41.3 ± 13.8 years were enrolled, and 65 (86%) were HCWs. A total of 69 (91%) patients had returned to their original work at 3-months after discharge. Most of the survivors had symptoms including fever, sputum production, fatigue, diarrhea, dyspnea, cough, chest tightness on exertion and palpitations in the three months after discharge. The serum troponin-I levels during the acute illness showed high correlation with the symptom of fatigue after hospital discharge (r = 0.782; P = 0.008) and lymphopenia was correlated with the symptoms of chest tightness and palpitations on exertion of patients after hospital discharge (r = −0.285, P = 0.027; r = −0.363, P = 0.004, respectively). The mean values of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), FEV1/FVC, total lung capacity and diffusion capacity were all normal (> 80% predicted) and lung HRCTs returned to normal in most of the patients (82%), however, 42% of survivors had mild pulmonary function abnormalities at 3-months after discharge. SARS-CoV-2 IgG turned negative in 11% (6 of 57 patients), 8% (4 of 52 patients) and 13% (7 of 55 patients), and SARS-CoV-2 IgM turned negative in 72% (41 of 57 patients), 85% (44 of 52 patients) and 87% (48 of 55 patients) at 1-month, 2-months and 3-months after discharge, respectively. Conclusion: Infection by SARS-CoV-2 caused some mild impairments of survivors within the first three months of their discharge and the duration of SARS-CoV-2 antibody was limited, which indicates the necessity of long-term follow-up of survivors of COVID-19.

Computational efficient FCS-MPC assisted by ANN for Three-level Converter

Kun Wang(쿤왕),Xinliang Yang(양신량),Ki-Bum Park(박기범) 전력전자학회 2023 전력전자학술대회 논문집 Vol.2023 No.7

Effect of PCL-b-PEG Oligomer Containing Ionic Elements on Phase Interfacial Properties and Aggregated Structure of PLA/PCL Blends

Ping Wang,Shang Gao,Xinliang Chen,Li Yang,Tian Cao,Bingyu Fan,Jin Liu,Xianhai Hu 한국고분자학회 2022 Macromolecular Research Vol.30 No.7

The polycaprolactone (PCL)-b-polyethylene glycol (PEG) oligomer (Oli) and its derivative containing ionic elements (ILs) were used as interfacial compatibilizers and regulators, and the polylactic acid (PLA)/PCL/Oli and PLA/PCL/ILs blends were prepared by solution blending. The effects of Oli and ILs on the phase interfacial properties, aggregated structure, crystallization and mechanical properties of PLA/PCL blends were systematically studied. The results show that the ILs with strong interfacial emulsification ability can improve the dispersion of PCL in PLA matrix, and enhance the two-phase interfacial adhesion. When the content of ILs is 5 %, ion clusters can form and alleviate the restricted crystallization of PCL, and promote the segment movement of PLA through the non-covalent bonding of ionic elements. So the crystallization ability of PLA and PCL improve simultaneously. ILs have a strong regulatory effect on the phase interfacial morphology and aggregated structure of PLA/PCL blends, and the PLA/PCL blends containing high content of 5 % ILs can significantly improve the mechanical properties of PLA/PCL blends.

A FPGA-based Spread Spectrum Modulation Method for Harmonic Performance Improvement in Photovoltaic Inverter

Youngseok Lee(이영석),Kun Wang(쿤왕),Xinliang Yang(양신량),Ki-bum Park(박기범) 전력전자학회 2022 전력전자학술대회 논문집 Vol.2013 No.11