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    Interpretation of the Global Tuberculosis Report 2022 by World Health Organization
    LIANG Chen, YU Jiajia, TANG Shenjie
    Journal of Diagnostics Concepts & Practice    2023, 22 (01): 21-30.   DOI: 10.16150/j.1671-2870.2023.01.004
    Abstract1004)   HTML43)    PDF(pc) (1105KB)(2906)       Save

    Global Tuberculosis Report 2022 (hereafter referred to as “report”), newly published by the World Health Organization (WHO), states that the coronavirus (COVID-19) pandemic has increased the tuberculosis (TB) disease burden and severely affected global TB prevention and control. In 2021, WHO approved a total of six molecular diagnostic technologies for TB diagnosis and anti-TB drug resistance detection, and three new TB antigen-based skin tests for TB screening were recommended. To reduce the burden on patients and the health system, WHO recommends a 4-month regimen for drug-susceptible TB and four shorter regimens for the treatment of multidrug-resistant/rifampicin-resistant tuberculosis (MDR/RR-TB). In addition, there were 26 drugs for TB treatment in clinical trials, and at least 22 clinical trials evaluating drugs and drug regimens for TB treatment were underway. In 2021, the TB epidemic remains severe in China, with the number of newly diagnosed cases ranking third among the 30 countries. In 2021, a total of 639 548 TB cases and 1 763 deaths were reported nationwide, with an incidence of 45.37/100 000 and a mortality of 0.13/100 000. China has the fourth largest number of MDR/RR-TB patients in the world. However, it is necessary to verify whether the regimens for MDR/RR-TB treatment recommended by WHO are suitable for patients in China.

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    New knowledge of prophylaxis and treatment about cancer-associated thrombosis
    DING Yongjie, ZHANG Liu, LI Qingyun
    Journal of Diagnostics Concepts & Practice    2023, 22 (04): 323-331.   DOI: 10.16150/j.1671-2870.2023.04.001
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    Cancer-associated thrombosis (CAT) is the second leading cause of death in cancer patients, second only to the progression of the tumor. It leads to extended hospitalization and re-hospitalization, resulting in a serious social medical burden. Tumor-specific gene mutations such as JAK2, ALK, and KRAS mutations are closely related to the risk of CAT in patients with solid tumors. Patients treated with immune checkpoint inhibitors have a high risk of CAT, with a 1-year cumulative incidence rate of 10.86%. Therefore, accurate risk assessment is important. The Khorana risk score (KRS) is the first model to assess CAT risk and has been validated in several studies. The new generation models are based on the improvement of KRS, but they have not yet undergone large-scale external verification, such as the Vienna CAT model, PROTECHT model, and CONKO model. Due to the strong correlation between tumors and CAT, several CAT-related prevention guidelines have been established domestically and abroad. All of these guidelines recommend that patients undergo preventive anticoagulation therapy after tumor surgery. Low molecular weight heparin (LMWH) is the most widely used anticoagulant drug to prevent CAT. New oral anticoagulants (NOAC) are also used to prevent CAT, despite the incidence of hemorrhaging increases, the overall benefits to patients outweigh the risks. The strategy for treating CAT is complex. For patients with non-gastrointestinal tumors, NOAC can be used as a first-line drug, while LMWH is recommended for anticoagulation in patients with gastrointestinal tumors. Since CAT patients receive anticoagulation and anti-tumor therapy at the same time, drug interactions need to be considered to avoid drug-induced bleeding, especially the impact of combined medication on NOAC pharmacokinetics. The ideal length of anticoagulation therapy for CAT remains unclear. Guidelines recommend that patients with CAT should indefinitely continue the anticoagulation therapy after completing 3 to 6 months of initial anticoagulation therapy. Therefore, when determining the course of anticoagulation therapy for cancer patients, physicians should evaluate the risk of recurrence of thrombosis and bleeding, and optimize the treatment plan.

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    Interpretation of Multiple Myeloma Guidelines update (version 2, 2023) of National Comprehensive Cancer Network (NCCN)
    TAO Yi, MI Jianqing
    Journal of Diagnostics Concepts & Practice    2023, 22 (02): 121-126.   DOI: 10.16150/j.1671-2870.2023.02.003
    Abstract1207)   HTML52)    PDF(pc) (1042KB)(2369)       Save

    Multiple myeloma (MM) is the second most common hematological malignancy. With the continuous advent of new drugs, the survival of MM patients has been significantly improved, with a median survival of 7-10 years. However, the overall survival of high-risk MM patients is still less than 3 years, and extending the survival of high-risk MM has always been a hot topic in this field. The National Comprehensive Cancer Network (NCCN) released the 2nd version of the MM guidelines for 2023 (2023. v2). Compared with the 5th edition of the MM guidelines for 2022, the update of this guideline in diagnosis is mainly reflected in the detailed description of high-risk MM in tabular form, including both cytogenetic high-risk factors containing 1q21 gain/amplification and clinical high-risk factors, such as extramedullary disease, renal failure and weakness. In terms of treatment, the updated guideline still emphasizes the importance of autologous hematopoietic stem cell transplantation in the era of new drugs, and indicates that the judgment of whether patients are suitable for transplantation needs to be dynamically adjusted based on the patients’ condition after initial treatment. 2023. v2 upgrades the recommendation of the new generation proteasome inhibitor carfilzomib in initial induction and CD38 monoclonal antibody in maintenance therapy. The combinations of these new drugs with immunomodulatory drug pomalidomide are also listed as the preferred regimens in relapsed patients. The diagnostic techniques for distinguishing high-risk MM and new drugs recommended in the updated guideline are currently available in China, Which greatly enhanc our confidence in the “clinical cure” of MM. A comprehensive interpretation of the 2023. v2 of the guidelines is expected to improve the diagnostic and therapeutic level of clinicians, and further improve the prognosis of China’s MM patient population, especially high-risk patients.

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    Clinical characteristics and risk factor analysis of 118 patients with cerebral venous sinus thrombosis
    LI Lei, WU Xi, DAI Jing, WU Wenman, DING Qiulan, WANG Xuefeng
    Journal of Diagnostics Concepts & Practice    2023, 22 (03): 261-269.   DOI: 10.16150/j.1671-2870.2023.03.09
    Abstract131)   HTML9)    PDF(pc) (991KB)(2332)       Save

    Objective: To analyze the clinical characteristics and thrombotic risk factors of cerebral venous sinus thrombosis (CVST) in Chinese population, in order to provide reference for the clinical diagnosis, prevention and treatment of CVST. Methods: A total of 118 CVST patients who visited the Thrombosis and Hemostasis Clinic of Ruijin Hospital from January in 2015 to December in 2022 were enrolled. The clinical data, imaging characteristics, and thrombotic gene panel were collected, and independent risk factors for thrombosis, recurrence, and multi-site thrombosis in CVST patients were studied through univariate and multivariate logistic regression. Results: Among 118 CVST patients, 88.1% (104/118) patients firstly developed CVST at age younger than 45 years old.It revealed that 57.6% patients (68/118) only suffered CVST once,and 33.1% patients (39/118) experienced thrombotic events at least twice, while 37.3% patients (44/118) suffered multi-site venous thromboembolism (VTE). The superior sagittal sinus was the most common venous sinus to form thrombosis (77/118), and multi-sites of venous sinus were involved simultaneously in 54.2% patients (64/118). The risk factor screening for thrombophilia showed that 70.3% patients (83/118) carried at least one thrombotic risk factor, including 53.3% patients (63/118) with inherited risk factors and 32.2% patients (38/118) with acquired risk factors. The main risk factors for males were anticoagulant protein deficiency (35/66) and antiphospholipid syndrome (5/66), while the risk factors for females mainly included anticoagulant protein deficiency (20/52), pregnancy/postpartum period (11/47), and contraceptive use (5/47). Among 35 patients with unknown risk factors, more than 30% of them experienced recurrent or multi-site thrombosis, and the underlying etiology in these patients still need to be further investigated. Univariate and multivariate logistic regression analysis showed that both inherited risk factors (odds ratio, OR=21.643, 95% confidence interval, CI 9.455-49.544, P<0.0001) and acquired risk factors (OR=10.836, 95% CI 4.306-27.270, P<0.0001) were independent risk factors for the occurrence of CVST. Genetic risk factor (OR=2.270, 95% CI 1.021-5.048, P=0.044) was an independent risk factor for recurrent thrombosis in CVST patients. Conclusions: In Chinese population, CVST is more common in middle-aged and young populations.,with 70.3% patients carrying at least one thrombotic risk factor. Genetic risk factors are the main cause of CVST in China and the detectable rate is 53.3%, which is significantly higher than that (22%) reported abroad. The patients with genetic risk factors have a significantly increased risk of developing CVST or recurrent thrombosis. Identification of thrombotic risk factors, prevention, diagnosis and treatment should be carried out earlier for individuals with high-risk CVST.

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    Chinese interpretation of Japanese Gastric Cancer Treatment Guidelines 2021 (6th edition) and Ruijin clinical practice
    YAN Chao, LU Sheng, YAN Min, ZHU Zhenggang
    Journal of Surgery Concepts & Practice    2023, 28 (04): 326-354.   DOI: 10.16139/j.1007-9610.2023.04.010
    Abstract929)   HTML23)    PDF(pc) (4954KB)(2286)       Save

    “Japanese Gastric Cancer Treatment Guidelines” have been important guidelines for the treatment of gastric cancer in Japan and worldwide. The English version “Japanese Gastric Cancer Treatment Guidelines 2021 (6th Edition)” published in January 2023 consists of two parts. The first part includes diagnostic and treatment methods, such as surgery, endoscopic resection, chemotherapy, follow-up. The second part addresses clinical issues, including recommendations and explanations for clinical hot topics. This article will provide a Chinese interpretation of the guidelines and briefly introduce our hospital's clinical practice in the diagnosis and treatment of gastric cancer.

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    Interpretation on the report of global stroke data 2022
    TANG Chunhua, GUO Lu, LI Qiong, ZHANG Lili
    Journal of Diagnostics Concepts & Practice    2023, 22 (03): 238-246.   DOI: 10.16150/j.1671-2870.2023.03.06
    Abstract2693)   HTML138)    PDF(pc) (2270KB)(2037)       Save

    In 2022, the World Stroke Organization released two new reports regarding global stroke statistics in the International Journal of Stroke. The reports updated the global incidence and mortality of stroke, evaluated the effects of gender and geographic factors, and provided updated statistics on attributable risk factors associated with stroke. This article briefly interprets the two reports in the context of stroke prevalence and disease burden in China. 2019 Global Burden of Disease Study findings show that stroke remains the second-leading cause of death and the third-leading cause of death and disability combined in the world. From 1990 to 2019, the burden (in terms of the absolute number of cases) increased substantially, with the bulk of the global stroke burden residing in lower-income and lower-middle-income countries. Moreover, people under 70-year-old were observed to have significant increases in stroke prevalence and incidence. The five major risks for stroke globally include high systolic blood pressure, high body mass index, high fasting glucose, environmental particulate matter pollution, and smoking. Stroke prevention and treatment in China are facing great challenges. Stroke has become the leading cause of death and disability among Chinese adults, as well as the leading cause of disability adjusted life year lost. The incidence, prevalence and mortality of stroke in China are geographically high in the north, low in the south and prominent in the central part of the country; the prevalence is higher in rural areas than that in urban areas; the morbidity and mortality rates are higher in men than those in women; the average age of onset is lower than in developed countries; the overall disease burden of ischemic stroke is on the rise, but that of hemorrhagic stroke is on the decline. The awareness of stroke prevention and treatment was low. In conclusion, it is of strategic importance to actively establish a graded stroke prevention and control system that meets the national conditions.

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    Interpretation of the Clinical Practice Guidelines for Non-small Lung Cancer (version 4 and version 5) of 2022 National Comprehensive Cancer Nerwork(NCCN)
    CHEN Guoqun, CAI Jiaodi
    Journal of Diagnostics Concepts & Practice    2023, 22 (01): 8-13.   DOI: 10.16150/j.1671-2870.2023.01.002
    Abstract598)   HTML28)    PDF(pc) (900KB)(1946)       Save

    Lung cancer is the leading cause of cancer-related deaths worldwide, with approximately 1.8 million patients dying of lung cancer each year, accounting for 18.0% of all cancer deaths. Non-small cell lung cancer (NSCLC) is the main type of lung cancer and accounts for more than 85% of all lung cancer patients. In China, more than 700 000 new cases of lung cancer are diagnosed each year, and more than 600 000 patients die of lung cancer, accounting for 21.7% of all cancer deaths. In 2022, the National Comprehensive Cancer Network (NCCN) updated the guidelines for clinical diagnosis and treatment of lung cancer. Compared with the third edition of the guidelines, the fourth edition of the guidelines added the reference significance of ERBB2 (HER2) mutation in the diagnosis and treatment of (NSCLC). The updated content was mainly focused on the detection of HER2 mutation as a standard biomarker and the treatment of patients with HER2 mutation. The detection of HER2 mutation is recommended for patients with metastatic NSCLC. Fam-trastuzumab deruxtecan and trastuzumab emtansine are recommended as second-line treatment options for patients with HER2 mutation. However, both are in clinical trials in China. The treatment strategies for NSCLC patients with HER2 mutations need to be considered comprehensively in light of the actual situation, and more data from domestic trials are needed. The fifth edition of the guidelines expanded the use of nivolumab, marking new progress in the study of immune checkpoint inhibitors.

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    Report on diagnosis and treatment of hemophilia in China 2023
    XUE Feng, DAI Jing, CHEN Lixia, LIU Wei, ZHANG Houqiang, WU Runhui, SUN Jing, ZHANG Xinsheng, WU Jingsheng, ZHAO Yongqiang, WANG Xuefeng, YANG Renchi
    Journal of Diagnostics Concepts & Practice    2023, 22 (02): 89-115.   DOI: 10.16150/j.1671-2870.2023.02.001
    Abstract2361)   HTML70)    PDF(pc) (1494KB)(1822)       Save

    In recent years, China attaches great importance to the prevention and treatment of rare diseases. As one of the representative diseases of rare diseases, management of Hemophilia has made great progress in China. From 1986 to 1989, the National Hemophilia Cooperative Group conducted China's hemophilia epidemiological survey according to the unified method and standard, and the results showed that the prevalence of hemophilia was 2.73/100 000, and there was no statistical difference in prevalence among different regions. In 2014, Meta-analysis showed that the prevalence of hemophilia in China was 2.8/100 000, and in 2018, based on the data of the urban population of Tianjin, the local prevalence of hemophilia was estimated to be 3.09/100 000. With the comprehensive promotion of the construction of hemophilia hierarchical diagnosis and treatment system, China requires that hospitals applying for hemophilia comprehensive management centers and diagnosis and treatment centers must be able to independently carry out screening tests and confirmatory tests related to hemophilia diagnosis. For diagnosis of hemophilia, most laboratories in China usually adopt the one-stage method (coagulation method) based on the activated partial thromboplastin time (APTT) for the determination of coagulation factor activity, but it should be noted that more than two activity detection methods are required for some special types of hemophilia. The types of each mutation in the F8 gene of patients in China are similar to those reported in international data, and the mutations in the F9 gene of our patients are mainly single base point mutations, with no mutation hotspots found. As of June 2023, a total of more than 40 000 cases with inherited bleeding disorders registered in 261 centers in China (including hemophilia), through the National Hemophilia Registration System. The history of hemophilia treatment in China has been explored through inadequate on-demand and low-dose prophylaxis, and is now moving towards higher-dose prophylaxis and individualized prophylaxis with higher efficacy. Based on the above registry data and literature, this report comprehensively summarizes the progress of basic and clinical research and medical protection in the field of hemophilia in China, and analyzes the shortcomings for further improvement of hemophilia diagnosis and treatment in China.

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    Interpretation of clinical practice guidelines for myelodysplastic syndrome (version 1, 2023) of National Comprehensive Cancer Nerwork(NCCN)
    SONG Luqian, CHANG Chunkang
    Journal of Diagnostics Concepts & Practice    2023, 22 (02): 116-120.   DOI: 10.16150/j.1671-2870.2023.02.002
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    Myelodysplastic syndrome (MDS) is a diverse and common group of myeloid malignant clonal diseases in the hematologic system, with different classification and grouping, clinical manifestations and natural course, and the iteration of different classification systems and versions in history, resulting distress in the correct diagnosis, classification and treatment options. The National Comprehensive Cancer Network (NCCN) released the first version (2023) of Clinical Practice Guidelines for MDS in September 2022. The guideline is based on the clinical practice and standards of high-level evidence and the latest research progress, and its attracts wide attention from clinicians worldwide. Currently, many clinicians in China have insufficient understanding of MDS, and there is still a certain gap with the international diagnosis and treatment level of MDS. This paper interprets the content of the new guidelines, and compares it with the previous guidelines, in order to provide a reference for the standardized diagnosis and treatment of MDS at the current stage in China.

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    Value of proton and heavy ion radiotherapy in treatment of retroperitoneal sarcoma
    WANG Zheng, BAO Cihang, JIANG Guoliang
    Journal of Surgery Concepts & Practice    2022, 27 (06): 506-510.   DOI: 10.16139/j.1007-9610.2022.06.05
    Abstract301)   HTML14)    PDF(pc) (826KB)(1541)       Save
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    An Identification Method for DC-Link Capacitor Capacitance of Grid Connected Inverter
    ZHU Chenghao, WANG Han, SUN Guoqi, WEI Xiaobin, WANG Fuwen, CAI Xu
    Journal of Shanghai Jiao Tong University    2022, 56 (6): 693-700.   DOI: 10.16183/j.cnki.jsjtu.2021.515
    Abstract1045)   HTML1284)    PDF(pc) (5050KB)(1230)       Save

    DC-link for the capacitor is one of the most vulnerable components of the grid connected converter, whose capacitance identification will help to improve the system reliability by finding and replacing the aging capacitor in time. An identification method for the DC-link capacitor capacitance of the grid connected inverter based on pre-charging circuit is proposed. By analyzing the relationship between the capacitance and the charging current, charging voltage during pre-charging process, and combining the historical operating data, the set of capacitance state feature vector is built. The support vector regression (SVR) model is trained and the regression prediction relationship between the state value and the capacitance is set. The model is optimized by using the particle swarm optimization (PSO) algorithm, which can be used for capacitance identification of the DC-link capacitor. Simulation and experiments results show that the proposed method can implement the accurate capacitance identification of the DC-link capacitor of the grid connected inverter, with an identification error of less than 0.95%. This method does not need to add hardware circuit and change the control algorithm, and has a certain practical value.

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    The fifth edition of WHO classification of digestive system tumors: update and progress on biliary system tumors
    LUO Fangxiu, MA Qianchen, YUAN Fei
    Journal of Surgery Concepts & Practice    2023, 28 (02): 124-131.   DOI: 10.16139/j.1007-9610.2023.02.08
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    Overall, there was little change in biliary system tumors of the 5th edition of WHO classification of digestive system tumors after update. The three-tiered classification of biliary intraepithelial neoplasia changed to two-tiered system: high-grade and low-grade, in the section of benign tumors and precancerous lesions. And both intracholecystic and intraductal papillary tumors associated with invasive carcinoma were added. The classification of intrahepatic bile duct tumors introduced parts of bile duct adenoma and bile duct adenofibroma, which were mentioned previously in the differential diagnosis with bile duct carcinoma. Intrahepatic cholangiocarcinoma was divided into small bile duct subtype and large bile duct subtype in the 5th edition of WHO classification, and the names of cholangiocellular carcinoma and cholangiole cell carcinoma were no longer recommended to use. Extrahepatic cholangiocarcinoma was listed as a separate part for the first time, including squamous cell carcinoma, adenosquamous carcinoma and undifferentiated carcinoma in addition to common histological types. Some new contents of molecular pathology in the 5th edition of WHO classification were added, which provided the basis for precise classification and diagnosis of tumors in biliary system.

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    Challenges of Distributed Green Energy Carbon Trading Mechanism and Carbon Data Management
    LI Xingzhi, HAN Bei, LI Guojie, WANG Keyou, XU Jin
    Journal of Shanghai Jiao Tong University    2022, 56 (8): 977-993.   DOI: 10.16183/j.cnki.jsjtu.2021.450
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    To achieve the double carbon goal of “carbon peaking and carbon neutrality”, the construction of the power system which is based on the green energy needs to be accelerated. With the growth of the system scale, the distributed green energy carbon trading mechanism and the carbon data management technology based on the blockchain technology can effectively encourage the development of green energy and become effective means for the implementation of low-carbon electricity. The accurate and real-time carbon emission calculation will further provide data support for the accuracy and security of carbon trading information. First, the current research status of green certificate trading and carbon asset management is introduced. Next, the adaptability analysis of the key technologies of the blockchain technology in the four directions of green electricity traceability, green certificate trading, carbon trading, and joint market of green certificate and carbon assets is performed. Afterwords, the specific mathematical models of carbon emission calculation is studied, and the data availability of carbon source traceability methods applicable to the blockchain architecture are discussed. Finally, some suggestions for the future development of carbon emission flow analysis are proposed.

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    Multi-Objective Optimization Strategy of Trajectory Planning for Unmanned Aerial Vehicles Considering Constraints of Safe Flight Corridors
    HUANG Yuhao, HAN Chao, ZHAO Minghui, DU Qiankun, WANG Shigang
    Journal of Shanghai Jiao Tong University    2022, 56 (8): 1024-1033.   DOI: 10.16183/j.cnki.jsjtu.2021.154
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    Aimed at the problem of generating a smooth, safe, and dynamically feasible continuous-time trajectory for unmanned aerial vehicles (UAV) in complex environments, a trajectory planning algorithm is proposed to minimize a multi-objective function based on safe flight corridors. The safe flight corridor represented by a collection of convex polyhedra is built based on the initial discrete waypoints generated by the improved rapidly-exploring random tree(RRT), namely the RRT* algorithm. The safety objective function is established according to the constraints of limiting the trajectory inside safe flight corridors. In combination with the flight smoothness, dynamic characteristics, and time performance, a multi-objective function is built. The gradient-based convex optimization algorithm is used to derive the continuous-time trajectory expressed as a piece-wise polynomial by optimizing the position, velocity, acceleration of waypoints, and time allocation. The effectiveness and performance of the proposed algorithm is tested and compared under complex environments such as the coal mine. The test results demonstrate that the proposed algorithm has a better comprehensive performance in comparison with existing algorithms.

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    Research progress of miRNA-206 on lung diseases
    ZHANG Lulu, WU Qiannan, HUO Rujie, et al
    Journal of Internal Medicine Concepts & Practice    2022, 17 (05): 413-417.   DOI: 10.16138/j.1673-6087.2022.05.014
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    Electric vehicle charging situation awareness for charging station ultra-short-term load forecast
    SHI Yiwei1 (史一炜), LIU Zeyu1 (刘泽宇), FENG Donghan1∗ (冯冬涵), ZHOU Yun1∗ (周 云), ZHANG Kaiyu2 (张开宇), LI Hengjie3 (李恒杰)
    J Shanghai Jiaotong Univ Sci    2023, 28 (1): 28-38.   DOI: 10.1007/s12204-023-2566-2
    Abstract259)      PDF(pc) (1518KB)(1048)       Save
    Electric vehicles (EVs) are expected to be key nodes connecting transportation–electricity–communication networks. Advanced automotive electronics technologies enhance EVs’ perception, computing, and communication capacity, which in turn can boost the operational efficiency of intelligent transportation systems (ITSs). EVs couple the ITS to the power system, providing a promising solution to charging congestion and transformer overload via navigation and forecasting approaches. This study proposes a privacy-preserving EV charging situation awareness framework and method to forecast the ultra-short-term load of charging stations. The proposed method only relies on public information from commercial service providers. In the case study, data are powered by the Baidu LBS cloud and EV-SGCC platform, and the experiment is conducted within an area of Pudong New District in Shanghai. Based on the results, the charging load of charging stations can be adequately forecasted more than 1 min ahead with low communication and computing power requirements. This research provides the basis for further studies on operation optimization and electricity market transaction of charging stations.
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    Interpretation of the Clinical Practice Guidelines for Lung Cancer Screening (version 2) of 2022 National Comprehensive Cancer Network(NCCN)
    YANG Wenjie, YAN Fuhua
    Journal of Diagnostics Concepts & Practice    2023, 22 (01): 14-20.   DOI: 10.16150/j.1671-2870.2023.01.003
    Abstract362)   HTML13)    PDF(pc) (919KB)(1042)       Save

    The National Comprehensive Cancer Network (NCCN) updated the Clinical Practice Guidelines for Lung Cancer Screening (version 2. 2022). In this version, only two factors, age and smoking history, are used to stratify people into high and low risk groups. Individuals aged ≥50 years with a smoking history ≥20 pack per year are at high risk for lung cancer. Low-dose CT (LDCT) screening is recommended for high-risk individuals. The NCCN guidelines are based on the data of randomized trials conducted in the North American population, whose lung cancer disease spectrum differs from that of the Chinese population in terms of disease characteristics and risk factors. Therefore, Chinese physicians should refer to the 2022 NCCN guidelines combined with the characteristics of the Chinese population in clinical practice. In China, individuals are at high risk for lung cancer if they are aged 50-75 years with at least one additional risk factor (≥20 pack/year smoking history, secondhand smoke exposure, occupational exposure, cancer history or family history of lung cancer, disease history of COPD or pulmonary fibrosis). The benefits of lung cancer screening include decreasing lung cancer mortality, improving life quality, and detecting other hidden health risks (breast cancer, thyroid nodules, asymptomatic coronary artery disease, aortic aneurysms, etc). The use of lung nodule risk calculators by multidisciplinary teams with expertise in thoracic radiology, pulmonary medicine, and thoracic surgery for risk assessment is recommended. The disadvantages of lung cancer screening include over-screening or even ineffective screening for indolent lesions, and ineffective screening for small invasive tumors. It suggests that Chinese physicians need to consider the actual situation, weigh the pros and cons, and seek optimal decision-making.

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    Interpretation of guidelines for the diagnosis and treatment of primary osteoporosis (2022 version) in China: essential introduction
    ZHANG Zhenlin, YUE Hua, LI Mei, XIA Weibo
    Journal of Diagnostics Concepts & Practice    2023, 22 (03): 230-233.   DOI: 10.16150/j.1671-2870.2023.03.04
    Abstract381)   HTML8)    PDF(pc) (913KB)(999)       Save

    China is now witnessing an accelerated aging process,and active reaction is an important issue that we are facing. Osteoporosis and the resulting fractures are particularly noteworthy. In order to further standardize the diagnosis and treatment of primary osteoporosis, the Osteoporosis and Bone Mineral Disease Branch of the Chinese Medical Association has developed and released the “Guidelines for the Diagnosis and Treatment of Primary Osteoporosis (2022 Version)” based on the epidemiological characteristics and pathogenesis of the Chinese population, which combined high-quality medical research evidence from both domestic and foreign sources. Based on evidence-based medicine evidence, and clinical practice in China, this article will focus on the interpretation of two key clinical issues in the new version of the guidelines, namely “fracture risk stratification and treatment selection” and “treatment course of anti-osteoporosis drugs”. Regarding the risk of fractures, this guideline divides it into high and extremely high fracture risks, cancels the classification of low and medium risks, and for one of the extremely high fracture risk indicators “recent brittle fractures”,defines “recent” as “24 months”.Given that the FRAX model underestimates the fracture risk of Chinese patients, it is proposed to develop a highly operational fracture risk stratification criteria in clinical practice. Regarding drug treatment, patients who use bisphosphonates should be fully evaluated before entering the medication holiday, and regular follow-up is still required. Although the Food and Drug Administration (FDA) of the United States has lifted the warning of osteosarcoma and 24- month treatment limit for terlipide, the user manual of the drug in China still suggests a treatment period of 24 months. This guideline is based on high-quality evidence-based medical evidence both domestically and internationally, and may provide reference and research directions for clinical practice.

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    Circulation Control of Airfoil Aerodynamic Force Under Ground Effect of Wavy Wall
    LIU Hao, SUN Jianhong, SUN Zhi, TAO Yang, WANG Dechen, LIU Guangyuan
    Journal of Shanghai Jiao Tong University    2022, 56 (8): 1101-1110.   DOI: 10.16183/j.cnki.jsjtu.2021.384
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    The interaction of airflow and sea waves seriously affects the flight stability and cruising safety of ground effect vehicles. The influence of different sea states and different angles of attack were analyzed numerically on the aerodynamic characteristics of the airfoil under ground effect of wavy wall. The influence of the constant blowing and periodic blowing methods was further studied on the aerodynamic force of the airfoil under ground effect. The simulation results show that the lift coefficient of the airfoil changes periodically with the wave under the wavy ground wall. The amplitude of the lift coefficient fluctuation is larger with the increasing of wave height and angle of attack, or the decreasing of wavelength. Applying the circulation control method for periodic blowing in the same period as the relative motion of the waves can effectively weaken the fluctuation of the airfoil lift coefficient under wavy sea conditions and improve the flight stability and safety of ground effect vehicles.

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    Lung cancer worldwide and in China from 1990 to 2020: prevalence and prevention measures
    WANG Zezhou, ZHENG Ying
    Journal of Diagnostics Concepts & Practice    2023, 22 (01): 1-7.   DOI: 10.16150/j.1671-2870.2023.01.001
    Abstract945)   HTML38)    PDF(pc) (946KB)(928)       Save

    From 1990 to 2020, the number of newly diagnosed cases of lung cancer in the world continued to grow, but the prevalence remained stable. As time went, the incidence (world standard incidence, adjusted with age structure of world population) of lung cancer changed in gender, region, age, and histological type. The difference between male and female in incidence continued to narrow, with male incidence declining by 12.5% and female incidence rising by 22.3%. There were obvious regional differences in the incidence of lung cancer. From 1998 to 2012, the incidence of male lung cancer in Europe, Asia and North America showed a downward trend (the average annual change percentages were -1.6%, -0.6% and -2.5%, respectively), while the incidence of female lung cancer showed a upward trend except North America. From 1998 to 2012, the average age of lung cancer patients in all regions of the world showed a trend of increasing year by year. The average age at diagnosis of lung cancer in Asian men increased from 67.21 years in 1998 to 69.14 years in 2012. Patterns of histological types of lung cancer have also changed. Since the early 1980s, the proportion of squamous cell lung cancer has declined. Since 2004, adenocarcinoma has become the most common histological type of lung cancer in the world. In 2020, China had the largest cases of newly diagnosed lung cancer in the world. From 1989 to 2008, urban-rural ratio of lung cancer incidence dropped from 2.07 to 1.14. In economically underdeveloped areas, the incidence of lung cancer was also rising, and the situation in some areas with high incidence of lung cancer had been controlled. China, as the largest tobacco producer and consumer country, has to be serious with the control of tobacco. Risk of lung cancer caused by environmental pollution is gradually lower. Controlling occupational exposure is also the key to preventing lung cancer in China, and establishing a mornitoring network for risk factors is the direction in future.

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    Evaluation of facial injection filling materials for medical aesthetics

    ZHAO Chenyu, LI Chongchong, SUN Xue, et al
    Journal of Tissue Engineering and Reconstructive Surgery    2023, 19 (5): 517-.  
    Abstract176)      PDF(pc) (874KB)(872)       Save
    With economic development and technological progress, the demand for medical aesthetics has increased sig
    nificantly, and medical biomaterials are widely used. It is necessary to further improve the evaluation of their effectiveness and
    safety. At present, the evaluation of its physicochemical properties and biology is adopted in China. However, the clinical effec
    tiveness is a multi-faceted evaluation without unified criteria. Most of the evaluation mainly adopts objective indicators for quan
    titative analysis, while subjective feelings are secondary criteria. In this paper, the main facial fillers and the evaluation methods
    of their physicochemical properties were reviewed.
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    An Admittance Reshaping Strategy of Three-Phase LCL Grid-Connected Inverter Based on Modified Passive Control
    WANG Han, ZHANG Jianwen, SHI Gang, ZHU Miao, CAI Xu
    Journal of Shanghai Jiao Tong University    2023, 57 (9): 1105-1113.   DOI: 10.16183/j.cnki.jsjtu.2022.120
    Abstract294)   HTML34)    PDF(pc) (3313KB)(849)       Save

    The passivity-based control (PBC) based on energy function has been studied for grid-connected converters to achieve a better performance. However, traditional PBC method relies on the accurate mathematical model of grid-connected inverter. In previous studies on PBC, the effect of digital control delay is rarely considered and the stability under grid impedance uncertainties is not discussed, especially in the capacitive grid or complex weak grid. To address these issues, this paper proposes an improved PBC method to reshape the output admittance for LCL-filtered grid-connected inverters. The system passive region is expanded up to the Nyquist frequency by adding a capacitor current feedback loop which can achieve active damping control of LCL resonant frequency under the wide range of grid impedance changes. The parameter design method is also presented for the proposed PBC control. To verify the correctness of the theoretical analysis, both simulation and experiments are conducted on a 3 kW grid-connected inverter prototype.

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    Ultra-Short-Term Load Forecasting of Electric Vehicle Charging Stations Based on Ensemble Learning
    LI Hengjie, ZHU Jianghao, FU Xiaofei, FANG Chen, LIANG Daming, ZHOU Yun
    Journal of Shanghai Jiao Tong University    2022, 56 (8): 1004-1013.   DOI: 10.16183/j.cnki.jsjtu.2021.486
    Abstract1107)   HTML397)    PDF(pc) (3182KB)(817)       Save

    Accurate electric vehicle load forecasting is the basis for maintaining the safe and economical operation of charging stations, and for supporting the planning and decision-making of new and expanded charging infrastructure. In order to improve the accuracy of the ultra-short-term load forecasting of charging stations, an ultra-short-term load forecasting method based on ensemble learning is proposed. First, aimed at the prediction accuracy and the response speed, the light gradient boosting machine (LightGBM) framework is utilized to build several basic regressors. Next, the basic regressors are integrated by using the adaptive boosting (Adaboost) method. Finally, by using hyperparameter adjustment and optimization, a dual-system for ultra-short-term load forecasting of charging stations named energy ensemble boosting-light gradient boosting machine (EEB-LGBM) is generated. The analysis of the numerical examples shows that the proposed model has a higher accuracy than the back propagation neural network (BPNN), convolutional neural networks-long short term memory (CNN-LSTM), autoregressive integrated moving average (ARIMA), and other load forecasting methods, which can greatly reduce the training time and the computing power requirements of the training platform.

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    Intelligent Global Sensitivity Analysis Based on Deep Learning
    WU Shuchen, QI Zongfeng, LI Jianxun
    Journal of Shanghai Jiao Tong University    2022, 56 (7): 840-849.   DOI: 10.16183/j.cnki.jsjtu.2021.191
    Abstract990)   HTML48)    PDF(pc) (1418KB)(809)       Save

    This paper proposes an end-to-end method that combines deep learning and sensitivity analysis, which can perform gradient back propagation calculation sensitivity on the saved weight information while training the model. The structure and activation function of the depth model are specially designed to adapt to the subsequent sensitivity calculation. The experimental results conducted on a Boston house prices dataset, a track information fusion dataset, and the G function show that the proposed method is more accurate than classical methods such as Sobol’ method when the parameter distribution is uneven, and has a stronger robustness. Compared with the traditional neural network method, the accuracy of the proposed method is higher. The experiment proves that the sample parameter sensitivity obtained by the deep learning model can be used to optimize the model output.

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    Interpretation of the 2022 edition of “guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis in China”
    XU Bojin, PENG Wenfang, HUANG Shan
    Journal of Surgery Concepts & Practice    2023, 28 (06): 512-519.   DOI: 10.16139/j.1007-9610.2023.06.05
    Abstract198)   HTML1)    PDF(pc) (889KB)(780)       Save

    “Guidelines for diagnosis and management of hyperthyroidism and other causes of thyrotoxicosis in China” (2022) (referred to as the “guidelines”) was officially published in August 2022 in the Chinese Journal of Endocrine Metabolism. These guidelines have been extensively updated from the 2007 version, with 15 sections covering the etiology, clinical manifestations, diagnosis, evaluation, and treatment of hyperthyroidism, as well as the management of specific types of thyrotoxicosis. The new version guidelines proposed 107 recommended opinions supported by stronger evidence, offering comprehensive and reliable guidance for clinical doctors and medical professionals dealing with thyrotoxicosis. This article aimed to extract the key points and recommended strategies from the guidelines to help clinical doctors better understand and apply the latest guiding principles.

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    Optimal Planning of Power Systems with Flexible Resources for High Penetrated Renewable Energy Accommodation
    GUO Yongtao, XIANG Yue, LIU Junyong
    Journal of Shanghai Jiao Tong University    2023, 57 (9): 1146-1155.   DOI: 10.16183/j.cnki.jsjtu.2022.269
    Abstract181)   HTML11)    PDF(pc) (2433KB)(778)       Save

    High penetrated renewable energy has brought great challenges to the flexibility of the power system due to its volatility and intermittency. To improve the capacity of renewable energy accommodation, the flexibility reformation of thermal power units, the construction of gas-fired units, and the electrical energy storage installation are considered as effective solutions. Thus, an optimization model for power system planning scheme considering multi-type flexible resources with their different output characteristics is established. The simulation results on a modified IEEE 24-bus power system and 12-node natural gas system demonstrate the effectiveness of the proposed model. In addition, the applicability of different flexible resource planning schemes is comprehensively evaluated from the perspectives of economy, accommodation capacity, and carbon reduction, so as to meet the different planning goals.

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    A Dual-System Reinforcement Learning Method for Flexible Job Shop Dynamic Scheduling
    LIU Yahui, SHEN Xingwang, GU Xinghai, PENG Tao, BAO Jinsong, ZHANG Dan
    Journal of Shanghai Jiao Tong University    2022, 56 (9): 1262-1275.   DOI: 10.16183/j.cnki.jsjtu.2021.215
    Abstract846)   HTML70)    PDF(pc) (4009KB)(777)       Save

    In the production process of aerospace structural parts, there coexist batch production tasks and research and development (R&D) tasks. Personalized small-batch R&D and production tasks lead to frequent emergency insertion orders. In order to ensure that the task is completed on schedule and to solve the flexible job shop dynamic scheduling problem, this paper takes minimization of equipment average load and total completion time as optimization goals, and proposes a dual-loop deep Q network (DL-DQN) method driven by a perception-cognition dual system. Based on the knowledge graph, the perception system realizes the representation of workshop knowledge and the generation of multi-dimensional information matrix. The cognitive system abstracts the scheduling process into two stages: resource allocation agent and process sequencing agent, corresponding to two optimization goals respectively. The workshop status matrix is designed to describe the problems and constraints. In scheduling decision, action instructions are introduced step by step. Finally, the reward function is designed to realize the evaluation of resource allocation decision and process sequence decision. Application of the proposed method in the aerospace shell processing of an aerospace institute and comparative analysis of different algorithms verify the superiority of the proposed method.

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    Differentiated Allocation Model of Renewable Energy Green Certificates for New-Type Power System
    ZHANG Shuo, LI Wei, LI Yingzi, LIU Qiang, ZENG Ming
    Journal of Shanghai Jiao Tong University    2022, 56 (12): 1561-1571.   DOI: 10.16183/j.cnki.jsjtu.2022.150
    Abstract1330)   HTML816)    PDF(pc) (1436KB)(760)       Save

    In order to achieve China’s “30·60” decarbonization goal, the green and low-carbon transformation of the energy system is the fundamental support; the construction of new-type power system is the key step, and the green certificate is the important voucher to reflect the green value of renewable energy. Currently, the distribution mechanism of green certificates in China is oversimplified, which neither effectively measures the variability of green values generated by different types of renewable energy, nor balances the coordinated development of renewable energy. Therefore, to differentiate the exchange mechanism of green certificates by different types of renewable energy power in this paper, an evaluation index system is established, which describes the difference between green certificates, considering the comprehensive value of renewable energy, and an evaluation model is built with the criteria importance by using the intercriteria correlation (CRITIC) method, the entropy weight method, and the technique for order preference by similarity to an ideal solution (TOPSIS) method. Under the development scenario of peaking carbon emissions before 2030, the impact of the differentiated distribution model on the green incomes of centralized photovoltaic distributed photovoltaic power, onshore wind power, and offshore wind power is analyzed. Moreover, the development plan of renewable energy is modified in consideration of the effect of the differentiated distribution model, and policy suggestions on green certificates are proposed accordingly. The results show that the differentiated distribution model of green certificates is practical to provide corresponding decision-making support to the construction and improvement of green certificates trading mechanism in China.

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    Real-Time Calculation of Carbon Emissions in County-Level Administrative Regions Based on ‘Energy Brain’
    CHEN Yun, SHEN Hao, WANG Jiayu, ZHAO Wenkai, PAN Zhijun, WANG Xiaohui, XIAO Yinjing
    Journal of Shanghai Jiao Tong University    2022, 56 (9): 1111-1117.   DOI: 10.16183/j.cnki.jsjtu.2021.364
    Abstract1007)   HTML782)    PDF(pc) (851KB)(747)       Save

    Existing calculation methods of carbon emission cannot well meet the needs of gradual refinement and real-time of carbon emission regions. In order to ensure the real-time and accuracy of carbon emissions responsibility allocation, a real-time calculation method of carbon emissions in urban regions is proposed. The improved K-means clustering algorithm is used to cluster and combine the operating periods and operating scenarios of the urban area energy load,so as to obtain the typical carbon emission characteristics. The regional unit electricity carbon emission is proposed as a carbon emission indicator, the operating period and scenario are classified, and the unit electricity carbon emission and the total carbon emission of urban regions for each cluster are calculated. The proposed algorithm is verified based on part of the historical data of energy consumption in the energy brain of a certain region in eastern China. The results show that the clustering method and carbon emission indicators can effectively calculate the total carbon emission of urban regions in real-time.

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    Radar Signal Recognition Based on Dual Channel Convolutional Neural Network
    QUAN Daying, CHEN Yun, TANG Zeyu, LI Shitong, WANG Xiaofeng, JIN Xiaoping
    Journal of Shanghai Jiao Tong University    2022, 56 (7): 877-885.   DOI: 10.16183/j.cnki.jsjtu.2021.209
    Abstract880)   HTML28)    PDF(pc) (4098KB)(747)       Save

    In order to solve the problems of difficult feature extraction and low recognition rate of radar signal at low signal-to-noise ratios, a dual channel convolutional neural network model based on Choi-Williams distribution (CWD) and multisynchrosqueezing transform (MSST) is proposed, which obtains two-dimensional time-frequency images by CWD and MSST time-frequency analyses on radar signals. Respectively, the time-frequency images are preprocessed and sequencely fed to a dual channel convolutional neural network for deep feature extraction. Finally, the features acquired by the two channels are fused, and the radar signal is classified and recognized through the convolutional neural network classifier. The simulation results show that when the signal-to-noise ratio is -10 dB, the overall recognition accuracy can reach above 96%, which is excellent at low signal-to-noise ratios.

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    Journal of Internal Medicine Concepts & Practice    2022, 17 (04): 344-348.   DOI: 10.16138/j.1673-6087.2022.04.015
    Abstract226)   HTML9)    PDF(pc) (526KB)(736)       Save
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    Mechanism of Forced Subsynchronous Oscillation of Large-Scale Photovoltaic Power Generation Grid-Connected System with Series Compensation Tranmmission Lines
    LIN Yong, KANG Jiale, YU Hao, CHEN Honglin, YANG Yanji, CHEN Wuhui
    Journal of Shanghai Jiao Tong University    2022, 56 (9): 1118-1127.   DOI: 10.16183/j.cnki.jsjtu.2021.415
    Abstract683)   HTML132)    PDF(pc) (1463KB)(734)       Save

    There exists the subsynchronous oscillation (SSO) instability risk in large-scale photovoltaic(PV) grid-connected systems with series compensation, which is generally explained by the negative damped oscillation theory. In this paper, the inter-photovoltaic harmonics due to maximum power point tracking (MPPT) control are used as the disturbance source and the large-scale PV grid-connected system with series compensation as the forced system. The forced oscillation theory is used to reveal the SSO mechanism of PV power generation based on the interaction between the perturbed MPPT and the series compensation grid-connected system, and verified in the PSCAD/EMTDC simulation platform. The results show that the perturbed MPPT-based PV inverter outputs interharmonic currents to the system due to the modulation coupling on the AC-DC side, which may lead to serious forced SSO problems when the interharmonic frequency is close to the frequency of inherent weakly damped mode of the system, causing a shock to the system stability. The simulation results verify the correctness of the proposed theory.

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    An LC Inverter Based on Novel Dual-Loop Control
    LI Shuang, SHI Jianqiang
    Journal of Shanghai Jiao Tong University    2022, 56 (9): 1139-1147.   DOI: 10.16183/j.cnki.jsjtu.2021.275
    Abstract894)   HTML129)    PDF(pc) (1553KB)(725)       Save

    To improve the voltage tracking and anti-disturbance performance of the LC inverter, a novel voltage-current dual-loop control strategy is proposed. First, the voltage loop is tuned to first-order inertia link by zero-pole cancellation based on virtual resistance, which restrains the overshoot during voltage tracking. Next, the hypo-time-optimal current-loop is adopted to enhance the response speed of the current loop, which suppresses the sudden change of transient voltage. Finally, the cause of overshoot during the voltage recovery period is analyzed and the overshoot is eliminated by the adaptive integrator initial value, which modifies the voltage waveform distortion under loading disturbance. Based on the traditional double-loop control, the voltage loop and the current loop are improved respectively by the proposed novel control strategy, which overcomes the shortcomings of step response and anti-load disturbance performance. The feasibility and effectiveness of this method are validated through simulations on MATLAB/Simulink.

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    Inertial Control Strategy for Wind Farm with Distributed Energy Storage System Based on Model Predictive Control
    SHEN Yangwu, SONG Xingrong, LUO Ziren, SHEN Feifan, HUANG Sheng
    Journal of Shanghai Jiao Tong University    2022, 56 (10): 1285-1293.   DOI: 10.16183/j.cnki.jsjtu.2022.134
    Abstract895)   HTML1099)    PDF(pc) (1641KB)(725)       Save

    Distributed energy storage (DES) wind turbine is an effective means to solve the problem of system frequency stability caused by large-scale wind power connection. In this paper, an inertial control method for DES wind farms based on model predictive control (MPC) is proposed.First, the linearized prediction model of the DES wind farm is established. Then, on this basis, in combination with the control framework of MPC, an optimization model and strategy of MPC inertial control are proposed considering the cost of energy storage loss and the balanced change of wind turbine rotor speed,in order to achieve the balanced change of wind turbine rotor speed during inertia control. The simulation results show that the proposed control strategy can effectively coordinate the active power output of the wind power generation unit and the energy storage system unit in the DES wind turbine, reduce the cost of charging and discharging loss of the energy storage system, and ensure that the rotational speed of all wind turbines in the wind farm tends to be average during the inertial control period, avoiding the problem of wind turbines exiting frequency regulation due to excessive reduction of the rotational speed of wind turbines. The inertial control strategy of the DES wind farm is beneficial to improve the frequency stability of the power grid, which is of great significance to ensure the safe operation of the power grid.

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    Real-Time Detection of Insulator Drop String Based on UAV Aerial Photography
    LI Dengpan, REN Xiaoming, YAN Nannan
    Journal of Shanghai Jiao Tong University    2022, 56 (8): 994-1003.   DOI: 10.16183/j.cnki.jsjtu.2021.416
    Abstract740)   HTML396)    PDF(pc) (28565KB)(721)       Save

    It is of great significance for unmanned aerial vehicle(UAV) to replace manual inspection of power insulators. Aimed at the problem of limited computing power and storage resources of the UAV, an improved real-time target detection algorithm suitable for insulator drop string failure detection is proposed. Based on the YOLOv5s detection network, first, the PANet networks in neck are replaced with bi-directional feature pyramid network(BiFPN) to improve the feature fusion ability. Next, DIoU is used to optimize the loss function to optimize the model. The channel pruning and fine tuning of the γ coefficient generally improve the accuracy, speed, and deployment ability of the detection network. Finally, the image is enhanced at the network output to improve the availability of the algorithm. The proposed algorithm is tested under a specially expanded insulator fault data set. The results show that compared with the original YOLOv5s algorithm, the average accuracy of the proposed algorithm is improved by 3.91%, the detection speed is improved by 25.6%, and the model volume is reduced by 59.1%.

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    Application of Plane Elements and Shell Elements in Imitating Ribs of Members in Compound Strip Method
    HOU Yanguo, LI Zhanjie, GONG Jinghai
    Journal of Shanghai Jiao Tong University    2022, 56 (6): 710-721.   DOI: 10.16183/j.cnki.jsjtu.2021.071
    Abstract835)   HTML448)    PDF(pc) (10465KB)(715)       Save

    Finite strip method (FSM) is a classical method to analyze the buckling of thin-walled members. The traditional FSM adopting trigonometric functions longitudinally can hardly analyze the members with spaced ribs along the longitudinal direction, while the compound strip method (CSM) can compensate for this shortcoming. Based on the CSM, the influence of utilizing plane elements and shell elements to respectively imitate stiffeners on buckling is investigated. Compared with the shell-element ribs, the plane-element ribs are prone to assembling the stiffener matrices with fewer degrees of freedom. But the shell-element ribs are more comprehensive as the out-plane displacement of ribs are taken into consideration. It is found that plane element ribs and shell element ribs have little difference on the buckling capacity of members. The buckling capacity has a small difference of mean absolute error (MAE) underneath 0.75% between the two types of CSMs, and the buckling capacity and modes are in good agreement with the finite element results. The buckling loads of the two types of CSMs are close to the FEM with a MEA less than 5%. The accuracy of the plane elements satisfies the predicted requirements, which helps to reduce the program computation and simplify the analysis complexity. The efficiency of analysis can be dramatically improved for fine meshing elements.

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    A Novel Prediction Model for Fatigue Strength
    DUAN Hongyan, TANG Guoxin, SHENG Jie, CAO Mengjie, PEI Lei, TIAN Hongwei
    Journal of Shanghai Jiao Tong University    2022, 56 (6): 801-808.   DOI: 10.16183/j.cnki.jsjtu.2021.051
    Abstract1062)   HTML123)    PDF(pc) (1208KB)(713)       Save

    Fatigue failure is one of the most important reasons for the failure of engineering application components. However, due to the high cost of fatigue experiments, it is necessary to use mechanical properties to predict fatigue strength. Based on the true stress-strain curves, a novel model for fatigue strength prediction is established and is used to calculate the fatigue strength. The strength predicted is compared with that calculated by the staircase method and the Basquin equation. The results show that the model could obtain the fatigue strength of the materials only by using tensile strength and work-hardening strength, and it is suitable for other steels, which greatly saves costs and increases accuracy.

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    Experiment on Wedge-Shaped Latticework Channel Cooling Applied in Aero Engine Gas Turbine Blade Trailing Edge
    XIAO Kehua, LUO Jiahao, RAO Yu
    Journal of Shanghai Jiao Tong University    2022, 56 (8): 1034-1042.   DOI: 10.16183/j.cnki.jsjtu.2021.162
    Abstract644)   HTML33)    PDF(pc) (20093KB)(702)       Save

    In order to study the flow and heat transfer performance of wedge-shaped latticework channels in the turbine blade trailing edge, this paper conducted an experimental study by employing the transient liquid crystal (TLC) technique to investigate the local heat transfer characteristics of the upper and lower main surfaces and applying the pressure scanning valve to mesure the pressure loss of the channels at different Reynolds numbers. The experiment shows that there is a significant difference between the upper and lower main surfaces under the turning flow configuration condition at the trailing edge section. The average Nusselt number of the lower main surface is over 30% higher than that of the upper main surface. In heat transfer coefficient, the wedge-shaped latticework channel is over 46% higher than that of the needle rib channel. There is a strong mass exchange at the interface between the upper and lower channels of the latticework channel. The intermittent high heat transfer areas on the upper and lower main surfaces are corresponding to the interface. As the inlet Reynolds number increases, the channel pressure drop increases rapidly. The pressure drop of the wedge-shaped latticework channel is 5 to 7 times that of the needle ribs, but the heat transfer area of latticework channel is 107.4% higher than the needle ribs channel, and the overall thermal performance of the wedge-shaped latticework channel is still approximately 66% higher than that of the needle ribs channel.

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    Frequency Control Strategy for Interconnected Power Systems with Time Delay Considering Optimal Energy Storage Regulation
    FU Yang, DING Zhiyin, MI Yang
    Journal of Shanghai Jiao Tong University    2022, 56 (9): 1128-1138.   DOI: 10.16183/j.cnki.jsjtu.2022.145
    Abstract752)   HTML128)    PDF(pc) (3139KB)(665)       Save

    Aimed at the problem of large frequency deviation caused by the source load uncertainty and the communication delay in the interconnected power system, a frequency control strategy for interconnected power systems with time-delay considering energy storage regulation is proposed. An interconnected power grid model with time delay which includes a steam turbine generator, a wind turbine generator, and energy storage equipment is established. According to the area control error (ACE), the energy storage device coordinates the steam turbine generator to participate in the frequency control, and the modified particle swarm optimization (MPSO) algorithm is used to optimize the proportional integral derivative (PID) load frequency controller to realize the secondary frequency adjustment, which improves the frequency stability of the load frequency control (LFC) system in a certain time-delay interval. A fractional order PID (FOPID) controller is designed for the energy storage device to adjust the output power and smooth the source load fluctuation. The frequency control performance of the energy storage system is improved to further control the frequency deviation of the interconnected power system. Different working conditions are compared and analyzed on the MATLAB/Simulink platform to verify the effectiveness of the proposed frequency control strategy.

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    Cryogenic Minimal Quantity Lubrication Assisted Cutting Process for Polyimide Materials
    CAO Zheng, LEI Xuelin, ZHANG Hang, CAI Xiaojiang
    Journal of Shanghai Jiao Tong University    2022, 56 (6): 784-793.   DOI: 10.16183/j.cnki.jsjtu.2021.173
    Abstract830)   HTML21)    PDF(pc) (21845KB)(663)       Save

    The cutting performance of the porous polyimide material assisted by cold air trace lubrication was investigated, and the influence law of cutting process parameters on the cutting effect (cutting force, surface finish quality, and oil content) of the porous material was explored. The results show that compared with dry cutting and low-temperature cold air cutting, the cutting temperature and the machined surface roughness of cold air micro-lubrication cutting are the lowest, and the damage to the porous runner is the smallest. The depth of cut and the feed volume are the factors that have the greatest influence on milling force and surface roughness, respectively. Defects such as chip burrs and tears are the main factors that lead to the increase in surface roughness. The existence of drawing, micro-crack, stacking, and tiny debris on the workpiece surface are the main causes for the decrease in the oil content and oil delivery rate of the material. The optimal machining parameters of the porous polyimide material in the orthogonal experiment with the aid of cold air trace lubrication are vc=(100±2) mm/min, fz=(0.3±0.01) mm/r, ap=(0.8±0.1) mm (vc is the cutting speed, fz is the feeding rate, and ap is the cutting depth). With the assist of the cryogenic minimal quantity lubrication technology, the low damage processing, high oil content, and high oil delivery rate of cage products can be obtained.

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