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Tracking Nonstationary Streaming Data via Exponentially Weighted Moving Average Stochastic Gradient Descent

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Journal of Systems Science & Complexity 2024年

作者： QIAN chengde JIANG Haiyan LIANG Decai School of Statistics and Data Science Nankai University Department of Machine Learning Mohamed Bin Zayed University of Artificial Intelligence (MBZUAI)

In many applications involving data streams, the sequences of data arise from highly dynamic and often unstable real-life processes, rendering untenable the standard assumption that current and future data come from the same distribution. In response, new methodologies, such as dynamic online learning, have been proposed in order to account for the nonstationary features in the data-generating process. Motivated by the stability and statistical efficiency of the notable stochastic approximation method, average stochastic gradient descent(ASGD) in time-invariant systems, the authors propose an exponentially weighted moving average(EWMA)-based stochastic gradient descent(SGD) which accommodates the dynamic structure by introducing a forgetting factor and replacing the simple averaging step in ASGD with an EWMA step. Provided that the dynamic drift is Lipschitz continuous, the mean squared tracking error rate of the proposed method achieves the optimal rate in the nonparametric statistical paradigm. The proposed framework also allows us to derive the dynamic regret bound and asymptotic normality with a path variation constraint in a natural manner. Numerical analysis has been conducted to verify the performance of the proposed method. In particular, the proposed method is much more robust to the selection of learning rates compared with the ordinary SGD method.

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基于电流源型逆变器驱动的五相永磁同步电机控制策略研究

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中国电机工程学报 2024年第7期44卷 2843-2852,I0027页

作者：杨士杰郑萍佟诚德隋义王明峤哈尔滨工业大学电气工程及自动化学院黑龙江省哈尔滨市150001

在现代电机驱动系统中,采用电流源型逆变器控制方案可有效提升系统可靠性,降低电机电流谐波含量,并提升电磁兼容性能。电流源型逆变器拓扑采用电感元件作为母线储能装置,对于功率回路中的短路故障具有较强的抵抗能力。同时,逆变器输出... 详细信息

在现代电机驱动系统中,采用电流源型逆变器控制方案可有效提升系统可靠性,降低电机电流谐波含量,并提升电磁兼容性能。电流源型逆变器拓扑采用电感元件作为母线储能装置,对于功率回路中的短路故障具有较强的抵抗能力。同时,逆变器输出侧并联滤波电容网络,实现对高频谐波的旁路作用。该文对五相电流源型驱动系统控制策略进行研究,采用五相半桥型逆变器拓扑结构,电机绕组采用星型连接方式以限制零序电流,给出基波与谐波电流矢量空间分布特征,提出双平面矢量脉宽调制策略,有效抑制3次谐波电流。考虑到逆变器输出侧CL型负载可能引起的谐振问题,采用基于电机电流的有源阻尼策略,降低谐振电流分量,提升系统稳定性。最后,通过实验验证所提控制策略的有效性。

关键词：五相永磁同步电机驱动电流源型逆变器电流型空间矢量调制 CL谐振有源阻尼

Continuation,reduction,or withdrawal of tofacitinib in patients with rheumatoid arthritis achieving sustained disease control:a multicenter,open-label,randomized controlled trial

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Chinese Medical Journal 2023年第3期136卷 331-340页

作者： Mengyan Wang Yu Xue Fang Du Lili Ma Liang-jing Lu Lindi Jiang Yi-Li Tao chengde yang Hui Shi Honglei Liu Xiaobing Cheng Junna Ye Yutong Su Dongbao Zhao Sheng-Ming Dai Jialin Teng Qiongyi Hu Department of Rheumatology and Immunology Ruijin HospitalShanghai Jiao Tong University School of MedicineShanghai 200025China Department of Rheumatology and Immunology Huashan Hospital Affiliated to Fudan UniversityShanghai 200040China Department of Rheumatology Renji HospitalShanghai Jiaotong University School of MedicineShanghai 200127China Department of Rheumatology Zhongshan HospitalFudan UniversityShanghai 200032China Department of Rheumatology and Immunology Shanghai Sixth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai 200233China Department of Rheumatology and Immunology Changhai HospitalNaval Medical UniversityShanghai 200433China

Background:Rheumatoid arthritis(RA),a chronic systemic autoimmune disease,is characterized by synovitis and progressive damage to the bone and cartilage of the joints,leading to disability and reduced quality of life.This study was a randomized clinical trial comparing the outcomes between withdrawal and dose reduction of tofacitinib in patients with RA who achieved sustained disease control.Methods:The study was designed as a multicenter,open-label,randomized controlled trial.Eligible patients who were taking tofacitinib(5 mg twice daily)and had achieved sustained RA remission or low disease activity(disease activity score in 28 joints[DAS28]≤3.2)for at least 3 months were enrolled at six centers in Shanghai,China.Patients were randomly assigned(1:1:1)to one of three treatment groups:continuation of tofacitinib(5 mg twice daily);reduction in tofacitinib dose(5 mg daily);and withdrawal of tofacitinib.Efficacy and safety were assessed up to 6 months.Results:Overall,122 eligible patients were enrolled,with 41 in the continuation group,42 in the dose-reduction group,and 39 in the withdrawal group.After 6 months,the percentage of patients with a DAS28-erythrocyte sedimentation rate(ESR)of<3.2 was significantly lower in the withdrawal group than that in the reduction and continuation groups(20.5%,64.3%,and 95.1%,respectively;P<0.0001 for both comparisons).The average flare-free time was 5.8 months for the continuation group,4.7 months for the dose reduction group,and 2.4 months for the withdrawal group.Conclusion:Withdrawal of tofacitinib in patients with RA with stable disease control resulted in a rapid and significant loss of efficacy,while standard or reduced doses of tofacitinib maintained a favorable state.Trial Registration:***,ChiCTR2000039799.

关键词： Tofacitinib Rheumatoid arthritis Withdrawal Dose reduction

杂萘联苯聚芳醚酮表面水凝胶涂层的制备及其抗菌性能

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合成树脂及塑料 2024年第1期41卷 1-7页

作者：柳承德张阿利刘文韬蹇锡高大连理工大学化工学院辽宁大连116024 大连理工大学辽宁省高性能树脂工程技术研究中心辽宁大连116024

在杂萘联苯聚芳醚酮(PPEK)与银粉掺杂制备的复合材料表面造孔后,采用银离子催化表面自由基聚合法制备聚丙烯酸/丙烯酰胺水凝胶涂层。通过傅里叶变换红外光谱仪、钨灯丝扫描电子显微镜、X射线光电子能谱仪等对水凝胶涂层的结构与性能进... 详细信息

在杂萘联苯聚芳醚酮(PPEK)与银粉掺杂制备的复合材料表面造孔后,采用银离子催化表面自由基聚合法制备聚丙烯酸/丙烯酰胺水凝胶涂层。通过傅里叶变换红外光谱仪、钨灯丝扫描电子显微镜、X射线光电子能谱仪等对水凝胶涂层的结构与性能进行表征,并研究水凝胶涂层改性PPEK的抑菌作用及其细胞相容性。结果表明:PPEK表面造孔后,涂层与基体材料的结合能从185.83 J/m^(2)提高到926.26 J/m^(2);该水凝胶涂层对大肠杆菌和金黄色葡萄球菌的抑菌率达到95%以上,且无细胞毒性,扩大了PPEK在医疗卫生领域的应用。

关键词：杂萘联苯聚芳醚酮水凝胶涂层自由基聚合抗菌活性细胞相容性

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细胞壁降解酶在球刺盘孢侵染过程中的作用

植物保护 2024年第3期50卷 88-98,110页

作者：金梦军杨成德李统华 OSEI Richard 蔡锋锋马婷甘肃省农作物病虫害生物防治工程实验室甘肃农业大学植物保护学院兰州730070

为明确球刺盘孢Colletotrichum coccodes产生的细胞壁降解酶(CWDEs)在其侵染马铃薯过程中的作用,本文对球刺盘孢离体和活体条件下产生的CWDEs种类及活性进行检测,并通过RT-qPCR测定了球刺盘孢侵染过程中多聚半乳糖醛酸酶(PG)基因的表达... 详细信息

为明确球刺盘孢Colletotrichum coccodes产生的细胞壁降解酶(CWDEs)在其侵染马铃薯过程中的作用,本文对球刺盘孢离体和活体条件下产生的CWDEs种类及活性进行检测,并通过RT-qPCR测定了球刺盘孢侵染过程中多聚半乳糖醛酸酶(PG)基因的表达情况。通过定性测定发现,球刺盘孢能够产生果胶酶、纤维素酶和蛋白酶;定量测定发现,球刺盘孢可产生羧甲基纤维素酶(Cx)、β-葡萄糖苷酶(β-Glu)、PG和聚甲基半乳糖醛酸酶(PMG)。在活体条件下,球刺盘孢可在马铃薯茎秆内产生PG、PMG和多聚半乳糖醛酸反式消除酶(PGTE),且酶活分别于接种后48、72 h和144 h达到最大值,分别为26.50、77.61 U/mL和0.16 U/mg。分别将羧甲基纤维素钠和果胶诱导后的酶液接种至马铃薯茎秆可引起植物组织浸腐,与球刺盘孢引起的典型症状相似。除此之外,球刺盘孢的4个PGs基因均在其侵染后24 h和48 h显著共上调表达。综上所述,该研究结果表明,果胶酶在球刺盘孢致病过程中发挥重要作用。

关键词：球刺盘孢马铃薯细胞壁降解酶多聚半乳糖醛酸酶

Presence of multiple abnormal immunologic markers is an independent prognostic factor of diffuse large B-cell lymphoma

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Frontiers of Medicine 2019年第1期13卷 94-103页

作者： Yiwen Cao Zhenhua Liu Wen Wu Ying Qian Qin Shi Rong Shen Binshen Ouyang Pengpeng Xu Shu Cheng Jin Ye Yiming Lu Chaofu Wang chengde yang Li Wang Weili Zhao State Key Lahoratory of Medical Genomics Shanghai Institute of HematologyRuijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200025China State Key Lahoratory of Medical Genomics Shanghai Institute of HematologyRuijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200025China Department of Pathology Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200025China Pole de Recherches Sino-Francais en Science du Vivant et Genomique Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200025China Department of Rheumatology Ruijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghai 200025China

Autoimmune diseases (ADs) increase the risk of non-Hodgkin's lymphoma and contribute to poor prognosis of patients. However, the association between immunologic markers and clinical outcome has rarely been investigated. This study aims to analyze the prognostic value of pretreatment immunologic markers in newly diagnosed patients with diffuse large B-cell lymphoma (DLBCL). We retrospectively reviewed the data on 502 patients with DLBCL treated in our institution from January 2013 to March 2018. Survival functions were estimated using Kaplan Meier method and Cox regression model. The 3-year progression free survival (PFS) and overall survival (OS) rates were 70.2% and 80.9%, respectively, and the complete remission (CR) rate was 78.1%. Among the patients, those with multiple (≥3) abnormal immunologic markers had significantly shorter 3-year PFS (52.7% vs. 77.3%, P 60 years for OS (P= 0.014). In conclusion, the immunologic status was closely related to lymphoma progression, and this study provides new insights into the risk stratification of patients with DLBCL.

关键词： immunologic marker diffuse large B-cell lymphoma prognosis

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《森林病理学》实践教学的探索与改革

山东农业工程学院学报 2024年第1期41卷 40-44页

作者：范龙飞何静杨成德甘肃农业大学植物保护学院甘肃兰州730070

《森林病理学》是新时代背景下新型林业人才培养的重要课程。本文分析了甘肃农业大学森林保护学专业《森林病理学》理论与实践教学环节中存在的客观问题,结合多所高校成功教改经验以及当地教学实践基地特色,通过对实践教学内容和教学方... 详细信息

《森林病理学》是新时代背景下新型林业人才培养的重要课程。本文分析了甘肃农业大学森林保护学专业《森林病理学》理论与实践教学环节中存在的客观问题,结合多所高校成功教改经验以及当地教学实践基地特色,通过对实践教学内容和教学方式进行初步探索和改革,初步形成了能够适应现代林业发展和林业人才培养需求的实践教学体系。从而全面提高《森林病理学》相关课程实践教学质量和学生的专业素养,为培养高层次林业科研人才奠定坚实基础。

关键词：森林病理学实践教学探索改革

Prediction for permeability index of blast furnace based on VMD-PSO-BP model

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Journal of Iron and Steel Research(International) 2024年第3期31卷 573-583页

作者： Xiao-jie Liu Yu-jie Zhang Xin Li Zhi-feng Zhang Hong-yang Li Ran Liu Shu-jun Chen School of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina chengde Branch HBIS Group Co.Ltd.Chengde 067000HebeiChina

The permeability index is one of the important production indicators to monitor the operation of blast furnace.It is crucial to grasp the trends of changes in the new permeability index in time.For the complex vibration spectrum of the permeability index,a prediction model of the permeability index based on the VMD-PSO-BP(variational mode decomposition-particle swarm optimization-back propagation)method was proposed.Firstly,the key factors that affect the permeability index of blast furnace were studied from multiple perspectives.Then,the permeability index was divided into multiple sub-modes based on the difference of frequency bands by the VMD algorithm,and a PSO-BP prediction model was established for each sub-mode.Finally,the prediction results of each sub-mode were summed to obtain the final one.The results show that the composite prediction accuracy by using the VMD algorithm is 3%higher than that of the traditional prediction method,which has better applicability.

关键词： Big data-Blast furnace Air permeability Variational mode decomposition Particle swarm optimization Back propagation Model prediction

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张掖市山丹县马铃薯枯萎病菌的鉴定

中国蔬菜 2024年第1期 68-73页

作者：何树文王彦崔凌霄许永锋王泽浩杨成德张掖市植保植检站甘肃张掖734000 甘肃农业大学植物保护学院甘肃兰州730070

为明确甘肃省马铃薯枯萎病菌种类,对采集自山丹县的马铃薯枯萎病病原菌进行分离和致病性测定,结合其形态学特征和分子生物学分析对病原菌进行分类鉴定。结果表明,分离得到的3株真菌分离物,经致病性测定均使马铃薯表现出枯萎病的典型症状... 详细信息

为明确甘肃省马铃薯枯萎病菌种类,对采集自山丹县的马铃薯枯萎病病原菌进行分离和致病性测定,结合其形态学特征和分子生物学分析对病原菌进行分类鉴定。结果表明,分离得到的3株真菌分离物,经致病性测定均使马铃薯表现出枯萎病的典型症状,其中病原菌3-2的大型分生孢子呈镰刀状,多为3~5个分隔,大小为(50~75)μm×(4~5)μm,小型分生孢子呈椭圆形;病原菌1-1菌落表面中心由白色逐渐变为红色,边缘白色,呈现不规则状,未观察到分生孢子;病原菌3-6菌丝红色,生长后期菌落中心表面呈黄色,菌丝有隔,厚垣孢子圆形,未观察到分生孢子。结合形态学特征、ITS与EF-1α基因序列同源性,将病原菌3-2鉴定为木贼镰刀菌(Fusarium equiseti),该病菌引起的马铃薯枯萎病为国内首次报道;将1-1和3-6鉴定为三线镰孢菌(F. tricinctum),该病菌引起的马铃薯枯萎病为甘肃省首次报道。

关键词：马铃薯枯萎病鉴定致病性