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Boosting for Distributed Online Convex Optimization

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Tsinghua Science and Technology 2023年第4期28卷 811-821页

作者： Yuhan Hu yawei zhao Lailong Luo Deke Guo Science and Technology on Information Systems Engineering Laboratory National University of Defense TechnologyChangsha 410073China Medical Engineering Laboratory of Chinese PLA General Hospital and also with the School of Cyberspace SecurityDongguan University of TechnologyDongguan 523000China

Decentralized Online Learning(DOL)extends online learning to the domain of distributed ***,limitations of local data in decentralized settings lead to a decrease in the accuracy of decisions or models compared to centralized *** the increasing requirement to achieve a high-precision model or decision with distributed data resources in a network,applying ensemble methods is attempted to achieve a superior model or decision with only transferring gradients or models.A new boosting method,namely Boosting for Distributed Online Convex Optimization(BD-OCO),is designed to realize the application of boosting in distributed ***-OCO achieves the regret upper bound O(M+N/MNT)where M measures the size of the distributed network and N is the number of Weak Learners(WLs)in each *** core idea of BD-OCO is to apply the local model to train a strong global ***-OCO is evaluated on the basis of eight different real-world *** results show that BD-OCO achieves excellent performance in accuracy and convergence,and is robust to the size of the distributed network.

关键词： distributed Online Convex Optimization(OCO) online boosting Online Gradient Boosting(OGB)

Mechanical Properties of Nano-CaCO_(3) and Basalt Fiber Reinforced Concrete:Experiments and Numerical Simulations

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Journal of Wuhan University of Technology(Materials Science) 2022年第5期37卷 922-932页

作者： DIAO Mushuang REN Qianhui SUN Xinjian zhao yawei WEI Chengpeng State Key Laboratory of Plateau Ecology and Agriculture School of Water Resources and Electric PowerQinghai UniversityXining810016China

In this study,the compressive,split tensile,and flexural strengths of concrete with nano-CaCO_(3) only were compared with those of concrete with nano-CaCO_(3) and basalt fibers through field experiments,and the underlying mechanisms were analyzed by the Scanning Electron Microscope (SEM) *** the mesoscale,a damage model of concrete was established based on the continuum progressive damage theory,which was used to investigate the influence of different lengths and contents of fibers on the mechanical properties of ***,the experimental and numerical simulation results were compared and analyzed to verify the feasibility of *** results show that nano-CaCO_(3) can enhance the compressive strength of the concrete,with an optimal content of 2.0%.Adding basalt fibers into the nano-CaCO_(3) reinforced concrete may further enhance the compressive,split tensile,and flexural strengths of the concrete;however,the higher content of basalt fiber can not lead to higher performance of *** optimal length and content of fiber are 6 mm and 0.20%,*** SEM result shows that the aggregation of basalt fibers is detrimental to the mechanical properties of *** numerical simulation results are in good agreement with the experimental results.

关键词： concrete nano-CaCO_(3) basalt fiber mechanical property microscopic characterization numerical simulation

Improved performance and air stability of perovskite solar cells based on low-cost organic hole-transporting material X60 by incorporating its dicationic salt

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Science China Chemistry 2018年第2期61卷 172-179页

作者： Jishuang Qu Xiaoqing Jiang Ze Yu Jianbo Lai yawei zhao Maowei Hu Xichuan Yang Licheng Sun State Key Laboratory of Fine Chemicals Institute of Artificial Photosynthesis DUT-KTH Joint Education and Research Center on Molecular Devices Dalian University of Technology (DUT) Dalian 116024 China Department of Chemistry School of Chemical Science and Engineering KTH Royal Institute of Technology 100 44 Stockholm Sweden

The development of an efficient, stable, and low-cost hole-transporting material (HTM) is of great significance for perovskite solar cells (PSCs) from future commercialization point of view. Herein, we specifically synthesize a dicationic salt of X60 termed X60(TFSI)2, and adopt it as an effective and stable "doping" agent to replace the previously used lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) for the low-cost organic HTM X60 in PSCs. The incorporation of this dicationic salt significantly increases the hole conductivity of X60 by two orders of magnitude from 10-6 to 10-4 S cm-1. The dramatic enhancement of the conductivity leads to an impressive power conversion efficiency (PCE) of 19.0% measured at 1 sun illumination (100 mW cm-2, AM 1.5 G), which is comparable to that of the device doped with LiTFSI (19.3%) under an identical condition. More strikingly, by replacing LiTFSI, the PSC devices incorporating X60(TFSI)2 also show an excellent long-term durability under ambient atmosphere for 30 days, mainly due to the hydrophobic nature of the X60(TFSI)2 doped HTM layer,which can effectively prevent the moisture destroying the perovskite layer. The present work paves the way for the development of highly efficient, stable, and low-cost HTM for potential commercialization of PSCs.

关键词： perovskite solar cells hole-transporting materials X60 stability sustainable energy

The Application and Simulation of Fuzzy Adaptive PID in Household Heating Metering System

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沈阳理工大学学报 2015年第1期34卷 82-86,94页

作者： zhao yawei LIU Ying Shenyang Ligong University

After heat is metered in each house unit,the heating system is regulated by variable *** temperature of the return w ater is controlled to regulate the flow to realize the temperature *** to the characteristics of the temperature control w ith big inertia,pure time-delay and degeneration,a fuzzy adaptive PID controller is designed w ith the advantages of the fuzzy control and PID algorithm,and the simulation model is established according to the characteristics of heating metering *** results show that the fuzzy adaptive PID controller proposed has small overshoot,short oscillation cycle,high precision and strong anti-jamming capability in comparison w ith conventional PID controller,w hich could meet the requirement of the dynamic and steady-state performance of the heating process.

关键词：加热系统控制器热计量仿真模型

Production of a novel non-toxicγ-PGA/casein composite hydrogel using MTG and optimization by response surface methodology

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Grain & Oil Science and Technology 2021年第2期4卷 71-80页

作者： Xin Wang Chenchen Gou Chunyuan Gao Yazhen Song Jinming Zhang Dandan Zhai yawei zhao Jihong Huang Ming Hui College of Biological Engineering Henan University of TechnologyZhengshou 450001China

Theγ-PGA-based food hydrogel exhibits good biodegradability and biocompatibility,and is non-toxic to *** this study,a novel hydrogel(γ-PGA/casein composite hydrogel)was prepared by combining casein with y-PGA separated from natto using microbial transglutaminase(MTG)as the *** effects of the MTG mass concentration,gelation time,crosslinking temperature,pH,and the mass ratio of y-PGA to casein on the crosslinking ratio of y-PGA and swelling ratio of theγ-PGA/casein hydrogel were ***,the synthesis conditions were optimized by response surface methodology to optimize three important factors,*** temperature,pH and the mass ratio of y-PGA to *** results of single factor experiments showed that the MTG mass concentration and crosslinking time had little impacts on the crosslinking ratio of y-PGA and the swelling ratio;the preferred MTG mass concentration,crosslinking time,temperature and pH were selected as 0.3%,7 h,40℃and 7.5;and the preferred mass ratio ofγ-PGA to casein was 0.1 for the crosslinking ratio ofγ-PGA and 0.2 for the swelling *** response surface experiment results showed that the optimum crosslinking temperature,pH and the mass ratio of y-PGA to casein ratio were 42.4℃,7.33,and 0.18,*** these optimum conditions,the predicted crosslinking ratio of y-PGA and swelling ratio reached 90.35%and 112.07%,which were highly consistent with the experimental values(88.00%and 115.87%).Theγ-PGA/casein composite hydrogel developed in this study shows promising application potential in food industry,biomedical field,and cosmetic industry.

关键词： Hydrogel synthesis MTG cross-linking y-PGA Casein Composite hydrogel

Multiplex genome editing using a dCas9-cytidine deaminase fusion in Streptomyces

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Science China(Life Sciences) 2020年第7期63卷 1053-1062页

作者： yawei zhao Jinzhong Tian Guosong Zheng Jun Chen Chuanwen Sun Zhongyi Yang Andrei A.Zimin Weihong Jiang Zixin Deng Zhijun Wang Yinhua Lu College of Life Sciences.Shanghai Normal University Shanghai 200234China State Key Laboratory of Microbial Metabolism School of Life Sciences and Biotechnology Shanghai Jiao Tong UniversityShanghai 200030China Key Laboratory of Synthetic Biology CAS Center for Excellence in Molecular Plant SciencesShanghai Institute of Plant Physiology and EcologyChinese Academy of SciencesShanghai 200032China School of Life Science Taizhou UniversityTaizhou 318000China Institute of Biochemistry and Physiology of Microorganisms Russian Academy of SciencesPushchino 142290Russia Shanghai Engineering Research Center of Plant Germplasm Resources College of Life SciencesShanghai Normal UniversityShanghai 200234China

CRISPR/Cas-mediated genome editing has greatly facilitated the study of gene function in Streptomyces. However, it could not be efficiently employed in streptomycetes with low homologous recombination(HR) ability. Here, a deaminase-assisted base editor d Cas9-CDA-ULstr was developed in Streptomyces, which comprises the nuclease-deficient Cas9(dCas9), the cytidine deaminase from Petromyzon marinus(PmCDA1), the uracil DNA glycosylase inhibitor(UGI) and the protein degradation tag(LVA tag). Using d Cas9-CDA-ULstr , we achieved single-, double-and triple-point mutations(cytosine-to-thymine substitutions)at target sites in Streptomyces coelicolor with efficiency up to 100%, 60% and 20%, respectively. This base editor was also demonstrated to be highly efficient for base editing in the industrial strain, Streptomyces rapamycinicus, which produces the immunosuppressive agent rapamycin. Compared with base editors derived from the cytidine deaminase rAPOBEC1, the PmCDA1-assisted base editor dCas9-CDA-ULstr could edit cytosines preceded by guanosines with high efficiency, which is a great advantage for editing Streptomyces genomes(with high GC content). Collectively, the base editor dCas9-CDA-ULstr could be employed for efficient multiplex genome editing in Streptomyces. Since the d Cas9-CDA-ULstr -based genome editing is independent of HR-mediated DNA repair, we believe this technology will greatly facilitate functional genome research and metabolic engineering in Streptomyces strains with weak HR ability.

关键词： base editors dCas9-CDA-ULstr multiplex editing Streptomyces

Task Partition Technology of pXCube Cloud Model

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China Communications 2011年第6期8卷 93-99页

作者：赵亚伟 Graduate University of Chinese Academy of Sciences

Query efficiency is bottleneck of XML data cube aggregate query. pXCube is a kind of XML data cube model based on path calculation. Join operations are avoided in this model, but the query efficiency of fact cell is become a new bottleneck. This paper focuses on parallel technology of cloud computing to improve query efficiency of pXCube. Mixed partitioning strategy for fact and dimensions is applied in pXCube cloud model, and the same partitioned vector is adopted. Query parallel algorithm of pXCube cloud model is presented as well. Experiments show that the query cost of pXCube cloud model decreases with the increasing number of parallel nodes gradually. The query cost of fact fragments of each node are close to or even lower than join operations of dimensions, and the Speedup is with better linear. So the model is well suited for decision supported query.

关键词： pXCube cloud model partition fact cell path query parallel dimension

Daily ETC Traffic Flow Time Series Prediction Based on k-NN and BP Neural Network

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国际计算机前沿大会会议论文集 2016年第2期 40-41页

作者： Yanjing Chen yawei zhao Peng Yan School of Engineering Science University of Chinese Academy of SciencesBeijingChina Beijing Sutong Technology Co. Ltd.BeijingChina

Daily Electronic Toll Collection(ETC)traffic flow prediction is one of the fundamental processes in ETC *** precise prediction of traffic flow provides instructions for transportation hub management solution planning and ETC lane *** present,some of studies are proposed in forecasting traffic ***,most studies of model presentation are in the form of mathematical expressions,and it is difficult to describe the trend ***,an ETC traffic flow prediction model based on k nearest neighbor searching(k-NN)and Back Propagation(BP)neural network is proposed,which takes the effect of external factors like holiday,the free of highway and weather *** *** traffic flow data of highway ETC lane somewhere is used for *** prediction results indicate that the total average absolute relative error is 5.01%.The accuracy suggests its advantage in traffic flow prediction and on site application.

关键词： ETC Traffic flow prediction Time series k-NN BP neural network

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基于混合范式的脑-机接口异步控制方法研究

中国生物医学工程学报 2020年第6期39卷 693-699页

作者：徐伟赵雅薇綦宏志天津大学精密仪器与光电子工程学院天津300072 天津大学医学工程与转化医学研究院天津300072

自动判别使用者是否处于操作状态的异步控制问题,是脑-机接口(BCI)领域的研究热点之一。由于BCI范式主要针对区分思维指令来诱发脑电特征,导致在区分操作态上信息含量有限,难以获得较理想的异步识别结果。针对上述问题,研究一种结合事... 详细信息

自动判别使用者是否处于操作状态的异步控制问题,是脑-机接口(BCI)领域的研究热点之一。由于BCI范式主要针对区分思维指令来诱发脑电特征,导致在区分操作态上信息含量有限,难以获得较理想的异步识别结果。针对上述问题,研究一种结合事件相关电位(ERP)与稳态视觉诱发电位(SSVEP)的混合范式方法,以提升异步控制效果。采集10名被试3种状态下的19导联脑电信号,包括在正常使用BCI时的控制状态和被试目光不在BCI界面以及在睁眼静息状态下的2种空闲状态。通过提取不同状态下ERP的幅值特征与SSVEP的相关系数,区分不同的使用状态,进一步采用贝叶斯方法分别对ERP和SSVEP特征的控制态后验概率进行估计,然后将两者综合并采用阈值法对控制态和空闲态进行二分类识别。结果表明,所发展的混合范式方法在不同状态下两种特征差异同时存在,控制态下会产生更高的P300幅值与SSVEP相关系数,并且与空闲态下的特征之间存在统计学差异。对控制状态和空闲状态的总体平均识别正确率达到92.1%,AUC达到0.98。研究结果表明,混合范式方法在异步识别问题上有很好的潜力,值得进一步研究和发展。

关键词：脑-机接口(BCI) 混合范式BCI 异步识别策略贝叶斯后验概率