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Prediction of COVID-19 spread by sliding mSEIR observer

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Science China(Information Sciences) 2020年第12期63卷 166-178页

作者： Duxin CHEN yifan YANG yifan zhang Wenwu YU Jiangsu Key Laboratory of Networked Collective Intelligence School of Mathematics Southeast University School of Information Science and Engineering Southeast University

The outbreak of COVID-19 has brought unprecedented challenges not only in China but also in the whole world. Thousands of people have lost their lives, and the social operating system has been affected seriously. Thus, it is urgent to study the determinants of the virus and the health conditions in specific populations and to reveal the strategies and measures in preventing the epidemic spread. In this study, we first adopt the long short-term memory algorithm to predict the infected population in China. However,it gives no interpretation of the dynamics of the spread process. Also the long-term prediction error is too large to be accepted. Thus, we introduce the susceptible-exposed-infected-removed(SEIR) model and further the metapopulation SEIR(mSEIR) model to capture the spread process of COVID-19. By using a sliding window algorithm, we suggest that the parameter estimation and the prediction of the SEIR populations are well performed. In addition, we conduct extensive numerical experiments to show the trend of the infected population for several provinces. The results may provide some insight into the research of epidemics and the understanding of the spread of the current COVID-19.

关键词： epidemic spread prediction sliding window algorithm COVID-19

The evolving views of hematopoiesis:from embryo to adulthood and from in vivo to in vitro

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Journal of Genetics and Genomics 2024年第1期51卷 3-15页

作者： yifan zhang Feng Liu Shandong Provincial Key Laboratory of Animal Cell and Developmental Biology School of Life SciencesShandong UniversityQingdaoShandong 266237China State Key Laboratory of Membrane Biology Institute of ZoologyInstitute for Stem Cell and RegenerationUniversity of Chinese Academy of SciencesChinese Academy of SciencesBeijing 100101China

The hematopoietic system composed of hematopoietic stem and progenitor cells(HSPCs)and their differentiated lineages serves as an ideal model to uncover generic principles of cell fate *** gastrulation onwards,there successively emerge primitive hematopoiesis(that produces specialized he-matopoietic cells),pro-definitive hematopoiesis(that produces lineage-restricted progenitor cells),and definitive hematopoiesis(that produces multipotent HSPCs).These nascent lineages develop in several transient hematopoietic sites and finally colonize into lifelong hematopoietic *** development and maintenance of hematopoietic lineages are orchestrated by cell-intrinsic gene regulatory networks and cell-extrinsic microenvironmental *** to the progressive methodology(e.g.,high-throughput lineage tracing and single-cell functional and omics analyses),our understanding of the developmental origin of hematopoietic lineages and functional properties of certain hematopoietic organs has been updated;meanwhile,new paradigms to characterize rare cell types,cell heterogeneity and its causes,and comprehensive regulatory landscapes have been ***,we review the evolving views of HSPC biology during developmental and postnatal ***,we discuss recent advances in the in vitro induction and expansion of HSPCs,with a focus on the implications for clinical applications.

关键词： Hematopoietic stem and progenitor cell Developmental hematopoiesis Postnatal hematopoiesis In vitro hematopoiesis

A review of linear carbon chains

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Chinese Chemical Letters 2020年第7期31卷 1746-1756页

作者： Kan zhang yifan zhang Lei Shi Check for updates State Key Laboratory of Optoelectronic Materials and Technologies Nanotechnology Research CenterSchool of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China

Linear carbon chains(LCCs)are a one-dimensional sp1-hybridized allo trope of ca *** are extre mely unstable:The longer the LCCs,the less stable the ***,it is a big challenge to synthesize long *** the research on the short LCCs,e.g.,polyynes,can be traced back to the 18th,LCCs are still not well-known compared to other allotropes of carbon,e.g.,fullerenes,carbon nanotubes and ***,introducing recent progress on LCCs is of great significance to draw more attention in the community of nanocarbons as well as nanomaterials in ***,various excellent properties have been ***,LCCs with different length in many kinds of forms have been successfully *** this review,we summarized recent studies of polyynic LCCs from both theoretical and experimental ***,perspectives are highlighted to point out the further investigations of the materials.

关键词： Linear carbon chains Polyyne Carbyne Carbon nanotubes Electronic property

A constrained neural network model for soil liquefaction assessment with global applicability

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Frontiers of Structural and Civil Engineering 2020年第5期14卷 1066-1082页

作者： yifan zhang Rui WANG Jian-Min zhang Jianhong zhang Department of Hydraulic Engineering State Key Laboratory of Hydroscience and EngineeringTsinghua UniversityBeijing 100084China

A constrained back propagation neural network(C-BPNN)model for standard penetration test based soil liquefaction assessment with global applicability is developed,incorporating existing knowledge for liquefaction triggering mechanism and empirical *** its development and validation,a comprehensive liquefaction data set is compiled,covering more than 600 liquefaction sites from 36 earthquakes in 10 countries over 50 years with 13 complete information *** C-BPNN model design procedure for liquefaction assessment is established by considering appropriate constraints,input data selection,and computation and calibration *** empirical relationships for overburden correction and fines content adjustment are shown to be able to improve the prediction success rate of the neural network model,and are thus adopted as constraints for the C-BPNN *** effectiveness of the C-BPNN method is validated using the liquefaction data set and compared with that of several liquefaction assessment methods currently adopted in engineering *** C-BPNN liquefaction model is shown to have improved prediction accuracy and high global adaptability.

关键词： soil liquefaction assessment case history dataset constrained neural network model existing knowledge

Achieving resource-centric access control for web-app interactions on android

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High-Confidence Computing 2022年第3期2卷 50-61页

作者： Xin zhang yifan zhang Computer Science Department Binghamton UniversityState University of New YorkNYUSA

The capability of interacting with web content has become increasingly common among mobile *** web-app interaction can facilitate many new functionalities and improve app user experience,they also cause various notable security attacks on mobile apps or web *** root cause is lack of proper access control mechanisms for web-app interactions on mobile *** solutions usually adopt either an origin-centric design or a code-centric deign,and suffer from one or several of the following limitations:coarse protection granularity,poor flexibility in terms of access control policy establishment,and incompatibility with existing apps/OSes due to the need of modifying the apps and/or the underlying *** importantly,none of the existing works can organically deal with all the five web-app interaction *** this paper,we first identify and survey five mechanisms through which web content interacts with mobile *** then propose ReACt,a novel Re source-centric A ccess C on t rol design that can coherently work with all the web-app interaction mechanisms while addressing the above-mentioned *** have implemented a prototype system on Android,and performed extensive evaluation on *** evaluation results show that our system works well with existing commercial off-the-shelf Android apps and different versions of Android OS,and it can achieve the design goals with small overhead.

关键词： Web-app interaction Access-control Android Binder replacement ART hooking

User Purchase Intention Prediction Based on Improved Deep Forest

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 661-677页

作者： yifan zhang Qiancheng Yu Lisi zhang School of Computer Science and Engineering North Minzu UniversityYinchuan750030China Laboratory of Graphics and Images of the State Ethnic Affairs Commission North Minzu UniversityYinchuan750030China

Widely used deep neural networks currently face limitations in achieving optimal performance for purchase intention prediction due to constraints on data volume and hyperparameter *** address this issue,based on the deep forest algorithm and further integrating evolutionary ensemble learning methods,this paper proposes a novel Deep Adaptive Evolutionary Ensemble(DAEE)*** model introduces model diversity into the cascade layer,allowing it to adaptively adjust its structure to accommodate complex and evolving purchasing behavior ***,this paper optimizes the methods of obtaining feature vectors,enhancement vectors,and prediction results within the deep forest algorithm to enhance the model’s predictive *** demonstrate that the improved deep forest model not only possesses higher robustness but also shows an increase of 5.02%in AUC value compared to the baseline ***,its training runtime speed is 6 times faster than that of deep models,and compared to other improved models,its accuracy has been enhanced by 0.9%.

关键词： Purchase prediction deep forest differential evolution algorithm evolutionary ensemble learning model selection

Rewiring local immune milieu by boosting dendritic cell for pancreatic cancer treatment

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Signal Transduction and Targeted Therapy 2020年第1期5卷 1445-1446页

作者： yifan zhang Qun-Ying Lei Fudan University Shanghai Cancer Center&Institutes of Biomedical Sciences Cancer InstitutesKey Laboratory of Breast Cancer in ShanghaiThe Shanghai Key Laboratory of Medical EpigeneticsShanghai Medical CollegeFudan UniversityShanghaiChina Department of Oncology Shanghai Medical CollegeFudan UniversityShanghaiChina State Key Laboratory of Medical Neurobiology Fudan UniversityShanghaiChina

A recent article by Hedge et al.(Cancer Cell 37,289–307.e289,2020)demonstrated that decreased dendritic cell and elevated Th17 cell could explain the immunosuppressive environment of PDAC when compared with that in lung *** DC population using Flt3L and CD40 agonist showed improved efficacy on PDAC mouse models and shed new light on its immunotherapeutic strategies.

关键词： al elevated lung

Cooperative Interference Game in Cognitive Radio Hidden Terminal Scenario

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China Communications 2015年第10期12卷 128-135页

作者： zhang yifan GUO Chunxia LI Wei Key Laboratory of Universal Wireless Communication Ministry of EducationBeijing University of Posts and Telecommunication Department of Electrical and Computer Engineering University of Victoria

Hidden terminal problem in spectrum sensing is one of the most challenging problems in cognitive radio network(CRN).To tackle this problem,we propose a novel Cooperative Interference Game scheme in this *** scheme adopted full duplex(FD)mode to sense over multiple sub-bands in an iterative manner without extra sensing *** implementation algorithm of the proposed scheme is consisted of three modules:the formulation of the maximum transmit power limitation of second user(SU);the self-interference cancellation coefficient;and the optimal location of SU for an optimized low collision *** Carlo simulation proved that compared with cooperative spectrum sensing,the proposed scheme significantly improves the performance of spectrum detection and mitigates hidden terminal problem to a large extent with less energy consumption.

关键词： cognitive radio hidden terminal full duplex interference

COMPARISON OF K-ε AND K-ω TURBULENCE MODELS FOR SIMULATION OF SHALLOW RECIRCULATING FLOWS IN AN OPEN CHANNEL

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Journal of Hydrodynamics 1998年第2期10卷 74-86页

作者： zhang, yifan Li, C.W. Nanjing Hydraulic Research Inst Nanjing China

The paper describes the comparison of commonly used k-ε and k-ω turbulence models for simulating the recirculating flows behind a sudden expansion in a straight open channel. The depth-average numerical model and the quasi three-dimensional multilayer model are presented respectively. The governing equations are split into three parts in the finite difference approach: advection, dispersion and propagation. Comparison of the results computed with the k-ε and k-ω models shows that the two turbulence models have strong robustness in simulating the reattachment length of the recirculating flows. The computed results are found in good agreement with the measured data.

关键词： turbulence k-ω modek k-ε model finite difference channel expansion