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Toward Privacy-Preserving Personalized Recommendation Services

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Engineering 2018年第1期4卷 21-28页

作者： CongWang yifeng zheng Jinghua Jiang Kui Ren Department of Computer Science City University of Hong Kong Hong Kong China City University of Hong Kong Shenzhen Research Institute Shenzhen Guangdong 518057 China Department of Computer Science and Technology Xi'an fiaotong University Xi'an 710049 China Institute of Cyber Security Research Zhejiang University Hangzhou Zhejiang 310058 China

Recommendation systems are crucially important for the delivery of personalized services to users. With personalized recommendation services, users can enjoy a variety of targeted recommendations such as movies, hooks, ads, restaurants, and more. In addition, personalized recommendation services have become extremely effective revenue drivers for online business. Despite the great benefits, deploying per- sonalized recommendation services typically requires the collection of users＇ personal data for processing and anafytics, which undesirably makes users susceptible to serious privacy violation issues. Therefore, it is of paramount importance to develop practical privacy-preserving techniques to maintain the intelligence of personalized recommendation services while respecting user privacy. In this paper, we provide a comprehensive survey of the literature related to personalized recommendation services with privacy protection. We present the general architecture of personalized recommendation systems, the privacy issues therein, and existing works that focus on privacy-preserving personalized recommendation services. We classify the existing works according to their underlying techniques for personalized recommendation and privacy protection, and thoroughly discuss and compare their merits and demerits, especially in terms of privacy and recommendation accuracy. We also identity some future research directions.

关键词： Privacy protectionPersonalized recommendation servicesTargeted deliveryCollaborative filteringMachine learning

Investigation of Ag(Ga,In)Se_(2)as thin-film solar cell absorbers:A first-principles study

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Science China(Physics,Mechanics & Astronomy) 2022年第10期65卷 101-108页

作者： Rong Wang Baoying Dou yifeng zheng Su-Huai Wei Institute of Advanced Semiconductors&Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices ZJU-Hangzhou Global Scientific and Technological Innovation CenterHangzhou 311200China Beijing Computational Science Research Center Beijing 100193China

Using first-principles calculations,the structural,electronic,and defect properties of AgInSe_(2)(AIS),AgGaSe_(2)(AGS),and their alloys(AIGS)are systematically studied and compared with their Cu counterparts as potential candidates for thin-film solar cell *** bandgap energies of AIS(1.24 eV)and AGS(1.84 eV)are larger than their Cu counterparts,despite their larger lattice *** to the Shockley-Queisser theory,AIS or AIGS could be more suitable for solar-cell-absorber materials than their Cu ***,after investigating the band structures and intrinsic defect properties of AIS and AGS,we find that,(i)AIS and AGS have large negative crystal field splitting,thus low density of states near the valence band maximum(VBM);(ii)similar to the Cu counterparts,Ag vacancy(V_(Ag))is the main hole-carrier provider,while In_(Ag)(or Ga_(Ag))serves as the hole-carrier killer in p-type AIS(or AGS).However,because the positions of theVBM and conduction band minimum of AIS(or AGS)are lower than those of Cu In Se_(2)(CIS)[or Cu Ga Se_(2)(CGS)],the compensation of the p-type doping in AIS(or AGS)is more ***,the p-type doping of AIS(or AIGS)is more difficult than that of CIS(or CIGS),which is consistent with the doping limit *** improve the p-type doping of the AIS(or AIGS)as the solar-cell absorber,thus,improve the power conversion efficiency(PCE),the Ag-rich/(In,Ga)-poor/Se-rich growth condition is *** engineering of AIS with AGS can enhance the PCE because it can tune the bandgap energy of the absorber and band alignment at the absorber/buffer *** importantly,we suggest that for AIS(or AIGS)solar cell,the traditional buffer material of Cd S is not suitable anymore due to the large conduction band offset between AIS and Cd S.A new buffer layer material with a lower conduction band edge is necessary for better electron transport in AIS(or AIGS)solar cell.

关键词： thin-film solar cells chalcopyrites point defects alloys first-principles calculations

ISSDE:A Monte Carlo implicit simulation code based on Stratonovich SDE approach of Coulomb collision

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Chinese Physics B 2021年第9期30卷 297-312页

作者： yifeng zheng Jianyuan Xiao Yanpeng Wang Jiangshan zheng Ge Zhuang School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China

A Monte Carlo implicit simulation program,Implicit Stratonovich Stochastic Differential Equations(ISSDE),is developed for solving stochastic differential equations(SDEs)that describe plasmas with Coulomb *** basic idea of the program is the stochastic equivalence between the Fokker-Planck equation and the Stratonovich *** splitting method is used to increase the numerical stability of the algorithm for dynamics of charged particles with Coulomb *** cases of Lorentzian plasma,Maxwellian plasma and arbitrary distribution function of background plasma have been *** adoption of the implicit midpoint method guarantees exactly the energy conservation for the diffusion term and thus improves the numerical stability compared with conventional Runge-Kutta *** is built with C++and has standard interfaces and extensible *** slowing down processes of electron beams in unmagnetized plasma and relaxation process in magnetized plasma are studied using the ISSDE,which shows its correctness and reliability.

关键词： Fokker-Planck equation Stratonovich SDE implicit slowing down process

Prediction of impedance responses of protonic ceramic cells using artificial neural network tuned with the distribution of relaxation times

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Journal of Energy Chemistry 2023年第3期78卷 582-588,I0016页

作者： Xuhao Liu Zilin Yan Junwei Wu Jake Huang yifeng zheng Neal PSullivan Ryan O'Hayre zheng Zhong Zehua Pan School of Science Harbin Institute of TechnologyShenzhen 518055GuangdongChina School of Materials Engineering Harbin Institute of TechnologyShenzhen 518055GuangdongChina Department of Metallurgical and Materials Engineering Colorado School of Mines1500 Illinois St.Golden 80401ColoradoUSA College of Materials Science and Engineering Nanjing Tech UniversityNo.30 Puzhu Road(S)Nanjing 211816JiangsuChina Department of Mechanical Engineering Colorado School of Mines1500 Illinois St.Golden 80401ColoradoUSA

A deep-learning-based framework is proposed to predict the impedance response and underlying electrochemical behavior of the reversible protonic ceramic cell(PCC) across a wide variety of different operating *** impedance spectra(EIS) of PCCs were first acquired under a variety of opera ting conditions to provide a dataset containing 36 sets of EIS spectra for the *** artificial neural network(ANN) was then trained to model the relationship between the cell operating condition and EIS ***,ANN model-predicted EIS spectra were analyzed by the distribution of relaxation times(DRT) and compared to DRT spectra obtained from the experimental EIS data,enabling an assessment of the accumulative errors from the predicted EIS data vs the predicted *** show that in certain cases,although the R^(2)of the predicted EIS curve may be> 0.98,the R^(2)of the predicted DRT may be as low as~*** can lead to an inaccurate ANN prediction of the underlying time-resolved electrochemical response,although the apparent accuracy as evaluated from the EIS prediction may seem *** adjustment of the parameters of the ANN framework,the average R^(2)of the DRTs derived from the predicted EIS can be improved to ***,we demonstrate that a properly tuned ANN model can be used as an effective tool to predict not only the EIS,but also the DRT of complex electrochemical systems.

关键词： Protonic ceramic fuel cell/electrolysis cell Electrochemical impedance spectroscopy Distribution of relaxation times Artiﬁcial neural network

Modeling of beam ions loss and slowing down with Coulomb collisions in EAST

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Chinese Physics B 2022年第7期31卷 389-403页

作者： yifeng zheng Jianyuan Xiao Baolong Hao Liqing Xu Yanpeng Wang Jiangshan zheng Ge Zhuang School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China Key Laboratory of Optoelectronic Devices and Systems College of Physics and Optoelectronic EngineeringShenzhen UniversityShenzhen 518060China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China

This paper uses the implicit Monte–Carlo full-orbit-following parallel program ISSDE to calculate the prompt loss and slowing down process of neutral beam injection(NBI)-generated fast ions due to Coulomb collisions in the equilibrium configuration of Experimental Advanced Superconducting Tokamak(EAST).This program is based on the weak equivalence of the Fokker–Planck equation under Rosenbluth Mac Donald Judd(RMJ)potential and Stratonovich stochastic differential equation(SDE).The prompt loss with the LCFS boundary and the first wall(FW)boundary of the two co-current neutral injection beams are *** results indicate that the loss behavior of fast ions using the FW boundary is very different from that of the LCFS boundary,especially for fast ions with a large gyration *** to our calculations,about 5.11%of fast ions generated by perpendicular injection drift out of the LCFS and then return inside the LCFS to be captured by the magnetic *** prompt loss ratio of fast ions and the ratio of orbital types depend on the initial distribution of fast ions in the Pζ–Λ*** the effect of Coulomb collisions,the pitch-angle scattering and stochastic diffusion happens,which will cause more fast ion *** short time scales,among the particles lost due to collisions,the fraction of banana ions reaches 92.31%in the perpendicular beam and 58.65%in the tangential beam when the fraction of banana ions in the tangential beam is 3.4%of the total ions,which means that the effect of Coulomb collisions on banana fast ions is more *** long time scales,the additional fast ion loss caused by Coulomb collisions of tangential and perpendicular beams accounted for 16.21%and 25.05%of the total particles,*** have also investigated the slowing down process of NBI fast ions.

关键词： NBI fast ion loss slowing down process EAST Coulomb collisions

Investigation of Ag(Ga,In)Seas thin-film solar cell absorbers:A first-principles study

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Science China(Physics,Mechanics & Astronomy) 2022年

作者： Rong Wang Baoying Dou yifeng zheng Suhuai Wei Beijing Computational Science Research Center Institute of Advanced Semiconductors & Zhejiang Provincial Key Laboratory of Power Semiconductor Materials and Devices ZJU-Hangzhou Global Scientific and Technological Innovation Center

Using first-principles calculations,the structural,electronic,and defect properties of AgInSe(AIS),AgGaSe(AGS),and their alloys (AIGS) are systematically studied and compared with their Cu counterparts as potential candidates for thin-film solar cell *** bandgap energies of AIS (1.24 eV) and AGS (1.84 e V) are larger than their Cu counterparts,despite their larger lattice *** to the Shockley-Queisser theory,AIS or AIGS could be more suitable for solar-cell-absorber materials than their Cu ***,after investigating the band structures and intrinsic defect properties of AIS and AGS,we find that,(i) AIS and AGS have large negative crystal field splitting,thus low density of states near the valence band maximum (VBM);(ii) similar to the Cu counterparts,Ag vacancy (V) is the main hole-carrier provider,while In(or Ga)serves as the hole-carrier killer in p-type AIS (or AGS).However,because the positions of the VBM and conduction band minimum of AIS (or AGS) are lower than those of CuInSe(CIS)[or CuGaSe(CGS)],the compensation of the p-type doping in AIS (or AGS) is more ***,the p-type doping of AIS (or AIGS) is more difficult than that of CIS (or CIGS),which is consistent with the doping limit *** improve the p-type doping of the AIS (or AIGS) as the solar-cell absorber,thus,improve the power conversion efficiency (PCE),the Ag-rich/(In,Ga)-poor/Se-rich growth condition is *** engineering of AIS with AGS can enhance the PCE because it can tune the bandgap energy of the absorber and band alignment at the absorber/buffer *** importantly,we suggest that for AIS (or AIGS) solar cell,the traditional buffer material of CdS is not suitable anymore due to the large conduction band offset between AIS and CdS.A new buffer layer material with a lower conduction band edge is necessary for better electron transport in AIS (or AIGS) solar cell.

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Linear monitoring for cast-in-place reinforced concrete arch bridge construction

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Global Geology 2012年第2期15卷 145-150页

作者： zheng yifeng CAO Yu WANG Yuanyuan College of Construction Engineering Jilin University Changchun 130026 China

Linear monitoring is an important link of bridge construction control,which is conducted in key processes of construction to ensure the security of bridge in construction procedure. Combining with main arch construction monitoring program of No. 2 bridge in north district of Changbai international tourism resort,main content and key technologies are recommended. Considering the various influential factors during the construction process,linear adjustment is handled to ensure that the stress and linear of main arch meet design requirements.

关键词： arch box linear monitoring pre-loading pressure bailey beam

Shaking table tests and numerical simulation of dynamic properties of underground structures

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Global Geology 2009年第3期12卷 168-173页

作者： ZHOU Lincong zheng yifeng PAN Shunchun College of Construction Engineering Jilin University Changchun 130026 China Jiaozhou Urban Planning Bureau Jiaozhou 266300 Shandong China

It is considered thai the damage of the underground structures caused by earthquakes is minor for a long time. However, the catastrophic damages induced by several recent earthquakes （e. g. Kobe earthquake in 1995 ） revealed that the study on the dynamic properties of the underground structures is indispensable. The dynamic behavior and damage mechanism of underground structure are analyzed by using shaking table tests （ both shallow-and deep-buried） and numerical simulation （3D FEM） including horizontal and vertical input motions, individually and simultaneously. From the results, the underground structure collapsed due to strong horizontal forces although vertical deformation is not negligible. The vertical excitation increases the response of structure, especially the stress and shear stress at the upper section; the soil influenced the property of soilstructure system. In the same excitation, the response in shallow-buried test is larger than deep case. Both overburden and vertical earthquake play important roles in the response of structure and those are two critical aspects in the design of the large-span underground structures, such as subway stations.

关键词： underground structures earthquake shaking table test simulation

Fu-zheng-Yi-Liu Formula inhibits the stem cells and metastasis of prostate cancer via tumor-associated macrophages/C-C motif chemokine ligand 5 pathway in tumor microenvironment

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Chinese Journal of Natural Medicines 2024年第6期22卷 501-514页

作者： CHEN Chiwei HUANG Renlun WANG Neng zheng yifeng ZHOU Jianfu YANG Bowen WANG Xuan ZHANG Juping PAN Bo CHEN Zhiqiang WANG Shengqi WANG Zhiyu XIANG Songtao The Research Center of Integrative Cancer Medicine Discipline of Integrated Chinese and Western Medicinethe Second Clinical College of Guangzhou University of Chinese MedicineGuangzhou 510000China The First Clinical College of Guangzhou University of Chinese Medicine Guangzhou 510000China Guangdong Provincial Key Laboratory of Clinical Research on Traditional Chinese Medicine Syndrome Guangdong Provincial Academy of Chinese Medical SciencesGuangdong Provincial Hospital of Chinese MedicineGuangzhou 510000China Guangdong-Hong Kong-Macao Joint Lab on Chinese Medicine and Immune Disease Research Guangzhou University of Chinese MedicineGuangzhou 510000China The Research Center for Integrative Medicine School of Basic Medical SciencesGuangzhou University of Chinese MedicineGuangzhou 510000China State Key Laboratory of Dampness Syndrome of Chinese Medicine The Second Affiliated Hospital of Guangzhou University of Chinese MedicineGuangzhou 510000China

Prostate cancer(PCa)is the second most common malignancy among men *** Fu-zheng-Yi-Liu(FZYL)Formula has been widely utilized in the treatment of *** study investigates whether the FZYL Formula can inhibit PCa by tar-geting the TAMs/CCL5 *** conducted in vitro co-cultures and in vivo co-injections of PCa cells and TAMs to mimic their *** showed that the FZYL Formula significantly reduced the proliferation,colony formation,subpopulations of PCSCs,and sphere-formation efficacy of PCa cells,even in the presence of TAM ***,the Formula markedly decreased the migration,invasion,and epithelial-mesenchymal transition(EMT)of PCa cells induced by *** FZYL Formula also reversed M2 phenotype polarization in TAMs and dose-dependently reduced their CCL5 expression and secretion,with minimal cytotoxicity *** studies confirmed that the TAMs/CCL5 axis is a critical target of the FZYL Formula,as the addition of exogen-ous CCL5 partially reversed the formula’s inhibitory effects on PCSCs self-renewal in the co-culture ***,the Formula also significantly inhibited the growth of PCa xenografts,bone metastasis,and PCSCs activity in vivo by targeting the TAMs/CCL5 ***,this study not only elucidates the immunomodulatory mechanism of the FZYL Formula in PCa therapy but also highlights the TAMs/CCL5 axis as a promising therapeutic target.

关键词： Traditional Chinese medicine Tumor-associated macrophages Prostate cancer stem cells CCL5 Tumor microenvironment