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An artificial intelligence-aided design (AIAD) of ship hull structures

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Journal of Ocean Engineering and Science 2023年第1期8卷 15-32页

作者： Yu ao Yunbo li Jiaye Gong Shaofan li College Of Shipbuilding Engineering Harbin Engineering UniversityChina Department of Civil and Environmental Engineering University of CaliforniaBerkeleyCA 94720USA College of Ocean Science and Engineering Shanghai Maritime UniversityChina

Ship-hull design is a complex process because the any slight local alteration in ship hull structure may significantly change the hydrostatic and hydrodynamic performances of a *** find the optimum hull shape under the design requirements,the state-of-art of ship hull design combines computational fluid dynamics computation with geometric ***,this process is very computationally intensive,which is only suitable at the final stage of the design *** narrow down the design parameter space,in this work,we have developed an AI-based deep learning neural network to realize a real-time prediction of the total resistance of the ship-hull structure in its initial design *** this work,we have demonstrated how to use the developed DNN model to carry out the initial ship hull *** validation results showed that the deep learning model could accurately predict the ship hull’s total resistance accurately after being trained,where the average error of all samples in the testing dataset is lower than 4%.Simultaneously,the trained deep learning model can predict the hip’s performances in real-time by inputting geometric modification parameters without tedious preprocessing and calculation *** machine learning approach in ship hull design proposed in this work is the first step towards the artificial intelligence-aided design in naval architectures.

关键词： Artificial intelligence Deep learning neural network Hull deformation Machine learning Ship hull design Total resistance

Understanding the multidimensional poverty in South Asia

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Journal of Geographical Sciences 2022年第10期32卷 2053-2068页

作者： li Yuheng JIN Qihui li ao CAS Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Economics and Management Xinjiang Agricultural UniversityUrumqi 830052China College of Tourism and Urban-Rural Planning Chengdu University of TechnologyChengdu 610059China

Special attention needs to be paid to achieve the world’s poverty reduction goal by 2030 in less than ten-year *** paper aims to investigate the multidimensional poverty in South Asia in the period *** constructs the Multidimensional Poverty Index(MPI)by selecting ten indicators in the fields of health,education and living *** research results show that the MPI of South Asia decreases in the research *** people in South Asian countries are still facing several forms of deprivation while cooking fuel,sanitation,housing,nutrition and years of schooling are the main restrictive factors to poverty reduction in this ***,India and Bangladesh face the worst poverty situation in terms of health,education and living *** poverty alleviation and resilient poverty reduction are proposed in the paper to improve the poverty reduction efficiency and individual/regional capacity against risks to avoid returning to poverty.

关键词： multidimensional poverty resilient poverty reduction sustainable development goals South Asia

Finite element analysis of dynamic stability of bearingless rotor

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航空动力学报 2014年第5期29卷 1112-1121页

作者： WEI li-jun li Shu li xue-chang School of Aeronautic Science and Engineering Beijing University of Aeronautics and Astronautics

Dynamic stability equations of bearingless rotor blades were investigated using a simplified *** aerodynamic loads of blades were evaluated using two-dimensional airfoil *** equations were obtained by linearization of the perturbation.A normal-mode approach was used to transform the equations expressed by nodal degrees of freedom into equations expressed by modal degrees of freedom,which can reduce the dimension of the *** stability results of rotor blades were presented using eigenvalue *** shape function matrix was obtained using spline interpolation,which simplified the analysis and made assembly of the inertial matrix,damping matrix,and stiffness matrix a simple mathematical *** results indicate that the method is efficient and greatly simplifies the analysis.

关键词：无轴承转子动态稳定性有限元法样条插值特征值分析

Density Functional Theory Investigation on the Reaction Mechanisms of Ti(^3F)with CH2Cl2 and CHCl3 to CH2=TiCl2 and HC÷TiCl3

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Chinese Journal of Structural Chemistry 2016年第2期35卷 193-198页

作者： CHENG xue-li (School of Chemistry and Chemical Engineering Taishan UniversityTai'anShandong 271021China

The reaction mechanisms of Ti（~3F）＋ CH2C12→CH2=TiCl2 and Ti（~3F）＋ CHC13→HC÷TiCl3 were investigated with Gaussian 03 program package at the B3PW91/6-311＋＋G（d,p）*** computational results revealed that：1） Both reaction systems are initiated by Ti（~3F） atom attacking the C atom of CH2C12 and CHCl3 to activate a C-Cl bond;2） Both reaction systems were carried out via triplet reaction channels;3） CH2=TiCl2 has singlet and triplet isomers,and the singlet one is more stable;4） The HOMO of CH2=TiCl2（S） illustrates a π-bonding interaction between C and Ti;5） Only singlet HC÷TiCl3 was located,and the Mulliken atomic spin densities show that the two single electrons are mostly on the C atom.

关键词： B3PW91 reaction mechanism Ti(~3F) CH2=TiCl2 HOTiCl3

Controllability of Nonlinear Discrete Systems with Degeneracy

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Acta Mathematicae Applicatae Sinica 2023年第2期39卷 293-305页

作者： Yue LYU xue-li TAN xue YANG Yong li School of Mathematics Jilin UniversityChangchun130012China Center for Mathematics and Interdisciplinary Sciences Northeast Normal UniversityChangchun 130024China

This paper concerns the controllability of autonomous and nonautonomous nonlinear discrete systems,in which linear parts might admit certain *** introducing Fredholm operators and coincidence degree theory,sufficient conditions for nonlinear discrete systems to be controllable are *** addition,applications are given to illustrate main results.

关键词： nonlinear discrete systems controllability degeneracy Fredholm operators coincidence degree theory

Rheological properties of a multiscale granular system during mixing of cemented paste backfill:A review

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International Journal of Minerals,Metallurgy and Materials 2023年第8期30卷 1444-1454页

作者： Cuiping li xue li Zhu’en Ruan Key Laboratory of the Ministry of Education of China for High-efficient Mining and Safety of Metal Mines University of Science and Technology BeijingBeijing100083China Shunde Innovation School of University of Science and Technology Beijing Foshan528399China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China

The technology of cemented paste backfill(CPB)is an effective method for green *** CPB,mixing is a vital process aiming to prepare a paste that meets the non-stratification,non-segregation,and non-bleeding *** a multiscale granular system,homogenization is one of the challenges in the paste-mixing *** to the high shearing,high concentration,and multiscale characteristics,paste exhibits complex rheological properties in the mixing *** overview of the mesomechanics and structural evolution is presented in this *** effects of various influencing factors on the paste's rheological properties were investigated,and the rheological models of the paste were outlined from the macroscopic and mesoscopic *** results show that the mechanical effects and structural evolution are the fundamental factors affecting the rheological properties of the *** problems and future development trends are presented to change the practice where the CPB process comes first and the theory lags.

关键词： cemented paste backfill rheology mixing process mesomechanics structural evolution

DOA estimation of incoherently distributed sources using importance sampling maximum likelihood

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Journal of Systems Engineering and Electronics 2022年第4期33卷 845-855页

作者： WU Tao DENG Zhenghong HU Xiaoxiang li ao XU Jiwei School of Automation Northwestern Polytechnical UniversityXi’an 710072China Equipment Management and UAV College Air Force Engineering UniversityXi’an 710051China School of Information Engineering Xi’an University of Posts and TelecommunicationsXi’an 710061China

In this paper, an importance sampling maximum likelihood(ISML) estimator for direction-of-arrival(DOA) of incoherently distributed(ID) sources is proposed. Starting from the maximum likelihood estimation description of the uniform linear array(ULA), a decoupled concentrated likelihood function(CLF) is presented. A new objective function based on CLF which can obtain a closed-form solution of global maximum is constructed according to Pincus theorem. To obtain the optimal value of the objective function which is a complex high-dimensional integral,we propose an importance sampling approach based on Monte Carlo random calculation. Next, an importance function is derived, which can simplify the problem of generating random vector from a high-dimensional probability density function(PDF) to generate random variable from a one-dimensional PDF. Compared with the existing maximum likelihood(ML) algorithms for DOA estimation of ID sources, the proposed algorithm does not require initial estimates, and its performance is closer to CramerRao lower bound(CRLB). The proposed algorithm performs better than the existing methods when the interval between sources to be estimated is small and in low signal to noise ratio(SNR)scenarios.

关键词： direction-of-arrival(DOA)estimation incoherently distributed(ID)sources importance sampling maximum likelihood(ISML) Monte Carlo random calculation

Binomial Proportion Estimation in Longitudinal Data with Non-ignorable Non-response

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Acta Mathematicae Applicatae Sinica 2013年第3期29卷 623-630页

作者： xue-li WANG School of Science Beijing University of Posts and Telecommunications

Non-random missing data poses serious problems in longitudinal studies. The binomial distribution parameter becomes to be unidentifiable without any other auxiliary information or assumption when it suffers from ignorable missing data. Existing methods are mostly based on the log-linear regression model. In this article, a model is proposed for longitudinal data with non-ignorable non-response. It is considered to use the pre-test baseline data to improve the identifiability of the post-test parameter. Furthermore, we derive the identified estimation （IE）, the maximum likelihood estimation （MLE） and its associated variance for the post-test parameter. The simulation study based on the model of this paper shows that the proposed approach gives promising results.

关键词： Binomial proportion information matrix identifiability non-ignorable non-response variance estimation

A robust and transparent nanosilica-filled silicone rubber coating with synergistically enhanced mechanical properties and barrier performance

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Journal of Materials Science & Technology 2023年第20期151卷 219-226页

作者： Shiyao Du Hui Yan Zihe liu ao Tang Ying li Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang 110819China

Implantable electronic devices(IEDs)are widely used by human beings to achieve medical treatment and diagnosis ***,ideal encapsulation of IEDs is still far from perfect as full prevention of body fluid diffusion into the coating remains ***,we develop a high-performance composite coating for IED encapsulation by introducing SiO_(2) nanoparticles into silicone rubber,which synergistically enhances mechanical properties and improves barrier *** fabricating composite coatings with different nanosilica contents,3%nanosilica is proved to be an optimal additive content with an excellent combination of improved fracture strength(from 2.5 MPa to 4.5 MPa),increased coating resistance(from 10^(4) to 10^(9) cm^(2))and ideal coating *** and electrochemical characterizations subsequently confirm substantially enhanced mechanical properties and barrier performance of the composite coating,which effectively resist crack propagation and impede penetrations of water and chloride ions through the *** calculations further uncover that modified SiO_(2) particles with enriched methyl groups endow a strong bridging effect to interact with silicone rubber monomer,which,together with anti-agglomeration property of methyl groups,contributes to a pronounced improvement in mechanical performance of nanosilica-filled silicone *** from the enhanced mechanical and barrier properties,the as-fabricated nanosilica-filled silicone rubber demonstrates superior protection for the encapsulated circuits with a significantly improved lifetime(709.1 h)compared to that of circuits coated by pure silicone rubber(472.8 h)and bare circuit boards(1 h),which offers great values for packaging material design in future IED encapsulation.

关键词： Organic coatings Implantable electronic devices Nanosilica DFT calculation Mechanical property