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Deterministic Time-inconsistent Optimal Control Problems - an Essentially Cooperative Approach

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Acta Mathematicae Applicatae Sinica 2012年第1期28卷 1-30页

作者： Jiong-min yong Department of Mathematics University of Central Florida Orlando FL 32816

A general deterministic time-inconsistent optimal control problem is formulated for ordinary differential equations. To find a time-consistent equilibrium value function and the corresponding time-consistent equilibrium control, a non-cooperative N-person differential game （but essentially cooperative in some sense） is introduced. Under certain conditions, it is proved that the open-loop Nash equilibrium value function of the N-person differential game converges to a time-consistent equilibrium value function of the original problem, which is the value function of a time-consistent optimal control problem. Moreover, it is proved that any optimal control of the time-consistent limit problem is a time-consistent equilibrium control of the original problem.

关键词： time-inconsistency pre-committed optimal control time-consistent equilibrium control multi-level hierarchical differential games

Backward stochastic Volterra integral equations——a brief survey

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Applied Mathematics(A Journal of Chinese Universities) 2013年第4期28卷 383-394页

作者： yong Jiong-min School of Mathematical Sciences Fudan University Department of Mathematics University of Central FloridaOrlando FL 32816 USA

In this paper, we present a brief survey on the updated theory of backward stochas-tic Volterra integral equations （BSVIEs, for short）. BSVIEs are a natural generalization of backward stochastic diff erential equations （BSDEs, for short）. Some interesting motivations of studying BSVIEs are recalled. With proper solution concepts, it is possible to establish the corresponding well-posedness for BSVIEs. We also survey various comparison theorems for solutions to BSVIEs.

关键词： backward stochastic diff erential equation backward stochastic Volterra integral equation M-solution comparison theorem

Concise extraction and characterization of the pore-throat network in unconventional hydrocarbon reservoirs: A new perspective

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Petroleum Science 2024年第3期21卷 1474-1487页

作者： Shu-Heng Du yong-min Shi State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing100190China School of Engineering Science University of Chinese Academy of SciencesBeijing100049China School of Earth and Space Sciences Peking UniversityBeijing100871China

In this study,a new image-based method for the extraction and characterization of pore-throat network for unconventional hydrocarbon storage and exploitation is proposed.“Pore-throat solidity”,which is analogous to particle solidity,and a new method for automatic identification of pores and throats in tight sandstone oil reservoirs are ***,the“pore-throat combination”and“pure pore”are defined and distinguished by drawing the cumulative probability curve of the pore-throat solidity and by selecting an appropriate cutoff *** the discrete grid set is recognized as a pore-throat combination,Legendre ellipse fitting and minimum Feret diameter are *** the pore and throat grid sets are identified as pure pores,the pore diameter can be directly *** the new method,the analytical results for the physical parameters and pore radius agree well with most prior *** results comparing the maximum ball and the new model could also prove the accuracy of the latter's in micro and nano *** new model provides a more practical theoretical basis and a new calculation method for the rapid and accurate evaluation of the complex processes of oil migration.

关键词： Hydrocarbon exploitation Pore Throat Porous media Identification

Thermodynamic model for deoxidation of liquid steel considering strong metal-oxygen interaction in the quasichemical model framework

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International Journal of minerals,Metallurgy and Materials 2024年第5期31卷 988-1002页

作者： yong-min Cho Youn-Bae Kang Graduate Institute of Ferrous and Eco Materials Technology Pohang University of Science and TechnologyPohangKyungbuk37673Rep.of Korea N.EX.T Hub POSCO HoldingsPohangKyungbuk37673Rep.of Korea Department of Materials Science and Engineering Pohang University of Science and TechnologyPohangKyungbuk37673Rep.of Korea

Herein,a thermodynamic model aimed at describing deoxidation equilibria in liquid steel was *** model provides explicit forms of the activity coefficient of solutes in liquid steel,eliminating the need for the minimization of internal Gibbs energy preliminarily when solving deoxidation *** elimination of internal Gibbs energy minimization is particularly advantageous during the coupling of deoxidation equilibrium calculations with computationally intensive approaches,such as computational fluid *** model enables efficient calculations through direct embedment of the explicit forms of activity coefficient in the computing *** proposed thermodynamic model was developed using a quasichemical approach with two key approximations:random mixing of metallic elements(Fe and oxidizing metal) and strong nonrandom pairing of metal and oxygen as nearest *** these approximations,the quasichemical approach yielded the activity coefficients of solutes as explicit functions of composition and temperature without requiring the minimization of internal Gibbs energy or the coupling of separate *** model was successfully applied in the calculation of deoxidation equilibria of various elements(Al,B,C,Ca,Ce,Cr,La,Mg,Mn,Nb,Si,Ti,V,and Zr).The limitations of the model arising from these assumptions were also discussed.

关键词： deoxidation equilibria thermodynamics quasichemical approach computational fluid dynamics

A transient energy function for power systems including the induction motor model

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Science China(Technological Sciences) 2007年第5期50卷 575-584页

作者： min yong CHEN Lei State Key Lab of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China State Key Lab of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China

A construction method for power system transient energy function is studied in the paper, which is simple and universal, and can unify the forms of some current en- ergy functions. A transient energy function including the induction motor model is derived using the method. The unintegrable term is dealt with to get an approxi- mate energy function. Simulations in a 3-bus system and in the WSCC 4-generator system verify the validity of the proposed energy function. The function can be applied to direct transient stability analysis of multi-machine large power systems and provides a tool for analysis of the interaction between the generator angle stability and the load voltage stability.

关键词： power system stability, transient stability, energy function, direct method, induction motor

Ligand-controlled NiH-catalyzed regiodivergent hydroalkylation of 2-alkenylazaarenes

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Science China Chemistry 2024年第6期67卷 1935-1940页

作者： Ya-Ping Shao Zhuo-min Chi yong-min Liang State Key Laboratory of Applied Organic Chemistry School of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou730000China

A nickel-hydride(Ni H)-catalyzed migratory and nonmigratory hydroalkylation reaction of 2-alkenyl azaarenes with alkyl iodines has been established through strategic modulation of N-or P-donor *** method enables the synthesis of diverseβ-orγ-branched aromatic *** mild regiodivergent protocols exhibit wide substrate scope,excellent functional tolerance,and great reaction yield with remarkable ***,deuterium labeling studies reveal Ni H-catalyzed interrupted chain-walking mode as the mechanism behind remotedβ-selective hydroalkylation reaction—an interesting phenomenon mediated through aromatic imine directing groups.

关键词： NiH regiodivergent hydroalkylation azaarenes interrupted chain-walking

Hybrid transmit antenna selection and maximal-ratio transmission systems

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Journal of Systems Engineering and Electronics 2007年第2期18卷 229-235页

作者： Zhu Yaolin Fang yong Wang min School of Communication and Information Engineering Shanghai Univ. Shanghai 200072P.R.China

Maximal-ratio transmission systems with transmit antenna selection is investigated. According to the order statistics of channel fiat fading coefficients, the closed-form expressions axe derived for average SNR with any amount of RF chains and average BER with two RF chains, respectively. The algorithm for calculating the minimum of total transmit antennas is presented in terms of reduced RF chains. The method of quantizing transmit precoders is employed in this study to decrease feedback information. Simulation results demonstrate the superiority of the proposed systems under full and quantized transmit precoders. The SNR of the proposed systems has been less degraded by the quantization of transmit precoder than that of pure maximal-ratio transmission systems.

关键词： Maximal-ratio transmission transmit antenna selection Lloyd quantization.

Modeling dual-scale epidemic dynamics on complex networks with reaction diffusion processes

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Journal of Zhejiang University-Science C(Computers and Electronics) 2014年第4期15卷 265-274页

作者： Xiao-gang JIN yong min AI Institute in College of Computer Science and Technology Zhejiang University College of Computer Science and Technology Zhejiang University of Technology

The frequent outbreak of severe foodborne diseases(e.g., haemolytic uraemic syndrome and Listeriosis) in 2011 warns of a potential threat that world trade could spread fatal pathogens(e.g., enterohemorrhagic Escherichia coli). The epidemic potential from trade involves both intra-proliferation and inter-diffusion. Here, we present a worldwide vegetable trade network and a stochastic computational model to simulate global trade-mediated epidemics by considering the weighted nodes and edges of the network and the dual-scale dynamics of epidemics. We address two basic issues of network structural impact in global epidemic patterns:(1) in contrast to the prediction of heterogeneous network models, the broad variability of node degree and edge weights of the vegetable trade network do not determine the threshold of global epidemics;(2) a ‘penetration effect', by which community structures do not restrict propagation at the global scale, quickly facilitates bridging the edges between communities, and leads to synchronized diffusion throughout the entire network. We have also defined an appropriate metric that combines dual-scale behavior and enables quantification of the critical role of bridging edges in disease diffusion from widespread trading. The unusual structure mechanisms of the trade network model may be useful in producing strategies for adaptive immunity and reducing international trade frictions.

关键词： Worldwide trade networks Foodbome diseases Scale-free networks Mean-field analysis

Dilemmas in diagnosis and management of hemophagocytic lymphohistiocytosis in children

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World Journal of Pediatrics 2020年第4期16卷 333-340页

作者： Xiao-Jun Xu yong-min Tang Division of Hematology-Oncology Children’s HospitalZhejiang University School of MedicineKey Laboratory of Reproductive Genetics of Ministry of EducationZhejiang UniversityHangzhou310003China

Background Hemophagocytic lymphohistiocytosis(HLH)is a life-threatening entity which is characterized by severe *** the HLH-2004 protocol has been widely accepted and clinically used;however,many questions still remain in clinical *** this review,we discuss the dilemmas in the diagnosis and treatment of HLH in *** sources Original research for articles and literature reviews published in PubMed was carried out using the key term“hemophagocytic lymphohistiocytosis”.Results As the gene sequencing technology progresses,the range of causal mutations and primary HLH has been *** monoallelic variants may contribute to the pathogenesis of the *** conditions without defective cytotoxicity of T or NK cells may lead to HLH,such as primary immunodeficiency(PID)and dysregulated immune activation or proliferation(DIAP).HLH shares overlapping clinical and laboratory characteristics with severe sepsis,but usually the single values are more pronounced in HLH than sepsis.H score is another approach to help the diagnosis of secondary *** Th1/Th2 cytokine patterns are very helpful tools to differentiate HLH(reactivation of HLH)from ***,it also has been used successfully to stratify the therapy *** treatment of HLH should consider underlying diseases,triggers and ***-94 is recommended for patients who need etoposide-based *** Dramatic progress has been made during the past decades in understanding the pathophysiology of ***,diagnosis and treatment of HLH remain with many dilemmas because of the heterogeneous nature of the *** understanding new gene defects and more effective diagnostic approaches and salvage regimens are goals for the future.

关键词： Cytokine Hemophagocytic lymphohistiocytosis Sepsis Transplantation