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Journal of Hydrodynamics 2013年第5期25卷 747-754页

作者： KOTTI Mariam KSENTINI Issam ben MANSOUR Lassaad Laboratory of Applied Fluid Mechanics Process Engineering and EnvironmentScience Faculty of Sfax

In this work, the effects of the presence of surfactants in the liquid phase and the hydrodynamic regime of the bubble flow on the oxygen transfer rate were investigated in an electroflotation process in batch mode. The volumetric mass transfer coefficient KLα and the oxygenation capacity were evaluated to improve the performances of the electroflotation process in terms of oxygenation. In order to evaluate the liquid-side mass transfer coefficient KLα the volumetric mass transfer coefficient KLα was dissociated into KL and the specific interracial area （a） since the last one was obtained from the gas hold-up and the bubble diameter. The effect of Reynolds number which define the hydrodynamic of the bubble flow has been also studied. Models of KLa and KL have been established to show the effects of the hydrodynamic parameters and liquid phase characteristics on the oxygen transfer rate.

关键词： electroflotation mass transfer coefficient hydrodynamic parameters surfactant

Nonlinear variable structure excitation and steam valving controllers for power system stability

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控制理论与应用（英文版） 2009年第1期7卷 97-102页

作者： ben WANG Zongyuan MAO School of Electricity Engineering Southwest Jiaotong University Chengdu Sichuan 610013 China College of Automation Science and Engineering South China University of Technology Guangzhou Guangdong 510641 China

A set of novel nonlinear variable structure excitation and steam-valving controllers are proposed in this paper. On the basis of the classical dynamic equations of a generator, excitation control and steam valving control are simultaneously considered. Design of these controllers combines the differential geometry theory with the variable structure controlling theory. The mathematical model in the form of ＂an affine nonlinear system＂ is set up for the control design of a large-scale power plant. The dynamic performance of the nonlinear variable structure controllers proposed for a single machine connected to an infinite bus power system is simulated. Simulation results show that the nonlinear variable structure excitation and steam-valving controllers give satisfactory dynamic performance and good robustness.

关键词： Excitation control Nonlinear control Steam valving control Variable structure control

Hadron productions and jet substructures associated with Z^(0)/γ in Pb+Pb collisions at the LHC

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Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 77-89页

作者： Shan-Liang Zhang Hongxi Xing ben-Wei Zhang Key Laboratory of Atomic and Subatomic Structure and Quantum Control(MOE) Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of MatterInstitute of Quantum MatterSouth China Normal UniversityGuangzhou 510006China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Guangdong Provincial Key Laboratory of Nuclear ScienceSouthern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Southern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China Institute of Particle Physics and Key Laboratory of Quarks and Lepton Physics(MOE) Central China Normal UniversityWuhan 430079China

We carry out a detailed study of medium modifications on Z^(0)/γ+hadron correlations as well as jet substructures in association with Z^(0)/γ in Pb+Pb collisions with √S_(NN)=5.02TeV at the *** utilize the linear Boltzmann transport(LBT)model to simulate the jet-medium interactions and medium response,and an extended cluster hadronization model to investigate the nonperturbative transition of quarks and gluons into final hadrons in heavy-ion *** hadronization effect,we can well describe Z^(0)/γ+hadrons correlations and Z^(0)/γ-tagged jet substructures in both p+p and Pb+Pb collisions *** modification on jet profile and jet fragmentation functions indicate that particles carrying a large fraction of the jet momentum are generally closely aligned with the jet axis,whereas low-momentum particles are observed to have a much broader angular distribution relative to jet axis in Pb+Pb collisions due to jet-medium *** particular,we find that Z^(0)/γ-tagged hadron correlations are sensitive to the soft particles from the dense medium and medium response,while jet-substructures show weak dependence on those soft hadrons with only a fraction of them falling inside the jet area.

关键词： relativistic heavy-ion collisions jet quenching hadronization jet substructures

Accelerating Optimization Design of Bio-inspired Interlocking Structures with Machine Learning

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Acta Mechanica Solida Sinica 2023年第6期36卷 783-793页

作者： Zhongqiu Ding Hong Xiao Yugang Duan ben Wang School of Mechanical Engineering State Key Lab for Manufacturing Systems EngineeringXi’an Jiaotong UniversityXi’an 710049China

Structural connections between components are often weak areas in engineering *** nature,many biological materials with remarkablemechanical performance possess flexible and creative *** this work,we propose a novel bioinspired interlocking tab considering both the geometry of the tab head and neck,and demonstrate a new approach to optimize the bio-inspired interlocking structures based on machine *** neural networks for different optimization objectives are developed and trained using a database of thousands of interlocking structures generated through finite element *** show that the proposed method is able to achieve accurate prediction of the mechanical response of any given interlocking *** optimized designs with different optimization objectives,such as strength,stiffness,and toughness,are obtained efficiently and *** optimum design predicted by machine learning is approximately 7.98 times stronger and 2.98 times tougher than the best design in the training set,which are validated through additive manufacturing and experimental *** machine learning-based optimization approach developed here can aid in the exploration of the intricate mechanism behind biological materials and the discovery of new material designs boasting orders of magnitude increase in computational efficacy over conventional methods.

关键词： Interlocking structure Performance prediction Additive manufacturing Artificial neural network Finite element analysis

THE RELATIONSHIP BETWEEN COMFORT PERCEPTIONS AND ACADEMIC PERFORMANCE IN UNIVERSITY CLASSROOM BUILDINGS

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Journal of Green Building 2016年第1期11卷 108-117页

作者： Simi Hoque ben Weil Dept.of Environmental Conservation University of Massachusetts-Amherst

This paper presents preliminary data on a series of building comfort experiments conducted in the *** performed physical in-situ measurements and solicited responses from 409(184 female;225 male)university students in six different classrooms at the University of Massachusetts-Amherst during three seasons(fall,winter and spring).Our questions focused on student perception of comfort in varied environmental(temperature and humidity,and air speed)*** collected records of student academic performance in the classes,correlating their comfort perceptions to their test *** analysis of classroom environ-mental variables,thermal satisfaction,and student scores suggest that by enhancing thermal comfort,we can improve academic performance.

关键词： thermal comfort student performance university classrooms energy conservation

Convergence and error bounds of adaptive filtering under model structure and regressor uncertainties

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控制理论与应用（英文版） 2012年第2期10卷 144-151页

作者： ben G. FITZPATRICK Tempest Technologies 8939 South Sepulveda Boulevard Suite 506 Los AngelesCA 90045U.S.A. Department of Mathematics Loyola Marymount UniversityLos AngelesCA 90045U.S.A.

Adaptive filtering algorithms are investigated when system models are subject to model structure errors and regressor signal perturbations. System models for practical applications are often approximations of high-order or nonlinear systems, introducing model structure uncertainties. Measurement and actuation errors cause signal perturbations, which in turn lead to uncertainties in regressors of adaptive filtering algorithms. Employing ordinary differential equation （ODE） methodologies, we show that convergence properties and estimation bias can be characterized by certain differential inclusions. Conditions to ensure algorithm convergence and bounds on estimation bias are derived. These findings yield better understanding of the robustness of adaptive algorithms against structural and signal uncertainties.

关键词： Adaptive filtering Structural uncertainties Robustness Estimation bias

Global Exponential Convergence of Neutral Type Competitive Neural Networks with D Operator and Mixed Delay

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Journal of Systems Science & Complexity 2020年第6期33卷 1785-1803页

作者： AOUITI Chaouki ASSALI El Abed ben GHARBIA Imen University of Carthage Faculty of Sciences of BizertaDepartment of MathematicsResearch Units of Mathematics and Applications UR13ES477021 ZarzounaBizertaTunisia

The models of competitive neural network(CNN)was in recent past proposed to describe the dynamics of cortical cognitive maps with unsupervised synaptic modifications,where there are two types of memories:Long-term memories(LTM)and short-term memories(STM),LTM presents unsupervised and slow synaptic modifications and STM characterize the fast neural *** paper is concerned with a class of neutral type CNN’s with mixed delay and D *** employing the appropriate differential inequality theory,some sufficient conditions are given to ensure that all solutions of the model converge exponentially to zero ***,an illustrative example is also given at the end of this paper to show the effectiveness of the proposed results.

关键词： Competitive neural networks D operator exponential convergence neutral type delay

Deformation correlations,stress field switches and evolution of an orogenic intersection:The Pan-African Kaoko-Damara orogenic junction,Namibia

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Geoscience Frontiers 2017年第6期8卷 1187-1232页

作者： ben Goscombe David A.Foster David Gray ben Wade Antonios Marsellos Jason Titus Integrated Terrane Analysis Research(ITAR) 18 Cambridge RdAldgate5154SAAustralia Department of Geological Sciences University of FloridaGainesvilleFL32611USA School of Earth Sciences University of TasmaniaHobartTASAustralia Adelaide Microscopy University of AdelaideAdelaide5005SAAustralia Hofstra University HempsteadNYUSA

Age calibrated deformation histories established by detailed mapping and dating of key magmatic time markers are correlated across all tectono-metamorphic provinces in the Damara Orogenic *** across structural belts result in an internally consistent deformation framework with evidence of stress field rotations with similar timing,and switches between different deformation *** principle compressive stress rotated clockwise ~180°in total during Kaoko Belt evolution,and^135° during Damara Belt *** most stages,stress field variation is progressive and can be attributed to events within the Damara Orogenic System,caused by changes in relative trajectories of the interacting Rio De La Plata,Congo,and Kalahari *** orogenesis occurred earliest and evolved from collision and obduction at ~590 Ma,involving E-W directed shortening,progressing through different transpressional states with ~45° rotation of the stress field to strike-slip shear under NW-SE shortening at ~550-530 *** orogenesis evolved from collision at ~555-550 Ma with NW-SE directed shortening in common with the Kaoko Belt,and subsequently evolved through ~90°rotation of the stress field to NE-SW shortening at ~512-508 *** Kaoko and Damara orogenic fronts were operating at the same time,with all three cratons being coaxially convergent during the 550-530 Ma period;Rio De La Plata directed SE against the Congo Craton margin,and both together over-riding the Kalahari Craton margin also towards the *** stress field rotation was punctuated by rapid and significant switches at ~530-525 Ma,~508 Ma and ~505 *** three events included:(1)Culmination of main phase orogenesis in the Damara Belt,coinciding with maximum burial and peak metamorphism at 530-525 *** occurred at the same time as termination of transpression and initiation of transtensional reactivation of shear zones in the Kaoko *** compressive stress switched from NW-

关键词： Damara Orogen Stress fields Orogeny Assembly of Gondwana Event geochronology Deformation correlations

Stochastic Stability of Discrete Time Positive Markov Jump Nonlinear Systems

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Journal of Systems Science & Complexity 2023年第5期36卷 1949-1960页

作者： ZHAO Ping ZHAO Yan SONG Xinmin NIU ben School of Information Science and Engineering Shandong Normal UniversityJinan 250358China School of Mathematical Sciences University of JinanJinan 250022China

This paper investigates the stochastic stability of discrete time positive Markov jump nonlinear systems(PMJNS).Some definitions on stochastic stability for discrete time PMJNS are introduced ***,using the multiply max-separable Lyapunov function method,some stochastic stability criterions of discrete time PMJNS are provided,and some corresponding criterions are also provided for discrete time positive Markov jump linear systems(PMJLS).Different from previous conclusions that require subsystems to be stable or marginally stable,the obtained results allow some subsystems to be *** on the proposed criterions,the stochastic stability behavior of discrete time positive Markov jump systems can be obtained just from the algebraic properties of the system function and the probability characteristics of the Markov *** illustrate the main results,two simulation examples are provided at the end.

关键词： Markov jump system nonlinear system positive system stochastic stability

On the Trends of Autonomous Unmanned Systems Research

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Engineering 2022年第5期8卷 20-23页

作者： ben M.Chen Department of Mechanical and Automation Engineering The Chinese University of Hong KongHong Kong 999077China

In recent decades,academia and industry have put increasing attention and investment into the research and development of autonomous unmanned *** autonomous unmanned vehi-cle is a machine equipped with necessary data-processing units,sophisticated sensors,environment perception,automatic control,motion planning,task planning,mission management,and com-munication systems.

关键词： autonomous systems equipped