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Numerical investigation of aerodynamic flow actuation produced by surface plasma actuator on 2D oscillating airfoil

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Chinese Journal of Aeronautics 2016年第4期29卷 882-892页

作者： Minh Khang phan Jichul Shin Department of Aerospace Engineering University of Ulsan

Numerical simulation of unsteady flow control over an oscillating NACA0012 airfoil is investigated. Flow actuation of a turbulent flow over the airfoil is provided by low current DC surface glow discharge plasma actuator which is analytically modeled as an ion pressure force produced in the cathode sheath region. The modeled plasma actuator has an induced pressure force of about 2 k Pa under a typical experiment condition and is placed on the airfoil surface at 0% chord length and/or at 10% chord length. The plasma actuator at deep-stall angles(from 5° to 25°) is able to slightly delay a dynamic stall and to weaken a pressure fluctuation in down-stroke motion. As a result, the wake region is reduced. The actuation effect varies with different plasma pulse frequencies, actuator locations and reduced frequencies. A lift coefficient can increase up to 70% by a selective operation of the plasma actuator with various plasma frequencies and locations as the angle of attack changes. Active flow control which is a key advantageous feature of the plasma actuator reveals that a dynamic stall phenomenon can be controlled by the surface plasma actuator with less power consumption if a careful control scheme of the plasma actuator is employed with the optimized plasma pulse frequency and actuator location corresponding to a dynamic change in reduced frequency.

关键词： Dynamic stall Flow control Numerical simulation Oscillating airfoil Plasma actuator

Poroelastodynamic responses and elastic moduli of a transversely isotropic porous cylinder under forced deformation test

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International Journal of Mining Science and Technology 2023年第7期33卷 793-800页

作者： Chao Liu Dung T.phan Aramco Research Center-Houston Houston TX 77084USA

Existing transversely isotropic poroelastodynamics solutions are limited to infinite domains and without experimental validation. Furthermore, there is a lack of analytical simulations for the elastic moduli dispersion of fluid-saturated porous cylinders. To address these three limitations and investigate the mechanisms of moduli dispersion, we present the analytical solutions of the poromechanical responses and the elastic moduli dispersion of a transversely isotropic, fluid-saturated, finite porous cylinder subjected to a forced deformation test. Through an example, we demonstrate the effects of loading frequency, boundary conditions, and material's anisotropy, dimension, and permeability on the responses of pore pressure,force, displacement, and dynamic elastic moduli of the cylinder. The specimen's responses are significantly influenced by the frequency of the applied load, resulting in a drained state at low frequencies and an undrained state at high frequencies. At high frequencies, the sample behaves identically for an open or a closed lateral boundary, and permeability has insignificant effects. The dynamic elastic moduli are mainly controlled by the loading frequency and the ratio of the sample's radius to its height. Lastly,we show excellent matches between the newly derived analytical solution and laboratory measurements on one clay and two shale samples from Mont Terri.

关键词： Poroelastodynamics Dynamic moduli Transversely isotropic Porous cylinder Forced deformation test

Stochastic Programming For Order Allocation And Production Planning

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Computer Systems Science & Engineering 2022年第1期40卷 75-85页

作者： phan Nguyen Ky Phuc International University-Vietnam National University Vietnam National UniversityHoChiMinh City70000Vietnam

Stochastic demand is an important factor that heavily affects production *** influences activities such as purchasing,manufacturing,and selling,and quick adaption is *** production planning,for reasons such as reducing costs and obtaining supplier discounts,many decisions must be made in the initial stage when demand has not been *** effects of non-optimal decisions will propagate to later stages,which can lead to losses due to overstocks or *** find the optimal solutions for the initial and later stage regarding demand realization,this study proposes a stochastic two-stage linear program-ming model for a multi-supplier,multi-material,and multi-product purchasing and production planning *** objective function is the expected total cost after two stages,and the results include detailed plans for purchasing and production in each demand ***-scale problems are solved through a deterministic equivalent transformation *** solve the problems in the large scale,an algorithm combining metaheuristic and sample average approximation is *** algorithm can be implemented in parallel to utilize the power of the *** algorithm based on the observation that if the remaining quantity of materials and number of units of products at the end of the initial stage are given,then the problems of the first and second stages can be decomposed.

关键词： Mixed integer programming two-stage stochastic programming production planning order allocation

Quantifying the impacts of the COVID-19 pandemic lockdown and the armed conflict with Russia on Sentinel 5P TROPOMI NO_(2)changes in Ukraine

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Big Earth Data 2024年第1期8卷 58-81页

作者： Anh phan Hiromichi Fukui Graduate School of Engineering Chubu UniversityKasugaiJapan Chubu Institute for Advanced Studies and International Digital Earth Applied Science Research Center(IDEAS) Chubu UniversityKasugaiJapan

This study investigated variations in nitrogen dioxide(NO_(2))levels in Ukraine during two significant periods:the COVID-19 pandemic lockdown in 2020 and the armed conflict with Russia in *** and reprocessed Sentinel 5P data products were utilized for the analysis.A machine learning model was employed to generate a business-as-usual NO_(2)time series that accounted for meteorological *** the nine most populous cities in Ukraine,during the lockdown in 2020 we observed a moderation of increases in NO_(2)levels during the lockdown compared to the pre-lockdown *** at the same months during the conflict period in 2022,we identified much more significant reductions in NO_(2)level in these cities,averaging 12.1%for original and 18.1%for reprocessed *** our examination of major urban areas,we observed reductions in NO_(2)levels in areas surrounding coal power plants damaged or destroyed by the *** the major urban areas in Ukraine,we conclude that changes in daily anthropogenic activities due to the conflict-related events had more substantial impacts on NO_(2)levels than did COVID-19 lockdown.

关键词： NO_(2) COVID-19 Russia-Ukraine armed conflict weather-normalization

Generation of Control Moments in an Insect-like Tailless Flapping-wing Micro Air Vehicle by Changing the Stroke-plane Angle

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Journal of Bionic Engineering 2016年第3期13卷 449-457页

作者： Hoang Vu phan Hoon Cheol Park Artificial Muscle Research Center Konkuk University Seoul 143-701 South Korea Deptment of Advanced Technology Fusion Konkuk University Seoul 143-701 South Korea

We propose a control moment generator to control the attitude of an insect-like tailless Flapping-wing Micro Air Vehicle （FW-MAV）, where the flapping wings simultaneously produce the flight force and control moments. The generator tilts the stroke plane of each wing independently to direct the resultant aerodynamic force in the desired direction to ultimately generate pitch and yaw moments. A roll moment is produced by an additional mechanism that shifts the trailing edge, which changes the wing rotation angles of the two flapping wings and produces an asymmetric thrust. Images of the flapping wings are captured with a high-speed camera and clearly show that the FW-MAV can independently change the stroke planes of its two wings. The measured force and moment data prove that the control moment generator produces reasonable pitch and yaw moments by tilting the stroke plane and realizes a roll moment by shifting the position of the trailing edge at the wing root.

关键词： insect-like Flapping-wing Micro Air Vehicle (FW-MAV) control mechanism stroke plane beetle flight

Cellular nanovesicles for therapeutic immunomodulation:A perspective on engineering strategies and new advances

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Acta Pharmaceutica Sinica B 2023年第5期13卷 1789-1827页

作者： Endong Zhang Philana phan Zongmin Zhao Department of Pharmaceutical Sciences College of PharmacyUniversity of Illinois ChicagoChicagoIL 60612USA Translational Oncology Program University of Illinois Cancer CenterChicagoIL 60612USA

Cellular nanovesicles which are referred to as cell-derived,nanosized lipid bilayer structures,have emerged as a promising platform for regulating immune *** to their outstanding advantages such as high biocompatibility,prominent structural stability,and high loading capacity,cellular nanovesicles are suitable for delivering various immunomodulatory molecules,such as small molecules,nucleic acids,peptides,and *** induced by cellular nanovesicles has been exploited to modulate immune cell behaviors,which is considered as a novel cell-free immunotherapeutic strategy for the prevention and treatment of diverse *** we review emerging concepts and new advances in leveraging cellular nanovesicles to activate or suppress immune responses,with the aim to explicate their applications for *** overview the general considerations and principles for the design of engineered cellular nanovesicles with tailored immunomodulatory *** also discuss new advances in engineering cellular nanovesicles as immunotherapies for treating major diseases.

关键词： Immunomodulation Cellular nanovesicle Extracellular vesicle Exosome Infectious disease Autoimmune disease Immunotherapy Immune cell

One-loopformulas for H→Zν_(ι)ν_(ι),forιe,μ,τin't Hooft-Veltman gauge

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Chinese Physics C 2023年第5期47卷 112-131页

作者： Dzung Tri Tran Khiem Hong phan Institute of Fundamental and Applied Sciences Duy Tan UniversityHo Chi Minh City 700000Vietnam Faculty of Natural Sciences Duy Tan UniversityDa Nang City 550000Vietnam

In this paper,we present analytical results for one-loop contributions to the decay processes H-Zvivi(for I=e,μ,T).The calculations are performed within the Standard Model framework in the't Hooft-Veltman ***-loop form factors are then written in terms of scalar one-loop functions in the standard notations of *** a result,one-loop decay rates for the decay channels can be evaluated numerically by using the ***,we analyze the signals of H→Zvivi via the production processes e-e+→ZH*-Z(H*→Zν_(ι)ν_(ι)),including the initial beam polarizations at future lepton *** Standard Model backgrounds,such as the processes e-e+→ν_(ι)ν_(ι)ZZ,are also examined in this *** results indicate that one-loop corrections make contributions of approximately 10%to the decay *** are sizeable contributions and should be taken into account at future *** show that the signals H-Zν_(ι)ν_(ι)are clearly visible at the center-of-mass energy√s=250 GeV and are difficult to probe in higher-energy regions owing to the dominant backgrounds.

关键词： Higgs phenomenology one-loop Feynman integrals analytic methods for quantum field theory dimensional regularization future colliders

AN EXTENSION OF ZOLOTAREV'S PROBLEM AND SOME RELATED RESULTS

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Acta Mathematica Scientia 2021年第5期41卷 1619-1634页

作者： Tran Loc HUNG phan Tri KIEN University of Finance and Marketing 77 Nguyen Kiem StreetPhu Nhuan DistrictHo Chi Minh CityVietnam

The main purpose of this paper is to extend the Zolotarev's problem concerning with geometric random sums to negative binomial random sums of independent identically distributed random *** extension is equivalent to describing all negative binomial infinitely divisible random variables and related *** Trotter-operator technique together with Zolotarev-distance's ideality,some upper bounds of convergence rates of normalized negative binomial random sums(in the sense of convergence in distribution)to Gamma,generalized Laplace and generalized Linnik random variables are *** obtained results are extension and generalization of several known results related to geometric random sums.

关键词： Zolotarev's problem geometric random sum negative binomial random sum negative binomial infinitely divisibility Trotter-operator technique

Designing Software to Analyze Sewing Process of Industrial Knitted Products

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Computer Systems Science & Engineering 2023年第2期44卷 1837-1852页

作者： phan thanh Thao Nguyen thanh Hung Pham Thi Le My Nguyen Xuan Hiep Duy-Nam phan Hanoi University of Science and Technology Hanoi10000Vietnam

In the textile industry,garment manufacturing contains four major pro-cesses containing cutting,sewing,ﬁnishing,and *** is the most crucial and intricate section,dealing with a large number of varied operations.A successful sewing process needs to be optimized regarding different factors,including time,sewing equipment,and skilled *** lineﬂow is combined by a set of operations with a particular *** utmost impor-tance of all garment industry is to arrange the workstations to minimize the num-ber of employees in order to produce at the best productive rate with the most reasonable cost,shortest time,and satisfying *** most garment factories,the production lines are balanced using the empirical judgment of the line *** the whole process the data of production time at each step,labor pro-ductivity,proper choices of equipment were always needed to calculate line efﬁ*** far as the issue is concerned,there has not been an academically sewing process analyzing software providing adequate data of sewing motions and sewing time as the credible input for the line balancing *** this goal,this paper presents the results of research on optimizing academically self-built software to analyze the sewing process of knitted products applied to industrial production using Java programming language on Google *** results achieved by the software are not only to analyze sewing products and the technological sewing process,calculate the sewing time on the machine but also analyze the sewing activities of workers into manipulations,movements,and motions to calculate the preparation time for two typical knitted products,namely,Polo-Shirt and T-Shirt with the case studies at General Textile Garment Joint Stock Company Hanoi and Star Fashion Company Limited.

关键词： Sewing motion sewing time GSD MTM polo-shirt T-shirt sewing process sewing operation analyzing software