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A review of control strategies used for morphing aircraft applications

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Chinese Journal of Aeronautics 2024年第4期37卷 436-463页

作者： Muhammed s.PARANCHEERIVILAKKATHIL Jafar s.PILAKKADAN Rafic M.AJAJ Mohammadreza AMOOZGAR Davood AsADI Yahya ZWEIRI Michael I.FRIsWELL Department of Aerospace Engineering Khalifa University of Science and TechnologyAbu DhabiUnited Arab Emirates Department of Aerospace Engineering Advanced Research and Innovation Center(ARIC)Khalifa University of Science and TechnologyAbu DhabiUnited Arab Emirates Department of Mechanical Materials&Manufacturing EngineeringUniversity of NottinghamNottingham NG72RDUK Department of Aerospace Engineering Adana Alparslan Turkes Science and Technology UniversityTurkey College of Engineering Swansea UniversitySwansea SA18ENUK

This paper reviews the various control algorithms and strategies used for fixed-wing morphing aircraft applications. It is evident from the literature that the development of control algorithms for morphing aircraft technologies focused on three main areas. The first area is related to precise control of the shape of morphing concepts for various flight conditions. The second area is mainly related to the flight dynamics, stability, and control aspects of morphing aircraft. The third area deals mainly with aeroelastic control using morphing concepts either for load alleviation purposes and/or to control the instability boundaries. The design of controllers for morphing aircraft/wings is very challenging due to the large changes that can occur in the structural, aerodynamic, and inertial characteristics. In addition, the type of actuation system and actuation rate/speed can have a significant effect on the design of such controllers. The aerospace community is in strong need of such a critical review especially as morphing aircraft technologies move from fundamental research at a low Technology Readiness Level(TRL) to real-life applications. This critical review aims to identify research gaps and propose future directions. In this paper, research activities/papers are categorized according to the control strategy used. This ranges from simple Proportional Integral Derivative(PID) controllers at one end to complex robust adaptive controllers and deep learning algorithms at the other end. This includes analytical, computational, and experimental studies. In addition, the various dynamic models used and their fidelities are highlighted and discussed.

关键词： Control strategies Morphing aircraft shape morphing Flight dynamics Aeroelasticity

Optimum Profiles of Endwall Contouring for Enhanced Net Heat Flux Reduction and Aerodynamic Performance

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Journal of Harbin Institute of Technology(New series) 2024年第2期31卷 80-92页

作者： Arjun K s Tide P s Biju N Division of Mechanical Engineering School of EngineeringCochin University of Science&TechnologyKalamassery 682022India

successfully utilized non-axisymmetric endwalls to enhance turbine efficiencies(aerodynamic and turbine inlet temperatures)by controlling the characteristics of the secondary flow in a blade *** is accomplished by steady-state numerical hydrodynamics and deep knowledge of the field of *** of the interaction between mainstream and purge flow contributing supplementary losses in the stage,non-axisymmetric endwalls are highly susceptible to the inception of purge flow exit compared to the flat and any advantage rapidly *** conclusions reveal that the supreme endwall pattern could yield a lowering of the gross pressure loss at the design stage and is related to the size of the top-loss location being productively *** has led to diminished global thermal exchange lowered in the passage of the vane *** reverse flow adjacent to the suction side corner of the endwall is migrated farther from the vane surface,as the deviated pressure spread on the endwall accelerates the flow and progresses the reverse flow core still *** depleted association between the tornado-like vortex and the corner vortex adjacent to the suction side corner of the endwall is the dominant mechanism of control in the contoured end *** this publication,we show that the non-axisymmetric endwall contouring by selective numerical shape change method at most prominent locations is advantageous in lowering the thermal load in turbines to augment the net heat flux reduction as well as the aerodynamic performance using multi-objective optimization.

关键词： endwall contouring turbine vane heat transfer phantom cooling coolant injection net heat flux reduction aerodynamic performance

Complexed amino acid minerals ***-glycinate chelated minerals:Impact on the performance of old laying hens

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Animal Nutrition 2024年第1期16卷 395-408页

作者： Marcos J.B.santos Maria C.M.M.Ludke Leandro M.silva Carlos B.V.Rabello Mércia R.Barros Fabiano s.Costa Clariana s.santos Jamille s.s.Wanderley Department of Animal science Rural Federal University of PernambucoRecifePEBrazil Department of Veterinary science Rural Federal University of PernambucoRecifePEBrazil

The present study was to evaluate the effect of trace minerals(Zn,Mn,and Cu)from complexed amino acid minerals(ZMCAA)and bis-glycinate chelated minerals(ZMCGly)in laying hen diets on performance,internal and external egg quality,yolk mineral deposition,intestinal morphometry,and bone *** 78 to 98 weeks of age,400 White LsL-Lite strain laying hens were distributed in a randomized design with 4 treatments with 10 replicates per *** were distributed in a 2×2 factorial arrangement using either Zn,Mn,and Cu of ZMCAA or ZMCGly source at 2 levels:low(20,20,and 3.5 mg/kg of Zn,Mn,and Cu,respectively)or high(40,40,and 7 mg/kg of Zn,Mn,and Cu,respectively).The analysis of variance was performed,and in cases where differences were observed,the means were compared using Tukey?s test(Psource and level of trace mineral supplementation had a significant impact on the performance of laying *** fed ZMCAA had higher egg production(P=0.01),egg weight(P=0.02),egg mass(P=0.01),and lower feed conversion ratio(P=0.05)compared to those fed *** ZMCAA supplementation showed higher albumen height(P=0.01),albumen weight(P=0.01),and eggshell thickness(Psition of Zn(Ps greater for hens received *** weight(P=0.04)and bone densitometry(Psmall intestine,ZMCAA resulted in longer villi(P=0.02)and shorter crypt depth(P=0.01)in the *** and ileum measurements were influenced by the level and source of trace minerals(Ps fed ZMCAA exhibited superior performance,egg quality,deposition of trace minerals in the egg yolk,and bone density compared to hens fed *** this study,older laying hens supplemented with ZMCAA at lower levels demonstrated adequate levels of supplementation.

关键词： Bis-glycinates Metal-amino acids Radiodensity Trace minerals

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Data-Driven Learning Control Algorithms for Unachievable Tracking Problems

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IEEE/CAA Journal of Automatica sinica 2024年第1期11卷 205-218页

作者： Zeyi Zhang Hao Jiang Dong shen samer s.saab the school of Mathematics Renmin University of ChinaBeijing 100872China IEEE the school of Engineering Lebanese American UniversityByblos 2038Lebanon

For unachievable tracking problems, where the system output cannot precisely track a given reference, achieving the best possible approximation for the reference trajectory becomes the objective. This study aims to investigate solutions using the Ptype learning control scheme. Initially, we demonstrate the necessity of gradient information for achieving the best ***, we propose an input-output-driven learning gain design to handle the imprecise gradients of a class of uncertain systems. However, it is discovered that the desired performance may not be attainable when faced with incomplete *** address this issue, an extended iterative learning control scheme is introduced. In this scheme, the tracking errors are modified through output data sampling, which incorporates lowmemory footprints and offers flexibility in learning gain *** input sequence is shown to converge towards the desired input, resulting in an output that is closest to the given reference in the least square sense. Numerical simulations are provided to validate the theoretical findings.

关键词： Data-driven algorithms incomplete information iterative learning control gradient information unachievable problems

Evaluation of the seismic behavior of reinforced concrete structures with flat slab-column gravity frame and shear walls through nonlinear analysis methods

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 713-726页

作者： M.A.Najafgholipour s.Heidarian Radbakhsh E.Erfani Department of Civil and Environmental Engineering Shiraz University of TechnologyShiraz ***Iran Department of Building Civiland Environmental EngineeringConcordia UniversityMontréal H3G 1M8Canada

This paper presents an investigation of the seismic behavior of reinforced concrete(RC)structures in which shear walls are the main lateral load-resisting elements and the participation of flat slab floor systems is not considered in the seismic design *** this regard,the behavior of six prototype structures(with different heights and plan layouts)is investigated through nonlinear static and time history analyses,implemented in the Opensees *** results of the analyses are presented in terms of the behavior of the slab-column connections and their mode of failure at different loading ***,the global response of the buildings is discussed in terms of some parameters,such as lateral overstrength due to the gravity flat slab-column *** to the nonlinear static analyses,in structures in which the slab-column connections were designed only for gravity loads,the slab-column connections exhibited a punching mode of failure even in the early stages of ***,the punching failure was eliminated in structures in which a minimum transverse reinforcement recommended in ACI 318(2019)was provided in the slabs at joint ***,despite neglecting the contribution of gravity flat slab-column frames in the lateral load resistance of the structures,a relatively significant overstrength was imposed on the structures by the gravity frames.

关键词： RC flat slab-column frames seismic behavior nonlinear analysis time history analysis

Emission colour tuning in KLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)phosphor

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Journal of Rare Earths 2024年第1期42卷 57-65,I0002页

作者： Janani K Gayathri E Vijayatha V Ramasubramanian s Thiyagarajan P Department of science and Humanities Nehru Institute of TechnologyKaliapuramThirumalayampalayamCoimbatoreIndia Department of sciences Amrita School of Physical SciencesAmrita Vishwa VidyapeethamCoimbatoreIndia Department of Physics Anna UniversityChennaiIndia

KLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)(Ln=Y,Yb,Gd)phosphors were prepared by solid-state reaction *** each of the Yb^(3+)/Er^(3+)and Yb^(3+)/Ho^(3+)co-doped phosphors independently,phase confirmation and morphological examination were accomplished using the X-ray diffraction technique and scanning electron microscope analysis.X-ray photoelectron spectroscopy analysis shows the charge state and existence of lanthanides and *** luminescence emissions of green and red colour were detected for the synthesized *** changes in the upconverted emission intensities and colour output pertaining to the change of the lanthanide host matrix along with dopants were investigated for the prepared *** the upconversion luminescence,erbium-doped samples exhibit a predominance of red emission while holmium-doped samples display a prevalence of green *** rare-earth Er/Ho doped KYbF4shows strong red emission compared to other ***_(4):Yb,Er/Ho exhibits relatively significant green upconve rsion emissions,while Yb,Er-doped KGdF_(4)host displays a 10-fold increase in green/red emission ratio with an increase in the input power of 20-780 *** photoluminescence studies and decay curve analysis were carried out using UV light excitation for the developed phosphors.A higher lifetime of 2.2 ms was measured for the downshifting red emission in the Ho doped KYbF_(4)*** study suggests a potential for colour tunability in the upconversion and downshifting emissions through host modifications to the fluoride phosphor.

关键词： Rare earths Energy transfer upconversion Downshifting Colour coordinates

PERIODIC sYsTEMs WITH TIME DEPENDENT MAXIMAL MONOTONE OPERATORs

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Acta Mathematica scientia 2024年第4期44卷 1280-1300页

作者： Zhenhai LIU Nikolaos s.PAPAGEORGIOU Center for Applied Mathematics of Guangri Yulin Normal UniversityYulin 537000China Guangri Key Laboratory of Universities Optimization Control and Engineering Calculation College of Mathematics and PhysicsGuangri Minzu UniversityNanning 530006China Department of Mathematics National Technical UniversityZografou Campus15780 AthensGreece

We consider a first order periodic system in R^(N),involving a time dependent maximal monotone operator which need not have a full domain and a multivalued *** prove the existence theorems for both the convex and nonconvex *** also show the existence of extremal periodic solutions and provide a strong relaxation ***,we provide an application to nonlinear periodic control systems.

关键词： periodic boundary condition time-dependent maximal monotone operator convex and nonconvex problems extremal solutions strong relaxation

Defining failure of endoluminal biliary drainage in the era of endoscopic ultrasound and lumen apposing metal stents

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World Journal of Gastroenterology 2024年第29期30卷 3534-3537页

作者： Faisal s Ali sushovan Guha Department of Gastroenterology Hepatologyand NutritionUniversity of Texas Health Science Center at HoustonHustonTX 77054United States Department of Clinical sciences Tilman J.Fertitta Family College of MedicineUniversity of HoustonHoustonTX 77204United States

The role of endoscopy in pathologies of the bile duct and gallbladder has seen notable advancements over the past two *** advancements in stent technology,such as the development of lumen-apposing metal stents,and adoption of endoscopic ultrasound and electrosurgical principles in therapeutic endoscopy,what was once considered endoscopic failure has transformed into failure of an approach that could be salvaged by a second-or third-line endoscopic *** of these advancements in routine patient care will require formal training and multidisciplinary acceptance of established techniques and collaboration for advancement of experimental techniques to generate robust evidence that can be utilized to serve patients to the best of our ability.

关键词： Endoscopic ultrasound Guided biliary drainage Gallbladder Biliary obstruction Lumen-apposing metal stent

Kinematic analysis of flexible bipedal robotic systems

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 795-818页

作者： R.FAZEL A.M.sHAFEI s.R.NEKOO Department of Mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous *** distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases ***,the human leg bones that are involved in walking are supported by viscoelastic muscles and ***,for achieving more exact results,it is essential to model the robot links with viscoelastic *** this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of *** most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational *** extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned *** overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient