In the present work, an efficient active flow control strategy in eliminating vortex-induced vibration of a cylinder at Re = 100 has been explored by two machine learning frameworks, from to reinforcement learning. Specifically, adaptive scheme pair jets placed on poles as actuators discovered. framework, Gaussian progress regression surrogate model is used predict amplitude using limited number numerical simulations combining Bayesian optimization algorithm with specified actions while soft...

In the present work, we propose an optimization framework based on active learning method, which aims to quickly determine conditions of tandem flapping wings for optimal performance in terms thrust or efficiency. Especially, multi-fidelity Gaussian process regression is used establish surrogate model correlating kinematic parameters and their aerodynamic performances. Moreover, Bayesian algorithm employed select new candidate points update model. With this framework, parameter space can be...

Film cooling is a crucial technique for protecting critical components of gas turbines from excessive temperatures. Multiparameter film optimization still relatively time-consuming owing to the substantial computational demands fluid dynamics (CFD) methods. To reduce cost, present study develops data-driven framework predicting and optimizing effectiveness high-pressure based on deep learning. Multiple rows holes located pressure surface turbine blade are optimized, with coolant hole...

The ability to manipulate fluids has always been one of the focuses scientific research and engineering application. rapid development machine learning technology provides a new perspective method for active flow control. This review presents recent progress in combining reinforcement with high-dimensional, non-linear, time-delay physical information. Compared model-based closed-loop control methods, deep (DRL) avoids modeling complex system effectively an intelligent end-to-end policy...

The wind shear layer is a naturally formed airflow that enables the albatross to soar for six days at almost no cost. modeling and prediction of can be very helpful long-endurance flight (dynamic soaring), but existing studies usually ignore turbulence structures layers. In this paper, on leeward side ridge simulated by large eddy simulation (LES) method analyze structures. numerical simulation, three-dimensional (3D) elevation data mountain used as topography bottom synthesized turbulent...

Abstract Silicon nanopillars with average diameters from 200 to 900 nm and heights 0.5 3 μm have been successfully fabricated by cesium chloride (CsCl) self‐assembly lithography dry etching as antireflection layer for solar cells. The photovoltaic characteristics the structures of silicon researched show that reflectivity, conversion efficiency (PCE), external quantum (EQE) are greatly influenced diameter height nanopillars. small large can supress reflection, but less‐favorable photovoltic...

Pyramids and nanoholes are integrated together to form a micro-nano-texture on silicon surface in order suppress reflection for solar cell application. The formed by inductively coupled plasma (ICP) dry etching employing nanoporous aluminum (Al) mask which is fabricated caesium chloride (CsCl) nanoislands lift-off technique. Reflection of less than 4% can be reached pyramid-nanohole texture, much lower that from pure pyramids or texture. Higher short circuit current density (J(sc))...

Nanotip arrays with high aspect ratio, which have attracted much attention due to their potential applications, been fabricated by many methods. Dry etching combined self-assembly masks is widely used because of the convenience dry and throughput self-assembly. In this paper, we report a method combining Cesium Chloride (CsCl) inductively coupled plasma (ICP) fabricate silicon nanotip ratio 15 achieved after optimization all parameters.

A simple fabrication technology for both nanoscrews and nanoholes by Cesium Chloride (CsCI) self-assembly lithography dry etching on silicon substrates is demonstrated. The porous Al template ranging from 400 nm to 2 μm average diameter formed lift-off the CsCl nanoislands in DI water as ICP masks nanoholes. Nanoscrews of desired height/depth 1.2 4 are obtained this method. reflectance nanoscrew nanohole structures can achieve below 5% wavelength 1000 which much lower than that pyramid but...

In light of the fact that existing centrality indexes disregard influence dynamic characteristics and lack generalizability due to standard diversification, this study investigates survivability centrality, which enables quantification oscillators’ capacity impact nonlinear oscillator systems. Taking an Erdős–Rényi random graph system consisting Stuart–Landau oscillators as illustrative example, typical symmetry synchronization is considered key mission be accomplished in value found...

Abstract Selective‐area nanopillar‐textured solar cells were fabricated by using a convenient method to overcome the problem of metal contacts on nanopillars surfaces. A Ti/Ag electrode layer was deposited onto planar surface after phosphorous doping, and then cesium chloride (CsCl) self‐assembly lithography. With this method, approximately 150 nm average diameter heights from 120 480 [corresponding inductively coupled plasma (ICP) etching time 15 75 s] silicon as an antireflection layer....

A new crashed airplane detection algorithm based on feature fusion is proposed in this paper. Considering the dihedral characteristic of airplane's tail and strong scattering intensity body, target constructed by combining above two polarimetric properties. Then Constant False Alarm Rate (CFAR) used for detection. Experimental results with real data from NASA/JPL UAVASR system demonstrate effectiveness method.

The fourth signal of BDS (BeiDou Navigation System) allows for measurements on frequency S. To take advantage this new signal, an investigation has been carried out the models and characteristics four carrier phase combinations. Four categories combinations are studied: ionosphere delay reduced combinations, troposphere minimum noise optimal ambiguity resolution. Among them, resolution mainly focused. In case, we have proved that low axis used searching also exists. Besides, sum combination...

Carrier phase measurements are always used in high precision situations. Though short baseline case, double difference technic can eliminate most of the systematic errors, some errors still remain. Therefore, stochastic characters and measurement quality carrier is vital importance. In this paper, residuals zero evaluated. Then observation qualities from different frequencies analyzed. Besides, multipath pseudorange also investigated. The result showed that case accuracy B3 worse than B1....