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In order to research the influence of the flexible and hinges clearance on the dynamic performance of a solar array during deployment, a lunar rover with a repeatable an unfolded two-stage solar array is used as the research subjects. The modified Coulomb model is taken to describe the friction and to express the clearance in terms of collision force. The finite element method is used for the flexible pannels. A dynamic model which makes the multi-clearance flexible coupling is established. In this paper, the Runge-Kutta method with variable step is applied to the numerical simulation of the deployment of the panel. The effects of the multiple clearances and flexibility on the acceleration of the mass center and the impact force of the hinges clearance are analyzed. The results show that under the premise of ensuring the stiffness requirements of the launching mechanism, the appropriate flexibility of the array can compensate acceleration fluctuation caused by the hinges clearance, weaken the sharp degree of the collision at the clearance and reduce the impact force amplitude, thereby improving the dynamic characteristics of the deployable mechanism. The results can be used to guide the dynamic optimization design of the flexible deployable panels with multiple clearances. [ABSTRACT FROM AUTHOR]

In this paper, a new class of impulsive differential variational inequalities (IDVIs) are introduced and studied in finite dimensional Euclidean spaces. Some existence results on the solutions for the IDVIs are presented under suitable conditions and a convergence theorem of the discrete Euler time-dependent procedure for solving the IDVI is proved by using constructed discrete approximation methods for the impulsive differential inclusions (IDIs). The stability results concerned with the solutions of the IDVIs are also considered when the variation of initial data, impulsive perturbation and right-hand sides happens. [ABSTRACT FROM AUTHOR]

Highlights: [•] “The accuracy problem” is replaced with “the non-physical behavior problem”. [•] A new Section 5.4 is added to analyze and improve the AUSM+-up Schemes by applying the proposed rules. [•] A new Section 6.5, NASA Rotor 37 Flow, to show the shock-capturing ability of the schemes. [ABSTRACT FROM AUTHOR]

The modulation jamming method for high-vivid false uniformly-moving targets against SAR-GMTI is proposed by using the imaging characteristics of the uniformly-moving target. Key jamming parameters are determined, and the influence of reconnaissance errors on the jamming effects is analyzed. Besides, the countering performance of the proposed jamming method against GMTT is investigated by using the three-aperture interference cancelling technique. The experimental results indicate that the proposed method is effective to produce false uniformly-moving targets, through which certain ground uniformly-moving targets can be protected against SAR-GMTI. At the same time, the new method is efficient and flexible. [ABSTRACT FROM AUTHOR]

The design of Air-breathing Hypersonic Vehicle (AHV) flight control system is encountering some new problems derived from the strong coupling physical fields including aerodynamic, aerodynamic heating, flexibility, propulsion, trajectory and attitude. In this paper, a modeling method based on integrated design for airframe-propulsion-control of AHV is developed. Firstly, a 3D vehicle configuration is designed by using the parametric system to determine the vehicle's overall performance. Secondly, the vehicle's flow field is analyzed, and by including the control constraints the aerodynamics are calculated accurately and efficiently through a set of engineering estimation methods. And the scramjet engine is modeled based on integrated design. Finally, the motion equations of the flexible vehicle are derived using Lagrange's Equations. The modeling method is verified by simulation and is a feasible and reliable method for hypersonic air-breathing vehicle integrated design. [ABSTRACT FROM AUTHOR]

Abstract: The problems of mixed low-speed/high-speed flows are not solved properly with existing compressible method. Based on preconditioning technology, a new scheme, All-Speed-Roe scheme, is proposed. Compared with Roe scheme, it decreases the effect of acoustic speed in its numerical dissipation when Mach numbers decrease. Compared with traditional preconditioned Roe scheme, it overcomes the limit of being cut-off by the global Mach number through modifying the eigenvalues only and has the good convergence acceleration rate for low-Mach-number flows through multiplying the spatial residual by the preconditioner. From another perspective, All-Speed-Roe scheme suggests that there is no necessity to replace the physical acoustic speed in denominator with pseudo-acoustic speed. In theory, All-Speed-Roe scheme is suitable for all speed flow calculations with capturing shock and simulating low-Mach-number flows. The numerical results of Euler nozzle flow, RANS of NASA rotor 37 flow, Euler simulation, Large Eddy Simulation (LES) and Detached Eddy Simulation (DES) of high-loaded blade T106 flow show that All-Speed-Roe scheme can replace traditional preconditioned Roe scheme because it is easier for programming, more robust in computations, more accurate in spatial, and has good convergence rate. [Copyright &y& Elsevier]

Abstract: One of the difficulties encountered in the application of reinforcement learning methods to real-world problems is their limited ability to cope with large-scale or continuous spaces. In order to solve the curse of the dimensionality problem, resulting from making continuous state or action spaces discrete, a new fuzzy Actor–Critic reinforcement learning network (FACRLN) based on a fuzzy radial basis function (FRBF) neural network is proposed. The architecture of FACRLN is realized by a four-layer FRBF neural network that is used to approximate both the action value function of the Actor and the state value function of the Critic simultaneously. The Actor and the Critic networks share the input, rule and normalized layers of the FRBF network, which can reduce the demands for storage space from the learning system and avoid repeated computations for the outputs of the rule units. Moreover, the FRBF network is able to adjust its structure and parameters in an adaptive way with a novel self-organizing approach according to the complexity of the task and the progress in learning, which ensures an economic size of the network. Experimental studies concerning a cart–pole balancing control illustrate the performance and applicability of the proposed FACRLN. [Copyright &y& Elsevier]

The article reports that the 12th Five-Year Plan, which was approved by the Chinese Government on March 14, 2011, focuses on the expansion of the country's power generation industry in many new directions. The plan says that the structure of power generation development will be optimized, including the proper balance of coal transportation and power transmission and it also puts forward specific requirements for energy conservation measures.

The Hylleraas-B-spline basis set is introduced for solving the Hamiltonian eigenvalue problem of a two-electron atomic system. We demonstrate this method by calculating the static dipole polarizabilities of the 1¹S-5¹S,2³S-6³S states of helium in both the length and velocity gauge, which shows a good agreement. Comparing to the traditional B-spline basis, the present approach can significantly improve the rate of convergence of energy eigenvalues. The final extrapolated values of the polarizabilities for these states are accurate to at least eight significant digits, indicating that this method can handle intermediate states, including the continuum, of the Hamiltonian sufficiently well. [ABSTRACT FROM AUTHOR]

In this paper, we analyze the detection performance of non-coherent radar for correlated gamma fluctuating targets in K distributed sea clutter. We present the radar signal models at first. Then we derive the mathematical expression of the radar detection probability. We verify the correctness of the theoretical derivations by Monte Carlo simulations. We further analyze the radar detection performances in various clutter and target circumstances. [ABSTRACT FROM AUTHOR]

This paper investigates a new general nonlinear system, which comprises a fractional differential equation and a history-dependent quasivariational inequality with a variable constraint set, as well as a quasivariational–hemivariational inequality with a variable constraint set. Such a general nonlinear system can be used to describe a nonlinear quasistatic thermoelastic frictional contact problem of viscoelastic materials with long memory, wear and implicit obstacles. By employing the fixed point theorem of the set-valued mapping, the solvability for such a general nonlinear system is proved under some mild conditions. Moreover, our abstract result is applied to obtain the solvability of a new nonlinear quasistatic thermoelastic frictional contact problem with long memory, wear and implicit obstacles. • A new general fractional differential system with variable constraint sets is introduced and studied. • A solvability theorem is given for such a system by using the fixed point theorem for a set-valued map. • A solvability theorem is obtained for a new nonlinear quasistatic thermoelastic frictional contact problem. [ABSTRACT FROM AUTHOR]

Using the idea of uniformly-accelerating motion modulation for reference, a novel active modulation jamming method of false uniformly-accelerating targets is proposed for countering Synthetics Aperture Radar (SAR)-Ground Moving Target Indication (GMTI) systems. Several key jamming parameters are determined, the jamming imaging result is analyzed, and the influence of reconnaissance errors on jamming performance is discussed. Furthermore, the countering performance of the proposed jamming method against GMTI is investigated by using the tri-antenna interference canceling technique. Simulation experiments have been done based on the raw data. The result shows that, this jamming signal carries the vivid uniformly-accelerating motion features, and is processed coherently in the range direction and partially coherently in the azimuth direction, thus producing a false image of the uniformly-accelerating target. The proposed method is effective and flexible in engineering. [ABSTRACT FROM AUTHOR]

• A new class of differential nonlinear system is introduced and investigated. • A unique solvability theorem for such a problem is given by using the surjectivity argument and Banach's fixed point theorem. • A unique solvability theorem is obtained for a long memory elastic frictional contact problem with wear and damage. • A fully discrete scheme is proposed to approximate the solutions for such a contact problem. • The error estimates are proved for numerical solutions of the contact problem. This paper is devoted to study a new nonlinear system involving a parabolic variational inequality, a history-dependent hemi-variational inequality and a differential equation in Banach spaces. By employing the surjectivity argument and Banach's fixed point theorem, we derive a unique solvability theorem for such a problem under some mild conditions. Moreover, the main results are applied to obtain the unique solvability of a long memory elastic frictional contact problem with wear and damage. Finally, we use the fully discrete scheme to approximate the contact problem and provide the error estimates for numerical solutions. [ABSTRACT FROM AUTHOR]

In this paper, we introduce and study Euler scheme for solving a class of stochastic differential variational inequalities (SDVIs). We show the convergence of the sequence construed by this Euler scheme for solving SDVIs under some mild conditions. Moreover, we apply the obtained results to simulate the electrical circuits with diodes and the collapse of the bridge problems in stochastic environment. • The convergence is proved for solving stochastic differential variational inequalities (SDVIs). • A new method is provided for guaranteeing the unique existence of the solutions for SDVIs. • Two applications are given to illustrate our theoretical results. [ABSTRACT FROM AUTHOR]

• We propose a model for addressing the challenge of detecting small-scale objects. • The model is built by innovatively incorporating visual gain into Faster RCNN. • The effectiveness of the new model on textile micro-defects detection is verified. • The results show that the proposed model outperforms the existing detection methods. • A unique textile micro-defect database is built for this and follow-up study. In modern textile industrial processes, fast and efficient detection of textile defects plays a crucial role in textile quality control. Recently, as a critical machine-learning method, faster region-based convolutional neural network (Faster RCNN) have arisen as a promising framework, providing competitive performance for object detection. However, detecting small-scale objects, such as micro-defects on textile, is still a challenging task for Faster RCNN. To address the challenge, this paper aims to develop a new detection model to improve the ability of detecting small-scale objects. First, by analyzing the relationship between the attention mechanism and the visual gain mechanism, we find that the attention-related visual gain mechanism can modify response amplitude without changing selectivity and improve the acuity of visual perception. Then, the relevant mechanisms are further incorporated into the Faster RCNN model to build a new model called Faster VG-RCNN. To evaluate the proposed detection model, a unique textile micro-defect database is built as the benchmark for micro-defect detection. Furthermore, we conduct extensive experimental validations for various design choices. The experimental results show that the proposed Faster VG-RCNN outperforms the existing detection methods. In particular, compared to Faster RCNN, Faster VG-RCNN improves the detection precision from 90.1% to 94.3%. [ABSTRACT FROM AUTHOR]

The article reports on the plan of China to add eight wind generating bases with solar photovoltaic installations to improve its variable generation (VG) industry. It stresses the significance of determining how the major bases will integrate to ensure grid stability. Moreover, it notes the proposed plan by researchers from North China Electric Power University on the renewable energy development plan of the country.

The article focuses on the analysis of North China Electric Power University which states that nuclear power (NC) is still a top development priority eventhough the pace of NC may decrease for a short time as a result of the Fukushima accident. It states that China is one of the countries that is equipped with technical conditions to accelerate the development of nuclear power. Also, the focus of China's nuclear development strategy is to ensure sustainability and nuclear power security.

Contrastive analysis of the performance of various polarimetric detectors is the basis of polarimetrie radar detector design in engineering. In this paper, the clutter and the target echo received by polarimetrie radar are modeled. Based on this, ideal detection performances of optimal polarimetrie detector (OPD), polarimetrie whitening filter (PWF), optimal span detector (OSD), polarimetrie matched filter (PMF), power maximization synthesis detector (PMSD) and single channel detector (SCD) are compared by using Monte Carlo simulations. At the same time, implementation difficulties of the six polarimetrie detectors are analyzed according to their test statistics. Simulation and analysis results indicate that PWF, OSD and PMSD have good ideal detection performances and are convenient to implement in engineering. Considering PWF and OSD require prior knowledge of clutter covariance in engineering application, adaptive detection performances of PWF, OSD and PMSD are further compared based on the estimated clutter covariance and its key parameters. Comparison results demonstrate that PWF has best adaptive detection performance when radar observation times is larger than 64. [ABSTRACT FROM AUTHOR]

Based on single-pass InSAR system, the inteferometric phase and InSAR 3 D imaging characteristics of target with rotational micro-motion are studied, and the "barrier" effect of target with rotational micro-motion in the InSAR image is revealed for the first time. Firstly, both 3D geometric model and signal model of the rotational target with arbitrary attitude are built in this paper, and the imaging results are derived. Then, by comparing the imaging results of InSAR's two channels, the interferometry phases of the rotational target are proved to be approximate equal to the inteferometry phase of the location where the rotational center lies in, and the effect of the rotational parameters and the attitude of the rotational target can be neglected. On the basis, it is pointed out that the InSAR image result of the rotational target shows the "barrier" effect which spreads along the cross range direction. The height and the length of the "barrier" depend on the vertical direction coordinate of the rotation center and the rotational parameters respectively. The analyses are verified by simulation experiments. [ABSTRACT FROM AUTHOR]

The article says that the 12th Five-Year Plan in China focuses on further development and use of renewable energy in the country. Chinese renewable energy policy focuses on the development of solar, wind energy and biomass gas as an effective and efficient way to meet increasing demand of energy, along with minimizing environmental impact.