Applied Mechanics and Materials Vols. 325-326

Abstract: Composite materials have been used in aircraft components since the early beginning of aircraft industry establishment.Undenaible advantages of composites in mechanical properties and light weight in comparison with conventional metal alloys make them desirable alternative for fabrication of different aircraft components. However, quality concerns and high costs of processing tackle the extensive usage of composites in aircraft structure, until the past decade, introducing new generation of composite processing techniques, needless of traditional autoclave processing and capable of fabricating aerospace-grade quality composite parts more time and cost efficiently. In this paper concise review over recent cost-efficient composite processing technologies with proven practicality in commercial aircraft applications, is presented.

Abstract: Traditionally a space propulsion unit has a propellant mass which is ejected trough a nozzle at highvelocity to generate thrust. This paper proposes the use of the quantum pair formation for generating a working mass, this is different than conventional anti-matter thrusters since the material particles generated are used as a propellant mass not as energy storage. Two thrusters will be compared: photonic and quantum pair generation. The latter will be shown to offer better momentum than photons above certain energy levels. The implication is that quantum pair thrusters may develop into a new class of space propulsion systems. Keywords: quantum pair formation, space propulsion, photonic propulsion

Abstract: In this paper, the improved adaptive genetic algorithm has been presented, which not only can overcome the early maturity and slow convergence speed of traditional genetic algorithm, and greatly improve the efficiency of genetic algorithm. This method can improve the quality of stacker path planning and work efficiency for modern automated building materials warehouse. Using the genetic algorithm toolbox of Matlab, the simulation results can further verified the feasibility and effectiveness of this method.

Abstract: ndustrial water requirement is usually influenced by multiple factors, among which have close relations, which can cause distortion of some forecasting results, and weaken the suitability of some formulas. To this end, we adopt BP neural network model, use principal component analysis (PCA) to analyze the relationships between variables of the model to solve the related issues between the various factors, in order to set up forecast model of industrial water requirement and take Zhengzhou City as an example to analyze. The results showed that this method could take the influenced factors of industrial water requirement into consideration comprehensively, offer higher and more accurate forecasts, and provide the reference framework for integrated planning of regional water resources and long-term water supply planning.

Abstract: The classical harmony search algorithm (HSA) can only be used to solve the unconstrained optimization problems with continuous decision variables. Therefore, the classical HSA is not suitable for solving an engineering optimization problem with mixed discrete variables. In order to improve the classical HSA, an engineering method for dealing with mixed discrete decision variables is introduced and an exact non-differentiable penalty function is used to transform the constrained optimization design model into an unconstrained mathematical model. Based on above improvements, a program of improved HSA is designed and it can be used for solving the constrained optimization design problems with continuous variables, integer variables and non-equidistant discrete variables. Finally, an optimization design example of single-stage cylindrical-gear reducer with mixed-discrete variables is given. The example shows that the designed program runs steadily and the proposed method is effective in engineering design.

Abstract: People in such huge information how to find useful information becomes a problem. In order to deal with hierarchical relations in text data, a novel method, called automatic non-negative matrix factorization of the hierarchy clustering, is proposed for the text mining. We use the vector space model as the research foundation, mainly discusses the feature selection and weight calculation two problems. The experimental results on the real data sets demonstrate that our method outperforms, on average, all the other 6 methods.

Abstract: In this paper, the iterative HDP-based optimal tracking algorithm for discrete-time nonlinear systems is studied. The optimal tracking control problem of original nonlinear system is transformed to the optimal regulator problem by transforming the system and performance index in this algorithm, then using the HDP iteration to solve the optimal regulation problem. Finally, the neural network implementation for the algorithm is detailedly elaborated, and the given simulation results show the effectiveness of the optimal time-varying tracking based on iterative HDP algorithm.

Abstract: A new set of travelling-standing-wave (TSW) basis functions are proposed for curved triangular patch in this paper. This kind of bases is not only able to describe the standing component of induced surface current but also able to simulate the phase variation of induced current accurately. The authors used these basis functions to discrete surface integral equation (SIE) with a series of coarse meshes (even larger than 2λ) to calculate the electromagnetic (EM) scattering from the perfect electric conductor (PEC) targets with method of moment (MoM). Numerical experiments indicate that the MoM-TSW scheme even has more advantages than the MLFMA-CRWG scheme in the aspects of computational efficiency and memory storage.

Abstract: Due to the single chaotic map on finite precisions chaotic characteristics emerge degradation,the length of cycle become shorter, the Hash algorithm constructed by it is easily forecast, the security is not strong.In this paper, the nonlinear devices in the traditional block cipher S-box is used to construct variable parameters Hash algorithm composed of multiple chaotic maps. By using the original message, intermediate values of iteration and number of iterations as the input of the S-box, output of S-box is used to determine the parameters of chaotic maps, on this account to change the chaotic mapping function for each round. By execute text testing, statistical analysis and collision analysis for this algorithm through simulation experiments, the experimental results show that this generalized chaotic Hash algorithm has good sensitivity of the information, low possibility of collision,good safety and operational efficiency.

Abstract: Nonlinear differential equations are sometimes found by using harmonic balance principle. If it is based on the complex power balance theory, some much more correct and rational results can be obtained. Non-autonomous circuits sometimes include two components, the forced and the self-excited oscillation, they must satisfy respectively the balancing condition of complex power. When we study the nonautonomous circuit, two notable questions should be considered. On the one hand ,the existence of self-excited oscillation of the circuit which contains the dissipative elements depends on whether or not active power can maintain balance. The existence is closely related to the amplitude of excited current source. When the current source is strong enough, the original self-excited oscillation will thus disappear, leaving only a forced component. On the other hand, the existence of the self-oscillation of the lossless circuit which does not contain the dissipative elements is independent from the current amplitude of the excited source. The forced and self-excited oscillation components can simultaneously coexist unconditionally. chaos can easy be produced by the nonlinear coupling of the two harmonic components. The intrinsic attributes of the chaos can be sufficiently revealed with the help of this kind of lossless circuits.