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Wavelet transform denoising is an important application of wavelet analysis in signal and image processing. Several popular wavelet denoising methods are introduced including the Mallat forced denoising, the wavelet transform modulus maxima method and the nonlinear wavelet threshold denoising method. Their advantages and disadvantages are compared, which may be helpful in selecting the wavelet denoising methods. At the same time, several improvement methods are offered.

Based on improved A* algorithm, this paper proposes the optimal path planning of robot fish in globally known environment, so as to achieve better coordination between the robot fish by means of improving their path planning. In the known obstacle environment which is rasterized, target nodes are generated via smoothing A* algorithm. The unnecessary connection points are removed then and the path is smoothed at the turning points. That improved algorithm, in combination with distributed scroll algorithms, is applied to multi-robot path planning in an effort to optimize the path with the avoidance of collision. The experimental results on the 2D simulation platform have verified the feasibility of that method.

A novel waterborne polyurethane (WPU) modified by tung oil was prepared with 2,4-tolylene diisocyanate, polyethylene glycol, dimethylol propinic acid, 1,4-butanedilo as main materials via acetone process. The structure of WPU molecule was characterized by FT-IR. Adhesive behavior for non-polar and/or low surface energy soft packing films was studied. Water resistance of films were evaluated by water contact angle and water uptake and thermal properties determined by thermal analysis instruments. The results show that the modified WPU films have good water and heat resistance. Both of modified WPUs or not have good adherence on BOPP films.

Based on the multi-source information fusion and complex network theory, through studying the effective matching and integration of safety equipment and spatial information of urban rail transit network operation, a safety assessment model is proposed: through equipment fusion and the node fusion, the global safety parameter is obtained, which is accurate in description and evaluation of urban rail transit operating than the partial safety factors and realize the transform from microscopic description to macroscopic description.

As network environment is becoming more and more complex, it is difficult for students to understand and master the complex and abstract network concepts. A virtual learning tool named Cisco Packet Tracer has been introduced into the classroom teaching, which provides the virtual configuration environment as real one. This article presents the features of the virtual simulation tool, and the configuration example for mini practice project, which can inspire students creativity. It makes teaching and learning computer network much easier than traditional teaching method.

Duo to the high cost of network entity equipment environment, network laboratory is not established completely in colleges and universities in china, students find that it is difficult to grasp the complex and abstract network concepts. Virtual learning tool software named Cisco Packet Tracer is free for students in anytime, which provides the same configuration environment as true network entity equipment. This paper presents the example of Dynamic Routing Protocol (RIP), and offers experimental design topology of RIP. This teaching mode not only reduces the dependence on the real environment, but also helps students to master the abstract network concepts and enhance theirs practical operation skills. This can cultivate student's innovative spirit.

A new hybrid algorithm based on Differential Evolution (DE) and Extremal Optimization (EO) is proposed to solve the premature convergence and low precision of standard differential evolution when applied to complex optimization problems. The key points of it lie in: the hybrid algorithm introduced the population-based Extremal Optimization algorithm in the iteration process of DE when population aggregation got the high degree, which uses the volatility of EO to increase the diversity of population and the ability of breaking away from the local optimum. Simulations show that the hybrid algorithm has remarkable global convergence ability, and can avoid the premature convergence effectively.

MATLAB is a powerful tool for data processing. This paper focused on how to enhance the efficiency of scientific computation in seismic data processing by improving the traditional MATLAB programming code. Some examples were presented to demonstrate the advantage of vector addressing over the traditional scalar addressing. Vector addressing programming can simplify the code significantly, and can it also improve the compiling efficiency and executing efficiency of the code. The other examples were given to illustrate the use of the colon and some special values that can improve the MATLAB programming efficiency. Some issues in this paper can also serve as guidelines for professionals in other disciplines.

The porous Ultra-high Molecular Weight Polyethylene (UHMWPE) is designed to fabricate the roadside safety devices fixed on the conventional metal or concrete road highway guardrails. When the UHMWPE with pores is shocked, the material is compressed because the pores are closed and much energy is absorbed. Next, elastic deformation and plastic deformation happen further under the stress, kinetic energy is transformed into deformation energy further. The cushioning capacity of UHMWPE will be improved when the pores are induced. Then the vehicles will not be destroyed seriously when they bounce. On the other hand, it will be convenient to fix the roadside safety devices on the conventional metal or concrete road highway guardrails and the cost must be lower than changing the whole guardrails. Experimental results indicate that: UHMWPE exhibited excellent shock-absorbing capacity and it was a promising roadside safety material.