Applied Mechanics and Materials Vols. 198-199

Abstract: In the processing of the polarimetric interferometric synthetic aperture radar (Pol-InSAR), the image registration is a key procedure. If the error of image registration occurs, the signal-to-noise ratio (SNR) of the interferometric image will be lowered and the precision of the height estimation will be decreased. Numerous registration algorithms have been proposed to solve the above-mentioned problem. However, in forested areas, the effect of volume scattering is significant. This property yields the fact that the characteristic of phase and frequency in the interferometric image is not obvious, leading to the worse performance of conventional registration algorithms. In this paper, a novel registration algorithm based on the random volume over ground (RVOG) model is presented. The method employs the fact that the coherence coefficients of the same pixel are displayed as a beeline in the complex coordinate plane for forested scenes. The image offset which yields the best linearity of coherence coefficients will be treated as the final estimation result. Simulation results verify that this method is able to provide the image registration estimation in the pixel and sub-pixel levels.

Abstract: Watermark information is embedded in three-dimensional mesh model through three-dimensional watermarking algorithm for effective copyright protection. The widely use of three-dimensional grid model attracts more attention on the copyright protection. The digital watermark algorithm with the NURBS model based on the wavelet transform aims to get the virtual grayscale images using the control point coordinate. Then we can embed the watermark into the virtual gray image watermark. It can change the three-dimensional models into two-dimensional images. And this algorithm can enhance the operability and simplicity of the watermark embedding. Experiments show that the proposed algorithm is easy to implement, simple in principle, and the extracted watermark is clearly visible, moreover, the model does not need to be directly modified, so it has good robustness. Watermarked model does not change in the visual, it has good invisibility.

Abstract: While the frame rate is higher and the image size is larger, sequence images processing is harder. Good real-time can be ensured by the multi-core DSP in the embedded image processing system. TMS320C6670 which is the multi-core DSP designed by TI corporation is selected as study object. Based on hardware characteristics analyzed, the Data Flow model is adopted as the multi-core processing model. Two data processing subtasks assigning methods are analyzed by comparing their advantages and disadvantages on the system idle time and memory requirements. The data processing subtask assigning flow is design for a serial sequence images processing example. An inter-core data transfer flow design idea is put forward. Using methods and occasion of two kinds of data buffer establishing techniques is studied and defined. An inter-core notification flow design idea is put forward. Using methods and occasion of three notification methods based on the interrupt controller and the Semaphore2 module is studied and defined.

Abstract: In order to improve the equalization effects of the constant modulus blind equalization algorithm (CMA) for Single-Input and Multiple-Output (SIMO) systems, orthogonal wavelet transform constant modulus algorithm (WT-CMA) based on SIMO is proposed. This proposed algorithm uses the orthogonal wavelet transform to decrease the autocorrelation of the input signals to accelerate the convergence rate and reduce the steady-state error. Theoretical analysis and computer simulations shows that the proposed algorithm has better performance and smaller steady-state error in SIMO systems, it is very easy to achieve in engineering.

Abstract: In order to improve the performance of constant modulus algorithm(CMA) in the noise which obeys α-stable distribution, wavelet frequency domain constant modulus blind equalization algorithm based on fractional lower order statistics(WT-FLOSFCMA) is proposed. This proposed algorithm uses fractional lower order statistics to restrain α-stable noise, and its computational loads can be greatly reduced by using FFT technique and the overlapping retention law. In the proposed algorithm, according to the minimum dispersion coefficient criterion, the CMA is optimized, orthogonal wavelet transform is used to improve the convergence rate. The computer simulations in underwater acoustic channels show that the proposed algorithm outperforms than CMA, orthogonal wavelet transform constant modulus algorithm(WT-CMA),and frequency domain blind equalization algorithm based on fractional lower order statistics(FLOSFCMA) in suppressing with inter-symbol interfere, improving convergence rate, and reducing mean square error.

Abstract: Noise reduction or cancellation is important for getting clear and useful signals. This paper deals with the implementation of the multi-channel wiener filter algorithm for noise suppression of seismic data. Known the velocity of reflection event, utilizes the resemblance of reflection signal in each seismic trace, the multi-channel wiener filter algorithm is effective in enhance reflection event and suppress the random noise. This algorithm is used to CDP gathers and the simulation shows the method is effective.

Abstract: Resource allocation and scheduling problems in the field of cloud computing can be classified into two major groups. The first one is in the area of MapReduce task scheduling. The default scheduler is the FIFO one. Two other schedulers that are available as plug-in for Hadoop: Fair scheduler and Capacity scheduler. We presented recent research in this area to enhance performance or to better suit a specific application. MapReduce scheduling research involves introducing alternative schedulers, or proposing enhancements for existing schedulers such as streaming and input format specification. The second problem is the provisioning of virtual machines and processes to the physical machines and its different resources. We presented the major cloud hypervisors available today. We described the different methods used to solve the resource allocation problem including optimization, simulation, distributed multi-agent systems and SoA. Finally, we presented the related topic of connecting clouds which uses similar resource provisioning methods. The above two scheduling problems are often mixed up, yet they are related. For example, MapReduce benchmarks can be used to evaluate VM provisioning methods. Enhancing the solution to one problem can affect the other. Similar methods can be used in solving both problems, such as optimization methods. Cloud computing is a platform that hosts applications and services for businesses and users to accesses computing as a service. In this paper, we identify two scheduling and resource allocation problems in cloud computing.

Abstract: Monkey-King genetic algorithm has the shortages of the lower searching ability in the local area and further in the whole area at monkey-king point in spite of the advantages of the simple principle and easy calculation. Monkey-king point was optimized iteratively by using immune evolutionary algorithm. This method overcomes the premature convergence because of the optimal searching in the out as well as in of the monkey-king point. At the same time, with the lapse of iteration, the algorithm closes in the whole of optimal solution with the higher precision because of the gradual strengthening of local searching ability. Calculation and comparison with several methods, such as monkey-king genetic algorithm, improved monkey-king genetic algorithm and common climbing operator genetic algorithm et al, has made. The results show that the monkey-king immune evolutionary algorithm has the optimal searching ability and the stability all the better.

Abstract: The double-byte character asymmetric encryption is always the difficult problem in information encryption technology, to choose algorithm not only depends on encryption information safety, but also considering the processing speed of plus and encryption information as well the system implementation of software and hardware. Depend on the large integer factor decomposition and the lower operation speed in public key system to discrete logarithm. The article proposes based on the processing algorithm of knapsack public key of Chinese characters plus and encryption information, introduces the password thought and decryption principle of Merke-Hellman knapsack algorithm, describes the experimental verification of the encryption algorithm to Chinese character.

Abstract: In order to improve the optimized performance of bee genetic algorithm, this paper proposed the evolution strategy by introducing immune evolution and chaotic mutation into bee genetic algorithm. This algorithm carries out the chaotic mutation to the some individuals with the lower fitness values, meanwhile the crossover and mutation operations were conducted between the some individuals with the higher fitness values and the optimal individual (queen) in population. In addition, the optimal individual in each generation should make iterative calculation by immune evolution. Therefore, as the iterations go on, this algorithm not only converges faster, but also close to the global optimal solution with higher precision.