Advanced Materials Research Vols. 532-533

Abstract: The advent of cloud is drastically changing the High Performance Computing (HPC) application scenarios. Current virtual machine-based IaaS architectures are not designed for HPC applications. This paper presents a new cloud oriented storage system by constructing a large scale memory grid in a distributed environment in order to support low latency data access of HPC applications. This Cloud Memory model is built through the implementation of a private virtual file system (PVFS) upon virtual operating system (OS) that allows HPC applications to access data in such a way that Cloud Memory can access local disks in the same fashion.

Abstract: Aiming at the generation of the scenario data in operation simulation, the comprehensive requirement building operation simulation scenario generation toolkit is analyzed in detail. Then the main functions and application flow are designed, and the correlativity between the toolkit and the other three subsystems are analyzed. Especially, in order to setup scenario database the entity-oriented simulation scenario structure description method is put forward. Finally, the main functions including scenario management, operation cooperation management, rule management, data validation &verification are achieved. The toolkit can satisfy the simulation scenario generation requirement of the operation simulation system, and can improve the efficiency greatly.

Abstract: A feature extraction method based on wavelet packet energy distribution and correlation coefficient has been put forward to recognize the different acoustic targets in this paper. In view of the characteristics of acoustic target, we employed principal component analysis (PCA) to compress data set of the features extracted based on wavelet packet energy distribution and correlation coefficient. The results have been inputted into the neural network as eigenvectors for pattern recognition. Simulation results indicate that the method suggested in this paper have a recognition rate better than 8% with only wavelet packet energy method, thus verifying its effectiveness .

Abstract: Copy-Move is a common forgery in the research field of digital image forensics, this paper proposes a detection approach based on wavelet transform and two-dimensional image principal component analysis. After reducing the image dimension by Discrete Wavelet Transform(DWT)，2DIMPCA is applied to the fixed sized overlapping blocks of a low-frequency image in the wavelet sub-band to yield a reduced dimension representation from the horizontal direction and the vertical direction. The eigenvectors are then lexicographically sorted, the forgery part are localized by detecting for all neighborhood vectors by a certain threshold. The experiments demonstrate that the proposed approach can not only localize the copy forgery regions accurately, but also reduce the amount of computation and improve the detection efficiency.

Abstract: As part of fingerprint image pre-processing, fingerprint image segmentation plays an irreplaceable role. This paper proposes a method based on the orientation field information combined with statistical characteristics of gray in order to realize the second segmentation of fingerprint image. Various experimental results show that the method proposed in this paper improves the effect of segmentation.

Abstract: The envelope extraction of Doppler signal spectrum is very important in ultrasonic blood flow detection, due to the fact that it can provide the diagnosis information of blood circulatory system. Doppler signals are often polluted by noises, which will affect the performance of the envelope extraction. Therefore, it is necessary to remove the noises before extracting the spectrum envelope. In this paper, a Doppler denoising method based on the Feature Adaptive Wavelet Shrinkage is proposed. The advantage of this method is that the threshold of each coefficient is set by using the coefficient at the current location and its two neighbor coefficients. Simulation results demonstrate that the proposed method can remove the noises of Doppler signals more effectively compared to the traditional wavelet threshold method.

Abstract: This paper studies a competition model between two species for two resources in the chemostat with the Beddington-DeAngelis functional response. The sufficient condition to the coexistence of positive steady state solutions is obtained by the mathematical methods of the fixed point degree theory in cones. Finally, Some results of numerical simulations is presented to prove and complement the previous mathematical results by numerical computation method. Furthermore, the research result implies that two species in the biological environment can be coexistence after a long time.

Abstract: Processors using stream architecture can make good use of the on-chip resources and explore the data locality and parallelism. DES algorithm is one of the most popular cipher algorithms. This paper proposes the novel implementation of DES algorithm on stream architecture based on both stream programming model and DES algorithm and the speedup is 1.27 times.

Abstract: C-mode imaging is one of the ultrasound imaging modalities. Compared with other modalities, e.g. A-mode, B-mode, M-mode, and Doppler, C-mode is mainly developed and used in industry testing. The potential of C-mode imaging for medical application has not been fully explored. In this paper, we design one 2-d plane array transducer through using the point spread function (PSF), and apply the 2d array transducer for C-mode imaging. The simulation results show that the generated C-mode images can display the anatomic structure and the pathological changes on the biological tissue.

Abstract: The response surface method (RSM) is widely used to alleviate the computational burden of engineering analyses. For reliability analysis, the common approach in the RSM is to use a linear interpolation technique. However, the experimental points are all arranged using the classical RSM in each process of interpolation. Therefore, the number of experimental points is large that resulting in the efficiency is lower. In this study, an improvement of the RSM for structural reliability analysis has been proposed based on the technique of successive linear interpolation. As seen from the example, the proposed method yields better results than those of the classical RSM, and the number of experimental points using the proposed method is less than that of classical RSM. It seems that the proposed method improves the convergence speed and reduces the computational effort.