Advanced Materials Research Vols. 798-799

Abstract: The network collaboration system refers to that the users in different locations can see and hear each other through the collaboration system, and can share and browse the text, video, web pages, etc., so as to achieve the purpose of joint work and joint learning. Based on the needs of this collaboration system, this system was studied and designed, the system was based on P2P bottom layer and designed different logical topologies under different collaborative application circumstances, and it designed the topology with the combination of mesh and tree structures according to the particularity of P2P live broadcast, moreover, regarding keys affecting the system performance, i.e. service node lookup, it proposed new algorithm and conducted the optimization.

Abstract: Based on the public and actual massive data of securities market, through testing the MA and RSI expert system of securities trading software by simulation experiment method, with the winning percentage, the annual rate of return, and the net profit margin as the management objectives, and with the theory of mathematical statistics as the research basis, the article carried out the comparative analysis of strength and weakness of these two systems. Except the annual transaction number, RSI expert system is comprehensively superior to MA expert system.

Abstract: A new technique that combines maximum variance method and morphology was presented for Synthetic Aperture Radar (SAR) image segmentation in target detection. Firstly, using the first-order differential method to enhance the original image for highlighting edge details of the image; then using the maximum variance method to calculate the gray threshold and segment the image; lastly, the mathematical morphology was used to processing the segmented image, which could prominently improve the segmentation effects. Experiments show that this algorithm can obtain accurate segmentation results, and have a good effect on noise suppression, edge detail protection and operation time.

Abstract: In the paper, we define the convergence of sequences and series of functions on fractal space. Some properties for convergence of sequences and series of functions also are considered .

Abstract: A new multi-frame joint quantization algorithm with dynamic weighted inter-frame linear prediction based on mixed excitation linear prediction (MELP) is proposed in this paper. In encoding stage, a super-frame consists of three adjacent single-frames. Fourier magnitudes and aperiodic jitter flag are eliminated. The other parameters are jointly quantized. LSF of the first and third frame are quantized as a 20-dimensional vector. According to the BPVs of super-frame, pitch is quantized with codebooks of dynamic size. In decoding stage, parameters are indexed from corresponding codebook. The LSF of middle frame are predicted from the first and third frame. The weighted factors keep changing in accordance with the BPVs of adjacent five frames. Results show that the reconstruction accuracy of LSF is significantly improved using dynamic weighted inter-frame linear prediction. Meanwhile the coding bit rate is reduced to 0.6 kbps.

Abstract: Because of the different types and function of the Underground engineering, a large number of geological drilling in construction area cost high, and will cause unnecessary security hidden danger in later construction. In consideration of the accuracy of other existing geological survey equipment is so poor that can not meet the data requirements of geological modeling, In this paper, we select a combination method between high density resistivity survey data and drilling data of Geological information access and data fitting, through the error analysis of the results, Two classes of data fitting equation are obtained, and through this method, the accuracy of the data of geological modeling are effectively corrected.

Abstract: In this paper, we mainly discuss the computation of the Perron root of a nonnegative matrix. We propose an algorithm for the Perron root of nonnegative matrices by using the generalized Perron complement. Based on this algorithm, for the Perron root of a nonnegative matrix with central symmetric structure, we construct an improved algorithm, which ensures significant saving of computation and store cost. We demonstrate this by analyzing theoretically and a numerical example.

Abstract: In order to solve the slowly processing speed, low precision problems in the Face location and detection, the comprehensive face location algorithm based on composite skin color was proposed in this paper. The YCrCb model algorithm and HSV model algorithm are skillfully applied to the comprehensive face location algorithm. The human body region and background region can be detected and judged by the color value of every pixel for image in the YCrCb and HSV space. Then, the connecting region can be screened and decided by the geometric features of human face, and the face can be accurately located and detected. The experimental results confirm that the algorithm can achieve the accuracy ratio of face location in three cases, such as simple, medium and complexity, are 99%, 92% and 85%, respectively. Furthermore, the accuracy ratio of face location and detection speed was improved in this algorithm.

Abstract: This paper proposes the estimation method for the maximum payload on spatial domain, concentrates on digital watermarking payload in the spatial domain image, on the constraint of perceptual invisibility research, the influence under the factors in Human Visual System. The maximum payload is influenced by the factors which include the size of image, the brightness masking, contrast masking and texture masking of the image. with such as noise visibility function visual model, gets the just noticeable different value to calculate the payload of the image, finally we get the watermarking payload, test and verify it with Matlab simulation experiments.

Abstract: Considering the requirement analysis，the thesis discusses and analyses the general design and function constitution of the civil air defense engineering management system. It adapts groupware GIS and Visual Studio platform by web interface to realize the system based on B/S model. The thesis detailedly analyses the design and implement of client layer, intermediate service layer and data layer. The system improves the shortage of the traditional civil air defense work, and realizes information office work.