Advanced Materials Research Vols. 989-994

Abstract: According to the communication demand between warship and ChongFeng Boat or between ChongFeng Boats, this paper researched the communication capability of shipboard radio boat when sailing and islanding. It analyzed the propagation characteristics of radio, the relation between path loss and distance/path loss and frequency, discussed the influence of path loss on the capability of radio based on simulation and made a conclusion.

Abstract: Aiming at the characteristics of the traditional multichannel rendering synchronization strategy and the existing problems, the paper proposes a new multichannel rendering synchronization strategy based on timestamp and makes a horizontal comparison between the experimental results and the traditional strategies, as well as verifies the advantages on systematic stability and fault tolerance of network transmission. The strategy will be suitable for using in a clustered, massive and high reliable multichannel system.

Abstract: Multi-sensor is deployed for the target-monitoring in complex environment. However, the distribution of sensory data is irregular and inconsistent and the data is also highly redundant. For the purpose of obtaining accurate information, this article proposes a method for data aggregation of multi-sensor based on clustering analysis and correlation. By computing the correlation of the sensory data and the clustering analysis, the overall distribution of the data is analyzed. Finally, the method integrates sensory data by the correlation and uses the joint probability density function to compute the best integrated point. Simulated results show that the method is more effective in data aggregation than traditional methods.

Abstract: Synthetic aperture radar (SAR) technique has been widely applied in disaster monitoring and evaluation, because of its all-weather and all-time capability. In particular, the integration of high resolution SAR image and GIS data has been proved to be an effective solution to change detection for rapid disaster response. However, accurate registration of SAR image and GIS data remains a challenging task. On the one hand, SAR image and GIS data are two different representation levels of the real world. GIS data lacks of grey value and texture information, thus traditional use of grey-based and texture-based feature descriptors for feature matching in GIS data is impossible. On the other hand, the extraction of matching primitives is difficult in the SAR image due to the speckle noise. Moreover, though features can be extracted in the SAR image, the matching can be difficult since features may be fractured and missing. In this paper, we propose a new method for vector-to-SAR image registration which utilizes conjugate line-pair intersections as matching primitives. The core idea consists in two aspects: 1) Different from traditional road intersection based registration methods, conjugate line-pair intersections are employed as matching primitive in the proposed method. 2) To find out the optimal set of matching features, a matching technique that using pairwise constraint and the iterative conditional mode (ICM) optimization algorithm is introduced. Experiment results proved the reliability and feasibility of the proposed method.

Abstract: High-resolution satellite remote sensing image are mostly used for accurate updating of GIS data. As the primary GIS data, urban roads on the image show the rich geometric features and radiation characteristics, that edge detection and grouping becoming an important way to solve the road extraction. However, edge elements obtained from images are always discontinuous for interference of noise and weak contrast between road and background. What more, vehicles, plant, buildings and shadow blocking results in weak grouping relation of elements. In processing, insignificant candidate road may be weeded out as noise and lead to failure road extraction. This paper presents a semi-automated extraction method for low contrast road basing on statistical grouping of orientation texture feature. Multi-direction and multi-scale Gabor filters are employed to detect directions of road texture. Then same direction pixels are grouped under constraining of rectangle template and generate road base elements. Finally, simulated annealing algorithm is used to optimize elements connection. Experiment results show that proposed method was effective in accurate extraction of low contrast road.

Abstract: Both maximum entropy method and Particle swarm optimization (PSO) are common threshold segmentation methods which have been used not only in image segmentation, but also in multi-threshold segmentation. Maximum entropy method is time-consuming, PSO may easily get trapped in a local optimum. In view of this concerning issue, we propose the PSO and maximum entropy are combined to make improvements on the PSO introduced in expansion model and opposition-based module. The objective functions of the maximum entropy as well as the PSO are obtained, which have improved to optimize them and search the optimal threshold combination, to achieve multi-threshold image segmentation. The results demonstrate that the new algorithm improved the segmentation speed and enhanced the robustness. And the optimizing results are stable.

Abstract: Speech enhancement is crucial for speech recognition accuracy. How to eliminate the effect of the noise constitutes a challenging problem in speech processing. This paper presents a new technique for speech enhancement in a noisy environment based on the empirical mode decomposition (EMD) algorithm and wavelet threshold. With the EMD, the noise speech signals can be decomposed into a sum of the band-limited function called intrinsic mode functions (IMFs), which is a zero-mean AM-FM component. Then wavelet threshold of the IMF components can be used to eliminate the effect of the noise for speech enhancement. Experimental results show that the proposed speech enhancement by de-noising algorithm is possible to achieve an excellent balance between suppresses noise effectively and preserves as many target characteristics of original signal as possible.

Abstract: In order to reduce peak to average power ratio (PAPR) higher of OFDMA problems, this paper proposes a power line communication system based on SC-FDMA model, compared this model and OFDMA system on peak to average, the same power with the throughput, the same throughput required simulation sub carrier number of needed power and power rate users; The results show that: when introduced the SC-FDMA into the power line communication, can effectively reduce the system PAPR, the terminal can obtain better emission efficiency.

Abstract: Proposed a new stitching algorithm to suit for coal mine. Cross-power spectrum phase information is used to coarse matching fast and overlapping regions can be found. Invariant features are extracted by using the dimensional reduced SIFT algorithm-sample principal component analysis. RANSAC combined with iterative L-M nonlinear optimization algorithm can improve projection matrix. New algorithm can improve the matching efficiency, and it’s suit for coal mine environment.

Abstract: Experimental phonetics development to today has undergone a long and complicated process. The field of study from the acoustic analysis of expansion to the physiological and perceptual field. Speech aerodynamics signal is one of the most important physiological signal language research, plays an important role in human phonation process. Air pressure signal as an important physiological signal, which has great significance to the study of speech physiology, mainly through speech aerodynamics equipment acquisition. In this paper, according to the need of research, established by MATLAB program analysis platform, can be edited on the speech, the airflow and pressure signal is better, which is more suitable for speech research.