Applied Mechanics and Materials Vols. 522-524

Abstract: In this paper, we proposed a parallel simulation method for performance analysis of the Global Navigation Satellite System (GNSS) based on simulation model portability 2(SMP2) and service-oriented modeling method. GNSS is a space engineering system with a large-scale and complex structure, and the proposed method can be used to construct large complex simulation systems to gain the reusability, composability and interoperability of heterogeneous simulation resources. Firstly, the method including the conceptual framework, system architecture and system engineering process is introduced. Then the parallel model development, composition and schedule method are detailed respectively. Finally, a distributed M&S environment based on service-oriented SMP2 is designed, and an example of navigation system volume simulation is given to validate the whole method.

Abstract: Satellite navigation systems are running in complex electromagnetic and space environment. There is few research studies the threat and protect ability of navigation system. Lacking of qualitative data makes it difficult to analyse the security of it. In this paper, we applied Functional Dependency Network Analysis (FDNA) to solve this problem. FDNA studies how the impact caused directly by attack spreads in the overall system through the dependencies between function nodes of system. Then we are able to assess the operability of the application of navigation system. This method avoid considerable statistic experiments. Make full use of principle data. Provide constructive decision making comments.

Abstract: Ground penetrating radar (GPR) is a kind of geophysical instruments, which has been widely applied in geology, engineering, resource, environment, military etc. The method mentioned in this paper based on QR decomposition, by solving equations to find the estimated value of the radar wave velocity. This method delivers the features of real-time, accurate, and the accuracy required is not high. It is suitable for real time estimation of GPR detection. By estimating the wave velocity, we can identify the spatial location of underground target. This method provides a convenient way for the detection of underground target.

Abstract: In case of no errors of known coincidence points coordinates the plane coordinate transformation model equation with four parameters and the plane coordinate transformation model equation with six parameters are derived, this algorithm needs not composed normal equation from error equation, which is verified by examples about transformation between the urban plane coordinate and CGCS2000 plane coordinate. Finally the some beneficial conclusions have been got.

Abstract: Using three dimensional coordinate transformation model with 7 parameters the coordinate transformation parameters are solved. Comparing the coordinates of the kilometer grid point on topographic maps in Beijing54, Xian80 and Urban Independent Coordinate System with the observation coordinates of same point inCGCS2000, Through watching their coordinate changes the moving changes regularity on topographic maps are discovered between Beijing54 and CGCS2000, between Xian 80 and CGCS2000, Urban Independent Coordinate System and CGCS2000

Abstract: The coordinate transformation models based on least square method and total least square are built and discussed. The least square model only includes the errors of observation vectors, the total least square model simultaneously takes into consideration to the errors of observation vectors and the errors of coefficient matrix. The both models are verified and compared in experiment. The experimental results showed that the model of total least square is more in line with actual, and more reasonable than by least square theoretically, and the coordinate transformation solution result of total least square with least square is more near.

Abstract: In aerospace, the design principles have transformed from the pursuit of performance to a balance among performance, costs, reliability and other aspects, and how to meet the system performance requirements under the premise of minimizing costs has become a serious problem. In this paper, the relationships between the constellation availability and the satellite reliability were modeled considering the replacement mode of the back-up satellite. A case study was presented to show the effects of the satellite reliability on constellation availability.

Abstract: Low-Xingouzui Formation II reservoir in the Xingou region of Jianghan Basin belongs to tight oil reservoir. By means of study about the geochemical characteristics of source rocks, lithology, physical property and pore structure characteristics, this paper confirms that the source rocks of Low-Xingouzui Formation II are mostly above medium in content of organic matter. The hydrocarbon source rocks are mainly of type II. The thermal maturity of most samples is immature-low mature. Dolomicrite and terrigenous clastic (intraclast) dolomite are the most favorable reservoir facies. The reservoir has mid to high porosity and extremely low permeability, and its space is dominated by dolomite dissolution with micro throat pore structure. This oil reservoir distributes widely and quasi continuous, while good conditions of petroleum formation exist. It could hopefully become new increasing point of Jianghan’s oil and gas output that has broad development prospects and studying value.

Abstract: This paper based on the previous researcher's work, studied the regional structure pattern and tectonic evolution history of Hunan. It combined the coalfield structure research method and Hunans actual situation showed that coal occurrence in Hunan controlled by the regional tectonic framework and tectonic evolution history. The coal occurrence has the conspicuous characteristics of partition, zoning and Classification. Synthesize the plans of geotectonic unit division and coal occurrence unit division, we proposed the new concept of occurrence tectonic unit of coal, divided Hunan into two secondary and five third occurrence tectonic units of coal and studied the characteristics of each unit. We also divided three types of the styles of structure control of coal.

Abstract: Based on the velocity contrast of rocks, the seismic logging is to study the relationship of the velocity-depth by using the seismic wave data acquired in borehole. The concept of average velocity used in conventional method of seismic logging data may lead to a wrong interpretation. With help of the raytracing technique, This paper deals with the seismic logging data by Fast Reconstruction (FR) technique to obtain a fine velocity structure in borehole. The results from numerical modeling show that the method can be used in complicated structure with a fast computation and high accuracy.