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Guo H.,Engineering Design Research Institute of Equipment of PLA | Lei X.,Engineering Design Research Institute of Equipment of PLA | Yang G.,Engineering Design Research Institute of Equipment of PLA | Niu Z.,China Taiyuan Satellite Launch Center
International Journal of Mining Science and Technology | Year: 2015

In order to study features of rock-water interaction, a self-developed experimental system called Intelligent Testing System for Water Absorption in Deep Soft Rocks (ITSWADSR) was utilized to analyze the hydrophilic behaviors of natural soft rock at high stress state. Combining X-ray diffraction and mercury injection test, main influencing factors on hydrophilic characteristics were studied. According to the results, it could be concluded as the following: (1) the effective porosity, and the content of illite, illite/smectite formation (S = 5%) and kaolinite have positive correlation with the water absorption capacity of rock; meanwhile, the initial moisture content, fractal dimension of effective pores, illite/smectite formation (S = 30%) and chlorite present negative correlation; (2) among the positive factors, the ascending order is kaolinite, illite/smectite formation (S = 5%) and illite; (3) the descending order among the negative factors are chlorite, illite/smectite formation (S = 30%) and fractal dimension of the effective pores; (4) influence of effective porosity on the pressurized water absorbing capacity of rock is minimal, while it is maximal in the process of no pressurized water absorption. © 2015 Published by Elsevier B.V. on behalf of China University of Mining and Technology.

Wang S.,Engineering University | Dong J.,Academy of Equipment Command and Technology | Xiang D.,Engineering University | Zhang Z.,Academy of Equipment Command and Technology | And 2 more authors.
QR2MSE 2013 - Proceedings of 2013 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering | Year: 2013

With the rapid development of Chinese transportation industry, the longitudinal rear-end collision accident on the highway shows a rising trend, which has become a major problem affecting family harmony and social harmony. This paper begins with the traffic safety on the highway, and uses the speed which is the main factors influencing the safety distance as the main parameters. A relatively complete and practical vertical anti-collision warning model according to the motion state of vehicle is established, and the working process of the anticollision warning system basing on that model is described. The system considers the various factors fully, adopts the two alarm way which is more in line with human ergonomics, is of great significance to safe driving on the highway. © 2013 IEEE.

Ma C.,Engineering University of APF | Dong J.,Academy of Equipment Command and Technology | Jin C.,Engineering University of APF | Hu N.,The Academy of Management | And 5 more authors.
QR2MSE 2013 - Proceedings of 2013 International Conference on Quality, Reliability, Risk, Maintenance, and Safety Engineering | Year: 2013

A conical nozzle was designed in order to increase the maximum range of impulse anti-riots water cannon and improve the jet structure. The large eddy simulation model of OpenFOAM software was used for the numerical calculation of the nozzle flow field. The influence of different structural parameters of jet nozzle was analyzed. The results showed that the conical nozzle with the ratio of inlet and outlet diameters D1/d1 = 2 and the length to diameter ratio L1/d1 = 2 could ensure the best effect of jet. © 2013 IEEE.

Wang C.,Xi'an Jiaotong University | Wang C.,China Taiyuan Satellite Launch Center | Deng K.,Xi'an Jiaotong University | Zhuang L.,China Taiyuan Satellite Launch Center | Yu X.,China Taiyuan Satellite Launch Center
Hsi-An Chiao Tung Ta Hsueh/Journal of Xi'an Jiaotong University | Year: 2013

A robust distributed relay beamforming (RDRB) algorithm is proposed to address the uncontrollable problem of the received interference power at the primary user (PU) caused by the fast varying channel state information (CSI) in amplify and forward cooperative cognitive radio networks. When there exists estimation error in CSI, the RDRB method maximizes the signal to noise ratio (SNR) of the secondary receive node under constraints of the maximum interference to PU and the maximum transmit power to each node by designing the distributed relay beamforming weights of cooperative secondary nodes. The RDRB algorithm finds the suboptimal solution of the non-convex original problem using the bisection search. This strategy reduces calculation cost significantly and controls the received interference power at the PU when channels are fast varying. Simulation results show that the RDRB algorithm controls the interference power at the PU under a given level strictly, at least 2 dB less than those of non-robust algorithms, and the communication of the PU is effectively protected.

Wang C.,Xi'an Jiaotong University | Wang C.,China Taiyuan Satellite Launch Center | Deng K.,Xi'an Jiaotong University | Li Y.B.,Xi'an Jiaotong University | And 2 more authors.
Science China Information Sciences | Year: 2014

Opportunistic relay selection (ORS) is a promising approach for cooperative communications owing to its low complexity by activating only the best relay. However, in mobile scenarios, the channel state information (CSI) estimated in relay selection may be different from the actual CSI employed in data transmission due to relatively fast varying channels, i.e., CSI is outdated, which may lead to incorrect relay selection, and hence system performance deteriorates. To address the problem, this paper designs a relay selection strategy with instaneous and statistical CSIs in amplify-and-forward (AF) cooperative networks whose instantaneous CSIs of two hops employed in relay selection are both outdated. Based on high signal-to-noise ratio (SNR) analysis, we propose a distinctive relay selection strategy which can be described as selecting the relay with the asymptotic optimum average symbol error probability (SEP) and outage probability at high SNR. The corresponding asymptotic outage probability and SEP performance analysis are also provided. Finally, simulation results not only validate our theoretical analysis, but also show that in asymmetrical outdated CSI scenarios, the proposed strategy achieves better performance than existing relay selection strategies at medium and high SNR values. © 2014 Science China Press and Springer-Verlag Berlin Heidelberg.

Zhang J.,China Taiyuan Satellite Launch Center
Proceedings of the International Astronautical Congress, IAC | Year: 2014

A new method of system risk analysis which is faced to test process is proposed according to risk analysis methods existed not describe the distribution of risk in operating process of system. With the new method, system and the risk event distribution can be described comprehensively. All risk events can be found and no one lost in the risk distinguish used risk distribution diagram and risk event analysis table. Manager and operator can understand the location and forms of risk in the system in the risk management stage used risk distribution diagram which can relate risk event and operate link. And this method is in favor of risk control. This method makes risk analysis even closer to practical project, and so it is easier to be understood by engineers.

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