Weng X.,PLA Air Force Aviation University |
Yan X.,PLA Air Force Aviation University |
Liu W.,General logistics of Xian Air Force Flight Institute |
Liang L.,PLA Air Force Aviation University |
Li X.,Air Force Command College
Advanced Materials Research | Year: 2013
In order to study the influence of interface bond condition between new and old cement concrete pavement on overlay performance, the three-dimensional finite element model of the airport double-layer pavement was established. The pavement overlay's load stress and deflection were analyzed, the coupling coefficient between new and old cement concrete pavement was calculated based on the bottom of overlay deflection basin shape factor. The results show that the coupling coefficient reflects the degrees of interface bond condition well. Poor interface bond condition increases the overlay's load stress and deflection. The points that more closely distance from the wheels load center, the bigger the pavement overlay's load stress and deflection is. Therefore, more attention should be paid to the interface bond condition during the airport pavement overlay's designs and constructions. © (2013) Trans Tech Publications, Switzerland.
Liu Q.-Z.,Air Force Command College
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2011
On the basis of the traditional AHP/ANP, a new decision making approach - MC-ANP (analytic Network Process based on finite state homogeneous Markov chain) - was proposed. In this approach we have used a direct graph to define the criteria and the dominance relations among them, have quantified the relations of dominations through comparison of criteria, and have described criteria dominance relations using the matrix of state transition of the Markov chain. This approach has focused on the synthesis of the dominance relations, has provided two synthetic models (among which the multiply model can be used to solve rank reverse problem thoroughly), and has pointed out the confusion existed in the traditional ANP using Cesaro mean limit. In the MC-ANP, the decision problems are classified in two categories: i) ranking the alternatives, the process of the solution is to find the specific left eigenvectors of eigenvalue 1 of matrix of state transition probability of the Markov chain; ii) ranking the criteria (no alternative), the solution is the right eigenvector of eigenvalue 1 of matrix of state transition probability of the Markov chain.
Jia J.,Institute of Military Operations Research and Analysis |
Zhan X.-S.,Institute of Military Operations Research and Analysis |
Cheng W.-J.,Air Force Command College
Xitong Fangzhen Xuebao / Journal of System Simulation | Year: 2012
The system framework of cyberwar's synthetical ability was built by three subability, such as reconnaissance, attack and defence. Through analyzing this system, the key index of evaluating the subability and the gray association analysis model of cyberwar's synthetical ability were taken out. At last, three objects's cyberwar's synthetical ability was analyzed and evaluated through the model. © copyright.
Wang H.-Y.,Beihang University |
Wu W.-Q.,Beihang University |
Xue X.-F.,Air Force Command College |
Zhao Y.-W.,Beihang University
Guangxue Jingmi Gongcheng/Optics and Precision Engineering | Year: 2012
To improve the precision, update rate and the anti-noise ability of star sensors, this study was focused on the extraction of star images. Firstly, the criterion to confirm whether a pixel attributes to the same star coverage with the local maximum pixel was established according to the gray distributing features of star images. Then, several kinds of methods for image extraction were introduced, such as the block division of imaging array, and the prediction of background noise. Finally, by regarding the peak value pixel as the origin of the circular region growing, the local region growing criterion was set up successfully based on the gray distributing features of star images. The simulation conducted in the case of no noises shows that all of the simulated star images in the reference star map can be extracted successfully, and the sub-pixel location accuracy is 0.028 2 pixel by using centroid method. Moreover, under upmost adverse condition with a Gaussian noise mean value of 20 and standard variance as high as 2.5, the success extraction rate can still reach 86.11% with a decreased centroiding accuracy of 0.219 6 pixel. The test about a faint star image in a star map with poor uniformity and a low SNR of 4.9 dB also proves the excellent detection ability of the proposed method, and it shows advantages of good real-time property and high correct extracting rate for star images.
Dong F.-Y.,PLA Air Force Aviation University |
Lei H.-M.,PLA Air Force Aviation University |
Li J.,PLA Air Force Aviation University |
Shao L.,PLA Air Force Aviation University |
Chen Z.-X.,Air Force Command College
Yuhang Xuebao/Journal of Astronautics | Year: 2012
Considering the weak robustness of dynamic inversion control, an incremental dynamic inversion control law for missiles with tracking differentiator is designed. Firstly, the over-load control model of the missile is established, which can be divided into the fast loop and the slow loop. Then through the feedback of state rate, the incremental dynamic inversion control law is proposed for each loop, and its robustness is analyzed. During the design process, the fast tracking differentiator is introduced to solve the immeasurability problem of state rate. Simulation result shows that the proposed control law has excellent robustness.