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Peng Y.,Lanzhou University | Gao P.,Lanzhou University | Lv W.,Lanzhou University | Yao B.,Lanzhou University | And 6 more authors.
IEEE Photonics Technology Letters | Year: 2013

Photo-induced balanced ambipolar transports in lead phthalocyanine organic field-effect transistor are observed. The transport mode of the device is changed from typical p-channel to ambipolar under illumination at 655 nm, 100 mW/cm2. The physical origins of this phenomenon are resulted from the photo-induced energy barrier lowering for electrons injection at the source-channel interface, which is suggested to be the downward bending of orbital level in the channel material near the source by accumulation of photo generated holes there. © 1989-2012 IEEE. Source


Gao F.,Beijing Institute of Technology | Zeng X.-F.,Beijing Institute of Technology | Zeng X.-F.,Dalian Air Force Communication NCO Academy | Bu X.-Y.,Beijing Institute of Technology
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2012

To improve the anti-interference performance of frequency hopping (FH) communications, Raptor code is applied in the FH communication as a forward error correction (FEC) code in this work. The proposed Raptor code is composed of 0.95 rate of regular LDPC pre-code and the cascading Luby transform (LT) code. By modeling and experiments on Matlab platform, the anti-interference performance of the FH communication system in different interference channels was analyzed. The results are as follows. In broadband interference channels, provided that the bit SNR is 2.5 dB, the BER is lower than 10 -3 and the system performance would be improved by 17.6 dB. In partial-band interference channels, provided that the bit SNR is 1.0 dB, the BER is lower than 10 -3, the system performance would be improved by 16.8 dB. It could be concluded that it is feasible to apply the proposed Raptor codes in FH as the FEC code. Source


Huo L.,Dalian Jiaotong University | Jiang B.,Dalian Maritime University | Ning T.,Dalian Jiaotong University | Yin B.,Dalian Air Force Communication NCO Academy
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

This paper presents a stock price forecast model using LM-BP algorithm, which has adopted three-layer back propagation neural networks. This model is more fast convergence rate and overcomes redundancy and noise of the samples. The proposed model is simulated in MATLAB platform and the experimental results of stocks price prediction show that the LM-BP model attains high accuracy of predicting the stock price in short-term. This paper provides also the comparison of actual value and forecast value, which proves that the model is effective and promising. © 2014 Springer International Publishing Switzerland. Source


Gao F.,Beijing Institute of Technology | Zeng X.-F.,Beijing Institute of Technology | Zeng X.-F.,Dalian Air Force Communication NCO Academy | Bu X.-Y.,Beijing Institute of Technology
Beijing Ligong Daxue Xuebao/Transaction of Beijing Institute of Technology | Year: 2013

Considering the features of small message size of frequency-hopping (FH) communication, an improved scheme for short-length Raptor codes is proposed in this research. The proposed short-length Raptor codes' average degree weight could be 29% less than original scheme. To investigate the performance of the short-length Raptor codes applied in FH communication, simulations has been done under Matlab environment. The results show that compared with the original scheme, the bit error rate using improved scheme would reduce 62.1 dB under the non-interference environment, while reduce 30.65 dB under broadband-interference environment with 4 dB SNR. The improved scheme provides a new forward error correction (FEC) encoding measure for FH anti-interference communication and it also opens up a new area for the application of fountain codes. Source


Jin H.,Dalian Jiaotong University | Ning T.,Dalian Jiaotong University | Yin B.,Dalian Air Force Communication NCO Academy
Applied Mechanics and Materials | Year: 2014

Roof pre-splitting roadway is a new technology in roof induced rock burst prevention and control of incline coal seam. With the purpose of increasing rock burst prevention and control effective, FLAC3D numerical simulation software was used to analyze stress distribution characteristics and roof pre-splitting effect and the layout of the roof pre-splitting roadway parameters. The results showed that the roof pre-splitting roadway changed roof and floor stress distribution, the stress concentration degree is high in the zone of roof and floor around pre-splitting roadway and the two ribs of pre-splitting roadway, which made the roof strength weakened and easy to break, avoiding a large overhang in the process of mining and rock-burst; The roof pre-splitting roadway led to stress concentration in the range of 5 ~ 10 m, roof effective weakening range 12 m, so the distance of two roof pre-splitting roadway should be more than 20m. The research provided the reference basis for rock burst prevention by roof pre-splitting roadway in the incline coal seam group mining. © (2014) Trans Tech Publications, Switzerland. Source

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