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Pan X.,Beihang University | Xin Z.,CAS Institute of Computing Technology | Li G.,Wuhan Maritime Communication Research Institute
IEEE Transactions on Reliability | Year: 2015

The IEEE Standard 1624 provides a foundation for the assessment of organizational reliability capability (ORC). However, to better match the individual characteristics of different industries, this standard needs to be suitably clipped and adjusted, so as to develop customized models for the reliability capability evaluations of different organizations. To evaluate the ORC of China's aviation enterprises effectively, we propose a reliability engineering capability maturity model (RE-CMM) for China's aviation industry, with adequate consideration of the features closely associated with China's aviation enterprises and China's military standards. The proposed RE-CMM model is established on the theoretical basis of Capability Maturity Model Integration (CMMI), combined with the IEEE standard and China's military standards for Reliability, Maintainability, and Supportability (RMS). Structural equation modeling (SEM) is used to verify the validity of the RE-CMM model. We use a fuzzy method for the evaluation of reliability engineering capability. Detailed steps of reliability engineering capability assessment are also provided for the application of the model. Finally, a case study on a Chinese aviation enterprise is given to illustrate the model and method. © 2015 IEEE. Source

Li J.,Wuhan University | He S.,Wuhan University | Yu D.,Wuhan University | Deng F.,Wuhan Maritime Communication Research Institute | And 2 more authors.
Optics Express | Year: 2011

A numerical matching method (NMM) based on the framework of the uniform geometrical theory of diffraction (UTD) is proposed to build the spectral functions for computing the diffraction field by anisotropic impedance wedge at an arbitrary skew incidence. The NMM starts from the coupled integral equations before they are converted into the coupled difference equations as the classic Maliuzhinets methods. Then, the spectral function in the Sommerfeld integral representation of the longitudinal components of the EM field is expanded by a series about the spectrum and the skew incident angle with unknown coefficients. With respect to the oblique incident angle based on normal to the edge incidence or grazing to the edge incidence, the spectral function is derived numerically by solving a system of algebraic equations constructed from the coupled integral equations, after choosing the numerical matching regions on the wedge faces and setting a Sommerfeld numerical integration path. On the basis of the sampled incidences, the asymptotic waveform evaluation (AWE) technique is employed to deduce the spectral function at any other skew incidence in the whole angle space (0°-90°) rapidly. Finally, the UTD solutions are provided far beyond the applicability of the perturbation approach and the numerical examples provide a uniform behavior of the field with respect to the observation angle. © 2011 Optical Society of America. Source

Wang Y.,Harbin Engineering University | Liu J.,Harbin Engineering University | Liu J.,Wuhan Maritime Communication Research Institute
Journal of Convergence Information Technology | Year: 2012

In Mobile Ad hoc Networks(MANET), topological dynamic changes may lead to link failure frequently and consequent serious packets loss. Since traditional TCP protocol cannot distinguish between different types of packets loss and thus it incorrectly estimates network condition and blindly starts congestion control which will thus degrades the network performance. Therefore, a Dynamic Topology-Multipath AODV (DT-MAODV) applicable for dynamic topology environment is proposed to improve the performance of TCP in MANET in this paper. The AODV adopts link-disjoint path strategy to set up many backup routes. When a route breaks, it firstly takes advantage of available local backup paths to recover it in order to decrease frequency of route rebuilding. At the same time, data salvage mechanism is also introduced to increase delivery ratio of data packets. Simulation results indicate that DT-MAODV protocol can effectively decrease packet loss rate and improve throughput of TCP protocol compared with AODV and DSR. Source

Dai K.,Huazhong University of Science and Technology | Wang J.,Wuhan Maritime Communication Research Institute | Chen R.,Huazhong University of Science and Technology | Chen J.,Huazhong University of Science and Technology | Kang Y.,Huazhong University of Science and Technology
Diangong Jishu Xuebao/Transactions of China Electrotechnical Society | Year: 2012

This paper takes a equivalent transformation from three-phase bridge inverter to a new topology looks like three single-phase full-bridge inverters triangle connected, but the transformed single-phase full-bridge inverters share one arm with another. Then build a new mathematical model base on the new topology. Compare three-phase bridge inverter with three single-phase full-bridge inverters triangle connected on control scheme, power capacity and output characteristics. Application fields of two inverters are defined. Source

Liu X.,Wuhan Maritime Communication Research Institute
2010 9th International Symposium on Antennas Propagation and EM Theory, ISAPE 2010 | Year: 2010

Microwave Low-profile E Shape Antenna is suitable for ultra wideband (UWB) communication system either independently or in array form. This article introduces the theory and experiment research of the UWB antenna model which can increase both of its impedance bandwidth and directional gain bandwidth. The simulation model and the test result are also presented. ©2010 IEEE. Source

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