基于博弈论的自适应波束成形算法

针对自适应波束成形算法中用户之间的动态相互干扰,提出了一种基于博弈论的自适应波束成形算法,构建了波束成形博弈算法数学模型。该算法将不同用户的发射权值调整描述为一个多用户的博弈过程,通过数学推导论证了基于博弈论的自适应波束成形算法纳什平衡点的存在性和唯一性,设计了收敛的发射权值更新算法。通过仿真实验验证了算法的性能以及讨论了代价因子、可调参数和收敛精度等参数对算法的影响。     

Hardware system design for UHF surface velocities radar

UHF surface velocities radar is developed based on the successful ocean state measuring and analyzing radar system. The design method for UHF radar system is presented. It is designed to operate at UHF channel, and the transmit power is under 5W. Maximum range of field test over fresh water can be a kilometer. The field tests at Tangsun River and at Majiatan and Gaohazhou proved that USVR System can be used successfully.     

单向单交叉并行链优先约束的可靠性系统测试优化

针对具有单向单交叉并行链优先约束的可靠性系统的最优测试序列问题,提出了一种最优测试原则,该测试原则的约束条件更接近复杂的实际情况。通过证明三个相关的定理,分别解决了单向单交叉并行链优先约束的问题转化形式,相交单元在最优测试序列中测试的先后顺序,以及反“Y”形优先约束问题的最优测试序列。利用这一测试原则,可使此类系统获得总期望测试成本最小。通过一系列证明,给出了该原则的求证过程及具体步骤。     

Reservation-based feedback scheduling of MPC tasks

A reservation-based feedback scheduling (FS-CBS) of a set of model predictive control (MPC) tasks is presented to optimize the global control performance subject to limited computational resource. Implemented as anytime algorithm, MPC task allows computation time to be traded for control performance. Each MPC task is assigned with a constant bandwidth server (CBS), whose reserved processor time is adjusted dynamically. The FS-CBS is shown robust against the varying of execution time of MPC tasks at runtime. Simulation results illustrate its effectiveness.     

Distributed power control algorithm based on game theory for wireless sensor networks

Energy saving is the most important issue in research and development for wireless sensor networks. A power control mechanism can reduce the power consumption of the whole network.Because the character of wireless sensor networks is restrictive energy,this paper proposes a distributed power control algorithm based on game theory for wireless sensor networks which objects of which are reducing power consumption and decreasing overhead and increasing network lifetime.The game theory and OPNET simulation shows that the power control algorithm converges to a Nash Equilibrium when decisions are updated according to a better response dynamic.     

离散时间不完全市场下基于计价单位投资组合法的期货定价模型

在具体的离散时间不完全市场模型中给出最优增长组合的刻画后，运用计价单位投资组合法推导出期货的无套利定价模型。随后对定价模型进行实证检验，结果表明，对于实证选取的股票期货样本，该定价模型给出的预测价格能够较好地拟合样本的实际价格，且其精度较持有成本理论单因素模型的略有提高。     

横坐标系捷联惯导系统极区导航及阻尼设计

针对水下潜器在极区工作时,其常用惯性导航系统机械编排存在精度下降、无北向基准等问题,设计了适用于水下潜器极区工作的横坐标系捷联惯性导航系统机械编排方案。在构建了横坐标系参考框架的基础上,推导出各导航参数在横坐标系统和常规坐标系统之间的转换关系,建立了横坐标系捷联惯导系统的机械编排,并在此基础上分析其误差传播特性。通过误差分析,确定了横坐标系捷联惯导系统中存在的周期性振荡,并提出了适用于横坐标系捷联惯导系统的阻尼技术,有效抑制了周期性振荡。最后,通过仿真试验验证了该系统在极区工作的可行性和阻尼技术有效性。     

Consistency analysis of accelerated degradation mechanism based on gray theory

A fundamental premise of an accelerated testing is that the failure mechanism under elevated and normal stress levels should remain the same. Thus, verification of the consistency of failure mechanisms is essential during an accelerated testing. A new consistency analysis method based on the gray theory is pro- posed for complex products. First of all, existing consistency ana- lysis methods are reviewed with a focus on the comparison of the differences among them. Then, the proposed consistency ana- lysis method is introduced. Two effective gray prediction models, gray dynamic model and new information and equal dimensional （NIED） model, are adapted in the proposed method. The process to determine the dimension of NIED model is also discussed, and a decision rule is expanded. Based on that, the procedure of ap- plying the new consistent analysis method is developed. Finally, a case study of the consistency analysis of a reliability enhancement testing is conducted to demonstrate and validate the proposed method.     

Conceptual design and RCS performance research of shipborne early warning aircraft

In order to improve the survivability of the aircraft,conceptual design and radar cross section（RCS） performance research are done. The CATIA software is used to design the 3D digital model of the shipborne early warning aircraft, and some measures are taken to reduce the RCS characteristics of the early warning aircraft at the same time. Based on the physical optics method and the equivalent electromagnetic flow method,the aircraft＇s RCS characteristics and strength distribution characteristics are simulated numerically, and compared with the foreign advanced shipborne early warning aircraft. The simulation results show that under the X radar band, when the incident wave pitching angle is 0？, compared with the foreign advanced shipborne early warning aircraft, the forward RCS average value of the conceptual shipborne early warning aircraft is reduced to 24.49%, the lateral RCS average value is reduced to 5.04%, and the backward RCS average value is reduced to 39.26%. The research results of this paper are expected to provide theoretical basis and technical support for the conceptual design and the stealth design of the shipborne early warning aircraft.     

Evidence for self-organized criticality in unscheduled downtime data of equipment

How to reduce downtime and improve availability of the complex equipment is very important. Although the unscheduled downtime（USDT） issues of the equipment are very complex, the self-organized criticality（SOC） is the right theory to study complex systems evolution and opens up a new window to the investigation of disasters, such as the sudden failure of the equipment. Firstly,SOC theory and its validation method are introduced. Then an SOC validation method for USDT of the equipment is proposed based on the above theory. Case study is done on bottleneck equipment in a factory and corresponding data pre-process work is done. The rescaled-range（R/S） analysis method is used to calculate the Hurst exponent of USDT time-series data in order to determine the long-range correlation of USDT data on time scale;at the same time the spatial power-law characteristic of USDT time series data is studied. The result shows that the characteristics of SOC are revealed in USDT data of the equipment according to the criterion of SOC. In addition, based on the characteristics of SOC,the overall framework of the prediction method for major sudden failure of the equipment is proposed based on SOC.