混编式防空导弹群目标分配模型

为达到高技术条件下防空作战的目的,混编式防空导弹集群作战成为符合部队实际的作战模式.混编式防空导弹群的目标分配问题属于非线性规划问题,如用一般的方法求解,过程将十分复杂,满足不了防空作战实时性要求.本文将动态规划的思想应用于目标分配,在一定的假设前提下,设计了一种基于多元动态规划的混编式防空导弹目标分配模型,并结合具体的实例计算验证了模型的正确性.结论表明,所建立的模型简单、实用,对进一步探讨符合实战要求的目标分配模型提供了参考.     

光电经纬仪伺服系统动态高型控制

光电经纬仪伺服系统一般是位置、速度双闭的随动系统,其跟踪精度和动态响应能力是衡量系统性能的重要标志.动态高型方法在原有控制系统基础上增加一个或多个积分环节构成高型系统,从而减小跟踪误差.将动态高型方法应用于光电经纬仪伺服系统中,从理论、仿真到工程实现进行了比较全面的研究,获得了一些具有独创性的结论.最后进行了动态Ⅲ型系统的跟踪能力Matlab仿真.当目标为最大加速度60(°)/s2、最大速度60(°)/s的等效正弦时,稳态跟踪误差达1.3″,对于最大加速度120(°)/s2、最大速度120(°)/s的等效正弦,仿真稳态跟踪误差达24″.     

以太网无源光网络的服务质量分析

以太网无源光网络正成为当前光接入网研究的热点课题．本文重点研究了服务质量问题。在分析EPON系统QoS问题的基础上，利用优先级排队理论对基于QoS的DBA算法的性能进行了理论分析，指出DBA算法进一步优化的方向。     

数字激光器在模拟光纤通信中的应用

本文尝试用数字光纤通信用激光器代替模拟光纤通信用激光器,通过加入温度控制,预失真补偿电路等线性补偿方法以及通过输入端加入AGC,固定衰减器等动态范围补偿的方法,使数字光纤通信用激光器在线性度以及动态范围两方面得到很大的提高,达到模拟光纤通信用激光器的水平,完全可以应用于短波,超短波以及微波模拟光纤通信中.     

Improved Self-Feedback Gain in the Context Layer of a Modified Elman Neural Network

The use of a range of values for the self-feedback gains in the context layer of a modified Elman neural network is shown to reduce RMS error when modelling a non-linear dynamic system.     

Molten polystyrene structures above the glass transition,T > Tg

The old controversial idea of structures in molten amorphous polymers is being accepted with theoretical and experimental evidence. Wool's twinkling fractal theory of the glass transition and recent atomic force micrographs are convincing proof of the dynamic, solid aggregate presence below and above T_g. This article offers detailed analysis of the experimental data from high‐pressure dilatometry, as well as from the oscillatory shear tests in the glassy and the molten state of polystyrenes. The results indicate the presence of a transient structure at T > T_g; transient as it depends on the structure of the vitreous polymer and the rate of heating it across T_g. Thus, molten polymer is not always at the thermodynamic equilibrium. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1369–1380, 2011     

Dynamic nuclear polarization studies of nitroxyl spin probes in agarose gel using Overhauser‐enhanced magnetic resonance imaging

Agarose is a tissue‐equivalent material and its imaging characteristics similar to those of real tissues. Hence, the dynamic nuclear polarization studies of 3‐carboxy‐2,2,5,5‐tetramethyl‐pyrrolidine‐1‐oxyl (carboxy‐PROXYL) in agarose gel were carried out. The dynamic nuclear polarization parameters such as spin lattice relaxation time, longitudinal relaxivity, leakage factor, saturation parameter and coupling parameter were estimated for 2 mM carboxy‐PROXYL in phosphate‐buffered saline solution and water/agarose mixture (99 : 1). From these results, the spin probe concentration was optimized as 2 mM, and the reduction in enhancement was observed for carboxy‐PROXYL in water/agarose mixture (99 : 1) compared with phosphate‐buffered saline solution. Phantom imaging was also performed with 2 mM concentration of carboxy‐PROXYL in various concentrations of agarose gel at various radio frequency power levels. The results from the dynamic nuclear polarization measurements agree well with the phantom imaging results. These results pave the way for designing model system for human tissues suited to the biological applications of electron spin resonance/Overhauser‐enhanced magnetic resonance imaging.     

Mode decomposition of a noise suppressed mixing layer

Noise is generated in atwo-dimensional mixing layer due to the growing of instability waves and vortex pairings. The adjoint-based control methodology has shown to be arobust tool to suppress noise radiation. The mode decomposition algorithms such as the compressible versionof proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD) are employed toanalyze thespatial/spatial-temporal coherent structures for a consecutive data sets of the controlled mixing layer and itsuncontrolled counterpart. The analyses of POD indicate that the y-direction body forcecontrol mainly modify themost energetic spatialstructures, and increase the uniformity of the flow. The analyses of DMD show us prevalent frequencies andcorresponding mode structures, and the stability characteristics of each mode can be obtained fromDMD-spectrum. The spectral signatures illustrate that a lot of neutral/slightly damping modesemerging in uncontrolled flow within the frequency range (ω < 0.4) are suppressed due to control, relevant spatial-temporal structures are also varied, which iscoincident with the change of far-field noise spectra. From the view of mode decomposition, the action of control redistribute the energy forfrequency components of ω < 0.4 by weakening nonlinearities and regularizing corresponding dynamicstructures in streamwise direction, and thus suppress the noise radiation. Moreover, the POD- and DMD-analysis in this studydemonstrate that DMD can serve as an important supplement for POD in analyzing a time-resolved physicalprocess.     

Consciousness and the structuring property of typical data

The theoretical base for consciousness, in particular, an explanation of how consciousness is defined by the brain, has long been sought by science. We propose a partial theory of consciousness as relations defined by typical data. The theory is based on the idea that a brain state on its own is almost meaningless but in the context of the typical brain states, defined by the brain's structure, a particular brain state is highly structured by relations. The proposed theory can be applied and tested both theoretically and experimentally. Precisely how typical data determines relations is fully established using discrete mathematics. © 2012 Wiley Periodicals, Inc. Complexity, 2012