综合优先级下相控阵火控雷达自适应调度算法

针对相控阵火控雷达多任务调度时的资源分配问题，提出一种综合优先级下的自适应调度算法。基于相控阵火控雷达需与高炮配合对待拦截目标进行火力打击的特性，进行目标射击有利度求解。利用两级二维优先级表级联的思想，结合目标射击有利度、工作方式优先级和任务截止期进行综合优先级规划。以加权时间偏移量平方和最小作为调度代价准则，构建任务调度代价模型，提出带有时间窗的一步回溯法与插空法相结合的自适应调度算法，并利用该算法求解调度模型。通过仿真将本文所提调度算法与传统工作方式优先级加截止期调度算法进行对比分析，结果表明：相比传统调度算法，本文所提调度算法提升了射击价值率，降低了平均时间偏移率和调度代价。     

基于动态优先级的相控阵雷达自适应调度

相控阵雷达需要在完成作战空域搜索的同时完成多个目标捕获以及精确跟踪。为了能够及时有效、充分地调度安排雷达时间资源,本文提出了基于动态优先级的雷达自适应调度模型,根据雷达事件调度时间窗偏移及其需求时间片与离散时间片的契合对优先级进行动态调整和排序,完成雷达事件自适应调度,并给出了相控阵雷达应用实例。与基于固定优先级的雷达自适应调度模型相比较,该模型能够提高雷达波束调度成功率和时间资源利用率。     

相控阵波束驻留调度综合优先级构造方法

在相控阵雷达自适应波束驻留调度算法中,任务的优先级设定是关键。文中提出一种新型综合优先级构造方法,该方法将任务的工作方式优先级、截止期和目标威胁度作为确定综合优先级的影响因素,利用二维优先级表思想,采用两级非线性加权方法构造综合优先级。仿真结果表明:在相控阵雷达自适应波束驻留调度算法中,提出的新综合优先级构造方法相较于现有的综合优先级构造方法,降低了跟踪任务丢失率,提高了实现价值率和修正价值率。     

多功能相控阵雷达自适应调度算法研究

由于阵列天线的波束捷变能力 ,多功能相控阵雷达可对多个目标交替进行搜索、验证、跟踪等工作方式的操作。为此 ,需要一种调度策略以有效地分配雷达时间和能量等资源 ,达到优化雷达整体性能的目的。针对多功能相控阵雷达 ,在分析自适应调度算法的设计原则基础上提出一种自适应调度算法 ,并给出具体的性能评估指标。算法能够根据雷达事件的优先级、驻留长度、期望发射时间及时间窗合理地安排一个调度间隔内的雷达事件序列 ,仿真结果验证了调度算法的有效性。     

相控阵制导雷达自适应调度技术应用

相控阵制导雷达需要在进行空域搜索、目标捕获跟踪的同时精确地导引导弹攻击来袭目标,为此需要使用基于优先级排序的雷达自适应调度技术完成各种雷达任务的调度,描述了相控阵制导雷达应用自适应调度技术的实现方法,实际应用结果表明该技术能够有效提高雷达时间资源的利用率,保证雷达整体工作效能。     

相控阵雷达自适应调度算法仿真

灵活、高效的调度算法是相控阵雷达发挥其性能优势的关键,而如何分配任务优先级对雷达性能有着决定性的影响。文章将BP神经网络引入调度算法,利用目标运动参数和跟踪状态实时自适应地分配任务优先级。算法根据优先级和时间约束,合理安排调度周期内雷达任务请求,选择优先级较高的那部分雷达任务执行,并通过仿真结果验证了算法的有效性。     

基于优先级的相控阵测量雷达调度设计

介绍了一种基于优先级的相控阵测量雷达调度设计。根据雷达具体测量要求划分了多个任务调度优先级．分析了远程弹道导弹测量任务对相控阵测量雷达数据率的要求。讨论了能量调度的相关约束条件，给出了系统实现框图。通过综合时间间隔门限的选择调整，完成对多个目标的搜索、验证、跟踪和目标特性测量等任务。     

一种改进的相控阵雷达脉冲交错算法

针对相控阵雷达波束快速扫描能力,提出了一种基于时间指针的相控阵雷达在线脉冲交错调度算法。首先建立了雷达驻留任务模型并分析了调度约束条件,然后引入时间指针来指向当前调度分析时刻,分别从波束的角度和脉冲的角度分析了驻留任务交错的几种方式,并给出了三种脉冲重叠方式的时间约束条件,最后在满足时间和能量资源约束的条件下,选取综合优先级最高的雷达驻留任务进行调度。仿真结果表明,与基于收益的调度算法相比,此算法能有效地降低任务丢失率,提高时间利用率和能量利用率。     

基于目标优先级的跟踪波束调度方法研究

针对协方差控制的策略不满足雷达跟踪目标的实时性要求,文中采用协方差和目标威胁度联合控制的方法来研究关于相控阵雷达波束调度的问题,建立相控阵雷达波束分配的最优化模型。该模型利用目标的运动状态信息,包括目标距离、目标径向速度、加速度和航向,利用层次分析法确定目标威胁度,然后与目标跟踪协方差相结合进一步确定目标优先级,实现目标动态的搜索加跟踪模式(TAS)的波束调度。将该算法与传统的顺序波束调度方法进行比较,仿真结果表明该算法具有较高的时间利用效率,同时也具有较好跟踪性能。     

基于变长度调度间隔的雷达资源调度算法

在相控阵雷达完成精密跟踪和目标识别等不同任务时,波形、数据率和积累时间等雷达资源需要自适应改变,基于固定长度调度间隔的自适应调度算法较为复杂且不能充分利用雷达资源。提出了一种基于变长度调度间隔的自适应资源调度算法,根据任务请求的重要性函数安排待执行的雷达事件顺序,并根据雷达资源的动态变化情况,自适应地调整调度间隔的时间长度。利用VC语言建模弹道导弹目标和多功能地基相控阵雷达,进行分布式仿真,通过直观观测资源调度的执行过程,以及通过目标跟踪数量和时间利用率两个指标,评价了资源调度算法性能。改进算法的软件实现较为容易,可以增加目标跟踪数量,节约时间资源。     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

GaAsSb/InAlAs PA DHBTs Grown by Production MBE

The epi material growth of GaAsSb based DHBTs with InAlAs emitters are investigated using a 4 × 100mm multi-wafer production Riber 49 MBE reactor fully equipped with real-time in-situ sensors including an absorption band edge spectroscope and an optical-based flux monitor. The state-of-the-art hole mobilities are obtained from 100nm thick carbon-doped GaAsSb. A Sb composition variation of less than ± 0.1 atomic percent across a 4 × 100mm platen configuration has been achieved. The large area InAlAs/GaAsSb/InP DHBT device demonstrates excellent DC characteristics,such as BVCEO＞6V and a DC current gain of 45 at 1kA/cm2 for an emitter size of 50μm × 50μm. The devices have a 40nm thick GaAsSb base with p-doping of 4. 5 × 1019cm-3 . Devices with an emitter size of 4μm × 30μm have a current gain variation less than 2% across the fully processed 100mm wafer. ft and fmax are over 50GHz,with a power efficiency of 50% ,which are comparable to standard power GaAs HBT results. These results demonstrate the potential application of GaAsSb/InP DHBT for power amplifiers and the feasibility of multi-wafer MBE for mass production of GaAsSb-based HBTs.     

Noise character analysis and the restraint of self-pulsation laser diodes

We calculate the Langevin noise sources of self-pulsation laser diodes, analyze the effects of active region noise and saturable-absorption region noise on the power fluctuation as well as period fluctuation, and propose a novel method to restrain the noise effects. A visible SIMULINK model is established to simulate the system, The results indicate that the effects of noise in absorption region can be ignored; that with the increase of DC injecting current, the noise effects enhance power jitter, and nevertheless, the period jitter is decreased; and that with external sinusoidal current modulating the self-pulsation laser diode, the noise-induced power jitter and period jitter can be suppressed greatly. This work is valuable for clock recovery in all-optical network.     

High-quality single-crystal CdSe nanoribbons and their optical properties

Large-scale synthesis of single-crystal CdSe nanoribbons is achieved by a modified thermal evaporation method, in which two-step-thermal-evaporation is used to control CdSe sources＇ evaporation. The synthesized CdSe nanoribbons are usually several micrometers in width, 50 nm in thickness, and tens to several hundred micrometers in length. Studies have shown that high-quality CdSe nanoribbons with regular shapes can be obtained by this method. Room-temperature photolumines-cence indicates that the lasing emission at 710 nm has been observed under optical pumping （266 nm） at power densities of 25-153 kW/cm^2. The full width half maximum （FWHM） of the lasing mode is 0.67 nm     

Propagation of hermite-cosh-gaussian beams passing through ABCD optical system with an annular aperture

By using the expansion of the aperture function into a finte sum of complex Gaussian functions, the corresponding analytical expressions of Hermite-cosh-Gaussian beams passing through annular apertured paraxially and symmetrically optical systems written in terms of ABCD matrix were derived, and they could reduce to the cases with squared aperture. In a similar way, the corresponding analytical expressions of cosh-Gaussian beams through annular apertured ABCD matrix were also given. The method could save more calculation time than that by using the diffraction integral formula directly.     

Influence of polarization extinction ratio on distributed polarization coupling detection

Distributed polarization coupling in polarization-maintaining fibers can be detected by using a white light Michelson interferometer. This technique usually requires that only one polarization mode is excited. However, in practical measurement, the injection polarization direction could not be exactly aligned to one of the principal axes of the PMF, so the influence of the polarization extinction ratio should be considered. Based on the polarization coupling theory, the influence of the incident polarization extinction on the measurement result is evaluated and analyzed, and a method for distributed polarization coupling detection is developed when both two orthogonal eigenmodes are excited.     

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正Communications—VLSI Researches and industries of telecommunications have been growing rapidly in the last 20 years and will keep their high growing pace in the next decade.The involved researches and developments cover mobile communications,highway and last-mile broadband communication,domain specific communications,and emerging D2D M2M communications.Radio communication steps into its