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1.
微波与激光混合链路中继卫星动态调度快速启发式算法   总被引:1,自引:0,他引:1  
针对微波与激光混合链路中继卫星系统实际应用中的动态变化,分析了混合系统动态扰动条件,依据中继卫星资源调度动态调整原则,研究了混合系统动态资源调度策略。以最大化调度任务优先级之和,以及扰动发生后对初始方案扰动变化最小为目标,建立了具有两级优化目标的混合系统动态调度模型。提出了动态插入快速启发式算法并对模型求解算法,算法包括直接插入任务操作、移动插入任务操作和删除插入任务操作。仿真结果表明与完全重调度的算法相比,动态插入算法的方案变化率平均降低了60.10%,且计算速度明显高于重新调度算法,能够有效解决混合链路中继卫星系统动态调度问题。  相似文献   

2.
以数据中继卫星光网络系统资源、任务和约束条件为参量,以任务对资源的选择为优化对象,提出了一种基于自适应遗传算法的数据中继卫星光网络资源调度算法.综合考虑多中继星、多时间窗口、多光学天线以及任务优先级要求,建立调度模型;采用当前任务调度时间的确定和后续任务可见时间窗口的更新的调度操作,对不同资源的任务集合进行调度安排并实现了可见时间窗口的动态更新,获得调度任务的总权值并将其作为参量计算适应度值,最后通过改进的自适应遗传算法对不同调度方案进行寻优.以3颗中继星、12颗用户星,6个光天线,60个任务为条件设置了仿真场景,仿真结果表明该算法在收敛速度、调度效率方面具有优势,适应于多任务、多天线的数据中继卫星光网络系统资源调度.  相似文献   

3.
针对用户星数据中继接入请求超额定购问题,分析了用户星业务种类,研究了中继卫星接入控制所受多类约束的特点,建立了约束满足模型;以接入业务总优先级权值最高为原则,根据业务的类型、时间有效性和业务优先级设置链路接入灵活度和业务冲突集,以业务的接入顺序和选择接入的中继星链路为优化对象,提出了一种基于业务类型和自适应小窗口蚁群算法双层优化的中继卫星混合链路接入控制算法。仿真实验表明,所建模型可实现多类型业务与多种类天线的接入控制,提出的双层优化算法较单层寻优效果更佳,且具有较快的收敛速度和较强的全局优化能力,因而所提算法可有效解决多约束条件下多业务类型、多种类天线和多中继星的接入控制问题。  相似文献   

4.
针对微波与激光混合链路中继卫星在执行初始调度方案过程中发生的各种动态扰动变化,分析研究各类扰动特点,把不同扰动下的动态问题归结为一类复杂约束下的任务插入问题。建立混合链路中继卫星动态调度问题的约束满足模型。提出基于启发式信息的动态调度算法对模型进行求解,基于初始调度方案的优良特性,极大降低动态调度复杂性。仿真结果验证了模型和算法的可行性,能够有效解决微波与激光混合链路中继卫星动态调度问题,对解决实际问题具有一定理论意义和现实意义。  相似文献   

5.
中继卫星资源调度问题研究现状与展望   总被引:3,自引:0,他引:3  
赵静  赵尚弘  李勇军  王翔  赵卫虎 《电讯技术》2012,52(11):1837-1843
随着跟踪与数据中继卫星系统(TDRSS)的发展以及中继应用需求的增加,其资源调度成为决定系统性能的关键因素之一.分析了包括描述方法、活动与资源、约束条件等在内的中继卫星资源调度问题基本内涵,研究了目前中继卫星资源调度的数学模型和实现算法,比较了不同数学模型和实现算法的优缺点.针对未来卫星激光和微波链路联合组网的发展趋势,提出了基于多终端-多节点及基于资源故障的激光/微波混合链路中继卫星资源调度的基本方法.  相似文献   

6.
针对微波/光混合链路中继卫星系统多资源约束下的多目标综合调度问题,分析了微波与激光混合链路的主要特点和影响因素,建立了混合链路资源调度多目标约束规划模型;将小生境技术引入遗传算法,并设计了基于精英保留的选择机制和自适应的交叉、变异算子,提出了一种改进的小生境遗传算法对模型进行求解。所提算法可有效避免遗传算法局部优化能力差及容易陷入局部最优等缺陷,同时能够防止最优解的丢失,解决了混合链路多资源约束下的多目标综合调度问题。仿真结果表明,相对与传统的遗传算法,本文算法在保持种群多样性和求解全局最优解方面具有优势,有效解决微波/激光混合链路中继卫星系统的多目标综合调度问题。  相似文献   

7.
针对微波/光混合链路中继卫星系统多资源约束 下的多目标综合调度问题,分析了微波与激光混 合链路的主要特点和影响因素,建立了混合链路资源调度多目标约束规划模型;将小生境技 术引入遗传 算法,并设计了基于精英保留的选择机制和自适应的交叉、变异算子,提出了一种改进的小 生境遗传算 法对模型进行求解。所提算法可有效避免遗传算法局部优化能力差及容易陷入局部最优等缺 陷,同时能够 防止最优解的丢失,解决了混合链路多资源约束下的多目标综合调度问题。仿真结果表明 ,相对与传统 的遗传算法,本文算法在保持种群多样性和求解全局最优解方面具有优势,有效解决微波/ 激光混合链路中继卫星系统的多目标综合调度问题。  相似文献   

8.
基于人工蜂群算法的中继卫星任务调度研究   总被引:1,自引:0,他引:1  
开彩红  肖瑶  方青 《电子与信息学报》2015,37(10):2466-2474
研究中继卫星任务调度问题可以为跟踪与数据中继卫星系统(TDRSS)的任务计划编排提供科学合理的决策方法,任务调度模型的建立与调度算法的设计是中继卫星任务调度的两个关键问题。该文针对中继卫星任务调度问题特点,综合考虑中继卫星与用户航天器之间具有可见时间窗、用户提交的任务属性、中继卫星前向资源受限等约束条件,建立了中继卫星任务调度约束规划模型并提出基于人工蜂群(ABC)算法的中继卫星任务调度算法。最后,通过仿真数据分析,表明基于人工蜂群算法的中继卫星任务调度算法是一种有效的、合理的调度方法。  相似文献   

9.
近年来随着我国在轨遥感卫星数量的不断增加,对当前中继星系统的数传能力提出了更高的要求。在卫星平台载荷能力受限的情况下,分布式卫星系统成为大幅提升中继星系统性能的可行方案。针对分布式卫星系统的数传任务调度问题,综合考虑系统与中低轨航天器用户之间的可见时间窗口、卫星剩余资源及数传任务属性等约束条件,提出了基于粒子群优化(PSO)的多星多任务数传调度方法。根据实际中继系统任务量级对经典PSO算法进行了改进,并通过计算机仿真验证了改进算法的有效性。  相似文献   

10.
多站多星任务调度模型及求解   总被引:2,自引:0,他引:2  
针对遥感卫星数据接收任务的特征,提出了多站多星任务调度的主要约束条件和优化目标函数,建立了基于约束满足优化问题的多站多星任务调度模型,采用贪婪算法和约束传播相结合的方法对多站多星任务调度进行了求解.该优化调度模型及求解算法已成功运用于遥感卫星数据接收站的日常运行工作中.  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

17.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

18.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.  相似文献   

19.
Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.  相似文献   

20.
An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.  相似文献   

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