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。     

基于并发流水线的直升机雷达多波束调度管理研究

武装直升机雷达为毫米波二维相控阵雷达,具有灵活、同时收发多个波束特征,基于此,本文提出了一种可以应用于同时多个波束通道的驻留任务管理算法。该算法在分析多波束驻留具有在时间重叠、独立波束间受能量等约束的基础上,给出最大化调度收益的多波束驻留调度模型。借鉴并发工作流水线的思想,提出一种启发式的驻留调度实现方法。仿真结果表明,由于该调度算法工作方式优先级原则和期望时间原则,有效地实现多波束驻留任务的调度,把各种任务丢失率控制在较低的范围,从而获得更高的系统实现价值率。     

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。     

一种基于模板法的自适应雷达驻留调度算法

针对多功能相控阵雷达的波束驻留调度问题,建立了可用于脉冲交错的合理驻留模型,该模型的参数变化受目标状态影响较小,使得离线情况下可预测驻留类型,从而进行离线的驻留模板设计。在线调度算法综合考虑驻留的优先级和截止期两个参数,在时间和能量约束条件下对模板进行选取。给出了算法的具体实现步骤。仿真结果表明,与传统自适应驻留调度算法相比,本文提出的算法对跟踪任务和搜索任务均有效地降低了驻留的丢失率。      

多功能相控阵雷达实时任务调度研究

针对多功能相控阵雷达资源调度问题,建立了合理的雷达任务模型并提出一种新的调度算法.在雷达任务模型中将每一类驻留请求合并为一种任务,这样可以为调度处理提供最大的灵活性,同时基于此任务模型分析了调度器的时间负载.所提出的调度算法综合考虑了任务的工作方式优先级和截止期两个参数,可以较好地适应不同的负载情况.给出了算法的具体实现步骤,并以截止期错失率作为评估指标进行了仿真验证.仿真结果表明,本文所提出的调度算法能够有效降低任务的截止期错失率,对调度性能有明显的改善.     

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。     

基于脉冲交错的分布式雷达组网系统波束驻留调度

该文针对分布式雷达组网系统提出了一种基于脉冲交错的实时波束驻留调度算法。该算法引入时间指针向量,用于指示何时选择具有最高综合优先级的波束驻留任务,该任务被分配至交错时间利用程度最低的雷达节点,有效减少了调度过程中引入的时间空隙;同时,脉冲交错分析方法决定对于被分配的波束驻留任务是否可以在相应的雷达节点成功调度执行,其中,引入时隙占用矩阵和能量消耗矩阵来表征各个雷达节点的时间与能量资源使用情况,简化了交错分析过程,并实现了具有不同脉冲重复周期与个数的波束驻留任务之间的交错。此外,为了提高波束驻留调度的效率,所提算法还引入交错时间利用率门限自适应选择时间指针的滑动步长。仿真结果表明,该文所提算法能实现分布式雷达组网系统实时的波束驻留调度,并能获得较现有波束驻留调度算法更好的调度性能。     

一种数字阵列雷达自适应波束驻留调度算法

 根据数字阵列雷达的信号处理特征,提出了一种应用于数字阵雷达的波束驻留调度算法.该调度算法以一种在线脉冲交错技术为基础,它使得不同的驻留任务能在满足系统时间和能量资源约束的条件下交错执行,其中,驻留等待期可用来执行其它驻留的发射或接收子任务且不同驻留任务的等待期可在时间上相互重叠.仿真结果表明,由于驻留任务等待期和接收期的充分利用,与传统波束驻留调度算法相比,此算法能有效地降低各类任务丢失率,从而获得更高的系统实现价值率.     

引入波形参数的相控阵雷达波束调度研究

在深入分析波形参数对脉冲交错波束驻留调度的影响下,提出了一种引入波形参数的波束驻留调度算法。算法深入分析了波形参数对驻留调度的影响,以一些启发式规则基础,它充分考虑雷达系统的时间和能量资源约束。该算法使得不同波束的多个脉冲在驻留线上交错发射且脉冲发射期没有重叠,并通过引入的占空比控制调度过程中的能量变化量。通过仿真表明,与经典的自适应波束驻留调度算法相比,该算法能够有效地降低任务丢失率,提高系统资源利用率。     

动态优先级下防空相控阵雷达在线交错调度算法

针对防空相控阵雷达中时间资源分配主观性强、利用率低的问题,结合任务内部结构,提出一种新的在线交错调度算法.该算法在将任务的重要性和紧急性均置于动态优先级的基础上,使得雷达任务收、发波束之间的等待期可以用来执行其它任务的发射期或接收期.仿真结果表明,相比于任务模式优先级加截止期的调度算法,所提算法的调度成功率、时间利用率和执行威胁率均得到有效提升.     

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。     

A scheduling approach for design activities in concurrentengineering

This paper presents an optimization scheduling approach for concurrent design projects, in which activities may be executed in more than one operating mode and renewable as well as nonrenewable resources exist. Research on the development of a scheduling approach for concurrent scheduling is expected to shorten development lead time, minimize cost, and eliminate unnecessary redesign periods. In this paper, an integrated criterion function is proposed to ensure optimal concurrent scheduling and effective utilization of resources along with fluent delivery of information. In the criterion function, some key factors such as time order, resources, lead time and overlapping time of activities, which can make concurrent activities execute successfully, are taken into account adequately. Besides, two cruxes in concurrent engineering-role allocation, prerelease, and feedback revision process are discussed in detail. The example is part of a certain product development process, and the scheduling results demonstrate that the proposed algorithm is feasible     

Network real-time scheduling algorithm based on multi-feature dynamic priority

Real-time task scheduling system structure and task model were proposed aiming at the network real-time scheduling problem.The task degree of urgency was defined by considering the deadline of task,execution time and interval time between works.The task degree of tightness was proposed based on service-level assurance,according to functional importance of different tasks in the real-time task scheduling system.The thrashing limit for avoiding task switching frequently was acquired through dynamic regulation to task priorities by degree of urgency and degree of tightness,which guaranteed the success rate of tasks execution and utilization ratio of client execution.Test simulation results suggest that the multi-feature dynamic priority scheduling strategy improves the success rate of task scheduling and shorten the average response time,which suggests it has obvious superiority compared with BE and EDF scheduling algorithm.     

Rate scheduling in multiple antenna downlink wireless systems

We consider scheduling strategies for multiantenna and multibeam cellular wireless systems for high-speed packet data services on the downlink. We establish a fundamental connection between the stability region of the queuing system and the set of feasible transmission rates, which provides the basis for the scheduling algorithm proposed in this paper. Transmission using adaptive steerable beams and fixed sector beams are considered and average delay versus throughput results are obtained through simulations for the proposed scheduling scheme in each case. While in single antenna systems multiuser diversity gains are achieved by the scheduling algorithms that transmit to a single user in each scheduling interval, our results show that with multiple antennas, transmitting to a carefully chosen subset of users has superior performance. The multiantenna scheduling problem is closely related to the problem of coordinated scheduling for transmission through multiple base stations, where a user can receive signals from several base stations simultaneously. We consider the special case when three single-antenna base stations are allowed to cooperate and transmit to the users in the triangular region between the base stations and propose scheduling strategies that demonstrate significant gains.     

SNR- Versus Rate-Based Proportional Fair Scheduling in Rayleigh Fading Channels

Wireless Personal Communications - The initial definition of the Proportional Fair scheduling was based on a transmission rate criterion. However, a Signal-to-Noise Ratio (SNR) based definition is...     

Hardware-software partitioning and pipelined scheduling of transformative applications

Transformative applications are computation intensive applications characterized by iterative dataflow behavior. Typical examples are image processing applications like JPEG, MPEG, etc. The performance of embedded hardware-software systems that implement transformative applications can be maximized by obtaining a pipelined design. We present a tool for hardware-software partitioning and pipelined scheduling of transformative applications. The tool uses iterative partitioning and pipelined scheduling to obtain optimal partitions that satisfy the timing and area constraints. The partitioner uses a branch and bound approach with a unique objective function that minimizes the initiation interval of the final design. We present techniques for generation of good initial solution and search-space limitation for the branch and bound algorithm. A candidate partition is evaluated by generating its pipelined schedule. The scheduler uses a novel retiming heuristic that optimizes the initiation interval, number of pipeline stages, and memory requirements of the particular design alternative. We evaluate the performance of the retiming heuristic by comparing it with an existing technique. The effectiveness of the entire tool is demonstrated by a case study of the JPEG image compression algorithm. We also evaluate the run time and design quality of the tool by experimentation with synthetic graphs.     

Priority-based grant-aware scheduling for low-latency switching

This paper introduces new scheduling algorithms supporting low-latency switching. The proposed grant-aware (GA) algorithm improves the average delay performance by using the grant information of previous iteration. The simulation result shows that the average delay of GA algorithm is about one-tenth of the existing algorithm in high-load condition. We also introduce two priority-based scheduling algorithms grant-aware and priority-aware (GAPA) algorithm and cyclic scheduling with the longest-queue-first (C-LQF) algorithm. In the priority-based scheduling, the scheduling priority of VoQ is determined based on its queue size. GAPA and C-LQF consider the priority only after the first iteration to prevent the starvation problem. The simulation result shows that GAPA and C-LQF scheduling achieves better performance than GA in terms of average delay, maximum delay, and hotspot throughput.     

一种基于Vxworks的多任务调度算法

针对机载二次配电系统(the Second Power Distribution Association,缩写为SPDA)的任务调度,提出了一种选择时间片轮转与静态权重优先级抢占混合的调度算法,并进行了算法仿真.     

Utility-based scheduling disciplines for adaptive applications overthe Internet

This letter presents packet scheduling disciplines based on application utility functions and network traffic measurements. The disciplines support different classes of adaptive applications over the Internet, providing differentiation, fairness, and dynamic allocation of network resources. They are composed of a decision procedure, where a fairness criterion based on utility functions is used; and a measurement procedure, which considers the statistics involving packet arrivals and departures. The underlying algorithm is then applied to emulate the proportional differentiation services, and is shown-via simulation-that its results outperform the best alternative algorithms published in the literature     

网格调度的算法研究及改进

优化网格资源调度算法可以提高网格系统执行效率,给任务安排合理的执行顺序和合适的处理器是优化网格资源调度算法需突破的关键技术.文中研究并实现了（Heterogeneous-Earliest-Finish） HEFT[1]算法和新的（Hierarchical Reliability-Driven Scheduling）HRDS算法.采用DAG[2]任务图生成函数,通过对已有HEFT算法进行研究,采用SimGrid为在分布计算环境下进行分布并行应用调度研究提供一个仿真环境,对HRDS算法进行了改进和验证.验证过程中在HRDS算法中加入了可靠性开销作为调度依据,并把算法分为两层调度,本地可靠性驱动调度和全局可靠性驱动调度.两算法的调度结果在SimGrid网格模拟器中仿真调度,仿真成功并且调度结果在可靠性和性能方面HRDS都比HEFT算法要好.