A new two-stage soft real-time scheduling algorithm based on priority table was proposed for task dispatch and selection in cluster systems with inaccurate parameters. The inaccurate characteristics of the system were...A new two-stage soft real-time scheduling algorithm based on priority table was proposed for task dispatch and selection in cluster systems with inaccurate parameters. The inaccurate characteristics of the system were modeled through probability analysis. By taking into account the multiple important system parameters, including task deadline, priority, session integrity and memory access locality, the algorithm is expected to achieve high quality of service. Lots of simulation results collected under different load conditions demonstrate that the algorithm can not only effectively overcome the inaccuracy of the system state, but also optimize the task rejected ratio, value realized ratio, differentiated service guaranteed ratio, and session integrity ensured ratio with the average improvement of 3.5%, 5.8%, 7.6% and 5. 5%, respectively. Compared with many existing schemes that cannen deal with the inaccurate parameters of the system, the proposed scheme can achieve the best system performance by carefully adjusting scheduling probability. The algorithm is expected to be promising in systems with soft real-time scheduling requirement such as E-commerce applications.展开更多
The problem of scheduling radar dwells in multifunction phased array radar systems is addressed. A novel dwell scheduling algorithm is proposed. The whole scheduling process is based on an online pulse interleaving te...The problem of scheduling radar dwells in multifunction phased array radar systems is addressed. A novel dwell scheduling algorithm is proposed. The whole scheduling process is based on an online pulse interleaving technique. It takes the system timing and energy constraints into account. In order to adapt the dynamic task load, the algorithm considers both the priorities and deadlines of tasks. The simulation results demonstrate that compared with the conventional adaptive dwell scheduling algorithm, the proposed one can improve the task drop rate and system resource utility effectively.展开更多
An improved differential evolution（IDE）algorithm that adopts a novel mutation strategy to speed up the convergence rate is introduced to solve the resource-constrained project scheduling problem（RCPSP）with the obj...An improved differential evolution（IDE）algorithm that adopts a novel mutation strategy to speed up the convergence rate is introduced to solve the resource-constrained project scheduling problem（RCPSP）with the objective of minimizing project duration Activities priorities for scheduling are represented by individual vectors and a senal scheme is utilized to transform the individual-represented priorities to a feasible schedule according to the precedence and resource constraints so as to be evaluated.To investigate the performance of the IDE-based approach for the RCPSP,it is compared against the meta-heuristic methods of hybrid genetic algorithm（HGA）,particle swarm optimization（PSO） and several well selected heuristics.The results show that the proposed scheduling method is better than general heuristic rules and is able to obtain the same optimal result as the HGA and PSO approaches but more efficient than the two algorithms.展开更多
In the imaging observation system, imaging task scheduling is an important topic. Most scholars study the imaging task scheduling from the perspective of static priority, and only a few from the perspective of dynamic...In the imaging observation system, imaging task scheduling is an important topic. Most scholars study the imaging task scheduling from the perspective of static priority, and only a few from the perspective of dynamic priority. However,the priority of the imaging task is dynamic in actual engineering. To supplement the research on imaging observation, this paper proposes the task priority model, dynamic scheduling strategy and Heuristic algorithm. At first, this paper analyzes the relevant theoretical basis of imaging observation, decomposes the task priority into four parts, including target priority, imaging task priority, track, telemetry & control(TT&C)requirement priority and data transmission requirement priority, summarizes the attribute factors that affect the above four types of priority in detail, and designs the corresponding priority model. Then, this paper takes the emergency tasks scheduling problem as the background, proposes the dynamic scheduling strategy and heuristic algorithm. Finally, the task priority model,dynamic scheduling strategy and heuristic algorithm are verified by experiments.展开更多
针对智慧医疗场景中高密度无线体域网(wireless body area network,WBAN)多优先级数据传输与计算资源受限的挑战,研究提出一种融合动态优先级评估与量子优化的任务卸载策略。首先通过构建医疗物联网(healthcare Internet of Things,H-I...针对智慧医疗场景中高密度无线体域网(wireless body area network,WBAN)多优先级数据传输与计算资源受限的挑战,研究提出一种融合动态优先级评估与量子优化的任务卸载策略。首先通过构建医疗物联网(healthcare Internet of Things,H-IoT)高密度WBAN网络模型,集成任务优先级分层机制与动态信道状态感知模块,建立基于生理数据特征的通信质量评估体系。其次设计多维动态调度框架,利用生理参数偏离度、数据滞留时间及抢占事件等指标实时调整任务优先级权重,结合抢占式调度策略保障急诊数据的低时延传输。再进一步改进量子遗传算法(improved quantum genetic algorithm,IQGA),采用动态量子旋转门角度调整机制优化局部搜索性能,并引入灾变修正函数提升全局收敛效率。仿真实验表明,该策略在任务平均处理时间、系统能耗、高优先级任务时延及收敛速度方面分别实现71.51%、88.21%、89.63%和78.74%的性能优化,系统综合收益提升达114.43%。研究成果为高密度医疗物联网场景下的实时任务调度与资源分配提供了理论支撑与技术路径。展开更多
针对海上船舶受损需要外界进行抢修支援问题,提出了海上船舶抢修优化调度模型并利用改进的多维动态列表规划算法(Multidimensional Dynamic List Planning Algorithm,MPLDS)进行求解。确立了船舶海上装备抢修基本流程,建立任务-资源的...针对海上船舶受损需要外界进行抢修支援问题,提出了海上船舶抢修优化调度模型并利用改进的多维动态列表规划算法(Multidimensional Dynamic List Planning Algorithm,MPLDS)进行求解。确立了船舶海上装备抢修基本流程,建立任务-资源的优化调度约束模型,模型分为基于效果的行动优化方法与优化调度的约束模型2部分,运用改进的MPLDS对约束模型求解,充分考虑优化调度过程中时间、成本以及任务与支援平台间的重要性,并进行算例分析验证准确性。改进的MPLDS算法充分利用优先权调解方法对优化调度约束模型求解,能够满足制定支援方案者对各方面考虑的基本诉求,实现海上受损船舶的高效抢修支援。展开更多
随着实时系统越来越多地应用于各种快速更新系统,尤其是各种片上系统,如PDA(personal digital assistant),PSP(play station portable)等,性价比已成为系统设计者的主要关注点.实际应用中,实时系统通常仅支持较少的优先级,常出现系统优...随着实时系统越来越多地应用于各种快速更新系统,尤其是各种片上系统,如PDA(personal digital assistant),PSP(play station portable)等,性价比已成为系统设计者的主要关注点.实际应用中,实时系统通常仅支持较少的优先级,常出现系统优先级数小于任务数的情况(称为有限优先级),此时,需将多个任务分配到同一系统优先级,RM(rate monotonic),DM(deadline monotonic)等静态优先级分配算法不再适用.为此,静态有限优先级分配是研究在任务集合静态优先级可调度的情况下,可否以及如何用较少或最少的系统优先级保持任务集合可调度.已有静态有限优先级分配可分为两类:固定数目优先级分配和最少优先级分配.给出了任意截止期模型下任务静态有限优先级可调度的充要条件以及不同静态有限优先级分配间转换时的几个重要性质,指出了系统优先级从低到高分配策略的优越性,定义了饱和任务组与饱和分配的概念,证明了在任务集合静态优先级可调度的情况下,最少优先级分配比固定数目优先级分配更具一般性.最后提出一种最少优先级分配算法LNPA(least-number priority assignment).与现有算法相比,LNPA适用范围更广,且复杂度较低.展开更多
基金Project(60573127) supported by the National Natural Science Foundation of China project(05JJ40131) supported by theNatural Science Foundation of Hunan Province
文摘A new two-stage soft real-time scheduling algorithm based on priority table was proposed for task dispatch and selection in cluster systems with inaccurate parameters. The inaccurate characteristics of the system were modeled through probability analysis. By taking into account the multiple important system parameters, including task deadline, priority, session integrity and memory access locality, the algorithm is expected to achieve high quality of service. Lots of simulation results collected under different load conditions demonstrate that the algorithm can not only effectively overcome the inaccuracy of the system state, but also optimize the task rejected ratio, value realized ratio, differentiated service guaranteed ratio, and session integrity ensured ratio with the average improvement of 3.5%, 5.8%, 7.6% and 5. 5%, respectively. Compared with many existing schemes that cannen deal with the inaccurate parameters of the system, the proposed scheme can achieve the best system performance by carefully adjusting scheduling probability. The algorithm is expected to be promising in systems with soft real-time scheduling requirement such as E-commerce applications.
文摘The problem of scheduling radar dwells in multifunction phased array radar systems is addressed. A novel dwell scheduling algorithm is proposed. The whole scheduling process is based on an online pulse interleaving technique. It takes the system timing and energy constraints into account. In order to adapt the dynamic task load, the algorithm considers both the priorities and deadlines of tasks. The simulation results demonstrate that compared with the conventional adaptive dwell scheduling algorithm, the proposed one can improve the task drop rate and system resource utility effectively.
基金supported by the National Natural Science Foundation of China(6083500460775047+4 种基金60974048)the National High Technology Research and Development Program of China(863 Program)(2007AA0422442008AA04Z214)the Natural Science Foundation of Hunan Province(09JJ9012)Scientific Research Fund of Hunan Provincial Education Department(08C337)
文摘An improved differential evolution（IDE）algorithm that adopts a novel mutation strategy to speed up the convergence rate is introduced to solve the resource-constrained project scheduling problem（RCPSP）with the objective of minimizing project duration Activities priorities for scheduling are represented by individual vectors and a senal scheme is utilized to transform the individual-represented priorities to a feasible schedule according to the precedence and resource constraints so as to be evaluated.To investigate the performance of the IDE-based approach for the RCPSP,it is compared against the meta-heuristic methods of hybrid genetic algorithm（HGA）,particle swarm optimization（PSO） and several well selected heuristics.The results show that the proposed scheduling method is better than general heuristic rules and is able to obtain the same optimal result as the HGA and PSO approaches but more efficient than the two algorithms.
基金supported by the National Natural Science Foundation of China(61773120,61473301,71501180,71501179,61603400)。
文摘In the imaging observation system, imaging task scheduling is an important topic. Most scholars study the imaging task scheduling from the perspective of static priority, and only a few from the perspective of dynamic priority. However,the priority of the imaging task is dynamic in actual engineering. To supplement the research on imaging observation, this paper proposes the task priority model, dynamic scheduling strategy and Heuristic algorithm. At first, this paper analyzes the relevant theoretical basis of imaging observation, decomposes the task priority into four parts, including target priority, imaging task priority, track, telemetry & control(TT&C)requirement priority and data transmission requirement priority, summarizes the attribute factors that affect the above four types of priority in detail, and designs the corresponding priority model. Then, this paper takes the emergency tasks scheduling problem as the background, proposes the dynamic scheduling strategy and heuristic algorithm. Finally, the task priority model,dynamic scheduling strategy and heuristic algorithm are verified by experiments.
文摘针对智慧医疗场景中高密度无线体域网(wireless body area network,WBAN)多优先级数据传输与计算资源受限的挑战,研究提出一种融合动态优先级评估与量子优化的任务卸载策略。首先通过构建医疗物联网(healthcare Internet of Things,H-IoT)高密度WBAN网络模型,集成任务优先级分层机制与动态信道状态感知模块,建立基于生理数据特征的通信质量评估体系。其次设计多维动态调度框架,利用生理参数偏离度、数据滞留时间及抢占事件等指标实时调整任务优先级权重,结合抢占式调度策略保障急诊数据的低时延传输。再进一步改进量子遗传算法(improved quantum genetic algorithm,IQGA),采用动态量子旋转门角度调整机制优化局部搜索性能,并引入灾变修正函数提升全局收敛效率。仿真实验表明,该策略在任务平均处理时间、系统能耗、高优先级任务时延及收敛速度方面分别实现71.51%、88.21%、89.63%和78.74%的性能优化,系统综合收益提升达114.43%。研究成果为高密度医疗物联网场景下的实时任务调度与资源分配提供了理论支撑与技术路径。
文摘针对海上船舶受损需要外界进行抢修支援问题,提出了海上船舶抢修优化调度模型并利用改进的多维动态列表规划算法(Multidimensional Dynamic List Planning Algorithm,MPLDS)进行求解。确立了船舶海上装备抢修基本流程,建立任务-资源的优化调度约束模型,模型分为基于效果的行动优化方法与优化调度的约束模型2部分,运用改进的MPLDS对约束模型求解,充分考虑优化调度过程中时间、成本以及任务与支援平台间的重要性,并进行算例分析验证准确性。改进的MPLDS算法充分利用优先权调解方法对优化调度约束模型求解,能够满足制定支援方案者对各方面考虑的基本诉求,实现海上受损船舶的高效抢修支援。
基金Supported by the National Natural Science Foundation of China under Grant No.69896250 (国家自然科学基金) the National High-Tech Research and Development Plan of China under Grant No.2001AA413020 (国家高技术研究发展计划)
文摘随着实时系统越来越多地应用于各种快速更新系统,尤其是各种片上系统,如PDA(personal digital assistant),PSP(play station portable)等,性价比已成为系统设计者的主要关注点.实际应用中,实时系统通常仅支持较少的优先级,常出现系统优先级数小于任务数的情况(称为有限优先级),此时,需将多个任务分配到同一系统优先级,RM(rate monotonic),DM(deadline monotonic)等静态优先级分配算法不再适用.为此,静态有限优先级分配是研究在任务集合静态优先级可调度的情况下,可否以及如何用较少或最少的系统优先级保持任务集合可调度.已有静态有限优先级分配可分为两类:固定数目优先级分配和最少优先级分配.给出了任意截止期模型下任务静态有限优先级可调度的充要条件以及不同静态有限优先级分配间转换时的几个重要性质,指出了系统优先级从低到高分配策略的优越性,定义了饱和任务组与饱和分配的概念,证明了在任务集合静态优先级可调度的情况下,最少优先级分配比固定数目优先级分配更具一般性.最后提出一种最少优先级分配算法LNPA(least-number priority assignment).与现有算法相比,LNPA适用范围更广,且复杂度较低.
