基于优先级调度算法的TXC设备的设计

多任务处理通常基于多任务操作系统，由多任务OS的核心系统调度器根据各个任务的优先级来调度CPU的控制权。但在多任务系统平台上进行产品开发，不仅成本高，而且开发周期长。以TXC设备为例，讲述了单任务平台上多任务处理的实现机制——基于优先级的调度算法。     

基于实时多任务操作系统的智能脱扣器系统软件设计

为了克服传统的顺序软件结构导致软件代码结构复杂、可移植性和可扩展性差的缺点，提出了基于实时多任务操作系统--IR-OS的智能脱扣器系统的设计方法，并得到实际应用。IR-OS采用了抢占优先级调度方式，内核代码简洁，并为用户提供开发接口，实际应用证明，采用实时多任务操作系统作为智能脱扣器开发和运行平台，具有很好的运行稳定性、可靠性和实时性。     

μC/OS-Ⅱ内核任务调度算法的改进

μC/OS-Ⅱ是一个基于任务优先级抢占式的实时内核,但它不具有相同优先级任务的实时调度功能.为了使μC/OS-Ⅱ内核既支持不同优先级的多任务抢占式调度,又支持同一优先级的多任务调度,提出对μC/OS-Ⅱ内核的改造,加入以时间片轮转调度算法进行相同优先级任务的调度.方法是保持原有不同优先级抢占式调度链表,增加相同优先级的时间片轮转调度链表,通过任务控制块指针使任务调度在2个链表之间切换.给出了在μC/OS-Ⅱ任务调度模块中算法改进的实现步骤、实验过程和结果.结果说明了提出的改进调度算法是可行的.     

uC/OS-Ⅱ在LPC2200平台上的移植

μC/OS-Ⅱ是一种基于优先级的抢占式多任务实时操作系统,本文介绍了μC/OS-Ⅱ操作系统内核在LPC2200平台上的移植实现过程极其测试方法。     

基于Matlab仿真平台的多任务实时调度仿真

任务的调度策略是实时系统中的关键内容,直接影响系统的性能,多任务实时系统的调度问题是实时系统中的重要研究方向。基于Matlab仿真平台,利用其自带的Simulink软件包,并结合Turetime-1.5工具箱,构建多任务实时系统的仿真平台,实现对典型的调度算法的调度仿真。     

一种实时多任务管理机制

研究一种实时多任务管理机制．讨论了ＲＭＤＯＳ系统结构与支撑环境、多任务控制流程和调度问题．该管理机制实现了可变优先级加时间片轮转的调度策略和网络任务的实时响应．它作为多任务操作系统的核心，成功地支持了分布式操作系统ＨＺＤＯＳ的实现和分布式并行任务分配，支持了分布式系统故障恢复与系统重构     

ARM GPU的多任务调度设计与实现

针对现有GPU任务调度系统在多任务环境下不能保证图形任务响应时间的问题,提出基于分类和多优先级队列(CPMQ)的调度方案,并在ARM的嵌入式GPU上实现验证。该方案中,将GPU的多任务划分为图形任务、通用计算任务和实时图形3类任务并分别建立队列排队,其中图形任务和通用计算任务按照优先级在各自队列中排队,实时图形按照任务截止时间排队。面向多队列的任务调度,优先从实时任务队列中选择任务,并按照加权公平算法分别在图形任务队列和通用计算队列中选择任务。实验结果表明:相比于ARM GPU的原有调度系统,CPMQ在不显著增加通用计算任务的执行时间和调度开销的情况下,将实时图形任务的帧率提升了5%~20%。     

基于通用DSP的数字电视信源解码器的软件实现

为实现数字电视信源解码器，提出了一种基于通用数字信号处理器的总体方案，并在嵌入式实时操作系统μC/OS-Ⅱ提出了以数据为驱动源，基于任务优先级的多任务实时调度策略，成功地实现了对传送流输入、解复用、音频解码、视频解码、视频显示和音频播放等任务的实时调度．本系统全软件实时实现了单路标准清晰度数字电视信源解码器的功能，CPU利用率约为90％．     

一种Linux用户态实时多任务调度框架

Linux内核调度器的调度开销巨大,无法满足实时应用需求.为此设计并实现了基于多核Linux的用户态实时多任务调度框架ULight.ULight共包括三个核心模块:多任务调度模块、定时器模块以及用户态中断处理模块.多任务调度模块在Linux用户态提供基于优先级可抢占的实时多任务调度方案,旨在减少任务调度和切换开销;定时器模块则为多任务调度提供高精度的定时服务,以支持分时调度和任务休眠,并提供更多的抢占点;用户态中断处理模块通过在内核态和用户态之间构造中断处理的快速通道,使用户态任务可以直接处理硬件中断,保证中断处理的实时性和高效性.实验表明,ULight的任务切换效率明显优于Linux的线程切换效率;定时系统可以提供精度为20μs的稳定的定时服务;用户态中断处理模块能够在用户态完成对硬件中断的快速响应.     

基于调度效益最大化的多功能组网认知雷达资源优化调度算法

在组网认知雷达中,针对多目标多任务(如搜索、跟踪与成像等)按优先级进行资源调度时易造成目标任务丢失的问题,提出基于调度效益最大化的多功能组网认知雷达资源优化调度算法。该算法将搜索与跟踪任务的时间窗考虑到目标函数中,通过目标任务的重要性(优先级)和有效性(时间窗)两个因素的加权来表示雷达对目标任务的调度效益,根据调度效益最大准则建立并利用遗传算法求解资源调度模型。对仿真结果分析表明,该方法能够提高组网认知雷达的整体效能。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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