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基于聚类状态隶属度的动态调度Q-学习 总被引:1,自引:0,他引:1
提出了一种利用Q-学习解决动态单机调度环境下的自适应调度规则选择的方法.该方法针对动态调度环境中系统状态空间大,Q-学习不易收敛的特点,首先提取系统状态特征,对系统状态进行合理聚类,有效地降低系统状态空间维数,然后在学习过程中令设备Agent根据瞬时状态向量对各聚类状态的隶属度做出综合判断,选择合适规则,并在每次迭代后根据隶属度将动作奖惩分配给各聚类状态的动作值函数.仿真结果表明,所提Q-学习算法较之传统Q-学习具有更快的收敛速度,提高了设备Agent的动态调度规则选择能力. 相似文献
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为提高精密减速器性能测试效率,提出一种单工位测试流程优化方法。基于测试项目序列描述定义,构建测试流程网络,将流程转化为起点与终点固定的最短路径的旅行商问题(travelling salesman problem, TSP)模型进行优化求解,通过最优解改进找到最优测试路径。该方法能够通过测试项目的序列描述,发掘出不同项目之间优化合并空间,最优解改进克服一般TSP模型仅对相邻项目间优化的问题。应用结果表明,该方法对精密减速器动态测试项目进行优化,可以缩短16.17%测试时间。 相似文献
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为解决配电测试系统的关键量测点存在不良数据时状态估计准确度差的问题,提出一种基于GM(1,1)和人工蜂群的状态估计方法。在一定时间窗口内读取量测值,采用灰色累加生成方法进行初步检测。引入GM(1,1)模型获得序列预测值,按照判定条件对不良数据进行处理。在此基础上采用改进的人工蜂群算法对目标函数进行优化求解,在每一次的优化过程中利用当前最优解的适应度函数建立局部搜索策略。将33节点配电测试系统作为算例,结果表明该方法能够有效地修正不良数据,提高状态估计的整体准确度和单节点准确度。与加权最小二乘算法和人工蜂群算法相比,该方法有功功率的MAE分别减少69%和43%,NMRE分别减70%和63%;对于无功功率,其MAE结果分别减少60%和33%,相应的NMRE分别减58%和57%。 相似文献
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提出了一种将多网格编码调制(MTCM)与正交频分复用(OFDM)系统相结合的方法,建立了一个MTCM-OFDM系统模型,并对其进行了性能分析和仿真.分析表明,MTCM可提高系统的误码率性能,将MTCM应用于OFDM系统,能增大OFDM符号内一组子载波上符号序列之间的欧氏距离,从而降低误码率,但不会造成信息速率和带宽效率的损失.根据MTCM网格图中不同状态下输出符号序列可以有较大欧氏距离的特点,给出了一种符号序列的两步检测算法:首先利用最大似然序列检测以较大概率检测出网格图的状态序列,然后在两个连续的状态之间检测判决符号序列.该算法利用了MTCM编码调制的特点,因而时延小、复杂度低,性能逼近直接的一步最大似然检测.理论分析和仿真结果均证明了MTCM-OFDM系统和这种检测算法的上述性能特点. 相似文献
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为解决主动噪声和振动控制中的执行器饱和约束条件问题,本文在子空间系统辨识的基础上,研究了一种新颖的子空间预测控制方法。该控制方法联合了系统辨识和控制器设计,直接由输入-输出数据得到将来时刻的输出预测值,自动校正系统中的参数,克服了传统的模型预测控制中繁琐的系统辨识环节。同时子空间预测控制允许执行器机构出现饱和现象,在考虑由饱和现象导致的约束条件时,利用线性矩阵不等式将约束优化问题转化为无约束优化问题。采用椭球优化算法迭代地产生一系列体积逐渐减小的椭球序列,该序列最终能收敛到一个最优解。在椭球算法的基础上推导了该算法达到收敛时所需要迭代次数的一个上界。这在智能优化算法中是很难求得到的。最后以直升机悬停状态时发生的颤振为例,利用本文中的子空间预测控制和椭球优化算法设计闭环系统的反馈控制器,验证闭环系统的输出响应能较好地跟踪期望值,从而得出本文方法的有效性。 相似文献
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《International journal for numerical methods in engineering》2018,113(9):1488-1506
In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method. 相似文献
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Standards are the basis for production enterprises to organize production ex-factory inspection trade 《中国标准化(英文版)》2008,25(1):24-25
Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.…… 相似文献
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A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa. 相似文献
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Steffen Müller-Probandt 《材料科学与工程:中英文B版...》2018,(4):161-177
We associate a variety of innovations with the term "Industry 4.0". The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di... 相似文献
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On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.…… 相似文献
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Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß. 相似文献
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Janet Lang 《Materials and Manufacturing Processes》2017,32(7-8):857-866
ABSTRACTThe production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them. 相似文献
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C. Qihong W. Zhan‐Wen J. Yi J. Yehua L. Fei F. Hanguang 《Materialwissenschaft und Werkstofftechnik》2014,45(7):582-590
In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M2(B,C), (W,Mo)2(B,C), M3(B,C), M23(B,C)6 type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm2. The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K1 mill housing of bar mill. 相似文献
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《中国标准化(英文版)》2014,(4)
正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from 相似文献