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1.
基于到达时间两台并行机上在线批调度   总被引:1,自引:0,他引:1  
考虑两台同构并行机上在线批调度问题.每个批具有不确定的到达时间,一旦机器可以利用,要在当前可以利用的批中选择出合适的批,并将其中的工件调度到机器上,且工件在加工过程中不允许中断.目标函数是使调度的最大完成时间最小.给出了一个批在线调度RBLPT算法,即选择当前批中加工时间之和最大的批按LPT 规则调度.另外,利用反证法,对算法的最坏情况进行了分析.  相似文献   

2.
霍满臣  唐立新 《控制与决策》2009,24(12):1826-1830

考虑两台同构并行机上在线批调度问题.每个批具有不确定的到达时间,一旦机器可以利用,要在当前可以利用的批中选择出合适的批,并将其中的工件调度到机器上,且工件在加工过程中不允许中断.目标函数是使调度的最大完成时间最小.给出了一个批在线调度RBLPT 算法,即选择当前批中加工时间之和最大的批按LPT 规则调度.另外,利用反证法,对算法的最坏情况进行了分析.

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3.
研究了供应链在线调度问题.该问题具有工件无等待、工序之间存在运输时间、加工时间介于一个区间等特点,制造商随时可能接到顾客订单,订单到达前,所有信息如订单数量、到达时间及加工时间等均未知.研究了在不改变已有工件调度的情况下,使用资源的可用时间区间最早完成临时订单的算法.计算机仿真表明,使用该算法求解大规模临时订单问题是十分有效的.  相似文献   

4.
常桂娟  张纪会 《控制与决策》2008,23(10):1092-1097

研究了供应链在线调度问题 .该问题具有工件无等待,工序之间存在运输时间,加工时间介于一个区间等特点,制造商随时可能接到顾客订单,订单到达前,所有信息如订单数量,到达时间及加工时间等均未知 .研究了在不改变已有工件调度的情况下,使用资源的可用时间区间最早完成临时订单的算法. 计算机仿真表明,使用该算法求解大规模临时订单问题是十分有效的.

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5.
提出了一种新的基于分类的SVM非线性回归算法(CSVR),首先将Y扩展为Y+ε和Y-ε两个数据集,再将n维输入空间X中的数据连同Y+ε和Y-ε组成n+1维空间χ中的两类数据,并用Z∈(+1,-1)来标识两类数据,再利用标准的SVM二分类算法求解。利用该算法对一系列的基准函数进行测试,取得了令人满意的结果。该算法对噪声数据不敏感,具有较好的鲁棒性,并且可以根据实际需要设定ε的大小,防止出现过拟合现象。该算法由于不需要先验地建立一个参数未知的回归模型,因此可以用在其他传统统计回归算法失效的场合。  相似文献   

6.
研究钢管加工流程中一类新型两台机器流水车间调度问题,工件在第一台机器上加工后被分解成多个子工件.对于最小化最大完成时间的情况,给出一个多项式时间的最优算法;对于最小化最大完成时间与惩罚费用之和的情况,给出一个拟多项式时间的动态规划算法;对于考虑生产前运输的最小化最大完成时间的情况,分析了问题的复杂性.证明了第一种情况的最优算法可作为后两种情况的2-近似算法.数值实验表明了算法的有效性.  相似文献   

7.
调度问题中在线算法只能够利用已经到达的工件信息进行调度,但在实际生产中,往往有可能预知即将到达的未来工件信息,并且利用信息进行决策.针对经典单机加权完工时间调度问题,根据预测控制的思想,提出了一种单步预测调度的算法,并且分别在理论证明和仿真两方面进行了分析.对单步预测调度算法进行了性能分析,在理论上证明了预测调度算法的竞争比下界为2,对于一般的情况进行了大鼍的仿真比较,由于在调度中增加了未来信息,单步预测调度算法的调度结果优于在线调度算法.  相似文献   

8.
贾兆红  杨洋  张以文 《控制与决策》2018,33(8):1363-1372
研究动态到达的差异工件在容量不同的平行批处理机环境下,最小化制造跨度的调度问题,并提出一种有效的元启发式算法.给出一个下界以评价算法的性能,针对所构建批的第1个工件的选择提出弱约束标准及两个基于弱约束的首工件选择策略,并引入到蚁群优化算法.最后通过仿真实验将所提出的改进蚁群算法与已有算法和使用传统选择策略的蚁群算法进行比较,实验结果表明,在建批过程中使用首工件弱约束策略和弱约束下工件尺寸大高概率选择策略是有效的,所提算法的搜索性能较其他算法具有明显优势.  相似文献   

9.
1 引言 本文在具有平均流程时间和延期工件数两个目标的情况下对单机多目标问题进行研究,所研究的调度环境为假设工件集N的n个工件在一台机器上进行无中断的加工,每个工件的加工时间、到达时间和交工日期分别为pi,ri和di,且每个工件在零时刻到达,即ri=0,其完工时间为Ci,流程时间Fi=Ci-ri=Ci,平均流程时间(F)=n∑i=1Fi/n.  相似文献   

10.
机加车间的工件动态到达热处理车间后因受到批处理设备合批等的约束不能及时得到加工,基于工件动态到达的热处理车间,以最小化工件等待时间期望为目标,建立批调度模型,根据工件到达时间实现了粒子群算法微粒的编码以及对工件的分批,通过仿真实验得到结论:缩短工件的加工时间,则在热处理车间内,可以减小工件等待时间期望;降低工件数规模,工件会密集到达热处理环节,从而减短工件等待时间;工件的等待时间期望的大小与工件规模数量有关,工件数规模较小时,大尺寸工件的等待时间期望优于小尺寸工件,规模较大时,则相反。最后,对比分析了本文改进的粒子群算法的效果,发现改进的粒子群算法最优。  相似文献   

11.
Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.  相似文献   

12.
European Community policy and the market   总被引:1,自引:0,他引:1  
Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.  相似文献   

13.
融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。  相似文献   

14.
Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.  相似文献   

15.
This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.  相似文献   

16.
Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008  相似文献   

17.
Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.  相似文献   

18.
This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)SM and Team Software Process (TSP){SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.  相似文献   

19.
基于复小波噪声方差显著修正的SAR图像去噪   总被引:4,自引:1,他引:3  
提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。  相似文献   

20.
Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.  相似文献   

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