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用白噪声信号作为输入信号对钻柱系统脉冲响应进行辨识。研究了伪随机信号的特征及伪随机信号产生的方法,得出了用伪随机信号代替白噪声信号辨识钻柱系统脉冲响应的结论。结合输入信号和输出信号,利用钻柱系统的脉冲响应,讨论了钻柱的临界转速、钻柱共振、钻柱与井壁之间的相互作用、所钻地层岩性等钻井工程问题。 相似文献
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《Journal of Statistical Computation and Simulation》2012,82(2):145-187
This paper studies the effects of non-normality and autocorrelation on the performances of various individuals control charts for monitoring the process mean and/or variance. The traditional Shewhart X chart and moving range (MR) chart are investigated as well as several types of exponentially weighted moving average (EWMA) charts and combinations of control charts involving these EWMA charts. It is shown that the combination of the X and MR charts will not detect small and moderate parameter shifts as fast as combinations involving the EWMA charts, and that the performana of the X and MR charts is very sensitive to the normality assumption. It is also shown that certain combinations of EWMA charts can be designed to be robust to non-normality and very effective at detecting small and moderate shifts in the process mean and/or variance. Although autocorrelation can have a significant effect on the in-control performances of these combinations of EWMA charts, their relative out-of-control performances under independence are generally maintained for low to moderate levels of autocorrelation. 相似文献
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《Journal of Statistical Computation and Simulation》2012,82(8):1463-1478
In some situations, an appropriate quality measure uses three or more discrete levels to classify a product characteristic. For these situations, some control charts have been developed based on statistical criteria regardless of economic considerations. In this paper, we develop economic and economic statistical designs (ESD) for 3-level control charts. We apply the cost model proposed by Costa and Rahim.[Economic design of X charts with variable parameters: the Markov chain approach, J Appl Stat 28 (2001), 875–885] Furthermore, we assume that the length of time that the process remains in control is exponentially distributed which allows us to apply the Markov chain approach for developing the cost model. We apply a genetic algorithm to determine the optimal values of model parameters by minimizing the cost function. A numerical example is provided to illustrate the performance of the proposed models and to compare the cost of the pure economic and ESD for three-level control charts. A sensitivity analysis is also conducted in this numerical example. 相似文献
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Hannah Landecker 《Sociological review mongraph》2016,64(1):79-99
Human social interactions and material cultures are increasingly understood as biologically consequent environmental signals. Within the explanatory framework of epigenetics, such signals become biologically inscribed when transduced into bodies as persistent patterns of molecular conformation. In the life sciences, persistence of the social as the biological is understood as establishment of gene expression potentials, physiological changes, or epigenetic memories. How did the social become interchangeable with the environmental? When did both become scientifically graspable as signals? This article recounts the history of how hormone biologists came to think in terms of signal transduction in the late 1960s. This cybernetic legacy is important for understanding the ‘environmental turn’ of epigenetics. To understand the social as signal in the present moment – a post-cybernetic rather than post-genomic moment – the theory of the signal must itself be excavated and analysed. 相似文献
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结合数字信号处理器的性能特点,对基2、基4、分裂基和Bruun FFT等快速傅立叶变换算法及其在TMS320C30上的实现进行了研究,开发出高效的FFT算法和程序。 相似文献
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根据EMD分解原理,提出通过选择平均包络中的突变点确定自适应滤波器截止分量阶,以此构造时空滤波器组进行非线性信号自适应分析的方法,成功应用于分析波音737飞机涡轮轴振动信号。从噪声中自适应地提取随转速变化的信号分量和低频振动分量,与小波分析方法相比,在轴向位移检测中取得了更为满意的效果。该方法不仅改进了涡轮轴振动信号分析方法,也适用于解决其他非线性信号的分析问题。 相似文献
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基于虚拟仪器的检测技术创新实验教学平台 总被引:1,自引:0,他引:1
文章讨论了对原有的检测技术实验教学体系进行改革,构建了检测技术创新实验教学平台,给出了基于虚拟仪器技术的检测技术创新实验教学平台构建方案。 相似文献
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中国是粮食生产大国和人口大国,粮食问题对于我国经济社会的发展具有举足轻重的影响。现有粮食供应链"层层批发"的流通体制不能满足消费者个性化需求。所以,本文基于客户的个性化需求,应用轮询系统理论来研究面粉、大米等粮食连续物料的订单分拣自动化控制机理。本文根据实际业务需求设定普通订单、优先订单,对优先订单的分拣实行完全服务控制策略,对普通订单分拣实行限定(k=1)服务控制策略,建立完全-并行限定(k=1)的二级优先级订单分拣轮询控制系统模型,确保优先业务订单顾客得到更优质服务,同时保证订单分拣系统的公平性。采用嵌入式Markov链、多维概率母函数和拉式变换求解理论模型,并通过数值计算分析,精确求解其一阶系统特性、二阶系统特性等关键性能参数,从而深入研究连续物料订单分拣的控制机理。 相似文献