共查询到18条相似文献,搜索用时 187 毫秒
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因望大质量特性在实践中无法达到无穷大,望小质量特性在实践中也无法达到0值,当补偿量恒定时,质量损益函数仅采用补偿量及二次项损失表达,直接删除一次项损失是不合理的.在不忽略一次项损失且补偿量恒定时,研究了望大与望小特性质量损益函数的表达形式及二次式损益函数中一次项损失系数和二次项损失系数确定的方法,比较分析了二次式损益函数中一次项损失和二次项损失的大小.研究结果显示,二次项损益函数是二次式损益函数的一种形式. 相似文献
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基于非对称损失函数的参数设计 总被引:4,自引:0,他引:4
本文针对望目特性的正态指标,在非对称的二次质量损失函数下,讨论了参数设计的可行性, 证明田口方法的稳健性设计和灵敏度设计依然行之有效.定义了调整参数,求出了使质量损失最小的数值解,并给出了参数设计的具体步骤. 相似文献
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基于测量质量损失函数的控制图控制界限的优化 总被引:1,自引:0,他引:1
控制界限和抽样间隔是控制图的两个基本参数。常规控制图是基于3σ原理确定的控制界限,该控制界限是在大量试验基础上依据经验确定的,并没有精确的公式推导.对于抽样间隔,常规控制图也没有明确的规定。田口博士的质量损失函数可以很好的解决质量经济性方面的一些问题.利用田口博士的理论,通过确定适宜的二次测量质量损失函数,可以确定控制图的最佳控制界限和最佳抽样间隔.文章简要介绍了常规控制图原理和田口博士的质量损失函数,重点叙述了田口博士反馈控制系统的测量质量损失函数,在此基础上,研究了控制图最佳控制界限和最佳抽样间隔,并且通过具体实例验证了该控制图良好的经济性. 相似文献
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《数学的实践与认识》2013,(21)
本文借用线性模型系数的Minimax估计方法,在二次损失函数下运用随机优化理论对Gua.ss-Markov非线性模型的系数进行了研究,建立了非线性模型系数Minimax估计的随机优化模型. 相似文献
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产品设计与质量控制的动态因素模型(下) 总被引:1,自引:1,他引:0
(续上期)5·5产品动态质量损失和产品技术损失田口的质量损失函数L(y)已被人们所熟知,它不考虑跟时间的关系,其自变量为产品的特性y,其函数形式为L(y)=K(y-y0)2,其中K为常数。质量损失函数的期望值E[L(y)}=K·E(y-y0)2称之为产品质量损失,它表示在统计意义下单位产品的平均质量 相似文献
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基于非对称损失函数指数分布总体的参数设计 总被引:2,自引:0,他引:2
田口玄一的参数设计思想只是针对对称的损失函数所做,有一定的局限性.讨论了非对称的损失函数,定义了损失系数比,并在指标服从指数分布的情形下定义了调整参数,并指出了调整参数在参数设计中的特殊位置和重要特性,给出了参数设计的方法和步骤. 相似文献
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本文研究了平衡损失函数下正态总体和非正态总体中有限回归系数的可容许预测.利用统计决策理论,获得了非正态总体中齐次线性预测为可容许预测的充分必要条件和在正态总体中齐次线性预测在一切预测类中可容许性的充要条件,推广了二次损失下的若干相关结果. 相似文献
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在二次损失下关于任意矩阵V对G-M模型讨论了齐次线性估计类中可估函数的条件Mimimax估计与性质。 相似文献
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Some modifications of improved estimators of a normal variance 总被引:1,自引:1,他引:0
Nobuo Shinozaki 《Annals of the Institute of Statistical Mathematics》1995,47(2):273-286
Consider the problem of estimating a normal variance based on a random sample when the mean is unknown. Scale equivariant estimators which improve upon the best scale and translation equivariant one have been proposed by several authors for various loss functions including quadratic loss. However, at least for quadratic loss function, improvement is not much. Herein, some methods are proposed to construct improving estimators which are not scale equivariant and are expected to be considerably better when the true variance value is close to the specified one. The idea behind the methods is to modify improving equivariant shrinkage estimators, so that the resulting ones shrink little when the usual estimate is less than the specified value and shrink much more otherwise. Sufficient conditions are given for the estimators to dominate the best scale and translation equivariant rule under the quadratic loss and the entropy loss. Further, some results of a Monte Carlo experiment are reported which show the significant improvements by the proposed estimators. 相似文献
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Real estate price prediction under asymmetric loss 总被引:3,自引:0,他引:3
Michael Cain Christian Janssen 《Annals of the Institute of Statistical Mathematics》1995,47(3):401-414
This paper deals with the problem of how to adjust a predictive mean in a practical situation of prediction where there is asymmetry in the loss function. A standard linear model is considered for predicting the price of real estate using a normal-gamma conjugate prior for the parameters. The prior of a subject real estate agent is elicited but, for comparison, a diffuse prior is also considered. Three loss functions are used: asymmetric linear, asymmetric quadratic and LINEX, and the parameters under each of these postulated forms are elicited. Theoretical developments for prediction under each loss function in the presence of normal errors are presented and useful tables of adjustment factor values given. Predictions of the dependent price variable for two properties with differing characteristics are made under each loss function and the results compared. 相似文献
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A Kind of direct methods is presented for the solution of optimal control problems with state constraints.These methods are sequential quadratic programming methods.At every iteration a quadratic programming which is obtained by quadratic approximation to Lagrangian function and Linear approximations to constraints is solved to get a search direction for a merit function.The merit function is formulated by augmenting the Lagrangian funetion with a penalty term.A line search is carried out along the search direction to determine a step length such that the merit function is decreased.The methods presented in this paper include continuous sequential quadratic programming methods and discreate sequential quadrade programming methods. 相似文献
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二次损失下增长曲线模型参数阵的线性Minimax可容许估计 总被引:3,自引:0,他引:3
本文在二次损失函数下,给出了增长曲线模型参数阵的线性估计在给定的线性估计类中是Minimax可容许估计的充要条件. 相似文献
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对带有随机效应的一般线性模型,本文提出了随机回归系数和参数线性组合的Minimax估计问题. 在二次损失下,研究了线性估计的极小极大性.关于适当的假设,得到了可估函数的唯一线性Mjnimax 估计. 相似文献
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Li Wen XU Song Gui WANG 《数学学报(英文版)》2007,23(3):497-506
In this paper, the authors address the problem of the minimax estimator of linear combinations of stochastic regression coefficients and parameters in the general normal linear model with random effects. Under a quadratic loss function, the minimax property of linear estimators is investigated. In the class of all estimators, the minimax estimator of estimable functions, which is unique with probability 1, is obtained under a multivariate normal distribution. 相似文献
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Lu Shi Hui 《European Journal of Operational Research》1984,15(1):110-120
An improved algorithm is proposed for the minimization of a quadratic function in zero-one variables under quadratic constraints which is based on the idea of additive penalties proposed by P. Hansen. At first, the quadratic function in which all the coefficients except the constant term are nonnegative is obtained by the introduction of the negative variables, and the constant term is a tighter bound of the function. Starting from the tighter bound, some properties are obtained and some efficient tests are established. To obtain a much tighter bound, a simple heuristic method is suggested instead of solving a linear programming problem. Furthermore, the flexibility dealing with some tests is discussed and it is also helpful to the algorithm. 相似文献