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1.
本文在基于标准被废除按比例进行时的标准体系使用期的两个新模型。首先给出了模型假设条件,然后定义了标准使用期。根据假设给出了两个模型条件下的标准使用期公式,最后通过数值示例说明了标准使用期的公式使用。  相似文献   

2.
本文从消费者的角度出发,提出了在产品的有限使用期内,可免费维修保修的产品的更换策略.假设产品在使用期内可以更换一次,更换前后产品的故障率不发生变化.在保修期内,发生故障的产品的维修费用由生产商承担,消费者不用为此支付任何费用.在保修期外产品发生故障,消费者需要为此支付一笔固定的维修费用.然而,只要产品在使用,每发生一次故障都会对消费者产生一笔固定的停机费用.在这种维修计划下,产品的更换将分两种情况讨论:免费保修前和免费保修后.本文将建立两类最优更换模型,给出消费者期望支付费用的数学模型,继而求得最优的更换时间以及此时最小的支付费用.最后会给出模型的算例分析,给出在不同的保修期和有限使用期下,最优更换策略的相关特征.  相似文献   

3.
通过对考试成绩序列统计特征的分析,本文提出考试成绩序列的一种模型——ARIMA(0,1.1)模型,此模型能较好解释考试成绩变化发展的基本规律,并由此提出了实际水平分,实际水平分稳定系数,考试成绩离均差的变动系数及学生成绩的分化速度等学业评估上的新概念及评估标准.应用此模型,有可能揭示一些隐藏于考试成绩内的教育现象,作为实例对小学语文、数学成绩变化上所存在的差异进行了讨论.  相似文献   

4.
DNA序列的分类模型   总被引:5,自引:0,他引:5  
本文针对 DNA序列分类这个实际问题 ,提出了相应的数学模型 .为了很好的体现 DNA序列的局部性和全局性的特征 ,我们给出了衡量分类方法优劣的标准 ,即在满足一定限制条件的情况下 ,是否能充分反映序列的各方面特性 .依据我们提出的判别标准 ,单一标准的分类是无法满足要求的 .我们的方法是侧重点不同的三种方法的综合集成 .这三种方法分别体现了序列中元素出现的概率 ,序列中元素出现的周期性 ,序列所带有的信息含量 .利用这个方法 ,完成了对未知类型的人工序列及自然序列的分类工作 .最后 ,对分类模型的优缺点进行了分析 ,并就模型的推广作了讨论  相似文献   

5.
基于三元区间数,提出三元区间支付合作对策理论,利用三元区间数的运算及序关系,建立了三元区间支付合作对策模型和具有偏好标准的三元区间支付合作对策模型,研究相应模型的几类核心解,如区间核心、区间优超核心及q-区间核心等,讨论了各相关核心解之间的关系,并加以证明.最后通过实例分析,验证了三元区间支付合作对策理论,具有一定的参考价值与现实意义,是对模糊支付合作对策理论的不断完善.  相似文献   

6.
本文提出了一种全新的偿付能力评价模型,即未偿率模型,随后讨论了未偿率模型在各种损失分布情况下的应用.在本文的最后,还讨论了未偿率模型在指数分布利正态分布条件下的一些特殊性质.  相似文献   

7.
灰色绝对关联度的改进模型   总被引:1,自引:0,他引:1  
基于刘思峰教授提出的灰色绝对关联度模型,提出了一点改进,给出了新的灰色绝对关联度模型,并讨论了新模型的性质及其算法.一方面保持了原绝对关联度模型的优点,另一方面改正了原模型在某些方面的不足.  相似文献   

8.
基于净现值的离散型多项目多期投资优化模型   总被引:1,自引:0,他引:1  
关于资本结构优化模型的讨论已经有了很好的结论,即基于项目组合的净现值最大化,对于多项目单期优化模型已经有了比较满意的结论.在已有结论的基础上研究了离散型多项目多期投资组合优化模型的一般形式,首先针对离散型多项目分期持续期相等的投资组合提出了一般优化模型,然后讨论离散型多项目分期持续期不全相等的投资组合优化模型,最后讨论了引进组合风险的投资组合优化模型。  相似文献   

9.
本文首次提出了 n维超立方体的层次结构模型 HHC,详细讨论了该结构中结点的分布及各结点的连接关系 .并利用 HHC,讨论了超立方体非对称比较模型的最优诊断算法 ,极大独立点集等问题  相似文献   

10.
在属性测度空间理论指导下,提出了属性测度下的属性粗糙集模型及依参量的属性粗糙集模型,并就不同属性粗糙集模型的精度进行了讨论.  相似文献   

11.
This paper proposes and illustrates a new perturbed gamma degradation process where the measurement error is modeled as a non‐Gaussian random variable that depends stochastically on the actual degradation level. The expression of the likelihood function for a generic set of noisy degradation measurements is derived, and the expression of the remaining useful life distribution of a degrading unit that fails when its degradation level exceeds a given threshold limit is formulated. A particle filter method is suggested, which allows one to compute the likelihood function and to estimate the remaining useful life distribution in a quick yet efficient manner. In addition, a closed‐form approximation of the perturbed gamma process is proposed to use in the special, yet meaningful, case where the standard deviation of the measurement error depends linearly on the actual degradation level. Finally, an applicative example is discussed, where the parameters of the perturbed gamma process, the remaining useful life distribution, and the mean remaining useful life of the degrading units are estimated from a set of noisy real degradation data.  相似文献   

12.
An appropriate and accurate residual life prediction for an asset is essential for cost effective and timely maintenance planning and scheduling. The paper reports the use of expert judgments as the additional information to predict a regularly monitored asset’s residual life. The expert judgment is made on the basis of measured condition monitoring parameters, and is treated as a random variable, which may be described by a probability distribution due to the uncertainty involved. Since most expert judgments are in the form of a set of integer numbers, we can either directly use a discrete distribution or use a continuous distribution after some transformation. A key concept used in this paper is condition residual life where the residual life at the point of checking is conditional on, among others, the past expert judgments made on the same asset to date. Stochastic filtering theory is used to predict the residual life given available expert judgments. Artificial, simulated and real data are used for validating and testing the model developed.  相似文献   

13.
根据 2 1 2位中国现代数学家 (1 1 7位逝世 )的生存资料进行分析 ,得到如下结果 . 62位院士的期望寿命为 84.68岁 ,标准误差为 1 .96岁 ;1 5 0位非院士数学家的期望寿命为 79.2 6岁 ,标准误差为 1 .1 3岁 .院士和非院士数学家的寿命差异有显著性意义 (P =0 .0 5 ) .分别给出了院士和非院士数学家两个群体的寿命表 .结论 :中国现代数学家属于长寿之列 .脑部疾病、心脏疾病和癌症为数学家的主要死因 .  相似文献   

14.
飞机的退役是航空装备管理中的重要问题之一.为科学合理地确定飞机退役时限,针对部队飞机使用情况,以某型飞机为例,对飞机的剩余寿命进行详细分析,应用统计学方法,探讨了飞机退役时限和数量的变化规律,在此基础上建立了飞机补充数量预测模型.并结合空军装备发展的实际,对飞机使用过程中的更新换代问题进行了探讨.  相似文献   

15.
An insurance company selling life annuities has to use projected life tables to describe the survival of policyholders. Such life tables are generated by stochastic processes governing the future path of mortality. To fix the ideas, the standard Lee-Carter model for mortality projection is adopted here. In that context, the paper purposes to examine the consequences of working with random survival probabilities. Various stochastic inequalities are derived, showing that the risk borne by the annuity provider is increased compared to the classical independent case. Moreover, the type of dependence existing between the insured life times is carefully examined. The paper also deals with the computation of ruin probabilities and large portfolio approximations.   相似文献   

16.
Relying on reliability growth testing to improve system designis neither usually effective nor efficient. Instead it is importantto design in reliability. This requires models to estimate reliabilitygrowth in the design that can be used to assess whether goalreliability will be achieved within the target timescale forthe design process. Many models have been developed for analysisof reliability growth on test, but there has been much lessattention given to reliability growth in design. This paperdescribes and compares two models: one motivated by the practicalengineering process; the other by extending the reasoning ofstatistical reliability growth modelling. Both models are referencedin the recently revised edition of international standard IEC61164. However, there has been no reported evaluation of theirproperties. Therefore, this paper explores the commonalitiesand differences between these models through an assessment oftheir logic and their application to an industrial example.Recommendations are given for the use of reliability growthmodels to aid management of the design process and to informproduct development.  相似文献   

17.
本文讨论了在指数型寿命数据中,对同时存在的异常大数据和异常小数据的检验方法,给出了一个明确的判别标准,并以一例说明其应用。  相似文献   

18.
复杂网络广泛存在于日常生活,首先,给出几类标准的网络模型;然后,利用稳定性控制方法设计并实现了具有时滞与非时滞耦合的复杂网络模型快速控制;最后,通过构造优化Lyapunov函数,讨论其模型的射影同步问题,得到了系统全局稳定的条件和有效的控制器,以实例数值验证其方法的可行性。  相似文献   

19.
In this paper we consider sufficient conditions in order to stochastically compare random vectors of multivariate mixture models. In particular we consider stochastic and convex orders, the likelihood ratio order, and the hazard rate and mean residual life dynamic orders. Applications to proportional hazard models and mixture models in risk theory are also given.  相似文献   

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