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181.
T. Wuttipornpun 《生产规划与管理》2013,24(8):703-715
This paper aims to develop a finite capacity material requirement planning (FCMRP) system based on TOC philosophy (TOC-MRP) for multi-stage assembly factory that has some bottleneck stations. The proposed TOC-MRP system tries to load and schedule operations on bottleneck stations in a manner that they are free of idle time and overtime. The schedules on non-bottleneck stations will be arranged until they are not conflicting with those on the bottleneck stations. The non-bottleneck stations are allowed to have idle time and overtime if necessary. To analyse whether TOC-MRP is effective, it is compared with a FCMRP method that does not adopt TOC philosophy. The experimental results reveal that the TOC-MRP outperforms the FCMRP without TOC philosophy. 相似文献
182.
D. T. Mc Nichols 《统计学通讯:理论与方法》2013,42(6):2043-2062
Nonparametric maximum likelihood estimation of decreasing and unimodal density functions, based on observations subject to arbitrary right censorship, was considered by McNichols and Padgett(1982). In order to compute their estimators, however, nonlinear equations with linear constraints had to be maximized using numerical techniques. The exact solution to this problem can now be found. An example illustrates the simplicity of the method. 相似文献
183.
地球生态系统是一个有机、有序、运动着的“活体” ;地球生态系统大体包括自然生态系统、社会生态系统、精神生态系统 ;文学艺术活动是生存的最为辉煌灿烂的景观 相似文献
184.
The joint models for longitudinal data and time-to-event data have recently received numerous attention in clinical and epidemiologic studies. Our interest is in modeling the relationship between event time outcomes and internal time-dependent covariates. In practice, the longitudinal responses often show non linear and fluctuated curves. Therefore, the main aim of this paper is to use penalized splines with a truncated polynomial basis to parameterize the non linear longitudinal process. Then, the linear mixed-effects model is applied to subject-specific curves and to control the smoothing. The association between the dropout process and longitudinal outcomes is modeled through a proportional hazard model. Two types of baseline risk functions are considered, namely a Gompertz distribution and a piecewise constant model. The resulting models are referred to as penalized spline joint models; an extension of the standard joint models. The expectation conditional maximization (ECM) algorithm is applied to estimate the parameters in the proposed models. To validate the proposed algorithm, extensive simulation studies were implemented followed by a case study. In summary, the penalized spline joint models provide a new approach for joint models that have improved the existing standard joint models. 相似文献
185.
通过对吉林地区人才需求分析,为促进学生职业能力的可持续发展,研究以就业为导向,构建突出职业能力的课程体系;"竞、技、协"相结合,构建个性化能力培养平台;校企共建虚实结合的教学资源,以提高人才培养质量。 相似文献
186.
清代咸同年间爆发的滇东南回民反对清政府的抗暴自卫斗争,具有维护民族生存自立的性质,与滇西杜文秀领导的各族反清大起义不同,故对其领导人马德新、马如龙不能以简单的投降、叛徒论之,而应给予客观评价。 相似文献
187.
利用CDMA系统多址复用的特点,提出了一种基于CDMA的多重水印算法,在小波变换域中同时嵌入多个水印。对多个原始水印进行卷积编码和交织编码后,采用Gold码组进行正交扩频,经CDMA编码的水印信息被叠加嵌入在除HH1以外的其他小波子带中。水印嵌入的幅值根据Watson小波域视觉感知模型确定。嵌入位置取决于一个PN序列随机发生器,检测时不需要原始图像。在此基础上对多重水印容量进行了分析,结果表明当嵌入两个水印时,其容量大于任何一个单一水印的容量,但小于两个单一水印容量之和。 相似文献
188.
MONTSERRAT GUILLEN JENS P. NIELSEN ANA M. PEREZ-MARIN 《Scandinavian Journal of Statistics》2007,34(2):419-431
Abstract. The Nelson–Aalen estimator is well known to be an asymptotically efficient estimator of the cumulative hazard function, see Andersen et al. ( Statistical models based on counting processes , Springer-Verlag, New York, 1993) among many others. In this paper, we show that the efficiency of the Nelson–Aalen estimator can be considerably improved by using more information in the estimation process than the traditional Nelson–Aalen estimator uses. While our approach results in a biased estimator, the variance improvement is substantial. By optimizing the balance between the bias loss and the variance improvement, we obtain results on the efficiency gain. Several examples for known failure time distributions are used to illustrate these ideas. 相似文献
189.
190.
略论企业家的成长机制 总被引:3,自引:0,他引:3
文章就如何适应市场经济发展要求 ,建立一个使企业家茁壮成长的机制进行了探索 ,认为 :企业家职业化 ,企业家市场选择是这一机制的核心 ;经营力商品化是这一机制的关键 ;建立一个能使成长机制正常运转的运行机制至关重要 ;成长机制还需要竞争、法律等约束机制相配合 相似文献