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91.
92.
2 0世纪 2 0年代后期 ,河南发生严重旱灾 ,旅平河南赈灾会组织了颇具规模的灾民移垦活动 ,他们经过比较周密的部署 ,将数万嗷嗷待哺的河南灾民移送到了东北 ,并尽可能地使灾民得到较为妥善的安置。旅平河南赈灾会的此次灾民救助活动在民国河南灾荒救济史上留下了光辉的一页。 相似文献
93.
We develop a ranking of compact, convex and comprehensive opportunity sets defined in the evaluative space of individual functionings. We suppose the existence of a target, that is a multi-dimensional bliss point in terms of functionings. This leads us to define concepts such as essentiality and freedomin a novel way. As a main result, we give an axiomatic characterization of the ranking obtained by minimizing the Euclidean distance between each opportunity set and the target. 相似文献
94.
本文将数据挖掘中事务数据库压缩的方法应用于对某县的移动通讯用户从2001年的9月到2002年的3月的消费水平的分析,并对消费情况进行了进一步的剖析,取得了良好的效果。 相似文献
95.
Arie Beresteanu Francesca Molinari 《Econometrica : journal of the Econometric Society》2008,76(4):763-814
We propose inference procedures for partially identified population features for which the population identification region can be written as a transformation of the Aumann expectation of a properly defined set valued random variable (SVRV). An SVRV is a mapping that associates a set (rather than a real number) with each element of the sample space. Examples of population features in this class include interval‐identified scalar parameters, best linear predictors with interval outcome data, and parameters of semiparametric binary models with interval regressor data. We extend the analogy principle to SVRVs and show that the sample analog estimator of the population identification region is given by a transformation of a Minkowski average of SVRVs. Using the results of the mathematics literature on SVRVs, we show that this estimator converges in probability to the population identification region with respect to the Hausdorff distance. We then show that the Hausdorff distance and the directed Hausdorff distance between the population identification region and the estimator, when properly normalized by , converge in distribution to functions of a Gaussian process whose covariance kernel depends on parameters of the population identification region. We provide consistent bootstrap procedures to approximate these limiting distributions. Using similar arguments as those applied for vector valued random variables, we develop a methodology to test assumptions about the true identification region and its subsets. We show that these results can be used to construct a confidence collection and a directed confidence collection. Those are (respectively) collection of sets that, when specified as a null hypothesis for the true value (a subset of values) of the population identification region, cannot be rejected by our tests. 相似文献
96.
在数据库中挖掘定量关联规则的方法研究 总被引：9，自引：3，他引：9
数据挖掘技术是实现智能决策支持系统的一个重要手段 ,关联规则是数据挖掘的一个重要内容 .传统的 Apriori算法仅适用于挖掘数据间的定性关联关系 ,但数据间的定量关联关系对决策更有帮助 .属性值的离散映射是挖掘定量关联规则的一个重要环节 ,离散映射中属性值区间的划分粒度是影响数据挖掘质量的一个重要因素 .本文结合粗集理论提出了一个确定属性值划分粒度的方法 ,在此基础上设计出一个挖掘定量关联规则的算法 :Apriori 2 ,利用Apriori 2可以挖掘出大量对决策有帮助的定量关联规则 相似文献
97.
Tuan Le Jon M. Stauffer Bala Shetty Chelliah Sriskandarajah 《Production and Operations Management》2023,32(3):740-761
We study an optimal matching problem in the context of dual-donor organ exchange, where a portion of two living donors' organs are transplanted to a single patient. This dual-donor transplant technique is becoming more widespread for lung and liver transplants. However, multiple medical compatibility criteria pose a serious challenge for matching a patient with two compatible donors. In the United States and many other countries, laws prohibit commercial (for-profit) deals for human organs, so donor exchanges are run by nonprofit organizations connecting donors with people in need of organs, with the goal of increasing transplant matches. We propose a simple chain mechanism in dual-donor organ exchange to increase the number of patient–dual-donor matches, which would maximize the number of patients receiving transplants. Based on this objective, we propose a general simple chain optimization framework for finding the maximum patient matching, taking into account multiple compatibility criteria (e.g., blood type and weight), and determine the complexity status of the problem. We provide theoretical results on the structures of simple chains, as well as a polynomial time algorithm to obtain the maximum patient matching simple chain with blood type compatibility. Through a numerical study for multiple compatibility criteria, we show that in many scenarios, a simple chain substantially increases the number of patients matched with dual donors for transplants, as opposed to exchange cycles. We also address the problem of maximizing the number of patients matched for dual-donor organ transplants via two-way and three-way exchange cycles, subject to donors' and recipients' medical compatibility criteria, along with a discussion of their computational complexity. Finally, we characterize the general configurations of large n-way exchange cycles and provide theoretical insights for their structural properties. Our findings provide general optimization models for dual-donor organ exchange operators to increase the number of patients matched for transplant, given multiple compatibility criteria. In addition, we show how exchange operators, using simple chains, can increase patient matches and reduce simultaneous surgical resource requirements over exchange cycles. 相似文献
98.
《Journal of nonparametric statistics》2012,24(4-5):505-516
Based on ranked set sampling procedure, a technique to obtain a controlled preferable sample is introduced. Using this technique it is possible to obtain an approximate preferable sample from a population of interest. In particular, the technique can be used to obtain sample points that tend to be from a specific portion of a distribution such as the lower or upper quartiles. The performance of the technique is investigated under perfect and imperfect ranking. Some other related topics are also discussed. 相似文献
99.
《Journal of nonparametric statistics》2012,24(4):505-518
This paper proposes a profile likelihood algorithm to compute the nonparametric maximum likelihood estimator of a convex hazard function. The maximisation is performed in two steps: First the support reduction algorithm is used to maximise the likelihood over all hazard functions with a given point of minimum (or antimode). Then it is shown that the profile (or partially maximised) likelihood is quasi-concave as a function of the antimode, so that a bisection algorithm can be applied to find the maximum of the profile likelihood, and hence also the global maximum. The new algorithm is illustrated using both artificial and real data, including lifetime data for Canadian males and females. 相似文献
100.
《Journal of nonparametric statistics》2012,24(6):729-741
The problem of estimating the surface area, L 0, of a set G⊂ℝ d has been extensively considered in several fields of research. For example, stereology focuses on the estimation of L 0 without needing to reconstruct the set G. From a more geometrical point of view, set estimation theory is interested in estimating the shape of the set. Thus, surface area estimation can be seen as a further step where the emphasis is placed on an important geometric characteristic of G. The Minkowski content is an attractive way to define L 0 that has been previously used in the literature on surface area estimation. Pateiro-López and Rodríguez-Casal [B. Pateiro-López and A. Rodríguez-Casal, Length and surface area estimation under smoothness restrictions, Adv. Appl. Prob. 40(2) (2008), pp. 348–358] proposed an estimator, L n , for L 0 under convexity type assumptions. In this paper, we obtain the L 1-convergence rate of L n . 相似文献