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161.
《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
162.
人口空间动态与区域经济发展的耦合关系是同城化区域间共同面对的重要课题。本文在解构人口空间动态维度主体的基础上,将人口空间动态的诉求机制与动因机理架构于更低交易费用的利益诉求之上,解析人口空间动态的模式选择,深入探讨人口空间动态与区域经济发展的耦合关联性。在此基础上,提出引导人口流动与合理分布的策略。研究成果将有助于更好地理解同城化态势下人口空间演变的动因机理,为同城区域的经济发展、城市规划、文化交融等方面的科学设计提供重要参考。 相似文献
163.
沈健 《西南石油大学学报(社会科学版)》2012,(2):114-119
环境对量子控制系统的消相干揭示了一个事实,即量子世界里的系统将是一种全新的系统,它是某种开放的、数学的、并且是基于量子逻辑的系统。笔者认为,假如仍然还是立足经典思维,则系统的独立性将难以得到保证,传统的整体论也将变得自相矛盾。只有发展全新的"量子整体论",并在这种新的框架下去审视和建构量子系统,我们才有可能重新获得某种连贯一致的整体论。 相似文献
164.
165.
根据2000—2009年国家统计年鉴中河北省的有关数据,选取有代表性的指标,构造评价可持续发展水平的指标体系,并采用熵理论确定各指标的权重,以观察近10年来河北省经济社会可持续发展的具体情况。实证研究结果表明:河北省正逐渐迈向可持续发展的道路,但任重道远。根据省际具体情况,在实证研究的基础上,就河北省经济社会的长期可持续发展提出了若干建议。 相似文献
166.
李永洪 《西华师范大学学报(自然科学版)》2012,(5):1-7
我国农村基层民主近年来在广度和深度上都得到了较大发展。但是,在这种发展的表象背后,却隐藏着农民政治冷漠的客观真象。对此,既有的"复合因果论"具有一定解释力,但也有值得补遗之处。农村基层民主制度运行成本与运行绩效的不对称、农民个体承担的基层民主制度运行成本过高才是导致当前农民政治冷漠的根本原因。 相似文献
167.
《统计学通讯:理论与方法》2012,41(16-17):3233-3243
In literature there are several studies on the performance of Bayesian network structure learning algorithms. The focus of these studies is almost always the heuristics the learning algorithms are based on, i.e., the maximization algorithms (in score-based algorithms) or the techniques for learning the dependencies of each variable (in constraint-based algorithms). In this article, we investigate how the use of permutation tests instead of parametric ones affects the performance of Bayesian network structure learning from discrete data. Shrinkage tests are also covered to provide a broad overview of the techniques developed in current literature. 相似文献
168.
Alfonso Dingemans 《Development policy review : the journal of the Overseas Development Institute》2016,34(5):643-669
Underneath impressive growth levels, the Chilean economy displays signs of being caught in a middle‐income trap. It has been unable to improve its productivity, increase the added value of its exports or upgrade its value chain. Its economy cannot compete either with low‐wage countries or highly productive, innovative countries. Its export strategy based on export promotion seems to have outlived its usefulness. It achieved remarkable quantitative success, but must now attend qualitative attributes. Instead of regarding market‐driven export promotion and state‐led export development as substitutes, this article proposes to view them as alternatives in different stages of development. To choose the appropriate time, more attention should be given to non‐traditional, structural indicators, like export sophistication and political‐institutional capabilities. 相似文献
169.
Marjolein J. E. Greuter Xiang‐Ming Xu Jie‐Bin Lew Evelien Dekker Ernst J. Kuipers Karen Canfell Gerrit A. Meijer Veerle M. H. Coupé 《Risk analysis》2014,34(5):889-910
Several colorectal cancer (CRC) screening models have been developed describing the progression of adenomas to CRC. Currently, there is increasing evidence that serrated lesions can also develop into CRC. It is not clear whether screening tests have the same test characteristics for serrated lesions as for adenomas, but lower sensitivities have been suggested. Models that ignore this type of colorectal lesions may provide overly optimistic predictions of the screen‐induced reduction in CRC incidence. To address this issue, we have developed the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model that includes the adenoma‐carcinoma pathway and the serrated pathway to CRC as well as characteristics of colorectal lesions. The model structure and the calibration procedure are described in detail. Calibration resulted in 19 parameter sets for the adenoma‐carcinoma pathway and 13 for the serrated pathway that match the age‐ and sex‐specific adenoma and serrated lesion prevalence in the COlonoscopy versus COlonography Screening (COCOS) trial, Dutch CRC incidence and mortality rates, and a number of other intermediate outcomes concerning characteristics of colorectal lesions. As an example, we simulated outcomes for a biennial fecal immunochemical test screening program and a hypothetical one‐time colonoscopy screening program. Inclusion of the serrated pathway influenced the predicted effectiveness of screening when serrated lesions are associated with lower screening test sensitivity or when they are not removed. To our knowledge, this is the first model that explicitly includes the serrated pathway and characteristics of colorectal lesions. It is suitable for the evaluation of the (cost)effectiveness of potential screening strategies for CRC. 相似文献
170.
旅游交通是旅游经济发展中重要的内容之一,通过对中国十大城市群城市旅游交通可达性、铁路交通流分布情况与旅游经济联系、总量和隶属度进行计算,借助Arcgis10.2对中国十大城市群交通空间流分布情况和旅游经济联系进行空间可视化处理,并对计算结果进行综合比较分析。研究发现:高铁使得中国十大城市群城市旅游交通可达性水平得到大幅提升,且交通流分布均衡。中国十大城市群城市可达性的提升给城市旅游经济带来了一定的积极影响。高铁网络下中国十大城市群旅游经济联系分布不均衡。 相似文献