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71.
Modeling household fertility decisions with generalized Poisson regression   总被引:1,自引:1,他引:0  
This paper models household fertility decisions by using a generalized Poisson regression model. Since the fertility data used in the paper exhibit under-dispersion, the generalized Poisson regression model has statistical advantages over both standard Poisson and negative binomial regression models, and is suitable for analysis of count data that exhibit either over-dispersion or under-dispersion. The model is estimated by the method of maximum likelihood. Approximate tests for the dispersion and goodness-of-fit measures for comparing alternative models are discussed. Based on observations from the Panel Study of Income Dynamics of 1989 interviewing year, the empirical results support the fertility hypothesis of Becker and Lewis (1973). Received January 7, 1997 /Accepted April 3, 1997  相似文献   
72.
73.
The purpose of this study was to evaluate one phase of a statewide program of deinstitutionalizing developmentally disabled individuals. Forty adults who had spent a minimum of six months in community placements were evaluated with respect to changes in behavior associated with movement out of state institutions and into community settings such as group homes and day activity centers. Pre- and post-deinstitutionalization measures were taken with the Behavior Development Survey. Post-deinstitutionalization measures on Cataldo and Risley's Resident Activity Manifest were compared to the same measures obtained on 159 developmentally disabled individuals scheduled for deinstitutionalization. A consistent pattern of positive changes on both instruments favored deinstitutionalization, but changes could not be unequivocally attributed to movement out of the institutions per se.  相似文献   
74.
本文建立了用于煤炭资源资产分类的ARTⅡ神经网络模型,编制了相应的计算机和软件,并将ARTⅡ模型与模糊分类模型和基于BP网络的分类模型进行了对比分析,实例运行结果表明,用ARTⅡ网络进行分类具有分类稳定、结果可靠等特点。  相似文献   
75.
The Evolution of Knowledge and the Dynamics of an Industry Network   总被引:1,自引:0,他引:1  
The paper moves a step forward in the direction of establishing a connection between the structure and evolution of knowledge bases and the structure and evolution of organizational forms in innovative activities in a science-intensive industry. The paper has an explicit focus on the dynamics of the network of collaborative agreements in R&D in the pharma/biotech industry after the “molecular biology revolution”. Using a comprehensive dataset, built by the authors integrating several sources in the industry, the dynamics of the network over time is extensively analyzed. With regards to network structure, it is found that, while the size of the network increases over time due to net flows of entry, its topological properties remain relatively unchanged. The evolution of the network has occurred without relevant deformations in the core-periphery profile. With regards to age-dependent propensity to collaborate, the paper finds that the extent of inter-generational collaboration is much more significant than intra-generational collaboration. In addition, the propensity of firms of a given generation to enter into collaboration with firms of a different generation increases with the distance between the two, while the total number of intra-generational collaborations decreases over time and, moreover, tends to decrease for most recent generations. In the paper a unitary and coherent explanation of the evidence is developed, coming to reveal the existence of a striking isomorphism between structural properties of the dynamics of knowledge and of the evolution of network structure. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
76.
The purpose of ISO 9001:2000 Quality Management System (QMS) is to provide businesses with a model to grow systematically while assuring the quality of their products. The validity of ISO 9001:2000 QMS stems, largely, from the fact that the best minds worldwide have contributed to its development and maintenance, and the fact that many companies have reported real business gains because of its implementation. Unfortunately, many small businesses fail to survive due to the absence or lack of adequate system for managing quality. An obvious recommendation would be to implement ISO 9001:2000 QMS. Nevertheless, small businesses often cite lack of resources and time as the main reasons for not implementing ISO 9001:2000 QMS.  相似文献   
77.
区域产品分类与选择是区域经济发展中最重要和最基础的工作.在产品选择与分类时,需要确定指标权系数和分类阈值等参数,这在实际应用中是比较困难的.针对这种情况,提出了一种信息不完全确定的区域产品模糊区间聚类方法.该方法构建了指标权系数信息不完全确定的最优模糊区间聚类模型,利用遗传算法和改进的FCM算法联合求解所得优化模型,得到指标权系数、最优聚类中心和最优划分,进而确定各产品所属类别.最后将该方法应用于某区域的产品分类和主导产品的确定中,实例计算说明该方法的可行性和有效性.  相似文献   
78.
The accelerating pace of change in science and technology has resulted in new attention to the process of identifying and developing ideas that ultimately lead to new scientific capabilities and business opportunities for an organization. The need to refresh research programs and capabilities is as important in federally funded research institutions as it is for industry. This paper explores the critical success factors for new initiatives at a federal laboratory, and building on lessons learned through this study and in private industry, identifies a more systematic process that could potentially improve the effectiveness of these initiatives in achieving results.  相似文献   
79.
债券增信能帮助企业以更好的条件发行债券,因而对企业的创新能力产生影响。通过对2007-2015年上市债券的研究发现:债券增信能够显著提升企业创新能力,但不同的增信方式(第三方保证、抵押和质押)其影响存在差异,其中,以采用抵押担保的增信方式效果为最佳;并且,债券增信对企业创新的提升效果在融资约束企业更为明显,从另一侧面证明了融资约束对企业创新的负面影响。  相似文献   
80.
弹性资本充足率监管加刚性杠杆率监管存在机理性缺陷。弹性资本充足率监管会影响刚性杠杆率监管的效果,刚性杠杆率监管也不能体现杠杆累积在时间维度和空间维度风险的变化。若引入弹性杠杆率缓冲,刚性杠杆率监管加弹性资本充足率监管的机理性缺陷就可以避免。因此,有必要实施弹性杠杆率监管,杠杆率的弹性化程度与银行的系统重要性程度相对应。  相似文献   
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