排序方式: 共有42条查询结果,搜索用时 468 毫秒
1.
"This study compares the fertility patterns of foreign-born and native-born women in Canada and examines whether [the] same set of social characteristics accounts for differential fertility among both the groups. The study also assesses the importance of social characteristics and assimilation on immigrant fertility behavior. Two generations of currently married/cohabiting women with spouse present are analyzed using multiple regressions. The results reveal similar effects on fertility of social characteristics for foreign-born and native-born, while in the case of younger generations the effects are stronger." 相似文献
2.
A typology of migration is presented that extends the one originally developed by William Petersen, which was based on ecological push, migration policy, people's aspirations, and social momentum. The proposed typology considers both the migrant's state of mind and two points in time. Examples of 36 migrant types are provided using data for Canada and selected other countries. (SUMMARY IN FRE AND SPA) 相似文献
3.
Urban Ecosystems - Urban vegetation is an essential requirement in cities for mitigating pollution, heat island effects and providing food and shelter to urban fauna. Efforts to conserve and... 相似文献
4.
Interspecies scaling factors (ISFs) are numbers used to adjust the potency factor (for example, the q1* for carcinogens or reference doses for compounds eliciting other toxic endpoints) determined in experimental animals to account for expected differences in potency between test animals and people. ISFs have been developed for both cancer and non-cancer risk assessments in response to a common issue: toxicologists often determine adverse effects of chemicals in test animals and then they, or more commonly risk assessors and risk managers, have to draw inferences about what these observations mean for the human population. This perspective briefly reviews the development of ISFs and their applications in health risk assessments over the past 20 years, examining the impact of pharmacokinetic principles in altering current perceptions of the ISFs applied in these health risk assessments, and assessing future directions in applying both pharmacokinetic and pharmacodynamic principles for developing ISFs. 相似文献
5.
6.
We investigate pricing incentives for competing retailers who distribute two variants of a manufacturer's product in a decentralized supply chain. Under a two‐dimensional Hotelling model, we derive decentralized retailers' prices for the products, and distortions in pricing when compared to centrally optimal prices. We show that price distortions decrease as consumers' travel cost between retailers increases, due to less intense competition. However, price distortions do not change monotonically in consumers' switching cost between products within stores. To fix decentralized retailers' price distortions, we construct a two‐part pricing contract that coordinates the supply chain. We show that the coordinating contract is Pareto‐improving and analyze increase in the supply chain profit under coordination. 相似文献
7.
8.
Though various studies on spatial mobility are available, little is known about occupational mobility in Canada. This study is concerned with the estimation of Canadian occupational mobility from aggregate census data. The process of occupational mobility is characterized as a stationary Markov chain and certain meaningful conditions are imposed on the transition probabilities to convert the estimation strategy into a linear programming problem. Cross-section data for 1951 and 1961 are employed for estimation purposes. The study reveals that in 1951–61, the Canadian females had higher rates of mobility than the males. 相似文献
9.
Namboodirl NK 《Demography》1969,6(3):287-299
In this paper a method to investigate the dependence of age structure and growth rate on a given sequence of fertility and mortality schedules under the conditions of unchanging mortality and absence of migration is discussed. The method consists in projecting an arbitrary population classified by age to the ends of successive periods assuming that a given age pattern of mortality will remain without change and that a given sequence of fertility schedules will repeatedly operate on the population in a cyclical fashion. It is shown that after a sufficiently large number of repetitions of the cycle, the shifts in age structure between the ends of successive periods and the changes in the growth of the different age groups from one period to the next show a cyclical pattern. Formulas are derived expressing the above changes in terms of a sequence of k growth multipliers, k being the number of schedules in the fertility sequence, and the survival rates in the mortality schedule. A numerical illustration of the theory is given using fertility data from Finland. 相似文献
10.
Jonathan Whitaker Sunil Mithas M. S. Krishnan 《Production and Operations Management》2007,16(5):599-612
Radio Frequency Identification (RFID) technology promises to transform supply chain management. Building on previous research in information systems and supply chain management, this paper proposes a theoretical framework for RFID adoption and benefits, and tests the framework using data on u. s. firms. Our analysis suggests that there is a positive association between information technology (IT) application deployment and RFID adoption. We find that RFID implementation spending and partner mandate are associated with an expectation of early return on RFID investment, and a perceived lack of industry‐wide standards is associated with an expectation of delayed return on RFID investment. These results suggest that firms with broad IT application deployment and a critical mass of RFID implementation spending are more likely to report early returns from RFID deployments. This paper extends previous research to understand the relationship between organization characteristics and adoption and expected benefits of the emerging RFID technology. 相似文献