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941.
942.
Martin MA 《Demography》2006,43(3):421-445
Using 24 years of data from the March supplements to the Current Population Survey and detailed categories of family structure, including cohabiting unions, I assess the contribution of changes in family structure to the dramatic rise in family income inequality. Between 1976 and 2000, family structure shifts explain 41% of the increase in inequality, but the influence of family structure change is not uniform within this period or across racial-ethnic groups. In general, the estimated role of family structure change is inversely related to the magnitude of the changes in inequality. Furthermore, by including cohabitation, I find lower levels of total inequality and a weaker role for demographic shifts in family structure for trends in income inequality. 相似文献
943.
Graham S Gill A Lamers D 《Women and birth : journal of the Australian College of Midwives》2006,19(1):23-28
A very small proportion of newborns fail to establish a normal respiratory pattern without some assistance at birth and newborns requiring resuscitative measures at birth should have a skilled practitioner able to provide it. In this small hospital midwives felt unskilled in newborn resuscitation and paediatricians were not always immediately available. A stakeholder group gathered to discuss the problem. A training program was implemented that improved the skills, confidence and support of the attending midwife to resuscitate the newborn effectively. The aim was to improve the outcome for the infant whilst maintaining the mother's choice of birthing in a small local hospital close to family and friends. 相似文献
944.
945.
Much of the current knowledge pertaining to information technology (IT) and decision making is based on decades old technologies that revolved around a central computing function and application-specific systems. The purpose of this research is to examine the IT decision-making relationship within the emerging organizational computing (OC) environment permeated by spontaneous utilization of both application-and nonapplication-specific computing and communication technologies. Specifically, this study seeks to explore managers' perceptions of the emerging OC environment as a facilitator of their decision-making activities. To achieve a higher level of clarity than previous works, a two-dimensional research framework is developed with the IT dimension consisting of computing and communication, and the decision-making dimension differentiated between operational and managerial decisions. A survey instrument was constructed that measured the computing and communication dimensions of information technology use and their perceived effects upon operational and managerial decisions. The major findings of the study confirmed that managers recognize the value of general, nonapplication-specific information technologies in decision making, and that this recognition is highly associated with how intensively these information technologies are used. Additionally, it was found that the two dimensions of IT differ in their relationships to decision making, and that IT usage relates to managerial decisions differently than operational decisions. These study findings have significant implication for practice and research, especially in the context of information resource management in which the primary purpose of the IS function is the delivery of general information service to users rather than the development of specific IS applications. 相似文献
946.
Lawrence A. Bennigson 《Production and Operations Management》1996,5(1):91-102
This paper demonstrates an approach to successfully managing change of manufacturing strategy. It first introduces the issues and management guidelines, and then describes how one company used this approach to achieve dramatic benefits from changing its manufacturing strategy. A third part of the paper elaborates on how the company made the approach work. 相似文献
947.
Michael L. Gargas Robin L. Norton Mark A. Harris Dennis J. Paustenbach Brent L. Finley 《Risk analysis》1994,14(6):1019-1024
Biomonitoring programs for urinary chromium (Cr) typically attempt to evaluate occupational exposure via the inhalation route. This study investigated whether Cr can be detected in the urine of people following the ingestion of soils that contain relatively high concentrations of chromium in chromite ore processing residue (COPR). To evaluate the reasonableness of using urinary monitoring to assess environmental exposure, six volunteers ingested 400 mg of soil/day (low-dose group), two others ingested 2.0 g of soil/day (high-dose group) for 3 consecutive days, and one person ingested a placebo on each of 3 days. The soil and COPR mixture contained concentrations of total chromium (Cr) and hexavalent chromium [Cr(VI)] of 103 ± 20 and 9.3 ± 3.8 mg/kg, respectively. Therefore, the low-dose group ingested 41 μg Cr/day [including 3.7 μg Cr(VI)] and the high-dose group ingested 206 μg Cr/day [including 18.6 μg Cr(VI)] on each of 3 consecutive days. All urine samples were collected and analyzed individually for total Cr on the day prior to dosing, during the 3 days of dosing, and up to the first void 48 h after the last dose. No significant increases in urinary Cr excretion were found when background excretion data were compared with data following each of the 3 days of dosing or in daily mean urine concentrations of the high- vs the low-dose groups. It appears that Cr present in a soil and COPR mixture at Cr doses up to 200 μg/day is not sufficiently bioavailable for biomonitoring of urine to be informative. These results are consistent with previously published findings suggesting that incidental exposure to dusts and soils containing comparable levels of Cr will not result in increased concentrations of Cr in urine. 相似文献
948.
We use genetic algorithms (GA) to solve the assembly line balancing (ALB) problem. Inparticular, we show how this technique can be used to generate feasible line balances, improve upon solutions obtained by other heuristics reported in the literature, and utilizeany one or more evaluation criteria that can be expressed in functional form. The procedure is demonstrated with two examples: (1) intimating the improvement of heuristic-generated ALB solutions by including them in the GA initial population, and (2) the possibility of balancing assembly lines with multiple criteria and side constraints. These examples suggest that GA can be a powerful tool in ALB. To investigate the utility of GA on single-criterion problems, an experiment is conducted that compares both the GA approach and conventional heuristics. Results indicate that the GA solutions are significantly improved over the heuristic solutions under the conditions studied. It is also found that the presence of heuristic-generated conventional solutions in the GA initial population leads to statistically preferred results. 相似文献
949.
The preceding critique [1] of the paper “The Information Problems in Organizations: A Research Model for the Value of Information and Information Systems” [3], reaches general conclusions with respect to the original paper and the applicability of economics to MIS research. These conclusions are based on arguments developed at a different level of analysis than that used in the original paper, and without considering the goals and intent of the original paper. The differences between the critique and the original paper are highlighted. 相似文献
950.
An important issue in planning capacity expansion under uncertain demand is the effect of lead time on the timing of plant construction. Our model helps decide whether (1) plant construction is initiated after a certain deficit is accumulated, or (2) plant construction is initiated ahead of demand when a certain capacity surplus is reached. In addition to our analytical results, we present computational results to show that it is economically attractive to delay plant construction beyond the time when existing excess capacity becomes fully absorbed, with relatively short construction lead time. 相似文献