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We present general results for finding or boundingt maxB , the maximum number of arbitrary whole blocks of observations which can be removed from a block design, and still leave all of the elementary treatment contrasts estimable. The block sizes may be larger than the number of treatments. The results are applied to BBDs, reinforced BIBDs and BBDs, BTIBDs, and a series of variance balanced incomplete block designs with two block sizes. Also given for most of these designs, are results fort max, the maximum number of arbitrary, scattered observations that can become unavailable, and still leave all of the elementary treatment contrasts estimable.The work was undertaken while Dr. Whittinghill was visiting Ohio State University, and supported by a grant from the Natural Sciences Division, Colby College, Waterville, Maine.  相似文献   
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This study is concerned with one aspect of the family cycle, namely, the transition from young married to young married with small children. The focus is on developing models to forecast entries into this latter stage for the purpose of marketing research. "Using ordinary least squares, forecasting models were estimated for (1) total number of first births, (2) number of white first births, and (3) number of nonwhite first births." Models are estimated for both the United States and California using data from official sources.  相似文献   
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This paper was published in the wake of Pope John Paul II's encyclical 'Evangelicum Vitae', which condemns abortion and contraception. The author describes how, in the mid-1970's, the Vatican blocked the implementation of President Nixon's 'National Security Study Memorandum 200', which was intended to combat global overpopulation. The author explains that excessive population growth is considered threatening to U.S. security interests, and concludes that "papal security-survival along with the influence of fundamentalist Protestant opposition to birth control is now pitted against the U.S. and world security-survival."  相似文献   
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Methods for estimating the population contribution to environmental change.   总被引:1,自引:0,他引:1  
"This paper introduces general methods for quantitative analysis of the role of population in environmental change. The approach is applicable over a wide range of environmental issues, and arbitrary regions and time periods. First, a single region is considered, appropriate formulae derived, and the limitations to quantitative approaches discussed. The approach is contrasted to earlier formulations, and shown to avoid weaknesses in a common approximation. Next, the analysis is extended to the multiple region problem. An apparent paradox in aggregating regional estimates is illuminated, and the risk of misleading results is underscored. The methods are applied to the problem of climate change with two case studies, an historical period and a future scenario, used to illustrate the results. The contribution of change in population to change in green house gas emissions is shown to be significant, but not dominant in both industrialized and developing regions."  相似文献   
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