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101.
James Mahoney Celso M.Villegas 《浙江社会科学》2008,30(3):12-19
本文讨论了比较政治学中历史研究的主要分析方法.第一类是因果分析法,包括横截面分析法和样本内分析法.第二类是时序分析法,包括对路径依赖和发展顺序的分析.本文认为,历史分析与众不同的分析方法使它成为比较政治研究中有力的分析工具. 相似文献
102.
Certain motor vehicle safety standards stipulate a collision test speed and a set of performance criteria that vehicles must satisfy during or after the collision test. For example, Federal Motor Vehicle Safety Standard 301 requires a 30 mile per hour (mph) barrier collision and specifies a certain maximum allowable limit on the total spillage of fuel. Vehicle designs are required to meet this standard; however, when collision tests are conducted at speeds higher than the standard, vehicles do not always satisfy the performance criteria. This paper develops a mathematical model for estimating the probability of meeting the standard by using a Bayesian framework to incorporate engineering judgment with collision test results. The model is based on the idea that there are random features to a vehicle's ability to meet performance standards in a collision, especially at such elevated speeds. Example calculations are included to illustrate the estimation of the probability of meeting the standard and to compare it with a maximum likelihood approach. 相似文献
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105.
Infants often protest the activities of their caregivers, and this particular social interaction may provide an important window on early communication and its development. This study used naturalistic methods to investigate the development of vocal protests. Fifteen mother‐infant dyads at each of 5 ages, from 3 to 18 months, were observed at home. Maternal behaviors of caregiving and prohibiting were tallied from videotapes, as were infants' protests of these behaviors. Maternal caregiving decreased with age, but maternal prohibitions increased. There were no changes over age in the probability of protesting maternal caregiving behavior; however, 12‐month‐olds were more likely to protest prohibitions than 6‐ or 8‐month‐olds. Older infants were also more likely to use intense protests, such as screams, than younger infants. These age‐related changes were mirrored by the differences in prohibitions and protests observed between 8‐month‐olds who could crawl and those who could not. Findings from this study were related to previous research on infant crying as an important part of the prelinguistic communication system. 相似文献
106.
Infants' Processing of Featural and Configural Information in the Upper and Lower Halves of the Face
Three‐ to 4‐month‐old and 6‐ to 7‐month‐old infants were administered an infant version of the Face Dimensions Test that has been used with adults (e.g., Bukach, Le Grand, Kaiser, Bub, & Tanaka, 2008). Infants were familiarized with a photograph of a woman's face and then tested with the familiar face paired with a face differing in the (a) distance separating the eyes (a configural/eyes change), (b) distance between the nose and mouth (configural/mouth change), (c) size of the eyes (featural/eyes change), and (d) size of the mouth (featural/mouth change). Infants were shown to be more sensitive to (a) configural than featural change, and (b) change around the eyes versus the mouth. Implications for the development of face processing are discussed. 相似文献
107.
The rise in human life expectancy has involved declines in intrinsic and extrinsic mortality processes associated, respectively, with senescence and environmental challenges. To better understand the factors driving this rise, we apply a two-process vitality model to data from the Human Mortality Database. Model parameters yield intrinsic and extrinsic cumulative survival curves from which we derive intrinsic and extrinsic expected life spans (ELS). Intrinsic ELS, a measure of longevity acted on by intrinsic, physiological factors, changed slowly over two centuries and then entered a second phase of increasing longevity ostensibly brought on by improvements in old-age death reduction technologies and cumulative health behaviors throughout life. The model partitions the majority of the increase in life expectancy before 1950 to increasing extrinsic ELS driven by reductions in environmental, event-based health challenges in both childhood and adulthood. In the post-1950 era, the extrinsic ELS of females appears to be converging to the intrinsic ELS, whereas the extrinsic ELS of males is approximately 20 years lower than the intrinsic ELS. 相似文献
108.
An integer linear programming model is presented for the scheduling of n products on m identical machines. The particular problem studied is one that occurs frequently in the fiberglass and textile industries. The model incorporates setup costs, lost production costs, and overtime costs. Due to the structure of the model, integer solutions can be obtained by explicitly restricting only a small number of the integer variables. This allows those responsible for scheduling to solve realistically sized problems in an efficient manner. Computational results are provided for a set of generated test problems. 相似文献
109.
Diversification gains in mean-variance efficiency derived from including real estate in financial asset portfolios are examined. Optimal financial and mixed-asset portfolios were generated by selecting from an investment universe including several distinct financial and real estate media. Deficiencies of previous studies were overcome by employing data with improved representativeness and comparability. The efficient mixed-asset portfolios dominated the efficient financial asset portfolios implying that purely financial asset diversification is inefficient. The optimal mixed-asset portfolio prescribed that approximately two-thirds of the investment wealth be allocated to real estate and one-third to the financial media. 相似文献
110.
Sabine S. Nooten Patrick Schultheiss Jules Wright Catriona Macdonald Brajesh K. Singh James M. Cook Sally A. Power 《Urban Ecosystems》2018,21(3):565-576
Recent concern over increasing loss of biodiversity has prompted considerable interest in the role of urban green spaces as reservoirs of local biodiversity. This study assessed the diversity of three indicator taxa - plants, ants and birds - on golf courses spanning a wide range of environmental variation in terms of climate, elevation, course age, size and connectivity to native woodland. Species richness and community composition was further compared between contrasting on-course habitat types that reflect different management intensities. We identified a set of taxon-specific environmental correlates indicating an intricate interplay of landscape- and local-scale variables that affect local species diversity. Our results show that floristic diversity is positively associated with the amount of rainfall, whereas ant and bird diversity are related to local-scale factors, particularly the number of trees and the size of water features on a site. The amount of on-course native habitat was a strong predictor of plant and ant diversity and was also associated with the number of unique species at the site level; this reinforces the value of remnant habitat patches as local biodiversity reservoirs that represent mini hot-spots in an otherwise species-poor urban landscape. Community composition for all three taxa differed markedly between non-playing and playing areas, with boundary and remnant habitats generally having more diverse, species-rich communities. Our results suggest that local floral and faunal biodiversity on urban golf courses can be enhanced by creating woody non-playing areas and, especially, by preserving, restoring or expanding remnant habitats. 相似文献