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81.
82.
Cochran N 《Evaluation and program planning》1979,2(1):1-4
Characteristics of the population and economic measures that constitute traditional social indicators are compared with more recent “quality of life” measures to demonstrate that social indicators are always value statements at the policy level. The possibility of alternative perspectives is illustrated. It is suggested that an awareness of the assumptions implicit in any given indicator is as important as the data they provide. 相似文献
83.
Ronald N. Taylor 《决策科学》1975,6(3):409-429
In this paper the implications of cognitive strain for decision-making effectiveness are explored. Literature concerning the psychological processes of decisionmakers which underlie the operation of cognitive strain and which predispose them to the effects of cognitive strain, is reviewed. Next, the impact of cognitive strain on narrowly constraining or “bounding” rational decision-making is examined, and the choice strategies of satisficing and incrementalizing are criticized as failing to broaden the bounds of rational decision-making. Finally, elements of an eclectic choice strategy designed to assist decision-makers handle the informational demands of complex decision problems are discussed. 相似文献
84.
以TEECE创建的技术创新资源获取机制理论框架为研究起点,进行了开放式创新背景下的拓展。根据其对技术资源与商业化资源的划分,运用"占有机制"与"合约交易"2个关键变量,分别揭示在封闭式创新模式向开放式创新模式转变过程中,创新资源获取机制本质由创新资源控制权拓展为创新资源联合共享,具体表现为2个方面:一是技术资源占有机制由正式制度拓展为正式制度与非正式制度的集合,从而其作用机理从环境决定的外生变量,拓展为企业内生性的战略选择;二是商业化资源交易契约从合约交易拓展为合约交易与嵌入式交易。 相似文献
85.
The authors examine the literature with respect to the pricing of initial public offerings and focus upon the relationship
of pricing to the structure and conduct of the investment banking industry. Using a data base of all share offerings undertaken
in the United States over a two and a half year period, the authors find that there is considerable evidence for the proposition
that large, prestigious, and well capitalised investment banks tend to price their share offerings at a higher absolute level
than those not meeting such characteristics. Using classical statistical methods, the authors find that the pricing strategy
of investment banks is connected to their affiliation with investment funds and unit trusts. The motives for such pricing
strategies, the authors argue, lie with the affiliation of investment banks with investment funds, suggesting that the pricing
of new share offerings may be a means of excluding retail investors from participating in the strong returns such issues exhibit. The authors raise legal and regulatory implications
of their findings in the context of the general consolidation observed within the investment banking industry.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
86.
Designing and integrating composite networks for monitoring multivariate gaussian pollution fields 总被引:2,自引:0,他引:2
J. V. Zidek W. Sun & N. D. Le 《Journal of the Royal Statistical Society. Series C, Applied statistics》2000,49(1):63-79
Networks of ambient monitoring stations are used to monitor environmental pollution fields such as those for acid rain and air pollution. Such stations provide regular measurements of pollutant concentrations. The networks are established for a variety of purposes at various times so often several stations measuring different subsets of pollutant concentrations can be found in compact geographical regions. The problem of statistically combining these disparate information sources into a single 'network' then arises. Capitalizing on the efficiencies so achieved can then lead to the secondary problem of extending this network. The subject of this paper is a set of 31 air pollution monitoring stations in southern Ontario. Each of these regularly measures a particular subset of ionic sulphate, sulphite, nitrite and ozone. However, this subset varies from station to station. For example only two stations measure all four. Some measure just one. We describe a Bayesian framework for integrating the measurements of these stations to yield a spatial predictive distribution for unmonitored sites and unmeasured concentrations at existing stations. Furthermore we show how this network can be extended by using an entropy maximization criterion. The methods assume that the multivariate response field being measured has a joint Gaussian distribution conditional on its mean and covariance function. A conjugate prior is used for these parameters, some of its hyperparameters being fitted empirically. 相似文献
87.
Factors influencing Soay sheep survival 总被引:4,自引:0,他引:4
E. A. Catchpole B. J. T. Morgan T. N. Coulson S. N. Freeman & S. D. Albon 《Journal of the Royal Statistical Society. Series C, Applied statistics》2000,49(4):453-472
We present a survival analysis of Soay sheep mark recapture and recovery data. Unlike previous conditional analyses, it is not necessary to assume equality of recovery and recapture probabilities; instead these are estimated by maximum likelihood. Male and female sheep are treated separately, with the higher numbers and survival probabilities of the females resulting in a more complex model than that used for the males. In both cases, however, age and time aspects need to be included and there is a strong indication of a reduction in survival for sheep aged 7 years or more. Time variation in survival is related to the size of the population and selected weather variables, by using logistic regression. The size of the population significantly affects the survival probabilities of male and female lambs, and of female sheep aged 7 or more years. March rainfall and a measure of the North Atlantic oscillation are found to influence survival significantly for all age groups considered, for both males and females. Either of these weather variables can be used in a model. Several phenotypic and genotypic individual covariates are also fitted. The only covariate which is found to influence survival significantly is the type of horn of first-year female sheep. There is a substantial variation in the recovery probabilities over time, reflecting in part the increased effort when a population crash was expected. The goodness of fit of the model is checked by using graphical procedures. 相似文献
88.
Binary probability maps using a hidden conditional autoregressive Gaussian process with an application to Finnish common toad data 总被引:3,自引:0,他引:3
I. S. Weir & A. N. Pettitt 《Journal of the Royal Statistical Society. Series C, Applied statistics》2000,49(4):473-484
The Finnish common toad data of Heikkinen and Hogmander are reanalysed using an alternative fully Bayesian model that does not require a pseudolikelihood approximation and an alternative prior distribution for the true presence or absence status of toads in each 10 km×10 km square. Markov chain Monte Carlo methods are used to obtain posterior probability estimates of the square-specific presences of the common toad and these are presented as a map. The results are different from those of Heikkinen and Hogmander and we offer an explanation in terms of the prior used for square-specific presence of the toads. We suggest that our approach is more faithful to the data and avoids unnecessary confounding of effects. We demonstrate how to extend our model efficiently with square-specific covariates and illustrate this by introducing deterministic spatial changes. 相似文献
89.
Charles N Halaby 《Social science research》1980,9(1):1-36
The two most marked trends in recent stratification studies are: (1) the shift away from a statical approach to attainment and toward a dynamical representation of achievement, and (2) the shift away from the assumption that achievement is largely a matter of individual characteristics, and toward the view that achievement is the outcome of an employer-employee exchange of productive resources for earnings and status. This paper forges a link between these parallel trends by elaborating on previous formulations of dynamic models of achievement and applying the results to the analysis of earnings attainment in an internal labor market. The modeling section of the paper joins within a single framework the growing interest in ascertaining how a given structure of opportunity shapes achievement and in determining the different points in the career line at which individual background and resource variables impact attainment. Special attention is devoted to the problems facing researchers who wish to bring a dynamic conceptualization of achievement to cross-sectional or otherwise deficient data. Although the empirical application of the various models is largely meant to be illustrative, it is of interest in its own right because it goes substantially beyond previous efforts in this area. 相似文献
90.
J. N. Ayertey 《Researches on Population Ecology》1980,22(1):101-116
Summary This paper describes a series of experiments conducted to determine whySitophilus zeamais
Mots. andSitotroga cerealella (Oliv.) could not survive together in maize cultures in the laboratory. The effect ofS. zeamais on different developmental stages ofS. cerealella was investigated. The presence of adultS. zeamais slightly affected moth copulation, egg laying and moth eggs in a mixed culture, but large numbers of developing moths inside
maize grains were killed by the adult weevil through feeding on the grains. The major cause of elimination ofS. cerealella byS. zeamais from mixed cultures was therefore found to be damage to the immature moths in grain and such moth mortality increased as
the developing moths became bigger in the grains. A weevil: grain ratio of approximately 1.4∶1 was found to be the critical
weevil density at which the moth disappeared from the mixed cultures. 相似文献