排序方式: 共有46条查询结果,搜索用时 31 毫秒
41.
Marc L. Miller 《Coastal management》2013,41(4):309-318
Abstract Natural resource management entities such as the Regional Fishery Management Councils established by the Magnuson Fishery Conservation and Management Act of 1976 depend heavily on science to inform policymakers and to legitimate the policy process. This paper discusses the importance of fishery science to the council system, contrasts the functions of Scientific and Statistical Committees (SSCs) serving the Pacific Fishery Management Council and the New England Fishery Management Council, and remarks on the implications of differences in the display of scientific authority by these SSCs. 相似文献
42.
Marc J.I. Gaudry 《Transportation Research Part B: Methodological》1981,15(2):97-103
This paper explores the properties of inverse Box-Cox and Box-Tukey transformations applied to the exponential functions of logit and dogit mode choice models. It is suggested that inverse power transformations allow for the introduction of modeler ignorance in the models and solve the “thin equal tails” problem of the logit model; it is also shown that they allow for asymmetry of response functions in both logit and dogit models by introducing alternative-specific parameters which make cross elasticities of demand among alternatives generally asymmetric. In the dogit model, modeler ignorance and consumer captivity remain conceptually distinct. Standard logit and dogit models appear as very special “perfect knowledge” cases in broad spectra of models which also include, among others, the reciprocal extreme value or log-Weibull variants. These improvements over the simple symmetric-thin-equal-tail-perfect-knowledge logit and the symmetric-pure-captivity dogit are achieved at the cost of introducing at the most two new parameters per alternative considered in the original logit and dogit mode choice models. 相似文献
43.
Marc J.I. Gaundry Marcel G. Dagenais 《Transportation Research Part B: Methodological》1979,13(2):105-111
This paper presents the dogit model. That model is flexible enough to permit the choice among specific pairs of alternatives to be consistent with the independence from irrelevant alternatives axiom, as in a logit model, but it simultaneously allows the choice among other pairs not to be. Dogit parameters add an “income effect” to the “substitution effect” already built into the logit model; alternatively, they allow for the joint presence of compulsive and discretionary elements in consumer behavior, or for the identification of captive markets. Eventual estimation of the values of the parameters of the dogit model appears simpler than for the probit model. 相似文献
44.
打开任何一份报纸的经济版你会发现越来越多有关汽车行业现状的坏消息。就在笔者撰写此文之时.我们刚看到Dana档案的第11章.捷豹放弃了统一平台的计划.同时大众的CEO Bemd Pischetsrieder正忙于应对工会扬言要罢工的状况。 相似文献
45.
We construct a first country-wide model of demand for road use and of road safety outcomes for Algeria making use of the DRAG-type framework and of flexible regression estimation methods that make a demonstrable difference to the quality of our results. We imply that the availability of high quality Algerian data could make it worthwhile not only to consider updates of the model with longer data series but also to study variants of the model, notably with disaggregation of freight activities across industrial sectors. 相似文献
46.
Michael Florian Marc Gaudry Christian Lardinois 《Transportation Research Part B: Methodological》1988,22(6)
This article puts forward the view that, for each transportation planning or management problem, there is a particular way to simultaneously define the multiple levels of procedures useful for the problem and set it in its proper perspective, the latter essentially by the identification of what is exogenous and endogenous to the problem at hand. The joint determination of these levels and of the exogenous/endogenous mix defines the two-dimensional frame of each problem. To develop our view, we extend our previous conceptual framework to include, in the first dimension, an activity location procedure, and to distinguish, in the second dimension, between operational, tactical, and strategic perspectives. We conclude by relativising the use of solution techniques by making them ancillary to the situation planning requirements. 相似文献