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本文对“楚帛书”(包含第二帛书和残帛书)上有关月名与历法问题的文字和图像进行了基础性研究,认为子弹库楚帛书群中可以看到边文月、十三行月和楚月名三种月名,并尝试就其对应关系与历法作了再验证。我们还以五行说为指标,通过对“日书”以及“卜筮祭祷简”进行比较,指出楚帛书群的年代可能接近九店楚简“日书”。同时就子弹库楚帛书群的史料性质以及定位及今后的课题研究简单地作了展望。 相似文献
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MAXIMUM LIKELIHOOD ESTIMATION OF GRAVITY MODEL PARAMETERS 总被引:2,自引:0,他引:2
Ashish Sen 《Journal of regional science》1986,26(3):461-474
ABSTRACT. It is shown that, under some very mild conditions, maximum likelihood estimates of gravity model parameters exist and are unique (up to a scale transformation for some parameters). An algorithm for finding such estimates is also proposed. 相似文献
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Ashish K. Sen 《Geographical analysis》1976,8(1):23-37
This paper considers contiguity preserving map transformations (or cartograms) that have a preassigned arcal scale. Because for each such scale it is possible to construct infinitely many transformations, this paper investigates restrictions under which such cartograms are possible. It is shown that it is possible to construct transformations that preserve the location of boundaries and of any finite number of predefined points. However, these cartograms are often quite distorted. Different types of distortions and suitable measures are discussed. 相似文献