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Two alternative methodological approaches (the IPFP-based and the intramax procedures) to the problem of pattern identification in spatial interaction data are compared and evaluated in this paper. After a general discussion of the major characteristics and shortcomings of these methodologies, the paper presents the findings of a case study relying on telecommunication data measured by the Austrian PTT in 1991, in terms of erlangs. The results clearly illustrate the superiority of the intramax approach in the context of medium-sized and relatively centralized flow systems.  相似文献   
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ABSTRACT. Löschian duopoly under heterogeneous cost conditions is examined to show that it is not equivalent, contra past findings, to spatial collusion. Moreover, within the confines of the assumed demand and cost conditions spatial collusion is shown to be superior to Loschian competition in terms of both (aggregate) consumer surplus and producer surplus, which implies a possible welfare gain from collusion. A general, if not the general, prices-and-welfare comparison of alternative pricing schema including collusive, Löschian, and optimal pricing is summarily presented in a table.  相似文献   
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T. Chen  B. Wang  H. Mai  H. Jiang 《Archaeometry》2020,62(4):847-862
The gut contents of ancient humans have been proven to be the most direct evidence for palaeodietary study. In the Xinjiang region of north-west China, large numbers of mummies are well preserved owing to the extremely dry environment to be found there. Fourier-transform infrared spectroscopy (FTIR) combined with multi-archaeobotanical methods, including macrofossil examination, starch grain analysis, phytolith analysis and bran fragments analysis, were applied to investigate the possible gut contents (c.1300 bp by 14C dating) of a person unearthed at tomb 75TAM601 in Astana Cemetery, which were the public graveyards of the ancient Gaochang people (residents of Turpan, dating from about the third to the ninth centuries ce ), in Turpan, Xinjiang. The result of the FTIR analysis showed that the matrix of the possible gut contents consisted of protein and starch and was characterized as undigested food residue. The white mineral fragments of this sample were from the decomposition products of the skeleton. The microfossil analysis demonstrated that Setaria italica, Panicum miliaceum and Triticum aestivum were the main cereal resources for the last meals eaten by the deceased. Moreover, direct macrofossil evidence also advocates for the importance of the three aforementioned cereal crops and fruits of Cucumis melo and Vitis vinifera in the person's diet.  相似文献   
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In addition to a series of chronological markers (artefacts, pottery) in the archaeological contexts of ancient Tayma (NW Saudi Arabia), optically stimulated luminescence (OSL) and radiocarbon dating techniques were applied to generate reliable ages for the city wall system of the oasis. A massive aeolian sand deposit burying the oldest part of the outer wall of Tayma was sampled to obtain a minimum age for the construction of this wall. The sequence of OSL ages from the inactive dune (ID) (4900 ± 300 a, 5100 ± 400 a, 4400 ± 300 a, 3900 ± 200 a, 4000 ± 200 a) is in full accordance with 14C-AMS ages of charcoal embedded into the same dune (4190–4420 cal BP, 3870–4080 cal BP). Underlying alluvial samples from the inactive gravel sheet (IGS) in contrast give maximum ages for the construction which scatter between 6600 ± 300 a and 4900 ± 400 a. The new dating sequence provides evidence that the oldest part of the ancient city wall system already existed in the 2nd half of the 3rd mill. BC which is earlier than expected thus far from archaeological and architectural interpretation.  相似文献   
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