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长三角地区在全国房地产"库存"的背景下,实现了房地产市场的不断向好.对长三角地区有关面板数据进行实证研究,实证结果表明房地产开发投资、医院床位数、工业生产总值与人均房地产成交面积呈正相关.城镇人口数,中、长期贷款利率与人均房地产成交面积呈负相关,高收入城市比低收入城市人均房地产成交面积低14.%,教育支出和城镇居民总的可支配收入对人均房地产成交面积影响不显著. 相似文献
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We formulate a sufficient condition for the existence of a consistent price system (CPS), which is weaker than the conditional full support condition (CFS). We use the new condition to show the existence of CPSs for certain processes that fail to have the CFS property. In particular this condition gives sufficient conditions, under which a continuous function of a process with CFS admits a CPS, while the CFS property might be lost. 相似文献
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The present work is intended as a first step towards applying semidefinite programming models and tools to discrete lot-sizing problems including sequence-dependent changeover costs and times. Such problems can be formulated as quadratically constrained quadratic binary programs. We investigate several semidefinite relaxations by combining known reformulation techniques recently proposed for generic quadratic binary problems with problem-specific strengthening procedures developed for lot-sizing problems. Our computational results show that the semidefinite relaxations consistently provide lower bounds of significantly improved quality as compared with those provided by the best previously published linear relaxations. In particular, the gap between the semidefinite relaxation and the optimal integer solution value can be closed for a significant proportion of the small-size instances, thus avoiding to resort to a tree search procedure. The reported computation times are significant. However improvements in SDP technology can still be expected in the future, making SDP based approaches to discrete lot-sizing more competitive. 相似文献
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This paper concerns optimal investment problem with proportional transaction costs and finite time horizon based on exponential
utility function. Using a partial differential equation approach, we reveal that the problem is equivalent to a parabolic
double obstacle problem involving two free boundaries that correspond to the optimal buying and selling policies. Numerical
examples are obtained by the binomial method. 相似文献
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When an organization decides on which groups of consumers it should target, the locations of these target consumers often play a role. Methods from the field of market segmentation are able to identify target groups with high benefit levels, but the expected costs of supplying products to the target groups are less well understood. These costs can play a large role if the locations of the customers, the demand locations, are geographically widely dispersed. This paper focuses on one-to-many distribution systems in which a central facility serves all demand points. We derive accurate logistics cost estimates from the dispersion of demand points for such systems, enabling a comparison of the expected logistics costs of different candidate target groups. The most accurate measure combines the average distance from the demand locations to a central location and the mutual distances between neighboring demand locations. The average of the distances between all pairs of locations forms a good alternative measure. 相似文献
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毛二万 《高校应用数学学报(英文版)》1999,14(4)
To some two-period economies with countable infinite state spaces,the existence of expectation equilibrium of real asset economies with transaction costs is given. This work extends the researches of Zame in 1993. 相似文献
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