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71.
本文基于西方经济学的局部均衡分析范式探讨由于电子商务降低产品边际成本,最终会对市场结构和社会物价水平造成的影响。得出了电子商务的普及有提高社会总产出和福利水平的作用的结论。 相似文献
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Zhao Dongfeng 《电子科学学刊(英文版)》1999,16(1):44-50
In this paper, the analyzing approaches proposed by Zhao Dongfeng, et al.(1997) have been extensively studied. The average cyclic times of the slotted multiple access systems are analyzed by using the average cycle method. Analytic formulae for mean values of a successful period and a colliding period and an idle period are derived. The upper bounds of the system throughput with capture effect and collision resolution are provided. Finally, the simulation results of the slotted multiple access channels are given. 相似文献
75.
在人们普遍给予全球移动通信系统高技术高效益评价的同时,其高投入高成本所带来的高负险也是不容忽视的。根据市场竞争的观点它同样面临着行为内和行业外多种力量的竞争。特别是近年来地面无线通信的迅速发展对该产业的怅惘敢巨大冲击。 相似文献
76.
中国移动电话市场发展迅速,目前用户总数已位居世界第三。近期的市场调查表明,移动电话市场中呈现出品牌意识强,中低档手机市场大,购机者关心因素多,个人购机比例高等现象。另外,中文手机仍然占主体,黑色手机备受用户青睐。 相似文献
77.
A market is considered where trading can take place only at discrete time points, the trading frequency cannot grow without bound, and the number of states of nature is finite. The main objectives of the paper are to show that the market can be completed also with highly correlated risky assets, and to describe an efficient algorithm to compute a self-financing hedging strategy. The algorithm consists off-line of a backwards recursion and on-line of the solution, in each period, of a system of linear equations; it is a consequence of a proof where, using a well-known mathematical property, it is shown that uniqueness of the martingale measure implies completeness also in our setting. The significance of ‘multistate’ models versus the familiar binomial model is discussed and it is shown how the evolution of prices of the (correlated) risky assets can be chosen so that a given probability measure is already the unique equivalent martingale measure. 相似文献
78.
The segmentation of customers on multiple bases is a pervasive problem in marketing research. For example, segmentation service providers partition customers using a variety of demographic and psychographic characteristics, as well as an array of consumption attributes such as brand loyalty, switching behavior, and product/service satisfaction. Unfortunately, the partitions obtained from multiple bases are often not in good agreement with one another, making effective segmentation a difficult managerial task. Therefore, the construction of segments using multiple independent bases often results in a need to establish a partition that represents an amalgamation or consensus of the individual partitions. In this paper, we compare three methods for finding a consensus partition. The first two methods are deterministic, do not use a statistical model in the development of the consensus partition, and are representative of methods used in commercial settings, whereas the third method is based on finite mixture modeling. In a large-scale simulation experiment the finite mixture model yielded better average recovery of holdout (validation) partitions than its non-model-based competitors. This result calls for important changes in the current practice of segmentation service providers that group customers for a variety of managerial goals related to the design and marketing of products and services. 相似文献
79.
宽带IP城域网及其应用 总被引:1,自引:0,他引:1
文章结合南京电信公众宽带IP城域网的建设,对宽带IP城域网的网络结构、用户接入安全、网络管理和认证计费作了阐述,并简要介绍了应用于宽带IP城域网上的一些业务。 相似文献
80.
This study sets out to examine whether the demand for softwood lumber in the United States is responsive to various market factors including the price of softwood lumber, the price of other building materials, and the level of economic activity (e.g. housing starts). Concern in the analysis is focused on overcoming some of the methodological shortcomings found in previous studies of this issue. The results are conclusive. The quantity of softwood lumber demanded does respond to the various economic factors considered. Moreover, when the structural stability of the estimated relationships is investigated, the results suggest that the demand for softwood lumber regionally in the United States has remained unaltered over the sample period (1950–1985). 相似文献