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排序方式: 共有990条查询结果,搜索用时 15 毫秒
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移动通信发展迅速,移动用户数逐年上升,伴随各种各样的业务与服务,互联网上的管理与维护相对出现一些问题,本文就相关问题进行讨论。 相似文献
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Risako Morimoto Author vitae 《Socio》2010,44(4):247-257
An innovative sensor system, designated ‘Smart Infrastructure,’ is being developed jointly by Cambridge University in the United Kingdom and Massachusetts Institute of Technology in the United States. This system provides real-time wireless information about the state of critical infrastructure. The Smart Infrastructure sensors are designed to monitor infrastructure, such as water pipelines, as well as to increase their capabilities for purposes of efficient maintenance. This paper presents a forecasting model that assesses the possible impacts of Smart Infrastructure technology currently being applied to the British water pipe market. In doing so, we identify key benefits of proactively managing infrastructure with such new technology. A probabilistic cost benefit analysis, which takes into account future uncertainty, is conducted using a Monte Carlo simulation. Our findings suggest that if the Smart Infrastructure sensor system is applied to water pipelines in the British market, there are likely to be significant economic benefits. They could be realised by avoiding disruption and damage costs (including water loss) due to water pipe bursts, as well as by reducing annual operating and maintenance costs. The mean cumulative net present value of savings derived from the case scenario for the period through year 2056 was estimated at US$ 23.7 billion. 相似文献
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We formulate a generalized constant growth valuation model incorporating inflation and capital maintenance. We find that in general there are two sources of growth: growth due to capital maintenance and growth due to net new investments. The generalized version of the constant growth model allows the reconciliation of the existing literature, particularly the works of Gordon and Shapiro (1956), Lally (1988), and Bradley and Jarrell (2008), which all employ particular definitions of capital maintenance. Evaluating the practical relevance of either model we find that each model is best suited for a very particular company set‐up, which does not necessarily correspond to the commonly observed business models. The generalized version of the constant growth valuation model, however, presents a flexible approach that is capable of capturing various conceptions of capital maintenance. 相似文献
817.
The introduction of top‐up fees for home‐domiciled undergraduate tuition in England from 2006–07 – and their planned increase in 2012–13 – raises important issues for university funding in Scotland, since it abolished tuition fees for Scottish and EU students in 2000–01. This paper focuses on what the increase in resources directed at English universities arising from top‐up fees means for the relative funding of English and Scottish undergraduates. Widely‐used funding‐per‐head figures do not provide an accurate picture of home‐ and EU‐domiciled undergraduate funding, as they include funding for research, postgraduate degrees and overseas students. The empirical work of this paper focuses on creating a consistent series of funding per full‐time equivalent undergraduate over time for England and for Scotland, stripping out funding for research, non‐EU students and postgraduate degrees to create a more accurate picture of the funding gap between the two countries. It also takes into account the different composition of undergraduate degree subjects taken in England and Scotland. The findings indicate that the apparent historical advantage in funding per head in Scottish institutions compared with English ones has been largely driven by compositional differences: Scotland has a high proportion of medical, science and engineering undergraduates – subjects that command greater funding due to their relative complexity to teach. The top‐up fee introduced in 2006–07 brought funding per head in England to a level similar to that experienced in Scotland, and the future increase will result in funding per head in England outstripping that in Scotland by some magnitude. This suggests that the funding of Scottish students will fall significantly behind that of English students unless additional new sources of public or private funding for nScottish universities are found. 相似文献
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电力系统运行的经济性与电能质量、无功功率有重大的关系。若对无功补偿装置维护管理不到位,将造成无功补偿投入不足,影响电能质量及加大电能损耗。文章针对无功补偿装置运行管理过程中存在的问题.从接线线径选择、装置接线要求、安装规范、维修要求、电容容量选择等各方面提出了具体措施,以确保无功补偿功率因数满足要求,达到降低电量损耗,保证电能质量的目标。 相似文献
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随着社会对环保的日益关注,人们越来越重视废旧物品的重新利用,许多国家也加大了这方面的立法力度,通过发展逆向物流来达到资源再生、物料增值和成本节约的目的。但目前我国在家电产品逆向物流方面仍然比较落后.所以发展家电产品回收物流、构建家电产品逆向物流体系已是刻不容缓。文章从家电产品回收的重要性谈起,分析我国家电回收过程中存在的问题,并讨论如何建立有效地回收物流体系。 相似文献
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