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排序方式: 共有173条查询结果,搜索用时 109 毫秒
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Abstract Due to substantial clean-up efforts, water quality in the River Thames in London has steadily improved over the last three decades. However, London's Victorian sewage system still discharges untreated sewage into the Thames, at times of moderate to heavy rainfall. This happens approximately 60 times every year, creating adverse environmental and amenity impacts on the river. Major and costly engineering works will be required to solve the sewage overflow problem. This paper reports the results of a stated preference study designed to value the multiple non-market benefits—eductions in sewage litter, risk to human health, and risk to fish populations—associated with a range of potential engineering solutions. Our findings indicate that household willingness to pay for these benefits is likely to be significantly greater than the projected costs per household of, at least, some potential technical solutions. Although arguably justifiable on economic grounds, the final decision on whether to proceed with such a large infrastructure project is unlikely to depend wholly on cost-benefit thinking, but involve complex trade-offs with other socially desirable criteria. 相似文献
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Abstract This paper reviews the processes by which groundwater and surface water flows are polluted by nitrates on the Island of Jersey in the English Channel. It is shown that the primary cause of such pollution is the use of nitrate fertilizers by the Island's farmers. The activities of the major government institutions involved in reducing nitrate pollution are described and the costs of such management are assessed. The instruments deployed are regulatory, infrastructural, and educational; in contrast, economic instruments have not been deployed. The article then moves on to consider the benefits of pollution reduction in respect of enhanced environmental quality and improved human health. In conclusion, it is suggested that the standard for the nitrate content of drinking water, based on European Community legislation of 1980, was set at a level for which no human health benefits have been demonstrated but at substantial costs to the citizens of Jersey. This “cost without benefit” hypothesis is applicable to many other countries with respect to nitrate pollution management. 相似文献
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《Structure and Infrastructure Engineering》2013,9(9):891-902
This article presents a novel simplified method for assessing seismic damage to low-rise reinforced concrete (RC) buildings by using the hazard curve of response spectral acceleration. Moreover, the occurrence of an earthquake is assumed to follow a Poisson process when analysing the occurrence probability of a specified damage state in the remaining service life and expected losses induced by seismic damage. Then, a novel procedure for estimating lifetime costs and benefits of seismic retrofitting is proposed. In the case study, 16 practical design projects for seismic retrofitting of RC school buildings in Taipei are subjected to lifetime cost-benefit analysis using the proposed method. It can be found that not only lifetime cost-benefit ratios but also the financial return period for each dollar invested seismic retrofitting can be identified conveniently. Additionally, they are useful information for making decisions about whether to retrofit a building or not. 相似文献
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蓝天虹 《山东电力高等专科学校学报》2010,13(4):9-12
需求响应可以引导用户进行更合理更有效的用电安排,改善电力生产资源效率。这个效率提高创造了一个多元的利益:所有参与者,电力的供需双方,系统的可靠性以及电力市场的可靠性。对需求响应各类成本及收益的构成、发生和归属作了分析,界定并提出了需求响应的利益分配和成本分担的主体及其机制。 相似文献
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Marquis Jean-Philippe; Goulet Sonia; Doré Fran?ois Y. 《Canadian Metallurgical Quarterly》2008,122(3):629
This research examined cognitive and motivational processes at different developmental stages in rats with neonatal ventral hippocampus (VH) lesions, an approach used to model schizophrenia. In Experiment 1, performance in a T-maze alternation task was assessed on postnatal days (PNDs) 22 and 23. VH-lesioned rats displayed a severe deficit relative to controls. In Experiment 2, behaviorally naive rats were tested for spontaneous alternation at PND 29. Alternation was intact in VH-lesioned rats only when successive alternations were separated by >5 s. In Experiment 3, motivation was tested in a cost-benefit T-maze task and in a saccharine-water preference test. Between PNDs 22-37, behaviorally naive rats with neonatal VH lesions displayed weaker saccharine preference than controls, but the 2 groups did not differ on the cost-benefit task. At adulthood, between PNDs 56-72, the difference on saccharine preference persisted and an impairment on the cost-benefit task emerged. Overall, these results suggest that working memory deficits observed at the weaning stage were not secondary to spontaneous alternation or motivation dysfunctions. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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电动汽车充换电站的成本效益模型及敏感性分析 总被引:1,自引:0,他引:1
电动汽车充换电站(battery charging and swapping station,BCSS)是中国电动汽车应用的重要基础设施之一,得到了广泛关注和示范推广。BCSS的成本收益模型对BCSS商业化推广是至关重要的,文中探讨了电动汽车BCSS的组成结构和运营模式,选择以电池租赁运营模式的BCSS为研究对象,考虑了其投资成本、运营和维护费用、人工薪酬等成本及充换电服务等收益,建立了基于净现值动态评价指标的电动汽车BCSS成本效益模型。最后以中国某大型电动汽车充换示范电站为实例,分析了该电站在全寿命周期内的成本收益模型,并进行了敏感性分析,得出了影响BCSS收益的关键因素依次为充换电服务价格、电池租赁费用、购电价格等。该模型及分析结果为电动汽车BCSS商业化运行提供了成本收益评估和决策依据。 相似文献
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时变可靠性约束下含风电系统旋转备用的随机规划模型 总被引:2,自引:0,他引:2
大规模风电并网后,系统运行经济性和可靠性之间的矛盾十分突出,传统确定旋转备用的方法存在较大的局限性。建立的含风系统旋转备用随机规划模型,能够根据系统容量冗余度,灵活分配各时段可靠性权重,实现调度周期内可靠性的协调优化。该模型充分考虑不同机组提供旋转备用的成本差异,允许机组对旋转备用进行报价,以发电成本、直接备用成本和期望停电成本三者之和最小为目标,实现发电侧和用户侧整体经济效益的最大化。应用该模型,可以对含风系统的旋转备用进行成本效益分析,为调度机构设置合理的可靠性水平提供决策依据。采用粒子群算法对模型进行求解,并通过算例分析验证了上述模型和算法的有效性。 相似文献
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Fals-Stewart William; Yates Brian T.; Klostermann Keith 《Canadian Metallurgical Quarterly》2005,19(1):28
The vast majority of outcome studies examining the effects of marital and family treatments focus exclusively on indicators of and changes in familial functioning and individual members' psychosocial adjustment, but fail to measure, report, or analyze treatment costs, benefits, cost-benefit ratio, or cost-effectiveness. Because of growing concerns about spiraling health care costs, clinical and economic outcomes constitute equally important and complementary aspects of any evaluation of marital and family treatments. The twofold purpose of this article is to define different components of cost analyses of health-related interventions, including marital and family treatments, and to describe methods for calculating and integrating clinical and cost outcome information when evaluating marital and family treatments. There are significant opportunities to promote the use of such treatments by conducting and reporting the results of cost analyses. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献