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文章首先介绍了BP网络数据标准化、隐层神经元选择、网络训练和有效性检验方法。以2003年胶州湾环境监测资料为基础,建立了多输入单输出的3层BP人工神经网络模型,采用8个水环境因子预测浮游植物生物量(Chla浓度)。检测集样本网络预测值与观测值的相关系数为0.8943,平均绝对误差为11.33%。为避免个别网络输入初值对输出的干扰,采取全局灵敏度的方法,分析了各水环境因子变化对浮游植物生物量的相对影响。结果表明,浮游植物生物量对各水环境因子变化响应的敏感系数顺序为DOCODPO4-PSSTpHOilDINSiO3-Si。 相似文献
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通过三臂液压凿岩台车在青岛胶州湾海底隧道施工中的应用研究,充分地发挥三臂液压凿岩台车作业范围大、灵活性强、空气粉尘污染小、安全文明、液压冲击钻高效的技术优势,不仅在Ⅱ,Ⅲ级围岩施工中体现了其无可比拟的优越性,而且在Ⅳ,Ⅴ级及破碎弱风化围岩施工中,也显示了其较强的适应性,实现了快速、优质、安全、高效施工。 相似文献
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随着国内城市群轨道交通互联互通发展进入关键期,跨区域、多制式、多运营主体背景下的轨道交通AFC票务清分互联互通问题得到广泛关注。分析研究粤港澳大湾区轨道交通线网运营现状、建设规划和轨道交通互联互通优先发展战略要求,探讨湾区轨道交通互联互通给AFC票务清分管理带来的问题和面临的挑战。综合分析对比城市群轨道交通AFC票务清分互联互通模式,在借鉴广佛城市轨道交通AFC票务清分互联互通部分成功经验的基础上,总结湾区轨道交通AFC票务清分互联互通最优实现模式和轨道交通湾区清分中心建设定位,提出湾区轨道交通AFC票务互联互通、一票通达管理思路和实现步骤,并指出湾区多网融合AFC票务清分互联互通下一步的技术实现方向。 相似文献
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This article presents the results of a three-year effort at applying information technology to the problem of collaborative natural resource management in San Diego Bay. As such, it represents an approach to integrated coastal zone management (ICZM). This effort resulted from a collaboration between the San Diego Supercomputer Center at the University of California, San Diego and the San Diego Bay Interagency Water Quality Panel for the purpose of (1) developing an environmental data repository to facilitate the acquisition and sharing of data and (2) the development of a visual model of the bay in support of the development of a comprehensive, coordinated management plan for San Diego Bay. It was determined from this study that information technology is an important and key component to ICZM but that sociopolitical factors may override the benefits of decision-support systems and should be considered at the outset of any project of this kind. 相似文献
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Wave climate evolution in the Bay of Biscay over two decades 总被引:3,自引:0,他引:3
As a background, a review of long term evolution of wave climate in the North Atlantic is discussed. Most studies show that interannual evolutions in wave heights may be related to climatic factors, such as the North Atlantic Oscillation Index for example.Data of a waverider, consisting of a time series of 20 years in the Bay of Biscay (off Biscarosse, France), are analysed. Based on these data obtained from 1980, wave heights tend to decrease over the period. Also, interannual evolutions exist, particularly in the wave period. The fact that the annual wave periods at Biscarosse are found to vary more significantly than the annual wave heights led us to assume that it is an indirect effect of the evolution in the location of generating storms relative to the buoy. The relationships between wave parameters and climatic factors such as the North Atlantic Oscillation Index and the Garonne discharge have been derived: they show that the NAO index is negatively correlated with the river discharge and positively correlated with the wave period. This result is in agreement with the general climate scheme associated with NAO cycle proposed by Kushnir et al. [Kushnir, Y., Cardone, V.J., Cane, M., 1995. Link between Atlantic climate variability of surface wave height and sea level pressure. Proc. Fourth Int. Workshop on Wave Incasting and forecasting, Banff, AB, Canada, 59–64.]: NAO+ shifts storm tracks northward and dry weather are encountered in the southern part of Europe (conversely NAO− brings storm tracks and rainfall closer). Concerning wave heights, the lack of dependence on NAO index may be associated with compensation effects between wind intensity and storm tracks: wave energy is partly dissipated while reaching the Bay of Biscay in case of severe but distant storms (NAO+), which is not the case for storms generated nearer to the buoy and associated with moderate westerly winds (NOA−). However, the reason of the decrease in wave heights is not clear. 相似文献
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陈海平 《城市轨道交通研究》2019,22(6):11-14
通过调研分析粤港澳大湾区内城际铁路运营管理现状,分别对城际类、通道类项目的运营管理模式进行分析讨论。对城际类项目,建议可独立运营的线路采用自管自营模式,与国家铁路联通紧密的广珠线可继续委托广州铁路(集团)公司运营,内地与港澳联合运输线路应与相关方签订联合运输协议。对通道类项目,建议按照高速铁路的运营管理选择代管模式。 相似文献