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201.
针对当前光纤线路运行中日益突出的维护和管理问题 ,笔者提出了开展光纤线路运行维护智能系统研究的问题。通过分析现有光纤运行维护技术 ,认为当前的网络运营维护思路“故障维修” ,已不适应现代网络运营的发展需要 ,应该采取“状态维修”的新思路和防患于未然的策略。为此 ,笔者运用系统工程的思想、人工智能技术、数据挖掘技术、Agent技术 ,研究了具有故障预警功能的光纤线路运行维护智能系统 ,给出了该系统的分析和设计方案 ,从整体上探索保障光纤网络的安全运行措施 ,为建立实际的预警系统奠定了基础。 相似文献
202.
A field investigation conducted on Boulder Creek in Boulder, Colorado evaluated impacts of flood control maintenance activities on flood conveyance, water quality, and fish habitat. Thirty-nine transects were monitored at one control site and two maintenance sites over a period of eight months. Each site was visited on more than 50 occasions in order to characterize pre- and post-maintenance conditions, and to monitor maintenance activities. Measurements along the transects included substrate composition, flow depth, velocity, and elevation. Reach-average values were assigned to variables such as in-stream vegetation, streambank stability, and woody vegetation before and after maintenance. Water temperature, dissolved oxygen, pH, specific conductance, and turbidity were sampled, and habitat suitability indices were developed pre- and post-maintenance for seven indicator fish species. Water quality impacts during maintenance consisted of high turbidity levels (> 400 NTU), which returned to background levels (0.1–15 NTU) overnight, as well as changes in mean temperature and pH. Alteration of physical channel characteristics as a result of maintenance had limited effects on habitat quality for four of seven fish species, but caused improvements in habitat quality for three fish species. The main implications of this study for floodplain management are that: (1) Flood control maintenance practices can be in direct conflict with water quality and fish habitat objectives, and should be carefully designed and implemented by an interdisciplinary team. (2) Physical habitat for some fish species can be improved as well as reduced by maintenance activities. Habitat suitability curves may be useful tools for evaluating limiting factors of the habitat and for identifying opportunities for habitat improvements as part of maintenance. 相似文献
203.
单台数字观测系统的维护和地震分析 总被引:1,自引:0,他引:1
根据温州台近两年测震数字观测系统的运行情况 ,结合作者自己的研究 ,介绍了在硬件配置、软硬件的应用以及地震分析、保证月报质量等方面的一些有效的做法和经验 相似文献
204.
F Douglas Shields Donald H. Gray 《Journal of the American Water Resources Association》1992,28(5):917-931
he influence of woody vegetation on the reliability of a sandy levee was investigated using field data in seepage and slope stability analyses. Field data were collected from selected sites within a 10-km segment of a channel levee on the Sacramento River near Elkhorn, California. Root architecture and distribution were determined using the profile-wall method in which root cross sections were exposed in the vertical wall of an excavated trench. Transects running both parallel and perpendicular to the crest of the levee were excavated at six sites. Each site was dominated by different plant species: five sites were adjacent to trees or woody shrubs, while one supported only herbaceous growth. Lateral plant roots were primarily restricted to, and modified, the near-surface soil horizons to a depth of approximately 1 meter. Root area ratios (RARs) did not exceed 2.02 percent and generally decreased exponentially with depth. At depths greater than 20 cm, mean RARs for sites dominated by wood species were not significantly different from the mean RAB for the herbaceous site. No open voids clearly attributable to plant roots were observed. Roots reinforced the levee soil and increased shear resistance in a measurable manner. Infinite slope and circular arc stability analyses were performed on the landward and riverward slopes under different hydraulic loading conditions. Infinite slope analyses indicated increasing root area ratio from 0.01 percent to 1 percent increased the factor of safety from less than one to more than seven. Circular arc analyses indicated that even the lower measured root concentrations sufficed to increase safety factors for arcs with maximum depths of about 1 m from less than one to about 1.2. Our findings suggest that allowing woody shrubs and small trees on levees would provide environmental benefits and would enhance structural integrity without the hazards associated with large trees such as wind-throwing. 相似文献
205.
基于安全性目标的车辆维护周期数学模型研究 总被引:1,自引:0,他引:1
徐安 《中国安全科学学报》1996,6(4):54-57
本研究旨在建立一个相应于不同的给定的行驶安全性的车辆最优维护周期数学模型,同时,利用汽车制动系、转向系等系统或装置的运行故障分布参数,求出了不同安全性水平下该数学模型的解。还依据原始数据,给出了同样基于行驶安全性目标的汽车维护周期允许上限。本研究结果可用于指导汽车维护工作,而且对保证或提高在用车辆的行驶安全性具有重要的作用 相似文献
206.
The high complexity of chemical and petrochemical installations determines a complex safety management of these establishments, therefore, there is a need to find innovative solutions to guarantee the prevention of failures and losses of containment from process equipment. In this frame, the use of the API Risk Based Inspection (RBI) assessment approach permits a significant reduction of maintenance costs and, simultaneously, the increase of plant's reliability and availability. To increase the level of industrial safety, a proper selection of measures is also needed, even if the adoption of such measures poses costs. Given that resources for the companies are usually limited, a comparison amongst various solutions has to be done with the aim to find the best one, based on a comparison of costs and benefit. To this scope, recently a software, named Inspection Manager, has been developed by ANTEA and implemented thanks to a cooperation with the University of Padova (Italy). The Inspection Manager provides support in the application of the RBI approach by means of the use of plant-specific data, which are stored in its database; its further implementation, presented in this paper, has made it able to support also cost-benefit analysis and, thus, the selection of measures to be adopted to prevent accidental events causing the release of hazardous materials. A case-study is presented to test the new functionality of the tool; after the identification of the most effective measures, a careful cost-benefit assessment has been executed as a basis for decision-making. 相似文献
207.
Personal initiative training is a promising way to increase entrepreneurial personal initiative, which is a key behavior for successful entrepreneurship. Although personal initiative training has been shown to promote personal initiative, little is known about how this proactive behavior can be maintained over time and what the consequences are. The training transfer literature suggests that training effects usually decline with time. It is not clear, however, which factors contribute to personal initiative maintenance and which benefits go along with it. In a randomized controlled field experiment with 912 microentrepreneurs in Lomé, Togo, we investigate the influence of need for cognition—a cognitive factor driving proactive behavior—on personal initiative maintenance after training. In addition, we examine the effect of need for cognition on the well‐being consequences of personal initiative maintenance. We show that people high in need for cognition tend to maintain posttraining personal initiative longer than those low in need for cognition. However, contrary to our predictions, need for cognition has no effect on the level of well‐being that results from personal initiative maintenance. Our findings contribute to a better understanding of personal initiative and its maintenance and could be used to increase training effectiveness. 相似文献
208.
建筑景观水体的水质会直接影响居民身体健康和生活环境,采用简单、高效的水质维护技术具有较大实用价值。采用混凝-沉淀法对比研究了硫酸铝(Al2(SO4)3)、聚合氯化铝(PAC)、三氯化铁(Fe Cl3)和聚合硫酸铁(PFS)4种常用混凝剂对建筑景观水体中主要污染物的去除效果,对混凝剂的电性中和特性与絮体特性进行初步分析。结果表明:在投药量为10~30 mg/L条件下PAC、PFS和Fe Cl3的混凝除污染效果均明显好于Al2(SO4)3;在投药量达到35 mg/L时,4种混凝剂的混凝效果趋于相近,均可达到较好的除污效果。由Zeta电位和絮体特性的分析可知:PAC电荷密度最高,PAC和PFS形成的絮体粒径和密度最佳。 相似文献
209.
目的确保系留气球在使用与维修过程中能提供与其相匹配的保障资源。方法根据使用与维修工作分析的特点,分别采用确定保障工作项目、细化保障工作、确定保障资源、汇总资源的步骤进行分析,最后进行综合分析确定系留气球所需的保障资源。结果通过该方法在实际研制型号中的运用,给出了系留气球使用与维修工作分析的流程、数据记录、以及保障资源汇总的具体要求和方法。结论使用与维修工作分析可解决系留气球所需保障资源配置的合理性与科学性,适用于工程实际。 相似文献
210.