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Modeling mercury speciation is an important requirement for estimating harmful emissions from coal-fired power plants and developing strategies to reduce them. First-principle models based on chemical, kinetic, and thermodynamic aspects exist, but these are complex and difficult to develop. The use of modern data-based machine learning techniques has been recently introduced, including neural networks. Here we propose an alternative approach using abductive networks based on the group method of data handling (GMDH) algorithm, with the advantages of simplified and more automated model synthesis, automatic selection of significant inputs, and more transparent input–output model relationships. Models were developed for predicting three types of mercury speciation (elemental, oxidized, and particulate) using a small dataset containing six inputs parameters on the composition of the coal used and boiler operating conditions. Prediction performance compares favourably with neural network models developed using the same dataset, with correlation coefficients as high as 0.97 for training data. Network committees (ensembles) are proposed as a means of improving prediction accuracy, and suggestions are made for future work to further improve performance. 相似文献
93.
When describing scenes, speakers gaze at objects while preparing their names (Z. M. Griffin & K. Bock, 2000). In this study, the authors investigated whether gazes to referents occurred in the absence of a correspondence between visual features and word meaning. Speakers gazed significantly longer at objects before intentionally labeling them inaccurately with the names of similar things (e.g., calling a horse a dog) than when labeling them accurately. This held for grammatical subjects and objects as well as agents and patients. Moreover, the time spent gazing at a referent before labeling it with a novel word or accurate name was similar and decreased as speakers gained experience using the novel word. These results suggest that visual attention in speaking may be directed toward referents in the absence of any association between their visual forms and the words used to talk about them. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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采用分布式计算技术,研究并实现了基于集群计算机的保护定值在线校核并行计算方法。首先分析了保护定值校核计算的计算量和计算特点,接着对可能采用的并行计算方法进行比较,最后选择了基于电网分块的并行计算方法。采用协调机加计算子机的计算模式,在协调机上执行分块算法,通过基于主导节点的图划分方法把电网分成几块,每台计算子机只校核1块电网内的保护定值,最后由协调机收集汇总计算结果。现场应用证明,该并行计算方法正确、有效。 相似文献
97.
ERP系统属于典型的联机事务处理系统,不可避免的存在许多不足,无法提供企业决策所需的决策信息。商务智能是一种正在快速发展的技术,它在ERP中的应用有效的解决ERP存在的问题。 相似文献
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森林火灾是造成森林资源破坏的重大灾害之一。作者根据近年来从事森林火灾卫星监刚的实践,结合国内外有关利用气象卫星监测林火的资料,介绍了林火卫星监测的原理、方法和实用效果。 相似文献
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混凝土大坝的变形,尤其是坝基和拱座的变形,是衡量工程安全与否的一个重要指标。变形自动监测仪器与人工测读的仪器相比,具有精度高、时间快的优点。本文参考国外资料,提出测斜仪、钻孔变位计、垂线自动监测仪等三种国内外正在试用的电子仪器。将有助于提高并改善大坝设计的经济性和安全性。 相似文献
100.
D. Clifton A. R. Mount G. M. Alder D. Jardine 《International Journal of Machine Tools and Manufacture》2002,42(11)
During the process of electrochemical machining the dependency of the inter-electrode gap with time and process parameters can be used to determine process characteristics and to define the shape of the workpiece surface relative to the tool surface. Defining process variables to map out the required gap-time function requires the use of time-consuming iterative trials. In-line monitoring of the gap would enable process control and tool to workpiece transfer characteristics to be achieved (for ideal conditions) without the requirement to generate such parameter maps. This work explores the use of ultrasound applied as a passive, non-intrusive, in-line gap measurement system for ECM. The accuracy of this technique was confirmed through correspondence between the generated gap-time and current time data and theoretical models applicable to ideal conditions. Gap measurements are also used to demonstrate and quantify the degree of departure from ideal behaviour for an In718/chloride system as the electrolyte flow rate is reduced from 16 to 4 l min−1. The monitoring of the gap size has also been shown to be effective when determining shape convergence under ideal conditions, for the example case of a 2D sinusoidal profile. 相似文献