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71.
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
72.
利用双种群遗传算法进行数值试井自动拟合 总被引:7,自引:0,他引:7
遗传算法以随机化技术为指导,通过对整个解空间的高效搜索而得到全局最优解,当解空间较大时,常规遗传算法难以同时保证搜索速度和最优解的精度。针对这种缺陷提出了应用双种群遗传算法,即利用具有不同搜索策略的2个种群进行联合搜索,既保证了最优解的精度,又提高了搜索速度,将其应用于数值试井自动拟合解释,比常规遗传算法能节省50%以上的计算时间。 相似文献
73.
This paper presents a new approach for using stereo and motion correspondences to solve the problem of tracking multiple independently moving features. In this approach, quantitative relational structure (QRS) is proposed as a framework for the integration of stereo–motion correspondences. The similarity function, tightly coupled to stereo and motion cues, is constructed on QRS, and then energy function E2 consisting of the similarity function is defined. The tracking problem can be converted into the maximization problem of the energy function E2. The stereo and motion correspondences that maximize E2 are recovered by applying an extended graduated assignment algorithm. The relaxation labeling method is also presented for the comparison with the proposed method. Experimental results are presented to illustrate the performance of the proposed method. 相似文献
74.
Abel Cadenillas 《Systems & Control Letters》2002,47(5):433-444
We consider a stochastic control problem with linear dynamics with jumps, convex cost criterion, and convex state constraint, in which the control enters the drift, the diffusion, and the jump coefficients. We allow these coefficients to be random, and do not impose any Lp-bounds on the control.
We obtain a stochastic maximum principle for this model that provides both necessary and sufficient conditions of optimality. This is the first version of the stochastic maximum principle that covers the consumption–investment problem in which there are jumps in the price system. 相似文献
75.
MV2000T智能变送器 总被引:1,自引:0,他引:1
较全面地介绍了ABB公司MV2 0 0 0T智能变送器的市场开发背景、工作原理、技术规格、性能特点及设计选型要点 相似文献
76.
Melting and crystallization behaviour of elastoplastic semicrystalline copolymers: poly(ether ester)
The melting and crystallization behaviour of an elastoplastic semi-crystalline poly(etherester) has been studied by differential scanning calorimetry. The shape of the melting endotherm is strongly dependent on heating rate and annealing time and results from the sum of simultaneous melting and crystallization phenomena. Samples prepared by different techniques, i.e. by solvent evaporation or by melt extrusion, behave very differently owing to specific crystal morphologies. By applying the Hoffman-Weeks plot, the equilibrium melting temperature has been extrapolated. The Avrami treatment allows the calculation of the index n and of the rate constant K from the isothermal kinetic data. 相似文献
77.
78.
本文利用美国LECO公司生产的TC-436氧氮仪,研究了光谱纯Fe2O3,Al2O3和在大量脱氧铁存在下Al2O3的氧释放曲线,得到了它们的分解功率、分解电流和分解计算温度.成功地分离了钢样的表面氧和体内氧,并对钢样不同表面氧的组成做了初步研究. 相似文献
79.
The effect of a range of organic additives on the thermal stability of poly(vinyl chloride), both with and without a chloroparaffin extender, was studied using a number of experimental techniques. Of the additives used the best overall balance was provided by pentaerythritol, which increased stability when the extender was present and had no effect when it was absent. The congo red test emerged as the most suitable technique, being consistent and inexpensive and able to screen several additives simultaneously. Isothermal differential thermal analysis correlated with the congo red test but required more expensive equipment, was time-consuming and demanded good mixing of the poly(vinyl chloride) compound to give reproducible results. Thermogravimetry was not sufficiently sensitive and the heat stability test was the least useful of all. 相似文献
80.
多任务调度算法在单片机控制系统中的应用 总被引:1,自引:1,他引:0
为了满足单片机控制系统的复杂要求 ,提出了多任务调度算法 ,通过与单任务程序结构的对比和分析 ,详细说明了多任务调度算法的实现 ,指出了应用该算法的必要性 ,并且以科研生产的实例说明其具体应用。 相似文献