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A Takagi-Sugeno adaptive neuro-fuzzy inference system (TSFIS) model is developed and applied to a dataset of wellhead flow-test data for the Resalat oil field located offshore southern Iran, the objective is to assist in the prediction and control of multi-phase flow rates of oil and gas through the wellhead chokes. For this purpose, 182 test data points (Appendix 1) related to the Resalat field are evaluated. In order to predict production flow rate (QL) expressed as stock-tank barrels per day (STB/D), this dataset includes four selected input variables: upstream pressure (Pwh); wellhead choke sizes (D64); gas to liquid ratio (GLR); and, base solids and water including some water-soluble oil emulsion (BS&W). The test data points evaluated include a wide range of oil flow rate conditions and values for the four input variables recorded. The TSFIS algorithm applied involves five data processing steps: a) pre-processing, b) fuzzification, c) rules base and adaptive neuro-fuzzy inference engine, d) defuzzification, and e) post-processing of the fuzzy model. The developed TSFIS model for the Resalat oil field database predicted oil flow rate to a high degree of accuracy (root mean square error = 247 STB/D, correlation coefficient = 0.9987), which improves substantially on the commonly used empirical algorithms used for such predictions. TSFIS can potentially be applied in wellhead choke fuzzy controllers to stabilize flow in specific wells based on real-time input data records. 相似文献
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Dison S. P. Franco Fábio A. Duarte Nina Paula G. Salau 《Chemical Engineering Communications》2019,206(11):1452-1462
AbstractIn this paper, we present an initial study relating the adsorption of indium (III) onto carbonaceous materials, namely the activated carbon (AC), multiwalled carbon nanotubes functionalized with OH (MWCNT–OH), and the multiwalled carbon nanotubes functionalized with COOH (MWCNT–COOH). The main objective of this study is the development of the adaptive neuro-fuzzy inference system (ANFIS) and an artificial neural network (ANN) for predicting the adsorption capacity in different operating conditions for different materials. Both models take into account the adsorbent type, adsorbent dosage (0.05, 0.25, 0.5, 1.0, 1.5, and 2.0?g L?1), and the contact time (5, 20, 60, and 120?min) for predicting the adsorption capacity, which varied from 12.896 to 981.000?mg g?1, a total record of 72 was used. Both modeling methodologies applied can represent the experimental data, taking into account the statistical values obtained. The ANFIS achieved the best performance when the hybrid method was selected, this leads into R of 0.9998, RMSE of 48,373 with 250 epochs. On the other hand, the ANN can represent the best performance when using the Levenberg–Marquardt algorithm, reaching an R of 0.9831, MSE of 0.0180 and 9 epochs. Considering the modeling and experimental aspects indicates that the increase of the adsorbent dosage diminished the adsorbent capacity. The increase of the contact time causes the effect to increase the adsorption capacity until its equilibrium. Lastly, it is possible to conclude that the MWCNT–COOH is the most suitable adsorbent to be used between the selected materials. 相似文献
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We consider the fractional cointegrated vector autoregressive (CVAR) model of Johansen and Nielsen (2012a) and make two distinct contributions. First, in their consistency proof, Johansen and Nielsen (2012a) imposed moment conditions on the errors that depend on the parameter space, such that when the parameter space is larger, stronger moment conditions are required. We show that these moment conditions can be relaxed, and for consistency we require just eight moments regardless of the parameter space. Second, Johansen and Nielsen (2012a) assumed that the cointegrating vectors are stationary, and we extend the analysis to include the possibility that the cointegrating vectors are non‐stationary. Both contributions require new analysis and results for the asymptotic properties of the likelihood function of the fractional CVAR model, which we provide. Finally, our analysis follows recent research and applies a parameter space large enough that the usual (non‐fractional) CVAR model constitutes an interior point and hence can be tested against the fractional model using a Chi‐squared‐test. 相似文献
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针对推荐精度不准确、数据稀疏、恶意推荐的问题,提出融合信任基于概率矩阵分解(PMF)的新推荐模型。首先,通过建立基于信任的协同过滤模型(CFMTS)将改进的信任机制融入到协同过滤推荐算法中。信任值通过全局信任及局部信任计算获得,其中局部信任利用了信任传播机制计算用户的直接信任值和间接信任值得到,全局信任采用信任有向图的方式计算得到。然后,将信任值与评分相似度融合以解决数据稀疏、恶意推荐的问题。同时,将CFMTS融入到PMF模型中以建立新的推荐模型——融合信任基于概率矩阵分解模型(MPMFFT),通过梯度下降算法对用户特征向量和项目特征向量进行计算以产生预测评分值,进一步提高推荐系统的精准度。通过实验将提出的MPMFFT与经典的PMF、社交信息的矩阵分解(SocialMF)、社交信息的推荐(SoRec)、加权社交信息的推荐(RSTE)等模型进行了结果的对比和分析,在公开的真实数据集Epinions上MPMFFT的平均绝对误差(MAE)和均方根误差(RMSE)比最优的RSTE模型分别降低2.9%和1.5%,同时在公开的真实数据集Ciao上MPMFFT的MAE和RMSE比最优的SocialMF模型分别降低1.1%和1.8%,结果证实了模型能在一定程度上解决数据稀疏、恶意推荐问题,有效提高推荐质量。 相似文献
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The integration of reinforcement learning (RL) and imitation learning (IL) is an important problem that has long been studied in the field of intelligent robotics. RL optimizes policies to maximize the cumulative reward, whereas IL attempts to extract general knowledge about the trajectories demonstrated by experts, i.e, demonstrators. Because each has its own drawbacks, many methods combining them and compensating for each set of drawbacks have been explored thus far. However, many of these methods are heuristic and do not have a solid theoretical basis. This paper presents a new theory for integrating RL and IL by extending the probabilistic graphical model (PGM) framework for RL, control as inference. We develop a new PGM for RL with multiple types of rewards, called probabilistic graphical model for Markov decision processes with multiple optimality emissions (pMDP-MO). Furthermore, we demonstrate that the integrated learning method of RL and IL can be formulated as a probabilistic inference of policies on pMDP-MO by considering the discriminator in generative adversarial imitation learning (GAIL) as an additional optimality emission. We adapt the GAIL and task-achievement reward to our proposed framework, achieving significantly better performance than policies trained with baseline methods. 相似文献
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为了使7075铝合金薄壁件表面喷丸加工应力得到松弛和均化,运用ANSYS建立平台式振动时效有限元模型,通过振动模态和谐响应分析,获得最佳激振频率和试样装夹位置。在此基础上,将薄壁框架件置于平台上进行振动时效处理,以验证仿真分析结果,评价其对试样表面应力作用效果。结果表明:在亚共振频率为112 Hz时,试样在平台零振幅和最大弯曲位置处分别对称布置,时效后表面均形成应力松弛,松弛率分别为29.5%和33.3%,不均匀波动分别为20.3%和20.7%,而沿振动方向松弛程度不均匀,说明激振力造成了材料表面组织屈服,且屈服程度与应力强度有关。提出再时效-位置交叠方法,使应力松弛不均匀度分别下降到9.9%和15.9%,应力均化得到改善,该研究工作为薄壁类零件表面应力均匀化提供了参考。 相似文献
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针对小壕兔-大16井区储层结构复杂、有利区预测困难的问题,运用贝叶斯挖掘算法,利用计算机辅助模拟手段,构建研究区精细水力单元模型,探明储层砂体发育规律。研究结果表明,基于贝叶斯推论的表征技术能高效识别储层水力单元类型,为气藏描述提供准确的地质信息;指数函数递增法在测井曲线划段过程中表现更加出色,Rt测井段间样点的聚簇规律归因于储层的高含水特性;3类水力单元具有较大的原始油气储量和潜力,亦是提高气藏采收率过程中亟待突破的对象。该研究成果对预测储层有利区具有重要参考价值。 相似文献
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