Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-17 Cooperative journals: 《计算机应用研究》
Abstract： In the framework of convolutional neural network (CNN) , how to obtain the hyper-parameters of its model automatically is an important and pressing research topic. In this paper, we proposed a hyper-parameter optimization method of CNN based on improved Bayesian optimization algorithm. This method uses the improved Thompson sampling method as the acquisition function. The improved Markov Chain Monte Carlo algorithm is used to accelerate the Gaussian surrogate model. The proposed method can be used to optimize hyper-parameters in frameworks of CNN with different hyper-parameter space. The performance of the algorithm was tested by using these testing sets: CIFAR-10, MRBI and SVHN. The experimental results show that the improved hyper-parameter optimization algorithm of CNN has better performance than the other algorithms.
Subjects: Physics >> General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. submitted time 2018-01-05 Cooperative journals: 《工程热物理学报》
Abstract：在实际运行过程中，槽式太阳能集热器的聚光过程可能受到太阳光入射角、安装误差、镜面误差和跟踪误差等各种实际因素的影响。本文用空间坐标变换的方法结合蒙特卡罗光线追踪法，分别计算出了各种实际因素单独存在时和多种实际因素耦合时的槽式集热器热流分布。结果显示，安装误差和跟踪误差使聚焦热流的不均匀性增大，镜面误差使聚焦热流的不均匀性减小；计算出的实际因素耦合热流分布，可以为槽式集热器光学性能和热性能的分析提供依据。
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-11-07 Cooperative journals: 《工程热物理学报》
Abstract： The concentration process of a parabolic trough collector can be affected by incidence angle, installation error, reflector slope error and tracking error in operation. The coordinate transformation method and the Monte Carlo Ray Trace method are integrated to compute heat flux distributions under individual and coupled optical errors respectively in this study. It is shown that installation error and tracking error increase the non-uniformity of the heat flux distribution while reflector slope error tends to decrease it. Besides, the heat flux distribution under coupled optical errors can provide foundations for thermal and optical analysis of parabolic trough collectors.
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-11-07 Cooperative journals: 《工程热物理学报》
Abstract：本文基于300MW燃煤电厂的设计参数，针对四种典型燃煤电厂碳减排系统进行了发电量和碳减排量的比较。同时，从经济性角度分析且比较了四种燃煤电厂碳减排系统的均化发电成本((LCOE)和碳移除成本((COR)。结果显示在碳捕集率为so%条件下，当碳捕集设备的价格降低到原价的70%且有机朗肯循环(ORC)设备价格低于s06s元/kW时，太阳能ORC辅助碳减排的发电成本比太阳能直接辅助碳捕集系统低，此时太阳能ORC辅助系统在经济性上具备竞争力。
Subjects: Dynamic and Electric Engineering >> Engineering Thermophysics submitted time 2017-10-17 Cooperative journals: 《工程热物理学报》
Abstract：制约碳捕集技术实用化的重要瓶颈在于捕集能耗过高,而热力学是能源系统效能分析的有力工具。基于将热力学研究方法应用到碳捕集技术效能分析的思想,本文以变温吸附碳捕集为例,按照"物性-过程-冷热源-循环"顺序,完成热力学碳泵循环(TCPC)的构建,进而考察循环参数对总能耗和第二定律效率的影响。结果显示;循环能耗主要受循环温度、吸附剂和吸附相等影响,吸附相显热大约占循环总能耗的2%;第二定律效率区间为13.91%~21.21%,具有较高节能潜力;TCPC作为一种基于热力学思想的"量化规尺",可对碳捕集技术展开效能分析,进而对影响循环总能耗的主要因素进行归纳,并可通过第二定律效率对技术成熟度进行判断,有效挖掘碳捕集技术的节能潜力。
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