Lyapunov-based design of locally collocated controllers for semi-linear parabolic PDE systems

The design problem of collocated feedback controllers is addressed in this paper for a class of semi-linear distributed parameter systems described by parabolic partial differential equation (PDE), where a finite number of local actuators and sensors are intermittently distributed in space. A Lyapunov direct method for the exponential stability analysis of the resulting closed-loop system is first presented for the system, in which the first mean value theorem for integration and the Wirtinger's inequality are employed. The corresponding stabilization condition is then derived through the analysis result. Finally, the proposed design method is implemented on the feedback control of a fisher equation and its effectiveness is evaluated through simulation results.     

一种基于多通道分解的图像测试信号设计方法

HVS中多通道分解模型用于度量误差图像空间尺寸的视觉感受,为了降低主观评价实验方法的条件要求,建立了一种基于多通道分解的图像测试信号设计方法。该方法通过控制白噪声在频域存在的区间,即白噪声经正交变换、掩膜量化矩阵,产生信噪比相同且空间尺寸不同的测试图像信号。分析和实验表明,多通道分解测试图像信号产生一对与高频和低频对应的误差图像,其信噪比基本相等但其空间尺寸的视觉感受不同,有利于考察与视觉感知相吻合的图像评价方法。     

技术异质下中国企业绿色创新效率及损失来源分析

   绿色创新是缓解当前资源环境压力,实现中国工业高质量发展的重要途径。本文基于区域技术异质性与创新投入共享关联特征,构建共同前沿-共享投入关联型两阶段DEA模型以测算2008—2017年中国省际工业企业绿色创新两阶段效率及整体效率。运用“技术落差比率”指标衡量东部、中部与西部地区企业之间的技术差距,并对创新无效率值进行分解以挖掘效率损失根源,定位各地区企业效率提升的关键环节与重点策略。研究结果表明：①共同前沿下中国工业企业绿色研发效率、成果转化效率和整体效率均值分别为0.774、0.831和0.647,共同前沿下各效率值均未超过群组前沿下效率值;考察期内全国及三大地区绿色创新两阶段效率并未有明显改善,呈稳中略降趋势。②三大地区间企业绿色研发与成果转化的技术落差比率差异均显著,绿色研发阶段东-中地区企业间技术差距徘徊于0.2左右,而成果转化阶段东-西地区企业间技术差距最为明显,并呈不断扩大趋势。③东部地区企业绿色创新两阶段效率损失主要源自区域内企业自身管理不当,而中西部地区企业则因技术差距无效和管理无效均造成效率损失,且由区域技术落后引起的效率损失占比超过50%。     

Information resources estimation for accurate distribution-based concept drift detection

Machine learning applications must continually utilize label information from the data stream to detect concept drift and adapt to the dynamic behavior. Due to the computational expensiveness of label information, it is impractical to assume that the data stream is fully labeled. Therefore, much research focusing on semi-supervised concept drift detection has been proposed. Despite the large research effort in the literature, there is a lack of analysis on the information resources required with the achievable concept drift detection accuracy. Hence, this paper aims to answer the unexplored research question of “How many labeled samples are required to detect concept drift accurately?” by proposing an analytical framework to analyze and estimate the information resources required to detect concept drift accurately. Specifically, this paper disintegrates the distribution-based concept drift detection task into a learning task and a dissimilarity measurement task for independent analyses. The analyses results are then correlated to estimate the required number of labels within a set of data samples to detect concept drift accurately. The proximity of the information resources estimation is evaluated empirically, where the results suggest that the estimation is accurate with high amount of information resources provided. Additionally, estimation results of a state-of-the-art method and a benchmark data set are reported to show the applicability of the estimation by proposed analytical framework within benchmarked environments. In general, the estimation from the proposed analytical framework can serve as guidance in designing systems with limited information resources. This paper also hopes to assist in identifying research gaps and inspiring new research ideas regarding the analysis of the amount of information resources required for accurate concept drift detection.     

碳中和目标下中国海洋渔业碳汇能力与潜力评估

通过海洋渔业固碳增汇是实现“碳中和”的重要路径,其中的关键在于科学、精准、系统测算海洋渔业碳汇能力。本文剔除经典“可移出碳汇”模型中部分不具有碳汇功能的碳,把贝藻通过释放POC和DOC形成的碳汇纳入测算模型,基于2006—2020年中国9个沿海省份贝藻养殖产量面板数据,评估中国海洋渔业碳汇能力,并基于LMDI分解方法解构中国海洋渔业碳汇能力提升的贡献因素,预测不同情景下2030年中国海洋渔业的碳汇潜力。研究发现：①2020年中国海洋渔业碳汇能力达302.63万t/年,区域差异显著;②包含不具有碳汇功能的碳会高估海洋渔业贝类碳汇24.24%,而不考虑贝藻通过释放POC和DOC形成的碳汇会低估海洋渔业碳汇50.70%;③在当前注重规模效应的发展模式下,到2030年海洋渔业碳汇能力为335.51万t/年~399.92万t/年,碳汇增长潜力有限。基于此,应推动中国海洋渔业碳汇的增长模式向技术驱动的高质量发展转变,不断提高中国沿海省份海洋渔业碳汇能力,持续为实现“碳中和”目标作出贡献。     

“分解串联-小组合作-逐步考试”教学模式对大学生身心健康影响的实证研究

采用“分解串联一小组合作一逐步考试”教学模式在高校太极拳教学中进行教学实验,考察此模式对大学生身心健康的影响程度。结果表明：“分解串联一小组合作一逐步考试”教学模式对大学生体质健康有一定的促进作用、对改善大学生心理健康水平有一定的作用。建议在课外对部分体质健康和心理健康影响不大的指标进行针对性练习,达到身心素质的全面提高。     

无穷大开簇上构型出现次数的强大数律和中心极限定理(英文)

考虑定义在整点格网Ld上的参数为p的上临界Bernoulli渗流,研究无穷大开簇上构型的发生情况.用Λn表示一个给定的构型P在限制于框B(n)=[-n,n]d中的无穷大开簇上发生的次数,得到了关于Λn的强大数律和中心极限定理.     

以频率估计概率的误差估计及其应用

阐述了以频率估计概率的误差估计公式，并举例说明公式在实际问题中的有关应用。     

关于用等价无穷小量代换定理求极限的一个推广命题

对用等价无穷小量代换定理求极限进行了推广。     

中国交通发展的能源消费与对策研究

本文通过建立能源消费分解模型,对1980-2001年交通能耗的因子贡献进行了测算。结果表明,服务量的增长是能源消费增长的主要驱动力,同时运输结构的变化加剧了这种增长,过去实现的能耗强度降低不足以抑制能源消费的增加,而近年来能耗强度更显示出增加的趋势,交通石油消费增长趋势不可避免。需要综合规划与布局,促进交通的可持续发展。