Advancements in Numerical Solutions:Fractal Runge-Kutta Approach to Model Time-Dependent MHD Newtonian Fluid with Rescaled Viscosity on Riga Plate

Fractal time-dependent issues in fluid dynamics provide a distinct difficulty in numerical analysis due to their complex characteristics,necessitating specialized computing techniques for precise and economical solutions.This study presents an innovative computational approach to tackle these difficulties.The main focus is applying the Fractal Runge-Kutta Method to model the time-dependent magnetohydrodynamic(MHD)Newtonian fluid with rescaled viscosity flow on Riga plates.An efficient computational scheme is proposed for handling fractal timedependent problems in flow phenomena.The scheme is comprised of three stages and constructed using three different time levels.The stability of the scheme is shown by employing the Fourier series analysis to solve scalar problems.The scheme’s convergence is guaranteed for a time fractal partial differential equations system.The scheme is applied to the dimensionless fractal heat and mass transfer model of incompressible,unsteady,laminar,Newtonian fluid with rescaled viscosity flow over the flat and oscillatory Riga plates under the effects of spaceand temperature-dependent heat sources.The first-order back differences discretize the continuity equation.The results show that skin friction local Nusselt number declines by raising the coefficient of the temperature-dependent term of heat source and Eckert number.The numerical simulations provide valuable insights into fluid dynamics,explicitly highlighting the influence of the temperature-dependent coefficient of the heat source and the Eckert number on skin friction and local Nusselt number.

Accelerating SAGE algorithm in PET image reconstruction by rescaled block-iterative method

A new method to accelerate the convergent rate of the space-alternatinggeneralized expectation-maximization (SAGE) algorithm is proposed. The new rescaled block-iterativeSAGE (RBI-SAGE) algorithm combines the RBI algorithm with the SAGE algorithm for PET imagereconstruction. In the new approach, the projection data is partitioned into disjoint blocks; eachiteration step involves only one of these blocks. SAGE updates the parameters sequentially in eachblock. In experiments, the RBI-SAGE algorithm and classical SAGE algorithm are compared in theapplication on positron emission tomography (PET) image reconstruction. Simulation results show thatRBI-SAGE has better performance than SAGE in both convergence and image quality.

基于Rescaled Hinge损失函数的多子支持向量机

针对多分类学习模型性能会受异常值影响的问题,提出基于Rescaled Hinge损失函数的多子支持向量机(RHMBSVM)。首先,该方法通过引入有界、非凸的Rescaled Hinge损失函数来构建相应的优化问题;然后,利用共轭函数理论将优化问题作等价变换;最后,使用变量交替策略形成一个迭代算法来求解非凸优化问题,该方法在求解的过程中可自动调节每个样本点的惩罚权重,从而削弱了异常值对K个超平面的影响,增强了鲁棒性。使用5折交叉验证的方法进行数值实验,实验结果表明,在数据集无异常值的情况下,该方法的正确率比多子支持向量机(MBSVM)提升了1.11个百分点,比基于Rescaled Hinge损失函数的鲁棒支持向量机(RSVM-RHHQ)提升了0.74个百分点;在数据集有异常值的情况下,该方法的正确率比MBSVM提升了2.10个百分点,比RSVM-RHHQ提升了1.47个百分点。实验结果证明了所提方法在解决有异常值的多分类问题上的鲁棒性。

Spontaneous combustion influenced by surface methane drainage and its prediction by rescaled range analysis

This study established numerical modeling using COMSOLTMto examine the influence of horizontal location and drainage ability of surface borehole on spontaneous combustion in longwall working face gob. Rescaled Range Analysis(R/S analysis) was employed to investigate the chaos characteristic of N_2/O_2 ratio from a surface borehole in 10416 working face gob, Yangliu Colliery, China. The simulation results show that there is always a circular ‘‘dissipation zone" around the drainage borehole and an elliptic ‘‘spontaneous combustion zone" in deep gob. Little influence was found on spontaneous combustion zone on the intake side of the gob but the width of spontaneous combustion zone in middle gob is enlarged, while the depth of spontaneous combustion zone near the return side is reduced. The R/S analysis indicates that the influence of surface borehole on spontaneous combustion can be divided into two stages by the chaos feature of N_2/O_2: safety drainage stage and spontaneous combustion initiating stage. It can be concluded that the methane drainage from gob through surface borehole can intervene in the distribution of spontaneous combustion zone in gob and the chaos feature of N_2/O_2 from surface borehole can effectively reflect coal spontaneous combustion condition in gob.

Langevin approach with rescaled noise for stochastic channel dynamics in Hodgkin–Huxley neurons

The Langevin approach has been applied to model the random open and closing dynamics of ion channels. It has long been known that the gate-based Langevin approach is not sufficiently accurate to reproduce the statistics of stochastic channel dynamics in Hodgkin–Huxley neurons. Here, we introduce a modified gate-based Langevin approach with rescaled noise strength to simulate stochastic channel dynamics. The rescaled independent gate and identical gate Langevin approaches improve the statistical results for the mean membrane voltage, inter-spike interval, and spike amplitude.

An rescaled range analysis on the characteristics of coal seam development in the Eastern depression of the Liaohe Basin

The characteristics of coal seam development,and the prospects of a favorable coal-forming area,were evaluated for the Liaohe Basin located in China.The Number 3 and Number 9 coal seam thickness series from 60 nearly equally spaced bores in the Eastern depression of the Liaohe Basin were examined by a rescaled range analysis.The results indicate that the Hurst exponents of the Number 3 and Number 9 coal seam thickness series are 0.69 and 0.68,respectively.This suggests the presence of persistence.As the bore spacing increases the Hurst exponent of the Number 3 series gradually decreases（H changes from 0.69 to 0.52） and shifts from persistence to randomness.The Hurst exponent of the Number 9 thickness data gradually increases（H changes from 0.68 to 0.91） and always shows the characteristic of persistence.A combination of geological characteristics and the series data allow the conclusion that it is more suitable for the Number 9 coal seam to form in the Northeastern part of the Eastern depression than the Number 3 coal seam.

Comparison of performance between rescaled range analysis and rescaled variance analysis in detecting abrupt dynamic change

In the present paper, a comparison of the performance between moving cutting data-rescaled range analysis （MC- R/S） and moving cutting data-rescaled variance analysis （MC-V/S） is made. The results clearly indicate that the operating efficiency of the MC-R/S algorithm is higher than that of the MC-V/S algorithm. In our numerical test, the computer time consumed by MC-V/S is approximately 25 times that by MC-R/S for an identical window size in artificial data. Except for the difference in operating efficiency, there are no significant differences in performance between MC-R/S and MC-V/S for the abrupt dynamic change detection. Mc-R/s and MC-V/S both display some degree of anti-noise ability. However, it is important to consider the influences of strong noise on the detection results of MC-R/S and MC-V/S in practical application

A rescaling algorithm for multi-relaxation-time lattice Boltzmann method towards turbulent flows with complex configurations

Understanding and modeling flows over porous layers are of great industrial significance.To accurately solve the turbulent multi-scale flows on complex configurations,a rescaling algorithm designed for turbulent flows with the Chapman-Enskog analysis is proposed.The mesh layout and the detailed rescaling procedure are also introduced.Direct numerical simulations(DNSs)for a turbulent channel flow and a porous walled turbulent channel flow are performed with the three-dimensional nineteen-velocity(D3Q19)multiple-relaxation-time(MRT)lattice Boltzmann method(LBM)to validate the accuracy,adaptability,and computational performance of the present rescaling algorithm.The results,which are consistent with the previous DNS studies based on the finite difference method and the LBM,demonstrate that the present method can maintain the continuity of the macro values across the grid interface and is able to adapt to complex geometries.The reasonable time consumption of the rescaling procedure shows that the present method can accurately calculate various turbulent flows with multi-scale and complex configurations while maintaining high computational efficiency.

生态环境保护中的尺度政治与正义实现:以A市绿中村改造为例

生态环境保护往往面临着保护责任和发展权益在整体社会与保护区局部群体间公平配置的难题。由于权益配置是不同层级政府与局部群体间博弈的结果,文章引入尺度政治与环境正义的理论框架,梳理用于解析生态环境保护中正义格局形成与演化的逻辑路径,并以中部某省会城市生态保护区内的村庄改造为例进行实证。研究发现:在未事先落实保护区居民发展权益的情况下,自上而下的刚性生态环境保护易造成不同尺度主体间的矛盾,表现为低尺度的居民发展权益受制于高尺度政府主体的保护要求;尺度重构成为前者寻求正义的一种非正规途径,表现为低尺度的居民寻求更高层级政府的介入,将其发展诉求的响应尺度上移,从而赋予发展与保护同等话语权,迎来环境正义实现的契机。诉诸非正规途径寻求正义本身也说明,中国城市生态环境保护中,缺乏保障低尺度群体合理权益的正规途径。文章结合理论与实证研究为此提供了解决思路。

长相关随机模型FBM对光伏发电短期预测

针对光伏发电功率具有较强的波动性、间歇性输出,光伏功率预测精度较低,且难于给出具体预测时间长度等问题,提出了一种长相关随机模型分数阶布朗运动(fractional Brownian motion,FBM),用于光伏功率预测。首先,采用重标极差法计算长相关(long-range dependence,LRD)参数-Hurst指数,Hurst指数用于判断光伏功率数据是否满足长相关性,并通过最大李雅普诺夫指数(Lyapunov)计算出模型最大可预测时间尺度;其次,采用随机微分法建立FBM光伏功率预测模型,同时估计FBM预测模型参数值;最后,选取澳大利亚沙漠知识太阳能中心(Desert Knowledge Australia Solar Center,DKASC)、美国国家可再生能源实验室(National Renewable Energy Laboratory,NREL)以及北京国能日新科技有限公司的光伏功率数据集,从不同的地理环境、不同的气候特征、不同的规模大小电站进行验证。仿真结果表明,该模型较传统的Kalman、LSTM模型具有更高的预测精度,可为光伏并网的稳定和安全运行提供更好的理论支持,对电网调度部门具有较高的参考价值。

基于深度可逆网络和差分编码的图像隐藏

伪装图像质量、恢复图像质量和传输安全性是图像隐藏最关注的3个问题。为解决这些问题,提出一种基于深度可逆网络和差分编码的图像隐藏方法,并用于保护电力巡检缺陷图像。首先训练深度可逆网络,利用训练好的可逆缩放网络对电力巡检缺陷图像进行向下缩放。与压缩感知等方法相比,可逆缩放网络能够恢复质量更高的缺陷图像。然后提出一种新的基于差分编码的嵌入算法,利用该算法将下缩放的缺陷图像嵌入到封面图像中。不同于现存很多方法直接对原图像像素值进行嵌入,所提方法先利用差分编码对缺陷图像进行编码,然后利用最低有效位算法完成嵌入操作,差分编码后的图像数值集中在更小的范围内,减少了嵌入对封面图像像素值的损害。实验结果表明,相较对比方法,所提方法伪装图像的峰值信噪比(PSNR)提高3.99 dB~16.56 dB,恢复缺陷图像的PSNR提高12.52 dB~17.02 dB。另外,该方法对SPAM的抗隐写分析性能优于对比方法。分析结果表明,所提方法在伪装图像质量、恢复缺陷图像质量和传输安全性方面的表现优于许多先进方法。

基于REOF分析的山东省年降水区域特征及趋势分析

[目的]探究山东省不同气候分区年降水量的时空特征,为该地区气候分析、防灾减灾提供更加区域性的参考依据。[方法]根据山东省95个国家地面气象观测站1991—2020年降水年值数据,首先对山东省年降水场进行气候分区,然后通过相关统计方法分析各分区降水的时空变化特征。[结果](1)山东省各降水模态降水偏少的年份更多,降水偏多的年份降水强度更大,年代际变化均较为明显,但各模态降水偏多偏少的年份分布及强度变化有所不同。(2)山东省年降水量大致由东南向西北递减,年降水场划分为东南沿海区(Ⅰ区)、西北平原区(Ⅱ区)和中部山地区(Ⅲ区)3个区域,各降水分区年降水均呈不显著增加趋势,趋势率各不相同,突变均不明显。(3)山东省各降水分区年降水量均具有较为明显的周期性特征,东南沿海区年降水场存在2个较为明显的能量中心,中心尺度均为2~3 a,未来变化具有强持续性;西北平原区年降水场存在3个较为明显的能量中心,中心尺度分别为5~7 a, 3 a和2~3 a,未来变化具有持续性;中部山地区年降水场存在2个较为明显的能量中心,中心尺度分别为2~3 a, 6 a,未来变化具有强持续性。[结论]山东省降水偏少的年份更多,降水偏多的年份降水强度更大,年降水场大致可分为3个分区,各分区年降水量均呈不显著增加趋势,均具有较为明显的周期性特征,且未来变化均具有持续性。

基于可缩放hinge损失的支持向量数据描述

支持向量数据描述(SVDD)极易受到异常值的影响,导致其鲁棒性不佳.利用可缩放的hinge损失函数,提出一种新的支持向量数据描述方法(RH-SVDD).将有界可缩放的hinge损失作为松弛变量构建超球模型;通过共轭函数理论将超球模型转化为凸优化问题;利用半二次优化技术迭代求解凸优化问题,并在迭代过程中实现权重更新,从而削弱异常值的影响,提升鲁棒性.实验结果表明,提出的RH-SVDD在分类任务中具有更好的性能优势.

新时代边疆绿色空间的概念内涵、尺度级联与重构路径

边疆绿色空间是指边疆多元治理主体秉持绿色价值理念,在边疆自然、社会、经济、文化等领域进行“绿化”实践的生态场域,是能够容纳和生产以“绿色”为底蕴的绿色生态、绿色政治、绿色经济、绿色文化等诸多美好要素的空间。边疆绿色空间重构是顺应时代潮流和回应边疆人民美好生活诉求的空间发展策略,也是融入国家整体发展战略,实现边疆高质量发展和绿色转型的必由之道。进入新时代,面对空间要素跨尺度流动持续加速、流动范围不断扩大的发展趋势,应将多尺度空间级联效应纳入我国边疆绿色空间重构的考虑范畴;基于边疆绿色空间尺度重组过程,识别不同空间尺度的发展目标,构建驱动边疆多尺度绿色空间重构的“尺度重组——尺度级联——空间重构”重构策略和重构路径,不断推动边疆多尺度绿色空间的耦合协同发展,构建面向边疆绿色空间可持续发展的多尺度级联福祉保障。

我国碳交易市场的弱式有效性检验及趋势分析

文章基于各碳交易市场日均交易价格数据,采用RS分析法和ADF检验法对中国八个试点省市的碳排放权交易市场和全国碳市场进行研究,以检验市场是否达到弱式有效水平,并追踪有效性特征随时间的演变。结果表明:各试点碳交易市场以及全国碳市场均未达到弱式有效水平,总体仍处于发展阶段。随着政策的完善、市场参与者的增加和技术的进步,预期市场效率将得到提升。本文为研究碳金融市场的演进提供了理论基础,还为全国统一碳排放权交易市场的建设提供了政策效果的评估和反馈,以消除内部阻碍碳排放权流动的约束,提高资源配置效率。

Translocalization and Social Rescaling:Case Studies of Linguistic Landscapes in Guangzhou

Languages and linguistic resources transport from one locality to another,adapting to the norms,customs,and regulations of a new locality.This process involves translocalization.Translocalization emphasizes the movement of linguistic resources against the backdrop of globalization and the combination or reframing of resources from different localities.This research explores the extent to which translocalization is reflected by the linguistic landscapes of three distinct commercial areas in Guangzhou,China.It goes on to discuss how translocalization works together with social rescaling to incur the movement of linguistic resources and to result in distinct linguistic landscapes of the three commercial areas.It concludes that some languages or linguistic resources,such as English,pinyin and traditional Chinese writing,are transported to local contexts for the purpose of rescaling,whereas other languages or dialects,like Cantonese,might gradually lose their function of rescaling and retain its function in indexing local identity and solidarity.This study calls for more attention to the local resources and contexts in linguistic landscape studies.It argues for the indexical function of linguistic resources in social rescaling and city planning.

Resizable, Rescalable and Free-Style Visualization of Hierarchical Clustering and Bioinformatics Analysis

Graphical representation of hierarchical clustering results is of final importance in hierarchical cluster analysis of data. Unfortunately, almost all mathematical or statistical software may have a weak capability of showcasing such clustering results. Particularly, most of clustering results or trees drawn cannot be represented in a dendrogram with a resizable, rescalable and free-style fashion. With the “dynamic” drawing instead of “static” one, this research works around these weak functionalities that restrict visualization of clustering results in an arbitrary manner. It introduces an algorithmic solution to these functionalities, which adopts seamless pixel rearrangements to be able to resize and rescale dendrograms or tree diagrams. The results showed that the algorithm developed makes clustering outcome representation a really free visualization of hierarchical clustering and bioinformatics analysis. Especially, it possesses features of selectively visualizing and/or saving results in a specific size, scale and style (different views).

Urban Transition Dynamics in the Regional Rescaling of the Pearl River Delta Area:a Qualitative Approach

The Pearl River Delta region has been the hub of urban vibrancy and boom ever since the country’s opening up and devolution reforms.However,the political and economic institutions of the cities in this region are so different and complicated that they pose great challenges to the integration of the whole region.This study takes one prominent experiment of urban expansion,Hengqin in Zhuhai,as a case study to investigate how institutional innovations are forged and managed to boost urban development and transitions towards sustainable growth and regional integration.We adopt a multi-level perspective framework to analyze Hengqin’s urban transition.Government archives,master plans,various documents and interviews with government officials,planners,residents,and businesses from Zhuhai,Hong Kong,and Macao are chosen as sources of the analysis,which delineates the complex interactions from a variety of stakeholders.Despite difficulties in the early days,Hengqin is now transitioning quickly,although still confronted with inter-scalar challenges.A better understanding of the governance and economic innovations that have taken place,and the investment-driven development strategies involved,will help shed light on the urban transition of other similar city regions.

改进可逆缩放网络的图像超分辨率重建

可逆缩放网络(IRN)的潜变量采用高斯分布嵌入图像高频信息,因其独立随机性无法充分保存图像高频信息,嵌入效果一般,影响重建性能。通过改进可逆缩放网络来提高嵌入高频信息的能力并进一步降低模型的复杂度。首先,特征提取模块采用密集连接结构和通道注意力机制来获取足够的特征信息,同时减少模块参数量;其次,网络的潜变量采用小波域高频子带插值设计,改善高频信息嵌入能力。实验结果显示该算法相比IRN,在Set5、Set14、BSD100和Urban100这4个基准测试集上的PSNR和SSIM分别平均提升了0.380 dB和0.014,参数量减少约1.64×10^(6),计算量减少约0.43×10^(9),运行时间减少3 ms。表明该算法的重建性能优良,模型复杂度低,具有实用价值。

基于滑坡累积位移的滑坡体危险状态分析

针对单体滑坡危险状态分析不全面的问题,提出了一种基于滑坡累积位移的滑坡体危险状态多角度分析方法。首先,利用极限位移准则确定滑坡所处预警阶段;其次,利用尖点突变理论对滑坡稳定状态进行评价;再次,采用重标极差分析确定滑坡体的发展趋势;然后,建立模糊矩阵确定滑坡体危险状态,但由于单个检测点无法准确反映滑坡整体危险状态,故采用多个监测点综合判断滑坡整体危险状态;最后,将该方法应用于八字门滑坡,验证其有效性。结果表明该方法能够有效地判断滑坡局部及整体的危险状态。