Study on the Improvement of the Application of Complete Ensemble Empirical Mode Decomposition with Adaptive Noise in Hydrology Based on RBFNN Data Extension Technology

The complex nonlinear and non-stationary features exhibited in hydrologic sequences make hydrological analysis and forecasting difficult.Currently,some hydrologists employ the complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)method,a new time-frequency analysis method based on the empirical mode decomposition(EMD)algorithm,to decompose non-stationary raw data in order to obtain relatively stationary components for further study.However,the endpoint effect in CEEMDAN is often neglected,which can lead to decomposition errors that reduce the accuracy of the research results.In this study,we processed an original runoff sequence using the radial basis function neural network(RBFNN)technique to obtain the extension sequence before utilizing CEEMDAN decomposition.Then,we compared the decomposition results of the original sequence,RBFNN extension sequence,and standard sequence to investigate the influence of the endpoint effect and RBFNN extension on the CEEMDAN method.The results indicated that the RBFNN extension technique effectively reduced the error of medium and low frequency components caused by the endpoint effect.At both ends of the components,the extension sequence more accurately reflected the true fluctuation characteristics and variation trends.These advances are of great significance to the subsequent study of hydrology.Therefore,the CEEMDAN method,combined with an appropriate extension of the original runoff series,can more precisely determine multi-time scale characteristics,and provide a credible basis for the analysis of hydrologic time series and hydrological forecasting.

Demonstration and Radiation Extension mode of Agricultural Technology——A Case of the Science and Technology Project of High Yield in Hebei Province

Firstly,relying on the science and technology project of high yield in Hebei Province,connotation of agricultural technology demonstration and extension mode and the high yield grain project in Hebei Province is introduced.Extension mode of agricultural technology demonstration and radiation is constructed.Agricultural technology demonstration and radiation mode includes the radiation center,primary irradiation and secondary irradiation.Secondly,management system and operational mechanism of agricultural technology demonstration and radiation mode are discussed,mainly expressed in establishing leading group in each demonstration county(city),carrying out leader contract responsibility system,establishing expert advisor steering group and setting up core experts group for subject,establishing technical experts group for subject,setting up leading group in the radiation area,carrying out chief expert responsibility system and technician matrix responsibility system,establishing the operating mechanism of "open,flow,competition and collaboration" with "test area-expert two-way selection" as the core content.Finally,countermeasures to improve the agricultural technology demonstration and radiation mode is put forward,such as establishing the rural technology demonstration base,strengthening cooperation with enterprises,and adopting flexible technical training,so as to promote the spread of agricultural high-tech,to increase the contribution rate of agricultural technology,and to offer ideas for agricultural technology extension model at the new era.

Properties study of LiNbO_3 lateral field excited device working on thickness extension mode

This paper investigates the properties of thickness extension mode excited by lateral electric field on LiNbO3 by using the extended Christoffel-Bechmann method. It finds that the lateral field excitation coupling factor for amode （quasi-extensional mode） reaches its maximum value of 28% on Xmcut LiNbO3. The characteristics of a lateral field excitation device made of X-cut LiNbO3 have been investigated and the lateral field excitation device is used for the design of a high frequency ultrasonic transducer. The time and frequency domain pulse/echo response of the LiNbO3 lateral field excitation ultrasonic transducer is analysed with the modified Krimholtz-Leedom-Matthae model and tested using traditional pulse/echo method. A LiNbO3 lateral field excitation ultrasonic transducer with the centre frequency of 33.44 MHz and the -6 dB bandwidth of 33.8% is acquired, which is in good agreement with the results of the Krimholtz-Leedom-Matthae model. Further analysis suggests that the LiNbO3 lateral field excitation device has great potential in the design of broadband high frequency ultrasonic transducers.

Assessment of bearing performance degradation via extension and EEMD combined approach

As a key component in rotating machinery, the operating reliability of bearing influences the performance and service life of the equipment directly. In order to describe bearing performance degradation(BPD) process effectively, an assessment approach combining extension and ensemble empirical mode decomposition(EEMD) was proposed. First, the extension was utilized to construct the matter-element of bearing operating state, and the energy moment of intrinsic mode functions(IMFs) was used as characteristic parameter of the matter-element. Then, to determine classical domains of characteristic parameters, the mathematical statistics method was adopted. Finally, the BPD was analyzed qualitatively and quantitatively according to the comprehensive correlation degree of bearing current operating state related to its healthy state. The analytic results of bearing test-rig show that the proposed method indicates the incipient fault approximately occurring in the 81 st hour, and the method also quantitatively presents the degree of BPD. By contrast, the BPD assessment based on time-domain features extraction method could not achieve the above two results effectively.

Signal prediction based on empirical mode decomposition and artificial neural networks

In view of the usefulness of Empirical Mode Decomposition （EMD）, Artificial Neural Networks （ ANN）, and Most Relevant Matching Extension （MRME） methods in dealing with nonlinear signals, we pro- pose a new way of combining these methods to deal with signal prediction. We found the results of combining EMD with either ANN or MRME to have higher prediction precision for a time series than the result of using EMD alone.

Parallelized Hashing via <i>j</i>-Lanes and <i>j</i>-Pointers Tree Modes, with Applications to SHA-256

j-lanes tree hashing is a tree mode that splits an input message into?j?slices, computes?j?independent digests of each slice, and outputs the hash value of their concatenation.?j-pointers tree hashing is a similar tree mode that receives, as input,?j?pointers to?j?messages (or slices of a single message), computes their digests and outputs the hash value of their concatenation. Such modes expose parallelization opportunities in a hashing process that is otherwise serial by nature. As a result, they have a performance advantage on modern processor architectures. This paper provides precise specifications for these hashing modes, proposes appropriate IVs, and demonstrates their performance on the latest processors. Our hope is that it would be useful for standardization of these modes.

A <i>j</i>-Lanes Tree Hashing Mode and <i>j</i>-Lanes SHA-256

j-lanes hashing is a tree mode that splits an input message to j slices, computes j independent digests of each slice, and outputs the hash value of their concatenation. We demonstrate the performance advantage of j-lanes hashing on SIMD architectures, by coding a 4-lanes-SHA-256 implementation and measuring its performance on the latest 3rd Generation IntelR CoreTM. For messages whose lengths range from 2 KB to 132 KB, we show that the 4-lanes SHA-256 is between 1.5 to 1.97 times faster than the fastest publicly available implementation that we are aware of, and between ~2 to ~2.5 times faster than the OpenSSL 1.0.1c implementation. For long messages, there is no significant performance difference between different choices of j. We show that the 4-lanes SHA-256 is faster than the two SHA3 finalists (BLAKE and Keccak) that have a published tree mode implementation. Finally, we explain why j-lanes hashing will be faster on the coming AVX2 architecture that facilitates using 256 bits registers. These results suggest that standardizing a tree mode for hash functions (SHA-256 in particular) could be useful for performance hungry applications.

ADOPT问题解决模式护理对大面积烧伤患者创面愈合及心理状态的影响

目的:探究ADOPT问题解决模式护理对大面积烧伤患者伤残接受度、创面愈合及美观满意度的影响。方法:前瞻性选择2020年1月-2022年12月笔者医院收治的患者460例大面积烧伤患者为研究对象,将2020年1月-2021年3月收治的患者纳入对照组,2021年4月-2022年12月收治的纳入观察组,对照组采用大面积烧伤后常规护理,观察组采用ADOPT问题解决模式护理,持续护理3个月。分别于干预前和干预3个月后,采用伤残接受度量表(Acceptance of disability scale,AODS)评估患者伤残接受度,采用视觉模拟评分(Visual analogue scale,VAS)评估患者创面疼痛程度,采用简明烧伤健康量表(Burn specific health scale,BSHS-A)评估患者生活质量;干预4周后,计算创面愈合率;干预3个月后,采用(Vancouver scar scale,VSS)评估患者创面愈合后瘢痕增生情况,采用美观满意度评分表评估患者美观满意度;记录创面愈合时间。结果:干预后,观察组患者AODS评分、创面覆盖率、美观满意度、BSHS-A评分均明显高于对照组,创面愈合时间明显短于对照组,VAS评分和VSS评分明显低于对照组(P<0.05)。结论:ADOPT问题解决模式能够提高大面积烧伤患者伤残接受度和美观满意度,有利于创面愈合,患者生活质量也得以显著提高。

高校图书馆经典阅读推广服务模式的探索与实践——以青岛职业技术学院图书馆为例

结合当前时代背景,以青岛职业技术学院图书馆为例,开展经典阅读推广服务模式的探索、实践,从经典中汲取灵感,充分挖掘经典中的文化养分与生活智慧,创新高校图书馆阅读推广服务模式,从理念建设、平台建设、主题活动建设、实施工程建设、阅读推广机制建设等方面着手,打造“书香青职·半亩方塘”经典阅读推广服务模式。推出有影响、有特色、有示范引领作用的读书活动、读书人物及读书成果,让经典在青年学生心中生根发芽,以期学生能在浓郁的阅读氛围中进行诗意的栖居、思想的顿悟与情感的升华,引领师生共读经典、共过幸福完整的教育生活。

EMD端点效应问题解决方法的研究

经验模态分解(EMD)是近年来兴起的一种非平稳信号处理方法,但在分解过程中因产生端点效应而造成分解结果严重失真。因此,研究了一种自适应波形匹配延拓法的改进方法,该方法根据信号端部不同特点确定延拓点并进行延拓,从而解决端点效应问题。实验结果表明,改进的自适应波形匹配延拓法能避免信号EMD分解失真。将改进的自适应波形匹配延拓法的EMD结合小波软阈值去噪方法用于处理加噪超声仿真信号,得到的信噪比比小波软阈值法处理后的信噪比高33.78%,说明该方法在非线性、非平稳信号处理方面有一定优势。

数字孪生战场地理环境平台建设探索

数字孪生技术在军事领域的应用虽然刚起步,但其科技优势巨大、应用前景广阔,将促进未来战场环境保障模式的变革。首先对数字孪生战场地理环境的概念、内涵、外延进行了界定和辨析,总结了其4个方面的特征,然后明确提出了数字孪生地理环境平台的建设目标、建设内容和架构设计,最后从4个方面总结了数字孪生战场地理环境平台建设的对策建议。

基于物元可拓模型的建筑安全管理评价

为了全面分析建筑施工安全管理问题,准确评价建筑施工安全管理状况,文中将物元可拓理论引入建筑安全管理评价,在函数关系和物元变换基础上建立物元可拓模型,通过专家打分得出各个指标的分值,计算出各项指标在不同评价等级下的关联度,对待评价指标进行等级排序。实际应用表明,该物元可拓模型合理可靠,能够较好地反映建筑安全管理的优劣程度。研究成果可为建筑安全管理评价提供新思路,丰富和改进安全管理评价方法。

基于宇称时间对称的P-SP拓扑无线电能传输系统特性分析

宇称时间(PT)对称原理已经被验证可以作为提高无线电能传输系统自由度的有力工具,但基于PT对称的并联-并联(P-P)拓扑结构无线电能传输(WPT)系统的工作范围仍然受到限制。为解决这一问题,提出了一种基于PT对称原理的并联-串并联(P-SP)补偿WPT系统。通过等效电路法化简系统电路模型,并利用耦合模理论(CMT)分析电容分配比对振荡频率、临界耦合系数、满足系统进入PT对称区域的耦合系数和负载电阻值范围以及传输效率等工作性能的影响。构建样机开展实验,以检验所提方法的适用性,结果表明:可以在仅损失2%系统传输效率的情况下,将传输距离由110 mm扩大到210 mm,该操作可为扩大应用范围、增加应用场景、优化激光无线充电系统中发送模块单元和接收模块单元的工作性能做准备。

EPC模式下装配式建筑成本风险评价研究--基于可拓云模型

为推动EPC模式在装配式建筑中的推广运用,提高总承包商对装配式建筑项目成本风险的识别、评价、管控能力,亟需对EPC模式下装配式建筑成本风险评价进行研究。本文在识别设计、生产、运输、施工、其他五个维度影响因素的基础上,用DEMATEL-ANP法计算指标的混合权重,并结合可拓云模型评价EPC模式下装配式建筑项目成本风险。最后,通过案例验证评价模型可以有效地对成本风险等级做出评价,并根据评价结果提出管控建议,希望为装配式建筑项目成本管控提供参考。

柱状晶生长取向对定向凝固Mg-Gd合金拉伸和压缩性能的影响

利用定向凝固技术,制备了生长取向为〈2110〉的柱状多晶Mg-6.3Gd合金和生长取向为〈3214〉的柱状多晶Mg-8.2Gd合金,并研究加载方式(拉伸、压缩)、柱状晶取向与力学性能之间的相关性。结果表明:拉伸载荷下,〈2110〉取向柱状晶的基面〈a〉滑移Schmid因子(Fs)低于0.051、柱状晶内启动{1011}压缩孪生协调应变,因此,Mg-6.3Gd合金屈服强度较高(为176 MPa),但伸长率仅8%;〈3214〉取向柱状晶的基面〈a〉滑移Fs高于0.46、柱状晶内启动{1012}拉伸孪生协调应变,因此,Mg-6.3Gd合金屈服强度较低(为57 MPa),但伸长率达到22%。压缩载荷下,两种取向合金启动{1121}和{1012}两种拉伸孪生协调应变,具有较高的形变硬化能力,抗压强度(分别为309 MPa和301 MPa)较屈服强度分别提高214 MPa和219 MPa,且具有较高的塑性。

补片结构设计对碳纤维复合材料修补试样拉伸性能的影响

复合材料结构件维修中较为常用的修补方式为胶接修补。提出一种新型的补片结构,以提升胶接修补后复合材料试样的承载能力,通过建立三维渐进损伤有限元模型,对不同复合材料修补试样在单轴拉伸过程中补片的损伤机理进行分析。通过实验与有限元仿真,得到不同修补结构的拉伸强度和位移量等实验数据。结果表明:在单轴拉伸试验中工字形修补结构的复合材料层合板在失效时的最大位移载荷和拉伸强度分别达到3.49mm和319MPa,相对于阶梯形修补结构分别提升14.4%和5.1%。所建立的有限元仿真模型与试验结果吻合较好,可用于预测复合材料修补结构破坏模式和损伤的扩展。

基于四项行动法延伸模式联合益生菌干预在慢性肾衰竭患者中的应用效果

目的探究基于四项行动法延伸模式联合益生菌干预在慢性肾衰竭患者中的应用效果。方法选取郑州大学第二附属医院2022年6月至2024年1月的92例慢性肾衰竭患者为研究对象,采用随机数字表法将其分为益生菌组和行动组。两组均给予传统护理干预,益生菌组行益生菌干预,行动组在益生菌组的基础上增加基于四项行动法延伸模式,对比两组患者的肾功能、肠道屏障功能、生活质量。结果两组干预3个月后尿素氮(BUN)、血肌酐(Scr)水平较干预前降低,行动组低于益生菌组(P<0.05)。两组干预3个月后内毒素、D-乳酸水平较干预前降低,行动组低于益生菌组(P<0.05)。两组干预3个月后精力、社会功能、躯体健康评分较干预前升高,行动组高于益生菌组(P<0.05)。结论基于四项行动法延伸模式联合益生菌干预可调节慢性肾衰竭患者肠道屏障功能,调控肾功能,改善生活质量。

疫情冲击下产业链延伸模式对于农民增收韧性的影响研究

在新冠疫情冲击的背景下,研究如何保障农民增收韧性对于实现乡村振兴和共同富裕的目标具有重要意义。文章利用2016-2022年的市级面板数据,在综合测算产业链延伸指数的基础上,采用双重差分模型实证研究了疫情背景下产业链延伸模式对于农民增收的作用机制。结果表明:(1)疫情冲击下产业链延伸模式对农民收入具有正向提升作用,相较于未采用该模式的地区,采用该模式的地区农民收入提升约12%。(2)异质性检验发现,疫情冲击下产业链延伸模式对农民收入的影响存在区域差异性,其中北方林区和南方林区的增收效果更为显著。(3)疫情背景下产业链延伸程度对农民收入的影响存在城镇化率的单门槛效应,当城镇化水平超过门槛值50.12%时,产业链延伸程度对农民增收的正向效应会加强。(4)在机制检验方面,疫情冲击下产业链延伸模式通过提升农业劳动生产率来保障农民增收韧性,农业劳动生产率在其中发挥了部分中介效应。文章创新性地完善了产业链延伸模式的概念,丰富了产业链延伸对于脱贫的作用机理,为深入探讨外生冲击与农民收入的相互关系提供了新视角。基于研究结论与讨论,提出加强农业产业链延伸、因地制宜制定发展策略、提高地区城镇化水平以及全面提升劳动生产率等政策启示。

重复压裂造缝的应力场分析

通过对重复压裂造缝的应力场进行分析,推导出满足重复压裂产生新裂缝的条件。主要分析了一次压裂的 裂缝、储层压力等多种因素对当前地应力场的影响,可以看出诱导应力改变了原地应力场,当原应力场最小水平主 应力大于原最大水平主应力时,重复压裂裂缝可能重新定向。

基层农业技术推广体系构建及运行机制研究——基于河北省640个农户的调查分析

通过对河北省640个农户的调查,分析了基层农业技术推广体系存在问题。农业科研、教育和推广缺乏良性协作机制、推广机构对推广工作创新不够、推广队伍供给与务农劳动者需求偏差大、推广体系缺乏政府长期稳定支持、推广工作法律法规有待完善是问题成因。研究提出了推行有效技术推广服务方式、创新推广体系运行机制、建立公益性推广管理体制、完善推广经费保障政策、修改完善农业技术推广法律法规和建立多元化农业技术推广体系等政策建议。